Abstract:
A golf shaft spine locating apparatus is provided having a frame. A pair of vertical supports for the shaft are mounted to both ends of the frame. The shaft is placed on the supports and is rotated on the supports. A weight is applied to the shaft and exerts a downward force on the middle of the shaft between the supports while permitting rotary motion of the shaft on the supports. As the downward force is applied on the shaft and the shaft is rotated on the supports, the spine of the shaft is located.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a golf shaft spine locating apparatus. 
     BACKGROUND OF THE INVENTION 
     There are numerous brands and models of golf shafts. In the highly competitive sport of golf, differences in the type of equipment one uses can affect how well one performs. 
     A spine is a seam or junction on the shaft that is created during the manufacturing process. The spine runs the length of the shaft and is the strongest point on the shaft. The spine affects the flex of each shaft. All shafts have spines. For instance, sheet-wrapped graphite shafts, made with overlapping pieces of graphite, contain an easily identifiable spine. Steel shafts, particularly those with a butt weld, also have spines. Even computer-controlled filament-wound graphite shafts and extruded seamless metal shafts have irregularities in the nature of spines created during manufacture. 
     The alignment of the spine in the clubhead affects the performance of each golf club. This alignment of spines in a set of golf clubs can affect how each golf club performs in relation to the others in the set. If the spines are not set in the clubheads at the proper angle in relation to the clubface, the user will not get the most out of their golf clubs. As a result, some golf clubs of one set will perform differently than others in the same set. 
     The generally accepted position is when the spine is located at three o&#39;clock, or at the rear of the shaft with respect to the direction of club tread movement. 
     SUMMARY OF THE INVENTION 
     A golf shaft spine locating apparatus has a longitudinally elongated frame. A pair of supports for the shaft are upstanding from the frame and longitudinally spaced from one another. The shaft is placed on the supports and is rotatable on the supports. A weight is applied to the shaft for selectably exerting a force on the shaft at a position substantially mid-way between the supports while permitting rotary motion of the shaft on the supports. As force is applied on the shaft and the shaft is rotated on the supports, the spine of the shaft is located. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevation view of a golf shaft spine locating apparatus of the present invention showing a golf club in a flexed position in the apparatus; 
     FIG. 2 is a top view of the apparatus of FIG. 1 but without the golf club; 
     FIG. 3 is a bottom view of the apparatus of FIG. 1; 
     FIG. 4 is a front elevation view of a donut weight utilized with the apparatus of FIG. 1; 
     FIG. 5 is a left side elevation of the apparatus of FIG. 1 but with the pivoting arm in the raised position; 
     FIG. 6 is a right side elevation of the apparatus of FIG. 1 but with the pivoting arm in the horizontal lowered position; 
     FIG. 7 is a side exploded view of a spring assembly for support posts; 
     FIG. 8 is a left side elevation view of a golf shaft seating and rotating assembly of the apparatus of FIG. 1; and 
     FIG. 9 is a right side elevation view of the golf shaft seated in roller bearings of a right support post of the apparatus of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIG. 1, a golf shaft spine locating apparatus  20  is shown. The apparatus  20  has a base  22  on which left and right support posts  26 ,  28 , a central weight assembly  82 , and a golf shaft seating and rotating assembly  84  are mounted. 
     The apparatus  20  locates the spine  16  of a golf club shaft  10  so that the golf club shaft  10  can be positioned in the clubhead  12  in the proper position. The left and right support posts  26 ,  28  are mounted on the base  22  and support each end of the golf club shaft  10  in the apparatus  20 . The central weight assembly  82  is mounted on the center of base  22  and applies a downward force to golf club shaft  10 . The golf shaft seating and rotating assembly  84  is part of the right support post  28  and is utilized to seat and rotate the golf club shaft  10  in the left and right support posts  26 ,  28  as the central weight assembly  82  applies a downward force to the golf club shaft  10 . As a downward force is applied on the golf club shaft  10  and the golf club shaft  10  is rotated on the left and right support posts  26 ,  28 , the spine of the golf club shaft  10  is located. 
