Patents by Inventor Stefan Rothaar

Stefan Rothaar 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: 4923373
    Abstract: A hydraulic single piston pump for manual operation has a piston (3) with a first channel (14, 20) running from piston chamber (7) to the rod chamber (5). The first channel has a check valve (15-19) opening in the return stroke. The piston (3) also has at least one second channel (22, 23, 25) running from the piston chamber (7) to the rod chamber (5). The second channel is configured as a choke bore (23, 25) along at least a part of its length.
    Type: Grant
    Filed: November 21, 1988
    Date of Patent: May 8, 1990
    Assignee: Flutec Fluidtechnische Gerate GmbH
    Inventors: Stefan Rothaar, Otfried Stuck