Patent GB-661079-A (GB)
Title: Improvements relating to the assembly of flexible bearings
IPC: B25B27/28
Filed: 1949-07-28
Abstract: 661,079. Assembling rubber bushes. SILENTBLOC Ltd., and HUTTON, P. C. July 28, 1949. No. 19872/49. Class 108(iii). Apparatus for inserting the inner sleeve of a flexible bearing of the extended bushing type, disclosed in Specification 617,527, comprises a press, means for holding the assembled outer sleeve and rubber bushing in one part of the press, means for holding the inner sleeve and also a tapered plunger or expander in the other part of the press, so that as the press closes, the plunger will enter the hole in the rubber bushing in advance of the inner sleeve, and an annular yieldable abutment in the first mentioned part of the press arranged to engage the radially outer portion of the adjacent end of the bushing, which portion will constitute an end of the radially compressed portion and the inner end of the adjacent annular clearance in the assembled bearing, the internal diameter of the annular abutment being appreciably greater than the external diameter of the inner sleeve, so as to provide an annular space to accommodate the extended end of the bushing. In the arrangement shown, a rubber bushing 3 is forced within a sleeve 2 in a press which is shown in the closed position in Fig. 3 and which comprises a plunger 7 which is movable towards or away from a fixed bed 6 by any suitable means, such as an air cylinder (not shown). A pusher 8 is connected to the plunger 7 and is surrounded by a housing 12 having a cylindrical bore 13 and a tapered bore 14 the lower extremity of which is of the same diameter as that of the internal diameter of the sleeve 2. The lower end of the housing 12 is counterbored to the external diameter of the sleeve 2 which is engaged by a shoulder 15. The lower end of the pusher 8 is provided with a head 18 of the same diameter as that of the internal diameter of the sleeve 2 and is counterbored at 19 to receive the extension 4 at one end of the bushing. A projection 20 on the pusher 8 is of approximately the internal diameter of the bushing when the latter is inserted in the sleeve 2. When the plunger 7 and pusher 8 are raised to their fullest extent, the housing 12 is slightly elevated to permit sleeve 2 being placed over a vertically adjustable abutment 24 having a counterbore 25 adapted to receive the extension 4 at the lower end of the bushing 3. The bushing is then inserted through an opening 17 in the housing 12 and is held in alignment with the projection 20 by its engagement with the bore 13. The press is then operated to move the housing over the end of the sleeve 2 and to force the bushing through the bore 14 into the sleeve. Air trapped within the counterbore 19 is discharged through a passageway 21. The assembled bushing and outer sleeve is subsequently supported in a counterbore 41 at the lower end of a housing 42 of a similar press, Fig. 4, which is shown in the partly closed position for insertion of the inner sleeve 1. The housing 42 is secured to a plunger 31 for movement towards or away from a bed 30. A spring-loaded hollow piston 46 having a shoulder 47 which seats on a shoulder 48 within the housing 42, is of an external diameter corresponding to the internal diameter of the sleeve 2 and is counterbored at its lower end to receive the extension 4 at that end of the bushing. The counterbore is of greater axial length than that of the extension 4, and a projecting annular end 51 of the piston 46 is of less radial thickness than the radial distance between the sleeves 1 and 2 on assembly, but greater than the clearance 5 in the complete assembly. The inner sleeve 1 is placed over a vertically adjustable projection 35 in a die 32 on the base 30 and supports a tapered punch 39. The upper end of the sleeve 2 seats in the recess 41 surrounding the piston 46, the extension 4 extends into the counterbore below the piston and the sleeve and bushing are thereafter forced downwardly over the punch 39 and sleeve 1 until the housing 42 and sleeve 2 abut the die 32 in which position the lower end of the bushing 3 abuts a shallow recess in the die. During the downward movement of the housing 42, the spring force behind the piston 46, overcomes any tendency for upward movement of the bushing relative to the sleeve 2. During the final closing movement of the press, the bushing expands upwardly against the piston 46, and after withdrawal from the press the ends of the bushing assumes the form shown in Fig. 1. In a modification, the tapered punch 39 may be mounted directly on the die 32, the sleeve 1 being placed over the punch and being suitably chamfered to facilitate entry of the sleeve into the bushing. Alternatively a chamfered ring may be provided on the punch, above the inner sleeve. The press may be arranged horizontally, the relative position of the parts may be reversed or the plunger may be stationary and the bed movable relative thereto. Water or petroleum jelly may be used as a lubricant between the sleeves and bushing during assembly Reference has been directed by the Comptroller to Specification 660,626.