Abstract:
A shaft structure with a configurable bending profile is provided for golf clubs, fishing rods, and the like. The shaft structure employs a plurality of tensioned sections. The golfer, in practice, configures the bending profile of a golf shaft by adjusting the internal pressure of the sections in order to change the stiffness of that section. The combination of sections and their associated stiffness results in an advantageous bending profile. The golfer can, at any time and very easily, change the bending profile of the golf shaft.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to shafts for golf clubs, fishing rods and the like; and more particularly where the overall bending profile of these devices can be configured by the golfer or user to match physical abilities. 
       BACKGROUND OF THE INVENTION 
       [0002]    Golf shafts and fishing poles are typically manufactured with a predetermined bending profile. The “bending profile” of a golf shaft refers to a distinct flex pattern that a conventional golf shaft exhibits when subjected to a force. The flex pattern is typically measured as the amount of deflection the shaft experiences when the shaft is positioned horizontally and subjected to a constant force. Presently, golf shafts are mass produced with a predefined and fixed bending profile without regard for a golfer&#39;s individual swing mechanics. Typically, these parameters are designed in an attempt to accommodate a vast multitude of golfers. 
         [0003]    Previous knowledge of golf shaft dynamics resulted in a general understanding that the stiffness of a golf shaft played a role in the performance of a golf club. However, it has been discovered that the overall bending profile of the shaft has much more to do with the performance of a golf club than merely its overall stiffness. The bending profile directly contributes to ball launch angle and spin, both of which can directly affect shot distance and accuracy. Additionally, the bending profile can influence club-head reaction and orientation before the clubface makes contact with the ball. 
         [0004]    Prevailing weather conditions can also affect optimum ball flight. For example, on a windy day, a golfer might choose to reconfigure their shaft for a bending profile that promotes a lower penetrating ball flight which reduces the affects of the wind. Conversely, on a day with little or no wind, a golfer may choose to configure the bending profile to promote a higher launch angle. 
         [0005]    Various proposals to provide variable stiffness for a golf club shaft (or even a fishing pole) have previously been made that involve using a hollow shaft charged with a gas or liquid fluid that can be pressurized and by mechanical devices such as rods, jackscrews and the like. Increasing the fluid pressure in the shaft increases the shaft stiffness. Increasing the length of the rod increases the tension and hence shaft stiffness. 
         [0006]    Such pressurizable shafts are illustrated, for example, by Menzies U.S. Pat. No. 1,831,255, Sears U.S. Pat. No. 2,432,450, Busch U.S. Pat. No. 3,037,775, Burrough U.S. Pat. No. 4,800,668 (a fishing rod), Simmons U.S. Pat. No. 5,316,300, Koch et al. U.S. Pat. No. 5,540,625, Painter U.S. Pat. No. 5,632,693 and Qualizza U.S. Pat. No. 7,226,365. 
         [0007]    So far as is known, these variable stiffness, hollow shaft structures of the prior art do not address changing a shaft&#39;s bending profile but rather have defined a device which indiscriminately promotes a stiffness change across the entire shaft and never addresses the ability to adjust the bending characteristics of the golf shaft. 
       SUMMARY OF THE INVENTION 
       [0008]    In order for a golf club to be effective and ultimately configured for a golfer by the golfer without requiring the golfer to have intimate knowledge or club-building skills, the present invention provides for a device whose performance characteristics can be easily changed to accommodate the golfer&#39;s abilities for any given day any given weather condition and course conditions as well. 
         [0009]    The present invention overcomes the inability of prior art shafts to create a unique bending profile. A shaft is provided which can be easily configured to create a variable bending profile that matches the golfer&#39;s abilities so as to maximize both shot accuracy and distance. 
         [0010]    More particularly, this invention relates to a shaft structure for golf clubs, fishing poles and like apparatus incorporating a variable, configurable bending profile shaft structure. The shaft structure consists of a plurality of sections which may be individually stiffened by virtue of applying a tension force to each individual section. The variable, configurable bending profile shaft does not require special tools or skills to affect the configuring of the bending profile. 
         [0011]    By adjusting the tension force in each of the sections and hence the stiffness of each section the golfer is able to accurately “tune” the bending profile of the shaft in order to maximize their skill level. 
         [0012]    One object of the present invention is to provide a shaft structure which allows a golfer to change the tension force of individual sections that in-turn changes the stiffness of the section and hence that portion of the golf shaft that is defined by the section. 
