Golf club

Abstract

A golf club has a shaft having a shaft axis; a club head connected to a first end of the shaft; and a grip connected to a second end of the shaft opposite the club head. The grip is provided with a first grip part and a second grip part, wherein the first grip part is torsionally movable to a limited extent relative to the second grip part and relative to the shaft about the shaft axis.

Claims

1. A golf club comprising: a shaft having a shaft axis; a club head connected to a first end of the shaft; a grip connected to a second end of the shaft opposite the club head; the grip comprising a first grip part and a second grip part, wherein the first grip part is torsionally movable to a limited extent relative to the second grip part and relative to the shaft about the shaft axis; a torsion damper provided between the first grip part and the second grip part, wherein the first grip part, the torsion damper, and the second grip part together are formed as one piece, and wherein the torsion damper is formed by a torsion-soft area disposed between the first grip part and the second grip part; a hard bearing layer, wherein the first grip part is seated with the hard bearing layer on the shaft.

2. The golf club according to claim 1, wherein the hard bearing layer is a support sleeve which is fastened to the first grip part.

3. The golf club according to claim 1, wherein at least the first grip part is comprised of a material that, for formation of the hard bearing layer, is harder than the a surrounding area of the first grip part that surrounds the hard bearing layer.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The invention will be explained in more detail with the aid of the embodiments illustrated in the drawings.

(2) FIG. 1 shows partially in section and partially in a side view a part of the golf club according to the invention.

(3) FIG. 2 shows a section, taken along the section line II-II of FIG. 3, of the torsion damper of the golf club according to the invention.

(4) FIG. 3 is a plan view of the torsion damper according to FIG. 2.

(5) FIG. 4 in an elevation view a portion of a golf club according to the invention in a further embodiment.

(6) FIG. 5 is a section along the line V-V of FIG. 4.

(7) FIG. 6 shows a section along the line VI-VI of FIG. 4.

(8) FIG. 7 shows in section a portion of a further embodiment of the golf club according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

(9) The golf club has at the upper end a grip 1 and at the lower end a club head H (only schematically indicated in FIG. 1). The connection of the club head H with the grip 1 is realized by a shaft 2 which is usually made of steel or of a carbon-fiber reinforced plastic material. The grip 1 comprises a first grip part (bottom grip part 1b) and a second grip part (top grip part 1a). The two grip parts 1a, 1b are designed such that the first grip part, i.e., the bottom grip part 1b, can perform limited torsional movements relative to the shaft 2 and relative to the second grip part, i.e., the top grip part 1a. The bottom grip part 1b can be rotated, for example, about an angle of +/5 about the shaft axis of the shaft 2.

(10) The top grip part 1a is fixedly connected to the shaft 2, for example, is adhesively connected thereto or in other ways fixedly (i.e., no rotation between top grip part and shaft is possible) connected thereto.

(11) The bottom grip part 1b is separated by a torsion damper 3 from the top grip part 1a. The torsion damper 3 (FIGS. 2 and 3) comprises an outer ring 4 and an inner ring 5. The inner ring 5 of the torsion damper 3 surrounds the shaft 2 with play (FIG. 1). Both rings 4, 5 are connected to each other by webs 6. In the embodiment, the two rings 4, 5 are of a circular design and are arranged coaxially relative to each other. Between the webs 6 and the rings 4, 5, hollow spaces or cavities 7 are formed which are axially penetrating the torsion damper 3.

(12) The torsion damper 3 is configured such that it comprises a flat topside 8 and a flat bottom side 9. The bottom grip part 1b is resting with flat surface contact on the flat bottom side 9 and is connected with the torsion damper 3 by an adhesive or by plastic fusing (welding). The top grip part 1a is fixedly connected to the flat top side 8 of the torsion damper 3 also by an adhesive or by plastic fusion (welding). In the embodiment, the torsion damper 3 has a smaller outer diameter compared to the two grip parts 1a, 1b. Of course, the torsion damper 3 can also have the same outer diameter as the grip parts 1a, 1b.

