US20160250532A1

US20160250532A1 - Counterbalanced wedges

Info

Publication number: US20160250532A1
Application number: US14/632,947
Authority: US
Inventors: Sean Patrick Griffin; Derek Luther
Original assignee: TaylorMade Golf Co Inc
Current assignee: TaylorMade Golf Co Inc
Priority date: 2015-02-26
Filing date: 2015-02-26
Publication date: 2016-09-01

Abstract

Described are embodiments of wedge-type golf clubs that include a counterbalance weight located at the butt end of the shaft. The shaft and/or grip of disclosed clubs can have reduced mass while the club head and the butt of the shaft can have increased mass compared to conventional clubs, which provides a similar overall total mass but with an increase in the moment of inertia (MOI). The increase in MOI compared to a conventional club of similar style and mass can provide increased swing stability during a stroke, decreasing unintentional waggling about the hand grip fulcrum. The added weight in the head and the added weight in the butt of the shaft can counterbalance each other so that the overall swingweight of the club can be about the same as for a conventional, non-counterbalanced club having the same total mass, thereby providing a familiar feel and easy playability.

Description

FIELD

This application relates to golf clubs, and more particularly to wedges.

BACKGROUND

Golf is a game in which a player, choosing from a variety of different golf clubs, seeks to hit a ball into each hole on the golf course in the fewest possible strokes. A wedge is one type of golf club, and is designed for hitting short, precise shots onto a green, hitting high-lofted shots, and for hitting shots from difficult lies, such as from tall grass or from a sand bunker. In some wedge shots, the head of a wedge may travel through turf, sand, or other materials prior to striking the ball. When swinging a wedge, it is desirable to maintain a smooth, stable stroke to provide optimal accuracy and precision.

SUMMARY

Described below are embodiments of wedges and other iron-type golf clubs that are counterbalanced with significant mass located near the butt of the shaft above the grip location. Additional mass may also be added to the club head compared to a conventional club head. In the disclosed golf clubs, the club head and the butt end of the club can have increased mass compared to an analogous conventional club, which provides an increase in overall total mass, an increase in the moment of inertia about the CG of the club (MOI_CG), while maintaining a balance about the hand grip fulcrum location that provides a similar swingweight compared to a conventional club. The increase in club head mass and MOI_CGcompared to a conventional club of similar style can provide increased swing stability during a stroke, decreasing unintentional waggling about the hand grip fulcrum, and thus providing increased accuracy and precision to wedge shots. The increase in club head mass and MOI_CGcan also help the club head travel through soil, grass, sand, etc., with more momentum and less interruption, providing more consistent and accurate ball striking. The familiar swingweight of the disclosed clubs compared to conventional clubs makes the disclosed club feel familiar to a golfer and therefore the disclosed clubs can be readily playable in place of a conventional club without the golfer having to significantly change his swing.
The foregoing and other objects, features, and advantages of the disclosed technology will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a conventional wedge-type golf club.

FIG. 2 shows an exemplary wedge-type golf club having a counterbalance weight positioned at the butt end of the club.

FIG. 3 is a cross-sectional view of a butt end of an exemplary club having a counterbalance weight positioned at the top end of a hand grip and having a radial outer surface that is substantially contiguous with a radial outer gripping surface of the hand grip.

FIG. 4 is a cross-sectional view of a butt end of another exemplary club having a counterbalance weight positioned within the top end of the hand grip and secured to the top end of the shaft.

FIG. 5 shows a wedge-type golf club at a point in a swing just prior to striking a ball or contacting the ground behind the ball.

FIG. 6 shows the wedge-type golf club at a point in the swing after travelling through the ground behind the ball and just after striking a ball.

FIG. 7 is a graph that illustrates displacement in the ground direction as a function of time for two different wedge-type golf clubs from the time they club head contacts the ground to a time after the club head lifts above the ground.

