DISPOSITIVO DI PREVENZIONE DAL CONGELAMENTO NEI CILINDRI DELLE SERRATURE IN PARTICOLARE PER I VEICOLI E PER EDIFICI.

摘要

An antifreeze electric heating device for vehicle and housedoor lock cylinders includes an electrically non-conducting pressure body having two transverse wing pairs forming guide grooves for an elastic tension member e.g., rubber band, detachably secured to the pressure body and adapted to surround a lock cylinder for biasing a bearing side of the pressure body into heat exchange relationship with the lock cylinder. The pressure body includes a recess in which is lodged a PTC electric resistance heating element embedded in a heat-conductive, electrically insulative silicone-based compound. A U-shaped sheet metal strip electrically connected to one contact of the PTC heating element closes the recess and is arranged to contact the lock cylinder so that the electric circuit for the PTC heating element is completed by engagement of the metal strip with the lock cylinder under the biasing influence of the tension member. The other contact of the PTC heating element is provided with a terminal plug for connection to a power supply.