GB2110191A

GB2110191A - Folding apparatus

Info

Publication number: GB2110191A
Application number: GB08232953A
Authority: GB
Inventors: Hermann Fischer
Original assignee: MAN Roland Druckmaschinen AG
Current assignee: Manroland AG
Priority date: 1981-11-21
Filing date: 1982-11-18
Publication date: 1983-06-15
Also published as: FR2516905A1; GB2110191B; FR2516905B1; IT1148657B; DE3146208C2; DE3146208A1; CH658641A5; IT8249472A0

Abstract

A folding apparatus has a folding blade cylinder (9) for the cross-folding of superimposed printed copies together which are supplied to it from two continuous webs (5, 6) folded longitudinally by formers (1, 2), guided to run together back-to-back by guide and draw rollers (7, 8, 10-14), and cut into sheet lengths by a cutting cylinder (17). In order to avoid a slipping-out of the inner copy 25a from the outer copy 25b when the folding blade (15) returns, means, such as a milled die stamp (23) or needles, are provided in a guide roller (13) for roughening the surface of one of the webs (6) at the unprinted regions (26) where the cross-fold lines A-A will be made and on the surface which will face the adjacent loosely lying copy 25b. The increased friction resulting from the roughening (26) is greater than the friction between the blade (15) and the sheet (25a) which it contacts. <IMAGE>

Description

SPECIFICATION Apparatus and method for processing sheets This invention relates to an apparatus and a method for processing sheets, in which at least two sheets are superimposed for an operation to be carried out on the superimposed sheets together.

The invention is particularly, although not exclusively, applicable to a folding apparatus or method.

A cross-folding device incorporating a folding blade cylinder for the joint folding of several superimposed printed copies is known from the book by Alexander Braun "Atlas of newspaper and illustration printing", in particular Figures 85 and 95. With this, several printed copies having a common longitudinal fold can be cross-folded together. For this purpose a folding blade of the folding blade cylinder presses the copies along the cross-fold line provided and into a folding jaw of the folding cylinder. When the folding blade returns, however, there is the danger that with the return of the folding blade, the inside copy comes loose from the outer copy. Thus continuous production is considerably disrupted.

The present invention provides a way in which when superimposed sheets are being operated upon together, they do not become misplaced relative to each other.

According to the present invention, there is provided apparatus for processing sheets, comprising means for superimposing at least two sheets ready for an operation, such as folding, to be carried out on the superimposed sheets together, and means upstream of the superimposing means for providing at least one of the two sheets with a roughening on that surface which will face the adjacent sheet when the two sheets are superimposed.

In a further aspect, the present invention provides a method of processing sheets, wherein at least two sheets are superimposed prior to an operation being carried out on the superimposed sheets together, in which before the sheets are superimposed one of them is provided with a roughening on that surface which will face the adjacent sheet when the two sheets are superimposed.

When the operation on the superimposed sheets is a folding operation, the roughening may be provided in a band or strip across each sheet to be superimposed with another sheet adjacent to where the fold is to be made. The danger of operational disturbances by the pulling out of the inner copy of the returning folding blade is then reduced.

Where the sheets are cut from continuous webs, the roughening is preferably provided on one of the webs at appropriate intervals, before they are brought together and cut into sheet lengths.

The invention may be put into practice in a number of ways but certain embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of a folding apparatus in accordance with the invention; Figures 2 and 3 show two variants of rollers for roughening; and Figure 4 is a schematic representation of two printed copies or sheets.

The folding apparatus of Figure 1 incorporates two longitudinal folding formers 1, 2 with which respective feed rollers 3,4 are associated. The printed continuous webs 5 and 6 conveyed longitudinally to the formers 1,2 are each longitudinally folded once.

The longitudinally folded web 5 subsequently reaches a folding blade cylinder 9 via a pair of draw rollers 7, two guide rollers 10, 11 and a further pair of draw rollers 8. Of the two guide rollers 10, 11 at least the guide roller 11 is driven, like the draw rollers. The other longitudinally folded web 6 reaches two guide rollers 12, 14, of which at least the guide roller 13 is driven, via a pair of draw rollers 12. The web 6 is guided around the guide roller 13 and conveyed to one of the draw rollers 7. With this the web is guided so that the two webs 5,6 run superimposed to the folding blade cylinder 9, lying back to back between the guide rollers 10, 11 and the draw rollers 8.

