Abstract
The present invention is direct to a set of golf clubs comprising long irons, mid-irons and short irons. The invention contemplates the use of titanium or steel for the main body portion and a tungsten weight member coupled to the toe and a tungsten heel weight member coupled in a hosel cavity.
Claims
1. A golf club head comprising: a y-axis extending vertically through a face center of the club head and a Moment of Inertia about said y-axis, a body comprising a heel, a toe, a topline, a sole, and a hosel; a striking face, located at a frontal portion of said golf club head; a toe weight member formed of tungsten and is coupled in a lower toe portion of said body and has a toe weight member mass that comprises greater than about 15% of a club head mass of said golf club head, and a heel weight member formed of tungsten and coupled in a lower hosel portion of said body and has a heel weight member mass that comprises between about 5% and about 10% of said club head mass of said golf club head, wherein said toe weight member further comprises; a main supported portion, defined as a portion of said toe weight member that contacts said striking face, and an unsupported extension portion, extending toeward from said main supported portion, wherein said unsupported extension portion of said tow weight member does not contact with said striking face.
2. The golf club head of claim 1, wherein said Moment of Inertia about said y-axis is greater than about 230 kg-mm.sup.2.
3. The golf club head of claim 2, wherein said Moment of Inertia about said y-axis is greater than about 280 kg-mm.sup.2.
4. The golf club head of claim 3, wherein said golf club head has a Moment of Inertia about a shaft axis that is between about 610 kg-mm.sup.2 and 700 kg-mm.sup.2.
5. The golf club head of claim 4, said striking face has a thickness of less than about 1.8 mm.
6. The golf club head of claim 5, wherein said unsupported extension portion of said toe weight member is separated from said striking face by a distance d1 of greater than about 0.05 mm.
7. The golf club head of claim 6, wherein said unsupported extension portion of said toe weight member is separated from said striking face by said distance d1 of greater than about 0.075 mm.
8. The golf club head of claim 7, wherein said unsupported extension portion of said toe weight member is separated from said striking face by said distance d1 of greater than about 0.1 mm.
9. The golf club head of claim 8, wherein a center of gravity of said toe weight member is located toeward of a bifurcation line within said toe weight member, wherein said bifurcation line is defined as a plane that separates said main supported portion of said toe weight member and said unsupported extension portion of said toe weight member.
10. The golf club head of claim 9, wherein said toe weight member has a specific gravity of between about 15 g/cm.sup.3 and about 20 g/cm.sup.3.
11. A golf club head comprising: a y-axis extending vertically through a face center of the club head and a Moment of Inertia about said y-axis, a body comprising a heel, a toe, a topline, a sole, and a hosel; a striking face, located at a frontal portion of said golf club head; a toe weight member formed of tungsten and is coupled in a lower toe portion of said body, and a heel weight member formed of tungsten and coupled in a lower hosel portion of said body, wherein said toe weight member further comprises; a main supported portion, defined as a portion of said toe weight member that contacts said striking face, and an unsupported extension portion, extending toeward from said main supported portion, wherein said unsupported extension portion of said tow weight member does not contact with said striking face, and wherein said unsupported extension portion of said toe weight member is separated from said striking face by a distance d1 of greater than about 0.05 mm.
12. The golf club head of claim 11, wherein said unsupported extension portion of said toe weight member is separated from said striking face by said distance d1 of greater than about 0.075 mm.
13. The golf club head of claim 12, wherein said unsupported extension portion of said toe weight member is separated from said striking face by said distance d1 of greater than about 0.1 mm.
14. The golf club head of claim 11, wherein said toe weight member has a toe weight member mass that comprises greater than about 15% of a club head mass of said golf club head.
15. The golf club head of claim 14, wherein said toe weight member mass comprises greater than about 20% of a club head mass of said golf club head.
16. The golf club head of claim 15, wherein said toe weight member mass comprises greater than about 25% of a club head mass of said golf club head.
17. The golf club head of claim 14, wherein said Moment of Inertia about said y-axis is greater than about 230 kg-mm.sup.2.
18. The golf club head of claim 17, wherein said Moment of Inertia about said y-axis is greater than about 280 kg-mm.sup.2.
19. The golf club head of claim 18, wherein said golf club head has a Moment of Inertia about a shaft axis that is between about 610 kg-mm.sup.2 and 700 kg-mm.sup.2.
20. A golf club head comprising: a y-axis extending vertically through a face center of the club head and a Moment of Inertia about said y-axis, a body comprising a heel, a toe, a topline, a sole, and a hosel; a striking face, located at a frontal portion of said golf club head; a toe weight member formed of tungsten and is coupled in a lower toe portion of said body and has a toe weight member mass that comprises greater than about 15% of a club head mass of said golf club head, and a heel weight member formed of tungsten and coupled in a lower hosel portion of said body, wherein said toe weight member further comprises; a main supported portion, defined as a portion of said toe weight member that contacts said striking face, and an unsupported extension portion, extending toeward from said main supported portion, wherein said unsupported extension portion of said tow weight member does not contact with said striking face, and wherein said Moment of Inertia about said y-axis is greater than about 230 kg-mm.sup.2.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a back view of an iron according to the present invention;
[0019] FIG. 2 is a perspective view of the iron in FIG. 1;
[0020] FIG. 3 is a front view of a long iron according to another embodiment of the present invention;
[0021] FIG. 4 is a front view of a long iron body member according to the present invention;
[0022] FIG. 5 is a front view of a mid-iron body member according to the present invention;
[0023] FIG. 6 is a front view of a short iron body member according to the present invention;
[0024] FIG. 7 is a front view of another embodiment of a short iron body member according to the present invention;
[0025] FIG. 8 is an exploded view of an iron according to the present invention;
[0026] FIG. 9 is a cross-sectional view of the iron in FIG. 8;
[0027] FIG. 10 is an exploded view of an iron according to the present invention;
[0028] FIG. 11 is a cross-sectional view of the iron in FIG. 10;
[0029] FIG. 12 is an exploded view of an iron according to the present invention;
[0030] FIG. 13 is a cross-sectional view of the iron in FIG. 12;
[0031] FIG. 14 is an exploded view of an iron according to the present invention;
[0032] FIG. 15 is a cross-sectional view of the iron in FIG. 14;
[0033] FIG. 16 is an exploded view of an iron according to the present invention;
[0034] FIG. 17 is an exploded view of an iron according to the present invention;
[0035] FIG. 18 is a back view of an iron according to the present invention;
[0036] FIG. 19 is an exploded view of the iron in FIG. 18;
[0037] FIG. 20 is a back view of an iron according to the present invention;
[0038] FIG. 21 is an exploded view of the iron in FIG. 20;
[0039] FIG. 22 is a side view of the iron in FIGS. 20 and 21;
[0040] FIG. 23 is a back view of an iron according to the present invention;
[0041] FIG. 24 is an exploded view of the iron in FIG. 23 from a heel perspective;
[0042] FIG. 25 is an exploded view of the iron in FIG. 23 from a sole perspective;
[0043] FIG. 26 is a back view of an iron according to the present invention;
[0044] FIG. 27 is an exploded view of the iron in FIG. 26 from a toe perspective;
[0045] FIG. 28 is an exploded view of the iron in FIG. 26 from a sole perspective;
[0046] FIG. 29 is an exploded view of the iron in FIG. 26 from a back perspective;
[0047] FIG. 30 is a back view of an iron according to the present invention;
[0048] FIG. 31 is a top view of the iron in FIG. 30;
[0049] FIG. 32 is a toe view of the iron in FIG. 30;
[0050] FIG. 33 is an exploded view of a portion of the iron in FIG. 30 from a heel perspective;
[0051] FIG. 34 is a front view of the iron in FIG. 30;
[0052] FIG. 35 is an exploded view of a portion of the iron in FIG. 30 from a toe perspective;
[0053] FIG. 36 is a cross-sectional view of the iron in FIG. 30 from a front perspective;
[0054] FIG. 37 is a cross-sectional view of second embodiment of the iron in FIG. 30 from a front perspective;
[0055] FIG. 38 is a cross-sectional view of the second embodiment of the iron in FIG. 30 from a toe perspective;
[0056] FIG. 39 is a cross-sectional view of the second embodiment of the iron in FIG. 30 from a heel perspective;
[0057] FIG. 40 is a top view of an iron according to the present invention;
[0058] FIG. 41 is a toe view of the iron in FIG. 40;
[0059] FIG. 42 is a cross-sectional view of the iron in FIG. 40 from a front perspective
[0060] FIG. 43 is an exploded view of a portion of the iron in FIG. 40 from a heel perspective;
[0061] FIG. 44 is an exploded view of a portion of the iron in FIG. 40 from a toe perspective;
[0062] FIG. 45 is a rear view of a golf club head in accordance with an alternative embodiment of the present invention;
[0063] FIG. 46 is a frontal view of a toe weight member in accordance with an alternative embodiment of the present invention;
[0064] FIG. 47 is an exploded cross-sectional view of a golf club head in accordance with an alternative embodiment of the present invention; and
[0065] FIG. 48 is a cross-sectional view of a golf club head in accordance with an alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0066] As illustrated in the accompanying drawings and discussed in detail below, the present invention is directed to an improved set of iron-type golf clubs, wherein the clubs have tungsten weight members that form a significant portion of the club heads' mass.
