Iron golf club head including weight members for adjusting center of gravity thereof

• US 6,077,171 A
• Filed: 11/23/1998
• Issued: 06/20/2000
• Est. Priority Date: 11/23/1998
• Status: Expired due to Fees

• Current Assignee: Yonex Kabushiki Kaisha
• Original Assignee: Yonex Kabushiki Kaisha
• Inventors: Yoneyama, Minoru
• Primary Examiner(s): Passaniti, Sebastiano
• Application Number:
  US09/197,416
• Time in Patent Office: 575 Days
• Field of Search: 473/334, 473/335, 473/336, 473/337, 473/338, 473/339, 473/291, 473/350
• US Class Current: 473/291
• CPC Class Codes: A63B 2053/0491 with added weights, e.g. changeable, replaceable
• CPC Class Codes: A63B 2209/00 Characteristics of used materials
• CPC Class Codes: A63B 2209/02 with reinforcing fibres, e.g. carbon, polyamide fibres
• CPC Class Codes: A63B 53/04 Heads
• CPC Class Codes: A63B 53/047 iron-type
• CPC Class Codes: A63B 60/00 Details or accessories of golf clubs, bats, rackets or the like

Abstract

An iron golf club head comprised of a head body 10 made of light metal such as titanium and containing a plurality of weight members 16. The head body 10 includes a front surface 13, a rear surface 13a, a cavity 12 disposed at the rear surface 13a, and a plurality of holes 15 disposed in the head body 10 at the rear surface 13a between a lower side wall 12b of the cavity 12 and a sole 14 of the head body 10 at predetermined intervals between a toe part 17 and a heel part 18. The center axis of each hole 15 is oriented substantially parallel to the sole 14 of the head body 10. The weight members 16 are press-inserted into the holes 15 in a direction going toward the front surface 13 of the head body 10 to a predetermined depth. Each weight member 16 is made of a material having a heavier specific weight than the light metal used for the aforesaid head body 10. Tungsten or tungsten alloy can be used as the material for the weight members 16. The combined weight of the weight members 16 does not exceed forty percent of the weight of the entire head.

Claims

1. An iron golf club head comprising:

a head body made of light metal and having a front surface, a rear surface, a cavity disposed at said rear surface, and at least four holes disposed in the rear surface between a lower side wall of said cavity and a sole of said head body,

said at least four holes forming groups of holes, each of said groups including two or more holes located at a toe part and at a heel part of said head body, respectively, and said holes in each of said groups being spaced at predetermined intervals;

a plurality of weight members fitted into said holes, respectively, wherein each of said weight members extends into said respective hole to a predetermined depth and is oriented in a direction toward the front surface of said head body, and each of said weight members is formed of a material having a specific weight that is heavier than a specific weight of the light metal forming said head body, thereby adjusting the location of the center of gravity between the toe part and the heel part of said head body,

wherein the weight percentage of said weight members does not exceed forty percent of the total weight of the club head, and

wherein each of said weight members has a diameter that is larger than a diameter of the respective hole in said head body and is press-inserted into the respective hole to a predetermined length so far as the length is within the depth provided by the respective hole.

2. An iron golf club head as claimed in claim 1, wherein each of said weight members has a circular cylindrical shape, and the center of gravity established by said weight members can be shifted by adjusting the length of the weight member inserted in the respective hole in said head body.

3. An iron golf club head as claimed in claim 1, wherein each of said weight members has a circular cylindrical shape, and the center of gravity established by said weight members can be shifted by adjusting the diameter of the weight members inserted in said head body.

4. An iron golf club head as claimed in claim 1, wherein said light material includes titanium.

5. An iron golf club head as claimed in claim 1, wherein said head body is formed by casting.

6. An iron golf club head as claimed in claim 1, wherein each of said holes has a diameter between four and ten millimeters and a depth between four and twenty millimeters.

7. An iron golf club head as claimed in claim 1, wherein said weight members are formed of a material including tungsten.

8. An iron golf club head as claimed in claim 1, wherein the weight of said weight members is not less than fifteen percent of the total weight of the club head.

9. An iron golf club head as claimed in claim 1, wherein the number of said weight members is from four to six.

10. An iron golf club head as claimed in claim 1, wherein each of said weight members is shaped as a cylinder.

11. An iron golf club head as claimed in claim 1, wherein each of said weight members is shaped as a polygonal cylinder in cross section.

12. An iron golf club head as claimed in claim 1, wherein each of said holes has a central axis which is oriented substantially parallel to said sole of said head body.

13. An iron golf club head as claimed in claim 1, further comprising an adhesive agent inserted between each of said press-inserted weight members and a bottom of the respective hole.

14. An iron golf club comprising:

a club head; and

a shaft connected to said club head,

said club head comprising a head body made of light metal, said head body having a front surface, a rear surface, a cavity disposed at said rear surface, and at least four holes disposed in the rear surface between a lower side wall of said cavity and a sole of said head body,

said at least four holes forming groups of holes, each of said groups including two or more holes located at a toe part and at a heel part of said head body, respectively, said holes in each of said groups being spaced at predetermined intervals;

a plurality of weight members fitted into said at least four holes to a predetermined depth, respectively,

each of said weight members being oriented in a direction toward the front surface of said head body, and each of said weight members being formed of a material having a specific weight that is heavier than a specific weight of the light metal forming said head body, thereby adjusting the location of the center of gravity between the toe part and the heel part of said head body,

wherein the weight percentage of said weight members is not more than forty percent of the total weight of the club head, and

wherein each of said weight members has a diameter that is larger than a diameter of the respective hole in said head body and is press-inserted into the respective hole to a predetermined length so far as the length is within the depth provided by the respective hole.

15. An iron golf club as claimed in claim 14, wherein said shaft is formed of a reinforced fiber material including boron.

16. An iron club set including long iron golf clubs and short iron golf clubs, each of said iron golf clubs including a club head, comprising:

a head body made of light metal and having a front surface, a rear surface, a cavity disposed at said rear surface, and at least four holes disposed in the rear surface between a lower side wall of the cavity and a sole of said head body,

said at least four holes defining groups of holes, each of said groups including two or more of said holes,

said groups being located at a toe part and at a heel part of said head body, respectively, wherein said holes in each of said groups are spaced from each other at predetermined intervals;

a plurality of weight members fitted into said holes, respectively, and each of said weight members being oriented in a direction toward the front surface of said head body and extending in said respective hole to a predetermined depth, each of said weight members being formed of a material having a specific weight that is heavier than a specific weight of said light metal, thereby adjusting the location of the center of gravity between the toe part and the heel part of said head body,

wherein the weight percentage of said weight members is not more than forty percent of the total weight of the club head, and

each of said weight members has a diameter that is larger than a diameter of said respective hole in said head body and is press-inserted into said respective hole to a predetermined length so far as the length is within the depth of said respective hole,

wherein said weight members are arranged in the club head of each of said long iron golf clubs so that the center of gravity established by said weight members is positioned at the toe part across the bottom center portion of said head body, and

said weight members are arranged in the club head of each of said short iron golf clubs so that the center of gravity established by said weight members is positioned at the heel part across the bottom center portion of said head body.

17. An iron club set as claimed in claim 16, wherein each of said weight members has a circular cylindrical shape, and the center of gravity established by said weight members can be shifted by adjusting the length of said weight members, which are inserted in respective holes in said head body.

18. An iron club set as claimed in claim 16, wherein each of said weight members has a circular cylindrical shape, and the center of gravity established by said weight members can be shifted by adjusting the diameter of said weight members, which are inserted in said head body.