US20110159984A1

Movatterモバイル変換

Info

Publication number: US20110159984A1
Application number: US13/043,867
Authority: US
Inventors: Hideo Shimazaki
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-07-22
Filing date: 2011-03-09
Publication date: 2011-06-30
Also published as: US20110021285A1; JP2011024999A; US8277337B2

Abstract

An iron head is provided with a recess portion provided in an upper portion of a backside surface thereof, and a protruding portion provided at a lower portion of the backside surface. A first hollow portion is provided on a heel side from a bottom surface of a recess portion to a sole surface; and a second hollow portion is disposed on a toe side. The first hollow portion and the second hollow portion do not exist behind a sweet area. The first hollow portion and the second hollow portion may be filled with a shock absorber formed of a rubber or an elastomer.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of a prior application Ser. No. 12/507,266, filed Jul. 22, 2009, pending.

BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT

The present invention relates to an iron head for an iron type golf club. More particularly, the present invention relates to an iron head having a hollow portion.

An iron type golf club includes a shaft and an iron head disposed at a distal end of the shaft, so that a striking face of the iron head hits a ball. The shaft is inserted and fixed into a hosel formed in the iron head. A side of the iron head where the hosel is formed is referred to as a heel, and an opposite side of the iron head, i.e., a distal end side thereof, is referred as a toe. A bottom side of the iron head facing a ground surface is referred to as a sole. A plurality of grooves, i.e., score lines, is formed in the striking face of the iron head with a certain distance therebetween in a vertical direction.

Patent Reference 1 has disclosed a conventional iron head. The conventional iron head has a recess portion disposed at an upper portion of a back surface thereof, and a hollow portion is disposed behind the striking face below the recess portion. With the hollow portion formed in the iron head, it is possible to lower the center of gravity of the iron head. Further, the center of gravity is shifted backward from the striking face of the iron head, thereby expanding a sweet area thereof. In addition, when the hollow portion is formed in the iron head, a weight of the iron head is reduced. Therefore it is possible to increase a size of the iron head without increasing the weight thereof. Further, when a weight distribution increases on the toe side and the heel side of the iron head, it is possible to increase the sweet area of the iron head without increasing the weight thereof.

In Patent Reference 1, the conventional iron head has the hollow portion extending from the proximity of the toe to the proximity of the heel. A thickness of a face plate, or a distance between the striking face and the hollow portion, is substantially uniform between the toe side and the heel side.

Patent Reference 2 has disclosed another type of conventional iron heads. The conventional iron head has a hollow portion disposed behind a striking face, and a shock absorber made of a rubber, urethane, or silicone is disposed in the hollow portion. The shock absorber has a thickness about 1.5 mm to 8.0 mm.

Patent Reference 3 has disclosed a golf club having a striking face capable of bending like a wood club. With the configuration, it is possible to hit a ball for a long distance.

Patent Reference 4 has disclosed an iron head having a hollow portion and a viscoelastic body disposed in the hollow portion. The viscoelastic body enables to dampen a vibration of the iron head.

Patent Reference 1: Japanese Patent Publication No. 2000-210400
Patent Reference 2: Japanese Patent Publication No. 09-117537
Patent Reference 3: U.S. Pat. No. 4,398,965
Patent Reference 4: Japanese Patent Publication No. 06-319836

In the conventional iron head disclosed in Patent Reference 1, the thickness of the face plate between the striking face and the hollow portion, in other words, the distance between the striking face and the hollow portion, is substantially uniform in a toe to heel direction. When the golf club having the iron head hits a ball at a middle portion thereof, it is difficult to obtain a strong impact feeling due to the hollow portion formed behind the middle portion and the small thickness of the face plate at the middle portion of the iron head.

In view of the problems described above, an object of the present invention is to provide an iron head having a wide sweet area and capable of obtaining a strong impact feeling when hitting a ball at a middle portion thereof.

SUMMARY OF THE INVENTION

In order to attain the object described above, according to a first aspect of the present invention, an iron head is provided with a striking face; a backside surface; a sole surface; a hosel; a recess portion provided in an upper portion of the backside surface; a protruding portion provided at a lower portion of the backside surface and projecting backward; a first hollow portion provided on a heel side of the protruding portion; and a second hollow portion disposed on a toe side of the protruding portion. The protruding portion has a middle portion between the first hollow portion and the second hollow portion.

According to a second aspect of the present invention, in the iron head in the first aspect, at least one of the first hollow portion and the second hollow portion penetrates from an upper surface of the protruding portion to a sole surface, and has a first lid to close the sole surface.

According to a third aspect of the present invention, in the iron head in the first aspect, at least one of the first hollow portion and the second hollow portion has a second lid to close an upper portion thereof.

According to a fourth aspect of the present invention, in the iron head in the first aspect, the first hollow portion is disposed away from the second hollow portion by a distance equal to a distance between the upper surface of the protruding portion and the sole surface.