(13) In order for the bottom grip part 1b to be able to perform limited torsional movements about the shaft axis of the shaft 2, the bottom grip part 1b is seated with at least one slide bearing 10 on the shaft 2. In the embodiment, two slide bearings 10, 11 are provided that are positioned at an axial spacing one behind the other and support the bottom grip part 1b on the shaft 2 so that the bottom grip part 1b is rotatable to a limited extent on the shaft 2. The two slide bearings 10, 11 each are positioned in an annular recess 12, 13. The annular recesses 12, 13 are arranged in the inner wall 14 of the through bore 15 of the bottom grip part 1b. The recess 12 is open in the direction toward the torsion damper 3. The slide bearings 10, 11 ensure that the bottom grip part 1b is supported on the shaft 2 free of torsion forces. The slide bearings 10, 11 can be formed by a suitable plastic material that can be connected with the shaft 2 and permits a limited torsion of the bottom grip part 1b.

(14) With the exception of a connection provided by the slide bearings 10, 11, the bottom grip part 1b is not connected to the shaft 2, i.e., the shaft 2 penetrates the central through bore 15 with play.

(15) The two grip parts 1a, 1b can be comprised of a material that is suitable for such golf club grips.

(16) When putting on the green, golfers experience that the hand that during putting determines the length of the putt suddenly involuntarily twitches shortly before the golf club contacts the golf ball. This causes the golf ball to move in a direction different from the intended direction. These involuntary jerky muscle twitches, known as yips, occur usually only in the hand with which the length of the putt is determined. In case of a right-handed person, this is the right hand. The lead hand which determines the direction of the golf does not experience such muscle twitches. A right-handed person grips during putting with his or her left hand the top grip part 1a which is fixedly connected to the shaft 2. The right hand grips the bottom grip part 1b. Since the bottom grip part 1b can be twisted to a limited extent about the shaft axis of the shaft 2, muscle twitches of the right hand have no effect on the putting direction. The muscle twitches are compensated by the bottom grip part 1b in that the grip part 1b is caused to move torsionally about the shaft axis of the shaft 2 in accordance with the muscle twitches. Since the bottom grip part 1b is supported by means of the slide bearings 10, 11 on the shaft 2, the muscle twitches have no effect on the putting direction which is determined by the left hand of the golfer. Therefore, the golfer can precisely putt the golf ball in the direction of the hole.

(17) In case of a left-handed person, the left hand grips the bottom grip part 1b while the right hand grips the top grip part 1a.

(18) The torsion damper 3 is designed such that the damping action can be adjusted depending on the strength and effect of the muscle twitches. The torsion damper 3 is comprised, for example, of a rubber mixture. By selecting the degree of hardness of the rubber mixture, the degree of the damping action can be adjusted. The damping action is also determined by the number of connecting webs 6 and/or the width of the connecting webs 6 and/or the height of the torsion damper 3. Accordingly, by suitable selection of the rubber mixture and/or the number of the connecting webs 6 and/or the width of the connecting webs 6 and/or the height of the torsion damper 3, the golf club can be optimally adjusted to the muscle twitches of the respective golfer. For the adaptation process, first a torsion damper 3 is employed that advantageously is connected by means of film magnets with the top and bottom grip parts 1a, 1b. Accordingly, in a very simple way a suitable torsion damper 3 can be determined. As soon as the proper torsion damper 3 has been determined, the corresponding torsion damper 3 is connected fixedly to the two grip parts 1a, 1b. In this way, the optimal damping action on the golf club grip 1 can be determined in a very simple way.

(19) FIGS. 4 to 6 show a further embodiment of a golf club. In accordance with the preceding embodiment, the grip 1 is comprised of top grip part 1a and bottom grip part 1b. The top grip part 1a is seated fixedly on the shaft 2; the shaft 2 also penetrates the bottom grip part 1b axially. The top grip part 1a is designed like a conventional golf club grip and has, for example, a non-round contour (FIG. 5). Centrally, the top grip part 1a has an axial through bore 16 into which the shaft 2 projects. The top grip part 1a is connected in a suitable way fixedly to the shaft 2.

(20) The top grip part 1a is provided at its bottom side with a thumb support 17. The bottom grip part 1b has a stable outer shell 18 (FIG. 6) that surrounds an inner sleeve 19 that is comprised of a hard material, preferably of polyethylene or polyamide. The inner sleeve 19 is connected by webs 20 with the outer shell 18. The webs 20 are separated from each other by interstices 21. The webs 20 are comprised of soft plastic material such as appropriate elastomers, rubber or caoutchouc compounds. It is fixedly connected to the outer side of the inner sleeve 19 as well as to the inner side of the outer shell 18. The shape-stable inner sleeve 19 is seated fixedly on the shaft 2. The webs 20 which are comprised of soft plastic material enable a limited torsion of the bottom grip part 1b about the shaft axis of the shaft 2. The torsion angle range can be, for example, approximately +/5. The width of the webs 20 and/or the number of the webs 20 influence in connection with the selection of the soft plastic material the torsion stiffness of the bottom grip part 1b.

