WO2000020076A1

WO2000020076A1 - Golf club with polyether block amide striking insert

Info

Publication number: WO2000020076A1
Application number: PCT/US1999/022734
Authority: WO
Inventors: Michael R. Peters; Bret H. Wahl
Original assignee: Taylor Made Golf Company, Inc.
Priority date: 1998-10-05
Filing date: 1999-09-30
Publication date: 2000-04-13

Abstract

A golf club head (14) has a polyether block amide insert (24) that establishes the striking surface (28) of the club head. The insert (24) has a hardness of at least shore 90 (Durometer A) and a rebound factor of at least 60 %. In one preferred embodiment, the golf club (10) is a putter.

Description

GOLF CLUB WITH POLYETHER BLOCK AMIDE STRIKING INSERT

FIELD OF THE INVENTION

The present invention relates generally to golf clubs, and more particularly to resilient inserts on the striking surfaces of golf club heads.

BACKGROUND

Resilient inserts have been fitted to golf club heads to establish the golf ball striking surface of the head. It is thought that such inserts provide the golfer with a better, softer feel when striking a golf ball, as compared to the feel obtained when striking a golf ball with a golf club that has a metal striking surface. Consequently, resilient inserts are thought to provide better control of the ball visa-vis golf clubs that have metal striking surfaces.

One drawback with resilient inserts is that a golf ball generally does not rebound off of an insert as far as it would otherwise rebound of off a metal striking surface. Consequently, a golfer must account for this by altering the vigor of his swing, depending on whether he is using a golf club with a metal striking surface or with a resilient striking surface. This is undesirable because golfers generally prefer to develop and use a consistent, repeatable swing.

Representative of past efforts to provide resilient inserts are U.S. Pat. No. 4,422,638 to Tucker and U.S. Pat. No. 5,674,132 to Fisher. Both of the above- mentioned patents use forms of urethane material for the resilient insert. As disclosed in Tucker, a type of urethane having a hardness of shore 83 (Durometer A) is "essential for good ball control as to direction and distance" as compared to urethanes having hardnesses of shore 90 (Durometer A) or more, because Tucker observes that the harder urethanes "failed to provide the desired feel and touch; and, additionally, had rebound characteristics [that were] inferior".

Likewise, Fisher discloses using single-ply urethane inserts having hardnesses up to shore 85 (Durometer A). Fisher also discloses a two-ply insert having an outer lamination of shore 90 and an inner lamination of shore 70, but the resulting average hardness of the insert is less than shore 90. Also, to establish his desired "feel", Fisher does not explicitly disclose a specific numerical rebound factor (that is, the ratio of the height reached by a ball bouncing off an insert to the height from which the ball was dropped onto the insert) of more than 50% .

Thus, neither Fisher nor Tucker appear to envision the use of a non- urethane insert. Further, the above-mentioned teachings appear to advise against the exclusive use of any single-ply resilient insert having a hardness of more than shore 85 (Durometer A), and in any case the above-noted teachings do not advise using any insert (whether single ply or two-ply) having an average hardness of shore 90 or more. As recognized by the present invention, however, in marked distinction to the above-noted teachings many golfers have determined that inserts should preferably have hardnesses of shore 90 (Durometer A) or more. Fortunately, the present invention recognizes that it is possible to provide a resilient insert for a golf club head that in turn provides a good "feel", good control, while possessing a hardness of shore 90 (Durometer A) or more.

SUMMARY OF THE INVENTION

A golf club head includes a metal body defining a cavity and a front surface, and a resilient insert made of poly ether block amide is disposed in the cavity. The insert defines a striking surface that is juxtaposed with the front surface.

In a preferred embodiment, the insert has a hardness of at least shore 90 (Durometer A), and more preferably has a hardness of at least shore 91 (Durometer A). Also, the preferred insert has a rebound factor of more than 50%. More preferably, the rebound factor is more than 60%. As disclosed in detail below, the preferred insert defines a main surface, and protrusions are formed on the main surface and extend beyond the main surface. The protrusions collectively define the striking surface.

In another aspect, a polyether block amide insert is configured for engaging a golf club head to establish a striking surface thereof.

In yet another aspect, a golf club includes a shaft and a metal body on an end of the shaft. A resilient insert is engaged with the body to define a golf ball- striking surface having a hardness of at least shore 90 (Durometer A) and a rebound factor of more than 50% .

