Method of manufacturing golf club head having stress-reducing features

Abstract

A method of manufacturing a golf club head with a plurality of stiffening members proximate the face, and particularly solid rods or a plate with one or more cutouts, is disclosed herein. The method includes the steps of preparing a wax of a golf club head body having at least one through-hole, a hollow interior, and at least one receiving pocket, preparing waxes of one or more stiffening members, inserting the wax of the stiffening members into the through-hole and seating its opposite end in the receiving pocket, bonding each of the stiffening members to the body with an adhesive material to form a combined wax mold, and casting a golf club head from the combined wax mold.

Description

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a method of manufacturing a golf club head with stress-reducing stiffening members, the stress-reducing stiffening members connecting a crown portion with a sole portion via a hollow interior and disposed proximate a striking face section.

Description of the Related Art

The prior art discloses various golf club heads having interior structures. For example, Kosmatka, U.S. Pat. No. 6,299,547 for a Golf Club Head With an Internal Striking Plate Brace, discloses a golf club head with a brace to limit the deflection of the striking plate, Yabu, U.S. Pat. No. 6,852,038 for a Golf Club Head And Method of Making The Same, discloses a golf club head with a sound bar, Galloway, U.S. Pat. No. 7,118,493 for a Multiple Material Golf Club Head, discloses a golf club head with a composite aft body having an interior sound component extending upward from a sole section of a metal face component, Seluga et al., U.S. Pat. No. 8,834,294 for a Golf Club Head With Center Of Gravity Adjustability, discloses a golf club head with a tube having a mass for adjusting the CG of a golf club head, and Dawson et al., U.S. Pat. No. 8,900,070 for a Weighted Golf Club Head discloses a golf club head with an interior weight lip extending from the sole towards the face. However, the prior art fails to disclose an interior structure that increases ball speed through reducing stress in the striking face section at impact, with a minimal increase in mass to the golf club head.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a method of manufacturing a golf club head comprising interior structures connecting a return section to a sole section to reduce the stress in a striking face section during impact with a golf ball. The interior structures are a plate or one or more solid rods that are co-cast with a body portion of the golf club head via a wax-welding processes.

One aspect of the present invention is a method comprising the steps of preparing a wax of a golf club head body, the wax of the golf club head body comprising a striking face section, a sole section extending from a lower edge of the striking face section, and a return section extending from an upper edge of the striking face section, the striking face section, sole section, and return section defining a hollow body interior, the return section comprising an elongated through-hole, and the sole section comprising an elongated receiving pocket, preparing a wax of a plate comprising an upper end and a lower end, inserting the plate into the elongated through-hole and seating the lower end in the elongated receiving pocket, bonding the plate to the body with an adhesive material to form a combined wax mold, and casting a golf club head from the combined wax mold, wherein the through-hole is aligned with the receiving pocket, wherein the plate is has a variable thickness ranging from 0.020 inch to 0.160 inch, wherein the plate is located within 1 inch of a rear surface of the striking face section measured along a vertical plane extending through a face center perpendicular to the striking face section, and wherein no portion of the plate makes contact with the striking face section.

In some embodiments, the plate may be spaced a distance of no more than 0.210 inch from the rear surface. In other embodiments, the step of bonding the plate to the body may comprise applying glue around an entire circumference of each of the upper and lower ends of the plate. In still other embodiments, the method may further comprise the step of applying hot wax to the upper end of the plate to seal it to the return section after the step of bonding the plate to the body. In yet another embodiment, the step of casting a golf club head from the combined wax mold may comprise casting the golf club head from a titanium alloy. In any of these embodiments, the plate may comprise at least one cutout. In another embodiment, the plate may have a length of 1 inch to 2.5 inches. In some embodiments, the upper end may be spaced a first distance from the rear surface, the lower end may be spaced a second distance from the rear surface, and the second distance may be greater than the first distance. In a further embodiment, the first distance may be 0.120 inch to 0.150 inch, and the second distance may be 0.180 inch to 0.210 inch. In any of the embodiments, the plate may extend through the hollow body interior approximately parallel with the rear surface.

