Apparatus for joining unvulcanised rubber tubes

1,000,511. Tube-splicing apparatus. DUNLOP RUBBER CO. Ltd. Dec. 8, 1961 [Dec. 23, 1960], No. 44205/60. Heading B4B. Apparatus for joining unvulcanized rubber tube ends comprises a pair of gripping members, one for each end, for gripping the outer surface of a rubber tube and supporting it in annular form considered cross-sectionally of the tube, the gripping members being disposed on a common axis and being movable towards and away from one another along the said axis, a support for the tube ends positioned between the gripping members and movable transversely with respect to the said axis, and a knife for each tube end movable transversely with respect to the said axis to sever a portion of said tube held in the support from a portion of said tube held in the associated gripping member. The mode of operation is as follows: two ends of a loop of rubber stock are inserted in the support 49, the operator shuts the safety lid (not shown) which operates the starter switch. The cam-shaft 35 begins to rotate. The clamp jaws 12, 13 are closed, then the cam 56 operates the heated blades 52, 53 to cut through the tube ends to provide a fresh surface. The carriages 7 are then drawn apart a little and the blades are lowered. The support 44 is then drawn well clear of the common axis of the gripping members at the same time bringing the valve which the operator placed in the slot 51 into a position between the tube ends. The carriages are then moved towards one another to press the two ends together firmly round the valve. At the end of the dwell period, the clamp jaws are opened and tube ejection plungers (not shown) free the tube from the clamp jaws. The carriages move back to their original positions. The operator then raises the transparent cover, removes the joined tube, and clears the trimmed ends of the tube from the sockets in the support.