Zahnradfabrik Friedrichshafen, Ag.

Zf Friedrichshafen Ag

Zf Friedrichshafeh Ag

Willy Holdenried

Karlheinz Mayr

Hubert Remmlinger

Karlmann Hamma

Georg Gierer

Wolfgang Schmid

Herbert Kiebler

Rudolf Michel

The invention relates to a vibration damper for damping fluid vibrations in a hydraulic system, especially in a hydraulic control circuit for a motor vehicle gear box with an elastically deformable damper element ( ), According to the invention, the vibration damper is provided with a separate sealing element ( ) which guarantees the functioning of the hydraulic system in the event of a breakdown e.g. the damper element ( ) bursting.

vibration damper for damping fluid vibrations in a hydraulic system

An electric plug-in connector ( ) having at least two coaxial round contacts ) provided on an electric component, e.g. a pressure regulator ( ) or the like, wherein one round contact, preferably the inner round contact ( ), contains an adjustment mechanism. There is further provided one connector ( ) having at least two plug-in contacts for connection with the round contacts ( ). The plug-in connector ( ) has hooks which are configured in such a way that in a plane which extends, e.g. perpendicular to the longitudinal axis ( ) of the round contacts ( ), the connector ( ) can be inserted onto the round contacts from any direction and can be locked thereon and/or on the pressure regulator ( ) and the adjustment mechanisms is freely accessible in the inner round contact ( ).

Electric plug-in connector

Arrangement for sealing a hydrualic control device

Control device

A hydrostatic transmission between a prime mover and a load, e.g. for driving an automotive vehicle, especially an automotive vehicle requiring a high degree of maneuverability such as a fork lift truck, comprises a reversible-output variable displacement pump connected to a motor which, in turn, drives the load. The control element of the pump is operated by a hydraulic piston-and-cylinder arrangement biased into a neutral position between positions of forward and reverse operation of the pump and pressurization of the oppositely effective chambers in this arrangement is controlled by a pedal-operated 'inch' valve whose flow cross section progressively increases with pedal actuation and controls the return of the pressure medium to the reservoir. The valve is designed so that even when the prime mover operates at high speed, starting movements of the pedal provide sensitive movement of the vehicle.

Hydrostatic transmission with inching control

An automatic control for an automotive-vehicle hydrostatic transmission in which the engine drives a variable-displacement hydrostatic (axial-piston) pump which is connected with the motor by hydraulic lines. The hydrostatic (axial-piston) motor can be connected to the wheels of the vehicle. The control circuit comprises a filling pump, a metering throttle, a reversing valve and an adjusting device. The metering throttle is provided in a bypass between the filling pump and the reversing valve and is connected to the line communicating with the control element. A further throttle is provided in this line and has a diameter/length ratio less than 1.

Automatic control for a hydrostatic vehicle transmission

A system for controlling the operation of a reversible hydrostatic transmission including an engine-driven pump, particularly for a self-propelled utility vehicle such as a forklift truck, comprises a switchover member coupled with a setting lever of the hydrostatic pump which is biased by a pair of counteracting springs into a normal centered position. A shift lever, upon being moved from 'neutral' to 'forward' or 'reverse', causes a displacement of the switchover member into a corresponding off-normal position by a fluidic or electromagnetic directive force generally proportional to engine speed. At a speed exceeding a certain limit in either direction, the switchover member deactivates the fluidic or electric operating circuit for the opposite direction whereby a shift from 'forward' to 'reverse', or vice versa, will let a change in direction take place only after the switchover member has been restored to near-normal exclusively by its biasing springs against the gradually decaying directive force previously applied. A pedal-operated linkage, coupled with the switchover member, serves for a rapid restoration of that member to normal or for fine speed control at near-zero velocities.

Growing community of inventors

Immenstaad, Germany

Willy Holdenried