US20240091607A1

US20240091607A1 - Method of forming a supported iron

Info

Publication number: US20240091607A1
Application number: US17/946,911
Authority: US
Inventors: Joshua D. Westrum; Christopher Savage
Original assignee: Acushnet Co
Current assignee: Acushnet Co
Priority date: 2022-09-16
Filing date: 2022-09-16
Publication date: 2024-03-21
Also published as: US20240374969A1

Abstract

The present invention is directed to a set of golf clubs comprising long irons, mid irons and short irons. Preferably, at least the long and mid irons have a face stabilizing bar and back panel and the face stabilizing bar includes a retainer clip and elastomeric material.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to iron golf clubs, and more particularly, to iron golf clubs that provide a structural support across the back surface of the face.

BACKGROUND OF THE INVENTION

In conventional sets of “iron” golf clubs, each golf club includes a shaft with a club head attached to one end and a grip attached to the other end. The club head includes a face for striking a golf ball. The angle between the face and a vertical plane is called “loft.” In general, the greater the loft is of the golf club in a set, the greater the launch angle a struck golf ball will have and it will travel less distance.
A set of irons generally includes individual irons that are designated as number 3 through number 9, and a pitching wedge. The iron set is generally complimented by a series of wedges, such as a lob wedge, a gap wedge, and/or a sand wedge. Sets can also include a 1 iron and a 2 iron, but these golf clubs are generally sold separately from the set. Each iron has a shaft length that usually decreases through the set as the loft for each golf club head increases, from the long irons to the short irons. The length of the club, along with the club head loft and center of gravity impart various performance characteristics to the ball's launch conditions upon impact. The initial trajectory of the ball generally extends between the impact point and the apex or peak of the trajectory. In general, the ball's trajectory for long irons, like the 3 iron, is a more penetrating, lower trajectory due to the lower launch angle and the increased ball speed off of the club. Short irons, like the 8 iron or pitching wedge, produce a trajectory that is substantially steeper and less penetrating than the trajectory of balls struck by long irons. The highest point of the long iron's ball flight is generally lower than the highest point for the short iron's ball flight. The mid irons, such as the 5 iron, produce an initial trajectory that is between those exhibited by balls hit with the long and short irons.
Prior art clubs include Titleist AP2 irons that included a support bar extending across the back of the iron from the heel to the toe. A portion of the support bar included a partial channel that was filled by a preformed polymer tab that was press fit into the channel.

SUMMARY OF THE INVENTION

The techniques described herein relate to a method of forming a golf club including the steps of: forging a body with a topline, sole portion, toe portion, heel portion, and a face stabilizing bar having a face stabilizing bar length between the heel portion and toe portion and a face stabilizing bar top surface facing the topline and a face stabilizing bar bottom surface facing the sole portion; machining an aperture into the face stabilizing bar from the top surface to the bottom surface, machining a ledge into the face stabilizing bar; attaching a weight member and a back panel to the body to form an undercut, placing a retention clip such that it abuts the ledge and forms a filler volume between the retention clip and the face stabilizing bar top surface; filling the filler volume with a flowable elastomeric material; and curing the elastomeric material. In some aspects, the techniques described herein relate to a method further including the step of machining the aperture to form an aperture length from the heel portion to the toe portion that is a distance of greater than about 50% and less than about 95% of the face stabilizing bar length and an aperture width.
In a preferred embodiment, the method further includes the step of machining a face side ledge having a first ledge width and a back side ledge having a second ledge width and an overall ledge length that is greater than the aperture length and the elastomer retention clip is formed to include a channel having a width less than the aperture width and extensions having an overall retention clip width of greater than the aperture width and less than the aperture width plus the first ledge width and second ledge width. Moreover, it is preferred that the retainer clip has a retainer clip length that is at least 10% greater than the aperture length. Preferably, the retention clip is formed from a non-metal material having a hardness of greater that 70 Shore D and a specific gravity of less than 2. In another embodiment, the retention clip is formed from a metal material, and more preferably, a metal having a specific gravity of less than 8, and most preferably less than 5.
In one preferred embodiment of the present inventive method, the elastomeric material is comprised of a cast urethane having a hardness of less than 70 Shore D and more preferably, less than 60 Shore D. Alternatively, the elastomeric material can be comprised of a cast silicone having a hardness of less than 50 Shore D, and more preferably, more than 60 Shore A. Most preferably, the elastomeric material has a material hardness of less than 50 Shore C and greater than 60 Shore A.
In a preferred method, the channel formed in the retention clip has a channel depth and the face stabilizing bar has a bar depth and the channel depth is greater than the bar depth. More preferably, the channel depth is at least 20% greater than the bar depth.
In some aspects, the method comprises forming the retainer clip to a first thickness and the elastomeric material to a second thickness greater than the first thickness, particularly when the retainer clip has a first harness and the elastomeric material has a second hardness less than the first hardness.
In another preferred embodiment, the method comprises forming the aperture at an angle relative to the face such that the aperture is spaced from the face a first, maximum distance at the top of the aperture and a second minimum distance at the bottom of the aperture. Moreover, the maximum distance and minimum distances are preferably between 1.5 mm and 5 mm and most preferably between 1.7 mm and 4 mm. In a preferred embodiment, the maximum distance between the face and the aperture is greater than 3 mm and the minimum distance between the face and the aperture is less than 3 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a back, exploded view of an iron golf club made according to the present invention;

