GB2614452A

GB2614452A - Golf club head with open back cavity

Info

Publication number: GB2614452A
Application number: GB2301694.2A
Authority: GB
Inventors: S Wang Calvin; M Stokke Ryan; R Jertson Martin
Original assignee: Karsten Manufacturing Corp
Current assignee: Karsten Manufacturing Corp
Priority date: 2019-02-06
Filing date: 2020-02-06
Publication date: 2023-07-05
Anticipated expiration: 2040-02-06
Also published as: GB202112052D0; GB2617043A; GB2614452B; GB2595398A; JP2022519733A; GB2615050A; GB2617043B; KR20210121233A; EP3921048A1; EP3921048A4; GB2595398B; GB2615050B; WO2020163652A1; GB202306639D0

Abstract

A golf club heads comprises a hollow body comprising a faceplate defining a strike face 7112, a heel region, a toe region opposite the heel region, a sole 7122 and a top rail 7124; a back wall 7132 opposite the strikeface 7112, wherein the back wall 7132 is divided into an upper back wall 7134 and a lower back wall 7136; the back wall also including an upper indentation wall 7142, top cavity wall 7138, bottom cavity wall 7140 and lower indentation wall 7144 that define a rear opening 7104 communicating with a cavity 7102. A rear opening rim including an upper rim 7150 and lower rim 7152 circumscribes the rear opening 7104. A midplane 7184 extends through the geometric centre of the strikeface 7112 and the rear opening 7104 is located between the midplane 7184 and the top rail 7124. A badge 7114 may at least partially cover the rear opening 7104.

Description

GOLF HEAPSWITH_OPENLPACK CAYCE'S"

TECHNICAL FIELD

100011 This disclosure relates generally golf clubs and relates more particularly: to [roll:club heads with energy storage characteristics.

CROSS REFERENCE

This.1' prionty to U.S. Provisional Patent Apol. No. 62/802.125, filed February INS iS a continuation in part Of U.S. Patent Apo. No. 16/231,053, filed on December 21, 2018. which is a continuation in part of U.S. Patent April. No. 15/628,639, tiled June 20, 2017 which is a continuation in part of U.S. Patent App]. No. 14 420,484., tiled October 22, 2015, and which is a continuation in part of U.S. Patent App]. No. 14/920,480, filed October 22, 2015.

U.S. Patent Appl. No /23 filed on December 21, 2018,15 also a continuation part of U.S. Patent Appl. No. 15/435,054, filed on February 16, 2017, which is a continuation in part c)1.--14/920,484, filed on October 22, 2015. Further, U.S. Patent Appl N 14/920,484, filed on October 22, 20:5, claims priority to U.S. Provisional Patent App. 62/206, 152, filed August 12 2015, U.S. Provisional Patent App!. No. 62/131,739, filed March 11, 2015, L.T.S. Provisional Patent.Appl. No. 62/105,460, filed on January 20, 2015, U.S. Provisional Patent Appl. No. 62/105,464, filed on January 20, 2015, and U.S. Provisional Patent.Appl. No. 62/068,232, filed on October 24, 2014.

U.S. Patent Appl. No. 14/920,480, filed on October 22, 2013, also claims priority to U.S. Provisional 'a tent Ap pl. 62/2.064 32, filed August 17, 2013, U.S. Provisi()nal Pa tent A.p pl. No. 62/131,739, Filed March 11, 2015, U.S. Provisional Patent App!. No. 62/105,460, filed on January 20, 2015, U.S. Provisional Patent App]. No. 62/105,464, filed on January 20, 2015, and U.S. Provisional Patent App]. No. 62/068,232, hied on October 24, 2014.

[0004] [00 U.S. Patent Appl. No. 15/435,054, filed on February 16, 2017, also claims priority to U.S. Provisional Patent Appl. No. 62/313,215, filed on March 25, 2016, and U.S. Prov isional Patent.Appl. No. 62/295,565, filed on February 16" 2016.

1-00061 U.S. Patent Apnl. No. 16/231,053, tiled on Decernber 21,2018. claims pri uitv to U.S. Provisional Patent Appl. No. 62/610,053, filed (Ai December 22, 2017, aja is also a continuation-in-part of U.S. Patent Appl. No. 15/908,427, Filed February 28, 2018, which is a continuation-in-part of U.S. Patent Appl. No. 14/920,484, filed October 22, 2015. Furthermore, U.S. Patent Appl. No. 15/628,639, filed on June 20, 2017, and further claims priority to U.S. Provisional Patent Appl. No. 62/484,529 filed on April 12, 2017, [LS. Provisional Patent Appl. No. 62/462,250, filed on February 22, 2017, U.S. Provisional Patent Appl. No. 62/436,019, filed on December 19, 2016, and U.S. Provisional Patent.Appl No. 62/352,495, filed on June 20, 2016.

10007] the contents of al I of the above-described disclosures are incorporated fully herein by reference in their entirety.

10008-1 BACKGROUND

Golf club manufacturers have designed golf club heads to relieve stress ni the sink-el:Ice of the golf club head. In many instances, These designs do not allow the golf club

-

head to flea in the crown to sole direction. Additionally, these designs ma.y not chancre iNherc peak bending of the golf club nead occurs and do not allow additional storage of spring energy in the golf club head due to impact vdth the golf ball. Additional spring energy can Increase Hal] speed across the strikeface.

BRIEF DESCRIPTION OF THE DRAWINGS

[00091 To facilitate hirther description of the embodiments, the following drawings ate provided to which: [0010] FIG.1 c.epicts a back, toe-side perspective view of a golf poll club head arcording to embodiment; [00111 HG. 2 depicts a back!eel-side perspective If du_ head according to the embodiment of H.G. 1; 10012] FIG. 3 depicts a cross-secijonat viewof the golf club bead A F1(.3. 1 along the cross-sectional line XII-X11 of FIG. 1; 1110131 NG. 4 depicts *a view of a portion of the Rol I club head of FIG. 3 suad a view of the same area of a standard golf club head; [0(1.4 FIG. 5 depicts a back, toe-side perspective view of a golf club according to another embodiment; [0015 HU 6 depicts across-sectional clew ofthe goh club head of 1.1G. 3 ag, the cross-sectional line XVI-X \IT of FIG. 5; [0016] 1.1G. 7 depicts a flow diagram illustratng a titethod of manufacturing a golf club head according to an embodiment of another method; [00171 FIG. 8 depicts a back perspective view of a golf club head according to vet another em I) ( -dii nent; [0018] FiG. 9 depicts a back, heel-side perspective view of I club head according to the entlaodimert cif FIG. 8; [0019] FiG. 10 depicts a cross-sectional view of the golf club dead of F-414-4. 8 along sectional line XXIV-XXIV of FIG. 8; FIG. 11 depicts a view of a portion of the golf head of I11G. 10 and -view of the same area of a standard golf club head; 100211 FIG. 12 depicts a simplified cross sectional view of the golf club head of biG. 8. similar to the detailed crass--sectional view of the golf club head in 1.1G. 10; 1-0022] FIG. 13 depicts a back-perspective view of a Rolf club head according to still yet another embodiment: [0023] FIG. 14 depicts a back heel--side perspective view of the golf club head accordinR to the embodiment of FIG. 13; [0024] FIG. 15 depicts a cross-sectional view Of the golt club head of FIG. 13 along the cross-sectional NXIX4XX1-1X of FIG. 13; [0025] tIC. 16 depicts a view of a porla onot the golf club head of 1.1Cview c, the same area of a standard golf club head; [0026] FIG. 17 depicts a simplified cress-sectional of the golf club head of FIG. 13, similar the detailed cross-sectional view of the. Rolf club head in 1.1C. 13; [0027] 1 IC. 18 depicts a back perspective view of a golf club head according, to still yet another embodiment; [0028] FIG. 19 depicts a back, heel -side perspect e view of the golf club head according 1.o the embodiment of PIG. 18; I00201 100291 FTG. 20 depicts a cross-sectional view of the golf' club head of FIG. 18 along the cross -sec:no NNVIV--XXiXiisf of FIG. 18; [0030] I,IG. 21 depicts a portion of the golf club head of FIG. 20; 10031] 10G. 22 depicts a simplified cross-sectional view of the golf dub head of IVIG. 18, similar to the detailed cross-sectional view of the golf club head in FIG. 20; [0032] FIG. 23 depicts a. back perspective view of a golf club head according to still ye: another embodiment; 10033] I 0G. 24 depicts a back, he. side perspective view of the god club head according to the embodiment of FIG 23; 100311 Elf 1. 23 depicts a cross--sectionai view of the club head of FIG. 23 alone the cross--sectional NAVIN-ANN rx of FIG. 231 [1035] FIG. 26 depicts a portion of the golf club head of FIG. 25: [0036] FIG. 27 depicts a simplified cross-sectional view of the golf club head of FIG. 23, similar to the detailed cross --sectional view of the golf dub head in 10(3. 25; 100371 FIG. 28 depicts an interior view of a portion of the golf club head of FIG. 23; [00381 NG. 29 depicts a front perspective view of the golf dub head of NC. 23; 10039_1 l'IG. 30 depicts a back perspective view of a golf club head according to still yet another embodiment; 10040] FIG. 31 depicts a back heel--side perspective view of the golf club head according to the embodiment of FIG. 30; 10041] FiG. 32 depicts a cross--sectional view o the vol., club head of FIG. 30 along the cross--sectional XJX]-XINI of FIG. 30; [0042] FIG. 33 depicts a portion of the golf ciub head of FIG. 32; [0043] HG. 34 depicts a simplified cross-sectional view of the golf club head of FIG. 30, stnaila to the detailed cross-sectional yieW of the golf club head in FIG 31 100441 35 depicts a luck perspective view of a golf club head according to sttil yet another embodiment; 0045] 10G. 36 depicts a luck, heel -sii_e pen; pective view of the golf dub head according t the embodiment-of 10(3. 3.5; 0016] FIG. 37 depicts a cross-sec oi or the golf club head of FIG along the cross-sectional ' of FIG. 35; [0047] FIG. 38 depicts a portion of golf club head of FIG 35 [0048] FIG. 39 depicts a simplified cross-sectional view of the golf club head of FIG. 35, similar the detailed cross-sectional view of the golf club head in MC. 37.

[00491 111G. 40 depicts an lifieriur view al a, portion of the golf dub head of 1,16. 35; 10050] FAG. 41 depicts a front perspective view of the golf club head of [0051] depicts a back perspective view of a golf club bead aLeordin.;:, to still tetnerment; [0052] 1.1G. 43 depicts a back, heel-side perspective vtew of the golf club head according to the embodiment of FIG. 42; [0053] FIG. 44 depicts a cross-secnonai vu c of the ncdf club head of FIG, 42 alonu the cross-of FIG. 42: [0054] FIG. 45 depicts a portion of the golt club head [00551 FIG. 46 depicts a simplified cross-sectional view of the golt club head of FIG. 12, similar to the detailed cross-sectional view of the golf club head in MC. 45: [00561 tIC.47 depicts a cross_sectional view of the heel portion of the golf club C of 11(3.

42, allong the cross -sectiomti line. 1..X14.X1; and [0057] FIG. 48 depicts an front view of the golf club head of FIG. 42, along the cross-sectional e [0058J NG 49 is a back perspective view of a golf club head.

[0059] FIG. 50 is a hack, heel-side perspective view of the golf club head of FIG. 49.

[0060] FIG. 51 is a front, toe-side perspective view of the golf club head of FIG. 49.

[0061] FIG. 52 is a front, toe-side exploded perspective view of the golf club head of i0062] FIG. 53 is a front, heel--side pctspoc c view of tIte golf club head of FIG. 49 with portions removed.

[0063] FIG. 54 is a back the lf club head of FIG. 49 with 'ons removed.

[0064] FIG, 55 is a c ss-sectional view of the col-club head of FIG, 49 taken alonit line 7- 7 of. FIG. 49, [0065] ;, 56 is another cross-sectional view of the golf club head of 49 taken alonc line -it or FIG. 49.

[0066] FIG. 57 is another cross-sectional view ofa portion of the golf club head of FTC. 49 taken along line 7----7 of FTC. 49.

N36171 FIG. 58 is another cross-sectional view of golf club head of Fl5,g. 49 taken alone of FIG. 49, similar to the cross-sectional view. of FIG. 55.

[0068] hIGS. 59A--591) are rear perspective views of the golf club head of "1(3 49 tncluding different en thoditnell tS Ora badge aS disclosed herein.

[00 NC. 60A-60D are cross-sectional views of the golf dub head of PIG. 49 i ucluding a filler matetial as disclosed herein.

[0070] ['or simplicity and clarity of tIlustrauon, the drawing figures illustrate Me general manner of construction, and descriptions and details of well features and tech niQues may be omitted to avoid unnecessarily obscuring, die golf clubs and their methods of manubcture. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of e elements in the figures may be exaggerated relative to other demerits to help trnprovc understanding of embodiments of the golf clubs and their methods of manufkturc. The same reference numerals In different figures denote the same elements.

100711 the terms 'first" 'second," "third," "fourth,' and the like in the descript n and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing, a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of golf clubs and methods of manufacture described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "contain," "include," and "have," and any variations thereof, are intended to cover a non--exclusive inclusion, such tint °,1 process, method, article, or apparatus that comprises a list of elements is not necessarily limited to those CleThentS, hut may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[9072] The terms "left," "right," "front," "back," "to, tom," "side, "under," 'over,'' and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appn)priate circurnstanc.es such that the embodiments o)If clubs ',Ind methods of naanuracture described herein are. Fr:r example, capable of operation in other orientations than those illustrated or otherwise described herein. The term 'coupled," as used herein, is defined as directly or indirectly connected in a physical, mechanical, or other trianner.

7,RIPTION OF EXAMPLES OF EM130DIMENTS 10073] thous embodiments of the golf club heads with energy storage characteristics include a golf club head comprising-a hollow body. The hollow body comprises strikeface, a heel region, a toe region opposite the heel region, a sole, and a crown. In many embodiments, the crown comprises an uPper region cornpnsing a tor] tall, and a lower region.

In some embodiments, a cavity is located below or rail, is located above the lower region of the crown, and is defined at least in part by the upper and lower regions of the crown. In many embodiments, the cavity comprises a. top wall, a back wall, a bottom incline, a. back cavity-angle measured between the top and back wails of the cavity, and at least one channel.

10074] Some embodiments include a golf club comprising a hollow-bodied golf club and a shaft coupled to the hollow-bodied golf club head. The hollow-bodied golf club head comprises a strikeface, a heel region, a toe region opposite the heel region., a sole, and a crown. In many embodiments, the crown comprises an upper region comprising a top rail, and a lower region. In some embodiments, a cavity is located below the top rail, is located above the lower region of the crown, and is defined at least in part by the upper and lower regions of the crown. in many embodiments, the cavity comprises a top wall, a back wall, a bottom incline, a back cavity angle measured between the top and back walls of the cavity, and at least one channel.

[0075] Other embodiments include a. method fiar nia.ittsfactnringif club head. In many embodiments. the method comprises providing a body. The smKetace, a heel region, a toe region opposite the heel region, a sole, and a crown. The crov.mt comprises an upper region comprising a top rail and A lower region. In some embodiments, a cavity is located below the top rail, above the lower region of the crown, and is defined at least in part by the upper and lower regions of the crown In many embodiments, the cavity comprises a top wall, a laack wall adjacent to the topwah, a bottom incline adjacent to the back wall, a back cavity angle measured between the top and back walls of the cavity, and at least one channel.

[0076] Various embodiments include club head comprising a hollow body. The hollow body comprises a strike face a heel region, a toe regton opposite the heel reii?ion, a sole, and a crown. In many embodiments, the crown comprises an upper region comprising a top rail, and a lower region comprising a lower exterior wall. In some embodiments, a cavity is located below the top rail, is located above the lower region Of the crown, and is defined at least in part by the upper and It Aver regions of the crown. in many embodiments, the cavity comprises a top wall, a back wall, a first inflection point adjacent the top wall and the back wall, a bottom incline, a second inflection point adjacent to the back wall and the bottom incline, a third inflection point adjacent to the bottom incline and the lower exterior wall, a lower angle measured from between the hot torn incline and the lower exterior wall, the lower angle is less than 180 degrees, a. back cavity,/ angle measured between the top and back walls of the cavity, and at least one channel.

[0077] Some emhodtments include a golf club comprising hollow-bodied C.1 ) and a shaft coupled to the hollow-bodied golf club head. The hollow-bodied golf club head comprises a SITITikeface, a heel region, a toe region opposite the heel region., a sole, and a crown. in many embodiments, the crown comprises an upper region comprising a top rail, and a lower region comprising a lower exterior wall. In some embodiments, a cavity is located below the top rail, is located above the lower region of the crown, and is defined at least in part by the upper and lower regions of the crown. in many embodiments, the cavity comprises a top wall, a back wall, a first inflection point adjacent: the top wall and the back wall, a bottom incline, a second inflection point adjacent to the back wall and the bottom incline, a third inflection point adjacent to the bottom incline and the lower exterior wall, a lower angle measured from between the bottom incline and the lower exterior wall, the lower angle is less than 180 degrees, a. back cavity angle measured between the top and hack walls of the cavity, and at least one channel.

I 00781 Other embodiments include a ethod for manufacturing a!golf club head. in many embodiments, the method comprises providing a body. The body having a stdkebace, a heel region, a la ie region opposite the heel region., a sole, and a crown.. The crown corn prises art upper region col:ands:nit a top rail and a lower region comprising a. lower exterior wall. in some embodiments, a cavity is located below the top rail, above the lower region o t the crown, and is defined at least in part by the upper and lower regions of the crown. in many embodiments, the cavity comprises a top wall, a back wall, a first inflection point adjacent the top wall,ind the back \van, a. bottom incline, a second Inflection point adjacent to the hack -wall and the bottom incline, a third inflection pomt adjacent to the bottom incline and the Tower exterior walk a lower angle measured from between the bottom incline and the lower exterior wall, the lower angle is less than 180 degrees, a back cavity arigle nieasured between the top and back walls of the cavity, t least one cfrannel.

[0079] Scatati embodiments include a golf club head including a HO dy C o rap rising back cavity located in an interior of the body. 'I he club head, includes a faceplate coupled to the body at a front end, defining a striking surface or strike face, and a cover or badge coupled to the body at a back end, opposite die front end. In some embodiments, as described below, the badge may be a partial [ridge, or the badge:nay be omitted entirely from the dub head. In addition to the front end and the back end, the body includes a heel region, a. toe region opposite the heel region, a sole, and a top ri uI opposite the sole. The partial back cavity contributes to a dynamic deflection or spring effect of the body when striking a golf ball.

100801 Other examples and embodiments are further disclosed herein. Such examples and embodiments may be found in the figures, in the claims, and/or in the present description.

1. Golf Club Head with Back Cav." [0081-1 In one embodiment, the golf club head has a back cavity located in an upper crown area of the golf club. In many embodiments, the back cavity can provide a box spring affect when s riking a golf ball. The back cavity can be combined with varying: thicknesses of the internal radius of the sole of the club head (cascading sole) to provide a. spring like effect.

[0082] Some embodiments are directed to a club head (hybrid or fairway wood or iron with hollow design) that features a hollowed construction club head that provides a more "iron-like" look and feel. In some embodiments, the golf club head can feature a flat strilteface ann iron like profile, which can provide improved workability and accuracy, similar to an iron. A back cavity located below a top rail and along the upper crown of the club head has been. designed for hybrids. fairway-woods and irons with a hollow construction. The back cavity may be a full channel from the heel to the toe just below the top rail and along the upper crown or back portion of the club head. The top rail and the cavity may be any design. In some ernbodirnents, the cavity is angled at approximately 90 degrees and provides a targeted hinge point in the crown region or the golf club head. This hinge or buckling region enables the top rail to absorb more of the impact force over a wider volumetric area causing the cawity and the top rail to act as a springboard by returning more recoiled fbrce back to the strikeracc as n returns to its original orientation thereby imparting more force into the ball. This greater club Faye deflection by the cavity design can lead to less spin, a higher loft angle of the golf hall upon impact, and,;(,iy.tater ball speed with the Sane club speed over standard golf club heads.

10083.1 In a standard hybrid club head, the top rail and upper crown regions do not have a cavity or this design. In comparison to the present disclosure, there is less club strikeface bending or deflection in such a standard hybrid club head. Standard hybrids are unable to have as great a spring-back effect because less energy is transferred to the top rail of the club due to the lack of a cavity. The disclosed golf club head with back cavity allows more of the impact force of the golf ball to be absorbed and then returned to the strikeface. In many embodiments, the angle of the cavity can provide a buckling point, or plastic hinge, or targeted hinge, for the strikeface to deflect more over the st.andard golf club.

I 0084d the recoiling-, effect of the cavity on the strikeface provides: (1) a higher golf ball speed relative to the same club head speed of a club head with an upper crown cavily (or Ina" cavity) and one without, due in part to the spring effect that is transferred from the hinged region to the strikeface to the ball; (2) less spin of the golf-ball after impact with the club, due in part to the hinge point above the cavity counters more force being absorbed by the dub and instead transfers more force to the ball thereby preventing; the ball from spinning backward off the strikelace; and/or (3) -a higher loft angle to the golf ball upon impact, due to the hinge and striker-ace acting as a diving board or catapult to the ball. In some embodiments, the cavity may provide an increase M ball speed of approximately 1.0 ---1.2%, and an increase in launch angle of approximately OA 0.7 degrees.

10085] 'Fuming hack to the drawings, FIG. I illustrates a back toe-side perspective view of an embodiment of golf club head 1000 and FIG. 2 illustrates a back heel-side perspective view of gol club head 1000 according to the embodiment or FIG. 1: Golf club head 1000 can be a hyl)rid-type golf club head. In other etnbeftliments, golf club head 1000 can be an iron-type golf club head i)ls a fairway wood-type gcdf club head. In many embodiments, golf club head 1000 does not include a badge or a custom tuning port.

[0086] Golf club head 1000 comprises a both 1001. In many embodiments, the body is hollow. In some embodiments, We body is at least partially hollow. -Body 1001 comprises a tO strikeilic 1012, a heel region 1002, a toe region 1 004 opposite heel reRion 1002, a sole 1006, and a crown 1008. Crown 1008 comprises an upper region 1011 and a lower region 1013. Upper region 1011 comprises a top rail 1015.1lie top rad 1013 begins in the toe region 1004, adjacent a. top edge of the strikeface 1012, and extends along the top of the golf club head 1000 towards the her.4 region 1002. From a cross-sectional side view, such as in FIG. 3, the top rail 1015 begins at the transition between the strikeface 1012 and a top of the golf club head 1000 and ends at the transition between the top of the crown 1008 of the golf club head 1000 and a section of the crown with a different orientation, such as a rear wall 1023. In some embodiment's, top rail 1015 can be a Batter and taller top rail than in irons known to one skilled in the art. 'The flatter and taller to rail can compensate for mishits on strikeface 1012 to increase playability off the tee.

[0087] In some embodiments, body 1001 can comprise stilt:Jess steel, titanium, aka um, a steel alloy (e.g. 455 steel, 475 steel, 431 steel, 17-4 stainless steel, maraging steel), a titanium alloy (e.g. 'II 7-4, Ti 6-4, T-9S), an alu annum alloy, or a composite material In some embodiments, strikeface 1012 can comprise, stainless steel, titanium, aluminum, a steel alloy 455 steel, 475 steel, 431 steel, 17-4 stainless steel, maraging steel), a titanium alloy (e.g. Ti 7-4, Ii 6.-- 93), an aluminum alloy, or a composite material. In some embodiments, body 1001 can comprise the same material as strikeface 1012. In some embodiments, body 1001 cim compnse a different material than strikeface 1012.

[0088] In many embodiments, a cavity 1030 is located below top tall 1015. In many embodiments, cavity 1030 comprises a top rail box spring design. In many embodiments, top rail 1015 and cavity 1030 provide an increase in the overall bending-of strikeface 1012. In some embodiments, the bending of strikeface 1012 can allow ti-Jr an approximi approximately 5% increase of energy. The cavity 1030 allows for the strikof Ice (012 to be thinner and allow addition"' overt[ bending. For some fairway wood-type golf club head embodiments, cavity 1030 can be A reverse scoop or indentation of crown 1008 with body 1001 comprising a greater thickness or width toward sole 1006.

100801 Referring to FIG. 1 in. some embodiments. Of club head 1000 can further comprise an insert 1062 at lower region 1013 of crown 1008 towards toe region 1004. S( embodiments comprise an internal weight at sole 1006. In many embodiments, insert 1062 may he comprised of tungsten or some other bight density rnaterial. In many embodiments, the insert shifts the center of yjavity (CC) back from strikeface 1012 by approJJarriately 0.04

II

inch (1 nam) to (1.1C inch (2.5 mrri) and provides a 3.5% to 5.5% Increase in launch angle, which can lead to an increase of playability off the tee and high or low mishits.

[00901 In many embodimeets, the CC is in lower region 101:3 of crovvii 1008, close to the intersectional toe region 1004 and sole 1006. in sollic embodiments, the CCE of golf club head 1000 is 0.597 inches along the CG y plane and 0.541 inches aloiig the CCz. plane. For the moment of inertia. Ixx, there was a 20.5% increase over Hie G30 iron and a 28!'j-, increase over the Rapture D1 by golf club head 1000. I 'or Ivy, there was a 1.73/4 increase over the (330 iron and a 22% increase over Rapture 1)1.

[0091] In some embodiments, approximately 3 to aporoxiniately I g is added to top rad 1015. In most embodiments, the overall mass of golf club head 1000 remains the same. in some embodiments, mass C:313 be removed from sole 1006 or tOC reLT1011 1004 to offset the addition of mass to top rail 1015. ln so me (3111)0(fillICMS, adding the approximately 3 g to approximately 4 g of mass to top rail 101 5 can assist in the golf club head resisting turning. In somie embodiments, the CC of the golf club head is slightly raised.

I 00921 11G. :3 illustrates a cross section of golf club head 1000 along the cross-sectional Line XII -X11 in FIG. 1, according to one embodiment. As seen in 11G. 3, strtlyeface 1012 comprises a high region 1076, a middle region 1074, and a low region 1072. In many embodiments, upper region loll of crown 1008 comprises the rear wall 1023, a top wall 1017 of cavity 1030 below and adjacent. to rear wall 1023, and a back wall 1019 of cavity 1030 below and adjacent to top wall 1017, 100931 in some embodiments, a height 1280 of rear wall 1023 of the upper region 1011 of crown 1008 can be approximately 0.125 inch 318 cm) to approximate:: 5 inch 0.91 cm), [0094] or approximately 0.15(.1 inch (0.381 cm) to approximately 0.400 inch (1.02 cm). For example, in some embodiments, the height 1280 of rear wall 1023 of the upper region 1011 of crown 1008 can be approximately 0.175 inch (0.4-45 cm), 0.275 inch (0.699 cm), 0.375 inch (0.953 cm), 0.475 inch (1.21 cm), 0.575 inch (1.46 cm), or 0.675 inch (1.71 cm). In some embodiments, the height 1280 of rear wall 1023 of the upper region 1011 of crown 1008 can. he approximately Stio to approximately 25% (:)f the height of golf club head 1000. In some embodiments, the length of top rail 1015, measured fn ma. heel region 1002 to toe region 1004, can be approximately 70% to approximately 95% of the length of golf dub head 1000.

The height 1280 of rear wall 1023 of the tipper region 1011 of crown 1008, as des.crbect herein, allows cavity 1030 to absorb at least 3 portion of the stress on strikelace 1012 din log -mpact with a c olf ball. A cull club h-oil haHng a rear wall height greater than the rear wall height 1280 described herein would absorb less stress (and allow less smkerace deflection) on impact than the golf club head 1000 described herein, due to increased dispersion of the impact stress along.t.be top rail prior to reaching the cavity.

[0095] In some embodiments, cavity 1030 is located above itregion 013 of crown 1008 and is defined at least in part by upper region 1011 and lower. region 1013 of crown 1008. Cavity 1030 '..oniprises a top wall 1017, a back wall 1019, and a bottom incline 1021. A first inflection point 1082 is located between top wall 1017 of cavity 1030 and rear wall 1019 of cavity. A second inflection point 1086 is located between rear wall 1019 of caviry 1030 and bottom incline 1021.

[0096] The top wall 1017 and the rear wall I 01 9 if the external cavity 1030 hinge about the first inflection point 1082. This hingelike inability at the first inflection point 1082 allows greater strikefacc 1012 deflection.

[00971 In some embodiments, the height of back wail 1019, rneasiared from first inflection point 1082 to second inflection point 1086, can be approximately 0.010 inch (0.25 mm) to approximately 0.138 inch (3.5 mm), or approximately 0.010 inch (0.25 mrn) to approximately 0.059 inch (1.5 ram). F...tr example, the height of back wall 1019 can be approximately 0.01 inch (0.25 mm), 0.02 inch (0.5 mm)" 0.03 inch (0.75 min), 0.04 inch (1.0 mm), 0.05 inch (1.25 trim), 0,06 inch (1.5 mm), 0.07 inch (1.75 mm), 0.08 inch (2.0 mm), 0,09 inch (2.25 min), 0.10 inch (2.5 nun), 0.11 inch (2.75 mm), 0.012 inch (3.0 mm), 0,13 inch (3.25 mm), or 0.14 inch (3.5 mm). In many embodiments, an apex of top wall 1017 can be anproxirmately 0.125 inch (0.318 cm) to approximately 1.25 inches (3.18 cm) or approximately 0.25 inch (0.635 cm) to approximately 1.25 inches (3.18 cm) below an apex of top rail 10:5. For example, the apex of top wall 1017 can be approximately 0.125 inch (0.318 cm), 0.25 inch ((.635 cm), 0.375 inch (0.953 cm), 0.5 inch (1.27 cm), 0.625 inch (1.59 cm), 0.75 inch (1.91 cm), 0.825 inch (2.10 cm), 1.0 inch (2.54 cm), 1.125 inches (2.88 cm), or 1.25 inches (3.18 cm) below the apex of top rail 1015 100981 In many embodiments, back. wall 1019 of cavity)30 can be sulgttantially parallel strikelace 1012. In other embodiments, back wall 1019 is not i-stantially parallel to striketa: 1012. In many embodiments, top wall 1017 of cavity is angled toward strikeface 1012 when moving toward the first inflection point 1082. This orientation or top wall 1017 creates a hucliling point or hinge point or plastic hinge to direct the stress of i npa,.r toward cavity 1030 and allowing increased flexing of strikelacx 1012 during impact.

[0099] Lower region 1013 of crown 1008 comprises bottom incline 1021 of cavity 1030. In _many embodirnents, the second inflection point 1086, adjacent to bottom nchne1021, can be at least approximately 0.25 inch (0.635 cm) to approximately 2.0 inches (5.08 cm), or approxinkitely 0.5 inch (1.27 cm] to::ipproximately 1.5:inches (3.81 cm) be1 ow the 2rpex i.)f top rail 1015. For example, the second inflection point 1086 can be at least approximately 0.25 inch (0.633 cm), 0.5 inch (1.27 cm.), 0.75 inch (1.91 cm), 1.0 inch (2.53 cm), 1.25 inches (3.18 cm), 1.5 inches (3.81 cm), 1.73 inches (4.15 cm) or 2.0 inches (5.08 cm) below the apex of top rail 1013. In some embodiments, the maximum height of the bottom incline, measured from the sole 1006 of the club head 1000 to the second inflection point 1086, carl be at least approximately 0.25 inch (0.635 cm) to approximately 3 inches (7.62 cm), or approximately 0.50 inch (1.27 cm) to approximately 2 inches (5.08 cm) above a lowest point of the sole 1006. I or ample, the second inflection point 1086 can be at least approximately 0.25 inch (0.635 cm), 0.375 inch (0.953 cm), 0.5 inch (1.27 cm), 0.625 inch (1.59 cm), 0.75 inch (1.91 cm), 0.825 inch (2.10 cm), 1.0 inch (2.54 cm), 1.125 inches (2.88 cm), 1.25 inches (3.18 cm), 1.375 inches (3.49 cm), 1.3 inches (3.81 cm), 1.625 inches (4.12 cm.), 1.73 inches 4.43 cm), 1.873 inches (4.76 cm), 2.0 inches (5.08 cm), 2.123 inches 5.40 cm...], 2.25 inches 71 cm), 2.375 inches (6.03 cm), 2.5 inches (6.35 cm), 2.625 inches (6.67 cn6, 2.75 inches (7.00 cm), 2.875 inches (7.30 cm), or 3.0 inches (7.62 cm) above a lowest point of the sole.

[00100] Cavity 1030 further comprises at least one channel 1039 (FIG. 1). in many embodiments, channel 1039 extends from heel region 1002 to toe region [004. A channel width 1032 (FIG. 3) Can be substantially constant throughout channel 1039. In some embodiments, channel,,vidth 1032 (FIG. 3) can be approximately 0.008 inch (0.2 min) to approximately 1 inch (25 mm), or approximately 0.008 inch (0.2 mm) to approximately 0.31 inch (8 mm). liar example, channel width 1032 can be approximately 0.008 inch (0.2 mm), 0.016 inch (0.4 min.), 0.024 inch (0.6 man), 0.031 inch (0.8 man), 0.039 inch (1.0 min), 0.079 inch (2 mm), 0.12 inch (3 rum), 0.16 inch (4 mm), 0.20 inch (5 mm). 0.24 inch ("6 mm), 0.28 inch (7 ruin), 0.31 inch (8 MITI), 0.39 inch (10 mm), 0.59 inch (13 trim), 0.79 inch (.20 mm), or 0.98 inch (25 mm). In other embodiments, a channel toe region width of channel 1039 is smaller than a channel heel region width of channel. In other embodiments, the channel heel region width is smaller than the channel toe region width. in other embodiments, a channel -middle region width of channel 1039 can be smailer at at at least one a F the channel heel reman width or the channel toe region width. In other embodiments, the channel middle region wid can be greater than at least one of the channel 1-1,e1 region width or the channel toe region width. In se.] ne embodiments, chaimel 1039 is symmetrical.. In other embodiments, channel 1039 is non-synitnetrical. in other embodiments, channel 1039 can further conThrise at least two partial channels. In. scale embodiments, channel 1039 can comprise a series of pat: channels interrupted by one or more bridges. In some embodiments, the one or more bridges can be approximately the same thickness as the thickness of upper region 1011 of crown 1008.

[001011 The channel width 1032, as described herein, allows absorption of stress from strikeface 1012 on impact. A golf club he id having a channel width less than the channel width described herein (e.g. a golf club head with a less pronounced cavity) would allow less stress absorption from the strikeface on impact (due to less material on the upper region 1011 of crown 1008), and therefore would experience less strikeface deflection than the golf club head 1000 described herein.

I 00102] In many embodiments, cavity 1030 further comprises a back cavity angle 1035. Back cavity angle is measured between top wall 1017 and back wall 1019 of cavity 1030. in many embodiments, back cavity angle 1.033 can be approximately 70 degrees to approximately 1.10 grecs. In some embodiments, back cavity angle 1035 can be approximately 80 degrees to lately 100 degrees. in some embodiments, back cavity angle 1035 is approximately 70, 75, 80, 85, 90, 95, 100, or 110 degrees. in many embodiments, back cavity angle 1035 provides -a buckling point or plastic hinge or targeted hinge at a top rail hinge point 1070, upon golf club head 1000 impacting the golf ball. In some embodiments, the wall thickness at top ratl hinge point 1070 is thinner than at top wall 1017 of cavity 1030 [00103] FIG. 4 illustrates anew of crown:008 of the cross--section of golt* club head 0100 of F1G. 3 alongside a similar cross-section of a. golf club head 1200 without:1 cavity-along similar cross-sectional line XII-XII in 11C. 1. Coif club head 1200 comprises a strikefacc 1212, a crown 1208, a top rail 1215, a top rail hinge point 1270, and a rear wall 1223. In many embodiments, golf club head 1000 cornprises a rear angle 1040, a top rail angle 1045, and a strikelace angle 1050. Upper region angle 1040 is measure:, front top wall 1017 to rear wall 1023 of upper region 1011. In many erni)odirn en ts, rex-angle 1040 can he apptat)xi.nhately degrees to approximately 110 degrees. In some embodiments, rear angle 1040 is approximately 90 degrees. Top rail angle 1045 is measured from rear wall 1023 of upper region 1011 to top rail 1015. In many embodiments, top rail angle 1045 can be approximately 35 degrees to approximately 120 degrees or 70 degrees to approximately 110 degrees. In some embodiments, top rail angle 1045 can be approximately 35, 40, 45, 30, 55, 60, 65, 70, 75, 80, 83, 90, 95, 100, 105, 110, 115, or 120 degrees. Strikelace angle 1050 is measured from strikeface 1012 to top rail 1015. In many embodiments, strikelace angle 1050 can be approximately 70 degrees to approximately 160 degrees or 70 degrees to approximately 110 degrees. In SOILle eadvpdinitentis, strikelace angle 1050 is approiiimately 70, 75, 80, 85, 90, 95, 100, 105, 110. 1 15, 120,125, 130, 135, 140, 14.5, 150, 153, or 160 degrees.

[001041 Referring: to FIG. 4, in some embodiments, a min gap 1090 between striketace 1012 and back wall 1019 is approximately 0.079 inch (2 riarn) to approximately 0.39 inch (10 mm). For example, the minimum gap 1090 between strikefa cc 1012 and back wall 1 01 9 can be sip seitnatelv 0.079 inch (2. mm), 0.16 inch (4 mm), 0.24 inch (.6 trim), 0.31 inch (8 tril), (sr 0.39 inch (10 trim). Its some embodiments, the minimum gap 1090 between the strikeface 1012 and back wal11019 is less than approximately 0.55 inch (14 natri), less than approximately 0.47 inch (12 mai), less than approximately 0.39 inch (10 mm), less than approximately 0.31 inch (8 mm), Less than approximately 0.24 inch (6 mm), or less than approximately 0.16 inch mm). Further, in some embodiments, a maximum gap between strikeface.1012 and rear wan 1023 of upper region 1011 of golf club head 1000 is greater than minimurn gap 1090. Further still, in some embodiments, a maximurn gap between strikeface 1012 and bottom incline 1021 in lower region 1013 of poif club head 1000 is greater than minimum gap 1090 and maximum pp in upper re ion 1011.

[00105] In many embodiments, cavity 1030 can provide an increase in golf hall speed over golf-club head 1201 or other standard golf club heads can reduce the spits rate. of standard hybrids club heads, and can increase the launch ang,le over both the standard hybrid and iron club heads. In many embodiments, the shape of cavity 1035 determines the level of spring and timing of the response of go1f clula head 1000. When the golf bail impacts strikeface 1012 of club head 1000 with cavity 1030, strikeface 1012 sptings hack like a drum. and. crown 1008 bends in a contndled buckle manner. In many embodiments, top rail 1015 can absorb more stress over greater volumetric space than a top rail in a golf club head without cavity 1030. The length, depth and width of cavity 1030 can vary. These parameters provide control regarding how rnuch spring back ispresenr in the overall design of club head 1000.

1001061 Upon nripact with the gait oa.lI, strikeface 1012 can bend Inward at a greater distance than on a golf club without cavity 1030. -In some embodiments, strikeface 1012. has an approximately 10% to approximately 50% greater deflection than a strikeface on a golf club head without cavity 1030. In some embodiments:, strikeface 1012 has an approximately 5% to approximately 40% or approximately 10% to approximately 20% greater deflection than a s trikeface 011 a golf club head without cavity 1035. For example, s trikelac e 1012 can have an approximately 5%, 10%, 15%, 20%, 25(10, 30%, 35% or 40% greater deflection than a strikeface on a golf club head without cavity 1035. In many embodiments, there is both a -eater distance of retraction by strikeEice 1012 due tc) the hinge and bending of cavity 1030 over a standard strikeface that does not Live a back portion of the club without the cavity.

[00107] In many embodiments, the fru:0 deflection is greater with club head 1000 having, cavity 1030, as a greater buckling occurs along top rail hinge point 1070 upon impact with the golf ball. Cavity 1030, however, provides a greater dispersion of stress along top rail hinge point 1070 region of the top rail and the spring back force is transferred from cavity 1030 and top mil 1015 to strikeface 1012. A standard top rail without a cavity does not have this hinge/buckling effect, nor does it absorb a high level of stress over a large volumetric area of the top rail. Therefore, the standard strikeface does not contract and then recoil as much as strikeiace 012. liurther, both a larger region of strikeface..101 2. and top rail 1015 absorb more stress than the same crown region of a standard golf club head with a standard lop rail and no cavity. In many embodiments, although there is greater stress along a greater area above cavity 1030 than the same area in a standard club without the cavity, the durability of the club head with and without the cavity ts the same. By adding more spring to the back end of the club (clue to the inward inclination of top wail 1017 toward striketline 012), more force Is displaced throughout the volume of the structure. The stress Is obscr:ed over a. greater area of strikeface 1012 and top rail 1015 of golf club head 1000. Peak stresses can be seen in the standard top rail club head. However, more peak stresses are seen in golf club head 1000 but distributed over a large volume of the inatedal. The hinge and bend regions of golf club head 1000 (i.e., the region above cavity 1030 and cavity 1 030 itself) will not deform as long as the stress does not meet the critical buckling, threshold. Cavity 1030 and its placement can he designed h) be under the critical K value of the buckling threshold.