According to a fifth aspect of the present invention, in the iron head in the first aspect, the first hollow portion is disposed away from the second hollow portion by a distance of 10 to 30 mm.

According to a sixth aspect of the present invention, in the iron head in the first aspect, the first hollow portion is disposed away from the second hollow portion by a distance gradually increasing from the upper surface of the protruding portion toward the sole surface.

According to a seventh aspect of the present invention, in the iron head in the first aspect, the first hollow portion is disposed away from the second hollow portion by a distance of 10 to 30 mm at the upper surface of the protruding portion.

According to an eighth aspect of the present invention, in the iron head in the first aspect, at least one of the first hollow portion and the second hollow portion is disposed not to reach the sole surface.

According to a ninth aspect of the present invention, in the iron head in the first aspect, at least one of the first hollow portion and the second hollow portion is filled with a shock absorber.

According to a tenth aspect of the present invention, in the iron head in the ninth aspect, the shock absorber is made of a rubber or an elastomer.

According to an eleventh aspect of the present invention, an iron head is provided with a striking face; a backside surface; a sole surface; a hosel; a recess portion provided in an upper portion of the backside surface; a protruding portion provided at a lower portion of the backside surface and projecting backward; and a hollow portion extending from a toe side to a heel side of the protruding portion. The protruding portion has a middle portion with a first face plate thickness in a toe to heel direction thereof. The first face plate thickness is larger than a second face plate thickness on a toe side with respect to the middle portion and a third face plate thickness on a heel side with respect to the middle portion.

According to a twelfth aspect of the present invention, in the iron head in the eleventh aspect, the hollow portion has a length of 15 to 30 mm in from the toe side to the heel side.

According to a thirteenth aspect of the present invention, in the iron head in the eleventh aspect, the middle portion has a width of 15 to 30 mm in the toe to heel direction.

According to a fourteenth aspect of the present invention, in the iron head in the eleventh aspect, the middle portion has the first face plate thickness equal to or more than 2.5 mm. The first face plate thickness is larger than the second face plate thickness and third face plate thickness by equal to or more than 0.5 mm.

According to a fifteenth aspect of the present invention, in the iron head in the eleventh aspect, the middle portion has the first face plate thickness increasing gradually from an upper portion toward a lower portion thereof.

According to a sixteenth aspect of the present invention, in the iron head in the eleventh aspect, the hollow portion penetrates from an upper surface of the protruding portion to the sole surface, and includes a bottom surface closed with a bottom lid.

According to a seventeenth aspect of the present invention, in the iron head in the eleventh aspect, a shock absorber fills the hollow portion.

According to an eighteenth aspect of the present invention, in the iron head in the seventeenth aspect, the shock absorber is made of a rubber or an elastomer.

In the first aspect of the present invention, the iron head is provided with the first hollow portion and the second hollow portion on the toe side and the heel side of the middle portion, respectively, thereby reducing a total weight of the iron head. Accordingly, it is possible to enlarge a sweet area without increasing the total weight. Further, it is possible to increase a partial weight on the toe side and the heel side, thereby increasing the sweet area of the iron head. In the iron head in the first aspect, the hollow portion is not provided behind the middle portion. Accordingly, it is possible to obtain a strong hitting impact feeling when hitting a ball at the middle portion.

In the eleventh aspect of the present invention, the iron head is provided with the hollow portion extending from the toe side toward the heel side of the middle portion. Accordingly, it is possible to reduce the total weight of the iron head. Therefore, it is possible to increase a size of the iron head without increasing the total weight thereof. In addition, it is possible to increase a partial weight on the toe side and the heel side of the iron head without increasing the total weight of the iron head, thereby increasing the sweet area. In the iron head, the face plate has the thickness at the middle portion greater than that of the toe side and the heel side. Accordingly, it is possible to obtain a strong hitting impact feeling when hitting a ball at the middle portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear view of an iron head according to a first embodiment of the present invention;

FIG. 2 is a side view of the iron head viewed from a toe side thereof according to the first embodiment of the present invention;

FIG. 3 is a sectional view of the iron head taken along a line III-III inFIG. 1 according to the first embodiment of the present invention;

FIG. 4 is a sectional view of the iron head taken along a line IV-IV inFIG. 1 according to the first embodiment of the present invention;

FIG. 5 is a sectional view of the iron head taken along a line V-V inFIG. 1 according to the first embodiment of the present invention;

FIG. 6 is a sectional view of the iron head taken along a line VI-VI inFIG. 3 according to the first embodiment of the present invention;

FIG. 7 is a rear view of an iron head according to a second embodiment of the present invention;

FIG. 8 is a sectional view of the iron head according to the second embodiment of the present invention;

FIG. 9 is a sectional view of an iron head according to a third embodiment of the present invention;

FIG. 10 is a sectional view of an iron head according to a fourth embodiment of the present invention;

FIG. 11 is a sectional view of an iron head according to a fifth embodiment of the present invention;

FIG. 12 is a sectional view of the iron head taken along a line XII-XII inFIG. 11 according to the fifth embodiment of the present invention;

