Patents by Inventor Karlheinz Widmann

Karlheinz Widmann 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: 4856278
    Abstract: According to the parent patent on inadequate power of the delivery pump the flow rate set at the directional control valves for the consumers is reduced in equal proportions in that electrical signals proportional to the flow rates are supplied to a summation stage and the sum voltage is compared in a comparison stage with a limit value corresponding to the maximum pump delivery flow. When the limit value is exceeded a control signal is generated with which the stroke of all the driven directional control valves can be jointly reduced. According to the application of addition the signal voltage supplied to the summation stages and corresponding to the respective flow rate can be obtained in a displacement pickup associated with each directional control valve or in a pressure pickup measuring the pilot pressure if the directional control valves are not controlled electrically but hydraulically.
    Type: Grant
    Filed: December 29, 1987
    Date of Patent: August 15, 1989
    Assignee: Mannesmann Rexroth GmbH
    Inventors: Karlheinz Widmann, Norbert Kreth, Martin Schmitt, Armin Stellwagen
  • Patent number: 4709619
    Abstract: Proportional magnet having a housing in which an armature bar is mounted which is movable under the influence of an armature winding arranged in the housing, wherein a hydraulic unit serving to operate the armature bar is additionally provided.
    Type: Grant
    Filed: November 18, 1986
    Date of Patent: December 1, 1987
    Assignee: Mannesmann Rexroth GmbH
    Inventors: Reiner Bartholomaus, Karlheinz Widmann