[001( Turning ahead in the drawings. FIG. 8 illustrates a back perspecti ye view of an embodiment of golf club head 2200 and MG, 9 illustrates a hack heel-side perspective view of golf club head 2.200 according to the embodiment: of FIG. 8. In some embodiments, golf club head 2200 can be similar to golf club head 10(:)0 (FIG. 1). Golf club head 2200 can be a hybrid-type golf club head. In other embodiments, golf club head 2200 can be an iron-type golf club head or a Eirway wood-type golf club head. In many embodiments, golf club head 2200 does not include a badge or a custom tar rung port.

po 1091 Golf club head 2200 ('()1111priSC.S a body 2201. In some embodiments, body-2201 cart be similar to body 1001 (FIG. 1). In many embodiments, the body is hollow. In some embodiments, the body is at least partially hollow. Body 2201 comprises a strikeface 2212, a heel region 2202, a toe region 2204 opposite heel region 22.02, a sole 2206, and a rear 2210. Rear 2210 comprises an upper region 2211 and a lower region 2213. Upper region 2211 comprises a top rail 2215. The top rail 2215 Can be similar to the top rail 1015 of golf club head 1000. In some embodiments, top rail 2213 can be a. flatter and taller top rail than in the in irons known to one skilled in the art. The flatter and taller top rail can compensate for mishits on strikeface 2212 to increase playability-off the tee.

I 00110_1 Body 2201 of FIGS. 8-12 Further comprises a blade length. 'the blade length for body 2201 can be measured similar to blade length 3725 as shown and described in leIG. 29 (i.e., a measurement parallel to the flat surface of the strikelace 3712, from a toe edge 3726 of the strikeiace:3712, to strikeface end 3727 tight before the strikeface 3712 integrally curves into the hosel). The blade length of the body 2201 can range from 2.80 inch (7.11 cm) to 3.00 inch (7.62 cm). For example, in some embodiments, the body 22.01 can comprise a blade length of 2.80 inch (7.11 cm), 2.82 inch (7.16 cm), 2,81 inch (I7.21 cm), 2.86 inch 1:7.26 cm), 2.88 inch (7.32 em), 2.90 inch (7.37 cm), 2.93 inch (7.44 cm), 2.94 inch (7.47 cm), 2.96 inch (7.52 cm), 2.98 Inch (7.57 cm), or 3.00 inch (7.62 cm).

[00111] The body 2201 further comprises a uniform thinned region ts-,nc+aionalav from the bottom of the strikeface 2212 to the sole 2206, toward a cascading sole portion of the sole (as described in greater detail below). in the illustrated embodiment, the uniform thinned region comprises a sole thickness measured perpendicular from the CXiletiOr surface 222.3 to the interior surbice al the uniform thinned region, which can remain constant from the bottom of the strikCEICe 2212 to adjacent the cascading sole portion of the sole. in some embodiments, the sole thickness of the uniform thinned region can be thinner than a cony emional sole. For example, In some embodimenN, the sole thickness of the uniform thinned region may range from appanatmateb: 0.010 inch to 0.080 inch. In other embodiments, the sole thickness of the uniform thinned region may within the range of 0.04inch to 1050 inch, 0.050 inch to 0.060 inch, 0.060 inch to 0.070 inch, 0.070 inch to 0.080 inch, 0040 inch to 0.055 inch, 0.045 inch to 0.060 inch, 0.050 inch to 0.065 inch, 0.055 inch to 0.070 inch, 0.060 inch to 0.075 inch, or 0.065 inch to 0.080 inch. For example, the sole thickness of the uniformed thinned region can be 0.040 inch, 0.045 inch, 0.050 inch, 0.060 inch, 0.065 inch, 0.070 inch, 0.075 inch, or 0,080 inch.

1001121 In some enibodirnents, body 2201 can comprise stainless steel, titanium, aluminum, a steel alloy (e.g. 455 steel, 475 steel, 431 steel, 17-4 stainless steel, mar-aging steel), a titanium alloy (e.g. It 7-4 -1, 1-98, Ti SSAT2011, Ti 8P700, Ti 15.-0-3, Ti 15-5-3, Ti 3-8-6-4.-4, Ti Ti, Ti-6-6-2, Ti--185, or any combination thereof), an aluminum alloy, or a composite material, In other embodiments, body 2201 can comprise carpenter grade 455 steel, carpenter grade 475 steel, C300 steel, C350 steel, a Ni-Co-Cr steel alloy, a. quench and tempered steel alloy, or 565 steel. In some embodiments, strikcthce 2212 earl comprise stainless steel, titanium, aluminum, a steel alloy (e.g. 455 steel, 475 steel, 431 steel, 17-4 stainless steel, maraging steel), a titanium alloy R.,. Li Ti 6-4, '.L-9S, Ti SS"AT2041, Ti SP700, Ti 15- 0-3, Ti 15-5-3, ii 3 8 6 4 1, Ti 10-2 3, Ti 15-3 3 3, Ti 6 -6 2, Ti-185, or any combination thereof, an aluminum alloy, or a composite material. In other embodiments, strikeface 2212 cart comprise carpenter grade 455 steel, carpenter grade 475 steel, C300 steel, C330 steel, a Ni,-' Co-Cr steel alloy, a quench and tempered steel alloy, or 565 steel. In some embodiments, body 22.01 can comprise the same material as strikeface 2212. in some embodiments, body 2201 can comprise a different material than snikelace 2212.

[0(113] In many embodiments, a cavity 2230 is located below t215. En some embodiments, the length of top rail 2215, measure: from heel region 2202 to toe region 2204, can be approximately 7011tb to approximately 95% of the length of golf club head 2200. In many-embodintients, cavity 2230 comprises a top rail box spring design. In many embodiments, top rail 2215 and cavity 2230 provide an increase in the overall bending of strikeface 2212. In some embodiments, the bending of strikelace 2212. can allot,v for an. approximtitely 200 to appitoxi.matay 5% increase of meta.I he cavity 2230 tilloNtis 11t It the strikethce 2212 to be. thinner and allow additional overall bending. For sorne fairway wood--type golf club head embodiments cavity 2230 can be a. reverse scoop or indentation of rear.2210 with body 2201 comprising a greater thickness or width sole 2206.

1001141 FIG. 10 illustrates a cross--section of 0. 2200 along: the eros s--sectional line XXIV:\ NW in FIG. A, according to one embodiment. As seen in FIG. 10, strikciacc 2212 comprises a high region 2476, a middle region 2474, and a low region 2472. In many embodiments., upper region 2211 of rear 2210 comprises a rear wall 2423, a top wall 2417 of cavity 2230 below and adjacent to rear wall 2423, and a back wall 2219 of cavity 2230 below and adjacent to top wail 2-117. 111 S ll-ruff embodiments, a top wad knoll 2491 of top wall 2417 can be approximately 0.090 inch (0.229 cm) to approximately 0.130 inch (0.330 cm). In some embodiments, top wall length 2491 of top wall 2417 can be approximately 0.090 inch (0.229 an), 0.100 inch (0.254 an), 0.110 inch (0.279 cm), 0.120 inch (0.305 cm), or 0.130 inch (0.330 ern).

[0(115] In some embodiments, a height 2480 of rear wall 2423 of the tippe r 2210 cast be approximately 0.125 inch (0.318 cm) to approximately 0.75 inch (1.91 cm), or approximately 0.150 inch (0.381 cm) to approximately 0.400 inch (1.02 cm). For example, in some embodiments, the height 2480 of rear wall 2423 of the upper region 2211 of rear 2210 can be approximately 0.175 inch (0.445 cm), 0.275 inch (0.699 cm), 0.375 inch (0.953 cm), 0.475 inch (1.21 cm), 0.575 inch (1.46 cm), or 0.675 inch (1.7 I cm). In some embodiments, the height 2480 of rear wall 2423 of the upper region 2211 of rear 2210 can be approximately 0.180 inch (0.4572 cm) to approximately 0.200 inch (0.508 cm). In some embodiments, the height 2480 of rear wall 2423 of die upper region 2211 of rear 22.10 can be approximately 0.190 inch (0.4826 cm). In some embodiments, the height 2480 of rear wall 2.423 of the upper region 2211 of rear 2210 can be approximately 5% to approximately 25°./b of the height of golf club head 2200.

[00116] The height 2480 of rear wall 242.3 of the upper region 2211 of rear 2210, as described herein allows cavity 2230 to absorb at least a portion of the stress on sinkeface 2212 during impact with a golf ball. A golf club head having a rear wall height greater than rear wall height 2480 described herein would absorb less stress (and allow less strike-face deflection) on impact rhan the golf club head 2200 described herein, due to increased dispersion of the impact stress along, the top rail prior to reaching the cavity.

[0011 In some embodiments, cavity 2230 is located alxive a II iwer regi on and is defined at least in part by upper region 2211 and lower region 2213 of rear 2210 ( 'avity 2230 comprises the top wall 2417, the back wall 2219, and a bottorn incline 2421. first inflection point 2482 is located between top wall 2417 of cavity 2230 and rear wail 2219 of cavi ty. A second inflection point 2486 is located between rear wall 2219 0:-ca: bottom incline 2421.

[001181 In some embodiments, a height 2488 of back wall 2219, measured from first inflection and point 2482 to second inflection point 2486, can be approximately 0.100 inch (0.254 cm) to approximately 0.600 inch (1.524 cm). For example, height 2488 of back wall 2219 can be approximately 0.100 inch (0.234 cm), 0.150 inch (0.381 cm), 0.200 inch (0.508 cm), 0.250 inch (0.635 cm), 0.300 inch (0.762 cm), 0.350 inch (0.889 cm), 0.400 inch (1.016 cm), 0.450 inch (1.143 cm), 0.500 inch (1.27 cm), 0.350 inch (1.397 cm), or 0.600 inch (1.524 cm). In many embodiment's, height 2188 of hack wall 2219 can he approximately 0.120 inch (1.067 cm) to approximately-0.520 inch (1.321 cm). In some embodiments, height 2488 of back wall 2219 can be approximately 0.420 inch (1.067 cm), 0.430 inch (01.092 cm), 0.140 inch (1.118 cm), 0.450 inch (1.143 cm) 0.460 inch (1.168 cm), 0.470 inch (1194 cm), 0.480 inch (1.219 cm), 0.490 inch (1.245 cm), 0.500 inch (1.27 cm), 0.510 inch (1.295 cm), or 0.520 inch (.321 cm).

[0011 In many embodiments, an apex of top wall 2417 can be approximately 0.123 inch (0.318 cm) to approximately 1.25 inches (3.18 cm) or approximately 0.25 inch (0.635 cm) to approximately 1.25 inches (3.18 cm) below an apex of top mad 2215. ['or example, the apex of top wall 2417 can be approximately 0.125 inch (0.318 cm), 0.23 inch (0.633 cm), 0.373 inch (0.953 cm), 0.5 inch (1.27 cm), 0.625 inch 0.59 cm), 0.75 inch (1.91 cm), 0.825 inch (2.10 ern), 1.0 inch (2.54 cm), 1.125 inches (2.88 cm), or 1.25 inches (3.18 c Below the apex of top rail 100120-1 In rmlnyi embodiments, back wall 2219 of cavity 2230 can be substantially par' Pci to stnkcifice 2212. In other embodiments, back wall 2219 is not substantially parallel to strikeface 2212. In some embodiments, back wall 2219 of Laiiiity 2230 is substantially parallel to rear wail 242.3 of upper region 2211 of rear 2210. In many embodiments, back wall 2219 of cavity 2230 is angled away from strikefilce 2212 when moving from first inflection point 2482 to second inflection point 2486. 'Ibis orientation of back wall 2219 creates a buckling point or hinge point or plastic hinge to direct the stress of) impact toward cavity 2.230 and to allow increased. flexing of strikelace 2212 during impact.

[001211 Lower region 2213 of rear 2210 comprises the bottom incline 2421 of cavity 2230 and.

a lower exterior wall 2427. In some embodiments, bottom incline 2121 of cavity 2230 can have a bottom incline length 2481 measured from second inflection point 2486 to a third inflection point 2492 positioned between Rimini. incline 2421 and lower exterior wall 2427.

In a number of embodiments bottom incline 1cm:id-I 2.484 can be approximately 0.150 inch (0.381 cm) to approximately 0.210 inch (0.533 crr). In inany embodiments, bottom incline length 2484 can be approximately 0.150 inch (0.381 cm), 0.160 inch (0406 cm), 0.170 inch (0.432 cm), 0.180 inch (0.457 cm), 0.190 inch (0.483 cm), 0.200 inch (0.508 cm), or 0.210 inch (0.533 cm).

[00 In sortie enibodiments a lower arislle 2451 CM]. lie 70. rd Fr( An the between the bottom incline 2421 and the lower exterior wall 2427. In some embodiments, lower angle 2451 can be less than 180 degrees. In a number of embodiments, lower -angle 2451 can be approximately.30 degrees to less than 180 degrees. In various embodiments, lower any;le 2451 can be. approximately 70 degrees to approximately 130 degrees. In some embodiments, lower angle 2451 can be approximately 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, or 1.30 degrees.

[00 -)] In some embodiments, an inflection angle 2496 measured from hack wall 2219 to bottom incline 2421 can be approximately 70 degrees to approximately 150 degrees. In some embodiments, inflection angle 2496 can be approximately 90 degrees to approximately 130 degrees. in some embodiments, inflection. angle 2496 is approximately 70, 75, 80, 85, 90, 95, :00, 110, 115, 120, 12.5, 130, 135, 140,145, or 1.50 degrees.

[00124] in many embodiments, second inflection point 2486, adjacent to bottom incline 24.21, can he at least approximately 0.25 inch (0.635 crr) to approximately 2.0 inches (5.08 cm:), or approximately 0.5 inch (1.27 cm) to approximately 1.5 inches (3.81 cm) below the apex of top rail 22.15. For example, the second inflection point 2,486 can be at least approximately 0.25 inch (0.635 cm), 0.5 inch (1.27 cm), 0.75 inch (1.91 cm), 1.0 inch 12.53 cm), 1.25 inches (3.18 cm), 1.5 inches (3.81 cm), 1.75 inches (4.45 cm) or 2.0 inches (5.08 cm) below the apex of top rail 221.5. In some embodiments, the maximum height of the bottom incline, measured from the sole 2206 of the club head 2200 to second inflection point 2486, can be at least approximately 0.25 inch (0.635 cm) to approximately 3 inches (7.62 cm), or approximately 0.50 inch (1.27 cm) to approximately 2 inches (5.08 cm) above a lowest point of the sole 2206.

r ex imple. the second inflection point 2486 can be at least approximately 0.25 inch (0.633 cm), 0.373 inch (0.933 cm), 0.3 inch (1.27 cm), 0.625 inch 0_39 cm), 0.73 inch (1.91 cm), 0.823 inch (2.1 0 cm), 1.0 inch (2.54 cm), 1.125 inches (2.88 cin), 1.25 inches (3.18 cm), 1.375 inches (3.19 cm), 1.5 inches (3.81 cm), 1.625 inches (4.12 cm), 1.75 inches (1.45 cm), 1.875 inches (4.76 cm), 2.0 inches (5.08 cm), 2.125 Inches 5.40 cm), 2.25 inches (5.71 cm), 2.375 inches (6.03 cm), 2.5 inches ((.55 cm), 2.625 if 2.73 inches (7.0 n inches (7.30 cm), or 3.0 inches (7.62 cm,) above a lowest point of the sole.

[00125.1 Ca ity 2230 further comprises at least one channel 2239 (14G. many embodiments, channel 2239 extends from heel region 2202 to toe region 2204. A channel width 2432 (HG. 10) measured from back viall 2219 (FIG. 10) to rear wall 2423 dIG. 10) and substantially perpendicular to a ground plane when golf club head 2200 is at address, can be substantially constant throughout channel 2239. In some embodiments, channel width 2432 (FIG. 10) can be approximately 0.008 inch (0.2 inin) to approximately 1 inch (25 mm), or approximately 0.008 inch (0.2 min) to approximately-0.31 inch (8 trim). For example, channel width 2432 can be approximately-0.008 inch (0.2 trim), 0.016 inch (0.4 mm), 0.024 inch (0.6 111111), 0.031 inch (0.8 mm), 0.039 inch (1.0 mm), 0.079 inch (2 mm), 0.12 inch (3 nun), 0.16 inch (4 Intin, 0.20 inch (5 mm), 0.24 inch (6 nun), 0.28 inch (7 min), 0.31 inch (8 mm), 0.39 inch (10 mm), 0.59 inch (15 mm), 0.79 inch (20 min), or 0.98 inch (25 mm). In other embodiments, a channel toe region -,..vidth of channel 2239 is smaller than a channel heel region width of channel. In other embodiments, the channel heel region width is smaller than the channel toe region width. in other embodiments, a channel middle region width of channel 2239 can be smaller than at least one of the channel heel region width or the channel toe region width. In other embodiments, the channel middle region width can be greater than at least one of the channel heel region width or the channel toe region width. In some embodiments, channel 2239 is symmetrical from heel region 2202 to toe region 2.204. In other embodiments, channel 2239 is non-symmetrical. hi other embodiments, channel 2239 can thither comprise at least two partial channels. Tn some embodiments, channel 2239 can comprise a series of partial channels interrupted by one or more bridges. In some embodiments, the one or more bridges can be approximately the same thickness as the thickness of upper region 2211 of rear 2210.

261 'Ihe channel width 2432, as described herein, allows al)sorpti on of stress from strilced on impact. A gel 1cmub head haying a channel width less than the channel width described herein (e.g. a golf club head with a less pronounced cavity) would allow less stress absorption from the strikefayn on impact (due to less material on the upper region 2211 of rear 2210), and therefore -would experience less snikelace deflection than the golf club head 2200 described herein.

1001271 In many embodiments, cavity 2230 further cOtTifl5e5 a back cavity angIe 2435. Hack cavity angle is measured between top wail 2417 and back wall 2219 of y 2231k In many embodiments, back cavity angle 2433 can be approximately 70 degrees to approximately 110 degrees. hi some embodiments, back cavity angle 2435 can be approximately 80 degrees to approximately 100 degrees. In some embodiments, back cavity an4e 2435 is approximately 70, 75, 80, 85, 90, 95, 100, or 110 degrees. In many embodiments, !tack cavity angle 2435 provides a buckling point or plastic hinge or targeted hinge at a top rail hinge point 2470, upon golf club head 2200 impacting the golf ball at strike face 2212. In some embodiments, the wall thickness at top rall hinge point 2470 is thinner than at top wall 2417 of cavity 22.30 [00 11 illustrates a -view of top rail 2215 and a portion of rear 2210 of the cross-section of golf club head 2200 of FTC. 8 different from cross-section of golf club head 1200 as shown in FIG. 4. In many embodiments, golf dub head 2200 composes a rear anp-le 2540, a top rail any,le 2545, and a, strikeface angle 2550. Rear angle 2540 is measured from top wall 24.17 to rear wall 2423 of upper region 2211. In many embodiments, rear angle 2540 can be approximately 70 degrees to approximateLy 110 degrees. In some embodiments, rear angle 2340 is approximately 70. /5, 80, 85, 90, 95, 100, 105, or 110 degrees. 'fop rail angle 2545 is measured from rear wall 2423 of -upper re,gion 2211 to top rail 2215. In many embodiments, top rail angle. 2545 cart be approximately 35 degrees to approximately 12.0 degrees or 70 degrees to approximately-110 degrees, Jr some embodiments, top rail angle 2543 can be approximately 35, 10, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 93, 100, 105, 110, 115, or 120 degrees. Strikeface angle 2550 is measured from strikeface 2212 to top rail 2215. In many embodiments, strikeface angle 2550 can be approximately 70 degrees to approximately 1.60 degrees or 71) degrees to approximately 110 degrees. In some embodiments, stnkerdce angle 2550 is approximately 70, 75, 80, 85, 90, 95, 00, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, or 160 degrees.

00129] In some embodiments, a mini muM gap 2590 measured perpendicularly to the strikeface 2212 to the back. wall 2.219 is approximately 0.079 inch (2 ram) to approximately 0.39 inch. (10 mita). For example, the tninimum gap 2.590 between strikeface 2212 and back wall 2219 can be approximately 0.079 inch (2 mm), 0.16 inch (4 mm, 0.24 inch (6 min), 0.31 inch (8 mm), or 0,39 inch 00 mm. In some embodiments, the minimum gap 2590 between the strikeface 2212 and back wall 2219 is less than approximately 0.55 inch (14 mm), less than approximately 0.47 inch (1 2 mrtt) less than approximately 0.39 inch (10 mm), less than approxirna.teY 0.al inch (8 mm), less than approximates 0.24 inch (6 mm), or less Mai --tpproxirnattly 0 min). Further, embodiments, a maximum gap between strikeface 2212 and rear wal12423 of upper region 2211 of golf club head 2200 is greater than _minimum gap 2590. Further still, in some embodiments, a maJdnium gap between strikeEtce 2212 and bottom incline 2421 (FIG. 10) in lower region 2213 (1.'l G. 10) of golf club head 2200 is greater than minimum gap 2590 and the maximum gap in tapper region 2211.

1001301 ['IC. 12 illustrates a simplified cross-sectional view of golf club head 2200, similar to the detailed cross-section of the golf club head 2200 illustrated in NG. 10. Golf club head 2200 includes the cavity 2230, an exterior surface 2223, the upper re ion 2211, and the lower region 2213. tipper re0on 2211 includes rear wall 2.42.3, cavity 2230 includes cavity exterior wall 2225, top wall 2.417, and back wall 221, while the lower region 2213 includes bottom incline 2421 and lower exterior wall 2427. In many embodiments, a maximum upper distance 2692 measured as the perpendicular distance from the exterior surflace 2225 nc the c<trikr'fici2212 to the exterior surface 2225 oc the rear wall 2423 of upper region 2211 can be approximately 0.20-0.59 inch (5-15 ranib example, maximum upper distance 2692 can be approximately 0.20 inch (5 ram), 0.24 inch (6 mm), 0.28 inch (7 mm), 0.31 inch (8 mm), 0.35 inch (8.89 mm), 0.39 inch (10 mr.), 0.43 inch (11 mm), 0.47 inch (12 min), 0.51 inch (l'i mm), 0.53 inch (14 mm), or 0.59 inch (13 tuna). In some embodiments, Maximum upper distance 2692 can be approximately 0.355 inch (9.02 mm).

1001311 Further, a minimum upper distance 2694 measured as the perpendicular distance from the exterior surface 2225 of the strikeface 2212 to the exterior surface 2225 of the back wall 2219 can be approximately 0.16-0.47 inch (4-12 trim). For example, minimum upper distance 2694 can be approximately 0.16 inch (4 mm), 0.20 inch (5 mm), 0.24 inch (6 min), 0.28 inch (7 ram), 0.31 inch (8 mm), 0.35 inch (9 mm), 0.39 inch (10 ram), 0.43 inch (Ii mm), or 0.47 inch (12 ram). In some embodiments, minimum upper distance 269.4 can he approxImately 0.284 inch (7.21 mm).

[00132] Further still, a rnaximum tox.ver distance.2696 measured as the perpendicular distance from tube exterior surface 2225 of the strikelace 2212170 the exterior surface 22.25 of the lower exterit)r wall 2427 can he approxin-iatelv 0.98-1.37 inch (25-40 mm). I or example, maximu rn lower distance 2696 can be approximately 0.98 inch (25 mm), 1.02 inch (26 rim 06 inch (27 min), 1.10 inch (28 mm), 1.14 inch (29 mm), 1.18 inch (30 mm), 1.22 inch (31 trim), 1.26 inch (32 mm), 1.30 inch (33 min), 1.31 inch (34 mm), 1.38 inch (35 mm), 1.42 inch (36 min), 1.46 inch (37 mn), 1.50 inch (38 mm), 1.54 inch (39 mm), 1.57 inch or (40 mm). in some embodiments, maximum lower distance 2696 can be approximately 1.043 inch (26.5 inn)). In many enthodirnents" maximum lower distance 2696 is greater than ntaximum upper distance 2692, and maximum upper distance 2692 is greater than minimum upper distance 2694.

[001 In many entbodbiletitS, cavity 2230 can provide an increase in golf ball speed over golf club head 1200 (E(i. 11) or other standard golf club heads, can reduce the spin rate of standard hybrids club heads, and can increase the launch angle over both the standard hybrid and iron club heads. In many embodiments, the shape of cavity 2230 determines the level of spring and timing of the response of golf club head 2200. When the golf ball trripacts striker:act 2212 of club head 2200 with cavity 2230, striketlice 2212 springs back like a drum, and rear 2210 bends in a controlled buckle manner. In many embodiments, top rail 2215 can absorb more stress over greater volumetric space than a top rail in a golf club head without cavity 2230. The length, depth and width of cavity 2230 can vary. These parameters provide control regarding how much spring back is present in the overall design of club head 2200.

00134] Upon impact with the golf ball, strikeface 2212 can bend inward at a greater distance than on a golf club without cavity 2230. In some ernbodiments, strikeface 2212 has an approximately 10% to approximately 50% greater deflection than a strikeface on a golf club head without cavity 2230. In some embodiments, strikeface 2212 has an approximately 5% to approximately 40',-;) or approximately 10% to approximately 20% greater deflection than a strikeface on a golf club head without cavity-2230. For example, stinkeface 2212 can have an appro)dmatelv 10N, 15%, 20%, 25%, 30%, 35% or 40II greater deflection than a sthkeface on a golf club head without cavity 2230. In many embodiments, there is both a greater distance of retraction by striketace 22 12 due to the hinge and bending of ca.vny 2230 over a standard strikeEt cc thr:,it does not have a back portion of the club without the cavity.

[001351 In many embodiments, the face deflection is greater with chili head 2200 having cavity 2230, as a greater truckling occurs along top rail hinge point 2470 upon impact with the golf hall. Cavity 2230, hoviever, provides a greater dispersion of stress along top rail hinge point 2470 region of the top rail, and the spring back force is transferred from cavity 2230 and top rail 2215 to strikelace 2212. A standard i-.(,)p mil without a cavity does not have this hinge/buckling effect, nor does it absorb a high level of stress over a large volumetric area of the top rail. 'Therefore, the standard strikelace does not contract and then recoil as much as strikeface 2212. Further, both a larger region ofstrikeface 7712 and ton rail 2.215 abs,ori, more stress than the same crown region ola standard golf club head with _ standard top rail and no cavity. -I many embodirrtenks, al thoupli there Is greater stress along a 0greater area above cavity 2230 than the same area in a standard club without the cavity, the durability of the club head with and without the cavity is the same. By adding more spring to the back end of the club (due to the inward inclination of top wad 2417 toward strike-lace 2212), more Force is displaced throughout the volume of the structure. The stress is observed over a greater area of strikeface 2212 and top rail 2215 or golf club head 2200. Peak stresses Can be seen in the standard top tad club head. However, more peak stresses are seen in golf club head.2200 but distributed over a large volume of the material. The hinge and bend regions of golf club head 2200 (i.e., the region above cavity 2230 and cavity 2230 itself) will not defdrtn as long as die stress does not meet the critical buckling' threshold. Cavity 2230 and its placement can be designed to be under the critical K value of the bucklinv threshold.

[00136] Turning to FIG. 5, FIG. 5 illustrates a golf club 1500 comprising a golf club head 1500 and a. shaft 1590 coupled to golf club head 1500. In some embodiments, iroif club head 1300 of golf club 15000 comprises a hybrid-type golf club head. In other embodiments, golf club head 1500 can be an iron-type golf club head or a fairway wood-type golf club head. in many embodiments, gulf club head 1500 cart be similar to golf dub head 100 or golf club head 1000 i1G. 1). Golf club head 1500 can be hollow-bodied and curnprises a strikeface 1512, a heel region 1502, a toe reckon 1504 opposite heel region 1502, a sole 1506, and a crown 1508. The crown 1508 comprises an upper region 1311 and a lower region 1513. The upper region 1511 comprises top rail 1515. Golf club head 1300 further comprises a cavity 1530 located below top rail 151 5 arid above lower region 1513 of crown 1508.

[00137] NG, 6 illustrates a cross-section of golf club head 1500 along the cross--sectional line in FIG. 5, according to one embodiment In some embodiments, cavity 1530 can be defined at least in part by upper region 1311 and lower region 1513. In many ernbodirdents, cavity 1530 cora-Trises a top wall 1517, a back wall 1519, a bottom incline 1521, a back cavity angle 1535 rneasured between top -wall 1517 and ba.cic wall 1319, and at least on e channel 1539, In some enthodiments, an apex of top wall 1317 is approximately 0.25 inch to approximately 1.25 inches below an apex of top rail 1513. In sonic embodiments, the apex of top wall 131/ is apprcudrnately 0.375 inch below the apex of top rail 1515. In some embodiments, bottom incline 1521 can be at least approxitnately 0.50 inch to approximately 2 inches be of top rail 1515. In many embodiments, back cavity angle 1535 can be approximately 70 degrees to approximately 110 degrees. In some embodiments, hack cavity angle 1535 can be approximately 90 degrees.

1001381 in many eilaboditnentS, the upper region 1511 comprises the top in id back walls of the cavity; and the lower region of the crown comprises the boltom incline of the cavity. in some eilabodiments, upper region 1511 further comprises a rear wall 1523 adjacent to top wall 1517 of cavity 1530 and a rear angle 1540 measured between top wall 1317 of cavity 1330 and rear wall 1523 of upper region 1511. in many enabodiments, rear angle.1540 is approximately 70 degrees to approximately 110 degrees.

1001391 In another embodiment, the colt club head can compthe a hosel. The hosei can comprise a hose]. notch. "The hose' notch can allow for iron -like range of loft and lie angle acijustahility.

[00140] A s shown in FIG. 12, a further deflection feature of the golf club bead 2200 can be the uniform thinned region 2660, located at the sole 2206 and stretching between the rear 2210 of the body-2201 and the strikeface 2212, toward a cascading sole portion of the sole (-as described in greater detail below). 'Ihe uniform thinned region 2660 can provide multiple benefits. First, the uniform thinned region 2660 can reduce stress on the strikeface 2212 caused during impact with the golf ball Second, the uniform thinned region 2660 can bend allowing the strikeface 2212 to experience greater deflection. 'third, the uniform thinned region 2660 removes weiahr from the sole area, allowing the weight to he redistributed more toward the c, rear of the golf club head 2200. At impact, the energy imparted to the strikelace 2212 by the golf ball can cause the uniform thinned region 2660 to bend outward, which in turn increases the strikeface 2212 deflection. After bending, the uniform thinned region 2660 rebounds back to its original position returning the majority of the energy from impact back to the golf ball. The result is the golf club head 2200 imparts increased ball speeds and greater travel distances to the golf ball after impact.

00141_1 Turning ahead in the drawings, 1/1(1. 13 illustrates a back perspective view of an embodiment of golf club head 2700 and FIG. 14 illustrates a back heel-side perspective -view of golf dui) head 2700 according to the embodiment of FIG. 13, in some embodiments" golf club head 2700 can be similar to in >11 club head 1000 (1/1G. 1), and/or golf club head 2200 (FIG. 8). Golf club head:2700 can be a hybrid 'typegolf dub head. Ti other embodiments, golf club head 2700 can he an iron -type golf club bead or a fairway wood-type golf-club head. In many embodiments, golf chit.; head 2700 does not include a badge or a custom tuning port.

J1 can 1001421 Golf club bean 2700 corn:prises a body 2701. ' onic embodiments, Tao similar to body 1001 (FIG. 1), and/or body 2201 (FIG. 8). In many embodiments, the body is hollow. In some embodinients, the body is at least partially hollow. Body 2701 comprises an exterior surface 2703, a strikeface 2712., a heel region 2702, a toe region 2704 opposite heel region 2702, a sole 2706, and a rear 2710.

[00143] Body 2701 of FIGS. 13-17 further comprises a blade length. The Idade length for 2301 can be measured similar to blade length 37.25 as shown and described in FIG. 43 (i.e., a measurement parallel to the flat surface of the strikelace 3712, From a toe edge 3726 of the strikeface 3712, to strikeface end I right before the sinktfithe 3712 intethidiv curves into the hosel). The blade length of the body 2701 can range from 2.80 inch (711 cm) to 3.00 inch (7.62 cm). For example, in some embodiments, the body 2701 can comprise a blade length of 2.80 inch (7.11 cm), 2.82 inch (7.16 cm). 2.84 inch (7.21 cm), 2.86 inch (7.20 cm), 2.88 inch (7.32 cm), 2.90 inch (7.37 cm), 2.93 inch (7.44 cm), 2.94 inch (7.47 cm), 2.96 inch (7.52 cm), 2.98 inch (7.57 cth Jr 3.00 inch (7.62 cm).

1001441 the body 2701 further comprises a uniform thinned region ticthcitioning from the bottom of the strikeface 2712 to the sole 2706, toward a cascading sole portion of the sole (as described in greater detail below). In the illustrated embodiment, the uniform thinned region comprises a sole thickness measured perpendicular from the exterior surface 2703 to the interior surface at the uniform thinned region, which can remain constant from the bottom of the strikeface 2.712 to adjacent: the cascading sole portion of the sole. In some embodiments, the sole thickness of the uniform thinned region can be thinner than a coilien1ional sole. For example, in sonic embodiments, the sole thickness of the uniform thinned region may range from approximately 0.040 inch to (080 inch. En other embodiments, the sole thickness of the uniform thinned region may be within the range of 0.040 inch to 0.050 inch, 0.050 inch to 0.060 inch, 0.060 inch to 0.070 inch, 0.070 inch to 0.080 inch, 0.040 inch to 0.055 inch, 0.045 inch to 0.060 inch, 0.050 inch to 0.065 inch, 0.053 inch to 0.070 inch, 0.060 inch to 0.075 inch, or 0.065 thch to 0.080 inch. For example, the sole thickness of the uniformed thinned region can be 0.040 inch, 0.045 inch, 0.050 inch, 0.060 inch, 0.065 inch, 0.070 inch, 0.075 inch, or 0.080 inch.

FIG. 15 illustrates a cross-section ogot F ch tb head 2700 along the cross-sec nal line TX-XXIX in FIG. 13, according to one erobodiment. As seen in FIG. 15, strikeface 2712 comprises a high region 2976, a middle region 2974, arid a iow region 2972.. Rear 2710 comprises an upper region 2711 and a lower egion 2713 (FIG. 15). Upper region 2711 composes a top rail 2715,a rear wall 2923, and a. top wall 2719. The top rail 2715 can be similar to Use top rail 1015 of golf club head 1000. In many embodiments, rear wall 2923 of rear 2710 is located below and adjacent CO top rail 2715, and a top wail 2719 of rear 2710 is located below and adjacent to rear wall 2923. Lower region 2713 comprises a back wall 2921, and a lower exterior.112927, wherein back wall 2921. is located below an adjacent the top wall 2719, and the lower exterior will 2927 is located below and adjacent the back wall 2921. Cavity 2730 is located on the exterior surface 2703 1J)wer region 2713 of ref.tr 2710, Jmd lower region 2713.

[00 6] In some crnbo a flatter and taller top below the top rail 2715 and rear wall 2923. above the s defined by at least in iart by upper rep-ion 2711 and it uppc. 2711 of the rear 2710 eJlil n irons known to one skilled in the art. The pp rail 2715 o ail skirt than in the flatter and taller top rail can compensate for mis-hits on striketke 2712 to increase playabihty off the tee. In some embodiments, the length of top rail 2715, measured from heel region 2702 to toe region 2704, can be 70% to 95% of the length of golt club head 2700. in many embodiments, cavity 2730 comprises a top rail box spring design. in many embodiments, top rail 2.715 and cavity-2730 provide an increase in the overall bending of strikeface 27:2. In some embodiments, the bending of sttikelace 2712 can allow for a 2% to 5% increase of energy. Cavity 2730 allows for strikeface 2712 to be thinner and allow additional overall bendinn-. For some fairway wood--type golf club head embodiments, cavity 2730 can be a reverse scoop or indentation of rear 2710 with body 2701 comprising a greater thickness or wrdth toward sole 2706.

[00117] In some embodiments"t netght 2980 of rear wall 2923 of the upper region 2711 of rear 2710 can range from 0.125 inch (0.318 cm) to 0.75 inch (1.91 em), or 0.150 inch (0.381 en)) to 0.400 inch (1.02 cm). For example, in some embodiments, the height 2980 of rear wail 2923 of the upper rep-ion 2711 of rear 2710 can he 0.175 inch (0.445 cm), 0.275 inch (0.699 cm), 0.375 inch. (0.953 cm), 0.47/5 inch (1.21 cm), 0,575 inch (1.46 cm), or 0.675 inch (1.71 cm). In some embodiments, the height 2980 of rear wall.2923 or the upper region 2711 of rear 2710 can range ingn 0.150 inch (0.381 cm) to 0.200 inch ((1508 cm). In J:4)rne embodiments, the height 2980 of rear wall 2923 of the upper region 2711 of rear 271 0 can be 0.170 inch (0.132 cm). In some embodiments, the height 2980 of rear wall 2923 of the upper region 2711 of rear 2710 can he 5% to 25% of the heiLrht of I:J;(4 I club head 2700.

[001481 The height 980 of rear wall 292.3 of the upper region 2711 of r 2710, as described herein, allows cavity 2730 to absorb at least a portion of the stress on strakchacci 2712 during impact with a golf ball. A golf club head haying a rear wall height greater than rear wall height 2980 described herein would absorb less stress (and allow less strikelace dcillection) on impact than golf club head 2700 described herein, due to increased dispersion of the impact stress alt (fit! the nip rail pritir to reaching the cavity.

1001491 in some embodiments, cavity 2730 is located above a lower region 2713 of rear 21/10 and is defined at least in part by upper region 2711 and lower region 2713 of rear 2710. Cavity 2730 cornprises top wall 2719, and a back -wall 2921. A first reference point 2922 is located between the top rail 2715 and rear wall 2923. A second reference point 2982 is located between rear wall 2923 and top wall 2719. A first inflection point 2986 is located between top wall 2719 of cavity 2.730 and back wall 2921. A third reference point 2924 is a point located on top wall 2719 closest to the strikeface 2712. First reference point 2922 and second reference point 2982 create a first reference line 2929. Second reference point 2982 and third reference point 2924. create a second reference line 2925. Third reference point 2924 and First inflection point 2986 create a third reference line 2926.

1001501 Golf club head 2700 further comprises a height 2988 of top wall 2719, measured parallel to strik-eface 2712 and from the second reference point 2982 to first inflection point 2986. In many embodiments, height 2988 can range from 0.100 inch (0.254 cm) to 0.600 inch (1.524 cm). For example, height 2988 can be 0.100 inch (0.251 cm), 0.150 inch (0.381 cm), 0.200 inch (0.508 cm), 0.250 inch (0.635 *.300 inch (0.762 cm), 0.350inch (0.889 cm), 0.400 inch (1.016 cm), 0.450 inch (1.143 cm), 0 inch (1.27 cm), 0.550 inch (1.397 cm), or 0.600 inch (1.524 cm). In many embodiments, height 2988 can range from 0.500 inch (1.27 cm) to 0.600 inch (1.524 cm). In some embodiments, height 2488 of top wall 2719 can be 0.500 inch (1.27 cm), 0.510 inch (1.295 cm), 0.520 inch (1.321 cm), 0.530 inch (1.346 cm), 0.540 inch (1..372 cm), 0.550 inch (1.397 cm), 0.560 inch (1.422 cm), 0.570 inch (1.448 cm), 0.580 inch (1.473 cm), 0.590 inch (1.499 cm), or.600 inch (1.524 cm).

1001511 In ninny embodiments, second reference point 2982 can be 0.125 inch (0.318 cm) to 1.25 inches (3.18 cm) or 0.25 inch (0.635 cm) to 1.25 inches (,3.18 cm) to apex 2928 of top rail 2715. For example, the second reference point 2982 can be 0.125 inch (0.318 cm), 0.25 inch (0.635 cm), 0.375 inch (0.953 crri1i, 0.5 inch (1.27 cm), 0.625 inch (1.59 cm), 0.75 inch (1.91 cm), 0.825 inch 0 cm), 1.0 inch (2.54 cm), 1.125 inches (2.88 cm), or 1.25 inches (3.18 pi-below the apex 2928 or top rail 2715.

[0(1521 In many embodiments, top v",all 2719 of cavity 2730 can be substantially parallel to strskefllce 2712. In other embodiments, top wall 2719 is not substantaily parallel to strikeface 2712. ha some embodiments, top wall 2719 of cavity 2730 is substantially arallel to rear wall 2923 or upper region 2711 of rear 2710. In a number of embodiments, a oortion of top wall 2319 extends away from rear wall 2923 toward strikeface 2712. from second reference point 2982 to third reference point 2924. In some embodiments, the portion of top wall 2719 extending away from rear wall 2.923 toward strikeface 2712 from second reference point 2982 to third reference point 2923 can be straight; curved upward, or curved downward. In many embodiments, a portion of top wall 2719 of cavity 2730 is angled away trom strikeface 2712 from third reference point 2924 to first inflection point 2986. in some embodiments, the portion of ton wall 2719 angled away from strikeface 2712 from third reference point 2.924 to First inflection point 2986 can be straight, curved upward, or curved downward. This orientation of top wall 2719 creates a buckling point, hinge point or plastic hinge to direct the stress of impact toward cavity 2730 and to allow increased flexing of strikeface 2712 during impact.

