Patent GB-648800-A (GB)
Title: Method and apparatus for splicing inner tubes
Inventor: ENGLER MAX
IPC: B29B15/04
Filed: 1948-07-16
Abstract: 648,800. Jointing rubber tubes. GENERAL TIRE & RUBBER CO. July 16, 1948, No. 19172. [Class 70] Rubber tubes are spliced by flattening the ends, cutting each end, abutting the cut ends, bringing the cut ends into full engagement and applying pressure whilst restricting lateral flow of rubber from the splice throughout its perimeter. A machine for this purpose comprises upper and lower elongated platens 17, 20 (Fig. 8), one movable towards and away from the other, pairs of tube gripping bars 3, 4, 8, 9, Figs. 5 and 11, mounted on opposed faces of said platens, the bars of each pair extending longitudinally of and movable transversely of their platen, clamping flanges 5, 6, with tube engaging faces on the opposed edges of the bars, a gap-covering bar 7, 12, mounted between the flanges, blocks between the gripping bars and also flanking the opposite side edges of the tube, the blocks and gap-covering bars preventing lateral flow of rubber from the splice, springs between the gap-covering and gripping bars and means for moving the gripping bars in opposition to said springs. In operation, the tube ends are flattened, cut, and pressed into complete contact, their cut ends engaged by the bars 3,4, having thin flanges 5, 6 and the bars 8, 9 with flanges 10, 11. Each bar 7, 12, has a thin groove. A supporting frame has a table 16, Fig. 8, to support the tube during splicing. The lower platen 17 is fixed to a standard 18 upon which a vertically slidable carriage 19 having the platen 20 pivoted thereto is mounted, and attached to an adjustable spring 21. An upper framework 24 has a vertical guideway 25 for a slide 26 actuated by a cam 27 which has a horizontal part 27a which continues pressure on the platen 20 whilst the cam makes a considerable part of a revolution. The cam is driven by a shaft 30 which is actuated by a motor 38 (not shown) through shafts 36 and 33 and suitable gearing. An adjustable plunger 40 has limited vertical movement relative to the slide and is connected to the platen 20 by a roller 49 and a cam slot 50. A counterweight 53 holds the head and platen in the elevated position. The shaft 30 turns and carries the slide to its lowest position carrying a head 45 and platen 20 down until the latter is parallel with platen 17, and the grippers 3, 4 of the platen 20 grip the tube. A spring 46 limits the pressure exerted by the platen, and the shape of the slot 50 is such as to equalize the pressure over the face of the platen. Springs hold the gripping bars in their spread position. After platen 20 grips the tube the gripping bars are moved towards the gap-covering bars, for endwise pressure, by means of front and rear actuating arms 71, 62. The rear arms are mounted on fixed pivots 63 and actuated by a cam 70 on the shaft 36. The front arms are pivoted on a slide 72 operated by a cam 73 and actuated by a collar 74, slide 77 and a cam 78. When the shaft 36 is rotated the arms 71 are first elevated and then actuated simultaneously with the arms 62 to apply pressure to the grippers of both platens. The motor 38 (not shown) is stopped by switches 84, 88 and started by switches 84, 85 which are actuated by cams 82, 83 on the shaft 33 in order that the pressure may be maintained for a suitable time to effect the splicing. The switches 84, 85 operate a timing system.