GB738247A - Automatic wear adjustment means for brakes - Google Patents

Abstract

738,247. Helical springs. WINGFOOT CORPORATION. Oct. 23, 1953 [March 27, 1953], No. 29312/53. Class 108 (3). [Also in Group XXXIV] In a brake assembly provision is made for the automatic adjustment for wear occurring in the movable friction lining brake block by the fitting of a return compression spring which is capable of assuming, in use, a plurality of progressively shorter lengths as it is stressed beyond its yield point in consequence of wearing down of the brake block, so as to retract the latter through a distance approximately independent of such wearing down. In the " spot-type " disc brake assembly illustrated in Fig. 1, a brake housing 2 is secured to a stationary axle 3 and carries a fluid pressure piston and cylinder mechanism 10 to frictionally engage a brake block 13 with a side surface of a brake disc 6, which is rotatable with and axially slidable on a vehicle wheel 4, to move the disc 6 axially into frictional contact with a fixed brake block 12. The return compression spring 18, shown diagrammatically in Fig. 2, in exaggerated form, may be of a low carbon steel (about 0.05 per cent carbon) are fitted to the brake assembly as shown in Fig. 1. Fig. 2 illustrates the initial length, its length when loaded, its initial yield point and the slight return from the yield point (i.e. the recovery). The recovery provides the necessary small clearance, when the brake is released, to bring the brake block 13 out of contact with the brake disc 6. It is stated that in operation the spring would have an almost infinite number of new released lengths as it would take a new permanent set every time an infinitesimal layer of brake lining is worn off and that when the brake blocks 12 and 13 are replaced, when worn, the spring 18 may be stretched out to substantially its original length ready for a second operative cycle.