Golf club head

Abstract

A golf club head includes a striking face, a sole portion, a top portion, a hosel, a rear surface, a loft no less than 40°, a virtual vertical plane, and a center of gravity. The striking face has a face center, a leading edge, and a virtual striking face plane. The hosel includes an internal bore configured to receive a golf shaft and includes a peripheral side wall and a shaft abutment surface configured to abut a tip end of the golf shaft. The rear surface is opposite the striking face and has an upper portion and a lower portion, the lower portion including a forward-extending recess. The insert covers the recess forming a hollow portion. The virtual vertical plane is perpendicular to the striking face plane and passes through the face center. The center of gravity is spaced a distance from the virtual vertical plane in the heel-to-toe direction.

We claim: 
     
         1 . A golf club head that, when oriented in a reference position, comprises:
 a striking face having a face center and defining a striking face plane;   a plurality of scorelines having a heel-most extent and a toe-most extent;   a rear portion opposite the striking face and having an upper blade portion and a lower muscle portion, the upper blade portion having a thickness that tapers in a toe-to-heel direction;   a sole portion having a sole width defined as a distance between the striking face plane and a trailing edge of the golf club head measured in a direction perpendicular to the striking face plane, wherein a heel-side sole width measured in a first virtual vertical plane passing through the heel-most extent of the plurality of scorelines is less than a toe-side sole width measured in a second virtual vertical plane passing through the toe-most extent of the plurality of scorelines;   a top portion;   a loft L no less than 40°;   a virtual vertical plane perpendicular to the striking face plane and passing through the face center; and   a club head center of gravity spaced from the virtual vertical plane in a heel-to-toe direction by a distance D 1  that is equal to or less than (0.08 mm/°)*L.   
     
     
         2 . The golf club head of  claim 1 , further comprising a hosel comprising a virtual hosel axis and an internal bore configured to receive a golf shaft, the internal bore including a peripheral side wall and a shaft abutment surface configured to abut a tip end of the golf club shaft, the hosel further comprising an auxiliary recess extending sole-ward from the abutment surface of the internal bore. 
     
     
         3 . The golf club head of  claim 2 , wherein the auxiliary recess comprises a width between 4 mm and 10 mm. 
     
     
         4 . The golf club head of  claim 2 , wherein the auxiliary recess is at least partially filled with a material having a density less than a density of the hosel. 
     
     
         5 . The golf club head of  claim 1 , wherein D 1  is equal to or less than (0.065 mm/°)*L. 
     
     
         6 . The golf club head of  claim 1 , further comprising:
 a virtual vertical axis passing through the center of gravity; and   a moment of inertia (Izz) measured about the virtual vertical axis, the Izz being no less than 2650 g*cm 2 .   
     
     
         7 . The golf club head of  claim 1 , further comprising a sole taper angle in the heel-to-toe direction no less than (0.10*L). 
     
     
         8 . The golf club head of  claim 1 , further comprising a beveled surface located between the top portion and the rear portion, wherein the beveled surface generally forms a crescent shape where a location of maximum width generally coincides with an upper toe-most corner of the golf club head. 
     
     
         9 . The golf club head of  claim 8 , wherein a width of the beveled surface tapers in a toe-to-heel direction from the upper toe-most corner and in a top-to-bottom direction from the upper toe-most corner, both along a periphery of the rear portion. 
     
     
         10 . A golf club head that, when oriented in a reference position, comprises:
 a toe portion;   a heel portion opposite the toe portion;   a striking face having a face center and defining a striking face plane;   a rear portion opposite the striking face and having an upper blade portion and a lower muscle portion, the upper blade portion having a thickness that tapers in a toe-to-heel direction;   a sole portion having a sole width defined as a distance between the striking face plane and a trailing edge of the golf club head measured in a direction perpendicular to the striking face plane, wherein the sole width generally tapers over the sole portion from the toe portion to the heel portion;   a top portion;   a loft L no less than 40°;   a center of gravity;   a virtual vertical axis passing through the center of gravity; and   a moment of inertia (Izz) measured about the virtual vertical axis, the Izz being no less than 2650 g*cm 2 .   
     
     
         11 . The golf club head of  claim 10 , further comprising:
 a virtual vertical plane perpendicular to the striking face plane and passing through the face center; and   a club head center of gravity spaced from the virtual vertical plane in a heel-to-toe direction by a distance D 1  that is equal to or less than (0.08 mm/°)*L.   
     
     
         12 . The golf club head of  claim 10 , further comprising a hosel comprising a virtual hosel axis and an internal bore configured to receive a golf shaft, the internal bore including a peripheral side wall and a shaft abutment surface configured to abut a tip end of the golf club shaft, and the hosel further comprising an auxiliary recess extending sole-ward from the abutment surface of the internal bore. 
     
     
         13 . The golf club head of  claim 12 , wherein the auxiliary recess is at least partially filled with a material having a density less than a density of the hosel. 
     
     
         14 . The golf club head of  claim 13 , wherein the material includes a density no greater than 4 g/cm 3 . 
     
     
         15 . The golf club head of  claim 10 , wherein D 1  is less than or equal to 3 mm when the loft L is between 46° and 52°. 
     
     
         16 . The golf club head of  claim 10 , further comprising a sole taper angle in the heel-to-toe direction no less than (0.10*L). 
     
     
         17 . The golf club head of  claim 10 , further comprising a beveled surface located between the top portion and the rear portion, wherein the beveled surface forms a generally crescent shape where a location of maximum width generally coincides with an upper toe-most corner of the golf club head. 
     
     
         18 . The golf club head of  claim 10 , further comprising a plurality of scorelines having a heel-most extent and a toe-most extent, wherein a heel-side sole width measured in a first virtual vertical plane passing through the heel-most extent of the plurality of scorelines is less than a toe-side sole width measured in a second virtual vertical plane passing through the toe-most extent of the plurality of scorelines. 
     
     
         19 . The golf club head of  claim 10 , wherein the striking face further comprises:
 a plurality of scorelines having a heel-most extent and a toe-most extent, and   a central region delimited by the heel-most extent and the toe-most extent of the plurality of scorelines, the central region comprising a textured surface.   
     
     
         20 . The golf club head of  claim 19 , wherein the textured surface includes at least one of a surface milled region, a media-blasted region, a chemical etched region, and a laser-milled region.