Patent GB-722709-A (GB)
Title: Improved controlling system for clutch-operated vehicle steering mechanism
IPC: B62D11/08
Filed: 1951-07-04
Abstract: 722,709. Operating clutches. GATES, G. R. G. June 25, 1952 [July 4, 1951; Feb. 26, 1952], Nos. 15918/51 and 5048/52. Class 80 (2) [Also in Group XXXI]. Relates to a vehicle driving and steering system (see Group XXXI) having a pair of normally engaged main clutches and a normally disengaged steering clutch, steering being effected by disengaging one main clutch and engaging the steering clutch through a lever device whose reaction during the disengagement of the main clutch effects engagement of the steering clutch, and the steering clutch being arranged between the crown wheel and planet carrier of a normal differential gear. As shown in Fig. 4 the driving element 15c of one of the main clutches 15 is integral with a drive input gear 12 which is splined to a shaft 11. The driven element 15b of the main clutch 15 is gear-connected to its road wheel and the driving and driven elements 15b, 15c are normally engaged through plates 15d by a spring 56; a similar arrangement is provided for the other main clutch 16, the spring 56 urging that clutch into engagement. The spring 56 acts on the clutches through spools 15g, 16g, each of which are abutted by push rods 15f acting on the plates. Pairs of clutch releasing levers 46b, 53b are pivoted below and above, respectively, the shaft 11 and carry projections 58 to operate on the spools against the action of the spring 56. Each pair of clutch releasing levers, for example 46b, are con-, nected to a cross bar 44, Fig. 2, secured by means of an adjusting nut 45 to a rod 43 which is forked and the forks pivoted at 41 to a lever 40. The lever 40 carries a cam 76, which in the clutch engaged position has one of its ends bearing against a roller 79 carried by a rod 35. The other end of the lever 40 is pivoted to an element 72 slidably mounted on a rod 67, the element bearing against lock nuts 70 on the rod. The rod 67 is connected by a cross bar. 65 to lever 66b for operating the steering clutch. The rods 35 are connected to a pair of steering levers or a steering wheel so that when it is desired to steer to the left, for example, the rod 35 is moved in the direction' of the arrow 38. Such movement of the rod 35 causes the lever 40 to be moved to the right, and with it the rod 43, to release the clutch 15 against the action of the spring 56. By the time the clutch 15 is fully disengaged the roller 79 is level with the pin. Further movement of the rod 35 causes the spring 56 to urge the lever 40 in a clockwise direction around the roller 79, and this causes the rod 67 to be moved to the left to engage the steering clutch. The rod 67 is formed with a fitting 85 which is connected to a brake pedal or lever (not shown), by means of which the steering clutch can be engaged whilst the main clutches are engaged to cause the arrangement to operate as a friction brake. In another embodiment, Fig. 5, levers 119, 120 for operating the main clutches are connected to cross arms 44, 52 which are each connected to a rod 43 through which passes a pin 101 engaging slots 104 in a U-shaped bracket 103 fixed to the vehicle. The rods 43 are interconnected by a spring 98 which urges the main clutches into engagement and the pins 101 are pivoted to levers 40, 47. The lever 47 is connected to a block 73 slidably carried on a rod 67 carrying a cross arm 65 connected to arms for operating the steering clutch, engagement of which is resisted by a spring 113. The rod 67 slidably carries a sleeve 108 which is connected by a reversing motion linkage 109, 110, 112 to the lever 40. The rod 67 carries a flange 118 acted on by arms 117 carried by a shaft 116, rotation of which causes the steering clutch to be engaged whilst the main. clutches are engaged to act as a brake. Movements of the levers 40, 47 are controlled through bell crank levers 106, actuation of which causes the levers 40, 47 to move to the left and right respectively. Such movement of the lever 47, for example, causes the rod 43 to move to the right to disengage its main clutch and the latter movement causes the force of the spring 98 to be partly applied to engaging the steering clutch. In a further embodiment, Fig. 7, the invention is applied to clutches which are fluid pressure operated, the main and steering clutches being controlled by, pressure regulating valves 126, 127, 128 of the reaction type, the valves 126, 127 for the main clutches being urged by springs 133, 137 into their clutch-engaged positions and the linkage being otherwise the same as that shown in Fig. 2. As rods 134, 139 are moved against the action of the springs 133, 137 to disengage the main clutches, the forces of the springs are transferred to cause movements of the levers 40, 47 and hence movement of the rod 67 to engage the steering clutch by movement of the valve 128. Specification 563,339, [Group XXXI], is referred to.