US20080113825A1 - Golf club head - Google Patents

Golf club head Download PDF

Info

Publication number
US20080113825A1
US20080113825A1 US11/937,868 US93786807A US2008113825A1 US 20080113825 A1 US20080113825 A1 US 20080113825A1 US 93786807 A US93786807 A US 93786807A US 2008113825 A1 US2008113825 A1 US 2008113825A1
Authority
US
United States
Prior art keywords
golf club
head
toe
inertia
length
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11/937,868
Other languages
English (en)
Inventor
Tomonari FUNAYAMA
Tomoyuki Sakai
Ken ARIYOSHI
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Endo Manufacturing Co Ltd
Original Assignee
Endo Manufacturing Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Endo Manufacturing Co Ltd filed Critical Endo Manufacturing Co Ltd
Assigned to K.K. ENDO SEISAKUSHO reassignment K.K. ENDO SEISAKUSHO ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ARIYOSHI, KEN, FUNAYAMA, TOMONARI, SAKAI, TOMOYUKI
Publication of US20080113825A1 publication Critical patent/US20080113825A1/en
Priority to US13/650,983 priority Critical patent/US20130102412A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B53/00—Golf clubs
    • A63B53/04—Heads
    • A63B53/0466—Heads wood-type
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B53/00—Golf clubs
    • A63B53/04—Heads
    • A63B53/0408—Heads characterised by specific dimensions, e.g. thickness
    • A63B53/0412—Volume
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B53/00—Golf clubs
    • A63B53/04—Heads
    • A63B53/0416—Heads having an impact surface provided by a face insert
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B53/00—Golf clubs
    • A63B53/04—Heads
    • A63B53/0458—Heads with non-uniform thickness of the impact face plate
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B60/00—Details or accessories of golf clubs, bats, rackets or the like
    • A63B60/02—Ballast means for adjusting the centre of mass
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B53/00—Golf clubs
    • A63B53/04—Heads
    • A63B2053/0491—Heads with added weights, e.g. changeable, replaceable
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B2209/00—Characteristics of used materials
    • A—HUMAN NECESSITIES
    • A63—SPORTS; GAMES; AMUSEMENTS
    • A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
    • A63B53/00—Golf clubs
    • A63B53/04—Heads
    • A63B53/0408—Heads characterised by specific dimensions, e.g. thickness