[0067] Referring to FIGS. 1 and 2, an iron 10 has a heel 12, a toe 14, a hosel 16, a back cavity 18 a top line 20 and a sole 22. The iron is comprised of two main components, the main body 24 and the weight members 26. The iron includes a hosel axis 32 and a Y-axis 34 that extends vertically through a face center FC. The main body 24 is formed from titanium, or more preferably, a titanium alloy. For at least the long irons and mid irons, the weight members include a toe weight member 28 and a heel weight member 30 that are formed from tungsten or more preferably a tungsten alloy having a specific gravity of 15 g/cm3 or greater. Thus, the main body 24 will have a specific gravity of about 4-5 g/cm3 and the weight members 26 will have a specific gravity of about 15-20 g/cm3.
[0068] Table I provides exemplary, non-limiting dimensions for the various measurements of clubs according to the Example of the invention. It is fully intended that all of the dimensions set forth below can be adjusted such that the overall objective of the individual irons is met.
TABLE-US-00001 TABLE I Club Number 3 4 5 6 7 8 9 P loft 21 24 27 30 34 38 42 46 Mass 238 245 252 259 266 274 282 286 Ti (g) 103 100 102 109 116 94 102 106 W (g) 135 145 150 150 150 Steel (g) 180 180 180 Ti % 43.3 40.8 40.5 42.1 43.6 34.3 36.2 37.1 W % 56.7 59.2 59.5 57.9 56.4 Steel % 65.7 63.8 62.9 Ti vol. (cm.sup.3) 22.9 22.2 22.7 24.2 25.8 20.9 22.7 23.6 W vol. (cm.sup.3) 9.0 9.7 10 10 10 Steel Vol. (cm.sup.3) 24 24 24
[0069] Referring to the data in Table I above, the set of irons according to the present invention can be separated into long irons that have a loft of between about 15 and 25 degrees, mid irons that have a loft of between about 26 and 35 degrees and short irons that have a loft of about 36 or greater. The total mass of the clubs increases throughout the set from about 235 grams to about 290 grams. Each club is preferably about 5 grams or more greater in mass than the previous iron. As shown, for example, the 4 iron is 7 grams greater than the 3 iron. Thus, the mass increases through the set.
[0070] Each of the irons includes a titanium body member. The long irons and the mid irons preferably have tungsten weight members 28 and 30 as shown in FIGS. 1 and 2. In the long irons, the titanium body member 24 has a mass that is less than about 120 grams and more particularly, about 100 grams. The toe weight member 28 and heel weight member 30 preferably have a mass of about 130 grams to 150 grams. Thus, the tungsten weight members are greater than 50% of the total club mass.
[0071] In the mid irons, the titanium body member 24 has a mass that is less than about 120 grams and more particularly, about 100 grams to about 115 grams. The tungsten toe weight member 28 and heel weight member 30 preferably have a mass of about 140 grams to 160 grams, and more particularly about 150 grams. Thus, the tungsten weight members are greater than 50% of the total club mass. Also, the tungsten weight members 28 and 30 have greater mass than the tungsten weight members 28 and 30 for the long irons.
[0072] In the short irons, the titanium body member 24 has a mass that is less than about 120 grams and more particularly, about 90 grams to about 110 grams. The toe weight member 28 and heel weight member 30 are preferably made of steel and preferably have a mass of about 160 grams to 200 grams, and more particularly about 180 grams. Thus, the steel weight members are greater than 50% of the total club mass. Also, the steel weight members 28 and 30 have greater mass than the tungsten weight members 28 and 30 for the long irons and of the mid irons.
TABLE-US-00002 TABLE II Club Number 2 3 4 5 6 7 8 9 P loft 17 20 23 26 29 33 37 41 45 Total Mass (g) 234 239 246 252 256 267 274 282 286 Body Mass (g) 116 117 118 118 132 139 164 170 240 Face Mass (g) 34 37 38 38 38 39 41 41 41 Toe W (g) 38 45 50 55 61 60 61 63 Heel W (g) 34 32 31 31 20 20 Steel Mass % 70 68 67 66 68 70 78 78 100 W Mass % 30 32 33 34 32 30 22 22 Steel vol. % 80 79 78 77 80 81 86 86 100 W vol. % 20 21 22 23 20 19 14 14
TABLE-US-00003 TABLE III Club Number 2 3 4 5 6 7 8 9 P loft 17 20 23 26 29 33 37 41 45 Blade 77.6 77.6 77.6 77.6 77.6 77.6 77.6 77.6 77.6 Length (mm) Toe 51.9 52.3 52.8 53.3 53.8 54.3 54.9 55.4 55.8 Height (mm) Scoreline 53.2 53.0 52.8 52.7 52.5 52.3 52.2 52 51.8 Width (mm) Scoreline 17.3 17.5 17.7 17.8 18 18.2 18.3 18.5 18.7 to Toe (mm) Hosel 62 63 64 65 66 67 68 69 70 Length (mm) Sole Width 19.7 19.4 19.0 18.5 18.0 17.4 16.8 16.1 15.4 (mm)
[0073] As shown in FIG. 3 and set forth in Table III above, another embodiment of the present invention includes a set of irons that have a substantially constant Blade Length (BL) throughout the set. The BL is defined at the length from the hosel axis (HA) intersection with the ground plane to the end of the toe. However in this set, the Toe Height (TH) progressively increases through the set. Thus, the TH of the mid iron is greater than the TH of the long iron and the TH of the short iron is greater than the TH of the mid iron and the long iron. The TH is defined as the maximum length from the leading edge to the top of the toe in the plane parallel to the face plane and perpendicular to the scorelines. Preferably, the TH increases by about at least 0.3 mm per club, and most preferably at least 0.4 mm per club. Also, the TH preferably increases at least 1 mm per club (or about 4 degrees of loft) for the short irons and only 0.3-0.6 mm per club for the long and mid irons.
[0074] Furthermore, even though the BL remains substantially constant through the set, the scoreline width (SLW) progressively decreases through the set and the scoreline to toe width (SLTW) progressively increases through the set. More particularly, the SLW decreases by at least about 0.1 mm per club (or per 4 degrees of loft). Thus, the SLW for the long iron is greater than the SLW for the mid iron and the SLW for the mid iron is greater than the SLW for the short iron. Moreover, because the SLTW progressively increases through the set, the non-grooved toe area increases throughout the set.
[0075] Still further, in this preferred embodiment of the present invention, the distance of the center of gravity from the face center progressively increases through the set. Thus, CG-Xfc progressively increases from less than 2 mm from the face center in the long irons to about 3 mm from the face center towards the hosel in the short irons.
[0076] Another aspect of the present invention is that the hosel length HL increases through the set. Preferably, the hosel length increases by about 1 mm/club (or per 4 degrees of loft) such that the HL of the mid irons is greater than the HL of the long irons and the HL of the short irons is greater than the HL of the mid irons. Also, the sole width, not shown in the figures because it is the width of the sole at the center of the club head perpendicular to the front view shown in FIG. 3, decreases through the set. Thus, the sole width of the mid irons is less than the sole width of the long irons and greater than the sole width of the short irons. Preferably, the sole width decreases by about 0.3 mm/club (or per 4 degrees of loft).
