Abstract:
A golf club having superior balance and sensory feedback which includes a shaft connected to a clubhead comprising two basic elements, an integrated hosel and body portion of relatively low mass and specific gravity which defines a striking surface and a distal toe portion and a heel portion of relatively high mass and specific gravity uniquely integrated with the combined hosel and body portion. In preferred embodiments the clubhead has a cylindrical striking surface, polar mass concentrations for optimum dynamic performance and a combination of unique sighting and alignment features which co-operate to provide optimum sensory perception and feedback. A body portion with a shaped striking surface surrounding a target point and a top surface with an identifying indicium is integrally formed with a hosel extending from the top surface of the body portion with a flat alignment surface configured to cooperate with the indium and thus enhance a golfer&#39;s alignment and stroking of the ball, thus providing resultant confidence and consistency.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This patent application claims priority to U.S. Provisional Patent Application No. 60/191,799, filed Mar. 24, 2000. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to the field of golf clubs, and more particularly, to the field of golf putters. 
     BACKGROUND OF THE INVENTION 
     The prior art has provided numerous golf clubs, and particularly, golf putters, that are designed to improve the performance of the golfer or otherwise enhance the golfing experience. For example, U.S. Pat. No. 3,042,405 to Karsten Solheim discloses a golf club having internal weights at the heel and toe ends of the club with two thin plates connecting them. U.S. Pat. No. 4,444,395 to Morton Reiss shows a golf putter having an elongated head. The head includes a low mass center section with a length at least 1½ times as long as the ball diameter and two more massive end sections. The sections have substantially the same transverse cross section forming a single continuous cylinder. A major portion of the mass is in the end portions which may be connected together longitudinally through the center section by two steel pins. The club shaft is secured to the head centrally in the center section. More recently, U.S. Pat. No. 5,090,698, issued to Thomas A. Kleinfelter, discloses a golf putter having a circular-cylinder clubhead with a striking face suspended between two flanges near the toe and heel respectively. This is said to provide a center of percussion extending along essentially the entire length of the clubhead to thereby provide an optimum strike against the ball even if the ball contact is off center. Another approach to putter shape, size and weight distribution is found in U.S. Pat. No. 5,938,543 to McGeeney et al. where a center section of the head is of relatively low mass density material and has a longitudinal dimension greater than one and one-half ball diameters. The head has higher density metallic heel and toe portions with an integrally formed hosel extending upwardly from the heel portion. The heel, center and toe portions extend depthwise from a striking surface to a back surface with a substantially uniform depthwise construction. 
     Numerous other golf clubs have been provided in the prior art described by the designers as enhancements of sound, balance, or human factor considerations. 
     Some golf clubs known in the art are said to have an awkward “feel” when striking a golf ball, believed to be in part because of the distribution of weight within the clubhead. In addition, while the prior art has provided other golf clubs that are said to have a proper feel and to be properly balanced, many of these golf clubs are unattractive and the physical appearance is distractive. Those configurations do not provide the optimum perspective to the golfer as the ball is addressed or audible response as the club strikes the ball. There thus exists a need in the art for a golf club that has an optimum feel, an appearance which supports concentration and a sighting perspective and audible response that optimize the relationship between golfer and putter. It is a general object of the invention to provide a club that satisfies the foregoing criteria. 
     Specifically, the general objects of the invention include the creation of a golf club, especially a putter, that provides sensual feed-back to the golfer for improved performance. The golfer, golf club and golf ball are connected during the swing and at impact to provide superior sensitivity to the action, a dynamic sense of balance and an enhanced “feel” which is fed back visually and by tactile sensations indicative of stroke quality. This is augmented by visual features whereby enhanced “sighting” is provided. The improved characteristics are believed to result from the shaft and a central body section with a uniquely configured striking surface that are integrated through a connective means. The function of the unique body/shaft configuration is augmented by the other structural and facial features of the invention as described and claimed. 
     SUMMARY OF THE INVENTION 
     The present invention provides a well-balanced golf club that satisfies the foregoing general objects. The golf club of the invention includes a shaft that has a handle end and a clubhead end. Means connects the clubhead end to a clubhead comprising two basic elements. The two basic clubhead elements are (1) a body portion defining a striking surface integrally related to an aligning surface, to a sighting surface and to the shaft and handle through connection means, and (2) polar weighting including a relatively massive distal toe portion and a similarly massive heel portion secured to the body at the toe end and heel end respectively. In a preferred embodiment, the body portion is secured between the heel and toe portions configured for optimum dynamic balance, inertial stability, sensitive golfer feed-back and related enhanced sighting. The body portion, shaft and connecting means are preferably of low mass density materials compared to the heel portion and toe portion to provide an optimum polar mass distribution. In one preferred embodiment, the toe portion and the heel portion are connected together through an integrally cast medial portion to form a shell by preliminary casting whereby the body is subsequently formed in the shell by a second casting step. This structure and procedure are disclosed in detail in International Patent Publication No. WO 01/10513, which is incorporated in its entirety in this application by reference. 
