GB682110A - Improvements in or relating to telescopic suspension devices for vehicles - Google Patents

Abstract

682,110. Oleo-pneumatic suspension devices. LEVITATION, Ltd. May 24, 1951 [May 26, 1950], No. 13346/50. Class 108 (iii). A telescopic suspension device for vehicles includes a first liquid chamber of variable volume, the liquid in which is subjected to pressure exerted by the weight of the vehicle, a second liquid chamber, the liquid in which is subjected to pressure exerted by compressed air, and a pair of separate oppositely acting non-return valves controlling separate passages connecting the first and second liquid chambers, each of the non-return valves being urged towards its closed position by the pressure of liquid in the chamber into which liquid flows through that valve acting on one side thereof, a smaller area on the other side of the valve being exposed to the liquid pressure in the other chamber, and the remaining area of the other side of the valve being exposed to a low, substantially constant pressure such as atmospheric pressure. In the arrangement shown, in which a first liquid chamber 34 is defined by a plunger head 16 and a cylinder 10 and in which a second liquid chamber 33 is defined by the plunger head and a floating piston 31 within a plunger tube 11, the latter is slidable with clearance in the cylinder 10 and the plunger head engages the cylinder 10 through a fluid-tight packing 17. A pair of opposed valve members 23, 24 disposed in a bore 18 in the head 16 are urged by a tension spring 28 into seating engagement with frustoconical recesses 19, 20 respectively, to which are connected one end of each hole 21 of a series surrounding the bore 18. A space 29 between the valve members 23, 24 is connected to atmosphere through a passage 30. The valve members 23, 24 do not provide a complete seal between the chambers 33 and 34 so that under static conditions the pressures in all chambers tend to equalize and air pressure in a chamber 32 balances the load. In another arrangement, Fig. 2 (not shown), the plunger head is of substantially greater diameter than the plunger tube and the additional space around the latter communicates through ports in the head with the first liquid chamber. No floating piston is provided in the plunger tube. In another arrangement, Fig. 3 (not shown), the second liquid chamber surrounds the first chamber in which the plunger head works, the valve members and holes being interposed between the two chambers. In a further arrangement, Fig. 3 (not shown), the two liquid chambers are interconnected by a conduit in which a valve unit is interposed including two spring-loaded valves each having a stem slidable in a bore open to atmosphere. In any of the arrangements, the air and liquid may be separated by a flexible bag or diaphragm instead of a floating piston.