Patent GB-1428281-A (GB)
Title: Brake device
IPC: F16D55/228
Filed: 1973-06-29
Abstract: 1428281 Spot-type disc brakes; slack adjusters PONT-A-MOUSSON SA 29 June 1973 [7 July 1972] 31178/73 Heading F2E A floating-caliper spot-type disc brake has two brake sub-assemblies disposed one at each side of the disc 1, Fig. 2, on a caliper 7 which is movable perpendicularly (e.g. by ears 6 on fixed pins 5, Fig. 1) relative to the disc; each sub-assembly comprises support components 16-18 associated with the caliper and having a support surface slightly inclined relative to the adjacent disc surface; at least one brake pad, e.g. 9, 10, Fig. 2, provided with a friction surface parallel to the disc surface and an inclined surface 10b, co-operates with the support surface (as shown, via a roller-bearing assembly 19); the pad 9, 10, is connected to actuating means 11, 12, 13, which act, for braking, in a direction substantially opposed to the relevant direction, f 2 , of movement of the disc 1, the two sub-assemblies being orientated in opposite senses at the two sides of the disc; each sub-assembly has means for ensuring that, in each direction of movement of the disc, one of the two brake pads is selectively rendered effectively integral with the floating caliper 7. As shown in Fig. 2, the brake is operative with the disc rotating in direction f 2 . Fluid has been supplied to both cylinders 13, 53. The force applied to pad 50, 59, via rod 52 is supplemented by the self-servo action of the disc until the skirt of the piston in cylinder 53 abuts the end of the cylinder, as shown. Thereafter, pad 50, 59, is effectively integral with caliper 7. The force applied to pad 9, 10, via rod 12, on the other hand, is opposed by the brake torque imposed by the disc motion, so the piston in cylinder 13 occupies an equilibrium position between the ends of the cylinder. Since each support structure 16-18 is effectively fixed to caliper 7 apart from provision for slack-adjusting (see below) pad 50, 59 is applied by caliper reaction. Automatic slack-adjustment.-Brake-applying movement of pad 9, 10, is transmitted by lever 31, pivoted at 32 to caliper 7, Fig. 2, to a slidable block 39 carrying downwardly-spring-loaded pawl 37a, Fig. 5, co-operating with ratchet wheel 25, and similar pawl 38a co-operating with ratchet wheel 26. Both ratchet wheels 25, 26, form part of a member 27 having a lost-motion connection 28, 29, with an axially-fixed rotatable screw 22, 23, threaded into a rotationallyfixed axially-movable sleeve 17 connected to plate 18 which has the support surface abovementioned. When pad 9, 10, has worn sufficiently, and when the disc is rotating in direction f 2 , pawl 37a rotates ratchet wheel 25 by one tooth on the release stroke of the pad, to advance plate 18 towards the disc. At the other side of the disc 1, movement of pad 50, 59, in the brakeapplying direction causes pawl 38, Fig. 1, to rotate its ratchet wheel 26 by one tooth in the direction which is the reverse of that for taking up wear. However, screw 22, 23 is not rotated because of the lost-motion connection 28, 29, and on the release stroke, pawl 37 restores member 27 via ratchet wheel 25, Fig. 1. For rotation of disc 1 in direction f 1 , the functions of the brake sub-assemblies are simply automatically reversed. The brake may be applied to a rail vehicle.