Transitioning hollow golf clubs

• US 20050239569A1
• Filed: 04/21/2004
• Published: 10/27/2005
• Est. Priority Date: 04/21/2004
• Status: Active Grant

• Current Assignee: Cobra Golf Company (Puma SE)
• Original Assignee: Acushnet Company (FILA Holdings Corp.)
• Inventors: Roach, Ryan L., Best, Christopher B.
• Granted Patent: US 7,137,903 B2
• Time in Patent Office: Days
• US Class Current: 473/290
• CPC Class Codes: A63B 53/005 Club sets
• CPC Class Codes: A63B 53/0408 characterised by specific dimensions, e.g. thickness
• CPC Class Codes: A63B 53/0454 Strengthening ribs on the rear surface of the impact face plate
• CPC Class Codes: A63B 53/047 iron-type
• CPC Class Codes: A63B 53/0475 with one or more enclosed cavities

Abstract

The present invention relates to a set of golf club irons in which some of the club heads have a hollow space, and some of the club heads do not have a hollow space. The hollow space is preferably defined by a lower portion of the front face, a portion of the sole, and a rear wall. The presence of the hollow space moves the club head center of gravity back (away from the face) and down (toward the sole), making it easier to get a golf ball airborne. The volumes of the hollow spaces generally transition or get progressively smaller with an increase in the club loft angle, thus altering the center of gravity location and moments of inertia by different amounts for different clubs. The hollow spaces may be empty or filled, in whole or part.

Claims

1. A set of golf clubs, comprising:

a plurality of iron-type golf club heads;

each of said club heads having a front face defining a loft angle, and a sole; and

each of said club heads having a sole width that is substantially constant throughout the set;

wherein;

some of said club heads have a hollow space; and

some of said club heads do not have a hollow space.

2. The set of claim 1, wherein each of said sole widths is greater than 1 inch.

3. The set of claim 2, wherein said sole width is measured in a direction from a front of said club head to a back of said club head.

4. The set of claim 1, wherein:

each of said hollow spaces is defined by a lower portion of said front face, a portion of said sole, and a rear wall;

said rear wall and said sole meet at a lower junction; and

said lower junction is at a predetermined distance from a lower edge of said front face.

5. The set of claim 4, wherein:

said rear wall is coupled to a rear surface of said front face at an upper junction; and

a distance from said upper junction to an upper edge of said front face is substantially constant throughout the set.

6. The set of claim 4, wherein said predetermined distances decrease through the set with an increase in loft angle.

7. The set of claim 1, wherein each of said hollow spaces defines a volume, and volumes of said hollow spaces generally decrease with an increase in loft angle.

8. The set of claim 1, wherein each of said hollow spaces defines a volume, and volumes of at least two of said club heads are substantially identical.

9. The set of claim 1, wherein:

the set contains long-distance clubs and short-distance clubs; and

those of said clubs that have a hollow space include long-distance clubs and those of said clubs that do not have a hollow space include short-distance clubs.

10. The set of claim 1, wherein:

the set contains long-distance clubs and short-distance clubs; and

those of said clubs that have a hollow space are long-distance clubs and those of said clubs that do not have a hollow space are short-distance clubs.

11. The set of claim 1, wherein each of said plurality of iron-type golf club heads has a center of gravity, and each center of gravity is less than 1 inch from a bottom of said sole.

12. The set of claim 11, wherein each center of gravity is less than approximately 0.8 inch from said bottom of said sole.

13. The set of claim 1, wherein each of said plurality of iron-type golf club heads has a center of gravity, and each center of gravity is from approximately 0.4 inch to approximately 0.6 inch behind said front face.

14. The set of claim 13, wherein each center of gravity is approximately 0.5 inch behind said front face.

15. The set of claim 1, wherein each of said plurality of iron-type golf club heads has a center of gravity and a moment of inertia as measured about a vertical axis passing through said center of gravity that is within the range of approximately 2300 g·

cm² to approximately 2900 g·

cm².

16. The set of claim 15, wherein a difference in moment of inertia between a first golf club within the set of golf clubs having a lowest loft angle and a second golf club within the set of golf clubs having a highest loft angle is less than 300 g·

cm².

17. The set of claim 16, wherein said difference is less than 200 g·

cm².

18. The set of claim 15, wherein said moments of inertia generally increase with an increase in loft angle.

19. The set of claim 1, wherein at least some of said hollow spaces are filled, at least in part, with a foam.

20. The set of claim 1, wherein at least some of said club heads further include:

a recess in a rear portion of said club head; and

an insert positioned within said recess.

21. The set of claim 20, wherein at least some of those of said clubs that have a recess further include a pocket within said recess.

22. The set of claim 20, wherein said insert is a medallion.

23. A set of golf clubs, comprising:

a plurality of iron-type golf club heads;

each of said club heads having a front face defining a loft angle and a sole; and

each of said club heads having a sole width that is substantially constant throughout the set;

wherein some of said club heads have a hollow space, an upper rear cavity, and a lower rear cavity adjacent said hollow space.

24. The set of claim 23, wherein each of said sole widths is greater than 1 inch.

25. The set of claim 23, wherein:

each of said hollow spaces is defined by a lower portion of said front face, a portion of said sole, and a rear wall;

said rear wall is coupled to a rear surface of said front face at an upper junction; and

a distance from said upper junction to an upper edge of said front face is substantially constant throughout the set.

26. The set of claim 23, wherein each of said hollow spaces defines a volume, and volumes of said spaces generally decrease through the set with an increase in loft angle.

27. The set of claim 23, wherein each of said hollow spaces defines a volume, and volumes of at least two of said club heads are substantially identical.

28. The set of claim 23, wherein said club heads having a lower rear cavity further include a composite insert within said lower rear cavity.

29. The set of claim 23, wherein said sole width is measured in a direction from a front of said club head to a back of said club head.

30. The set of claim 23, wherein each of said plurality of iron-type golf club heads has a center of gravity, and each center of gravity is less than 1 inch from a bottom of said sole.

31. The set of claim 30, wherein each center of gravity is less than 0.8 inch from said bottom of said sole.

32. The set of claim 23, wherein each of said plurality of iron-type golf club heads has a center of gravity, and each center of gravity is from approximately 0.4 inch to approximately 0.6 inch behind said front face.

33. The set of claim 32, wherein each center of gravity is approximately 0.5 inch behind said front face.

34. The set of claim 23, wherein each of said plurality of iron-type golf club heads has a center of gravity and a moment of inertia as measured about a vertical axis passing through said center of gravity that is within the range of approximately 2300 g·

cm2 to approximately 2900 g·

cm2.

35. The set of claim 34, wherein said moments of inertia generally increase with an increase in loft angle.

36. The set of claim 34, wherein a difference in moment of inertia between a first golf club within the set of golf clubs having a lowest loft angle and a second club within the set of golf clubs having a highest loft angle is less than 300.

37. The set of claim 36, wherein said difference is less than 200.

38. The set of claim 23, wherein at least some of said club heads further include:

a recess in a rear portion of said club head; and

an insert positioned within said recess.

39. The set of claim 38, wherein at least some of those of said clubs that have a recess further include a pocket within said recess.

40. The set of claim 38, wherein said insert is a medallion.