GB1381785A - Vehicle bumper mounted on a shock absorber - Google Patents

Abstract

1381785 Shock absorber piston valves; valves FICHTEL & SACHS AG 9 May 1972 [15 May 1971] 21622/72 Headings F2S and F2V A shock absorber piston 42 is provided with a relief valve comprising a passage 43 and a valve member 44, the valve member being moved by fluid flowing through the passage from a position of maximum closing effect to positions of increasingly less closing effect, the force which resists movement of the valve member being substantially constant. In Fig. 4, and in Fig. 5 (not shown), the valve member provides its own restoring force, whereas in Figs. 3 and 6 (not shown), the valve member is backed up by disc springs, which may be prestressed. The spring is used over the range AB of its force-deflection characteristic shown in Fig. 9 so as to provide a constant force. In Figs. 7, 8 (not shown), the valve member is backed up by conical helical springs whose force-deflection characteristic (Fig. 10, not shown) is a straight line at a slight angle to the horizontal. The shock-absorber (Fig. 3, not shown) mounts a vehicle bumper. The construction of the relief valve ensures that the damping force is constant over the whole piston stroke regardless of the impact velocity (graphs in Figs. 1 and 2, not shown).