GB2417909A

GB2417909A - Golf club head with a metal/organic composite rear body

Info

Publication number: GB2417909A
Application number: GB0518130A
Authority: GB
Inventors: Anthony D Serano; John C Bliss; Dale F Obeshaw
Original assignee: Karsten Manufacturing Corp
Current assignee: Karsten Manufacturing Corp
Priority date: 2004-09-08
Filing date: 2005-09-06
Publication date: 2006-03-15
Anticipated expiration: 2025-09-06
Also published as: US20070032313A1; US20060052181A1; US20070032312A1; CA2518641A1; GB2417909B; GB0518130D0; US20070155533A1

Abstract

A golf club head is formed of a hollow body, the rear body portion of which includes a metallic stringer 38 that extends along the crown-skirt interface and a plurality of ribs 40 intersecting the metallic stringer to form a lattice frame, the openings 34 of which are filled with an organic composite material such as graphite epoxy. An additional aperture 36 formed in the skirt may also be filled with the same graphite epoxy material. Because the graphite epoxy is lighter than the surrounding metal frame, the rear body portion of the golf club head is lighter than a comparable all metal club head. Yet, the presence of the metallic stringer and frame renders the metal-organic composite rear body portion substantially stiffer than a comparable all-composite rear body portion.

Description

GOLF CLUB HEAD

This invention relates generally to golf clubs and, in particular though not exclusively, to so-called metal wood drivers.

Recent developments in golf club design have included improvements in drivers, which are clubs used primarily to strike a golf ball resting on a golf tee. These improvements have resulted in drivers with club heads consisting of a hollow shell usually made of metal, SUC}I as steel, aluminum, or titanium. One example of a golf club head consisting of a hollow metal shell is disclosed in II.S. Patent No. 5,851,160 to Rugge, et al. In an effort to obtain better and better perfonnance from these hollow medal wood drivers, however, golf club manufactures have increased the head volume from a moderate volume of 250 cubic centimeters as disclosed in Rugge, et al. to over 400 cubic centimeters in recent years. The striking face of a medal wood driver must be of a certain minimal thickness in order to withstand the impact forces generated upon impact with a golf ball. Accordingly, as head size increases, less and less material is available for fabricating the crown, sole and skirt of the club head while mainkaining tle club head of these super-oversized drivers within acceptable weight limitations (i.e., around 200 grams mass) .

More recently, in U.S. Patent No. 6,471,604, one golf club manufacturer has suggested a clul? head having a metallic face bonded to an an body composed of a non-mekal material such as a composite or thermoplastic material. The lightweight plastic rear body enables more metal to be dedicated to the striking face, however, many golfers dislike the impact sound produced by a club head having a low resonance highly damped nonmetallic rear body. Moreover, because of the discontinuity between the all-composite or thermoplastic rear body and the striking face, the striking face is not significantly supported by the rear body. Consequently, more material must be dedicated to striking face itself, thereby canceling out much of the weight savings attributable to the nonmetallc rear body.

Accordingly, the invention may provide a club head having a metal-organc composite rear body, which is Integral to the striking face and therefore maintains some of the stiffness (and frequency) of a fully-metallic rear body, while still providing a lightweight rear body structure.

The present Invention preferably comprises a golf club head formed of a hollow body having a metallic face and a rear body portion forming a shell at least a portion of which is made of a metal-organic composite material. According to a preferred embodiment, the rear body portion of the club head includes a metallic stringer that extends along a crown- skirt interface and a plurality of ribs intersecting the metallic stringer to form a lattice frame, the openings of which are filled with an organic composite material such as graphite epoxy. In the preferred embodiment, the lattice frame may form at least a portion of the crown of the rear body portion. An additional aperture formed in the skirt preferably is also filled with the same graphite epoxy material. Because the graphite epoxy is lighter than the surrounding metal lattice frame, the rear body portion of the golf club head is lighter than a comparable all metal club head. Yet, the presence of the metallic stringer and lattice frame renders the metal-organic composite rear body portion substantially stiffer than a comparable all-composite rear body portion.

