Method for manufacturing a golf club head

The present invention relates to a method for manufacturing a golf club head. The method comprises using a bladder with an open face and a flange clamped over the open face during pressurization and molding. In a preferred embodiment, the bladder is composed of a material with a higher rigidity than latex.

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the manufacture of golf club heads. Particularly to the manufacture of wood-type or driver-type heads.

2. Description of the Related Art

The prior art discloses various methods for manufacturing a composite golf club head. One such method is disclosed in U.S. Pat. No. 6,824,636 issued to Nelson et al., for Method of Manufacturing a Composite Golf Club Head. This patent discloses a method for manufacture of a hollow, complex three-dimensional fiber golf club head having at least one hole, which comprises a fluid-removeable core shaped in the general form of a golf club head, which is placed in a flexible, pressurizable bladder around a core.

Another example is U.S. Pat. No. 4,581,190 issued to Nagamoto et al. which discloses a process for making a golf club head where a fibrous bag of reinforcing fiber is placed over a rigid molding core. Yet another example is U.S. Pat. No. 4,575,447 to Hariguchi for Method for Producing a Wood Type Golf Club Head. This patent comprises the use of a thermoplastic synthetic resin core instead of the conventional rubber air bag for stable and reliable shaping.

A method currently in use for the manufacture of multiple material golf club heads involves using dip molded latex bladders to mold composite bodies. The bladder is dip molded on a shape softened mandrel. The bladder comprises a tubular neck for introducing pressuring gas, preferably nitrogen. The need to stretch to remove them from the convex mandrel requires a smooth contour. The process of molding comprises feeding the neck through a plate attached to each mold for each cycle. The bladder can be used approximately 2-3 times before failing during the cure cycle, due to leaks.

There presently exists a need for a bladder with more definition, which may be easily installed and maintains durability due to better fit.

The purpose of this invention is to create a method which comprises a barrier being paced between the pressurized gas and the composite material being cured. The method of the present invention accomplishes this with more definition, increased durability and improved molding operations.

BRIEF SUMMARY OF THE INVENTION

The method of the present invention reduces definition due to the bladder's definition, relative rigidity, stretch and uniformity of stretch of a molded article. The primary construction of the bladder is created with a material that is more rigid than the conventional materials used, such as latex. The use of a more rigid material improves durability of the bladder and the definition of the components molded. Use of the neck-less version of the bladder eliminates complexity in the tool, press and operation used in the molding process. Latex can be used for the neck-less configuration, however the bladder must be clamped by a face plate on the tool, or have enough rigidity to hold its approximate location prior to pressurization.

The method of the present invention comprises a bladder that may be produced from various materials to address specific needs or goals. Unlike the dip-molded bladder, the bladder of the present invention comprises an open face. The bladder forms a seal through a broad flange that is clamped during pressurization and molding. The flange does not need to stretch the degree the bladders off a smooth mandrel or using a neck need to. The method of the present invention does not involve threading a neck tube through a port or using an associated face plate for each tool. Tool/part subassemblies are molded in multiple heat and pressure cycles. The bladder of the present invention is more durable. The bladder may be produced using silicone and/or other materials, including reinforced materials, to accomplish a more inert bladder and a better fit for better control of details.

DETAILED DESCRIPTION OF THE INVENTION

As shown inFIGS. 1 and 2, the method of the present invention comprises wrapping resin impregnated reinforcing fiber around a bladder20. The bladder20has an open face22and a flange24disposed over the open face22. In a preferred embodiment, the bladder20further comprises a neck21. The flange24is preferably clamped during pressurization and molding. The bladder20is placed inside a mold26having a shape of a desired golf club head42, such as a driver. Once in the mold26, the bladder20is pressurized. The mold26is heated to cure the resin. The bladder20is then removed from the mold26.

In a preferred embodiment the bladder20is composed of a material that has a higher rigidity than latex. As shown inFIG. 2, in an alternative embodiment, the bladder20does not include a neck21. In such alternative embodiment, the bladder20may be composed of latex. The bladder20may be composed of silicone or other materials, including reinforced materials.

As shown inFIGS. 3-7, a golf club head of the present invention is generally designated42. In a preferred embodiment, the club head42is generally composed of a face component60and an aft-body component61. The aft body component61preferably has a crown section62and a sole section64and may include a ribbon section66. The body further comprises a toe side68and a heel side70.

The golf club head42, when designed as a driver, 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 460 cubic centimeters. The volume of the golf club head42will also vary between fairway woods (preferably ranging from 3-woods to eleven woods) with smaller volumes than drivers.

The golf club head42, when designed as a driver, preferably has a mass no more than 215 grams, and most preferably a mass of 180 to 215 grams. When the golf club head42is designed as a fairway wood, the golf club head preferably has a mass of 135 grams to 200 grams, and preferably from 140 grams to 165 grams.

In one method, an inflatable bladder positioned within the hollow interior formed by the precursor components of the golf club head is preferably inflated at a pressure ranging from 50-200 pounds per square inch (“PSP”), and most preferably at 150 PSI. During the co-curing, a source of pressurized gas (not shown) is attached by a gas line to the inflatable bladder, and the bladder is inflated within the hollow interior of the pre-form unit. The bladder engages the inside surface of the pre-firm unit, forcing the plies of pre-preg sheets against the inner wall of the tool assembly. The tool assembly is heated within the press at the predetermined temperature for the selected period of time, i.e., a time sufficient to allow proper curing of the resin within the pre-preg sheets. After depressurizing, the bladder is removed through the bladder port and the molded unfinished golf club head is removed from the tool assembly.

Additional information concerning the method of the present invention is found at Reyes et al., U.S. Pat. No. 7,582,248 for an Apparatus And Method For Manufacturing A Multiple Material Golf Club Head, and Murphy et al., U.S. Pat. No. 6,607,623 for a Method Of Manufacturing A Composite Golf Club Head, both of which are hereby incorporated by reference in their entireties.