Multi-material golf club

Abstract

A golf club including a golf club head having improved mass distribution characteristics. The golf club includes a golf club head that is constructed multiple materials and includes a body member, a mass member, and an interface that allows the mass member to be coupled to the body member.

We claim: 
     
         1 . An iron-type golf club head, comprising:
 a body member including a face defining a front ball-striking surface and a rear surface, a perimeter weight portion, a muscle portion and a hosel, wherein the face extends between a top line, a leading edge, a heel and a toe of the body member, wherein the perimeter weight portion extends rearward from the rear surface of the face and defines an upper cavity of the body member, wherein the muscle portion is an elongate portion of the body member extending from the heel to the toe of the body member and rearward from the leading edge of the face, wherein the muscle portion defines an elongate receptacle extending from the heel to the toe of the body member, wherein the receptacle only intersects an outermost surface of the golf club head and is adjacent the leading edge of the face and extends rearward from the leading edge of the face, wherein the body member constructed of a first material that includes a base element; and   an elongate weight member including an elongate mass member and an elongate interface is disposed in the receptacle so that an outermost surface of the interface is flush with an outermost surface of the muscle portion, wherein the mass member and the interface are coupled at a bond surface, wherein the mass member and the interface are exposed only from a lower surface of the body member that extends rearward from the leading edge of the face, wherein the mass member is constructed of a second material that includes a base element, wherein the specific gravity of the second material is greater than the specific gravity of the first material, and wherein the interface is constructed of a third material that is an alloy of the base element of the second material.   
     
     
         2 . The golf club head of  claim 1 , wherein the third material has a specific gravity that is less than the specific gravity of the second material. 
     
     
         3 . The golf club head of  claim 1 , wherein the second and third materials are different tungsten alloys. 
     
     
         4 . The golf club head of  claim 1 , wherein the first and third materials are weldable to each other, and wherein the first and second materials are not weldable to each other. 
     
     
         5 . The golf club head of  claim 1 , wherein the interface is bonded to the body member by welding. 
     
     
         6 . The golf club head of  claim 1 , wherein the interface is constructed with a constant thickness from the outermost surface toward the top line of the body member. 
     
     
         7 . The golf club head of  claim 1 , wherein the mass member and the interface are coupled only on a single surface. 
     
     
         8 . The golf club head of  claim 7 , wherein the mass member has a varying thickness from the interface toward the top line of the golf club head, wherein the varying thickness includes at least one of a heel portion and a toe portion of the mass member that has a greater thickness than a central portion that is interposed between the heel portion and the toe portion. 
     
     
         9 . The golf club head of  claim 1 , wherein the interface defines a width between a weight member leading edge and a weight member trailing edge, wherein the mass member defines a width corresponding to the direction of the width of the interface, and wherein the width of the interface is equal to the width of the mass member.