DETAILED DESCRIPTION

Disclosed herein are embodiments of wedges and other golf iron-type clubs that are counterbalanced with a counterbalance weight located at or near the upper end or “butt end” of the shaft above the gripping location. As used herein, the terms “wedge” and “wedge-type golf club” mean any iron-type golf club having a static loft angle that is greater than 45°. Any of the disclosure described herein in relation to a wedge or wedge-type golf club can be embodied in any of various wedges having different loft angles, such as a pitching wedge, gap wedge, sand wedge, lob wedge, flop wedge, and/or wedges having static loft angles of 46°, 48°, 50°, 52°, 54°, 56°, 58°, 60°, greater than 60°, and any other angles greater than 45°. The disclosed technology can also be embodied in iron-type golf clubs having static loft angles of 45° or less, such as a 9-iron or lower-numbered irons.
In disclosed embodiments, the club head and the butt end of the shaft have increased mass compared to a conventional club of the same loft and style. Such clubs can have an increased overall total mass as compared to a conventional club of similar type, and can have an increase in the moment of inertia (MOI) of the club about the CG and/or about the hand grip fulcrum location (e.g., where the club pivots when a golfer rotates his hands/wrists). The increase in MOI can provide increased swing stability during a swing stroke, decreasing unintentional waggling about the CG and hand grip fulcrum, and thus providing increased accuracy and precision to shots. In addition, the increase in MOI, and in particular the increase provided by the added mass in the club head, can provide greater momentum and stability as the club head travels through turf, sand, or other material, leading to less disruption of the path, orientation, and velocity of the club head.
At the same time, the added weight in the club head and the added weight in the butt end of the shaft can counterbalance each other in such a way that the overall swingweight of the club (e.g., rotational moment about the hand grip fulcrum location due to gravity) can be about the same as for a conventional, non-counterbalanced club having significantly less total mass. Having the same or similar swingweight can provide the golfer a familiar feel and sensation during a swing that makes the disclosed clubs readily playable in place of a conventional club without having to adjust one's swing.

Club Length Dimensions

FIG. 1 shows a conventional wedge-type golf club 10 and illustrates an exemplary methodology for measuring club length dimensions based on the center of gravity (CG) and other features of the club. Club 10 has a shaft 14 that couples its grip 16 to its head 12. The overall shaft length (L₁) of the club 10 can be measured from a point 18 where the shaft center axis intersects the bottom/sole of the head 12 to the butt end 20 of the club. A dimension “d₁” can be defined as the distance from the CG to the lower shaft axis intersection point 18 and a dimension “c₁” can be defined as the distance from the CG to the butt end 20 of the club.
Club Swingweight
FIG. 1 also illustrates a methodology for calculating the swingweight of a golf club. The club 10 has a hand grip fulcrum point 22, which is an approximation of the pivot point about which a club pivots when a golfer holding the club rotates his hands/wrists. The fulcrum point 22 can be defined as being a predetermined distance “e” from the lower shaft axis intersection point 18 along the shaft axis. For example, the distance “e” can be defined as 30 inches. The swingweight of the club can then be defined as the moment about the fulcrum point 22 caused by gravity when the club is horizontal and fixed at the fulcrum point. This swingweight moment “M_e” can be calculated as the product of the gravitational force “Fab” multiplied by the distance from the CG to the fulcrum point 22, which is equal to the distance “e” minus the distance “d₁”. F_clubis equal to the total mass “m” of the club multiplied by the gravitational constant “g”. Thus, M_e=(e−d₁)*m*g. Accordingly, changing the total mass of a club and/or shifting the location of the CG along the shaft axis (changing the distance “d₁”) can change the swingweight of the club and cause the club to feel different when held and during a swing. Thus, it can be desirable to provide a club that maintains a similar swingweight compared to conventional clubs such that a golfer is provided with a familiar feel and sensation when switching to a new club. In some embodiments, the swingweight can be maintained at a similar level when additional mass is added to the club by increasing the mass at the butt end of the club, which shifts the CG toward the butt end of the club and increases d₁, thereby counterbalancing a smaller amount of mass added to the club head.

