Patent GB-813816-A (GB)
Title: Apparatus for making can bodies
IPC: B21D51/28
Filed: 1956-09-12
Abstract: 813,816. Making cans. BLISS CO., E. W. Sept. 12, 1956 [Sept. 13, 1955], No. 27860/56. Classes 83 (2) and 83 (4). [Also in Group XVI] Can-making mechanism includes a magazine for storing body blanks and means for feeding said blanks to hook or edge-forming means, said forming means comprising an anvil positioned to contact one marginal portion of a body blank, said portion projecting laterally beyond said anvil, a hook-forming die member adapted to reciprocate adjacent said anvil, said die member including a forming die adjacent said anvil and a cam-follower remote therefrom, a cam having a cam face positioned to guide the die member in the path of reciprocal travel, said path of travel being perpendicular to the plane of the blank until the die contacts and deflects said projecting marginal portion of the body blank, and then inwardly to bend said portion back upon itself to form a hook or flange. From a stack of can body blanks in a bin 24, Fig. 2, the lowermost blanks are withdrawn singly by suction cups 88, reciprocated vertically by eccentric operated linkage 90, and are deposited on a plate 84. A pusher-bar 98 also connected with the linkage 90 is slid to push the blank thus deposited off the plate 84 and through driven flexing rolls 104, 106, which remove irregularities in the blank, to work feed-mechanism. This comprises a pair of feed bars 110, 112, having a plurality of spring-loaded fingers 114, Fig. 5, which engage the rear edge of the blank and carry it forward from one work station to another on the forward stroke of a reciprocating motion given the bars by a lever 142 oscillated by a crank 136. On the backward stroke of the feed-bars 110, 112, the blank is urged by spring- loaded fmgers 119. 121, Fig. 8, on a fixed part of the machine, back against spring-loaded positioning fingers 105 or 107 on fixed bars 118 (not shown), 120, the fingers 119, 121 having been loaded by the previous forward movement of the blank. A third reciprocated feedbar 111 has spring-loaded fingers 132, 134 which engage a blank at the fluxing station and strip a formed blank from a forming horn, respectively. The blank is fed to a station B where its edges are knurled or serrated, then to a station C where the edges are notched, the four corners of the blank being cut away, then to a station D where an upwardly-bent hooked flange is formed on one edge of the blank and a downwardly bent hooked flange on the other edge, then to a station E where flux is applied to the hooked edges, then to a station F where the blank is bent round the forming horn and seamed to form a can body, and then to soldering means. The positioning means 107, 121 and 105, 119 operate at stations C and D respectively. Knurling.-Each side edge of a blank is knurled or serrated by a serrated wheel 150, Fig. 9, moved into and out of contact with the edge by a cam-actuated lever 164 engaging a slide 154 carrying the wheel, the slide being urged by a spring 158 towards the blank. Punching.-Each side of the blank is notched by a punch 176, Fig. 10, vertically reciprocated by eccentric operated lever means 180 and co-operating with a fixed mating die 190. Angular bending.-The blank has each side edge positioned between and projecting from a fixed anvil lower part 224, Fig. 11, and an upper anvil part 226, carried by a pivoted arm 232, urged by a spring 227 to clamp the blank between the anvil parts just prior to the flanging operation. A rod 235 connected to an eccentric on a drive shaft 30 or 32 opens the anvil parts after flanging. One edge of the clamped blank is bent up and inwardly over an upper anvil part by a die 211 and the other edge is bent down and inwardly over a lower anvil part by a die 210. The die 210 is mounted on a head 206 on an arm 204 reciprocated vertically by a lever 200, rocked by an eccentric 196 on the shaft 32 and guided by a fixed cam 212 so that the die 210 first moves downwardly to contact and deflect the projecting portion of the blank and then inwardly, as the head 206 engages a part 214 of the cam 212, to bend the portion back upon itself to form a hook. The other die 211 is similarly operated to move upwardly. The dies and lower parts of the anvils may be reversed when one edge becomes worn. Fluxing for soldering.-Liquid soldering flux is applied to the bent part of each hooked flange by a brush 240 rotated by an electric motor 244 and dipping in a bath 242 supplied by dispensing means 254. Angular bending; seaming; expanding.-At station F a flanged blank is held on to a forming horn 52, Figs. 3, 14, by a clamp 44 moved downwardly by an eccentric disc 280 on a crossshaft oscillated by a rack 272 reciprocated by a cam 56. Wing members 46, 48, pivoted to the clamp 44 and to lever and link means 340, 344 rocked by cranks on shafts 30, 32, swing round the horn 52 to bend the blank therearound and interlock the hooked edges. The wings 46, 48 then withdraw and the horn 52 is expanded to completely interlock the hooked edges. The horn 52 comprises, Fig. 16, a fixed segment 318 and an expandable segment 316 which latter is moved outwardly by the longitudinal movement of a bar 312 formed with cam surfaces 320 engaging rollers 322 bearing on the segment 316. The bar 312 is moved by a lever 308, Fig. 15, rocked by a lever 298 in turn rocked by pins 294, 296 reciprocated by out-of-phase cams 290, 292. After the horn 52 has been expanded a hammer 50, Fig. 3, is moved upwardly to press the interlocked hooked edges flat to form a seam. The horn 52 is then contracted and the can body is pushed off on to a soldering horn by the finger 134 on the reciprocated bar 111.