High response unloading valve

摘要

A high response relief or unloading valve is disclosed for use in a pressurized hydraulic system. The valve includes a housing supporting a reciprocable spool valve element having opposite ends cooperable with separate fluid receiving chambers in the housing and which chambers receive fluid at a given system pressure. The valve includes a common discharge passage for the chambers and to which one of the chambers is opened before the other and in response to fluid pressure in the other chamber exceeding the given system pressure. Movement of the spool element in the opening direction is accelerated by the decrease in fluid bias in the one chamber and the excess pressure in the other chamber, and the spool element is structured for the opening movement thereof to be decelerated following release of the fluid at excess pressure from the other chamber.