Magnetically controlled fluid pressure device

Abstract From the Canadian patent

A fluid pressure device wherein a relatively low powered analog electrical signal readily controls the position of the output member of a fluid pressure powered actuator which in turn can be used to exert mechanical forces or operate mechanical devices such as fluid pumps motors, or valves. Inlet and outlet passages communicate a pressure chamber to high and low pressures respectively. A control element totally within the chamber so as to have balanced pressure forces thereon and made of a magnetically sensitive material is moved to a fixed position in the chamber by an externally generated magnetic field. At least one of the passages moves with an output member of the actuator so as to be …