EP0037304A1 - Perforating rule or the like usable on printing machines like offset machines and method of using it on the said machines - Google Patents

Abstract

The invention relates to a perforating device or similar cutting means especially adapted for use with printing machines such as those of the offset kind. The perforating device herein comprises a rigid, thin metal plate which presents, in protrusion, on one of its two faces, at least one cutting or perforating element, a layer of adhesive material applied to the side of said thin metal plate opposite said cutting or perforating element, said adhesive layer capable of being protected by a protective strip, and a double faced self-adhesive tape adhering upon one of its faces to the side of said thin metal plate adjacent to said cutting or perforating element, the other face of the double faced self-adhesive tape capable of being protected by a protective strip.

Description

The present invention relates to a perforating net or the like usable in particular on printing machines such as offset machines, as well as its method of implementation on said machines.

In general, it is known that the perforating nets currently used on printing machines consist of a generally metallic strip having a toothed or sharpened lateral edge, which has on its face opposite the toothing, a layer of adhesive material on which is arranged a protective tape which is removed at the time of use.

These perforating nets are intended to be stuck on a pressure cylinder of the printing machine and more particularly in the case of an offset on the margining cylinder compressing the sheets to be printed on the blanket cylinder.

• - On nettoie tout d'abord le cylindre de pression de manière à permettre une bonne adhérence des filets.
• - On décalque ensuite sur le cylindre de pression le texte à imprimer afin d'avoir un repère pour la mise en place des filets.

The placement of these perforating nets is then carried out as follows:

• - The pressure cylinder is first cleaned so as to allow good adhesion of the threads.
• - The text to be printed is then transferred to the pressure cylinder in order to have a mark for the placement of the threads.

After cutting the necessary lengths of thread, remove the protective strip and glue the threads to the pressure cylinder in the desired locations.

We then carry out printing tests to verify that the nets are in place and then we make the final prints. Of course, in the case where the threads are not in their place, either that they moved during the manipulations or else due to an error, these operations must be at least partially repeated.

• - Elle n'est pas pratiquable sur toutes les machines d'impression, en particulier celles dans lesquelles le rouleau presseur ou de margeage n'est pas accessible.
• - Sa mise en oeuvre est particulièrement délicate et impose un travail dans des conditions pénibles. L'opérateur doit souvent se contorsionner pour parvenir à coller les filets sur le rouleau presseur.
• - Elle nécessite des temps de mise en oeuvre relativement importants qui sont la cause d'arrêts fréquents et prolongés de la machine d'impression, ce qui nuit à la rentabilisation de la machine et augmente le prix de revient des imprimés.

This technique has a number of disadvantages

• - It cannot be used on all printing machines, in particular those in which the pressure or margining roller is not accessible.
• - Its implementation is particularly delicate and requires work in difficult conditions. The operator often has to contort to achieve sticking of the threads on the pressure roller.
• - It requires relatively long processing times which are the cause of frequent and prolonged shutdowns of the printing machine, which harms the profitability of the machine and increases the cost price of the printed matter.

• - une âme rigide pouvant se présenter sous la forme d'une bande métallique, ou en matière plastique, et qui présente en saillie, sur l'une de ses deux faces, au moins un élément coupant ou de perforation,
• - une couche de matière adhésive disposée sur le côté de l'âme opposée audit élément de perforation, çette couche pouvant être protégée par une bande de protection à retirer au moment de l'utilisation, et
• - un ruban adhésif double face adhérant, par l'une de ses faces, sur le côté de l'âme adjacente au susdit élément de perforation, l'autre face de ce ruban adhésif pouvant être protégée par une bande de protection à retirer au moment de l'utilisation.