         [0013]    Another object allows for tuning golf shaft performance by creating a flex profile that results from the cooperation of a multitude of sections under tension. Each section under tension has a unique stiffness that is directly related to the amount of tension applied to a section. Increasing the tension increases the stiffness and reducing the tension reduces the stiffness. 
         [0014]    Another object of the present invention is to provide a shaft structure that has a selectable bending profile. Hence, a single assembled shaft structure can replace many different combinations and permutations of golf shafts, golf clubs, and manufacturing procedures and can avoid the need for large inventories of golf clubs with golf club shafts pre-set to different stiffness values, thereby effecting a saving of what would otherwise be an expenditure of substantial amounts of money. 
         [0015]    Another object of the present invention is to provide a golf club shaft structure which allows a golfer to customize the bending profile of each shaft of a set of clubs, or of a fishing pole, according to his ability or wishes without being dependent upon the shaft stiffness that happens to result from shaft manufacturing procedures as in the prior art. 
         [0016]    Other and further objects, aims, features, advantages, applications, embodiments and the like regarding the present invention will be apparent to those skilled in the art from the present specification, attached drawings, and appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which, like reference numerals identify like elements, and in which: 
           [0018]      FIG. 1  illustrates a perspective view of one embodiment of a golf club which incorporates a shaft structure of the present invention; 
           [0019]      FIG. 2  illustrates a diagrammatical view of the butt section of the shaft structure of  FIG. 1 ; 
           [0020]      FIG. 3  illustrates a diagrammatical view of the mid and tip sections of the shaft structure shown in  FIG. 1 ; 
           [0021]      FIG. 4  illustrates a detailed view of a piston unit of the butt/mid section of shown in  FIG. 2 ; 
           [0022]      FIG. 5  illustrates a detailed view of a piston unit of the mid/tip section of shown in  FIG. 3 ; 
           [0023]      FIG. 6  illustrates an alternative embodiment of the piston unit as shown in  FIG. 4  and  FIG. 5 ; 
           [0024]      FIG. 7  illustrates an alternative embodiment of the present invention which reveals fill valves in lieu of the piston units as shown in  FIGS. 2 and 3 . 
           [0025]      FIG. 8  illustrates an alternative embodiment of the piston unit arrangement as shown in  FIG. 4  and  FIG. 5 ; 
           [0026]      FIG. 10  reveals another embodiment of the current invention that utilizes tensioning rods in lieu of the piston units as shown in  FIGS. 4 and 5 . 
       
    
    
     DETAILED DESCRIPTION 
       [0027]      FIG. 1  shows an illustrative golf club  20  that incorporates an embodiment of a shaft structure  21  of the present invention. In the preferred embodiment, shaft structure  21  includes separate, internal sections under tension which may be tensioned to different levels. Three separate, internal, sections  22 ,  23  and  24  are shown to illustrate the present invention. Fewer or additional separate, internal tensioned sections are within the scope of the present invention. In the preferred embodiment the tensioning of each section  22 ,  23  and  24  occurs from a fluid being pressurized internally to each section. As well known in the art shaft structure  21  may be made from graphite, ferrous metal such as steel, non-ferrous metal such as aluminum or titanium and the like, plastics, nylons, aramids or any combinations of material. 
         [0028]    Tensioned section  22  may be affixed at one end of a conventional club head  30  (not detailed structurally) and tensioned section  24  connects at one end to a circumferentially extending, conventional golf grip  25  (not detailed structurally). 
         [0029]    Tensioned section  22  defines a section of the shaft structure  21  which is typically referred to as the tip section; tension section  23  is often referred to as the mid section of the shaft structure  21  and tensioned section  24  is often referred to as the butt section of the shaft structure  21 . 
         [0030]    In the preferred embodiment and referring to  FIG. 2 , butt section  24  is defined by a proximal and distal end. The distal end of butt section  24  is further defined by piston unit  26 . Proximal end is defined by piston unit  31 . 
         [0031]    With reference to  FIG. 3  the proximal end of the mid section  23  is defined by piston unit  26  and at the distal by piston unit  29 . Tip section  22  is defined at the proximal end by piston unit  29  and by bulkhead  68  at the distal end. The distal end of tip section  22  connects to hose  27  of golf club head  30 . Those skilled in the art will recognize and appreciate that a plurality of tensioned sections as well as a plurality of tensioning means can be incorporated and that such an arrangement does not deviate from the scope and spirit of the present invention. 
