GB866315A - Vehicle suspension - Google Patents

Abstract

866,315. Lifting weight off springs; pneumatic or hydropneumatic suspensions. GIRLING Ltd. Nov. 9, 1959 [Aug. 7, 1958], No. 25311/58. Class 108(2). A vehicle with a pneumatic or hydropneumatic suspension system, has a strut 26 (Fig. 5) which can be locked in position to prevent the vehicle from sinking on its suspension when stationary. During travel of the vehicle an electric motor 10 drives a compressor 11 which delivers air to a reservoir 13 from which air is supplied through a levelling valve 14 to a suspension unit. A pipe line 19 leads from the reservoir 13 to a pressure-operated spring- loaded switch 16, in series with the motor and the ignition switch 22, and also to a pressureoperated spring-loaded switch 21 in series with the ignition switch 22 and controlling the energization of a solenoid 23. This solenoid is adapted to withdraw a spring-loaded pawl 24 which, when the solenoid is de-energized i.e. when the ignition switch is opened holds the pawl in engagement with ratchet teeth 25 on a strut 26. If the pressure in the reservoir 13 and hence in the suspension unit falls while the vehicle is stationary, the switch 16 closes and the switch 21 opens so that when the ignition switch is closed the motor 10 is energized to restore the pressure in the system. The solenoid 23 is not energized until the pressure has returned to normal. In modifications (not shown), the means for controlling the pawl 24 may be a spring and piston and cylinder device, or two solenoid operated pawls may be provided co-operating with oppositely directed ratchet teeth on the strut 26. In a further modification (not shown) two solenoid operated pawls are provided, one of which holds the strut in the highest position to which it is moved during travel of the vehicle. The strut may be replaced by a quadrant having ratchet teeth.