Patent GB-653917-A (GB)
Title: Improvements relating to vibration absorbing mountings for machines, vehicle bodies,and like objects subject to vibration
IPC: F16F1/38
Filed: 1948-05-21
Abstract: 653,917. Resilient mountings. PIRELLI SOC. PER AZIONI. May 21, 1948, Nos. 13876 and 13877. Convention dates, May 21, 1941 and April 30, 1942. [Class 108(iii)]  In a vibration absorbing mounting of the type comprising at least one resilient unit consisting of a sleeve of rubber interposed between two metal bushes disposed one within the other in load-transmitting relationship, one with the foundation upon which the supported object is supported through the intermediary of the mounting and the other with the supported object, the sleeve being bonded to the bushes and the arrangement being such that the rubber of the sleeve is subjected, when the mounting is under load, to shear-flexion stress, the resilient unit or each resilient unit is in load-transmitting relationship with the foundation and the supported object through the intermediary of a rigid surface or surfaces in stationary relation to a supporting member or members therefor in load-transmitting connection with the foundation or supported object, the supporting member or members being a separate entity or separate entities, from the metal bushes of the resilient unit or units, devoid of connection herewith, and being, or (in the case of a plurality of supporting members), one of them being, in the form of a housing surrounding the outer bush of the resilient unit, the rigid surface or surfaces being of such a shape, relatively to the shape of the ends of the rubber sleeve of the unit, as to be adapted to check and limit the deformation of the rubber sleeve. In the arrangement according to Fig. 1, a resilient unit consisting of a rubber sleeve 1 having frusto-conical end portions, and bonded to outer and inner metal bushes 2 and 3 respectively, is housed within a casing 9 between an upper flange 8 formed integral with the casing and a lower flange 10 formed integral with a sleeve 11 secured within the lower end of the casing. The casing is secured to a foundation or the like by means of a flange 12. A metal sleeve 7 extends through the bush 3 and is secured against axial movement relative thereto by collars 5 and 6 respectively, by which the object to be supported is secured to the mounting. Relative axial movement of the sleeve 7 and casing 9 deforms the rubber sleeve 1, the frusto-conical ends of which progressively engage the flanges 8 or 10. The resilient unit is sheathed in an oil resistant material 4, which may be reinforced with fabric or wire-net insertion. In a modification, (Fig. 2, not shown), the flange 12 is at the top of the casing and the flange 8 is carried by an annular disc overlying the flange 12 and overhanging the interior of the casing, the flange 10 being formed on the lower end of the casing. The outer bush 2 may be slit lengthwise thereof, and the sleeve 1 may be subdivided transversely thereof into two or more parts. In another arrangement, Fig. 1a, as applied to a rail truck suspension, two axially aligned pairs of resilient units are disposed between a metal casing 7 and a metal core 8 with the interposition between the inner and outermost units of a metal inner casing 26 which is rigidly connected to a part 2 of a chassis frame. The casing 7 and the core 8 are rigidly connected to the axle structure 1 through rings 10 and 9 respectively. which are recessed into an annular rubber disc 19. Metal rings 13, 14, 15 and 16 are located between the upper and lower pairs of units and annular flanges 11 and 12 are screwed on to the core 8 and casing 7 respectively to effect precompression of the rubber sleeves 3, 4, 5 and 6. Metal rings 17 and 18 locate the resilient units within the casing 26. The upper end of each outer metal bush is turned inwardly and embedded in the rubber sleeve to prevent tearing of the rubber from the bush, under load.