FIG. 2 is a perspective view of a portion of an iron golf club made according to the present invention;

FIG. 3 is a perspective view of a portion of another iron golf club made according to the present invention;

FIG. 4 is a cross-sectional, close-up view of a portion of an iron golf club made according to the present invention; and

FIG. 5 is a cross-sectional, close-up view of a portion of another iron golf club made according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated in the accompanying drawings and discussed in detail below, the present invention is directed to a method of forming an iron-type golf club, wherein the golf club has an improved face stabilizing bar.
Referring to FIG. 1 , an iron golf club in the set includes an iron head 10 attached to a shaft (not shown) in any manner known in the art, at a hosel 20. The hosel 20 is bored to received the shaft and form the shaft axis SA. The irons of the present invention have a lofts of between about 15 and 48 degrees as is well known in the art. Club head 10 includes, generally, the hosel 20, a striking or hitting face and a back portion that can be cavity backed or muscle backed as is well known in the art. The club head also has a heel portion 12, a toe portion 14, a top line portion 22 and a sole portion 24. As is well know in the art, the club head 10 and hosel 20 are designed such that the club has a center of gravity CG that is located between the toe portion 14 and heel portion 12 and between the top line portion 22 and the sole portion 24.
The iron head 10 further includes a face stabilizing bar 38 extending from proximate the heel portion 12 to proximate the toe portion 14. Most preferably, the face stabilizing bar 38 extends across the back of the striking face near or coincidental with the face center FC. As shown in FIG. 2 , the face stabilizing bar 38 includes an aperture 40 that has an aperture length AL from the heel portion 12 to the toe portion 14 that is a distance of greater than about 50% and less than about 95% of the face stabilizing bar length SBL.
Preferably, the golf club is formed by: forging an iron head 10 with a topline 22, sole portion 24, toe portion 14, heel portion 12, and a face stabilizing bar 38 having a face stabilizing bar length SBL between the heel portion 12 and toe portion 14. The face stabilizing bar 38 includes a face stabilizing bar top surface 42 facing the topline 22 and a face stabilizing bar bottom surface 44 facing the sole portion 24. Then, an aperture 40 is machined into the face stabilizing bar 38 from the top surface 42 to the bottom surface 44. Then, the top surface 42 is machined to form a ledge in the face stabilizing bar 38. The process further comprises attaching at least one weight member (32 and 34) and a back panel 16 to the iron head 10 preferably by welding. Then, a retention clip 50 is located within the face stabilizing bar 38 such that it abuts the ledge and forms a filler volume between the retention clip 50 and the face stabilizing bar top surface 42. The retention clip 50 and face stabilizing bar 38 form a filler volume that can be filled with a flowable elastomeric material that is then cured. When machining the aperture 40 to form an aperture length AL, it is preferred that the aperture length AL is a distance of greater than about 50% and less than about 95% of the face stabilizing bar length SBL.
The face stabilizing bar 38 also has a bar depth DB and the retention clip 50 sits within the machined aperture 40 by abutting the machined ledge such that the retention clip forms a retention clip depth DRC with the stabilizing bar top surface 42. In the preferred embodiment, the retention clip depth DRC is greater than the stabilizing bar depth DB, and more preferably, more that 20% greater.
In an embodiment of the present invention, the iron golf club shown in FIG. 1 also includes the plurality of weight members 32 and 34. The weight members 32 and 34 may be embedded into a lower chamber or cavity 17 as set forth in detail in U.S. Pat. No. 8,157,673, which is incorporated by reference in its entirety since the patent is entirely directed to the weight members used in the preferred type of construction having the preferred center of gravity CG location and the frequencies of the preferred irons that can be made thereby.