The object of the invention is to eliminate all these drawbacks. To this end, it offers a perforating net essentially comprising:

• a rigid core which may be in the form of a metal strip, or made of plastic, and which has projecting, on one of its two faces, at least one cutting or perforating element,
• a layer of adhesive material placed on the side of the core opposite to said perforating element, this layer being able to be protected by a protective strip to be removed at the time of use, and
• a double-sided adhesive tape adhering, by one of its faces, to the side of the core adjacent to the aforesaid perforating element, the other face of this adhesive tape being able to be protected by a protective strip to be removed at the time of use.

According to another characteristic of the invention, the above-mentioned core consists of a steel strip having a toothed or simply sharpened edge, which extends perpendicular to the plane of said strip.

• - la réalisation d'une maquette sur une feuille de papier en ôtant s'il existe le ruban de protection de la bande adhésive double face, puis en collant les filets au verso de la feuille aux emplacements choisis grâce à la face adhésive ainsi dégarnie, les éléments coupants ou de perforation venant porter sur la feuille,
• - le passage dans la machine d'impression de la maquette ainsi réalisée, après avoir ôté, si elles existent, les bandes de protection de la couche adhésive des différents filets, de manière à ce que, au cours de ce passage :
• - les filets viennent se coller sur le rouleau presseur ou de margeage aux emplacements qu'ils doivent occuper, et que le ruban adhésif double face soit extrait en même temps que la feuille sur laquelle il demeure collé, en raison de ses propriétés d'adhérence sur le papier et sur le métal.

The method for using perforating nets according to the invention therefore comprises the following operations:

• - the realization of a model on a sheet of paper by removing if there is the protective tape from the double-sided adhesive strip, then by gluing the nets on the back of the sheet in the locations chosen thanks to the adhesive side thus stripped, the cutting or perforating elements coming to bear on the sheet,
• - the passage through the printing machine of the model thus produced, after having removed, if they exist, the protective strips from the adhesive layer of the different nets, so that, during this passage:
• - the threads are stuck on the pressing or margining roller in the places they must occupy, and the double-sided adhesive tape is removed at the same time as the sheet on which it remains stuck, because of its adhesion properties on paper and on metal.

According to another characteristic of the invention, to facilitate the production of the above-mentioned model, it is possible, in a preliminary phase, to print the sheet which will then be used to produce the model.

• la figure 1 est une perspective schématique d'un tronçon de filet perforant selon l'invention ;
• la figure 2 est une coupe transversale du filet perforant représenté figure 1 ;
• la figure 3 représente schématiquement une machine d'impression de type Offset.

An embodiment of the invention will be described below, by way of nonlimiting example, with reference to the appended drawings in which:

• Figure 1 is a schematic perspective of a section of perforating net according to the invention;
• Figure 2 is a cross section of the perforating net shown in Figure 1;
• FIG. 3 schematically represents an offset type printing machine.

With reference to FIGS. 1 and 2, the perforating net 1 comprises a core in the form of a steel strip 2 comprising a flange 3 at right angles to the upper part of which are sharp teeth 4 so as to produce a serrated perforation edge.

As previously mentioned, the lower side of the strip 2, opposite the serrated edge, is coated with a layer of adhesive material 5 covered with a protective strip 6 which can be removed for the use of the perforating mesh 1.

Furthermore, the upper side of the strip 2, adjacent to the serrated edge is covered with a double-sided adhesive strip, that is to say a strip 7 carrying on its two faces an adhesive coating 8, 9, the coating adhesive 8, located on the side opposite to the steel strip 2, being protected by a protective strip 10 which can be removed when using the perforating net 1.

The implementation of this net on an Offset type printing machine will be described below with reference to FIG. 3.

Such a machine conventionally comprises a plate cylinder 12 provided with ink rollers 13 and wetting rollers 14, a blanket cylinder 15 and a pressure cylinder or margining cylinder 17.