[001531 Lower region 2713 of rear 2711 comprises back wall 2921 ofcavity 2730 and the lower exterior wall 7927. In some embodiments, back wall 2921 of cavity 2730 can have a back wall length 2990 measured from first inflection point 2986 to a second inflection point 2992 located between the back wall 2921, and the lower exterior wall 2927. In a number of embodiments., back wall length 2990 can range from 0.150 inch (0.381 cm) to 0.400 inch (1.02 cm). In many embodiments, back wall leng,th 2990 can be 0.150 inch (0.381 can, 0.1.60 Inch (0.406 cm), 0.1.70 inch (0.432 cm), 0.180 inch (0.437 cm), 0.190 inch (0.483 cm), 0.200 inch (( .508 cm), 0.210 inch (0.533 cm), 0.220 inch (0.559 cm), 0.230 in (0.584 cm), 0.240 inch (0.61 cm), 0.250 inch (0.635 cm), 0.260 inch (0.660 cm), 0.270 inch (0.686 cm), 0.280 inch (0.711 cm), 0.290 inch (0.737 cm), 0.300 inch (0.762 cm), 0.310 inch (0.787 cm), 0.320 inch (0.813 cm), 0.330 inch (0.838 cm).. 0.340 inch (0.864 cm), 0.350 inch (0.889 cm), 0.360 inch (0.914 cm.), 0.370 inch (0.94 cm), 0.380 inch (0.965 cm), 0.390 inch (0.991 cm), or 0.300 inch (1.02 cm.).

1001541 In some embodiments, a lower angle 2951 can be measured from between the hack wall 2921 and the lower exterior wall 2927. In some embodiments, lower angle 2931 can be less than 180 degrees. In a number or embodiments, lower angle 2951 can range from 30 degrees to 180 degrees. Fri various embodiments, lower angle 2951 can t.. .) degrees to 130 degrees some embodiments, lower angle 2951. can be 70 degrees, 75 degrees. 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, or 130 degrees.

[001551 In some embodiments, an inflection angle 2996 measawed front third reference line 2926 to 1.-tack wall 2921 can range fix an 70 degrees to 150 degrees. In some embodiments, inflection angle 2996 can range From 90 degrees to 130 degrees. In some embodiments, inflection angle 2996 can be 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 D degrees, 140 degrees, 145 degrees, or 150 degrees. In many embodiment's, inflection angle 2996 allows first inflection point 2986 to act as a buckling point or plastic hinge upon golf club head 2700 impacting the golf ball at strike face 2712. In some embodiments, the wall thickness at the first inflection point 2986 Can be thinner than at the top wall 2719 and back wail 2921.

I 00156_1 In many embodiments, first inflection point 2986, adjacent to back wall 2921, can range from 0.25 inch (0.635 cm) to 2.0 inches (5.08 cm), or 0.5 inch (1.27 cm) to 1.5 inches (3.81 cm) below the apex 2928 of top rail 2715. For example, the first inflection point 2986 can be 0.25 inch (0.615 cm), 0.5 inch (1.27 cm), 0.75 inch (1.91 cm), 1.0 inch (2.53 cm), 1.25 inches (3.18 cm), 1.5 inches (3,81 cm), 1.75 inches (4.45 cm) or 2.0 inches (5.08 cm) below the apex 2928 of top rail 2715. In some embodiments, the maximum height of the hack wall 2921, measured perpendicular to a ground plane 2903 when golf club head 2.700 is at address from a lowest point of solo 2706 to first inflection point 2986, can range ti-otn 0.25 inch (0.635 cm) to 3 inches (7.62 cm), or 0.50 inch (1.27 cm) to 2 inches (5.08 cm). For example, the first inflection point 2986 can be 0.25 inch (0.635 cm.), 0.375 inch (0.95.3 cm), 0.5 inch (1.2.7 cm), 0.625 inch (1.59 cm), 0.75 inch (1.91 cm), 0.825 inch (2.10 cm), 1.0 inch (2.54 cm), 1.125 inches (2.88 cm), 1.25 inches (3.18 cm), 1.375 inches (3.49 cm), 1.5 inches (5.81 cm), 1.625 inches (4.12 cm), 1.75 inches (4/15 cm), 1.875 inches (4.76 m), 2.0 inches (5.08 cm), 2.125 inches (5.40 cm), 2.23 inches (5.71 cm), 2.373 inches (6.03 cm), 2.3 inches (6.35 cm), 2.623 inches (6_67 cm), 2.75 inches (7.00 cm), 2.873 inches (7.30 cm), or 3.0 inches (7.62 cm) above alOnlest point of sole 2706 petpendicular to the ground plane 2901 when golf club head 2700 is at address. 4'2

In some embodii ents back V. 7 2905 measured from back wall 2921 to ground --lane 2903 can rarigetre 15 (legreeS to 45 degrees. In some embodiments, back wall angle 2905 can be 13 degrees, degrees, I 7 degrees, 18 degrees, 19 degrees, 70 degrees, 71 degrees, 22 degrees, 23 degrees, 24 degrees, 25 degrees, 26 degrees, 27 degrees, 28 degrees, 29 degrees 30 degrees, 31 degrees, 32 degrees, 33 degrees, 3.4 degrees, 35 degrees, 36 degrees, 37 ctegrecs,38 degrees. 39 degrees, 40 degrees, 41 degrees, 42 degrees, 43 degrees, 44 degrees, or 45 degrees.

(00158j in sorne embodiments, cavity 2730 can Further comprise at least one channel 2739 (FIG. 13). In many embodiments, channel 2739 extends from heel region 2702 (FIG. 13) tD toe region 2704 (FIG. 13). Channel 2739 comprises a channel width measured from second reference point 2982 to top wall 2719 substantially parallel to ground 1)lane 2903, where channel width can vary in a direction from top rail 2715 to sole 2706. In Some einbodiMents, maxirnurn channel width 2932, measured from first inflection point 2986 to second reference point 2982 substantially parallel to ground plane 2903, can be substantially constant throughout channel 2739 from heel region 2702 to toe region 2704. In some embodiments, maximum channel width 2932 (FIG. 15) can range from 0.008 inch (0.2 mm) to 1 inch (25 mm). or 0.008 inch (0.2 mm) to 0.31 inch (8 nun). For example, maximum channel width 2932 can be 0.008 inch (0.2 mm), 0.016 inch (0.4 mm), 0.024 inch (0.6 null), 0.031 inch (0.8 ram), 0.039 inch (1.0 mm), 0.079 inch (2 mm), 0.12 inch (3 mm), 0.16 inch (4 mm), 0.20 inch (5 mm), 0.24 in (6 mm), 0.28 inch (7 mm), 0.31 inch (8 mm), 0.39 inch (10 mm), 0.59 inch (15 mm), 0.79 inch (2.0 rnrrn, or 0.98 inch (25 mm). In other embodiments, a channel toe region width of channel 2739 is less than a channel heel region width of channel 2739. in other embodiments, the channel heel region width is less than the channel toe region width. In other embodiments, a channel middle region width of channel 2739 can be less than at least one of the channel heel region width or the channel toe region vridth. In other embodiments, the channel middle region width can be greater than at least one of the channel heel region width or the channel toe region width. In some embodiments, channel 2739 is syminetrical from Eitel to tot. In other eml,ndiments, channel 2739 is non-symmetrical. In other embodiments, channel 2739 can further comprise at least two partial channels. In some embodiments, channel 2739 can comprise a series of partial channels interrupted by one or more bridges. In some embodiments, the one or inore bridges can be approTrArna Left the same thickness as the thickness of mop rail 2715.

71 mutti channel width 2.932, as described heroin, allows absorption of ss from sir:kr:Face 2.712 on impact. A golf club bead haying-a channel width less than the maximum s- .i. -chat-Aiel width described herein (e.g. a golf club head with a less pronounced cavity) would allow less stress Absorption from the strikeface on impact (due to less material on the upper region 2711 of rear 271(1)5 and therefore -would experience less strilieface deflection than golf club head 2700 described herein.

1001601 In many embodiments, cavity 2730 further comprises a back cavity angle 2935. Back cavity angle 2935 is measured from first reference line 2929 to second reference line 2925. In many embodiments, back cavity angle 2935 can range from 15 degrees to 80 degrees. In some embodiments, back cavity Al-4 if 2935 is 15 degrees, 20 degrees, 25:degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees or 80 degrees.

[00161] FIG. 16 illustrates a view of top rail - and a. portion of rear 2710 of the cross-section ol golf club head 2700 of 1Y1G. 13 different from cross-section of golf club head 1200 as shown in NC. 4. In many embodiments, golf club head 2700 comprises a rear angle 3040, a top rail angle 3045, and a strilieface angle 3030. Rear angle 3040 is measured from second reference line.2923 to rear wall.2923 of upper region 2711. in many embodiments, rear angle 3040 can range from 70 degrees to 140 degrees. In some embodiments, rear angle 30.4.0 can be '70 degrees, 75 degrees, 80 degrees, 83 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, or 140 degrees. Top rail angle 3045 is measured from rear wall 2923 of upper region 2711 to top rail 2715. In many embodiments, top rail angle 3045 can range from 35 degrees to 120 degrees or 70 degrees to 110 degrees. In some embodiments, top rail angle 3045 can be 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, 05 degrees, 110 degrees, 1.15 degrees, or 120 degrees. Strikeface angle 3050 is measured from strike:face 2712 to top rail 2715. In many embodiments, strikeface angle 3050 can range from 70 degrees to 160 degrees or 70 degrees to 110 degrees, In sonic embodiments, strikelace angle 3030 can be 70 degrees, 73 degrees, 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, 140 degrees, 145 degrees, 130 degrees, 155 degrees, or 160 degrees.

1001621 Upper region 2711 Further compn3e. t minimum rap 3090 measured from third inference point 2924 of an inner surface 2919 of top wall 2719 to an inner surface 2919 of strikeface 2712, perpendicular to strikeface 2712. In some embodiments., minitnum yap 3090 can range ttom 0.079 inch (2 mm) to 0.39 inch (10 mm). For example, the minimum gap 3090 can be 0.079 inch (2 MM), 0.16 such (4 mm), 0.24 inch (6 mm), 0.31 inch (8 mm), or 0.39 inch (10 rum). In other embodiments, the minirnurn gap 3090 can range from. 0.16 inch (4 min) to 0.33 inch (14 mm). In some embodiments, the minimum gap 3090 can be 0.33 inch (14 min), 0.47 inch (12 mm), 0.39 inch (10 mm), 0.31 inch (8 mm), 0.24 inch (6 n-un), or 0.16 inch (4 min).

1001631FIG. 17 illustrates a simplified cross -sectonal new of golf club head 2700, snnslar to the detailed cross--section of p-pft club head 2700 illustrated in FIG. 15. Golf club head 2700 includes cavity 2730, upper region 2711, lower region 2713, and exterior surface 2703. In many embodiments, a maximum upper distance 3192 measured as the perpendicular distance from exterior surface 2703 of strikeface 2712 to exterior surthce 2703 of second reference point 2982 of upper region 2711 can range from 0.20 inch to 0.59 inch (5 mm to 15 mm).

example, maximum upper distance 3192 can be 0.20 inch (5 mm), 0.24 inch (6 0.28 inch (7 mm), 0.31 inch (8 min), 0.35 inch (8.89 mm), 0.39 inch (10 mm), 0.43 inch (11 mm), 0.47 inch (12 mm), 0.51 inch (13 ma), 0.53 inch (14 mm), or 0.59 inch (15 mm). In some embodiments, maximum upper distance 3192 can be 0,358 inch (9.09 Iran). Further, a minimum upper distance 3194 measured as the perpendicular distance from exterior surface 2703 of strikeface 2712 to exterior surface 2703 of third inflection point 2924 can range front 0.09 inch to 0.47 inch (2.28 mm to 12 mm). For example, minimum upper distance 3194 can be 0.16 inch (4 mm), 0.20 inch (5 min), 0.24 inch (6 mm), 0.28 inch (7 rum), 0.31 inch (8 Tr1111), 0.35 inch (9 ram), 0.39 inch (10 nun), 0.43 inch (11 mm), or 0.47 inch (12 tram). In some embodiments, minimum upper distance 31 94 can he 0.309 inch (7. mm). Further still, a maximum lower distance 3196 measured as the perpendicular distance from exterior surface 2703 of strikeface 2712 to exterior surface 2703 of a fourth reference point 2920 located between the lower rsysterior vsall 2927 and the sole 2706 can range from 0.98 inch to 1.57 inch (23 mm to 40 mtn). For example, rnaxirnurn lower distance 3196 can be 0.98 inch (25 mm), 1.02 inch (26 mom), 1.06 inch (27 mm), 1.10 inch (28 mm), 1.14 inch (29 mm) 1.18 inch (30 mm), 1.22 inch (31 mm), 1.26 inch (32 mm), 1.30 Inch 33 mm)., 1.34 inch (34 mm), 1.38 inch (33 min), 1.42 Inch (36 mm), 1.46 inch (37 mm), 1.50 inch (38 mm), 1.54 inch (39 mm), 1.57 inch or ("40 min). In some embodiments, maximum lower dts tencc 3196 can be 1.302 inch 23.1 myri). In many embodiments, maximum lower distance 3196 is greater than maximum upper distance 3192, and maximum upper di Stall cc 3192 is greater titan minimum upper distance 3194.

[001641 In many ell lbed 'merits, cavity 273 ci provide an increase in golf ball speed over golf club head 1200 (E(i. 16) or other standard golf club heads, can reduce the spin rate of standard hybrids club heads, and can increase the launch angle over both Fie standard hybrid and iron club heads. In many embodiments, the shape of cavity 2730 determines the level of spring and timing of the response of golf club head 2700. When the golf ball in-:pacts strikeface 2712 of club head 2700 with cavity 2730, strikefitce 2712 springs back like a drum, and rear 2710 bends in a controlled buckle manner. In Many embodiments, top rail 2715 can absorb more stress over greater volumetric space than a top rail in a golf club head without cavity 2730. The length, depth and width of cavity 2730 can vary. These parameters provide control regarding how much spring back k present in the overall design of club head 2700.

I 00165[ Upon impact with the golf ball, strikeface 2712 can bend inward at a greater distance than on a golf club without cavity 2730. In some embodiments, strikeface 2712 has a I ON tx.) a 50% greater deflection than a strikeface on a golf club head wi hOUt cavity 2730. In some embodiments, strikeface 2712 has a 5% to a 40% or a 10% to a 20% greater deflection than a strikelace on a golfclub head without: cavity 2730. For example, strikeface 2712 can have a 5%, 10%, 13%, 20')/i, 25%, 307-b, 35% or 40% greater deflection than a strikeface on a golf club head without: cavity 2730. In many embodiments, there is both a greater distance of retraction by strikeface 2712 due to the hinge and bending of cavity 2730 over a standard strikeface that does not have a back portion of the club without the cavity.

[00166] In many embodiments, the face deflection is greater with club head 27()0 having cavity 2731), as a!greater buckling occurs at first inflection angle 2986 of top waIl 2719 upon impact with a golf ball. Cavity 2730, however, provides a. greater dispersion of stress along top rail 2715, rear wall 2923, and top wall 2719, and the spring hack force is transferred from cavity 2730 and first inflection point 2986 of top wall 2719 to strikeface 2712. A standard top rail, rear wall and top wall vyithout a cavity does not have this hinge /buckling effect, nor does it absorb a high level of stress over a large volumemic area of the top rail, rear wall and top wall. Therefore, Me standard strikerace does not contract and then recoil as much as strikeface 2712. Further, both a larger region of strikeface 2712, top rail 2715, rear wall 2923, and top wall 2719 absorb more stress than the same crown region of a standard golf club head wit-h standard top rail, top wall and no cavity. in many embodiments, although there alotig, a greater area ahoy e cavity 2730 than the same area ma standard club without the ca the durability of the club head with and without the cavity is the same. By adding more spring to the back end of the club (due to the inward inclination of a portion of top wall 2719 toward strikethce 2712), more force is displaced throughout the Nr( duffle of the stmcture. 'file stress is observed over a,greater area of strikeface 2712, top rail 2715, rear wall 2.923, and top wall 2.719 of golf club head 2700. Peak stresses can be seen in the standard top rail club head. However, more peak stresses are seen in {golf club head 2700 but distributed over a large -volume of the material. The hinge and bend regions of golf club head 2700 (i.e., the region above cavity 2730 and cavity 2730 itself) will not deform Jirs long as the stress does not meet the critical buckling threshold. Cavity 27,30 and its placement can be designed to be under the critical K value of the buckling threshold.

167 As shown in PIC. 17, a, further deflection teature of the pvilf club head 2700 can be the uniform thinned region 3160, located at the sole 2706 and stretching between the rear 2710 of the body 2701 and the strikeface 2712, toward a cascading sole portion of the sole (as described in greater detail below). The uniform, thinned region 3160 can provide multiple benefits.l'irst" the uniform thinned region 3160 can reduce stress on the strikeface 271.2 caused during impact with the golf ball, Second, the uniform thinned region 3160 can bend allowing the strikeface 2712 to experience greater deflection. Third, the uniform thinned region 3160 removes weight, from the sole area, allowing the weight to be redistributed more toward the rear of the golf club head 2700. At impact, the energy imparted to the striketjace 2712 by the golf ball can cause the uniform thinned region 3160 to bend outward, which in turn increases the strikef Ice 2712 deflection. After bending, the uniform thinned region 3160 rebounds back to its original position remmityg the majority of the energy from impact back to the golf ball. The result is the golf club head 2700 imparts increased hall speeds and greater travel distances to the golf ball after impart.

1001681 in some embodiments:, body 2701 can C. muprise stainless steel, titanium, alumian La, a steel alloy (e.g. LISS steel, 475 steel., 431 steel., 17-1 stainless steel, naaraging, steel), J., titanturn.

alloy (e.g. Ti 7-4, Ti 6-4, T--9S, Ti SS/VI:12041, Ti SP700, Ti 15-0-3, Ti Ti 3-8-6-4-4, 10-2-3, Ti 15 -6-6-2, Ti-185, or any combination thereof), an aluminum alloy, or a composite M a teria. In other embodiments, body 2701 can comprise carpenter grade 455 steel, carpenter gra.c-le 475 steel, C300 steel, C350 steel, a. Ni--Co-Cr steel alloy, y quench and tempered steel alloy, or 365 steel. In some embodiments, strikeface 2712 can comprise stainless steel, titanium, alimainum, a steel alloy (e.g,. 455 steel, 473 steel, 431 steel, stainless steel, inan..ging steel), a titanium. alloy (e.g. Ti 6-4, T-98, Ti SS.A.T2041, Ti SP700,Ii 15-- 0-3, Ti 15-5-3, Ti 3 8 6 4 1, Ti 10-2-3, Ti 15-3 33, 6 -6 2, Ti 183, or any combination thereof), an aluminum alloy, or a composite material. In other enabodirnents, strikelace 2712 can comprise carpenter grade 435 steel, carpenter grade 475 steel, C300 steel, C350 steel, a Co-Cr steel alloy, a quench and tempered steel alloy, or 563 steel. In some embodiments, body 2701 can comprise the same matetial as strikeface 2712. in some embodiments, body 2701 can comprise a different material than strikeface 2712.

[00169] FIG. 18 illustrates a back perspective view of -an ernbochcolt' club head 3200, and FIG. 19 illustrates a back heel-side perspective view of golf club head 3200 according to the embodiment of FIG. 18. In some embodiments., golf club head 3200 can be similar to golf club head 1000 (NG. 1), golf club head 2200 (IR:. 83, and/or golf club head 2700 (FIG. 13.) Golf club head 3200 can be an iron-type go:, club head. In other embodiments, golf club head 3200 can be a hybrid-true, or aftnrs-yay wood-type golf club head. In some enabodiments, golf club head 3200 does not comprise a badge or a custom tuning port.

[00170] Golf club head 3200 corn. a body.3201. In some embodiments, body 3201 can be similar to body 1001 (FIG. 1), body 2201 (FIG. 8), and/or r'odiy 2701 (Jai. 13). In some embodiments, the body 3201 is hollow. In other embodiments, the body is at least partially hollow. Body 3201 comprises an exterior surface 3203, a strikeface 3212, a heel region 3202, a toe region 3204 opposite the heel region 3202, a sole 3206, a top rail 32:5, and a rear 3210.

[00171] Body 3201 of FIGS.18-22 fintlicr comprises a blade length. The blade length tbr body 3201 can be measured similar to blade length 3725 as shown and described in FIG. 29 (i.e., a measurement parallel to the flat surface of the strikeface 3712, from a toe edge 3726 of the strike:bum 3712, to strikeface end 3727 right before the stri heface 3712 integrally eunres into die hose]). The blade length of the body 3201 can range front 2.70 inch (6.86 cm) to 3.00 inch (7.62 cm). For example, in some emlJodiments, the body 3201 can comprise a blade length 2.74 inch (6.96 cm), 2.78 inch (7.06 cm), 2.82 inch (7.16 cm), 2.86 inch (/.26 cm), 2.90 inch (7.37 cm), 2.94 inch (7.47 cm), 2.98 inch (7.57 cm), or 3.00 inch (7.62 cm).

[00172] The body 3201 further comprises a uniform thinned region transitioning From the bottom of-the strikeface 3212 to the sole 3206, toward a cascading sole portion of the sole (as described in greater detail below). In the illustrated embodiment, the uniform thinned region comprises a sole thickness measured perpendicular Evora the exterior surface 3203 to the interior surface at the uniform thinned region, which can remain constant from the bottom of the snikeface 3212 to adjacent the cascading sole portion of the sole. In some embodiments, the sole thickness of the uniform thinned region can be thinrier than a conventional sole. For example, in some embodiments, the st de thickness of the unifi am thinned region may range Crain approximately 0.040 inch to 0.080 inch. In other embodiments, the sole thickness of the unifonn thinned region may be within the range of 0.040 inch to 0.050 inch, 0.050 inch tc, 0.060 inch, 0.060 inch to 0.070 inch, 0.070 inch to 0.080 inch, 0.040 inch to 0,055 inch, 0.045 inch to 0.060 inch, 0.050 inch to 0,065 inch, 0.055 inch to 0.070 inch, 0.060 inch to 0.075 inch, or 0.065 inch to 0.080 inch. For example, the sole thickness of the uniformed thinned region can be 0.040 inch, 0.045 inch, 0.050 inch, 0.060 inch, 0.065 inch, 0.070 inch, 0.075 inch, or 0.080 inch.

[00173I 1,IC. 20 illustrates a cross-section of golf club head 3200 along the cross-sectional line X2iXIV-XXX1 V in PIG. 18, according to one embodiment. As seen in FI.G. 18, strikeface 3212 comprises a high region 3476, a middle region 3474, and a low region 3472. Rear 3210 can comprise an upper region 3211, a lower region. 3213, and a cavity 3230. Upper region 3211 comprises top rail 3215, a rear wall 34:23, and a top wall 3219. In many embodiments, the rear wall 3423 of rear 3210 is located below and adjacent, to the top rail 3215, and the top wall 3219 of rear 3210 is located below and adjacent to rear wall 3423. Lower region 3213 comprises a back wall 3421, and a lower exterior wall 3427. Cavity 3230 Is located on the exterior surface 3203, below the top rail 3215 and rear wail 3423, above the lower exterior wall 3427 of rear 3210, and is defined by at least in part by upper region 3211 and lower region 3213.

[0017,1] In sortie embodiments, top rail 3215 of the upper region 32.11 can be a flatter and taller top rail or skirt than in irons known to one skilled in the art. The flatter And taller rail 3215 can compensate for mis-hits on strikeface 3212 to increase playaliility off the tee. In some embodiments, the length of top rail 3215, measured from heel region 3202 to toe region 3204, can be 70% to 95'3i) of the length of in club head 3200. In many embodiments, cavity 3230 comprises a top rail box spring design. In many embodiments, top rail 3215 and ciwity 3230 provide an increase in the overall bending of surikelace 3212. In some embodiments, the bending of strikelace 3212 can allow for a 2',4 to 511/4) increase of energy. Cavity 3230 allows for strikeface 3212 to be thinner and allow additional overall bending. For some fainktay iron-type golf club bead embodtments, cavity 3230 can be a. reverse scoop or n of rear 3210 with body 3201 comprising a greater thickness toward sole 3206.

[001751 In sortie embodiments, a height 3480 of rear -wall 3423 of ii prier egio n321,f rear 3210 can range from 0.113 inch (0.292 clan to 0.23 inch (0.635 cr10, or 0.130 inch (0.330 ern) to 0.20 ii ich (0.508 cm). For example, in seine enibodiments" the height 3480 of rear wad 3423 Of lac upper region 3211 01 rear 3210 can be 0.115 inch (0.292 cm), 0.125 inch (0.318 cm), 0.135 inch (0.343 cm), 0.145 inch (0.368 cm), 0.155 inch (0.394 cm), 0.165 inch (0.419 cm), 0.175 inch (0.445 cm), 0.185 inch (0.470 cm), 0.195 (0.495 cm), or 0.250 inch (0.635 cm). In some embodiments, be height 3480 of rear wall 3423 of the upper region 3211 of rear 3210 can range from 0.150 inch (0.381 cm) to 0.210 inch (0.533 cm). In some embodiments, be height 3480 of rear wall 3423 of the upper region 3211 of rear 3210 can be 0.166 inch (0.422 cr1). In some embodiments, the height 3480 of rear wall 3423 of upper region 321 I of rear 3210 cart range from 3% to 15% of the height of the golf club head 3200.

[001761 The height 3480 of rear wall 3423 of the upper region 3211 of rear 3210, as described herein, allows cavity 3230 to a bsorb at least a pohnon of the stress on strikeface 3212 during impact with a golf bail. A golf club head having a rear wall height greater than rear wall height 3480 described herein would absorb less stress (and allow less striheface deflection) in impact than golf club head 3200 described herein, ate to increased dispersion of the impact stress along-lhe top rail prior to reaching the cavity.

[001771 In some embodiments, cavity 32.30 is located above a lower region 3213 of rca and is defined am least in parr by upper region 3211 and lower -egl on 3213 of rear 3210 Cavity 3230 comprises top wall 3219, and hack wall 34:21. A first reference point 3422 is located betu the top rail 3215 and roar-wall 3423. A second refdrence point 3482 is located between rear wall 3423 and top wall 3219. A first inflection point 3486 is located between top wail 3219 of cavity 3230 and back wall 3421. A third reference point 3424 is point located on top wail 321 9 closest to the strikeflice 3212. first reference point 3422 and second reference point 3482 create a first reference line 342.9. Second reference point 3482 and third reference point 34.24 create a second reference line 3423. 'third reference point 3424 and First inflection point 3486 create a third reference line 3426 1001781 Golf club head 3200 further comprises a height 3488 of top wail 3219 neasilred parallel to strikelace 3212 and from the second reference point 3482 to first inflection point 3486. In many embodiments, height 3488 can range from 0.100 inch (0,25-4 cm) to 0.700 inch (1.778 cm). For example, height 3488 can be 0.100 inch (0.254 cm), 0.150 inch (0.381 cm), 0.200 inch (0.508 cm), 0.250 inch (0.635 cm), 0.300 inch (0.762. cm), 0.350 inch (11.899 cm), 0.400 inch (1.016 cm), 0.450 inch (1.143 cm), 0.500 inch (1.270 cm), 0.550 inch (1.397 cm), 0.600 inch (1.524 cm), 0.630 inch (1.651 cm), or 0.700 inch (1.778 cm). In many embodiments, height 3488 can range from 0.300 inch (0.762 cm) to 0.550 inch (1.397 cm). In some embodiments, height 3488 of to wall 3219 can be 0.300 inch (0.762 cm), 0.330 inch (0.838 cm), 0.360 inch. (0.914 cm), 0.390 inch (0.991 cm), 0.420 inch (1.067 cm), 0.450 inch (1,143 cm), 0.480 inch (1.219 cm), 0.510 inch (1.295 cm), or 0,540 inch (1.312 cm).

[001791 In many embodiments, second reference point 3482 can range from 0.075 inch (0.191 cm) to 1.00 inches (2.54 cm) or 0.150 inch (0.381 cm) to 0.180 inches (0.457 cm) to apex 3428 of top rail 3215. For example, the second reference point 3482 can be 0.075 inch (0.191 cm), 0.095 inch (0.241 cm), 0.115 inch (0.292 cm), 0.135 inch (0.343 cm), 0.155 inch (0.394 cm), 0.175 imit (0.445 cm), 0.190 inch (0.483 cm), or 1.000 inch (2.54 cm) below the apex 3428 of top rail 3215.

100180)1 in many embodiments, top wall 3219 of cavity 3230 can be substantially paralie1 to strikeface 3212. In other embodiments, top wall 3219 is not substantially panne] to strikethce 3212. In some embodiments, top wall 3.219 of cavity 3230 is substantially parallel to rear wall 3.4.2:3 of upper region 3211 of rear 3210. In a number of embodiments, a portion of top wall 3219 extends away from top rail 3215 toward sirikelace 3212 from second reference point 3482 tc) third reference point 342.4. In some embodiments, the portion of top wall 3219 extending away from top rail 3215 toward strikeface 3212. from second reference point 3482 to third reference point 3424 can be straight, curved upward, or curved downward. In many embodiments, a portion of top wall 3219 of cavity 3230 is angled away from strikeface 3212 from third reference point 3424 to first inflection point 3486. In some embodiments, the portion of top wal13219 angled away from strikefilce 3212 from third refrrence point 3424 to rst inflection point 3486 can he straight, curved upward, or curved downward. 1141S orientation of top wall 3219 Creates a buckling point, hinge point or plastic hinge to direct the stress of impact toward cavity 3230 and to allow increased flexing E:if strikeface 3212 during impact.

[001811 Lower region 3213 of rear 3210 comprises back wall 3421 of cavity. 3230 and lower exterior wall 3127. In some embodiments, back wall 3421 of cavity 3230 can have a back Wan length 3490 measured from III'S E inflection point 3486 to a second inflection point 3192 located between the bier call 3421 and the lower exterior wall 3427. In number of embodiments, back wall length 3490 can range from 0.100 inch (0.234 cm) to 3.350 inch (0.889 cm). in many embodiments, back wall length 3490 can be 0.100 inch (0.254 cob, 0.125 inch (0.318 cm), 0.150 inch (0.381 cm), 0.175 inch ((.445 cm), 0.200 inch (0.508 cm), 0,225 inch (0.572 cm), 0,250 inch (0.635 cm), 0,275 inch (0.699 cm), 0,300 inch (0.762 cm), 0,325 inch (0.826 cm), or 0,350 inch (0.889 cm.).

1001821 in some embodiments, a lower angle 3451 can be measured from between the back wall 3421 and the lower exterior wall 3427. In some embodiments, lower angle 3451 can be less than 180 d-vrees in a number of embodit lower angle 3451 can range from 30 degrees to 180 degrees. in various embodiments, lower angle 3451 can range from 70 degrees to 130 degrees. In some embodiments, lower angle 3451. can be 70 degrees, 75 degrees. 80 degrees, 83 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, or 1311 degrees.

1001831 in some embodiments, an inflection angle 3496 measured from third reference line 3426 to back wall 3421 can range from 70 degrees to 150 degrees. In some embodiments, inflection angle 3496 can range from 90 degrees to 130 degrees. In some embodiments, inflection angle 3496 can be 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 10 degrees, 115 degrees, 20 degrees, 125 degrees, 130 degrees, degrees, 140 degrees, degrees. or 150 deorees, In many embodiments, inflection angle 3496 allows first inflection point 3486 to act as a buckling point or plastic hinge upon golf club head 3200 irnpactnigdie), . . volf bail at strikerace 3212. In some embodiments, tlic wall thickness at the first inflection point 3486 Can be thinner than at the top wall 3219 and back wall 3421.

[00184] In many embodiments, first inflection point 3186, adjacent to hack wall 3421 can range from 0.20 inch (0.508 cm) to 1.0 inch (2.54 cm), or 0.5 inch (1.27 cm) to 0.7 inch (1.778 cm) below the apex 3428 of top rail 3215. For example, the first inflection point 3486 can be 0.20 inch (0.508 cm), 0.25 inch (0.635 cm), 0.30 inch (0.762 cm), 0.35 inch (0.889 cm), 0.40 inch (1.016 cm), 0.43 inch (1.143 cm), 0.50 inch (1.27 crn), 0.33 inch (1.397 cm), 0.60 inch (1.524 cm), 0.6.3 inch (1.631 cm:), 0.70 inch (1.778 cm"), 0.73 inch (1.903 cm), 0.80 inch (2.032 cm), 0.85 Inch (2.159 cm), 0.90 inch (2186 cm), 0.95 inch (2.413 cm), or 1.0 inch (2.54 cm) below the apex 3428 of top rail 3215. In some embodiments, the mm)arnum height of the back wall 3421, measured perpendicular to a ground 3403 when golf dub head 32.00 is at address, from lowest point of le 3206 to first intacction point 3486, can range from 0.25 inch (0.635 cm) to 3 inches (7.62 cm), or 0.50 inch (1.27 cm) to 2 inches (5.08 cm). For example, the first inflection point 3486 can be 0.25 inch (0.635 cm), 0.375 inch (0.953 cm), 0.3 inch 1.27 cm), 0.625 inch (1.59 ciM" 0.75 inch (1.91 cm), 0.825 inch (2.10 cirn, 1.0 inch (2.54 cm), 1.125 inches (2.88 ern), 1.25 inches (3.18 cm), 1.375 'niches (3-49 cm), 1..5 inches (3.81 cm), 1,625 inches (4.12 cm). 1.75 inches (4.15 cm)" 1.875 inches (4.76 can, 2.0:Inches (5.08 cur), 2.125 inches (5.40 cm), 2.25 inches (5.71 cm), 2.375 inches (6.03 cm), 2.5 inches (6.35 cm), 2.625 inches (6.67 cm), 2.75 inches (7.00 cm), 2.875 inches (7.30 cm) or 3.0 inches (7.62 crn) above a lowest point of sole 3206 to the ground 3403 when golf club head 3200 is at address.

1001851 In some em[,odiments, a back wall angle_ 3405 measured from back will 3421 to ground plane 3403 can rarwe from 15 degrees to 45 degrees. In sonic ombocliments, back v,Tall angle 3405 can be 15 degrees, 16 (kg:cos, 17 degrees, 18 degrees, 19 degrees, 20 degrees, 21 degrees, 22 degrees, 23 degrees, 24 degrees, 25 degrees, 26 dq.7rees, 27 degrees, 28 degrees, 29 degrees, 30 degrees, 31 degrees, 32 degrees, 33 degrees, 34 degrees, 35 degrees, 36 degrees, 37 degrees, 38 degrees, 39 degrees, 40 degrees, 41 degrees, 42 degrees, 43 degrees, 4-4 degrees, or 45 degrees.

100186] in some embodiments as illustrated in FI.C. 18, cavity 3230 can further comprise at least one channel 3239. In many embodiments, channel 3239 extends from heel region 3202 to toe region 3204. Channel 3239 comprises a channel width measured from second reference point. 3482 to top wall 3219 substantially parallel to ground plane 3403, where channel width can vary in a direction from top rail 3215 to sole 3206. In some embodiments, a maximum channel width 3432, measured from first inflection point 3486 to second reference point 3482 substantially parallel to ground plane 3403, can be substantially constant throughout the channel 3230 from heel region 3202 to toe region 3204. In some embodiments as illustrated in If1(1. 20, maximum channel width 3432 can range front 0.039 inch (1 mm) to 0.590 inch (15 rum), or 0.150 inch (3,81 mm) to 0.400 inch (10.16 mm). hor example., maximum channel width 3432 can he 0.039 inch (1.0 mm), 0.079 inch (2 mm), 0.12 inch (3 mm), 0.16 inch (4 min), 0.20 inch (Finam), 0.24 inch (6 nun), 0.28 inch (7 mai), 0.31 inch (8 min), 0.39 inch (10 mm), or 0.39 inch (15 aim). In other embodiments, a channel toe region width of channel 3239 is less than a channel heel region width of channel 3239. In other embodiments, the channel heel region width is less than the channel toe rep1on width. In other embodiments, a channel middle region width of channel 3-239 can he less than at least one of the channel heel region [di or the channel toe region wad h. In other embodiments, the channel middle region width can 140 greater Wan at least one of the channel heel region width or the channel toe region width. In some embodiments, channel 3239 is symmetrical from heel to toe. in other embodiments, channel 3237 is non-symmetrical. In other embodiments:, channel 3239 can further comprise at least two partial channels. In some embodiments, channel 3239 can comprise a series of channels interrupted by one or more bridges. In some embodiments, the one or more bridges can be approximately the same thickness as the thickness of upper region 3211 of top rail 3215.

[001871 Maximum channel width as described hereni, allows absorption of stress from s Rib:et-ace 3212 on impact:. A golf club head Inning a channel width less than the maximum channel width 3432 described here (e.g., a golf club head with a less pronounced cavity) would allow loss stress absorption from the strikeface On impact (due to less material on the upper region 3211 of rear 3210), and therefore would experience less strtkeflacc deflection than golf club head 3200 described herein.

100188_1 In many embodiments, back cavity 3230 further comprises a cavity angle 3.435. Back cavity angle 3.435 is measured from first reference line 3429 to second reference line 3425. In many embodiments, back cavity angle 3435 can range from 15 degrees to 80 degrees. In some embodiments, back cavity angle 3435 can be 15 degrees, 20 degrees, 25 degrees, 30 degrees, 33 degrees, 40 degrees, 35 degrees, 30 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, or 80 degrees.

10018911 FIG. 21 illustrates a view of top rail 3215 and a porhon of rear 3210 of the cross--section of golf club head 3200 of FIG. 1.8 different from cross-suction of golf club head 200 as shown in FIG. 4. In many embodiments, golf dub head 3200 comprises a rear angle 3540, a top rail angle 3545, and a. strikefacc angle 3550. Rear angle 3540 is measured from second reference line 3425 to rear wall 3423 of upper region 3211. In many embodiments, rear angle 3.540 can range from 70 degrees to 140 degrees. In some embodiments, rear angle 3540 can he 70 degrees, 7.5 degrees, 80 degrees, 85 degrees, 90 degrees, 100 degrees, 105 degrees, 110 ciegrees, 113 degrees, 1211 degrees,. 123 degrees" 130 degrees, 135 degrees, or 110 degnies. Top rail angle 3343 is measured from rear wall 3423 of upper region 3211 tti top rail 3213. In many embodiments, top rail 3515 can range from 35 degrees to 120 degrees or 70 degrees to 110 degrees. In some embodiments, top rail angle 3545 can be 35 degrees, 40 degrees, 15 degrees, 50 degrees, 55 degrees, 60 de.grees, 65 degrees, 70 degrees, 75 clegrees, 80 degrees, 85 degrees, degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, or 120 degrees. Snikela.ce angle 3550 is measured from strikeluce 3212 to top rail 3215. In many embodiments, strikeface angle 3550 can range (corn 70 degrees to 160 degrees or 70 degrees to 110 degrees. In some embodiments, stri ketace angle 3350 can be 70 degrees, 75 deprees 80 decrees 90 degrees, 95 de:grees, 100 degrees 10.5 degrees., 110 degrees, 113 degrees, 120 de,grees, 125 degrees, 130 degrees" 135 degrees, 140 degrees, 145 degrees, 150 degrees, 1.55 degrees, or 160 degrees.

100190j Upper region 3211 further comprises a minimum gap 3390 measured from third reference point 3424 of an inner surface 3419 of top wail 3219 to an inner surface 3119 of strikeface 3212, perpendicular to strikeface 3212. In some embodiments, minimum gap 3390 can range from 0.079 inch (2. mm) to 0.24 inch (6 mm). For example, the minimum gap 3590 can be 0.079 inch (2 mm), 0.118 inch (3 turn), 0.16 Mch (4 intM, 0.197 Inch (5 min) or 0.24-inch (6 mni). In other embodiments, the tn.turnum gao 3590 can range from 0.118 inch (3 mm) to 0.16 inch (4. mm). In some embodiments, the minimum gap 3590 can be 0.135 inch (3.429 nini).

