Golf club head

Abstract

An iron-type golf club head is disclosed having a heel portion, a sole portion, a toe portion, a top-line portion, a front portion, a rear portion, and a striking face. A back wall is also disclosed in the rear portion enclosing a portion of the rear portion to create an enclosed cavity. The cavity is defined by at least a rear surface of the striking face, an inner back wall surface, and the sole portion. A plug and a filler material is located within the enclosed cavity. The filler material surrounds the plug and is configured to hold the plug in place. The plug is lighter than the filler material.

We claim: 
     
       1. A hollow iron-type golf club head comprising:
 a heel portion, a sole portion, a toe portion, a top-line portion, a front portion, a rear portion, and a striking face having an unsupported face area of between about 300 mm 2  to about 4,000 mm 2 ;   a back wall in the rear portion enclosing a substantial portion of the rear portion to create a substantially enclosed cavity, the enclosed cavity being defined by at least a rear surface of the striking face, an inner back wall surface, and the sole portion,   at least one plug located within the enclosed cavity, the at least one plug being compressed between the rear surface of the striking face and the back wall in the rear portion;   a filler material located within the enclosed cavity, the filler material substantially surrounding the at least one plug and being configured to hold the at least one plug in place, the golf club head defining an aperture into the enclosed cavity, the aperture being configured to allow the cavity to be filled with the filler material;   wherein the unsupported face area includes a thickened central region;   wherein the at least one plug is positioned to be in contact with at least a portion of the thickened central region; and   wherein the at least one plug occupies less than 20% of the total club head cavity volume in the enclosed cavity.   
     
     
       2. The iron-type golf club head of  claim 1 , wherein the enclosed cavity has a volume between about 1 cc and 200 cc. 
     
     
       3. The iron-type golf club head of  claim 1 , wherein the enclosed cavity has a volume between about 10 cc mid 20 cc. 
     
     
       4. The iron-type golf club head of  claim 1 , wherein the at least one plug has a volume between about 0.1 cc and about 1 cc. 
     
     
       5. The iron-type golf club head of  claim 1 , wherein the at least one plug occupies between about 1% to about 10% of the total club head cavity volume in the enclosed cavity. 
     
     
       6. The iron-type golf club head of  claim 1 , wherein the at least one plug occupies between about 0.5% to about 5% of the total club head cavity volume in the enclosed cavity. 
     
     
       7. The iron-type golf club head of  claim 1 , wherein the filler material is an expanding foam material having a density between about 0.03 g/cc and about 0.19 g/cc. 
     
     
       8. The iron-type golf club head of  claim 1 , wherein the filler material occupies about 50% to about 99% of the total club head cavity volume in the enclosed cavity. 
     
     
       9. The iron-type golf club head of  claim 1 , wherein the back wall includes at least a first aperture, the first aperture being configured to allow the at least one plug to be inserted into the first aperture and is configured to allow the at least one plug to move from a first position to a second position. 
     
     
       10. The iron-type golf club head of  claim 9 , wherein the back wall includes at least one slot, the at least one slot being connected to the first aperture and is configured to secure the at least one plug. 
     
     
       11. A hollow iron-type golf club head comprising:
 a heel portion, a sole portion, a toe portion, a top-line portion, a front portion, a rear portion, and a striking face having an unsupported face area of between about 300 mm 2  to about 4,000 mm 2 ;   a back wall in the rear portion enclosing a substantial portion of the rear portion to create a substantially enclosed cavity, the enclosed cavity being defined by at least a rear surface of the striking, face, an inner back wall surface, and the sole portion;   at least one plug located within the enclosed cavity, the at least one plug being compressed between the rear surface of the striking face and the back wall in the rear portion;   wherein the at least one plug occupies less than 20% of the total club head cavity volume in the enclosed cavity, and   wherein the back wall includes at least a first aperture, the first aperture being configured to allow the at least one plug to be inserted into the first aperture and being configured to allow the at least one plug to move from a first position to a second position.   
     
     
       12. The iron-type golf club head of  claim 11 , wherein the enclosed cavity has a volume between about 1 cc and 200 cc. 
     
     
       13. The iron-type golf club head of  claim 11 , wherein the enclosed cavity has a volume between about 10 cc and 20 cc. 
     
     
       14. The iron-type golf club head of  claim 11 , wherein the at least one plug has a volume between about 0.1 cc and about 1 cc. 
     
     
       15. The iron-type golf club head of  claim 11 , wherein the at least one plug occupies between about 1% to about 10% of the total club head cavity volume in the enclosed cavity. 
     
     
       16. The iron-type golf club head of  claim 11 , wherein the at least one plug occupies between about 0.5% to about 5% of the total club head cavity volume in the enclosed cavity. 
     
     
       17. The iron-type golf club head of  claim 11 , further comprising a filler material located within the enclosed cavity, the filler material substantially surrounding the at least one plug and being configured to hold the at least one plug in place. 
     
     
       18. The iron-type golf club head of  claim 17 , wherein the filler material is an expanding foam material having a density between about 0.03 g/cc and about 0.19 g/cc. 
     
     
       19. The iron-type golf club head of  claim 17 , wherein the filler material occupies about 50% to about 99% of the total club head cavity volume in the enclosed cavity. 
     
     
       20. The iron-type golf club head of  claim 17 , wherein the filler material completely fills a remaining cavity volume around the at least one plug. 
     
     
       21. The iron-type golf club head of  claim 11 , wherein the coefficient of restitution of the club is greater than about 0.8. 
     
     
       22. The iron-type golf club head of  claim 11 , wherein the back wall includes at least one slot, the at least one slot being connected to the first aperture and is configured to secure the at least one plug. 
     