The blank sheets to be printed are stacked in a feed station 18 and are transmitted one by one in a margining area 19 before passing between the blanket cylinder 15 and the margining cylinder 17 where the printing takes place. The sheets thus printed are then stacked in a receiving station 20. The difficulty of placing perforating nets of the conventional type, directly on the margining cylinder 17, in the case where the structure of the machine allows it , appears clearly. On the other hand, this operation is simplified by virtue of the perforating net 1 according to the invention which requires no intervention by the operator on the margining cylinder 17.

Thus, with a view to laying perforating nets 1 of the type shown in FIGS. 1 and 2, the operator first of all prints a sheet.

After having removed the protective strips 10, it sticks the perforating nets on the back of the sheet at the locations where the perforations are to be made, thanks to the adhesive face 9 of the strip thus stripped, the serrations of the steel strip being naturally oriented towards the leaf.

Once the perforating nets are in place on the back of the sheet, the operator removes the protective strip 6 covering the adhesive layer 5 of the perforating nets 1 and then passes the sheet thus equipped (sheet 22) through the machine, perforating nets 1 located on the cylinder side of margining 17.

During their passage between the blanket cylinder 15 and the margining cylinder 17, the perforating threads 1 automatically stick to the margining cylinder 17 (threads in broken lines 23). At the same time, the double-sided adhesive strip 7, 8, 9, which remains stuck on the sheet, is detached from the perforating nets 1 (the adhesion of the double-sided adhesive strip 7, 8, 9 on the paper being stronger than its adhesion on the perforating net 1).

At the end of the passage of the sheet, the perforating nets 1 are placed on the margining cylinder 17 at the suitable locations. The operator can therefore perform his printing operations with perforation.

Of course, the invention is not limited to the type of perforating thread shown in Figures 1 and 2. It also relates to all threads of this kind such as grooving threads and cutting threads.

The advantages of perforating nets or the like according to the invention appear clearly.

They can be used on all Offset printing machines, even those that do not allow sufficient access to the margining cylinder.

They eliminate any direct intervention by the operator on the margining cylinder, and the drawbacks which result therefrom.

They considerably facilitate the operations of placing perforating nets. Task operator is reduced to laying perforating nets on a printed sheet that can be laid flat on a work table, which significantly reduces the time and increases the accuracy of the position of the nets.

They allow an appreciable reduction in the cost price of perforated prints and better profitability of machinery, in particular, thanks to the time saved.

Claims (4)

1.- Perforating mesh or the like, usable in particular on printing machines such as offset machines, characterized in that it comprises: a rigid core 2 which can be in the form of a metal strip, preferably made of steel and which has, projecting, on one of its two faces, at least one element possibly cutting or perforating 3, 4, a layer of adhesive material 5 disposed on the side of the core 2 opposite said element 3, 4, this layer being able to be protected by a protective strip 6 to be removed at the time of use, and - A double-sided adhesive tape 7, 8, 9 adhering, by one of its faces, to the side of the core 2 adjacent to the aforementioned element 3, 4, the other face of this adhesive tape. 7, 8, 9 can be protected by a protective strip 10 to be removed at the time of use. 2.- perforating net according to claim 1, characterized in that the said core consists of a steel strip having a toothed or simply sharpened edge, which extends perpendicular to the plane of said strip. 3.- Method for the implementation of perforating nets according to one of claims 1 and 2, characterized in that it comprises at least the following operations: - the realization of a model on a sheet of paper by removing, if there is one, the protective tape from the double-sided adhesive strip, then by sticking the nets on the back of the sheet at the chosen locations thanks to the adhesive side as well stripped, the cutting or perforating elements coming to bear on the sheet, - the passage through the printing machine of the mock-up thus produced, after having removed, if they exist, the protective strips from the adhesive layer of the different nets, so that, during from this passage: - the threads are stuck on the pressing or margining roller in the places they must occupy, and the double-sided adhesive tape is removed at the same time as the sheet on which it remains stuck, because of its adhesion properties on paper and on metal. 4.- Method according to claim 3, characterized in that it further comprises a prior phase which consists in printing the sheet which will then be used to make the model.

Images