GB2225777A

GB2225777A - Continuity of web supply

Info

Publication number: GB2225777A
Application number: GB8923721A
Authority: GB
Inventors: Werner Kmoch; Gerhard Heinrich; Juergen Koerner
Original assignee: Nagema VEB
Current assignee: Nagema VEB
Priority date: 1988-11-04
Filing date: 1989-10-20
Publication date: 1990-06-13
Also published as: IT1237178B; DD276666A1; IT8948519A0; DE3933214A1; JPH02182651A; BR8905655A; GB8923721D0

Description

APPARATUS FOR GUIDING TOGETHER WEBS OF PACKAGING MATERIAL The present

invention relates to apparatus for guiding together webs of packaging material.

A foil-attaching device for a laminating machine is described in DE-OS 27 37 776. In that device, two mutually opposite sides of a workpiece are laminated in one operating step. The foil to be applied to the upper side and to the lower side of the workpiece is selectably supplied from one of two supply rolls, while producing a glued connection. It is disadvantageous in this device that joining of the foil webs to each other requires the start of the new web to be provided with adhesive substance or adhesive strips, against which the end of the web that is nearly finished is pressed. Joining of the webs to each other without a glued connection is not possible with this device. Moreover, the device is not suitable for use with packaging machines operating in the high-performance range, since the required time for production of the glued connection is not available and glued zones or glued strips would lead to disruption of the packaging process.

A further device of this kind is disclosed in DE-OS 36 34 369. This device also serves for connection of the end piece of a band from an emptying spool with the starting piece of a band of a new spool. In the case of, for example, wrapping machines for cigarette packets, the band is of paper or thermoplastic foil. This device is constructed for only two spools, which is not sufficient for sweet packaging machines operating in the high-performance range, as standstill times would arise during spool changes. Enlargement of this device to accommodate four spools is not acceptable in view of the required space. Mareaver, a longer distance for overlapping is required for connection of packaging material webs by welding or gluing together, in order to produce a durable connection at higher speeds. The contact time necessary for this reduces performance and the overlapping leads to disturbance of the packaging process.

There is thus a need for apparatus that may enable packaging material webs to be joined together in high performance packaging machines without the use of otherwise necessary connecting means and with avoidance of standstill times and operational disturbances.

According to the present invention there is provided apparatus for guiding together webs of packaging material, comprising a plurality of pairs of transport rollers and presser rollers associated with guide paths for the webs, the transport rollers being mounted on a mounting member and rotationally interconnected and the presser rollers being movable independently of each other relative to respectively associated ones of the transport rollers.

is Such apparatus may allow the time for replacement of web bobbins by an operative to be extended, while keeping the overlap between old and new webs small and permitting the joining process to take place without firm connection of the webs in the overlap region.

In a preferred embodiment, a roller pair consisting of a trans- port roller and a presser roller is associated with each bobbin, wherein the transport rollers are mounted on a crossbeam and constrainedly kinematically connected together and the presser rollers can each be urged independently of each other against the transport rollers. The kinematic connection of the transport rollers and the kinematic connection of the presser rollers with the transport rollers preferably takes place by way of toothed wheels with a transmission ratio of 1:1. The presser rollers are arranged to be pivotable at a presser plate h' displaceable obliquely relative to the transport rollers and to be controllable by way of electromagnetic switches. By this means, it is possible to perform a bobbin change at greater intervals in a highperformance packaging machine without glued or welded zones, which may disturb the function of the packaging machine, being required at the joins.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a schematic front elevation of apparatus embodying the invention; and Fi 9. 2 is a plan view of the apparatus of Fig. 1.

Referring now to the drawings there is shown apparatus to guide packaging material webs from four bobbins and comprising a machine frame 1 at which a crossbeam 2 is fastened. Mounted on the crossbeam 2 are transport rollers 3.1,.3.2, 3.3 and 3.4, which are interconnected by way of toothed wheels 4.1, 4.2, 4.3, 4.4, 4.5 and 4.6. Two further toothed wheels 5.1 and 5.2, which are in engagement with each other, are arranged at the transport rollers 3.3 and 3.4. Two deflecting rollers 6.1 and 6.2 are mounted below the crossbeam 2.

