| 摘要 |
361,318. Making paper bags. ANDREAS, A., 3, Engelstrasse, M³nster, Westphalia, Germany. Aug. 12, 1930, No. 24168. Convention date, Aug. 12, 1929. [Class 94 (ii).] In a tubular bag blank having end portions spread oppositely from a preliminary transverse fold line, in which a crossed end is produced by making two fold-inducing creases, one in each end portion, parallel to the transverse line and spaced therefrom to form two end flaps, one in each end portion, which are folded about the creases to lie flat and are so retained by adhesive, a reinforcing strip of material is applied to the folded end flaps. The blank may comprise several plies of paper and one end of the bag be formed to provide a filling valve. Tubular blanks, with their ends opened out as shown in Fig. 6 and the opened-out portion facing downwards, are placed on a table 1, Fig. 1, and fed sideways by arms 3 past feed rollers 4 and gumming rollers 5, 6 to creasing rollers 9, 10. The rollers 9 have an annular groove adapted to cooperate with an annular ridge on the rollers 10 to crease the blanks along the lines 84 and provide at each end two flaps 85, 86 of sufficient width to overlap when folded under by folders 13 and pressed down by bars 15 which reciprocate at right-angles to the path of the blank. A U-shaped member 16 retains the closed flaps. The ends of the bag are sealed by strips 90, Fig. 10, material for which is drawn from a roll 19, severed into pieces of the desired length by rotary cutters 23 and accelerated in speed by rollers 21,22 before reaching rollers 26 adapted to apply gum &c. to the undersurface thereof. A U-shaped guide 24 directs the gummed strip to pressing rollers 18 which unite it with the closed end of the bag and the sealed end is pressed by rollers 28 which may be heated. If a valve is to be formed in the bag end, the apparatus shown in Fig. 2 is used. Strips of greater length are cut from a web roll 30 by cutters 23 and the severed strip is gummed by a roller 33 as it moves along guide bars 31 till arrested by a stop 37 on a sliding table. 35. Suction means retain the strip on the table, which moves upward, until similar means on the underside of a former table 43 grip it and hold it with one end depending on the guide 31 and the other pressed against the opened end of the bag tube between the flaps 85, 86. The folding bars 15 now close the flaps down on to the strip and a folder 42 folds the outer portion over on to the closed flaps providing a valve. If no bag is fed to the machine, a spring 50, adapted to be raised by the bag, contacts with a member 49, and when a contact piece 52 on the shaft of the roller 10 bridges two contacts 53, 54, an electric circuit is completed which renders ineffective the operation of the cutting rollers 23 and so stops the feed of the strip. The apparatuses shown in Figs. 1 and 2 may be combined in a single machine to form bags with a valve at one end. |
