Golf club head

Abstract

A cavity back iron type club head includes a striking plate having a substantially planar striking surface and a rear surface defining a thickness therebetween. The rear surface defines a striking plate rear cavity region. A perimeter support is coupled to a peripheral portion of the striking plate. The surface area of the striking surface is related to the club head loft angle by the equation SSA≧14.4(L)+2875, where SSA is the surface area of the striking surface in units of square-millimeters and L is the club head loft angle in units of degrees.

We claim: 
     
         1 . A cavity back iron type club head having a prescribed loft angle, the club head comprising:
 a striking plate having a substantially planar striking surface, a rear surface, and a striking plate thickness, the rear surface defining a striking plate rear cavity region; wherein the striking plate thickness is defined as a thickness between a selected point on the striking surface and the rear surface along an axis perpendicular to the striking surface;   an unsupported striking plate area defined as the portion of the striking plate rear cavity region lacking a backing support structure having a modulus of elasticity greater than about 25 GPa;   an unsupported area ratio defined as a ratio of the unsupported striking plate area to the surface area of the striking surface;   wherein an average striking plate thickness within the striking plate rear cavity region is less than about 2.2 mm;   wherein the unsupported striking plate area is greater than about 2572 mm 2 , and the loft angle ranges from 22.5 degrees to 34.5 degrees.   
     
     
         2 . The cavity back iron type club head of  claim 1 , wherein the average striking plate thickness within the striking plate rear cavity region is less than about 2.1 mm. 
     
     
         3 . The cavity back iron type club head of  claim 1 , wherein the average striking plate thickness within the striking plate rear cavity region is less than about 2.0 mm. 
     
     
         4 . The cavity back iron type club head of  claim 1 , wherein the average striking plate thickness within the striking plate rear cavity region is less than about 1.9 mm. 
     
     
         5 . The cavity back iron type club head of  claim 1 , wherein the average striking plate thickness within the striking plate rear cavity region is less than about 1.8 mm. 
     
     
         6 . The cavity back iron type club head of  claim 1 , wherein the unsupported striking plate ratio ranges from about 83% to about 88%. 
     
     
         7 . The cavity back iron type club head of  claim 3 , and wherein the unsupported striking plate ratio ranges from about 83% to about 88%. 
     
     
         8 . The cavity back iron type club head of  claim 7 , wherein the loft angle ranges from 27.5 degrees to 30.5 degrees. 
     
     
         9 . A cavity back iron type club head having a prescribed loft angle, the club head comprising:
 a striking plate having a substantially planar striking surface, a rear surface, and a striking plate thickness, the rear surface defining a striking plate rear cavity region; wherein the striking plate thickness is defined as a thickness between a selected point on the striking surface and the rear surface along an axis perpendicular to the striking surface;   an unsupported striking plate area defined as the portion of the striking plate rear cavity region lacking a backing support structure having a modulus of elasticity greater than about 25 GPa;   an unsupported area ratio defined as a ratio of the unsupported striking plate area to the surface area of the striking surface;   wherein an average striking plate thickness within the striking plate rear cavity region is less than about 2.2 mm;   wherein the unsupported striking plate ratio is greater than or equal to 80%, and the loft angle ranges from 22.5 degrees to 34.5 degrees.   
     
     
         10 . The cavity back iron type club head of  claim 9 , wherein the average striking plate thickness within the striking plate rear cavity region is less than about 2.1 mm. 
     
     
         11 . The cavity back iron type club head of  claim 9 , wherein the average striking plate thickness within the striking plate rear cavity region is less than about 2.0 mm. 
     
     
         12 . The cavity back iron type club head of  claim 9 , wherein the average striking plate thickness within the striking plate rear cavity region is less than about 1.9 mm. 
     
     
         13 . The cavity back iron type club head of  claim 9 , wherein the average striking plate thickness within the striking plate rear cavity region is less than about 1.8 mm. 
     
     
         14 . The cavity back iron type club head of  claim 9 , wherein the unsupported striking plate ratio ranges from about 83% to about 88%. 
     
     
         15 . The cavity back iron type club head of  claim 11 , wherein the unsupported striking plate ratio ranges from about 83% to about 88%. 
     
     
         16 . The cavity back iron type club head of  claim 15 , wherein the loft angle ranges from 27.5 degrees to 30.5 degrees. 
     
     
         17 . An iron type club head comprising:
 a main body;   a striking plate attached to the main body, the striking plate having a substantially planar striking surface and a rear surface defining a striking plate thickness there between, the rear surface defining a striking plate rear cavity region;   an unsupported striking plate area defined as the portion of the striking plate rear cavity region lacking a backing support structure; and   wherein at least a portion of the striking plate is a precipitation-hardenable alloy club head and the striking plate thickness is less than 2.2 mm over a substantial portion of the unsupported striking plate area, and wherein the unsupported striking plate area is greater than about 2572 mm 2 , and the loft angle ranges from 22.5 degrees to 34.5 degrees.   
     
     
         18 . The iron type club head of  claim 17 , wherein an average striking plate thickness within the striking plate rear cavity region is less than about 2.0 mm, the unsupported striking plate ratio ranges from about 83% to about 88%, and the loft angle ranges from 27.5 degrees to 30.5 degrees.