AU759655B2

AU759655B2 - Method and device for applying a protective coating to stacks of printed products

Info

Publication number: AU759655B2
Application number: AU10368/00A
Authority: AU
Inventors: Karl Ernst Timmerbeil
Original assignee: Ferag AG
Current assignee: Ferag AG
Priority date: 1998-12-07
Filing date: 1999-10-13
Publication date: 2003-04-17
Anticipated expiration: 2019-10-13
Also published as: EP1140630A1; WO2000034127A1; PL348061A1; DE59903938D1; RU2230691C2; AU1036800A; CA2353836A1; ATE230369T1; EP1140630B1; ES2190262T3; JP2002531340A; DK1140630T3

Abstract

Stacks (1) of printed products which products are characterized in that they each have an edge of increased thickness are wrapped in such a manner that those stack sides in which the above-mentioned edges are arranged are completely covered by the coating (4) and are thus well protected. Since said stacks (1) are less stable in a direction transversal to the mentioned edges, the stacks (1) are discharged from a stacking shaft (20) in which the stacks are produced in a direction parallel to the mentioned edges and directly between the forks (12 and 13) of a pair of forks (12/13). The stack (1) is compressed between the forks (12 and 13) and the pair of forks (12/13) containing the compressed stack (1) is guided through a curtain (14) of a coating material. Said coating material is closed around the pair of forks (12/13) and the stack (1). Once the coating is applied, the coated stack (1/4) is separated from the pair of forks (12/13) by performing a movement of the pair of forks (12/13) relative to the stack (1/4) and is conveyed on.

Description

METHOD AND DEVICE FOR PROTECTIVE WRAPPING OF STACKS OF PRINTED PRODUCTS The invention belongs to the field of packing technology and relates to a method and a device according to the generic terms of the corresponding independent claims.

Method and device serve for putting a protective wrapper around stacks of printed products. Method and device according to the invention are especially suited for application in connection with stacks of printed products having an edge region which edge region is thicker than the other regions and therefore decreases stack stability and which edge region needs to be protected in particular. Printed products of this kind are e.g. doubly folded newspapers with a folded edge (edge of the second 10 fold) or magazines with a glued or stitched spine.

Newspapers are supplied by rotation presses, from reels or by various devices for further processing collating drum) in formn of a scaled stream in which the newspapers are positioned with their folded edges facing downstream. For transport and distribution, these newspapers are stacked (mostly in cross stacks), the stacks are optionally equipped with a cover sheet and the stacks are then strapped and/or wrapped.

In a doubly folded newspaper, the front page constitutes its outer surfaces and the printed information continues across the folded edge substantially without interruption. This means that the front page is very exposed. On the other hand, the front page of the newspaper, being well visible, usually carries information which is considered important and for this reason should not be impaired. This however, as e, C will be shown, is not simple.

yr_ The same can be said about magazines or similar printed products in brochure-form having a glued spine or being bound in another manner. Such products have spine edges with an increased thickness which reduces stack stability. These spine edges may carry printed information and are in the stack exposed and therefore prone to getting damaged.

Newspaper and magazine stacks are, even when stacked crosswise, less stable in a direction perpendicular to the folded edges or spines (edges distinguished by their 10 increased thickness) than in parallel to these edges. This is due to the fact that even when stacked on a horizontal support a part of the products in the stack is sloping in ~a direction perpendicular to the distinguished edges and therefore, tend to start slipping even at a low momentum. This is not the case in the direction parallel to the distinguished edges. For this reason, shifting such a stack in parallel to the distinguished edges is considerably less difficult, i.e. it can be carried out with o. considerably simpler means and with greater accelerations than shifting perpendicular to the distinguished edges. Therefore, stacking shafts are usually designed such that the stacks being produced in the shaft are ejected in a direction perpendicular to the distinguished product edges.

According to the state of the art, stacks are wrapped with a wrapping material (e.g.

plastic sheet of foil) by moving them through a curtain of wrapping material put up in a substantially vertical manner. Thereby, the wrapping material is wrapped around the downstream side of the stack and can be closed on the upstream side of the stack to form a ring-shaped wrapping. At the same time, the wrapping material is severed in such a manner that it again forms a curtain for the following stack. If according to the named method, a stack is to be wrapped in such a way that the distinguished edges folded edges or spines) of the stacked products are protected by the wrapper, the stack must be moved through the curtain of wrapping material in a direction perpendicular to the distinguished edges, which, as mentioned above, leads to problems due to the low stack stability.

