PROPORTIONAL PRESSURE DIFFERNCE ACTUATOR

摘要

Actuation of a pressure actuator is manifested solely when the pressures from two separate systems exceed a predetermined differential or the absence of pressure is evidenced by including a piston having one face sensitive to one of the pressures and the opposing face sensitive to the other pressure, and a pair of smaller pistons slidably mounted on connecting shaft of the piston, each having a face adapted to subtract a force from the total force when the pressure acting on one face of the sensing piston is at a predetermined value. The piston is spring loaded in an actuating position when no pressure is acting on the piston.