Definitions

  • the present invention relates to a golf club head with improved ball-hitting directionality, and more specifically, relates to a golf club head having a large moment of inertia and improved stability of direction of a hit ball.
  • head masses have in the prior art been no greater than approximately 210 g. That is, given the configuration of the prior art, although heads have tended to increase in size the total mass has been limited, and so excess mass to control the position of the center of gravity, or in other words, excess mass to increase the moment of inertia has in the prior art been limited to approximately 10 g, due to the constraint that the total mass should not be increased.
  • the pendulum test method is adopted to measure the restitution coefficient of the face surface.
  • This testing method entails fixing the club, causing a steel sphere to collide with the face surface, and measuring the contact time; the contact time is called the characteristic time, and the rule limits this characteristic time to 257 ⁇ s (microseconds) or less (including a tolerance of 18 ⁇ s).
  • the thickness of the face portion sheet tends to become thick, but there is a limit to the extent to which the face portion mass can be reduced.
  • the hosel portion connected to the shaft is positioned on one end of the face portion, and the weight of this portion is also relatively great.
  • the above-described rules also impose various constraints on external dimensions, such as that the length from the heel portion to the toe portion must not be longer than the length from the face portion to the rear surface; that the length from the heel to the toe must be 127 mm (5 inches) or less; and that the length from the sole to the crown must be 71.12 mm (2.8 inches) or less. And, there is the further constraint that the volume must be 470 cm 3 (including a tolerance of 10 cm 3 ) or less. Given these constraints as well, the center of gravity position cannot be located in a position so as to increase the “sweet” area, and moreover the overall head mass becomes large. Due to such constraints, it is extremely difficult to increase the weight or other excess mass so as to increase the moment of inertia.
  • heads are known in which mass is distributed in at least one direction among the three major inertial axes in orthogonal coordinates passing through the center of gravity, or in sites in proximity thereto, or with masses distributed in such a manner (see for example Japanese Patent Laid-open No. 5-57034).
  • clubs are known in which the golf club head comprises metal material members and fiber-reinforced resin members, with the head bonded together by an adhesive of thickness 0.05 to 1 mm (see for example Japanese Patent Laid-open No. 2003-320060).
  • This invention was devised in order to resolve the above-described problems of the prior art, and attains the following objects.
  • An object of the invention is to provide a golf club with an increased moment of inertia of a metal hollow golf club head with large volume, and with improved ball-hitting directionality.
  • a further object of the invention is to provide a golf club with an increased moment of inertia of a metal hollow golf club head with large volume without increasing the head mass, and with improved ball-hitting directionality.
  • the golf club of Invention 1 is a golf club having a metal hollow golf club head, comprising: a face portion positioned on a front surface of the metal hollow golf club head and having a striking face to strike a golf ball; a crown portion forming an upper surface of the club, and a sole portion forming a lower surface of the club, characterized in that the mass of the metal hollow golf club head is 210 g or less, characteristic time (CT value) of the metal hollow golf club head, relating to a restitution characteristic, is 257 ⁇ s or less; and when a lie angle of the metal hollow golf club head is 60°, volume of the metal hollow golf club head is 470 cm 3 or less, and moment of inertia about an axial line which is the center of a plumb line passing through the center of gravity of the metal hollow golf club head, is in the range 5000 to 6000 g-cm 2 .
  • CT value characteristic time
  • the golf club of Invention 2 is the golf club of Invention 1, characterized in that the metal is a titanium alloy sheet member, and a substantial center portion and an outer peripheral portion including sites of the plumb line within the curved surface of the crown portion and/or the sole portion constituting the body differ in thickness.
  • the golf club of Invention 3 is the golf club of Invention 1 or Invention 2, characterized in that the metal hollow golf club head is formed by joining, by welding, the face portion, the sole portion, the crown portion, and a hosel portion to which the shaft is connected.
  • the golf club of Invention 4 is the golf club of Invention 2, characterized in that a weight of 20 g or more is positioned at a position of a rotation radius most distant from the plumb line and at the crown portion and/or the sole portion.
  • the golf club of Invention 5 is the golf club of Invention 4, characterized in that, in the golf club of Invention 4, the weight is positioned on the back side of the toe portion.
  • the golf club of Invention 6 is the golf club of Invention 5, characterized in that the toe-side and back-side sites of the sole portion are formed in shapes protruding outward relative to the crown portion, and that the weight is positioned in this protruding sole portion.
  • the golf club of Invention 7 is the golf club of Invention 1, characterized in that the metal hollow golf club head has:
  • MOI ( aY 2 +bY+c ) ⁇ ( dX+e )/ f (1)
  • X is the length from the heel portion to the toe portion
  • Y is the length from the face portion to the rear surface
  • a, b, c, d, e, and f are constants.
  • the golf club of Invention 8 is the golf club of Invention 1, characterized in that the metal hollow golf club head has:
  • X is the position in the direction from the heel portion to the toe portion
  • Y is the position in the direction from the face portion to the rear surface
  • g, h, j, and k are constants
  • X has its origin at the center of the distance from the heel portion to the toe portion
  • Y has its origin in the face portion.
