| 摘要 |
899,726. Making bags. OTT K., [trading as HABRA-WERK., W. F. OTT]. Nov. 9; 1959 [Nov. 15, 1958], No. 37841/59. Class 94(2). Bags are made by a method which comprises folding a web of heat-sealable material into a U-shape, inserting into the fold a plurality of sets of plate members, pressing and welding together, between the plate members, the upright portions of the U to form pockets and separating the pockets to form individual bags. Baffles 3a combine with a wedge 3 to impress a U-form on the web. Plates 5, 6, suspended by arms 9 from a conveyer belt 4, enter the inside of the U-fold and are spread apart, by the operation of mechanism on the supports 9, and so cause the web to be advanced with the belt to position II, where heated radial projections 12 from a drum 13 co-operate with projections 14 from a drum 15 to weld seams 16 across the web. The projections may be resiliently mounted. At position III a pocket has been formed open only at the top. At position IV cutting means 17, 18 co-operate to separate the web into bags. A cam 25 spreads the plates 5, 6 to open the bags completely at position V. Each opened bag is swung around a roller 8, through position VI, to position VII, where spring-pressed fingers 20, 21, mounted on a drum 23, fold the bottom end flaps 19 against the bag bottom. The jaws may be in two parts, Fig. 4, and cutters may function between the two parts whereby the bags are separated as soon as they are welded. In the arrangement shown in Fig. 8 the bags are turned through an angle of 90 degrees, from A to B, and the weld seams pass between heated guide bars 110 by which they are secured to the side walls of the bag. The bottom end flaps 19 are folded in by a guide rail 105 and are heat-sealed by elements 106 carried by a drum 107. The welding jaws may be mounted on chains which move them along with the web, so giving a longer welding time. The edges of the spreading plates may converge, resulting in tapered bags. Also the spreading plates may have hinged joints whereby, when apart, they also provide a backing for the bag bottom. The web may be of plastic material, or of paper coated with thermoplastic material on one or both sides, or coated on one side with plastic and on the other with lacquer, and may carry printed matter. The movement of the belt 4 may synchronize with that of a delivery conveyer operating in the direction 26. |
