Patents Assigned to Mannesmann Rexroth AG
  • Patent number: 5913333
    Abstract: In a hydraulically actuatable directional control valve the servo-piston of which is to be controlled by electromagnetically actuatable pilot valves of small nominal size developed as insertion cartridges integrated in the directional control valve housing, the hydraulic connection between the pilot valves and the directional control valve are effected via channels extending in the directional control valve housing, the channels in the directional control valve housing are produced as cast channels, in particular for mass production, and the connections of the pilot valves are adapted to the size and arrangement of these channels.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: June 22, 1999
    Assignee: Mannesmann Rexroth AG
    Inventors: Rainer Biener, Richard Rauscher, Winfried Rub
  • Patent number: 5911407
    Abstract: In the case of cast housing bodies with highly stressed regions of the housing, and in particular in the case of housings for valves with control pistons, the regions of the housings subjected to high stresses are developed as independent parts from a material which withstands the stressing and forms a cast unit together with the housing body.
    Type: Grant
    Filed: July 2, 1997
    Date of Patent: June 15, 1999
    Assignee: Mannesmann Rexroth AG
    Inventors: Wolfgang Lukasczyk, Karl Rub
  • Patent number: 5871201
    Abstract: In an electromagnet with sleeve-shaped magnet housing with integrated valve body, in particular for the actuating of valves, the pole core is developed as a separate part and is surrounded by the sleeve-shaped magnet housing. The magnet housing has inward-directed corrugations distributed uniformly over its circumference which serve as axial support for the pole core in the direction of the electric windings.
    Type: Grant
    Filed: January 17, 1996
    Date of Patent: February 16, 1999
    Assignee: Mannesmann Rexroth AG
    Inventors: Marius Cornea, Helmut Patze, Franz-Josef Schleifstein
  • Patent number: 5868160
    Abstract: A two-way insert valve having an insert assembly which can be installed in a receiving bore hole and having a valve cover for closing the receiving bore hole, the insert assembly consisting of two parts, has a bush with several radial passages and with an axial passage and a ring arranged between the bush and the valve cover and has a valve piston by which a connection between the radial passages and the axial passage can be controlled and which is displaceable in opening direction up to a stop. A closing spring urges the valve piston in closed direction. The valve piston in its closed position is guided by the bush at least approximately up to the first end of the bush facing the ring.
    Type: Grant
    Filed: September 5, 1997
    Date of Patent: February 9, 1999
    Assignee: Mannesmann Rexroth AG
    Inventors: Karl Cords, Hubert Feser, Karlheinz Hunschede, Gotz-Dieter Machat, Georg Rausch
  • Patent number: 5857479
    Abstract: A precontrolled three-way pressure reduction valve having essentially vibration-free operation is encased in a cartridge and has a hollow control piston wherein a working fluid space is formed as a T-shaped cavity within the control piston. In the cavity, there are axial and transverse bores of approximately the same diameter. A groove encircles the control piston, and has a width which is slightly larger than a diameter of the transverse bore, the transverse bore communicating with the groove.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: January 12, 1999
    Assignee: Mannesmann Rexroth AG
    Inventors: Karl Cords, Gotz-Dieter Machat, Karl-Josef Meyer, Michael Schulte, Wilfried Stroka
  • Patent number: 5832807
    Abstract: A hydraulic control for a dividing machine tool, in particular a shear or cutting press, in which a damping device is provided in order to counteract a sudden downward movement of the working piston upon the cutting through of a workpiece during an operating stroke.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: November 10, 1998
    Assignees: Mannesmann Rexroth AG, Thyssen Industrie AG
    Inventors: Georg Rausch, Heinrich Wilkens, Klaus Biermann, Georg Zoller
  • Patent number: 5802847
    Abstract: A hydraulic system for a mobile machine, in particular a wheel loader, has a longitudinal oscillation damping function. The hydraulic system has at least one hydraulic cylinder (13) with which a tool can be operated and whose inner space is divided by a piston (15) into two pressure chambers (17, 18); a stop valve (12) which connects one of the two pressure chambers (17, 18) to a hydraulic reservoir (42) which can be filled via a filling pipe; and a distributing or directional control valve (11) with a spool or slide valve (40) for the separate pressurization of the two pressure chambers (17, 18) in the hydraulic cylinder (13) and/or for connecting them to a tank (29). To facilitate low-cost and space-saving construction of a system of this type, the stop valve is incorporated in the distributing valve (11) in such a way that the hydraulic reservoir (42) and the first pressure chamber (17) of the hydraulic cylinder (13) can be connected to each other via the spool valve (40) of the distributing valve (11).
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: September 8, 1998
    Assignee: Mannesmann Rexroth AG
    Inventor: Edwin Harnischfeger
  • Patent number: 5794505
    Abstract: A positioning drive having a hydraulic motor with a cam disc which is rotatable with a motor shaft and has a cam, a control valve which, with the hydraulic motor forms a unit with a housing and has a valve piston which is displaceable between several positions, a control element via which the valve piston can be supported on the cam disc, and an adjustment element which is operatively disposed between the control element and the valve piston and coaxial to the latter. The relative position between the valve piston and control element is variable by relative adjustment of the adjustment element with respect to the valve piston. The position of the adjustment element relative to the valve piston is securable by a releasable locking element. The outer of the two parts, valve piston and adjustment element, is guided outwards through the housing, and the locking element is accessible externally of the housing.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: August 18, 1998
    Assignee: Mannesmann Rexroth AG
    Inventors: Gunter Fischer, Rainer Knoll
  • Patent number: 5752384
    Abstract: The present invention proceeds from a control arrangement for at least two hydraulic consumers which has a positive displacement pump the setting of which is variable by a load-sensing regulator which can be acted on via a load-signaling line by the highest load pressure, on which a maximum-pressure and an output regulation are superimposed, two displaceable metering diaphragms a first one of which is connected between the positive displacement pump and a first hydraulic consumer and the second between the positive displacement pump and a second hydraulic consumer, and two pressure compensators a first one of which is arranged behind the first metering diaphragm and the second behind the second metering diaphragm and the regulating pistons of which can be acted on, in opening direction on a front side, by the pressure behind the corresponding metering diaphragm and in closing direction on the rear side by the pressure in the load-signaling line.
    Type: Grant
    Filed: November 20, 1996
    Date of Patent: May 19, 1998
    Assignee: Mannesmann Rexroth AG
    Inventors: Martin Schmitt, Thomas Weickert