Trw Limited

Fredrick D Venable

Wendell L Gilbert

Jerry L Cage

David C Shropshire

Michael R Morsches

A hydraulic power steering gear (10) comprises first and second relatively rotatable valve members (40 and 42). The first valve member (40) includes a radially extending passage (64). The second valve member (42) has an arcuate cam surface (184). A detent member (220) acts between the first and second valve members (40 and 42). The detent member (220) has a curved outer surface (252). A spring (240) biases the detent member (220) radially outward against the cam surface (184). The spring (240) is disposed in the radially extending passage (64) in the first valve member (40). The detent member (220) is disposed in the arcuate cam surface (184) in the neutral condition and provides a physically perceptible indication to a driver of the vehicle of operation of the steering gear (10) between the neutral condition and the actuated condition.

Detent mechanism for a hydraulic power steering gear

A steering apparatus for artificially establishing steering feel in a steering system not having a mechanical connection between the steering wheel and the steerable wheels. The apparatus includes a hydraulic steering motor connected to the steerable wheels. A steering wheel position sensor and a steerable wheel position sensor each produce an electrical signal respectively indicative of the steering wheel position and the position of the steerable wheels. An electronic control unit monitors the sensor signals and controls a solenoid operated directional control valve to steer the vehicle in a direction and at a steering rate in response to the monitored signals. An electromagnetic friction brake is connected to a support and to the input shaft and is controlled by the electronic control unit to provide steering feel. The friction brake includes an armature fixed to the support and a brake member secured for rotation with the input shaft via a spline conneciton. The brake member is movable toward the armature under the influence of the magnetic field generated by the armature. The degree of mechanical coupling between the armature and the brake member is proportional to the magnetic field strength. Steering feel is controlled by the electronic control unit in response to the difference between the desired steering direction, as determined from the steering wheel position sensor, and the actual steering direction, as determined from the steerable wheel position sensor.

Apparatus for establishing steering feel

A steering column having a pair of steering column members arranged coaxially about a first axis. One of the steering column members is axially movable along the first axis relative to the other steering column member. The steering column members are supported for angular movement about a second axis extending transverse to the first axis. A first lock releasably locks the members in one of a plurality of relative axial positions along the first axis. A second lock releasably locks the members in one of a plurality of angular positions about the second axis. A control lever is mounted for pivotal movement toward and away from a neutral position. An actuator operates in response to pivotal movement of the control lever away from the neutral position in a direction of desired movement of the one member to actuate one or both of the first and second locks to release the one member for movement to the desired position in the same direction in which the control lever is moved.

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Lafayette, IN, United States of America

Fredrick D Venable