Patent GB-1446312-A (GB)
Title: Disc brakes
IPC: F16D65/84
Filed: 1972-12-21
Abstract: 1446312 Full-face disc brakes; cooling DUNLOP Ltd 4 Dec 1973 [21 Dec 1972] 59246/72 Heading F2E In a multi-plate wheel disc brake of the kind comprising a number of annular stator discs 1, Fig. 1, slidably mounted by inner-periphery keyways engaging keys projecting radially from a torque-taking structure 4 and interleaved with a number of rotor discs 5 similarly mounted by outer-periphery keyways in a wheel (not shown), whereby inner peripheral torque-transmitting portions of the stator discs 1 between the keys of the torque-taking structure 4 extend radially inwardly beyond the inner peripheries of the rotor discs, and a similar situation exists at the wheel, the rotor and stator discs being of a carbonaceous material, and a brake-applying mechanism 9-12 being provided, a number of arcuate filler pieces 17 or 18 are disposed in and occupy most of the free spaces within the disc pack between the keys and between the said torquetransmitting portions of alternate discs at either or both the radially-inner and radiallyouter peripheries of the disc pack. Fig. 1 is an axial section through the lower half of a torque tube 4, one piston-and-cylinder assembly 9, and the lower half of the disc stack. Each rotor disc 5 has a filler piece 17 bonded, pegged or otherwise secured to each face; each stator disc 1 has filler pieces 18 similarly secured. Fig. 2 shows part of a radial section of the upper part of the brake. Between each two adjacent keys 3 on the torque tube 4, and radially inwardly of the rotor discs 5 and the filler pieces 18 of the stator discs 1 is located a sheet metal heat shield 13 (see also Fig. 1) spaced from the torque tube 4 by mounts 14 of heat-insulating material (see Specification 1,443,709). In Figs 3, 4, (not shown) each one of a pair of filler pieces at each location is of L-section, the horizontal parts of the sections extending along the axial edge of the disc and abutting each other. Each space bounded by torque-transmitting portions of two adjacent stator (or rotor) discs, the intervening rotor (or stator) disc periphery, and two adjacent torque tube (or wheel) keys may be occupied by a single unattached filter piece. The filler pieces may be formed as integral parts of the discs, or a double-thickness block may be secured to, or formed integrally on, one side of each disc. To facilitate air cooling, the radially-inner edges of the torque-transmitting portions of the stators 1 between the keyways 2, as well as the radially-inner peripheries of the filler pieces 181 secured thereto, may be formed with circumferential flutings 24, Fig. 7. Alternatively or additionally, axial flutings may be formed (Fig. 8, not shown). In Fig. 9 each filler piece 182 secured to a stator 1 is of L-section turned outwards, the spaces between them and the adjacent rotors 5 being occupied by filler pieces 27 each secured to the periphery of a rotor. Preferably the filler pieces 27 are of more crushable material than the filler pieces 182 to permit movement towards one another of adjacent pairs of filler pieces 182 as the discs 1 and 5 wear down. Preferably the discs are of carbon reinforced with, e.g. carbonised cloth or tape. The filler pieces may be made from scrap disc material or high - density unreinforced graphite, or as sacrificial components of low-density carbon, or from an asbestos or ceramic-based heat insulator.