| 摘要 |
1,206,211. Vehicle mechanical power steering. MICAPIA, and ETABS. PIAT. 11 April, 1968 [13 April, 1967; 18 Aug., 1967], No. 17689/68. Heading B7H. A servo-control system for steering a vehicle or controlling a machine-tool such as a press, comprises a driving member 24 adapted to rotate a driving shaft 25 at a constant rate, a device 18 to convert rotation of a steering wheel controlled shaft 7 into translatory movement of a sliding driven element 20 of a clutch, two selectively engageable driving clutch elements 23A, 23B, which are arranged on either side of the driven element 20 and are connected to be driven by the driving shaft 25 in opposite senses but at the same speed, and a kinematic chain coupling the driven clutch element to a member for actuating vehicle steering means or a press. In Fig. 1 an electric motor drives the driving shaft 25 which drives through epicyclic gear trains 25, 28 and 32A, 33, the clutch members 23A, 23B which have conical surfaces engageable with corresponding conical surfaces 21A, 21B of the driven clutch member 20. On rotation of the steering wheel shaft 7, due to the action of a multi-start thread 18, the driven clutch element 20 engages one or other of the members 23A, 23B by which it is driven and in turn drives two or more planet gears 13A, the carrier 12 of which has a pinion 10 formed thereon which meshes with a steering rack 9 or sector. Alternatively, Fig. 4, the clutch driving elements 23A, 23B are provided with external ratchet teeth engaged by pawls carried by 2 sets of eccentrics 53a, 53b, 53c and 54a, 54b, 54c on the driving shaft 24 and the pinion 10 and driven clutch member are interconnected by splines 50 to permit relative axial movement between them. In a further alternative, Fig. 6, the driven clutch element has keyed thereto the pinion 10 and is moved axially, on rotation of the axially-movable shaft 56 to engage one of the clutch driving elements 23A, 23B, by the reaction between the helically cut teeth of the rack 9 and pinion 10. The driving shaft 24 may be driven at a selected one of two speeds or at a speed inversely proportional to the speed of the vehicle in which it is used. |
