Abstract:
A golf ball compression testing apparatus has a main body with a ball receiving chamber and pistons movably mounted in aligned bores in the body and extending into the chamber to engage opposite portions of the ball. The first piston is spring loaded into an advanced position engaging the ball, while the second piston is spring loaded away from the ball and urged by a handle operated actuator into an extended position engaging the ball. A pressure gauge associated with the first piston measures a compression rating of the ball when the second piston is moved into the advanced position. Rotation of the handle away from a test position retracts the actuator and allows the second piston to move away from the ball. In one embodiment, a clutch assembly associated with the actuator resists the tendency of the handle to snap back into the inoperative position under the action of the piston return spring.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates generally to an apparatus for testing the hardness or compressibility of a ball, and is particularly concerned with a hand held apparatus for golf ball compression testing. 
         [0003]    2. Related Art 
         [0004]    Golf balls vary in hardness or compressibility, and golfers can select balls of desired hardness or compression rating based on their skill level and playing conditions. For example, in cold weather conditions a softer ball may be preferable, while a golfer may wish to play with a harder ball in hot weather. Softer balls are generally preferred by players with less physical strength. Various test devices have been used in the past to measure the compression rating of a golf ball, including larger scale machines such as that described in U.S. Pat. No. 4,555,028 of Valehrach, and smaller, hand held devices that can be used by the individual golfer, for example the hand held golf ball compression and sphericity tester described in U.S. Pat. No. 6,196,073 of Harding. In Harding, a golf ball is inserted into the testing apparatus into a position between two opposing plates, one of which is attached to a calibrated spring and the other of which is attached to a screw used to drive the attached plate against the ball. This applies a predetermined force to the ball, and the amount of compression can be read on a scale on the apparatus. 
         [0005]    Another hand held golf ball compression and sphericity tester is manufactured by Majestix Golf of Temecula, Calif. (see www.majestixgolf.com). This also involves compressing a ball between two plates or pistons, but in this case the movable plate is actuated by a rotatable drive shaft which has cam or roller bearings which act against a face of the plate or piston to drive it into an extended position against the action of a return spring. A handle is secured to the drive shaft and is actuated by the user to rotate the shaft between an operative position in which the plate is extended and an inoperative position in which the plate or piston is returned by a spring into the retracted position. 
       SUMMARY 
       [0006]    In one embodiment, a golf ball compression testing apparatus is provided, which comprises a main body with a ball receiving cavity and first and second pistons movably mounted in aligned bores in the body and extending into the cavity to engage opposite portions of the ball. The first piston is spring loaded into an advanced position engaging the ball, while the second piston is spring loaded away from the ball and urged by a handle operated actuator or drive shaft into an extended position engaging the ball. A sensor or gauge associated with the first piston measures a compression rating of the ball when the second piston is moved into the advanced position. Rotation of the handle away from a test position retracts the actuator and allows the second piston to move away from the ball. In one embodiment, a clutch associated with the actuator or drive shaft resists the tendency of the handle to snap back into the inoperative position under the action of the piston return spring. 
         [0007]    The actuator comprises a drive shaft extending transverse to the second piston and linked to a handle which rotates the shaft between an operative position driving the second piston into the advanced position and an inoperative position allowing the second piston to move into the retracted position. In one embodiment, a resilient grommet or ring surrounds the clutch associated with the drive shaft to resist rotation of the clutch and drive shaft. The clutch assembly thus resists the tendency of the handle to snap back into the inoperative position under the action of the spring as the operator starts to rotate the handle back towards the release position. This reduces the risk of injury as a result of the handle snapping back under the action of the ball return spring. The clutch may be a roller clutch or one-way clutch in one embodiment, and allows free turning of the drive shaft towards the test position, but resists free rotation back to a released position. 
         [0008]    In one embodiment, the drive shaft extends transverse to a rear end face of the second piston, and at least one cam or projection on the drive shaft acts to urge the piston into the advanced position when the drive shaft is rotated into the operative position. The cam may comprise one or more bearings or rollers mounted on one side of the drive shaft. The clutch engages over an outer end of the drive shaft, and the resilient plastic ring or grommet engages over the clutch to resist rotation. A set screw or other adjustment device may be provided to vary the compression of the grommet. 
