| 摘要 |
1,127,606. Disc brakes. DUNLOP CO. Ltd. 9 Nov., 1965 [19 Nov., 1964], No. 47057/64. Heading F2E. In a disc-brake assembly, a caliper housing 3 is mounted on a non-rotatable member 5 (not shown) so as to be axially movable relative to a rotatable brake disc 2, one friction element 10 being fixed to one limb 6 of the caliper housing and a movable friction element 11 is associated with the other limb of the caliper and is adapted to be actuated when a brake-applying mechanism presses the movable friction element 11 towards the brake disc, the brake-applying mechanism comprising a thrust member 14 mounted in the limb 7 of the caliper housing, an hydraulically-operated piston and cylinder device 21 and a mechanically-operated actuating device in the form of a lever mechanism 36, 31, the thrust member 14 being adjustable in length such that means associated with the lever mechanism is provided to effect automatic adjustment of the length of the thrust member to take up clearances arising from wear of the friction elements. The thrust member 14 comprises an outer member 16 within which is threadedly mounted an inner member 18 provided at its outer periphery with ratchet teeth 20. These ratchet teeth are adapted to be engaged by a pawl mechanism 38 pivotally mounted on a portion of the lever mechanism 28 such that when the brake is applied, either by the hydraulic mechanism 21 or by the mechanical brake applying mechanism 36, 31, the lever 28 is tilted towards the disc about a pivot pin 29. If the brake clearance is such that movement of the lever required to apply the brake exceeds a predetermined value, the pawl member 38 will re-position itself behind a fresh tooth on the ratchet wheel 20 and, on release of the brake, will be drawn back by a spring 40 to rotate the inner portion 18 of the thrust member 14 so as to increase the effective length of the thrust member. Between the hydraulic mechanism 21 and the thrust member 14 there is provided a push-rod 25 formed with a flange 27 between its ends for engagement by the lever mechanism 28. Alternative embodiments are disclosed in the Specification wherein instead of the hydraulic mechanism being axially aligned with the thrust member the hydraulic mechanism engages one end of a lever mechanism having a fulcrum on the caliper intermediate the ends of the lever mechanism and a mechanical brake operating mechanism provided at the other end of the lever such that the lever is arranged to apply pressure to the thrust member at a point between the ends of the lever. |
