Patent GB-934305-A (GB)
Title: Disc brake
IPC: F16D65/18
Filed: 1961-11-07
Abstract: 934,305. Disc brakes. D.B.A. S.A. Nov. 7, 1961 [Nov. 10, 1960], No. 39847/61. Class 103 (1). A disc brake comprises a rotatable disc and a floating housing, the said housing including a support plate which extends radially along one side of the disc, a pair of circumferentially spaced yoke members straddling the disc and mounted on the support plate, first and second friction elements mounted on the yoke members each in opposition to a different face of the disc, and application means mounted on the yoke members and adapted to move the first friction element with respect to the yoke members to bring the first friction element into engagement with one face of the disc, the yoke members being slidably mounted on the support plate to permit their displacement in reaction to the application of the first friction element against the disc, in a direction substantially parallel to the axis of the disc, thereby to bring the second friction element into engagement with the other face of the disc, the application means being arranged adjacent that face of the disc which is remote from the support plate. The rotating disc 2 is fixed to the hub 4 of the wheel, the support plate 6 being fixed on the spindle or axle casing, and the housing 8 being adapted to slide parallel to the axis of the wheel on the support plate 6. The support plate is L-shaped, its vertical branch being adjacent to one of the faces of the disc. The housing 8 comprises two yoke members 10, 12 which are formed of two C-shaped metal sheets connected by the body of a fluid pressure motor or cylinder block 14 placed with respect to the disc on the side remote from the support plate 6, the yoke members being fixed to the cylinder block by bolts 16. The two yoke members carry the friction pads 54, 56, the pad 56 having no lining in its centre portion. The yoke members 10, 12 are supported on lugs 18 provided on the horizontal branch of the plate 20. The lugs 18 are fitted slidably in slots 20 in the yoke members to permit axial displacement of the housing 8 with respect to the support plate 6. A mechanical brake-applying lever 80 is pivotally mounted on an axle 82 carried by the cylinder block 14. A fluid under pressure is admitted to the bore 26 in the cylinder and force exerted on the piston 28 is transmitted directly to the pad 54, the forces exerted on the bottom of the bore 26 being transmitted by the yoke members 10, 12 to the pad 56. An automatic adjusting device is interposed between the piston 28 and cylinder block 14. The device comprises a rod 34 disposed along the axis of the bore, the threaded extremity of the rod being screwed into the bottom of the cylinder. A sleeve 36 slidable on the rod is pushed against the head of the latter by a spring 38. A ring 40 disposed in an annular groove 42 provided on the sleeve 36 is frictionally mounted in the bore of the piston 28, the axial width of the groove 42 is greater than the thickness of the ring 40 whereby the latter is permitted to move axially with respect to the sleeve. A spring 46 pushes the ring 40 against the edge of the groove 42 which is farthest from the head of the piston 28. Movement of the piston within the cylinder 14 is permitted with substantial opposition when an actuating force is applied which produces movement of the piston beyond the distance determined by the axial width of the groove 44. The spring 38 temporarily absorbs any return movement of the piston-ring-sleeve assembly as a unit beyond a distance greater than the clearance between the ring and groove.