Patent GB-677885-A (GB)
Title: Resilient joint and method of making same
IPC: F16L3/16
Filed: 1948-05-14
Abstract: 677,885. Assembling rubber bush mountings. GENERAL TIRE & RUBBER CO. May 14, 1948 [Oct. 27, 1947], No. 13302/48. Class 108(iii) The invention relates to a method of assembling resilient joints or mountings of the kind comprising a rubber annulus disposed under radial compression between a rigid core member and an outer rigid member, the annulus in its unstressed state having a body portion of external diameter greater than the diameter of the outer rigid member, and of internal diameter less than the diameter of the core member. According to the invention, the annulus is positioned on one of the members in a relatively unelongated condition, the trailing face of the annulus is then rigidly and immovably supported while the annulus is axially elongated by telescopically forcing the second rigid member into concentric relation with the first rigid member. The trailing face is defined as the last face of the annulus to be enclosed between the outer rigid member and the core member. During assembly, the outer sleeve 3 is mounted on a tubular holder 5 beneath a guide 2. The latter is mounted for sliding movement against a spring 13, on spaced pins 14 (one only, visible) vertically upstanding from the machine frame 7. An hydraulic press, Fig. 1 (not shown), is mounted above the holder 2 with its plunger coaxial with the guide 2 and the sleeve 3. The plunger forces the resilient annulus 1 through the guide into the sleeve 3. Friction between the annulus 1 and the guide 2 drives the guide downwards against the spring 13 into self-centring abutment with the sleeve 3. This action is augmented by the action of a collar slidably mounted on the plunger against the action of a coiled spring, so that it comes into abutment with the upper surface of the guide 2, Fig. 4, (not shown). The holder 5 is rigid with a block 6, which is movable under the action of a lever (not shown) within a guide channel 7a in the frame 7, so as to position the annulus 1 and sleeve 3 beneath a second hydraulic press (not shown) and a sleeve-restraining member 19, Fig. 3. The latter is carried by a frame 27 which is slidably mounted on spaced vertically-upstanding pins 28 (one only, visible in Fig. 3). The height of the frame 27 is manually adjustable through linkage 29, 30, and a pinion 33 which meshes with the toothed segment of a handle (not shown). The member 19 is mounted for vertical sliding movement relative to the frame 27 against a spring 24. The upper end of the inner rigid sleeve is secured to the plunger of the press and a tapered leader member 20, Fig. 5, having a maximum diameter equal to that of the inner sleeve, is mounted on the lower end of the latter. During the projection of the inner sleeve into the annulus, the holder 5 limits downward movement of the annulus. The outer sleeve 3 is forced to rise due to the axial elongation of the annulus, and moves against the resilient restraint of the member 19 which prior to the operation is lowered over the end of the sleeve 3 by its associated operating handle. In a modified method, the annulus 1 is first placed on the inner rigid sleeve 18, Fig. 11, which is then mounted in the annular recess of a holder 51. The outer sleeve 3 is then pressed on the annulus with the aid of a tapered guide 56. The upper annular surface of the holder 51 prevents downward movement of the annulus 1 while the central piston-like portion of the holder serves to guide the upward movement of the inner sleeve 18, which corresponds to the upward movement of the outer sleeve 3 in the previous method. The thick body-portion of the bush may be cylindrical as in Figs. 2 and 5, however the preferred shape (before assembly) of bush is shown in Fig. 8. The invention is particularly applicable to the assembly of mountings described in Specification 677,902.