Patents by Inventor Arthur Bert Bertholf

Arthur Bert Bertholf 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).

  • Apparatus for continuously forming opposed C-shaped cuts in plastic film
    Patent number: 3956956
    Abstract: Opposed C-shaped cuts can be made in plastic film in a continuous manner by passing the film between a punch roll bearing specially designed punches and a mating roll having wells for receiving the punches. The special design of the punches overcomes the problem of stretching and tearing of the film normally encountered in attempting to make such cuts in plastic film using a rotary punch.
    Type: Grant
    Filed: September 8, 1975
    Date of Patent: May 18, 1976
    Assignee: Crown Zellerbach Corporation
    Inventor: Arthur Bert Bertholf