1001911 lila 22 illustrates a simplified cross-sectional view of golf club head.3200, similar to the detailed cross-section of golf club head 3200 illustrated in N.G. 20. Golf club head 3200 include cavity 3230. upper region 3211, lower region 321.3, and exterior surface 3203. In many embodiments, a maximum upper distance 3692 measured as the perpendicular distance from exterior surface 3203 of strikeface 3212 to exterior surface 3203 of second reference point 3482 of upper region 3211 can range from 0.20 inch to 0.59 inch (5 tarn to 15 mm). For example, niaxirnurn upper distance 3692 can be 0.20 inch (5 inn:), 0.24 inch (6 mm), 0.28 inch (7 mm), 0.31 inch (8 mm), 0.35 inch (8.89 mm), 0.39 inch (10 rnm), 0.43 inch (11 rum), 0.47 inch (12 rum), 0.51 Inch (13 nun), 0.55 inch (14 intM, or 0.59 inch (15 mm). In some embodiments, maximum upper distance 3692 can be 0.348 inch (9.09 mm). Further, a minimum upper distance 3694 measured as the perpendicular distance from exterior surfkce 320?) of strikeface 3212. to exterior surface 3203 of third. reference point 3424 can range From 0.10 inch to 0.47 inch (.54 rim: to 12 clam). For example, minimum upper distance 3694 can be 0.10 inch (2.54 mm). 0.16 inch;4 mmy, 0.20 inch (5) mm)., 0.24 inch (6 mm). 0.28 inch;7 trim), 0,31 inch (8 mm), 0,35 inch (.9 rnm),11.39 inch (10 mrn), 0.13 inch (11 in' ,or 0.47 inch (12. mm). in some embodiments, minimum upper distance 3694 can be 0.309 inch (7.85 mm). Further still, a maximum lower distance 3696 measured as the perpendicular distance from exterior surface 3203 of striketace 3212 to exterior surface 3203 of a fourth reference point 3420 located between the lower exterior wall 3427 and the sole 3206 can range from 0.670 inch to 0.98 inch (17 mm to 25 nn-M. For example, maximunt lower distance 3696 can he 0.670 inch (17 mm), 0.709 inch (18 mm), 0.748 inch (19 mm), 0.787 inch (20 mm), 827 inch (21 min), 0.866 inch (22 mm), 0.906 inch (23 mm), 0.945 inch (24 ruin), or 0.98 inch (25 ram). In some ernIs)(Innen ts, mathrillfill lower distance 3696 can lyr 0.863 inch (21.9 mm). In many embodiments, maximum lower distance 3696 is greater than maximum upper distance 3692 and trialsimitin upper distance 3692 is greater than nainimum upper distance 3694.

1001921 In many embodiments, cavity 3230 can provide an increase in golf ball speed ove club head 12.00, or other standard golf club heads, can reduce the spin rate of standard hybrids club heads, and can increase the launch angle over both the standard hybrid and iron club heads. In many embodiments, the shape 3230 determines the level of spring and timing of the response of.oilf club head 3200. When the golf club ball itymxicts strikeface 3212 of club head 3200 with cavity 3230, strikeface 3212 springs back like a drum, and a rear 3210 bends in a controlled buckle manner. in many embodiments, top rail 3215 can absorb more stress over greater volumetric space than a top rail in a, golf club head without cavity 3230. ',the length, depth and width of cavity 3230 can vary. These parameter provide control regarding how much spring back is present in the overall design of club head 3200.

[00193-1 Upon impact with the golf fall, strikeface 32.12 can bend inward at a greater distance than on a golf club without cavity 3230. In some embodiments, strikeface 3212 has a 10% to a 30 clis greater deflection than a strikelace on a golf club head without cavity-3230. In some embodiments, strikeface 3212 has a5% to 40% or a 10% to a. 20% greater deflection than a strikeface on a. golf club head without cavity 3230. For example, strikefice 3212 can have a 5%, 10%., 15%, 20% 25%, 30%, 35°71), or 40% greater deflection than a strikeface on a golf' club head without cavity 3230. In many embodiments, there is both a greater distance of retraction by strikeface 3212 due to the hinge and bending of cavity 3230 over a standard strikelace that does not have a back porn' on of the club with the cavity.

[001 94j In many embodiments, the Lice deflection is greater with club head 3200 having cavity 1, as a greater buckling occurs at first inflect"( a, angle 3486 of top wall 3219 upon impact with a golf ball. Cavity 3230, however, provides a greater dispersion of stress along top rail 3215, rear wall 3123, and top wall 3219, and the spring back force is transferred from cavity 3230 and first inflection point 3486 of top wall 3219 to strikelace 3212. A standard top rail, 4'7 rear wall and top wall without a cavity does riot have this bin e/ huerl trig effect, nor does it absorb a high level of stress over a large volumetric area of the top ratil, rear wall and top wall. Therefore, the standard strikeface does not contract and then recoil as much as strikeface 3212. Further, both a. larger region of strik.eface 3212, top rail 3215, rear wall 3423, and top wall 3219 absorb more stress than the same crown region of a standard golf club head with a standard top rail, top wall and ra) caviw. In many embodiments, alert; nigh there is greater stress a] °rig a greater area above cavity 3230 that the same area in a standard club without the cavity, the durability of the club head with without the cavity is the same. By adding more spring to the back end of the club (due to inward inclination of a portion of top wall 3219 toward trikeface 3212), more farce is displaced throughour the volume of the a tincture. The stress is observed over a greater area of strikeface 3212, tow rail 3215, rear wall 3423, and top wall 3219 of golf club head 3200. Peak stresses can be seen in the standard top rail club head I towever" more peak stresses seen in golf. club head 3200 but distributed over a lam volume of the material. The hinge and bend regions of golf club head 3200 (i.e., the region above cavity 3230 and cavity '3230 itself) will not deform as long as the stress does not meet the critical buckling threshold. Cavity 3230 and its placement can be designed to be under the critical 1K value of the buckling threshold.

1001951 As shown in 14.G. 22, a further deflection feature of the golf club head 32.00 Call be the uniform thinned region 3660, located at the sole 3206 and stretching between the rear 32.10 of the body 3201 and the strikeface 3212, toward a cascading sole portion of the sole (as described in greater detail below). The uniform thinned region 3660 can provide multiple benefits. First, the unifbrm thinned region 3660 can reduce stress on the strikefice 3212. caused (luting impact with the golf ball. Scco-id the uniform thinned region 3660 can bend allowing the strikefa.ce 3212 to experience greater deflection. Third, the uniform thinned region 3660 removes weight from the sole area allowing the weight to be redistributed more toward the rear of the golf club head 3200. At impact, the energy imparted to the strikeface 3212 by the golf halt can cause the uniform thinned region 3660 to bend outward, which in turn increases the strikeface 3212 deflection. After bending, the uniform. thinned region 3660 rebounds back to its original position returning the tnajority of the energy front inapact back to the. Rolf ball. The result is the golf club head 3200 imparts increased ball speeds and greater travel distances to the golf ball after impact.

[001961 in 1_ embodiments, body-3201 can comprises stainless steel, titanium, aluminum, a steel alloy (e.g. 455 steel, 475 steel, 431 steel, 17-1 stainless steel, maraging steel), a titaniurn alloy (e.g.)Ii 7-4, Ti 6-4, T-93, Ti 3SAT2041., Ti SP700" Id 15-0-3, lh 15 5 3, 't Ti 10-2-3, Ti 15-3-3-3, Ti-6-6-2, '13-185, or any combination thereof), an aluminum alloy, or a compote. material, in:Aber e.mbodi tents,body 3201 can conlmise/a1rpenter grade 455steeh carpenter grKlyy 175 steel, C300 steel, C350 SITTL a 7.04: r st el alloy, a quench and tempered steel alloy, or 565 steel. In some embodiments, strikeface 3212 can comprise stainless steel, titanium, aluminum, a steel alloy (e.g. 455 steel, 475 steel, 431 steel, 17-4 stainless steel, mara);ing steel), a Maniurn alloy (e.g. Ti 7-4, Ili 6-4, T-98, Ti SSAT2041, Ti 3P700, Ili 15- 0-3, Ti 15-5-3, Ti 3-8-6-4-4-, Ti 10-2-3, Ti-6-6-2, 11-185, or any combination thereof), an aluminum alloy, or a composite matenal. In other embodiments, strikeface 3212 can comprise carpenter grade 455 steel, carpenter grade 475 steel, C300 steel, C350 steel, a Nis Co-C1r steel alloy, a quench and temptd.,1 steel alloy, or 565 steel. In some embodiments, body 2701 can comprise the same material as strikeface 3212. In some embodiments, body 2701 can comprise a different material than strikelace 3212.

1001971 14C. 23 illustrates a back perspective view of an embodiment of golf club head 3700 and Ida 24 illustrates a back heel-side perspective view of golf club head 3700 according to the embodiment ofhIG. 23. In some embodiments, golf club head 3700 can be similar to golf club head 1000 (FIG, 1), golf club head 2200 (FIG. 8), golf club head 2700 (FIG. 13), and/or golf dub head 3200 (FIG. 18). Golf club head 3700 can be an iron-type,golf club head. In other embodiments, golf club head 3700 can be a hybrid-type, or a fairway wood-type golf club head. In some embodiments, golf club head 3700 does not comprise a. badge or a custom tuning port, [00198] Golf club head 3700 comprises a body 3701. In some embodiments, body 3701 can be similar to body 1001 (1/1.G. 1), body 2201 (1IC.1. 8), body 2701 (FIG. 13), and/or body 3201 (PIG. 18). in some embodiments, the body 3701 is hollow with an internal cavity 3716. In other embodiments, the body-is at least partially hollow. In embodiments wherein body 3701 is hollow or partially hollow, body 3701 can comprises a volume void of internal cavity 3716 ranging from 1:71 inches' (28 cc) to 2.3 inches' (37.69 cc). In some lic;llow and partially hollow embodiments, body 3701 can comprise a volume of 1.70 inched' (27.86 cc), 1.80 inches (29.50 cc), 1.90 inches' (31.11 cc), 2.00 inches' (32.77 cc), 2.10 indles:1 (34.41 cc) 2.20 inches' (36.05 cc), or 2.30 inches3 (37.69 cc). Body 3701 Hrther comprises an exterior surface 3703, a strikeface 3712, a heel region 3702, a toe region 3704 opposite the heel region 3702, a sole 3706, a top rail 3715, and a. rear 3710.

[001991 Body 3701 of FIGS. 23-29 further comprises a blade length 3725, a toe edge 3726, and striketlace end 3727. The toe edge 3726 is the farthest edge of the strikeface 3712 at. the toe region 3704, and the strike:face end 3727 is the end of the strikeface 3712 at the heel region 3702, right before the snikellice 3712 integrally curves into the hose!. As illustrated. in FIG. .29, blade length 3725 is the distance measured from the toe edge 3726 to the striketlace end 3727. The blade length 3725 is measured parallel to the flat surface of the strikeface 3712 between the toe edge 3726 and the strikeface end 3.727 at the heel end 3702 before the strikeface 3712 integrally curves with the hosel. The blade length of the body 3701 can range from 2.70 inch (6.86 cm) to 3.00 inch (7.62 cm). For example, in some embodiments the body 3701 can comprise a blade length of 2.74 inch (6.96 cm), 2.78 inch (7.06 cm), 2.82 inch (7.16 cm), 2.86 inch (7.26 cm), 2.90 inch (7.37 cm), 2.94 inch (7.47 cm), 2.98 inch (7.57 crn), or 3.00 inch (-7.62 crn).

I 00200_1 the body 3701 farther comprises a uniform thinned region transitioning from the -bottom of the strikeface 3712 to the sole 3706, toward a cascading sole portion of the sole (as described in greater detail below). In the illustrated embodiment, the uniform thinned region comprises a sole thickness measured perpendicular from the exterior surface 3703 to an interior surface 3919 at the uniform thinned region, which Call remain constant from the bottom of the strikelace 3712 to adjacent the cascading sole portion of the sole. In son-le embodiments, the sole thickness of the uniform thinned region can be thinner than a conventional sole. For example, in sonic embodiments, the solo thickness of the unifbrm thinned region may range from approximately 0.040 inch to 0.080 inch. In other embodiments, the sole thickness of the uniform thinned region may be within the range of 0.040 inch to 0.050 inch, 0.050 inch to 0.060 inch, 0.060 inch to 0.070 inch, 0.070 inch to 0.080 inch, 0.040 inch to 0.055 inch, 0.045 inch to 0.060 inch, 0.050 inch to 0.065 inch" 0.055 inch to 0.070 inch, 0.060 inch to 0.075 inch, or 0.065 inch to 0.080 inch. For example, the sole thickness of the uniformed thinned region can he 0.040 inch, 0.045 inch, 0.030 inch, 0.060 inch, 0.065 inch, 0.070 inch, 0.073 inch, or 0.080 inch.

[0020 hj FIG. 25 illustrates a cross-section of go:Iclub head 3700 along the cross-sectional line XXX1X-XXXIX in FIG. 23, according to one embodiment. As seen in FIG. 25, stnkelace

SO

3712 comp-hi. a high region 3976, a middle region 3974, and a low region 3972. Rear 3710 can comprise an upper region 3711, a lower region 3713, and a cavitv 3730.

[002021 Upper region 3711 of rear 3710 composes top rail 3713, a rear wall 3923. a top wad 3719, and a back wall 3921. In many embodiments, the rear wall 3923 of rear 3710 is located below and adjacent to the top rail 3715, the top wStil 3719 of rear 3710 is located below and adjacent to the rear wall 3923, and the back wall 3721 is located behw and adjacent to the top wall 37.10. Upper region Further comprises a First reference point 3922 located between top rail 3715 and rear wall 3923, a second reference point 3982 located between rear wall 3923 and top wall 3719, a first inflection point 3986 located between top wall 3719 and back wall 3921, and a second inflection point 3992 located between the back wall 3921, and a bottom incline 392.5 of the lower region 3713. First reference point 3922 and second reference point 3982 create a reference line 3939 a.s illustrated in FIG. 26.

[00203] 'The top wall 3719 is angled toward the strikciace and away from the ji rail 3 /15 direction toward the first inflection point 3986. The described configuration of the top wall 3719 allows increased bending of the top rail 371 5 of the club head 3700 on impact with a golf ball, compared with a club head devoid of the described top wall configuration.

1002041 Cavity 3730 is located on the exterior surface 3703, below top rail 3715 and rear wall 392.3, above the lower region 3713 of rear 3710, and is defined by at least in part by upper repo-3711 and lower region 3713.

[002051 In some embodiments, top re 15 ot the upper region 3711 can be a flatter and taller top rail skirt than in irons known to one skilled in the art. The Batter and taller rail can compensate for mishits of strikefa.ce 37 12 to increa.se playability off the tee. In some embodiments, the length of top rail 3715, measured from heel region 3702 to toe region 3704, can be 70% to 95% of the length of golf club head 3700. in many embodiments, cavity 3730 comprises a top rail box spring design. For some fairway iron-type golf club head embodiments, cavi ty 3730 can be a reverse scoop or indentation of rear 3710 with body 3701 comprising a greater thickness toward sole 3706. In many embodiments, top rail 3715 and. cavity 3730 provide, an increase in. the overall bending of strikelace 37]2. In some embodiments" the bending of a trikelace 3712 can allow for a 2% to 3% n;:reast.i of energy. Cavity 3730 allows for strike:race 3712 to be thinner and allow additional overall bending.

[002061 Strikefilise 3712 of body 3701 comprises a thickness 3954 measured perpendicularly to strikeface 3712 from the exterior surface 3703 to the interior surface 3919. 'The thickness 3954 of the strikeface 3712 can range from 0.060 inch to 0.110 inch, For example, the thickness 3954 of the s nilic face 3712 can be 0.060 Inch, 0.065 inch, 0.070 inch, 0.075 inch, 0.080 inch, 0.085 inch, 0.090 inch" 0.095 inch, 0100 inch, 0.105 inch, or 0.110 inch. In some embodiments, thickness 3954 of strikeface 3712 can remain constant from heel region 3702 to toe region 3704, atid/or from lop rail 3715 to sole 3706. In other embodiments, thickness 3954 of trikebice 3712 can vary from heel region 3702 to toe region 3704, and/or from top rail 3715 to sole 3706. For example, the thickness 3954 of strikeface 3712 can be greatest at a central portion of strikeface 3712 near the middle region 3974, and taper along the periphery of strike/lice 3712 near the high region 3976, and the low region 3972. In rmnv embodiments, the center of the sitikelace 3712 near the middle region 3974 can have a thickness 3934 of 0.100 inch and the periphery of the strikeface 3712 can have a thickness 3954 of 0.1180 inch.

In other examples, the thickness 395-1 can increase, or decreases, or a. ariation thereof starting at a. central region near the middle region 3974 of strikefacc 3712 and extending toward the periphery near the high region 3976 and the low region 3972.

100207_1 Golf club head 3700 further comprlses a height 3980 for rear wall 3923 of upper region 3711 of rear 3710 measured from first reference. point 3922 to second reference point 3982. In some embodiments, height 3980 of rear wall 3923 of upper region. 3711 of rear 3710 can range from 0.115 inch (019.2 cm) to 0.250 inch (0.635 cm), 0.130 inch (0.330 ern) to 0.2.00 inch (0,508 cm), or 0.130 inch (0.381 cm) to 0.180 inch (0.437 cm). For example, in some embodiments, lhe height 3980 of rear wall 3923 of the upper region 3711 of rear 3710 can be 0.115 inch (0.292 cm), 0.123 inch (0.318 c * 135 inch (0.343 cm), 0.115 inch (0.368 cm), 0.1.55 inch (0.394 cm), 0165 inch (0,419 cm), 0.173 inch (0.445 cm), 0.185 inch (0.470 cm), 0.195 (0.495 cm), or 0.250 inch (11.635 cm). In some embodiments, the height 3980 of rear wall 392.3 of the upper region 3711 of rear 3710 can range from 0.150 inch ((.381 an) to 0.210 inch (0.533 cm). In some embodiments, the height:3980 of rear wall 3923 of the tipper region 3711 of rear 3710 can he 0.166 inch (0.422 cm). In some embodiments, the height 3980 of rear wall 3923 of upper region 3711 of rear 3710 can range from 3% to 15D/li of the height of the golf club head 3700.

[0020 The height 3980 of rear wall 3923 of the upper region 3211 of reir 3210, as descrihed herein, allows cavity 3730 to absorb at least a portion of the stress on kelace 3712 during in-Tact with a golf ball. A golf club head haying a rear wall height greater than rear wall height 3980 described herein would absorb less stress (and allow less strikeface deflection) in impact than go.f club head 3700 described herein, due to.increased dispersion or the impact stress along the top rat: Enor to reaching the cavity.

[002091 Rear wall 39213 farther comprises a thickness measured perpendicularly from the exterior surface 3703 to the interior surface 3919 of the rear wall 3923. 'the thickness of the rear with 3923 can range froin 0.037 inch to 0.058 inch, 0.037 inch to 0.048 inc]i., or 0.042 inch. to 0.058 inch. For exi,imple, the thickness of the rear wall 3923 can be 0.037 inch, 0.040 inch, 0.043 inch, 0.046 inch, 0.049 inch, 0.052 inch, 0.035 inch, or 0.018 inch. the thickness or the rear wan 3923 can aid in stress distribution as well as increase the bending of the strilveface 100210-1 ln many embodimentssecond reference point 1982 of upper repaon 3711ot rear 3710 can have a oistance ranging from 0.150 inch (0.381 cm) to 1.00 inch (2.54 cm), 0.150 inch (0.381 cm) to 0.350 inches (0.457 cinh 0.300 inch (0.457 cm) to 0.500 inch (1.27 cm), 0.450 inch (1.14 cm) to 0.650 inch (1.65 cur), 0.600 inch (1.52 cm) to 0.800 inch (2.03 cm), or 0.750 inch (1.91 cm) to 1.00 inch (2.54 cm) from apex 3928 of top rail 3715. For example, the second reference point 3982 of upper region 3711 can be 0.150 inch (0.381 cm), 0.450 inch (1.14 cm), 0.600 inch (1.52 cm), 0.750 inch (1.91 cm)., 0.900 inch (2.29 cm), or 1.000 inch (7.54 cm) below the apeK 3428 of top rail 3215.

[002111 Golf club head 3700 further corriii)ri,..es a length 3988 of top was 3719 o [upper region 3711, measured from the second reference point 3982 to first inflection point 3986. In many embodiments, top wall length 3988 can range from 0.030 inch (0.076 cm) to 0.100 inch (0.254 cm). In many embodiments, top wall length 3988 can range from 0.030 inch (0.076 cm) to 0.050 inch (0.127 cm), t 1.040 inch (0.102 cm) to 0.060 inch ( 0.152 cm), 0.050 (0.127 cm) to 0.080 inch (0.203 cm), or 0.070 inch ei.178 crm to 0.100 inch (0.254 cm). For example, top wall length 3988 can be 0.030 inch (0.076,:r), 0.035 inch (0.089 cm), 0.040 inch (0.102 cm), 0.045 inch (0.114 cm), 0.050 inch (0.127 cm), 0.055 inch (0.140 cm), 0.060 inch (0.152 cm), 0.065 inch (0.165 cm), 0.070 inch (0.178 cm), 0.075 inch (0.191 cm), 0.080 inch (0.203 cm), 0.085 inch (0.216 cm), 0.090 inch (0.229 cm), 0.095 inch (0.241 crn), or 0.100 inch (0.254 cm).

121 In a number of embodiments, a portion t'd top wall 3719 of upper region 3711 extends AWAY-from rear wall 392'3 at second reference point 3982, toward siriketrace 3712 at firsr inflection point 1986. In some embodiments, the portion or top wall 3719 extending away from rear wall 3923 toward strikelace 3712 can be straight, curved upward, or curved ward. This orientation of top wall 3719 creates a, buckling point, hinge point or plastic hinge to direct the stfess of impact toward cavity 3730 and to allow increase flexing of strikerace 3712 during-in-11)21GL [002131 The first inflection point 3986 of the upper region 3711, cart have a dtstancefrom the first reference point 3922 ranging from 0.20 inch (0.508 cm) to 1.0 inch (2.54 cm), or 0.5 inch (1.27 cm) to 0.7 inch (1.778 cm). For exatriple, the first inflection point 3986 can be 0.20 inch (0.308 cm), 0.25 inch (0.635 Ci111), 0.30 inch ((1.762 cm), 0.33 inch (0.889 cm), 0.10 inch. (1.016 cm), 0.45 inch (1.143 cm), 0.50 inch (1.27 c 1.55 inch (4.307 cm), 0.60 inch (1.324 crn), 0.65 inch (1.631 cm), 0.70 inch (1.778 cm), 0.75 inch (1.905 cm), 0.80 inch (2.032 crn), 0.85 inch (2.159 cm), 0.90 inch (2.286 cm), 0.95 inch (2.113 cm), or 1.0 inch (2.34 cm) below the first reference point 3922.

[00211] TT1 SOFTIC embodiments, upper recion 3711 further comnorises an inflection angle 3996 measured from top wall 3719 to ba.ck wall 3921, wherein inflection angle 3996 can range from 70 degrees to 150 degrees. In some embodiments, inflection angle 3996 of upper region can range from 90 degrees to 130 degrees. In some embodiments, inflection angle 3996 of upper region can be 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees. 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, 140 degrees, 145 degrees, or 150 degrees. in many embodiments, inflection angle 3996 of upper region allows first inflection point 3986 to act as a buckling point or plastic hinge upon golf club head 3700 impacting the golf ball at strikelace 3712. In some embodiments, the wail thickness at the tint inflection poi it 3986 can be thinner than at the top wall 3719 and back wall 3921.

[00215] In some embodiments, back wall 3921 of cavity 3730 of upper 711 can have a back wall length 3990 measured from first inflection point 3986 to second inflection point 3992. In a. number of embodiments, back wail length 3990 can range from 04 00 inch (0.254 cm) to 0.550 inch (0.889 cm). In many embodiments, back wan length 3990 can be 0.100 inch (0.254 cm), 0.125 inch (0.318 cm), 0.150 inch (0.381 cm), 0.175 inch (0.415 cm), 0.200 inch (0.508 cm), 0,225 inch (0.572 cm), 0,250 inch (0.635 cm), 0,275 inch (0.699 cm), 0,100 inch (0.762 cm), 0,325 inch (0.826 cm), 0,330 inch (0.889 cm).

[002161 The hack wall 3921 of the cavity 3730 can further comprise a thickness measured perpendicularly from the interior surface 3919 to the ei.aerior surface 3703 of the back wall 3921. The thickness of We back wall 3921 can range from 0.028 inch to 0.039 inch, 0.028 inch to 0.032 inch, or 0.032 inch to 0.039 inch. For example, the thickness of We back wall 3921 can be 11.028 inch, 0.030 inch, 0.032 inch, 0.034 inch, 0.035 rich, 0.037 inch, or 0.039 inch. The thickness of the back wall 3921 can help distribute stress ndtncrease the bending of the strikeface 3712.

1002171 i some embodinfeats, the maximum height of the back wall 3921 of the upper region 3711, measured perpendicular to a ground plane 3903 when golf club head 3700 is at address, to first infection point 3986, can range from 0.25 inch (0.635 cin) to 3 inches (7.62 cm), or 0.30 Inch (1.2'7 cm, nches (5.08 ctn..). [or example, the first inflection point 3986 can be 0.25 inch (0.635 cm.), 0.375 inch (0))53 cm, 0.3 inch 117 cm.), 0.625 inch (1.59 cm), 0.75 inch (1.91 cm), 0.825 inch (2,10 cm), 1.0 inch (2.54 cm), 1.125 inches (2.88 cm), 1.25 inches (118 cm), 1.375 inches (3.49 cm), 1.5 inches (3.81 cm), 1,625 inches (4.12 cm), 1.75 inches (4.45 cm), 1.875 inches (4.76 cm), 2.0 inches (5.08 cm), 2.125 inches (5.40 cm), 2.25 inches (5.71 cm), 2.375 Inches (6.03 cm), 2.5 inches (5.35 cm), 2.625 inches (6.67 2.75 inches (7.00 cm), 2.875 inches (7.30 cm) or 10 inches t7.62 crii) alxr,c a lowest point of sole 3706 to the ground plane 3903 when,golf club head 3700 is at address.

[00218_1 In many embodiments, second inflection point 3992 of cavity 3730 of upper region 711, adjacent to bottom incline 3925 of lower region 3713, can have a distance from apex 3928 of top rail 3715 ranging from at least 0.25 inch (0.635 cm) to 2.0 inches (5.08 cm), or, inch (1.27 cm) to 1.5 inches (3.81 cm). For example, the second inflection point 3992 cart be at least 0.25 inch (0.635 cm), 0.5 Inc; (1.27 cm), 0.75 inch (1.91 cm), 1.0 inch (2 53 cr 1,25 inches (3.18 cm), 1.75 inches (4.45 cm), or H.,. inches (5.08 cni) below the apex 3928 of top rail 3715.

[00219] In some embodiments as illustrated in FIG. 23, cavity 3730 of upper region 37(1 can comprise at least one channel 3739. In man,/ embodiments, channel 3739 extends from heel region 3702 to toe region 3704. Channel 3739 comprises a channel width 3932 measured from back wall 392] to the second reference point 3982 substantially parallel to ground plane 3903, where channel width can vary in a direction from top rail 3215 to sole 3206. In some embodiments as illustrated in FIG. 23, channel width 3932 can range from 0.039 inc min) to 0.590 inch (13 trim), or 0.150 inch (3,81 mix)) to 0.400 inch (10.16 mm). 1,:.*)r. example, channel width 3932 can be 0.039 inch (1.0 ram), 04079 inch. (2 mr), 0.12 inch (3 min), 0.16 inch (4 mm), 0.20 inch (5mm), 0.24 inch (6 mm), 0.28 inch (7 mm), 0.31 inch (8 mm), 0.39 inch (10 mm), or 0.59 inch (15 mm). In other embodiments, a channel roe region width of channel 3739 is less than a channel heel region width of channel 3739. In other embodiments, the chiginel heel region widal Is less than the channel toe reg2on width. In other ornbodirnents, chin me] middle region width of channel 3739 can be less than at least one of the channel heel region width or the channel toe region width. in other embodiments, the channel middle region width can be greater than at least one of the channel heel region width or the channel toe region width. In some embodiments, chantiril 3739 is symmetrical front heel to toe. In other embodiments, channel 3739 is rui,rissynittriettical. In other enabodiments" channel 3739 can further comprise at least toe partial channels. In some embodiments, channel 3739 can comprise a series of partial channels interrupted by one or more bridges. In some embodiments, the one or more bridges can be approximately the same thickness as the thickness of ton rail 3713.

[00220] Channel width 3932, as described herein, allows ahsor non of stress from strikeface 3712 on impact. A golf club head having a channel width less than the channel width 3932 described here (e.g., a. golf club head with a less pronounced:Jai( would allow less stress absorption from the strikeface on impact (due to Less material on the upper region 3711 of rear 3710), and therefore would experience less strikeface deflection than golf club head 3700 described herein.

1002211 in many embodiments, back cavity 3730 further comprises a back cavity angle 3935.

Back cavity angle 3935 is measured from reference line 3939 to top wall 3719. In many embodiments, back cavity angle 3935 can range from 5 degrees to 80 decrees. In some embodiments, back cavity angle 3935 can be 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 10 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, or 80 degrees.

[00222] In some embodiments., back wail 3921 of cavity 3730 of upper region 3711 can further comprise a planar surface. In other embodiments, at least a portion of back wail 3921 can comprise a protrusion 3940 extending outward, away from strike face 3712. At least a portion of back wall 3921 comprising protrusion 3940 can range from 1.5% to 100%. example, at least 15%, 20%, 239k 33%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75 tics, 80%, 850/u, 90%, 95%, or 100% of hack wall:3921 cart comprise protrusion 3940. Protrusion 3940 can be positioned on at least a portion or hack wall 3921 closer to toe region 3704, closer to heel region 3702, closer to lower exterior wall 1927, closer to top wall 3719, or centered on the back wall 3921. Protrusion 3940 comprises a length 3942, measured From heel region 3702 to toe region 3704, and a width 39.44, measured from top rail 371 3 to sole 3706.

1002231 The protrusion 3940 can comprise t thickness measured perpendicularly-from the interior surface 3919 to the exterior surface 3703 of the protrusion 3940. The thickness of the protrusion 3940 can range from 0.028 inch to 0.045 inch, 0.028 hick to 0.032 inch, 0.032 inch to 0.039 inch, or 0.039 inch to 0.045 inch. For example, the thickness of the hack wall 3921 can be 0.028 inch, 0.030 inch" 0.032 inch, 0.034 inch, 0.035 inch, 0.037 inch, 0.039 inch, 0.041 inch, 0.043 inch, a 0.045 inch, The thickness of the pnarusion 3940 can help distribute stress and increase the bending of the strikeface 3712.

[00224] FIG. 26 illustrates a view of top rail 3715 and a portion of rear 3710 of the cross--section of golf club head 3700 of FIG. 23, along a cross-sectional line XXX1X-XXXIX in FIG. 23 that is similar to the cross-secnon of FIG. 23. In many embodiments, golf club head 3700 comprises a rear angle 4-041T a top rail angle 4045, and a sthkeface angle 4050. Rear angle 4040 is measured from top wall 3719 to rear wall 3923 of upper region 3711 hi many embodiments, rear angle 4040 can range from 70 degrees to 140 degrees. its some embodiments, rear angle 4040 can be 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, WO degrees, 103 degrees, 110 degrees, 115 degrees, 120 degrees, 123 degrees, 130 degrees, 135 degrees, or 140 degrees. Top rail angle 4045 is measured from rear wall 3923 of upper region 371 1 to top rail 3715. In many embodiments, top rail angle 4045 can range from 35 degrees to 120 degrees or 70 degrees to 110 degrees. In some embodiments, top rail angle 4043 can be 33 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 73 degrees, 80 degrees, 83 degrees, 90 degrees, 93 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, or 120 degrees. Strikeface angle 4030 is measured from strike:face 3712 to top rail 3715. In many embodiments, strike:Lice angle 4030 can range from 70 degrees to 160 degrees or 70 degrees to 110 degrees, In some embodiments, strilteflice angle 4050 can be 70 degrees, 75 degrees, 80 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees. 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, 140 degrees, 143 degrees, 150 degrees, 155 degrees, or 160 degrees.

[00225] The upper region 3711 Further comprises a minimum gap 4090 measured as a perpendicular distance fnima an inner surface of the cavity at the first inflection point 3986 to the inner surface 3919 of strike face 3712. In some embodiments, minimum gap -4090 can range from 0.079 inch (2 torn) to 0.24 inch (6 ram). For example, minimum gap 1-090 can be 0.079 inch (2 trim), 0.118 inch (3 min), 0.16 inch (4 min), 0.197 inch mm) or 0.24 inch;6 min). In other embodiments, minimum 13 4090 can range froin t).118 inch (3 min) to 0.16 inch (4 mm). In some embodiment:, minimuin gap 4090 can be 0.133 inch (3.429 turn).

[002261 Lower region 3713 of rear 3710 of body 3701 comprises the bottom inc] bile 3925, and a lower exterior wall 3927. 'the lower exterior wall 3927 is located below and adjacent the bottom incline 3925. A third inflection point 3994 is Located between the bottom inch ne 3925 and the lower exterior wall 3927 ri third reference point 3920 is located betAveen lower exterior wall 3927 and sole 3706.

1002271 A top portion or the lower exterior wall 3927 of the lower regic.th 3713 can Lomprise a thickness. The thickness of the top portion of the lower exterior wall 3927 can be measured perpendicular from the interior surRice 3919 to the exterior surface 3703 of the top portion of the lower cxter+or wall 3927. The thickness of the top portion of the lower exterior v,rall 3827 can range from 0.037irieh to 0.038 inch, 0.037 inch to 0.(148 inch, or 0.042 inch to 0.038 inch. For example, the thickness of the top portion of the lo\ver exterior wall 382.7 can be 0.037 inch, 0.040 inch, 0.043 inch, 0.046 inch, 0.049 inch, 0.052 inch, 0.055 inch, or 0.058 inch. the thickness of the top portion of the lower exterior wall 3827 can aid in stress distribution as well as increase the bending of the strikeface 3712.

100228i in some embodiments, bottom incline 3925 of lower region 3713 comprises a,,Dtt_ad.

incline length 3929. Bottom incline length 3929 is measured from second inflection D 3992 to the third inflection point 3994. In a number of embodiments, bottom incline length.3994 can range from 0.010 inch (0.025 cm) to 0.210 inch (0.533 cm), 0.010 inch (0.025 cm) to 0.050 inch (0.127 cm), 0.050 inch (0.127 cm) to 0.100 inch (0.254 cm), 0.100 inch (0.234 cm) D) 0.150 inch (0.381 cm), or 0.150 inch (0.381 cm) to 0.210 inch (0.333 cm). in many embodiments, bottom incline length 3929 can be 0.010 inch (0.025 cm), 0.030 inch 0.076 cm), 0.050 inch (0.12 cm), 0.070 inch (01178 cm), 0.090 inch (0.229 ctM, 0.110 inch (0.279 cm), 0.130 inch (0.330 cm), 0.150 inch (0.381 cm), 0.160 inch (0.406 cm), 0.170 inch (0.432 cm), 0.180 inch (0.457 cm), 0.190 inch (0.483 cm), 0.200 inch (0.508 cm), or 0.210 inch (0.533 cm). In some embodiments, the bottom incline length 3929 can vary from heel region 3702 to toe region. 3704. In other embodiments, the. bottom incline length 3929 can remain constant from heel region 3102 to toe region 3704.

[00229-1 In some embodiments, the maximum bottom incline _ fleas] :red perpendicular (morn ground plane 3903 when both 3701 is at address, to second intiectmon point 3992, can be 0.25 inches (0.635 cm) to 3 inches (7.62 cm), 0,05 inch (1.27 cm) to 2 inches (5.08 cm) above ground 3903. For example, the second inn/ n point 3992 can be 0.25 inch (0.635 cm), 0.375 inch (0.953 cm), 0.5 inch (1.27 cm), 0.625 inch (1.59 cm) 0.75 inch (1.91 cm), 0.825 inch (2.10 cm), 1.0 inch (2.54 cm), 1.125 inches (23.8 cm), 1.25 inches (3.18 cm), 1.375 inches (3.49 cm), 1.5 inches (3.81 cm), 1.625 inches (4.12 cm), 1.73 inches (4.45 cm), 1.875 inches (4.76 cm), 2.0 inches (5.08 cm), 2.125 inches 5.40 cm), 2.25 inches (5.71 cm), 2.375 inches (6.03 cm), 2.5 inches (6.35 cm), 2.625 inches (6.67 cm), 2.73 inches (7.00 cm), 2.875 inches (7.30 cm), or 3.0 inches (7.62 cm) above ground 3903.

[00230] In some embodiment, lower region 3713 further compnsc-s a lowerangle 3951 measured from between the bottom incline 3925 of barer region 3713 and lower exterior wall 3927 of lower region 3710, as illustrated in FIG. 27. In some embodiments, lower angle 3951 can be less than 180 cieptes. In a number of embodiments, lower angle 3951 can he:30 degrees to 160 degrees, or 70 degrees to 130 degrees. For example, lower angle 3931 can he 30 degrees, 40 degrees, 50 degrees, 60 degrees, 70 degrees, 80 degrees, 90 degrees, 100 degrees, 110 degrees, 120 degrees, 130 degrees, 140 degrees, 150 degrees, or 160 degrees.

1002311 In some embodiments, lower region 3713 further comprises a bottom. incline angle 3905 measured from bottom incline 3925 to ground 3903. Bottom incline angle 3905 can range from 15 degrees to 1.5 degrees. In sonic embodiments, bottom incline angle 3905 can be 15 degrees, 16 degrees, 17 degrees, 18 degrees, 19 degrees, 20 degrees, 21 degrees, 22 degrees, 23 degrees, 24 degrees, 25 degrees, 26 degrees, 27 degrees, 28 degrees. 29 degrees, 30 degrees, 31 degrees, 32 degrees, 33 degrees, 34 degrees, 35 degrees, 36 degrees, 37 degrees, 38 degrees, 39 degrees, 40 degrees, 41 degrees, 42 degrees, 43 degrees, 44 degrees, or 45 degrees.

[00232] FIG. 27 illustrates a simplified cross-sectional view of golf club head 3700, similar to the detailed cross-section of go:: dub head 3700 illustrated in FIG. 25. Golf club head 3700 include cavity 3730, upper region 3711, lower region 3713, and exterior surface 3703. In many embodiments, a maximum upper distance 4192 measured as the perpendicular distance from exterior surface 3703 of striiceface 3712 to exterior surface 3703 of second reference point 3982 of upper region 3711 can range from 0.20 inch to 0.59 inch (5 mm to 15 mm). For examiple, IMIXIATIMI1 Upper a:St/Mice 4192 can be 0.20 inch (5 mm), 0.24 inch ir6 mm), 0.28 inch (7 mm), 0.31 inch (8 nand), 0.35 inch (8.89 mm), 0.39 inch (10 ram), 0.43 inch (11 ram), 0.47 inch (12 mm), 0.51 inch (13 mm), 0.55 inch (14 mm), or 0.59 inch mm). hi some embodiments, maximum upper distance 4192 can be 0.348 inch (9.09 mm). Further, a minimum upper distance 4-194 measured as the perpendicular distance from exterior surface 3703 oistrikeface 3712 to the exterior surface 3703 of the back wall 3921 at the first inflection point 3986 can range from 0.16 inch to 0.47 inch (4 nun to 12 min). For example, minimum upper distance 4194. Can be 0.16 inch (4 min)" 0.20 inch (5 mm), 0.24 inch (6 mm), 0.28 inch (7 mm), 0.31 inch (8 rnm), 0.35 inch (9 nun), 0.39 inch (10 mm), 0.43 inch (11 min), or 0.47 inch (12 turn). in some embodiments, mini nurn upper distance 41 94 can be 0.309 inch (7.85 rum). Further still, a maximum lower distance.4196 measured is the perpendicular distance from exterior surface 3703 of strikeface 3712 to exterior surface 3703 of third reference:Join:, 3920 of lower region 3713 can range from 0.670 inch to 0.98 inch (17 nun to 25 mm). For example, maximum lower distance 4196 can be 0.670 inch (17 nun), 0.709 inch (18 mm), 0.748 inch (19 min), 0.787 inch (20 min), 827 inch (21 min), 0,866 inch (22 nun), 0.906 Inch (23 nun), 0.945 inch (2.4 HITT:), or 0.98 inch (25 111111). fT1 some embodiments, maximum lower distance 4196 can be 0.863 inch (21.9 nun). In many enThodiments, maximum lower distance 4196 is greater than trialaTiParil upper distance 4192. and maximum upper distance 4192 is greater than minimum upper distance 4194.