         [0009]    The pressure gauge or indicator in one embodiment is associated with a rotatable ring carrying a scale covering golf ball compression indices from soft to hard, for example around 35 to 135, with a set point indicated at a standard golf ball compression rating of around 115 psi. The ring is rotated prior to testing a ball until the indicator or pointer associated with the gauge plunger or sensor pin points to the set point. A ball is then inserted into the ball chamber between the pistons, with the second piston in the retracted position. The handle is turned to advance the second piston and apply force to the ball, and the pointer then moves to the left or right of the set point, depending on whether the ball is harder or softer than the standard. In one embodiment, a color scale may be included on the scale ring, either in addition to or instead of the numeric scale, to provide a visual indication of ball hardness or softness. This scale may have different colors corresponding to firm, moderate, soft, and extra soft compression ratings so the ball quality may be read quickly and easily by a golfer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0010]    The details of the present invention, both as to its structure and operation, may be gleaned in part by study of the accompanying drawings, in which like reference numerals refer to like parts, and in which: 
           [0011]      FIG. 1  is a front perspective view of one embodiment a golf ball compression testing apparatus, illustrating the apparatus in a start position prior to testing a ball compression index; 
           [0012]      FIG. 2  is a view similar to  FIG. 1  but showing the apparatus in the test position in which the ball compression index is measured; 
           [0013]      FIG. 3  is an exploded perspective view illustrating the separated components of the ball compression testing apparatus of  FIGS. 1 and 2 ; 
           [0014]      FIG. 4  is a cross sectional view on the lines  4 - 4  of  FIG. 1 ; 
           [0015]      FIG. 5  is an enlarged top plan view of the compression gauge or dial face of the apparatus of  FIGS. 1 to 4 , illustrating the numeric and color scale; and 
           [0016]      FIG. 6  is a side elevation view of the apparatus in the test or operative position of  FIG. 2 , but with the outer body transparent to reveal the inner components. 
       
    
    
     DETAILED DESCRIPTION  
       [0017]    Certain embodiments as disclosed herein provide for a ball compression or hardness testing apparatus. 
         [0018]    After reading this description it will become apparent to one skilled in the art how to implement the invention in various alternative embodiments and alternative applications. However, although various embodiments of the present invention will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation. 
         [0019]    Although the apparatus in the following description is designed for testing golf balls, it should be understood that this apparatus may alternatively be used for testing other types of balls as used in various sports, or other spherical objects, with appropriate adjustment of the testing chamber dimensions and the gauge or sensor set point. 
         [0020]      FIGS. 1 to 6  illustrate one embodiment of a golf ball testing apparatus  10  which has a main body or housing  12  with a longitudinal through bore  14  in which the internal components of the testing apparatus are mounted, as described in more detail below. The outer surface of body  12  is of hexagonal shape, but may be of other shapes in alternative embodiments, such as cylindrical or other polygonal shapes. A gauge or deflection sensor  15  is mounted at a first end of the housing. A ball testing chamber in the through bore communicates with a transverse entry opening  18  in the side of the housing for inserting a ball  19  into a ball receiving seat  16  in the chamber, as best illustrated in  FIGS. 1 and 6 . As best seen in  FIGS. 3 and 6 , first and second pistons  20 , 22  are mounted coaxially in the bore  14  on opposite sides of the testing chamber, and the pistons have respective end faces  24 , 25  which bear against diametrically opposed portions of the ball  19  when in the operative position of  FIGS. 2 and 6 . A handle  26  mounted on the outside of the housing is rotatable between a released position as illustrated in  FIG. 1  in which it extends transverse to the longitudinal axis of the housing, and a test position as illustrated in  FIG. 2  rotated through approximately ninety degrees from the position of  FIG. 1  and parallel to the longitudinal axis of the housing. Handle  26  is associated with an actuator or drive assembly  28  which moves the second piston  22  between a retracted position as in  FIG. 1  and an advanced position as in  FIGS. 2 and 6 , as explained in more detail below. 
         [0021]    As illustrated in  FIG. 3 , shaft or sensor pin  30  of gauge  15  extends through an opening in end cap  32  of the housing to engage the outer end  34  of piston  20 . Piston  20  has an enlarged annular flange  35 , and a pair of wave springs  36 , 37  are located between an inner face of end cap  32  and the flange  35  to urge the piston outwardly into engagement with ball  19 . A pair of set screws  38  extend radially through outer end portion  40  ( FIG. 5 ) of the end cap  32  to cradle and guide the shaft or pin  30 . The gauge may be a conventional deflection sensor or gauge and the shaft  30  is associated with a rotating needle or pointer  42  on the dial face  44  of the gauge in a known manner to move in response to deflection or movement of the piston  20 . The pressure gauge is modified to provide a custom annular scale  45  connected to an outer, bezeled adjustment ring  46 . The dial face  44  of one embodiment, including annular scale  45 , is described in more detail below in connection with  FIG. 5 . The adjustment ring  46  is rotated by a user prior to testing a ball until the needle  42  points to a test position  48  on scale  45 , providing a standard start position of piston  20  for every test. 
