WO1995005990A1

WO1995005990A1 - Arrangement at the delivery end of a sheet cutter

Info

Publication number: WO1995005990A1
Application number: PCT/FI1994/000364
Authority: WO
Inventors: Matti Paatelainen
Original assignee: Matti Paatelainen
Priority date: 1993-08-20
Filing date: 1994-08-19
Publication date: 1995-03-02
Also published as: GB2296010A; SE504112C2; GB2296010B; FI98451C; SE9503463L; FI98451B; SE9503463D0; FI942318A; FI942318A0; GB9603012D0; AU7463094A

Abstract

The invention relates to an arrangement at the delivery end of a sheet cutter, comprising a conveyor means (5) for transporting sheets (6) from cutting blades to the delivery end; a stacking space (7); and means for guiding and stacking the sheets into the stacking space (7). To facilitate stacking, the means for guiding the sheets (6) into the stacking space (7) comprise a planar grate means formed by at least one moving grate (12a, 12b) having a frame (13) around which a receiving means (14) is arranged in a track-like manner, the receiving means covering the frame (13) so that the sheets (6) positioned on the planar grate means are in contact with the receiving means (14) only, and that the receiving means (14) is arranged to remain immovable with respect to the sheets when the grate moves in a plane parallel with the sheets (6). The grate is further arranged to move along guides in the vertical direction.

Description

Arrangement at the delivery end of a sheet cutter

The invention relates to an arrangement at the delivery end of a sheet cutter, comprising a conveyor means for transporting sheets from cutting blades to the delivery end; a stacking space; and means for guiding and stacking the sheets into the stacking space.

Arrangements of the type described above are today known from various connections. In general, sheet cutters uncoil sheet paper in web form from a large roll, whereafter the web is first cut into a desired width in the longitudinal direction. At the following stage, the web is cut in the transverse direction, thus obtaining sheets of a desired length. At the following stage, sheets cut into size are fed onto a transport platform into stacks made according to the order.

Prior art solutions include the use of rods in the cutting of paperboard, which is not suitable for the sheeting of paper, and a platform-change system in the cutting of paper, where part of the paper web is passed into a broke port during the platform change while the machine is on. The speed of the machine is thereby reduced in order that the amount of broke could be decreased.

However, the change of the transport platform has become problematic in prior art solutions. This is because the change of the transport platform has been carried out in such a way that it has been necessary to interrupt the cutting or, correspondingly, it has been necessary to pass part of the sheets into the broke. This is due to the fact that the prior art solutions have not provided any place where cut sheets could have been positioned during the change of the transport platform. This problem is particularly severe with lines having a high cutting speed and correspondingly a high rolling speed. Interruption of the cutting, in turn, retards the process to such an extent that the end result will not be advantageous. A further drawback of the prior art solutions has been that sheets tend to crease or fold very easily, which causes disturbances in the process and deteriorates the quality. The object of the invention is to provide an arrangement which eliminates the drawbacks of the prior art. This is achieved by an arrangement accord¬ ing to the invention, which is characterized in that the means for guiding the sheets onto the transport platform comprise a planar grate means formed by at least one moving grate having a frame around which a receiving means is arranged at least partially in a track-like manner, the receiving means covering the frame at least partially so that the sheets positioned on the planar grate means are in contact with the receiving means only, and that the receiving means is arranged to remain immovable with respect to the sheets when the grate moves in a plane parallel with the sheets. An advantage of the invention over the prior art solutions is that the web cutting process need not be interrupted when the transport platform is changed nor needs the speed to be reduced, and so the total speed of the process will not decrease. Moreover, sheets need not be passed into the broke when the platform is changed, thus avoiding any losses. The above-mentioned matters are due to the fact that the moving planar grate means is used as an intermediate store during the change of the transport platform. A further advantage of the invention over the prior art solu- tions is that the stacking of sheets will be improved, as no creasing and so-called tail formation occur. This is because no sliding occurs between the sheet surface and the surface of the planar grate means. Still another advantage is that the running speed of the apparatus need not be reduced during the change of the transport platform, and so the greatest possible benefit can be derived from the apparatus. A further essential advantage is that the arrangement according to the invention can be fitted in an advantageous way in existing equipment, as it does not require more space than previously used structures.