     By having the connecting means strategically located on the body, close to the heel portion and of the same low density material as the body and shaft, optimum weight distribution advantages are obtained. The body portion is visible as a flat top surface which assists the golfer in addressing the ball and aligning the club and ball for the putt. The configuration of the connecting means that may be a hosel includes a flat alignment surface which has a synergistic relationship to the body shape and has body/shaft interaction through the connection means. 
     In preferred embodiments of the invention, the clubhead body portion has a striking surface having a cylindrical surface configuration and preferably a cylindrical configuration the longitudinal axis of which is aligned with the longitudinal axis of the clubhead. The striking surface extends between the top surface and a bottom surface forming a portion of the sole of the club. The striking surface is defined by a central segment of a circle centered on the intended hitting spot that correlates with the sweet spot or center of gravity and the top and bottom surfaces. It is a portion of the striking face of the clubhead. 
     In a preferred embodiment, the combined shaft and body portion and the connecting means includes a reinforcing armature connecting the shaft and body portion, and the body portion is a generally rectilinear blade having an exposed striking surface, a sole surface, a sighting top surface and a rearward sole back shelf. The back configuration of the toe and heel portions may conform to the body. In another preferred embodiment the rear of the body portion is cut-away to define a rear sole shelf to further augment the polar mass distribution while the toe and heel portions are not cut away, thus provided augmented polar mass. However, the invention provides advantages in blade-type putters with or without a cut-away back and in mallet-type putters having various back configurations. The connecting means preferably includes a double offset portion to provide an upper portion aligned with the shaft axis and with the striking surface. 
     Other features and objects of the invention will be apparent from the following description of the invention. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     For clarity, the following nomenclature, adapted from the prior art, will be employed in the description. The ball striking surface or ‘strike face’ of the clubhead, which is intended to hit the golf ball, is located on the ‘front’ of the clubhead. The terms ‘top’ and ‘bottom’ assume that the clubhead is oriented as it would be if the golf club were held by a golfer in an at rest position, i.e., the bottom of the clubhead, also called the sole, would contact the ground when at rest. The heel of the clubhead is located longitudinally opposite the toe of the clubhead. The heel portion of the clubhead would be nearest the golfer when the golfer holds the club in an at rest position. The term “depth” refers to a dimension extending from the front to the back of the golf club. The terms “length” of the clubhead and “longitudinal” refer to a dimension extending from the heel end to the toe end. 
     FIG. 1 is an overview perspective of one embodiment of the invention; 
     FIG. 2 is a perspective view of the clubhead of the embodiment of the invention shown in FIG. 1; 
     FIG. 3 is a front elevation of the clubhead of FIG. 2 when in a putting position; 
     FIG. 4 is a perspective view of the clubhead of FIG. 2 showing the top and backside thereof; 
     FIG. 5 is a perspective view of the toe portion of the clubhead of FIG. 2 showing one interface configuration; 
     FIG. 6 is a fragmentary view taken on the line  6 — 6  of FIG. 5 further illustrating the interface thereof; 
     FIG. 7 is a perspective view of a clubhead toe fragment configured as shown in FIG. 2 showing an alternative interface; 
     FIG. 8 is a perspective view of the embodiment of FIG. 2 showing the striking face thereof and details of one embodiment of the body with a fragment of the shaft and the connecting means. 
     FIG. 9 is a cross-sectional view taken on the line  9 — 9  of FIG. 8; 
     FIG. 10 is a heel-end elevation view of the embodiment of FIG.  9 . 
     FIG. 11 is a perspective fragmentary view of another embodiment of the invention in the mallet configuration; 
     FIG. 12 is a rear fragmentary elevation of the embodiment of FIG. 11; 
     FIG. 13 is a sectional view taken on the line  13 — 13  of FIG.  12 . 