FIG. 13A is an exploded sectional view of the iron head according to the fifth embodiment of the present invention;

FIG. 13B is an exploded sectional view of the iron head according to the fifth embodiment of the present invention;

FIG. 14 is a sectional view of an iron head according to a sixth embodiment of the present invention;

FIG. 15 is a sectional view of an iron head according to a seventh embodiment of the present invention;

FIG. 16 is an exploded sectional view of the iron head shown inFIG. 15;

FIG. 17 is a sectional view of an iron head according to an eighth embodiment of the present invention;

FIG. 18 is a sectional view of an iron head according to a ninth embodiment of the present invention;

FIG. 19 is a sectional view of an iron head according to a tenth embodiment of the present invention;

FIG. 20 is a sectional view of an iron head according to an eleventh embodiment of the present invention;

FIG. 21 is a sectional view of an iron head according to a twelfth embodiment of the present invention;

FIG. 22 is a sectional view of an iron head according to a thirteenth embodiment of the present invention;

FIG. 23 is an exploded sectional view of the iron head according to the thirteenth embodiment of the present invention;

FIG. 24 is a sectional view of an iron head according to a fourteenth embodiment of the present invention;

FIG. 25 is an exploded sectional view of the iron head according to the fourteenth embodiment of the present invention;

FIG. 26 is a rear view of an iron head according to a fifteenth embodiment of the present invention;

FIG. 27 is a sectional view of the iron head taken along a line27-27 inFIG. 28 according to the fifteenth embodiment of the present invention;

FIG. 28 is a sectional view of the iron head taken along a line28-28 inFIG. 26 according to the fifteenth embodiment of the present invention;

FIG. 29 is an exploded perspective view of an iron head according to a sixteenth embodiment of the present invention;

FIG. 30 is a perspective view of an elastic member according to the sixteenth embodiment of the present invention;

FIG. 31 is a sectional view of the iron head taken along a line31-31 inFIG. 29 according to the sixteenth embodiment of the present invention;

FIG. 32 is a sectional view of the iron head according to the sixteenth embodiment of the present invention;

FIG. 33 is a sectional view of the iron head taken along a line33-33 inFIG. 31 according to the sixteenth embodiment of the present invention;

FIG. 34 is a front view of an iron head according to a seventeenth embodiment of the present invention; and

FIG. 35 is a sectional view of the iron head according to the seventeenth embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereunder, preferred embodiments of the present invention will be explained with reference to the accompanying drawings.

First Embodiment

FIGS. 1 through 6 show aniron head10 according to a first embodiment of the present invention. Theiron head10 is provided with astriking face11 for hitting a ball, atoe side12, aheel side13, asole surface14, and ahosel15 for connecting a shaft. Further, theiron head10 is provided with acavity portion16 disposed in an upper portion of a backside surface thereof; a protrudingportion17 disposed at a lower portion of the backside surface thereof and projecting backward; a firsthollow portion18 disposed on theheel side13 of the protrudingportion17 and penetrating from abottom surface16bof thecavity portion16 to thesole surface14; a secondhollow portion19 disposed on the toe side of the protrudingportion17; and abottom lid20 disposed on the sole surface to close the

hollow portions

18 and19.

As shown inFIG. 6, thecavity portion16 is recessed from a rear side of the iron head to the striking surface side thereof not only at anupper edge10tof thecavity portion16 but also at both thetoe side12 and theheel side13. Thecavity portion16 extends from thetoe side12 to theheel side13. It is desirable that a thickness of a face plate at thecavity portion16 is between 1.5 mm and 3.5 mm, especially between 2 mm and 3 mm. As shown inFIG. 2, thecavity portion16 has a maximum length H1 in a direction parallel to thestriking face11 at proximity of thetoe side12. Further, thestriking face11 has a maximum length H2 in a vertical direction. It is desirable that the maximum length H1 is 20% to 50%, especially 25% to 40%, of the maximum length H2.

The protrudingportion17 projects backward at a lower portion of thecavity portion16. The protrudingportion17 has theupper surface16bwhich is substantially perpendicular to thestriking face11. As shown inFIG. 2, the protrudingportion17 has a maximum length H3 at the proximity of thetoe side12 in the top to bottom direction of the iron head and in a direction parallel to thestriking face11. It is desirable that H3 is 48% to 78%, especially 58% to 73%, of the maximum length H2 of the striking face in the vertical direction. A same ratio is applied to a desirable ratio between a maximum length of theheel side13 in the top to bottom direction of the iron head and in the direction parallel to thestriking face11 and a maximum length of thestriking face11 in the top to bottom direction.

The

hollow portions

18 and19 penetrate from theupper surface16bof the protrudingportion17 to thesole surface14. In the embodiment, the

hollow portions

18 and19 have a width, in a toe to heel direction, being substantially same anywhere from an upper end thereof to a lower end thereof. Further, as shown inFIG. 2, the

hollow portions

18 and19 have a thickness E, a width in the direction perpendicular to thestriking face11. The thickness E is substantially same anywhere from the upper end of the

hollow portions

18 and19 to the lower end thereof.