     Referring to FIGS. 1 and 2, the base  22  is rectangularly shaped with cutouts or slots  24  for mounting the left and right support posts  26 ,  28 . The left and right support posts  26 ,  28  support the ends of golf club shaft  10 . The left support post  26  supports the end of golf club shaft  10  connected to the clubhead  12 . The right support post  28  supports the end of golf club  10  connected to the grip  18 . Additionally, the right support post  28  is mounted to the golf shaft seating and rotating assembly  84  which is utilized to seat and rotate golf club shaft  10 . 
     Referring to FIGS. 3 and 7, the left and right support posts  26 ,  28  are spring mounted in the slots  24  of the base  22  with spring assemblies  70 . Both the left and right support posts  26 ,  28  preferably utilize identical spring assemblies  70 . As shown in FIG. 7, each spring assembly  70  includes a bolt  78 , a spring  74 , an upper cap  72  and a lower cap  76 . The bolt  78  is inserted through the lower cap  76 , the spring  74  and the upper cap  72 . To mount the left and right support posts  26 ,  28  on to base  22 , bolt  78  with the lower cap  76 , the spring  74  and the upper cap  72  in place, is inserted from the bottom of the base  22  through the slot  24  and is threaded into an aperture  86  in bottoms  88  of left and right support posts  26 ,  28 . The spring assembly  70  is then tightened by tightening head  80  of bolt  78  with a conventional Allen wrench. 
     Left and right support posts  26 ,  28  are longitudinally slidable within slots  24  for accommodating different shaft  10  lengths. To slide the left and right support posts  26 ,  28  within the slots  24 , the spring assembly  70  is loosened by loosening the head  80  of the bolt  78  with a conventional Allen wrench. The left and right support posts  26 ,  28  are then longitudinally slidable within slots  24  of the base  22 . After adjustment, the spring assembly  70  is tightened to hold left and right support posts  26 ,  28  in the desired positions. 
     Tops  90  of left and right support posts  26 ,  28  include roller bearings  34 . The roller bearings  34  allow rotational motion of golf club shaft  10  in the left and right support posts  26 ,  28 . The roller bearings  34  are standard roller bearings that are 0.005 inches apart. 
     Referring to FIGS. 8 and 9, the golf shaft seating and rotating assembly  84  is utilized to seat and rotate the golf club shaft  10  in left and right support posts  26 ,  28  as the central weight assembly  82  applies a downward force to the golf club shaft  10 . The seating and rotating assembly  84  is part of the right support post  28 . The seating and rotating assembly  84  includes a wheel actuation handle  32 , a wheel actuation shaft  33 , a rubber wheel  30 , and a wheel support  31 . 
     As shown in FIG. 8, the rubber wheel  30  is rotatably attached to the wheel support  31 . The wheel support  31  is attached to the right support post  28  and is vertically adjustable by pivotally rotating wheel actuation shaft  33  via wheel actuation handle  32  about a pivot pin  66 . By vertically adjusting the wheel support  31 , rubber wheel  30  is lowered into contact with the golf club shaft  10  or raised away from the golf club shaft  10 . When the rubber wheel  30  is lowered into contact with the golf club shaft  10 , the golf club shaft  10  can be rotated by rotating the rubber wheel  30 . 
     A portion  96  of the wheel actuation shaft  33  passes through a front  92  of the right support post  28 . Another portion  98  of the wheel actuation shaft  33  projects out from the front  92  of the right support post  28 . The wheel actuation handle  32  is threaded on to the free end of portion  98  of the wheel actuation shaft  33 . 
     The seating and rotating assembly  84  further includes a spring  60 , a bolt  62 , a roller  64 , a pivot pin  66 , and a reaction pin  68 . Inside right support post  28 , bolt  62  passes through the spring  60 . Roller  64  is attached to the wheel actuation shaft  33 . A head  63  of bolt  62  contacts roller  64 . Pivot pin  66  is located in the wheel actuation shaft  33 . Reaction pin  68  is located in wheel support  31  and engages portion  96  of the wheel actuation shaft  33 . 
