Patent GB-746710-A (GB)
Title: Vehicle stabilizing system
IPC: B60G21/00
Filed: 1954-04-20
Abstract: 746,710. Spring suspensions; preventing lateral canting; preventing wheel slip. CHIODO, G. I. April 20, 1954 [April 24, 1953], No. 11314/54. Class 108(2). [Also in Groups XXIX, XXXI and XXXIV] In a stabilizing system for a steerable wheeled vehicle when travelling at high speed around a curve, all the road wheels are tiltable in unison toward the inside of the curve by a hydraulic system acting on all the wheels, the system comprising two sections each consisting of hydraulic means, one for holding the wheels vertical and the other for tilting the wheels to the right or to the left under the control of the steering means, a selector controlled by the speed of the vehicle being provided for selectively actuating the first section when the speed of the vehicle is below a predetermined value and for actuating the second section when the speed of the vehicle is above that value. As shown, each wheel 100 of a rear wheel axle assembly, Figs. 7 and 8, is carried by a short axle 0 connected to the vehicle frame by a leaf spring 1 through universal joints 1A and drivingly connected through pairs of gears 6A, 6B to a main rear driving axle. Equalizing springs 3 and hydraulic cylinders 5 are located between the axle 0 and a frame member 8 on a rear axle housing. Each front wheel of the vehicle is carried on a short axle 15, Figs. 4 and 5, tiltably supported by a bracket 11A which is vertically slidable on clamp belts 10 between supports 11. Equalizing springs 3, 9 bias the axle 15 to a horizontal position while tilting of the axle is controlled by hydraulic cylinders 5. The supports 11 are connected to suspension links 12A through universal joints 12, to permit steering of the wheel. Tilting of the vehicle wheels is controlled by a hydraulic system, Fig. 3, comprising a low pressure reservoir 79, a high pressure pump 78, a differential pressure valve 80, a balancing pressure relay 81, a high pressure reservoir 82, a selector valve 83, a cooling coil 86 and the hydraulic cylinders associated with the vehicle wheels. The cylinders 5 comprise, for each wheel, a pair of cylinders 5V on opposite sides of the axle for maintaining the wheel vertical and pairs of cylinders 5L and 5R on opposite sides of the axle for tilting the wheel to the left or the right. The differential pressure valve 80, Fig. 9, is actuated by a steering shaft 16 which, through worm gear 21, 31 and a linkage 18, 22, controls a spring-loaded slide valve 25, a casing for which is provided with an inlet port 30 for pressure fluid from the valve 83 and a discharge port 29 connected through the cooler 86 to reservoir 79. Ports 32L and 32R are connected respectively to the cylinders 5L and 5R and in the neutral position of the valve a cone-shaped opening in the valve is centred above these ports to maintain pressures at the ports 32R and 32L and consequently to the cylinders 5L and 5R. A restricted flow of pressure fluid is permitted to the port 29 through annular recesses on either side of the cone-shaped opening the arrangement being such that movement of the shaft 16 in either direction effects a change in pressure as between the ports 32L and 32R which is applied to the associated cylinders 5L and 5R to tilt the wheels. The balancing pressure valve 81, Fig. 10, is responsive to output pressure of the pump 78 at a port 39 on a spring-loaded, adjustable high pressure piston 40 and a similar low pressure piston 41. The spring loading of piston 40 is set so that excess pressure from the pump overcomes the spring loading and escapes through passages 42 from a pump inlet 36 to the reservoir 79. When the vehicle is moving at a speed below the minimum for tilting the wheels fluid flow to the pump is permitted through ports 36 and 35 to the reservoir 79, the piston 41 being moved to the right of Fig. 10. If the pump pressure is insufficient to move piston 41, fluid is supplied from the selector valve 83 to port 45 to maintain pressure in the reservoir 82. Failure of pump pressure at any speed of the vehicle causes the piston to return to the position shown to connect ports 37, 38 to the reservoir 82 and the wheel cylinders 5V thus to hold the wheels vertical. The selector valve 83, Fig. 11, is actuated by a governor 54 on the vehicle drive shaft 56 the governor being connected through linkage 58 with a spring-loaded adjustable valve 61. The loading of the valve is adjusted such that at vehicle speeds above a predetermined minimum the valve is moved to the left to connect a groove 76 with a pump inlet port 68 and a port 72 connected to the valve 80. At speeds below the minimum the wheels are maintained vertical irrespective of steering movements, the valve 61 then being in the position shown to connect ports 73 and 70. An adjustable bleed port 69 is connected to the port 45 of the valve 81 as described above. The vehicle is also provided with pneumatic tyres (see Group XXXIV).