| 摘要 |
1,144,247. Making gusseted plastics bags; seaming non-metallic sheet material. GOGLIO LUIGI MILANO S.p.A. 2 June, 1966, No. 24611/66. Headings B5D and B5K. [Also in Division B8] A gusseted heat-sealable bag formed from one or two sheets is made by welding a shim 22 to a sheet 23 at a position where the bottom seam of the bag is to be welded in order to produce a seam of uniform thickness. The shim 22, cut from a strip 29, is welded to a plastics web 23 on a drum 33 by a welding jaw 34 reciprocated by a pneumatic cylinder 35. The welding jaw 34 and cylinder 35 are mounted on a crank member 36 which is arcuately moved with the web 23 until a microswitch is operated, whereupon the welding jaw 34 is released and the crank 36 returned by a spring to its original position. The web 23 is superposed over a second web 24, formed with side gussets by a folding mechanism 41, and the two webs sealed to each other by longitudinal welding jaws (43), (Fig. 8, not shown), and transverse jaws (44) mounted on a moving carriage (45). The webs are finally cut into individual bags. The bags may alternatively be made from a single web (Fig. 9, not shown). |
