| 摘要 |
A method and apparatus of forming a hinge valve comprising a valve tube and a leaf hinge and incorporating it in a folded end closure of a bag. The method of attaching the tube to the hinge and adhering the preformed valve to a corner tuck of the end closure before the latter is finally folded utilizes apparatus comprising two pairs of feed rollers rotatable at equal speeds for simultaneously feeding, in superimposed relationship, a first web of material for forming a plurality of leaf hinges and a second web of material for forming a plurality of valve tubes, one pair of the feed rollers being spaced downstream of the other pair with rotary perforating means being disposed upstream of the one pair of feed rollers and extending across the webs for perforating both webs along transverse lines at a spacing equal to the desired length of each valve tube. Direction changing rollers for the second web are disposed between the other pair of feed rollers and the perforating means for laying the second web in a loop of a length such that the second web becomes offset in an upstream direction relative to the first web by a distance substantially equal to half the desired length of each valve tube. An adhesive applicator is positioned within the loop for applying adhesive to the second web beginning at each perforating line therein and extending for a distance substantially equal to half the spacing between adjacent perforating lines, the other pair of feed rollers being effective to bring the webs together and adhesively connect each valve tube length to an underlying length of leaf hinge. Means are provided for feeding bags in which hinge valves are to be incorporated at a predetermined speed, and a folding cylinder downstream of the other pair of feed rollers rotatable at a peripheral speed which is equal to the predetermined bag speed and greater than the peripheral speed of the web feed rollers, for tearing off successive adhesively interconnected valve tube and a leaf hinge lengths, folding each leaf hinge length double, finally forming each hinge valve and feeding successive hinge valves to successive bags, means being provided for applying adhesive to each folded-over leaf hinge portion before the hinge valves are applied to the bags.
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