Club MOI

The moment of inertia (MOI) of a wedge or other iron-type golf club can be determined based on a selected axis perpendicular to the shaft. The MOI about a given axis provides a measure of the club's inertial resistance to rotating about that axis. For example, the MOI of the club 10 about an axis extending perpendicular to the shaft axis (e.g., perpendicular to the page in FIG. 1) and passing through the CG of the club is referred to as the “MOI_CG” of the club 10. Similarly, the MOI of the club 10 about an axis extending perpendicular to the shaft axis and passing through the grip fulcrum point 22 is referred to as the “MOI_e” of the club.
Calculating the true MOI of a club about any axis can be difficult. One method of calculating the MOI of a club about a selected axis is by measuring the undamped period of oscillation of the club while it is fixed to a torsional spring of a testing machine at a point where the selected axis intersects the shaft axis, with the torsional spring being aligned with the selected axis. The overall MOI of the system (club plus torsional spring fixture) can then be calculated using the formula MOI=(k*T²)/(4π²), where “k” is the coefficient of the torsional spring, and T is the undamped period of oscillation of the whole system. The MOI of the club about the selected axis is then equal to the overall MOI of the system minus the MOI of the torsional spring fixture by itself. Thus, the MOI of the club about the selected axis can be calculated as MOI_club=(k/4π²)*(T²−(T_fixt)²), where “T_fixt” is the period of oscillation of the torsional spring fixture by itself without a club fixed to it. T_fixtcan be a known value for a given MOI testing system. Using such a testing system and method, the MOI of the club about any axis intersecting the shaft can be calculated, such as the MOI_CGor the MOI_e.
MOI values for a club can also be approximated, such as by assuming the mass of the shaft and grip are negligible and representing the club head as a point mass at the center of the head. The MOI about a given axis perpendicular to and intersecting the shaft axis can then be approximated as the mass of the club head multiplied by the square of the distance from the center of the head to the given axis. This is illustrated in FIG. 1 for the club 10. The club head 12 has a center 24 (e.g., CG of the head or geometric center of the head, etc.) and the distance from the center 24 to the grip fulcrum point 22 is shown as “X₁”, such that the MOI_eof the club 10 about the grip fulcrum axis 22 can be approximated as the mass “N₁” of the head 12 multiplied by the square of the distance “X₁”, or N₁*X₁ ².

