초록 ▼

A road vehicle has steerable front and rear wheels, the rear wheels being steered by an electro-hydraulic system responsive to the manual control input to the front wheels. The hydraulic actuator of the system is biased to the straight-ahead steering position by springs, so that the rear wheels are

A road vehicle has steerable front and rear wheels, the rear wheels being steered by an electro-hydraulic system responsive to the manual control input to the front wheels. The hydraulic actuator of the system is biased to the straight-ahead steering position by springs, so that the rear wheels are centered in the event of electric or hydraulic failure, and an hydraulically restrained latch element is spring biased to then latch the actuator piston in its centered position.

대표청구항 ▼

A steering control system for a vehicle having steering wheel means, said system comprising: a power source, said power source comprising a pressure fluid circuit, an actuator adapted to apply power from said power source to effect steering movement of said steerable wheel means, said actuator compr

A steering control system for a vehicle having steering wheel means, said system comprising: a power source, said power source comprising a pressure fluid circuit, an actuator adapted to apply power from said power source to effect steering movement of said steerable wheel means, said actuator comprising an hydraulic actuator included in said pressure fluid circuit, said actuator having a piston therein, control means for controlling said application of power to said actuator, said control means comprising a control unit adapted to provide a command signal and a servo-valve included in said pressure fluid circuit and responsive to said command signal to operate said hydraulic actuator, centering means adapted to effect movement of said wheel means to the straight ahead condition thereof on failure of said system, a latch cylinder, a latch piston movable in said latch cylinder and held by fluid pressure in normal operation of said system in a first position, spring means biassing said latch piston to a second position, and ball means held by said latch piston in said second position thereof in latching engagement with said actuator piston to hold said actuator piston against axial movement, said ball means being movable by said actuator piston out of said latching engagement in said first position of said latch piston.