FR2671496A1 - Industrial process for producing stencils, stencils thus obtained and their use - Google Patents

Abstract

Whereas the production of a stencil and its employment for decorative purposes currently constitute an essentially craft (artisanal) activity practised by specialists, the present invention opens this field to industry. In fact, it develops an industrial process for producing a stencil, the said stencil being suitable for the reproduction of at least one copy of at least one part of a pattern, defined by empty areas which are made in a support, each having a contour, the said process comprising: * a computer processing phase consisting: . in obtaining data about the geometry of the said at least part of the said pattern, and . in creating a stream of instructions suitable for controlling a cutting instrument so that the said instrument makes a cut along each of the said contours of the said empty areas defining the said at least part of the said pattern, * a phase of manufacture of the said stencil consisting in transmitting the said stream of instructions to a numerically controlled machine suitable for operating the said cutting instrument and for receiving the said support so that the said support is cut by the said instrument along the said contours and that the said empty areas are created there, characterised in that the said stream of instructions is created, at least partially, in an automatic way. With the aid of this process, applicable in a standard way to any pattern, it is possible furthermore to obtain either a stencil possessing beforehand all the patterns which are to be reproduced, or several stencils suitable to be joined together in order to form the desired overall pattern. They may therefore be used by non-professionals, for example for decorating walls.

Description

 The present invention relates to a process making it possible, on the basis of the very idea of any a priori pattern, to industrially manufacture one or more stencils suitable for reproducing this pattern on a surface. The stencils thus obtained are also suitable for quick and easy use, so that non-professionals can use them.

 Among other things, the technique of stencil drawing is used in decoration to decorate interior facades or walls. Very often, it then consists in choosing a pattern, designing a stencil suitable for reproducing this pattern and applying this stencil to the surface to be decorated, in turn in each of the places where the pattern is to be reproduced, while using a paintbrush or a brush, paint is spread on the stencil. In particular, the very operation of reproducing the motif requires a great deal of know-how, so that it can only be successfully carried out by specialists. This restricts the market for this kind of ornamental work, which is therefore satisfied with stencils developed under artisanal conditions.

 The present invention aims to bring the realization of stencils in the industrial field. For this, it aims on the one hand the development of an industrial process for making stencils without leading to a standardization of decorative patterns. On the other hand, it strives to widen the market for stencils by guaranteeing them easy and quick use within the reach of non-professionals.

This object is achieved in the context of the present invention by using a numerically controlled cutting machine. As recalled in particular by an article published in February 1985 in the British journal METALWORKING PRODUCTION (cf. page 67 of volume 129, number 2), it is indeed known to cut using an automatic cutting machine provided with means computer such as a microprocessor in at least one copy at least part of a pattern determined by voids which are formed in a support and each have an outline. The corresponding method then comprises:
* a computer processing phase consisting of:
to enter data on the geometry of said at least part of said pattern, and
~ to create a stream of instructions adapted to the control of a cutting instrument
so that said instrument makes a cut along each of said
contours of said voids determining said at least part of said pattern,
* a manufacturing phase consisting in transmitting said flow of instructions to a
numerically controlled machine adapted to implement said instrument
cuts and receives said support so that said support is cut by said
instrument along said contours and that said voids are created there.

 However, this process remains economically viable only if the contour to be cut is simple or if it has to be cut into a large number of copies.

In one case, in fact, the effort to enter the data on the geometry and to create the flow of instructions is reduced. In the other, this effort is certainly greater, but it is justified by the repetition of the cutting work proper. In other words, the process summarized above is rather reserved for cases where the second manufacturing phase represents, in particular by its duration, a task comparable to that performed upstream, during the computer processing phase.

 However, with regard to stencils, the elements to be cut correspond to patterns having a certain artistic value with very often relatively complex contours. At the same time, the number of stencils to be produced from these patterns is not particularly large, the users of this decoration mode rather seeking a personalization of their ornamental elements.

