Patent GB-1147639-A (GB)
Title: Improvements in spot type disc brakes
Inventor: SCHUCHMANN GERHARD ERNST LUDWI
IPC: F16D55/228
Filed: 1965-11-15
Abstract: 1,147,639. Disc brakes. GIRLING Ltd. 11 Nov., 1966 [15 Nov., 1965(2), 22 Jan., 1966], Nos. 48283/65; 48286/65; 3002/66. Heading F2E. In a spot type disc brake of the kind comprising a yoke 11 which surrounds the disc on a chord thereof and is slidable in grooves 20 on opposite sides of a housing 10 which is either secured by lugs 18 or is pivotally mounted on a fixed support (not shown), the yoke carrying an indirectly operated pad 12, and a directly operated pad 13 being applied by an actuator associated with the housing 10, vibration and binding of the yoke in the grooves 20 are prevented by resilient members acting between the yoke and housing. In the embodiment of Fig. 2, the resilient members are leaf springs 21 each of which includes an integral clip portion 45 which passes around the edge of the aperture in the yoke which accommodates the housing 10 and the disc, a downwardly projecting end portion (46, Fig. 4, not shown) of the clip portion 45 engaging an opening (47, Fig. 1, not shown) in the yoke to retain one end of the leaf spring, the other end of the leaf spring being retained by either an upwardly projecting end portion, as shown, which is at one side of the spring and engages a notch (51, Fig. 1) in the yoke, or by a tongue (53, Fig. 5, not shown) formed integrally with the clip portion and extending along the edge of the yoke towards the opposite end of the leaf spring. The leaf spring presses against the lower edge 40 of the associated groove 20 and urges the yoke against the upper edge 41 of the groove. In the embodiment of Fig. 7, the same is achieved by the use of a single wire spring having a portion 63 extending across the upper face of the yoke and joined at each side of the housing to, first, a support portion 65, then a vertical portion 64 which passes through a notch 69 in the yoke, then a free portion 66 the free end of which has an inturned, flattened end (67, Figs. 9 and 11, not shown) which bears against the groove edge 40, whilst a kink between the free and vertical portions engages the lower face of the yoke to urge the latter against the groove edge 41. In a further embodiment the springs are replaced by a pair of resiliently deformable members 42, Fig. 5A, each of which comprises a hollow stem 43, which passes through an aperture in the yoke, and either one or a pair of feet 44 which engage the lower edge of the corresponding groove 20. The members 42 are made of nylon or similar material, as a result of which they not only resist vibration of the yoke but also act as an automatic wear compensator for the yoke which also resists 'knockback' sufficiently to enable resilient seals (40, 41, Fig. 4A, not shown) associated with a pair of pistons (15, 16), which are arranged within a through bore (17) of the housing between pad 13 and the yoke 11, to function correctly in maintaining pad clearance at a desired value. This piston arrangement is common to all of the embodiments. The yoke 11 has a tongue (22) engaged in a blind bore of the outer piston (15) and located by an insert member (23) in the blind bore. The pads 12 and 13 are carried by backing plates having respective lugs 31, 32 which are apertured to receive pins 27 which are removably secured between an upstanding member 26, carried by the yoke, and the housing, so that the pads can be removed in a radial direction.