Abstract:
A bowling ball thrower includes a frame positionable adjacent to a bowling lane, a throwing arm pivotably attached to the frame, the throwing arm having a rest position and a pivoted position and including a ball-gripping mechanism for gripping a bowling ball, and a cocking arm pivotably attached to the frame, the cocking arm being selectively couplable to the throwing arm such that the cocking arm is pivotable with the throwing arm. A method for throwing a bowling ball includes holding the bowling ball with a ball thrower having a throwing arm and a cocking arm, and coupling the throwing arm to the cocking arm. The method also includes pivoting the throwing arm to a pivoted position to achieve a velocity, uncoupling the throwing arm from the cocking arm, and releasing the bowling ball such that the bowling ball moves at the velocity.

Description:
CROSS-REFERENCE APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 60/136,470, filed May 28, 1999. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to an automatic ball thrower for delivering a bowling ball under controlled conditions. 
     BACKGROUND OF THE INVENTION 
     Various prior art devices have sought to simulate a bowler&#39;s motion in throwing a bowling ball. Some devices vary the velocity at which a ball is thrown, and some can impart a spin to the ball. Most of these have been associated with amusement devices. 
     SUMMARY OF THE INVENTION 
     One of the problems with the prior art devices is that the devices are limited in the number of variables they can simulate. For example, a device may be able to produce a spin in a bowling ball before it is released, but it cannot produce the spin consistently or at a known speed. Another problem with the prior art devices is that the devices do not offer repeatability of a given motion. 
     Because of the limited number of variables these devices can simulate, and because these devices cannot simulate a given variable consistently, none of these prior art devices can be use to test lane conditions, ball throwing conditions, or the bowling balls themselves. Some devices may be able to simulate more variables than other devices, but these devices tend to be very complex, virtually immovable due to their bulk and weight, and extremely expensive. 
     The automatic ball thrower of the present invention overcomes the shortfalls of prior art devices. 
     Specifically, the invention defines a bowling ball thrower including a frame positionable adjacent to a bowling lane, a throwing arm pivotably attached to the frame, the throwing arm having a rest position and a pivoted position and including a ball-gripping mechanism for gripping a bowling ball, and a cocking arm pivotably attached to the frame, the cocking arm being selectively couplable to the throwing arm such that the cocking arm is pivotable with the throwing arm. 
     The invention also defines a bowling ball thrower including a frame positionable adjacent to a bowling lane, a throwing arm pivotably attached to the frame, the throwing arm including a ball-gripping mechanism and having a rest position, and a gripper mechanism movably coupled to the frame, the gripper mechanism being operable to grip and maintain the throwing arm at a pivoted position from the rest position. 
     The invention also defines a method for throwing a bowling ball, the method including holding the bowling ball with a ball thrower having a throwing arm and a cocking arm, and coupling the throwing arm to the cocking arm. The method also includes pivoting the throwing arm to a pivoted position to achieve a velocity, uncoupling the throwing arm from the cocking arm, and releasing the bowling ball such that the bowling ball moves at the velocity. 
     The invention provides an apparatus and method for automatically throwing a bowling ball down a bowling lane to simulate a bowler&#39;s throw. The apparatus allows for variability of ball rotational speed, rotational axis, angle of delivery, loft, and velocity, which are the primary parameters a bowler influences. The apparatus can thus be used as a tool in improving a bowler&#39;s form. The apparatus can also be used to test lane conditions, the interaction between ball and lane, and bowling balls themselves. Among other factors, the slide-roll-hook phenomenon, ball-lane friction characteristics, flare, and angle of entry can all be studied to better understand how technology and the bowler are working together to throw the perfect shot. 
     One advantage of the present invention is that the apparatus can simulate each variable controllable by a human bowler. 
     Another advantage of the present invention is that the automatic ball thrower is compact, inexpensive, and easy-to-use. It will support research on bowling balls, lanes, and lane dressing patterns. 
     These and other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description of the preferred embodiment of the invention, which is given by way of example only, reference being made to the appended drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an automatic ball thrower embodying the invention. 
     FIG. 2 is a cutaway view of the automatic ball thrower taken along line  2 — 2  of FIG.  1 . 
     FIG. 3 is a cutaway view of a cocking arm gripper mechanism and a throwing arm cleat taken along line  3 — 3  of FIG.  2 . 
     FIG. 4 is a partial elevation view of a gripper assembly for the automatic ball thrower. 
     FIG. 5 is a cutaway view of the gripper assembly taken along line  5 — 5  of FIG.  4 . 
