Patent ID: 6512360
Filing Date: 2003-01-28
Classification: F15B,G01D

Abstract:
A stroke sensor for detecting a stroke position of a movable member linearly movable relative to a body within a space formed in said body, said stroke sensor comprising:a sensor member having one end supported in a cantilever fashion adjacent a predetermined end of said body and having another end extending into the space of said body, said movable member having an inner space formed therein to permit entry of said sensor member into said movable member; a coil section having a plurality of coil segments excitable by a predetermined A.C. signal and sequentially arranged along a direction of linear movement of said movable member, said coil section being provided on one of said sensor member and an inner peripheral wall of said movable member defining said inner space; and a magnetism-responsive substance provided on other of said sensor member and the inner peripheral wall of said movable member defining said inner space in such a manner that said magnetism-responsive substance is movable relative to said coil section, wherein relative positions of said magnetism-responsive substance and said coil section vary in accordance with a stroke position of said movable member, in response to which respective inductance of said coil segments are caused to vary in such a manner that during movement of said magnetism-responsive substance from one end to another of a particular one of said coil segments, a voltage across the particular coil segment is caused to progressively decrease or increase.