Patent GB-1382493-A (GB)
Title: Brake disc assembly
IPC: F16D65/12
Filed: 1972-04-17
Abstract: 1382493 Brake discs GOODYEAR TIRE & RUBBER CO 17 April 1972 [24 May 1971] 17702/72 Heading F2E An annular brake disc has one or more metal members around one of its circumferences, the or each member having side portions engaging the disc faces, the side portions being interconnected by one or more portions extending across that circumference, and spaced fastening means for the or each member extending through one side portion, the disc and the other side portion, the clearance between the fastening means and the disc being greater than that between the fastening means and the metal member side portions. The disc material may consist of or include carbon or a carbon compound. As shown in Figs. 1, 3 and 5, the metal members 10 are equally spaced around the outer circumference of the disc and each is attached to the disc by four fasteners in the form of rivets 30; each member 10 is U-shaped in cross-section so that it straddles the outer edge portion of the disc and each is provided with a notch 18 for engaging drive splines of a wheel by which the disc is rotated. The disc has a plurality of arcuate notches 24 in its outer edge portion to allow for the depth of the notches 18. In a modification, instead of the rivets passing directly through the holes in the disc, bushings are provided through which the rivets pass. The difference in clearances is stated to be sufficient to compensate for uneven thermal expansion between the disc and the metal members 10. In an alternative construction, Fig. 7, aligned pairs of metal portions 34 are provided at spaced intervals around the outer circumference of the disc 32; each portion has an upwardly-projection portion 36, and a metallic insert 38 is brazed or otherwise secured between the portions 36; the inserts 38 serve to engage drive grooves of a wheel. The portions 34 are secured to the disc by rivets as previously described. In a further construction, Fig. 10, the disc is made from a plurality of separate elements 42 which are secured together by metal members 52; side portions of one end portion of each of the members 52 are offset as indicated at 58 so as to overlap the opposite side portions of the adjacent member 52, a rivet 60 being passed through the overlapping portions and the disc to secure the members together and to the discs; additional rivets 60 are also used which pass through the side portions of the members and the disc. Each of the members has a notch 54, the torque-transmitting sides 56 of which are machined to their final dimensions after the members have been riveted to the disc to ensure uniform stress loading of the disc assembly. The notches receive splines to hold the disc stationary. The rivets pass through bushings in the holes of the disc rather than directly through the holes of the discs as described above. In a further construction shown in Fig. 13 the disc has a central core and wear pads on both sides thereof, the inner circumference carrying metal members 58 which are of U-shape and straddle the inner circumference; they are attached by rivets 62 and are spaced to provide driving notches 60 between adjacent pairs of members. Three modifications of the first construction are described: in the first, the only difference is that the disc has a central core with wear plates on opposite sides; in the second, each metal member is designed so that the central portions of the side portions underneath the notch can buckle under compressive loading caused by thermal expansion; in the third, instead of the disc beng notched underneath each of the notches 18, no notches are provided in the disc and instead each metal member is designed so that the notch is above the circumference of the disc. Each of these three forms of construction can be used around either the outer circumference or the inner circumference of the disc. A construction is also described in which a single metal member which is U-shaped in cross-section and which extends around the entire circumference of the disc is provided.