Another aspect of the present invention is a method comprising the steps of: preparing a wax of a golf club head body, the wax of the golf club head body comprising a striking face section, a sole section extending from a lower edge of the striking face section, and a return section extending from an upper edge of the striking face section, the striking face section, sole section, and return section defining a hollow body interior, the return section comprising an elongated receiving pocket, and the sole section comprising an elongated through-hole, preparing a wax of a plate comprising an upper end, a lower end, and at least one cutout, inserting the plate into the elongated through-hole and seating the upper end in the elongated receiving pocket so that the plate is located within 1 inch of a rear surface of the striking face section measured along a vertical plane extending through a face center perpendicular to the striking face section, bonding the plate to the body with an adhesive material to form a combined wax mold, and casting a golf club head from the combined wax mold, wherein the through-bore is aligned with the receiving pocket, wherein the plate is has a variable thickness ranging from 0.020 inch to 0.160 inch, and wherein no portion of the plate makes contact with the striking face section.

In some embodiments, the step of bonding the plate to the body may comprise applying glue around an entire circumference of each of the upper and lower ends of the plate. In another embodiment, the method may further comprise the step of applying hot wax to the lower end of the plate to seal it to the sole section after the step of bonding the plate to the body. In any of the embodiments, the step of casting a golf club head from the combined wax mold may comprise casting the golf club head from a titanium alloy. In still other embodiments, the plate may have a length of 1 inch to 2.5 inches, and the plate may extend through the hollow body interior approximately parallel with the rear surface.

Yet another aspect of the present invention is a method comprising the steps of preparing a wax of a golf club head body, the wax of the golf club head body comprising a striking face section, a sole section extending from a lower edge of the striking face section, and a return section extending from an upper edge of the striking face section, the striking face section, sole section, and return section defining a hollow body interior, the return section comprising an elongated receiving pocket, and the sole section comprising an elongated through-hole, preparing a wax of a plate comprising at least one cutout, an upper end, and a lower end, inserting the plate into the elongated through-hole and seating the upper end in the elongated receiving pocket so that the plate is located within 1 inch of a rear surface of the striking face section measured along a vertical plane extending through a face center perpendicular to the striking face section, bonding the plate to the body with an adhesive material to form a combined wax mold, applying hot wax to the lower end of the plate to seal the lower end of the plate to the sole section and casting a golf club head from the combined wax mold, wherein the through-bore is aligned with the receiving pocket, wherein the plate has a variable thickness ranging from 0.020 inch to 0.160 inch and a length of 1 inch to 2.5 inches, wherein the plate extends through the hollow body interior approximately parallel with the rear surface, and wherein no portion of the plate makes contact with the striking face section.

In some embodiments, the plate may comprise a flared region at the lower end sized to fill the elongated through-hole. In still another embodiment, the plate may comprise a plurality of cutouts. In yet another embodiment, the step of bonding the plate to the body may comprise applying glue around an entire circumference of each of the upper and lower ends of the plate.

Having briefly described the present invention, the above and further objects, features, and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a flow chart describing the process of co-casting stiffening members such as one or more rods or a plate with a golf club head body of the present invention.

FIG. 2 is a top perspective view of a wax mold of a first embodiment of the golf club head body of the present invention.

FIG. 3 is an enlarged view of the circled portion of the wax mold shown in FIG. 2.

FIG. 4 is an exploded view of the wax mold shown in FIG. 2 with two wax rods.

FIG. 5 is a top perspective, assembled view of the wax mold shown in FIG. 4.

FIG. 6 is a partially transparent view of the wax mold shown in FIG. 5.

FIG. 7 is a top perspective, partially transparent view of the wax mold shown in FIG. 6.

FIG. 8 is a cross-sectional view of the wax mold shown in FIG. 7 along lines 8-8.

