Patent GB-578281-A (GB)
Title: Vehicle suspension and steering mechanism
IPC: B62D7/14
Filed: 1943-09-28
Abstract: 578,281. Vehicle suspension and steering mechanism. COLLIS, R. Sept. 28, 1943, No. 15873. Convention date, Sept. 21, 1942. [Class 79 (v)] [Also in Group XXXII] A motor vehicle or trailer is provided at one end at least with road wheels 8 mounted on steerable stub axles 7 pivoted at the ends of a main axle 6 from which the weight of the vehicle is suspended at points 10 below the level of the road wheel axes in such a manner as to permit lateral movement of the body of the vehicle relatively to the axle 6, this lateral movement being utilised through front track rods 26, fixable to the body, to steer the road wheels. In the case of a trailer, the drawbar 16 causes the lateral movement ; in the case of a motor vehicle a power device 29, Fig. 6, may be used to cause the movement and steer the vehicle. The vehicle may have four wheels as shown in full lines in Fig. 6, or six wheels, a central pair of driving wheels being provided as indicated in dotted lines. Preferably the steering movements of the wheels at one end of the vehicle are transmitted to those at the other end by fluid transmission pipe-lines 21a ... 21d, means being provided for locking the rear wheels against steering movement when desired, these means being preferably controlled by the gear lever so that (1) the rear wheels are steered only when the vehicle is in low gear, and (2) both front and rear wheels are locked against steering and lateral movement of the vehicle body is prevented when the gear is in neutral. In the construction shown in Figs. 4-6, the vehicle frame (not shown) is mounted on springs 4 on secondary axles 1 suspended by links 9, having pivots 10, 12 from the main axles 6. The stub axles 7 have steering arms 13 connected together by front and rear track rods 14. These track rods have pistons 25 and pistonrods 26 working in hydraulic or pneumatic cylinders 24 fixed to the secondary axles 1. The front cylinders of the front wheels are connected to the front cylinders of the rear wheels by pipes 21a, 21b, and the rear cylinders of the front and rear wheels are connected by pipes 21c, 21d, all these pipes passing to and from a controlling valve 28. In the case of a trailer, the tow-bar 16 is connected to the tractor (not shown) and any turning movement of the tractor causes lateral movement of the tow-bar and thus of the front secondary axle 1. If the front wheels only are to be steered, the valve 28 is set so that the liquid flow in pipes 21a, 21b is stopped, thus locking the front piston 25 in the middle of its cylinder, and so that liquid can pass freely through the valve and the front halves of pipes 21c, 21d, so that the rear track rod of the front axle can move freely. The result is that the tow-bar causes lateral movement of the secondary axle 1 relatively to the axle 6 and the wheels are steered as shown in Fig. 4. If it is desired to steer the rear axles from the front wheels the valve 28 is set so that the flow in pipes 21a, 21b is stopped, but the front and rear halves of the pipes 21c, 21d are put in communication, so that when the front steering wheels are moved to the position shown in Fig. 4, the consequent movement of the rear piston 25 forces liquid through the pipe 21c to the rear cylinder 24 of the rear axle and moves the corresponding piston to the left to steer the rear wheels in the opposite direction to the front wheels, the liquid in this rear cylinder returning to the rear cylinder of the front axle through the pipe 21d. When the trailer is to be drawn in the reverse direction, the tow-bar 16 is attached at the new front end and the valve 28 is set so as to interchange the connections between the cylinders as required by the change of direction. Mechanical means instead of fluid-pressure may be used to control the movements of the steering wheels. In the case of a motor vehicle or tractor, a power jack 29 may be used to cause relative movement between the secondary and main axles to steer the front wheels ; the rear wheels may be steered either by (1) transmission means such as the pipes 21a ... 21d between the front, and rear axles, and (2) the lateral swing of the front of the vehicle, if there are six wheels, causes the vehicle to pivot about the central axle and the opposite lateral swing of the rear of the vehicle steers the rear wheels accordingly. Alternatively, a power jack 29 may be provided at each end of the vehicle for steering.