Two presser plates 7.1 and 7.2 are displaceably mounted on the frame 1 on either side of the crossbeam 2. Four pivot levers 8.1, 8.2, 8.3 and 8.4, on which four presser rollers 9.1, 9.2, 9.3 and 9.4 are mounted to be rotatable, are mounted on the presser plates 7.1 and 7.2. The pivot levers are operatively connected with electromagnetic switches 10.1, 10.2, 10.3 and 10.4. Four toothed wheels 11.1, 11.2, 11.3 and 11.4, which in a contact pressure setting are disposed in i_ engagement with the toothed wheels 4.1 to 4.4, are fastened to the presser rollers 9.1 to 9.4.

In use, initially the presser plates 7.1 and 7.2 are pushed back for insertion of the four packaging material webs 1, 11, 111 and IV.

The web I is led between the presser roller 9.1 and the transport roller 3.1, the presser roller 9.2 and the transport roller 3.3 and between the rollers 6.1 and 6.2 and thus gets into the range of action of a packaging material take-off of a packaging machine. The web II is preliminarily drawn only between the presser roller 9.1 and the transport roller 3.1 and ends below this roller pair. The same insertion process occurs on the oppositely disposed side with the packaging material webs III and IV, the web III being led between the presser roller 9.3 and the transport roller 3.2 and between the presser roller 9. 4 and the transport roller 3.4 and ending below this roller pair.

The web IV is preliminarily drawn only between the presser roller 9.3 and the transport roller 3.2 and ends below this roller pair. The presser plates 7.1 and 7.2 are now pushed manually in direction of the crossbeam 2. In that case, the toothed wheels 11.1 to 11.4 engage the toothed wheels 4.1 to 4.4. Initially, a gap remains between the transport rollers 3.1 to 3.4 and the presser rollers 9.1 to 9.4, so that entrainment of the webs 1, 11, 111 and IV does not yet take place. Before starting of the packaging machine, the switch 10.2 is actuated and the web I is clamped against the transport roller 3.3 through application of the presser roller 9.2. By means of the packaging material take-off of the packaging machine, the web I is drawn from its bobbin and the transport rollers and the presser rollers 9.1, 9. 2, 9.3 and 9.4 are brought into rotation without having any n t j - 5 drive of their own. When the web I starts to run out, the presser roller 9.1 is urged against the transport roller 3.1 through actuation of the switch 10.1, whereby the web II is also drawn off. The web I is still effective as drive of the apparatus until the web 11 has reached the take- off of the packaging machine and now becomes the drive of the apparatus. The presser roller 9.2 is pivoted back at this instant through actuation of the switch 10.2. When the web II starts to run out, the presser roller 9.4 is urged against the transport roller 3.4 through actuation of the switch 10.4 and the web III is set into movement. When this has reached the take-off of the packaging machine, the presser roller 9.1 is pivoted back through actuation of the switch 10.1. The presser plate 7.1 can now be pushed back and further packaging material webs I and II can be inserted in the manner already described. When the web III starts to run out, the web IV is switched in through actuation of the switch 10.3 so as to urge the presser roller 9.3 against the transport roller 3.2, until the web IV has reached the take- off of-the packaging machine. Thereafter, the presser roller 9.4 pivots back through actuation of the switch 10.4. The pivoting-back of the presser rollers 9.1 to 9.4 respectively associated with the webs I to IV can also take place through actuation of the respective electromagnetic switches at the instant at which the switched-in web has reached the take-off of the packing machine. Further such joining processes can be carried out in like manner.

C'

Claims

1. Apparatus for guiding together webs of packaging material, comprising a plurality of pairs of transport rollers and presser rollers associated with guide paths for the webs, the transport rollers being mounted on a mounting member and rotationally interconnected and the presser rollers being movable independently of each other relative to respectively associated ones of the transport rollers.

2. Apparatus as claimed in claim 1, wherein the transport rollers are rotationally interconnected by toothed wheels.

3. Apparatus as claimed in either claim 1 or claim 2, wherein the presser rollers are rotationally connectible with the associated rollers by way of toothed wheel pairs with a transmission ratio of 1:1.

4. Apparatus as claimed in any one of the preceding claims, wherein the transport rollers are carried by carrier members pivotably mounted on mounting elements which are movable relative to the transport rollers.

5. Apparatus as claimed in claim 4, comprising electromagnetic means to control pivot movement of the carrier members.

6-. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.

0 aLThe Patent Office, State House. 66'71 High Holborn. London WClR 4TP Further copies maybe obtained from The Patent Office. v-t-'RRs 3RD. Printed by Multiplex techniques lid, St Mary Cray. Kent. Con. 187,