    
    
     DESCRIPTION OF THE INVENTION 
     The invention provides a golf club which may constitute any one of a set of golf clubs designed for the game of golf including, for example, a driver, a fairway “wood” or “iron” or other club. Preferably, however, the golf club of the invention is in the form of a putter and is thus designed to facilitate controlled golfer action in striking a golf ball on a relatively smooth, slightly yielding, playing surface to cause the golf ball to roll toward its intended target. The club is to impart a slight positive loft to the ball. With reference to FIG. 1, the golf club  10  has a clubshaft  11  which may be fabricated from graphite, a metal such as tubular steel or other conventional materials. In the preferred embodiment the shaft is made of graphite material or a fiberglass reinforced resin. At the golfer gripping end  12  of shaft  11 , an overlying grip  13  is provided which may be leather or a synthetic cover, and may have any conventional surface treatment and authorized shape. Opposite the gripping end  12 , the shaft  11  has a clubhead end  14  which is mounted to a clubhead  15  by a connecting means such as hosel  17 . 
     The clubhead  15  comprises two basic components, a central body portion  21  and polar masses including a heel portion  20  and a toe portion  22  (end portions). A connecting means such as hosel  17  includes a central portion  38  that provides an offset whereby the shaft  11  is aligned with a striking surface  28 . The connecting means may be an integrally formed portion of the body  21  as illustrated by hosel  17  in FIGS. 1-3. The connecting means may also be formed integrally with the shaft  11  and the body  21  in a single casting operation. The casting may be in graphite, a fiber filled resin or other appropriate low mass density material. 
     The casting may also comprise only the connecting means  17  and body  21 , as shown in FIGS. 1-3, or only the connecting means  17  and shaft  11 . The connecting means  17  may also be cast separately as a hosel and integrated with the shaft  11  and body  21  as by a fusion process or cementation adequate to provide physical integrity and aesthetic appeal. As shown in FIGS.  3  and  8 - 10 , in a preferred embodiment when the hosel  17  is integrally cast with the body portion  21  to form a body/hosel  16 , a reinforcing armature  24  integrates the two elements as described further hereinafter. If the hosel  17  is cast separately, it is integrated with the body  21  by armature  24 . In such a construction an aperture is provided in the body  21  to receive the lower end  36  of the hosel and the armature  24  (see FIG.  10 ). The hosel and body are appropriately cemented within the aperture. 
     The body portion  21  has a flat top surface  26  extending between similar top surfaces on end portions  20 ,  22 . The top surface has a back edge generally parallel with a striking surface  28 , and, in preferred embodiments the top elongate surface is narrower than the total depth of the club. There is a central point on the striking surface, identified in the Figures with cross-hairs  29 , which is related to the center of gravity of the clubhead and the so-called “sweet-spot.” In the embodiment of FIGS. 2,  3  and  10 , the body portion  21  has a cylindrical-type striking surface  28  which conforms to a similar cylindrical-type striking surface  30  on heel portion  20  and a striking surface  32  on the toe portion  22 . The striking surfaces  28 ,  30  and  32  align to define a clubhead striking face  46 . In the preferred embodiment, the striking face  46  comprises a segment of a right circular cylinder, the directrix  47  of which aligns with but is below and behind the longitudinal axis of the clubhead through the hit spot  29  (seen best in FIG.  3 ). In one preferred embodiment, that directrix is slightly below the longitudinal central axis of the clubhead, and the radius for the cylinder is 4.6 inches. Thereby, when the clubhead strikes a golf ball with an optimum stroke, it imparts a slight positive loft to the ball. In one standard configuration the tangent to the striking surface at the central longitudinal axis through cross-hairs  29  forms an angle of about 4° to the vertical, called the loft angle. 
     In the preferred embodiment an indicia is formed in the top surface  26  to assist the golfer in alignment and stroking. As shown in the drawings, the indicia is a straight groove  27 , normal to the striking surface  28  and aligned with the sweet spot  29 . The flat top surface  26  extends upwardly in the form of a flat surface  18  on hosel  17 . It has been found that the hosel flat surface  18  and the flat top surface  26  co-operate to provide a unique visual perception for the golfer. The indicia  27  on the top surface  26  aligned with the sweet spot  29  further enhances the alignment capability of the relatively narrow flat surfaces  26  and  18 . In one preferred embodiment the indicia  27  is formed as a transverse groove, either in the process of casting or molding the body  21 , or with an appropriate tool in a post-casting cutting operation. 
