Patents by Inventor Duane W. Tressler

Duane W. Tressler has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Automatic ball throwing machine
    Patent number: 4611571
    Abstract: An automatic ball throwing machine comprising a motorized arm for activating a ball receiving arm which is adapted to be positioned under a ball delivery chute and following the delivery of a ball into the receiving arm, a coil spring mounted at the other end of the receiving arm is released whereupon the receiving arm is caused to be projected upwardly and upon reaching its uppermost position the ball is released and projected toward one using the machine to practice hitting the ball with a suitable bat.
    Type: Grant
    Filed: August 26, 1985
    Date of Patent: September 16, 1986
    Inventors: Duane W. Tressler, J. C. McLeod