GB2322361A

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Publication number: GB2322361A
Application number: GB9803769A
Authority: GB
Inventors: Roland Von Der Heide; Armin Hutzenlaub
Original assignee: Kampf GmbH and Co Maschinenfabrik
Current assignee: Kampf GmbH and Co Maschinenfabrik
Priority date: 1997-02-25
Filing date: 1998-02-23
Publication date: 1998-08-26
Anticipated expiration: 2018-02-23
Also published as: JPH10291193A; GB9803769D0; DE19707427A1; GB2322361B

Abstract

An arrangement for leading a strip of foil into a processing machine having guide rolls 3, comprises a driven traction belt 5 closely adjacent the rolls along at least one side, and deflected therearound by a number of guide rollers 11 positioned along a arc and a profile 13. A clamp 14 is secured to the belt and extends across the surface of the rolls for the leading edge of the foil.

Description

1 TITLE 2322361 Apparatus for Drawing a Strip of Material This invention

relates to an apparatus for drawing a strip of material, particularly a foil, into a processing machine containing guide rolls over which the strip passes.

When plastic foils are being processed the foil has to be drawn into the processing machine as quickly as possible after an interruption to the production caused, for example, on re-starting after a tear in the strip of material.

Known draw-in devices include traction elements, such as chains, ropes and the like, which are arranged along the draw-in path and which are fitted with a securing element,'such as a draw hook, to which the starting end of the strip of material is fastened. The traction element & w,, thLE, Lihd 6f the f6ii bv(-,r thL- (quired df,w-ih disth6 thf6ugh thc. processing machine.

EP 0 221 524-Bl describes various versions of a draw-in device, for example a traction rope having a projecting draw hook and movable along the inside of a guide tube. The traction rope is driven by friction wheels provided with peripheral semicircular recesses for the traction rope guiding system. The said patent specification points out the difficulty of drawing in foils when the strips of material move at speeds of overlOOm/min. It is therefore proposed that the foils are drawn in by means of an elastic bar with a detachably mounted clamping part guided and transported in grooves provided in draw-in pulleys.

One object of this invention is to provide a draw-in device for plastic foils which enables a foil to be drawn in as rapidly and reliably as possible.

According to this invention there is provided apparatus for drawing a strip of material, particularly a foil, into a processing machine containing guide rolls over which the strip is passed, the apparatus having a rotating driven traction belt along at least one longitudinal side of the processing machine which said belt:during the draw-in operation moves at a short distance to the side of the guide rolls and substantially in the plane of the path followed by the strip of material, is deflected in the zone of the guide rolls by guide elements, which in each case contain a number of guide rollers positioned along a circular arc, in order to form a guide path taking a course along the end face of the roll, and has a clamping element affixed thereto for the starting end of the foil, the said element extending inwardly of the processing machine as far as the zone of the surace of the roil.

Thu!, And ACC&Cling to thi,,, ihviihti6h, the., path f01i6w(d by thd traction belt largely coincides with the path covered by a drawn-in strip of material. This enables the strip to be inserted when the guide rolls are already rotating at the operating speed without an excessive relative speed occurring between the guide rolls and the foil in the draw-in 3 process. The strip can thus be drawn trouble free into the processing machine at the operating speed. The distance between the end faces of the guide rolls is so small that the draw-in device reliably places the strip of material on the said rolls.

This invention will be further described and illustrated with reference to an embodiment shown as an example and illustrated on simplified lines in the drawings.

In the drawings:- Figure 1 shows a side view of a so-called foil take-up station following a stretching machine in an installation for the production of foiis, Figure 2 shows a side view of part of a guide element for the traction belt, and Figure 3 shows a cross section in the zone of the ends of the rolls.

Referring to Figure 1 of the drawings, the draw-in device is integrated into a so-called foil take-up device 1 positioned in succession to the stretching machine in a foil production installation. Inside the foil take-up device the foils 4 are cooled in a known manner, cut along their edges and/or surface-treated before they are wound up into laps on a subsequent winding or lapping machine 2.