Also, as shown in FIG. 1 herein, the heel weight 34 can be preferably inserted into an aperture machined into the sole portion 24 adjacent the heel portion 12. As shown, the weight aperture can be formed to be coextensive with the shaft axis SA such that the heel weight 34 is located such that it is intersected by the shaft axis SA. Alternatively, as shown in FIG. 2 , the weight aperture 42 can be formed into the heel portion 12 adjacent the sole portion 24, but can still allow the heel weight member 34 to be intersected by the shaft axis SA. The toe weight member 32 is most preferably secured into a weight cavity 18 formed in the lower toe portion of the cavity 17. In the preferred embodiment, the weight members 32 and 34 have a greater density than the material used to form the iron head 10 and preferably a density of greater than 2 times the density of the iron head 10. Most preferably the weight members 32 and 34 have a density of about 17 g/cc.
In the iron head 10 construction, the weight members 32 and 34 are sized and positioned to optimize the irons moment of inertia about a vertical axis through the center of gravity CG, MOI-Y, and the moment of inertia about the shaft axis SA, MOI-SA. Preferably, the long iron weight members 32 and 34 are each between about 10 g and 40 g. Combined, the weight members 32 and 34 should comprise greater than about 10% of the total iron head 10 weight. Preferably, the weight members 32 and 34 for the long irons are located such that the weight members 32 and 34 are located below the club CG in the vertical direction. Most preferably, the weight members 32 and 34 are located at least about 75% of the blade length BL away from each other to maximize MOI-Y. The iron head 10, including the weight members 32 and 34, is constructed such that the CG is also allocated in an optimal position relative to the face center FC and the shaft axis SA.
Referring now to FIGS. 3 and 4 , the iron head 110 includes the topline 122, the toe portion 114, the sole portion 124 and the back panel 116. As shown, the face stabilizing bar 138 includes the retention clip 150 located within the aperture 140. In the close up view of FIG. 4 , the ledge 142 and 144 is shown more clearly. The ledge includes a face side ledge 142 and a back side ledge 144. The aperture 140 has a width W1, the face side ledge 142 had a width W2 and the back side ledge 144 has a width W3. The retention clip 150 is formed to have an overall width W4 and a channel width W5. The retention clip overall width W4 is greater than the aperture width W1, but the channel width W5 is less than the channel width W1 such that the channel portion of the retention clip can extend through the aperture 140. The retention clip overall width W4 is preferably greater that W1, but less that W1+W2+W3.
In a preferred embodiment of the invention, the aperture width W1 is between about 5 mm and 15 mm and the channel width W5 is between 60% and 95% of the aperture width W1. The front side ledge width W2 and the back side ledge width W3 are preferably substantially the same and are between about 1 mm and 4 mm. Also, the overall retention clip width W4 is more that 105% of the aperture width W1 and less than 95% of the aperture width W1 plus the face side ledge width W2 and the back side ledge width W3. Thus, the following equations are satisfied in the preferred embodiment:

- a. W4>1.05×W1
- b. W4<0.95 (W1+W2+W3)

Still further, the aperture 140 is spaced from the face 120 a first, maximum distance DFAM at a top portion of the aperture 140. The distance DFAM is measured to perpendicular from to the face 120 to the aperture 140. The aperture 140 is spaced a second, minimum distance from the face 120, DFAm, at the bottom portion of the aperture 140. Preferably, the distance DFAM is at least 5% greater than the distance DFAm and both distances are preferably between 1.5 mm and 5 mm and more preferably between 1.7 mm and 4 mm. More preferably, the maximum distance DFAM is greater than 3 mm and the minimum distance DFAm is less than 3 mm.
Referring to FIG. 5 , in another embodiment of the present invention, an iron head 200 can include a face stabilizing bar 238 having an aperture 240 machined therethrough and a front side ledge 242 and a rear side ledge 244 machined therein. Preferably, the face stabilizing bar 238 is located near the face center FC in the vertical direction. Similar to the embodiment above, the aperture width W1 is between about 5 mm and 15 mm. The front side ledge width W2 and the back side ledge width W3 are preferably substantially the same and are between about 1 mm and 4 mm. Also, the overall retention clip width W4 is more that 105% of the aperture width W1 and less than 95% of the aperture width W1 plus the face side ledge width W2 and the back side ledge width W3. Thus, the following equations are satisfied in the preferred embodiment:

- a. W4>1.05×W1
- b. W4<0.95 (W1+W2+W3)

Moreover, in this embodiment, the retention clip has an overall length in the x-direction, parallel to the face, that is at least 120% of the aperture length AL (shown in FIG. 2 ). Also, the retention clip is substantially flat with a retention clip depth DR and the elastomeric material has a depth DE that is preferably greater than the retention clip depth DR, and more particularly, the elastomeric material depth DE is greater than 1.2 times the retention clip depth DR.
In this embodiment, it is preferred that the retention clip is formed of metal, such as aluminum, or a firmer plastic such as a thermoplastic material having a Shore D hardness of greater than 50, such as Kyron Max. Preferably, the elastomeric material is formed of a material that is substantially softer than the retention clip, and more preferably, comprises a thermoset silicon having a Shore C hardness of less than 80, and most preferably, having a Shore A hardness of less than 90.
While it is apparent that the illustrative embodiments of the present invention disclosed herein fulfill the objectives stated above, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Therefore, it will be understood that the appended claims are intended to cover all modifications and embodiments which would come within the spirit and scope of the present invention.

Claims

What is claimed is:

1. A method of forming a golf club comprising the steps of:

forging a body with a face, a topline, sole portion, toe portion, heel portion, and a face stabilizing bar having a face stabilizing bar length between the heel portion and toe portion and a face stabilizing bar top surface facing the topline and a face stabilizing bar bottom surface facing the sole portion;

machining an aperture into the face stabilizing bar from the top surface to the bottom surface,

machining a ledge into the face stabilizing bar;

attaching a weight member and a back panel to the body to form an undercut,

placing a retention clip such that it abuts the ledge and forms a filler volume between the retention clip and the face stabilizing bar top surface;

filling the filler volume with a flowable elastomeric material; and

curing the elastomeric material.

2. The method of forming a golf club according to claim 1, further comprising the step of machining the aperture to form an aperture width and an aperture length from the heel portion to the toe portion that is a distance of greater than about 50% and less than about 95% of the face stabilizing bar length and an aperture width.

3. The method of forming a golf club according to claim 2, further comprising the step of machining a face side ledge having a first ledge width and a back side ledge having a second ledge width and an overall ledge length that is greater than the aperture length.

4. The method of forming a golf club according to claim 3, further comprising the step of forming the elastomer retention clip to a include a channel having a width less than the aperture width and extensions having an overall retention clip width of greater than the aperture width and less than the aperture width plus the first ledge width and second ledge width.

5. The method of forming a golf club according to claim 1, wherein the retention clip is formed from a non-metal material.

6. The method of forming a golf club according to claim 1, wherein the retention clip is formed from a metal material.

7. The method of forming a golf club according to claim 1, wherein the elastomeric material is comprised of a cast urethane.

8. The method of forming a golf club according to claim 1, wherein the elastomeric material is comprised of a cast silicone.

9. The method of forming a golf club according to claim 3, wherein the channel has a channel depth and the channel depth is greater than the aperture width.

10. The method of forming a golf club according to claim 9, wherein the face stabilizing bar has a bar depth and the channel depth is greater than the bar depth.

11. The method of forming a golf club according to claim 9, wherein the face stabilizing bar has a bar depth and the channel depth is at least 20% greater than the bar depth.

12. The method of forming a golf club according to claim 6, wherein the retainer clip has a first thickness and the elastomeric material has a second thickness greater than the first thickness.

13. The method of forming a golf club according to claim 12, wherein the retainer clip has a first harness and the elastomeric material has a second hardness less than the first hardness.

14. The method of forming a golf club according to claim 13, wherein the retainer clip has a retainer clip length that is at least 10% greater than the aperture length.

15. The method of forming a golf club according to claim 1, wherein the method further comprises forming the aperture at an angle relative to the face such that the aperture is spaced from the face a maximum distance at a top portion of the aperture that is greater than 3 mm and a minimum distance at a bottom portion of the aperture that is less than 3 mm.