[0077] As shown in FIGS. 4-7 and set forth in the table above, the set includes a long iron 100, a mid iron 200, a first short iron 300 and a second short iron 400. In FIG. 4, the long iron 100 includes a body member 110, heel 112, a toe 114, a hosel 116 and a sole 118. The iron body 110 includes an insert aperture 120 and a hollow portion 122. A face insert, not shown, is welded to the insert aperture 120 to enclose the hollow portion 122. Both the body member 110 and the face insert are preferably formed of steel. Inside the hollow portion 122, a tungsten toe weight member 124 and a tungsten heel weight member 126 are located proximate the toe 114 and the heel 112, respectively, to create a high moment of inertia. As shown in Table II above, the body member 110 preferably has a mass of about 110 grams to 120 grams and the face insert has a mass of about 30 grams to 45 grams. In the long irons 100, the toe weight member 124 preferably has a mass of about 35 to 55 grams. Preferably, the toe weight member 124 mass increases with each club by about 5 grams per club. The heel weight member 126 is preferably about 30 grams to 35 grams and preferably decreases by about 1 or 2 grams per club. Preferably, the tungsten mass of the toe weight member 124 and the heel weight member 126 are at least 25% of the total club head mass and at least 15% of the total club head solid volume. More particularly, the toe weight member 124 and the heel weight member comprise about 30% of the total mass or more and 20% of the total solid volume. Preferably, the toe weight member 124 has greater mass than the heel weight member 126.
[0078] As shown in FIG. 5 and set forth in Table II above, the set includes a mid iron 200 that includes a body member 210, heel 212, a toe 214, a hosel 216 and a sole 218. The iron body 210 includes an insert aperture 220 and a hollow portion 222. A face insert, not shown, is welded to the insert aperture 220 to enclose the hollow portion 222. Both the body member 210 and the face insert are preferably formed of steel. Inside the hollow portion 222, a tungsten toe weight member 224 and a tungsten heel weight member 226 are located proximate the toe 214 and the heel 212, respectively, to create a high moment of inertia. As shown in Table II above, the body member 210 preferably has a mass of about 115 grams to 145 grams and the face insert has a mass of about 30 grams to 45 grams. In the mid irons 200, the toe weight member 224 preferably has a mass of about 50 to 70 grams. Preferably, the toe weight member 224 mass increases with each club by about 5 grams per club. The heel weight member 226 is preferably about 35 grams or less and preferably decreases per club. Preferably, the tungsten mass of the toe weight member 224 and the heel weight member 226 are at least 25% of the total club head mass and at least 15% of the total club head solid volume. More particularly, the toe weight member 224 and the heel weight member 226 comprise about 30% of the total mass or more and about 20% of the total solid volume. Preferably, the toe weight member 224 has greater mass than the heel weight member 226, and more preferably, is about twice the amount of mass.
[0079] As shown in FIG. 6 and as set forth in Table II above, the set can include a short iron 300 that includes a body member 310, heel 312, a toe 314, a hosel 316 and a sole 318. The iron body 310 includes an insert aperture 320 and a hollow portion 322. A face insert, not shown, is welded to the insert aperture 320 to enclose the hollow portion 322. Both the body member 310 and the face insert are preferably formed of steel. Inside the hollow portion 322, a tungsten toe weight member 324 is located proximate the toe 314, to create a high moment of inertia. As shown in Table 11 above, the body member 310 preferably has a mass of about 150 grams to 200 grams and the face insert has a mass of about 30 grams to 45 grams. In the short iron 300, the toe weight member 324 preferably has a mass of about 55 to 70 grams. Preferably, the tungsten mass of the toe weight member 324 is at least 20% of the total club head mass and at least 10% of the total club head solid volume.
[0080] As shown in FIG. 7 and as set forth in Table II above, the set can include a short iron 400 that includes a body member 410, heel 412, a toe 414, a hosel 416 and a sole 418. The iron body 410 includes an insert aperture 420. A face insert, not shown, is welded to the insert aperture 420. The short iron 400 is preferably substantially solid and does not contain tungsten weight members.
[0081] Referring now to FIGS. 8-19, the present invention also includes a number of ways to attach the tungsten weight to a club head such that the weight and the head can be manufactured and finished separately. Preferably, the club head frame is cast or forged and then polished. The weight can be manufactured out of 17 g/cm3 tungsten and polished. After both components are polished, the weight member can be attached to the body via a mechanical fastener as discussed in more detail below.
[0082] As shown in FIG. 8, the iron body 500, includes a heel 512, a toe 514, a hosel 516 and a sole 518 and is preferably formed by forging steel or titanium as discussed above. The club head also includes a toe weight member 528 that is coupled to the body 500 by a mechanical fastener 530. The body 500 includes an indentation 532 on the toe 514 and sole 518 for receiving the weight member 528. The indentation 532 includes an inner wall 534 that surrounds a portion of the weight member 528 and a receptacle 536 for coupling with the mechanical fastener 530. In this embodiment, the receptacle 536 is a threaded aperture. As shown in the cross-sectional view of FIG. 9, the wall 534 is formed at an angle α such that the weight member is press fit into the indentation 532 when the mechanical fastener is tightened. Preferably, the angle α is between about 10 degrees and 60 degrees. The weight member 528 and the indentation 532 form a bottom interface 538. In a preferred embodiment, an adhesive tape may be applied at this interface to further secure the weight member 528 to the body 500. The body 500 also includes a back surface 510 and the weight member 528 has an outer surface 540. The outer surface of the weight member 528 preferably creates a lower portion of the toe 514, an outer, toe portion of the sole 518 and a portion of the back surface 510 for maximum MOI efficiency. In the preferred embodiment shown in FIGS. 8 and 9, the body 500 also includes a front surface 542 for welding the front face to, not shown. Further, a paint fill edge 544 can be formed in the weight member 528, the body 500 or both, as shown, to finish the club head and provide a visual separation of the weight member 528.
[0083] As discussed above, the toe weight member 528 preferably has a mass of about 35 to 65 grams. Preferably, the toe weight member 528 mass increases with each club by about 5 grams per club through at least a portion of the set. The club can further include a heel weight member that is not shown that is preferably about 30 grams to 35 grams and preferably decreases by about 1 or 2 grams per club through at least a portion of the set. A heel weight can be attached in the same manner as the toe weight member shown or can be placed behind the face insert as discussed above with respect to FIGS. 4 and 5. Preferably, the tungsten mass of the toe weight member 528 and the heel weight member are at least 25% of the total club head mass and at least 15% of the total club head solid volume. As set forth in Table II, and for all the embodiments, the toe weight member is preferably between about 15% and 25% of the total club mass.
[0084] As shown in FIG. 10, the iron body 600, includes a heel 612, a toe 614, a hosel 616 and a sole 618 and is preferably formed by forging steel or titanium as discussed above. The club head also includes a toe weight member 628 that is coupled to the body 600 by a mechanical fastener 630. Like the embodiment in FIG. 8, the body 600 includes an indentation 632 on the toe 614 and sole 618 for receiving the weight member 628. The indentation 632 includes an inner wall 634 that surrounds a portion of the weight member 628 and a receptacle 636 for coupling with the mechanical fastener 630. In this embodiment, the indentation 632 further includes a conical collar 637. As shown in the cross-sectional view of FIG. 11, the conical collar 637 is formed at an angle β such that the weight member is press fit into the indentation 632 when the mechanical fastener is tightened. Again, the weight member 628 and the indentation 632 form a bottom interface 638 that can include an adhesive tape juxtaposed the interface to further secure the weight member 628 to the body 600. As above, the outer surface of the weight member 628 preferably creates a lower portion of the toe 614, an outer portion of the sole 618 and a portion of the back surface 610 for maximum MOI efficiency. The body 600 also includes a front surface 642 for welding the front face, not shown, to and a paint fill edge 644 can be formed in the weight member 628, the body 600 or both, as shown, to finish the club head and provide a visual separation of the weight member 628.
