Patent GB-652698-A (GB)
Title: Improvements in or relating to suspension systems for vehicles and the like
IPC: B60G21/06
Filed: 1948-02-25
Abstract: 652,698. Adjusting vehicle-body height; hydro-pneumatic shock absorbers. SOC. D'INVENTIONS AERONAUTIQUES ET MECANIQUES S.I.A.M. Feb. 25, 1948. No. 5660. Convention date, Feb. 26, 1947. [Classes 108(ii) and 108(iii)] A vehicle suspension system comprises  one or more oleo-pneumatic shock absor-  bers, a pressure fluid line, a control valve  or valves operable to connect the shock absorbers to the supply line or to exhaust,  and actuating means for the valves opera-  tively connected to the body and wheels  so that relative movement of the latter  actuate the valves. Each suspension unit  (Fig. 3) comprises a plunger 18 slidable  in a cylinder A and having a damping head 19 provided with blade-spring flap-  valves 28 30, of the kind described in Specification 652,697. The effect of the valves 28, 30 is supplemented by a series of grooves 37 of varying length, in the cylinder wall. The cylinder A has a rigid diaphragm 23 through which the plunger is slidable to compress air in an upper chamber a. The chamber 20 below the diaphragm 23 is full with liquid which extends into the chamber a to a level defined by the termination of an air conduit 26 which is surrounded by a baffle 27. The conduit 26 of each suspension unit A, A<SP>2</SP> and A<SP>3</SP>, A<SP>4</SP> corresponding to the front and rear pairs of wheels, is connected to a  valve B or C Fig. 2 (not shown) respectively. The valves B, C are operatively connected with the respective front or rear  pairs of wheels so that in the normal posi-  tion of one of the pairs the corresponding  valve is set to connect by pipes 7 the res-  pective pair of conduits 26 with a reservoir  9. A mean deflection of the pair of wheels of a predetermined amount causes the valve to connect the conduits by pipes 6 with a pneumatic accumulator 8 (charged by a compressor 10) and disconnect them from the reservoir. The compressor 10 draws its .air supply from the reservoir 9, through a pipe 10a. The opening 14 of the pipe 10a has a jagged contour and overlies a quantity of liquid 12 contained in the reservoir 9. The liquid 12 is connected by conduits 15 with a liquid chamber 34 surrounding the plunger 18 of each cylinder A, between main and auxiliary glands 33, 34 of the kind described in Specification 651,869, [Group XXVI]. In a modified construction (Fig. 6) (not shown), the unit A is disposed horizontally and its diaphragm 23 is provided with a pair of longitudinally spaced glands between which there is a liquid space in direct communication with the liquid in the space a. The front and rear pair of wheels are connected by a respective anti-roll stabilizer bar the midpoint of which is linked with the operating arm of the corresponding valve B or C. Operation. The valves B and C operate to connect the units A with the reservoir 9 or accumulator 8 according the nature of the vehicle load. If the liquid level in one of the units A rises above the level of the exit of the conduit 26, it is blown into the reservoir as soon as the respective valve B or C is correspondingly set. When the level of the liquid rises above the outlet 14 of the pipe 10a in the reservoir 9, it is drawn by the pump and discharged into the accumulator as at 38 and from thence it is discharged to the respective units A<SP>1</SP>-A<SP>4</SP> when the settings of the valves B, C so allow.