GB793667A - Control valves more particularly for power-assisted steering - Google Patents

Abstract

793,667. Valves. TEVES, H., and TEVES, E. A., [trading as TEVES MASCHINENUND ARMATURENFABRIK KOMM-GES., A.]. March 15, 1956 [April 9, 1955], No. 8156/56. Class 135. [Also in Group XXXI] A vehicle steering-box has an integral valve block 1, Fig. 1, within which is the steering shaft 2 having a valve disc 3 splined thereon, the disc 3 being arranged between the flange 4 of a shaft 8, rotatably mounted on the shaft 2, and a thrust member 6 secured to the flange 4 by bolts 5 passing through holes in the disc 3 that are of greater diameter than the bolts. The shaft 8 carries the steering worm-gear 7. With the steering-wheel in the neutral position the disc 3 is spaced from the flange 4 so that pressure fluid entering a passage 11 passes to a reservoir through a port 17 via an annular channel 12 and passages 13 in the shaft 8, ports 14 in the upper surface of the flange 4, the space between the latter and the disc 3 and a chamber 16. Upon clockwise rotation of the steering-wheel the disc 3 firstly rotates relatively to the flange 4 and member 6 so causing balls 10 between the disc 3 and member 6 to ride up the inclined surfaces of recesses 9 in the latter and urge the disc 3 to seat upon the flange 4. Fluid in ports 14 then flows through arcuate grooves 15 in the disc 3 to ports in the flange 4, adjacent one side of the ports 14, from which it travels via an outlet passage 20 to one of the working cylinders, not shown, connected to the steering arm, whilst radial grooves in the disc 3 coincide with other ports in the flange to connect a second working cylinder to the reservoir by way of a passage 21 and chamber 16. When the clearance between the bolts 5 and disc 3 has been taken up the parts 4, 6, 7 and 8 will rotate as one with the disc 3 and shaft 2. Counter-clockwise movement of the steering-wheel causes the second working cylinder to receive pressure fluid and the first cylinder to be exhausted. In a modification, the thrust member is dispensed with and the steering shaft 33, Fig. 6, enters from the top of the casing; the grooves 15, Fig. 1, are replaced by arcuate bushes. Relative motion between the disc 30, Fig. 6, and flange 31 displaces hemispherically ended pins 32 in a vertical direction to draw the disc toward the flange until the bushes seat upon the latter. In another modification, the disc 48, Fig. 7, is fixed to a spider 47 riveted to an annular member 45 splined to the steering shaft 44; balls in the spider 47 engage tapered recesses in the disc 48 and a thrust member 43 secured to the flange 40 of the worm-carrying shaft 41 by a sleeve 42.