  • a golf club of this invention employs a hollow golf club head, the materials comprised by which are in essence all metals; under the constraints that the head volume be 470 cm 3 or less (including a tolerance of 10 cm 3 ), that the head mass be 210 g or less, and that the head characteristic time (CT value) related to the restitution characteristic be 257 ⁇ s or less (including a tolerance of 18 ⁇ s), a method and conditions were discovered for obtaining a golf club head for which the moment of inertia about the axial line centered on the plumb line passing through the center of gravity of the metal hollow golf club head is in the high range 5000 to 6000 g-cm 2 .
  • CT value head characteristic time
  • FIG. 1 is an external view showing the overall configuration of a golf club
  • FIG. 2 is a plane view of Aspect 1 of a driver club head
  • FIG. 3 is a front view of Aspect 1 of a driver club head
  • FIG. 4 is a side view of Aspect 1 of a driver club head
  • FIG. 5 is a cross-sectional view along X-X in FIG. 4 ;
  • FIG. 6 is a plane view of Aspect 2 of a driver club head
  • FIG. 7 is a plane view of Aspect 3 of a driver club head
  • FIG. 8 is a front view of Aspect 3 of a driver club head
  • FIG. 9 is a side view of Aspect 3 of a driver club head
  • FIG. 10 arranges the external shapes of the heads 1 for which the moment of inertia MOI is calculated
  • FIG. 11 shows the relation between head width and moment of inertia, when the toe-heel length is held constant
  • FIG. 12 shows the relation between toe-heel length and moment of inertia when the head width is held constant
  • FIG. 13 is a graph showing the relation between toe-heel length and head width for different moments of inertia
  • FIG. 14 is an example in which the position of weight placement in a head 1 is changed.
  • FIG. 15 shows the relation between moment of inertia and position of center of gravity.
  • FIG. 1 is an external view of an entire golf club of this invention, and shows the driver club head having a metal hollow golf club head.
  • a golf club of this invention employs a metal hollow golf club head; the driver club head (hereafter also called a “head”) of Aspect 1 similarly is a metal hollow golf club head.
  • the basic construction of a driver club head is well-known, and a detailed explanation is omitted; however, in order to facilitate understanding of the invention, a summary explanation is given as follows.
  • a driver club head 1 of this invention has one end of the shaft A fixed.
  • FIG. 2 to FIG. 4 show an aspect of a driver club head 1 of a metal hollow golf club of this invention.
  • FIG. 2 to FIG. 6 show only the head portion; the shaft A and other members are not related to the gist of this invention, and so are omitted from the drawings.
  • FIG. 2 is a plane view of the head 1
  • FIG. 3 is a front view of the head 1
  • FIG. 4 is a side view of the head 1
  • the metal hollow driver club head 1 comprises a crown portion 2 , which is the upper portion; a sole portion 3 , which is the bottom portion; a face portion 4 , which strikes the golf ball; a toe portion 5 , which is the front portion of the head 1 ; a heel portion 6 , which is the rear portion of the head; a back portion 10 , positioned on the opposite side from the face portion 4 , forming the rear portion of the head 1 ; and a hosel portion 7 , which is a member which supports and fixes the driver club head 1 on the shaft A.
  • the principal portions are the face portion 4 , crown portion 2 , sole portion 3 , and hosel portion 7 .
  • each of these portions comprises either one or a plurality of sheet members, which are joined together.
  • sheet members are press-molded to the desired curved-surface shape, and are then integrated by welding or other means.
  • Rolled members are particularly suitable for use as sheet members for purposes of controlling the sheet thickness.
  • the body member comprising the head 1 is formed by combining four members, which are a face member; a sole member, comprising a toe portion 5 , heel portion 6 , and a portion of the back portion 10 ; a crown member, comprising a toe portion 5 , heel portion 6 , and a portion of the back portion 10 ; and a hosel member.
  • Each of the four members is formed by cutting the sheet members into prescribed shapes and then heating and pressing.
  • the face member for example is heated to 400°, and the sole member, crown member, and other body member were heated to 900°. After pressing, burrs were cut away (trimming), and TIG welding was performed.
  • TIG welding is a type of welding also called argon welding; a welding rod of the deposit metal itself is used, and argon gas is released from the periphery of a tungsten electrode, to shield the molten metal from the atmosphere during welding.
  • laser and plasma welding methods may be used, with fewer welding beads or thermal effects, making such methods more appropriate.
  • Each of the members may also be manufactured by casting, forging, or another method.
  • the metal material is a titanium alloy
  • the face member and sole member are opposed as members in manufacturing, and thereafter the hosel member is joined, and then the pressed crown member is bonded by TIG welding or similar.
  • TIG welding or similar.
  • an integrated driver club head 1 is formed by welding.
  • the face portion 4 has a minutely curvature surface, and is formed in a plate shape.
  • the area of maximum restitution coefficient is the center portion which is the striking face, that is, the “sweet” area 9 near the center of gravity 8 .
  • Titanium alloys often used in driver club heads 1 include ⁇ -type titanium alloys and ⁇ + ⁇ -type titanium alloys. These alloys have enhanced strength as well as excellent machinability, ductility, toughness, and strength, and are reliable alloys.
  • the basic driver club head 1 comprised by such a golf club has improvements added to the crown portion 2 and sole portion 3 in particular, in order to increase the moment of inertia.
  • the moment of inertia is represented by m ⁇ r 2 ; hence it is clear to a practitioner of the art that it is sufficient to increase either m (the mass of the head 1 ) or r (the distance from the center of gravity).
  • the mass of the general head overall is limited to approximately 210 g due to the fact that, as described above, if the head is made too heavy the swing balance suffers. In particular, due to the larger volumes of recent heads 1 , the mass of the head 1 cannot be made too great.
  • the moment of inertia is increased.
  • the lie angle of a metal hollow golf club head is set to 60°, the moment of inertia about the axial line centered on the plumb line passing through the center of gravity of the head 1 is increased.
  • FIG. 5 is a cross-sectional view along X-X in FIG. 4 .
  • the cross-sectional view is in the same direction as FIG. 3 , passing through the center of gravity 8 .
  • the symbol B is the distance from the center of gravity 8 to the hosel portion 7 , that is, the center-of-gravity distance.