[0085] Even with the additional conical collar 637, the toe weight member 628 preferably has a mass of about 35 to 55 grams and the toe weight member 628 mass increases with each club by about 5 grams per club. Preferably, the tungsten mass of the toe weight member 628 and any heel weight member are at least 25% of the total club head mass and at least 15% of the total club head solid volume.
[0086] FIG. 12 is an exploded view of another embodiment of the present invention. The iron body 700, includes a heel 712, a toe 714, a hosel 716 and a sole 718 and is preferably formed by forging steel or titanium as discussed above. The club head 700 also includes a toe weight member 728 that is coupled to the body 700 by a mechanical fastener 730. Like the embodiment in FIG. 8, the body 700 includes an indentation 732 on the toe 714 and sole 718 for receiving the weight member 728. The indentation 732 includes an inner wall 734 that surrounds a portion of the weight member 728. In this embodiment, as shown in FIG. 13, a threaded receptacle member 736 is inserted into the body 700 through the face side of the body 700 for coupling with the mechanical fastener 730. In this embodiment, the receptacle member 736 is covered from view when the face member, not shown, is welded to the face securing surface 742. As shown in the cross-sectional view of FIG. 13, the fastener 730 and the receptacle member 736 capture the weight member 728 to the body 700. Again, the weight member 728 and the indentation 732 form a bottom interface 738 that can include an adhesive tape juxtaposed the interface to further secure the weight member 728 to the body 700. As above, the outer surface of the weight member 728 preferably creates a lower portion of the toe 714, an outer portion of the sole 718 and a portion of the back surface 710 for maximum MOI efficiency. The body 700 also includes a paint fill edge 744 can be formed in the weight member 728, the body 700 or both, as shown, to finish the club head and provide a visual separation of the weight member 728.
[0087] Referring to FIGS. 14 and 15, another embodiment of the present invention is an iron body 800 including a heel 812, a toe 814, a hosel 816 and a sole 818. The iron 800 further comprises a toe weight member 828 that is secured to the body 800. In this embodiment, the weight member 828 is secured to the body 800 by a mechanical fastener 830 that is inserted through the face of the iron 800. The iron body 800 can be formed by casting, but is preferably forged. An aperture 804 is formed in the back wall 806 and the weight member 828 is attached to the back wall 806 via the mechanical fastener 830 that is inserted through the face. Then, a face member can be welded to the face retaining surface 842.
[0088] As in the other embodiments, the toe weight member 828 preferably has a mass of about 35 to 55 grams. Preferably, the toe weight member 828 mass increases with each club by about 5 grams per club. The club can further include a heel weight member that is not shown that is preferably about 30 grams to 35 grams and preferably decreases by about 1 or 2 grams per club. A heel weight can be attached in the same manner as the toe weight member shown or can be placed behind the face insert as discussed above with respect to FIGS. 4 and 5. Preferably, the tungsten mass of the toe weight member 828 and the heel weight member are at least 25% of the total club head mass and at least 15% of the total club head solid volume. In yet another embodiment, the body 800 can include a hosel weight instead of a heel weight to further increase the MOI about the horizontal axis.
[0089] Referring to FIG. 16, another embodiment of the present invention is an iron body 900 including a heel 912, a toe 914, a hosel 916 and a sole 918. The iron 900 further comprises a toe weight member 928 that is coupled to the body 900. In this embodiment, the weight member 928 is coupled to the body 900 by a mechanical fastener 930 that is nut fastener inserted through the face of the iron 900 that tightens onto a threaded portion 931 of the weight member 928. The iron body 900 can be formed by casting, but is preferably forged. An aperture is formed in the back wall 906 and the weight member 928 is attached to the back wall 906 via the mechanical fastener 930 that is inserted through the face. Then, a face member can be welded to the face retaining surface.
[0090] Referring to FIG. 17, another embodiment of the present invention is an iron body 1000 including a heel 1012, a toe 1014, a hosel 1016 and a sole 1018. The iron 1000 further comprises a toe weight member 1028 that is coupled to the body 1000. In this embodiment, the weight member 1028 is coupled to the back surface 1006 of the body 1000 by a plurality of mechanical fasteners 1030 that are inserted through the back cavity 1020 of the iron 1000. More particularly, a plurality of apertures 1004 can be formed in a bottom surface 1008 of the back cavity 1020 such that the threaded fasteners 1030 can couple to the weight member 1028. The iron body 1000 can be formed by casting, but is preferably forged. As shown, a face member can be welded to the face retaining surface, but this embodiment can also allow for the face to be integrally formed with the body 1000.
[0091] Referring to FIGS. 18 and 19, another embodiment of the present invention is an iron body 1100 including a heel 1112, a toe 1114, a hosel 1116 and a sole 1118. The iron 1100 further comprises a toe weight member 1128 that is coupled to the body 1100. In this embodiment, the weight member 1128 is coupled to the body 1100 by a mechanical fastener 1130 that provides an abutting lock. More particularly, a recess 1104 is formed in an outer surface 1108 of the iron body 1100 and the weight member 1128 such that the head of the threaded fastener 1030 can couple the weight member 1128 to the back surface 1106 of the body 1100. A retaining wall 1134 surrounds the weight member 1128 such that the weight member 1128 is press fit when the fastener member 1130 is secured in the recess 1104. The iron body 1100 can be formed by casting, but is preferably forged. As shown, a face member can be welded to the face retaining surface, but this embodiment can also allow for the face to be integrally formed with the body 1100.
[0092] Referring to FIGS. 20, 21 and 22, another embodiment of the present invention is a set of golf clubs comprising at least a long iron having a loft between about 15 and 25 degrees and a first club head mass, a mid iron having a loft of between about 26 and 35 degrees and a second club head mass, and a short iron having a loft of about 36 degrees or greater and a third club head mass. The long iron, for example, comprises a steel body 1200 that comprises a heel 1212, a toe 1214, a topline 1220, a sole 1218, and a hosel 1216. A front face insert 1210 and a back wall 1224 form a hollow cavity 1226 therebetween.
[0093] Preferably, the iron body is cast with the main cavity 1226 and the hosel cavity 1232. The front face insert 1210 is preferably stamped from a high strength sheet metal and is welded to the body after a toe weight member 1228 is secured with in the hollow cavity 1226. A heel weight member 1230 is inserted into the face side of the hosel cavity 1232 and then a hosel cover member 1234 is welded to the front portion of the hosel 1216 to secure the heel weight member 1230 within the hosel cavity 1232.
[0094] The toe weight member 1228 is formed of tungsten and is coupled to a toe portion of the hollow cavity 1226. Preferably, as set forth in Table IV below, the toe weight member 1228 is greater than about 65 grams and comprises about 25%-35% of the long iron club head mass. The long iron head further comprises the heel weight member 1230, also formed of tungsten, that is about 10 to 20 grams and is coupled into the hosel cavity 1232 formed in the front, lower portion of the hosel 1216. Preferably, the heel weight member 1230 comprises about 5%-10% of the long iron head mass. In this embodiment, the heel weight member 1230 is preferably secured in the hosel cavity 1232 by a steel cover member 1234 that forms at least a front portion of the hosel 1216.
[0095] In the preferred set, the mid iron has the same or similar construction as the long iron, and thus, similarly comprises a steel, hollow body with a heel, a toe, a topline, a sole, and a hosel. As set forth in Table IV below, the toe weight member for at least one of the mid irons is also formed of greater than 65 grams of tungsten and comprises about 25%-35% of the mid iron head mass.
[0096] The club heads according to the present invention have high Moment of Inertias. Because they have such large tungsten weight members, the Moment of Inertia about the y-axis (34 shown in FIG. 2), MOIy, is greater than 250 kg-mm.sup.2 for all of the irons. Still further, the irons in the preferred set as presented in Tables IV and V below are not oversized. That is, the blade length is less than 82 mm. Thus, the MOIy to blade length ratio is very high. More particularly, the MOIy to blade length ration is greater than 3 kg-mm, and more preferably, between about 3.1 kg-mm and 3.5 kg-mm.
[0097] Moreover, because the mid irons and the long irons are hollow, the Center of Gravity is relatively deep. More particularly, the Center of Gravity depth from the face center, CGzFC, is preferably greater than 6 mm for all of the irons. In a preferred embodiment, the CGzFC can be around 8 mm for the long irons. Preferably, the CGzFC is almost 1/10 of the blade length for the long irons.
