GB1057621A - Pneumatic suspension for vehicles - Google Patents

Abstract

1,057,621. Vehicle suspensions. G. FRESIA. July 24, 1963, No. 29392/63. Heading B7D. In a motor vehicle supported at least partially upon a pair of adjacent axles, one axle is mounted by mechanical spring means and the other by pneumatic spring means to which air under pressure is supplied through a valve con, trolled in dependence upon change of ride height of the mechanical suspension. The pneumatic suspension may be controlled by a single valve, or may comprise a spring at each end of the axle, each of which is separately controlled by its own valve. Lateral and longitudinal stability are given to the air sprung axle by a transverse bar and a triangular frame, respectively, disposed between the axle and the vehicle. The control valve comprises an air inlet port 38, a port 39 connected to the spring and a discharge port 40. A piston 25 is slidable within the cylindrical valve casing 20 being guided by a stem 25<SP>1</SP> and upwardly urged by a spring 27. A seal 24 is retained against the piston 25 by a collar 23 and spring 34 and apertures through the piston 25 connecting the space above the piston with the discharge port 40 may be closed by a valve 32 integral with a valve 33 downwardly urged by a spring 21. The spring 27 bears against a member 28 which is movable axially to an upper position in which the valve 32 isolates the discharge aperture 40 and the spring port 39 is connected to the inlet port 38 through the space C, or to a lower position wherein inlet port 38 is isolated and the spring port 39 is connected to discharge aperture 40. Axial movement of the member 28 is produced by relative movement of a pair of rotary cams 37, 36 attached, respectively, to the member 28 and a bracket 29. A lever 43 is pivotally mounted upon a spigot 45 integral with a block 46<SP>1</SP> to which are keyed a pair of levers 47. The block 46<SP>1</SP> is connected to the member 28 so as to impart rotary movement thereto and is movable relatively to the bracket 29. The levers 47 contact the lever 43 through an adjustable pair of screws 48 forming a lostmotion device and the actuating lever 43 is connected through a linkwork to the mechanically sprung axle, the arrangement being such that the lost-motion device provides a range in which the height correction is not operative, and beyond this lost motion, the lever 43 contacts one of the levers 47 through the screw 48 to rotate the block 46<SP>1</SP>, whereby the member 28 is moved axially to operate the valve. Rotation of the block 46<SP>1</SP> is influenced by a brake band 49. In modified constructions, the piston device is replaced by one or a pair of flexible diaphragms;