The foii take-up device contains, as a processing machine, a row of guide rolls 3 over which the foil 4 is deviated and caused to pass through the separate processing stations. For drawing a foil 4 in through the foil take-up device 1 and as far as the lapping machine 2, a rotatable 4 drivable traction belt 5 is provided at least along one longitudinal side of the said foil take-up device 1, with the drawing side extending along the draw-in path as far as a point underneath the lapping machine 2. At this point the traction belt 5 is reversed around a deviating roll 6 and moved back underneath the guide rolls 3. One of the rolls guiding the traction belt 5, for example the deviating roll 6, is connected with a rotary drive by which the traction belt 5 with a foil 4 secured thereto can be accelerated sufficiently and drawn through the foil take-up device 1.

On the input side the draw-in device already starts at a certain distance in front of the foil take-up device 1, so that an acceleration section 7 is formed. The input side deviating roil 8 of the traction beit 5 is therefore positioned sufficiently far in front of the first guide roll 3 of the foil take-up device 1, for example 1m to 2m. Thefoil can thus be accelerated, before reaching the first guide roll 3, to an operating speed of about 150 m/min to 200 m.min.

The traction belt 5 has a polygonal cross section, preferably hexagonal, so that it can be guided in such a way that it cannot rotate about the longitudinal axis. To prevent rotation within the free paths without a guide the traction belt is provided with torsionally rigid inserts.

In the zone of each guide roll 3 the traction belt 5 is in each case guided by means of a guide element 9, a section through one of these elements being shown in Figure 2. The guide eiements 9 are each so designed and positioned that the traction belt is guided a certain distance to the side of the guide rolls 3 in such a way that the course which it takes through the entire processing machine is substantially within the running plane 10ofthefoi14. As shown in Figure 3, the free distance between the traction belt 5 and the end faces of the guide rolls 3 is so small that when the foil 4 is drawn in it is reliably placed on the guide rolls 3. The preferred distance is between 2 and 10 mm. 05 The guide elements 9, positioned in the zone of the guide rolls 3 contain a number of guide rollers 11 mounted so as to be freely rotatable on a circular arc along the end face of the guide roll and parallel to the course taken by the deviated foil 4. On their peripheral surface the guide rollers 11 have an internal profile adapted to the external profile of the 10 traction belt 5, in order to provide a lateral guide for this latter. In a radial direction on the outside an arcuately curved guide profile is affixed to the bearing shell 12 of the guide rollers 11 and contains a guide groove of which the cross section is adapted to the profile of the traction belt 5 in the outer zone. The belt 5 is thus guided as shown in Figure 2, between 15 the guide rollers 11 and the guide profile 13 over the desired arcuate path. The inside of the guide element 9, facing towards the end faces of the guide rolls 3, is provided with a free space in the form of a throughslit, through which extends a clamping element 14, affixed to the neutral 20 run of the traction belt 5, in the centre of the latter. The clamping element 14, serving to hold the starting end of the foil, extends inwards as far as the zone of the outer surface of the guide roll, in order to guide a foil 4 affixed thereto over the roll 3 in a reliable manner. The clamping element 14 is preferably designed to close automatically under the traction exerted by an inserted foil 4, preference being given to a traction 6 element 14 taking the form of a self-closing clip or clamp device.

In one embodiment of this invention, as a means of releasing the starting end of the foil from the clamping element 14, a fixed cutting device is provided at the end of the draw-in path, for example in the zone of the deviating roll 6. The cutting device preferably consists of a toothed knife arranged in such a way that the foil 4 enters and is automatically cut off. The new starting end with which the foil is thus provided can be wound onto cores inserted into the lapping machine 2. The cut-off foil remaining in the clamping device 14 is removed at the desired point in the course of the return transport of the clamping device 14, to the input side.

Alternatively, the clamping device 14 can be so designed that it opens automatically at the end of the draw-in path, thus releasing the starting end of the foil at the desired point. In this version no cutting device is required.

In various processing machines processing units are provided inside the rectilinear path of the traction belt 5, between the guide rolls 3, and may consist of cutter blades 15 for the edge cutting operation and edge expansion rollers 16 or measuring heads for determining the foil thickness. As these units 15, 16 are not required in the draw-in operation they can be moved into a stand-by position which does not impede the draw-in operation, for example, opened up or pushed outwards transversely to the direction OT the path followed by the strip of material.