In the following the invention will be described more fully by means of a preferred illustrating em- bodiment shown in the attached drawings, wherein

Figure 1 is a general side view of a sheet cutter having an arrangement according to the inven¬ tion at its delivery end;

Figures 2a and 2b show the delivery end of the apparatus shown in Figure 1 from the top and another embodiment of a grate frame;

Figures 3a and 3b illustrate the operating prin¬ ciple of the arrangement according to the invention when the grate moves in a plane parallel with the sheets;

Figures 4a and 4b schematically illustrate the operating principle of a second embodiment of the arrangement according to the invention when the grate moves in a plane parallel with the sheets; and Figures 5 to 8 are general side views of the operation of the arrangement according to the in¬ vention when the transport platform is changed.

Figures 1, 2a and 2b are general views of a sheet cutter having an arrangement according to the invention at its delivery end. Sheets are formed of a rolled material web, such as a paper web. In Figure 1, a paper roll is indicated with the reference 1. The paper web in turn is indicated with the reference 2. The paper web 2 is first cut into a desired width in the longitudinal direction and then into sheets of a desired length in the transverse direction. In Figure 1, the above-mentioned cutting points are indicated generally with the reference numerals 3 and 4.

Sheets 6 cut into size are transported by a conveyor or band system 5 to the delivery end. During this stage the sheets are overlapped. This is done by suitably selecting the speed of the conveyor. Figures 5 to 8 show the conveyor 5 and the overlap of the sheets 6. A stacking space 7 is provided at the delivery end. A transport platform 8, for instance, can be placed in the stacking space 7. The transport platform 8 is shown only in outline in Figure 1, whereas it is shown in more detail in Figures 5 to 8. When sheets 6 are transferred into the stacking space, they are aligned by aligning plates 9 in the sideward direction and by stoppers 10, 11 in the longitudinal direction.

The matters described above are fully obvious to one skilled in the art, so they will not be discussed more closely herein.

According to an essential aspect of the inven¬ tion, means for guiding the sheets 6 onto the trans¬ port platform 8 comprise a planar grate means formed by at least one moving grate 12a, 12b comprising a frame 13 around which a receiving means 14 is arranged in a track-like manner. The receiving means may com¬ prise one or more receiving elements 14a. The receiv¬ ing means covers the frame so that sheets positioned on the planar grate means are in contact with the receiving means 14 only. The receiving means 14 is arranged to remain immovable with respect to the sheets when the grate moves in a plane parallel with the sheets 6. The above-described detail can be im- plemented e.g. by attaching the receiving means 14 that forms a closed loop at one point to the frame structures of the arrangement, so that the above- mentioned situation will be achieved when the grate, i.e. its frame 13, is moved. The receiving means may also be made immovable with respect to the sheets in some other way; it is not essential how the receiving means is kept in position when the grate moves with respect to the sheets but that the receiving means remains in position with respect to the sheets. In the example of the figures, the frame is arranged in a substantially horizontal position. In the embodiment shown in Figure 2a, the frames of the grate 12a and 12b are integral frames, upon which three separate receiving elements 14a forming the receiving means 14 are positioned at the grate 12a; in the grate 12b, the receiving means 14 is formed by a single receiving element. Figure 2b, in turn, shows the grate frame 13, which can be used in both of the grates 12a and 12b and which comprises separate elongated means 13a extending in parallel with the frame so that two grates can be pushed into each other. In this embodi¬ ment, the receiving means 14, of course, is formed by a receiving element 14a positioned at each elongated means 13a and having a width no greater than that of the elongated means in such a way that several receiv¬ ing elements form the receiving means 14 as they move simultaneously in parallel with each other.

The receiving elements 14a of the receiving means 14 are preferably attached to the frame struc- tures of the arrangement at a point of attachment 15 at their ends. This appears clearly from Figures 3a and 3b. The idea is that when the grates 12a, 12b move in a plane parallel with the sheets e.g. in such a way as shown in Figures 3a and 3b, the receiving element 14a remains immovable with respect to the sheets posi¬ tioned upon it. No sliding occurs between the receiv¬ ing means and the sheets positioned on the grate, i.e. on the receiving means 14, even though the grate is displaced with respect to the sheets. When the grate is displaced, each one of the receiving elements 14a moves in a track-like manner around the frame 13.

According to the invention, the planar grate means can be formed by one or two grates. The figures show an embodiment where the planar grate means is formed by two grates 12a, 12b. The grates 12a, 12b can be arranged to move into abutment with each other, as shown in Figure 7. The grates 12a, 12b may also be arranged to move in the vertical direction, by means of vertical guide rails 16, for instance. In principle, the operation shown in Figures 4a and 4b corresponds to that shown in Figures 3a and 3b except that the receiving means 14 has been formed in a different way. In the figure, when the grate is in its right-hand position, i.e. in its forward position, the receiving element 14a forming the receiving means extends from its point of attachment 15 around the grate 13 to its other side and joins there to a separ¬ ate mounting means or mounting piece 14b. The mounting piece 14b in turn is attached to a capstan 16 by a separate draw belt 17. When the grate is displaced from the position shown in Figure 4a to the left in the figure at a speed V, the draw belt 17 is displaced by the capstan 16 at a speed 2V, i.e. at a double speed as compared with the grate frame 13. The receiv- ing means 14 thereby has all the time a desired tight- ness with respect to the frame and it remains im¬ movable with respect to the sheets. In the same way, when the grate moves to the right in the figure, the mounting piece 14b as well as the draw belt 17 move in the same direction at a double speed. By using a suit¬ able mounting piece structure, it is possible to attach e.g. several parallel receiving elements to it so as to form the receiving means 14, and so the entire structure will operate in a desired way. In principle, the arrangement according to the invention operates in the following way. The operation will be described below with reference to Figures 5 to 8. As shown in Figure 5, the sheets 6 are passed on the conveyor 5 to the delivery end. The sheets 6 are transferred onto the transport platform 8 as described above. After a predetermined quantity of sheets have been stacked on the transport platform 8, the trans¬ port platform is displaced downwards as shown by arrow A. When the transport platform moves downwards, the grate 12a is displaced in a plane parallel with the sheets as shown by arrow B, so that the situation shown in Figure 6 will be arrived at. In the situation shown in Figure 6, the sheets are displaced onto the grate 12a. At the same time, the other grate 12b is displaced as shown by arrow C in a plane parallel with the sheets, and the grate 12a simultaneously backwards as shown by arrow D, so that the situation shown in Figure 7 will be arrived at, where the grates are in abutment so that their ends are positioned substan- tially in the middle of the sheet.

At the same time as the sheets are stacked into the intermediate store formed by the grates, a new transport platform is brought in alignment with the grate. It is to be noted that the grates are also able to move in the vertical direction along the guide rails 16 when they act as intermediate stores, so that a sufficient quantity of sheets can be positioned on the grate and the transport platform can be changed.

Figure 7 shows a situation where a new transport platform is brought from below as shown by arrow E, and the grates are displaced into the position shown in Figure 5 as shown by arrows F and G. When the grates 12a, 12b are displaced as shown by arrows F and G, the sheets fall, particularly in the case of paper sheets, with their mid portion ahead on to the trans¬ port platform, whereby any creasing is avoided. It is to be noted that when the grates move, sliding never occurs between the sheets and the receiving means 14, as the receiving means remains immovable with respect to the sheets, as shown in Figures 3 and 4. In a way, the receiving elements 14a of the receiving means 14 move in a track-like manner around the frame 13, when the grates move in a plane parallel with the sheets. From the situation shown in Figure 8, the process continues as shown in Figure 5.

The above-described example is by no means intended to restrict the invention, but the invention can be modified at will within the scope of the claims. Accordingly, it is obvious that the arrange- ment according to the invention or its details need not necessarily be exactly similar to those shown in the figures, but other solutions are possible as well. For instance, the planar grate means can be formed of a single grate in place of two grates, as already men- tioned above. This kind of embodiment could be e.g. such as shown in Figures 5 to 8 with the exception that the right-hand grate is omitted, so that the single grate moves in the same way as the left-hand grate in Figures 5, 6 and 8. The invention is not either limited to any specific material, but it can be applied with any suitable material. Suitable materials include paper, paperboard, plastic, textiles, metals, sensitive coated materials, etc. The invention is not either limited for use in connection with the trans- port platform, even though it has been described in the above example by means of an example associated with a transport platform. The sheets may be delivered and stacked on some other surface, such as a belt; when the grate is pushed, the belt can thus, if required, be rotated by a drive motor at a speed pro¬ portional to the speed of the paper web. The receiving element 14a of the receiving means 14 may be formed e.g. by a belt-like body, but this embodiment is not the only alternative. The receiving element may also be formed by smaller elements, which are combined similarly as track chains into a belt-like means, etc. In the example of the figures, the frame is formed by rigid pieces. This, however, is not the only altern¬ ative, but it is also possible to form the frame of parts attached in abutment with each other so that they define an elongated frame when positioned in the grate plane. An advantage of this solution is that the frame can be brought into the grate plane e.g. in the vertical direction with respect to the grate plane, etc. The frame may be integral and rigid or it may be made up of grid portions or of some other suitable structure, provided that guides and preferably wheels or rolls are provided at the frame ends for the re¬ ceiving elements. When an integral frame is used in the two-grate structure, the grates cannot be pushed one within the other. If it is desirable that the grates are inserted one within the other at least to some extent, the frame 13 is made in such a way that it comprises elongated elements 13a at least over the insertion length, whereby the grate frames 13 may be pushed one within the other. Correspondingly, a separ¬ ate receiving element 14a is provided at each elong¬ ated element 13a of the frame so that the receiving elements 14a and thus the receiving means 14 formed by them can also be inserted between each other. The receiving means may be an integral receiving element or it may be formed of several parallel receiving elements that are operationally similar. The receiving element may be a belt, chain, lamella structure, or the like, or an entity formed by a number of such elements. Instead of a closed loop, the receiving element may also be partly open, provided that its ends are attached in such a way that the receiving element extends over the entire length of the planar grate means around the frame and passes around the frame as the planar grate means moves so that it remains substantially tight. This may also be im¬ plemented in such a way that when the planar grate means is in its extended position, the receiving element extends across the entire grate means up to its forward edge or preferably around it, whereafter the ends of the receiving element may be attached to a separate mounting piece which is transferred at a speed double as compared with the motion of the planar grate means in the same direction as the grate means.