For wrapping newspaper or magazine stacks it is e.g. suggested to push the stacks through the curtain of wrapping material directly when being ejected from the stacking shaft. This can be done without problems if the stacks are ejected in parallel to the distinguished edges and are wrapped in parallel to these edges. However, this leads to a wrapper which does not lay tightly against the distinguished product edges and thus does not protect these. It is also suggested to eject the stacks in a direction .::perpendicular to the distinguished product edges and to move them directly through the curtain. This leads to a wrapper which lays tightly against the distinguished product edges and effectively protects these. This method leads to the desired product but is afflicted with problems due to the low stack stability in ejection direction. These problems cannot be solved satisfactorily for high speeds and high S. accelerations on ejection.

•oo* 00o* In view of the above mentioned problems it is also suggested to eject the stacks from the stacking shaft in a direction perpendicular to the distinguished edges and to strap them immediately after being ejected perpendicular to the ejection direction for giving them enough stability for being wrapped. In such a way wrapping for protecting the distinguished edges is rendered problem-free but the strapping prior to the wrapping constitutes a high risk of damaging the distinguished edges.

There seems to be no satisfactory method with which in a stack of printed products, edges distinguished by increased thickness, e.g. the folded edges or spines of newspapers or magazines, can be protected in a lasting manner by means of wrapping as it is possible for packages of rolled printed products, the manufacture of which also belongs to the state of the art.

Publication US-4341056 describes a device for wrapping stacks which stacks are to be pressed as strongly as possible in wrapped condition. In order to not have to create the pressure with the wrapping, the stack is pressed between pressing jaws, is wrapped together with the jaws and is then separated from the jaws.

Therefore, it is an object of the invention to creat a method and a device making it possible, with simple means and at high speeds, to eject from a stacking shaft stacks of printed products having an edge distinguished by increased thickness in a direction parallel to these edges and to wrap the stacks immediately afterwards with a protective wrapper such that the wrapper fits tightly to the sides of the stack on which the distinguished edges are positioned. Furthermore, the inventive method and the device for carrying out this method are to be applicable for the serial wrapping of o stacks with different individual heights.

This object is achieved by the method and the device as defined in the patent claims.

The inventive method is based on the idea of ejecting stacks from a stacking shaft in a direction parallel to the distinguished product edges and immediately on ejection, positioning them between two forks forming a pair of forks. Then the stack is pressed between the forks, the pair of forks is moved through the curtain of wrapping material together with the pressed stack and the wrapping material is closed on the upstream side of the pair of forks. Then the wrapped stack is separated from the pair of forks by moving the stack relative to the forks. This means that the movement of the stack necessary for the wrapping procedure is carried out in a direction perpendicular to the distinguished edges which however does not cause any problems as the stack is clamped between the forks and such stabilized and can therefore be moved quickly and without problem's even against the resistance of the wrapping material.

Because the wrapping is initially positioned not around the stack but around the stack pressed together by the forks, i.e. is fitted and closed around the stack and the pair of 10 forks, and because the pair of forks is separated from the stack by drawing the forks out of the wrapper, the inventive method produces a taut wrapping only if the printed •products are sufficiently elastically compressible in their thickness and/or if the wrapping material is of sufficient elasticity such that it can contract to a sufficient tightness around the stack after withdrawal of the forks.

0e It shows that with the inventive method, stacks of newspapers or magazines of usual 0000 height can be fitted with a protective wrapper of polyethylene sheeting of a thickness 000000 of 15 to 50m without problems. The wrapped stacks can then easily be strapped or further processed in any suitable manner.

The inventive method and the inventive device are described in more detail in connection with the following Figures, wherein Figure 1 shows a stack of newspapers or other printed products having an edge distinguished by increased thickness, the stack being wrapped in a protective wrapper; Figure 2 shows a diagram of the successive steps of the inventive method; Figures 3 and 4 show in a schematic manner two exemplified embodiments of the inventive device; Figure 5 shows an exemplified embodiment of a pressing fork being additionally equipped for positioning a cover sheet on the stack.

:io .Figure 1 shows a stack 1 of printed products 2 having each one edge 3 distinguished by increased thickness, e.g. a Stack of newspapers or magazines with folded edges or spines respectively. In the shown stack all distinguished edges are arranged superimposed on the same side of the stack such that the stack has a greater height on :this side than on the opposite side. The stack could also, however, be a cross stack in S. which groups of printed products (part stacks) are stacked on top of each other such s sethat the groups of dastinguished edges are arranged alternatingly on two opposite Ssides of the stack. In a cross stack the instability due to the edges of increased thickness is less important than in a stack as shown in Figure 1. All the same, the instability exists and cannot be neglected when handling cross stacks.

