Abstract:
A hybrid golf club face comprising: a surface having a metallic outer surface with an anisotropic composite material affixed to the inside of a metal wood head section in such an orientation to provide a restated hitting characteristic.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention is directed to the field of golf clubs. In particular, the present invention discloses a metal wood golf club utilizing composite anisotropic materials bonded or co-molded to an interior surface of a golf club striking head in order to achieve or alter a preset coefficient of restitution (COR).  
       BACKGROUND OF THE INVENTION  
       [0002]     The Coefficient of Restitution, or “COR,” relates to the energy transfer that occurs when one object collides with another. In terms of golf clubs, COR is directly related to the speed of a golf ball as it rebounds from a clubface. Generally, a club with higher COR will generate greater ball velocity, equaling more distance.  
         [0003]     COR is expressed as a percentage. To measure a club&#39;s COR, balls are fired at a clubface at a fixed speed, known as initial speed. The speed at which the balls rebound is known as rebound speed. The COR is generally equal to the rebound speed divided by the initial speed. For example, if the initial speed is 100 mph, and the rebound speed is 84 mph, the COR would be approximately 0.840. The Rules of Golf maintained by the USGA limits the COR on driving clubs to 0.830.  
         [0004]     In terms of distance, a player with a swing speed from 100 to 120 mph should gain about two yards for every one percent increase in COR. Players with slower swing speeds will generally gain less yardage.  
         [0005]     Maximizing the area of 0.830 COR and remaining within the constraints set forth by of the USGA has long been the principal goal of golf club manufacturers. Golf head manufacturers and developers have long since had to contend with appropriate mix of materials and constructions to maximize the 0.830 COR zone. Golf club heads have been constructed from a wide variety of materials over the years. A number of patents have issued in the area of golf clubs.  
         [0006]     U.S. Pat. No. 6,183,374 discloses a golf club shaft formed partially of an anisotropic material such that a fibrous angle of the anisotropic material and/or an orientation angle thereof is differentiated from other portions thereof partly in the circumferential direction of the golf club shaft and in at least one portion in a thickness direction thereof to deviate a principal elastic axis of the golf club shaft and a principal geometrical axis thereof from each other. When a plane parallel with an intersection line formed by the intersection of a front face of a club head and a horizontal plane and including the principal geometrical axis of the golf club shaft is set as a specified plane, the principal elastic axis of the golf club shaft is so positioned that a plane including the principal elastic axis and the principal geometrical axis intersect with the specified plane at an intersection angle of 45 degrees-90 degrees, with a region of 200 mm of the golf club shaft with respect to an end at a grip side thereof fixed.  
         [0007]     U.S. Pat. No. 6,605,007 discloses a golf club head provided with a hitting face and a body. The face has a central zone and an intermediate zone adjacent and surrounding the central zone. The central zone has a first flexural stiffness and the intermediate zone has a second flexural stiffness. The club head face is configured and dimensioned such that the first flexural stiffness is significantly greater than the second flexural stiffness such that upon ball impact with the face, the intermediate zone exhibits substantial deformation so that the central zone moves into the club head. At the same time, the central zone exhibits minimal deformation so that it moves into and out of the club head as a unit. Furthermore, the face exhibits a high coefficient of restitution.  
         [0008]     U.S. Pat. No. 5,643,546 discloses a pitch-type carbon fiber made from a pitch having a glass transition temperature width of at most 40 degrees C. as measured by a differential scanning calorimeter, a proportion of the optically anisotropic phase of at least 10% by volume, and a quinoline-insoluble content of at most 5% by weight, as a spinning raw material pitch.  
         [0009]     U.S. Pat. No. 6,440,008 discloses golf club having a club head with a striking plate composed of a composite material and having a thickness in the range of 0.010 to 0.250 inches is disclosed herein. The golf club head also has a coefficient of restitution greater than 0.8 under test conditions such as the USGA test conditions specified pursuant to Rule 4-1e, Appendix II, of the Rules of Golf for 1998-1999. The golf club head body is also composed of a composite material, and a weight strip is placed within a ribbon of the body.  
         [0010]     U.S. Pat. No. 6,228,473 discloses a plate-like carbon fiber-reinforced composite material comprising carbon fibers, wherein that the carbon fibers have a strain at compressive break of 1.7 to 5%, a tensile elastic modulus of 5 to 160 GPa, and a density of 1.5 to 1.9 g/cm 3  and further in that the composite comprising said carbon fibers cause no delamination by an impact energy of less than 1.4 J/mm in the test of compression after impact in accordance with JIS K 7089.  
         [0011]     U.S. Patent Application No. 2004/0048022 discloses a method towards construction and advantages of improved wavy composite structures made from wavy composite, unidirectional composites, and damping materials is revealed. By combining wavy composite laminae in various waveforms, offsets, angular orientations and material combinations, it is possible to provide axial, torsion, or shear properties equivalent to unidirectional materials but without the limitations related to fiber discontinuity, labor costs for fabrication, and weakness at seams where laminates overlap. By combining wavy composite layers with unidirectional crossplies, or by using woven mats with various fill fiber levels where the warp fibers are sinuously arranged, improved strength and damping is possible. Several examples of both wavy crossply laminates and unidirectional crossply laminates are analyzed and compared.  
