GB835413A - Improvements in suspensions of vehicles - Google Patents

Abstract

835,413. Road-vehicle spring suspensions; pneumatic suspension units. SOC. DES BREVETS J. A. GREGOIRE. June 14, 1956 [June 15, 1955; Jan. 9, 1956], No. 18401/56. Classes 108(2) and 108(3) The suspension of each road wheel comprises a mechanical spring 3 the rate of which is practically constant, and a pneumatic spring 45 of variable, rate, the rate of the suspension as a whole varying in a linear manner with reference to the load. The spring may be a leaf spring, as shown, or alternatively a torsion bar, rubber, or coil spring. The pneumatic spring comprises a hemispherical shaped member 44 of metal rigid with the chassis frame 2, and a correspondingly shaped diaphragm 46 of rubber which is in abutment with a member 53 rigid with the axle 1. When the vehicle is unloaded and at rest the pressure in the pneumatic spring is equal to that of the atmosphere, nearly all the load being taken by the spring 3. In a modification the spring 45 is replaced by a combined pneumatic suspension unit and hydraulic shock absorber (Fig. 2). This comprises liquid chambers 17, 18, connected by one-way valve and restricted passages 21, 22, and a chamber 15 in which air is compressed by the action of a piston 12. On compression of the device, liquid displaced from the chambers 17, 18 is displaced into a central tube 23. In a modification of this device (Fig. 4, not shown), the chambers 15 and 17 provide the hydraulic chambers of the unit and the chamber 18 contains compressed air to function as the pneumatic spring. The chamber 15 also contains some air to compensate for entry of the piston rod 23 into the chambers 15 and 17 on compression. In this connection the piston rod is solid and the valves 21, 22 are formed in the piston 12.