Golf club head manufacturing method

Abstract

A method of manufacturing golf club heads, and particularly putter heads, using metal injection molding and plasma polishing is disclosed herein. The metal injection molding process is facilitated with a base tool having a golf club head shaped cavity and interchangeable hosel core tools. The use of interchangeable hosel core tools allows a manufacturer to quickly and easily alter the overall shape of the putter head, and greatly reduces the number of base tools needed to create an entire line of putter heads with different hosel designs. This plasma polishing process yields a glossy cosmetic shine appearance, increases corrosion and rust resistance, and provides a smoother surface to which post process operations can adhere.

Claims

1. A method comprising the steps of: blending a metal powder with a polymer to create a stock feed material; heating the stock feed to create a liquid material; providing a base tool with a putter head-shaped cavity and a first hosel cavity; providing a plurality of hosel core tools, each having a second hosel cavity with a shape that differs from a shape of each other hosel cavity of the plurality of hosel core tools; inserting one of the plurality of hosel core tools into the first hosel cavity to create a combination tool with a combination cavity; injecting the liquid material into the combination cavity; cooling the combination tool so that the liquid material hardens into a first intermediate product having a size and shape of the combination cavity; removing the first intermediate product from the combination tool; heating the first intermediate product to melt away the polymer material and create a second intermediate product having a smaller size than the first intermediate product; affixing the second intermediate product to a tree housing; placing the tree housing into a chamber comprising an aqueous solution comprising 2.5-5% NaCl; increasing temperature to no more than 100° C. and voltage levels to no less than 200 volts within the chamber to anodically polarize the second intermediate product; placing the second intermediate product into the aqueous solution to create a putter head; and removing the putter head from the chamber.

2. The method of claim 1, wherein the metal powder is stainless steel.

3. The method of claim 2, wherein the metal powder is 304 stainless steel.

4. The method of claim 1, further comprising the step of decorating the finished putter head.

5. The method of claim 4, wherein the step of decorating the finished putter head comprises painting the putter head.

6. The method of claim 4, wherein the step of decorating the finished putter head comprises applying decals to the putter head.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) FIG. 1 is a flow chart describing a preferred golf club head manufacturing method of the present invention.

(2) FIG. 2 is a transparent side perspective view of an exemplary golf club head engaged with a combination tool of the present invention.

(3) FIG. 3 is a top perspective view of the embodiment shown in FIG. 2 with its cover removed.

(4) FIGS. 4-6 are exploded views of the embodiment shown in FIG. 2.

(5) FIGS. 7-8 are exploded views of the embodiment shown in FIG. 2 with the cover removed.

(6) FIGS. 9-12 are side and top views of an exemplary golf club head engaged with a first hosel core.

(7) FIGS. 13-16 are exploded views of the golf club head engaged with the hosel core shown in 9-12.

(8) FIG. 17 are views of putter heads engaged with various hosels that can be created using the hosel cores described in the present invention.

(9) FIG. 18 is a drawing of a plasma polishing assembly described herein.

DETAILED DESCRIPTION OF THE INVENTION

(10) The present invention is directed to golf club heads, and particularly putter heads, that are created via metal injection molding (MIM) within a tool that has interchangeable hosel cores, and are then finished with plasma polishing. MIM is the preferred manufacturing process because it allows for the creation of complex three dimensional geometries. The preferred method 100 of the present invention is illustrated in FIG. 1, and drawings of the various tooling pieces 50 and putter head 10 parts illustrated in FIGS. 2-17.

(11) In a first step 110, metal powder is blended in a mixer with a polymer to create a stock feed material. The metal powder is preferably composed of 304 stainless steel, though it in alternative embodiments it may comprise or be composed of another metal alloy. In a second step 115, the stock feed material is heated in an extrusion machine hopper to create a liquid material. In third step 120, which may be performed simultaneously with the first and second steps 110, 115, a first, base tool 50 with a putter head-shaped cavity 52 is loaded into an extruder machine. This base tool 50 also includes a hosel cavity 54 sized to receive a hosel core tool 60, which can be designed to mold any hosel 12 construction conforming with USGA criteria.