 The present invention however succeeds in adapting the known process summarized above to the cases of stencils thanks to a creation of said flow of instructions which is itself made automatic at least partially and at least enough so that the process is economically feasible whatever either the reason.

 Said instruction flow is preferably created essentially using processing software, said input data being compatible with said processing software and being supplied to it as input. If necessary, said processing software is also suitable for calculating, from said data, said cutting contours.

Said entered data may be supplied as input to said processing software by means of a floppy disk.

 Said data on the geometry of said at least part of said pattern are entered on a microcomputer using a terminal. When a drawing software is installed on said microcomputer and said terminal comprises at least one device taken from the set of devices formed by a keyboard, a mouse, a stylus, a screen, a graphic table, it is possible drawing said at least part of said pattern at least partially using said drawing software. However, if said terminal includes a scanner, said at least part of said pattern can be drawn at least partially by hand.

 Advantageously, said cutting instrument is mounted at the end of a movable arm secured to said machine. According to a possible embodiment, said movable arm is adapted to move in a first direction of space, said support of said stencil being mounted on said machine so as to move in a second direction of space perpendicular to said first direction. According to another possible embodiment, said movable arm is adapted to move in a plane parallel to that of said support of said stencil. In the latter case, said support is advantageously mounted on said machine in several superimposed layers so that said layers are cut at the same time.

 Advantageously, said cutting instrument consists of a nozzle emitting a jet of water. For example, the water pressure at the outlet of said nozzle is 2000 bars.

On occasion, an abrasive is diffused in said water jet. However, said cutting instrument can also be adapted to emit a laser beam.

 Optionally, said method further comprises a final phase of handling said cut support. For example, said manipulation consists in applying an adhesive on one face of said support in order to make it self-adhesive.

 Preferably, when the surface of said pattern is smaller than that of said support, said flow of instructions is adapted to control said cutting instrument so that each of said voids determining the whole of said pattern is created a predetermined number of times in said support , said stencil being thus adapted to the reproduction of said pattern in a number of copies identical to said predetermined number. For example, each of said voids determining the whole of said pattern is created a predetermined number of times in said support at regular intervals, said stencil being thus adapted for reproducing said pattern according to a frieze.

 Preferably, when the surface of said pattern is greater than that of said support, during said first computer processing phase of said method, data on the geometry of all of said pattern are entered while indications of breaking up of said pattern into a number predetermined parts are provided.

 The stencil obtained by the method according to the present invention can be produced by means of a support consisting of a material taken from all of the following materials: sheets of paper, plastic film, nonwoven. Advantageously, said support is a sheet of paper with a basis weight between 100 and 500 g / m2. In this way, said stencil can be used by non-professionals, advantageously for decorating walls.

 The method according to the invention combines, by means of data processing, a purely creative approach and industrial operations. Indeed, the owner of a room can very well expose his decoration wishes to a designer for example.

Both then design a pattern according to their taste and the characteristics of the local.

After this phase, where both imagination and personalization have their place, comes a standard phase. First implemented in the design office, it continues at the factory in a manner comparable to the production of metallurgical parts by machines with digital controls. This is how a stencil is produced in industrial conditions independent of the motif originally designed.

 This process is mainly justified in two cases. On the one hand, when the pattern must appear a large number of times on the walls of the room such as a frieze running all around one or more rooms, the method of the invention makes it possible to obtain a stencil, no longer of the basic motif only, but of the entire frieze. On the other hand, when the motif occupies an entire wall, the present process authorizes its fragmentation so that it results from the assembly of several stencils. There is always a guarantee as to the location of the various decorative elements in relation to each other. Thanks to the pre-gluing of the stencils, for example, the latter can be posed without difficulty. Finally, the paint is applied once for the entire ornament, thus avoiding any downtime between the reproduction of each decorative element. These different advantages of the stencils produced according to the invention allow their use by non-professionals and at the same time justify, by an increase in the market, the immobilization of the industrial material necessary for the implementation of the stencil manufacturing process.

