Contactless linear rotary potentiometer
AssigneeIllinois Tool Works Inc.
InventorsEdward Frank Sidor, Frank B. Desio
Life of this patent
Estimating the term…
Abstract
A contactless potentiometer which has a linear output characteristic is constructed with a pair of elongated, hollow cylindrical tubes which are made of magnetically saturable material and are aligned so that their axes form an angle less than 180.degree., with both of said tubes having at least one conductive wire coupled therewith which is interconnected with the wire that is coupled with the other tube, and a moveable magnet which is formed as a segment of a circle with a pair of straight sides that move adjacent to said tubes so that the total volume of said tubes that is magnetically saturated remains substantially constant while the inductance ratio of the tubes varies.
Claims10
A rotary contactless potentiometer comprising first and second elongated sensing elements, each of which have a substantially straight longitudinal axis and are shaped to form a rectangular projection in a plane, said sensing elements being positioned so that said elongated axis intersect to form a first angle which is less than 180.degree. , at least one permanent magnet positioned adjacent said sensing elements, rotation means coupled to said permanent magnet to provide for the rotation thereof and limit means constructed to limit the range of rotation of said permanent magnet by said rotation means relative to said sensing elements, said permanent magnet being shaped to have first and second substantially straight sides each of which passes adjacent one of said rectangular projections so as to intersect the associated longitudinal axis of said sensing elements, said sides lying along lines that intersect to form a second angle that faces said first angle and is less than 180.degree. and is further limited so that neither of said sides can pass beyond the outer edges of the respective projection adjacent said side over the limited range of rotation of said permanent magnet that is allowed by said limit means, and so that the total area of said projections that are positioned adjacent said permanent magnet is substantially constant regardless of the relative position of said permanent magnet and said sensing elements within said limited range of rotation.
Dependencies are inferred from the claim text.