Tennis Ball pitching apparatus with anti-jamming ball feed mechanism

Abstract

Apparatus for propelling tennis balls at timed intervals from a storage hopper. The hopper has the configuration of an inverted truncated cone. At the base of the cone and in a position to receive balls from the cone, is a rotating ball selector. The ball selector is driven through a clutch which disengages at a predetermined torque. Upon disengagement, the clutch permits the drive to rotate for approximately one-half revolution without transmitting any torque to the ball selector, and then induces a partial counter-rotation or reverse motion of the ball selector by the action of a spring loaded pin engaging an inclined face on a clutch cam. .Iadd.

Having described my invention, I now claim: 
     
       1. Apparatus for propelling individual balls from a randomly arranged quantity of balls at pre-determined intervals, including a storage hopper and apparatus for accelerating and releasing the balls wherein the improvement comprises: a ball selector connected to said storage hopper and comprising a substantially cylindrical body having at least one peripheral axial aperture of sufficient size to permit one of said balls to pass vertically through said aperture,   drive means for rotating said selector,   said selector being positioned above a ball delivery opening,   said ball delivery opening communicating with a corridor comprising means for delivering said balls to said apparatus for accelerating and releasing balls,   clutch means for disengaging said drive means from said ball selector at a predetermined torque, and for subsequently imparting a reverse rotation to said selector and re-engaging said drive means with said selector.   
     
     
       2. Apparatus according to claim 1 wherein: said aperture has a circumferential size that is substantially greater than the diameter of a single ball and less than twice such diameter.   
     
     
       3. Apparatus according to claim 1, further including: an ejector arm mounted for rotation with said selector,   said ejector arm being mounted in the plane of said passage way,   the long axis of said ejector arm being rotationally displaced from the angular orientation of said aperture.   
     
     
       4. Apparatus according to claim 1 and further including: a selector shaft mounted for rotation with said selector and projecting within said hopper,   said selector shaft having a plurality of spaced projections along at least a portion of its length.   
     
     
       5. Apparatus for propelling individual balls comprising: a hopper for storing a quantity of balls,   a rotating ball selector means for removing a single ball from said quantity of balls at periodic intervals,   drive means for rotating said selector,   and clutch means for disengaging said drive means from said ball selector means at a pre-determined torque, and for subsequently imparting a reverse rotation to said selector means and a re-engaging of said drive means with said selector means.   
     
     
       6. Apparatus according to claim 5 wherein: said clutch means comprises a body portion secured for rotation with a first shaft, and a clutch cam portion secured for rotation with a second shaft,   said clutch cam being substantially cylindrical and having at least one substantially V-shaped notch in said cylindrical surface,   said body portion having a cam drive pin mounted for movement thereon,   said cam drive pin being spring biased into said notch.   
     
     
       7. Apparatus according to claim 6 wherein: said cam body portion is received within a clutch housing, and   said cam drive pin is spring biased by a helical compression spring that bears against said housing at one end thereof and against said body portion at the opposite end.