As shown inFIG. 6, thehollow portion18 has a width W2, in the toe to heel direction, equal to or more than 10 mm but does not extend over the edge of thecavity portion16 on the heel side, more preferably, between 15 mm and 20 mm. Thehollow portion19 has a width W3, in the toe to heel direction, equal to or more than 10 mm but does not extend over the edge of thecavity portion16 on the heel side, more preferably, between the 15 mm and 20 mm. A middle portion M between the

hollow portions

18 and19 corresponds to a sweet area situated at the lower portion of the center part of thestriking face11. The middle portion M is not a hollow portion and is made of a metal material such as iron and an iron-base alloy, which are also used to produce theiron head10.

As shown inFIG. 6, in the embodiment, the middle portion M has the width W1, in the toe to heel direction, which is substantially same from the upper end thereof to the lower end thereof. It is desirable that the width W1 has a width equal to or more than 10 mm but does not extend over the edge of thecavity portion16 on the toe side, more preferably, between equal to or more than 15 mm and equal to or less than 20 mm.

The

hollow portions

18 and19 have bottom ends closed by thebottom lid20. As shown inFIGS. 2 and 6, thebottom lid20 is fitted into arecess portion20aprovided in the sole surface, and fixed thereto by crimping, welding such as a laser welding, shrink fitting, and cooling fitting.

As shown inFIG. 5, a depth A is a depth of thehollow portion19 on the backside surface side of the iron head, and a depth B is a depth of thehollow portion19 on thestriking face11 side thereof. As shown inFIG. 4, a depth C is a depth of thehollow portion18 on the backside surface side thereof and a depth D is a depth of thehollow portion19 on thestriking face11 side thereof. Examples of A, B, C, D are shown in a table below for each of iron golf clubs No. 3 through No. 9 and a pitching wedge.


A	B	C	D

#3	14.6	17.1	9.3	11.8
#4	15.3	18.2	9.7	12.6
#5	15.8	19	9.8	13
#6	16.1	19.7	10.2	13.7
#7	16.9	20.8	10.7	14.6
#8	17.9	21.8	11.4	15.3
#9	18.5	23	12.1	16.6
PW	18.8	23.2	12.7	17.1

In this configuration, theiron head10 has thehollow portion18 and thehollow portion19 located closer to thetoe side12 or theheel side13 respectively outside of the middle portion M thereof. With the

hollow portions

18 and19 formed in the iron head, it is possible to reduce the weight of the iron head. Therefore, it is possible to increase a size of theiron head10 without increasing the total weight thereof. Further, when a weight distribution increases on the toe side and the heel side of the iron head, it is possible to increase a sweet area of theiron head10 without increasing the total weight thereof. Because the middle portion M is provided with no hollow portion, theiron head10 in this configuration is capable of providing strong impact feeling when hitting a ball.

As examples of iron or an iron-base alloy used to produce theiron head10, there are stainless such as SUS630, 303 and 304; low-carbon steel such as S20C, S15C, and S25C; and maraging steel. A specific gravity of these materials is about 7.8 to 8.2. The iron head may be produced by either forging or casting.

Thebottom lid20 may be made of either the iron or the iron-base alloy mentioned above, but a metal or an alloyed metal, which has a larger specific gravity, is more desirable as it is capable of lowering the center of gravity of the iron head. As such metal or alloyed metal, tungsten alloy is suitable as a specific gravity thereof is 10 to 15. More specifically, tungsten-nickel alloy, tungsten-copper alloy, and tungsten-iron alloy, for example, may be used.

Second Embodiment

FIGS. 7 and 8 show aniron head10A according to the second embodiment of the present invention. According to the first embodiment, the width W1 of the middle portion M in the toe to heel direction is substantially same from the upper end thereof to the lower end thereof. According to the second embodiment, instead of the

hollow portions

18 and19 in the first embodiment, theiron head10A is provided with ahollow portion18A disposed away from ahollow portion19A by a distance gradually increasing from the upper surface of the protruding portion toward the sole surface.

It is desirable that thehollow portion18A and thehollow portion19A have a distance therebetween, at the top end thereof, being same as the width W1 mentioned above. Further, at the bottom end, it is desirable that the distance between thehollow portion18A and thehollow portion19A is equal to or less than 1.2 times, especially equal to or less than 1.1 times, of the distance between thehollow portion18A and thehollow portion19A at the top end thereof. Other configurations of theiron head10A are same as the first embodiment, and same reference numerals denote same components.