         [0022]    The second piston  22  has an enlarged flange  50  at its outer end having a recessed outer bearing or cam follower face  52 , and a pair of guide posts or pins  54  extending outwardly from one side of the bearing face or channel. A wave spring  55  is located between a shoulder  56  in through bore  14  and the flange  50  so as to bias piston  22  in a direction away from the ball seat  16  into a retracted, start position. The second piston is held in the housing by end cap  56  which engages in the second end of bore  14  as illustrated in  FIGS. 3 and 6 . The outer ends of pins  54  engage an inner face of cap  56  in the retracted, start position (see  FIG. 6 ). 
         [0023]    The actuator assembly  28  extends into a transverse bore  31  in housing  12  which extends transversely through the main bore  14  adjacent the outer cam follower face  52  of the second piston when in the retracted position (see  FIGS. 1 ,  2  and  4 ). As best seen in  FIG. 4 , actuator assembly  28  includes an actuator or pivot shaft  58  having a first end connected to the handle  26  by fastener screw  60  and a second end pivotally mounted in bearing  62  at the inner end of bore  30 . Rotation of the handle  26  between the start position and the test position rotates shaft  58  through approximately ninety degrees. A cam mechanism or projection is mounted on one side of the shaft and is positioned to engage the cam follower face  52  of the piston so as to move the piston into the operative position of  FIGS. 2 and 5 . In the illustrated embodiment, the cam mechanism comprises a pair of bearings or cam rollers  64  rotatably mounted on dowel pin  65  between mounting brackets  66  on the shaft  58 . However, in alternative embodiments, any type of cam projection or device may be provided on the shaft  28 , including an eccentric projection formed integrally with the shaft itself. The shaft  28  extends from the cam mechanism between the guide posts  54  of the second piston  22  and into bearing  62 . 
         [0024]    As illustrated, a clutch  68  engages over the outer end of pivot shaft  28  and is surrounded by resilient ring or grommet  70  which is seated in a recessed counter bore at the outer end of bore  30 , as best illustrated in  FIG. 4 . In one embodiment, clutch  68  comprises a bearing or roller clutch having a plurality of inner rollers or bearings  69  engaging the drive shaft. A small threaded bore  72  extends from the end face  74  of housing  12  into the outer end of bore  30 , and a set screw  75  in bore  72  can be adjusted so as to engage and compress grommet or ring  70  so that it engages and acts on the outer surface of roller clutch  68 . 
         [0025]    Handle  26  is of a shape similar to an eyeglass frame, and is of suitable rigid material such as metal or hard plastic. The handle has a central bridge portion  76  and a pair of end portions  78 ,  79  each having a generally hexagonal outer shape and a central circular opening  80 ,  81 , respectively. As best illustrated in  FIGS. 3 ,  4  and  6 , the end portions  78 , 79  which the user grips when actuating the handle are coplanar and offset from the central bridge portion  76  by angled connector portions  82 . The end portions  78 , 79  and the bridge portion  76  lie in parallel planes. The handle end portions  78 ,  79  are therefore spaced away from the body  12  of the apparatus, reducing the risk of a user&#39;s fingers becoming trapped when the handle is actuated. Fastener screw  60  extends through an opening at the center of bridge portion  76 . Indicia may be engraved or printed on the upper surface of handle  26  to indicate the direction in which the handle should be rotated in order to test a ball and return to an inoperative position. For example, as illustrated in  FIG. 1 , an engraving or other marking  84  of the word “TEST” is provided on handle portion  78 , along with an arrow  85  pointing in a clockwise direction. An engraving or other marking  86  of the word “RELEASE” is located on handle portion  79 , along with an arrow  88  pointing in the opposite, anti-clockwise direction. 
         [0026]    The circular openings  80 ,  81  in the handle are for ball diameter testing purposes and are of different standard golf ball diameters. For example, one opening may be of standard United States Golf Association (USGA) diameter, while the other may be of other standard golfing association size, such as the slightly smaller standard diameter set by the British Golf Association. These openings allow the golfer to test their balls for roundness and also for proper diameter. 