         [0032]    With attention toward  FIG. 2  therein is shown in detail butt section  24 . Conventional golf grip  25  is connected to butt section  24  by a standardized process. The distal end of the butt section  24  is defined by piston unit  26 . Additionally, positioned within the proximal end of butt section  24  is piston unit  31  which includes piston  33 , piston seal  34 , bulkhead  39 , jackscrew  43  and stiffness indicator  41 . Fluid  37  resides within butt section  24  as defined by piston unit  26  at the distal end and by piston unit  31  at the proximal end. Jackscrew  43  has at one end a hex cap arrangement that allows for the inserting of a hex wrench in order to facilitate the turning of jackscrew  43 . The turning of jackscrew  43  in cooperation with the threaded arrangement between jackscrew  43  and bulkhead  39  causes piston  33  to move up and down accordingly. Fluid  37  may be a gas, liquid or other material sufficient to carry the forces as presented by the change in volumes as facilitated by the position of piston  33 . Those skilled in the art will recognize that a multitude of other materials may be used as fluid  37  and that using other materials does not deviate from the scope or the intention of the current invention. 
         [0033]    Referring to  FIG. 4  therein shown in detail is a representation of piston unit  26 . In particular, piston unit  26  is comprised of piston  50 , piston seal  52 , spline  62 , wall spline  64 , stay collar  58  and stiffness indicator  60 . Piston unit  26  serves to define both the butt section  24  above and mid section  23  below. Piston  50 , in cooperation with piston seal  52 , serves to maintain pressure in both butt section  24  and mid section  23 . The representative pressure in butt section  24  as maintained by piston unit  31  at the proximal end and piston unit  26  at the distal end serves to promote an axial tension force upon the butt section  24  of shaft structure  21  that is located between piston  33  of piston unit  31  and piston unit  26 . The axial tension force creates a corresponding increase or decrease in stiffness in the butt section  24  of the shaft structure  21 . The stiffness of butt section  24  is indicated by stiffness indicator  41  as viewed through window  12  directly affixed to and made part of shaft structure  21  ( FIG. 1 ). When a desired stiffness is achieved piston unit  26  is locked in place by the cooperative engaging of spline  62  with wall spline  64 . In free-movement spline  62  of piston unit  26  is not engaged with wall spline  64  and therefore is free to traverse up or down. The location of piston unit  26  serves to increase/decrease the volume of mid section  23  while simultaneously decreasing/increasing the volume of butt section  24  and hence a corresponding increase/decrease in pressure of the respective sections  23  and  24 . When a desired pressure is reached within mid section  23  as defined by the position of piston unit  26 , stay collar  58  adjusting hex screw  54  is turned in order to decrease the circumference of stay collar  58 . This in turn slightly reduces the diameter of shaft structure  21  which then prompts spline  62  to cooperatively engage with wall spline  64 . The wall of the shaft structure  21  adjacent to stay collar  58  is sufficiently thin enough so as to allow the reduction of the diameter of stay collar  58  to effect the engagement of spline  62  with wall spline  64 . The combination of stay collar  58  and the wall of shaft structure  21  at the point of contact provides for structural integrity. In this manner piston unit  26  is effectively locked in place. With piston unit  26  locked in place a pressure is developed within butt section  24  as defined by the position of piston  30 . In this manner a unique, independently stressed butt section  24  of shaft structure  21  occurs. 
         [0034]    Referring to  FIG. 5  therein is shown in further detail a representation of piston unit  29 . In particular, piston unit  29  is comprised of piston  70 , piston seal  72 , spline  82 , wall spline  84 , stay collar  78  and stiffness indicator  80 . Piston unit  29  serves to define both the mid section  23  above and tip section  22  below piston unit  29 . Piston  60 , in cooperation with piston seal  62 , serves to maintain pressure in both mid section  23  and tip section  22 . The representative pressure in mid section  23  as maintained by piston unit  26  at the proximal end and piston unit  29  at the distal end serves to promote an axial tension force upon the section of the shaft  21  that is located between piston unit  26  and piston unit  29 . The axial tension force creates a corresponding increase or decrease in stiffness in the mid section  23  of shaft structure  21 . The stiffness of mid section  23  is indicated by stiffness indicator  80  as viewed through window  10  which is affixed to and made part of shaft structure  21  ( FIG. 1 ). Piston unit  29  is locked in place by the cooperation of spline  82  with wall spline  84 . In free-movement spline  82  of piston unit  29  is not engaged with wall spline  84  and therefore is free to move. When a desired pressure is reached which is, in part, defined by the position of piston unit  29  stay collar  78  hex adjusting screw  74  is turned in order to decrease the circumference of stay collar  78 . This in turn reduces the diameter of shaft structure  21  at that point which then causes spline  82  to cooperatively engage wall spline  84 . The combination of stay collar  78  and the wall of shaft structure  21  at the point of contact provides for structural integrity. In this manner piston unit  29  is effectively locked in place. With piston units  26  and  29  locked in place and with the corresponding loads carried by the piston units  26  and  29  a unique tension exists within the mid section  23  of shaft structure  21  as defined by piston units  26  and  29 . The unique tension exhibits an axially tension force within this section and a corresponding stiffness results within the mid section  23  of shaft structure  21 . 
