GB812272A - Improvements in disc brakes - Google Patents

Abstract

812,272. Disc brakes. DUNLOP RUBBER CO. Ltd. April 25, 1956 [May 7, 1955], No. 13264/55. Class 103 (1). In a " spot-type " disc brake, the brake disc is rotatable in a fixed casing and the housing containing the friction pads and fluid pressureoperated mechanism is fitted in an aperture in the casing and is detachably secured thereto. In the embodiment illustrated the brake comprises a flanged boss 1 attached to the rear axle housing 2 of a vehicle and a disc 17 is secured to and rotatable with a wheel. The rear axle or half-shaft 7 passing through axle housing 2 and outwardly of boss 1 is secured to the hub of the wheel 8. A sleeve 10 is secured to the inner periphery of the wheel 11 by bolts 12 and the disc 17 is provided with a splined connection 14, 15 with the sleeve 10; the disc, however, being axially fixed in operation by means of pin 15a. Secured to the fixed flanged boss 1 is a cylindrical outer member 20, formed with two diametrically opposed rectangular openings for the insertion and removal of rectangular, arcuate cover-plates 26 containing the piston and cylinder mechanisms to actuate cylindrical friction pads 29 located in horizontally opposed cylinders 28 adjacent the opposite radial faces of the brake disc 17. Within the annular space bounded by sleeve 9, flanges 1a and 21, outer member 20, coverplates 26 and flanges 13 and 23 is a completely liquid-tight chamber such that cooling liquid may flow around the space and cool the disc 17 and ancillary equipment. A liquid seal 45, 46 is inserted between a rotatable and non- rotatable portion of the brake and urged into liquid-tight sliding relationship with a resilient flexible metal annulus 48 and the admission of grit, dust or mud into the interior of the brake is prevented by the provision of an annulus 71 provided in close proximity of the disc 11 of wheel 8. Cooling liquid is conveyed from inlet connection 65 to chamber 51 and thence to a heat exchanger via outlet connection at 66 to a heat exchanger. A circulating pump (not shown) is incorporated in the circuit for this purpose. The brake disc 17 may have formed therein a series of pockets 67 so disposed that they produce a centrifugal effect. The cooling liquid used may be oil or water and glycol. Alternatively, the brake may be caused to operate as a " dry brake " or with the inlet connection connected to an air compressor and the outlet connection being left open to atmosphere. Specification 688,382 is referred to.