Golf club head with increased shaft bonding strength

Abstract

Embodiments of a golf club comprising a club head, a shaft, and features that improve bonding strength between the club head and the shaft are described herein. The club head comprises a hosel that receives a tip end of the shaft. The shaft tip end defines a shaft bonding area and an effective bonding area. The features described herein are designed to increase the effective shaft bonding area with the hosel to improve bonding strength between the club head and the shaft. In some embodiments, the features comprise microgrooves located within the shaft bonding area. The microgrooves can increase the effective bonding area and provide multi-directional resistance to forces applied to the shaft. In some embodiments, the features comprise a ferrule including a weighting feature that replaces a tip weight. In some embodiments, the features comprise a hot melt weight located within the shaft.

1 . A golf club comprising:
 a club head, a shaft, and a grip, wherein:
 the club head comprises a body and a hosel, wherein:
 the hosel comprises a hosel bore having an inner surface that defines a hosel bonding area; 
 
 the shaft comprises a shaft tip end, a shaft butt end, and a shaft outer surface, wherein:
 the hosel bore receives the shaft tip end forming a head-shaft connection; 
 the shaft defines a longitudinal axis that runs from a geometric center of the shaft butt end to a geometric center of the shaft tip end; 
 the shaft outer surface defines a shaft bonding area, and an effective bonding area near the shaft tip end, wherein the shaft bonding area is a portion of the shaft outer surface that is inserted into the hosel bore, and the effective bonding area is a portion of the shaft outer surface that is in contact with the hosel bonding area; 
 the effective bonding area comprises a plurality of microgrooves, wherein:
 the plurality of microgrooves are recessed into the shaft away from the shaft outer surface via a plurality of side walls, and the plurality of side walls increase the effective bonding area; 
 the plurality of microgrooves are formed in lines and define a first plurality of microgrooves, extending in a first direction, and a second plurality of microgrooves, extending in a second direction; 
 the first plurality of microgrooves, and the second plurality of microgrooves are interconnected and extend circumferentially around the shaft; and 
 
 
 the grip is coupled to the shaft butt end. 
   
     
     
         2 . The golf club of  claim 1 , wherein the first plurality of microgrooves and the second plurality of microgrooves are formed integrally with the shaft. 
     
     
         3 . The golf club of  claim 1 , wherein the first plurality of microgrooves and the second plurality of microgrooves define an individual microgroove depth;
 wherein the individual microgroove depth is less than 0.0038 inch.   
     
     
         4 . The golf club of  claim 1 , wherein the first plurality of microgrooves and the second plurality of microgrooves define a total microgroove depth, wherein:
 the total microgroove depth is measured along the longitudinal axis, and the total microgroove depth is a depth of the shaft tip end that comprises microgrooves, and the total microgroove depth is between 1.00 inch to 3.00 inches.   
     
     
         5 . The golf club of  claim 1 , wherein the first plurality of microgrooves and the second plurality of microgrooves cover between 50% to 90% of the shaft bonding area. 
     
     
         6 . The golf club of  claim 1 , wherein the plurality of microgrooves each comprise a floor, wherein the floor is perpendicular to the plurality of side walls of an individual microgroove, and the individual microgroove is U-shaped in a cross-sectional view. 
     
     
         7 . The golf club of  claim 1 , wherein each microgroove of the first plurality of microgrooves extends in the first direction and is parallel to the adjacent microgrooves of the first plurality of microgrooves, and each microgroove of the second plurality of microgrooves extends in the second direction and is parallel to the adjacent microgrooves of the second plurality of microgrooves. 
     
     
         8 . The golf club of  claim 7 , wherein the first direction and the second direction are diagonal relative to the longitudinal axis. 
     
     
         9 . The golf club of  claim 8 , wherein the first plurality of microgrooves and the second plurality of microgrooves provide resistance to a normal force and a torsional force. 
     
     
         10 . The golf club of  claim 7 , wherein the first direction is perpendicular to the longitudinal axis, and the second direction is parallel to the longitudinal axis. 
     
     
         11 . A golf club comprising:
 a club head, a shaft, and a grip, wherein:
 the club head comprises a body and a hosel, wherein:
 the hosel comprises a hosel bore having an inner surface that defines a hosel bonding area; 
 
 the shaft comprises a shaft tip end, a shaft butt end, and a shaft outer surface, wherein:
 the hosel bore receives the shaft tip end forming a head-shaft connection; 
 the shaft defines a longitudinal axis that runs from a geometric center of the shaft butt end to a geometric center of the shaft tip end; 
 the shaft outer surface defines a shaft bonding area, and an effective bonding area near the shaft tip end, wherein the shaft bonding area is a portion of the shaft outer surface that is inserted into the hosel bore, and the effective bonding area is a portion of the shaft outer surface that is in contact with the hosel bonding area; 
 the effective bonding area comprises a plurality of microgrooves, wherein:
 the plurality of microgrooves are recessed into the shaft away from the shaft outer surface via a plurality of side walls, and the plurality of side walls increase the effective bonding area; 
 the plurality of microgrooves are formed in shapes; 
 the plurality of microgrooves are not interconnected and extend circumferentially around the shaft; and 
 
 
 the grip is coupled to the shaft butt end. 
   
     
     
         12 . The golf club of  claim 11 , wherein the plurality of microgrooves are formed integrally with the shaft. 
     
     
         13 . The golf club of  claim 11 , wherein the plurality of microgrooves define an individual microgroove depth;
 wherein the individual microgroove depth is less than 0.0038 inch.   
     
     
         14 . The golf club of  claim 11 , wherein the plurality of microgrooves define a total microgroove depth, wherein:
 the total microgroove depth is measured along the longitudinal axis, and the total microgroove depth is a depth of the shaft tip end that comprises microgrooves, and the total microgroove depth is between 1.00 inch to 3.00 inches.   
     
     
         15 . The golf club of  claim 11 , wherein the plurality of microgrooves cover between 50% to 90% of the shaft bonding area. 
     
     
         16 . The golf club of  claim 11 , wherein the plurality of microgrooves each comprise a floor, wherein the floor is perpendicular to the plurality of side walls of an individual microgroove, and the individual microgroove is U-shaped in a cross-sectional view. 
     
     
         17 . The golf club of  claim 11 , wherein each microgroove comprises a shape selected from a group consisting of: triangles, lines, squares, rectangles, or spirals. 
     
     
         18 . The golf club of  claim 17 , wherein each of the microgrooves comprises the same shape. 
     
     
         19 . The golf club of  claim 17 , wherein each of the microgrooves comprises a different shape. 
     
     
         20 . The golf club of  claim 11 , wherein the plurality of microgrooves provide resistance to a normal force and a torsional force.