GB549354A - Improvements in and relating to rotary steering - Google Patents

Abstract

549,354. Fluid-pressure servomotors. STOCK, C. S. R., and ASSOCIATED EQUIPMENT CO., Ltd. Feb. 5, 1941, No. 1521. [Class 135] A servomotor steering arrangement for motor road vehicles has the servomotor distributing valve and the parts operating it from the steering wheel concentrated in or closely associated with the steering wheel in what may be termed a steering wheel assembly so that the device may be fitted to existing steering gears without structural alterations. In the form shown in the Figures the hand wheel is mounted for limited relative rotary movement on a flanged boss c secured to the tapered upper end of the steering column b, movement being limited by a projection k on the flange d engaging a slot l in the hand wheel. The projection k is fitted with abutments m, n loaded by pre-compressed springs adapted to come into operation when about half the clearance has been taken up. To prevent the servomotor coming into operation until a predetermined pull is exerted on the handwheel a spring- loaded plunger f carried by the wheel engages a recess j in the flange. The rotary disc distributing valve 4 is held to its seat by a spring- pressed ball 7 and is oscillated by a spindle v fitted with a crank arm u engaging a slot t in a sleeve s slidably mounted on the boss c. This sleeve s is formed with a pair of lugs 2 pivoted to arms 1 on a shaft rotatably mounted in the boss and having a further arm by engaging a slot x in a web w integral with the handwheel. The valve seat has two exhaust ports and two connected ports leading to each side of a doubleacting piston. The valve member has a segmental supply port 4b and passage 4c and a segmental exhaust passages 4a so arranged that when the valve is in its neutral position the exhaust passage connects the two sides of the power piston while the supply and exhaust connections are blanked off.