Patent GB-692696-A (GB)
Title: Improved flexible joint or mounting
IPC: F16F1/38
Filed: 1950-04-03
Abstract: 692,696. Resilient mountings. THIRY, L. F. April 3, 1950 [July 19, 1949], No. 8262/50. Class 108 (iii). A flexible joint or mounting comprises inner and outer rigid members, the outer member having first and second interior cylindrical or substantially cylindrical surfaces and a first transverse shoulder joining them, and the inner member having third and fourth exterior cylindrical or substantially cylindrical surfaces and a second transverse shoulder joining them and facing oppositely to the first shoulder, but spaced therefrom, a rubber sleeve extending between the surfaces and the shoulders and bonded to or under radial compression between them to prevent relative slippage between the rubber and the surfaces, the members being arranged so that the first surface is opposite the third surface and the fourth surface is opposite the second surface, whereby the rubber intermediate the shoulders provides an intermediate zone which will be deformed by the shoulders into end zones defined by the surfaces, against the resistance of the rubber therein, when the joint is loaded so as to reduce the distance between the shoulders. In the arrangement shown, a rubber insert 7 is disposed between inner and outer sleeves 3 and 5, each of which is formed with relatively enlarged upper portions 9 and 15, respectively providing axially-spaced shoulders 13 and 19. Zones band c of the insert, on either side of a central zone a, which is defined by the shoulders 13 and 19, are preferably at least as long as the zone a and preferably also of equal length. The insert 7 may be moulded in place and bonded to the sleeves or forced therebetween under pressure, whereby it is radially compressed and axially elongated. In its free state, the insert, Fig. 2 (not shown), is of cylindrical shape and is formed: with internal and external shoulders for engagement with the shoulders 13 and 19 respectively. For achieving greater amplitudes of relative axial movement between the sleeves, the insert has a rolling action and in its free state approximates to ring shape, Figs. 3 and 4 (not shown), having a substantially circular cross-section and inner and outer peripheral cut-outs by which the ring seats on the shoulders 13 and 19. In a modification, Fig. 5 (not shown), both portions of each of the sleeves 3 and 5 are tapered. In another modification, Fig. 6 (not shown), the upper portion only of the inner sleeve and the lower portion only of the outer sleeve, are tapered. In a further modification, Fig. 7 (not shown), the sleeve shoulders radially overlap. In another modification, Fig. 9 (not shown), the central section of the insert is substantially the same width and on the same radius as the zone a whereby the central section is unstressed or stressed to a lesser degree than the end sections of the insert during assembly of the joint. In an arrangement in which the joint is subjected to torsional stresses, the insert, Fig. 8 (not shown), is formed at its central section with internal and external shoulders which are thicker than the end sections of the insert. In another arrangement, Figs. 10 and 11 (not shown), the end zones band c of the joint after assembly, are shorter than the central zone a and in the unloaded condition of the joint, the end surfaces of the insert are tapered. Relative axial movement of the inner and outer sleeves of the joint is limited by a laterally projecting shoulder at one end of the inner sleeve and a flange having a rubber washer thereon at the other end. In a further arrangement, Fig. 12 (not shown), a single insert, or a pair of axially-spaced inserts is disposed between inner and outer sleeves providing two pairs of axially-spaced shoulders. In the inserts according to Figs. 7, 9 and 11 (not shown), radially extending annular grooves may be provided between the intermediate and end sections of the insert. Where the sleeve shoulders are of substantial width, or overlap, the joint is assembled with the inner sleeve formed initially, generally conical adjacent the shoulder position, the sleeve being expanded subsequently to cylindrical shape by any suitable means. Specifications 309,952, [Class 108 (iii)], and 388,095 are referred to.