  • the mass and shape of the hosel portion 7 in effect cannot be changed, due to the circumstances of mounting of the prescribed shaft A.
  • it is effective to increase the distance at which a mass is positioned from the center of gravity 8 , that is, the separation distance C, and to increase the mass.
  • the separation distance C is increased.
  • the crown portion 2 is formed by pressing of a sheet-shape titanium alloy member; this press-machined member is formed into an even thinner shape.
  • the thickness in the area D on the periphery of the center of gravity above the center of gravity 8 is made thin. That is, when the lie angle of the head 1 is set to 60°, this center-of-gravity periphery area D is the area on the reverse face of the crown portion 2 centered on the plumb line (not shown) passing through the center of gravity 8 of the head 1 .
  • the machining method to reduce the thickness of this center-of-gravity periphery area D is, in this example, chemical etching treatment.
  • This chemical etching treatment is well-known, and a detailed explanation is omitted.
  • Chemical processing is used to reduce the thickness in the center-of-gravity periphery area D of the crown portion 2 , to further reduce the thickness of the crown portion 2 .
  • cutting and coining by press machining are also possible to some degree; but use of such machining methods is limited by the machining hardness of the materials and by various machining-related constraints, and thicknesses beyond a certain limit cannot be attained.
  • the thickness of the center-of-gravity periphery area D can be reduced to the desired value.
  • titanium alloy alone can be used to maintain strength, rather than opening a hole in the crown portion and covering with a fiber-reinforced resin instead of a metal material in a composite configuration, as in the prior art.
  • Cutting-away of the center-of-gravity periphery area D of the crown portion 2 results in reduced mass of the crown portion 2 , and consequently the mass at sites relatively distant from the center-of-gravity periphery D is increased.
  • the portion in which cutting-away is avoided is the side of the toe portion 5 opposed to the hosel portion 7 from the center of gravity 8 . More rigorously, the position of the boundary portion on the side of the toe portion 5 and back portion 10 (see FIG. 2 ) is preferable. This portion can be made distant from the center of gravity 8 , and has the greatest effect in increasing the moment of inertia. Moreover, it is preferable that further mass be placed at this portion, that is, at the end position at the separation distance C.
  • this is accomplished by reducing the mass of the center-of-gravity periphery area D and leaving a thickness 2 a at the end position at the separation distance C in the crown portion 2 .
  • This results in the occurrence of a relative difference in mass between the center-of-gravity periphery area D and the end portion at the separation distance C.
  • the separation distance C was increased to the extent possible within the limitations of the overall mass. This was accomplished by enlarging the grown portion 2 b on the side of the toe portion 5 , and forming a substantially rectangular shape. The shape approximates a so-called square wood. This result was accomplished by reducing the thickness of the center-of-gravity periphery area D within the limitation of the overall mass.
  • an excess mass 3 a is provided at the sole end portion position at separation distance C in the sole portion 3 .
  • This is a means to directly increase the mass, but in contrast with masses provided with the aim of more effective striking as in the prior art, the position of placement of the mass is limited, and the mass is provided at the site farthest removed from the position of the center of gravity 8 , that is, at the site positioned at the separation distance C.
  • the mass increase due to this excess mass 3 a is within the limitation on overall mass, but to the extent that the mass of the center-of-gravity periphery D of the crown portion 2 is cut away, this mass can be added, so that greater mass increase is possible than in the prior art.
  • an added mass was approximately 10 g
  • addition of a mass of 20 to 25 g is possible.
  • An added weight does not only take the form of provision of a separate body, but also includes weight added by increasing the thickness of a plate member itself.
  • a portion of the crown portion 2 is removed by chemical etching, and a mass 3 a is provided in the sole portion 3 , to increase the value of the mass m to the extent possible.
  • the separation distance C of the mass 3 a from the center of gravity 8 can be increased. This separation distance from the center of gravity 8 is indicated by C in FIG. 5 ; in FIG.
  • the extended crown portion 3 b is in a position on the side opposite the substantially diagonally line opposing the center-of-gravity distance B on the side of the hosel portion 7 , and has an enlarged shape compared with the extended crown portion 3 b in the position of the prior art.
  • FIG. 6 is a plane view showing Aspect 2 of the invention.
  • the end portion 3 b of the sole portion 3 on the side of the toe portion 5 and back portion 10 is enlarged, and a mass 3 a is positioned.
  • Other portions of this head 1 are effectively the same as in Aspect 1, and explanations are omitted.
  • the numerical value of the distance r equivalent to the separation distance C is further increased, so that the moment of inertia can be further increased.
  • the lie angle is set to 60°.
  • the lie angle is the angle bade by the face of the head in contact with the ground and the shaft; in the case of a metal hollow golf club head, even when the head is enlarged with increased volume and large moment of inertia, experiments have indicated that a lie angle of approximately 60° is most satisfactory.
  • FIG. 7 to FIG. 9 show Aspect 3 of a driver club head;
  • FIG. 7 is a plane view of Aspect 3 of a driver club head,
  • FIG. 8 is a front view of Aspect 3 of a driver club head,
  • FIG. 9 is a side view of Aspect 3 of a driver club head.
  • the external shape of this head 1 is substantially quadrilateral as seen in plane view, with the angle in one corner formed into an arc, as represented characteristically in the plane view of FIG. 7 .
  • the metal hollow driver club head 1 of this Aspect 3 is created entirely from titanium alloy sheet.
  • the body members comprised by the head 1 of this Aspect 3 are the four members which are the face portion 4 , sole portion 3 , crown portion 2 , and hosel portion 7 .