[0098] Also, the Center of Gravity from the ground, CGy, is very low through the set. As set forth in Table V below, preferably, the CGy is less than 18 mm from a ground surface for the long irons and less than 19 mm for the mid irons and short irons when the club head is in the standard address position.
TABLE-US-00004 TABLE IV Club Number 3 4 5 6 7 8 9 P loft 19 22 25 28 3 35 39 43 Total Mass (g) 239 247 254 261 268 274 284 286 Body Mass (g) 85 86 87 118 261 267 278 280 Face Mass (g) 58 58 58 56 Toe W (g) 67 74 77 73 Heel W (g) 14 15 18 Steel Mass % 60 58 57 67 W Mass % 34 36 37 28
TABLE-US-00005 TABLE V Club Number 3 4 5 6 7 8 9 P Blade 81 81 81 80 80 80 80 80 Length (mm) Toe 31 31.5 32 32.3 32.7 33.3 34 34.5 Height (mm) Scoreline 54.5 54.3 54.1 54 53.8 53.6 53.3 53.1 Width (mm) Sole Width 16.8 16.3 15.8 15.3 14.8 14.65 14.5 14.35 Center (mm) CGy (mm) 17.75 17.8 17.9 18 18.4 18.6 18.7 18.7 MOIy 257 259 266 261 260 262 267 274 (kg .Math. mm.sup.2)
[0099] Referring to FIGS. 23 through 25, another embodiment of the present invention is a set of golf clubs comprising at least a long iron having a loft between about 15 and 25 degrees and a first club head mass, a mid iron having a loft of between about 26 and 35 degrees and a second club head mass, and a short iron having a loft of about 36 degrees or greater and a third club head mass. The long iron, preferably, comprises a steel body 1300 that comprises a heel 1312, a toe 1314, a topline 1320, a sole 1318, and a hosel 1316. A front face insert 1310 and a back wall 1324 form a hollow cavity 1326 therebetween.
[0100] Preferably, the iron body is cast to form the hollow cavity 1326 and a hosel cavity 1332. The front face insert 1310 is preferably stamped from a high strength sheet metal and is welded to the body after a toe weight member 1328 is secured with in the hollow cavity 1326. As shown in the Tables II and IV above and Table VI below, it is important for the face member to be light weight to create a high MOI. Preferably, the face member 1310 has a mass of less than 45 grams, and more preferably, has less mass that the toe weight member 1328. It is even more preferred that the face insert mass is less than % the mass of the toe weight member 1328. In a preferred embodiment, the face member 1310 is formed from steel having an Ultimate Tensile Strength of greater than 2000 MPa. In the most preferred embodiment, the face insert 1310 is formed to a thickness t of 1.8 mm or less and has an Ultimate Tensile Strength of 2300 MPa or greater. In one embodiment, the long irons can be formed with a face insert 1310 stamped from AerMet 340 with the face insert 1310 having a thickness t of about 1.75 mm or less when measure at the center of the face. The face insert 1310 preferably has a uniform thickness, but may have a thinner perimeter region surrounding a thicker center with a smooth transition zone connecting the center to the perimeter. In this embodiment, the center section is at least 10% thicker than the perimeter region. The face insert material for either embodiment preferably has a Fatigue Strength of greater than 800 MPa, and more preferably, greater than about 900 MPa, which is extremely important for the durability of the iron.
[0101] A heel weight member 1330 is inserted into the face side of the hosel cavity 1332 and then a hosel cover member 1334 is welded to the front portion of the hosel 1316 to secure the heel weight member 1330 within the hosel cavity 1332. The toe weight member 1328 is formed of tungsten and is coupled to a toe portion of the hollow cavity 1326. Preferably, as set forth in Table VI below, the toe weight member 1328 is greater than about 65 grams and comprises about 25%-40% of the long iron club head mass. The long iron head further comprises the heel weight member 1330, also formed of tungsten, that is about 10 to 25 grams and is coupled into the hosel cavity 1332 formed in the front, lower portion of the hosel 1316. Preferably, the heel weight member 1330 comprises about 5%-10% of the long iron head mass and the mass increases with loft through the set. In this embodiment, the heel weight member 1330 is preferably secured in the hosel cavity 1332 by a steel cover member 1334 that forms at least a front, lower portion of the hosel 1316.
[0102] As shown in FIG. 24, the face insert 1310 includes a face insert sole portion 1340 that extends from the leading edge 1342 toward the back wall 1324. Preferably, the face insert sole portion 1340 extends in the front-to-back direction from the leading edge 1342 a distance d.sub.fisp that is at least 25% or the sole width distance. Moreover, it is preferred that the face insert sole portion 1340 extends from the heel 1312 toward the toe 1314. Preferably, the face insert sole portion 1340 has a length d.sub.fiht in the heel-to-toe direction that is between 50% and 80% of the blade length. This enables the face insert 1310 to form a majority of the front portion of the sole, but allows the body portion of the sole 1318 to hold the toe weight member 1328.
[0103] The toe weight member 1328 can also be formed of two portions, the toe extremity portion 1328a and the toe central portion 1328b. In order to maximize the MOI of the iron, it is preferred that the toe extremity portion 1328a has a first width t.sub.tw1 and the toe central portion 1328b has a second width t.sub.tw2 that is less than the first width. More preferably, the first width t.sub.tw1 is at least 50% greater than the second width t.sub.tw2.
[0104] In the preferred set, the mid iron has the same or similar construction as the long iron, and thus, similarly comprises a steel, hollow body with a heel, a toe, a topline, a sole, and a hosel. As set forth in Table VI below, the toe weight member for at least one of the mid irons is also formed of greater than 65 grams of tungsten, and more preferably greater than 90 grams of tungsten. The toe weight member 1328 for the mid iron preferably comprises about 25%-40% of the mid iron head mass.
[0105] The club heads according to the present invention have high Moment of Inertias. Because they have such large tungsten weight members, the Moment of Inertia about the y-axis (34 shown in FIG. 2), MOIy, is greater than 230 kg-mm.sup.2 for all of the irons. Still further, the irons in the preferred set as presented in Tables VI and VII below have small blade lengths, that is less than 82 mm and more preferably less than 78 mm. Thus, the MOIy to blade length ratio is very high. More particularly, the MOIy to blade length ration is greater than about 3 kg-mm, and more preferably, between about 3.0 kg-mm and 3.5 kg-mm.
[0106] Moreover, because the mid irons and the long irons are hollow, the Center of Gravity is relatively deep. More particularly, the Center of Gravity depth from the face center toward the back wall 1324, CGz, is preferably greater than 6 mm for all of the irons. In a preferred embodiment, the CGz can be between 6 mm and 6.5 mm through the set. Preferably, the CGz is almost 1/10 of the blade length for the long irons.
[0107] Also, the Center of Gravity from the ground, CGy, is very low through the set. As set forth in Table V below, preferably, the CGy is less than about 18 mm from a ground surface for the long irons and less than about 19 mm for the mid irons and greater than about 19 mm for the short irons when the club head is in the standard address position.
TABLE-US-00006 TABLE VI Club Number 3 4 5 6 7 8 9 P loft 20 23 26 29 32 36 40 44 Total Mass (g) 239 245 251 258 265 274 281 286 Body Mass (g) 89 89 93 94 94 117 281 286 Face Mass (g) 42 42 42 43 44 41 Toe W (g) 88 87 93 91 97 83 Heel W (g) 17 23 20 25 27 28 Steel Mass % 55 53 54 53 52 58 100 100 W Mass % 44 45 45 45 47 41
TABLE-US-00007 TABLE VII Club Number 3 4 5 6 7 8 9 P Blade 76 76 76 76 75 75 75 75 Length (mm) Toe 51 51 51 53 53 53 55 56 Height (mm) Scoreline 53 53 52 52 52 52 52 51 Width (mm) Sole Width 17 17 16 16 16 15 15 15 Center (mm) CGy (mm) 18.1 18.2 18.4 18.5 18.6 18.9 19.4 19.2 CGz (mm) 6.4 6.3 6.3 6.2 6.15 6.05 6.35 6.35 MOIy 231 237 230 236 240 249 232 239 (kg .Math. mm.sup.2)
[0108] Referring to FIGS. 26 through 29 and Tables VIII and IX below, another embodiment of the present invention is a set of golf clubs comprising at least a long iron having a loft between about 15 and 25 degrees and a first club head mass, a mid iron having a loft of between about 26 and 35 degrees and a second club head mass, and a short iron having a loft of about 36 degrees or greater and a third club head mass. The long iron, preferably, comprises a steel body 1400 that comprises a heel 1412, a toe 1414, a topline 1420, a sole 1418, and a hosel 1416. A front face insert 1410 and a back wall 1424 form a hollow cavity 1426 therebetween and a medallion 1444 is secured to the outer surface of the back wall 1424. In a preferred embodiment, the medallion 1444 can also cover one or more apertures 1446 in the back wall 1424.
