Patent GB-389589-A (GB)
Title: Improvements in or relating to bags and envelopes
IPC: B31B23/00
Filed: 1931-12-21
Abstract: 389,589. Making paper bags. ELLENS, W. E., Tresco Brow, Chesham Road, Berk hamsted, and DICKINSON & CO., Ltd., J., Apsley Mills, Hemel Hempstead, both in Hertfordshire. Dec. 21, 1931, No. 35292. [Class 94 (ii).] A method of producing window bags and envelopes consists in using a bag-making machine of the kind employed in manipulating a travelling web of paper into continuous tubular form and cutting the tube into bag lengths, and providing same with a web of transparent or opaque material, creasing, folding, and gumming the edges and placing in predetermined positions thereon cut sections of opaque or transparent material of dimensions adapted to allow of the desired lateral or end overlap upon the first web being cut to provide the length of a bag &c. ; the cut sections being obtained from a seeond travelling web or from a wad or pile. A fast-running web of transparent material is led from a reel 1 through edge-creasing discs 5, 6 to edge-gumming rolls, fed from a gumming tank 24, thence over rolls 33, 30 and under pressure rolls 62. A web of opaque paper, moving at a slower speed, from a reel 66, is led over a rubber-covered roller 70, on to which is periodically depressed a perforating blade 103 to perforate the web which is subsequently divided at the perforations by the gripping of the two webs between rolls 36, 33, the roll 36 being alternately raised from and lowered on to the roll 33 by cam and lever action 126, 44. The continuous web from reel 1 then proceeds onwards with detached portions from web 66 held tightly to its upper surface by the pressure rolls 62, 62, to edge-folding devices 133, which turn over the adhesively coated edges of web 1 on to the separated portions of web 66. The web 1 is then severed by any suitable means and the bag bottom formed by any known mechanism. To permit of the manufacture of different sized bags the working parts of the machine are adjustably mounted and the gear trains are capable of variation in speed by an interchangeable gear 74. The perforating blade 103 is reciprocated horizontally by an adjustable slotted disc arrangement 90, 91, 93, and depressed by cams 115 to cause it to contact with the web 66 as it passes over the rubbercovered roll 70. As an alternative, the web may be completely severed at this point by contacting with a knife-provided roll, the blade 103 being then replaced by a knife. As a further alternative the separate portions of web 66 to be imposed on the web 1 may be drawn from a pile of blanks or transparent patches and not severed from a web. The feeding device used in this case is of the suction-picker type. A shoe 144, with suction holes, is dropped on to the top of the pile by the vertical movement of a square rod 137. The rod 146 then moves the sheet to the left into the space between grip rolls 148, 33, the rolls 148 then moving downwardly to grip the sheet to feed it forward as in the former case. Instead of transparent material being led from reel 1 and opaque from reel 66 the reverse procedure may be adopted. Figs. 14 and 15 show two types of window bag capable of manufacture by the apparatus above described.