  • the crown portion 2 comprises titanium alloy sheet (specific gravity 4.51) of uniform thickness 0.5 mm.
  • the sole portion 3 comprises titanium alloy sheet (specific gravity 4.51) of uniform thickness 0.75 mm.
  • the hosel portion 7 and weight 3 a comprise titanium alloy (specific gravity 4.51).
  • the face portion 4 is entirely formed from titanium alloy sheet (specific gravity 4.42); the thickness is different in different portions.
  • the thickness In the ellipse-shaped center portion 4 a , the thickness is 3.1 mm.
  • the thickness In the outer portion 4 b on the outside of the center portion 4 a , the thickness is 2.3 mm. In this way, the thickness differs in different portions of the face portion 4 in order to cause the characteristic time (CT value) of the restitution coefficient of the face portion 4 to be the stipulated 257 ⁇ s or less (including a tolerance of 18 ⁇ s), and so that the mass of the face portion 4 is not increased.
  • the flange 4 c on the outer periphery of the face portion 4 is of 1.3 mm thick titanium alloy sheet (specific gravity 4.42) with constant width.
  • the flange 4 c is also placed at the positions of the crown portion 2 and sole portion 3 .
  • This flange 4 c supports the face portion 4 on the outer periphery, and in addition functions to link the crown portion 2 and sole portion 3 , which are thin, and the face portion 4 .
  • the construction of the hosel 7 has a generally employed shape, and the shape is not special, so that a detailed explanation is omitted.
  • a weight 3 a On both sides of the back portion 10 is placed a weight 3 a . As shown in FIG. 7 , more of the weight 3 a is placed at the corner portions on both ends. This is in order to increase the distance from the center of gravity 8 and increase the moment of inertia MOI. As shown in FIG. 8 , the distance from the end of the toe portion 5 of the head 1 to a point in the heel portion 5 at a height of 22.23 mm (0.875 inches) from the bottom face of the sole portion 3 is called the “toe-heel length X”. As shown in FIG. 9 , the length from the end of the face portion 4 to the end of the back 10 is called the “head width Y”.
  • FIG. 10 arranges the external shapes of heads 1 for which the moment of inertia MOI was calculated.
  • Heads 1 arranged in this way have increasingly larger “toe-heel lengths X” in moving rightward along the horizontal axis (in the figure) (87 to 127 mm), and have increasingly larger “head widths Y” in moving upward along the vertical axis (in the figure) (86 mm to 126 mm).
  • These heads 1 have a hosel portion 7 with the same shape and dimensions as in Aspect 3; the flange width dimension of the outer periphery 4 c of the face portion 4 is also the same, and as shown in FIG. 10 , only the head width Y and toe-heel length X were varied.
  • rules for golf equipment stipulate that the “toe-heel length X” must not be longer than the “head width Y”. Hence heads 1 in the upper-left in FIG. 10 cannot be used, and so calculations were omitted.
  • the heads 1 shown in the first column (right-hand column) in FIG. 10 have a “toe-heel length X” fixed at 127 mm, and “head widths Y” of 126 mm, 116 mm, 106 mm, 96 mm, and 86 mm.
  • the moment of inertia MOI was calculated for each of these as described below.
  • the head width Y (mm), head volume (cm 3 ), moment of inertia MOI (g-cm 2 ), and mass of the weight 3 a (g) appear in Table 1.
  • the overall masses for heads 1 were 205 g in each case. Hence as shown in Table 1, the volumes, and the masses of weights differed for each of the heads 1 .
  • the moment of inertia about the axial line (lateral) centered on the plumb line passing through the center of gravity of the head 1 which has been an object of this invention, was in the range 5000 to 6000 g-cm 2 .
  • a moment of inertia of approximately not less than 5000 g-cm 2 which was an object of this invention, was exceeded.
  • the heads 1 in the second column from the right in FIG. 10 have the “toe-heel length X” fixed at 117 mm, and “head widths Y” of 126 mm, 116 mm, 106 mm, 96 mm, and 86 mm; the moments of inertia MOI for each of these were calculated.
  • Table 2 As is seen from this Table 2, when the “head width Y” is 126 mm or 116 mm, the desired moment of inertia of 5000 g-cm 2 or higher is achieved.
  • FIG. 11 shows the relation between head width and moment of inertia, when the toe-heel length is held constant. That is, FIG. 11 plots the results of Tables 1 and 2 with the head width Y along the horizontal axis and the moment of inertia MOI along the vertical axis; the moment of inertia MOI is plotted along the vertical axis with the “toe-heel length X” dimension fixed. This FIG. 11 plots the moments of inertia MOI of the heads 1 with the construction of Aspect 3, holding the “toe-heel length X” constant.
  • heads with a moment of inertia MOI exceeding 5000 g-cm 2 which is an object of this invention, are approximately three in number when the “head width Y” is 126 mm, and are approximately two in number when the “head width Y” is 116 mm.
  • the moment of inertia is near 5000 g-cm 2 when the “toe-heel length X” is 127 mm, and so this data is adopted as an approximating equation.
  • FIG. 11 each of the points of the moment of inertia for which the “toe-heel length X” is 127 mm are connected, the resulting figure is a quadratic curve.
  • An approximating equation for this quadratic curve is equation (3) below, and so when the “toe-heel length X” is fixed, this approximating equation is adopted in the vicinity of 5000 g-cm 2 .
  • heads 1 in the first row from the top in FIG. 10 have the “head width Y” fixed at 126 mm, and the “toe-heel length X” at 127 mm and 117 mm. However, a “toe-heel length X” of 117 mm violates the rules, and so was removed from consideration.
  • heads appearing in the second row in FIG. 10 have the “head width Y” fixed at 116 mm, and a “toe-heel length X” of 127 mm and 117 mm.
  • heads appearing in the fourth row of FIG. 10 have the “head width Y” fixed at 106 mm, and a “toe-heel length X” of 127 mm, 117 mm, and 107 mm.
  • heads appearing in the fourth row of FIG. 10 have the “head width Y” fixed at 96 mm, and a “toe-heel length X” of 127 mm, 117 mm, 107 mm, and 97 mm.
  • heads appearing in the fifth row of FIG. 10 have the “head width Y” fixed at 86 mm, and a “toe-heel length X” of 127 mm, 117 mm, 107 mm, 97 mm, and 87 mm. In this way, moments of inertia MOI of the heads were calculated with the “head width Y” dimension fixed.
