GB387036A - Method of and apparatus for the manufacture of window bags - Google Patents

Abstract

387,036. Window bags. MOND, A. L., 19, Southampton Buildings, London.- (Continental Paper & Bag Corporation ; 220, East 42nd Street, New York, U.S.A.) Sept. 18, 1931, No. 26151. [Class 94 (ii).] A bag-making machine for window bags comprises a forming plate, folders for the marginal edges of a relatively wide web, means for gumming marginal portions of a relatively narrow web and guiding the same into superposed relation to the infolded margins of the wide web to form a tube enclosing the forming plate, the latter being continued beyond the folders to form a severing edge, and tube feeding means disposed between the folders and the severing point for advancing the tube to the severing point and gripping it firmly during the severing operation, the forming plate having a portion at the feeding means provided with marginal notches and an aperture, the feeding means comprising three rollers at one side of the tube for acting respectively through the notches and the aperture, and roller means at the opposite side of the tube co-acting with the three rollers through the notches and the aperture to grip the tube at both margins and substantially midway between the margins. A wide web of transparent material 1 is led from a reel 4, the two outer edges being turned in over a plate 11 by posts 12. If a bellows bag is to be formed blades 13 form the bellows folds and the upper edge of the web is flattened over a plate 14 by folding blades 19 which may carry guide rollers. A narrower web of opaque material 2 is led from a roll 16, the edges being gummed by apparatus 8, 9 18. The two separate webs are pressed together by rolls 20, 21, the latter being the feed roll. The roll 20 is formed in three adjustable portions, Fig. 6, the two outer portions pressing on the edges of the tube while the middle one, which acts through a slot in the folding plate 11, co-acts with the feeding roll 21 and prevents relative slipping of the two webs. Where the transparent web is much narrower than the opaque one intermediate pressing rollers 38 carried by pivoted spring-urged shafts 39 may be used. The edge of the plate 11 is formed straight and carries saw-teeth 22, above which is situated a plate 23 formed with a concave edge carrying saw teeth 24. A striking blade 25 which acts when the tube is gripped between rollers 26, 28 severs the tube into bag elements one top edge being straight and the other convex. The severed bag element is fed by rollers 29, 30 to the usual bottom forming rollers 31, 32 with pasting bar 34 and folders 33, 35, which complete the bag bottom. The finished bag is led away by delivery and drying conveyers 37. An alternative form of apparatus is shown in which the bottom forming rollers fold the bottom in the reverse direction, so that the transparent part of the bag extends right to the bottom unobstructed by the folded bottom portion.