[0109] Preferably, the iron body 1400 of at least the long iron is cast to form the hollow cavity 1426 and a hosel cavity 1432 located below the hosel 1416. The front face insert 1410 is preferably stamped from a high strength sheet metal and is welded to the body after a toe weight member 1428 is secured within the hollow cavity 1426 and a heel weight member 1430 is secured in the hosel cavity 1432. As shown in the Tables II, IV and VI above and Table VIII below, it is important for the face member to be light weight to create a high MOIy. Preferably, the face member 1410 has a mass of less than 55 grams, and more preferably, has less mass that the toe weight member 1428. In a preferred embodiment, the face member 1410 is formed from steel having an Ultimate Tensile Strength of greater than 2000 MPa. In the most preferred embodiment, the face insert 1410 is formed to a thickness t of 1.8 mm or less and has an Ultimate Tensile Strength of 2300 MPa or greater. In one embodiment, the long irons and mid irons can be formed with a face insert 1410 stamped from AerMet 340 with the face insert 1410 having a thickness t of about 1.8 mm or less when measure at the center of the face and the short irons can be formed with a face insert 1410 having a thickness t of 2.0 mm or less. The face insert 1410 preferably has a uniform thickness, but may have a thinner perimeter region surrounding a thicker center with a smooth transition zone connecting the center to the perimeter. In this embodiment, the center section is at least 10% thicker than the perimeter region. The face insert material for either embodiment preferably has a Fatigue Strength of greater than 800 MPa, and more preferably, greater than about 900 MPa, which is important for the durability of the iron.
[0110] As stated above, the heel weight member 1430 is inserted into the hosel cavity 1432 which is cast into the lower portion of the hosel 1416. In FIG. 27, the arrow 1432a points to the hosel cavity 1432, which is located under the hosel 1416. The heel weight member 1430 is formed from tungsten having a specific gravity of about 15-20 g/cm.sup.3 and is an arcuate weight member having an arc angle α of about 5 degrees to about 60 degrees. More preferably, the heel weight member has an arc angle α of about 20 degrees to about 45 degrees. The heel weight member 1430 also has an inner arc radius R of between about 10 mm and about 50 mm. More preferably, the arc radius R of the heel weight member 1430 is between about 15 mm and 40 mm and is less than ½ the blade length. The heel weight member 1430 also includes welding grooves 1431 as a welding area to secure the heel weight member 1430 within the hosel cavity 1432. When the heel weight member 1430 is inserted into the hosel cavity 1432, preferably at least 80% of the heel weight mass is located further heelward (in the x direction) of the heel-side front wall 1436. More preferably, the all of the heel weight member mass is located heelward of the heel-side front wall 1436 such that the shaft axis SA intersects the heel weight member 1430 below the hosel 1416.
[0111] The toe weight member 1428 is also formed of tungsten having a specific gravity of about 15-20 g/cm.sup.3 and is coupled to a toe portion of the hollow cavity 1426. The toe weight member 1428 is preferably located in the lower (y direction) toe portion of the hollow cavity 1426. Preferably, the toe weight member includes welding grooves 1429 for securing the weight member to the iron body 1400 before the face insert 1410 is welded to the body 1400.
[0112] Preferably, as set forth in Table VIII below, the toe weight member 1428 is greater than about 65 grams and comprises about 25%-40% of the long iron club head mass and mid iron club head mass. The long iron head and mid iron head further comprises the heel weight member 1430, also formed of tungsten that is about 10 to 25 grams for the long iron and 25 to 40 grams for the mid irons. As stated above, the heel weight members 1430 are coupled into the hosel cavity 1432 formed in the lower, front portion of the iron body 1400 below the hosel 1416 such that the shaft axis SA intersects the heel weight member 1430. Preferably, the heel weight member 1430 comprises about 5%-10% of the long iron head mass and comprises about 8%-15% of the mid iron head mass. Preferably, the mass of the heel weight members increases with loft through the set. In this embodiment, the heel weight member 1430 is preferably secured in the hosel cavity 1432 by a weld bead formed in the weld groove 1431.
[0113] As shown in FIGS. 28 and 29, the face insert 1410 includes a face insert sole portion 1440 that extends from the leading edge 1442 toward the back wall 1424 (in the z direction). Preferably, the face insert sole portion 1440 extends in the front-to-back direction from the leading edge 1442 a distance d.sub.fisp that is at least 25% of the sole width. Moreover, it is preferred that the face insert sole portion 1440 extends from the heel-side front wall 1436 toward the toe 1414 (the x direction). Preferably, the face insert sole portion 1440 has a length d.sub.fiht in the heel-to-toe direction that is between 50% and 80% of the blade length. This enables the face insert 1410 to form a majority of the front portion of the sole, but allows the body portion of the sole 1418 to hold the toe weight member 1428.
[0114] In the preferred set, the mid iron has the same or similar construction as the long iron, and thus, similarly comprises a steel, hollow body with a heel, a toe, a topline, a sole, and a hosel. As set forth in Table VIII below, the toe weight member for at least one of the mid irons is also formed of greater than 65 grams of tungsten, and more preferably greater than 70 grams of tungsten. The toe weight member 1428 for the mid iron preferably comprises about 25%-40% of the mid iron head mass. The mass of the toe weight member preferably increases with loft through the set as set forth in Table VIII below. Within the preferred set, there are preferably at least two long irons and two mid irons that include toe weights 1428 and the mass of the toe weights increases with loft. Also, within the preferred set, there are preferably at least two long irons and two mid irons that include heel weights 1430 and the mass of the heel weights increases with loft.
[0115] The club heads according to the present invention have high Moment of Inertias. Because they have such large tungsten weight members, the Moment of Inertia about the y-axis (34 shown in FIG. 2), MOIy, is greater than 230 kg-mm.sup.2 for all of the irons, and more preferably, greater than about 260 kg-mm.sup.2 for all of the irons. Still further, the irons in the preferred set as presented in Tables VIII and IX below have medium blade lengths, that is between 80 mm and 84 mm. Thus, the MOIy to blade length ratio is very high. More particularly, the MOIy to blade length ration is greater than about 3 kg-mm, and more preferably, between about 3.0 kg-mm and 3.5 kg-mm.
[0116] The club heads according to the present invention have more consistent Moment of Inertias about the shaft axis (SA shown in FIG. 26). Because the tungsten heel weight members 1430 are located in the hosel cavity 1432 such that the shaft axis SA intersects the heel weight members 1430, the Moment of Inertia about the shaft axis, MOI.sub.SA, is less than 700 kg-mm.sup.2 for all of the irons, and more preferably, between about 650 kg-mm.sup.2 and 700 kg-mm.sup.2 for all of the irons. More particularly, the long irons have a MOI.sub.SA that is with 10% of the MOI.sub.SA for the mid irons and more preferably within 5%. Preferably, [(mid iron MOI.sub.SA−long iron MOI.sub.SA)/mid iron MOI.sub.SA]*100<5. Also, the mid irons have a MOI.sub.SA that is within 10% of the MOI.sub.SA for the short irons and more preferably within 5%. Preferably, [(short iron MOI.sub.SA−mid iron MOI.sub.SA)/short iron MOI.sub.SA]*100<5. Still further, the long irons have a MOI.sub.SA that is with 10% of the MOI.sub.SA for the short irons and more preferably within 5%. Preferably, [(short iron MOI.sub.SA−long iron MOI.sub.SA)/short iron MOI.sub.SA]*100<5.