     The totality of the alignment system also includes coordination of the striking surface  28  with the flat surfaces  26  and  18  and indicia  27 . The striking surface  28  has upper and lower longitudinal edges conforming to top surface  26  and sole  25 . The heel edge  31  and toe edge  33  are segments of a circle extending between the upper and lower edges. The radius  23  of the circle that determines the heel and toe edges of the striking surface is greater than the radius of a golf ball but less than 1.5 times the radius of a golf ball. One standard golf ball has a diameter of 1.68 inches. In one preferred embodiment, the radius  23  is 1.25 inch. 
     As shown best in FIG. 3, the center for the heel edge  31  and toe edge  33  is shown as cross-hairs  29  and a golf ball  19  is shown in broken lines centered on the crosshairs  29 . As previously mentioned, the cross-hairs  29  locate what is perceived to be the optimum point of impact with the ball, related to the center of gravity, center of momentum and the so-called “sweet spot.” 
     The impact point at  29  is at about the midpoint between sole surface  25  and top surface  26 . The height of the striking surface  28  is preferably in the range of about 0.8 inch to about 1.2 inch. 
     The body  21  is shown in FIG. 3 cast as an integral non-metallic unit with hosel  17  surrounding armature  24 . The armature  24  strengthens and integrates the body portion  21  and hosel  17 . As shown in FIG. 8, a reduced diameter portion  42  of hosel  17  is configured to receive a hollow cylindrical portion  44  of the clubhead end  14  of the shaft  11 . The outer diameter of the clubhead end  14  of shaft  11  is substantially the same as the outer diameter of the upper shaft portion  40  of hosel  17 . The shaft and hosel are sealed in an aligned abutting relationship. In embodiments where the shaft  11  and connecting means  17  are cast simultaneously, that part will include the armature  24  as shown in FIGS. 3 and 8 and the integrally formed connecting means  17  and shaft  11  may appear to be and actually be seamless. 
     In embodiments with the hosel  17  formed as a separate connecting means, the body  21  has a generally vertical aperture extending from the top surface  26  to a location above the sole  25  and having a cross-section to closely receive an extension (shown as broken lines  35  in FIG. 10) of the hosel  17 . 
     A fairing  34  blends the clubhead portion  36  of hosel  17  to the heel portion  20  while, in the preferred embodiment, a gradual curved surface  48  joins the flat surface  18  on the body side of the hosel clubhead portion  36  with the top surface  26  of the body  21 . The flat surfaces  18 ,  26  and  48  provide an aesthetic as well as visually advantageous pattern to the golfer for sighting as the club addresses the ball. As shown in FIG. 2, the front side of the clubhead end  36  of hosel  17  has a flattened surface  50  which joins and blends with the striking surface  28  of body portion  21 . Similarly, as shown in FIG. 4, the straight portion  36  of hosel  17  has a flattened surface  52  which joins and blends with the rear surface  53  of the body portion  21  above a sole shelf  55 . Shelf  55  extends rearwardly from the upright portion  59  of the body  21 . 
     As discussed above, a preferred embodiment of the invention shown in the Figures employs a clubhead of the cutaway blade type. In this embodiment the body portion  21  is cut away as best shown in FIGS. 2 and 4 to provide the upright striking section  59  and a horizontal shelf section  55  which extends to the rear edge of the head between the toe portion  22  and heel portion  20 . The shelf  55  cooperates with the toe and heel portions to define the rear section of the sole  25 . 
     A putter  110  constructed according to the invention and of the mallet type is shown in FIGS. 11-13. The body  121 , connecting means  117  with the offset portion  138 , the heel end portion  120  and toe end portion  122  conform to the teaching with respect to FIGS. 1-10. The high mass heel end portion  120  and toe end portion  122  will have interfaces as exemplified in FIGS. 5-7 and will comprise inserts in the mold when the body  121  is cast. 
     The connecting means  117  may be simultaneously cast with the body  121  to form an integral part or cast separately and appropriately integrated by fusion or cementation, as already described above. Similarly, the shaft, extending upwardly from the shaft portion  140  of the connecting means, may be cast in graphite or other materials of similar specific gravity and physical characteristics simultaneously with the body  121  and connecting means  117 . Such procedures and embodiments have already been described above. 
     The incorporation of an armature in these embodiments, whether the parts are cast simultaneously or not, is believed to provide worthwhile improvement in strength, reliability and structural integrity. Moreover, the sighting indicia  127 , flat hosel face  118  and other features described above are advantageously incorporated in the mallet-type putter  110 . As best seen in FIG. 13, the rearwardly extending sole shelf  155  is significantly extended beyond that shown in FIGS. 1-10. Similarly, the toe end  122  and heel end  120  have a more bulbous and massive appearance and feel preferred by many golfers. The mallet-type putter, when configured according to this disclosure, accomplishes the advantages set forth above. The striking face has the loft and configuration described above to provide the sighting and dynamic benefits as well as the aesthetic appeal already described. 
