Improvements in servo-steering systems for automobile vehicles

Abstract

Abstract 1,132,497. Steering vehicles. ANDRE CITROEN S.A. 24 Feb., 1966 [16 March, 1965], No. 8225/66. Addition to 1,002,557. Heading B7H. In order to overcome unsteadiness in the return to straight-ahead position in the power assisted steering mechanism of Specification 1,002,557, wherein a cam follower acting upon a cam geared to a motor vehicle steering shaft is subjected to a variable-pressure fluid circuit in order to create steering resistance, a return-flow restriction valve is included in the circuit. In one embodiment, a steering movement causes the cam follower to move a piston against the pressure exerted in the fluid circuit, the fluid moving through an orifice controlled by a spring-loaded clapper valve. The clapper valve is urged against its seating during the return movement, and has a calibrated orifice allowing restricted fluid flow. In a modification, Fig. 2, the clapper valve 31<SP>1</SP> closes an orifice 34<SP>1</SP> and a slide valve 35 having a calibrated orifice 36 is acted upon by the pressure in the fluid circuit 11 and by a spring 38 and co-operates with an orifice 39 in a chamber 37. During the steering movement, fluid flows through orifice 34<SP>1</SP>, and during the return movement, the return flow through orifice 39 is throttled by the slide valve 35. In a further modification, Fig. 3, the slide valve comprises a fixed member 42 and a slide 43 acted upon by a spring 45 whose other end acts upon the piston 46. The orifice 49 through the fixed member 42 includes a baffle portion 47 which is closed during steering movements. Return flow is through the orifices 49 and 44 and is restricted by the baffle 47 and the pressure upon piston 46 during a return movement to straight-ahead steering is due to spring 45.

Inventors

No inventors recorded.

Bibliographic Details