Variable durometer golf club face

Abstract

Described herein are embodiments of a putter-type club head with a variable durometer face insert. The face insert achieves a variable durometer profile with three or more discrete regions, or zones, wherein a central zone has the lowest hardness, and each consecutive distal zone has a greater hardness than the adjacent medial zone. The face insert strategically reduces the smash factor in the center of the face to normalize the smash factor across the face to provide more predictable ball roll out distances on miss hits.

1 . A putter-type club head comprising:
 a body having a toe end, a heel end opposite the toe end, a front end, a rear end opposite the front end, a top, and a bottom opposite the top;   a front surface of the front end and a front recess extending from the front surface toward the rear end;   a face insert disposed in the front recess and having a geometric center;   wherein:
 the face insert comprises a face plate, a middle layer, and an adhesive layer; 
 the middle layer comprises:
 a central zone formed of a central zone material having a central zone hardness ranging from 28 to 32 on a Shore D hardness scale; 
 a first toe zone located between the central zone and the toe end, the first toe zone is formed of a first toe zone material having a first toe zone hardness ranging from 33 to 37 on the Shore D hardness scale; 
 a first heel zone located between the central zone and the heel end, the first heel zone is formed of a first heel zone material having a first heel zone hardness ranging from 30 to 35 on the Shore D hardness scale. 
 
   
     
     
         2 . The putter-type club head of  claim 1 , wherein:
 a second toe zone located between the first toe zone and the toe end;   a second heel zone located between the first heel zone and the heel end;   the first toe zone borders the central zone; and   the first heel zone borders the central zone.   
     
     
         3 . The putter-type club head of  claim 2 , wherein:
 the second toe zone is formed of a second toe zone material having a second toe zone hardness ranging from 35 to 42 on the Shore D hardness scale; and   the second heel zone is formed of a second heel zone material having a second heel zone hardness ranging from 35 to 42 on the Shore D hardness scale.   
     
     
         4 . The putter-type club head of  claim 3 , wherein:
 the middle layer is formed from a PEBAX® material; and   the face plate is formed from an aluminum material.   
     
     
         5 . The putter-type club head of  claim 3 , wherein:
 The face plate has a thickness that is less than 0.050 inch; and   The middle layer has a thickness that is between 0.10 and 0.25 inch.   
     
     
         6 . A putter-type club head comprising:
 a body having a toe end, a heel end opposite the toe end, a front end, a rear end opposite the front end, a top, and a bottom portion opposite the top;   a front surface and a front recess located on the front surface;   a face insert having a geometric center; and   wherein:
 the face insert comprises a face plate, a middle layer, and an adhesive layer; 
 the face plate is formed from a metallic material and completely covers the middle layer and adhesive layer such that no portion of the middle layer or the adhesive layer are visible when in the front recess; 
 the face plate forms a portion of the front surface to form an uninterrupted front surface configured to impact a golf ball; 
 the middle layer comprises a central zone, a first toe zone, a first heel zone, a second toe zone, and a second heel zone; 
 the central zone comprises a central zone toe surface and a central zone heel surface; 
 the first toe zone comprises a first toe zone distal surface and a first toe zone medial surface; 
 the first heel zone comprises a first heel zone distal surface and a first heel zone medial surface; 
 the second toe zone comprises a second toe zone distal surface and a second toe zone medial surface; 
 the second heel zone comprises a second heel zone distal surface and a second heel zone medial surface; 
 the central zone toe surface abuts the first toe zone medial surface, the central zone heel surface abuts the first heel zone medial surface; 
 the first heel zone distal surface abuts the second heel zone medial surface, the first toe zone distal surface abuts the second toe zone medial surface; 
 the central zone comprises a central durometer ranging from 28 to 32 on a Shore D hardness scale; 
 the first toe zone comprises a first toe zone durometer ranging from 33 to 37 on the Shore D hardness scale; 
 the first heel zone comprises a first heel zone durometer ranging from 30 to 35 on the Shore D hardness scale; 
 the second toe zone comprises a second toe zone durometer ranging from 35 to 42 on the Shore D hardness scale; and 
 the second heel zone comprises a second heel zone durometer ranging from 35 to 42 on the Shore D hardness scale. 
   
