US 4,614,627 AGranted

Method of injection molding a thermoplastic hollow or hollow foam filled one piece head of a golf club

AssigneeDunlop Limited

InventorsMichael E. Curtis, Robert C. Haines

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Abstract

A one-piece, hollow, moulded head for a golf-club of the "wood" or "driver" type is made by injecting a thermoplastics material around a fusible core having a melting-point below the injection temperature, allowing the injected material to set and melting out the core. One or more holes are provided, the holes extending completely through the core, so that the injected material fills each hole and sets therein to provide corresponding internal "struts" in the moulding. The injected material may be, e.g., a polyamide, a polycarbonate, a poly(phenylene oxide), an acetal resin or an ABS resin. The material may be reinforced with up to 50% by weight of glass and/or carbon fibres. The moulded head may optionally be filled with a polyurethane foam. The finished moulding may have the conventional face-pieces and/or sole-plates attached thereto.

Claims10

Dependent claims

A method of making a hollow, one piece head for a golf club of thermoplastics material comprising:

(a) forming a fusible core member of a material having a melting point below the injection temperature of said thermoplastics material and with at least one hole extending through the core member;
(b) placing the core member in a mold of the desired size and shape of the finished article, said mold completely surrounding the core member and supporting the core member within the mold;
(c) injecting said thermoplastics material into said mold to fill both the space around said core member and said hole therethrough;
(d) allowing said thermoplastic material to set so as to form a molding surrounding the core member and at least one internal strut within the molding and corresponding to said hole;
(e) raising the temperature of the mold and core member to a level sufficient to melt the core member but insufficient to melt or deform said thermoplastics material;
(f) removing the melted core material to leave a hollow golf club head with at least one internal strut completely enclosed within the hollow space at a position corresponding to the location of said hole with the molding of the club head completely surrounding strut.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/530,129Filed 7 Sep 1983
Priority: GB 82284235 Oct 1982
Granted: 30 Sep 1986
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

B29C 33/52
With means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles: soluble or fusible
B29C 45/4457
For undercut articles: using fusible, soluble or destructible cores
B29K 2101/12
Use of unspecified macromolecular compounds as moulding material: thermoplastic materials
B29K 2105/12
Containing reinforcements, fillers or inserts: of short lengths, e.g. chopped filaments, staple fibres or bristles