Third Embodiment

In the first and second embodiments, the

hollow portions

18,19,18A, and19A have a width E, which is the thickness thereof in the vertical direction to the face surface. The width E is substantially same from the top end to the bottom end of the

hollow portions

18,19,18A, and19A. As shown inFIG. 9, in aniron head10B according to the third embodiment, each of hollow portions18B (not shown) and19B has a thickness gradually increasing from the top end of the hollow portions toward the bottom end thereof. Further, thehollow portions18B and19B have a thickness, at the upper end thereof, being same as the width E in the first and second embodiments. It is desirable that the thickness of the bottom end of thehollow portions18B and19B is equal to or less than twice, especially equal to or less than 1.2 times, of that of the upper end thereof. Other configurations of the third embodiment are same as the first embodiment, and same reference numerals denote same components.

Fourth Embodiment

In the first and second embodiment, the

hollow portions

18,19,18A, and19A extend from theupper surface16bof the protruding portion to thesole surface14 in a parallel direction to thestriking face11. The distance between the hollow portions and thestriking face11, i.e., the thickness of the face plate, is substantially same from the top to the bottom thereof. As shown inFIG. 10, according to the fourth embodiment, aniron head10C has a thickness of a face plate between hollow portions18C (not shown) and19C and thestriking face11 being gradually increasing from the top to the bottom thereof. Other configurations of the fourth embodiment are same as the first embodiment, and same reference numerals denote same components.

Further, in the first to fourth embodiments described above, the

hollow portions

18,19,18A,19A,18B,19B,18C, and19C are opened to thecavity portion16, and lids (not shown) may be fixed to the upper ends of the hollow portions. A same type of the lid may be used as those in other embodiments described later.

In the first to fourth embodiments described above, each of hollow portions penetrates from thecavity portion16 to the sole surface, but the hollow portions may be made of holes starting from thecavity portion16 toward the sole surface but not reaching it. Lids may be fixed at openings of the hollow portions opened to thecavity portion16. Further, the hollow portions may be made of holes starting from the sole surface toward thecavity portion16 but not reaching it. In this case, a bottom lid, as described in the first to fourth embodiments, is fixed to the entrance opened at the sole surface.

Fifth Embodiment

As shown inFIGS. 11 and 12, according to the fifth embodiment, in the iron head in the first embodiment, aniron head10D is provided with

shock absorbers

21 and22 inserted into the

hollow portions

18 and19, and

lids

23 and24 fixed at the upper ends of the

hollow portions

18 and19. It is desirable that the

shock absorbers

21 and22 are made of an elastic material such as a rubber, an elastomer, and a foam made of those.

Further, it is desirable that the

lids

23 and24 are made of a metal, a synthetic resin, or an elastomer harder than the shock absorber. The

lids

23 and24 are fixed to the top end of the

hollow portions

18 and19 by welding, caulking, shrink fitting, cooling fitting, and bonding.

As shown inFIG. 13A, in the embodiment, the

shock absorbers

21 and22 have a wedge shape cross section having a thickness gradually increasing toward the bottom. As shown inFIG. 13B, the

shock absorbers

21 and22 are pushed from the sole side into the

hollow portions

18 and19, and after that, thebottom lid20 is fixed into arecess portion20adisposed in the sole surface. The

upper lids

23 and24 may be installed in the upper part of the

hollow portions

18 and19 either before or after the

shock absorbers

21 and22 are pushed into the

18 and19, an adhesive may be added to at least one of the inside wall of the

hollow portions

18 and19 or the outside wall of the

shock absorbers

21 and22.

Other configurations inFIGS. 11 to 13 are same as the first embodiment, and the same reference numerals denote same components.

Further, the hollow portions may be filled with shock absorbers which are made into a certain shape beforehand. Instead, a material having liquidity may be poured into the hollow portions and hardened to form a shock absorbent. Such materials to be used are, for example, unvulcanized or low vulcanization rubber, and an elastomer. Also, the lids may be formed by pouring a material having liquidity, such as an unvulcanized or low vulcanization rubber, or an elastomer, into the hollow portions and hardening the material instead of installing lids which are made into a certain shape beforehand. Moreover, the upper end of the hollow portion may be closed by hard materials capable of working as a lid, such as a rubber, an elastomer or a synthetic resinous material, for example, transparent acrylic acid resin. The lower part of the hollow portions may be filled with material with less hardness, such as a rubber or an elastomer. Materials with high viscosity, such as, butyl rubber and brominated butyl rubber, may be used as a shock absorber.

Sixth Embodiment

In the fifth embodiment, the

lids

23 and24 are fitted into inside of the upper part of the

hollow portions

18 and19. As shown inFIG. 14 according to the sixth embodiment, aniron head10E may be provided with recess portions18E (not shown) and19E being larger than the

hollow portions

18 and19 and disposed at theupper surface16bof the protruding portion. Therecess portions18E and19E face the

hollow portions

18 and19, and lids23E (not shown) and24E may be fixed into therecess portions18E and19E. Other configurations are the same as the first embodiment, and the same reference numerals denote the same components.