  • FIG. 12 shows the relation between the toe-heel length and the moment of inertia when the head width is held constant. That is, FIG. 12 plots the “toe-heel length X” along the horizontal axis and the moment of inertia MOI along the vertical axis with the “head width Y” dimension fixed. From this data, heads with a moment of inertia exceeding 5000 g-cm 2 , which is an object of this invention, are only heads with the head width Y fixed at 106 mm. The line connecting these points is a straight line, an approximating equation for which is given by equation (4); this equation (4) is adopted as an approximating equation in the vicinity of 5000 g-cm 2 .
  • This equation (5) is a product of the approximating equation (3) and the approximating equation (4); by taking the product of the two approximating equations, a relation is derived between the moment of inertia in the vicinity of 5000 g-cm 2 , the head length X, and the head width Y.
  • the numerical value “5424” is the moment of inertia when the “toe-heel length X” in approximating equation (4) is 127 mm.
  • Approximating equation (5) is the product of approximating equation (3) and approximating equation (4), and so is divided by the moment of inertia calculated using approximating equation (3) in the vicinity of 5000 g-cm 2 . By this means, the value of the moment of inertia of approximating equation (5) is corrected.
  • the numerical values in approximating equation (5) are intrinsic numerical values arising from the shape, construction, materials, masses, and similar of the head specific to this Aspect 3, and so these values can be replaced with constants. That is, the approximating equation (5) can be represented as the following general equation.
  • MOI ( aY 2 +bY+c ) ⁇ ( dX+e )/ f (1)
  • X is the length from the heel portion to the toe portion
  • Y is the length from the face portion to the rear surface
  • a, b, c, d, e, and f are constants.
  • FIG. 13 is a graph showing the relation between the toe-heel length and the head width for different moments of inertia.
  • FIG. 13 is a general summary of the above explanation; here the horizontal axis indicates X (toe-heel length) and the vertical axis indicates Y (head width).
  • values above the diagonal line have a head width greater than the toe-heel length, and violate the rules, and so describe heads which cannot be commercialized.
  • the area below the diagonal line describes heads which comply with the rules, and represents heads having a lateral moment of inertia of 5000 g-cm 2 or higher, an object of this invention, which have been manufactured and commercialized.
  • the above-described approximating equation (5) was calculated for each of the moments of inertia 5000, 5200, 5400, 5600, 5800, and 5900 g-cm 2 . From FIG. 13 , if a golf club head having a moment of inertia in the range 5000 to 5900 g-cm 2 , which is an object of this invention, is to be obtained, the toe-heel length and head width of a head with the shape of that of Aspect 3 can be determined. Further, as a result, the weight magnitude can also be determined.
  • FIG. 14A to 14E are examples in which the position of placement of a weight 3 a in the head 1 is varied.
  • the specifications and thicknesses of the crown portion 2 , sole portion 3 and face portion 4 are as described above.
  • the specifications of this head 1 include a “toe-heel length X” of 127 mm, “head width Y” of 126 mm, volume of 460 cm 3 , and head mass of 205 g
  • the weight mass is 43.9 g.
  • FIG. 15 shows the relation between moment of inertia and center of gravity position for heads with these specifications.
  • FIG. 15 indicates the X-direction center of gravity position, in the toe-heel length direction.
  • the vertical axis Y indicates the Y-direction center of gravity position, in the head width direction.
  • the origin (O) of the horizontal axis X is the center position of 127 mm.
  • the origin (O) of the vertical axis Y is the surface of the face portion 4 .
  • FIG. 15 is equivalent to a plane view of the head 1 .
  • the curve in FIG. 15 for a moment of inertia of 5000 g-cm 2 is the result of using the above-described approximating equation (5) to plot the center of gravity in the vicinity of a moment of inertia of 5000 g-cm 2 .
  • This curve is the result of fixing the overall mass of the head 1 at 205 g, the mass of weight 3 a at 43.91 g, the toe-heel length at 127 mm, the head width at 126 mm, and the volume at 460 cm 3 , so that the moment of inertia is 5000 g-cm 2 , and representing the center of gravity position when the position of the weight 3 a is varied as shown in FIG. 14 .
  • the mass of the weight 3 a is determined when the overall mass of the head 1 is 205 g and the volume is constant at 460 cm 3 .
  • the center of gravity position of head 1 is changing, and the moment of inertia is changing, when the position of the weight 3 a is varied as in FIG. 13 , the maximum moment of inertia area, and the area in which the moment of inertia is 5000 g-cm 2 , can also be calculated.
  • This maximum moment of inertia area and area resulting in a moment of inertia of 5000 g-cm 2 are indicated by line segments.
  • the center of gravity position be set in the area enclosed between these approximating equations (6) and (7).
  • the position and size of the “sweet” area of the face portion 4 are also related to this center of gravity position, and so are important.
  • each of the numerical values of the approximating equations (6) and (7) are intrinsic numerical values arising from the shape, construction, materials, masses, and similar of the head specific to this Aspect, and so these values can be replaced with constants. That is, the approximating equation (5) can be represented as the following general equations.
  • X is the position from the heel portion in the toe portion direction
  • Y is the position from the face surface in the rear face direction
  • g, h, j, and k are constants
  • the origin of X is taken to be the center of the length from the heel portion to the toe portion
  • the origin of Y is taken to be the face surface.
  • the above-described crown has different thicknesses in substantially the center portion and in the outer peripheral portion, but the entire crown portion may be of a smaller thickness than other body portions.
  • the thickness of the center area of the sole portion may be reduced, or the thickness of the entire sole portion may be made thinner than other body portions.
  • the materials comprised by the head are in essence all metal; but very small amounts of other materials can be used in some portions.
  • the numerical values stipulated by rules include tolerances, and of course even when related numerical values fluctuate within the ranges of tolerances they remain within the technical scope of this invention.

