Patents by Inventor Edgar Mark

Edgar Mark 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: 4295000
    Abstract: An electrode-position control for arc furnaces includes a hydraulic cylinder-and-piston unit 1 having a cylinder chamber 43 and a piston 1 connectable with an electrode 4 to be moved; a control valve 8; a first pressure conduit 14, 15 which connects the control valve 8 with a source of pressure fluid, and a working conduit 17, 18 which connects the valve 8 with the chamber 43; a pre-selectable two-way valve 5, 6 in each of the conduits 14, 15; 17, 18 a second pressure conduit 34, 33, 17, 42 connecting the chamber 43 directly with the source; and a pre-selectable two-way valve 7 arranged in the second pressure conduit 34, 33, 17, 42 in parallel to the control valve 8, the valve 7 being closed when the valves 5, 6 are open, and vice versa.
    Type: Grant
    Filed: January 10, 1980
    Date of Patent: October 13, 1981
    Assignee: G. L. Rexroth GmbH
    Inventor: Edgar Mark