Proven Designs, Inc.

David Z Dike

William D Ellsworth

David I Laber

In a bag making machine the longitudinal side edges and adjacent portions of an elongate plastic web, which is folded in half medially of its centerline, pass from a set of inlet rolls over and under, respectively, a pair of vertically spaced separating rolls before merging at a set of outlet rolls. The separating arms extend inwardly between the two separated portions of the web only part way toward the fold line, and are spaced apart exactly twice the depth of the gusset that is to be formed. The remaining portions of the web, which are bisected by the folded line, are disposed in a vertical plane transverse to the separating arms, and upon traveling from the arms to the outlet rolls are folded inwardly between the merging portions of the web by the inner, pointed end of a triangularly shaped plow, which engages and progressively urges the fold line inwardly to the desired gusset depth The separating arms are vertically adjustable relative to each other; and the plow is adjustable transversely of the fold line of the web selectively to adjust the depth of the gusset.

Gusset folding mechanism and method for plastic bag making machine

The two separable elements of a conventional plastic zipper are advanced through a zipper guide slot from the inlet to the outlet end of a machine, simultaneously with two sections of a plastic film or web, one section of which overlies one of the zipper elements, and the other section of which overlies the other zipper element. Intermittently two jaws are advanced toward the web sections to squeeze them against opposite sides of the zipper, at which time a pair of registering hot bars that are resiliently mounted on the jaws adjacent the inlet end of the machine fuse each web section to a different one of the two zipper elements. At the same time, a pair of cold bars carried by the jaws adjacent the outlet end of the machine engage and cool portions of web sections which were previously fused to the two zipper elements. Idler rolls inclined to the zipper guide slot retain the folded web tautly over opposite sides of the zipper guide slot. One side of the guide slot is formed by an elongate metal plate having an elongate stiffening bar secured to one face thereof, and having secured in spaced openings therein a plurality of aluminum plugs which prevent undue distortion of the plate in response to extreme temperature changes.

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Port Gibson, NY, United States of America

David Z Dike