     As wheel actuation shaft  33  is rotated counterclockwise about the pivot  66  via wheel actuation handle  32 , roller  64  releases pressure on head  63  of bolt  62  and spring  60  is decompressed. Wheel actuation shaft  33  pivots upward around pivot pin  66 . Portion  96  of wheel actuation shaft  33  lowers reaction pin  68  which in turn lowers wheel support  31 . As wheel support  31  lowers, rubber wheel  30  lowers into contact with golf club shaft  10 . 
     As wheel actuation shaft  33  is rotated clockwise about the pivot pin  66  via wheel actuation handle  32 , the roller  64  presses down on head  63  of bolt  62  and compresses spring  60 . Wheel actuation shaft  33  pivots downward around pivot pin  66 . Portion  96  of wheel actuation shaft  33  raises reaction pin  68  which in turn raises wheel support  31 . As wheel support  31  lifts up, rubber wheel  30  will also lift up and away from golf club shaft  10 . 
     Referring to FIGS. 2,  5  and  6  the central weight assembly  82  is mounted on the center of the base  22  and is utilized to apply a preferably downward force to golf club shaft  10 . As a downward force is applied on golf club shaft  10  and golf club shaft  10  is rotated on left and right support posts  26 ,  28 , the spine of golf club shaft  10  is located. The central weight assembly  82  includes a pivoting weight support  36 , an upstanding arm  38 , and an arm extension  40 . 
     The upstanding weight support  36  is mounted on the center of the base  22 . The pivoting arm  38  is pivotally rotatable within and about the upstanding weight support  36  by means of detent depressions  42  (not shown in the Figures) in the sides of the pivoting arm  38  within the upstanding weight support  36 . A weight support set screw  44  threadably resides within the weight support  36  and engages detent depressions  42  of pivoting arm  38 . The weight support set screw  44  can be tightened to hold pivoting arm  38  in the desired open or closed position. Pivoting arm  38  is shown in the open position in FIG.  5  and the closed position in FIG.  6 . 
     Referring again to FIG. 2, arm extension  40  is part of pivoting arm  38 . The free end of arm extension  40  contains a bore for receiving a weight extension shaft  48 . An arm extension set screw  47  is located on the end of arm extension  40  for retaining weight extension shaft  48  in position. The weight extension shaft  48  is a solid cylinder and preferably comes in three different lengths of 2 inches, 4 inches and 6 inches for providing different downward forces. 
     Donut weights  50  are attached to the free end of weight extension shaft  48  for providing downward force on the golf club shaft  10 . As shown in FIG. 4, donut weights  50  have 3 inch outside diameters and 1 inch diameter bores  51  for receiving the free end of weight extension shaft  48 . The donut weights  50  come in different sizes for providing different forces to different golf shafts  10 . For example, the donut weights  50  have thicknesses of 0.5 inch, 1 inch or 1.5 inches. Set screws  46  for donut weights  50  located on the outside diameter of the donut weights  50  are tightened to retain donut weights  50  on weight extension shaft  48 . 
     Referring to FIG. 2, a dial indicator support post  58  is mounted to base  22  and supports a dial indicator  52 . The dial indicator  52  reads the amount of relative deflection of the golf club shaft when downward force is applied by the central weight assembly  82  to golf club shaft  10 . As shown in FIGS. 5 and 6, the dial indicator  52  contains a adjustable bezel  56  for setting the dial indicator  52  to zero. Additionally, the dial indicator  52  contains a pointer stem  54  that is engaged by the pivoting arm  38  to indicate shaft deflection resulting from force applied to the golf club shaft  10  when the pivoting arm  38  is in the closed position shown in FIG.  6 . 
