GB400382A - Improvements in controlling devices for hydraulic shock absorbers - Google Patents

Abstract

400,382. Vehicle &c. shock-absorbers. SALENIUS, C. G. T., 44, Birger Jarlsgatan, Stockholm. Aug. 10, 1932, No. 22413. Convention date, Sept. 14, 1931. [Class 108 (iii).] Relates to hydraulic shock-absorbers for use on motor vehicles &c. and of the kind in which an operated member such as a piston or vane moves within a pressure chamber filled with liquid and forces the liquid through an escape opening formed of two relatively movable parts, at least one of which is actuated partly in one direction by a spring and partly in the opposite direction by the liquid pressure in the chamber, the latter movement being against the effort of the spring and increasing the resistance at the escape orifice. According to the invention, the movable valve part is connected to a piston so influenced by the pressure in the chamber that a counter-balancing pressure is obtained which assists the efforts of the spring on the movable part, and thereby allows a lighter spring to be employed. The escape opening may be varied by throttling the same or by increasing the length thereof or by both methods in conjunction. In the construction shown in Fig. 1 the valve 5 actuated by the pressure of the liquid in the chamber P is adapted to throttle the escape opening 2 in the wall 1 against the action of the spring 4, and the counter-balancing pressure is derived from an independent piston 17 connected to the valve 5 by a double-armed pivoted lever 15. In another construction, Fig. 2, the valve 34 is made to act as a differential piston by connecting a space 38 at the rear of the valve spindle 37 to the area 36 of reduced pressure by means of a bore 39 in the valve. Other modifications are described in which the valve is formed integral with a cushioned piston, and in which a bore through the valve connects the pressure side of the valve to a chamber in which the pressure so transmitted reacts on a piston integral with the valve. Fig. 5 shows another arrangement similar to that last described, in which the length of a helical passage 72 formed on the valve 71 is increased with increasing pressure in the chamber P, while in a still further construction, Fig. 7, the valve or piston 94 with bore 93 is adapted to regulate the size of a wedge-shaped opening 91 in the cylinder wall 92, the spring 95 being disposed in the counter-pressure chamber.