FIG. 9 is a cross-sectional view of the wax mold shown in FIG. 7 along lines 9-9.

FIG. 10 is a rear elevational view of a wax mold of a second embodiment of the golf club head body of the present invention.

FIG. 11 is a rear perspective view of the wax mold shown in FIG. 10.

FIG. 12 is a sole perspective view of the wax mold shown in FIG. 10.

FIG. 13 is a sole plan view of the wax mold shown in FIG. 10.

FIG. 14 is a cross-sectional view of the wax mold shown in FIG. 13 along lines 14-14.

FIG. 15 is an enlarged, angled view of the circled portion of the embodiment shown in FIG. 14.

FIG. 16 is a rear elevational view of the wax plate portion of the wax mold shown in FIG. 10.

FIG. 17 is a rear plan view of the wax plate shown in FIG. 16.

FIG. 18 is a rear elevational view of a wax mold of a third embodiment of the golf club head body of the present invention.

FIG. 19 is a rear plan view of the wax plate portion of the wax mold shown in FIG. 18.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a method of manufacturing a body for a golf club head that includes structural members, also referred to as stiffening members, and particularly a pair of solid rods or a variable thickness plate with or without cutout portions, that extend between a return section and a sole section approximately parallel with a rear surface of a striking face section (and, in the case of multiple stiffening members, with each other) without touching the rear surface (or one another), even during impact with a golf ball. In particular, the present invention is a method of co-casting the stiffening member(s) with the body.

As illustrated in FIG. 1, the preferred method includes a first step 110 of preparing a wax of the main body 20. As shown in FIGS. 2-9, the wax of the main body 20 in a first embodiment has a striking face section 30 with a face center 34 and a rear surface 36, a return section 32 extending rearwards away from an upper edge 31 of the striking face section 30, a sole section 22 extending rearwards away from a lower edge 33 of the striking face section 30, a hosel 24 for engaging a shaft, a heel end 23, a toe end 25, an upper opening 26, a hollow interior 27, and an aft end 28. A pair of holes 40, 42 extends through the return section 32 and communicates with the hollow interior 27; each hole 40, 42 is aligned with one of a pair of receiving pockets 44, 46 extending from an interior surface 22a of the sole section 22 into the hollow interior 27. As shown in FIGS. 8 and 9, shallow depressions 45, 47 extend into an outer surface 22b of the sole section 22 and are aligned with the receiving pockets 44, 46 to indicate their locations within the hollow interior 27. This configuration can be reversed in an alternative embodiment, such that the holes 40, 42 extend through the sole section 22 and the receiving pockets 44, 46 extend from the return section 32 into the hollow interior 27. The body 20 also includes three cutouts 70, 72, 74 in a center area 21 of the sole section 22.

The wax of the main body 20 in other embodiments, such as the second and third (preferred) embodiments shown in FIGS. 10-15 and 18, has many of the same features as that of the first embodiment, except that it includes a cutout portion 35 in the striking face section 30 sized to receive a face insert (not shown), a single, elongated hole 41 extending into the sole section 22, and a single, elongated receiving pocket 43 extending from the return section 32 into the hollow interior 27. Both the elongated hole 41 and the elongated receiving pocket 43 extend in a heel 23 to toe 25 direction approximately parallel with the striking face section 30. The configuration of the elongated hole 41 and the elongated receiving pocket 43 may be reversed in alternative embodiments, such that the elongated hole 41 extends through the return section 32 and the receiving pocket 43 may extend from the sole section 22 into the hollow interior 27. Either way, the elongated hole 41 aligns with the elongated receiving pocket 43.

