GB949694A - Improvements in or relating to disk brakes - Google Patents

Abstract

949,694. Disc brakes. AUTOMOTIVE PRODUCTS CO. Ltd. Oct. 12, 1962 [Oct. 31, 1961], No. 38979/61. Heading F2E. A disc brake of the kind in which friction pads are applied to opposite sides of a brake disc by calliper mechanism having pivotal movement in a plane normal to the plane of rotation of the disc, has a calliper mechanism which comprises two pad support members 14, 15, each acted on by frictional means 50, 46 resisting movement thereof about its pivot 13 and has an operating member 35 pivoted at 36 to one of the pad support members 14 and acting on the pad support member 15 through a ratchet device capable of transmitting load only in a direction to apply the brake, opposition to the return movement of the member 15 being opposed by the frictional means so that the operating member 35 is able to move relatively thereto to adjust the relative positions of the members 14, 15. Automatic adjustment of the brake to compensate for pad wear is thus effected. The common pivot-pin 13 of the members 14, 15 is mounted in a flange 12 extending from the bracket 10 which is bolted to a fixed support. The member 14 is substantially flat and has an opening 17 through which part of the brake disc 16 extends and supports, at one side of the opening, a backing plate 18 carrying a pad 19 of friction material. The member 15 is U-shaped and disposed so that the member 14 can move relatively to it between its limbs, which have inwardly bent portions 28 which assist in locating a backing plate 29 carrying a pad 34 of friction material. The ratchet device between the operating member 35 and the member 15 comprises a rod 37 pivoted to the member 15 at 38 and having a buttress thread or circumferential buttress-shaped teeth, with which a split ring 40, Fig. 4, mates, being surrounded with a spring band 41 and held against a flat surface 42 on a cross-pin 39 which extends between the sides of the operating member 35. The other end of the operating member 35, near the pivot 13, is connected to a pull rod 44 and to a return spring 45. The frictional means which act on the pad support member 14, Fig. 8, comprise a pad 50 of friction material which bears against a link 25 of the U-shaped member 15. The frictional means which act on the pad support member 15, one limb 25 of which is shown in Fig. 7, comprise a clip 46 anchored to the fixed flange 12 by a pin 47 and holding a pad 48 of friction material against the limb 25. Alternatively, the pad may be omitted and the frictional effect supplied by the resilience of the clip- On release of the brake the split ring 40 tends to be moved along the rod 37 while the pad support members 14, 15 tend to be held by the frictional means described, so if the pads are worn the threads on the rod are ridden over, whereby the amount of movement of the operating member necessary for the next brake application is reduced. The opening 17 in the member 14 is shaped to receive a fluid pressure cylinder 22, the piston 23 of which bears on the backing plate 29 on the member 15, preferably through a rounded projection 33. The limbs 24, 25 of the member 15 are bowed outwards at 27 to embrace the cylinder 22. In operation, the piston 23 presses the pad 34 against one side of the disc 16 and the reaction on the cylinder 22 is applied through the member 14 to the pad 19 to press it against the other side of the disc. Specification 941,556 is referred to.