(21) The two grip parts 1a, 1b can be separate components which are fastened in the described way on the shaft 2. In deviation from the illustrated and described embodiment, the two grip parts 1a, 1b together can also be formed as one piece. The transition area 33 between the two grip parts 1a, 1b comprises in this case a reduced wall thickness (weakened material section) in comparison to the two grip parts 1a, 1b. In order for the bottom grip part 1b to be able to twist optimally relative to the shaft 2 to a limited extent, the transition area 33 is preferably of a wave-shaped configuration about the circumference of the grip 1.

(22) As a result of the limited torsion possibility of the bottom grip part 1b, it is ensured also for this golf club that involuntary muscle twitches of the golfer have no effect on the precision of the putting direction during putting.

(23) FIG. 7 shows an embodiment in which the grip 1 is embodied as one piece, i.e., is monolithic. The grip 1 is formed by a grip sleeve comprised of plastic material and fastened on the shaft 2 (illustrated schematically by the shaft axis). The portion of the grip sleeve which forms the top grip part 1a is fixedly connected to the shaft 2, for example, is adhesively connected thereto. The part of the grip sleeve which forms the bottom grip part 1b is arranged so as to be turnable to a limited extent on the shaft 2. This can be achieved, for example, in that this grip sleeve area (1b) is fastened on a support sleeve 34, provided as a bearing layer, which is supported so as to be turnable to a limited extent on the shaft 2.

(24) The grip sleeve forming the grip 1 is comprised of elastic plastic material and the transition area 33 between the two grip parts 1a, 1b is formed by a jacket section of the grip sleeve forming the grip 1 that has a reduced thickness (weakened material section). When thus the grip part 1b as a result of the twitch movements of the lead hand of the golfer is rotated relative to the shaft 2 to a minimal extent, the transition area 33 is elastically deformed accordingly by a torsional movement. Accordingly, the muscle twitch has no effect on the putting direction. The transition area 33 forms the torsion-soft area with which the involuntary torsional movements of the lead hand are compensated in that the transition area 33, in accordance with the amount of the torsional movements, is elastically deformed so that the muscle twitches are compensated in this way. Since the transition area 33 has a reduced wall thickness, i.e., a weakened material section, the bottom grip part 1b can be rotated to a limited extent by elastic torsion relative to the shaft 2 and relative to the top grip part 1a. As in the preceding embodiments, the torsion angle range can be, for example, approximately +/5 (relative to the neutralno loadposition.

(25) The support sleeve 34 (bearing layer) is comprised of a hard material, for example, of metal or a hard plastic material. The grip sleeve forming the grip 1, or its bottom grip part 1b, is fixedly connected in a suitable way with the support sleeve 34. The inner diameter of the support sleeve 34 (hard bearing layer) corresponds advantageously to the inner diameter of the top grip part 1a.

(26) Instead of providing the support sleeve 34, it is also possible to produce the bottom grip part 1b of two materials of different hardness. The area of the bottom grip part 1b which is contacting the shaft 2 is comprised of a correspondingly hard material, preferably of a correspondingly hard plastic material. This hard area can be configured to be thin because it is only provided to enable the bottom grip part 1b to carry out a limited turning movement about the shaft axis of the shaft 2. The remaining part of the bottom grip part 1b can be comprised of a gripping-friendly softer material, in particular a softer plastic material.

(27) The grip sleeves forming the grips 1 are components that are commercially available and are comprised of a multi-compound composite. These grip sleeves can be purchased inexpensively and, when they are attached in the described way on the shaft 2 of the golf club, can compensate excellently the involuntary muscle twitches of the golfer without impairing the putting precision.

(28) In the described embodiments, the bottom grip part 1b always returns into its initial (neutral) position as soon as the involuntary muscle twitches stop.

(29) The specification incorporates by reference the entire disclosure of German priority document 10 2015 006 155.0 having a filing date of May 8, 2015.

(30) While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.