GB964594A - Improvements relating to hydraulic or pneumatic motor vehicle controls - Google Patents

Abstract

964,594. Controlling vehicles; levelling vehicles. G. D'ESPINASSEY DE VENEL. March 24, 1961 [March 26, 1960; Feb. 22, 1961], No. 10805/61. Headings B7D and B7H. [Also in Divisions F1, F2 and G3] An hydraulic or pneumatic control system in a vehicle comprises a source 31, Fig. 9, of fluid under pressure or suction connected in circuit with several fluid-operated mechanical devices, such as for power steering, wheel suspension, gear shifting and clutch actuation of the vehicle, and a multi-positional distributer 181, 182 connected in the circuit and selectively displaceable to different positions in each of which only a single one of the devices is effectively connected to the source so as to permit the individual testing of any one of the devices. The distributer consists of two parts 181, 182 connected by a passage 186, part 181 having a control passage 184 selectively connectable by radial passages to a number of taps a . . . x each connected to parts of the circuit such as the cylinders 37, 37<SP>1</SP> and valve 45 of the wheel suspension, the cylinder 101 and valves 97, 97<SP>1</SP> of the power steering, the cylinder 124 and valves 128, 133 of the clutch actuator, and the selector valve 165 and cylinders 166, 166a, 166b, 166c of the gear change mechanism. The taps a to x of the part 182 are connected to corresponding parts of the circuit. The part 181 can be moved clockwise from an operative position shown, in which the pump 31 and a hydro-pneumatic accumulator 33 are connected to the circuit, to a position wherein the pressure from the pump and accumulator is indicated on a gauge 57, and anticlockwise to a position wherein the pressure from the pump only is indicated on the gauge. With the part 181 in the operative position shown, the part 182 of the distributer can be moved to bring a radial passage 183 into correspondence with any one of the taps a to x to enable the pressure in the device connected to the selected tap to be indicated on the gauge 47. A relief valve 56 determines the maximum pressure in the circuit and a safety valve 60 protects the gauge 57. The mechanical devices and distributer may be housed in a single casing or be located in various positions and connected by conduits to the distributer. Wheel suspension.-The front wheels 2, 3, Figs. 7 and 8, of the vehicle are carried by axles 8 connected to triangular arms 12, 13, 12<SP>1</SP>, 13<SP>1</SP> pivotally mounted on the chassis 1, the upper links 12, 12<SP>1</SP> being extended to form levers 36, 36<SP>1</SP> engaging the ends of pistons 37, 37<SP>1</SP> in cylinders 38, 381. The pistons are urged upwardly by fluid pressure from hydropneumatic accumulators 41, 41<SP>1</SP>, supplied with fluid pressure from an inlet 46 connected to the pump 31 (Fig. 9), under the control of a valve 45 urged upwardly by a spring 53 into engagement with a lever 51 secured to a rod rotatably mounted on the chassis and joined by links 52 to the arms 12, 12<SP>1</SP> the arrangement maintaining the trim of the front of the vehicle to compensate for variations of load. The arms 23 for the rear wheels 4 are secured to rods 61 which act through linkages 62, 63, 64 on a similar arrangement of pistons, accumulators and valve which maintain the trim of the rear of the vehicle irrespective of the load. In an alternative arrangement, the accumulators are disposed adjacent their respective wheels. Various points in the circuit of the suspensions, such as the pistons 32 and valve 45, are connetted to a distributer which selectively connects the points to a gauge for testing the operation of the circuit (Division F1). Power steering.-The steering wheel 81, Fig. 4, of the vehicle is connected by a column to a pinion 83 engaged by planet wheels 84 mounted on a carrier 85 and engaging an internal gear 86 having external teeth 87 engaging a rack 88 on a rod 89 connected by links 91 to the front wheels of the vehicle. The planet carrier 85 has arms 85a, 85b cooperating with valves 97, 97<SP>1</SP> so that when the steering wheel is moved in one direction or the other, the carrier displaces the valves 97, 97<SP>1</SP> and fluid pressure from an inlet 104 connected to the pump 31 (Fig. 9) is supplied to one side or the other of a piston 105 on the rod 89 which moves to steer the wheels, the space on the opposite side of the piston being connected to exhaust 103. The movement of the rod 89 causes the gear 87 to rotate and return the carrier to its original position and disconnect the inlet and exhaust passages from the piston. Various points in the circuit of the power steering, such as the valves 97 and the cylinder 101 for the piston 105, are connected to a distributer which selectively connects the points to a gauge for testing the operation of the circuit (Division F1). Clutch actuation and gear change.-The clutch and gear change of the vehicle are actuated by a lever 121, Fig. 6, on the steering column 82 which, when moved upwardly, causes downward movement of a rod 122, Fig. 3, connected by links 131 to a bell-crank which is rocked to displace the spool of a valve 128 against a spring so that fluid pressure from an inlet 130 connected to the pump 31 (Fig. 9) moves a piston 24 against the springs 126 of a clutch which is thereby disengaged; the exhaust passage 132 from the cylinder of piston 124 is closed by a valve 133 to maintain the clutch temporarily disengaged during the ensuing gear change. Movement of the selector 164 connected by a link 174 to the rod 122 rotates a hub 163 on which is pivotally mounted a rod 161. The hub 163 carries an arm 169 having an arcuate segment and a hole 168 which can be positioned by the selector beneath a selected one of four piston-and-cylinder devices 266 associated with first, second, third and reverse gear, respectively. When the hole is positioned beneath the selected device, fluid pressure from an inlet 172 connected to the pump 31 (Fig. 9) moves the piston 166 downwardly so that a plunger engages the lever 161, one end of which rocks one or other of bell-crank levers 151, 152 to axially move one or other of a pair of rods 141 engaging the dog 144 of the gearbox for movement into engagement with one or other of gears 146, 147; the opposite end of the arm 161 displaces the spool of valve 133 upwardly to connect the space above the clutch-actuating piston 124 to the exhaust 135 and a sump 47 to permit the springs 126 to re-engage the clutch. When the selector is moved to engage a different gear, the plunger of the piston 166 of the previously selected gear temporarily prevents rotation of the hub 163 and a cam surface 173 axially displaces the spool 120 of the selector valve to disconnect the inlet 172 from the device 166 which is then connected to exhaust, the cam face permitting the inlet to be reconnected to the devices after movement of the selector to its next position. Various points in the circuit of the clutch actuator and gear change mechanism, such as the cylinder 124, valves 128, 134, 170 and the cylinders 166, are connected to a distributer which selectively connects the points to a gauge for testing the operation of the circuit (Division F1).