Patents by Inventor Donald P. Pratt

Donald P. Pratt 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).

  • Patent number: 5775193
    Abstract: A crush-slitting anvil structure including a frame, a backup roll rotatably mounted on the frame, an axle mounted on the frame in substantially parallel relationship to the backup roll, a roller anvil mounted on the axle and in engagement with the backup roll, and a rotatable knife mounted on the frame in contiguous relationship to the roller anvil. In one embodiment the axle is directly mounted on the frame, and in another embodiment the axle is mounted on a housing which is mounted on the frame.
    Type: Grant
    Filed: June 25, 1996
    Date of Patent: July 7, 1998
    Inventor: Donald P. Pratt
  • Patent number: 5370337
    Abstract: An expandable shaft for mounting of a hollow core having an internal surface including an elongated polygonal base member having an axis of rotation, outer surfaces on the member defining a circumference having a diameter which is slightly less than the diameter of the internal surface of a core which is to be mounted on the expandable shaft, a selectively inflatable elongated expandable bladder extending longitudinally on the elongated base member in circumferentially spaced relationship to the outer surfaces for engaging the inside surface of the core and drawing it into engagement with the plurality of surfaces when the elongated expandable bladder is inflated.
    Type: Grant
    Filed: September 10, 1993
    Date of Patent: December 6, 1994
    Inventor: Donald P. Pratt