Wear and licking alarm for crown or disk brake

Claim 1

A monitoring and alarm device for crown or disk brakes, which brakes have a metal crown or disk which is firmly attached to a rotating assembly, for instance a vehicle wheel, and on opposite sides of the crown or disk at least one lining having a friction surface of a material of high coefficient of friction intended to rub on the crown or disk, this device comprising a first electrically conductive feeler arranged in each brake lining with one end thereof intended to come into contact with the crown or disk at a level of maximum wear of the lining and with an other end connected by a line to one pole of an alarm circuit, characterized by the fact that the first feeler is contained in a first cavity in the lining and comprises a spring exerting its pressure in the direction towards the crown or disk; by the fact that the end of the first feeler, which is intended to come into contact with the crown or disk at the level of maximum wear of the lining, is immobilized at said level; by the fact that a second cavity, which extends from the level of maximum wear of the lining to the friction surface of the lining intended to rub against the crown or disk, contains a second electrically conductive feeler electrically connected to and superposed on the first feeler, the second feeler wearing down like the material of high coefficient of friction of the lining; and by the fact that the line connecting the first feeler to the alarm circuit is provided with a switch which is kept open upon each braking maneuver and is closed at times other than during the braking maneuvers.