GB1011095A - Improvements in or relating to a method and a device for regulating the level and/ortrim of a vehicle - Google Patents

Abstract

1,011,095. Levelling vehicles. REGIE NATIONALE DES USINES RENAULT. Dec. 18, 1961 [Dec.28, 1960], No. 45256/61. Heading B7D. In a system for maintaining the level of a vehicle, each wheel is connected by links 13, 12, Fig. 2, to the piston of a wheel cylinder 11 connected to a levelling valve 19 in a fluid circuit comprising a reservoir 15 and a pump 17. The reservoir, Fig. 4, comprises a container 40 having a fluid space 42 separated from an air space 43 by a diaphragm 41 acted upon by a spring 44. The levelling valve, Fig. 3, comprises a housing 20 and a sliding spool 23 having axial bores 24 and 29, radial bores 26, 26a and 31 and annular grooves 27 and 27a. The housing 20 has a recess 21, radial bores 22, 28 and 30 extending into the recesses 21 and groove 27 and 27a respectively, in the shown position of the valve spool, and a longitudinal bore 38 connecting the recess 21 with a chamber 32a formed by a flexible bellows 32 and a plate 33 connected to the valve spool 23 and acted upon by a spring 34a, the chamber 32a being contained within a cap 36 into which air may be pumped through a one-way valve 37.. The bore 29 is closed and a piston 25 is located in the bore 24. In the position shown, corresponding to the normal riding height, the pump 17 is short-circuited by the passage 38, represented in Fig. 2 by the line 39, and the cylinder 11 is connected by the line 16 and passage 28 to the bore 27, the forces on the spool 23 due to the fluid pressures in the bore 24, and chambers 21 and 32a, and the pressure of spring 34a, being in equilibrium. If a load is applied to the vehicle, increasing pressure in the bores 28 and 24, the spool is moved against the action of spring 34a and pressure of the gas in the chamber 36a, and the groove 27 comes into register with the bore 30, the pressure fluid from pump 17 now being delivered to the wheel cylinder to restore the vehicle height. If the load upon the vehicle is decreased causing a drop of pressure in the bores 28 and 24, the spool will ascend to the position whereby the groove 27 opens into the chamber 21 and thus exhausts to the reservoir whereby the vehicle height is diminished.