GB1000557A - Improvements in and relating to disc brakes - Google Patents

Abstract

1,000,557. Disc brakes; hydraulic control of brakes. AUTOMOTIVE PRODUCTS CO. Ltd. June 6, 1962 [June 6, 1961], No. 20421/61. Headings F2E and F2F. A self-servo disc brake comprises a fixed caliper 1, applying means mounted on the caliper at one side of the disc for applying one pad 3 to a disc 2, the pad 3 being able to be displaced circumferentially. or tangentially with respect to the disc under the influence of drag forces exerted by the disc, and a system of rockers and link rods connecting the pad 3 to another pad 4 on the opposite side of the disc to communicate the displacement of the pad 3 to mechanical means for applying the pad 4 so that the latter is applied to the disc solely by the drag forces exerted on the pad 3. In the embodiment of Fig. 1, rockers 16, 17, 18, 19 are interconnected by tappet rods 22, 23 to form two parallel rocker systems, and further tappet rods 28, 29 connecting the free ends of the rockers 16, 18 with the backing plate 6 of the pad 3. Recesses are provided for the tappet rods in the rockers and plate 6, and in separate threaded elements 22b, 23b provided in the rockers 16, 18 for adjustment purposes. The backing plate 6 of the other pad 4 is located between guide pieces 15 to prevent circumferential movement, the free ends of the rockers 17, 19 acting on the pad 4 via a tappet 26 having a stem 27, one end of which is guided in the caliper 1 and the other end of which engages a recess 27a in the backing plate 6 of pad 4. An alternative rocker system, Fig. 2, consists again of the rockers 16, 17, 18, 19 and interconnecting rods 22, 23, but the tappet rods 28, 29 are replaced by balls 33 operating in grooves 34 provided in the rockers 16, 18 and in the backing plate of the pad 3 so that upon displacement of the pad 3 a camming action occurs which applies the other pad through the rockers 17, 19 and, in this embodiment, a pair of tappet rods. One of the parallel rocker systems is omitted in a further embodiment (Fig. 3, not shown) in which the applying means acts on one side of pad 3 instead of centrally, as shown. In all the embodiments the applying means consists of an hydraulic cylinder 7 containing a piston 8 linked by a tappet rod 12 to the backing plate of the pad 3, the piston having a rod 30 extending through a sealed bore in the closed end of the cylinder and adapted for operation by a hand-operated linkage, e.g. through a lever 31.