Patent GB-423588-A (GB)
Title: Improvements in damping devices or shock absorbers
IPC: F16F3/07
Filed: 1933-07-03
Abstract: 423,588. Shock - absorbers. MERCIER, J., 7, Rue Pierre Cherest, Neuilly-sur-Seine, France. July 3, 1933, No. 18838. Convention date, July 5, 1932. [Class 108 (iii)] In a device for damping the relative displacements of two elements comprising a deformable container having two opposite walls each connected with one element and which communicates with an auxiliary chamber through valvecontrolled passages in a partition separating the container and chamber, a member slidable in the partition and co-operating with the valves controlling the passages is acted on by springs which are compressed or expanded by the relative displacements of the walls of the container, the slidable member and the valves acting to close only one of the passages for a relative displacement of the walls away from the initial position and to close both passages at the beginning of a relative displacement of the walls towards their initial position. In the double-acting shock-absorber shown in Fig. 1, disc-valves 38, 43 are pressed against a fixed disc 35, so as to cover two sets of concentric apertures 36, 37 therein, by springs 40, 44 bearing against flanges 41, 45 connected by a rod 45<a> and acted on also by springs 42, 46. As the piston 4 moves upwards the spring 40 is increasingly compressed while pressing the disc 38 on the disc 35 to cover the apertures 36, fluid passing through the central apertures 39 to a chamber 27 against the decreasing pressure of the disc 43. At the beginning of the return movement, the resisting pressure is maximum due to the spring 40, but gradually decreases. The action is similar but reversed on downward movement of the piston from its mean position. In modifications (a) the fixed disc 35 is replaced by two fixed discs each with a single set of apertures; (b) the whole disc-valve device is fixed at the inner end of a hollow piston, the fluid passing from one side to the other of the device instead of to a separate chamber ; (c) the piston 4, Fig. 1, is replaced by a flexible bag secured between a vehicle axle and frame and adapted when compressed to force fluid direct through the valves to one or more chambers 27 ; (d) the disc-valve device is replaced by a spring-balanced slotted cylindrical slide-valve 71<1>, 90, 72<1>, Fig. 10, which is slidable through a piston 4 and contains a ball-valve 94 controlling apertures 92, 93 therein. In a modification of the last construction, the slide-valve is movable vertically inside a hollow piston to control openings in the upper and lower surfaces of the piston and is provided with a ball-valve device at each end. The Specification as open to inspection under Sect. 91 comprises also several other constructions. In the construction illustrated in Fig. 1 (Cancelled), movement of the piston 4 in either direction away from the mean position shown gradually compresses one of the springs 16, 17 ; for example, on upward movement of the piston the spring 16 is compressed thus causing the ball-valve 14 to be pressed strongly on its seating to cover a passage 12, the fluid passing comparatively freely through another passage 13 due to the spring 17 gradually extending and thus decreasing its force on the valve 15. At the beginning of the return movement the resistance offered to the fluid is maximum due to the compression of the spring 16, but gradually decreases as the piston approaches its mean position and the spring 16 extends. In a modification the piston 4 is replaced by a rotating vane. Fig. 3 (Cancelled) shows a single-acting device wherein, on the upstroke of the piston 4, fluid is forced through a non- return valve 29 into a chamber 27 while a spring 30 acting on a ball-valve 28 is compressed so that at the beginning of the return movement the resistance is maximum due to the compression of the spring 30, but gradually decreases as the piston descends. In the construction shown in Fig. 18 (Cancelled), relative movement of a vehicle frame and axle causes a crank 116 to act upon the piston 4 so as always to move it upwardly from its normal position, fluid passing through a conduit 174 and past a ball-valve 175 in the piston. A valve 176 is pressed with increasing force by a spring 46 to cover an aperture 70 in the piston so that maximum resistance occurs on the beginning of the downward stroke. Fig. 17 (Cancelled) shows a double-acting shock-absorber incorporating two separate valves 108, 108<1> pressed by springs 46, 46<1> and contained in chambers 113, 113<1> connected to a central chamber 115 through passages 114, 114<1>. The action of the springs 46, 46<1> on the valves is normally counteracted by springs 42, 42<1> acting on projecting members 107, 107<1> bearing on the valves. As the piston 4 moves to the left the fluid passes through the port 111<1> and passage 114<1> to the chamber 115, the total resistance of the valve 108<1> decreasing due to the pressure of the member 107<1> counteracting the force of the spring 46, while fluid also passes from the chamber 115 through passage 114 and port 111 to the chamber 104, the total resistance of the valve 108 increasing due to the decrease in pressure of the member 107. At the beginning of the return movement maximum resistance which gradually decreases is offered by the valve 108 and minimum resistance which gradually increases, by the valve 108<1>. In another construction, a slide-valve 126, Fig. 20 (Cancelled), is adapted gradually to uncover a port 124 through which fluid flows on return or downward movement of the piston 4, the fluid, on upward movement of the piston passing through a non-return valve 120 to a chamber 27. In a modification the valve 126 is acted on both by a spring and by atmospheric pressure. In the double-acting construction shown in Fig. 22 (Cancelled), the resistance on the return movement depends on the distance of one of the ends of the spring-balanced valve 126 from the ends of the cylinder 123. A fluid, preferably gas, replaces springs in the construction shown in Fig. 23 (Cancelled), the fluid being byepassed on upward movement of the piston 4 to the space beneath a piston 142 connected to the restricting valve 28. In a modification, the valve 28 is connected to the magnetic core of a solenoid, the energizing current in which is varied according to the relative movements of the vehicle frame and axle. In a modification of the construction shown in Fig. 10, connected disc-valves 71, 72, Fig. 16, (Cancelled), are pressed by springs 42, 46 abutting the ends of the container 3, passages 98, 99 through the piston being controlled by non-return valves 100, 101. In another modification the fluid passes through byepassages 75, 81, Fig. 13, (Cancelled), controlled by non- return valves 77, 83. In a further modification, in order to adjust the shock-absorber automatically in accordance with the load on a vehicle, the spring 46, Fig. 10, instead of pressing against the casing 3, bears on a floating, spring-pressed, apertured piston. To reduce the elasticity of this device the position of the piston may be varied by screw means or by any device subject to mechanical, hydraulic, or electric control. In the last case the current may be controlled by a hand-operated switch, the brake pedal, the steering-gear, or by a pendulum. The application of a shock-absorber according to the invention for opposing the torsion couple of a vehicle axle was also included in the Specification as open to inspection. This construction forms the subject of Specification 423,789, [Group XXXI]. This subject-matter does not appear in the Specification as accepted-