GB1176791A - Improvements in and relating to Vibration or Shock Isolation Units. - Google Patents

Abstract

1,176,791. Vibration damping unit. DELANEY GALLAY Ltd. 4 Jan., 1967 [6 Oct., 1965], No. 42478/65. Heading F2S. A vibration shock-isolation, or absorption, unit, e.g. for use as a vehicle or engine suspension unit, comprises at least a pair of cylindrical pads of matted fine springy metal wire which is woven, knitted, or compressed into a tubular resilient mass mounted on a former concentrically about a common axis and arranged so that one of the pads is preloaded in compression and the other is unloaded in the free standing condition of the unit or, at a lower unit compressive loading than the first-mentioned pad. Three cylindrical wire mesh pads 2 and a single wire mesh pad 2<SP>1</SP>, all formed as described in Specifications 711,898 and 715,796, are mounted in a precompressed state, on a central tube 4 between end plates 6, 6. The unit is adapted to resist stresses in both upward and downward directions. The tube 4 acts as one loading connection the other consisting of the flange 8 of a sleeve 10 which has an inwardly directed part 12 located between the uppermost pad 2 and the single pad 2<SP>1</SP> with the corresponding flange of a cylindrical member 20. Stiffer limiter metal wire mesh pads 14, 18 are located respectively concentrically around the pads 2, 2<SP>1</SP> between an end plate 6, and the corresponding flange 8, or cylindrical member 20. When the unit is loaded the static load is taken up by the difference in load bearing capacity between the pads 2 and the pad 2<SP>1</SP> so that the deflection curve is symmetrical about the load point, the curve having a soft ride characteristic over the straight characteristic portion and a smooth transition into the progressively increasing stiffer portions due to the concentric limiter pads 14, 18. In a modification, Fig. 3 (not shown), which is generally similar to that shown in Fig. 1, there are three upper pads (2<SP>1</SP>) which are made of finer metal wire mesh than a single lower pad (2) which is stiffer. The intermediate connection comprises a sleeve (28) and an upper concentric limiter comprises a pad 38, a coil spring (32) being located between the lower end plate (6) and the sleeve (28). The load-deflection curve is substantially the same as the first embodiment. In a further modification, Fig. 4 (not shown), a shorter pad (2<SP>1</SP>) is concentrically located around an outer pad (2), no limiters being provided in this case.