The body 20 in all embodiments disclosed herein preferably has a volume from 200 cubic centimeters to 600 cubic centimeters, more preferably from 300 cubic centimeters to 500 cubic centimeters, and most preferably from 420 cubic centimeters to 470 cubic centimeters, with a most preferred volume of 450 to 460 cubic centimeters. The striking face section 30 or face insert (not shown) preferably has a varying thickness such as that described in U.S. Pat. No. 7,448,960, for a Golf Club Head With Variable Face Thickness, which is hereby incorporated by reference. Other alternative embodiments of the thickness of the striking face section 30 or face insert (not shown) are disclosed in U.S. Pat. No. 6,398,666, for a Golf Club Striking Plate With Variable Thickness, U.S. Pat. No. 6,471,603, for a Contoured Golf Club Face and U.S. Pat. No. 6,368,234, for a Golf Club Striking Plate Having Elliptical Regions Of Thickness, all of which are owned by Callaway Golf Company and which are hereby incorporated by reference. Alternatively, the striking face section 30 or face insert (not shown) may have a uniform thickness.

The second step 120, preparing a wax of one or more stiffening members, can be performed at the same time as the first step 110. As shown in the first embodiment, the stiffening members are solid rods 50, 52, each of which is cylindrical, has a diameter of 0.050 inch to 0.200 inch, and has a length of 1 to 2.5 inches. Each of the rods 50, 52 also has an upper end 50a, 52a and a lower end 50b, 52b. The solid rods 50, 52 have a variable diameter to reduce their overall mass, such that the upper ends 50a, 52a and lower ends 50b, 52b have diameters that are larger than, and taper towards, a midpoint 50c, 52c of the solid rods 50, 52, so that the solid rods 50, 52 each has an approximate hourglass shape. In the first embodiment, the upper ends 50a, 52a and lower ends 50b, 52b have a diameter of 0.140 to 0.170 inch, while the midpoints 50c, 52c have a diameter of 0.100 to 0.125 inch.

In the preferred embodiment, the stiffening member is a plate 90 with a variable thickness pattern. The variable thickness pattern may be designed using artificial intelligence or machine learning techniques. The plate has an upper end 91, a lower end 92 with a flared region 93, a vertical length L of 1 inch to 2.5 inches, and a front to back thickness T ranging from 0.020 inch to 0.160 inch. The plate 90 preferably has at least one cutout section 94 as shown in FIGS. 10-17, and more preferably a plurality of cutout sections 94 as shown in FIGS. 18-19 to minimize the overall weight of the plate 90 and to maximize performance benefits of the resulting cast golf club head.

Once the waxes of the main body 20 and the stiffening members (solid rods 50, 52 or plate 90) have been prepared, the third step 130 of the method is performed: with respect to the first embodiment, the first solid rod wax 50 is inserted through the first hole 40 until the lower end 50b seats in the first receiving pocket 44, and the second solid rod wax 52 is inserted through the second hole 42 until the lower end 52b seats in the second receiving pocket 46. With respect to the second and third embodiments, the wax plate 90 is inserted through the elongated hole 41 until the upper end 91 seats in the elongated receiving pocket 43. The holes 40, 41, 42 and receiving pockets 43, 44, 46 preferably are oriented such that, when engaged with the body 20, each stiffening member 50, 52, 90 is closer to the striking face section 30 than to an aft end 28 of the body 20.

More preferably, the stiffening members 50, 52, 90 are both located within 1 inch of the rear surface 36 of the striking face section 30 measured along a vertical plane 60 extending through the face center 34 perpendicular to the striking face section 30. No portion of any stiffening member 50, 52, 90 should be located outside of this 1-inch range; in fact, it is more preferable for each stiffening member 50, 52, 90 to be located even closer to the rear surface 36 of the striking face section 30, e.g., 0.136 inch to 0.210 inch from the rear surface 36, with the upper end 50a, 52a, 91 of each stiffening member 50, 52, 90 spaced a distance D₁ that is slightly closer to the rear surface 36 than the spacing D₂ of the lower end 50b, 52b, 92 as shown in FIG. 9. In the preferred embodiment, D₁ ranges from 0.120 inch to 0.150 inch, while D₂ ranges from 0.180 inch to 0.210 inch. As shown in FIG. 8, if rods 50, 52 are the stiffening members employed, the rods 50, 52 are also spaced from one another by a distance D₃ of 0.500 to 2.00 inch, more preferably approximately 0.75 to 1.50 inch, and most preferably approximately 1.00 inch.