The present invention will now be described with the aid of examples with reference to the accompanying drawings. On the drawings
FIG. 1 represents a stencil making it possible to reproduce a pattern,
- Figure 2 shows a stencil for reproducing a series of patterns.

It illustrates how a stencil obtained by the present process can be used
in order to decorate a wall with a frieze,
- Figure 3 is a schematic representation of a first step of a
first phase of the process according to the present invention,
- Figure 4 is a schematic representation of a second step of the
first phase of the process according to the present invention,
- Figure 5 is a schematic representation of a second phase of the
process according to the present invention,
- Figure 6 is a schematic representation of a third phase of the
method according to the present invention.

 FIG. 1 shows a stencil suitable for reproducing a pattern M. The latter in this case comprises a ribbon 10 tied in the shape of a favor 11 and the two sides 12 and 13 of which fall along a sort of bouquet 18 The stems 15 of the bouquet 18 are sketched. They are held together by a piece 14 of ribbon while the bouquet 18 consists of a set of leaves 17 and three fruits 16. The various elements of the pattern M are all hollowed out in a support 20 made of waterproof material and relatively rigid. However, so that the support 20 is not too weakened by the recesses and that all the elements of the pattern M are well delimited, bridges 21 have been provided in the support 20. Their location also meets an aesthetic concern. example the piece 14 of ribbon supporting the bouquet 18 is crossed by two bridges 21 arranged so as to suggest a twist.

This is why the adaptation of a stencil pattern is preferably a task reserved for a specialist.

 The stencil, thus made up of a support comprising voids, is used by placing it directly against a surface (a wall, a piece of furniture, a packaging, etc.) on which the pattern must be reproduced. Then, a paint is applied to the support, both on its solid parts and in its voids. For this, it is common to use a spray can to spray paint or a brush or a brush to brush it. When the stencil is far from the reproduction surface, the paint applied appears in the voids of the support. According to this well-known stencil drawing technique, various masks can be used in order to color each element of the pattern differently. Although this possibility remains within the scope of the present invention, it will however not be discussed in more detail in the following pages which rather try to present particularly simple examples.

 In the prior art, the stencil comprising a single pattern M which has just been described, was then often placed at another location on the reproduction surface and the operation of applying the paint started again. This method, commonly used for decorating walls, for example, requires a mastery of the stencil drawing technique that only professionals can guarantee for a neat and fast execution.

 According to a first example of the present invention, on the contrary, a stencil P is produced comprising in advance all the patterns to be reproduced. Figure 2 shows for example how the pattern M of Figure 1 can be repeated at regular intervals to form a frieze. The stencil P is then in the form of a strip 20 of rather flexible material. It can be paper of a grammage advantageously between 100 and 500 g / m2, plastic material, a nonwoven, etc. . The elements of the patterns M are hollowed out in the strip 20 with bridges 21 identical to those of the simple stencil of FIG. 1. One of the faces of the strip, its back 22, is preferably glued. Gluing can, as the case may be, be carried out just before laying the stencil P or even preexisting on the back 22 of the stencil P which has then been made self-adhesive.

 The strip 20 is placed on the surface to be decorated in the manner of an interior tapestry. The entire stencil P is then covered with paint. It then only remains to take off the strip 20 to release the frieze thus produced. Since, unlike the stencil with a unique pattern, it does not have to be reused, it is not particularly resistant. It is peeled off the reproductive surface, possibly in shreds which are finally thrown away.

 According to this first example of the present invention, a method is proposed for developing, for example, the stencil P of FIG. 2. It comprises two main phases.

The first, shown schematically in Figures 3 and 4, corresponds to design and calculation tasks. These use IT resources and can be carried out at the office. The second, illustrated in Figure 5, is associated with the actual manufacture of the stencil. It requires the use of a cutting machine. A third phase possibly involves various manipulations carried out in the factory such as that shown diagrammatically in FIG. 6.