     FIG. 6 is a flow chart illustrating a method for throwing a bowling ball. 
    
    
     Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of the construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates an automatic ball thrower  10  for consistently throwing a bowling ball B to test lane conditions, bowling ball performance, and bowler delivery methods. The thrower  10  can control ball rotational speed, rotational axis, angle of delivery, loft, and velocity, which are the primary parameters a bowler influences. The thrower  10  generally includes a frame  14  supporting a throwing arm  18  and a gripper assembly  22 . 
     As illustrated in FIG. 1, the frame  14  includes a generally U-shaped base  26 . The base  26  rests on retractable rollers  30  during movement. When the ball thrower  10  is in position for operation, the rollers  30  are retracted, leaving the base  26  resting on suction cup feet  34 . A standard vacuum system of a pump and hoses (not shown) draws a vacuum within each suction cup foot  34  to establish a seal between each suction cup foot  34  and the bowling lane floor  38  (see FIG. 2) sufficient to anchor the ball thrower  10 . 
     Mounted on the base  26  is a riser  42  including a lower riser section  46  and an upper riser section  50 . The lower riser section  46  is mounted to the base  26 . The upper riser section  50  is sized to fit within the lower riser section  46  and is slidably attached to the lower riser section  46 . A standard pneumatic cylinder (not shown) is mounted between the base  26  and the bottom end of the upper riser section  50  within the lower riser section  46  such that the upper riser section  50  may be raised and lowered with respect to the lower riser section  46 . 
     A spring anchor  54  is fixedly attached to a spring anchor plate  58 , which is movably attached to the lower riser section  46  such that the spring anchor plate  58  and thus the spring anchor  54  may be manually adjusted up and down with respect to the lower riser section  46 . 
     An upper frame section  62  is mounted to the top of the upper riser section  50 . Mounted on the upper frame section  62  are a winch  66 , a pulley  70 , and a pivot axle  74 . The winch  66  contains cable  78 , which is preferably steel cable but which may be any suitable equivalent. 
     As illustrated in FIG. 2, the pivot axle  74  mounted within the upper frame section  62  supports three arms: a biasing or spring arm  82 , a cocking arm  86 , and the throwing arm  18 . The spring arm  82  is pivotably attached to the pivot axle  74  at the pivot end  90  of the spring arm  82 . The spring arm lever  94  is adjustably attached to the spring arm  82  near the pivot end  90  of the spring arm  82  such that the angle of the spring arm lever  94  with respect to the spring arm  82  may be varied. A contact peg  98  is attached to the spring arm lever  94  extending generally perpendicular to the spring arm lever  94 . 
     A spring end  102  of the spring arm  82  is opposite the pivot end  90  of the spring arm  82 . Attached to the spring end  102  of the spring arm  82  is a first end  106  of a spring  110 . In alternate embodiments, any suitable device that stores sufficient energy may be used in the place of the spring  110 . A second end  114  of the spring  110  is attached to the spring anchor  54  on the spring anchor plate  58 . The spring anchor  54  may be adjusted vertically with respect to the lower riser section  46  to vary the position of the spring  110 . As the spring arm  82  is rotated about the pivot axle  74  (clockwise as seen in FIG.  2 ), the spring  110  is stretched, thus storing energy. 
     The cocking arm  86  is also pivotably attached to the pivot axle  74  at a pivot end  118  of the cocking arm  86 . Opposite the pivot end  118  of the cocking arm  86  is a gripper end  122  of the cocking arm  86 . A gripper mechanism  126 , best shown in FIG. 3, is attached to the gripper end  122  of the cocking arm  86 . The gripper mechanism  126  includes an attachment pivot  130 , which is mounted on the cocking arm  86 , two fingers  134 , which are movably attached to the attachment pivot  130 , and a pneumatic cylinder  138 . A pneumatic system controlled by the operator causes the fingers  134  to open and close as desired. In alternate embodiments, an electromagnetic system or another suitable system may be used to control the fingers  134 . 
     As shown in FIG. 2, the cable  78  extends from the winch  66  over the pulley  70  and is attached near the gripper end  122  of the cocking arm  86 . Operating the winch  66  such that the cable  78  is retracted causes the cocking arm  86  to be raised, or to pivot about the pivot axle  74  (clockwise in FIG.  2 ). Operating the winch  66  such that the cable  78  is extended causes the cocking arm  86  to be lowered. A standard first encoder (not shown) is also mounted on the pivot axle  74  to indicate the position of the throwing arm  18 . The first encoder is preferably a disk encoder, but any suitable encoding system may be used. 