The folding blade cylinder 9 has folding blades 15 and swivellably mounted bodkins or spikes 16. It co-operates with a blade cylinder 17 to cut the individual printed copies fom the webs 5, 6. The folding blade cylinder 9 also co-operates with a folding jaws cylinder 18 which is provided with two movable folding jaws 19 which extend over the entire length of the folding jaws cylinder 18. To each folding jaw 19 there is attached an abutment 20 which can be adjustably disposed in the circumferential direction of the folding jaws cylinder 18 to take into account different thicknesses of the copies to be folded.

With the embodiment shown, the guide roller 13 forms a carrier for means for roughening the web 6.

Forthis, as Figure3shows,the guide roller 13 has two diametrically opposite grooves extending parallel to its axis. Into each axial groove an insert 21 is located and secured by means of screws 22. The outer part of each insert 21, slightly projecting outwards over the circumference of the guide roller 13,forms a die stamp 23which has a stamping pattern constructed like a kind of milled edge (or knurling) with raised parts and depressions arranged between them. The circumference of the guide roller 13 is equal to twice the length of the printed copy which is to be cut from the webs 5,6 by means of the blade cylinder 17. For stamping, the die stamp 23 co-operates with the guide roller 14, which is made of hard rubber or a plastics of similar hardness.At least the guide roller 13 is driven so that its surface speed corresponds to the speed of the web 6.

Instead of a die stamp which is continuous along its length, it can also be interrupted, i.e. with axial portions of milling or knurling separated by unmelted portions.

In operation of the folding apparatus a roughening in the form of embossing is applied at regular distances onto one side, i.e. one surface, of the web 6 by means of the die stamp 23. Thus, the die stamps 23 are so arranged that there is a roughening adjacent each side of where the cross fold line will be made. Instead of the guide roller 13, a guide roller can also be used whose circumference is only half as large as that of the guide roller 13, therefore which corresponds only to the length of a printed copy. In this case only one die stamp is to be provided.

Similarly the circumference of the guide roller could also be increased to a multiple of the length of a printed copy.

The web 6 then comes to abut against the web 5 with the roughened surface of the web 6 facing the web 5 and they run thus to the folding blade cylinder 9 on which printed copies 24, 25 are cut from the webs 5,6 by means of the cutting cylinder 17. These printed copies are held on the folding blade cylinder 9 by means of the bodkins 16. As soon as a set of copies 25 has reached the cross-fold position, the folding blade 15 swings out and presses the copies 25 between a folding jaw 19 and an abutment 20.

Then the folding blade 15 is swung back. At the same time the folding jaw 19 firmly grips the copies 25 on the abutment 20. Since, as is schematically shown in Figure 4, the inner-lying copy 25a coming from the web 6 is provided with a rougening 26 in the area of the unprinted edge adjacent each side of the folding line A-A, when the folding jaw 15 is returned this copy 25a does not slip out of the copy 25b coming from the web 5 even though the sheets 25a and 25b are only loosely superimposed, since owing to the roughening the friction between the two copies 25a and 25b is greater than the friction between the copy 25a and the folding blade 15.

However, there is also the possibility of conveying to the folding apparatus according to Figure 1 only via the former 1 a web 5 which is longitudinally folded once, and with this web carrying out assembly production or collection on the folding blade cylinder 9. With this type of production, the folding blade cylinder 9 rotates twice before a cross-folding operation begins. Therefore, there is applied for example on the copies 24 or 25 a further set of printed copies which also come from the web 5. With this type of production, in order to prevent a slipping out of the inner printed copies from the outer ones, the guide roller 11 is constructed as a carrier for the roughening means. To this end the guide roller 11 has two grooves parallel to its axis into which two inserts with die stamps 27, indicated in dotted lines, can be located. At least the guide roller 11 is driven.

The circumference of the guide roller 11 is equal to the circumference of the guide roller 13. If the guide roller 10 is made of metal and is provided with an insert of a softer material co-operating with the die stamps, then this roller is also driven. If the die stamps 23 or 27 are not required, then two blind inserts can be used which complete the casing of the guide rollers to form a cylinder. Instead of interchangeable inserts, there could also optionally be used two different guide rollers, of which one is made with a die stamp and the other without a die stamp.

