Elongate pressure actuated electrical switch

Abstract

A rugged pressure actuated cable switch especially suitable for use in road vehicle detection comprises a central elongate conductor; a flexible insulating element helically wound around central conductor; a flexible tubular body of electrically conductive plastics material surrounding the central conductor; two elongate conductors in electrical contact with the outer surface of the flexible tubular body, and an overall insulating sheath of a transverse cross-section of approximately semi-circular shape having a flat surface for supporting the cable switch on the ground. Each outer conductor is embedded in the sheath alongside the flexible electrically conductive tubular body at a position intermediate of the flat surface and the longitudinal axis of the central conductor. When a pressure is applied to a part of the overall outer sheath remote from its flat surface, the central conductor is urged in a direction towards the flat surface to effect electrical contact with the two outer conductors via the flexible electrically conductive tubular body.

Dependencies are inferred from the claim text.