GB236526A - Improvements in brake mechanism - Google Patents

Abstract

236,526. Bendix Brake Co., (Assignees of Dodge, A. Y.). July 2, 1924, [Convention date]. Blocks and shoes acting on drums.-Relates to brakes of the internal expanding type comprising a pair of shoes connected by a floating pivot so that the application of one of the pair is assisted by the frictional reaction on the other. Fig. 1 shows a form comprising a pair of shoes 2, 3 connected by a floating pivot 4, and mounted on a fixed pivot 7 and a third shoe 5 mounted on a fixed pivot 6. The shoes 2, 5 are engaged by a cam 9 the pivot axis 15 of which is eccentric so that there is a tendency to balance the forces on opposite faces of the cam, the arrangement of the shoes being such that one part of the cam must be moved further than the other part in order that the forces thereon may balance. The shoes 3, 5 are arranged to overlap as described in Specification 245,459 so that the gap between the friction surfaces thereof is reduced to a minimum. With the drum rotating in the direction of the arrow, the frictional reaction on the shoe 2 increases the pressure on the shoe 3 applied by the cam 9. With reversed rotation this intensifying action of the shoes 2, 3 is not produced but the shoe 5 being pivoted at a point towards the centre of the drum, the frictional force augments the pressure applied by the cam to this shoe. Releasing springs 10, 11 extend between the shoes 2, 5 and between the shoe 3 and a fixed point 12 respectively. The position of the joint 4 is adjustable by an eccentric 14 as described in Specification 244,037. According to the Specification as open to inspection under Sect. 91 (3) (a) the shoe 5 may comprise two articulated sections. This subject matter does not appear in the Specification as accepted.