Exemplary Counterbalanced Clubs

FIG. 2 shows an exemplary counterbalanced wedge-type golf club 50 that comprises a head 52, a shaft 54, a grip 56, and a counterbalance weight 57 at or near the butt end of the club. The overall length “L₂” of the club 50 is measured from the lower shaft axis intersection point 58 to the butt end 60 of the club, which can be the end of the counterbalance weight 57. The MOI_CGof the club 50 can be increased due the presence of the counterbalance weight 57 and/or additional mass added to the club head. The MOI_eof the club 50 about the fulcrum point 62 can also be increased. Note that the fulcrum point 62 is the same predetermined distance e (e.g., 30 inches) from the lower shaft axis intersection point 58 as in the conventional club 10.
The MOI_eof the club 50 can be approximated as the sum of the inertial effect of the head 52 and the inertial effect of the counterbalance weight 57. As described above, the inertial effect of the head 52 can be approximated as N₂*X₁ ², where “N₂” is the mass of the head 52. Similarly, the inertial effect of the counterbalance weight 57 can be approximated as N₃*X₂ ², where “N₃” is the mass of the counterbalance weight 57 and “X₂” is the distance from the center 66 of the counterbalance weight to the grip fulcrum point 62, as shown in FIG. 2. Thus, the MOI_eof the club 50 can be approximated as the sum of (N₂*X₁ ²)+(N₃*X₂ ²).
The MOI_CGof the club 50 can be approximated in a similar manner using analogous dimensions from the mass centers 64 and 66 to the CG. The MOI_eand MOI_CGof the club 50 will therefore be greater than the MOI_eand MOI_CGof the club 10 if the mass of their heads are equal or if the mass of the head 52 of club 50 is greater than the mass of the head 12 of club 10. The greater MOI_eand/or greater MOI_CGof the club 50 can provide greater swing stability during a swing and can make it more difficult for a golfer to accidentally adjust the swing path of the club when it is in motion, giving the golfer more consistent, predictable ball striking. This also gives the club head more inertial resistance while traveling through turf, sand, or other material prior to striking the ball, thereby maintaining swing speed and swing path.
While an increase in MOI_eand/or MOI_CGis desirable, it can also be desirable to increase the mass of the club head and/or maintain the same or similar swingweight compared to a conventional club 10. To add mass to the club head 52 and add mass to the butt end of the club in the form of the counterbalance weight 57, it may be desirable to subtract mass from elsewhere in the club so the club does not become too heavy and feel awkward to the golfer. For example, the mass of the shaft and/or the mass of the grip can be reduced to accommodate the added mass of a counterbalance weight and the added mass in the club head. In some embodiments, a lightweight shaft can be used instead of a conventional shaft. For example, the shaft can comprise substantially all graphite and/or other lightweight materials. In another example, a bi-matrix shaft can be used that comprises graphite and/or other lightweight material in an upper portion and steel and/or other strong, plastically deformable material in a lower portion or tip portion to allow the tip portion to be plastically bent to adjust the orientation of the head relative to the shaft axis. The grip can also be comprised of lightweight material and/or can be reduced in volume to reduce its mass contribution to the club. By reducing the mass of the shaft and/or grip, more mass can be added to the club head and counterbalance weight without making the club overly heavy.
The counterbalance weight 57 can comprise any dense material, can have any shape, and can be coupled to the shaft and/or grip in any manner. In some embodiments, the counterbalance weight can be adjustable and/or removable. In some embodiments, two or more counterbalance weights can be provided to allow a user to select which one to couple to the club. For example, the different counterbalance weights can have different masses, different shapes, different lengths, and/or different aesthetic appearances. A person may be able to remove one weight from the shaft and attach another weight to the shaft to change the characteristics of the club. In some embodiments, two or more counterbalance weights may be attached to the club at the same time, such as one on top of the other or side-by-side, etc. For example, a first weight may attach to the shaft and a second weight may attach to the first weight. In some embodiments, the different weights can appear identical, but have different masses (e.g., different materials and/or hollow regions). In some embodiments, the counterbalance weights can require a tool to be removed from the club or to be secured to the club, while in other embodiments no tool is required. When attached to the club, the counterbalance weights may be non-adjustable or may be adjustable.