100233_1 As illustrated in FIGS. 25-27, body 3701 is a hollow body club head that further comprises internal cavity 3716. Internal cavity 3716 of the body 3701 comprises a volume. I he volume of the internal cavity 3716 can range from 0.70 inch' (11.47 cc) to 1.70 inches' (27.86 cc:). In some embodiments, the internal cavity 3716 can comprise a volume of be 0.70 inch' (11.47 cc), 0.80 inch (13.11 cc), 0.90 inch' (14.75 cc), 1.00 inch' (16.39 cc), 1.10 inches' (18.03 cc), 1.20 inches' (19.66 cc), 1.30 inches' (21.30 cc), 1.40 inches' (22.94 cc), or 1.30 inches' (24.58 cc), 1.60 inches' (26.22 cc), or 1,70 inches' (27.86 cc), [00234] The internal cavity 3716 of the body 3701 further comprises interior surface 3919. In some mbodiments, interior surf:ice 3919 of rear 3710 is a planar and smooth surface. In other ernbodimients as illustrated in FIG. 28, the interior surface 3919 of the internal cavity 3716 of rear 3710 comprises a plurality of ribs 3952. The plurality of ribs 3952 extend in a direction from top mil 3715 toward sole 3706. Phi ral Lig of ribs 3952 can he located anywhere on interior surface 3919 of rear 3710. In sonic examples, plurality of ribs 3952 can be positioned onto a portion of interior surface 3919 of lower exterior wall 3927. In other examples, plurality ( ribs 3952 can be position on a portion of interior surfIuce 3919 of rear wall 3923. In some embodiments, plurality of ribs 3952 can be positioned on a portion of in tenor sin-lace 3919 of rear 3710 and can eKtend into another portion of the rear 3710. For example, plurality of ribs 3952 are positioned on a portion of interior surface 3919 of rear wall 3923 and can extend up to at least a port-ion of the Intvrior surface 3919 of top wail 3719, at least a. portion of back wall 3921, or at least a portion of lower exterior wall 3927. The plurality of ribs 3952 can comprise benveen I to 8 nos. For e.s.ample, the plurality of ribs 3952 can comprise one rib 3952, two ribs 3952, three ribs 3952, four ribs 3952, five ribs 3952, six fibs 3952, seven ribs 3952, or eight ribs 3952. In embodiments haying one Or more plurality of ribs 3952, the plurality of ribs 3952 can. be spaced equidistance from each other or rnsire concentrated near Lee] region 3702, toe region 3704, top rail 3715, or sole 3706. The plurality of ribs 5952 and the location of the plurality of ribs 3952 can help optimize the frequency and amplitude of sound response, [00235] In many embodiments, internad cavity 3716 of body 3701 cial be void of any substances. In other embodiments, internal avity 3716 of body 3701 can further cornianse polymer, wherein the polymer can at least partially fill the internal cavity 3716. The polymer can be polyethylene terephthalatc, high-density polyethylene, polVVillyi chloride, polycarbonate, polypropylene, other thermoplastics, composite polymers or any combination thereof. 't he polymer can fill 10% to 80% 10% to 25%, 15(Yii to 30%, 30% to 45%, 45% to 60%, 60% to 75%, 75% to 80%, 10% to 40%, 30% to 60%, or 40% to 80% of the internal cavity 3716 of the hod y-5701. bor example, the polymer can till 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, of 85% of the internal cavity 3716 of the body 3701. In some embodiments, the polymer tills 80c'.ib of the internal cavity 3716 of 70the body 31, [002361 The polymer comprises a specific gravity ranging from 0.5 to 4. For example, the specftc gravity of the polymer can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, or 4. In some embodiments, the spectftiT gntvity of the polymer is proportional to the mass of the polymer, wherein 1 specific gravity or le polymer is equal to 1 gram, 2 specific gravity of the polymer is equal to 2 grains and etc. Similarly, in some embodiments, the volume of the polyrner is proportional to the polymer specific gravity. I;:ir example, the nit° of polymer mass to polymer volume can be 1 g to 1 cc, 2 g to 2 cc, 3 p; to 3 cc, or 4 g to 4 cc. However, in other embodiments, while the specific gravity of the polymer is proportional to the polymer mass, the volume does not correlate to the specific gravity. tor example, the ratio of polymer mass to polymer volume can be 1 g to 1 cc, 2 g to 0 CC, 3 g to 1 4 g to 2 cc, 4 g to 3 cc, 3 g to 2 cc, 3 g to 4 cc, or any other suitable ratio.

[002371 The mass of the poi, 11( s tor the swing weight or the golf dub head 3700 to be customizable for each player easing the volume of polymer, and thus the mass, increases the swing wet j6-41t, while decreasing the volume of polymer decreases the swing weight. Having the appropriate swing v.ileig,ht: for each individual player improves feel during a swing and can 'improve performance such as swing speed, swing path and this ball speed, and ball trajectory. The polymer can fiirther increase the overall mass.)fthe golf club head 3700 more -1-(Jsward the rear 3710 and sole 3706. Increasing the mass more toward the rear 3710 and sc,4e 3706 can. keep the center of gravity low and back, and there improve, the moment of the inertia The polymer can further still act as a dampener to improve sound and absorb shock during impact.

[0023/11 The nolviner volume when filled within the internal cavity 3716 can range from 0 inch' (0 cc) to 1.53 inches (25 cc), 0.244 inch3 (4 cc) to 1.22 inches' (20 cc), 0.305 inch' (5 cc) to 0.915 inch' (15 cc), 0.122 Inch$ (2 cc) to 0.488inch1 (12 cc), or 0.854 inch' (14 cc) to 1.34 inch3 (22 cc). In some embodiments, the polymer volume inside the internal cavity 3716 can be 0 inch' (0 cc), 0.244 inch' (4 cc), 0.244 inch' (8 cc), 0.488 inch" (12 cc), 0.976 inch' (16 cc), 1.22 inches' (20 cc), or 1.53 inches' (2 The polymer filled within the internal cavity 3716 can cover a percentage of the interior surface 3919 of the strikeface 3712 ranging from 0 % to 100%, 15% to 85%, 30% to 70%, 45% to 60%, 20% to 40%, or 60% to 80%. In some embodiments, the polymer covers 0%, 15%, 30%, 43%, 60%, 75%, 90% or 100% of the interior surface 3919 of the strikeface 3712. Increasing the percent coverage of the polymer on the interior surface 3919 of the strikeface 3712. increases the support: for the strikeface 3712, thereby allowina: for a thinner strikeface 3712. Thinning the strikeface 3712 can increase the deflection or the strikefil.ce 37:2 upon impact with a ball which can impart the ball with increases speed and spin. Thinning the strikeface 3716 also allows for weight to be redistributed elsewhere on the body 3701 to optimize center of gravity and moment of inertia.

1002391 in some embodiments as illustrated in JCL 29, the golf club head 3700 can further comprise a first aperture 3934 located on toe region 3704 and a second aperture 3936 located in a hose] of the golf club head. 3700. The first anerrore 3924 is configured. to receive a toe weight Mot pictured), wherein the tot weight cart range from.2 grams to 7 grams. In some embodiments" the toe weight can be.2 grams, 3 grams, 4 grams, 5 grams, 6 grams, or 7 grants. The second aperture 3936 is conliglired to receive a tip weight (not pictured), wherein the tip weight can range from 2 grains to 7 grams. in some embodiments, the tip weight can be 2 grams, 3 grants, 4 grarns, 5 grams, 6 grams, or 7 grams. In many embodiments, the first aperture.. 1 and the second aperture 3936 can further be cc. Trod to receive the polymer The first aperture 3934 can receive I gram to 9 grains of polymer (6.0 1 grain, 2 gram, 3 oE -grams, 4 i".), aims, 5 grams, 6 grams, 7 grains, 8 grams, or 9 grams). Similarly, the second aperture 3936 can receive 1 gram to9 gr ins cif polymer (e.g., 1 gi:am, 2 grams, 3 grams, 4 grams, 5 grams, 6 grams, 7 grains, 8 grams, or 9 grams). the toe and tip weight, and the polymer housed within the first aperture 3934 and the second aperture 3936 can affec t the swing weight to optinaize CC and MOT [00240] in many embodiments, cavity can provide an increase in golf ball speed over golf club head 1200, or other standard golf club heads, can reduce the spin rate of standard hybrids club heads, and can increase he launch angle over both the standard hybrid and iron club heads. En many embodiments, the shape pf cavity 3730 determines the level of spring and timing of the response of golf club head 3200. When the golf club ball impacts strikeface 3712 of club head 3700 with cavity 3730, strikeface 3712 springs back like a drum, and a rear 3710 bends in a controlled buckle manner. In many-embodiments, top rail 3713 can absorb more stress over greater volumetric space than Li top rail in a golf club head without cavity 3730. The length, depth and width of cirmy 3730 can var. These parameter provide control regarding now much spring back, is present in the overall design of club head 3700.

[002411 1iport impact -with the go.. ball, strikeface 3712 can bend inward at a greater distance than on a golf club without cavity 3730. In some embodiments, strikeface 3712 has a 10% to a 30 % greater deflection:ban a strikeface on a golf club head without. cavity 3730. In some embodiments, strikeface 3712 has a 5Y° to 40% or a 10% to a 20% greater deflection than a strikeface on a golf club head without cavity 3730. For example, strikeface 3712 can have a 5%, 10 %, 15%, 20%, or 40% greater-0 deflection than -stilly-face on a. golf club head without eavip embodiments, there is both a gmater distance retraction lw strikeface 3712 due to the hinge and bending of cavity 3730 over a standard striketane that does not have a back portion of the club with the cavity.

[00242] In many embodiments, the face deflection is greater with club head 3700 haying may:, 3730 as a greater buckling occurs at first in angle 3986 of top wall 3219 upon impact with a g I aCavit Tides a greitter dispersion of stress ilk -nag top rail 3715, rear wail 3923, and top wall 3719, and the spring back force is transferred from cavity 3730 and First inflection point 3986 0,1 top wall 3719 to strikelace 3712.A standard top rail, rear wall and top wall without-cavity does not have this hinge/b' cidil effect, nor does it absorb a high level of stress over a large volume rtiC area. of the tot) rail, rear wall and top wall.

Therefore, the arjindard a triketacc does not contract and then recoil much as s trikelacc 3712. Further, both a larger region of sfiikel)ice 3712, top rail 3713, rear wall 3923, and top wall 3719 absorb more stress than the same crown region of a standard golf club head w1di a standard top rail, top wall and no cavity. In SlialitY embodiments, although there is greater stress ah mg, a greater area above cavity 3730 that the same tirea in a Sttadard club without the cavity., the durability of the club head with and without the cavity is the satne. By adding more spring to the back end of the club (due to inward inclination of a portion of top wall 3719 toward strikeface 3712), inure force is displaced throughout the volume of the structure. The stress is observed over a greater area of strikeface 3712, fop rail 3715, rear wall 3923, and top wall 3719 of golf club head 3700. Peak stresses can be seen tn the standard top rail club head. However, more pea.k stresses are seen in golf club head 3700 but distributed over a large volume of the material. The hinge and bend regions of golf club head 3700 (i.e., the region above cavity 3730 and cavity 3730 itself) will not deform as long as the stress does not meet the critical buckling threshold. Cavity 3730 and its placement can be designed to be under the critical K value of the buckling threshold.

[00243] As shown in Id(113. 28, a flirther deflection feature of the golf club head 3700 can be the uniform thinned region 4160, located at the sole 3706 and stretching between the rear 3710 of the body 3701 and the strikeface 3712, toward a cascading sole portion of the sole (as described in,r.:reater detail belay). The uniform thinned re ion 4160 can provide multiple benefits. First, the uniform thinned region 4160 can reduce stress on the strikeface 3712 caused during impact with the golf ball. Second, the uniform thinned region 4160 can bend allowing the strike:lice 3712 to experience greater deflection. Third, the uniform thinned region 4160 removes weight from the sole area, allowing the weight to be redistributed more toward the rear of the golf club head 3700. At impact, the energy imparted to the strikelace 371 2 by the golf ball can cause the uniform thinned region to bend Gun:yard, which in turn increases the strikelac.e 3712 deflection. After bending, the uniform thinned region 4160 rebounds back to ifs origirtil position returning the majority of the energy fnariimpact back r.i.) the golf ball. The result is Hat golf club head 3 700 in-Tarts iniireased ball speeds and greater travel disPinces to the gplf ball after impact.

[0024 1 In some embodiments, body 3701 can comprise stall teel, titanium, alunununrt, steel lloy (e.g. 455 steel, 475 steel, 431 steel, 17-4 stainless steel, inaraglrig steel), a titanium alloy (e.g. Ti 7-4, Ti 6-4, T-93, Ti SSAT2041, Ti SP700, Ti 15-0-3, Ti 15-5-3, Ti 3 8 6 4 4, Ti 10-2-3, Ti 15-3-3-3, Ti 6 6 2, 'n 185, or any combination thereof), an aluminum alloy, or a composite material. In other embodiments, body 3701 can comprise carpenter grade 455 steel, carpenter grade 475 steel, C300 steel, C350 steel, a Ni--Co-Cr steel alloy, a quench and tempered steel alloy, or 565 steel. In some embodiments., strikeface 3712 can comprise stainless steel, titanium, aluminum. a steel alloy (e.g. 455 steel,. 475 steel, 431 steel., 17-4 stainless maraging steel), a titanium alloy (e.g. Ti 7-4, Ti 6-4, 'f-95,'Fi 5SA12044,'ll 51700, Ti 15-0-3, 'fi 15-5-3, Ii 3-8 6 4 4, Ti 10.2 3, Ii 1 5 3 -3 3, Ti-6-6-2, Ii-185, or any combination thereof), an i.iluminum alloy, or a composire material. in odier embodiments, a trikelace 3712 can comprise carpenter grade 455 steel, carpenter grade 475 steel, C300 steel, C350 steel, a NI,-Co-Cr steel alloy, a quench and tempt,,,,I Keel alloy, or 565 steel. In some embodiments, body 3701 can comprise the same material as striketace 3712. In some embodiments, body 3701 can comprise a different material than strikeface 3712.

[00245] 1 i1C. 30 illustrates a back perspective view of an embodiment of golf club bead 4400 and FIG. 31 illustrates a back heel-side perspective view of golf club head 4400 according to the embodiment of FIG. 30. In some embodiments, golf club head 4400 can be similar to golf club head 1000 GIG. 1), golf club head 2200 (HG. 8), golf club head 2700 (14G. 1.3), golf club head 3200 (FIG. .18), and/or golf club head 3700 (FIG. 23). Golf club head -4400 can be an iron-type golf club head. In other embodiments, golf club head 4400 can be a hybrid-type, or a fairway. wood-type golf club head. In some embodiments, golf club head 4400 does nor comprise a badge or a custom tuning port.

[00246] Golf club head 4400 comprises a body 4401. in some embodiments, both' -1401 can be similar to body 11101 (FIG. 1), body 22( 1 (FIG. 8), body 2701 (FIG. 13), body 320.I (FIG. 18), and/or body 3701 (FIG. 23). Body 4401 finther comprises an extenor surface 4-403, a strikeface -4412, a heel region 4402, a toe region 4404 opposite the heel region 4402, a sole 4406, a top rail 4-415, and a rear 4410.

[00247] Body 4401 of FIGS. 44-48 further comprises a blade length. The blade length for body 4401 can be measured similar to idade length 3725 as shown and described in FIG. 29 (i.e.. a measurement parallel to the flat surbice of the strikeface 3219, from a toe edge 3726 of the strikeilace 3712, to strikeface end 372.7 before the strikeface 3712 integrally curves into the hoseb. The blade length of the body 44-01 can range from 2.50 inches (6.35 cm) to 2.90 inches (7.37 cm). For example, in sonic cml id re ik, the body 3701 can cornririse iblade length of 2.50 inch (6.35 cm), 2.54 inch (6.45 cm), 2.58 inch (6.55 cm), 2.62 inch (0.65 cm), 2.66 such (6.76 cm), 2.70 inch (6.86 cm), 2.74 inch (6.96 cm.), 2. 78 inch (7.06 cm, 2.82 inch (7.16 ern), 2.86 such (7.26.4 cm), or 2.90 inch (7.37 cm).

1002481 As shown in 1'1(3. 34, a furtlier deflection feature of the golf dub head 4400 can he the unifbrm thinned region 4860, located at the sole 4406 and stretching between the rear 4410 of the body 4101 and the strikeface 4412, toward a cascading sole portion of the sole (as described in greater detail below). in the illustrated embodiment, the uniform thinned region -4860 comprises a sole thickness measured perpendicular from the exterior surface 4403 to an interior surface 4619 at the uniform thinned region 4860, which can remain constant from the bottom of the strikeface 4412 to adjacent the cascading sole portion of the sole. In sonic embodiments, the sole thickness of the uniform thinned region 4860 CM be thinner than a conventional sole. For example, in some embodiments, the sole thickness of the uniform thinned region 1-861) may range frofn approxiinatelv 0.040 inch to 0.080 inch. In other embodiments, the sole thickness of the uniform thinned region 4860 may be within the range of 0.040 inch to 0.050 inch, 0.050 inch to 0.060 inch, 0.060 inch to 0.070 inch, 0.070 inch to 0.080 inch, 0.040 inch to 0.055 inch, 0.045 inch to 0.060 inch, 0.050 inch to 0.065 inch, 0.055 inch to 0.070 inch, 0.060 inch to 0.075 inch, or 0.065 inch to 0.080 inch. For example, the sole thickness of the uniformed thinned region 1-860 can be 0.040 inch, 0.04.5 inch, 0.050 inch, 0.060 inch, 0.065 inch, 0.070 inch, 0.075 Inch, or 0.080 inch.

[002491 FIR;. 32 illustrates a cross-section of golf club head 4400 along the cross-sectional line XLVI-K1 VI in FIG. 30, according to one embodiment. As seen in FIG. 32, sifikelace 4412 comprises a high region 4676, a iniddle region 4674, and a low region 4672.

[00250] The strike:lila! 4412 of the body 4401 further comprises a thickness 4654 measured porpondicularl, to the strikeface 4412 from the exterior surface 4403 to an interior surface 4619. The thickness 4654 of the strikeface 4412 can range from 0.040 inch to 0.100 inch. For example, the thickness 4654 of the strikeface 4412 can be 0.040 inch, 0.045 inch, 0.050 inch, 0.055 inch, 0.060 inch, 0.065 inch, 0.070 inch, 0.075 inch, 0.080 inch, 0.0:85 inch, 0.090 inch, 0.095 inch, (T 0.100 tnch. In some embodiments, thickness 4654 of the strikelace 4412 can vary from the heel region 4402 to the toe region 4404, And/or from the top rail 4415 to the sole 4406. For example, the thickness 4654 of the strikeface 4412 can lie greatest at the central portion near the middle region 4674 of the strikeface 4412, and taper along the periphery near the high region 4676 and the low region 4672 of strikeface 4412. In many embodiments, the curt ter of the strikelacc 4412 can have a thickness 4634,.,C 0.090 inch and the periphery of the s triketace 4412 can have a thickness 4654 of 0.070 inch, in other examples, the thickness 4654 can increase, decrease, or any variation thereof starting at the central region near the middle region 4674 of the strikelace 4412 and extending toward the periphery near the high region 4676 and the low region 4.672.

[00251] The cross-section of golf club head 4400 in FIG. 32 further illustrates the rear 4410.

the rear 4410 can comprise an upper region 4411,a lower region 4413, and an inflection point 4686 disposed be8A,een the upper region 4411 and the lower region 4413. 't he inflection point 4686 is further located at the junction between the rear wall 4623 and the bottom incline -4625. The inflection point 4686 is located nearer to the sole of the club head than the ton rail 4415.

[00252] The tipper region 4411 of rear 4410 comprises a top rail 4415, an apex 4628 of ton ear wall 4623 orientated parallel to the snit:hi:ace 4412, and a first reference point 4622 dtsposed between the top rail 441 5 and the rear wall 4623. The first reference point 4622 is located at the junction between the top rail 441 5 and the rear wall 2623 parallel to the strikeface 4412. In many embodiments, the rear wall 4.623 of upper region 4411 is located below and adjacent the top rail 4415.

100253] in some embodiments, top rail 4415 of upper regior 4411 can be a flatter and taller top rat.l or skirt than in irons known to one skilled in the art The flatter and taller rail can compensate for mishits or strikelace 4412. to increase playability off the tee. In some embodiments. The length of top rail 4413, measured from heel region 4402. to toe region 4404, ctin be 70'lto to 95'70 of the length of the golf club head 4400.

[00234] The top rail 4415 of the upper region 4411 comprises a thickness 4652. The thickness 1652 of the top rail 4-415 can range from 0.040 inch to 0.080 inch. For example, the thickness 4652 of the top rail 4415 can be 0.040 inch, 0.043 inch, 0.046 inch, 0.049 inch, 0.051 inch, 0.054 inch, 04057 inch, 0.060 inch, 0.063 inch, 0.066 inch, 0.069 inch, 0.071 inch, 0.07,4 inch, 0.077 inch, or 0.080 inch. In many embodiments, the thickness 4652 of the top rail 44.15 is constant throughout. In other embodiments, the thickness 4652 of the top rail 4415 can. vary. In the exemplary embodiment, the thkiktiviss 4632 of the tep rail 441 3 decreases from the strikelace 4412 toward die rear VT:1114623. In many embodiments clue to the thickness 4652 of the top rail, top rail 4415 can provide an increase in the overall bending of strikelace 4412. in some embodiments, die bending of strikeface 4412. can allow for a 2&b to 53/4 increase of energy. 0/

1002551 illustrated the ap rail 4415 and a portion of t le rear 4410 of the cross-section of c 5-olf club head 4400 of. 32, different from cross-section of golf club head 1200 as shown in 11114. 4. The strike face 4412 further comprises a strikerace angle 4750. Strikefnce angle 4750 is measured from the strikeface 4412 to the top rail 4415, wherein the strike-I:ace angle 4750 can range from 70 degrees to 160 degrees or 70 degrees to 110 degrees. In some embodiments, a trikarbice angle 4050 can be 70 degrees, '75 degrees, 80 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrrxts, 120 degrees, 123 degrees, 130 degrees, 133 degrees, 110 degrees, 143 degrees, 150 degrees, 155 degrees, or 160 degrees.

[002561 FIG. 33 further illustrates the top rail 4415 comprising a top rail angle 4745. The top rail angle 4'74-5 is measured from rear wall 4623 to he top rail 4115. In many embodiments, the top rail angle 4745 can range from 35 degrees to 120 degrees or 70 degrees to 110 degrees. In some embodiments, top rail angle 4745 can be 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 1 1 0 degrees, 1.15 degrees, or 120 degrees.

1002571 11:he rear wall 4623 of the upper region 4411 comprises a height 4680. The height 4680 of the rear wall 4623 is measured from the first reference point 4622 to the inflection point 4686, wherein the first reference point 1622 is positioned at the;unction between the top rail 4415 and the rear wall 4623 parallel to the strikeface 4412. 'the height 4680 of the rear wall 4623 can range from 0.055 inch to 0.060 inch, 0.060 inch to 0.070 inch, 0.070 inch to 0.080 inch, 0.080 in to 0.085 or 0.55 inch to 0.85 inch. For example, the height 4680 of the rear wall 4623 can be 0.55 inch, 0.58 inch, 0.61 inch, 0.64 inch, 0.67 inch, 0.70 inch, 0.73 inch, 0.76 inch, 0.79 inch, 0.82 inch, or 0.85 inch. In sortie cm: )orliments, the height 4680 of the rear wail 4623 range from 35% to 60%, 35% to 45%, 45% to 68%, 40% to 55%,30% to 40%, 35% to 45%, 40?/1: to 50 %, 45% to 55%, or 50% to 60% of the total height of the golf club head 4400. For example, the height 4680 of the rear wan 4623 can he, 44%, 47%, 50%, 53%, 56%, or 60% of the total height of the golf club head 4400 [00258] The rear wall 4623 of the upper region 1411 can also comprise a height 4680.A. The hr ght 4.680A is measured from the apex 4628 of the for rail 4415 to the inflection point 4686. The height 4680A can range from 0.60 inch ITO 1.0 tnch. ror example, the height 4680A can be 0.60 inch, 0.61 inch, 0.64 inch, 0.67 inch, 0.70 inch, 0.73 inch, 0.76 inch, 0.79 inch, 0.82 inch, 0.85 inch, 0.90 inch, 0.95 inch, or 1.0 inch. In some embodiments, the height 4680A can range from 401% to 75% of the total height of le golf club head 4400. For example, the height 4680A can be 40%, 44%, 47%, 50% 53% or 75% of the total height of the golf club head 4400.

[002591 The rear wall 4623 of the upper region 4411 further comprises a thickness 4656. The thickness 4656 is the perpendicular distance of the rear wall 4623 from the outer surface 4403 to the inner surface 4619. the thickness 4656 of the rear wall 4623 can range from 0.040 inch to 0.080 inch. For ex,:ifriple, the thickness 4656 (if the rear wall 4623 can be 0.040 inch, 0.043 inch, 0.046 inch, 0.049 inch, 0.05i inch, 0.054 inch, 0.037 inch, 0.060 inch, 0.063 inch, 0.066 inch, 0.069 inch, 0.071 inch, 04074 inch, 0.077 inch, or 0.080 inch. in many embodiments, the thickness 1656 of the rear wall 4623 is constant throughout.. In other embodiments, the thickness 4656 of die rear wail 1623 can vary. In the exemplary embodiment, the thickness 4656 of the rear wall 4623 is a constant 0.05 inch. The thickness 4656 of the rear wall 4623 allows energy from an impact to transfer to the inflection point 4686 to help induce a buckling effect.

[002601 'Elie lower region the icts, 4401 comprises 'a oottorn incline 4625, a lower exterior wall 4627, a second reference point 4682, and a third reference point 4620. '1 he bottom incline 4625 is below and adjacent the inflection point 4686. The lower exterior wall 4627 is below and adjacent the bottom incline 4623. The second reference point 4682 is disposed between or positioned at the junction between the bottom incline 4625 and the lower exterior wall 4627. The third reference point 4620 is disposed between the lower exterior wall 4727 and the sole 1106. The bottom incline 1625 is angled Wray from the 1-op rail 4415 and away from the strikelace 4112 in a direction toward the second reference poin14682.

[00261] In some embodiments, bottom incline 4625 of the lower region 4413 comprises bottom incline length 462.9. Bottom incline length 4629 is measured from the inflection point 4686 to the second reference point 4682. The bottom incline length 4629 can range from 0 inch to 0.45 inch. For example, the bottom incline length. 4629 can be 0 inch, 0.05 inch, 0.10 inch, 045 inch, 0.20 inch, 0.20 inch, 0.25 inch, 0.30 inch, 0.35 inch, 0.40 inch, or 045 inch. In some embodiments, the bottom incline length 4629 can remain constant from the heel region. 4402 to the. toe region 1404. In other embodiments, the bottom incline length 4629 can -,7,iry from the heel region 44.02 to the. ti regi()n 4404, For example, the IJottom incline length 1629 can increase from the heel reczio n 4402 to the toe region 4404 as illustrated in FI.G. 44. In other embodiments, the bottom incltne length 162.9 can decrease from the heel region 4102 to the toe region 4401.

1002621 In sonic enthodirients, the lower region 4413 further comprises a lower angle 4651 measured from between the bottom incline 4625 to the lower exterior wall 4627. In some enlbodiinents, the lower angle 4631 can be less than 180 degrees. In a number of embodiments, the lower angle 4631 can be 130 degrees to 175 degrees. For example, the lower angle 4651 of the lower region 4413 can be 130 degrees, 135 degrees, 140 degrees, 145 degrees, 150 degrees, 155 degrees, 160 degrees, 165 degrees, 170 degrees, ;-4.: 175 degrees.

1002631 'The upper region 4411 and the lower region 4413 of the rear 4410 is separated by the inflection point 4686. Due to the height 4680 of the rear wall 4623, the inflection point 4686 is positioned low on the body 4401. In num.' embodiments, the inflection point 4686 is positioned at least 40% down on the body 4-401 below the apex 4628. For example, the inflection point 4686 can be positioned 40%, 42%, 4 46%, 48%, 50%, 52%, 54%, 56, 58%, or 60% down on the body 4401 below the apex 4628. The low positioned inflection point 1686 allov.,s for more leverage on the upper region 4411 to experience increased bending during iihriact with a ball, compared to a similar golf club head having a higher inflection point position.

1002641 The inflection point 4686 comprises an inflection angle 4696 measured from the rear wall of the upper region 4411, to the bottom incline 4625 or the lower region 4413. In some embodiments, the inflection angle 4696 can be measured from the rear vrall 4623 to the lower exterior wall 1627 in the absence of the bottom Incline 4625 (i.e., the bottom incline length 4629 is 0 inch). The inflection angle.4696 of die inflection point 4686 can range from at least 95 degrees to 150 degrees. In some embodiments, the inflection angle 4696 can be at least 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, 140 degrees, 145 degrees, or 150 degrees. In some embodiments, the inflection angle 4696 Can be consistent from the heel region 4402 to the toe region 4404. In other embodiments, the inflection angle 4696 can vary from the heel region 4402 to the toe region 4404. In many embodiments, the inflection angle 4696 allows for inflection point 4686 to act as a budding point or plastic hinge upon the golf dub head 4400 impacting the golf:ball at strike face 4412. in other examples of a similar gplf clu b head having an inflection angle, wherein the inflection angle is less than 93 degrees (i.e., 90 degrees, or the bottom incline is oriented approximately perpendicular to the strike face). the inflection angle would impede energy transfer arid prevent bending at the 1:1 tlec bon point.

R3032651 The inflection point 4686 timber comprises a thickness 4660. The thickness 4660 of the inilec don nomt 4686 is measured perpendicularly of the inflection point 4686 from the exterior surface 4403 to the interior surface 4619. '1:lie thickness 4660 of the i nilectton point 4686 can range from 0.040 inch, to 0.080 inch. For example, the thickness 4660 can be 0.0.40 inch, 0.045 inch, 0.050 inch, 0.055 inch, 0.060 inch, 0.65 inch, 0.065 inch, 0.070 inch, 0.075 inch, or 0.080 inch. In many emliodiments, the thickness 4660 at We inflection point 4686 is constant with the thickness 4656 of thereat wall 4.623 and the thickness 4658 of the bottom. incline 4625. In other embodiments, the thickness 4660 at the inflection point 4686 can be less than the thickness 4656 of the rear wall 4623 and the thickness 1658 of the bottom incline 4656. The thickness 1660 at the inflection point 4686 being consistent with or less than the thickness 1656, 4658 of the rear wall 4623 and die bottom incline 4656 allows for more uniform energy transfer and bending.

[00266] FIG. 34 illustrates another cross-sectional view of die golt club head 4400, similar to the detailed cross-section of golf club head 4400 illustrated in 1,4(3. 30. 'the body 4401 of golf club head 4400 further comprises a minimum distance 4616, and a maximum distance 4618. the. minimum distance of the body 4401 is measured as the perpendicular distance from the exterior surface 4403 of the strikeface 4412 in the upper region 4411 to the exterior surface 44.03 of the rear wall 4623. '11-ki minimum distance 4616 can range from 0.2.0 inch. to 0.40 inch. For example, the minimum distance 4616 can be 0.20 inch, 0.22 inch, 0.7,4 inch, 0.26 inch, 0.28 inch, 0.30 inch, 0.32 inch, 0.34 inch, 0.36 inch, 0.038 inch, or 0.40 inch. In some embodiments, the minimum distance 4616 of the body 4401 can be less the bottom incline length 4629. The maxitrium distance 4618 of the body 4401 is measured as the perpendicular distance from the exterior surface 4403 of the strike:ace 4412 in the lower region 4413 to the exterior surface 4403 of the third reference point 4620. The maximum distance 4618 can range Frain 0.60 inch to 0.90 inch. For example, the 111-1XIM111T1 distance 4618 can he 0.60 inch., 0.64. inch, 0.68 inch, 0.72 inch, 0.76 inch, 0.80 inch, 0.84 inch, 0.88 inch, or 0.90 inch.

[00267] _As illustrated in FIG. 32-34, the golf club head 4400 can he 3 hollow, or at leas:partially hollow body comprising an internal cavity 4116. Internal cavity 4416 (1f the body 4401 comprises a volume The vi ilume of the internal cavity 4416 can range from 0.65 inch' (10.65 crns.) to 1.05 inch' (17.21 cn-13). In some embodiments, We internal cavity 4416 can comprise a volume of 0.65 inch' (10.65 crab, 0.70 inch3 (41.47 cm3). 0.75 inch' (12.29 cm., 0.80 inch3 (13.11 cm3), 0.85 inch' (13.93 cm3), 0.90 inch' (14.75 cm3). 0.95 inch' (15.57 cm3), 1.00 inch.' (16.39 cm'), or 1.05 inch' (17.21 cm3). Similarly, the solid portion of the body 4401, void of the cavity 4416, hirther comprises a. material volume. The material volume or the body 4401 can range from 2.50 inch' (40.97 crni5 to 3.50 inch' (57.33 cm3). ['or examp]e, Me material volume or the body 4401 can be 2.50 inch' (40.97 cm"), 2.60 inch (42.61 cna'), 2.70 inch' (44.25 cm?), 2.80 incbd (45.88 cm"), 2.90 inch' (47.52 cm"), 3.00 inch' (49.16 ctid)'" 3.10 incld (30.80 cna'), 3.20 inch' (52.44 C1113), 3.30 inch' (54.08 MO, 3.40 inch.' (55.72 cm.), or 3.50 inch' (57.35 cm).

[00268] in many embodiments, the internal cavity 4416 of the body 4401 can be void of any substance. In other embodiments, the internal cavity 4416 of the body 4401 can comprise a polymer (not pictured), wherein the polymer can be at least partially filling the internal cavity 4416. The polymer can be polyethylene ten-phthalate, high-density pohTthylene, polyvinyl chloride, polycarbonate, polypropylene, other thermoplastics, composites polymers or any combination thereof: 'The polymer can fill 10% to 80% 1 (rd) to 25%, 15% to 30%, 30% to 45%, 45% to 60'1/4, 60Y.0 to 75%, 75% to 80%, 10% to 401:., 30% to 60%, or 40% to 80% of the internal cavity 4416 of the body 4401. For example, the polymer can fill 10%, 15%, 20%, 25%, 30%, 35%, 40'1/4), 45%, 50%, 55%, 601/i., 65%, 70%, 75%, 80%, or 85% of the internal cavity 4416 of the body 4401. In some embodiments, the polymer tills 80% of the internal cavity 4416 of the body 4401.

100269-1 The polymer to at least partially fill the internal cavirv 1416 ot me body 4101 comprises a specific gravity ranging from 0.05 to 4. For example, the specific gravity of the polymer can be 0.3, 1.0, 1.3,2..0, 2.5, 3.0, 3.3, or 4. In some embodiments, the specific gravity of the polymer is proportional to the mass of the polymer, wherein 1 specific gravity of the polymer is equal to I gttimn.Similarly, in those exemplary embodiments, the volume is proportional to the polymer specific gravity, wherein 1 specific gravity of the polymer is equal to icc. In other embodiments, the volume is not proportional to the specific gravity of the polymer. For example, the ratio of the polymer specific gravity to the polymer vo.lume can he 2:1 cc, 2:3 cc, 2:4 cc, 3:1 cc, 3:2 cc, 3:4 cc, 4:1 cc, 4:2 cc, or 4:3 cc.

[00270] The mass of the polymer allows for the swim* we:ght of the golf cm} head 1400 to be CUStomizable for each player. In the vcAurrte of the polytner, and thus the mass, increases the swing weight. Similarly, decreasing the volume of the polymer decreases the swing weight. Having the appropriate swing -weight For each individual player improves feel during a swing and can i:nptove performance such as g speed, swing path, ball speed, and Hall trajectory. The polymer can further increase the overall mass of the golf club head 440! more toward the sole 4406. incieasmg He mass more toward the sole shifts the CG low and back, TECA-eh,/ Tinprov;:s the mm tient of Titertia.

002711 In some embodiments, the golf club head 4400 can fnrther comprise an aperture (not pictured) located on the toe region 4404. the aperture comprises internal threads and is configured to receive a threaded screw weight (Eli)11 pirated;. The threaded screw eight comprises a mass, wherein the mass of the threaded screw weight can range from 2 grams to 12 crams. In other embodiments, the mass of the threaded screw weight can range from 4 grams to 10 grams. In some embodiments, the screw weight can be 2 grit:is, 3 grAMS, 4 grams, 3 grams, 6 {grams, 7 cralns, 8 grams, 9 grains, 10 grams, 11 grams, or 12 grams. The mass of the screw weight correlates with the length of the screw weight, wherein a. longer threaded screw weight equates to a greater mass. The threaded screw weight further at its the mass and overall swing weight of the golf club head 4400. Therefore, the threaded screw weight can improve the feel of the golf club head 4400, as well as performance characteristics;;;e.g., swing speed, ball speed, and ball flight).

[00272] In many embodiments, the low positioning of the inflection point 4686 can pn :increase in. golf ball speed over golf club head 1200 (or other standard golf club heads), can reduce the spin rate of standard hybrid club heads (or other standard golf club heads), and can increase the launch angle over both the standard hybrid and iron club heads. An inflection point positioned less than 40% down the body from the apex cannot buckle as easily because the high positioning decreases the leverage for the upper region to bend. Therefore, when die golf ball impacts strikeface 44 12 of the club head 4400 with inflection point 4686 positioned at least 40% down the body 4401 from the apex 4628, the strikeface 4412 springs back like a drum, and the rear 4410 bends in a controlled buckle mariner more than a. golf club head having an inflection point positioned less than 40% down the body from the apex.

00273] A standard top rail, and rear wall without a low positioned nail ecrion point does not have this hinge/buckling; effect, nor does it absorb a high level of stress over a large volumetric area of the top rail and rear wall. 'therefore, the standard strikelace does not contract and then recoil as much as strikeface 4-412. By adding more spring to the, back end of the club (due to the thinness of the top rail 4415 and rear wall 4623, and the low position of the inilection point 4686), more Force is displaced throughout the volume of the structure. l'he stress is observed over a greater area of striketace 4412, top rail 4415, and rear wail 4623 of the golf club head Peak stresses can he seen in the typically just along the top nil in a standard club head. I towever, more peak stresses are seen in the golf club head 4400 but distributed over a large volume of the material. The hinge and bend regions of the golf club head 4400 (i.e., the in point 4686) will not deform as long as the stress does riot meet tile critical buckling iiireshold. Inflection point 4686 and its placenient can be designed to be under the critical K. value of the buckling threshold.

1002741 Purifier, LipOn impact with the golf ball, strikelac.e 4412 can bend inward at a,greater distance than on a golf club with OLI t a thin top rail 4413, a thin rear wall 4.623, and an inflection point 4686 positioned at least 40% down the body from die apex 4628. In some embodiments, the strikeface 4412 has a 10% to a 50% greater deflection than a strikeface on a golf club head without a thin top rail, a thin rear wall, and a low positioned inflection point. For evample, the strikeface 4412 can have a 10%, a 15%, a 20%, a 30%, a 35%, a 40%, a 45%, or a 511% greater deflection than a strikeface of a golf club head without a thin top rail 4415, thin rear wall 4623, and low positioned inflection point 4686.

100275_1 As shown in I 4G. 34, a fiirther deflection feature of the golf club bead 4400 can be the uniform thinned region 4860, located at the sole 4406 and stretching between the rear 4410 of the body 4.4.01 and the saikeface 4412, toward a cascading sole portion of the sole (as described in greater detail below). 'the unifprrit thinned region 4860 can provide multiple benefits. First, the uniform thinned region 4860 can reduce stress on the strikeface 4412 caused during impact with the golf ball. Second, the uniform thinned region 4860 can bend allowing the strikeface 4412 to experience greater deflection. Third, he uniform dunned region 4860 removes weight from the sole area, allowing the weight to be redistributed more toward the reir of the golf club head 4400. At impact, the energy imparted to the strikefacc 4412 by the golf ball can cause the uniform thinned region 4860 to bend outward, which in turn increases the strikeface 4412 deflection. After bending, the uniform thinned rerrion 4860 rebounds back to its original position returning the majority of the energy from impact back. to the golf bail. The result is the golf club head 4400 imparts increased ball speeds and greater travel distances to the golf ball alter impact.

[002761 in some embodiments, body 4401 can comprise stainless steel, titankim, aluminum, a steel alloy (e.g. 455 steel, 475 steel, 131 steel, 17-4 stainless steel, maraging steel), a titanium alloy (e.g. Ili 7-4, Ti T-98, Ti 88AT2041, Ti 8P700, Ti 15-0-3, Ti 15-5-3, Ti 3-8-6-4-4, Ti -n 15-3-3-3, 11-6-6-'2, Ti-185, or any cornlaination thereof), an aluminum alloy, or a composite material. In other embodiments, body 4401 can comprise carpenter grade 455 steel, carpenter grade 475 steel, C100 steel, C350 steel, a Ni-Co-Cr steel alloy, a quench and tempered steel alloy, or 565 steel. In some embodiments, strikeface 4412 can comprise stainless steel, titanium, aluminum, a steel alloy 455 steel, 475 steel, 431 steel, 17-4 stainless steel, n-iaraging steel), a ti]aniuni alloy;e.g. Ti 7 4, Ti 6 4, I 93, SSAT2041, Ti SP700, Ti 15- (1-3, Ti Ti 3-8-6-4-4, Ti Ti 15-3-3-3, Ti-6-6-2, Ti -183, or any combination thereof), an aluminum alloy, or a composite material. in other embodiments, s trike face 4412 can comprise carpenter grade 435 steel, carpenter grade 475 steel, C300 steel, C:350 steel, aNLCo--Crsteel alloy, a quench and tempered steel alloy, or 563 steel. In some embodiments, body 4401 can comprise the same material as snikefice 4412. In some embodiments, body -4401 can comprise a different material than strikcface 4412.

[00277] FIG, 35 illustrates a back perspective yjeV,7 of an cr.

tent of a golf club head 4900, and FIG. 36 illustrates a back heel-side perspective view of the golf club head 4900 according to the embodiment of 111G. 35. In some embodiments, the golf club head 4900 can be similar to golf club head 1000 1), golf club head 2200 (FKt 8), golf dub head 2700 (1'1G. 13), golf club head 3200 (NG. 18), golf club head 3700 (FIG. 23), and/or golf club bead 4400 (PIG. 30). the golf club head 4900 can be an iron-type golf club head. in some embodiments, the golf club head 4900 does not comprise a badge or a custom tuning, port.