     
     
         7 . The putter-type club head of  claim 6 , wherein:
 the middle layer comprises a third heel zone and a third toe zone;   the third heel zone comprises a third heel zone distal surface and a third heel zone medial surface;   the third toe zone comprises a third toe zone distal surface and a third toe zone medial surface;   the third heel zone medial surface abuts the second heel zone distal surface;   the third toe zone medial surface abuts the second toe zone distal surface;   the third heel zone comprises a third heel zone durometer ranging from 38 to 47 on the Shore D hardness scale; and   the third toe zone comprises a third toe zone durometer ranging from 38-47 on the Shore D hardness scale.   
     
     
         8 . The putter-type club head of  claim 7 , wherein:
 the body comprises an imaginary insert midplane that is perpendicular to a ground plane and extends through the geometric center;   the central zone comprises a central zone midline that is perpendicular to the front surface and is equidistant from the first toe zone medial surface and the first heel zone medial surface and extends perpendicular to the front surface;   the first heel zone comprises a first heel zone midline that is perpendicular to the front surface and is equidistant from the first heel zone distal surface and the first heel zone medial surface;   the second toe zone comprises a second toe midline that is perpendicular to the front surface and is equidistant from the second toe zone distal surface and the second toe zone medial surface;   the second heel zone comprises a second heel zone midline that is perpendicular to the front surface and is equidistant from the second heel zone distal surface and the second heel zone medial surface;   the third toe zone comprises a third toe zone midline that is perpendicular to the front surface and is equidistant from the third toe zone distal surface and the third toe zone medial surface;   the third heel zone comprises a third heel zone midline that is perpendicular to the front surface and is equidistant from the third heel zone distal surface and the third heel zone medial surface;   the third toe zone comprises a third toe zone midline that is perpendicular to the front surface and is equidistant from the third toe zone distal surface and the third toe zone medial surface;   the central zone midline is coplanar with the imaginary insert midplane;   the first heel zone midline is 0.20 to 0.30 inch away from the imaginary insert midplane;   the second toe midline is 0.20 to 0.30 inch away from the imaginary insert midplane;   the second heel zone midline is 0.45 to 0.55 inch away from the imaginary insert midplane;   the third toe zone midline is 0.45 to 0.55 inch away from the imaginary insert midplane;   the third heel zone midline is 0.65 to 0.75 inch away from the imaginary insert midplane; and   the third toe zone midline is 0.65 to 0.75 inch away from the imaginary insert midplane.   
     
     
         9 . The putter-type club head of  claim 7 , wherein:
 the face plate has a thickness that is between 0.005 and 0.050 inch; and   the middle layer has a thickness that is between 0.025 and 0.25 inch.   
     
     
         10 . The putter-type club head of  claim 9 , wherein:
 the front surface defines a loft angle that is between 0 and 8 degrees;   the body comprises a mass between 345 and 380 grams; and   the front surface comprises a max height that is less than 1.25 inches.   
     
     
         11 . The putter-type club head of  claim 8 , wherein:
 the face plate comprises a plurality of horizontal grooves extending in a heel-toe direction.   
     
     
         12 . A putter-type club head comprising:
 a body having toe end, a heel end opposite the toe end, a front end, a rear end opposite the front end, a top, and a bottom portion opposite the top;   a front surface and a front recess located on the front surface;   a face insert having a geometric center; and   a midplane that is perpendicular to a ground plane and extends through the geometric center;   wherein:
 the face insert comprises face plate, a middle layer, and an adhesive layer; 
 the face plate is located outboard, the adhesive layer is located inboard, and the middle layer is disposed between the face plate and adhesive layer; 
 the face insert further comprises a first heel point, a first toe point, a first heel zone point, and a second toe point; 
 the first heel point is located 0.25 inch horizontally and heelward of the midplane; 
 the first toe point is located 0.25 inch horizontally and toeward of the midplane; 
 the first heel zone point is located 0.50 inch horizontally and heelward of the midplane; 
 the second toe point is located 0.50 inch horizontally and toeward of the midplane; 
 the middle layer comprises a center durometer at the geometric center that is less than 30 shore; 
 the middle layer comprises a first heel durometer at the first heel point that is between 30 and 35 shore; 
 the middle layer comprises a first toe durometer at the first toe point that is between 35 and 40 shore; 
 the middle layer comprises a first heel zone durometer at the first heel zone point that is between 35 and 40; and 
 the middle layer comprises a second toe durometer at the second toe point that is between 40 and 45 shore.