The grates may be made of elongated elements fully separate from each other, which are attached to each other at suitable intervals so that the elongated elements of the other grate can be passed between them. A band-like or belt-like receiving element is thereby positioned at each elongated element, whereby the receiving elements of one grate always move at the same speed in the same direction and together form the receiving means of the grate.

Claims

Claims:

1. Arrangement at the delivery end of a sheet cutter, comprising a conveyor means (5) for trans- porting sheets (6) from cutting blades to the delivery end; a stacking space (7); and means for guiding and stacking the sheets into the stacking space (7), c h a r a c t e r i z e d in that the means for guiding and stacking the sheets (6) into the stacking space (7) comprise a planar grate means formed by at least one moving grate (12a, 12b) having a frame (13) around which a receiving means (14) is arranged at least partially in a track-like manner, the receiving means covering the frame (13) so that the sheets (6) positioned on the planar grate means are in contact with the receiving means (14) only, and that the receiving means (14) is arranged to remain immovable with respect to the sheets when the grate (12a, 12b) moves in a plane parallel with the sheets (6). 2. Arrangement according to claim 1, c h a r¬ a c t e r i z e d in that the receiving means (14) is attached to the frame structures of the arrangement at one point (15).

3. Arrangement according to claim 1 or 2, c h a r a c t e r i z e d in that the receiving means

(14) is formed by a single receiving element (14a).

4. Arrangement according to claim 1 or 2, c h a r a c t e r i z e d in that the receiving means (14) is formed by at least two parallel receiving elements (14a).

5. Arrangement according to any of the preceding claims, c h a r a c t e r i z e d in that each one of the receiving elements (14a) forms a closed loop around the frame (13). 6. Arrangement according to any of claims 1 to 4, c h a r a c t e r i z e d in that each one of the receiving elements (14a) is shorter than a length around the frame and is attached at one end to the frame structures of the arrangement and at the other end to a separate mounting piece which is displaced in the same direction as the frame (13) of the grate (12a, 12b) and at a speed of motion double as compared with the speed of motion of the frame (13).

7. Arrangement according to any of the preceding claims, c h a r a c t e r i z e d in that the planar grate means is formed by two grates (12a, 12b) posi¬ tioned in the same plane.

8. Arrangement according to claim 7, c h a r¬ a c t e r i z e d in that the frame (13) of the grate (12a, 12b) comprises elongated elements (13a) over at least a portion of its length, a receiving element (14a) being correspondingly positioned at each elongated element, whereby the grates (12a, 12b) are arranged to be inserted one within the other at least over a portion of their length.

9. Arrangement according to claim 8, c h a r¬ a c t e r i z e d in that the grates (12a, 12b) are formed by mutually spaced, elongated elements (13a) positioned side by side, that a band-like or belt-like receiving element (14a) is positioned at each element (13a), the receiving means (14a) of the same grate (12a, 12b) together form the receiving means (14) and the grates (12a, 12b) are arranged to be inserted one within the other at least over a portion of their length.

10. Arrangement according to any of claims 7 to 9, c h a r a c t e r i z e d in that the grates (12a, 12b) are arranged to move into abutment with each other. 11. Arrangement according to any of the preced- ing claims, c h a r a c t e r i z e d in that the grate/grates (12a, 12b) are arranged to move in the vertical direction.