Golf irons with sealed undercut

Abstract

A golf club head includes a body, a first polymeric insert, and a second polymeric insert. The body includes a face, a sole, and a rear wall that collectively define an undercut volume. The first polymeric insert is provided within the undercut volume to define a sealed cavity within the undercut volume; and, the second polymeric insert is secured to the body and defines an open cavity extending from the rear wall toward the face.

1 . A golf club head comprising:
 a body comprising a face, and a rear wall, wherein;
 the rear wall is opposite the face; 
 a rear recess is defined where a portion of the rear wall is recessed into the body toward the face; 
   a first insert comprising a front surface, a rear surface, and a perimeter, wherein;
 the first insert is received within the rear recess such that the front surface is in contact with the rear wall; 
 the rear surface is opposite the front surface; 
 the perimeter comprises a topline portion, a lower portion, a heel-side portion, and a toe-side portion; 
 a portion of the rear surface is recessed into the first insert towards the front surface, thereby defining an open cavity, wherein; 
 the topline portion, the lower portion, and the toe-side portion of the perimeter circumscribe the open cavity; 
 the first insert further comprises a reinforcing feature comprising a channel comprising a first end near the toe-side portion and a second end near the heel-side portion of the perimeter; 
 wherein the channel extends across the open cavity between the heel-side portion and the toe-side portion of the perimeter; 
 wherein the channel is connected to the insert rear surface by at least one support member sidewall along at least a portion of a length of the channel; and 
 the first insert is formed from a first polymeric material; 
 wherein the first polymeric material has a Shore D hardness between 75 D to 90 D; 
   the body further comprises a sole, wherein the face, the sole, and the rear wall define an undercut volume;   the rear wall defines, at an upper edge thereof, a threshold surface defining an upper threshold of the undercut volume, and a sloped ledge adjoining the threshold surface and projecting at an obtuse angle from the threshold surface into the undercut volume;   the golf club head further comprises a second insert between a rear surface of the face and the sloped ledge of the rear wall within the undercut volume to thereby define a fluidly sealed empty cavity within the undercut volume; and   wherein the second insert includes a top surface and a sloped surface projecting at an obtuse angle from the top surface, the top surface of the second insert being seated against a bottom perimeter of the first insert, and the sloped surface being seated against the sloped ledge of the rear wall.   
     
     
         2 . The golf club head of  claim 1 , wherein the channel is supported by the at least one support member sidewall along an entirety of the length of the channel. 
     
     
         3 . The golf club head of  claim 1 , wherein at least a portion of the first insert is formed of polyetheretherketones (PEEK). 
     
     
         4 . The golf club head of  claim 1 , wherein a normal projection of the open cavity onto the face defines a first area, and a normal projection of the undercut volume onto the face defines a second area, and wherein the first area and the second area do not overlap. 
     
     
         5 . The golf club head of  claim 4 , wherein the normal projection of the undercut volume includes a normal projection of the fluidly sealed empty cavity onto the face that defines a third area, and wherein a ratio of the first area to the third area is from about 1.1:1 to about 1.9:1. 
     
     
         6 . The golf club head of  claim 1 , wherein the second insert extends across a central region of the face behind a designated hitting zone. 
     
     
         7 . The golf club head of  claim 1 , wherein the first insert is in contact with the body along an entirety of the topline portion. 
     
     
         8 . The golf club head of  claim 1 , wherein the first insert defines a width, measured normal to the face, and the width varies around the perimeter. 
     
     
         9 . The golf club head of  claim 8 , wherein the width is about 2.5 mm to about 6.0 mm along an upper portion directly adjacent to the topline portion and the width is about 5.0 mm to about 20 mm along a lower portion directly adjacent the second insert. 
     
     
         10 . A golf club head comprising:
 a body comprising a face, and a rear wall, wherein;
 the rear wall is opposite the face; 
 a rear recess is defined where a portion of the rear wall is recessed into the body toward the face; 
   a first insert comprising a front surface, a rear surface, and a perimeter, wherein;
 the first insert is received within the rear recess such that the front surface is in contact with the rear wall; 
 the rear surface is opposite the front surface; 
 the perimeter comprises a topline portion, a lower portion, a heel-side portion and a toe-side portion; 
 a portion of the rear surface is recessed into the first insert towards the front surface, thereby defining an open cavity, wherein; 
 the topline portion, the lower portion, and the toe-side portion of the perimeter circumscribe the open cavity; 
 the first insert further comprises a reinforcing feature comprising a beam comprising a first end near the toe-side portion and a second end near the heel-side portion of the perimeter; 
 wherein the beam is suspended above the open cavity between the heel-side portion and the toe-side portion of the perimeter; 
 wherein the beam is supported only at the first end and the second end; and 
 the first insert is formed from a first polymeric material; 
 wherein the first polymeric material has a Shore D hardness between 75 D to 90 D; 
   the body further comprises a sole, wherein the face, the sole, and the rear wall define an undercut volume;   the rear wall defines, at an upper edge thereof, a threshold surface defining an upper threshold of the undercut volume, and a sloped ledge adjoining the threshold surface and projecting at an obtuse angle from the threshold surface into the undercut volume; and   the golf club head further comprises a second insert between a rear surface of the face and the sloped ledge of the rear wall within the undercut volume to thereby define a fluidly sealed empty cavity within the undercut volume; and wherein the second insert includes a top surface and a sloped surface projecting at an obtuse angle from the top surface, the top surface of the second insert being seated against a bottom perimeter of the first insert, and the sloped surface being seated against the sloped ledge of the rear wall.   
     
     
         11 . The golf club head of  claim 10 , wherein at least a portion of the first insert is formed of a thermoplastic aliphatic or semi-aromatic polyamide that is filled with chopped fiber, such as chopped carbon fiber or chopped glass fiber. 
     
     
         12 . The golf club head of  claim 10 , wherein at least a portion of the first insert is formed of polyetheretherketones (PEEK). 
     
     
         13 . The golf club head of  claim 10 , wherein a normal projection of the open cavity onto the face defines a first area, and a normal projection of the undercut volume onto the face defines a second area, and wherein the first area and the second area do not overlap. 
     
     
         14 . The golf club head of  claim 13 , wherein the normal projection of the undercut volume includes a normal projection of the fluidly sealed empty cavity onto the face that defines a third area, and wherein a ratio of the first area to the third area is from about 1.1:1 to about 1.9:1. 
     
     
         15 . The golf club head of  claim 10 , wherein the second insert extends across a central region of the face behind a designated hitting zone. 
     
     
         16 . The golf club head of  claim 10 , wherein the first insert is in contact with the body along an entirety of the topline portion. 
     
     
         17 . The golf club head of  claim 10 , wherein the first insert defines a width, measured normal to the face, and the width varies around the perimeter. 
     
     
         18 . The golf club head of  claim 17 , wherein the width is about 2.5 mm to about 6.0 mm along an upper portion directly adjacent to the topline. 
     
     
         19 . The golf club head of  claim 17 , wherein the width is about 5.0 mm to about 20 mm along a lower portion directly adjacent the second insert.