The present invention will be hefter understood from a reading of the following detailed description, taken in conjunction with the accompanying drawings figures in viich lily references designate lil<e elements and, in shicin 1 I('i. I is a front view ova poll' club head incorporating features of an embodiment of the present invention, I;l(i. 2 is a rear perspective view of to golf club head of 1 IG. 1, I I(i. 3 is a top view of the goll'clul. head of' 1 T(i. 1; }'I(i. 4 is a toe-end side view oi'tle gclf'club head of 1-'I(i. I, T; l('i. 5 is a heel-end side view ot'the goli'clb head ol'T;l('i. 1; };IG. 6 is a bottom view of'the golf club head of i'l(J. 1; TRIG 7 is a cross-sectional view of the golf club head of T IG. 6 taken along line 7- 7; TO IG. is a top view of an alternative embodiment ova golf club head incorporating features of an embodiment of the present invention; and Thai. 9 is a rear perspective view of' another alternative embodiment of a golf club head incorporating i'caturcs of Ian embodiment of the present invention.

I'he drawing figures are intended to illustrate the general manner of' construction and are not necessarily to scale. In the detailed description and in tle drawing figures, specific illustrative examples are shoNvn and herein described in detail. It should be understood, however, that the drawing figures and the detailed description are not intended to limit the invention to the particular form disclosed but are merely illustrative and intended to teach one of ordinary skill how to make and/or use the invention claimed herein and for setting forth the best mode for carrying out the invention. - 3

With reference to Figs. 1-7, and in particular Figs. I and 2, golf club head 10 comprises a hOIIONV body 12 longed ol'a metal material having a front wall including a face 14 tor inpactng a golf' ball, and a hosel 16 adapteci to receive a goli'clh siraf't (not sio\vn). I iollo\v body 12 f'urtler conpriscs a rear body portion I X, wlicl is made up of'a cro\vn 2(), a sole 22 anti a skirt 24 Blat fore, a shell. Crown 2() and skirt 24 meet at apex 26 \vhicl conpriscs an area havhg a small cross sectional radius oi'curvature 27 (1 ig. 7) and which extends in an arcuate path (as vic\ved In 1'g 3) Irons a position proxual the heel end 2X of'hollcw body 12 to a position proximal the toe end 30 olhollow body 12.

The region surrounding apex 26 fonns an arcuate perineter region 32 that smoothly blends the high crown curve of apex 26 into the low crown curve of crown 20 and skirt 24. Arcuate perimeter region 32 preferably extends 0.700 inches above and 0.700 inches below the peak of apex 26, preferably 0.350 inches above and 0.350 inches below to peak of apex 26 and most preferably about 0.250 inches above anti ().250 inches below the peak of apex 26. Arcuate perimeter region 32 is unsupported above and below by any of the metal forming hollow body 12 for at least a portion of its span.

llollow body 12 may be assembled from a series of forged metal pieces that are welded or brazed together, but in the illustrative embodiment <of Figs. 1-7, comprises a titanium investment casting. Crown 20 is formed with a solid return portion 33 that extends rearward *tom Lace 14 and a series of apertures 34 proxhnal the rear end of hollow body 12. Skirt 24 is formed with solid return portions 35 and 37 that extend rearward from face 14 and an aperture 36 proximal the rear end of hollow body]2. Apertures 34 and 36 cooperate to form a metallic stringer 38 that extends along a portion of the arcuate perimeter region 32 as well as a plurality of ribs 4() that support stringer 38 along a portion of its span. In the illustrative embodiment, a second stringer 42 disposed radially upward from stringer 3X is tied to ribs 40 to fore, an open lattice frame.

Apertures 34 and 3G are filled with a material that is of lower density than the relatively denser metallic hollow body 12 'I'he material may be a hghtweight non-netallic material 44 such as thermoplastic, or thernoset plastic, or preferably a filer reinforced Organic resin such as fiberglass-epoxy, fiberglass-polyester, ccranic-liLer epoxy, aramicl 5epoxy or other- fiber-organic resin conpostes 1'rcierably, the nonnetallic material comlJrses graphite-epoxy, which is laid up on the interior surface 46 (}jig. 7) of' hollow body 12 extending across all ol'the stringers 3X, 42 and ribs 4() to Corns a part titanium part carbon graphite composite rear body portion I X. In the illustrative embodiment of Figs. 1-7, non-metallic material 44 comprises 10prepreg layers of' graphite epoxy which are laid up on the interior surface 46 of' hollow body 12 covering apertures 34, 3(j and an inflatable bladder (not shown) is then inserted into the cavity 4X of'hollo\v body 12 Trough one of the apertures 50 and 52 disposed in the bottom of' weighs pockets 54 and 5G. Ilollow body 12 is placed in a mold cavity (not shown) that conforms to the outer surl'acc of tlc hollow body 12. 'I'hc bladder is then I Sintlalcd and the mold heated to cure the prcprcg epoxy.