[0117] Moreover, because the mid irons and the long irons are hollow, the Center of Gravity is relatively deep. More particularly, the Center of Gravity depth from the face center toward the back wall 1424 (in the z direction), CGz, is preferably greater than 6 mm for all of the irons. In a preferred embodiment, the CGz can be between 7.5 mm and 8.5 mm through the set. Preferably, the CGz is almost 1/10 of the blade length for the long irons and mid irons.
[0118] Also, the Center of Gravity from the ground, CGy, is very low through the set. As set forth in Table IX below, preferably, the center of gravity in the y direction, CGy, is less than about 18 mm from a ground surface for the long irons and less than about 19 mm for the mid irons and short irons when the club head is in the standard address position.
TABLE-US-00008 TABLE VIII Club Number 4 5 6 7 8 9 P W loft 21 24 27 30 34 38 43 48 Total Mass (g) 245 252 259 265 273 281 286 289 Body Mass (g) 93 93 93 93 218 224 228 231 Face Mass (g) 52 52 52 52 50 51 51 51 Toe W (g) 68 72 75 78 Heel W (g) 22 25 28 31 Medallion (g) 3.5 3.5 3.5 3.5 3.3 3.3 3.3 3.3 Steel Mass % 59 58 56 58 98 98 98 98 W Mass % 37 38 40 41
TABLE-US-00009 TABLE IX Club Number 4 5 6 7 8 9 P W Blade 83 83 82 82 82 8 81 81 Length (mm) Toe 55 55 55 56 56 56 57 57 Height (mm) Scoreline 54 54 54 54 54 53 53 53 Width (mm) Sole Width 22 21 21 20 20 19 19 18 Center (mm) CGy (mm) 17.7 17.8 17.9 18.0 18.3 18.5 18.6 18.6 CGz (mm) 7.5 7.5 7.4 7.4 7.8 7.9 8.0 8.2 MOIy 270 275 284 290 274 279 284 288 (kg .Math. mm.sup.2) MOI.sub.SA 658 667 674 678 677 684 685 690 (kg .Math. mm.sup.2)
[0119] Referring to FIGS. 30-38, another embodiment of the present invention is a set of golf clubs comprising at least a long iron having a loft between about 15 and 25 degrees and a first club head mass, a mid iron having a loft of between about 26 and 35 degrees and a second club head mass, and a short iron having a loft of about 36 degrees or greater and a third club head mass. The long iron, for example, comprises an iron body 1500 that is preferably formed from steel and comprises a heel 1512, a toe 1514, a topline 1520, a sole 1518, and a hosel 1516. A front face insert 1510, preferably formed from titanium such as 15-3-3-3, and a back wall 1524, preferably formed from a composite, a thermoplastic compound such as PEEK, PSU or PPS, or a light weight material having a specific gravity of less than 1.6, form a hollow cavity 1526 therebetween. In the preferred set, the mid iron has the same or similar construction as the long iron.
[0120] Preferably, the iron body 1500 is cast with the hollow cavity 1526 and the hosel cavity 1532. However, the hosel bore 1517 and the hosel cavity 1532 can be machined. The front face insert 1510 can also be formed from stamped, high strength sheet metal and welded to the body 1500 after a toe weight member 1528 is secured with in the hollow cavity 1526. A heel weight member 1530 is inserted into the hosel cavity 1532, and optionally, a hosel cover member can be welded to the front portion of the hosel 1516 to secure the heel weight member 1530 within the hosel cavity 1532.
[0121] The toe weight member 1528 is formed of tungsten and is coupled to a toe portion of the hollow cavity 1526. Preferably, as set forth in Table X below, the toe weight member 1528 is greater than about 65 grams and comprises about 25%-35% of the long iron club head mass. The long iron head further comprises the heel weight member 1530, also formed of tungsten, that is about 10 to 20 grams and is coupled into the hosel cavity 1532 formed in the lower portion of the hosel 1516 such that the heel weight member 1530 is intersected by the shaft axis SA. In this embodiment, the shaft is inserted to the upper hosel bore 1517. Preferably, the heel weight member 1530 comprises about 5%-10% of the long iron head mass.
[0122] With reference to FIGS. 33, 35 and 36, the iron body 1500 preferably includes a body insert groove 1550 that extends across the topline, 1520, the toe 1514 and the sole 1518 and a face insert tongue 1551 that fits within the body insert groove 1550. Moreover, the iron body 1500 includes a body insert tongue 1552 on the heel side of the face and a face insert groove 1553 on the heel side of the face insert 1510 that couples to the body insert tongue 1552. The coupling of the tongue and grooves facilitates a better welding of the face insert 1510 when the face insert 1510 is made from the same material as the iron body 1500, either steel or titanium, or facilitates brazing if the iron body 1500 is steel and the face insert 1510 is titanium. Preferably, the face insert 1510 is formed of titanium and has a face thickness of between about 2 mm and 2.5 mm.
[0123] Referring to FIGS. 37-39, the iron body 1500 can further comprise a second heel weight member 1531 coupled in the hollow cavity 1526. In the most preferred embodiment, the iron body 1500 comprises a first heel weight member 1530 that is intersected by the shaft axis SA and a second heel weight member 1531 that is located in the hollow cavity 1526. The second heel weight member 1531 preferably has greater mass that the first heel weight member 1530. Moreover, the first heel weight member 1530 and the second heel weight member 1531 combined have a mass of greater than about 20 grams and more preferably between about 20 and 30 grams. Still further, the first heel weight member 1530 and the second heel weight member are preferably spaced apart by distance d.sub.HW of no more than 10 mm and preferably less than 5 mm.
[0124] The club heads according to the present invention have high Moment of Inertias. Because they have such large tungsten weight members, the Moment of Inertia about the y-axis (34 shown in FIG. 2), MOIy, is greater than 250 kg-mm.sup.2 for all of the irons and more preferably greater than 280 kg-mm.sup.2. Still further, the blade length is preferably greater than 82 mm, but the MOIy to blade length ration is greater than 3 kg-mm, and more preferably, between about 3.4 kg-mm and 4 kg-mm. Still further, the Moment of Inertia about the shaft axis MOI.sub.sa is greater than 600 kg-mm.sup.2 and, more preferably, between about 610 and 700 kg-mm.sup.2.
[0125] Moreover, as shown in FIG. 32 and because the mid irons and the long irons are hollow, the Center of Gravity CG is relatively deep and low. More particularly, the iron body 1500 has a Center of Gravity depth from the face center FC, CGz, that is preferably greater than 6 mm for all of the irons. In a preferred embodiment, the CGz can be around 8 mm for the long irons. Preferably, the CGz is approximately 1/10 of the blade length for the long irons. Also, the Center of Gravity from the ground, CGy, is very low through the set. Preferably, the CGy is less than 18 mm from a ground surface for the long irons and less than 19 mm for the mid irons and short irons when the club head is in the standard address position.
[0126] Referring to FIGS. 40-44, another embodiment of the present invention is a set of golf clubs comprising at least a long iron having a loft between about 15 and 25 degrees and a first club head mass, a mid iron having a loft of between about 26 and 35 degrees and a second club head mass, and a short iron having a loft of about 36 degrees or greater and a third club head mass. The long iron, for example, comprises an iron body 1600 that is preferably formed from steel and comprises a heel 1612, a toe 1614, a topline 1620, a sole 1618, and a hosel 1616. A front face insert 1610, preferably formed from titanium, and a back wall 1624, preferably formed from a composite, thermoplastic compound or light weight material having a specific gravity of less than 1.6, form a hollow cavity 1626 therebetween. In the preferred set, the mid iron has the same or similar construction as the long iron.
[0127] Preferably, the iron body 1600 is cast with the hollow cavity 1626 and the hosel cavity 1632. However, the hosel bore 1617 and the hosel cavity 1632 can be machined. The front face insert 1610 can also be formed from stamped, high strength sheet metal and welded to the body 1600 after a toe weight member 1628 is secured with in the hollow cavity 1626. A heel weight member 1630 is inserted into the hosel cavity 1632, and optionally, a hosel cover member can be welded to the front portion of the hosel 1616 to secure the heel weight member 1630 within the hosel cavity 1632. Although not shown, the iron body 1600 can include a second heel weight member secured in the heel side of the hollow cavity 1626.
