×

Tennis ball throwing machine with continuously rotatable barrel having friction strip on one side only of inner wall

  • US 4,570,607 A
  • Filed: 08/18/1983
  • Issued: 02/18/1986
  • Est. Priority Date: 08/18/1983
  • Status: Expired due to Fees
First Claim
Patent Images

1. A tennis ball throwing machine comprising a barrel, support means for supporting the barrel for rotation about its lengthwise axis,means for successively feeding tennis balls to the barrel,means for successively propelling said balls through the barrel,friction strip means on one side only of the inner wall of the barrel for imparting spin to a ball propelled therepast,and motor means connected to the barrel for continuously rotating the barrel through 360 degrees about the longitudinal axis of the barrel so as to continuously rotate the friction strip means around said longitudinal axis whereby to continuously vary the sense of the spin from top spin to back spin and side spin to side spin.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×