         [0027]      FIG. 5  illustrates one embodiment of the pressure gauge dial  45  which incorporates both a numeric scale  90  and a color scale  92  for ease of reading by a golfer. In one embodiment, numeric scale  90  may extend from a compression rating or hardness of 35 to a compression rating of 135. Golf balls having a high compression rating of over 110 are normally considered hard while golf balls having a compression rating under 90 are normally considered soft. Generally, harder golf balls are used by stronger or more experienced golfers, since they can withstand the higher impact force generally applied by a stronger golfer. The hardness of the golf ball selected for play is also dependent on playing conditions, such as ground conditions and weather. In cold weather, a softer ball is generally selected, while a harder ball is preferable in hot conditions. 
         [0028]    The set point  48  on the dial  45  of gauge  15  is at around 116, which represents a relatively hard golf ball. The color scale  92  has different colors for the different compression rating ranges  94 ,  95 ,  96 ,  97  indicated in  FIG. 5 . In one example, the following ranges and colors were used: 
         [0000]                                                    COMPRESSION RATING               COLOR   RANGE   HARDNESS                           RED (94)   115-135   FIRM           YELLOW (95)    95-115   MODERATE           GREEN (96)   75-95   SOFT           BLUE (97)   55-75   EXTRA SOFT                        
The different colors listed above and used for the different compression rating ranges in the illustrated embodiment are just one possible example, and clearly other colors could be used in different combinations in alternative embodiments. All that is needed is that the golfer can easily recognize the type of ball from the color to which the pointer is directed on testing. In addition to the broad ranges based on basic colors as defined in the table above, each range may be further subdivided into ranges with different shades of the same color. For example, the firm part of the scale may be divided into subdivisions in different shades from light pink at the lower end of the range to dark red at the highest end of the range, e.g. light pink from 115 to 120, darker pink from 120 to 125, lighter red from 125 to 130, and dark red from 130 to 135. The other ranges can be similarly subdivided with different shades of the same basic color for each five unit range, with the highest end of the yellow part of the scale being orange, for example. This makes the gauge very easy to read without having to consider the precise numerical compression index. In one embodiment, the numbered scale may be eliminated completely and the color scale alone may be used to determine relative hardness level, with the set point indicated at the appropriate location.
 
         [0029]    As noted above,  FIG. 1  illustrates the apparatus  10  in an inoperative, start position, with the handle extending transversely across one end portion of the body  12  spaced from the ball receiving opening  18 . At this point, the second piston  22  is in a retracted position so that a ball  19  can be easily inserted through the opening  18  and seated on seat  16  between the two pistons  20  and  22 . The golfer or operator then rotates adjustment ring  46  on the gauge  15  until the pointer  42  is directed towards the set position on dial  45 . The handle  26  is then turned from the position illustrated in  FIG. 1  to the test position illustrated in  FIG. 2 . This in turn rotates the pivot shaft  58  from the start position illustrated in  FIG. 4 , in which the roller bearings  64  extend in a direction parallel to the bearing or cam face  52  at the rear end of piston  22 , to the test or operative position illustrated in  FIG. 6 , in which the rollers engage face  52  and push the piston towards the ball testing chamber (to the left as viewed in  FIG. 6 ) into the extended position in which end face  25  engages and applies force to one side of golf ball  19 . The resultant movement of first piston  20  on the opposite side of the golf ball against the loading of wave springs  36 ,  37  is indicative of the compressibility, or hardness, of the golf ball, and this movement is proportional to the deflection of needle or pointer  42  of gauge  15 . The pressure or compression gauge  15  thus reads the compression rating or relative hardness of the ball  19 . 
         [0030]    Once the test is complete, the golfer or operator rotates the handle  26  back in the release direction from the position in  FIG. 2  to the inoperative position of  FIG. 1 . At the same time, this rotates the pivot shaft and attached roller bearings back away from piston end face  52 , and the piston  22  is urged back by wave spring  55  into the retracted or inoperative position. The ball can then be removed from the cavity or seat. The roller clutch  68  stops the handle from rotating or snapping back quickly under the action of spring  55 , as could occur in the prior art design, and reduces the risk of the operators&#39; fingers being trapped or injured in the process. This risk is further reduced by the overall design of the handle  26  in which the end portions  78  and  79  are raised or offset from the central attachment portion  76  and thus raised or spaced from the body  12  of the apparatus. The set screw  75  can be adjusted if necessary to apply further gripping force against the outside of roller clutch  68  and further resist sudden rotation of the handle in the release movement. 
         [0031]    The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles described herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, it is to be understood that the description and drawings presented herein represent a presently preferred embodiment of the invention and are therefore representative of the subject matter which is broadly contemplated by the present invention. It is further understood that the scope of the present invention fully encompasses other embodiments that may become obvious to those skilled in the art and that the scope of the present invention is accordingly limited by nothing other than the appended claims.