 The first phase of the present process is divided into two stages. According to FIG. 3, a first of these steps is carried out by a specialist. The latter uses for example the blank E of the pattern M which he imagined with the owner of the room to be decorated. This blank E does not necessarily necessarily yet include the solid bridges essential for the good performance of the final stencil. The designer then introduces them at the same time as he puts the pattern M into computer data. For this, he preferably uses a microcomputer 110 on which drawing software is installed. Depending on the type of software, data can be entered by typing instructions on a keyboard 111 or by manipulating an input tool such as a mouse or a stylus (not shown). In the latter case, the input tool can be applied to a screen 112, or even a graphic table (not shown). When the blank E already has the form of the final pattern M, the data can also be carried out using a scanner (not shown). This is how the geometry of the pattern M is captured, that is to say translated into terms suitable for computer processing. These are optionally copied onto a D1 floppy disk as suggested in Figure 3.

 This floppy disk D1 is then useful for the implementation of a second step of this first phase of the present method according to FIG. 4. This can be carried out by the designer himself or by another specialist and also uses to computer means 120 such as a microcomputer or a more powerful computer.

Specific software is installed on these means 120, if necessary using one or more floppy disks D. Its function is first of all to interpret the pattern M which is supplied to it as input by means of the floppy disk DI. This of course presupposes the compatibility of the information stored on this D1 floppy disk with the software.

 Then the latter possibly calculates the thickness of the cuts which will have to be made in the physical support 20 of the stencil P. For example, the side 12 of the ribbon 10 of the pattern M admits an outline 121 which will finally have to be perforated so that the interior of the pan 12 is detached from the support 20 of the stencil P and constitutes a vacuum there.

However, the end of this pan 12 is very tapered. It should therefore be hollowed out in a particular way (by a simple cutting path for example). It is up to the software to be careful.

 Finally, the software combines the data entered on the geometry of the pattern M as well as the results of these possible calculations with various instructions understandable by the cutting machine used in the subsequent manufacturing phase. These instructions will allow him, for example, to direct the movement of the cutting instrument along the contours of the voids in the pattern or even to bring this instrument from one point to another of the pattern without puncturing the support of the stencil during this journey. Occasionally, they can be completed by the operator (to indicate the repetition interval of the pattern on the stencil support, etc.). The flow of instructions resulting from the processing of the software is then copied for example on a floppy disk D2 which will be used in the next phase of the present process.

 In the above description, various floppy disks D, D1 and D2 have been mentioned. It should however be emphasized that they are there above all in order to concretize the course of this first phase of the present process. And it will appear to those skilled in the art a whole series of variants using other computer storage media. Besides, it can be both external memory and internal memory. Indeed, the separation of this first phase into two stages, each carried out by specific software is not compulsory. A single software can both allow the entry of the data relating to the pattern M and their processing. It is even conceivable that these two tasks are carried out in a nested manner, the entry of a contour 121 of the stencil P being for example immediately followed by its interpretation into instructions for the cutting machine. In this case, it goes without saying that the floppy disk D1 would not have place to be. As for the D2 diskette or its equivalent, it seems more necessary in order to simply transfer the flow of instructions thus created from the designer's office to the cutting plant. Optionally, it is previously made compatible with the electronic system of the cutting machine.

 According to FIG. 5, the instructions are in fact given at the input of a machine 200 with digital controls. In addition to a computer or a microprocessor capable of understanding these instructions, the machine includes cutting means adapted to execute them. These consist of a cutting instrument 201 advantageously mounted on a movable arm. The arm is designed to move at least in a direction x of the space. It is then for example secured to a carriage moving in a rail 202. The cutting instrument 201 therefore makes the perforations which are provided along the line II shown in dotted lines in FIG. 5. The support 20 of the stencil is gradually cut along the contours 121 while the support 20 is animated by a movement in the direction y perpendicular to the direction x. This can be achieved by means of motors allowing the support 20 to wind or unwind, the support 20 being for example stretched above the cutting machine 200 between two rollers 24 supported by uprights 203 integral with the machine 200.