100278] The golf club head 4900 comprises a body -4901. In some embodiments, the body 4901 can be similar to body 1001 (FIG. 1], body 2201 (FIG. 8), b: 01 (FIG. 13), body 3201 (FIG. body 3701 (FIG. 23), and/or body -4401 (FRI. 30). The body 4901 Eirther comprises-an exterior surface 4903, a strikeface 4912, a heel region 4902, a toe region 4904 opposite the heel region, a sole 4906, a top rail 4915, and a rear 4910.

279] The body 4901 of FIGS. 49-52 nirther comprises a blade length. The blade length for the;Jodi] 4901 can be measured similar to blade length 3725 as shown and describedto r golt club head 3700 in leIG. 43 (i.e., a measurement parallel to the fiat surface of the strikeface, from a toe edge of the strlkerace. to strils efac.e end before the strikeface integrally curves into the hoseb. The 1)1ade length of the body 4901 Cart range ln]rri 2.30 inches (6.33 cm) to 2.90 inches (7.37 cm). In some embodiments, the length can range from 2.50 inches (6.35 cm) to 2.60 inches (6.60 cm), 2.60 inches (6.61 to 2.70 inches (6.86 inches), 2.70 inches (6.86 cm) to 2.80 inches (7.11 cm), or 7.80 inches (7.11 cm) to 2.90 inches (7.37 cm). For e]mmple, iii some embodiments, *che body 4901 can comprise a blade length of 2.50 inches (6.35 cm), 2.54 inches (6.45 cm), 2.58 inches (635 cm), 2.62 inches (6.65 cm), 2.66 inches (6.76 cm), 2.70 inches (6.86 cm), 2.74 inches (6.96 cm), 2.78 inches (7.06 cm), 2.82 inches (7.16 cm), 2.86 inches (7.264 cm), or 2.90 inches (7.37 cm).

1002801 As shown in 11(3.39, a further deflection feature of the golf club head 4900 can be the uniform thinned region 5360, located at the sole 4906 and stretching between the rear 4-910 of the body 1901 and the strikeface 1912, toward a cascading sole portion Of the sole (as described in greater detail below). In the illustrated embodiment, the uniform thinned region 5360 comprises a sole thickness 5361 measured perpendicular from the exterior surface 4903 to an interior surface 5119 at the uniform thinned region 5360, which can remain constant from the bottom of the strikeface 1912 to adjacent the cascading sole ponion of the sole -1906. In some embodiments, the sole thickness 5361 of the uniform thinned region 5360 can be thinner than a conventional sole. For example, in some Calbodirnents, the sole thickness 5361 of the uniform thinned region 5360 may range from approximately 0.040 inch to 0.080 inch. in other embodiments, the sole thickness 5361 of the uniform thinned region 5360 may be within the range of 0.040 inch to 0.050 inch, 0.050 inch to 0.060 inch, 0.060 inch to 0.070 inch, 0.070 inch to 0.080 inch, 0.040 inch to 0.055 inch, 0.045 inch to 0.060 inch, 0.050 inch to 0.065 inch, 0.055 inch to 0.070 inch, 0.060 inch to 0.075 inch, or 0.065 inch to 0.080 inch. for example, the sole thickness of the uniformed thinned region 5360 can be 0.040 inch, 0.045 inch, 0.050 inch, 0.060 inch, 0.065 inch, 0.070 inch, 0.075 inch, or 0.080 inch.

[002811 FIG. 37 illustrates a cross-section of the golf club head 4900., according to one embodiment. As seen in 111(-3. 37, the strikelace 1-912 comprises a high region 5176, a middle region 5174, and a. low region 5172.

[00282] The strikef ace 4912 of the body 4901 further comprises a thickness 5154 measured perpendicular to the strikeface 4912 from the exterior surface 4903 to an interior surface 5119. the thickness 5154 of the strikeface 4912 can range from 0.040 inch to 0.200 inch. in some embodiments, the thickness 5154 of the strikeface 491 2-can rang,-from 04040 incls to 0.080 inch, 0.080 inch to 0.120 inch, 0.120 inch to 0.160 inch, or 0.160 inch to 0.20 inch. For example, the thickness 5154 of the strikeface 4912 can he 0.040 inch, 0.045 inch, 0.050 inch, 0.055 inch, 0.060 inch, 0.065 inch; 0.070 inch, 0.075 inch, 0.080 inch, 0.085 inch, 0.090 inch, 0.095 inch, 0.100 inch, 0.150 inch, or 0.200 Inch. In some embodiments, the thickness 5154 or the strikeface 1912 can vary From the heel region 190-2. to the toe region 4904, and/or from the top rail 4915 to the sole -4906. For example, the thickness 515-4 of the strikeface 1912 can he greatest at the central is ion no, the middle region 3174 of the strokefacc 4912 and hiper along the periphery near the high region 5176 and the low region 3172 of striker:ace 4912. In many ernbodiments, the center of the strikeface 4912 can have a thickness 5134 range of 0.10 inch to 0.14 inch, and the periphery of the strikeface 4912 can have a thickness 51 54 range of 0.06 inch to 0.10 inch. ta some embodiments, the center of the strikeface 4912 can have a thickness 5131 range of 0.10 inch to 0:12 inch, or 0.12 inch to 0.14 inch. In other embodiments, the periphery of the strikeface 4912 can have a thickness 5154 range of 0.06 inch to 0.08 inch, or 0.08 inch to 0.10 inch. In other examples, the thickness 3154 can increase, decrease, or any variation thereof starting at the central region near the middle region of the strikeface and extending toward the periphery near the high repoi1 5176 and the low region 3172.

[00283] The cross-section of the golf club head in FIG. 37 further illustrates the rear 4910.

The rear 4910 can comprise an upper region 4911, a lower region 4913, and r inflection point 5186 disposed between the upper region 4911 and the lower region 4913.4 he inflection point 5186 is further located at the junction between the rearwall 5123 and the bottom incline 5125. The inflection point. 51 86 is located nearer to the sole 4906 of the club head 4900 than the top rail 4913.

[00284] 'the upper region 4911 of rear 4910 comprises a top rail 4.915,an apex of top rail 5128, a rear wall 5123 orientated parallel to the strikelace 1912, and a first reference point 5122 disposed between the top rail 1913 and the rear wall 5123. The first reference point 5122 is located at the junction between the top rail 4915 and the rear wall 5123 parallel to the stnkeface. In many embodiments, the rear wall 5123 of the upper region 4911 is located below and adjacent the top rail 4915.

[00285] In sortie embodiments, top rail 49 13 of the upper region 491 1 can be a flatter and taller top rail or skirt than in irons known tc one skilled in the art. The flatter and taller rail can compensate for mishits or striker-rice 4912 to increase provability off the tee, ha some embodiments. The length of top rail 4915, measured from heel region 4902 to toe region 4904, can Ire 60% to 93% (if the length of the golf club head 4900.

[002861 The top rail 4915. of the upper re:viola 4911 comprmses a thickness SI 52.1he thickness 5152 of the top rail 4915 can range Cron-, 0.040 inch to 0,080 inch. In some embodiments, the thickness 5157 of the top rail 4915 can range from 0.040 inch to 0.060 inch, or 0.060 inch to 0.080 inch. For ertample, the thickness 3152 of the top rail 1915 can be 0.010 inch, 0.043 inch, 0.046 inch, 0,049 inch, 0.051 inch, 0.054 inch, 0.057 inch, 0.063 inch, 0.063 inch, 0.066 inch, 0.069 inch, 0,071 inch, 0.074 inch, 0.077 inch, or 0.080 inch. In many embodiments, the thickness 5152 of the top mil 4915 is constant throughout. In other embodiments, the thickness 5152 of the top rail 4915 can vary. In the exemplary embodiment, the thickness 5152 of the top rail 4915 decreases from the strikeface.4912 toward the rear wall 5123. In many embodiments, due to the thickness of the top cad, top rail can provide an increase in the overall bending of sitikeface. In some embodiments, the bending of strikelac.e can allow for a 2% to 5th increase of energy.

[002871 FIG. 38 illustrates the top rail 3915 and a portion of the rear 4910 of the cross-section e golf club head of FIG. 35, different from cross -section of golf club head 1200 as shown in FIGThe strike:lace 4912 further comprises a strikeface angle 5250. The strikeflice angle 5250 a measured from the strikeface 4912 to the top rail 4915, wherein the strikeface angle 5250 can range from 70 degrees to 160 degrees or 70 degrees to 110 degrees. In some embodiments, strikeface angle can be 70 degrees, 75 degrees, 80 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, 140 degrees, 145 degrees, 150 degrees, 155 degrees, or 160 degrees.

[00288] VIC, 38 further illustrates the top rail 4915 comprising a top rail angle 5235. The top rad angle 5245 is measured from rear wall 5123 to the top rail 4915. In many embodiments, the top rail angle 5245 can range from 35 degrees to 150 degrees or 70 degrees to 145 degrees. In some embodiments, top rail angle 5245 can be 35 degrees, 40 degrees, 45 degrees, 50 degrees, 35 degrees, 60 degrees, 65 degrees, 70 degrees, 5 degrees, 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, 140 degrees, 145 degrees, or 150 degrees.

[00289] The rear wall 5123 of the upper region 4911 comprises a height 5180. The height 5[80 of the rear wall 5123 is measured from the first reference point 5122 to the inflection point 5186, wherein the first reference point 5122 is positioned at the;unction between the top rail 4915 and the rear wall 512.3 parallel to the strikeface 4912. The height 5180 of the rear wall 5123 can range from 0.53 inch to 0.60 inch, 0.60 inch to 0.70 inch, 0,70 inch to 0.80 inch, 0.80 inch to 0.83, 0.85 inch to 0.90 inch, 0.90 inch to 0.93, 0.95 inch to I inch or 0,55 inch to 1 inch. For example, the ht. 5180 of the rear wall 5123 can be 0,55 inch, 0.58 inch, 0.61 inch, 0.64 inch, 0.67 inch, 0.70 inch, 0.73 inch, 0.76 inch, 0.79 inch, 0.82 inch, 0.83 inch, 0.88 inch, 0.91 inch, 0.91 inch, 0.97 inch, or I inch. In some embodiments, the height 5180 of the rear wall 5123 range front et) 60%, 35% to 45%, 45% to 68%, 40% x.) 55%, 30 to 40%, 35% to 45%, 40% to 50 11ii, 4511⁄4 t-55%, or 50% to 60% of the total height of the golf dub head 4900. For example, the height 5180 of the rear wall 3123 can be 35%, 38%, 4 50%, 57%, 569'i., or 60% of the total height of the golf dub head 4900.

[002901 The rear wall 3123 of the upper region 4911 can also comprise a seccn idary height 5180A. The secondary height 5180A is measured from the apex 51:28 of the top rail 4915 to the inflection point 5186. The secondary height 5180A can range from 0.60 inch to 1.2 inch. In some embodiments. the secondary height 5180A can range from 0.60 inch to 0.80 inch, 0.80 inch to 1.0 inch, or 1.0 inch to 1.20 inches. For example, the secondary height 5180A can be 0.60 inch, 0.61 inch, 0.64 inch, 0.67 inch, 0.70 inch, 0 a, 0.76 inch, 0.79 inch, 0.82 inch, 0.85 inch, 0.90 inch, 0.95 inch, 1.0 inch, or 1.2 inches. In sOrTIC embodiments, the secondary height 51803 ears range. from 40% to of the tottO height of the 0-..olt dub head 4900. For example, the secondary height 51.80A can be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 489/7., 49%, 50%, 31171, 5.r.1), 53%,54%, 35%, 56%, 60%, 65%, 70%, or 73% of the total height of the golf club head 4900.

[002911 The rear wall 5123 of the upper region 4911 further comprises a thickness 3156. The thickness 5136 is the perpendicular distance of the rear wall 5123 from the outer surface 4903 to the inner surface 5119. The thickness 5156 of the rear wall 5123 can range from 0.040 inch. to 0.080 inch. In some embodiments, the thickness 5156 of the rear wall 5123 can range from 0.040 inch to 0.060 inch, or 0.060 inch to 0.080 inch. For example, the thickness 5156 of the rear wall 5123 can be 0.040 inch, 0.043 inch, 0.046 inch, 0.049 inch, 0.051 inch, 0,054 inch, 0.057 inch, 0.060 inch, 0.063 inch, 0.066 inch, 0.069 inch, 0.071 inch, 0.074 inch, 0.077 inch, or 0.080 inch. In many embodiments, the thickness 51 56 of the rear wall 5123 is constant throughout. in other embodiments, the thickness 5156 of the rear wall 5:23 can vary. Un the exemplary embodiment, the thickness 5156 of the rear wall 5123 is a constant 0.045 inch. 'the thickness of the rear WA H allows energy from an impact to transfer to the inflection point to help induce a buckling effect.

1002921 The lower region 4913 of the body 4901 comprises a bottom incline 312:: a lower exterior wall 5127, a second reference point 5182, and a third reference point.5120. the bottom incline 51 25 is below and adjacent the inflection point 5186. The lower exterior wall 5127 is below and adjacent the bottom incline 5125. The second reference point 5182 is disposed between or positioned..the junction between the bottom incline 512.5 and the lower exterior wall 5127. The tInrd reference point 3120 is disposed between the lower 10 312.7 and the sole 4906. The bottom incline 5125 is angled away from the top n 915 and away from the strike:ft:cc 4912 in a direction toward the second reference point 5182.

I 00293_1 In some embodiments, bottom incline 5125 of the lower region 4913 comprises a bottom incline length 3129. Bottom in ch te length 5129 is nleasured from the inflection Out 5186 to the second reference point 5182. The Imttorn incline length 5129 can range from 0 inch to 0.33 inch. In some embodiments, the bottom incline length 5129 can range From 0 inch to 0.33 inch, or 0.35 inch to 0.55 inch. For e.:arriple, the bottom incline length 5129 can be 0 inch, 0.05 inch, 0.10 inch, 0.13 inch, 0,20 inch, 0.20 inch, 0.25 inch, 0.30 inch, 0.35 inch, 0.10 inch, 0.45 inch, 0.30 inch, or 0.33 inch. In some embodiments, the bottom incline length 3129 can remain constant from the heel region 4902 to the toe region 4904. In other embodiments, the bottom incline ictiw,th 5129 can vary front the heel region 4902 to the toe region 490-4, as illustrated in FIG. 35. For example, the bottom incline length 5129 can increase From the heel region 4902 to the toe region 4904. In other embodiments, the bottom incline length 5129 can decrease from the heel region 4902 to the toe region 4904.

1002941 in some embodiments, the lower region 4913 farther comprises a lower angle 5151 measured from between the bottom incline 5123 to the lower exterior wall.5127. In some embodiments, the lower angle 5131 can be less than 180 degrees. In a number of embodiments, the lower angle 3131 can be 130 degrees to 175 degrees. For example, the lower angle 5151 of the lower region 4913 can be 130 degrees, 133 degrees, 140 degrees, 143 degrees, 130 degrees, 133 degrees, 160 degrees, 165 degrees, 170 degrees, or 175 degrees.

[00295] The upper region 4911 and the lower region 4913 of the rear 4910 is separated by the rflection point 3186. Due to the he+ lt of the rear wail, the inflection point 5186 is positioned low on the body 1901. In many embodiments, the inflection point 5186 is positioned at least 40% down on the body.4901 below the apex 3128. 1or example, the inflection point 5186 can be positioned.40%, 4-2%, 4.4%, 46%, 48%, 50%, 52%, 5.4%, 56%, 58%, or 60% down on the boch,T 4901 below the apex 5128. The tow positioned inflection point 5186 allows for more leverage. on the upper region 4911 to experience increased bending during impact with a ball, compared to a similar golf club head having a higher inflection point position..

[002961 The inflection point 5186 comprises an inflection angle 5196 measured from the rear wall 5123 of the upper region 1911, to the bottom incline 5125 of the lower region 4913. fit some embodiments, the inflection angle 5196 can be measured from the rear wall 5123 to the lower exterior wail 5127 it the absence of the bottom incline 5125 (lc., the bortoi length is 0 inch). The inflection angle 5196 of the inflect-gen point 5186 can range from at least 95 degrees to 150 degrees. In some embodiments, the Miley_ Lion angle 5196 can be at least 95 degrees, 100 degrees, 103 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, 140 degrees, 145 degrees, or 130 degrees. In sonic embodiments, the inflection amile 3196 can he ceinsis tent from the heel region 1902 to the toe 'region 4901. In other embodiments, the inflection angle 3196 can vary from the heel region 4902 to the toe region 4904. In manv embodiments, the inflection angle 5196 allows for the inflection point 5186 to act as a buckling point or plastic hinge upon the golf club head 1900 impacting the golf ball at snikefrice 4912. In other examples of a similar golf club head haying an inflection angle, wherein the inflection angle is less than 95 degrees (i.e,, 90 degrees, or the bottom incline in oriented approximately perpendicular to the strikeface), the inflection angle would impede energy transfer and prevent bending-at the inflection point.

1002971 The rear wall at the inflection point 5186 further comprises a thickness 5160. The thickness 5160 at the inflection point 5186 is measured perpendicularly of the inflection point 5186 from the exterior surface 1903 to the interior surface 5119. The thickness 5160 of the inflection point 3186 can range From 0.040 inch to 0.080 inch. In some embodiments, die thickness 5160 of the inflection point 3186 can range from 0.010 inch to 0.060 inch, or 0.060 inch to 0.080 inch. For example, die thickness 5160 can be 0.040 inch, 0.043 inch, 0.050 inch, 0.055 inch, 0.060 inch, 0.63 inch, 0.065 inch, 0.070 inch, 0.073 inch, or 01180 inch. In many embodiments, the thickness 3160 of the inflection point 5186 is constant with the thickness 5156 of the rear wall 5123 and the thickness 5158 of the 'bottom incline 5125. In other embodiments, the thickness 5 160 of the inflection point 5186 can be less than the thickness 5156 of the rear wall 5123 and the thickness 5158 of the bottom incline 5125. The thickness 5160 of the inflection point 51.86 being consistent with or less than the thickness 5156, 3158 of the rear wall 5123 and the bottom incline 3125 allows for more uniform energy transfer and bending 1002981 The:. body: /901 E)f the ge:ilFcluli head 4900 further comprises a minimum distance 3116, and a maximum distance 3118. The minimum distance 5116 of the body.1901 is measured as the perpendicular distance from the exterior surface 1903 of the strikeface 491 2 in the upper region 1911 to the exterior surface 4903 of the rear wall 5123. The minimum distance 5116 can range from 0.20 inch to 041 inch. In some embodiments, the minimum distance 3116 can range froni 0.20 inch ro 0.30 inch, or 0.30inch to 0.4z inch For exarriole, the Tuntmurn,tista.nce 5116 can be 0.2.0 inch, 0.22 inch, 0.2.4 inch 0.26 inch, 0.28 mch, 0.30 inch, 0.32 inch, 0.34 inch, 0.36 inch, 0.38 inch, 0.40 inch, 0.42 inch, or 0.44 inch. The maximum distance 5118 of the body 4901 is measured as the perpendicular distance from the exterior surface 4903 of the strikeface 4912 in the lower region 4913 to the exterior surface 4903 of the third reference point 5120. The maximum distance 5118 can range 1170111 0.60 inch to 1.0 inch. In some embodiments, the maximum distance 5118 can range from 0.60 inch to 0.80 inch, or 0.80 inch to 1.0 inch. [or example, the may.imum distance 5118 can be 0.60 inch, 0.64 inch, 0.68 inch, 0.7' inch, 0 76 inch. 0.80 inch, 0.84 inch, 0.88 inch, 0.90 inch, 0.92 inch, 0.94 inch, 0.96 inch, or [00299] '[lie body 4901 of the golf club head 4900 fUrther comprises an internal cavity distance 5114 as illustrated in FIG. 39. The internal cavity distance 5114 is measured a.s the perpendicular distance from the exterior surface 4903 of the strikeface 4912 in the lower region 4913 to the interior surfrice 3119 of the rear wall 3123. 'the internal cavity distance 3114 can range from 0.40 inch to 0.80 inch. In some embodiments, the internal cavity distance 5114 can range from 0.40 inch to 0.60 inch, or 0.60 inch to 0.80 inch. Icor example, the natt.Tnal cavity distance 5114 can be 0.40 inch, 0.44 inch, 0.48 inch, 0.52 inch, 0.56 inch, 0.60 inch, 0.64 inch, 0.68 inch, 0.72 inch, 0.76 inch, or 0.80 inch.

100300] As illustrated in F1G. 35-38, the golf club head 4900 can be a hollow, or at least parlially hollow body comprising an internal cavity 4916. Internal cavity 4916 of the body 4901 comprises a volume. The -volume of the internal cavity 4916 can range from 1.20 inch' (19.66 crn) to 2.0 inch3 7 (71113). En some embodiments, the internal cavity 4916 can range from 1.2.0 inch' (19.66 cm3) to 1.6 inch3 (26.22 cm), or 1.6 inch3 (26.22 cin3) to 2.0 inch3 (32.77 crn3). For example., the internal cavity 4916 can comprise a. volume of 1.20 inch3 (19,66 cm3), 1.30 inch?' (21.30 cm3), 1.40 inch3 (22.94 cm3), 1..50 inch' (24.58 cm), 1.60 inch' (26.22 cm), 1.70 inch3 (27.86 cm3), 1.80 ilICT.50 cm), 1.90 inch' (31.14 cm"), or 2.0 inch" (32.77 cm).

Sinallarly, the solid portion of the body 4900, void of the cavity 4916, further comprises a material vc)lutne The Fraterial volume of Hie body: can range From 3.0 inch3 (49.16 cm') to 4.0 inch' (65.55 (TnE) n some end oclimen4.-the material 'volume of Ole 1,-ivcan range fri m '3.0 inch3 (49.16 cm3) to 3.5 inch3 (57.35 cm3), or 3.5 inch3 (57.35 cm3) to 4.0 inch3 (65.55 cm3). For exatnple, the material volurtle of the body Can be 3.0 inch' (,40.97 cm3), 3.10 inch' (50.80 cm3), 3.70 inch3 (52.44 cm3) 3.30 inch' (54.08 cm3), 3.40 inch3 (55.72 3 1.50 inch' (57.35 cm3), 3.60 inch 3 (58.99 cm3), 3.71 inch3 (60.63 cite), 3.80 inch3 (62. 3.90 inch ( or 4.0 inch' (65.55 cm).

[003011 In Marty embodiments:, the internal cavity 4916 of the body 4900 can be void of any substance. In other embodiments, the internal cavity 4916 of the body 4900 can comprise a polymer (not pictured), wherein the poly tret can at least partially fill the internal cavity 4916. The polymer can be polyethylene toreiguthalute, high-density polyethylene, polyvinyl chloride, polvcarbonate, polypropylene, other thermoplastics, composites polymers or any combination thereof the polymer can fill 10% to 80%, 10% to 25%, 13% to 30%, 30% to 43%, 430 to 60%, 60% to 73%, 73% to 80%, 10% to 10%, 30% to 60%, or 40% to 80% of lile nternal cavity of the hoc.y For example, the polymer can 61110%, 13%, 20%, 23%, 30%, 33%, 40%, 50%, 55%, 607/, 65%, 70%, 75%, 80%, or 85% of the internal cavity of the body. In embodiments, the polymer fills 80% of the internal cavity 4916 of the body 4901.

[00302] The polymer to at least 'Dart:ally till the internal cavity 4916 of the body 4901 comprises specitte gravity ranging from 0.05 to 4. In some embodiments, the specific gravity ranges from 0.05 to 0.10, 0.10 to 0.50, 0.50 to 1.0, 1.0 to 2.0, or 2.0 to 4.0. FOr example, the specific gravity of the polymer can be 0.50, 1.0, 3.0, 3.5, or 4.0. In some embodiments, the specific gravity of the polymer is proportional to the mass of the polymer, wherein 1 specific gravity of the polymer is equal to i gram. Similarly, in those exemplary embodiments, the volume is proportional to the polymer specific gravity, wherein I specific t:myity of the polymer is equal to 1 cc. In other embc)diments, the volume is not proportional to the specific gravity of the polymer. For example, the ratio of the polymer specific gravity to the polymer volume can be 2:1 cc, 2:3 cc, 2:4 cc, 3:1 cc, 3:2 cc, 3:4 cc, 4:1 cc, 4:2 cc, or 4:3 cc.

[00303] In some embodiments, as illustrated in PIG. 40, the golf club head 4900 can flirther comprise a first aperture 5134 located on the toe region 4904 and a second aperture 51.36 located in a hosel of the golf club head 4900. The first aperture 5134 is configured to receive a roe weight (not pictured), wherein the toe weight can range from 2 grams to 7 grams. In some embodiments, the toe weight can range from 2: grams to 5 grams, or 5 grams to 7 grams. )r example, the toe weight can he 2 grams, 3 grams, 4 grams, 3 grams, 6 grams., or 7,grams. The second aperture 3136 is configured to receive a tip weight (Ng pictured), wherein the tip weight can range from 2 grams to 7 grains. In some embodiments, the tip weight cart range tram 2 grams to 3 WaTTH or 5 grams to 7 grains. For example, the op weight grams, 3 prams 1 grams. 5 grams, 6 prams, or 7 prams. In many embodiments, the first aperture. 5134 and the second aperture 5136 can further be configured to receive the polymer. The first aperture 5134 can receive I gram to 9 grants of polymer (e.g., I gram, 2 grams, 3 grains, 4 grams, 5 grams, 6 grams, 7 grams, 8 grains, or 9 grams). Similarly, the second aperture 5136 can receive 1 gram to 9 grams of polymer (e.g., 1 griun, 2 grams, 3 grams, 4 grams, 5 g,rams" 6 grams, 7 grains, 8 grains, or 9 ',.z,rams). 'Ile toe and tip weight, and the polymer housed within the first aperture 5134 and the second aperture 5136 can affect the swing weiL,;tat to optimize CC and MCI.

1003041 the internal cavity 4.916 of the body 4901 further comprises surface 5119. In some embodiments, the interior suthice 5119 of the rear 4910 is a planar and smooth surface. In other embodiments as illusizated in FIG. 38, the interior surface 3119 of the internal cavity 4916 of die rear 4910 comprises a plurality of ribs 4952. The plurality of ribs 4952 extend in a direction from top rail 4915 toward the sole 4906. The plurality of ribs 4952 can be located anywhere on interior surface 5119 of the rear 4910. ha some examples, the plurality of ribs 4952 can be positioned onto a portion of interior surface 3119 of the lower exterior wall 5127. In other examples, the plurality of ribs 4952 can be positioned on a portion of the interior surface 5119 of the rear wall 5123. In some embodiments, the plurality of ribs 4952 can be positioned on a portion of the interior surface 5119 of the rear 4910 and can extend into another portion of the rear 49.10. For example, the plurality of ribs 4952 are positioned on a portion of the interior surface 5119 Of the rear wall 5123 and can extend up to at least a portion of the bottom incline 5125, or at least a portion of the lower exterior wall 5127. The plurality of ribs 4952 can comprise between one to eight ribs. For example, the plurality of ribs 4952 can comprise one rib, two n hs, three ribs, flair ribs, five ribs, six ribs, seven ribs, or eight ribs. In embodiments having one or more plurality of ribs 4952, the plurality of ribs 4952 can be spaced equidistance front each other or more concentrated near the heel region 4902, toe region 4904, top rail 4915, or sole 4906. The plurality of ribs 4952 and the location of the plurality of ribs 4952 can help optimize the frequency and amplitude of sound response.

[00305] In some embodiinents, body 4901 ran comprise stainless steel, titanium, aluminum, a steel alloy (e.g. 453 steel, 475 steel, 431 steel, 17-4 stainless steel, maraging steel), a titanium alloy (e.g. Ti 1Ti 6-4, T-9S, SSX112041., Ti'tPt0" N103 Ti 1[5-3-3, Ti 3 8 6 4 4, Ti 10-2-3, 15-3-3-3, Ti-6-6-2, Ti-185, or any combination thereof), an aluminum alloy, or a composite material, ha other embodiments, body 4901 can comprise carpenter grade 455 steel, carpenter grade 175 steel, C300 steel, C350 steel, a Ni-Co-Cr steel alloy, a quench and tempered steel alloy-, or 565 steel, in lents, strilieface 4912 can comprise stainless steel, titanium, aluminum, a steelsteel, 475 a tee], 431 steel, 17-4 stainless niiaraitting, steel) a titanium alloy (e.g. 7-4, Ti 6-4 '1 -93, Ti SSAT2041, 3P700, 15-- 0-3, Ti 'ti 3 8 6 4 4, Ti 10 -2 3, 15 3 -3 3, i 6 6 2, 14-185, or any combination thereof), an aluminum alloy, or a composite material. in other einbuditnents, strike Face. 4912 can comprise carpenter grade 455 steel, carpenter grade 475 steel, C300 steel, C350 steel, al3:1-Co-Cr steel alloy, a quench and tempered steel alloy, or 363 steel. In some embodiments, the body 4901 can comprise the same material as the strikelace 4912. In some embodiments, the body 4901 can comprise a different material than the it trikeface 4912.

00306] F1G. 42 illustrates a back perspective view of an embodiment of golf club head 3600 and FIG. 43 illustrates a back heel-side perspective vie\ of golf club head 5600 according to the embodiment of FIG, 42. In some embodiments, golf club head 5600 can be similar to golf club head 1000 (FIG. 1), golf club head 2200 (FIG. 8), golf club head 2700 (FIG. 13), golf club head 3200 dIG. 18), golf club head 3700 (111.C. 23), and/or golf club head.4400 (J.1G. 30). Golf club head 5600 can be an iron-type golf club head.

100307.1 Golf club head 5600 comprises a body 5601. In some embodiments, body 5601 can be similar to body 1001 (11C. 1), body 2201 (14G. 8), body 270 (1.1G. 13), body 3201(11G. 18), body 3701 (FIG. 23), and/or body 4401 (li1G. 30). The body 5601 comprises an exterior surface 3603, a strik-eface 3612, a heel region 5602, a toe region 560-4 opposite the heel region 5602, a sole 5606, a top rail 5613 and a rear 3610. The strike:lace 5612, sole 5606, top rail 5613, and rear 5610 of the body 3601 togetner form an internal cavity 5616. Furthermore, the golf c, club head 5600 can be divided into upper regIon 5611 and a. lower region 5613 (sec FIG, 44).

[00 The rear 5610 of the golf club head 5600 can comprise an tndention 5630 that alters the deflection and/or weighting of the club head. The rear 5610 of the golf club head can fiirther comprise a ledge 5825 or step wall below the indention 5630. The rear 5610 further comprises an upper perimeter portion 5609, which extends along the top rail 5615 and wraps down. the sides of-the toe region 3604 and heel region 5602. A toe sli r 3666 And a, heel slit 5662 are. each positioned. between a part of the upper perinaeter portion 3609 and a lower exterior wail 3727 of a lower region 5613 of the club head 5600, allowing structural bending between upper and lower halves of the club head 3600. This bending allowed by the toe slit 5666 and heel slit 5662 results in greater deflection Of the stir:Iced:ace 3612 oyer a club head without these slits. The club head 5600 can hardier comprise: a vibration damping layer 5878 on an interior surface $819 of the strike:ace 5612. in some embodiments, the internal cavity 3616 can be filled or partially filLd with a polymer material.

100309_1 Body 5601 of FIGS. 42-48 comprises a blade length. 'the blade length for body 5601 can be measured similar to blade length 3725 as shown and described in FIG. 29 0.e., a rneasurernent parallel to the flat surface of the s trikeface 3712, from a toe edge 3726 of die strikeface 3712, to strikeface end 3727 before the strikeface 3712 integrally curves into the hoseb. The blade length, oldie body 5601 can range from 2.50 inches (6.35 cm) to 2.90 inches (7.37 cm). For example, in some embodiments, the body 3701 can comprise a blade length of 2.30 inch (6.33 cm), 2.34 inch (6.45 cin), 2,58 inch (6.55 cm), 2.62 inch (6.63 cm), 2.66 inch (6.76 cm), 2.70 inch (6.86 coi), 2.74 inch (6.96 cm), 2. 78 inch (7.06 erM, 2..82 inch (7.16 cm), 2.86 Inch (7.264 cm), or 2.90 inch (7.37 cm).

[00310] The sole can comprise a cascadinfcr sole portion of the sole, as described in p-reciaor detail below. As shown in FIG. 46, a. deflection feature of the golf club head 5600 can be a uniform thinned region 6060, located at the sole 5606 and stretching between the rear 5610 of the body 5601 and the strilaeface 5012, toward the cascading sole portion of the sole. In the illustrated embodiment, the unifpfart thinned region otibt; comprises a sole thickness measured perpendicular from the ex-terior surface.5603 to an interior surface 5819 at the uniforrn thinned region 6060, which can remain constant from the bottom of the strikelace 5612 to adjacent the cascading sole portion of the sole. in some embodiments, the sole thickness of the uniform thinned region 6060 can be thinner dun a coaftenrional sole. For example, in some embodiments, the sole thickness of the uniform thinned region 6060 may range from approximately 0.040 ',rich to 0.080 inch. In other embodiments, the sole thickness of the uniform thinned region 6060 may be within Inc range of 0.040 inch to 0.050 inch, 0.050 inch to 0.060 inch, 0.060 inch to 0.070 inch, 0.070 inch to 0.080 inch, 0.040 inch to 0.055 inch, 0.045 inch to 0.060 inch, 0.050 inch to 0.065 inch, 0.055 inch to 0.070 inch, 0.060 inch to 0.075 inch, or 0.065 inch to 0.080 inch. For example., the sole thickness of the uniformed thinned. region 4860 can he 0.040 inch, 0.045 inch, 0.050 inch, 04060 inch, 04165 inch, 0.070 inch, 0.073 inch, or 0.080 inch.

1003111 FIG. 44 illustrates a cross-section cargo:Iclub head 5600 along the cross-sectional line INTIf-I.Vati in FIG. 42 accordirp-no one embodiment. As seen in FIG. 44, stribeface 5612 comprises a high region 3876, a middle region 5874, and a low region 5872. ca.

1003121 The strikeface 612 of the body 5601 further comprises a thick s measured poTendicularly to the strikeface 5612 from the exterior surface 5603 to an interior surface 5819.111e thickness 5854 of the strikerace 5612 can range front 0.040 inch to 0.100 inch. For example, the thickness 5834 of the strikeface 4412 can be 0.040 inch, 0.043 inch, 0.050 inch, 0.055 inch, 0.060 inch, 0.065 inch, 0.070 inch, 0.075 inch., 0.080 inch, 0.085 inch, 0.090 inch, 0.095 inch, or 0.100 inch. In some embodiments, thickness 5854 of the strike.kice 5612 can vary from the heel region 5602 to kite toe region 5604, and/or front the top rail 5615 to the sole 5606. Icor example, the thickness 5854 o the strikeface 5612 can be greatest at the central portion near the middle region 5874 of the strikelace 3612, and taper along the periphery near the high region 5876 and the low region 5872 of strikeface 5612. In maim ernbodiments, the center of the strikeface 5612 can have a thickness 5854 of 0.090 inch and the periphery of the strikeface 5612 can have a thickness 5854 of 0.070 inch. In other examples, the thickness 5854 can increase, decrease, or any variation thereof starting at the central region near the middle region 58.74 of the strikeface 5612 and extending toward the periphery near the high region 5876 and the low region 5877.

100313I The tipper region 5611 of rear 5610 comprises the upper perimeter portion 5609, the indention 5630, and the ledge 3825.'1he upper perimeter portion comprises the top rail of the club head and wraps down around a length of the toe and heel regions of the club head. 'the upper perimeter portion 5609 extends along a top edge of the golf club head 5600 from the heel region 5602 to the toe region 3604. In the toe region 5604 the upper perimeter portion 5609 extends down along a perimeter of the roe region 5604. In some embodiments, the upper perimeter portion 5609 extends roughly halk,vay down along the perimeter of the toe region 5604. The upper perimeter portion abuts the indention. The upper perimeter portion 5609 of the rear 5610 can provide perimeter weighting for the club head 5600. In addition, the upper perimeter portion 5609 alkiws stresses in the top rail 5645 to be dissipated into the rear 5610 of the club head 5600.

1003141 The indention 5630 is located on the exterior surface 5603, below the upper perimeter portion i:ind above the lower region 3613 if the club head 5600. the indention 5630 of the rear 3610 CX1TelICIS inwards towards the strikeface of the golf club head 5600. The indention 5630 is located in the upper portion 5611 of the club head 5600. In some embodiments, the indention 5630 is located primarily in an upper half of the golf club head 5600. The indention 5630 is bounded on as top, toe, and heel sides lir-the upper perimeter f)Ortteli 56 09. The indention 5630 is bounded on its bottom side}iv the ledge 5825.

[00315I 'The ledge 5825 extends ill a direction generally from the heel region 5602 towards the toe region 5604. The ledge 5825 helps fbrm a lower boundary of the indention 5630. The ledge 5825 can be located at various heights above the ground plane 10 whey: the dub head 5600 is at address posirkTL The ledge 5825 can comprise multiple segments, wherein each segment is located at a different height above the ground plane 10, as shown in the rear view of 11G. 42. For example, the ledge 5823 can comprise a segment located b the toe region 5604 that is higher from the ground plane 10 than a segment located, at least partially-, in the heel region 5602.

[0(316] The ledge 5825 of e rear 5610 of the club head 5600 can be positioned in a plane forwli[v pc:Tend:anal-to the strikeface 5612 plane. The It dg 5825 runs t- it of the club head 5600 from the heel region 5602 to the toe region 5604. The ledge 5825 can also be thought of as a ledge or groove. At the heel end the ledge 5825 can blend into the heel slit 5662. At the toe end, the iedge 5825 can blend into the toe slit 5666.

[0031 'The ledge 5825 can be angled with respect to the ground plane 10 at a ledge angle (not illustrated). In some embodiments, the ledge angle, measured from the ledge 5825 to ground plane:0, can range from 13 degrees to 45 degrees. in sortie embodiments, the]edge angle can be 15 degrees, 16 degrees, 17 degrees, 18 degrees, 19 degrees, 20 degrees, 21 degrees, 22 degrees, 23 degrees, 24 degrees, 25 degrees, 26 degrees, 27 degrees, 28 degrees, 29 degrees, 30 degrees, 31 degrees, 32 degrees. 33 degrees, 34 degrees, 35 degrees, 36 degrees, 37 dewtes, 38 degrees, 39 degrees, 40 degrees, 41 degrees, 42 degrees, 43 degrees, 44 degrees, or 45 degrees.

[0(318] The toe and heel slits 5666, 5662 arc positioned on the rear 5610 of the club head 5600 roughly halfWay upward from the ground plane 10 towards the top rail 5615. The toe and heel slits 5666, 5662 span short lengths across the toe and heel regions 5604, 5604 of the club head 5600, respectively. The toe and. heel slits 5666, 5662 extend from either end of the ledge 5823. 'the toe slit 3666 is posi dotted in the toe region 560.4 between the upper perimeter portitm 3609 and the lower region 3613 of the dub head 5600. The heel slit 3662 is positioned in the heel region 5602 between the upper perimeter portion 5609 next to and 11117.eilL the hosed 1003191 The toe slit 5666 and the heel slit 5662 are oriented in a toe-to-heel direction The roe slit 3666 can be positioned between.approximately halfway and approximately 2/3 of the way upwards from the ground plane 10 towards the top rail 5615, nitasured parallel to the strikefrice 5612.1:he heel slit 5662 can also be positioned between approximately halfway up and approximately 2/3 of the way upwards from the::,,round plane 10 towards the top rail 3615. In sense embodiments, the heel slit 5662 is positioned lower with respect to the ground plane 10 than the toe slit 5666. In these embodiments, the upper perimeter portion 3609 extends lower in the heel region D60::. than in the toe region 5604.- 1003201 The toe slit 5666 has a depth 6267 such that a deepest surface if the slit 3666 blends into the indention 3630. The toe slit depth 6267 can he measured from the outer surface of the upper porn-not:sr portion a lowest point inside the toe slit. The toe slit depth 6267 can range Hem sy.r: 0.05 inch and 0.20 inch. For example, the toe slit depth 6267 can range between 0.05 inch and 0.15 inch, or 0.15 inch and 0.2.0 inch. A toe slit height 5668 can be measured hi a direction general ft orthogonal to the ground plane from the intersection of the upper perimeter portion 5609 and the toe slit 5666 to the intersection of the ledge 5825 and the toe slit 5666. The toe slit height 5668 can range between 0.10 inch and 0.30 inch. I:or example, the toe slit height 5668 can range between 0.15 inch and 0.17 inch, 0.10 inch. and 0.15 inch, 0.13 inch and 0.20 inch, or 0.20 inch and 0.30 inch.l.be toe slit 5666 can comprise a length. 3669 between the outer edge of the toe re2oms 5604 to the indention 3630 where the toe slit 5666 terminates, as shown in Fla 42. The toe slit length 5669 can range between 0.318 inch and 0.418 inch. For example, the toe slit length 5669 can be 0.318 inch, 0.320 inch, 0.330 inch, 0.340 inch, 0.350 Inch, 0.360 inch, 0.368 inch, 0.370 inch, 0.380 inch, 0.390 inch, 0.400 inch, .0410 inch, or 0.418 inch. The dimensions of the toe slit 5666 can affect the deflection of the strike:race 56:2, as described below.