The stack 1 in Figure 1 comprises a protective wrapper 4 which surrounds the stack in a direction perpendicular to the distinguished edges 3 and nwhich is at least as wide as the length of the distinguished edges. The wrapper covers tightly the lateral surfaces of the stack in which the distinguished edges are arranged as well as the lower side of the stack and to the upper side of the stack and it protects the distinguished edges well. The wrapping material may protrude from the stack on both sides and the protruding wrapper parts can, in a further processing step, e.g. be closed across the uncovered sides of the stack such protecting the stack on all sides.

The wrapper 4 of the stack as shown in Fig. 1, has apart from a protecting function also an at least limited stabilizing function. The wrapped stack can be accelerated in a direction perpendicular to the distinguished edges with considerably less problems than the not yet wrapped stack.

o Figure 2 shows successive steps a to e of the inventive method for producing a protective wrapper 4 around a stack 1, e.g. around a cross stack comprising three oooo crosswise stacked product groups. The viewing direction is in parallel to the distinguished edges. The steps are the following: S.:a A stack 1 is ejected in a direction parallel to its distinguished edges 3 from a ooo stacking shaft, into an ejection position, the stack being guided laterally and on its face-side by ejection guides (10/10', 11/11') and being positioned on a carrier fork 12 (ejection direction perpendicular to the paper plane of the figure).

b In the ejection position, a pressing fork 13 is lowered onto the stack 1, the stack 1 is pressed between carrier fork 12 and pressing fork 13 and the ejection guides (10/10', 11/11') are at least partly removed from their guiding position.

c The stack 1 being pressed betweencarrier fork 12 and pressing fork 13 is moved in a direction perpendicular to the distinguished edges through a curtain 14 of a wrapping material into a wrapping position.

d The wrapping material is closed on the upstream side of the pair of forks 12/13 and stack 1 to form a protective wrapper 4, by e.g. producing a connection 15 each on wrapping 4 and curtain 14.

e Stack 1 and fork pair 12/13 are separated from one another by a relative movement in a direction parallel to the distinguished edges between stack 1 and fork pair 12/13, the separation being carried out in the wrapping position or advantageously in a separation position into which the pair of forks 12/13 and stack 1 are moved before the separation.

The steps c, d and e are shown in two embodiments being depicted in an upper and a lower part of the figure. According to the upper embodiment, the pressed stack 1 is moved through the curtain 14 of wrapping material without change of orientation such that the wrapping material must be connected on a side of the stack containing distinguished edges (connection 15). For an even better protection of the o distinguished edges this is prevented according to the embodiment depicted in the lower part of Fig. 2 by rotating the stack 1 pressed between forks 12 and 13 by 900 between the ejection position and the wrapping position such that either fork 20 12 or 13 constitutes the downstream side of the stack. The connection 15 is therefore made at a distance from the printed products and there is no risk of damaging the products or their distinguished edges.

Figure 2 diagrammatically shows the most important parts of the inventive device.

These are the following: SThe lateral and face-side ejection guides 10/10' and 11/11' arranged in the Iejection position and being at least partly able to be displaced from a guiding -9position into a rest position e.g. vertical shifting of upper (10, 11) and lower 11') guide elements; The pair of forks 12/13, which is able to be moved from the ejection position into the wrapping position and possibly from the wrapping position into a separation position, the pair of forks comprising the carrier fork 12 and the pressing fork 13, the two forks being able to be pressed against each other and in the ejection position, the two forks having a distance from each other which corresponds to at least the stack height (possibly the pair of forks is in addition able to be moved 10 for the separation and/or to be rotated between ejection position and wrapping o* position around its own axis by 900).

oooo *0o0 The known means for positioning the strapping material as a substantially vertical curtain 14 at the entrance to the strapping position d) and for connecting and severing it on the upstream side of the stack to form a connection ;15, e.g. on the closed wrapper 4 and on the newly formed curtain 14.

0 •go• 000000 The device for carrying out the inventive method further comprises separating means 20 (not shown in Fig. 2) for separating stack 1 from the pair of forks 12/13. The separating means are e.g. pins able to be introduced into slots of the forks 12 and/or 13 and to be moved relative to the pair of forks 12/13 in a direction parallel to the distinguished edges (as shown in Fig. 3).

Figure 3 shows a diagrammatic top view of a possible spatial arrangement of the parts of the inventive device. An arrow S indicates the supply of printed products 2 with distinguished edges 3 (shown by means of a bold line) positioned downstream.

