Golf club head aft body construction

Abstract

A golf club head having a face portion and aft body is shown. The aft body is made of a composite material having fibers with a particular orientation to prevent expansion of the aft body when striking a golf ball.

What is claimed is: 
     
         1 . A golf club head comprising:
 a face portion having a striking face; and   an aft body located rearward of said face portion;   said aft body comprising:
 a crown portion; 
 a sole portion opposite said crown portion; and 
 a skirt portion formed between an outer perimeter portion of said crown portion and an outer perimeter portion of said sole portion, 
   wherein a face center of said striking face defines an origin of a coordinate system, said coordinate system having an x-axis extending in a heel-to-toe direction, a y-axis extending in a crown-to-sole direction and perpendicular to said x-axis, and a z-axis extending in a front-to-rear direction and perpendicular to said x-axis and said y-axis,   wherein a hoop-direction is defined as a 360 degree path around said aft body which extends in said heel-to-toe direction along said crown portion, in said crown-to-sole direction over a toe-side section of said skirt portion, in said heel-to-toe direction along said sole portion, and in said crown-to-sole direction over a heel-side section of said skirt portion,   wherein at least a portion of said aft body is made of a composite material having carbon fibers, and   wherein at least 50% of said carbon fibers are hoop-direction oriented fibers.   
     
     
         2 . The golf club head of  claim 1 , wherein a forwardmost portion of said composite material is located within 1.5 inches from said striking face. 
     
     
         3 . The golf club head of  claim 1 , wherein said at least a portion of said aft body includes at least part of said crown portion, at least part of said toe-side section of said skirt portion, at least part of said sole portion, and at least part of said heel-side section of said skirt portion. 
     
     
         4 . The golf club head of  claim 1 , wherein said composite material comprises a stack of unidirectional fiber plies. 
     
     
         5 . The golf club head of  claim 4 , wherein said hoop-direction oriented fibers are included in alternating layers of said stack of unidirectional fiber plies. 
     
     
         6 . The golf club head of  claim 1 , wherein said hoop-direction oriented fibers are part of woven fiber plies. 
     
     
         7 . The golf club head of  claim 1 , wherein at least 55% of said carbon fibers are hoop-direction oriented fibers. 
     
     
         8 . A golf club head comprising:
 a face portion having a striking face; and   an aft body located rearward of said face portion;   said aft body comprising:
 a crown portion; 
 a sole portion opposite said crown portion; and 
 a skirt portion formed between an outer perimeter portion of said crown portion and an outer perimeter portion of said sole portion, 
   wherein a face center of said striking face defines an origin of a coordinate system, said coordinate system having an x-axis extending in a heel-to-toe direction, a y-axis extending in a crown-to-sole direction and perpendicular to said x-axis, and a z-axis extending in a front-to-rear direction and perpendicular to said x-axis and said y-axis,   wherein at least a portion of said aft body comprises a composite material having fibers, and   wherein at least 50% of said fibers are oriented substantially perpendicular to said z-axis.   
     
     
         9 . The golf club head of  claim 8 , wherein a forwardmost portion of said composite material is located within 1.5 inches from said striking face. 
     
     
         10 . The golf club head of  claim 9 , wherein at least 55% of said fibers are oriented substantially perpendicular to said z-axis. 
     
     
         11 . The golf club head of  claim 10 , wherein said at least a portion of said aft body includes at least part of said crown portion, at least part of said sole portion, and at least part of said skirt portion. 
     
     
         12 . The golf club head of  claim 11 , wherein said composite material comprises a stack of unidirectional fiber plies. 
     
     
         13 . The golf club head of  claim 12 , wherein alternating layers of said stack of unidirectional fiber plies consist of said fibers oriented substantially perpendicular to said z-axis. 
     
     
         14 . The golf club head of  claim 11 , wherein said fibers oriented substantially perpendicular to said z-axis are part of woven fiber plies.