GB1414810A - Hydraulic dampers of the telescopic type - Google Patents

Abstract

1414810 Preventing foaming in shock absorbers F M ALLINQUANT and J G ALLINQUANT 20 Dec 1972 [23 Dec 1971] 59724/72 Heading F2S An hydraulic piston-and-cylinder damper has a gas-containing compensation chamber 9 separated from the working chamber 8 by a partion 7 having one-way valves for each direction of flow and carrying a deflector 24 which allows passage of fluid from the compensation chamber 9 to the working chamber 8 only through a reduced passage, the passage being below the liquid level when the damper is horizontal. Fluid from the chamber 8 passes through an opening 13 (which is at the "top" with the damper horizontal), an arcuate groove 14 and a passage 12 closed by a spring steel valve member 18. In the reverse direction flow is through three circular or rectangular holes 20 (which are at the "bottom' with the damper horizontal) closed by a washer 21 having an arcuate groove 22 therein to allow extra flexibility. The entry to the holes 20 is masked by the deflector which is a spring washer 24 seating round a ridge 27 except for an angle α of about 70 degrees at the bottom, where it rests on studs 28. The deflector may be cut away at A-A in Fig. 4, or the partition grooved at B-B in Fig. 2 to increase the size of the passage. A recess 32 shows the correct attitude for use. A small passage (34, Fig. 3, not shown) links the passage 12 with one of the holes 20 bypassing the valve member 18 to prevent excessive damping of small oscillations. Alternatively there may be a by-pass notch in a washer 15. The damper may be inclined to the horizontal, so that the liquid level is represented by line 33. Reference has been directed by the Comptroller to Specification 1,018,092.