 It is also possible to envisage an arm capable of moving in both directions x and y of space. The perforation can then follow the contour 121 of each element of the pattern M to be hollowed out. In this case, the support 20 of the stencil does not expressly need to be moved during cutting. This can be advantageous in order to cut at the same time several supports arranged one on the other (for example twenty sheets of 250g paper).

 The cutting instrument 201 is preferably a nozzle projecting a powerful jet of water. Water comes out of the sprinkler, for example, around 2000 bars. Depending on the nature of the support 20 of the stencil (paper, plastic film, nonwoven, etc.), an abrasive may possibly be diffused in the water jet. A laser head is also possible.

 When the stencil P has thus been manufactured, manipulations may take place in the context of a third phase of the present process. For example, a worker removes the pieces of support 20 corresponding to the hollowed out elements of the stencil and which have not come off well. n makes the sheets or rollers undergo a treatment to make them waterproof or even coat one of their faces with glue. This last operation is preferably carried out with a gun 300 as shown in FIG. 6.

However, the use of a gluing machine, using rollers for example, cannot be excluded. The stencil P is now ready to be delivered and used as described above.

 In the preceding description illustrated by the drawings, the relative dimensions of the pattern M and of the support 20 are such that the latter gives a stencil suitable for reproducing the complete pattern M in one or more copies. However, the size ratio of the pattern and the media may be reversed. This is the case, for example, of a motif holding more than one painting which should adorn the whole of a wall. Indeed, as it is necessary that the support 20 adapts to the cutting machine, it often consists of a panel having sides of the order of a meter. From this point of view, a panel measuring two by three meters today seems to be a maximum. It is therefore necessary to provide several stencils, each hollowed out differently and adapted to be placed next to each other to reconstitute the overall picture. crafts of the prior art are delicate tasks requiring a particular know-how. As for the first example mentioned above, the application of the present invention to a very large pattern represents progress towards easy execution.

 In truth, the final size of the reproduced motif is a perfectly transparent element throughout the first phase of the present process. Nothing prevents, for example, from implementing its first input step from a draft of the pattern on a reduced scale. It then suffices to specify a scale for the computer means employed either in this first stage or in the following stage of creation of the flow of instructions for the cutting machine.

 Then, in the same way as in the previous example, a repetition interval was introduced during the creation of this flow, indications of fragmentation are this time entered by the operator. They can simply consist in the data of the size of the various supports. If the processing software is planned accordingly, it directly calculates the intersection of the contours of the pattern with the edges of the supports and defines an appropriate partition of the instruction flow. This advantageously results in as many D2 floppies as there are supports, each containing the instructions useful for making a partial stencil.

  The second phase of the present process takes place as previously except that it must be repeated for each of the supports. In turn, they are placed on the cutting machine in order to be hollowed out according to the corresponding instruction flow. Likewise, each partial stencil can then undergo the third phase of manipulation of the present process according to what has been said above. On this occasion, markers can be transferred to the partial stencils to facilitate assembly. It then remains for the end user only to have edge to edge, or rather with a predetermined overlap, the various partial stencils.

The application of paint on their assembly will give the desired picture.

Claims (23)

