Abstract:
A golf club head comprises a front striking plate that in turn comprises a front striking surface, a rear surface, and a first boss generally centrally located on and attached to the rear surface. A rear body section is fixedly coupled to the front striking plate. A longitudinal member is adjustably coupled to the rear body section and has a first end configured for pivotal movement in engagement with the first boss. The longitudinal member applies a force of compression onto the rear surface of the striking plate.

Description:
FIELD OF THE INVENTION 
   This invention relates generally to golf clubs, and more particularly, to golf club heads commonly referred to as “woods” including clubs known as “drivers”. More particularly, this invention applies to such clubs that comprise a hollow, flat faced bulbous shape. 
   BACKGROUND OF THE INVENTION 
   Golf clubs of the type known as “woods” are commonly used in the sport of golf. The heads of such clubs may be made of metal (e.g. stainless steel), high-tech plastic, or reinforced plastic. If made of metal, these heads are sometimes referred to as “metal woods”. For purposes of this description, the use of the term “wood” shall be intended to include driving clubs made of metal, plastic, graphite, and the like. 
   Metal woods present numerous options to the golf club manufacturer to provide customized weight and balance for a golfer, whether amateur or professional. It is not uncommon for a golfer, in order to improve the accuracy of their game, to seek a club with an enlarged “sweet spot” (i.e. that area on the striking face of a club that, upon impact with the ball, will send the ball on a preferred trajectory, without hooking or slicing). In addition, most golfers prefer a golf club head that is generally lightweight but configured to perform as if a significant portion of its weight were located behind the sweet spot. Hollow metal heads may be engineered to incorporate these desired features into a given golf club. 
   A problem associated with some clubs is that the substantially flattened striking surface supported around its edge acts like a drum when struck. That is, the relatively thin metal striking plate is free to deflect upon impact and then rebound. The nature and direction of the rebound depends on the location of the point of impact on the striking surface and can affect the speed, rotation, and direction of the golf ball as it leaves the club-head, thereby affecting the trajectory of the ball. 
   U.S. Pat. No. 5,464,211 issued Nov. 7, 1995 and entitled “GOLF CLUB HEAD” attempts to solve this problem by providing a rigid, unyielding striking surface. A striking surface having an inner surface and an outer surface is coupled to an opposed rear portion to form the golf club head body. A partially threaded stem having an externally threaded proximal portion and a broadened distal portion with a substantially flat surface threadably engages an internally threaded cylinder within the head body such that when the stem is threaded into the head body, the distal flat surface of the broadened portion of the stem applies a compressive force to the inner surface of the striking face. The amount of force may be adjusted by turning the threaded portion of the stem. In this manner, the impact zone on the striking face of the club is rendered more rigid. 
   Unfortunately, the above described apparatus has certain disadvantages. For example, due to the rigid design of the jackscrew/stem assembly including the broadened distal end, and because the ball is not always struck at a location on the striking surface corresponding to the center of the broadened distal end of the stem, significant bending stresses are transmitted to the entire stem assembly eventually damaging the assembly with repeated use. 
   Accordingly, it would be desirable to provide an improved golf club head that provides a more rigid, unyielding striking surface or impact zone. It would further be desirable that the improved golf club head be sturdier and more reliable than prior art devices. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanied drawings and the background of this invention. 
   BRIEF SUMMARY OF THE INVENTION 
   According to an aspect of the invention, there is provided a striking plate for use on a golf club head. The striking plate comprises a front striking surface and a rear surface. A boss is generally centrally located and attached to the rear surface, and a recess is substantially centrally located in the boss. 
   According to a further aspect of the invention, there is provided a golf club head, comprising a front striking plate, the striking plate comprising a front striking surface and a first boss generally centrally located on and attached to the rear surface. A rear body section is fixedly coupled to the front striking plate. A longitudinal member is adjustably coupled to the rear body and has a first end configured for pivotal movement in engagement with the first boss. The longitudinal member applies a force of compression onto the rear surface of the striking plate. 
   According to a still further aspect of the invention, there is provided a golf club comprising a front striking plate that comprises a front striking surface and a first boss generally centrally located and attached to the rear surface. A rear body section is fixedly coupled to the front striking plate. A longitudinal member is adjustably coupled to the rear body and has a first end configured for pivotal movement in engagement with the first boss. The longitudinal member applies a force of compression onto the rear surface of the striking plate, and a gripping shaft is fixedly coupled to the rear body section. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and 
       FIGS. 1 ,  2 ,  3 , and  4  are front surface, rear surface, top, and side views respectively of a golf club striking plate in accordance with the present invention; 
       FIG. 5  is a top, partially cut-away view of a golf club head utilizing the striking plate shown in  FIGS. 1 ,  2 ,  3 , and  4  in accordance with the present invention; 
       FIG. 6  is a plan view of a jackscrew suitable for use with the golf club head shown in  FIG. 5 ; 
       FIGS. 7 and 8  are rear and front views respectively of the golf club head shown in  FIG. 5 ; and 
       FIG. 9  is partial cutaway view of a golf club head in accordance with a second embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The following detailed description of the invention is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description of the invention. 
