Patent ID: 6057692
Filing Date: 2000-05-02
Classification: F01L,F02M,G01B

Abstract:
A measuring arrangement for determining the lift of a valve member including a hollow cylindrical valve stem member arranged in overlapping telescope relationship with a stationary cylindrical member extending into said hollow cylindrical valve stem member so as to be movable relative thereto, said stationary cylindrical member having axially adjacent first and third capacitor structures formed on its surface so as to be electrically insulated from one another and the hollow cylindrical valve stem member having, on its surface adjacent the stationary cylindrical member a continuous electrically conductive second capacitor structure having an axial length so as to cover both said first and third capacitor structures when said valve is in a fully closed position but only said third capacitor structure when said valve is in its fully open position, said second capacitor structure forming with said first and third capacitor structures first and second capacitors respectively, whose capacitance changes with axial movement of said valve stem relative to said stationary cylindrical member, said first, second, and third capacitor structures being electrically connected to a control unit for determining the capacitance between said first and third and said second capacitor structures which indicates the position of said valve member.