GB1041598A - Improvements in or relating to fluid valves - Google Patents

Abstract

1,041,598. Power-assisted steering. BENDIX CORPORATION. Dec. 10, 1963, No. 48633/63. Heading B7H. [Also in Division G3] A valve for a vehicle power steering system comprises two passages between a pressure fluid inlet- 16 and an outlet 12 to a reservoir 22, each passage containing an inlet orifice 48 or 50, an outlet orifice 56 or 58 and between the orifices a port 66 or 68 leading to a working cylinder and a flapper valve 38 which simultaneously restricts the inlet orifice of one passage through a plunger 90 or 92 and the outlet orifice of the other passage while increasing the openings of the other two orifices when rotated to move the piston 26 in the working cylinder. In the embodiment a steering shaft 34, which has the flapper valve 38 formed thereon, is connected, by a torsion bar 40, to a rotary valve member 44 with annuli 46, 74, 76 and passages interconnecting the inlet, outlets and orifices. Resilient pads 83, 84 on the flapper valve and the plungers 90, 92, maintained in contact with the flapper valve by the fluid pressure on their ends 91, 93, coact with the orifice openings and, should the pressure fluid supply fail, contact the openings to provide a direct connection between the steering shaft 36 and output member 42 to maintain steering control. The degree of " feel " is determined by the dimensions of the torsion bar 40 and the relative diameters of the orifices and the neutral position of the valve is adjustable by rotation of the threaded orifices in the valve member 44.