Multiple displacement hydraulic motor drive apparatus

Multiple position fluid conductor apparatus

Multiple-stage actuating device

Pneumatically operated percussion boring apparatus

Power steering device

Power steering device

Power steering gear with proportional flow divider

Pressure detecting device

Pressure medium servo motor, especially for servo steering syste

Proportional control valve with preconditioned inlet modulating

Servo system method and apparatus, servo valve apparatus therefo

Simplified fail-fixed servovalve

Spring centered balanced resolver valve

Supply apparatus for two receiving means having a pressure summa

Three way valve and electro-hydraulic actuator using same

Tilt tip circuit with bypass valve

Vaned hydraulic motor

Variably biased control mechanism