In embodiments where a counterbalance weight is adjustable when attached to the club, the axial position of the counterbalance weight relative to the shaft and/or grip may be adjusted. For example, the counterbalance weight may be adjustable along the shaft axis by rotating the counterbalance weight relative to the shaft. A threaded attachment with the shaft may be used, for example. In some embodiments, the positional adjustability can be limited to a group of discrete positional settings, rather than a continuous or analog range of positions. In such embodiments, the weight can be fixable at each of the discrete positional settings, such as by using a tool to tighten a set screw, or the like.
FIGS. 3 and 4 are cross-sections of exemplary butt ends of clubs that include a counterbalance weight. FIG. 3 shows a club 70 that comprises a shaft 72, a grip 74 mounted around the top end of the shaft, and an external counterbalance weight 76 mounted around the top end of the grip. In this example, the grip 74 includes a thin or narrowed upper and a top portion 82 that extends around the top end of the shaft 72. The counterbalance weight 76 has a recess that receives the upper portion 80 and top portion 82 of the grip. The counterbalance weight 76 can have a top portion 84 that covers the top portion 82 of the grip and forms the upper surface of the club 70. The grip can be secured to the shaft with an adhesive or other means, and the counterbalance weight can be secured to the grip with an adhesive or other means.
A counterbalance weight can have a radial outer surface that is substantially contiguous with and/or blends into the radial outer gripping surface of the grip, such that a smooth transition is formed at an annular joint 78 (see FIG. 3) between the radial outer surfaces of the grip and the weight. In some embodiments, the appearance of the grip and the weight can be similar such that the transition at the joint 78 is minimally noticeable visually or tactiley, while in other embodiments, they may have different colors or finishes such that the transition at the joint 78 is visually noticeable but minimally noticeable by feel. As shown in FIG. 3, the counterbalance weight may increase in diameter or width moving upwardly from the joint 78. This can provide more volume and mass per vertical length of the counterbalance weight.
FIG. 4 is a cross-sectional side view of the butt end of another exemplary club 90 that has an internal counterbalance weight 96. The club 90 comprises a shaft 92, the counterbalance weight 96 mounted to the top end of the shaft, and a grip 94 mounted around the top end of the shaft and covering the counterbalance weight, including a grip top portion 100 positioned over the top of the weight 96. The weight 96 includes a lower portion 98 that is inserted into and secured to the top end of the shaft, such as by threads, friction fit, welding, adhesive, etc. In this embodiment, substantially the entire outer surface of the butt end of the club 90 is provided by the grip 94. The weight 96 can have about the same diameter as the shaft 92, such that the weight effectively extends the length of the shaft.
In any of the embodiments disclosed herein, the counterbalance weight can have any axial length, provided the width and density of it are sufficient to provide the desired mass addition to the butt end of the club. In some circumstances, it may be undesirable for the butt end of a club to extend too far above the golfer's hands. For example, rules may prohibit the butt end of the club from contacting or being anchored to the golfer's torso or other body portion other than the hands. Further, the butt end of the club may undesirably contact the golfer's legs or other body part during a swing if it projects too far above the golfer's hands. Thus, a shorter counterbalance weight can be desirable. To provide a maximum mass per axial length added to the club, the counterbalance weight can be made wider (e.g., as wide as the grip or wider) and can be made from a relatively dense material, such as steel, tungsten, or other dense metals. In some embodiments, the axial length of the counterbalance weight is less than four inches, less than 3 inches, less than 2 inches, and/or less than 1 inch. The overall length “L₂” of a counterbalance wedge-type clubs as described herein including a counterbalance weight can be less than or equal to 40 inches, less than or equal to 39 inches, less than or equal to 38 inches, less than or equal to 37 inches, and/or less than or equal to 36 inches.
The mass added to the club head 52 can be added in any manner. In some embodiments, one or more adjustable and/or removable weights can be coupled to the club head. Such weights may be removable and interchangeable with other weights having different masses. In other embodiments, the size and/or materials of the club head may be changed to increase the mass of the club head a desired amount.
