| 摘要 |
989,756. Expanding flattened bags. R. W. BARRACLOUGH Ltd., and R. W. BARRACLOUGH. Dec. 23, 1963 [Jan. 5, 1963], No. 604/63. Heading B8C. A flattened bag is formed into a blockbottom container by inflating the bag and causing its lower regions to be drawn upwardly through a restricted opening by the forces developed in the bag walls during inflation. In the machine shown a gussetted bag 11, Fig. 1, with a bottom seam 11e is supported at its upper end by a reciprocable back plate 35, Fig. 10, and a pair of jaws 32, 33, pivoted to a turret 31, and having shoes 32a, 33a which enter the gussets. As the turret 31 is indexed the bag bottom enters between nylon-covered rollers 72c, 73c, Fig. 12, which are then brought together by lever action to form a restricted opening, and at the same time a carrier 55 is advanced so that a beak 63a thereon controlled by an electromagnet 65 is carried to a position above the bag. The beak is then lowered into the bag mouth and opens it as the carrier 55 is withdrawn, so that a nozzle 48 lowered by the action of a push-rod 51 enters the bag mouth. The carrier 55 advances again farther than before so that a resilient pad 60 thereon clamps the bag mouth firmly against the nozzle 48 as in Fig. 7. The bag is inflated by high pressure gas entering via nozzle 48, and during inflation the back plate 35 is held in position by a push-rod and bell-crank. As the bag is inflated the gussets in its upper regions are expanded and then the lower regions are withdrawn upwardly from between the rollers by the forces developed in the bag walls, and are formed into a block bottom as in Fig. 5. The pad 60 and nozzle 48 are then withdrawn and the turret 31 indexed to the next working station. To deal with bags of differing lengths rollers 72c, 73c can be adjusted vertically. In a second embodiment the roller 72c is mounted on a spring-loaded lever and the roller 73c on a push-rod operated bell-crank. Specification 972,231 is referred to. |