         [0035]    With reference to  FIG. 3  tip section  22  is defined by piston unit  29  at the proximal end and by bulkhead  68  at the distal end. Piston unit  29 , in cooperation with bulkhead  68 , serves to maintain pressure in tip section  22 . The representative pressure in tip section  22  as maintained by piston unit  29  at the proximal end and bulkhead  68  at the distal end serves to promote an axial tension force upon the tip section of shaft structure  21  that is located between piston unit  29  and bulkhead  68 . The axial tension force creates a corresponding increase or decrease in stiffness in the section of the shaft structure  21 . The stiffness of the tip section  22  is indicated by stiffness indicator  80  as viewed through window  8  ( FIG. 1 ). 
         [0036]    Configuring a unique bending profile is defined by the pressure in each individual section  22 ,  23  and  24  which in-turn creates a unique axial tension force in each section  22 ,  23  and  24  which further promotes a stiffness in each section  22 ,  23  and  24  that is unique to that section. Piston units  26  and  29  are sufficiently small enough and strategically placed so as to accurately control the position and length of the individual sections  22 ,  23  and  24 . Those skilled in the art will recognize that a plurality of sections may be incorporated into the present invention as well as further means to ideally locate and define each section and that doing so does not deviate from the scope or the spirit of the present invention. 
         [0037]    As an alternative, a spline section similar in design to spline sections  64  and  84  may run the entire length of shaft structure  21 . In this manner sections  22 ,  23  and  24  can be defined to be a large or as small as the golfer may favor. Additionally, those skilled in the art will recognize that a multitude of locking device may be discovered to lock both piston units  26  and  29 . As well piston unit  31  may be served by a multitude of different devices and that such devices does not deviate from the scope nor the spirit of the current invention. 
         [0038]    In practice and when a golfer chooses to adjust the bending profile the golfer will first loosen stay collars  58  and  78  for piston units  26  and  29  respectively. The golfer then turns jackscrew  43  via a hex wrench. Clockwise movement of jackscrew  43  causes piston  33  of piston unit  31  to move downward (with reference to  FIG. 2 ). Counter-clockwise movement of jackscrew  43  causes piston  33  of piston unit  31  to move upward (with reference to  FIG. 2 ). A downward movement of piston  33  compresses fluid  37 . Compression of fluid  37  exerts a force upon piston unit  26  causing piston unit  26  to move downward. Movement of piston unit  26  compresses fluid  35  ( FIG. 3 ). Compression of fluid  35  promotes a force upon piston unit  29  causing piston unit  29  to move downward. Movement of piston unit  29  compresses fluid  31 . Continued clockwise turning of jackscrew  43  continues the process until the desired stiffness is reached in tip section  22  as indicated by stiffness indicator  80  as viewed through window  8  located on shaft structure  21 . At this time the golfer tightens stay collar  78  which effectively locks piston unit  29  in place. In this manner pressure in tip section  22  is maintained as well as isolating and segregating it from mid section  23  and butt section  24 . 
         [0039]    After configuring the stiffness in tip section  22  the golfer then adjusts the stiffness in mid section  23  by either turning jackscrew  43  clockwise to increase the pressure in mid section  23  or counter-clockwise to decrease the pressure. If an increase in stiffness for mid section  23  is required turning jackscrew clockwise further compresses fluid  37  which then exerts further pressure on piston unit  26  causing it to move downward. Further downward movement of piston unit  26  compresses fluid  35 . Since piston unit  29  is now locked in position pressure builds within mid section  23 . If a decrease in stiffness for mid section  23  is required turning jackscrew counter-clockwise will decompress fluid  37  which then reduces pressure on piston unit  26  causing it to move upward. Upward movement of piston unit  26  increases the volume within mid section  23  and therefore reduces the pressure which necessarily reduces the axial force and, hence, the stiffness. Movement of piston unit  26  continues until the required stiffness is achieved as indicated by stiffness indicator  60  and as viewed through window  10  located in shaft structure  21 . At this time stay collar  58  is tightened thereby restricting further movement of piston unit  26 . Therefore, a unique mid section  23  is defined by locked piston unit  26  and  29 . Mid section  23  then experiences a unique and isolated pressure. The unique pressure facilitates a unique stiffness within mid section  23 . 