     
       23. An iron-type golf club head comprising:
 a heel portion, a toe portion, a top-line portion, a sole portion, a striking face having a variable face thickness and joining the top-line portion to the sole portion, a rear portion joined to the striking face by the sole portion, and a badge attached to the golf club head;   wherein the rear portion extends upward from the sole portion toward the top-line portion and creates an enclosed cavity bounded by at least a portion of the rear portion, at least a portion of the sole portion, at least a portion of the striking face, and at least a portion of the badge, and a filler material is located within the enclosed cavity;   wherein an upper portion of the striking face has a first thickness and a central region of the striking face has a second thickness, wherein the second thickness is greater than the first thickness;   wherein a portion of the striking face bounding the enclosed cavity has a face thickness of less than about 3.0 mm;   the striking face has a minimum face thickness of no more than about 2.5 mm, and the sole thickness of a portion of the sole portion bounding the enclosed cavity is no more than about 2.0 mm; and   wherein a coefficient of restitution of the club head is greater than about 0.8.    
     
     
       24. The iron-type golf club head of claim 23, wherein the striking face is welded to the club head.  
     
     
       25. The iron-type golf club head of claim 24, wherein the enclosed cavity has a volume of 20 cc or less.  
     
     
       26. The iron-type golf club head of claim 25, wherein the sole portion has a minimum sole portion thickness of no less than 1 mm.  
     
     
       27. The iron-type golf club head of claim 23, wherein the striking face is welded to the club head along a portion of the top-line portion and a portion of the sole portion.  
     
     
       28. The iron-type golf club head of claim 23, wherein the filler material has a density of greater than 0.03 g/cc and the filler material weighs less than about 5% of a total club head weight.  
     
     
       29. The iron-type golf club head of claim 28, wherein the filler material is a cure-in-place elastomeric material.  
     
     
       30. The iron-type golf club head of claim 29, wherein the elastomeric material contains an inorganic filler material.  
     
     
       31. The iron-type golf club head of claim 28, wherein the elastomeric material is a foamed polymer material.  
     
     
       32. The iron-type golf club head of claim 28, wherein the elastomeric material is a urethane.  
     
     
       33. The iron-type golf club head of claim 28, wherein the elastomeric material contains a filler material with a particle size between about 2 μm and about 90 μm.  
     
     
       34. The iron-type golf club head of claim 27, wherein the rear portion includes a recess located below an ideal impact location, wherein the recess forms a ledge having a length greater than the face thickness.  
     
     
       35. The iron-type golf club head of claim 28, further including a weighting element located in the enclosed cavity and in contact with the filler material, wherein the weighting element has a greater density than the face portion.  
     
     
       36. The iron-type golf club head of claim 28, wherein the filler material has a filler material thickness measured in a front to back direction, and the filler material thickness is greater below the central region of the striking face than the filler material thickness above the central region of the striking face.  
     
     
       37. The iron-type golf club head of claim 36, wherein an upper portion of the enclosed cavity is completely filled with the filler material.  
     
     
       38. The iron-type golf club head of claim 28, wherein the filler material has a filler material thickness measured in a front to back direction, and the filler material thickness varies within the enclosed cavity and is greatest proximate the sole portion.  
     
     
       39. An iron-type golf club head comprising:
 a heel portion, a toe portion, a top-line portion, a sole portion, a striking face joining the top-line portion to the sole portion, a rear portion joined to the striking face by the sole portion, and a badge attached to the golf club head;   wherein the rear portion extends upward from the sole portion toward the top-line portion and creates an enclosed cavity bounded at least in part by a portion of the rear portion, a portion of the sole portion, and a portion of the striking face, and a filler material is located within the enclosed cavity;   wherein a portion of the sole portion bounding the enclosed cavity has a sole thickness of less than about 2.0 mm;   wherein the striking face has a minimum face thickness of no more than about 2.0 mm;   wherein the enclosed cavity has a volume of 20 cc or less;   wherein the filler material occupies no less than 50% of the enclosed cavity, the filler material weighs less than about 5% of a total club head weight, and the filler material has a density of greater than 0.03 g/cc; and   wherein a coefficient of restitution of the club head is greater than about 0.8.    
     
     
       40. The iron-type golf club head of claim 39, wherein the enclosed cavity has an enclosed cavity depth measured in a front to back direction and the enclosed cavity depth varies.  
     
     
       41. An iron-type golf club head comprising:
 a heel portion, a toe portion, a top-line portion, a sole portion, a striking face having a variable face thickness and joining the top-line portion to the sole portion, and a rear portion joined to the striking face by the sole portion;   wherein the rear portion extends upward from the sole portion toward the top-line portion and creates a cavity bounded by at least a portion of the rear portion, at least a portion of the sole portion, and at least a portion of the striking face, and a filler material is located within the cavity;   wherein an upper portion of the striking face has a first thickness and a central region of the striking face has a second thickness, wherein the second thickness is greater than the first thickness and no more than 3 mm;   the striking face has a minimum face thickness of no more than about 2.5 mm, and the sole thickness of a portion of the sole portion bounding the enclosed cavity is no more than about 2.0 mm; and   wherein a coefficient of restitution of the club head is greater than about 0.8;   wherein the cavity has a cavity depth measured in a front to back direction and the cavity depth varies;   wherein the filler material occupies weighs less than about 5% of a total club head weight, and the filler material has a density of greater than 0.03 g/cc;   wherein the striking face is a steel alloy and is welded to the club head;   wherein the cavity has a volume of 20 cc or less.