GB411175A - Drag shoe devices for vehicles - Google Patents

Abstract

411,175. Skid brakes. BORJYMSKY, T. M. VON, 32, Rue de Boulainvilliers, Paris. Dec. 7, 1932, No. 34661. [Class 103 (i).] A brake shoe which is adapted to be lowered into engagement between a vehicle wheel and the track is raised by driving mechanism which is automatically put out of action when the shoe reaches a predetermined ineffective position. The driving gear may be driven by hand, electric motor, or by the wheel axle or a shaft geared thereto. In Fig. 3, the brake shoe 1 mounted upon arms 2 pivoted upon the axle of the wheel 3 is raised by a cable 6 wound upon a drum 7 driven by a handle 34 through a clutch 33 and chain 30. When the shoe reaches a predetermined raised position, a projection 27 on the drum strikes a rod 24 which through a bell-crank 35 disengages the clutch. The shoe may be retained in the raised position by a detent which can be released by the driver to allow the shoe to fall. The shaft 37 may be driven from a power source instead of by hand, for example from the gear box of a motor vehicle. In another arrangement the drum 7 is geared to an electric motor in the circuit of which is a switch comprising a sliding element which is pushed to break the circuit by a projection and rod such as 27, 24. In Figs. 5, 7, 7<a>, the shoe is raised by reverse movement of the vehicle. The shoe is retained in the raised position by a spring catch 61, 60 of which the element 60 is pivoted on a fixed bracket 53 and carries the armature of a magnet 56. The arm 2 which carries the shoe 1 and which pivots about the axle 40 is secured to one member 39 of a ball ratchet clutch, the other member 43 of which is slidably keyed upon the axle. The balls 42 are normally out of alignment with the projections 41 so that the clutch is inoperative in either direction of rotation of the axle. By momentarily energizing the magnet 56 the shoe 1 drops into operative position and the movement of the catch member 60 towards the bracket 53 after disengagement of the shoe actuates, through connections 50, the fork 46 to move the balls into the effective position shown in Fig. 7<a>. Upon reversing the vehicle the rotation of the axle then raises the shoe until the outward movement of the catch member 60 as it receives the member 61 returns the clutch to the inoperative position. Specification 411,176 is referred to. Reference has been directed by the Comptroller to Specifications 15435/90, 13863/91, and 15362/92, [all in Class 108].