Seventh Embodiment

In the fifth and the sixth embodiments, the lids are attached to the upper end of the hollow portions from above. As shown inFIGS. 15 and 16, in aniron head10F according to the seventh embodiment, lids23F (not shown) and24F are attached from below the

hollow portions

18 and19. The upper ends of the

hollow portions

18 and19 are connected to thecavity portion16 through small holes18F (not shown) and19F. Alid24F is provided with a board-shaped main part24aand aprojection portion24bprojecting from the top surface thereof. Theprojection portion24bis inserted into thesmall hole19F. Although it is not shown, the lid23F, to be attached to thehollow portion18, has the same constitution. Other configurations inFIGS. 15 and 16 are same as in the first embodiment, and same reference numerals denote same components.

Eighth Embodiment

As shown inFIG. 17, according to an eighth embodiment, in theiron head10B inFIG. 9, aniron head10G is provided with shock absorbers21G (not shown) and22G inserted into the hollow portions18B (not shown) and19B respectively. Further, theiron head10G is provided with lids23G (not shown) and24G at the upper ends of the hollow portions18B (not shown) and19B. Theupper surface16bof the protruding portion is provided with recess portions (not shown) similar to the hollow portions18E (not shown) and19E shown inFIG. 14. Thelids23G and24G are fitted and fixed into the recess portions. Other configurations inFIG. 17 are same as the embodiment shown inFIG. 9, and the same reference numerals denote same components.

Ninth Embodiment

As shown inFIG. 18, according to the ninth embodiment, aniron head10H is provided with lids23H (not shown) and24H, instead of thelids23G and24G in theiron head10G shown inFIG. 17. Thelids23H and24H have a substantially same shape as that of thelid24F shown inFIGS. 15 and 16. Similar toFIGS. 15 and 16, the small holes18F (not shown) and19F are provided at the upper end of the hollow portions18B (not shown) and19B. The projection portions disposed on thelids23H and24H are inserted into thesmall holes18F and19F. Other configurations inFIG. 18 are same as the embodiment shown inFIG. 9, and same reference numerals denote same components.

Tenth Embodiment

As shown inFIG. 19, according to a tenth embodiment, in theiron head10 shown inFIGS. 1 to 6, similar toFIGS. 11 to 13, an iron head10I includes shock absorbers21I (not shown) and22I inserted into the hollow portions18 (not shown inFIGS. 19) and 19, respectively. Unlike theiron head10D inFIGS. 11 to 13, thelid23 is not installed at the upper end of the

hollow portions

18 and19. The upper surfaces of shock absorbers21I and22I are exposed to thecavity portion16 and leveled with theupper surface16bof the protruding portion. Other configurations are same as the first embodiment, and same reference numerals denote same components.

Eleventh Embodiment

As shown inFIG. 20, according to an eleventh embodiment, in theiron head10C inFIG. 10, aniron head10J is provided with the shock absorbers21J (not shown) and22J inserted into the hollow portions18C (not shown) and19C, respectively. No lid is installed at the upper end of the hollow portions18C and the19C, and the upper surface of theshock absorbers21J and22J are leveled with theupper surface16bof the protruding portion. Other configurations are same as the embodiment shown inFIG. 10, and same reference numerals denote same components.

Twelfth Embodiment

As shown inFIG. 21, according to a twelfth embodiment, in theiron head10B inFIG. 9, aniron head10K is provided with shock absorbers21K (not shown) and22K inserted into the hollow portions18B (not shown) and19B. No lid is installed at the upper end of thehollow portions18B and19B, and the upper surface of theshock absorbers21K and22K is leveled with theupper surface16bof the protruding portion. Other configurations are same as the embodiment shown inFIG. 10, and same reference numerals denote same components.

Thirteenth Embodiment

As shown inFIGS. 22 and 23, according to a thirteenth embodiment, instead of thebottom lid20 in the iron head10I inFIG. 19, aniron head10L is provided with abottom lid20L having a wedge-shapedprojection portion20t. Further, instead of the shock absorber22I, theiron head10L is provided with ashock absorber22L having a V-shapedditch22hat the bottom surface thereof. Theshock absorber22L is inserted into thehollow portion19 from above. A width of theditch22his smaller than a thickness of the wedge-shapedprojection portion20t.

When theshock absorber22L is pushed into thehollow portion19 from above, theprojection portion20tis pushed into theditch22h. Then, the bottom end ofshock absorber22L is extended by a force and pushed to the inside wall of thehollow portion19 whose lower side is wider than the upper part thereof. Therefore, theshock absorber22L is prevented from falling out from thehollow portion19.

Although it is not shown, thebottom lid20L is also provided with a projection portion, similar to theprojection portion20t, disposed at a point facing thehollow portion18. Further, the shock absorber inserted into thehollow portion18 is provided with a ditch, similar to theditch22h, disposed at the bottom surface of thereof. The projection portion and the ditch make it possible to prevent the shock absorber from falling out from thehollow portion18.