Landscapes

  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Physical Education & Sports Medicine (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Golf Clubs (AREA)
US11/937,868 2006-11-10 2007-11-09 Golf club head Abandoned US20080113825A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US13/650,983 US20130102412A1 (en) 2006-11-10 2012-10-12 Golf club head

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2006305003 2006-11-10
JP2006-305003 2006-11-10

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US13/650,983 Continuation-In-Part US20130102412A1 (en) 2006-11-10 2012-10-12 Golf club head

Publications (1)

Publication Number Publication Date
US20080113825A1 true US20080113825A1 (en) 2008-05-15

Family

ID=39369894

Family Applications (1)

Application Number Title Priority Date Filing Date
US11/937,868 Abandoned US20080113825A1 (en) 2006-11-10 2007-11-09 Golf club head

Country Status (2)

Country Link
US (1) US20080113825A1 (enExample)
JP (1) JP5084454B2 (enExample)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100273567A1 (en) * 2010-02-24 2010-10-28 Sri Sports Limited Golf club
US20140100055A1 (en) * 2010-05-12 2014-04-10 Callaway Golf Company Hosel construction
US8758156B2 (en) 2009-05-13 2014-06-24 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US8821309B2 (en) 2009-05-13 2014-09-02 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US8821311B2 (en) 2009-05-13 2014-09-02 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US8951142B2 (en) 2010-02-24 2015-02-10 Sri Sports Limited Golf club
US20160016053A1 (en) * 2011-01-04 2016-01-21 Karsten Manufacturing Corporation Golf club heads with apertures and methods to manufacture golf club heads
US9370696B2 (en) 2009-05-13 2016-06-21 Nike, Inc Golf club assembly and golf club with aerodynamic features
US20160250534A1 (en) * 2011-01-04 2016-09-01 Karsten Manufacturing Corporation Golf club heads with apertures and filler materials
US9526954B2 (en) 2012-05-31 2016-12-27 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US20170312599A1 (en) * 2014-05-20 2017-11-02 Gisle Solhaug Golf Club Head Having Center of Gravity Offset
US10729944B2 (en) 2014-07-11 2020-08-04 Sumitomo Rubber Industries, Ltd. Wood golf club with curved weight inside hollow body
US20220249922A1 (en) * 2021-02-05 2022-08-11 Sumitomo Rubber Industries, Ltd. Golf club head
US20230020888A1 (en) * 2013-12-31 2023-01-19 Taylor Made Golf Company, Inc. Golf club
US20230173357A1 (en) * 2021-12-07 2023-06-08 Acushnet Company Low drag clubhead with asymmetric aft portion
US20230271067A1 (en) * 2020-03-24 2023-08-31 Acushnet Company Golf club head with improved variable thickness striking face
US20230321502A1 (en) * 2019-07-02 2023-10-12 Sumitomo Rubber Industries, Ltd. Golf club head with external and internal ribs

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5714793B2 (ja) * 2008-10-07 2015-05-07 ブリヂストンスポーツ株式会社 ゴルフクラブヘッド
JP5404921B2 (ja) * 2009-05-13 2014-02-05 ナイキ インターナショナル リミテッド 空気力学的特徴を有し特定の形状のクラブヘッドからなるゴルフアセンブリおよびゴルフクラブ
JP5715520B2 (ja) * 2011-07-28 2015-05-07 ダンロップスポーツ株式会社 ゴルフクラブヘッド及びその評価方法
CN104060123A (zh) * 2013-03-19 2014-09-24 复盛应用科技股份有限公司 高尔夫球杆头合金及以该合金制作高尔夫球杆头的方法
JP6717332B2 (ja) * 2018-03-20 2020-07-01 ヤマハ株式会社 ウッド型ゴルフクラブヘッド
JP7528667B2 (ja) * 2019-09-27 2024-08-06 ヤマハ株式会社 ゴルフクラブ

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040259663A1 (en) * 2001-06-05 2004-12-23 Earl Grim Impact point development for golf clubs
US7258626B2 (en) * 2004-10-07 2007-08-21 Callaway Golf Company Golf club head with variable face thickness
US7390269B2 (en) * 2005-01-03 2008-06-24 Callaway Golf Company Golf club head
US7568985B2 (en) * 2002-11-08 2009-08-04 Taylor Made Golf Company, Inc. Golf club head having movable weights

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11155982A (ja) * 1997-11-28 1999-06-15 Bridgestone Sports Co Ltd ゴルフクラブヘッド
AU2005323014A1 (en) * 2005-01-03 2006-07-13 Callaway Golf Company Golf club head

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040259663A1 (en) * 2001-06-05 2004-12-23 Earl Grim Impact point development for golf clubs
US7568985B2 (en) * 2002-11-08 2009-08-04 Taylor Made Golf Company, Inc. Golf club head having movable weights
US7258626B2 (en) * 2004-10-07 2007-08-21 Callaway Golf Company Golf club head with variable face thickness
US7390269B2 (en) * 2005-01-03 2008-06-24 Callaway Golf Company Golf club head