     With the foregoing description in mind, the golf shaft spine locating apparatus operates as follows: The first step is to make sure pivoting arm  38  of the central weight assembly  82  is in the open position and does not contact pointer stem  54  of dial indicator  52  as shown in FIG.  5 . Pivoting weight support set screw  44  engages detent depressions  42  in pivoting arm  38  to ensure pivoting arm  38  stays in the open position. At this point, golf club shaft  10  is not in apparatus  20 . 
     The left and right support posts  26 ,  28  are then longitudinally adjusted within the slots  24  of base  22  to accommodate the length of golf club shaft  10  being spined. The spacing between the left and right support posts  26 ,  28  should be close to the maximum length of golf club shaft  10  between the bottom of the grip  18  and the top of the hosel  14 . 
     As shown in FIG. 1, golf club shaft  10  is then placed in the apparatus  20 . The club head  12  end of the golf club shaft  10  is rested on roller bearings  34  of left support post  26 . The top end of golf club shaft  10  just below grip  18  is rested on roller bearings  34  of the right support post  28 . 
     Next, the golf shaft seating and rotating assembly  84  of the top support post  28  engages the right end of the golf club shaft  10 . As shown in FIG. 8, the wheel actuation handle  32  is rotated counterclockwise about the pivot pin  66  to lower rubber wheel  30  on to golf club shaft  10 . The rubber wheel  30  seats golf club shaft  10  on the roller bearings  34  of the right support post  28  as shown in FIG.  9 . 
     The pivoting arm  38  is then released from the open position shown in FIG.  5  and moved into the closed, or horizontal, position shown in FIG.  6 . The pivoting arm  38  is locked in the closed or horizontal position by utilizing the weight support set screw  44  to engage detent depressions  42  in pivoting arm  38 . 
     Once pivoting arm  38  is in the closed or horizontal position of FIG. 6, dial indicator  52  is set at the reference point or zero position. To set the dial indicator  52  at the zero position, the rotatable bezel  56  is rotated until the dial indicator  52  reads zero. 
     Next, the weight support set screw  44  which held the pivoting arm  38  in the closed or horizontal position is released. At this point, the force which had been applied to golf club shaft  10  is released and golf club shaft  10  releases and returns to its unstressed, unflexed position. Pivoting arm  38  is now located slightly above the horizontal. 
     Weight extension shaft  48  is inserted into the end of arm extension  40 . The arm extension set screw  47  is tightened to hold the weight extension shaft  48  in place in the arm extension  40 . 
     Next, donut weight  50  is applied to the weight extension shaft  48  until pivoting arm  38  moves back to the horizontal position and flexes golf club shaft  10 . At this point, golf club shaft  10  is flexed and is free to flex, back and forth, as golf club shaft  10  is rotated via the rubber wheel  30 . The horizontal position of the pivoting arm  38  is determined by the flexing of golf club shaft  10  in reaction to donut weight  50  in position on the end of weight extension shaft  48 . (Previously, the horizontal position of the pivoting arm  38  was determined by the weight support set screw  44 .) 
     Once again, the dial indicator  52  is set at the zero position. To set the dial indicator  52  at the zero position, the rotatable bezel  56  is rotated until the dial indicator  52  reads zero. This is the reference position of the golf club shaft  10  to determine the location of the spine  16 . 
     The rubber wheel  30  is rotated by hand until a position of minimum deflection is indicated by pointer stem  54  on dial indicator  52 . It is a very distinctive tactile sensation. The rubber wheel  30  is continuously rotated until golf club shaft  10  assumes a position of minimum deflection which is the position at which spine  16  is at the top dead center position of golf club shaft  10 . Location of spine  16  is shown specifically in FIG.  9 . Once spine  16  is located, a piece of masking tape is applied to golf club shaft  10  to mark the location of spine  16 . 
     Golf club shaft  10  can then be removed from the apparatus  20  and golf club shaft  10  can be repositioned in club head  12  according to the desired placement of spine  16  to golf club shaft  10  relative to the hitting surface.