Multi-material iron golf club head

Abstract

Described herein is a tour iron having a golf club head with a faceplate, a body, and an insert. A sole, top rail, rear, and the faceplate enclose a cavity within the body. The cavity can house the insert. The insert can comprise a low-density material, allowing weight to be concentrated around the peripheral edge of the golf club head. The rear of the golf club head has an inflection seam running from the heel to the toe. The golf club head has an upper portion, above the inflection seam and a lower portion below the inflection seam. The upper portion can have a rear opening. The faceplate, body, and insert can be formed of different materials having different densities. The golf club head has a comparatively high moment of inertia and a low center of gravity. Other embodiments and methods are described herein.

1 . A golf club head comprising a faceplate, a body, and an insert;
 the body comprising an upper portion, a lower portion, a sole, a rear, and a top rail;
 wherein: the faceplate and a portion of the body define a striking surface of the golf club head; 
 the faceplate, the sole, the rear, and the top rail enclose a cavity; 
 the rear comprises an inflection seam; 
 the sole rests on a ground plane; 
 a loft plane is tangential to the faceplate and intersects the ground plane; 
 a centerplane, perpendicular to the loft plane, and coincident with a centerpoint of the striking surface; 
 the upper portion is bounded by the top rail and the inflection seam; 
 the lower portion is bounded by the inflection seam and the sole; 
 the upper portion comprises a first depth and the lower portion comprises a second depth, wherein the depths are measured perpendicular to the loft plane from the striking surface to an outer surface of the rear, along the centerplane; 
 the first depth is constant and is less than the second depth; 
 the sole, the rear, the top rail, and the faceplate enclose a cavity; 
 the cavity comprises a cavity volume; 
 the cavity volume in the lower portion is greater than the cavity volume in the upper portion; 
 the insert is received in the cavity, and the insert complements 90% or more of the cavity; 
 the insert comprises a first portion and a second portion; 
 the faceplate comprises a first material of a first density; 
 the body comprises a second material of a second density; 
 the first portion of the insert comprises a third material of a third density; 
 the second portion of the insert comprises a fourth material of a fourth density; 
 the third density is less than the first, second, and fourth densities; 
 and the third density is between 2.4 and 5.0 g/cc. 
   
     
     
         2 . The golf club head of  claim 1 , wherein:
 the upper portion comprises a height measured along the centerplane from the top rail to the inflection seam, in a direction parallel to the loft plane;   the lower portion comprises a height measured along the centerplane from the sole to the inflection seam, in a direction parallel to the loft plane; and   the height of the upper portion and the height of the lower portion have a ratio of between 9:8 and 6:11.   
     
     
         3 . The golf club head of  claim 1 , wherein the second portion of the insert does not contact the faceplate. 
     
     
         4 . The golf club head of  claim 3 , wherein the second portion of the insert is wholly located in the lower portion of the body. 
     
     
         5 . The golf club head of  claim 1 , wherein the fourth density is greater than the first and second densities. 
     
     
         6 . The golf club head of  claim 1 , wherein a ratio of the first depth to a maximum of the second depth is between 1:3 and 4:5. 
     
     
         7 . The golf club head of  claim 1 , further comprising:
 a center of gravity;   a lead edge axis, parallel to the ground plane, extending in a heel-to-toe direction, and coincident with a point on the centerplane that is lowest on the striking surface;   a lead edge plane, parallel to the ground plane and coincident with the lead edge axis;   a y-axis, orthogonal to the ground plane, and coincident with the center of gravity;   and wherein the center of gravity of the golf club head is located between 0.380 inch and 0.670 inch above the lead edge plane.   
     
     
         8 . The golf club head of  claim 1 , further comprising:
 a heel and a toe; a cylindrical hosel integral to the body;   a hosel reference plane, parallel to a front edge of the cylindrical hosel, when viewed from a toe side view;   a hosel axis, defined as the central axis of the cylindrical hosel;   a lead edge axis, parallel to the ground plane, extending in a heel-to-toe direction, and coincident with a point on the centerplane that is lowest on the striking surface;   a hosel-X distance, measured from the intersection of the lead edge axis with the centerplane to the intersection of the lead edge axis with the hosel axis when viewed from a front view;   wherein the hosel-X distance is less than 1.5 inches;   an offset distance, measured as the minimum distance between the lead edge axis and the hosel reference plane, and;   wherein the offset distance is between 0.05 inch and 0.27 inch.   
     
     
         9 . The golf club head of  claim 1 , further comprising a tape disposed between the insert and the faceplate. 
     
     
         10 . The golf club head of  claim 1 , wherein the first depth is less than 0.290 inch. 
     
     
         11 . The golf club head of  claim 1 , wherein the third density is between 2.4 and 3.0 g/cc. 
     
     
         12 . The golf club head of  claim 1 , wherein: the third material comprises a material selected from the group consisting of: aluminum and titanium; and the fourth material comprises tungsten. 
     
     
         13 . The golf club head of  claim 1 , further comprising:
 a total mass and a toe weight;   wherein the body further comprises:
 a toe cavity; 
 the toe cavity receives the toe weight; 
 and the toe weight comprises a mass between 5% and 45% of the total mass of the club head. 
   
     
     
         14 . The golf club head of  claim 1 , further comprising:
 a heel and a toe; an x-axis, extending in a heel-to-toe direction, parallel to the striking surface, and coincident with a center of gravity of the club head;   a y-axis, orthogonal to the ground plane and coincident with the center of gravity;   wherein:
 a moment of inertia, Ixx, measured about the x-axis ranges between 78 gram square inches and 120 gram square inches, and; 
 a moment of inertia, Iyy, measured about the y-axis ranges between 310 gram square inches and 466 gram square inches. 
   
     
     
         15 . A method of forming a golf club head comprising the following steps:
 (1) providing a faceplate comprising a first material of a first density;   (2) providing a body, comprising a second material of a second density, an upper portion, a lower portion, a sole, a rear, and a top rail; wherein:
 the faceplate and a portion of the body define a striking surface of the golf club head; 
 the rear comprises an inflection seam; the sole rests on a ground plane; 
 a loft plane is tangential to the faceplate and intersects the ground plane; 
 a centerplane, extending in a top rail-to-sole direction, and coincident with a centerpoint of the striking surface; 
 the upper portion is bounded by the top rail and the inflection seam; 
 the lower portion is bounded by the inflection seam and the sole; 
 the upper portion comprises a height measured along the centerplane from the top rail to the inflection seam, in a direction parallel to the loft plane; 
 the lower portion comprises a height measured along the centerplane from the sole to the inflection seam, in a direction parallel to the loft plane; 
 the height of the upper portion and the height of the lower portion have a ratio of between 1:1 and 2:1; 
 the upper portion comprises a first depth and the lower portion comprises a second depth, wherein the depths are measured perpendicular to the loft plane from the striking surface to an outer surface of the rear, along the centerplane; 
 the first depth is constant and is less than the second depth; the sole, the rear, and the top rail define a cavity; 
   (3) providing an insert, comprising a first portion and a second portion; wherein:
 the first portion comprises a third material of a third density; 
 the second portion comprises a fourth material of a fourth density; 
 the third density is less than the first, second, and fourth densities; 
 the third density is between 2.4 and 5.0 g/cc; 
   (4) placing the insert within the cavity; where after the insert fills 90% or more of the cavity; and   (5) securing the faceplate to the body, wherein the faceplate further defines and encloses the cavity.   
     
     
         16 . The method of forming a golf club head of  claim 15 , wherein securing the faceplate to the body in step (5) comprises: swedging the faceplate onto the body; heat treating (or laser welding) a boundary between the faceplate and the body. 
     
     
         17 . The method of forming a golf club head of  claim 15 , wherein laser welding the boundary of the faceplate and the body comprises creating a heat affected zone comprising a depth of less than 0.070 inch. 
     
     
         18 . The method of forming a golf club head of  claim 15 , wherein:
 the golf club head further comprises:
 a heel and a toe; 
 an x-axis, extending in a heel-to-toe direction, parallel to the striking surface, and coincident with a center of gravity of the club head; 
 a y-axis, orthogonal to the ground plane and coincident with the center of gravity; wherein: 
 a moment of inertia, Ixx, measured about the x-axis ranges between 78 gram square inches and 120 gram square inches; 
 and a moment of inertia, Iyy, measured about the y-axis ranges between 310 gram square inches and 466 gram square inches. 
   
     
     
         19 . The method of forming a golf club head of  claim 15 , further comprising placing a tape layer onto the insert between steps (4) and (5), wherein the tape layer is sandwiched between the insert and the faceplate upon completion of step (5). 
     
     
         20 . The method of forming a golf club head of  claim 15 , wherein the first portion and the second portion of the insert are integrally formed prior to step (4).