Patent GB-1290949-A (GB)
IPC: F16D55/00
Filed: 1970-05-29
Abstract: 1290949 Sliding-caliper spot-type disc brakes KELSEY-HAYES CO 29 May 1970 [26 June 1969] 26145/70 Heading F2E A spot-type disc brake assembly includes a first torque reaction arm 73 fixed relative to the disc 32, edge 81 on the backing plate 47 of the first pad 46 being engageable with arm 73 when the disc is rotating in one direction, and a second torque reaction arm 74, portion 89 on the backing plate 53 of the second pad 52 being engageable with arm 74 when the disc is rotating in the same direct on, when the brake is applied, the area of engagement of the first pad with the first torque reaction arm and the area of engagement of the second pad with the second torque reaction arm being located on opposite sides of a radial plane containing the axis of rotation of the disc. As shown, a ventilated rotor 32 is fixed to a hub 35 rotatably supported on a fixed wheel spindle 37. A caliper assembly 42 has spaced legs 43, 44, joined by an intermediate portion 45. The portion 45 has cut-out portions in its sides (Fig. 3, not shown), but otherwise is slidably engaged with a torque reaction member 67 secured at 71 to a flange 69 of the wheel spindle 37. The torque reaction member 67 has two arms 73, 74, extending axially over the outer periphery of the disc 32. The backing plate 47 of the first brake pad 46, (acted on by piston 49), is provided with tangs 78, 79, Fig. 4, which rest on the bottoms of grooves 76, 77, in arms 73, 74, respectively, but are spaced from the sides of the respective grooves. The backing plate 53 of the second brake pad 52 (acted on by the caliper), is provided with notches 88, 89, (Fig. 5, looking in the opposite direction to Fig. 4), for supporting the pad on outwardly-extending portions 91, 92 of arms 73, 74, the vertical surfaces 95, 96 of portions 91, 92, respectively, being slightly spaced from the adjacent surfaces of notches 88, 89, respectively. In operation, assuming the disc 32 is rotating in the direction of arrows 114 in Figs. 2, 4 and 5, piston 49 urges brake pad 46 into engagement with the disc, such engagement tending to rotate pad 46 counter-clockwise, Fig. 4. Consequently, edge 81, Fig. 4, of its backing plate 47 comes into contact with the adjacent surface 83 of arm 73 of torque reaction member 67, so this arm alone takes the braking force of pad 46. (The vertical space 78-76 is reduced but not eliminated.) Brake pad 52, upon engagement with disc 32, is urged to rotate clockwise, Fig. 5, until the vertical surface of notch 89 makes contact with the vertical surface 96 of portion 92 of arm 74 of torque reaction member 67. Thus, arm 74 alone takes the braking force of pad 52 at this stage If the disc is rotating in the opposite direction, the functions of arms 73, 74 are reversed. In the case of excessive loading of arm 74, Fig. 5, by pad 52, sufficient to cause deflection of the arm so as to bring a vertical surface 77 on its inner face into engagement with a surface 116 on the caliper 42, the caliper is moved thereby until an equivalent surface 115 on the other edge of the caliper makes contact with an equivalent vertical surface 76 on the other arm 73. Thus, a portion of the brake force from pad 52 is transferred from arm 74 to arm 73. On brake release the pads return to light rubbing contact with the disc 32 in known manner. The caliper assembly 42 is slidably secured by clamping members 104, 105, bolted to the torque arms and separated from the caliper assembly by anti-rattle springs 107. Figs. 8 and 9 show another clamping arrangement and interposed rattle spring. Figs. 10 to 13 (not shown) depict minor variations of the shape of the caliper tongue 157 and of the spring of Figs. 8 and 9. In Fig. 14 a wedging member 306 is incorporated. In Fig. 17 a nylon anti-friction member 403 is located between caliper and torque arm, and the anti-rattle assembly is completed by a resilient clamping member 409. In Fig. 16 (not shown) the clamping member resembles that of Fig. 8. Figs. 19 to 22 (not shown) incorporate a wedging member as in Fig. 14, but it is generally flat with a bevelled edge and is partly accommodated in a slot in the caliper. Fig. 23 resembles Fig. 17 but the nylon antifriction member is omitted.