GB959118A - Improvements in or relating to brakes for mine winding gear - Google Patents

Abstract

959,118. Winding gear brakes. M. B. WILD & CO. Ltd. March 11, 1963 [Dec. 9, 1961], No. 44145/61. Heading F2E. In a brake for mine winding gear top and bottom arcuate brake shoes 5, 6 symmetrically disposed about, and contractible on, a horizontal axis drum 7 and fulcrumed at 8 on a rigid support 10 are mechanically interconnected by meshing gear segments or, as shown, a linkage such that pivotal movement of one shoe causes equal and opposite pivotal movement of the other, the shoes thereby acting as counterweights to each other, and the braking force is mechanically or, as shown, hydraulically applied at or near the free ends 28. Pairs of equal length arms 22, 18, respectively secured to the shoes 5, 6 are disposed at equal angles to, and on opposite sides of, the common centre line of the fulcra 8 and are connected by a link 19. For relative adjustment of the shoes and drum the arms 22 and/or 18 may be angularly adjustable relative to the shoes or, as shown, the link 19 may be screw-threaded for adjustment relative to the arms 22 and provided with adjusting and locking nuts 23, 24. The bottom shoe assembly may be heavier than the top shoe assembly or may be spring-urged downwardly, the downward movement being limited by an adjustable stop 25, so that with the brake released the bottom shoe holds the top shoe clear of the drum. The fulcra 8 may be adjustably mounted on the support 10 to vary their centre distance. The shoes are applied and released by a double-acting hydraulic cylinder 26 and a screw-threaded, adjustable length piston 27 respectively connected to the shoe free ends. A dead-weight stand-by brake operating means comprises a lever 33 pivoted at its ends to the bottom shoe and to a deadweight 32. A screw-threaded, adjustable length rod 37 pivoted to the free end of the top shoe has a slot 35 engageable, with lost motion, with a cross-pin 34 of the lever 33. The dead-weight 32 is maintained in its raised position by the brake actuation hydraulic pressure acting in a fixed cylinder having a piston connected to the lever 33. If hydraulic pressure is not available for actuating the cylinder 26, the dead-weight is released, the lost motion in the slot 35 taken up, and the brake applied mechanically. Alternatively, the lever 33 may be pivoted to the top shoe, the pivotal connections of the lever 33 with the shoe and the rod 37, and, conveniently, the hydraulic cylinder 26 and the rod 37, being interchanged.