     Finally, the throwing arm  18  is also pivotably attached to the pivot axle  74  at a pivot end  142  of the throwing arm  18 . The throwing arm  18  is free to pivot about the pivot axle  74  in either direction. For the purposes of description, backwards is the direction of pivoting or swing upwards and away from a substantially vertical rest position of the throwing arm  18 . Forwards is the direction of pivoting or swing back toward the rest position. 
     The throwing arm  18  includes a cleat  146  mounted on the throwing arm  18  such that when the throwing arm  18  and the cocking arm  86  are generally vertical and aligned, the gripper mechanism  126  on the cocking arm  86  is aligned with the cleat  146  on the throwing arm  18 . The cleat  146  is generally T-shaped in horizontal cross section, as shown in FIG. 3, and is sized such that the fingers  134  of the gripper mechanism  126  can releasably engage the cleat  146 . 
     The throwing arm  18  also includes (see FIGS. 4 and 5) a gripper assembly  22  attached to an end of the throwing arm  18  opposite the pivot end  142  of the throwing arm  18 . The gripper assembly  22  includes a gripper assembly attachment plate  150 . One end of the attachment plate  150  includes a second attachment bracket  154 . The end of the attachment plate  150  opposite the end including the second attachment bracket  154  includes a semicircular slot  158  with its concave side facing toward the throwing arm  18  (see FIG.  5 ). The attachment plate  150  is pivotably attached to the end of the throwing arm  18  such that the attachment plate  150  can pivot about a horizontal pivot  162 . The amount of pivot in either direction is controlled by a vertical pivot control  166 . 
     As shown in FIG. 4, the vertical pivot control  166  includes a first thumbwheel  170  mounted on a top end  174  of a threaded rod  178 . The threaded rod  178  is supported adjacent the top end  174  by a first attachment bracket  182  mounted on the throwing arm  18  above the pivot point  162 . The threaded rod  178  is pivotably supported at a bottom end  186  by the second attachment bracket  154  mounted on the attachment plate  150 . Turning the threaded rod  178  by use of the first thumbwheel  170  causes the rod  178  to move up or down relative to the first attachment bracket  182 . For example, if the first thumbwheel  170 , and thus the rod  178 , are turned clockwise, the rod  178  will move down, causing the attachment plate  150  to pivot around the pivot point  162  in a clockwise direction (in FIG.  4 ). Once the desired amount of pivot of the attachment plate  150  is achieved, a nut  190  located on the threaded rod  178  between the bottom end  186  and the first attachment bracket  182  is tightened against the first attachment bracket  182 , locking the threaded rod  178  and thus the attachment plate  150  in place. 
     The gripper assembly  22  also includes a gripper frame  194  rotatably attached to the attachment plate  150  at a pivot point  198 , enabling the gripper frame  194  to rotate in a generally horizontal plane about the pivot point  198 . The extent of horizontal pivoting of the gripper frame  194  allowed is controlled by a second thumbwheel  202  mounted on a bolt  206 . The bolt  206  extends through the slot  158  in the attachment plate  150  into a threaded hole in the gripper frame  194 . When the gripper frame  194  is rotated to its desired position, the second thumbwheel  202 , and thus the bolt  206 , are turned clockwise to tighten the second thumbwheel  202  against the attachment plate  150  and the attachment plate  150  against the gripper frame  194 , thus locking the attachment plate  150  and the gripper frame  194  together and preventing further rotation of the gripper frame  194 . 
     The gripper assembly  22  also includes a servo motor  210  (schematically illustrated) mounted on a first end  214  of the gripper frame  194 . Mounted within the servo motor  210  is a standard second encoder (not shown) that sends an electronic signal indicating the position of a bowling ball B as the ball B spins within the gripper assembly  22 . 
     A first frame leg  218  is also attached to the gripper frame  194  at the first end  214 . A driving ball cup  222  is rotatably mounted on the first frame leg  218 . A drive shaft  226  with a right-hand component  230  is connected between the servo motor  210  and the driving ball cup  222 . A driven ball cup  234  is rotatably mounted on a second frame leg  238 , which is pivotably attached to a second end  242  of the gripper frame  194  such that the second frame leg  238  can move toward and away from the first frame leg  218 . Movement of the second frame leg  238  is preferably controlled by a pneumatic cylinder  246  attached between the second frame leg  238  and the gripper frame  194 . This arrangement allows the gap between the driving and the driven ball cups  226 ,  234  to be opened to accommodate the ball B. The gap can also be closed, thus capturing the ball B between the ball cups  226 ,  234 . The ball cups  226 ,  234  can be lined with rubber pads or any other suitable material to assist the ball cups  226 ,  234  in capturing and holding the ball B. The gripper assembly  22  can also be equipped with a mechanical lock (not shown) to ensure that the ball B remains captured between the ball cups  226 ,  234  until the desired release point is reached. In an alternate embodiment, both the first and second frame legs  218 ,  238  may be movable. 
