Pneumatic line valve arrangement for vehicular levelling system - includes relief valve with control lines from upstream and downstream sides of non-return valve supplying pneumatic cylinder

摘要

The valve arrangement has a compressor (2) which draws atmos. air through a filter (3) and drives it through two non-return valves (5,7) and a desiccator (6) to a pneumatic cylinder (4). The latter is connected to a supply line (1) via an electrically controlled valve (8). A spring-loaded relief valve (13) when open connects the downstream side (18) of the first valve (5) to atmos. Control lines (14,15) to opposite sides of the relief valve are linked through a constriction (17). The second non-return valve (7) is bypassed by a third (11) in the reverse direction with another constriction (10). The output from the compressor is restricted by a pressure-limiting valve (19). ADVANTAGE - Reliable mechanism requires few components and no external power supply, and can be mfd. at favourable cost.