         [0040]    Further turning of jackscrew  42  facilitates the final adjustment of butt section  24 . Turning jackscrew  43  clockwise serves to compress fluid  37  while turning jackscrew counter-clockwise serves to decompress fluid  37 . Since piston unit  26  is now locked in place pressure in butt section  24  will proportionately increase/decrease which serves to change the axially force upon the butt section  24  of shaft  21  which is defined at the proximal end by piston unit  31  and at the distal end by piston unit  26 . Stiffness indication of the butt section is indicated by indicator  41  as viewed through window  12  of shaft structure  21 . 
         [0041]    Given the ability to configure the stiffness of individual shaft  21  sections, a substantial bending profile can be obtained. For instance, if one were to desire a mid kick-point shaft structure  21 with a “soft tip” tip section  22  will require a pressure less than butt section  24 . However, because of the need for a mid kick tip section  22  pressure would be greater than mid section  23 . In this configuration stiffness indicators would reveal, as an example,  9 ,  5 ,  6  for sections  24 ,  23  and  22  respectively. Conversely, if one requires a low kick-point tip section  22  pressure would be less than both mid section  23  and butt section  24  pressure. Requiring a high kick-point would necessarily dictate pressure in tip section  22  and mid section  23  be greater than pressure in butt section  24 . 
         [0042]      FIG. 6  reveals another embodiment of locking piston units  26  and  29 . In this embodiment locking pawls  93  and  99  cooperates with detents  96  and  98  respectively when the piston unit  100  is locked into place. When the piston unit  100  is chosen to move magnetic collar  94  is placed over the shaft  21  in the appropriate position so as to cause pawl  93  and  99  to retract against springs  95  and  91  by virtue of the magnetic force between magnetic collar  94  and locking pawls  93  and  99 . With the retraction of locking pawls  93  and  99  piston unit  100  is allowed to move freely to another position so as to allow a greater or lesser pressure and hence a greater or lesser stiffness. When the appropriate stiffness is achieved magnetic collar  94  is removed causing pawls  93  and  99  to extend by virtue of the force imparted by springs  91  and  95  upon locking pawls  93  and  99 . Thus locking pawls  93  and  99  engage detents  96  and  98  respectively. 
         [0043]      FIG. 7  reveals an alternative embodiment wherein sections  24 ,  23  and  22  are fitted with micro-miniature valves  101 ,  104  and  108  respectively. Pressurized fluids  37 ,  35  and  31  would be introduced into the accompanying sections  24 ,  23  and  22  by virtue of miniaturized valves  101 ,  104  and  108 . In this manner pressurization units  26 ,  29  and  31  would be eliminated. 
         [0044]      FIG. 8  reveals yet another embodiment where each section has as an associated pressurization unit that is adjacent to and contiguous with the associated section. As an example and as shown, mid section  123  would be pressurized by piston  191  and seal  196 . Facilitating the movement up or down of piston  191  occurs through a longitudinal transaction as facilitated by jackscrew  192  in threaded cooperation with bulkhead  189 . The golfer would facilitate the turning of jackscrew  192  via hex detail  87  through slot  193  strategically placed in shaft structure  21 . 
         [0045]      FIG. 10  reveals another embodiment where tensioning of the sections  22 ,  23  and  24  occurs from an adjustable mechanical means located internal to each section  22 ,  23  and  24 . One such mechanical means could be an adjustable length rod  224 . The adjustable length rod  224  would serve to create a force on opposite ends of the adjustable length rod  224  which would transfer the force to the ends of section  23  by virtue of bulkheads  227  and  229 . In this manner the adjustable length rod  224  would serve to create a tension within the section  23 . The golfer adjusts the tension within each section by adjusting the length of the adjustable length rod  224  via hex arrangement  226 . Turning hex arrangement  226  causes the threaded arrangement  223  to turn as well causing adjustable rod  224  to expand or contract. Facilitation of turning hex arrangement  226  is via slot  225  in shaft structure  21 . Adjusting the adjustable length rod  224  to be longer increases the tension within a section and adjusting the adjustable length rod  224  to be shorter decreases the tension within a section. 
         [0046]    Although in the preferred embodiment three tensioned sections are shown those skilled in the art will readily recognize and appreciate that a plurality of tensioned sections can be used and in doing so does not deviate from the scope and the spirit of the present invention.