Patent GB-607412-A (GB)
Title: Improvements relating to shock absorbers
IPC: F16F9/30
Filed: 1946-02-02
Abstract: 607,412. Shock absorbers. WASDELL, W.K. Feb. 2, 1946, No. 3358. [Class 108 (iii)] .In a shock absorber of the kind comprising a member having angular or linear oscillatory or reciprocable motion under the restraint of a medium contained in a chamber, the medium is uncured or unvulcanized natural rubber, devulcanized rubber, " Government Rubber Styrene," or other synthetic rubber coming in the category generically known as Elastomers, the medium retaining its plasticity, between a temperature well below zero and 200‹ F. and completely filling the spaces in the chamber which are unoccupied by mechanical parts. Suitable Elastomers include poly-chloroprenes, butadiene, acrylonitrile copolymers, isobutene diolefin copolymers, silicone rubbers, organic poly-sulphides or thioplasts. In the construction shown in Figs. 8, 9 the chamber is in the form of a cylinder 26 and the member comprises a piston 27 reciprocable therein by an arm 28 connected by a crank 29 with an axle or other part, the motion of which is to be damped. In a second construction, Fig. 2, the member comprises a rotor 16 of annular cross-section having a hollow spigot 16a by which it is mounted in the chamber which comprises a cylindrical body 12 closed at its outer end by a screwed portion on a cover 15. The cover 15 has a projecting rib 15c which projects into, and sub-divides, the cylindrical space inside the annulus 16. Four symmetrically disposed ports 16c are provided around the periphery of the annulus which together with the peripheral clearance of the rotor in the chamber enable the plastic material to pass between the two semi-cylindrical spaces on rotation of the rotor. The action is assisted by the formation of two flats on the periphery of the rotor 16 each adjacent one of the holes 16c. The shock absorber is charged with the working medium through the hollow rotor spigot which is closed by a screw plug 23, the setting of which may be used to vary the initial working pressure of the material. A fibre, graphite, &c. washer 17 prevents ingress of dirt, and centres the rotor during the filling operation. In a modification of this construction, Figs. 6 and 7, not shown), the rotor 16 is solid and has radially projecting paddles and the working medium is charged through a screw-plugged hole in the chamber 12. In a further construction (Fig. 11, not shown), two rotors, each in the form of a gear in mesh with the other, are mounted in a chamber of approximately oval cross section. One of the rotors has an arm connected to the axle &c. and in operation the plastic material is forced between the meshed teeth. A passage may be cut in the side of the chamber to provide a return path for the material that has been displaced through the teeth from one part of the chamber to the other. A further construction of vehicle shock absorber described in the Provisional Specification comprises a cylindrical body mounted on the vehicle chassis by a square or otherwise-shaped stud and having a central collar carrying a peripheral series of radial projections. The collar is surrounded by a split casing embodying a wheel-carrying arm, which contains the working medium. Rotation of the working medium as a whole, relative to the casing, is prevented by projections which extend radially inwards from flanged portions of the casing. In a second construction described in the Provisional' Specification a piston rod carries a frustoconical shaped piston having substantial clearance for movement in a cylinder containing the working medium. According to the Provisional Specification, greater resistance in one direction of relative movement may be effected either by the provision of valves or rockable members, or by designing the parts to have a stream-lined action in one direction of movement.