Patent GB-1174149-A (GB)
Title: Improvements in and relating to Suspension Systems for Vehicles
Inventor: PITCHER ROBERT HAZELL
IPC: B60G17/015
Filed: 1967-08-16
Abstract: 1,174,149. Adjusting suspension height. AUTOMOTIVE PRODUCTS CO. Ltd. 30 July, 1968 [16 Aug., 1967; 12 Feb., 1968], Nos. 37582/67 and 6828/68. Heading B7D. [Also in Division F2] A vehicle suspension having a telescopic fluid-filled strut, the length of which is varied in order to control the body height with respect to the ground, is controlled by a unit comprising a spool valve, the spool being movable in opposite directions to connect the strut respectively to a fluid pressure source or to a drain, and a linkage including a member movable by relative wheel-to-body movement, from which is pivotally suspended a weight, attached at a point lower than its point of suspension, to a second member which is coupled to the valve spool, the weight tending to maintain a constant position relative to the first member, thus causing the second member to follow the movements of the first member, and thus actuating the valve to adjust the body height. As shown, the suspension comprises a wheel carrier member 13, upper link 14 and lower link 16 upon which is seated the control member 25 and to which is connected the hydraulic strut 18 which incorporates a gas spring 23, or may be in series with another compression spring. The control member 25, Fig. 3, has a fluid pressure supply connection 26, an output connection 24 to the strut, and a connection 28 to drain. Fluid flow from the connection 26 is blocked by the valve spool 38 in the neutral position shown, and by movement of the spool 38 to the right is connected to the strut via 24. Movement of the spool to the left opens the strut to drain via 24, a chamber 35, port 44 and connection 28. A sliding member 33 is connected by a link 32 to the wheel carrier 13 so that upward and downward movements of the wheel move the member to the right and left, respectively. A weight 36 is suspended from the member 33 and connected by a link 39 to the spool 38 so that the latter follows the movement of member 33 with damping caused by the action of the fluid in chamber 35 upon the weight 36. A spring-loaded pressure control member 43 acting on the flow connection 24 maintains a minimum pressure in the strut. The vehicle height is controlled by virtue of movements of the member 33 and centrifugal force acting on the weight 36 thereby operating the spool 38 to control roll while cornering. Alternatively, the control device may be arranged obliquely so that both roll and pitch are controlled. A single control unit may be associated with each wheel suspension, all being connected in parallel to a common source of pressure and drain. A rear live beam axle may have a telescopic strut adjacent each wheel, both struts being controlled from a single unit 25 arranged longitudinally whereby height and pitch only are controlled. Rapid suspension movements due to road shocks are controlled by virtue of inertia movements of the weight 36 about its centre of gravity. Alternatively, the valve spool may be connected to the weight at its centre of gravity to eliminate the latter control. In a modification, Fig. 5, the weight 54 is suspended from the member 33 by a pivotal connection and by a spring 55, the connection to the valve spool being either at or below the centre of gravity. In a modification of Fig. 1, the control unit is mounted on the vehicle body 10, the control member 33 being connected to the upper link through a crank.