DE2065534A1 - DEVICE FOR CUTTING FILM ROLLS - Google Patents

Description

Applicant; Ingeni / rfirmaet Hans Hansen, DK-34OO Hiller ^ d and Ingenieirfirmaet Bdrge Christensen, DK-3520 i'aruni. Denmark

Device for cutting through foil webs

The invention relates to a device for cutting through I ¹ 'ο lisabahne η and the like by means of a knife that can be moved transversely to the film web.

Such devices are e.g. B. in connection with machines for the automatic packing of goods by means of a Polishing tube used. The latter is pulled down over the property and then cut through immediately above the property. If necessary, two edges are welded together at the same time, i. h, the bottom of a bag is when packing formed above.

When using relatively thin plastic sheets the film webs can be cut through by means of a filament without any noticeable interruption in their movement will. This method cannot be used for heavy foils because relatively large amounts of material are very short Time to be melted.

Instead of the filament, scissors or knives could be used with a blade cut from a the side surfaces of the film web is guided against the film web. To do this, a suitable counter-hold can be provided. However, such scissors or knives require a complicated drive mechanism and lots of space.

The invention is based on the object to provide a space-saving knife mechanism that has a fast Cut off the polishing tube achieved.

40-9820 / 000-1

206553a

The solution according to the invention is characteristic Part of claim 1 characterized.

The entire mechanism with the exception of the topmost tip of the knife is arranged on one of the side surfaces of the film web and thus the space on the other Side of the film web are kept free. Furthermore, the drive mechanism for the knife is extraordinary simple and compact design. The use of the pneumatic cylinder allows a very high working speed for the knife. The cutting takes place without interrupting a packaging process.

When continuously pre led film webs to be cut _t can the endless wire and the pneumatic cylinder in a direction perpendicular to the screening direction of the film web plane mounted at a small angle, so that the spawned section lies in the film due to the relative movement perpendicular to the longitudinal direction of the film web. However, this assumes that the blade is single-acting, during the movement w in one direction only supply cuts and then executes an invalid return stroke.

If, on the other hand, the film web is advanced step by step, the web standing still during the cutting through, the knife can be effective in both directions of movement. It is then run through a double acting cylinder with wire driven.

It is useful that both guide rollers and knife holders are arranged inside the cylinder;

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The device according to the invention can be used synchronously with welding devices used for the automatic packing of goods use by the welding jaws moved towards one another, the film web at the same time during the welding operation and hold on while cutting.

Embodiments of the invention are shown below explained in more detail using the drawing. Show it:

Fig. 1 schematically shows an embodiment, partially

in a section transverse to the longitudinal direction of the film material, and

• · *. _r

Fig. 2 shows another embodiment, wherein guide rollers and wire run are arranged in the interior of the cylinder.

A cylinder 1 has bottoms 2, 3 to which and outlet lines 4 and 5 for compressed air are connected. The lines are connected to a suitable switchover valve 6.

In the cylinder works a piston 7, which is attached to an endless wire, which wire around free-running Guide rollers 8 and 9 is stretched. These guide rollers are each outside of an edge of the film web, which is shown in dashed lines is indicated.

A wire run 10, which is connected to the piston 7, runs axially through the interior of the cylinder and thus replaces

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the piston rod of the cylinder. Another wire run 11 carries a fin-shaped knife 12. When the piston J controlled by the Umsohalt valve 6 in the cylinder 1 moves back and forth, the knife 12 performs an opposite movement and cuts the film web through.

In the "Ausfuhrungsf o: ra nach Pig", 1 the guide rollers 8 and 9 and the knife-carrying wire run 11 are outside of the cylinder 1 arranged, and the piston-connected wire barrel 10 must therefore airtight through the end covers 2 and 3 of the Cylinder be guided.

In the Ausungsforra of Fig. 2 are the guide rollers 8, 9 and the two wire runs 10, 11 inside the cylinder arranged. The knife-carrying wire run 11 runs directly under a longitudinal gap in the cylinder wall, and the knife 12 protrudes through this gap. The endless wire seals the gap sufficiently, because it preferably as a flat band has a greater width than the gap »

The device according to the invention is not limited to that Cutting of plastic sheeting limited. It can be used to cut through other webs of film as well as paper and Textile webs are used.

409820/0 0 01

Claims (2)

2085534 A F S PRD-CHE ί 1.) Device for cutting through foil webs and the like by means of a knife movable transversely to the film web, characterized in that the knife (12) on a Wire run (11) of an endless flexible wire is attached, which wire is stretched between and around two guide rollers (8, 9) is, and is axially guided with another wire run (lo) through the interior of a pneumatic cylinder (1), where the other wire run (lo) replaces the piston rod of the cylinder » 2. Device according to claim 1, characterized in that that both the guide rollers (8, 9) and both wire runs (lo, 11) are arranged in the interior of the cylinder ". 409820/0; ο 1 Blank page