Fourteenth Embodiment

As shown inFIGS. 24 and 25, according to a fourteenth embodiment, aniron head10M is provided with hollow portions18M (not shown) and19M extending from theupper surface16bof the protruding portion toward thesole surface14 but not reaching it. Thehollow portions18M and19M are filled with shock absorbers21M (not shown) and22M. A shape and a size of thehollow portions18M and19M are substantially same as those of the

hollow portions

18 and19 in the first embodiment. No lid is installed at the upper end of thehollow portions18M and19M, and theshock absorbers21M and22M has an upper surface being leveled with theupper surface16bof the protruding portion.

When theshock absorbers21M and22M are pushed into thehollow portions18M and19M, theshock absorbers21M and22M are fixed to the inside of thehollow portions18M and19M by adhesives added onto the outside wall of theshock absorbers21M and22M or the inside wall of thehollow portions18M and19M, in order to prevent theshock absorbers21M and22M from falling out from thehollow portions18M and19M.

Theshock absorbers21M and22M have a rounded edge at the bottom end thereof. This is to prevent the edge of theshock absorbers21M and22M from being pushed to the corner of thehollow portions18M and19M and creating a strong stress at a certain limited area.

Fifteenth Embodiment

As shown inFIGS. 26 to 28, according to the fifteenth embodiment, in theiron head10D in the fifth embodiment, aniron head10N is provided with arecess portion25aextending from thehollow portion18 to thehollow portion19 at theupper surface16bof the protruding portion. Further, alid25 is installed into therecess portion25aand fixed by welding, caulking, shrink fitting, cooling fitting, and bonding. Thelid25 has an upper surface being leveled with theupper surface16bof the protruding portion. Other configurations are same as in the fifth embodiment, and same reference numerals denote same components.

Sixteenth Embodiment

FIGS. 29 to 33 show aniron head10P according to a sixteenth embodiment. Similar to theiron head10, theiron head10P is provided with thestriking face11 for hitting a ball, thetoe side12, theheel side13, thesole surface14, and thehosel15 for connecting the shaft, thecavity portion16 disposed at the upper portion of the backside surface, the protrudingportion17 projecting backward under thecavity portion16. Further, theiron head10P has ahollow portion40 penetrating from theupper surface16bof the protruding portion to thesole surface14, ashock absorber50 filled in thehollow portion40, and abottom lid49 disposed at the sole surface for closing thehollow portion40.

Thehollow portion40 extends from the proximity of thetoe side12 to the proximity of theheel side13. Amiddle portion41 of thehollow portion40 on the sole side in a toe to heel direction is situated in the backside area of the sweet area of thestriking face11. Theiron head10P has a plurality of thicknesses t1, t2, and t3. The thickness t1 is a thickness of themiddle portion41 in a range between thehollow portion40 and thestriking face11, i.e., the thickness of the face plate. The thickness t2 is a thickness of the face plate at atoe side part42. The thickness t3 is a thickness of the face plate at aheel side part43. The thickness t1 is larger than both a thickness t2 and the thickness t3.

It is desirable that a length of thehollow portion40 in a toe to heel direction is 35 mm to 80 mm, especially 40 mm to 80 mm. A length of themiddle portion41 in a toe to heel direction is 15 mm to 40 mm, especially 18 mm to 35 mm. At the sole side end, it is desirable that the thickness t1 of the face plate is equal to or more than 2.5 mm, especially more than 5.0 mm. Further, it is desirable that the thickness t2 and the thickness t3 are 2.0 mm to 5.0 mm, especially 2.0 mm to 3.0 mm.

Around theupper surface16bof the protruding portion, a width of thehollow portion40 in the vertical direction to the striking face is substantially same as a distance from thetoe side part42 to theheel side part43. In other words, at the upper part of the protrudingportion17, the thickness of the face plate is substantially same in a toe to heel direction.

The thicknesses t2 and t3 of the face plate at thetoe side part42 and theheel side part43 of thehollow portion40 are substantially same as those from the top to the bottom of the protrudingportion17. Also, the thicknesses t2 and t3 of the face plate at the lower portion of the protrudingportion17 may be slightly larger than the thicknesses t2 and t3 of the face plate at the upper portion of the protrudingportion17.

At themiddle portion41 of thehollow portion40, the thickness t1 of the face plate increases gradually from the top to the sole side of the protrudingportion17.

Ashock absorber50 fits perfectly into thehollow portion40 or has a size and a shape slightly larger than those of thehollow portion40. Amiddle portion51 of theshock absorber50 in a toe to heel direction has a thickness being same as a thickness from a top to a bottom thereof in a front to back direction or in the direction to which a ball flies. At atoe side part52 and aheel side part53, a thickness of theshock absorber50 is smallest at the top thereof and increases toward the bottom thereof.

Theiron head10P is provided arecess portion47 for fixing thebottom lid49 at the sole surface thereof. Thebottom lid49 is fitted and fixed into therecess portion47. A method for fixing thebottom lid49 includes welding, a laser welding for example; caulking; shrink fitting; and cooling fitting and bonding.

An upper surface of theshock absorber50 is exposed to thecavity portion16 and is leveled with theupper surface16bof the protruding portion. A lid may be installed at the upper surface of theshock absorber50.

