Patent GB-998726-A (GB)
Title: Improvements in and relating to disc brakes
Inventor: CHOUINGS LESLIE CYRIL
IPC: F16D55/2255
Filed: 1960-10-18
Abstract: 998,726. Disc brakes. AUTOMOTIVE PRODUCTS CO. Ltd. Oct. 16, 1961 [Oct. 18, 1960], No. 35727/60. Heading F2E. In a disc brake of the kind wherein an actuator on one side of an axially fixed disc applies a pad or pads on that side of the disc and the reaction force is, transmitted to a pivotally mounted calliper supporting a pad or pads on the other side of the disc, whereby the latter pad or pads are applied to the other side of the disc, the calliper is constructed of sheet metal and is in the form of a closed loop which encircles a peripheral portion of the disc and is pivoted to a pin carried by a fixed supporting platform. In one embodiment, Figs. I, 2, 4, 5, 6, the calliper is constructed from two pressings 13, 14 which are secured together by rivets 15. An hydraulic cylinder actuator 9 is fitted between opposed cylindrical portions 16 of the calliper and is secured by bolts 17. The piston 10 acts directly on backing plate 7 of one pad 5 tc apply the latter to disc 3. The reaction swings the calliper about pivot-pin 25 by which the calliper is mounted on fixed support 1 which has a flange 22 by which the calliper is supported through rubber bushes 33, Fig. 6, to eliminate or reduce chatter. The swinging of the calliper applies pressure to the backing plate 8 of the other pad 6 through the abutment 19, so applying the pad 6 to the opposite side of the disc. The pads are located in the gap 4 which accommodates a peripheral portion of the disc, the backing plates 7, 8 being supported by a flange 24 of the support 1, and by shoulders 27 which retain the pads against circumferential movement, and are retained by spring clips 28. The pads are of the shape shown, Fig. 2, and are of tapering thickness, the taper becoming less pronounced as wear takes place owing to the calliper swinging more towards a position in which the line of action of the piston is at right angles to the plane of the disc. To limit the return swinging of the calliper so as to maintain a predetermined pad clearance a pin 29, Fig. 5, is secured to the flange 22 of the fixed support so as to extend within the calliper where it passes through a friction sleeve 30 retained with limited axial play by a bush 32 mounted in the calliper. In a second embodiment, Figs. 7, 9, 10, 11, the calliper is similar to that of the first embodiment but the pads are of uniform thickness, the swinging of the calliper being allowed for by omitting the shoulders 27 and pivotally mounting the pads on the calliper by a pivotal mounting of the cylinder on pins 34, and the provision of a fork 36 on the rear face of the backing plate 8 for pivotal engagement with a pin 37 carried by the calliper. A modified chatter-reducing mounting of the calliper is provided by a pair of rubber sleeves 42, Fig. 10, supported on opposed limbs of a wire frame 43 carried by the flange 22. Also the automatic clearance adjuster is modified in that a friction sleeve 38 is retained with play in a slot in the flange 22, while a pin 41 sliding within the sleeve 38 is mounted on the calliper. In a third embodiment, Fig. 13, the arrangement is similar to that of the first embodiment but the calliper is formed by three flat plates 45, the cylinder being retained by flanges 54 thereof being trapped between the upper and lower plates 45 and also by a flange 55 seating in an aperture in the upper and middle plates 45 to prevent axial movement. The support plate 60 has a surface 66 to support the calliper and is formed so as to guide and retain the backing plate 62 of one pad 48, the backing plate 63 of the other pad 49 being guided and retained by the calliper. In a fourth embodiment, Fig. 19, the calliper, which is formed by two superposed plates 70, is supported at its end remote from the pivot-pin 71 by a link 75 which is pivotally connected at its ends to the calliper and the support respectively. In a fifth embodiment, Fig. 21, the calliper is in the form of a single flat plate having a U-shaped portion 82 by which it is pivoted on a pin 85 extending between flanges 80, 83 of the support 81. In a sixth embodiment, Fig. 22, the calliper again consists of a single flat plate which is pivoted on a pin 96 and rests on a flange of the support plate, but neither pad is supported by the calliper, the backing plates 99 of the pads 91, 92 being guided by shoulders 102 on edges 100, 101 of a flange of the support plate. In the embodiments of Figs. 19, 21 and 22, the cylinder 94 is wedged in place by the engagement of a chamfered portion 87, Fig. 21, with inclined edges of an aperture in the calliper plate. Specification 998,727 is referred to.