     FIGS. 1 ,  2 ,  3 , and  4  are front, rear, top, and side views respectively of a novel striking plate  10  for use on a golf club head in accordance with the present invention. As can be seen in  FIGS. 3 and 4 , striking plate  10  may be slightly curved and have a generally flat striking surface  12  shown in  FIG. 1 . Striking surface  12  may be provided with a plurality of grooves  14  shown as horizontal, in  FIG. 1 ; however, it should be clear than any desired pattern of grooves may be utilized. 
   Striking plate  10  has a generally flat rear surface  16  except for a generally centrally located raised portion or boss  18  having a generally centrally located, spherical concavity or recess  20  therein. While boss  18  is shown as being generally circular, other shapes could be utilized. 
   Boss  18  may be formed integrally with the remainder of striking plate  10 . Thus, by way of example, striking plate  10  may have a thickness of approximately 0.09 inches at its flat, peripheral regions and increase to approximately 0.18 inches in the area of boss  18 . Recess  20  may have a depth of approximately 0.09 inches and a diameter of approximately 0.5 inches. Finally, if desired, a plurality of locating bosses  22  (shown only in  FIG. 2  for clarity) may be provided to assist in the placement of striking plate  10  when it is attached to the rear portion  24  ( FIG. 5 ) of the club head as, for example, by welding. 
     FIGS. 5 ,  7 , and  8  are top cutaway, rear, and front views respectively of a golf club head  26  in accordance with the present invention. Club head  26  is adapted at  28  with a housel fitted to an elongated shaft  30  terminating with a gripping portion  31  (shown only in  FIG. 8 ) that is held by a player using the golf club. Striking plate  10  is attached (e.g. welded) to a generally hollow, bulbous rear section  32  to form the golf club head. Both striking plate  10  and rear section may be made of stainless steel or other suitable material as previously mentioned. Furthermore, while the construction of the golf club head has been described as the joining of a striking plate  10  to a rear bulbous section  24 , it should be clear that other assembly techniques may be utilized without department from the spirit and scope of the invention. 
   A belled, internally-threaded tube  34  is fixedly coupled to a rear section  32  as is shown at  36  and is accessible through opening  38 . Internally threaded tube  36  is configured to threadably receive a jackscrew  40  therein through opening  38 . Jackscrew  40  comprises a threaded portion  42  and a stem  44  ( FIG. 6 ) having a rounded or hemispherical tip  48  that is matingly received within recess  20 . Jackscrew  40  may be turned by means of, for example a screwdriver inserted into slot  46 . If jackscrew  40  is rotated clockwise, tip  48  is brought into contact with the surface of recess  20 . Counter-clockwise rotation of jackscrew  40  will cause tip  48  to be extracted from recess  20 . 
   After tip  48  is brought into initial contact with the inner surface of recess  20 , further rotation of jackscrew  40  produces a force against the inside surface  16  of striking plate  10 , and an equal and opposite force drives tube  34  against the inside wall of the rear section  32 , placing the entire striking plate and tube system into compressive loading, which we refer to as a pre-stressed condition. This pre-stressing involves the skin of the club head as well as the striking plate, placing the skin in tension to balance the force being applied to the striking plate and belled tube system. The overall effect is to produce a club head that is more rigid than are those of the prior art, especially in the reaction of the club to impact on the face thereof. In this manner, the “sweet spot” of the club head has been substantially enlarged. 
     FIG. 9  is a top, cutaway view of an alternate embodiment of a golf club head in accordance with a present invention wherein like reference numerals denote like elements. In this embodiment, a second raised portion or boss  50  (e.g. generally hemispherical) is located substantially centrally on boss  18 . The tip of stem  44  includes a concavity  52  (e.g. generally hemispherical) for matingly receiving boss  50  in order to apply a force of compression on striking plate  10  as above described. 
   Thus, there has been provided an improved golf club that provides a more rigid, unyielding striking surface or impact zone. Jackscrew  40  and boss  18  generally have mating convex and concave hemispheres (or vice versa). Boss  18  and striking plate  10  are permitted to pivot with respect to tip  48  of stem  44 . Bending stresses and torque that result when a ball is struck result in a pivoting of striking plate  10 . Through this pivoting, these stresses are not transmitted to stem  44  and threaded section  42  of jackscrew  40 . Therefore such stresses are not transmitted to internally threaded tube  34 . This results in a sturdier golf club head. 
   While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient roadmap for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims.