Patent GB-680263-A (GB)
Title: Improved machine for folding sheet material into bellows
IPC: B31F1/00
Filed: 1950-09-01
Abstract: 680,263. Pleating and crimping. GENERAL MOTORS CORPORATION. Sept. 1, 1950 [Sept. 12, 1949], No. 21578/50. Class 141. [Also in Group XVI] Sheet material e.g. paper im. pregnated with a thermo-setting resin, is folded into tubularbellows formation by a machine in which the paper stock, wound on a drum, is fed to a pair of concentric cylindrical formers which shape the flat strip into a tube, a pair of rollers sealing the edges of the strip as they meet ir the formers, the tube then being fed continuously over opposed pairs of internal formers which alternately move outwardly and longitudinally to form the bellows pleats and to insert them between the faces of fingers of opposed pairs of external formers which move together to pinch and set the creases of the pleats and at the same time move longitudinally to advance the tube and bellows continuously through the machine. As described, the circular tube is passed over a rectangular former and the vertical and horizontal opposed pairs of iniernal and external pleat-forming members operate, alternately, to form pleats 538, Fig. 2, on the upper and lower faces, interposed between pleats 540 on the side faces of the tube. The paper strip 26, Fig. 1, fed from a roll 20, passes over a guide roll 28 through heating and humidifying chambers (not shown) under the machine table 34, to condition the paper. The strip then passes, by way of guide rolls 40, 42 to a plate 60 having an adjustable edge guide for the strip, adhesive being applied to one edge of the paper by a nozzle 72 to which compressed air is supplied by a flexible hose 96, the nozzle being controlled by a valve actuated by an arm 78 and solenoid 82, through springs 80, 84 so that the valve opens and closes with the starting and stopping of the machine. The strip then passes to outer formers 104 where a light mist of e.g. light machine oil is applied by a sprayer 98 and where the paper is gradually shaped into circular form, passing over an inner former 128, Fig. 9 extending onwards from the central region of the outer formers. The edges of the strip are guided into overlapping relation and are then pressed together between rolls 352, 354, Fig. 9, to seal the edges. A gear box 160, Figs. 1, 14 houses a cam 182 actuating bell cranks 206 which reciprocate rods 210, 212 carrying the horizontally and vertically disposed internal pleating formers 258 and 272 respectively, these formers being pivotally and resiliently mounted on their actuating members. The tube is formed into rectangular section by corner rods 436, Fig. 11, and as the pleats formed by the formers 272, 258 advance, they are seized between fingers 508 on driven chains located one at each of the four sides of the tube and pinched; heating pads 512 maintain the fingers at appropriate temperature to complete and set the pleats. The strip is advanced through the tube-forming members by a belt 392, Fig. 1, urged upwardly against the strip round the inner former by a spring-pressed pad 394. The machine is driven by a motor 132 adjustable by a screwed shaft 135 controlled by a hand-wheel 140 to suit the belt drive on to the gear box 160, the drive being transmitted by a magnetic clutch. A worm-driven longitudinal shaft 178 drives through gearing 310, 308 a vertical shaft geared to a transverse shaft which carries a driving pulley 362 for the belt 392, and sprocket wheels for chains driving the strip feed-roller 28 and the roller 352 for sealing the strip in tubular form. The shaft 178 also drives the gearing 476, 478 for the chains carrying the external pleating formers 508, Fig. 11. A cam 294 Fig. 1, on the wheel 286 driven from a shaft in the gear box 160 actuates a paint sprayer (not shown) for marking the paper tube in lengths appropriate to the bellows to be formed.