The disclosed counterbalanced clubs can have any overall mass, though in some embodiments the overall mass of the club, including any weights, can be at least about 400 grams, at least about 450 grams, at least about 475 grams, at least about 500 grams, and/or at least about 525 grams.
The counterbalance weight(s) itself can also have any mass, though in some embodiments the mass of the counterbalance weight is at least about 25 grams, at least about 40 grams, at least about 50 grams, at least about 70 grams, and/or at least about 100 grams.
The mass of the club head can be, for example, at least about 280 grams, at least about 300 grams, at least about 310 grams, at least about 320 grams, and/or at least about 340 grams.
The mass added to the club head, whether in the form of one or more weights movable relative to the head body or increased mass of the head body, can be at least 5 grams, at least 8 grams, at least 10 grams, and/or at least 15 grams. In one particular example, the club head has a total mass of about 309 grams, including added mass in the form of one or more weights that have a mass of about 9 grams, while the counterbalance weight has a mass of about 50 grams.
The shaft can have any mass, such as 130 grams or less, 100 grams or less, 80 grams or less, 70 grams or less, and/or 60 grams or less. In one particular example, a bi-matrix shaft is included that has a graphite upper portion with a mass of about 50 grams and a steel lower portion with a mass of about 20 grams, providing a total of about 70 grams.
The grip can also have any mass, such as 100 grams or less, 50 grams or less, 40 grams or less, and/or 35 grams or less. In some embodiments, the grip comprises a lightweight EVA material.
The total mass of the shaft and grip together can be lower than in a conventional club, such as less than 200 grams, less than 150 grams, less than 125 grams, less than 110 grams, and/or less than 100 grams.
The disclosed counterbalance clubs can have any MOI_CG, such as at least 500 kg*cm², at least 525 kg*cm², at least 550 kg*cm², at least 575 kg*cm², at least 600 kg*cm², and/or at least 625 kg*cm². Similarly, the disclosed counterbalance clubs can have any MOI_e(with e=30 inches), such as at least 2000 kg*cm², at least 2025 kg*cm², at least 2050 kg*cm², at least 2075 kg*cm², at least 2100 kg*cm²and/or at least 2200 kg*cm².
Another meaningful parameter type for counterbalanced golf clubs are ratios of a club moment of inertia divided by the club length squared (L²). For example, the ratio MOI_CGper unit length²(in units of kg*cm²/inch²) for the disclosed counterbalance clubs can be from about 1.4:1 to about 1.1:1, from about 1.35:1 to about 1.15:1, and/or from about 1.3:1 to about 1.2:1.
Yet another meaningful parameter for counterbalanced golf clubs are ratios of a club moment of inertia divided by the total club mass. For example, the ratio MOI_CGper unit mass (in units of kg*cm²/g) for the disclosed counterbalance clubs can be at least 1.05, at least 1.10, at least 1.15, at least 1.20, and or at least 1.23.
Still another meaningful parameter type for counterbalanced clubs is the ratio of the MOI_CGper unit length²divided by the total club mass. This parameter can be expressed in terms of a unitless percentage and can be referred to as “inertial efficiency” since it represents how effectively the mass and length of the club are utilized to maximize the MOI_CG. The disclosed counterbalance clubs can have an inertial efficiency of at least 13%, at least 13.3%, at least 13.5%, at least 13.8%, at least 14.0%, at least 14.2%, at least 14.4%, at least 14.6%, at least 14.8%, and/or at least 15.0%.
The disclosed counterbalance clubs can have a swingweight that is similar to a conventional club of the same type having less mass. For example, the disclosed counterbalance clubs can have a swingweight (with e=30 inches) of less than 3.0 N*m, less than 2.8 N*m, less than 2.7 N*m, greater than 2.6 N*m, greater than 2.64 N*m, greater than 2.68 N*m, between 2.5 N*m and 3.0 N*m, between 2.6 N*m and 2.8 N*m, between 2.63 N*m and 2.75 N*m, and/or between 2.66 N*m and 2.70 N*m.
Table 1 below provides representative data for two different exemplary wedges. Wedge A is an exemplary embodiment of the counterbalanced clubs described herein, having a 58° loft. Wedge B is an exemplary conventional wedge having the same 58° loft and same general style as Wedge A, but without a counterbalance weight at the butt end of the shaft and less club head mass. As shown in Table 1, Wedge A is slightly longer than Wedge B due to the counterbalance weight added to the butt end of the shaft. Wedge A also has a greater mass, greater MOI_CG, and greater inertial efficiency than Wedge B. However, Wedges A and B have about the same swingweight.