     Referring to FIGS. 2 and 3 showing the clubhead configuration, the connecting means or hosel  17  is shown extending upwardly in clubhead section  36  with a curved intermediate section  38  and a straight shaft end  40 . The angle at which the shaft end  40  of hosel  17  engages and supports the shaft  11  is selected for optimum golfer comfort and accuracy. The angle  57  of the shaft  11  and shaft end  40  of the connecting means  17  is preferably about 71° relative to the vertical and is sometimes referred to as the lie angle. In the preferred embodiment, the lie angle is correlated with the position of the connecting means on the body portion and the length of the shaft so that the golfer&#39;s line of sight along the toe edge of the shaft and hosel portion  40  generally passes close to the hitting spot as identified in FIG. 3 with cross hairs  29 . 
     In addition to forming the lie angle  57 , the central offset portion  38  of hosel  17  also defines a forward offset of the shaft axis relative to the striking surface. This determines the alignment of the shaft and consequently the golfer&#39;s line of sight relative to the striking face  46  as best shown in FIG.  10 . 
     The golf club of the invention may be fabricated of various materials employing various processing steps and manufacturing techniques. In the preferred embodiment the body  21  as well as the shaft  11  and connecting means  17  are fabricated of a graphite reinforced urethane. The heel portion  20  and toe portion  22  of the head are preferably of metal, and preferably high density metal such as alloys e.g., stainless steel. The heel and toe portions in preferred embodiments do not have the rearward section cut away to match the body upright section  59  and shelf  55 . This optimizes the polar weight distribution wherein 75-90 percent of the mass is in the end portions. 
     The preferred sequence for the manufacture of the golf club described herein is to cast the high mass heel portion  20  and toe portion  22  as separate component parts and in a subsequent operation employ those two component parts as inserts in an appropriate mold which defines the shape and nature of the body  21  disposed therebetween as well as the shaft  11  and connecting means  17 . Two preferred configurations for the heel portion and toe portion are shown in FIGS. 5-7 which enhance the structural integrity of the ultimate product. 
     FIG. 5 shows a toe portion  22  which can be employed as an insert in a casting operation. The interface of insert  22  with the body  21  to be formed includes a flat interface surface  56  which has a T-shaped tie or key  58  integrally formed therewith. This key rigidly, permanently and immovably secures the insert  22  to the body  21  after casting as shown in FIGS. 1-4. The key  58  includes a base  60  with a cross key  62  extending from the face  56  shown best in FIG.  6 . The insert  22  in FIG. 5 has the striking surface  32  with the cylindrical shape already described above. That striking surface  32  is cut away along the arc  64  to define a cavity between the recessed insert surface  66  and a congruent portion of the mold for the body  21 , not shown. Thus, while the insert interface  56  can be a flat surface, the cavity defined by surface  66  and the mold will form an arcuate extension of the body as identified by the arc  33  in FIG.  3 . The back side of the insert has a transverse exposed vertical face  68  and a shelf surface  70 . The shelf joins with the shelf  55  of body  21  and is sealed thereto. The mold for body  21  will define the surface of the body shelf  55  in alignment with the surface  70  of the insert. This configuration with the facia defined by surfaces  64  and  66  further enhance the polar mass distribution. 
     An alternate interface for the heel and toe portions  20  and  22  is shown in FIG.  7 . There, rather than the T-shaped key to lock the body and toe together, a set of pins  72  with heads  74  provide adequate locking of the inserts in the body that is cast therebetween. In all other respects the heel and toe portions of FIGS. 5 and 7 are the same. 
     While the material used to form the body, shaft and connecting means has been described as graphite fiber reinforced urethane, the material used may be selected from a group of materials having the strength and rigidity characteristics required for this application which might include styrene copolymers, copolyesters and polyurethanes. These may incorporate inorganic fillers. Similarly, while a stainless steel alloy is preferred for the high mass toe and heel portions, it is relatively expensive. Various materials having the proper mass densities could be employed and formed by appropriate processes. 
     While various embodiments of the invention have been described and incorporate various elements of the invention in different optimum combinations, the overall objectives of the invention and the specific enhancements described with respect to certain embodiments are all parts of the invention. It is contemplated that the invention may be implemented in such various combinations all of which are intended to be encompassed within the scope of the following claims.