     Also mounted on the base  26  is (see FIG. 1) a feeder arm assembly  250 . The feeder arm assembly  250  includes a feeder arm  254  (connected to the base  26 , as illustrated in dashed lines in FIG.  1 ), a ball cup  258  with a central vacuum port  262 , and a pneumatic cylinder (not shown) for raising and lowering the feeder arm  254 . 
     Also mounted on the base  26  is a control panel  266 . This control panel  266  contains the standard pneumatic, vacuum, and electronic controls (not shown) necessary to operate the various pneumatic, vacuum, and electronic components of the ball thrower  10 . Pneumatic and vacuum hoses and electronic wires that run from the control panel  266  to various components are not shown for reasons of simplicity. Supplying and controlling air to pneumatic cylinders, a vacuum to vacuum systems, and electricity to electronic components, are accomplished by conventional means. While the device is illustrated with pneumatic devices, other suitable devices may be used. For example, hydraulic systems or any other suitable system may replace the pneumatic systems. The control panel  266  also contains controllers (not shown) to coordinate the various operations of the ball thrower  10 . 
     In operation, the automatic ball thrower  10  is staged at the head of a bowling lane selected for testing. The ball thrower  10  is oriented with an open end  270  of the base  26  toward a bowling lane. Once the ball thrower  10  is in its final position, the rollers  34  are retracted so that the ball thrower  10  rests on suction cup feet  38 . A vacuum pump (not shown) is operated to create a vacuum between the suction cup feet  38  and the floor  42 , thus removably but securely anchoring the thrower  10  to the floor  42 . 
     A bowling ball B is selected for testing and is placed in the ball cup  258  when the feeder arm  254  is in its lowered position. A vacuum is applied to the central vacuum port  262  of the ball cup  258 , thus securing the ball B within the ball cup  258 . The feeder arm  254  is then raised, thus properly positioning the ball B for testing. 
     The ball delivery conditions to be tested are determined, including the ball throw variables of ball rotational speed, rotational axis, angle of delivery, loft, and velocity. The ball rotational speed is the speed at which the ball rotates about any given axis, and is typically measured in revolutions per minute. The operator sets the desired ball rotational speed by entering the speed setpoint value in the computer in the control panel  266 . The computer then instructs the servo motor  210  to turn the driving cup  222  at the given speed. 
     The ball rotational axis is the direction of the axis about which the ball rotates. The rotational axis of the ball can affect the ball&#39;s path of travel because most balls are not homogeneous; most balls have finger holes on one side and a weight located within the ball. These non-homogeneities cause the ball to roll differently about different axes. Two factors determine the ball rotational axis. First, the orientation of the ball B in the ball cup  258  of the feeder arm  254  determines in what orientation the gripper cups will hold the ball B. Second, the spin angle of the gripper assembly  22  with the ball B in place is determined by manually setting the pivot position of the gripper assembly  22  using the vertical pivot control  166  as described above. By controlling the orientation of the ball B in the ball cup  258  and thus within the gripper assembly  22  and by properly setting the gripper assembly  22  vertical pivot, the ball rotational axis can be controlled. The second encoder within the servo motor  210  monitors the position the bowling ball B as it spins so that the ball B can be released when it is in a predetermined position with respect to its non-homogeneities. 
     The angle of delivery is the angle with respect to the longitudinal axis of the bowling lane at which the ball is released. The angle of delivery is changed largely to simulate right- and left-handed bowlers. The ball angle of delivery is manually set by loosening the second thumbwheel  202 , rotating the gripper frame  194  about the pivot point  198  to the desired angle, and then tightening the second thumbwheel  202  to lock the gripper frame  194  in place. 