         [0012]     While there have been previous attempts at maximizing the COR of golf clubs within regulation, those solutions have been directed to incorporating added materials such as forged titanium and weights in the club head, including the use of cone technologies. Those technologies have been complicated and expensive. Moreover, all have relied upon the use of isotropic materials. Isotropic materials produce equal properties in all planes of reference.  
         [0013]     There is a long felt need for a golf club head which can maximize a club&#39;s 0.830 COR zone at the legal limit without adding undue weight to the club head. The use of anisotropic materials such as graphite would improve club performance.  
         [0014]     It is an object of the present invention to provide a metal wood golf club head which incorporates anisotropic materials and fibers.  
         [0015]     It is a further object of the present invention to provide a golf club head in which the use of anisotropic fibers maximize the COR zone of the club head.  
         [0016]     It is a further object of the invention to provide a golf club head in which the COR can be varied and tuned.  
         [0017]     These and other objects of the invention will become apparent from the detailed description which follows.  
       SUMMARY OF THE INVENTION  
       [0018]     In accordance with the invention, a hybrid golf club face comprising: an interior striking surface having an anisotropic composite material affixed thereto in such an orientation to provide a preset hitting characteristic.  
         [0019]     In a further embodiment, a hybrid golf club face comprising: a shaped anisotropic reinforced material affixed to the interior of the striking area of a metal wood golf club head; the orientation of the shaped and anisotropic material determining the coefficient of restitution and the size of the optimal striking COR zone of the club head.  
         [0020]     In still a further embodiment, the invention is an anisotropic metal wood to meet a preset coefficient of restitution; a composite layer affixed to the interior of the club striking surface comprising a plurality of anisotropic graphite fibers positioned and oriented so as to provide a level of rigidity such that the coefficient of restitution can be preset. In preferred embodiment, the anisotropic material is a plurality of graphite fibers, and are embedded within a resin.  
         [0021]     In yet another embodiment, the invention is an anisotropic metal wood to meet a preset coefficient of restitution; a composite layer affixed to the interior of the club striking surface comprising a plurality of anisotropic graphite fibers positioned and oriented so as to provide a level of rigidity such that the coefficient of restitution can be preset. 
     
    
     DESCRIPTION OF THE FIGURES  
       [0022]      FIG. 1  is a perspective view of the present invention.  
         [0023]      FIG. 2  is a perspective view of an alternative embodiment.  
         [0024]      FIG. 3  is a side view of the anisotropic material affixed with a club face.  
         [0025]      FIG. 4  is an overhead view of the resin and fibers. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]     The present invention is described with reference to the enclosed detailed embodiment, wherein the same numbers are used. In particular, the present invention is directed to improved metal wood clubs which incorporate a composite, reinforced build up of an anisotropic fiber material such as graphite.  
         [0027]     Referring to  FIG. 1 , the present invention comprises a hybrid golf club face  10  comprising an anisotropic material such as fiber and graphite  12  affixed as an insert in the resin. The fibers and graphite are affixed to the inside club face  16 .  
         [0028]     The graphite crystal is one of the most anisotropic (meaning exhibiting properties with different values when measured along axes in different directions) bodies known. Anisotropy is the direct result of the layered structure with extremely strong carbon-carbon bonds in the basal plane. Properties of graphite crystals illustrating this anisotropy are shown in Table 1. Of particular interest for the electronics cooling market is the very high basal plane thermal conductivity (˜2000 W/mK) achievable in single crystal graphite.  
               TABLE 1                       Properties of Graphite Crystals at Room Temperature Property                   Value in Basal Plane       Value Across Basal Plane       Resistivity · m       0.40       ˜60       Elastic Modulus GPa       1020       36.5       Tensile Strength (est.) GPa       96       34       Thermal Conductivity       W/mK       ˜2000       10       Thermal Expansion oC − 1       −0.5 × 10−6         27 × 10−6                  
 
         [0029]     The anisotropy of the single crystal is carried over in the properties of commercial graphite materials to varying degrees. Graphites can be made with a very wide range of properties and degree of anisotropy depending on the selection of raw materials and processing.  
         [0030]     Referring to the  FIG. 4 , the present invention is directed to a composite build up of an anisotropic fiber  12  such as graphite embedded with a resin  15 . The fibers  12  and resin  15  is preferably a polymer and bonded or affixed to the inside of the club face  16  as shown in  FIG. 3 . The bonded material is anisotropic and is set in a preset orientation and thickness in order to maximize the tensile structure of the fibers. In this way, the rigidity of the club face and its COR can be precisely altered.  
         [0031]     By varying the orientation of the direction of the fibers  12 , the COR can be varied. The fibers provide a high tensile strength in a first direction. For this reason, the club head will exhibit the appropriate stiffness and COR.  
         [0032]     As shown in  FIGS. 1 and 2 , the composite material of the invention can be affixed the club head in a variety of shapes and configurations. The critical element is that the fibers be placed at a position with a proper orientation to maximize the size of the spot having a 0.830 COR. The resin/fiber matrix material can have a plurality of thicknesses, can have a plurality of fibers and can be placed in multiple locations.  
         [0033]     The present invention has been described with reference to the enclosed figures and detailed description It is to be appreciated that the true nature and scope of the present invention is to be determined with reference to the claims appended hereto.