The products 2 are e.g. supplied as a scaled stream. The products are supplied to a i0 stacking shaft 20 to form a stack 1. The stacking shaft 20 is arranged such that the es

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*000 0*0O*O 0 stack 1 is ejected in a direction substantially perpendicular to the supply direction (arrow The lateral and face-side ejection guides 10 and 11 of the ejection position and the pair of forks 12/13 of which only the pressing fork 13 is visible are arranged on the ejection side of the stacking shaft. The pair of forks 12/13 is movable in a direction perpendicular to the ejection direction (in parallel to the supply direction) through the curtain 14 into the wrapping position. For separating the wrapped stack from the pair of forks, e.g. in the wrapping position, pins 21 are inserted into slots 22 of the forks and are moved towards the end of the fork (arrows B) while the pair of forks 12/13 remains stationary. Through this movement of the pins 21 the wrapped 10 stack 1/4 is separated from the pair of forks and is then conveyed away (arrow W) e.g. on a conveying belt (not shown) in a direction perpendicular to the supply direction (arrow S).

A device, as shown in Figure 3, is operable with a single pair of forks 12/13 if it is equipped with means for moving the pair of forks back an forth between the ejection position and the wrapping position. For an increased capacity of the device it is advantageous to equip the device with a plurality of pairs of forks 12/13, the pairs beinge.g. arranged equidistantly on an endless chain and being moved stepwise by 20 this chain along a closed path. Fig. 3 shows two pairs of forks 12/13 and part of a driving chain 23.

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It is easily seen from Fig. 3 that the path of the fork pairs 12/13 can pass, in addition to the ejection position, further processing positions e.g. arranged in a line: e.g. a processing position following downstream after the wrapping position and being equipped for e.g. printing on the wrapper of the stack or for closing parts of the wrapper protruding from the stack etc. Downstream of a plurality of such processing positions, follows a separation position for separating the wrapped stack from the 30 pair of forks 12/13, which according to Fig. 3 is done in the wrapping position. Of T*i -11 course, there may be additional processing positions between the ejection position and the wrapping position for processing the not yet strapped stack.

The individual parts of the device shown in Fig. 3 as well as the drives and guide means necessary for its operation can easily be designed by one skilled in the art and therefore, need not be shown and described in more detail here.

Figure 4 shows a further, exemplified embodiment of the device for carrying out the inventive method. The function of the device parts are the same as in the device shown in Fig. 3. The same reference numbers are used for the device parts. The device comprises four pairs of forks 12/13 which are arranged around a substantially vertical axis 30 spaced from each other by 900. The axis is driven to rotate in the direction of the arrow. The ejection position (9 o'clock position), the wrapping position (6 o'clock position) and the separation position (3 o'clock position) are arranged in a circular manner, also spaced from each other by 90'. Obviously it is also possible to arrange a processing position in the 3 o'clock position and the 0 separation position in the 12 o'clock position.

In similar devices to the one shown in Fig. 4 there may be more or less than four pairs of forks 12/13 arranged at regular angles.

Figure 5 shows a pressing fork 13 with an additional function. The fork is equipped with a movable compartment for a cover sheet 31 or other flat product to be positioned on a stack in the ejection position. The pressing fork 13 is shown in two positions, above in a position distanced from an ejected stack and below in a position V lowered onto the stack 1.

-12- The pressing fork 13 comprises a compartment 32 which is fastened on its the lower side in a pivoting manner such that in a force-free status it is distanced from the free end of the fork and can receive between fork 13 and compartment 32 a cover sheet e.g. directly from a printer. When the fork 13 is lowered onto a stack 1 the compartment 32 is pressed against the lower side of the fork and is thus substantially closed. When separating the wrapped stack and the pair of forks the compartment 32 is pulled out of the wrapping together with the pair of forks and the cover sheet e: 10 remains on the stack 1.

i Although the inventive method and the inventive device are designed for stacks of products with an edge distinguished by increased thickness they can obviously also be used for products without such edges.

