Pressure sensor for protecting motor vehicle drop=head against damage

摘要

A sensor (21) for protecting the drop-head mechanism of a motor vehicle against damage by an obstruction during retraction into its stowage compartment employs a weight sensitive mat to register the pressure of an extraneous object.The mat has a pair of flexible insulating sheets (23, 27) on each of which a matrix of metallic conductors (25, 29) is deposited by screen printing and the matrices (25, 29) are separated by compressible insulating beads (31) which are deposited on the lower sheet (27).The assembly (21) is completed by a dimpled polycarbonate pressure intensifier pad (51) a fibreglass base (35) and a carpet covering (61) and is capable of sensing a 100 gm object e.g. a golfball.