93
5.5.1.1 Wedge mechanism is shown in Fig. 69.
1-adjusting nut; 2-toothed coupling; 3-adjusting ring; 4-roller; 5-O-ring; 6-cleat wedge; 7-release spring; 8-
locking ring; 9, 12-spring cap; 10-cartridge; 11-housing; 13-roller cage; 14-washer; 15-adjusting bolt; 16-
leaf spring; 17-globe joint
dome; 18-toothed wheel; 19-protective collar; 20-spiral sring; 21-pistons; 22-
spiral groove; 23-shoulder screw; 24-compression spring (a short one); 25- compression spring (a long
one); 26-pin
Fig. 69 – Wedge release mechanism
5.5.1.2 Wedge mechanism automatic adjustment. For every piston of the wedge
mechanism, an automatic adjuster is provided in order to ensure constant control over the clear-
ance between the brake drum and the brake linings.
When applying the brake, the cleat wedge 7 (Fig.70), overcoming the resistance of the re-
lease spring 1, presses the rollers 6 which turn over in downward direction on the cleat wedge sur-
face 7 and piston 5. At this, piston 5 with a toothed ring 2 and adjusting nut 3 moves outwards —
and the braking process begins. Due to the piston 5 lengthwise displacement, a special sprung pin
4 thrusts into the toothed ring 2 via the spiral groove «
А
», and turns it over so that the rotation ex-
tent of the latter depends directly on the piston 5 stroke.
When braking is stopped, the whole mechanism is back to initial state.