TABLE 1

		Sole-			MOI_CGper	Inertial
	Length	to-CG	Mass	MOI_CG	Unit Mass	Efficiency	Swingweight
Wedge	(in)	(in)	(g)	(kg * cm²)	(kg * cm²/g)	(unitless)	(N * m)

A	35.75	9.50	527	647	1.23	14.9%	2.693
B	35	7.55	471	489	1.04	13.2%	2.632

Ground Interaction

FIGS. 5 and 6 illustrate the interaction of an exemplary wedge 100 with the ground 104 during a swing prior to and just after striking a ball 102. FIG. 5 shows the head of the wedge 100 just prior to contacting the ground 104, while FIG. 6 shows the head of the wedge 100 contacting the ball 102 after traveling through a section of the ground 104.
FIG. 7 is a graph showing the depth of the lower surface of the head of the wedge 100 below the surface of the ground 104 as a function of time, for an exemplary 58° counterbalanced wedged (dashed line) and for a convention 58° wedge of the same general style (solid line), each traveling at 80 mph club head speed relative to the ground. The data in FIG. 7 was generated using a simulation method wherein the ground model is simulated using smoothed particle hydrodynamics to represent soft sand, wherein the solid mesh turns into particles when the solid mesh reaches 0.01 strain and thereafter the particles interactions are modeled. In the simulation, the counterbalanced wedge includes an additional 40 gram counterbalance weight located 0.5 inches above the butt end of the shaft (where the conventional shaft ends) and an additional 10 grams of mass added to the club head compared to the convention club head (via increased density), with the same size club head in both wedge models. The same velocity conditions were used with both wedge models.
As shown in FIG. 7, the counterbalanced wedge digs further below the surface of the ground (about 10 mm, compared to about 9 mm for the conventional wedge), which illustrates that the counterbalanced wedge has more downward momentum and is less impeded by the ground. In addition, the counterbalanced wedge rebounds from the lowest point quicker than the conventional wedge and also exits the ground (displacement >0) slightly sooner than the conventional wedge, again illustrating less disruption from the ground. Because the counterbalanced wedges as disclosed herein have greater inertia and suffer less disruption from the ground prior to striking the ball, compared to conventional wedges, the counterbalanced wedges provide more consistent, accurate ball striking and maintains a greater velocity while traveling through the ground, leading to greater shot distances.

Exemplary Materials

The components of the embodiments disclosed herein can be formed from any of various suitable metals, metal alloys, polymers, composites, or various combinations thereof.
In addition to those noted elsewhere herein, examples of metals and metal alloys that can be used to form the components include, without limitation, carbon steels (e.g., 1020 or 8620 carbon steel), stainless steels (e.g., 304 or 410 stainless steel), PH (precipitation-hardenable) alloys (e.g., 17-4, C450, or C455 alloys), titanium alloys (e.g., 3-2.5, 6-4, SP700, 15-3-3-3, 10-2-3, or other alpha/near alpha, alpha-beta, and beta/near beta titanium alloys), aluminum/aluminum alloys (e.g., 3000 series alloys, 5000 series alloys, 6000 series alloys, such as 6061-T6, and 7000 series alloys, such as 7075), magnesium alloys, copper alloys, nickel alloys, and tungsten.
Examples of composites that can be used to form the components include, without limitation, glass fiber reinforced polymers (GFRP), carbon fiber reinforced polymers (CFRP), metal matrix composites (MMC), ceramic matrix composites (CMC), and natural composites (e.g., wood composites).
Examples of polymers that can be used to form the components include, without limitation, thermoplastic materials (e.g., polyethylene, polypropylene, polystyrene, acrylic, PVC, ABS, polycarbonate, polyurethane, polyphenylene oxide (PPO), polyphenylene sulfide (PPS), polyether block amides, nylon, and engineered thermoplastics), thermosetting materials (e.g., polyurethane, epoxy, and polyester), copolymers, and elastomers (e.g., natural or synthetic rubber, EPDM, and Teflon®).
In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are only examples and should not be taken as limiting the scope of the disclosure. Rather, the scope of the disclosure is at least as broad as the following exemplary claims. We therefore claim all that comes within the scope of the following claims.

Claims

1. A wedge-type golf club comprising:

a club head having a static loft angle greater than 45°;

a shaft having an upper end and a lower end that is coupled to the club head;

a hand grip coupled to the shaft between the upper end and the lower end; and

a counterbalance weight coupled to the upper end of the shaft, the counterbalance weight having a mass of at least 40 grams;

wherein the golf club has a total mass of at least 500 grams, a total length of from about 35 inches to about 38 inches, an MOI_CGof at least 600 kg*cm², and an inertial efficiency of at least 13.5%, wherein inertial efficiency is a unitless ratio of the MOI_CGper unit length squared divided by the total club mass.