Claims  1.- Industrial process for producing a stencil, said stencil (P) being suitable for reproduction in at least one copy of at least part of a pattern (M) determined by voids which are formed in a support (20) and each have a contour (121), said method comprising:  * a computer processing phase consisting of:  . to be entered using data entry means (110, 111, 112)  on the geometry of said at least part of said pattern (M), and  . to create with a steep flow in particular of computer processing means (120)  instructions adapted to control a cutting instrument (201) so  that said instrument (201) cuts along each of said contours  (121) said voids determining said at least part of said pattern (M),  * a phase of manufacturing said stencil (P) consisting in transmitting said flow  instructions to a machine (200) with numerical controls adapted to set up  operates said cutting instrument (201) and receives said support (20) so that  said support (20) is cut by said instrument (201) along said contours  (121) and that said voids are created there, characterized in that said flow of instructions is created in a sufficiently aromatic manner that said process is economically feasible regardless of said pattern (M).  2.- Method according to claim- 1, characterized in that said instruction flow is created essentially by processing software installed on said computer processing means (120), said entered data being compatible with said software processing and being provided as input.  3.- Method according to claim 2, characterized in that said processing software is also suitable for calculating, from said data, said contours (121) of cut.  4.- Method according to any one of claims 2 or 3, characterized in that said entered data are supplied as input to said processing software by means of a floppy disk (De).  5.- Method according to any one of claims 1 to 4, characterized in that said data on the geometry of said at least part of said pattern (M) are entered on a microcomputer (110) using 'a terminal (111).  6.- Method according to claim 5, characterized in that a drawing software is installed on said microcomputer (110) and in that said terminal (111, 112) comprises at least one device taken from the set of apparatus formed by a keyboard, a mouse, a stylus, a screen, a graphic table so that said at least part of said pattern (M) is drawn at least partially using said drawing software.  7.- Method according to claim 5, characterized in that said terminal (111, 112) comprises a scanner so that said at least part of said pattern (M) is drawn at least partially by hand.  8.- Method according to any one of claims 1 to 7, characterized in that said cutting instrument (201) is mounted at the end of a movable arm secured to said machine (200).  9.- Method according to claim 8, characterized in that said movable arm is adapted to move in a first direction (x) of space, said support (20) of said stencil (P) being mounted on said machine (200 ) so as to move in a second direction (y) of the space perpendicular to said first direction (x).  10.- Method according to claim 8, characterized in that said movable arm is adapted to move in a plane parallel to that of said support (20) of said stencil (P).  11.- Method according to any one of claims 8 to 10, characterized in that said support (20) is mounted on said machine (200) in several superimposed layers so that said layers are cut at the same time.  12.- Method according to any one of claims 1 to 10, characterized in that said cutting instrument (201) consists of a nozzle emitting a jet of water.  13.- Method according to claim 12, characterized in that the water pressure at the outlet of said nozzle is 2000 bars.  14.- Method according to claim 12 or claim 13, characterized in that an abrasive is diffused in said water jet.  15.- Method according to any one of claims 1 to 11, characterized in that said cutting instrument (201) is adapted to emit a laser beam.  16.- Method according to any one of claims 1 to 15, characterized in that it further comprises a final phase of manipulation of said support (20) cut.  17.- Method according to claim 16, characterized in that said manipulation consists in applying an adhesive on a face (22) of said support (20) in order to make it self-adhesive.  18.- Method according to any one of claims 1 to 17, the surface of said pattern (M) being less than that of said support (20), characterized in that said flow of instructions is adapted to control said cutting instrument (201) so that each of said voids determining the whole of said pattern (M) is created a predetermined number of times in said support (20), said stencil (P) being thus adapted to the reproduction of said pattern (M) in a number of copies identical to said predetermined number.  19.- Method according to claim 18, characterized in that each of said voids determining the whole of said pattern (M) is created a predetermined number of times in said support (20) at regular intervals, said stencil (P) being thus adapted to the reproduction of said pattern (M) according to a frieze.  20.- Method according to any one of claims 1 to 17, the surface of said pattern (M) being greater than that of said support (20), characterized in that, during said first computer processing phase of said method, data on the geometry of all of said pattern (M) are captured using said computer input means (110, 111, 112) while indications of breaking up said pattern (M) into a predetermined number of parts are provided to said computer processing means (120).  21. Stencil obtained by the method according to any one of the preceding claims, characterized in that said support (20) consists of a material taken from all of the following materials: sheets of paper, plastic film, nonwoven .  22. Stencil according to claim 21, characterized in that said support (20) is a sheet of paper with a basis weight between 100 and 500 g / m2.  23.- Use of the stencil according to any one of claims 21 or 22, characterized in that said stencil is used for the decoration of walls, in particular by non-professionals.