Patents by Inventor Hugo Preun

Hugo Preun 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: 4221156
    Abstract: The hydraulic lifting device for harvesting machines includes a hydraulic cylinder-piston unit mounted on the wheel frame of the machine and supporting most of the weight of the harvesting apparatus so that the latter abuts against the ground with residual weight only. The cylinder-piston unit is controlled by a multi-way selector valve and a locking valve unit connected in a first working pipeline system. The hydraulic device further includes a pressure limiting valve for setting a reference pressure for the hydraulic cylinder-piston unit, the limiting valve being connected in an additional working pipeline that is branched upstream the limiting valve to a nonreturn valve and therefrom is connected by a direct conduit to a hydraulic accumulator and the hydraulic cylinder-piston unit.
    Type: Grant
    Filed: August 23, 1978
    Date of Patent: September 9, 1980
    Assignee: Robert Bosch GmbH
    Inventors: Wilhelm Zirps, Hugo Preun
  • Patent number: 4080994
    Abstract: A control arrangement for supplying pressure fluid through a supply conduit from a source of pressure fluid to at least two hydraulically operated consumer devices includes, for each of the consumer devices, a valve having a valve member movable axially between a neutral position preventing flow of pressure fluid to the respective consumer device and two working positions respectively connecting the consumer device to the source of pressure fluid or a return conduit. A throttle is located in the supply conduit between a first point of the latter from which a first branch conduit branches off to a first of the valves and a second point from which a second branch conduit branches off to the second of the valves. The arrangement includes further a control valve and a control circuit therefor, controllable at least by the valve member of one of the valves. In the neutral position of all valve members the supply conduit is connected with the return conduit to form therewith a neutral fluid circulation passage.
    Type: Grant
    Filed: December 1, 1976
    Date of Patent: March 28, 1978
    Assignee: Robert Bosch GmbH
    Inventors: Heinz Flaschar, Peter Kroll, Petrus Thomassen, Heinz Kleinschmidt, Hugo Preun