Abstract: A brake comprises two pivoting arms adapted to apply brake shoes to a member to be braked, a disk, for example, and a piston-and-cylinder actuator with one member, either the cylinder or the piston, coupled to one of the arms and the other member coupled to the other arm. A brake application device connected to one chamber of the actuator urges the piston in one direction and a brake release device connected to the other chamber urges the piston in the opposite direction. An electrical switch has two parts of which one is adapted to move with one part of the actuator and the other is adapted to move with the other part of the actuator. A lost-motion coupling is provided between one part of the electrical switch and the associated part of the actuator.