Abstract: A horn switch assembly including an airbag module cover, a bend sensor and a backing plate. The module cover has a front outer face and a rear inner face deformably depressible from the front face. A plurality of parallel, spaced-apart, elongated force concentration ribs are located on the rear inner face of the cover. The bend sensor is positioned under the force concentrators and includes a flexible substrate and a variable resistance circuit connectable to a horn control circuit. The variable resistance circuit has a plurality of spaced-apart resistive elements connected by a plurality of conductive strips. The variable resistance circuit is arranged in a plural of parallel spaced-apart columns adhered to the substrate so that the columns are generally perpendicular to the force concentration ribs and each resistive element is positioned under a force concentration rib. The generally rigid backing plate has a forward surface positioned under the bend sensor.

Abstract: A variable resistor that utilizes, as its resistive component, an extension type conductive elastomer such as a conductive silicone rubber cross-linked and then impregnated with a silicone oil, that will experience a change in electrical resistance responsive to an extension thereof. The elastomer is interposed as a sheet between a pair of electrodes and a pushing member that is capable of movement so as to press the elastomer against the ends of electrodes, creating an extension of that elastomer between the electrodes. The magnitude of which elastomer extension corresponds to the force exerted on the pushing member, and in proportion to the change in electrical resistance of that elastomer as measured across the electrodes.