GB767453A - Improvements in or relating to a wear compensating device more particularly for friction brakes and similar applications - Google Patents

Abstract

767,453. Automatic adjustment devices. SOC. ANON. DES USINES CHAUSSON. Jan. 19, 1955 [Jan. 20, 1954], No. 1688/55. Class 103 (1). [Also in Group XXIV] In an automatic wear compensating device, particularly for friction brakes, the shaft 1, to which the cam 2 for operating the friction members of the brake is keyed, is carried in a fixed bearing 3 and is provided at its reduced diameter end la remote from the cam with a rigidly mounted sleeve 6. The sleeve 6 is provided at one end with wide notches 9 limited by teeth 10 and at the other end by an annular crown 11 provided with ratchet teeth 13 which are adapted to engage with a corresponding set of teeth on the socket 15 of the crank 16 which is adapted to be rotated in the direction #1 by fluid under pressure introduced into chamber 23 behind piston 21 in cylinder 22, or alternatively by mechanical means. An annular ring 26, fitted on sleeve 6, is formed with teeth 25 which are adapted to coact with teeth 10 on sleeve 6 under certain conditions, and is also provided with ratchet teeth 27 which coact with teeth 28 provided on toothed annular member 29 rigidly secured to bearing 3. In operation when fluid pressure is introduced into cylinder 22, the piston is moved to the left against the action of return spring 24 to the position illustrated in Fig. 2 wherein the crank 16 has been moved anti-clockwise in the direction #1 ; the sleeve 6 and consequently the shaft 1 being driven in the same rotational direction by teeth 13, 14 to rotate cam 2 and expand the friction members of the brake. For relatively light braking action, the teeth 10 do not come into contact with teeth 25 and consequently the annular ring 26 remains motionless. Should wear occur in the friction linings the teeth 10 of the sleeve 6 will move teeth 25 of ring 26 and move the latter in the same rotational direction which moves the teeth 27 with regard to the teeth 28 of the fixed toothed annular member 29, by one tooth, for example. On release of the brake, the teeth 10 after covering the whole width of notches 9 stop against the other face of the teeth 25 of ring 26 which cannot be moved due to the particular inclination of teeth 27, 28 consequently offsetting the teeth 13 with regard to the teeth 14 by an amount similar to the movement of the teeth 27 with regard to the teeth 28 in the opposite direction. This offsetting of the teeth has the effect of returning the cam 2 in an offset position with regard to its original position so that the wear of the linings is taken up.