GB777124A - Improvements in or relating to disc brakes for wheels and power transmissions - Google Patents

Abstract

777,124. Disc brakes. POVEY, W. A. June 3, 1955 [June 3, 1954], No. 16464/54. Class 103 (1). In a disc brake comprising substantially coaxial rotatable and non-rotatable brake discs, a brake disc 14 is mounted, for example, on the rotatable hub member 5 of a vehicle wheel and is adapted to be braked by two non-rotatable axially slidable brake discs 7 and 8 mounted on a plurality of spigot members 9 secured to the fixed brake housing 1 and provided with friction linings 17. The brake may be applied hydraulically by operating devices 21 provided at positions 180 degrees apart on the back plate 2. When hydraulic fluid is supplied from a source of pressure via ports 25 to each of the hydraulic operating devices 21, the piston 26 is forced to the left to frictionally engage non-rotatable disc 8 with the rotatable disc 14 and to force body 22 of the operating device 21 to the right to frictionally engage non-rotatable disc 7 with the rotatable disc 14 by means of connecting bolts 28. Alternative mechanical applying means - are shown at 50 (Figs. 1 and 3) such that when arms 53 are turned in a clockwise direction, shafts 41 will be gripped and turned slightly to cause engagement of cam faces 44, 42 to impart lateral movement to the non-rotatable discs 7, 8 to-bring their linings into friction contact with disc 14. Automatic adjustment means are provided as indicated at 31 (Figs. 1 and 4) such that when the wear of the friction lining occurs, the clearances 37 and the lateral movement of discs 7, 8 will become greater than the movement as preset by the distance between shoulder 35 of rod 32 and face 36 of disc 7 so that, when the brake is next applied fully, each rod 32 will be displaced through its self-locking washer 39 by an amount corresponding to the wear of the lining. Rotatable brake disc 14 is provided with a series of radially extending cooling passages 18 which communicate with axial passages 19, the open ends of which are covered by air scoops 20 extending over a 90 degrees sector of the disc on opposite sides of the disc. An alternative mechanical applying means is described in the Provisional Specification.