     The ball loft is essentially the height above the lane at which the ball is released. Some bowlers release the ball while the ball is essentially in physical contact with the lane, while other bowlers tend to release the ball when the ball is above the lane, resulting in a vertical component of the ball&#39;s path of travel. In extreme cases, the bowler appears to be tossing the ball. Ball loft is set by the operator in the computer in the control panel  266 . Based on the setpoint chosen by the operator, the first encoder connected to the pivot axle  74  determines the position of the throwing arm  18  as it swings forward. When the position of the throwing arm  18  equals the setpoint, the ball B is released, which is explained in more detail below. Ball loft can also be affected by the position of the upper riser section  50  with respect to the lower riser section  46 . An increase in height of the upper riser section will raise the upper frame section  62  and thus the throwing arm  18 . 
     Finally, ball velocity is simply the translational speed at which the ball is traveling at the point of release and is measured in miles per hour. Ball velocity is also set by the operator in the computer in the control panel  266 . Generally, the higher the desired velocity, the farther back the throwing arm  18  is pulled in its backswing. 
     For any given test, the attachment between the spring arm  82  and the spring arm lever  94  will not be adjusted. Thus, for that test, the spring arm  82  and the spring arm lever  94  will move as one unit. 
     Once the ball thrower  10  is set properly to effect the desired throw, the operator begins the test by operating the computer on the control panel  266 . The cocking arm gripper fingers  134  open and the cocking arm  86  is lowered from its raised, disconnected position by running the winch  66  to let out cable  78 . The cocking arm  86  is lowered until it contacts the throwing arm  18 . The gripper fingers  134  close about the cleat  146 , thus causing the cocking arm  86  to become detachably affixed to the throwing arm  18 . The direction of winch  66  direction is reversed, causing the cocking arm  86 /throwing arm  18  assembly to be pulled back and up into a backswing. This motion stops when the gripper assembly  22  is aligned with the ball B resting in the ball cup  258  on the feeder arm  254 . 
     The driven cup  234  of the gripper assembly  22  closes on the ball B, thus capturing the ball B between the driving cup  222  and the driven cup  234 . The vacuum to the ball cup  258  is turned off, thus releasing the ball B from the ball cup  258 . The cocking arm  86 /throwing arm  18  assembly is then pulled further into the backswing until the backswing necessary to produce the desired ball velocity is reached. 
     For higher ball velocities requiring greater backswings, the throwing arm  18  comes into contact with the contact peg  98  of the spring arm lever  94 . If the backswing continues from that point, the throwing arm  18  will push the contact peg  98  and thus the spring arm lever  94 . Because the spring arm lever  94  is fixedly attached to the spring arm  82 , moving the spring arm lever  94  will cause the spring arm  82  to rotate about the pivot end  90  (clockwise in FIG.  2 ). As the spring arm  82  rotates, the spring  110  attached to the spring end  102  extends, thus storing energy to be used in the ball throw. 
     When the cocking arm  86 /throwing arm  18  assembly reaches the apex of the backswing, the operator begins the test when ready by pressing the start button on the control panel  266 . The servo motor  210  drives the drive shaft  226 , which in turn drives the driving ball cup  222 , thus turning the bowling ball B and the driven ball cup  234  until the ball B reaches the desired rotational speed. The gripper fingers  134  then open, releasing the cleat  146  and thus the throwing arm  18 . Gravity pulls the throwing arm  18  downward and forward (counter-clockwise in FIG.  2 ). For higher ball velocities, if the spring arm  82  has been engaged, the spring  110  also pulls the throwing arm  18  forward by way of the spring arm  82 , spring arm lever  94 , and contact peg  98 . 
     When the throwing arm  18  reaches the point in its swing corresponding to the desired ball loft as described above, the first encoder indicates this position to the computer, causing the computer to open the driven cup  234  of the gripper assembly  22 , thus releasing the ball B. The ball B will be thrown down the bowling lane with the desired rotational speed, rotational axis, angle of delivery, loft, and velocity. The motion of the ball B with respect to the lane and the pins can be monitored by known methods to accomplish different tasks. 
     Without any further adjustments, the identical throw can be repeated indefinitely using the same ball B and the same lane to eliminate ball throw conditions as variables in testing lane conditions. Subtle differences in lane conditions can be tested for their effects on the motion of the ball B. 
     The effect of altering any given ball throw condition, such as ball rotational speed, loft, etc. can be tested by holding the other ball throw condition variables constant, and by holding lane conditions constant. In this way, using the ball thrower  10  to imitate the bowler&#39;s delivery and altering whatever variables are within the bowler&#39;s control can be used to optimize a bowler&#39;s delivery. 
     Finally, bowling balls themselves can be tested by holding all of the ball throw and lane condition variables constant and throwing different balls. 
     Various features of the invention are set forth in the following claims.