Patent ID: 6390129
Filing Date: 2002-05-21
Classification: F15B,G05D,H01F,Y10T

Abstract:
A device for accurate metering of fluid, comprising:a housing defining a valve chamber in fluid communication with an inlet port and an outlet port; an electromagnet coil disposed within the housing that when energized by an input signal generates magnetic flux; an armature translatable along a stroke axis toward the coil by a force induced by the magnetic flux; a metering valve movable along the stroke axis by the armature; and a piece-wise non-linear spring communicating with the armature and having a plurality of spring fingers extending radially with respect to the stroke axis to independently engage between the armature and a stationary structure at different points as the armature is translated along the stroke axis so as to provide a summing of forces from each spring finger acting on the armature counter to the force induced by the magnetic flux so that the positioning of the metering valve is more nearly a linear function of the input signal to the coil.