| 摘要 |
1,152,555. Power - assisted steering mechanism. BURMAN & SONS Ltd. 22 April, 1968 [8 May, 1967], No. 21329/67. Heading B7H. In hydraulically-assisted rack-and-pinion steering mechanism comprising a pair of relatively rotatable co-axial valve members 13, 14 extending one within the other and connected by a torsion bar 16, the inner valve member 14 has a generally square cross-section and is adapted for connection to a steering shaft, and the outer valve member 13 is formed integrally with or connected to the pinion 11. Two corners of the inner member 14 co-operate with slots 20, 21 formed at right angles in the outer member 13 to control fluid flow. A sleeve 17 mounted on the outer member 13 is surrounded by sealing members 18, 19. When the inner member 14 occupies the neutral position shown, fluid supplied from a pump to an inlet port 22 flows around an annular space 23 and through ports 25, 27 to a space 29, thence across the grooves 20, 21 to spaces 8, 9 communicating with a reservoir. When the inner member 14 is rotated with respect to the outer member 13, the fluid supplied to the space 29 is directed through one groove 20 or 21 and associated openings in the sleeve 17 and one sealing member 18 or 19 to one end of a ram connected to the rack 10, the other end of the ram communicating with one of spaces 8, 9 through the other groove 20, 21. Cut-outs 41, 42 adjacent the grooves 20, 21 permit insertion of a straight-edged tool through the outer member 13 for centring the inner member 14 during assembly. Dogs 45, 46 on the members 13, 14 provide for manual operation should the torsion bar fracture or the fluid supply fail. |