The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is an exploded perspective view of the present golf club, with portions of the golf club shaft broken away for clarity;

Figure 1 A is a front plan view of the club shown in Figure 1 , with the insert engaged with the club head; and

Figure 2 is a cross-sectional view as seen along the line 2-2 in Figure 1A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Figures 1 and 2, a golf club is shown, generally designated 10, that includes an elongated club shaft 12 and a golf club head, generally designated 14, on a distal end 16 of the shaft 12. The golf club head 14 is engaged with the shaft 12 in accordance with principles known in the art. In one embodiment, the golf club 10 is a putter.

As shown in cross-reference to Figures 1 and 2, the golf club head 14 includes a metal body 18 defining a front surface 20 and a cavity 22 formed in the front surface 20. The body 18 can be made of steel, titanium, aluminum, or other appropriate metal.

A single unitary resilient insert 24 is disposed in the cavity 22 in a close interference fit with the body 18. If desired, the insert 24 can be parallelepiped- shaped or other shape, but more preferably is somewhat catenary-shaped as shown.

To hold the insert 24 in the cavity 22, a double-backed adhesive tape strip 26 can be disposed between the insert 24 and body 18 as shown in Figure 2. Other means for holding the insert 24 in the body 18 can be used, e.g. , ultrasonic welding, rf sealing, gluing, or other bonding techniques known in the art.

Still referring to Figures 1 and 2, the preferred insert 24 is made of poly ether block amide having a hardness of at least shore 90 (Durometer A), and preferably having hardness of at least shore 91 (Durometer A) up to a hardness of shore 99 (Durometer A). It will readily be appreciated that because the preferred insert 24 is established by one and only one lamination or piece of material, the above hardnesses establish the average hardness of the insert 24.

Further, the insert 24 has a rebound factor of more than 50%, and preferably a rebound factor at least 60%. In one preferred embodiment, the insert 24 is made of type Pebax 1205 poly ether block amide marketed under the trademark "Pebax" by Elf Atochem of France. The preferred chemical structure for the polyether block amide consists of a regular linear chain of rigid polyamide segments (designated "PA" below) interspaced with flexible polyether segments (designated "PE" below), the general chemical formula for which is: HO - C - PA - C - O- PE - O - H O

In cross-reference to Figures 1 and 2, the insert 24 defines a striking surface, generally designated 28, that is juxtaposed with and indeed that is substantially flush with (or slightly extending beyond, by about five mils) the front surface 20 of the body 18. In the preferred embodiment, the insert 24 includes a planar main surface 30 and disc-shaped protrusions 32 formed integrally on the main surface 30. As shown in Figure 1, the protrusions 32 extend beyond the main surface 30. In accordance with the present invention, exposed circular surfaces 34 of the protrusions 32 collectively establish the striking surface 28. Details of the preferred protrusions 32 are set forth in co-pending U.S. patent application serial no. 09/035,277, filed March 9, 1998, for an invention entitled "Golf Club Head", owned by the same assignee as the present invention and incorporated herein by reference. Owing to the tackiness of the insert 24 and its cushiness, a golf ball dwells longer on the striking surface 28 of the head 14 during the stroke, compared to a metal-only head against which a golf ball might undesirably slip or skid laterally during the stroke.

While the particular GOLF CLUB WITH POLYETHER BLOCK AMIDE STRIKING INSERT as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more" . All structural and functional equivalents to the elements of the above- described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims.

Claims

WHAT IS CLAIMED IS:

1. A golf club head (14), comprising: a metal body (18) defimng a cavity (22) and a front surface (20); and a resilient insert (24) made of polyether block amide disposed in the cavity (22), the insert (24) defining a striking surface (28) juxtaposed with the front surface (20).

2. The golf club head (14) of Claim 1, wherein the insert (24) has a hardness of at least shore 85 (Durometer A).

3. The golf club head (14) of Claim 1, wherein the insert (24) is made of Pebax 1205.

4. The golf club head (14) of Claim 1, wherein the insert (24) has a hardness of at least shore 90 (Durometer A).

5. The golf club head (14) of Claim 4, wherein the insert (24) has a hardness of at least shore 91 (Durometer A).

6. The golf club head (14) of Claim 1, wherein the insert (24) has a rebound factor of more than 50% .

7. The golf club head (14) of Claim 6, wherein the insert (24) defines a main surface (30), and the golf club head (14) further comprises protrusions (32) on the insert (24) extending beyond the main surface (30).

8. The golf club head (14) of Claim 1, in combination with a golf club shaft (12) to establish a golf club (10).

9. The golf club of Claim 8, wherein the golf club (10) is configured as a putter.

10. A golf club, comprising: a shaft (12); a metal body (18) on an end of the shaft (12); and a resilient insert (24) engaged with the body (18) to define a golf ball-striking surface (28) having a hardness of at least shore 90 (Durometer

A) and a rebound factor of more than 50%.