According to the sixteenth embodiment, theiron head10P is provided with thehollow portion40 extending from the toe side to the heel side. With thehollow portion40 being provided, it is possible to reduce the weight of the iron head. Therefore, it is possible to increase a size of the iron head without increasing the weight thereof. Further, when a weight distribution increases on thetoe side12 and theheel side13 of the iron head, it is possible to increase the sweet area of the iron head without increasing the weight thereof. Theiron head10P has a plurality of thicknesses t1, t2, and t3. The thickness t1 is a thickness of a face plate at the rear side of themiddle portion41. The thickness t2 is a thickness of the face plate at thetoe side12. The thickness t3 is a thickness of the face plate at theheel side13. Because the thickness t1 is larger than the thicknesses t2 and t3, theiron head10P is capable of providing a strong impact feeling when hitting a ball.

Theiron head10P has a thickness of the face plate at themiddle portion41 being substantially same as the thickness of the face plate at thetoe side part42 and theheel side part43 above the protrudingportion17. The thickness of the face plate at themiddle portion41 may be larger than that of thetoe side part42 and theheel side part43. Theiron head10P has thehollow portion40 filled with theshock absorber50, and theshock absorber50 may be omitted.

Seventeenth Embodiment

FIGS. 34 and 35 show aniron head10Q according to a seventeenth embodiment.FIG. 34 is a front view of theiron head10Q according to the seventeenth embodiment. As shown inFIG. 34, theiron head10Q is provided with a plurality of score lines formed on theface plate11 thereof. The score lines consist of a plurality of lines extending in parallel with a certain distance therebetween equal to or more than 3 mm. Alongest score line60 is located near thesole surface14.

FIG. 35 is a sectional view of theiron head10Q according to the seventeenth embodiment. Theiron head10Q is provided with thestriking face11 for hitting a ball, thetoe side12, theheel side13, thesole surface14, and thehosel15 for connecting the shaft. Further, theiron head10Q has thecavity portion16 disposed at the upper portion of the backside surface, the protrudingportion17 disposed at the lower portion of the backside surface and projected backward thereof, the firsthollow portion18 penetrating from thebottom surface16bof thecavity portion16 to thesole surface14 and disposed at the heel side of the protrudingportion17, the secondhollow portion19 disposed at the toe side of the protrudingportion17, and thebottom lid20 disposed at the sole surface and closing the firsthollow portion18 and the second theportion19.

The middle portion M between the firsthollow portion18 and the secondhollow portion19 corresponds to a sweet area located at the lower central part of thestriking face11. The middle portion M is not a hollow but made of metal material, which is used to produce theiron head10, such as iron and iron basis alloy.

In theiron head10Q, the middle portion M is located so that a centerline C1 (cf.FIG. 35) of the middle part M is aligned with a centerline C2 (cf.FIG. 34) of thelongest score line60. With such a configuration provided, it is possible to align the centerline C1 of the middle portion M with the hitting point regardless of the distance between the firsthollow portion18 and the secondhollow portion19.

Claims

1. An iron head comprising:

a recess portion provided in an upper portion of the backside surface;

a protruding portion provided at a lower portion of the backside surface and projecting backward;

a first hollow portion provided on a heel side of the protruding portion; and

a second hollow portion disposed on a toe side and inside the protruding portion, said protruding portion including a middle portion between the first hollow portion and the second hollow portion,

wherein said first hollow portion is disposed away from the second hollow portion by a distance gradually increasing from an upper surface of the protruding portion toward the sole surface.

2. The iron head according toclaim 1, wherein at least one of said first hollow portion and said second hollow portion penetrates from an upper surface of the protruding portion to the sole surface, and has a first lid to close the sole surface.

3. The iron head according toclaim 1, wherein at least one of said first hollow portion and said second hollow portion has a second lid to close an upper portion thereof.

4. The iron head according toclaim 1, wherein said first hollow portion is disposed away from the second hollow portion by the distance equal to a distance between the upper surface of the protruding portion and the sole surface.

5. The iron head according toclaim 1, wherein said first hollow portion is disposed away from the second hollow portion by the distance of 10 to 30 mm.

6. The iron head according toclaim 1, wherein said first hollow portion is disposed away from the second hollow portion by the distance of 10 to 30 mm at the upper surface of the protruding portion.

7. The iron head according toclaim 1, wherein at least one of said first hollow portion and said second hollow portion is disposed not to reach the sole surface.

8. The iron head according toclaim 1, wherein at least one of said first hollow portion and said second hollow portion is filled with a shock absorber.

9. The iron head according toclaim 9, wherein said shock absorber is made of a rubber or an elastomer.

10. The iron head according toclaim 1, wherein said striking face includes a plurality of score lines including a longest score line, said middle portion being disposed so that a center line of the middle portion is aligned with a center line of the longest score line.

11. The iron head according toclaim 1, wherein said first hollow portion has a first length in a vertical direction, said second hollow portion having a second length in the vertical direction greater than the first length.