Patents by Inventor Rolf Zurwelle

Rolf Zurwelle 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).

  • Card file control
    Patent number: 4015350
    Abstract: This invention provides control means for use in card files and the like for fanning the cards apart for improved readability. Resilient pleated members are provided along the opposite sides of the cards, while the cards are held relatively together at their bottoms, whereby the cards are fanned apart at their tops for improved readability and ease of selection.
    Type: Grant
    Filed: November 17, 1975
    Date of Patent: April 5, 1977
    Assignee: Business Efficiency Aids, Inc.
    Inventor: Rolf Zurwelle