(12) In a fourth step 125, one of a plurality of hosel core tools 60 are engaged with the first tool 50 to create a combination tool 70. The use of interchangeable hosel core tools 60 allows a manufacturer to quickly and easily alter the overall shape of the putter head 10, and greatly reduces the number of base tools 50 needed to create an entire line of putter heads 10 with different hosel 12 designs. In prior art processes, the intricate design shapes of putter hosels 12 did not allow the usage of forging to create more than one tool for each head shape. By using a MIM process with the tools 50, 60 of the present invention, a manufacturer can quickly and easily create many unique putter head 10 designs.

(13) Once all components of the tools 50, 60 are secured in place, the manufacturing chamber of the machine is closed so that the injection molding process can begin. In a fifth step 130, the liquid material is injected into the combination tool 70 to form a first intermediate putter head 20 with a hosel 22 corresponding to the selected hosel core tool 60. The specific time, heat, and holding pressure parameters under which this fifth step 130 are performed are tailored for the style of putter head 10, depending on its body shape and the shape of the hosel selected via an interchangeable hosel core tool 60.

(14) In a sixth step 135, the combination tool 70 undergoes a cooling operation so that the liquid material hardens into a first intermediate product 20, and in a seventh step 140, the first intermediate product 20 is removed from the combination tool and placed into a sintering oven to melt away polymer material, leaving only SS304 material. During this process, the overall shape and size of the first intermediate product 20 shrinks as the polymer material is removed, leaving a second intermediate product 30. The metal injection molding process allows this second intermediate product 30 to be almost identical to the ideal design shape, e.g., “near-final,” with precision within thousandths of inches. By moving to the MIM process, less material is wasted, less CNC machine time is required to machine to final part, and a precision, mass-produced part can be obtained. This technology also can produce shapes that were unobtainable with previous technology. This process has less human involvement and is far more automated, which decreases the amount of operators needed to manage process and also makes parts more easily obtainable.

(15) In an optional, eighth step 145, the second intermediate product 30 may be subjected to a CNC machining process to remove small burs or imperfections. The use of CNC machining in the inventive process is minimal compared with prior art manufacturing processes.

(16) In a ninth step 150, the second intermediate product 30 is affixed with other second intermediate products 30 onto a metal tree housing 80 via their hosels 32, as illustrated in FIG. 18. In a tenth step 155, the metal tree housing 80 is loaded into a plasma polishing chamber 90 and clamped into place so that the second intermediate products are suspended from an aqueous solution of 2.5-5% NaCl solute and water. In an eleventh step 160, the temperature and the current are increased to desired levels, which preferably are no more than 100° C. and no less than 200 volts, respectively. The tree housing 80 spaces the second intermediate products 30 from one another and allows current from the machine to be evenly distributed between all second intermediate products 30. In a twelfth step 165, the second intermediate products 30, now anodically polarized, are placed into solution, where surface micro-discharges occur in process-induced formation of a plasma cloud around the heads, micro leveling the material with minimal material loss, and creating finished putter heads 10. This plasma polishing process yields a glossy cosmetic shine appearance, increases corrosion and rust resistance, and provides a smoother surface to which post process operations can adhere.

(17) In a thirteenth step 170, the putter heads 10 are removed from the plasma polishing machine and cleaned. The manufacturer can then paint, apply decals, or otherwise decorate the finished putter heads 10 in preparation for sale.

(18) In an alternative embodiment, one or more putter heads 10 (or other types of golf club heads) created via form, investment, die, or permanent mold casting processes, or machined entirely from a billet, can be plasma polished according to the ninth, tenth, eleventh, and twelfth steps 150, 155, 160, 165.

(19) Though described and illustrated herein in connection with putter heads 10, the methods of the present invention can be used to create other types of golf club heads, including drivers, fairway woods, irons, wedges, and hybrids.

(20) 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.