In the fourth step 140, the wax stiffening members 50, 52, 90 are bonded to the wax of the main body 20, preferably using a glue and hot wax. With respect to the first embodiment, the upper ends 50a, 52a of the solid rods 50, 52 should be flush with an upper surface 32a of the return section 32 as shown in FIG. 8, and with respect to the second and third embodiments, lower end 92 of the plate 90 should be flush with the outer surface 22b of the sole section 22. The flared region 93 of the lower end 92 of the plate 90 serves to fill in any excess space in the elongated hole 41. In each embodiment, glue is applied around the entire circumference of each stiffening member 50, 52, 90 so that it has a 360° bond to the body 20 at each connection point between the stiffening member 50, 52, 90 and the wax body 20, i.e., at the holes 40, 41, 42 and the receiving pockets 43, 44, 46. Hot wax is then used to melt the upper ends 50a, 52a of the rods 50, 52 and seal them to the return section 32 for the first embodiment, and to melt the lower end 92 of the plate 90 and seal them to the sole section 22 for the second and third embodiments.

The resulting combined wax mold 80 is then used to cast the body via lost-wax casting 150. The metal used for this step preferably is titanium or a titanium alloy such as 6-4 titanium alloy, alpha-beta titanium alloy or beta titanium alloy for forging, and 6-4 titanium for casting. Alternatively, the body 20 is composed of 17-4 steel alloy.

From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.

Claims

1. A method of manufacturing a golf club head having stress-reducing features, the method comprising: preparing a wax of a golf club head body, the wax of the golf club head body comprising a striking face section, a sole section extending from a lower edge of the striking face section, and a return section extending from an upper edge of the striking face section, the striking face section, sole section, and return section defining a hollow body interior, the return section comprising an elongated through-hole, and the sole section comprising an elongated receiving pocket;inserting a wax of a plate into an elongated through-hole of a return section of a wax of a golf club head body, and seating a lower end of the wax plate in an elongated receiving pocket of a sole section of the wax of the golf club head body;bonding the wax of the plate to the wax of the golf club head body with an adhesive material to form a combined wax mold; andcasting a golf club head from the combined wax mold;wherein the elongated through-hole is aligned with the receiving pocket;wherein the wax of the plate is located within one inch of a rear surface of a striking face section of the wax of the golf club head body as measured along a vertical plane extending through a face center perpendicular to the striking face section, andwherein the wax of the plate comprises at least one cutout.

2. The method of claim 1, wherein the plate is spaced a distance of no more than 0.210 inch from the rear surface.

3. The method of claim 1, wherein the step of bonding the plate to the body comprises applying glue around an entire circumference of each of the upper and lower ends of the plate.

4. The method of claim 1, further comprising the step of applying hot wax to the upper end of the plate to seal it to the return section after the step of bonding the plate to the body.

5. The method of claim 1, wherein the step of casting a golf club head from the combined wax mold comprises casting the golf club head from a titanium alloy.

6. The method of claim 1, wherein the step of casting a golf club head from the combined wax mold comprises casting the golf club head from a steel material.

7. The method of claim 1, wherein the plate has a length of 1 inch to 2.5 inches.

8. The method of claim 1, wherein the upper end is spaced a first distance from the rear surface, wherein the lower end is spaced a second distance from the rear surface, and wherein the second distance is greater than the first distance.

9. The method of claim 8, wherein the first distance is 0.120 inch to 0.150 inch, and wherein the second distance is 0.180 inch to 0.210 inch.

10. The method of claim 1, wherein the plate extends through the hollow body interior approximately parallel with the rear surface.