[0128] The toe weight member 1628 is formed of tungsten and is coupled to a toe portion of the hollow cavity 1626. Preferably, as set forth in Table X below, the toe weight member 1628 is greater than about 65 grams and comprises about 25%-35% of the long iron club head mass. Preferably, the mass of the toe weight member 1628 is greater than the mass of the face insert 1610. The long iron head further comprises the heel weight member 1630, also formed of tungsten, that is about 10 to 20 grams and is coupled into the hosel cavity 1632 formed in the lower portion of the hosel 1616 such that the heel weight member 1630 is intersected by the shaft axis SA. In this embodiment, the shaft is inserted to the upper hosel bore 1617. Preferably, the heel weight member 1630 comprises about 5%-10% of the long iron head mass.
[0129] With reference to FIGS. 43 and 44, the iron body 1600 preferably includes a body insert groove 1650 that extends across the topline 1620 and the sole 1618 and a face insert tongue 1651 that fits within the body insert groove 1650. Moreover, the iron body 1600 includes a body insert tongue 1652 on the toe side and heel side of the face and a corresponding face insert groove 1653 on the toe side and heel side of the face insert 1610 that couples to the body insert tongue 1652. The coupling of the tongue and grooves facilitates a better welding of the face insert 1610 when the face insert 1610 is made from the same material as the iron body 1600, either steel or titanium, or facilitates brazing if the iron body 1600 is steel and the face insert 1610 is titanium. Preferably, the face insert 1610 has a face thickness of between about 2 mm and 2.5 mm and if formed of a titanium alloy such as 15-3-3-3.
[0130] Moreover, as shown in FIG. 41 and because the mid irons and the long irons are hollow, the Center of Gravity CG is relatively deep and low. More particularly, the iron body 1600 has a Center of Gravity depth from the face center FC, CGz, that is preferably greater than 6 mm for all of the irons. In a preferred embodiment, the CGz can be around 9 mm for the long irons. Preferably, the CGz is approximately 1/10 of the blade length for the long irons. Also, the Center of Gravity from the ground, CGy, is very low through the set. Preferably, the CGy is less than 18 mm from a ground surface for the long irons and less than 19 mm for the mid irons and short irons when the club head is in the standard address position.
[0131] The following tables demonstrate the properties of the irons discussed above with steel bodies 1500, 1600, titanium face inserts 1510, 1610 brazed to the steel bodies, tungsten weights 1528, 1530, 1531, 1628, 1630 and a composite or thermoplastic backwall 1524, 1624.
TABLE-US-00010 TABLE X Club 1600 1500 loft 20 22 Total Mass (g) 245 241 Ti Mass (g) 36 86 Steel Mass (g) 99 22 Toe W (g) 76 101 Heel W (g) 20 11 Heel W2 (g) 16 Steel Mass % 40 9 W Mass % 39 53
TABLE-US-00011 TABLE XI Club 1600 1500 Blade Length (mm) 85 83 Toe Height (mm) 53 50 Scoreline Width (mm) 55 57 Sole Width Center (mm) 22 27 CGy (mm) 18 17 CG.sub.z (mm) 7 9 MOIy 312 317 (kg-mm2)
[0132] FIG. 45 of the accompanying drawings shows a rear view of a golf club head 4500, with the sole cover 4635 (shown in FIG. 46) in accordance with a further alternative embodiment of the present invention. In this alternate embodiment of the present invention, the body portion 4510 has a heel, a toe, a topline, a sole, and a hosel which forms the main chassis of the golf club head 4500. Although some of the previous embodiments of the present invention may have utilized a titanium face insert, the present invention has a striking face that is formed out of steel like the remainder of the body portion 4510 and is generally formed as a unitary forged body with the remainder of the body portion 4510 to create the consistency and feel associated with a forged golf club head 4500. However, it should be noted that the striking face could be formed separately from the body portion 4510, out of the same material or even a different material, all without departing from the scope and content of the present invention.
[0133] With the sole cover 4735 (shown in FIG. 47) removed, the toe weight member 4528 and the heel weight member 4530 are now visible for the sake of illustration. It should be noted here that the heel weight member 4530 has a shape and geometry that is consistent with the various heel weight members previously, and the hosel axis still intersects the heel weight member 4530 below the hosel. The toe weight member 4528, on the other hand, differs from previously shown toe weight members 4528 in that it has an unsupported extension portion 4528-b, that separates the toe weight member 4528 into a main supported portion 4528-a and the aforementioned unsupported extension portion 4528-b.
[0134] In order to provide a better explanation of the unique toe weight member 4528 shown here in FIG. 45, FIG. 46 is provided in an attempt to illustrate how the toe weight member 4528 is divided into its main supported portion 4528-a and its unsupported extension portion 4528-b. FIG. 46 of the accompanying drawings shows an enlarged frontal view of a toe weight member 4628 in accordance with this alternative embodiment of the present invention. In this perspective view shown in FIG. 46, the toe weight member 4628 is divided into a main supported portion 4628-a and an unsupported extension portion 4628-b, separated by the bifurcation line 4633. The bifurcation line 4633 here is an imaginary line created at the transition between the main supported portion 4628-a. This imaginary bifurcation line is created by the toeward most point of the weight member 4628 that still come in contact with the striking face. Consequently, as the definition suggests, the unsupported extension portion 4628-b extends toeward from the main supported region 4628-a and does not contact the striking face of the golf club head. Utilizing this unsupported extension portion 4628-b of the toe weight member 4628 allows the center of gravity 4637 of the toe weight member 4628 to be located toeward of the bifurcation line 4633, which helps its structural integrity in being retained within the lower cavity of the golf club head. In addition to helping preserve the structural integrity, the unsupported extension portion 4628-b of the toe weight member 4628 reduces stresses in the striking face of the golf club head as it impacts a golf ball. Reducing stress in the striking face portion of the golf club head is critical to the performance of the golf club head, as it balances the need for increased moment of inertia of the golf club head with the increased stress created when the tungsten toe weight member 4628 touches the rear of the striking face.
[0135] FIG. 47 of the accompanying drawings shows an exploded perspective view of a golf club head 4700 in accordance with this alternative embodiment of the present invention. In this exploded perspective view shown in FIG. 47, we can see that the heel weight member 4730 and the toe weight member 4728 are both attached to the lower heel and toe portion of the body portion 4710 of the golf club head 4700 respectively. These high density heel weight member 4730 and toe weight member 4728 may generally be brazed to the rear surface of the striking face utilizing alignment indicators, with both of these weights being cradled by the sole cover 4735.
[0136] FIG. 48 of the accompanying drawings shows a cross-sectional view of a golf club head 4800 taken along the middle of the golf club head 4800 in order to illustrate the relationship between the unsupported extension portion 4828-b of the toe weight member 4828 and the striking face to be shown more clearly. In this cross-sectional view, we can see that the toe weight member 4828, including the unsupported extension portion 4828-b, does not extend all the way into the center of the face, which is where this cross-sectional view is provided. Based on this view, we can see that the main supported portion 4828-a of the toe weight member 4828 is in direct contact with the rear surface of the striking face, while the unsupported extension portion 4828-b of the same to weight member 4828 does not actually come in contact with the striking face but is separated by a distance d1. The distance d1 of separation, in this embodiment of the present invention may generally be greater than about 0.05 mm, more preferably greater than about 0.075 mm, and most preferably greater than about 0.1 mm, all without departing from the scope and content of the present invention.
[0137] While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objectives stated above, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Therefore, it will be understood that the appended claims are intended to cover all modifications and embodiments which would come within the spirit and scope of the present invention.
[0138] Other than in the operating example, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials, moment of inertias, center of gravity locations, loft, draft angles, various performance ratios, and others in the aforementioned portions of the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear in the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the above specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
[0139] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Furthermore, when numerical ranges of varying scope are set forth herein, it is contemplated that any combination of these values inclusive of the recited values may be used.
[0140] It should be understood, of course, that the foregoing relates to exemplary embodiments of the present invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