Cited By (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8821311B2 (en) 2009-05-13 2014-09-02 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US9802085B2 (en) 2009-05-13 2017-10-31 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US9956459B2 (en) 2009-05-13 2018-05-01 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US8758156B2 (en) 2009-05-13 2014-06-24 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US9375617B2 (en) 2009-05-13 2016-06-28 Nike, Inc Golf club assembly and golf club with aerodynamic features
US8821309B2 (en) 2009-05-13 2014-09-02 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US9370696B2 (en) 2009-05-13 2016-06-21 Nike, Inc Golf club assembly and golf club with aerodynamic features
US9314677B2 (en) 2009-05-13 2016-04-19 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US8784231B2 (en) 2010-02-24 2014-07-22 Sri Sports Limited Golf club
US20100273567A1 (en) * 2010-02-24 2010-10-28 Sri Sports Limited Golf club
US8951142B2 (en) 2010-02-24 2015-02-10 Sri Sports Limited Golf club
US8241139B2 (en) 2010-02-24 2012-08-14 Sri Sports Limited Golf club
US20160008674A1 (en) * 2010-05-12 2016-01-14 Callaway Golf Company Hosel construction
US20140100055A1 (en) * 2010-05-12 2014-04-10 Callaway Golf Company Hosel construction
US9526953B2 (en) * 2010-05-12 2016-12-27 Callaway Golf Company Hosel construction
US10994177B2 (en) 2011-01-04 2021-05-04 Karsten Manufacturing Corporation Golf club heads with apertures and methods to manufacture golf club heads
US11612793B2 (en) * 2011-01-04 2023-03-28 Karsten Manufacturing Corporation Golf club heads with apertures and filler materials
US11684832B2 (en) * 2011-01-04 2023-06-27 Karsten Manufacturing Corporation Golf club heads with apertures and methods to manufacture golf club heads
US20170225048A1 (en) * 2011-01-04 2017-08-10 Karsten Manufacturing Corporation Golf club heads with apertures and methods to manufacture golf club heads
US20160250534A1 (en) * 2011-01-04 2016-09-01 Karsten Manufacturing Corporation Golf club heads with apertures and filler materials
US10124224B2 (en) * 2011-01-04 2018-11-13 Karsten Manufacturing Corporation Golf club heads with apertures and filler materials
US10195498B2 (en) * 2011-01-04 2019-02-05 Karsten Manufacturing Corporation Golf club heads with apertures and methods to manufacture golf club heads
US10238927B2 (en) * 2011-01-04 2019-03-26 Karsten Manufacturing Corporation Golf club heads with apertures and methods to manufacture golf club heads
US20190126109A1 (en) * 2011-01-04 2019-05-02 Karsten Manufacturing Corporation Golf club heads with apertures and methods to manufacture golf club heads
US10576336B2 (en) * 2011-01-04 2020-03-03 Karsten Manufacturing Corporation Golf club heads with apertures and methods to manufacture golf club heads
US10625129B2 (en) 2011-01-04 2020-04-21 Karsten Manufacturing Corporation Golf club heads with apertures and filler materials
US11000744B2 (en) * 2011-01-04 2021-05-11 Karsten Manufacturing Corporation Golf club heads with apertures and filler materials
US20160016053A1 (en) * 2011-01-04 2016-01-21 Karsten Manufacturing Corporation Golf club heads with apertures and methods to manufacture golf club heads
US9526954B2 (en) 2012-05-31 2016-12-27 Nike, Inc. Golf club assembly and golf club with aerodynamic features
US20230020888A1 (en) * 2013-12-31 2023-01-19 Taylor Made Golf Company, Inc. Golf club
US20170312599A1 (en) * 2014-05-20 2017-11-02 Gisle Solhaug Golf Club Head Having Center of Gravity Offset
US10729944B2 (en) 2014-07-11 2020-08-04 Sumitomo Rubber Industries, Ltd. Wood golf club with curved weight inside hollow body
US20230321502A1 (en) * 2019-07-02 2023-10-12 Sumitomo Rubber Industries, Ltd. Golf club head with external and internal ribs
US20230271067A1 (en) * 2020-03-24 2023-08-31 Acushnet Company Golf club head with improved variable thickness striking face
US12201880B2 (en) * 2020-03-24 2025-01-21 Acushnet Company Golf club head with improved variable thickness striking face
US20220249922A1 (en) * 2021-02-05 2022-08-11 Sumitomo Rubber Industries, Ltd. Golf club head
US11666805B2 (en) * 2021-02-05 2023-06-06 Sumitomo Rubber Industries, Ltd. Golf club head
US20230173357A1 (en) * 2021-12-07 2023-06-08 Acushnet Company Low drag clubhead with asymmetric aft portion

Also Published As

Publication number Publication date
JP2008136861A (ja) 2008-06-19
JP5084454B2 (ja) 2012-11-28

Similar Documents

Publication Publication Date Title
US20080113825A1 (en) Golf club head
US10213662B2 (en) Golf club head having stiffening members and variable face thickness
US10201733B2 (en) Golf club head with structural columns
US9855476B2 (en) Golf club head with structural columns
US9776058B2 (en) Golf club head having optimized ball speed to CT relationship
US7857713B2 (en) Wood-type golf club head
US6669577B1 (en) Golf club head with a face insert
US8167737B2 (en) Wood-type golf club head
US10406408B1 (en) Golf club head having stiffening members and variable face thickness
US7883431B2 (en) Golf club head
JP4326559B2 (ja) ゴルフクラブヘッド
US7942759B2 (en) Golf club head
US8038546B2 (en) Wood-type golf club head
US20030064825A1 (en) Wood-type golf clubhead
US20030036442A1 (en) Golf club head having a high coefficient of restitution and method of making it
US20070117648A1 (en) Golf club head
US20050101404A1 (en) Golf club head with localized grooves and reinforcement
US10850168B2 (en) Golf club head
CN110354467B (zh) 具有结构柱的高尔夫球杆头
US7766765B2 (en) Wood-type golf club head
US20070105656A1 (en) Golf club head
US20130102412A1 (en) Golf club head
JP2019165905A (ja) ゴルフクラブセット
US9814946B2 (en) Golf club head
KR20170099388A (ko) 최적의 볼 속도 대(對) 특성 시간(ｃｔ) 관계를 갖는 골프 클럽 헤드

Legal Events

Date Code Title Description
AS Assignment

Owner name: K.K. ENDO SEISAKUSHO, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:FUNAYAMA, TOMONARI;SAKAI, TOMOYUKI;ARIYOSHI, KEN;REEL/FRAME:020342/0555

Effective date: 20071108

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION