Method of manufacturing titanium golf club having a striking surface free of oxygen-stabilized alpha phase titanium

• US 6,604,568 B2
• Filed: 08/16/2001
• Issued: 08/12/2003
• Est. Priority Date: 08/16/2001
• Status: Active Grant

• Current Assignee: Karsten Manufacturing Corporation
• Original Assignee: Karsten Manufacturing Corporation
• Inventors: Sayler, Gregory C., Bliss, John C.
• Primary Examiner(s): Dunn, Tom
• Assistant Examiner(s): LIN, ING HOUR
• Application Number:
  US09/931,659
• Publication Number:
  US 20030034142A1
• Time in Patent Office: 726 Days
• Field of Search: 164/76.1, 164/55.1, 164/56.1, 148/669
• US Class Current: 164/76.1
• CPC Class Codes: A63B 2053/0491 with added weights, e.g. changeable, replaceable
• CPC Class Codes: A63B 53/04 Heads
• CPC Class Codes: A63B 53/0408 characterised by specific dimensions, e.g. thickness
• CPC Class Codes: A63B 53/0416 Heads having an impact surface provided by a face insert
• CPC Class Codes: A63B 53/0433 with special sole configurations
• CPC Class Codes: A63B 53/0458 with non-uniform thickness of the impact face plate
• CPC Class Codes: A63B 53/0462 characterised by tapering thickness of the impact face plate
• CPC Class Codes: A63B 53/0466 wood-type
• CPC Class Codes: A63B 60/00 Details or accessories of golf clubs, bats, rackets or the like
• CPC Class Codes: A63B 60/02 Ballast means for adjusting the centre of mass A63B60/24, A63B60/54 take precedence

Abstract

The present invention comprises a method of making a golf club head by casting a molten titanium alloy and thereafter removing the alpha case that is formed on the surface of the titanium by means of a conformal milling process. The conformal milling process uniformly dissolves the alpha case without distorting the underlying metal. The reduction in wall thickness caused by the conformal milling results in a concomitant reduction in the weight of the part without any loss in the critical impact strength of the part. In fact, impact strength is increased. This weight can then be redistributed as a supplemental weight member, which can be used to lower the center of mass of the club. The weight member can further be positioned on the sole plate or club body in such a way so as to permit fine tuning of the location of the center of mass of the club, as well as shaped so as to increase the polar moment of inertia of the club head about the golf club shaft.

Claims

1. A method of making a golf club head comprising:

forming a golf club body by casting a molten material chosen from the group consisting of titanium and alloys of titanium in a mold and allowing said molten material to solidify, once solidified, said golf club body comprising a hollow body having a face portion, a top wall, a side wall and a heel portion adapted to receive a golf club shaft, said face portion having a front surface and a rear surface, said face portion further comprising an alpha case and an underlying base material;

attaching a sole plate to said golf club body to form an assembled club comprising a hollow golf club head defining an outer surface and an inner surface, said sole plate including a weight member located on an inner surface thereof, said weight member having a center of gravity located beneath the center of gravity of said golf club body; and

removing said alpha case from said golf club body by exposing said golf club body to a conformal milling process capable of selectively removing said alpha case such that a sufficient quantity of said alpha case is removed from said face portion so as to expose said underlying base material.

2. The method of claim 1, wherein:

said weight member is shaped such that the weight moment of inertia of said weight member relative to a longitudinal axis of said golf club shaft is greater than the weight moment of inertia of a circular cylinder.

3. The method of claim 2, further comprising:

selecting a weight member; and

fixing said weight member to said inner surface of said sole plate in one of a plurality of possible locations, whereby the center of gravity of the assembled club can be moved toward or away from the face of the assembled club based on the location of said weight member relative to said sole plate.

4. The method of claim 2, further comprising:

selecting one of a plurality of sole plates each having an integral weight member located in a plurality of possible locations along said inner surface of said sole plate, whereby the center of gravity of the assembled club can be moved toward or away from the face of the assembled club based on the location of said integral weight member relative to said sole plate.