In order to ensure that the traction belt 5 will not impede these units in their working position, the processing machines of this kind contain additional means by which the traction belt, in the zone of the said 7 units 15, 16, after the draw-in operation, are deflected outwards transversally to the direction followed by the material and into a standby position leaving the operation unimpeded.

If a processing unit 15, 16 is present in the zone of a free belt section between two guide rolls 3, a gripping device can be provided in that position by which the traction belt 5 is gripped and deflected in this zone. Either the gripping device itself or an additional holding device holds the belt 5 in the stand-by position during the production operation.

As an alternative means of deflecting the traction belt 5 the guide elements 9 can be displaceable transversally to the path of the strip of material. For this purpose the guide element 9 to be displaced is affixed to a bar-shaped holder 17 mounted in the machine frame and transversally displaceable by the necessary adjustment distance.

The deflection of the traction belt 5 is only effected during the production operation, that is during the operation of the units 15, 16. For drawing in a foil 4 the traction belt 15 moves in a straight line without any deflection transversally to the path of the strip of material. The deflection of the traction belt 5 is preferably effected in opposition to a springmounted storage roll 18, so that it can automatically return to the rectilinear path.

the operation of drawing in a fresh foil 4 is effected by first of al 1 suspending the starting end of the foil, the traction beit 5 being stationary, into the clamping device 14 present in the zone of the deflecting roller 8 on the inlet side. While the processing machine (foil take-up device 1) is running at operating speed the belt 5 with the starting end of the foil, 8 affixed to the clamping device 14, is accelerated within the acceleration section 7 up to the operating speed. The operation of drawing in the foil 4 by the foil tclke-up device 1 now takes place at the said operating speed. Between the guide rolls 3 and the foil 4 the draw-in operation is not accompanied by any unacceptable relative speed, as the path followed by the foil in the said operation is largely the same as that followed by a drawn-in foil 4.

9

Claims

1 Apparatus for drawing a strip of material, particularly a foil, into a processing machine containing guide rolls over which the strip is passed, the apparatus having a rotating driven traction belt along at least one longitudinal side of the processing'machine which said belt during the draw-in operation moves at a short distance to the side of the guide rolls and substantially in the plane of the path followed by the strip of material, is deflected in the zone of the guide rolls by guide elements, which in each case contain a number of guide rollers positioned along a circular arc, in order to form a guide path taking a course along the end face of the roll, and has a clamping element affixed thereto for the starting end of the foil, the said element extending inwardly of the processing machine as far as the zone of the surface of the roll.

2. Apparatus in accordance with Claim 1, wherein the clear distance of the traction belt from the end face of the guide rolls is between 2 and 10 mm.

3. Apparatus in accordance with Claim 1 or 2, wherein the guide elements in each case comprise, radially outwards, a guide profile with a guide groove of which the cross section is adapted to the profile of the traction belt in the outer zone.

4. Apparatus in accordance with any one of Claims 1 to 3, wherein the traction belt has a polygonal cross section, preferably a hexagonal cross section, and/or is constructed so that it does not rotate about its longitudinal axis.

5. Apparatus in accordance with any one of Claims 1 to 4, wherein the clamping element is affixed to the neutral strand in the middle of the traction belt.

6 Apparatus in accordance with any one of Claims 1 to 5, wherein the clamping element is preferably a self-closing clip or clamp device which closes automatically.

7. Apparatus in accordance with any one of Claims 1 to 6, wherein a cutting device through which the drawn-strip of material is cut off from the clamping device, is mounted on the end of the draw-in section.

8. Apparatus in accordance with Claim 7, wherein the cutting device comprises a toothed knife arranged in such a way that the strip of material will enter and be automatically cut off.

9. Apparatus in accordance with any one of Claims 1 to 6, wherein the clamping device is arranged so that it automatically opens at the end of the draw-in section and releases the starting end of the foil.

10. Apparatus in accordance with any one of Claims 1 to 9, wherein in order to form an acceleration section the draw-in device starts a certain 0,5 distance in front of the first guide roll of the processing machine.

11. Apparatus in accordance with any one of Claims 1 to 10, wherein means are provided for deflecting the traction belt laterally away from the zone of processing units which are positioned in the path during the draw10 in operation.

12. Drawing apparatus for a strip of material constructed and arranged to function as described herein and illustrated by the drawings.

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