Level sensor for use with an electrically insulating liquid

Claim 1

A sensor for sensing the level of an electrically insulating liquid, the sensor comprising an elongate housing fixed substantially vertically in a casing containing the liquid whose level is to be sensed, said housing having a top opening and a bottom opening and containing a longtiudinally extending heat sensitive V-shaped resistive wire having its end situated at the top of the housing, said wire being arranged for form two substantially parallel branches along a major portion of their longitudinal length, the sensor including the improvement of means for positioning the and fixedly holding the respective end of the heat sensitive wire to ensure a substantially constant gap between the ends of the wire and the two branches thereof over a major portion of their length, said branches of said wire lying in and defining a plane so that the plane defined by the branches of the wire has a position which is stable relative to the elongate housing, said positioning means comprising, at the top of said housing, side slots receiving respective connection members associated with each branch of the heat sensitive wire and each connection member including respective center portions for providing said electrical connections to the corresponding ends of said wire, and, at the bottom of said housing, a transverse column fixed to the housing, said column ensuring both the desired separation between the two branches of the wire and for providing support means for a resilient fastening member for fastening to the point of the V-shape, said fastneing means being disposed behind said column in a direction furthest away from the top of said housing, said fastening member urging said V-shape point of said wire in a direction away from said top of said housing.