Patent GB-484528-A (GB)
Title: Improvements in shock absorbers or vibration damping devices
IPC: F16F9/26
Filed: 1937-03-10
Abstract: 484,528. Hydraulic shock - absorbers. RIPPINGILLE, F. S. March 10, 1937, No. 7012. [Class 108 (iii)] In a vehicle hydraulic shock-absorber of the piston-and-cylinder type, the effective size of the resistance passage for the liquid is varied automatically by a regulating-device formed or carried by an angularly-movable member which is disposed within the space containing or occupied by the piston and its actuating means and constitutes an interior part of the pistonactuating mechanism, the device being positively moved relatively to the resistance passage during loading of the vehicle. The arrangement is such that the resistance opposing shocks is automatically varied according to the load carried by the vehicle. The shock-absorber shown in Fig. 1 comprises a piston 1 adapted to be reciprocated in a cylinder 2 fixed to the chassis by means of a gudgeon pin 6 rotatably mounted in the piston and having an aperture engaged by the lower end of a pin 5 the upper end of which fits in a hole in a spindle 4 mounted on bearings in the shock-absorber casing and adapted to be rotated by an arm 3 linked to a road-wheel axle. On movement of the piston to the right, Fig. 6, fluid passes through passages 7, 8, 9, 10, 11 on the piston to the lefthand end of the cylinder, while on movement of the piston to the left the fluid is forced back through the same passages and also through valve-controlled ducts 13, the final part of the movement being checked by a tapered pin 12 fixed to the cylinder co-operating with the passage 11. In order to restrict the flow of fluid automatically with compression of the vehicle springs due to shock and also according to the weight of the vehicle, each end of the gudgeon pin 6 is formed with a part-spherical portion 18 which projects into the adjacent passage 9 so as to restrict the passage slightly when the piston is in the position, shown in Figs. 1, 6, it assumes when the vehicle is unloaded. As the vehicle is loaded the projection 18 further restricts the passage proportionally with the increase in load ; complete closure of the passage may be prevented by a gap or notch in the projection. Only one of the passages 9 may be regulated by the projection. In modifications one or each end of the gudgeon pin may (a) be cut obliquely ; (b) be formed with a transverse passage ; (c) be formed with a plurality of transverse holes of different diameters ; (d) be formed with an eccentricallydisposed boss ; (e) carry an eccentricallymounted needle-valve ; or (f) carry a pivoted part-circular flap, in order to regulate the flow of fluid. Alternatively, in a further modification, a groove may be formed in the gudgeon pin having a uniform depth for a portion of its length and a progressively-diminishing depth for the remainder, and adapted to co-operate with an additional passage drilled through the body of the piston. Instead of the control being effected by the gudgeon pin it may be effected by the sliding movement of the pin 5 in the gudgeon pin, or by the angular movement of the spindle 4. Moreover, instead of the pin 5 passing through the gudgeon pin it may carry a joint member mounted in or on the piston and arranged to control an oil passage through or outside it. Specifications 385,390 and 387,299 are referred to.