By eliminating rectal from portions of the crown 20 and the skirt 24, as represented by apertures 34 and 36, the illustrative embodiment of'Figs. 1-7 accomplishes a club head in excess oi'400 cubic centimeters in volume with the hollow bocly 12 weighing from to 170 grams and the composite i'illcr weighing from 10 to 40 grams. In doing so, the 20face 14 can be increased to at least 5.00 square inches (preferably approximately 5.30 square inches) with a maximum thickness of between 0. 110 and 0.160 inches proxhnal the geometric center 5X (I;ig 7) of the face 14 tapering downward to a lesser thickness ot' 0.070 to 0.090 inches towards the peruneter 60 of tire lace 14. 'Ibis Is accomplisled without sacrificing structural integrity and without cxcccding the desired total weight of 25about 200 grams mass. Morcovcr, the presence oi'thc metallic stringers 3X, 42 and ribs 4O, - 5 which are integrally attached to the face 14 (i.e. , formed as a single casting, welded or breed together as opposed to adhesively bonded or attached with fasteners) provide support tor the t'ace 14 not present in pure composite back body designs while also naintaining tle desirable dominant natural frequency oi'at least 3,500 hertz With reference to log. X, an alternative embodnent ol'a metalorganic composite golf' club heat us accordance with the present invention comprises a hollow body 62 having a crown 64. A series oJ'apertures 66 are t'ormetl ha crown 64 ha three rows, which form a plurality of' rites 68, an outer metallic stringer 7() as well as inner metallic stringers 72 and 74, each ot'the inner metallic stringers 72 and 74 being displaced radially inward front stringer 70. As with the emboduneut ot' figs. 1-7, apertures (j6 are tilled with a ligltweght non-metallic material, preferably a graphite epoxy to seal the interior cavity of hollow body 62 and to provide a smooth exterior surface.

With reference to Fig. 9, another alternative crnbodimcrt of a metalorganic composite golf' club head in accordance with the present invention comprises a hollow body 82 having a crown 84 and a skirt 86. As with the embodiment oi'Figs. 1-7, crown 84 and skirt 86 each have a metallic return portion 88 and 9(), rcspcctively, that extends rearward from the face of the club head. Single large apertures 92 and 94 arc formed in crown 84 and skirt 86 which results in a metallic stringer 96 that extends almost the full length of arcuate perimeter region 98 oi'hollow body 82. As with the embodiment oi'Figs.

1-7, apertures 92 and 94 are filled with a lightweight non-metallc material, preferably a graphite epoxy.

Although certain illustrative embodiments and methods have been disclosed herein, it will be apparent from the foregoing disclosure to those skilled in the art that variations and modifications of' such cmbodincnts and methods may be made without departhg from the spirit and scope of the invention. Accordingly, it is intended tIvat the invention should be limited only to extent required by the appended claims and the rules and principals of applicable law. - 7

Claims

CLAIMS: I. /\ golf club head comprising: a hollow body having a heel end,

a toe end, a front wall and a rear body portion; saici front \vall hclucling a metal face adapted for impacting a golf ball; and said rear body portion forming a Sheila at Ieast a portion of'xvhich is made from a metal/organic composite nraterial.

1 () 2. 'I'he goli'club head of clain, I, wherein: said rear body portion comprises a metal t'rame having a plurality of' apertures and at Ieast one layer oi'iiber reinforced organic resin extending across a portion oi'said natal frame cover-in" at least cane oi'said Rurality of'apertures 3. 'I'he golf'clh head of any preceding claim, wherein: said metal face and said metal trarme are formed of the same metallic material.

4. The golfelub head of claim 3, wherein: said metal Face and said metal frame are integral. 2()

5. Tile golfelub inroad of any preceding claim, wherein: said rear body portion comprises a crown made from a metal organic composite material. x

6 The golf club head of any preceding claim, wherein: said rear body portion comprises a skirt made from a metal organic composite material.

7. 'I'hc golf'club 11 i any preceding claim, wherein: said hOIIO\V body includes a rectal lortc\n NVhICh ranges by weight from 150-170 grams, and the portion of'said rear body portion made from said composite material ranges from 10-40 grams.

1() X 'I'hc golt'club head of'' any preceding claim, wherein: said natal trace has a maxinun, thickness ot'irom 0.110 to ().160 ucnes proximal the geometric center of the face, tapering toward a thinner region proximal the heel and toe ends of'said club head.

] 5 9. The gol 1'club head of' any preceding claim, wherein: said metal face has an area of'at least 5.00 square inches.

