GB294042A - Improvements in brake mechanism - Google Patents

Abstract

294,042. Crockett, R. A. Nov. 25, 1927. Shoes acting on drums.-In brake mechanism for vehicles, machinery, &c. of the type in which a series of shoes are pressed radially against a brake drum, the shoes being capable of a limited degree of peripheral displacement relatively to the drum, the shoes form an uninterrupted sequence around the entire periphery of the drum, the braking torque exerted by the shoes being taken up by a single fixed abutment located between the two terminal shoes of the series. An actuating-arm 5 extends radially from a central cam 6 coacting with spring-pressed plungers 10, 11, 12 which move in guides 13 on a plate fixed to the, axle casing &c. and have mushroom heads 16 engaging rollers 21, 22, Fig. 3, on each end of the brake shoes 17, 18, 19. The shoe 17 is free to move peripherally until it abuts against the end of the shoe 18, which in turn moves to abut against the shoe 19, on which is an abutbent 23 engaging an inclined surface 24 on the guide 13, so as to force the shoe 19 radiadly outwards as it is displaced peripherally. In order to provide for braking in the opposite direction of rotation, the first shoe 17 is also provided with an abutment 25 engaging an inclined surface 26. A pull-off spring 26a is provided between the end shoes 17, 19 of the series. In a modification, the end shoe 19 of the series is. pivoted on a pin rigid with the guide 13, the other shoes being capable of a limited free peripheral displacement.