Golf club heads with improved characteristic time

Abstract

Embodiments of golf club heads comprising a club face with a variable thickness profile to adjust stiffness and characteristic time (CT) are described herein. The variable thickness profile comprises strategically positioned thickened and thinned regions. In many embodiments, variable thickness profile can taper from a thickened region to a thinned region. The thickened region can comprise a maximum thickness of the club face, and the thinned region can comprise a minimum thickness of the club face. The variable thickness profiles described in this disclosure increase stiffness in a high toe area of the club face and decrease stiffness in a heel area of the club face.

What is claimed is: 
     
         1 . A golf club head comprising:
 a heel; a toe; a crown; a sole; and
 a face comprising a striking surface, which further comprises a face perimeter surrounding the striking surface, and configured to impact a golf ball; 
 wherein the face comprises a face center defining an origin for a coordinate system including a horizontal x-axis extending parallel to the ground and in a direction extending from the heel to the toe when the club head is at an address position; 
 wherein the face defines a variable thickness including a thickened center region encompassing the face center, a perimeter region, and a transition region tapering a face thickness from the thickened center region to the perimeter region to adjust a characteristic time of the face; 
   wherein the thickened center region comprises a center region center offset toward the toe from the face center; wherein center region center is offset from the face center by a horizontal offset distance measured parallel to the horizontal x-axis, the horizontal offset distance ranges from greater than 0 to 0.5 inch;   wherein the center thickened region is offset from the face center by an offset angle, the offset angle being defined between the horizontal x-axis and a line extending through the face center and the center region center, the offset angle ranges between greater than 0 and 10 degrees;
 wherein the perimeter region surrounds the transition region and abuts the face perimeter; 
   wherein the perimeter region comprises a top perimeter region, a toe perimeter region, a bottom perimeter region, and a heel perimeter region and further comprises a thickened perimeter portion located at the top perimeter region and toe perimeter region, and a thinned perimeter portion located at the bottom perimeter region and heel perimeter region;   wherein a thickened perimeter portion thickness is in a range of 0.07 inch to 0.10 inch and a thinned perimeter portion thickness is in a range of 0.05 inch to 0.07 inch;   wherein the face further comprises a first reference point along the horizontal x-axis at approximately a 10 mm offset from the face center in a direction toward the heel; and a second reference point along the horizontal x-axis at approximately a 10 mm offset from the face center in a direction toward the toe; and
 wherein the characteristic time measured at approximately 10 mm intervals between the first reference point and the second reference point along the horizontal x-axis deviates less than 10 μs from the characteristic time at the face center. 
   
     
     
         2 . The golf club head of  claim 1 , wherein the face comprises a rear surface opposite the striking surface; wherein when viewing the rear surface of the face, the center region comprises a shape from the group consisting of elliptical, oval, circular, egg, asymmetric elliptical, and oblong-ellipse. 
     
     
         3 . The golf club head of  claim 1 , wherein the thickened center region comprises a center thickness ranging between 0.06 to 0.1 inch. 
     
     
         4 . The golf club head of  claim 1 , wherein transition region comprises a perimeter edge including a toe edge, a heel edge opposite the toe edge, a top edge, and a bottom edge opposite the top edge; wherein the transition region comprises a heel side width measured at the heel edge; wherein the transition region comprises a toe side width measured at the toe edge; and wherein the toe width of the transition region is greater than the heel width of the transition region. 
     
     
         5 . The golf club head of  claim 1 , wherein the characteristic time at the first reference point deviates less than 10 μs from the characteristic time measured at the second reference point. 
     
     
         6 . The golf club head of  claim 1 , wherein the club head comprises a weight port configured to receive and retain a removable weight. 
     
     
         7 . The golf club head of  claim 1 , wherein the golf club head comprises a center of gravity defining an origin for a coordinate system including a horizontal CG x-axis parallel to the ground and in a direction from the heel to the toe, and a vertical CG y-axis perpendicular to the ground and in a direction extending from the sole to the crown when the club head is at the address position; the club head comprises a moment of inertia Ixx measured about the CG x-axis and a moment of inertia Iyy measured about the CG y-axis. 
     
     
         8 . The golf club head of  claim 7 , the moment of inertia Ixx is greater than 1400 g-cm 2 , and the moment of inertia Iyy is greater than 2800 g-cm 2 .