FIELD: automobile manufacture; brake levers of brake drums.
SUBSTANCE: proposed lever includes worm gear, worm, adjusting mechanism, guide and cam bush. Worm gear is fitted rotatably and is provided with internal splines for connection with splined shaft of S-shaped expansion cam. Adjusting mechanism includes gear connected with worm by means of spring-loaded gear train and provided with internal splines for connection with shaft and carrier connected with it by means of single-acting clutch. Carrier is mounted coaxially relative to worm gear and axis of worm is coaxial relative to shaft axis. Cam bush provided with helical bore is intended for realization of considerable range ratio of automatic adjusting lever; it is thrown into engagement with inserts by means of threads. Inserts are fixed relative to each other in axial direction due to projections and is thrown into engagement with carrier by means of pin fitted with anti-friction ring. Inserts are parallel to axis of cam bush which has limited axial displacement relative to inserts by means of return spring and bush of clutch member thrown into engagement with cam bush by means of pin fitted with anti-friction ring and connected with shaft by means of single-sided stroke clutch. Clearance is provided between end surfaces of inserts and cam bush. Proposed automatic adjusting lever ensures increased ratio of adjusting mechanism at enhanced accuracy of control of clearance between lining and drum in the course of operation of drum brake with S-shaped expansion cam.
EFFECT: enhanced efficiency and enhanced accuracy of control of clearance between lining and drum.
3 dwg
