Patent GB-916059-A (GB)
Title: Improvements in or relating to the manufacture of tubular members such as can bodies
IPC: B21D51/26
Filed: 1961-04-17
Abstract: 916,059. Making cans; breaking; shearing; forging. CONTINENTAL CAN CO. Inc. April 17, 1961 [July 6, 1960 (2)], No. 13835/61. Classes 83 (2) and 83 (4). A method of separating tubular sheet metal members such as can bodies, connected together by tabs comprises moving the members in an axial direction and effecting separation by heating or by heating and stressing of the tabs. An apparatus for carrying out the method comprises a frame F supported by legs 22 on which is mounted a pair of aligned tube guides 15, a breaker apparatus 17 and a tab separating assembly 18. The guide 15 comprises a frame 23 supporting a pair of vertical and horizontal waisted guide rollers 24, 23. The breaker assembly 17 consists in a shaft 28 retained by bearing units 35 35 on an adjustable bracket 33 to which is secured a drive sprocket 36 and a breaker roller 26, an idler sprocket 37 mounted on a stub shaft 38 is also carried by the bracket 33. A pair of side plates 40, 41 with retaining plates 43, extend longitudinally on frame members 19, 20 to receive a sliding plate 42 on which is mounted bearings 44, 45 to retain a shaft 46 to which is fixed an adjusting crank arm 61 and which extends beyond bearing 44 to carry a drive sprocket 52 and a drive pulley 53. A pair of pivoting arms 47, 48 keyed to the shaft 46 carry bearing units 50 which house the shaft 29 on which the lower breaker roller 27 and the driven sprocket 54 are fitted. A cleated belt 55 connects the pulleys 53, 54. The longitudinal position of the lower breaker roller assembly is adjusted by moving the plate 42 controlled by the nut and screw arrangement 60, 56, whilst the height is set by releasing the locking screw 70 of the crank arm 61 fitted to the shaft 46 and the nut and screw assembly 68, 67 connected at one end to a fixed plate 63 and at the other to the crank 61. The breaker apparatus is driven by a drive unit D through a gear-box 72 via a belt driven, variable speed gear-box 73 which has fitted to its output shaft 75 a pulley 77 and a sprocket 76 which drives a chain 78 over sprockets 76, 52, 36, 37 and an adjustable idler sprocket 80. The tab-severing device comprises a supporting frame structure 85 mounted on a frame assembly F, the supporting plate 93 of which supports the feed and guide assembly 94 comprising a series of shaft assemblies 105, 117, 127 and 132 mounted along the arcuate-shaped bar 95 fixed to a plate 93. The shaft assembly 105 comprises a shaft 105 supported by bearings 101, 102 carrying a pinned drive gear 107 and two pinned pulleys 112, 115. A pair of pulleys 123, 124 rotate about the shaft 117 and a pulley 130 rotates about shaft 132 whilst a multiple groove pulley 128 rotates about a shaft 127 corresponding to shaft 105. Circular sectioned driving belts 126, 131 couple the pulleys 112, 123, 115, 124 and 128, 130 respectively and engage the lower part of the can body B. The pulley shafts are driven by gears 107, 129 and intermediate gears 135 via a drive belt 138 which is entrained over a motor-driven pulley 77, an idler pulley 141 and a driven pulley 137 which is attached to an extension of one of the shafts 105. Due to the decreasing diameters of the gears 107, 129 and that the breaker driving sprocket 76 is on a common driving shaft 75 with the pulley 77, the belts 126, 131 of each set are progressively driven faster and the bodies fed in timed relation to the feeding of the tube through the breaking device. The guide assembly comprises a plurality of adjustable brackets 146 and supporting bars 164 spaced along the plate 93, which support the inner 142 and outer 143 sets of guide rolls, each set comprising of a parallel and conical shaped roller fitted to a shaft, the pitch of the rollers is adjusted to suit the can diameter. A transition guide assembly comprises a pair of horizontally mounted waisted rollers 194 and two pairs of vertical rollers 209, 220 suspended by brackets and shafts from the plate 93 and is positioned between the breaker roller assembly 17 and the start of the feed and guide assembly 94 to facilitate the transfer of the partially flattened can body from the breaker rollers on to the feed and guide assembly. A hollow conductor 222 supported by insulating clamp blocks 223 carried on a bracket 224 is adjustably fixed to the plate 93 and provided with coolant inlet and outlet fittings 227, 228. The electrical connections are made at 232, 233 and a series of brush units 237 comprising a plurality of thin resilient metallic strips are fitted to the contacting electrodes 235 which are fixed to the mounting blocks 236 brazed to the conductor 222. Operation.-A tube T having score lines S is passed through the guides 15, 16 and diverted upwardly from its line of travel between breaker rollers 26, 27 which partially squeeze the tube causing it to fracture along the score line S remote from the welded seam W. A continuous line of can bodies B so separated and interconnected by tabs t along the welded seam W pass through the transition guide assembly 180 to the feed and guide assembly 94 and into contact with the brush units 237. The tabs t are progressively heated due to the shunted circuits formed across them and with or without the increased tension across the tabs due to the increasing speed of the belts 126, 131 separation of the car bodies occurs followed by their ejection from the machine. In a first modification the gears of the drive and feed assembly may be replaced by a series of belt-driven pulleys. In a second modification.an A.C. or D.C. circuit comprising a pair of electrodes 309, 310, a transformer T.F. and a control device 316 may be used to heat and sever the tab whilst it is bridging the gap between the electrodes with or without any tensile or shear stresses being imparted due to the relative speeds of the drive rolls 307, 308. In a further modification, a reciprocating shearing device comprising a knife 321 fitted to a shaft 320 of an electromagnetic operator 319 may be fitted into the above circuit and controlled by the control device 316 so that the knife is operated simultaneously with the heating and tensioning cycle.