GB977534A - Improvements in hydraulic suspension units - Google Patents

Abstract

977,534. Hydraulic shock-absorbers. FLUGZEUGWERKE DRESDEN VEB. March 10, 1961, No. 8776/61. Heading F2S. In an hydraulic suspension unit, e.g. for motor vehicles a piston 17 workable in a cylin der 2 accommodates, loosely within a bore 27, a pistor valve 28 controlled by a pair of springs 24, 30 which are located respectively in ar upper chamber 10 of the cylinder 2 and in the lowel end of the bore 27 and which are arranged to open a passage through the piston 17 when the latter is above its normal centre position and the compression of the upper spring 24 exceeds the upward thrust of the lower spring 30. Radial openings 32, 31 respectively in the piston 28 and the bore 27 are brought into alignment to provide the passage through the piston 17 when, during an upward movement of the piston 17 from its centre position, the compression of the spring 24, fixed between a sealing bush 23 in an end plate 3 for the cylinder 2 and a pin 25 which extends through the piston 28 and is axially movable in a slot 26 in the piston rod 16, overcomes the upward thrust of the spring 30 and moves the piston 28 downwards. The superior force of the spring 30 maintains the piston 28 raised and the radial openings 32, 31 out of alignment over the lower half of the piston stroke. A pressure chamber 12, with an outer casing 1 and accommodating a flexible tube 13 filled with a compressible liquid, communicates with the upper and lower ends of the cylinder 2 through one-way valves 11, 15 respectively, the upper end of the cylinder 2 being connected to a reservoir 7 through a one-way valve 9 in a cover plate 4 which is tightened down by threaded ring 5. A rubber cap 6, interposed between the cover plate 4 and the ring 5 and having sealed connections with the plate 3, forms the reservoir 7.