Patents by Inventor Karl Stemmann

Karl Stemmann 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: 4113074
    Abstract: An improved technique for regulating the contact pressure of a pantograph brush on an overhead guide conductor is described. The brush is supported for vertical movement in a brush support member for adjustable wiping contact with the overhead conductor. The brush support member is in turn supported for movement in a vertical plane via a two-arm scissors arrangement which is supportable on the roof of an electric vehicle. A high-frequency signal picked up by a transducer situated in the area of the brush and representative of the instantaneous contact pressure of the brush on the wire is compared with an adjustable reference indication indicative of a desired contact pressure, and the resulting difference signal is employed to incrementally adjust the brush contact pressure.
    Type: Grant
    Filed: May 20, 1976
    Date of Patent: September 12, 1978
    Assignee: August Stemmann OHG
    Inventors: Karl Stemmann, Gerhard Holtmeier