1003211 The heel slit 5662 is similar in depth and orientation to the tee slit 5666. However, in some embodiments, the angular orientation of the heel slit 5662 with respect to the ground plane differs slightly from the angular omen ration ()T the toe slit 5666. In some embodiments, the heel slit 3662 does not extend to a heel-rn( st point of the club head 5600. A heel slit height 5664 can he. measured in a direction generally orthogonal to the ground plane from the intersection of the upper perimeter portion 5609 and the heel slit 5662 to the intersection of the ledge 5825 and the heel slit 5662. The heel slit height 5664 can range between 0.10 inch and 0.30 inch. For example, the heel slit height 3664 can range between 0.13 inch and 0.16 inch, 0.10 inch and 0.15 inch, 0.15 inch and 0.20 inch, or 0.20 inch and 0.30 inch. The heel slit can comprise a length 5665, measured from adjacent an edge of the perimeter portion towards the heel region, as shown in FIG. 42. The heel slit length 5665 can be longer than the toe slit length 5669. In other embodiments, the heel and toe slits are the Sall le. length. The heel slit length 5665 can range bet-,\Leen 0.325 inch and 0.425 inch. For exainple, the heel slit length 5665 can be 0.325 inch, 0.330 inch, 0.335 inch, 0.340 inch, 0.345 inch, 0.350 inch, 0.353 inch, 0.360 inch, 0.365 inch, 0.370 inch, 0.375 inch, 0.380 inch, 0.385 inch, 0.390 inch, 0.395 inch, 0.400 inch, 0.405 inch, 0.410 inch, 0.413 inch, 0.420 inch, or 0.423 inch. ilie dimensions of the heel slit 5662 can affect the deflection of the sttakeface 5612, as described below, 100322-1 In the lower region 5613 of the club head 5600, the body 5601 extends a greater perpendicular distance front the strikefa.ce 5612 than the upper perimeter portion 5609 or the indention 5630. The lowerregion 5613 compnscs, in par. s. solid region adjacent the sole 5606 and the rear 5610 of the club head 5600. The solid region provides perimeter weighting to the dub head 5600. The solid region is bounded by the sole 3606 and a lower exterior wall 5727. A front edge of the solid region defines a part of the internal wall of the internal cavity 5616.

[00323] [he cross-section of golf dub head 5600 in FIG. 44 further illustrates the rear 5610.

1 he rear 3610 can be divided and understood with respect to the -Lipper region 5611 and the lower region 5613 of the club head 5600. the upper region 6511 of the rear comprises the tapper perimeter portion 5609 and the indention 5630, including the ledge 5825. As illustrated in FIG. 1-4, the upper perimeter portion 5609 comprises the top rail 5615, a rear wall 5723, and a top wall 5719. The indention 5630 is formed by the top wall 5719 of the upper perimeter portion, an indention wail 5821, and a ledge 5825.

100324] As seen in FIG. 44, from a cross-sectional view, the upper region 5611 of rear 5610 comprises the top rail 5615, the rear wall 5723, the top wall 5719, the indention wall 5821, and the ledge 5825. 'the rear wall 5723 of rear 5610 is located below and adjacent to the top rail 5615. The top wall 5719 of rear 5610 is located below and adiacent to the rear -wall 5723. 'the indention wall 5821 is located below and Adjacent to the top wall 5719. The ledge 5825 is located below and adjacent to the indention wall 3821. In short, the, top wall 3719 and the ledge 3823 are angled towards the strikelace and connect to the indention wall 3821, to Form the indention 5630. The upper region 5611 Further comprises a first reference point 5722 located between top rail 5615 and rear wall 5723, a second reference point 5782 located between rear wall 5723 and top wall 5719, a first inflection point 5786 located between top wall 5 19 and the indenron wad 5821 a. second inflection point 5792 located between the indentton wall 5821 and the ledge 5825, and a third inflection point 5794 located between the ledge 5825 and the lower region 5613.

[00325_1 In some embodiments, top rail 5613 of the upper perimeter portion Ca n be a flatter and taller top rail or skirt than in irons known to one skilled in the art. 'the flatter and taller rail can compensate 17 a rnishits s trikefAce 5612 to increase playabiti ty off the tee. in some embodiments, the length of top rail 3615, measured from heel region 5602 to toe region 5604, can be 70% to 95% of the length of golf club head 5600. In many embodiments, indention 5630 comprises a top rail box sprng design. For some fair- ype golf club head embodiments indention 5630 can be a reverse scoop or indentation of rear 5610 with body 5601 comprising a greater thickness terward sole 5606. In many CInbodiments, the top rail of the upper perimeter portion and the indention 5630 provide an increase in the (rycrall bending of striketace 5612. ha some embodiments, the bendinp-of strikeface 5612 can allow rbr a 2% to 5% increase of energy. The indention 5630 allows for strikeface 5612 to be thinner and allow additional overall bend b"W.

1003261 The top rail 5.615 of the upper perimeter portion comprises a thickness 6052. 'file thickness 6032 of the top rail 3615 can range from 0.040 inch to 0.080 inch, hor example, the thickness 6052 of the top rail 5615 cart be 0.010 inch, 0.043 inch, 0.046 inch, 0.019 inch, 0.051 inch, 0.051 inch, 0.057 inch, 0.060 inch, 0.063 inch, 0.066 inch, 0.069 inch, 0.071 inch, 0.074 inch, 0.077 inch, or 0.080 inch. In many embodiments, the thickness 6052 of the top rail 5615 is constant throughout. in other embodiments, the thickness 6052 of the top rail 5615 can vary. [Ti the exemplary embodiment, the thickness 6052 of the top rail 5615 decreases from the strikeface 5612 toward the rear wall 5823. In many embodiments due to the thickness 6052 of the top rail, top rail 561 5 can provide an increase in the overall bending of strikefa.ce 5612.

10032-71 14R 45 illustrates a view of top rail 5615 and a portion of rear 5610 of the cross--section of golf club head 5600 of FIG. 42, along a cross-sectional line INIII-1_,V111. in FIG. 42 that is similar to the cross-section of FIG. 44. In many embodiments, golf club head 5600 comprises a rear angle 5940, a top rail angle 5945, and a strikeface angle 5950. Rear angle 5940 is measured from top wall 3819 to rear wall 5823 of upper region 5611. In many embodiments, rear angle 5940 can range from 70 degrees to 110 degrees. In some embodiments, rear angle 5940 can be 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, or 140 degrees. In some embodiments, the rear angle 5940 is anproximatelv 122 degrees.

[00 z. I '.['he strikeface 3612 further comprises a strikeface angle 3930. Strikeface angle 3950 is measured front the strikeface 5612 to the top rail 5613, wherein the strikeface;angle 3930 can range front 70 degrees to 160 degrees or 70 degrees to 110 degrees. In some embodiments, strikeface angle 5950 can he 70 degrees, 75 degrees, 80 degrees, 90 degrees, 95 degrees, 100 degrees, 103 degrees, 110 degrees, 115 degrees, 120 degrees, 12.5 degrees, 130 degrees, 135 degrees, 140 degrees, 143 degrees, 150 degrees, 135 degrees, or 160 degrees. In some embodiments, the strikeface angle 5950 is approximate4 90 degrees.

1003291 FIG. 45 further Illustrates the ton rail 5615 comprising a top rail angle 5945. The top rail angle 5945 is measured from rear wall 5823 to the top rail 56[5. In many embodiments, the top rail angie 5945 can range from 70 degrees to 160 degrees or 90 degrees to 110 degrees. In some embodiments., top rail angie 5945 can he 70 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees, 95 degrees, 100 degrees, 103 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, 140 degrees, 145 degrees, 150 degrees, 155 degrees, or 160 degrees. In some embodiments, the top rail angle 5945 is approximately 131 degrees.

[003301 The rear wall 3723 extends from the first reference point 5722 to the second reference point in an orientation roughly parallel to the suikelace. The rear wall 3723 connects the top rail and the top wall 5719. The rear wall 5823 of the upper region 5611 comprises a height 3880. 'The height 5880 of the rear wall 5823 is measured from the first reference point 5722 to the second reference point 5782. The height 5880 of the rear wall 5823 can range from 0.055 Inch to 0.060 inch, 0.060 inch to 0.070 inch, 0.070 inch to 0.080 inch, 0.080 in to 0.085 or 0.55 inch to 0.85 inch. For example, the height 4680 of the rear wall -1623 can be 0.55 inch, 0.58 inch, 0.61 inch, 0.64 inch, 0.67 inch, 0.70 inch, 0.73 inch, 0.76 inch, 0.79 inch, 0.82 inch, or 0.85 inch. In sortie embodiments, the height 5880 of the rear wall 4623 rang,e from 35% to 600,713, 35% to 45%, 43% to 63%, 40% to 35%, 30% to 40%, 35% to 45%, 40% to 30 180" 45% to 35%, or 30% to 60% of the total height of the g( 'If club head 11600. For example, the height 5880 of the rear wall 5823 can be 35%, 38%, 41 'lib, 44%, 47%, 30%, 53%, 56%, or 60% of the total height of the zolt i.71u1) head 5600.

[003311 The rear wall 5823 of the upper region 5611 can also comprise a height 5680A height 5680A is measured from the apex 5828 of the top rail 5613 to the second reference point 5782. The height 5880 A can range From 0.00 Inch to 1.0 inch. For example, thy height 5880A can he 0.60 inch, 0.61 inch, 0.64 inch, 11.67 inch, 0.70 inch, 0.73 inch, 0.76 Inch, 0.79 inch, 0.82 inch, 0.83 inch, 0.90 inch, 0.95 inch, or 1.0 inch. In some embodiments, the height 5880A can range from 40% to 75% of the total height of the golf club head 5600. For example, the height 5880A can be 40%, 44%, 47%, 30%, 53%, 36%, 60%, 65%, 70%, or 75% of the total height;-)t-the golf chi]) head 5600.

[003321 The rear wall 5823 of the upper region 5611 farther comprises a rear wall thickness 5856. the rear wa]l thickness 3836 is the perpendicular distance of the rear wall 3823 from the outer surface 3603 to the inner surface 5619 of the internal cavity 5630. The rear wall thickness 5856 can range from 0.040 inch to 0.080 inch. For example, the rear wall thickness 5856 can he 0.040 inch, 0.043 inch, 0.046 inch, 0.049 inch, 0.051 inch, 0.054 inch, 0.057 inch 0.060 inch, 0.063 inch, 0.066 inch, 0.069 inch, 0.071 inch, 0.074 inch, 0.1177 inch, or 0.080 inch. In many embodiments, the rear wall thickness 5856 Is constant throughout. hi other embodiments, the rear-wall thickness 5836 5823 can vary. In the exemplart, embodiment, the rear wall thickness 5856 is a constant 0.05 inch. The rear wall thickness 5856 allows energy From an impact to transfer to the inflection point 3886 to help induce a buckling effect.

100333] The top wall 5719 is angled toward the strikeface and away frorn the top rail 3615 in a direction toward the first inflection point 5786. 'The top wall 5719 extends front the second reference point 3782 to the first inflection point 5786. The described configaration of the rear wall 3723 and top wall 3719 allows increased bending of the top rail 3615 of the club head 5600 on impact with a golf bail, compared with a club head devoid of the described rear and top wall configuration. The top wall 5719 connects to the indention wall 5821 at the first inflection point 5786.

[00334] The indention 5630 is farmed by Li? wall 5719, the indention wall 5821, ann tne ledge 5825. In some embodiments, the indention wall 5821 can he roughly planar. In some embodiments, the indention wall 5821 can comprise an at least partially curved profile, when viewed from a cross -sectional view, as shown in FIG. 44, An indention wail thickness 3838 is measured perpendicularly fnna-i the exterior surface 3603 re the interior surface 3819 at a point along the inden n riwall 3821 between the first inflection point 5786 and the second inflection point 5792. The indention wail thickness 5858 can range from 0.040 Inch, to 0.080 Inch. For example, the indention wall thickness 5858 can be 0.040 inch, 0.045 inch, 0.030 inch, 0.055 inch, 0.060 inch, 0.65 inch, 0.063 inch, 0.070 inch, 0.075 inch, or 0.080 inch. In many embodiments, the indention wall thickness arhi8 i. constantwith the rear wall thickness 5856 and a ledge thickness 5860. In other ernhcdirnen ts, the indention wall thickness 5858 can be Tess than the rear wall thickness 5856 and the ledge thickness 5860. the indention wall thickness 5858 being consistent with or less than the thickness 5823, 5860 of the rear wall 5723 and the ledge 5825 allows for more uniform energy transfer and bending.

[00335] As best understood A an a rear view, such as 11(-:. 42, the indent's m wall 582.1 can cot era surface area between 10% and 40'70 of the surface area of the rear 5610. For eaample, the indention wall 5821 can cover a surface area between 10% and 20%, 20% and 30%, or 30% and 40% of the surface area of the rear 5610. In some embodiments, the indention wall 5821 can cover a surf'ace area approximately 29% of the surface area of the rear 5610.

[00336] A height 5888 of the indention 5630 is measured perpendicular to the ground plane.

from the second reference point 5782 to the third inflection point 5794. The height 5888 of the indention 5630 can range from 0.15 inch to 1.1 inch. For example, the height 5888 of the indention 5630 can range from 0.15 inch to 0.30 inch, 0.30 inch to 0.45 inch, 0.45 inch to 0.60 inch, 0.60 inch to 0.75 inch, 0.75 inch to 0.90 inch, or 0.90 inch to 1.0 inch. or example, the height 5888 of the indention 3630 can be approximately 0.21 inch in the heel region 5602, approximately 0.63 inch in a center_ of the club head between the heel region 5602 and the toe region 5604, and approximately 0.98 inch in the toe region 5604. In some embodiments, the maximum height 5888 of the indention is between 0.80 inch and 1.1 inch.

[003371 The second inflection point 5.792 comprises a second inflection angle measured from the indented wall 5721 to the ledge 3825. The second inflection angle of the second inflection point 5792 can range from at least 95 degrees to 150 degrees. In some embodiments, the second inflection angle 5796 can be at least 95 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, [30 degrees, 135 degrees, 140 degrees, 145 degrees, or 150 degrees. In some embodiments, the second inflection angle can he consistent from the heel region 5602 to the toe region 5604. In other embodiments, the second inflection angle 5796 can -vary from the heel region 5602 to the toe region 5604. In many embodiment, the second in Election angle 3796 allows for the second inflecti(a-t point 3686 to act as a buckling point or plastic hinge -upon the golf dui) head 3600 impacting the golf ball at strikeface ST12.

1003381 As illustrated in FIG. 41, in some embodiments, the ledge comprises a ledge width 5829, The ledge width 5829 is measured along the ledge 5825 from the second inflection p/sint 5792 to the third Inflection point 5794. The ledge width 5829 can range from 0.088 inch to 0.128 inch. For example, the ledge width 5829 can be 1.090, 0.094 inch,1.098 inch, 0.100 inch, 0.104 inch, 0.108 inch, 0.110 inch, 0.112 inch, 0.114 inch, 0.118 inch, 0.120 inch, 0.124 inch, or 0.128 inch. In some embodiments, the ledge width 5829 can remain cc:distant from the heel region 5602 to the toe region 3604. In other embodiments, the ledge width 5829 can vary from the heel region 5602 to the toe region 5604. For example, the ledge width 5829 Can increase frt lift the heel region 5602 to the toe region 3604. In other enabodirnents, the ledge width 3829 can decrease from the heel region 5602 to the toe region 5602.

1003391 The ledge 5825 comprises a ledge thickness measured perpendicularly from the exterior surface 3603 to the interior surface 5819 at a point along tile ledge 5823 between the second inflection point 5792 and the third inflection point 3794. The ledge thickness can be similar to the indented wall thickness.

[00340] The upper region 5611 and the hywcr ret:tri 5613 of the ear 5610 are separated by the third inflection point 5794. In mans embodiments, the third inflection point 5794 is positioned at least 40% down on the body 5601 below the apex 5828. [for example, the third inflection point 5694 can be positioned 40%, 42%, 44%, 467°, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, or 70% down on the body 5601 below the apex 3828. The low positioned third inflection point 5794 allows For more leverage on the upper region 5611 to experience increased bending during impact with a ball, compared to a similar golf club head having a higher inflection point position.

[003411 The lower region 5613 of the body 3601 begins at the third inflection point 5794 and comprises a lower exterior wall 5827. 'The lower exterior wall 582'7 extends from the first inflection point 5794 to the sole 5606. The lower exterior wall 5827 can be angled 'with respect to the strikefacc. The lower region 5613 comprises a. height measured from the ground plane 5703 to the third inflection point 5794 adjacent a lowest end of the ledge 5825. The lower region 5613 height can range between 0.40 inch and 1.20 inch. For example, the lower region 561 3 height can range between 0.40 inch and 0.70 inch, 0.60 inch and 0.80 inch, 0.70 inch and 0.90 inch, 0.80 inch and 1.00 inch, 0.90 inch and 1.10 inch, or 1.00 inch and 1.20 inch.

1003421 A third inflection angle 5851 is measured between the ledge 38.25 and the lower extent)r wall 5727, at the third inflection. point 3794. in some embodiments, the third inflection angle 5851 can be less than 160 degrees. In a number or embodiments, the third inflection angle 5851 can be 90 degrees to 175 degrees. For example, the third intlecnon angle 3851 can be 90 degrees, 93 degrees, 100 degrees, 105 degrees, 110 degrees, 115 degrees, 120 degrees, 125 degrees, 130 degrees, 135 degrees, 140 degrees, 145 degrees 150 degrees, 155 degrees, 160 degrees, 165 degrees, 170 degrees, or 175 degrees [003431 lower exierioi. wall 5727 is located in the lower region 5611 of the dub head 5600.

The lower exterior wall 3727 extends downward from the third inflection point 5794 at an edge of the ledge 3825 to the sole of the club head 5600. A section of the lower exterior wail 5727 fOrals an outer rear edge of the solid regi;113 of the lower region 5613. The lower exteri( wall 5727 hounds the rear of the club head 5600 below the ledge 5823.

[00344] FIG, 46 illustrates another cross -secth-inal view of the golf club head 5600, similar to the detailed cross-section of gull club head 5600 illustrated in FIG. 42. The internal cavity 5616 comprises a top cavity width 5993, a minimum cavity width (minimum gun) 5990, a ina.ximurn cavity width 6095, and a lower region cavity width 6097, all measured in a direction perpendicular from the strihcfacc 5612 from an interior SUTEICC 5819 of the strikeEtce 56[2 to a back edge of the internal cavitv 5616. The top cavity width 5993 is located above the minimum upper cavity width 5990. the region of the internal cavity 5616 having the greater top cavity width 5993 corresponds to the upper perimeter portion 5609. The portion of the internal cavity 5616 adjacent the minimum upper cavity width 5990 corresponds to the indention 5630. The top cavity width 5993 is above the niMitIlt11171 cavity width 5990, which is above the maximum cavity-width 6095, which is above the lower region cavity width 6097. In some embodiments, the maximum cavity width 5990 is located in the lower region 5613 of the club head 5600. In many embodiments, the lower region 5613 of the body 5601 comprises a solid region adjacent the rear 5610. The solid region provides weighting to the rear 5610 of the club head 5600. This solid region causes the lower region cavity width 6097 to be less than a width of the cavity adjacent and below the indention 5630. The minimum ca.vitv width 5990 can be between 20% and 55% of the lower region cavity width 6097 in a central portion of the club head 5600, such as is shown in the cross-secnon of FIG. 46. For example, the rainimum cavity width 5990 can be 20%, 25%, 30%, 35%, - .45%, or 50% of the lower region cavity width 6097.

1003451 The top cavity width 5993 IS measured between the rear wall 3723 and a hack surface of the strikelace 5612. In sonic embodiments, top cavity width 5993 can range from 0.079 inch (2 mm) to 0.24 inch (6 trim). For example, top cavity width can be 0,079 inch (2 mm), 0.118 inch (3 rntri), 0.16 inch (4 mm), 0.197 inch (5 mm) or 0.24 inch (6 mm). in other embodiments, top cavity wid ni can r 8 inch intn) to 0.16 inch 04 mnth Tn some embodiments, top cavity width can be 0.135:h (3.429 mm).

[003461 In sonic. embodiment, the thlininaurn cavity width 5990 is locate( between the first inflection point 5786 and the back surface of the strikelace 5612. In some embodiments, the minimum cavity width 5990 is located bc:bveert the indentioit wall 5821 and the back surface of the strikeface 5612. In some embodiments, minimum cavity width 3990 can range from 0.079 inch (2 min) tO 0.'lit c.h (6 11111-1). Fc,,t example, tninimu.m cavity width 5990 can be 0.079 inch (2 mm), 0.118 inch (3 min), 0.16 inch (4. mm). 0.197 inch (5 mm) or 0.24 inch (6 rarM. In other embodiments, minimum cavity width 3990 can range from 0.118 inch (3 rtir) to 0,16 inch (4 mm). In some embodiment's, minimum cavity width 5990 can lie 0.135 inch (3.429 torn).

[00] 'Ihe 1-MIK1111MT1 arc -1 6095 is located beneath the Indention 5630. In some embodiments, maximum cavity width 6095 can range from 0.40 inch to 0.70 inch. For example, the maximum cavity vvjth can be 0.4-0 inch, 0.45 inch, 0.50 inch, 0.55 inch, 0.60 inch, 0.65 inch, or 0.70 inch. In other embodiments, maximum cavity width 6095 can range From 0.55 inch to 0.60 inch. In some embodiments, maximum cavity width 6095 can be 0.59 inch, [00.3481 The lower region cavity width 60 s measured between the solid region and the interior surface 5819 of the strike:ace 5612. In some embodiments, lower region cavity width 6097 can range from 0.13 inch to 0.40 Inch. For example, the lower region cavity width 6097 can be 0.15 inch, 0.20 inch, 0,25 inch, 0.30 inch, 0.33 inch, or 0.10 inch. In other embodiment's, lower region cavity width 6097 can range from 0.27 inch to 0.31 inch. In some embodiments, top cavity,,:',/idth can be 0.29 inch.

[00319] Referring agam to FIG. 46, the body 3601 of golf club head 5600 tiirther comp in upper perimeter portion distance 6092, a minimum distance 6094, and a maximum distance 6096. The upper perimeter portion distance 6092 of the club head 5600 adjacent to the top rail 5613 is measured as the perpendicular distance from the exterior surface 3603 of the striketTac.e 5612 to the exterior surface 5603 ofthe rear wall 5623. 'Ile upper pedmeter portion distance 6092 of the club head is between 0.303 inch and 0.325 in In some embodiments, the upper perimeter portion distance 6092 oF the club head is between 0.303 inch and 0.310 inch, 0.310 inch and 0.315 inch, 0.315 inch and 0.320 Inch, or 0.320 Inch and 0.325. In some embodiinents, the upper perimeter portion distance 6092 of the dub head 56 Ut is rearer than the ledge width 5829.

[00350] minimum distance 6094 of the body 5601 is measured as the perpendicular stance from the exterior surface 5603 of the strikelace 3612 in the upper region 5611 to the exterior surface 5603 of the rear wall 5623. The minimum distance 6094 can range front 0.20 inch to 0.40 inch. For example, the mininaum distance 609-4 can 1-)e 0.20 inch, 0.22. inch, 0.24 inch, 0.26 inch, 0.28 inch, 0.30 inch, 0.32 inch, 0.34 inch, 0.36 inch, 0.038 inch, or 0.40 inch. In some embodiments, the minimum distance 6094 of the body 5601 can be greater than the ledge. width 5829. The maximum disFince 6096 of the body 5601 is measured as the perpendicular distance from the exterior surface 5603 of strikeface 5612 to the exterior surface 5603 of the rear 5610. The maximum distance 6096 can range from 0.611 inch to 0.90 inch. For example, the niaxlmnuln distance 6096 can be 0.60 inch, 0.64 inch, 0.68 inch, 0.72 inch, 0.76 inch, 0.80 Inch, 0.84 Inch, 0.88 inch, or 0.90 inch.

[00351] As illustrated in FIG. 44-48, the golf club head 5600 can be a hollow, or at least partially hollow body comprising an internal cavity 3616. Internal cavity 5616 of the body 5601 comprises a volume. the volume of the internal cavity 5616 can ra age from 0.65 inch? (10.63 crol) to 1.05 inch' (17.21 cm). In some embodiments, the internal cavity 3616 can comprise a volume of 0.65 inch' (10.65 cria), 0.70 inch' 01.47 cm), 0.73 inch' 11.29 eiTC'it, 0.80 inch' (13.11 crn'), 0.85 inch' (13.93 cm), 0.90 inch' (14.75 crn.3), 0.95 inch' (15.57 cm), 1.00 inch' (16.39 cm3), or 1.05 inch' (17.21 crn3)-. Similarly, matetial portion of the body 5601, void of the cavm7 5616, turd er comprises a. material -volume. The material volume of the bock-5601 can range from 2.50 inch (40.97 ern) to 3.50 inch' (57.35 cm3). For example, the material volume of the body 5601 can be 2.50 inch' (40.97 cm"), 2.60 inch' (42.61 cm3), 2.70 inch3 (44.25 cm), 2.80 inch' (45.88 crr('), 2.90 inch' (47.52 cm3), 3.00 inch' (49.16 cm), 3.10 inch' (50.80 Gin), 3.20 inch' (52.44 crd), 3.30 inch' (54.08 cm3), 3.40 inch' ;35.72 cm3), or 3.50 inch' (57.35 cm'.

I 003521 In many embodiments, the internal cavity 5616 of the body 3601 can be void of any substance. In other embodiments, the internal cavity 5616 of the body 5601 can comprise a polymer (not pia/wed), wherein the polymer can 1)e at least partially Filling the internal cavity 5616. the polymer can he polyethylene terephthalate, high-density polyethylene, polyvinyl chloride, polycarbonate, polypropylene, other thermoplastics, composites polymers or any combination thereol The polymer can fill 10% to SO% UM% to 25%, 15% to 10%, 30% to 45%, 45% to 60%, 60% to 75%, 75% to 811%, 10% to 4 /0 to 60%, or 40% LO 80% of the internal emity 5616 of the body 560.1. For example, the polymer can fill 100/U, 15%, 20%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 85% of the internal cavity 5616 of the body 5601. In some embodiments, the polymer fills 80% of the internal cavity 5616 of the body 5601.

[00353] llhe polymer at least partially filing, the internal cavity 5616 GI the body 5601 can comprise a specific gravity ranging From 0.05 to 4. For example, the specific gravity of the polymer can be 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, or 4. income embodiments, the specific gravity of the polymer is proportional to the mass of the polymer, wherein I specific gravity of die polymer is equal to l gram. Similarly, in those exemplary embodiments, the volume is proportional to the polymer specific gravity,wherein 1 specific gravity of he polymer is equal to 1 cc. in other embodiments, the volume is not proportional to the specific gravity of the polymer. For example, the ratio of the -poi v mut specific gravity to the polymer \folume can be 2:1 cc, cc, 3:2 cc, 3:4 cc, 4:1 cc, 4:2 cc, or 4:3 cc.

[00354] The mass of the polymer allows for the swing; weight of the golf dub head. 4400 to be.

customizable for each player. Increasing the volume of the polymer, and thus the mass, increases the swing weight. decreasing the volume of the polymer decreases the swing.weight. Having the appropriate swing weight for each individual player improves feel -ring a swing and can improve performance such as swing speed, swing path, ball speed, and ball trajectory. The polymer can Mrther increase the overall mass of the golf club head 5600 more toward the sole 5606. Increasing the mass more toward the sole shills the CG-low and back, thereby improves the moment of inertia.

[00355] The strikefacc 5612 can be coated with a durable finish. For example, the stnkcface 5612 can be coated with I.Eydropearl 2.0 chronic plate finish or 2. high polished chrome. In some embodiments, the sftikefacc 5612 is ffirther finished with brushing or blasting. The golf club head 5600 can fiirther comprise a vthration damping layer 5878 on the interior surface 5819 of the strikeface 5612. The vibration damping layer 5878 can be fbrmed from an elas rOMCS material or any other suitable material. For example, the vibration damping layer 5878 can be formed frona a Jr-ethane and oranhene CC9÷Lt10-a urethrae (-1)9÷:110-or a cilice me gel. The V 1111.(1011 clamping lay et 5878 can have a,yeight of 1-7 grams. For exatrtp1e, the ibration damping material can have a weight of 1 gram, 3 grains, 5 grams, or 7 grams. The.vibranon damping layer 5878 can fill between 10%-30% of the -volume of the internal cavity of the club head 5600. The vibration damping laver 5878 can partially or fully cover the interior surface 5819 of the sir:kr:Flee 3612. The thickness of the vibration danipnc Liver 5878, measured perpendicular to the s e 5612, can either vary or be uniform across the interior surface 5819 of the strikeface 5612.

[00356] In some embodinients, the golf club head 5600 can further comprise an aperture 5634 located on the toe region 5604. The aperture 5634 comprises internal threads and is configured to receive a threaded screw weight 5637, as seen in FIG. 42. FIG. 42 illustrates the threaded screw weight 5637 removed from the aperture 5634 but positioned for insertion into the aperture 5634. The threaded screw weight 3637 coltirrises a mass, ,..vherein the mass of the threaded screw weight 5637 can range from z grams to 12 grams, In other embodiments, the mass of the threaded screw weight 5637 can range from 4 grains to 10 grams. in some embodiment the screw weight 5637 can weight 2 gams, 3 grams, 4 grants, 5 gams, 6 grams, 7 grams, 8 grams, 9 grams, 10 grams, ii grams, 12 gams, 13 grams, or 14 grams. The mass of the screw weight 5637 correlates with the length of the screw weight 5637, wherein a longer threaded screw weight 5637 equates to a greater mass. The threaded screw -weight 5637 further affects the mass and overall swing weight of the golf club head 5600. The.Tefore, the threaded screw weight 5637 can improve the feel of the golf club head 5600, as well as performance characteristics c'e.g., swing speed, ball speed, and ball flight).

100357.1 'the hose: of the club head 5600 can house a tip weight 5638. le1G. 42 depicts the tip weigFit363b removed from the hose], but in pos1ion for insertion into the hose:. The tip weight 5638 can have a weight that ranges between 0.1 and 10 grams. For example, the tip weight 5638 can have a weight of 0.2, 0.4, 0.6, 0.8, 1, 2., 3, 4, 5, 6,7. 8, 9, or 10 grams.

[00338] Although both -the toe slit 5666 and heel slit 5662 affect the deflection of the club head 5600, the toe slit 5666 has a. greater effect on the deflection. The slits 5666, 5662 reduce concentrated StItssCS at toe and heel junctions between the lower region 5613 and the upper perimeter portion 5609 and spread impact stresses across a greater volume of the club body 5601. 't he toe and heel slits 5666, .5662 allow structural bending between the upper region 5611 and the lower region 5613 of the club head 3600, which results in greater deflection of the strikeEtce 3612 than would be present in a sinailar golf club head lacking toe and/or heel slits. The slits 5666, 5662 can increase the bending between. the lower region 561 3 and the upper region 5611 around the second inflection point 5792. The greater deflection of the s ttheface 5612 provides a higher dynamic loft angle to the golf club 5600. The loft angle is an acute angle measured from the strikelace 3612 to aground reference plane 10. dy dynamically increasuic tlte deflection of the club head 5600, the conventional lo ft angle can be lowered without sacrificing trajectory. FOC example, a first club head with a lort angle lower than a second club head can have a trajectory equal to the trajectory or the second club head if the first club head comprises slits that increase the deflection of the club head. hi some embodiments, the conventional loft angle can be reduced by up to 0.6 degrees, up to 0.5 degrees, or up to 0,1 degrees. The lower loft or the first club head can result in a higher lxiii speed for a golf ball impacted by the club head due to the lower loft angle of the first club. 1 he gapping between clubs in a set can be more uniform in a club head set that comprises the slits disclosed herein.

1003591 Furthermore, in niany embodiments. indentic.'n 3630 can provide an increase in golf ball speed over ball speeds of standard golf club heads and can increase the launch angle over both the standard hybrid aicl tron club beads. A golf club head lacking the indention 5630 cannot buckle in a controlled manner during impact or spring back like a drum after impact as well as the club head 5600. The first, second, and third inflection points 5786, 5792, and 5794 allow the body 5601 to bend backwards when a!golf ball impacts the strikelace in a manner not possible for a golf club head lacking these inflection points.

[00360] The upper perimeter portion can provide spring to the back end of the club and exhibit low peak stress concentrations. The interaction of the strikelace 3612, the top rail 5615, the rear wall 5723, and the top wall 5719 is affected by the strikelace angle 5950, the top rail angle 5915, and the rear angle 5910. The strikeface 5612, the top rail 5613, the rear wall 5723, and the top wall 3719 interact and benefit the hinging of the club head in a manner similar to the respective components of golf club head 3700 described above.

[00361] The unitbnyi thinned region 6060 on the sole 5606, described above, can provide multiple benefits, similar to those described above far the uniform thinned regions of golf club heads 2200, 2700, 3200, 3700, 4.400, and 1900.

[00362] in some embodiments, body-5601 can comprise stainless steel, , titanium, aluminum, steel lloy (e.g. 455 steel, 475 steel, 431 sieel, 174 stainless steel, maraginp steel), a titanium alloy (e.g. Ti 7-4, 6-1,119S, Ti SSA1'2041, Ti 5P700, Ti Ti 15-3-3, Ti Ti 1S 3 3 3, Ti-6-6-2, Ti-183, or any combination thereof), an aluminum alloy, or a composite material. In other embodiments, body 3601 can comprise carpenter grade 455 steel, carpenter grade 475 steel, C300 steel, (.1350 steel, a Ni-taa-Cr steel alloy, a auerich and tempered steel alloy, or 365 steel. In some embodiments, strikelace 4412 can comprise tainless steel hi um, alumn urn, a steel 5 steel, 475 steel, 431 steel, 17--4 stainless steel, maragin2; steel), titanium alloy (e.g. T. -4, Ti 6-4, T-98, Ti 88AT2041, Ti 8P700, Ti 15- 0-3. Ti 15-5-3, 6-4-4, ii 10-2-3, Ti 15-3-3-3, Ti-6-6-2, Ti-183, or any combination thereof), an aluminu in alloy, or a composite material. in other embodiments, strikeface 4412 can comprise carpenter grade 455 steel, carpenter grade 475 steel, C300 steel, C350 steel, a Nis Cr steel alloy, a quench and tempered steel alloy, or 565 steel. i 1. some embodiments, body 5601 can comprise the same material as strikeface 5612. In some embodiments, body 5601 can comprise a different material than strike:ace 5612.

fi?:ad.1+; a.PkirtiaUf3ack Cavity [00363] FIGS. 49-601) illustrate a golf club head 7100 that includes a partial back cavity 7102 and a ear opening 7104 according to enboditnents of the present invention. In the illustrated embodiment, the club head 7100 is an iron-type club head 7100. 'the club head 7100 includes a body 7106, a faceplate 7108 coupled to the body 7106 at a front end 7110 and defining a striking surface or strikeface 7112, and a cover or badge 7114 coupled to the body 7106 at a back end 7116 opposite the front end 7110. In some embodiments, body 7106 can be similar Co body 1001 (FIG. 1), body 2201 (11G. 8), body 2701 (11G. 13), body 3201 (1:16. 18), body 3701 (FIG. 23), and/or body 4401 (FIG 30). In some embodiments as will be described below, the badge 7111 may be a partial badge 7111 (FIGS. 59A-59C), or the badge 7114 may be omitted entirely from the club head 7100 (FIG. 59D). In addition to the from end 7110 and the back end 7116, the body 7106 includes a heel reciti 7: 8, a toe region 7120 opposite the heel region 7:18, a sole 7122, and a to rail 7124 opposite the sole 7122. The body 7106 also includes a hosel 77126 proximate the heel region 7118 for coupling the golf club head 7100 to a shaft (not shown) to form a golf club.

1003 41 With reference to 1.k1C. 52, the rear opening 7104 is defined by the body 7106 and is Formed in the back end 7116. The body 7106 further defines a front opening 7128 formed in the front end 7110 and located opposite the rear opening 7104. I& faceplate 7108 covers and closes the Front orieninit 7128. In some embodiments as will be described below. the badge 7114 partially or fully covers and closes the rear opening 7101. The faceplate 7108 and the body 7106 together define the partial bark cavity 7102.. The partial back cavity 7102 is also described as a partially closed internal space forrned within die body 7106 and partially bounded by the faceplate 7108. The partial back cavity 7102 is referred co herein as 'partial' in the sense that it remains partially open to the exterior of the club head 7100 due to the existence of the rear opening 7104, which comnikElicates the partial back cavity 7102 with the exterior of the club head 7100. In othCC embodimefits (not shown), the body 7106 can be formed integrally with a faceplate such that the body alone defines the partial back cavity 7102.

1003651 With reference to FIGS. 54 and 55, the body 7106 also defines an open external cavity 7130, hereafter referred to as an indention 7130, extending inward from the back end 116 toward the front end 7110 and toward the strikefac.e 7112. The rear opening 7.104 is formed within the indention 7130. The indention 7130 alters the deflection and/or WC At of the club head 7100. Specifically, the indention 7130 allows the club head 7100 to buckle in a controlled manner during impact with a golf ball, or spring back like a. drum after impact Thus, the indention 7130 can provide a relative increase in golf bolt speed and in launch angle as Tared to known prior art iron-type golf club heads.

100366.1 With reference to FIGS. 55 and 58, the body 7106 includes a back wall 7132 formed at e hack end 7116. '[he back wall 7132 surrounds and. defines the indention 7130 and generally extends between the top rail 7124 and the sole 7122, and between the heel region 7118 and the toe region 7120. The back. wall 7132 is further divided into an upper back wall 7134 farmed adjacent the top rail 7124, and a lower back wall 7136 formed adjacent the sole 7122. 'The upper back wall 7134 extends downward from the top rail 712,4 to a top ledge or to cavity wall 7138. In the illustrated embodiment, the upper back wall 7134 is generally parallel to the strikeface 7112. in other embodiments, the upper back wall 7134 can generally slope toward or away from the strikefacc 7112 as the upper back wall 7134 extends from the top rail 7124 to the top cavity wall 7138. The lower back wall 7136 extends upward from the sole 7122 to a bonTom lalge or bottotn cavity wall 7140. In the illustrated embodiment, the Town: back wall 7136 generally slopes away from5 the strikeface 7112 as the lower hack wall 7136 extends from the sole 7122 toward the bottom cavity wall '7140. In other embodiments, the tower back wail 7136 can. he generally parallel to the strikeface 711.2 or the lower back wall 7136 can slope toward the a trikefice 7112.

[003671 With continued reference to 1.1G. 58, the top cavity wall 7138 extends from the upper back wail 7134 to an upper indention wall 7142 in a direction generally-toward tile ark:Let-ace 7112. 'The top cavity wail 7138 generally follows the contour of the top rail 7124 as the top cavity wall 138 extends between the heel region 7118 and tile toe region 7120. The bottom cavity wall 7140 extends from the lower back wall 7136 to a lower indention wall 7144 in a direction generally toward the sinkcEice 7112. The bottom cavity wall 7140 generally follows the contour of the sole 71 22 as the bottom cavity wall 7140 extends between the heel region 7118 and the toe region 7120, c..scept, that the bottom cavity wall 7140 includes a stepped portion 146 54) located toward the toe region 7120 that steps upward toward the top tad 124.

100.3681 A rear opening rim 7148 (FIG. 34) further defines and circumscribes the rear opening 04 -ear opening rim 7148 is divided into an upper rim 7130 located closer to the top rail 7124, and a lower rim 7152 located closer to the sole 7122 (FIGS. 57, 58), The upper rim 7150 generally follows the contour of the top rail 7124 Isid of the top cavity wall 7138. The lower rim 7152 generally follows the contour of the bottom cavity wall 7140, and can include generally linear, arcuate, or segmented extent (e.g., a step-wise extent) as the lower rim 7152 extends between the heel region 7118 and the toe region 71211. The upper indention wall 71.42 extends from the top cavity wall 7138 to the upper rim 7130 of the rear opening 7104, in a x:tion generally toward the sole 7122. The upper indention wall 71-42 is generally parallel to the upper back wall 71 34. The upper indention wall 7142 is also generally parallel to the strikeface 7112. In other embodiments, the upper indention wall 7142 call slope generally away From the striker:ace 7112 as the upper indention wail 7142 extends from the to cavity wall 7138 to the upper rim 7150. The lower indention wall 71-44 extends from the bottom cavity wall 7110 to the lower rim 7152 of the rear opening 7104, in a direction generally toward the top rail 7124. The lower indention wall 7144 generally slopes toward the strikeface 7112 as the lower indention wall 7144 extends from the bottom cavity wall 7140 to the lower rim 7152, Tog-ether, the top and bottom cavity walls 7138, 7140 and the upper and lower indention walls 7142, 7144 cooperate to define the indention 7130. In embodiments that include the badge 7114, the badge 7114 further defines the indention 7130, and closes off the indention 7130 from the partial back cavity 7102. Furthermore, in some embodiments that include the badge 7114, the badge 7114 further defines the indention 7130 and closes off the indention 7130 from Has partial back cavity 7102, by being positioned within the, rear opening rim 7148, In SE)111e embodtalents, the hail, 1 can be adhered to the upper rim 71 50 and the lower rim 7152.