10. A golf club head cornprishg: a hollow body having a heel cud, a too end, a front wall and a rear body portion, said front wall including a metallic face adapted for impacting a golf ball, said rear body portion including a crown, a sole and a skirt, the crown and the skirt meeting along an ar-cuatc pcrimetcr region; a metallic stringer integrally attached to said front wall and extending along at least a portion of said arcuatc perimeter region; and a composite filer extending from said metallic stringer generally toward said front wall to f'onn at least a portion of said hollow body.

11. 'I'he golfclub head ol'clain 1(), whercn said composite tiller forms at least a portion ol'sad skirt of said hollow body.

12. The golf club head of,any of claims 10 to 11, wherein said composite filler forms at least a portion ot'said crown of said hollow body.

13. 'I'he golfclub lead of claim 12, further comprising: a second composite filler extending from said metallic stringer toward said sole to forth at least a portion of the skirt ot'said hollow body.

14. 'I'he golt'club head of claims 10 to 13, further comprising: a plurality of ribs intersecting said metallic stringer to form a lattice frame that supports said composite filer.

15. 'I'he golf club head of any of claims 10 to 14, further comprising: a second stringer displaced radially inward from said first strhger.

16. 'I'he golf club head of claim 15, further comprising: a third stringer displaced radially Howard front said second stringer.

17. The golfclub head of any of claims 10 to 16, wherein: said hollow body is at least 400 cubic centimeters ha volume.

18. The golfcluh head of any of claims 10 to 17, wherein: said front avail and said mctallc strngemirc lor,necl toyetlemas a sanitary pccc 1). 'I'hc golfchb head of' any of claims 10 to 18, wherein: said Iront wall and said metallic stringer are fondled together as a unitary casting.

20. A golt'club head comprising: a hollow body having a heel end, a toe end, a front wall and a rear body portion, said front wall h,cluding, a metallic face adapted for impacting a golfball, said rear body portion including a metallic lattice frame having a plurality of'ribs intersecting at least one stringer; and at least one layer officer reinforced organic resin extcndng across said metallic lattice name covering said plurality oi'apcrturcs 21. A method of fabricating a golf club comprising: forming club head having a crown, a sole, a skirt, a heel end and a toe end, said club head comprising a hollow body having an integral metallic face and a metallic rear body portion, said metallic rear body portion including an arcuatc perimeter region extending continuously from said toe end to said heel end; and attaching a fiber reinforced organic resin to said metallic perimeter region to extend from said metallic perimeter region toward said metallic Face to form at least a portion of' one of said crown and said skirt oi'said club head.

I I

22 The method of claim 21, wherein the step of attaching the fiber reinforced organic resin to said metallic perimeter region to form at least a portion ot'one ot'saici crown and said skirt of said club head comprises.

placing said hollow body In a mold cavity; layhg up a prepreg composite inside said hollow body; inserting a bladder info said hOIIONV body and inflating the bladder lo force the prepreg to conform to an inner surface ot'said hollow body; and curing the prepreg composite to torm said portion of one ot'said crown and said skirt of said club head.

23. A golf club head comprising: a hollow body made ot high density material, said hollow body having a heel end, a toe end, a front wall and a rear body portion; said rear body portion including a crown, a sole, a skirt extending between said crown and said sole, and an arcuate perimeter region formed where said crown and said skirt noes; a stringer spaced radially inwardly from said areuate perimeter region and a plurality ot'ribs connecting said arcuate perimeter region and said stringer; and said arcuate perimeter region, said stringer and said ribs defining a lattice which includes a plurality ot'apertures formed in said crown.

24. 'I'he golt'club head of claim 23, further comprising a layer of low density material f fling said apertures in said lattice. - I 2

25. The golf club head of claim 24, wherein said high density material is metal and wherein said low density material is resin.

26. The golf club head of any of claims 23 to 25, wherein said plurality of apertures comprises five apertures located between said arcuate perimeter region and said stringer.

27. The golf club head of any of claims 23 to 26, further comprising another stringer located radially inward from said frst-mentoned stringer and being connected to said frst-mentioned stringer by said plurality of ribs.

2X. The golf club head of claim 27, wherein said plurality of apertures comprises five apertures located between said arcuate perimeter region and said first-mentioned stringer and five apertures located between said first-mentioned stringer and said another stringer.

29. I he golf club need of claim 8, wnereh, said thinner region has a thickness of 0.070 to 0.090 inches.

30. A golf club head substantially as described in any embodiment hereinbefore with reference to the accompanying drawings.

31. A method of fabricating a golf club head substantially as described in any embodiment hereinbefore with reference to the accompanying drawings.