GB862402A - Frictional drag apparatus and brake provided therewith - Google Patents

Abstract

862,402. Locking rods. GOODYEAR TIRE & RUBBER CO. Sept. 25, 1958 [Oct. 11, 1957], No. 30643/58. Class 80 (3). [Also in Group XXXIV] Axial movement in either direction of a rod 4, Fig. 1, slidable in a block 1 is frictionally resisted by an apertured disc 5 which is canted by two oppositely acting springs 9, 10 to grip the rod, the axial thrust on the rod which produces slip in one or other direction being determined by the respective strengths of the two springs. The different spring strengths may be adjusted by screws 11, 12. Opposed fulcrum surfaces 15, 16 for the disc may be provided by screws 17, 18 which are adjusted to provide a small clearance. In a modification an apertured disc 66, Fig. 3, on a rod 52 is canted by springs 62, 64 in the form of bowed rings, each of which is secured at one point only by a screw whose head forms a fulcrum for the disc. The springs 62, 64 are of unequal strength so that the disc 66 provides a high frictional resistance to movement of rod 52 to the right and a low resistance to movement to the left. The spring 62 is attached to a flanged disc 60 which is clamped by a threaded cover to a cylinder head 45 carrying the spring 64, a dowel pin 65 on the cover entering a selected locating hole in the head to provide angular adjustment of the disc 60 and hence adjustment of the spring effect. As shown, the rod 52 forms an automatically adjustable stop for a piston 43 in a disc brake wherein a disc 37 slidably keyed at 39 to an aircraft or other wheel 36 is clamped between a pad 41 on a fixed support 40 and a pad 42 on the piston 43. The piston return spring 49 reacts against a flange 51 on the rod 52, which flange forms a stop for the piston when the brake is retracted. The position of rod 52 thus determines the brake clearance. The stronger spring ring 64 causes the canted disc 66 to prevent movement of the rod 52: to the right under the reaction of the spring 49 as the brake is applied. As the brake pads or disc wear, however, the piston travel increases until a ring 50 thereon strikes the flange 51 and overcomes the high resistance of the canted disc 66 to shift the rod 52 to the right to restore the desired brake clearance. Should this shifting movement be too great, due for example to distortion of the disc 37 or support 40, so that the disc 37 rubs on the pads when the brake is released, the rod 52 is able, due to the low strength of spring ring 62, and the consequent low resistance of the canted disc 66, to be automatically pushed back slightly until rubbing contact between the brake disc and pads ceases.