[003691 With continued reference to FIG. 58, the body 7106 Further includes a front wall 7154 Formed at the Front end 7110. The Front wall 7154 surrounds the front opening 7128 and genera J.-tenos by.men the top rail 7124 and the sole 7122., and between the heel ref 7118 and tne toe region 7120. The front wall 7154 is further divided into an upper front wall 7156 formed adjacent the top rail 7124, and a lower frot it wall 7158 6-frilled adjacent the sole 7122. A front opening rim 7160 defines and circumscribes the front opening7 128. The upper front will 7156 extends downward from the top rail 71 24 to the front opening rim 7160. In the illustrated embodiment, the upper front wall 7156 is slenerally parallel to the striketlice 7112. The lower front wall 7158 extends upward from the sole 7122 to the front opening rim 7160. In the illustrated embodiment, the lower front wall 7158 is also generally parallel to the sink-et-ace 7112.

10037111 The body 7106 also includes a top rail wall 7162 that extends across the top rail 7124 between the upper front wall 71 56 and the upper back wall 713-4. The top rail wall 71.62 includes a smoothly curved contour as the top rail waIl 7162 extends between the upper front wall 7156 and the upper back wall 7134. The body 7106 further includes a bottom wall 7164 that extends across the sole 71 22 between the lower front wall 7158 and the lower back wall 7136. The bottom wan 7164 includes a smoothly curved contour as the bottom wall 7164 extends between the lower front wall 7158 and the lower back wall 71:36.

1003711 A portion o the bottom wail 7164 adjacent the lower front wall 7 158 defines a uniform thinned region 7:66. The uniform thinned region 7166 has a sole thickness 7168, measured perpendicular to an exterior surface of the bottom wall 7164 and between the exterior surface and an interior surface thereof. The sole thickness 7168 is relatively thinner as compared to the thicknesses of the remaining portions of the bottorn wail 7164. The sole thickness 7168 is also relatively thinner a.s compared to that of known prior art iron-type clubs. In some embodiments, the sole thickness may range from appnoxirnately 0.040 inch to 0.080 inch. In other embodiments, the sole thickness 7168 may be within the range of 0.040 inch to 0.050 inch, 0.050 inch to 0.060 inch, 0.060 inch to 0.070 inch, 0.070 inch to 0.080 inch, 0.040 inch to 0.055 inch, 0.0-45 inch to 0.060 inch, 0.050 inch to 0.065 inch, 0.055 inch to 0.070 inch, 0.060 inch to 0.075 inch, or 0.065 inch to 0.080 inch. For example, the sole thickness 716$ can. be 0.040 inch, 0.045 inch, 0.050 inch, 0.060 inch 0.065 inch 0.070 inch, 0.075 inch, or 0.080 inch.

1003721 With reference to FIGS. 57 and 58, the partial back cavity 7102 nclucies an upper channel 7170 defined within die top rail 7124 of the body 7106 and generally extending lengthwise across the club head 7100 between the heel region 7118 and the toe region 7120.

The upper channel 7170 is bounded between the top eavit wafl 7138 and the top rail wall 7162, and between the faceplate 7108 and the upper back wall 7134. Due in part to the upper channel 7170, the top rail wall 7162 and the upper back wall 7134 cooperate to define a first buckling or first hinge region 7172 of the body 7106. 'the first hinge region 7172 experiences increased bending as compared to other regions of the body 7106 when the strikeflace 7112 impacts a golf ball. The first hinge region 7172 allows the -Nip rail 7121-to dynamically deflect to a greater extent as compared to known prior art iron--type club heads and enables the top rail 7124 to react to the impact force over a wider \, oh:metric area of the body 7106. in turn, the to rail 7121-acts as a springboard by-returning more recoiled force back to the faceplate 7108 as the top rail 7124 returns to its original orientation, thereby imparting more energy into the golf ball [00373] The deflection of the to rail 7124 also causes the faceplate 7108 to deflect to a greater extent during impact with the golf ball, leading to less spin, a higher loft angle, and greater ball speed for a given club speed as compared to standard iron-type golf club heads. As the first hinge region 71'72 bends during impact, the faceplate 7108 deflects, causing a loft angle (defined between the strikeface '7112 and a ground plane with the golf club head 7100 at an address position) to increase relative to that of the club head 7100 at rest. The resting, state loft angle of the club head 7100 (prior to impact with the golf ball) is reduced relative to that of typical 1-inor-art iron-type club heads. 'This reduction of the resting state loft angle accounts for the deflection of the top rail 7124 at the hinge region 7172, and the resultant, dynamically-creased loft angle experienced while striking a golf ball. Jr some embodiments, the resting state loft angle can be reduced by up to 0.6 degrees a.s compared to known prior art iron-type club heads and still achieve a comparable launch angle of the golf ball during impact. Moreover, the club head 7100 including the relatively reduced loft angle can achieve a. relatively higher ball speed due to the reduced loft angle.

I00374] With continued reference to [Kis,. 57:gild 58, the partial back cavity 7102 also includes a lower channel 7174 defined within the sole 7122 of the body 7106 and;generally extending lengthwise across the club head 7100 between the heel region 711 8 and the toe region 7120. The lower channel 717,4 is bounded between the bottom cavity wall 7140 and the bottom. wall 7164, and between the faceplate 71 08 and the lower back wall 7136. One in part to the lower channel 7174, uniform thinned region 7166 defines a second buckling or hinge region 7176 of the body 7106. Much like the first hinge region 7172, the second hinge region 7176 experiences increased bending as compared to other regions of the body 7106 when the golf club head 7100 impacts a golf ball. The second hinge region 7176 dynamically deflects to a greater extent as compared to kJ-town prior art iron-type club heads and enables the sole 7122 to react to the Impact force over a wider volumetric area of the body 7106. In turn, the sole 7122 acts as a springboard by returning more recoiled force back to the flAceplate 7108 as the sole 7122 returns to its original men ration. thereby imparting more energy into the golf lab 100373] With reference to PIG, 33, the body 7106 also includes a solid region 7178 located toward the toe region 7120, the sole 7122, and the back end 7116 of the body 7106. The solid region 7178 includes a reladvely greater volume of the material forming the body 7106 as compared to other regions of the body 7106. Thus, the solid region 7178 has a relatively greater Mass as compared to other regions of the body 7106 and provides perimeter weighting to the club head 7100.

[00376] With reference to FIGS. 52 and 53, an external toe cavity 7180 is fanned within the body 7106. '1 he toe cavity 7]80 is located. generalfr within the solid region 7178, toward the toe region 7120 and the sole 7122. Abe toe cavity 7180 is cylindrical in shape for receiving a cylindrical toe weight 7182. In some embodiments, the toe cavity 7180 is threaded For receiving a threaded toe weight 718.2. In other embodiments, the toe weight 7182 is swedged into the toe cavity 7180. In other embodiments, the toe cavity 7180 can be trapezoidal in shape for receiving a non-cylindrical toe weight 7182. The body' 7106 can include multiple toe cavities for receiving multiple weights. le to, cavity 7180 0 eAteuu:. through the solid region 7178 to connect with the partial back cavity 7102. In other embodiments, the toe cavity 7180 extends partially into the solid region 7178 but does riot extend to the partial back cavity 7102, in some embodiments, the toe weight 7182 can have a mass between 2 and 14 grains. The toe weight 7182 improves the swing weight and overall feel of the golf club head 7100, as well as other performance characteristics (e.g., swing speed, ball speed, and ball flight).

I 003771 With reference to NG. 55, the strikeface '7112 is generally flat and has a centerpoint 7184 located at A geometric center of the strikeface 7112. A rnidplane 7188 coincident with the center:point 7184 extends perpendicular to the striketTice 7112 to generally divide the club head 7100 into an -upper region and a lower region, The rear opening 7104 is located al aye the midplane 7188, so that the rear opening 7104 is located between the inicIplane 7188 and the top rail 7124. In other embodiments, at least 50iTo of the area or the rear opening 7104 IS located between the rnidplane 7188 and the top rail 7124. In further embodiments, 50'31-600,l), 60%-70%, 709/1-80%, 80%-90%, or 90%-100(Iiii of the area of the rear opening 7104 can be positioned between the midpIane 7188 and the top rail 7124.

[00378] With reference to FIG. 58, an area of the rear opening is circumscribed and defined by the rear opening rim 7148. A projected area 7189 of the rear opening 7104 is defined by projectilig the area of the rear opening 71 04 onto the strikeface 7112 along a direction parallel Ft the midplane 7181, as shown by the dashed lines in FIG 58. Inc midplane 7184 divides the strikefac.e 7112 into an upper region 7112A located above the midplane 7184 and closer to the top rail 7124, and a lower region 711213 located below the midplane 7184 and closer to the sole 7122. The projected area 7189 of the rear opening 7104 is located on the upper region 7112A. In other embodiments, at least: 501.I.0 of the projected area 7189 is located on the upper region 71127\. In fUrther embodiments, 50c,Xt-60%, 707h-80%, 80°,./i1-90%, or 90%- 100% of the area projected area 7189 can be located on the upper region 7112A.

[00379] The strikefiec 7112 is coated with a durable finish (e.g.,1Tydropearl 2.0 chrome plate Finish or a high polished chrome). In some embodiments, the strikeface 7112 is further finished with brushing or blasting. The golf club head 71 00 also includes a vibration damping layer 7190 applied to an interior surthce of thit. faceplate 7108. 'the vibration damping layer 7190 is Formed from an elastomer material (e.g., a urethane and graphene coating, a urethane coating, a silicon. gel, etc.). The vibration damping layer 7190 can alter and/or reduce the sound (e.g., "dank' or "pinging:" noises) generated as the strikeface 7112 impacts the golf ball. The vibration clamping layer 7190 can weigh between 1:7 grams and can fill between 109'o-30/0 of the volume of the partial back cavity-7102 of the club head 7100. The vibration clamping later 7190 can partially or fully cover the interior suriiiec of the faceplate 7108. The thickness of the vibration damping layer 7190, measured perpendicular to the faceplate 7108, can either vary or be uniform across the Interior surface of the faceplate 7108.

[003801 With reference to lilt ',S. 60A-601), the partial back cavity 7102 of the club head 7100 can be filled with a vibration damping filler material 7192. In some embodiments, the entire volume of the partial back. cavity-7102 is completely filled with the filler material 7192 (FIG. 602k). In other errdiodiments" most of the volume of the partial IJack cavity-7102 (FIG. 6013), or approximately one half of the volume (e.g., a lower half of the volume) (FIG. 60(T), or appniximately one quarter of tile volume (e.g., tlie lower one quarter of the Ha net(FIG. 601)) of the partial back cavity 7102 is tilled with the filler material 7192. In other embodiments, the filler material 71 92 can till 10% to 80%, 10% to 25%, 15% to 30%, 30rin to 45 to 60%, 60% to r' 75% to 80° 0% to z, 609, or 01, to 8094 of the partial back cavity 7102. For example, the Ciller material 7192 can fill 10%, 15%, 2094, 25%, 30%, 359./c), 409-1, 45%, 5091, 5594, 6094C, 659/i., 7091, 75%, 8091, or 85% of the partial back cavity 7102. i fl some embodiments, the filler material 7192 fills 80% of the partial back cavity 7102. In vet other en tbodiinc.iits, the partial back cavity 7102 does tlot contain the filler material.

1003811 The filler material 7192 can be a synthetic polymer elas tomer (e.g., polyethylene terephthalate, high-density polyethylene, polyvinyl chloride, polvcarbonate, polypropylene, hot melt., other thertnonlastics, composites, polymers or any combination thereof). In other embodiments, the filler material 7192 can be a natural polymer (e.g., rubbers, natural polymers derived from feathers, etc.), or the filler material 7192 can be a non-polymer material (e.g., quartz or other minerals). The filler material 7192 can have a. specific gravity ranging from 0.05 to 4. For example, the specific avity of the filler material 7192 can he 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, or 4. In some embodiments, the specific gravity of the filler material 7192 is proportionally equal to the mass of the filler material 7192, where 1 specific gravity of the filler material 7192 is equal to 1 gram. Similarly, in those exemplary embodiments, the volume occupied by the filler material 192 is proportionally equal to the specific gravity of the filler material 7192, wherein i specific gravity of the tiller material 7192 is equal to 1 cc. In other embodiments, the volume proportionally greater or less than the specific gravity of the filler material 192. For example, the ratio of the specific gravity to the volume of the filler material 192 can be 2:1 cc, 2:3 cc, 2:1 cc, 3:1 cc, 3:2 cc, 3:1 cc, 4:1 cc, 4:2. cc, or 4:3 cc.

[00382] The mass of the filler material 7192 allows a. 3,,ving weight of the volf club head 7100 to be customizable for each player increasing the volume of the filler material 7192 that occupies the open back cavity 7102 increases the overall mass of the club head 7100, and thus increases the swing weight thereof Similarly, reducing the volume of the filler material 7192 that occupies the open hack cavity 7102 reduces the swing weight of e club head 7100. Achieving the appropriate swing weight of the club head 7100 for each individual player improves the feel of the golf club (hiring a swing and can improve performance by optimizing swing speed, swing path, ball speed, and ball trajectory. The tiller material 7192 can further concentrate the mass of the golf club head 7100 more toward die sole 7127 Concentrating the mass more toward the sole 7122 shifts a center ofgravity (CC) of the club head 100 toward the sole 7122 and toward the back end 7116, thereby improving a moment of inertia of the club head measured about an axis defined by the hose: 7126 of the club head 7100.

[003831 The rear opening 7104 provides access to the partial back cavity 7102 for applying the vibration damping layer 7190 to the back surface of the faceplate 7108. In those embodiments that include the filler material 7192, the rear opening 7104 also provides access to the partial F rack cavity 102 for depositing the tiller material '7192 into the partial back cavity 7102.

[003841 1 With reference to FIGS. 57 and 58, the badge 7114 covers the tear opening 7104.

During assembly of the golf club head 7100, the badge 7114 is coupled to the body 7106 after the vibration damping layer 7190 is applied to the faceplate 7108, and after the filler material 7192 is deposited witfljn the partial back cavity 7102. When the faceplate 7108 and ihe badge 7114 are both coupled to the body 7106, the partial back cavity 7102 becomes a fully enclosed internal volume within the golf club head 7100. The badge 7114 includes an extruded portion 7194 (FIG. that extends into the rear Opening 7104. The badge 7114 can be;greater in width than the upper and lower indention walls 7142, 7144, while the extruded portion 7194 can be equal in width to the upper and lower indention walls 7142, '7144.

[00385.1 In some embodiments, such as those illustrated in FIGS. 59A-59C, the badge 7114 is partial badge 7114 that only covers a portion of the rear opening 7104. l'or examp]e, the partial badge 7114 can cover an. upper portion of the rear opening 7104 adjacent the upper rim 7130 (FIG. 591s), leaving a lower portion of the rear opening 7104 uncovered. In other embodiments, the partial badge 7114 can cover a lower portion of the rear opening 7104 adjacent the lower rim 7152 (FIG. 391$), leaving an upper portion of the rear opening 7104 uncovered. In further embodiments, the partial badge 711.4 can include a. central aperture 7 [96 (FRI 59(11.) such that a. central re ion of the rear opening 7104 remains uncovered. Fri some embodiments, the badge 7114 is permanently affixed to body 7106, while in other embodiments the badge 7114 is selectively removable. limbodiments including the selectively removable 1)adg: pr(wirle a user more flexibility in customizing the type and volume of filler material 7192 deposited within the partial back cavity 7100' Other embodiments of the chili head 7100 do not include the badge (FIG. 591)), such that the rear opening 7104 remains unc( vered.

1003861 In some erribodiments,the body 7106 is formed from 17-4 stainless steel In other embodiments, the bod 7106 chi be formed frorn On mi ira lurrew um, another steel allov (e.g. 435 steel, 473 steel, 431 steel, maragillg steel), a lit nn alloy (e.g. Ti 7-4, Ii 6-4, 1-9S, SSAT2041, Ti SP700, Ti 13-0-3,43 15-5-3, Ti 3-8-6 4 4, Ti 10-2-3, Ti 15 3 3 -3, Ti-6-6-2, Ti--185, o en cv combination thereof), an aluminum alloy, or a composite. material. In other embodiments, the body 7106 can be formed from carpenter grade 455 steel, carpenter grade 475 steel, C300 steel, C350 steel, a. Ni-Co-Cr steel alloy, a quench and tempered steel alloy, or 565 steel.

[00387] The faceplate 7108 is formed from C300 steel. In other embodirrients, the faceplate 108 can be formed from stainless steel, titanium, aluminum, another steel alloy (e.g. 455 steel, 475 steel, 431 steel, 17-4 stainless steel, maraging steel), a titanium alloy (e.g. Ti 7-4, 'Ii 6 4, T 95, Ti 5S4T2041, Ti 51700, di Ti 15-5-3, Ti 3-8-6-44, fl 10-2-3, Ti 15-3-3-3, Ti-6-6- 2, 'Ti-185, (di any combination thereof), an aluminum alloy, or a composite material. In other embodiments, the fa.cenlate 108 can be farmed from carpenter grade 455 steel, carpenter grade 475 steel, C300 steel, C350 steel, a Nr-Co-Cr steel alloy, a quench and tempered steel alloy, or 565 steel. In the disclosed embodiment, the body 7106 is formed from a different material than the faceplate 7108. In other embodiments, the body 7106 can be formed from the SalTle material as the faceplate 7108.

100388] In some embodiments, the badge 7114 is formed from aluminum. In other embodiments, the badge 7114 can be formed from other metals (e.g., titanium metal alloys, etc.), or non-metals (e.g. polymers, elastomers, composites, wood, etc.). The material forming the badge 7111 has a lower density than that of the material forming the body 7106, resulting in relatively more perimeter weighting of the club head 7100 as compared to that of prior-art iron-type club heads. The material forming the badge 7114 cart have a specific gravity between approximately 0.1 and 8.0.

[00389] The body 7106 is formed by casting. The front and r openings 7128, 71.01 of the body 7106 simplify, the casting-process by reducing tight contours and eliminating, undercuts and similar geometries. dlie faceplate 7108 can be cast, stamped (punched), machined, or otherwise formed. The badge 7114 can be cast, molded., or stamped. During manufacturing of the club head 71.00, the faceplate 7108 is swedged or welded onto the body 7106. The damping layer -7190 and the filler material 7192 are inserted, injected, sprayed, or otherwise deposited into the partial at cavity-7102 via the rear opening 7101, and then the badge 7114 is subsequently-adhered, welded, snap-lit, or otherwise secured to the body 7106 to cover the rear opening 7104. Other stages, such as polishing or p of the roan Li I:actin-Inc, process. _ can also be perl.ormed as part Ill [00390] The po] I dUO heads vu Hi energy storage characteristics discussed herein mar he implemented in a.yariery Of embodiments, and theldregoing discussion of these embodiments does not necessarily represent a complete descriptiono/all possible embodiments. Rather, the del:J.11(.4d description of the drawings, and the drawings themselves, disclose at least one preferred embodiment of golf club heads with energy storage characteristics:, and may disclose alternative embodiments of gyitf club heads with tiered internal thin sections.

EXAMPLES

(Ex hi( 'ty Bale it. Rot/on' Body/J nilkdi on Point C O4Iyb [041391] Retbrrimtg to Table 1 below, the exemplary club head 3700 being a hollow bodied iron club head with an ittdectiori point 3986 was compared to two control club head (hereafter "Control 1" and 2'). Control 1 and Control 2 were cavity back iron club heads that were similar in size ann ott angle to exemplary club head 3700, but were devoid of an inflection point Control 2 has a more pronounced cavity and wider sole than Control 1. Ball speed (measured in mph), launch angle (measured in degrees), carry distance (measured in yards). and spin rate (measured in rpm) were measured between the exemplary club head 3700, Control and Control 2.

Table 1: erformanee of Club Head 3700 vs. Control (lob Heads 1 and 2 Avera4-4,Y. Bail:Average 1 Average Average Carry Distance Cyan Speed (mph) Launch Ange 40eprees) Spin Rare

I

I Crum) Club Head 3700 127.3 15.9 1 5931 193 Control 1 127.6... _ 15, 4 5972 190 Control 2 f 126.3 15.8 6551 185 [00392] As shown in 'fablk 1, the exemplary club head 3700 having a hollow body and inflect-kin on 3986 produced an avera eIi P peed of 127.3 mph; n averaw launch angle of 15.9 degrees, an average carry distance of 193 yards, and an aventge spin rate of 5931 rpm. Coniparatively, Control 1 produced an average ball speed of 127.6 mph, an average launch angle of 1.5.4 degrees, an average carry distance of 190 yards, and an average spin rate of 5972 rpm, and Control 2 produced an average ball speed of 126.3 mph, an average launch angle of 15.8 deg;rees, a Et net o, carry distance of 185 yards, .4r44.4 art ',iv-crag:: spin nUe of 6551 rpm, Al though the exemplary dub head 3700 experienced a decrease of about 0.29/h in average bail speed compared to Control 1 and an increase of about 0.8% to 1% in average ball speed compared to Control 2, the average launch angle and average spin rate increased the average carry distance farther due to the hollow body and inflection point 3986 of the exemplary club head 3700. The exemplary club head 3700 experienced a 3.25% increase in the average launch angle compared to Control 1, and a 0.6% to 19/h increase in the average launch angle compared to the Control 2 respectively. Further, the exemplary club head 3700 experienced around a 0.7% decrease mayerage spin rate compared to Control 1 and a 9.46% decrease in average spin rate compared to Control 2 respectively. The increased average launch angle and decreased average spin rate of die exemplary club head 3700 compared to the Control 1 and 2 inc., cas;v1 the carry distance of the ball during impact. More specifically, the exemplary club head 3700 experienced a 1.58()./b compared to Control 1 and 4.32(/ increase In average carry distance of the ball compared to Control 1 arid Control 2. Therefore, the hollow body and inflection point 3986 of the exemplary dub head 3700 increases the bending of the strikeface 3712 to produce optimal ball performance characteristic compared to similar sized club heads devoid of an inflection point.

12Atv; Cati(t) Back. mm. /follow Bady/LVIer:thill PaFit Got/ Reierrng to Table 2 below, the exemplary club head 4400 being a hollow bodied iron club head with an inflection point 4686 that is 557o from the top rail apex to the inflection point of the club head 4400 was compared to a control club head (hereafter "Control Club I lead'') . Control Club Itead was a cavity back Iron club head similar in siye and loft angle to exemplary club head 4400, but devoid of an inflection point and hollow body. Similar to Table 1 above, the parameters measured to compare the exemplary club head 4400 and the Control Club Head were as follows: ball speed (measured in mph), launch angle (measured in degrees), carry distance (measured in yards), and spin rate (measured in rpm).

Table 2: Performance tt OH; Head 44Q(vs Control Club Head II Average Ball Average Spi Average Speed (mph) Launch Rate) (rpni) (..arry Al Iglu Distance (degrees) (yards) Club Head 4400 I 123.8 16.8 6211 179.2 100394] As shown in 'fable 2, the exemplary club head 4400 having a hollow body and inflection point 4686 produced an average ball speed of 123.8 mph, an average aunch angle of 16.8 degrees, an average carry distance of 179.2 yards, and an average spin rate of 62:1 rpm, compared to the Control Club Head which produced an average ball speed of 123.3 mph, an average launch angle of 16.1 degrees, an average carry distance of 175.7 yards, and an average spin rate of 6716 rpm. The exemplary club head 4400 experienced a 0.5-1% increase in ball speed compared to the Control Club Head, but due to the hollow body and inflection point 4686 which increased the bending of the strikeface 1412, the exemplary club head 4100 experienced a 4.35% increase in the launch angle and a 7.93% decrease in the spin rate. Because of the 4.35°.-i increase in the launch angle and 7.93% decrease in spin rate, the exemplary club head 4400 experienced an increase of around 2% of the carry distance Farther than the Control Club Head. 'therefore, this increase in -bending of the strilieface 4412 due to the hollow body and inflection 4686 of the exemplary club head 4400 allov,Ts for farther carry distances of the compared to dub head similar in size, devoid of an inflectkm point.

9 Evmple Smailff - (me 1101192v B0(.6, Turns Ms. I /O&M!' ITSOily (mit:Ter Referring to Table belcy, the exemplary club head 3700, and exemplary club head - " 4100 were compared to exemplary club bead 2700. All three exemplary club heads 3700, 4400, and 2700 had similar loft angles and comprised a hollow body, and an inflection point. Exemplary club heads 3700 and 4400 arc both significantly smaller in si2e (volume ranging from 0.65 inch' to 1.70 inches') than the exemplary club head 2700 (volume around 1.75 inches'). Similar to Table 1 and Table 2 above, the parameters measured for the exemplary club heads 3700, 4400, and 2700 are ball speed (measured in mph), launch angle (measured in degrees), carry distance (measured in yards), and spin rate (measured in rpm).

Tabit Perti maneeof Club Head 3700 and Club Head 400 vs. Club Ffea.d 2700 (-.ontroi I ! AVera.!:-' Ball I Speed I 123.3 Atcera.,,w tau rich Angle Ave rigs Carry Distance Average Bait Speed (mph) nch Ayerape Spin Rate (rpm) _Average Carry Distance (yards) (degrees) Chits 1-lead 3700 138.8 2 4322 219 cad 4400 oh Head 2700 138.0 1 11.4 4133 216 21.7 1393 11.8 4312 [00396] As shown in Table 3, the exemplary: club head 3700 produced an average ball speed of 138.8 mpli, an average Launch angle of 122 degrees, an average spin rate of 4322 rpm, and an average carry distance of 219 vards; the exemplary club head 4400 produced an average ball speed of 13R.0 mph, an average launch angle of 11.4 degrees, an average spin rate of 4135 rpm. ',Ind an ewerage carry dist2ince at -216 -,tardst, and the exen-iplary club head 2700 proditced an average ball speed of 139.3 mph, an average launch angle of 11.8 degrees, an ay erage spin rate o[4312 rpm, and an average carry distance of 217 yards. 't he exemplary club head 3700 cs:perienced a 0.92% increase in carry distance over the e.ten-iplary club had 2700, while the exemplary club head 4400 experienced a 0.461!"0 decrease in carry distance compared to the exemplary club had 2700. The small percent difference of the carry distance of the ball between [Ile exemplary club heads 3700, 4400, and 2700, were indicative to the bending of the strikelace due to the hollow body and inflection poinN, regardless of the significantly smaller sizes of the exemplary club head 3700 and exemplary club head 4400. Because of the smaller size and lower inflection point, the exemplary club heads 3700 and 4400 allows a player the benefit of the look and feel of a smaller iron body club head, with the ball performance results g launch angle, carry distance) of a higher volume sized hollow body club head with a higher infection point exemplary club head 2300). [0039

Examide 4: C Referring to Table 4 L head with an inflection point 4900 was compared to a coil Head was a cavity back iron club Back, on. I lotion Bozb, / nilect?tht Point God Liu b the exemplary club head 4900 is a hollow bodied iron club 6 located roughly 522/0 below the top rail apex. The club head I club head (hereafter "(,:ontrol Club Head"). Control ub lead similar in size to exemplary club head 4900, hut devoid ortut inflection point and hollow body. The Control Club Head comprised a loft angle roughly lower than the exemplary club head 4900. Similar to Table I above, the parameters measured to compare the exemplary club head 4900 and the Control Club Head were as loll s: ball speed (measure; iii nmh), launch angle (measu degrees), carry distance (i neasured in yards), and spin rate (meyisured in rprri).

Table 4: Perfonnance of (Hub Head 4900 Control Club Head I Average Bali A veraide;-\verage Sly-in Rate (rpm) Average _ Speed (mph) 0 Larry Launch Angle (degrees) IDis lance (yards) Club Head 4900 143.1 lIT 3980 229 Control 1 1.46.1 11.1 4073 227 1003981 As shown in 'table 2, the exemplary club head 4900 having a hollow body and Ii flection point 5186 ply-id:Iced nax,reragfi ball speed of 145.1. mph; an average blunch angle (Di [1.6 degrees, II 1.-y-erage carry-distance of 229 yards, and an a\--erage spin rate of 3980 rpm, compared to the Control Club!lead which produced an ay erage ball speed of 146.1 mph, an average bunch angle of 11.1 degrees, an average carry distance of 227 yards, and an average spin rate of 4073 rpm.

100399_1 The higher launch angle of the club head 4900 results ft in its higherloft angle. Tim lower ball speed can also be expected due to the higher loft angle of the club head 4900. The unexpected result IS in the spin rate of the club head 4900 versus the spin rate of the Control Club Head. One of skill in the art would expect the spin rate of the higher-lofted club head (in this example the club head 4900) to be significantly (treater than the n rate of the lower-lotted club head (in this example the Control Club Head), However, the measured spin rates are close to each other, to the extent that in the measured data, the error bars of the spin rates ovedap. The spin rates of the club head 4900 and the Control Club Head are not significantly different. Thus, this test shows that the golf dub head 4900 exhibits lower spin rates than the Control Club I lead for a given loft angle. This lower spin rate reduces the ballooning of the golf bail during flight. Golf balls that are imparted a high spin rate upon impact tend to twist upwards, or balloon, during Bight. This dynamic increase in the flight trajectory height of the doff ball can adversely affect the carry distance and result in unpredictable shots. the average carry (ilSilifICt for the exemplary golf club 4900 is roughly the same as the average carry distance of the Control Club Head. The Me:et:don point 5186 of the exemplary club head -4900 along with -dm hollow body allow the faceplate 4912 to bend in a manner that reduces the spin imparted to the golf ball.

[0040(1] In addition to the data. in Table 4 above, the test revealed an averfigc statts neal plot area within which the test shots landed. The aVeraPt SLInStical plot area for the exemplary club head 4900 was 6.2% smaller than the average statistical plot area fbr the Control Club Head. 'this shows that the exemplary club head 4900 demonstrated higher precision than the Control Club Head. 'therefore, the hinging of the faceplate.4912 about the inflection point 51 86 does not adversely affect the golfer's ability to control their shots. Rather, the golfer's shot precision is increased.

[004011 Replacement of one or more claimed elements constitutes reconstruction and not repair., Additionally, benefits, other advantages, and solutions to problerns have been described with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element or elenlentS that may cause any benefit idvantage, or solution to occur or become more pronounced, however, are not to be construed as critical, required, or essential features or elements of any or all of the claims, unless such benefits, advantages, solutions, or elements are expressly stated in such claims.

[00.402] As the rules to golf may change from time to time, new regulations may Dc adopted or old rules may be eliminated or modified by golf standard organizations and/or irovernlng bodies such as the United States Golf Association (USGA), the Royal and Ancient Golf Club of St. Andrew's ER&A"), etc."), golf equipment related to the apparatus, methods, and articles of manufacture described herein may be conforming or non-conforming to the rules of golf at any particular time. Accordingly, golf equipment related to the apparatus, methods, and articles of manufacture described herein may be advertised, offered for sale, and/or sold as conforming or non-conforming golf equipment. The apparatus, methods, and articles of manufacture described herein are not lirnited in this regard.

[0(403] While the above examples may be described in connection with a drtvertvpe _golf club, the apparatus, methods, and Articles of manufacture described herein may he applicable to other types of golf club such as a fairway wood-type golf club, a hybrid-type golf club, an iron--type golf club, A wedge-type golfclub, or a putter-type golf club. Alternatively, the apparatus, methods, and articles of manufacture described herein may be applicable to other type of sports equipment such as a hockey stick, a tennis racket, a fishing pole, a ski pole, etc. [0) ] Moreover, embodiments and lirnitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiments and/or limitations: (1) are not expressIv clairned in the claims; and (2) are or are potentially equivalents of express elements and:imitations in the claims in Ider the doctrine °I:equivalents.

C LA USES

gol: club head comprising:: a body having a sole and a top rail opposite th faceplate defining a strikeface; a back wall opposite the strikeface; a Partial back cavity defined within the club head between the faceplate, the back wall, the sole, and the top rail; an indention formed in the back wall and extending toward the strikefac a rear opening defined within the indention, the rear opening coinmuncanc with the pa al hack cavity at or proximate the exterior of the golf club head; and wherein a midrilane extends through a geometric center of the stbikelace and perpendicular thereto between the top rail and the sole such that at lea.st half of the rear opening is located between the mid-plane and the top rail.

2 The go:f club head of clause 1, wherein the michalane divides the strikeface into an upper region and a lower region: and wherein a projected area of the rear opening is defined by proje af the rear opening onto the strikefilce along a. direction parallel to the midplane.

3. The g cad of clause 2, wherein at least 50% of the projected area is ircated on iN upper region, The golf club head of clause 1, wherein the back wall sum and defines the non, and the back w extends between the top rail and the sole, 5. The golf club head of clause 4, wherein the back wall is further divided into an upper back wall and a lower back wail; wherein the upper back wall is adjacent the [op rail and extends downward horn the top rail; and wherein the lower back wall is adjacent the sole and extends upward from the sole.

6. Thee grIt club bead (if clause t, wnet'ein a tear opening tint circumscribes the rear open 6; wherein opening rill; is divided into in upper rim and a lower ran; wherein upper rim is near the top rail and follows a contour of the upper back wall; and wherein the lower riin near the sole and follows a contour of idle lower hack wall from th Parial back cavity.

clause6, wherein a badge closes at least a portion of tie indention osi tioned within die rear opening tin:.

c golf ci ub head of clause 7, wherei., the badge is adhered to the upper rim and lot nrri.

9. lilt golf-club head of clause 8 the badge is made from any one or the following materials: aluminum, titanium, polymer, clastorner, or composite.

The ctolf club head or clause 1, wherein the faceplate. is made fri any one of tile toiiowtncr materials; C300 steel, 17-4 stainless steel, 453 steel, 475 steel, 431 steel, minagang steel, if:arm:an, composite, (1350 steel, a Ni--( r-(steel allot', a:fuer:eh and tempered steel alit y, or 565 steel.

The golf club head of clause 1, wherein the body is made from any one of the foliowirai materials: 17-4 stainless steel, 455 steel, 475 steel, 431 steel, managing steel, titanium, or composite.

The golf club head of clause 1, a: in the strikeface is coated * a durable finish; herein the durable finish can be a Hydropearl 10 chrome plate finish or a high polished chronic finisli.

13. The golf club head clause 7, herein the badge cove the enre rear opening. golf

14. The golt club head of clause - tin the badge covers an upper po on of th rear opening; wherein the upper portion of the rear opening adjacent the upper rim.

15. The golf club head of clause 7, wherein the badge cover,: a lower portion of the rear opening; wherein the lower portion of the rear opening is adjacent the lower rim.

16. The golf cluh head of clause 7, wherein the badge is selectively removable.

The golf club head of clause 7, wherein the partial back cavity of the club head can he tilled with a vibraiott dampinv, filter material.

18. The golf club head of clause 17" wherein the vibration damping filler material cart Hi 10% to 80% of a volume of the partial hack cavity.

19. The golf club head of clause 18, wherein the vibration damping filler material can be any one of the following materials: polyethylene terephthaiate, high-density polyethylene, polyvinyl chloride, polvcarbonite, polypropylene, hot melt, other thermoplastics, composites, or polymer.

20. The golf club head of clause 7, wherein the vibraion damping filler material can comprise a specific gravity ranging from 0.05 to 4.

Claims

MS1. A golf club head comprising: a body having toe region, a heel region, a sole, a al a iop rail opposite the sole; a faceplate defining a strikeface; a back s,val; opposite the strikethce the Hack wall is farther duided into an upper back wall generally parallel to the strikeface and a lower back wall; wherein the upper back wall extends downward from the top rail and the lower back wall extends upward from the sole; the back wail further comprising a top cavity wall and a bottom cavity walk wherein the upper back wall extends from the top rail to the top cavity wall and the lower back wall extends from the sole to the bottom CaVity wall; a partial hack cavity defined within the golf club head between the faceplate, the upper hack wall, the top cavity wall, the lower back wall, the bottom cavity wall, the sole; and the top rail; an indention formed in the back wall between the top cavity wail he bottom cavity wall, and extending toward the strikeface; wherein the top cavity wall follows a contour of the top rail as the top cavity wail extends between the heel region and the toe region; and wherein the top cavity wall extends from the upper back wall to an upper indention wail in a direction towards the strikeface and the bottom cavihtwall extends from the lower back wail to a ter indention wall in a direction toward the strikeface; a rear opening defined within the indention, and defined between the top cavity wail and the bottom cavity wall, the rear opening communicating with the partial back cavity with an exterior of therpif cluh head; wherein the partial back cavity remains open to the exterit)r of the golf club head; and wherein a rear opening rim further circumscribes the rear opening; wherein the rear opening rim is divided into an upper LEM and a lower and wherein the upper rim follows the contour of the top rail and the top cavity walk; wherein a midplane extends through a geometric center of the strikeface and perpendicular thereto between thc top rail and the sole such that the rear opening is located csKelusively between the midpiane and the top rail.
2. The golf club head of claim l, wherein the miciplane dhlicles the strikeface into an upper region al /OVe the al:tip:Jule and a lower region below the miciplanc; and wherein a projected area of the rear opening is defined by projecting an area of the rear opening onto the strikeface along a direction parallel to the midplane.
3. Inc go1f club I lead of claii pfyjerted ascii ot tire rear open ii L, rs located' * r the upper region.
4. The golf club head of claim 1, wherein a badge covers the rear cdpenin. lose off the partial back cavity-from the exterior of the golf club head.b head of chain herein the badge is located eN Chi SiVilt midplane and the top raft 6. jt'lle golf cii bead olclaim 5 wherein the badge is adhered Co the rear opening rim 7. The golf club head or claim 6, wherein the badge s permanently affixed to the rear opening rim.club head of claim 5; wherein the badge is made from any one of the foliowin materials: alumini nil, titanium, polymer, elasromer or composite.9. The golf club head of claim 1, wherein the partial back cavilt ic g.lfclub head can be filled with a vibration damping tiler material.10. The p' )]1: chili head of claim wherein tlx L darni %I tri Fill 10° 0 to 80?/e of a volume of the partial back cavity, club head comprising: aving toe region, a heel re Eceplate defining a strikeface; sole, and a top rail opposite the sole; a hack wall opposite the strikeface; the hack wall is further divided into an upper hack wall generally parallel to the striketace and a lower back wall; wherein the upper back wall extends downward from the top rail and the tower back wall extends upward horn the sole; the back wail thither comprising; a top cavity wall and a bottom cavity wall; wrierein ti upper back wall extends from the top rail to the top cavity wall and the lower back wail extends from the sole to iii a: bottorii cavity wall; a partial back cavity defined within the goll club head between the faceplate, the upper back wall, the top cavity wall, the lower back wall, the bottom cavity wail, the sole, and the top rail; an indention formed in the back wall between the top cavity wall and the bottom cavity wall, and extending toward the strikeface; wherein the top cavity wall follows a contour of the top raal as the top cavity wall extends between the heel region and the toe region; and wherein the top cavity wall extends from the upper hack wall to an upper indention wall in a direction towards the strikeface and the bottom cavity wall extends from the lower back wall to a lower indention wall in a direction toward the stribeface; a rear opening defined within the indention., and defined between the top cavity wail and the bottom cavity wall, the rear opening communicating \nth the partial back cavity with an exterior of the golf club head, wlicrcin the partial back cavity remains open to the exterior of the golf club head; wherein a rear opening rim Further circumscribes the rear opening; wherein the rear opening rim is divided into an upper rim and a lower rim; a.ttd wherein the upper rim Irdlows the contour of the top cad and the top cavity wall; wherein a midplane extends through a geometric center of the snit:el:ace and perpendicular thereto between the top rail and the sole such that the rear opening is located between the midplane and the top wherein a badge covers the rear opening to dose off the partial Hex_ cavity from enor of the club head.; and wherein the badge is located exclusively between the midplang and the top rail.1 2. The golf cluh head of claim ii, wherein the midpiane divides the strikef an upper refyon above the midplane and a lower region below the midplane; and wherein a projected area of the rear opening is defined by projecting an area of the rear opening onto the strikeface along a direction parallel to the miciplane, 13. The golf club head of claim 12, wherein the projected area of the rear opening is located on the upper region.14. The golf club head of clairn 11, wherein the rear opening is located exclusively between the midpiane and the top rail.13. The golf club head of claim 11, wherein the badge is adhered to the rear opening rim.16. The golf club head of claim 15, wherein rim badge is permanently affixed to the rear opening rim.17. The golf club head of claim 11, wherein rite badge covers the entire rear opening.18. The golf club head of claim 11, wherein the badge is made from any one of the following materials: akin:it-11mA, titanium, polymer, elastorner,, or composite.19. l'he golf club head of claim 11, wherein the partial hack cavity of ot the golf club head can be filled with A vibration damping filler material.20. The golf club head of claim 19, wherein the vibration damping filler material can fill 10''./0 to 80% of:1 volume of the partial back. cavity.