2. The golf club of claim 1, wherein the golf club has an inertial efficiency of at least 14.8%.

3-5. (canceled)

6. The golf club of claim 1, wherein the counterbalance weight has a mass of at least 50 grams.

7. The golf club of claim 1, wherein the golf club has a swingweight that is between 2.6 N*m and 2.8 N*m.

8. The golf club of claim 1, wherein the counterbalance weight is removably coupled to the upper end of the shaft, or is positionally adjustable relative to the shaft.

9. (canceled)

10. The golf club of claim 1, wherein the hand grip has an outer gripping surface and the counterbalance weight has an outer surface, and the counterbalance weight is positioned above the hand grip such that the outer surface of the counterbalance weight is substantially contiguous with the outer gripping surface of the hand grip.

11. The golf club of claim 1, wherein the shaft comprises a bi-matrix shaft that comprises graphite material in an upper portion of the shaft and steel in a lower portion or tip portion of the shaft.

12. A wedge-type golf club comprising:

a club head having a static loft angle greater than 45°;

a shaft having an upper end and a lower end that is coupled to the club head;

a hand grip coupled to the shaft between the upper end and the lower end; and

a counterbalance weight coupled to the upper end of the shaft separate from the grip;

wherein the counterbalance weight has a mass of at least 40 grams; and

wherein the golf club has a total mass of at least 500 grams, a total length of from about 35 inches to about 38 inches, an MOI_CGof at least 600 kg*cm², and a swingweight that is in a range from about 2.5 N*m to about 3.0 N*m.

13. The golf club of claim 12, wherein the couterbalanance weight has a mass of at least 50 grams.

14. The golf club of claim 12, wherein the golf club has a swingweight that is in a range from about 2.6 N*m to about 2.8 N*m.

15. (canceled)

16. The golf club of claim 12, wherein the golf club's total mass is between 500 grams and 600 grams.

17. The golf club of claim 12, wherein the counterbalance weight is removably coupled to the upper end of the shaft, or is positionally adjustable relative to the shaft.

18. The golf club of claim 12, wherein the club head has a total mass of between 300 grams and 320 grams.

19. The golf club of claim 12, wherein the hand grip has a radial outer gripping surface and the counterbalance weight has a radial outer surface, and the counterbalance weight is positioned above the hand grip such that the radial outer surface of the counterbalance weight is substantially contiguous with the radial outer gripping surface of the hand grip.

20. The golf club of claim 12, wherein the shaft comprises a bi-matrix shaft that comprises graphite material in an upper portion of the shaft and steel in a lower portion or tip portion of the shaft.

21. The golf club of claim 1, wherein the club head has a total mass of between 300 grams and 320 grams.

22. The golf club of claim 21, wherein the hand grip and the shaft have a combined mass of 150 grams or less.

23. The golf club of claim 18, wherein the hand grip and the shaft have a combined mass of 150 grams or less.

24. A wedge-type golf club comprising:

a wedge-type club head having a static loft angle greater than 45°;

a shaft having an upper end portion and having a lower end portion that is coupled to the club head;

a hand grip coupled to the upper end portion of the shaft, the hand grip having a lower hand grip portion positioned around the shaft and an upper hand grip portion that is positioned around the upper end portion of the shaft, wherein the upper hand grip portion has an outer diameter that is smaller than an outer diameter of the lower hand grip portion; and

a counterbalance weight positioned around the upper hand grip portion of the hand grip and positioned above the lower hand grip portion, the counterbalance weight having a greater density than the hand grip and the shaft;

wherein the lower hand grip portion has a radial outer gripping surface and the counterbalance weight has a radial outer surface, and the counterbalance weight is positioned above the radial outer gripping surface such that the radial outer surface of the counterbalance weight is substantially contiguous with the radial outer gripping surface of the lower hand grip portion.

25. The wedge-type golf club of claim 24, wherein the counterbalance weight increases in diameter from a lower end of the counterbalance weight to an upper end of the counterbalance weight.

26. The wedge-type golf club of claim 24, wherein the upper hand grip portion extends at least partially over the upper end of the shaft, and the counterbalance weight extends at least partially over an upper end of the upper hand grip portion.