When a folded packaging film is cut off by an L-type sealer, in packaging apparatus it is required that a remaining selvage of the film is wound up or hauled by a vacuum source to prevent some problems, to await it becoming reattached to the folded packaging film, as stated in the U.S. Pat. No. 4,219,988.
Especially when a belt conveyor is used for an infeed conveyor to the packaging apparatus, a folded film is hauled out from a web by interference with the products or articles transported and with a preceding severed film portion.
Accordingly the folded packaging film will not be unwound uniformly.
So it is necessary for a package wrapping apparatus to be furnished with a device for hauling the remaining selvage of the packaging film.
In prior art of film hauling devices, a remaining selvage was wound up on a drum by means of clamping the selvage between upper and lower endless chains which are provided in a longitudinal direction in parallel to a discharge conveyor of the wrapping apparatus.
In this case it was required that the above endless chains be meshed with each other strongly by spring loaded action to clamp the selvage of the film.
So there was a problem that cut-away selvage could not be easily removed, since the above strongly meshed chains could not be opened easily.
Instead of the above constructions there are methods of sucking the severed selvage of the film by means of a vacuum source, however the folded packaging film can not be hauled out uniformly by this means.
USPTO Backgrounds
USPTO Backgrounds