In this specification, except where the context requires otherwise, the words "comprise", "comprises", and "comprising" mean "include", "includes", and "including", respectively. That is, when the invention is described or defined as comprising specified features, various embodiments of the same invention may also include additional features.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

Claims

1. Method for sequentially wrapping stacks produced in a stacking shaft and comprising printed products having an edge distinguished by increased thickness, wherein in an ejection position, each stack is positioned in a pair of forks consisting of a carrier fork and a pressing fork and is pressed by the forks, wherein the pair of forks together with the pressed stack is moved through a curtain of wrapping material into a wrapping position and in the wrapping position, the wrapping material is closed around the stack and the S* pair of forks to form a wrapper, wherein the stack together with the wrapper is separated from the pair of forks by a relative movement between the stack and the pair of forks and wherein the produced wrapper fully covers the bottom and top sides of the stack as well as the lateral stack surfaces in which the distinguished edges are positioned, characterized in that each stack is ejected from the stacking shaft in a direction parallel to the distinguished 15 edges and directly onto the carrier fork being positioned in the ejection position, the stack being guided solely by lateral and face-side ejection guides, that for pressing the stack, the pressing fork is then lowered onto the stack being positioned on the carrier fork, that for moving the pair of forks together with the stack into the wrapping position, the ejection guides are at least partly removed, the stack being moved in a direction perpendicular to the distinguished edges such that the wrapper covers the lateral stack surfaces in which the distinguished edges are positioned.

2. Method according to claim 1, characterized in that the pair of forks together with the pressed stack is moved through the curtain of the wrapping material T 25 in a direction substantially perpendicular to the ejection direction. Ov -14-

3. Method according to claim 1, characterized in that the pair of forks together with the pressed stack is rotated by 900 while being moved through the curtain of the wrapping material.

4. Method according to any one of claims 1 to 3, characterized in that the pair of forks together with the pressed stack is rotated around its own axis before being moved through the curtain of the wrapping material.

5. Method according to any one of claims 1 to 4, characterized in that a stack cover sheet is applied to the pressing fork before the pressing fork is lowered onto the stack and that the stack cover sheet is separated from the pair of forks together with the stack.

6. Method according to any one of claims 1 to 5, characterized in that the pair of forks together with the pressed stack is submitted to further processing steps before or after wrapping.

7. Method according to claim 6, characterized in that in the further processing steps, the stack and/or the wrapper is printed on or parts of the wrapper protruding from the stack are closed around the stack.

8. Method according to any one of claims 1 to 7, characterized in that the wrapping material has a width which is at least as large as the length of the distinguished edges of the printed products.

9. Method according to any one of claims 1 to 8, characterized in that the wrapping material is a polyethylene sheeting of a thickness in the range of to Device for sequentially wrapping stacks produced in a stacking shaft and comprising printed products having each an edge distinguished by an increased thickness, which device for pressing one stack and for moving the stack from an ejection position into a wrapping position, comprises at least o one pair of forks with a carrier fork and a pressing fork pressable against the carrier fork, which device further comprises means for positioning a curtain of a wrapping material between the ejection position and the wrapping .ig• position, means for closing and severing the wrapping material on an upstream side of the stack, and means arranged in the wrapping position or in a separation position and cooperating with the pair of forks for separating the .wrapped stack from the pair of forks characterized in that the carrier fork is go•• positionable in the ejection position for direct ejection of the stack from the stacking shaft onto the carrier fork and that the device for stabilizing the stack on ejection comprises only lateral and face-side ejecting guides being at least I' ~partly movable into a guiding position and into a rest position.

11. Device according to claim 10, characterized in that it comprises a plurality of pairs of forks being movable on at least one cyclic path such that one pair of forks after another is movable through the ejection position,the wrapping position and back to the ejection position.

12. Device according to claim 11, characterized in that the plurality of pairs of forks is designed and driven for passing at least one further processing Sposition between ejection position and wrapping position and/or for passing a -16- separation position or at least one processing position and a separation position after the wrapping position.

13. Device according to claim 11 and 12, characterized in that the pairs of forks are arranged around a substantially vertical axis.

14. Device according to claim 13, characterized in that the ejection position, the wrapping position and the separation position are distanced from each other or from a processing position by an angle of 90° each.

15. Device according to any one of claims 10 to 14, characterized in that the pairs of forks are rotateable around their own axis.

16. Device according to any one of claims .10 to 15, characterized in that the separating means are pins meshing with longitudinal slots of the carrier fork and/or of the pressing fork.

17. Device according to any one of claims 10 to 16, characterized in that the pressing fork is equipped for reception of additional products to be added to the stacks.

18. A method for sequentially wrapping stacks, substantially as hereinbefore described with reference to the accompanying drawings. .7 *7 -17-

19. A device for sequentially wrapping stacks, substantially as hereinbefore described with reference to the accompanying drawings. Dated this 15th day of October 2002 FERAG AG By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and STrade Mark Attorneys of Australia e* o*