| 摘要 |
614,756. Compensating for wear in brakes. PRATT, J. H., and MANLEY, G. E. July 26, 1946, No. 22235. [Class 103 (i)] In automatic wear-compensating devices of the type in which a stop member is carried by a brake shoe or other friction member and engages the surface to be braked so as to be adjusted relative to the shoe &c. against a frictional resistance as the lining wears, this stop member engaging a fixed abutment to determine the " off " position of the shoe etc.; the stop member 18, 182, Fig. 1, or 184, Fig. 3, has an inclined surface 183 or conical end 185 engaging the abutment 23 so that the thrust between the member and abutment is inclined to the axis of movement of the member and a high frictional resistance is created between the member and its mounting which prevents adjustment of the member by the means, such as a spring 27, for withdrawing the brake shoe &c. from the surface to be braked. The frictional resistance against which the member is adjusted by engagement with the surface may therefore be reduced to a value just sufficient to prevent relative movement of the member when it is out of engagement with the surface or abutment, and wear between the member and surface is thus avoided. In Fig. 1, the plate 18 forming part of the stop member has an elongated slot 181 embraced by friction washers on a bolt 17 passing through a hole in the shoe web, the washers being loaded by a spring interposed between the opposite side of the web and a nut on the bolt. The plate is secured to a feeler. 182 which is a sliding fit in a hole in the shoe flange 101 and extends through a clearance hole in the lining 102. In Fig. 3, the member 184 is slidable in a block 29 secured to the shoe web and is engaged frictionally by a spring 30. The abutments 23 are carried by eccentrics 24 which may be rotated in the backplate to adjust the clearance between the shoes and the drum. Specification 314,607, [Class 103 (i)], is referred to. |