With the die stamps of the guide roller 11, roughenings are applied, in the area of the cross fold line provided, on the side of the web 5 which comes to lie outwards when the web 5 is wrapped around the folding blade cylinder 9. Thus, the die stamps 27 are again so arranged that the embossed roughenings lie adjacent each side of where the later formed cross-fold lines will be made. During the subsequent cross-fold process, therefore, the roughening of the first printed copy faces the subsequently applied second printed copy, whilst the roughening of the second printed copy faces the folding jaws cylinder 18. This latter roughening in itself is not absolutely necessary. However, to avoid it either the guide roller 11 would have to be disposed disconnectibly from the web 5, which would mean a large structural expense, or a die stamp has to be taken out of the roller 11.The relevant groove can then be provided with a blind insert. From the above description it can be seen that instead of the guide rollers 10, 11 provided with a full casing, merely lever-type carriers for the die stamps and the abutment necessary for the die stamping could also be provided, which are then to be respectively placed onto a driven shaft.

Instead of using a die stamp for roughening there is also the possibility, indicated in Figure 2, of using inserts 28, from the surface of which there projects a plurality of only schematically indicated short needle points 28 which roughen the printed copies.

Whilst the above described embodiments show folding apparatus, it will be appreciated that the idea of using a roughening applied on sheets to be loosely superimposed on other sheets to prevent them becoming relatively dislodged, could find use in other sheet processing where an operation is carried out on the two (or more) sheets together.

Where more than two sheets are loosely superimposed the roughening may be provided between each pair of adjacent sheet surfaces, or just between the top sheet and the one underneath since it is the top sheet, which is contacted by an operating member (such as the folding blade 15), which is the one most likely to be dislodged.

The apparatus of the invention may be installed as part of or in association with a rotary printing machine.

Claims

1. Apparatus for processing sheets, comprising means for superimposing at least two sheets ready for an operation, such as folding, to be carried out on the superimposed sheets together, and means upstream of the superimposing means for providing at least one of the two sheets with a roughening on that surface which will face the adjacent sheet when the two sheets are superimposed.

2. Apparatus as claimed in claim 1, in which the roughening means is adapted to roughen sheets each across a strip or band where a fold is to be made.

3. Apparatus according to claim 1, or claim 2, in which the means for roughening includes a set of needle points.

4. Apparatus according to claim 1,or claim 2, in which the means for roughening includes a die stamp.

5. Apparatus according to claim 3 or claim 4, in which the set of needle points or die stamp is arranged interchangeably on a carrier.

6. Apparatus according to any one of the preceding claims, in which the means for roughening is disposed in, and parallel to the axis of, a rotatingly driven carrier.

7. Apparatus according to claim 6, in which the carrier is constructed as a roller the circumference of which is equal to the length of a sheet or a whole number multiple thereof.

8. Apparatus according to claim 6 or claim 7, in which the rotatingly driven carrier is a guide roller for a printed web connected upstream of cross-cutting means and a folding blade cylinder.

9. Folding apparatus substantially as specifically described herein with reference to the accompanying drawings.

10. A method of processing sheets, wherein at least two sheets are superimposed prior to an operation being carried out on the superimposed sheets together, in which before the sheets are superimposed one of them is provided with a roughening on that surface which will face the adjacent sheet when the two sheets are superimposed.

11. A method as claimed in claim 10, wherein the sheets are superimposed by bringing two continuous webs together and cutting the superimposed webs transversely into sheet lengths, and wherein the sheets so formed from one of the webs are each provided with the roughening by roughening the appropriate surface of that web at appropriate locations along the web, before the two webs are run together.

12. A method as claimed in claim 11, wherein the oneweb is roughened in strips or bands across the web at locations adjacent to where a fold is to be made across the sheets into which the web is cut.

13. A method as claimed in claim 12, wherein the webs are printed with matter on their surfaces, the roughening being provided at unprinted regions.

14. A method as claimed in any one of claims 10 to 13, wherein the superimposed sheets are folded.

15. A method of producing folded sheets, substantially as specifically described herein with reference to the accompanying drawings.

16. A method as claimed in claim 10, wherein the sheets are superimposed by cutting a continuous web into sheet lengths and collecting sets of two or more sheets superimposed by means of a collecting device, and wherein the sheets or some of them are provided with roughening by roughening the appropriate surface of the web at appropriate locations along the web before it is cut into sheet lengths.