EP1534501B1 - Machine for processing sheets with cutouts or folds transverse to their forward moving direction - Google Patents

Abstract

The machine has a conveyer (12) with drive belts (16,18) moving the workpieces forward. The workpieces pass between a tool (53,53') and a counter unit (56) in a working region (T) between an entry zone (E) and an exit zone (S). The tool and counter unit are mounted on shafts (52,54) above and below the path followed by the workpieces. The tool and counter unit produce the folds and the cutouts.

Description

The present invention relates to a sheet processing machine for the manufacture of packaging materials such as cardboard or plastic, comprising drive means adapted to drive sheets in a driving direction at a substantially speed of training constant through a processing zone located between the inlet and the outlet of the machine and processing means comprising a tooling and a counter-tooling respectively carried by a first and a second rotary bearing shaft which extend transversely to the driving direction being arranged facing each other on either side of the path of the sheets, said processing means being intended to practice in these sheets cutouts and / or folds arranged transversely with respect to the driving direction.

A sheet processing machine of this type according to the preamble of claim 1 is known from PCT patent application WO 02/02305, filed by the applicant company. This prior patent application is concerned with the control of the rotation of the carrier shaft of the tooling, which is operated such that, at the moment when the processing means cooperate with a sheet to produce in the latter the cuts or transverse folds with respect to the driving direction, the tangential speed of the tooling is equal to the drive speed of the sheet in the machine.

These arrangements make it possible to operate the machine continuously while it was previously necessary, to make cuts or folds transverse to the driving direction of a sheet, to momentarily stop the latter and to operate a tool of cutting or discharge carried by a movable beam perpendicular to the direction of driving of the sheets.

Although the machine described in WO 02/02305 is satisfactory, it turns out that, under certain conditions of use, the cutting or the repression carried out by the tooling carried by the first bearing shaft leaves traces of wrinkles on processed leaves in the machine. This is particularly the case when these sheets are made in corrugated cardboard whose grooves are oriented transversely to the direction of advance of the sheets, that is to say that the cutting or the discharge are operated parallel to these grooves.

A corrugated cardboard has at least two layers of paper or cardboard between which is disposed at least one corrugated whose corrugations form the aforementioned grooves. For example, these sheets may comprise a lower paper or cover layer, a first corrugated, an intermediate paper layer, a second corrugated and an upper or inner paper layer. In this case, if cutting or unloading is performed by first co-operating the tooling with the top paper layer, the folds may form on the lower paper layer.

These wrinkle problems can also occur in the treatment of sheets of other materials, in particular sheets having a multilayer structure with intermediate corrugations, made at least in part of plastic.

The present invention aims to remedy these drawbacks or at least to limit the intensity.

This object is achieved thanks to the characterizing part of claim 1.

For the treatment of a sheet, in particular for making cuts or folds in certain regions of the sheet, the sheet is pinched between the tooling and the counter-tooling. By convention, it is considered in the following that, during the treatment of the sheet, its upper and lower layers are respectively on the side of the tooling and the counter-tooling. The applicant company has found that, with conventional counter-tools having a perfectly cylindrical surface, the sheet tends to be crushed against the tooling by the tooling. Penetration of the tool into the thickness of the sheet first deforms the top paper layer, which is brought closer to the outer paper layer due to the local crushing of the corrugation (s) between these layers. The upper layer is thus stretched to approach the lower sheet, while the latter is not and remains held against the cylindrical surface of the counter-tooling.

As a result, the lower layer can not accompany the displacement of the upper layer, and folds are thus created on this layer, these folds being all the more troublesome that this layer is in general the outer layer which is visible when the packaging is shaped.

The applicant company has found that the fact of having the tooling cooperate with the radially offset work strip with respect to the adjacent portions of the counter-tooling surface makes it possible to avoid the creation of these folds or at least of make sure that these folds are less marked.

Indeed, when the working strip is radially projecting relative to the adjacent portions of the counter-tooling surface, the lower layer is not pressed against this cylindrical surface in the immediate vicinity of the working strip. As a result, it can move slightly to accompany the aforementioned displacement of the upper layer, and this displacement takes place in the clearance formed on either side of the working strip, above the adjacent portions of the surface of the counter-tooling, so that the lower layer is not compressed and that displacement does not create folds.

Another possibility is to make the working strip recessed relative to the adjacent portions of the counter-tooling surface. In this case, when the tool cooperates with the sheet, it has the first effect of pushing the latter inside such a recess. In other words, it is not only the upper layer that moves and is stretched under the action of the tool, but it also forces the lower layer to move and stretch, although in slightly smaller proportions. The plaintiff company has found that this slight tension applied to the lower layer avoids the creation of folds on the latter.

The counter-tooling surface is substantially cylindrical, the portions adjacent to the working band defining portions of the same cylindrical surface.

The first carrier shaft is controlled so that, when the tool cooperates with the sheet, it is in the right region of this sheet, and is driven by a tangential speed equal to the speed of advancement of the latter . Also knowing the position of the working strip or strips on the surface of the counter-tooling, the motor of the second bearing shaft is controlled so as to correctly angularly position a working strip so that it cooperates with the tooling at the moment when it processes the sheet and so, at this time, animate said working band a tangential speed equal to the forward speed of the sheet. It is therefore according to the control of the first bearing shaft that determines that of the second bearing shaft.

Advantageously, the machine comprises means for controlling the rotational drive of the carrier shafts which are able to control this drive so that, during the successive processing of several sheets, the tool cooperates successively with different working strips.

These provisions make it possible to avoid premature wear of the working strips.

Advantageously, the counter-tooling surface has a plurality of angularly spaced working strips.

Thus, advantageously, the surface of the counter-tooling has a regular alternation of protruding strips and recessed strips.

The multiplication of the number of working tapes is interesting from a practical point of view. In addition, by choosing that these working strips are arranged at regular intervals, it simplifies the control of the driving means of the bearing shaft of the counter-tooling.

In addition, it is possible, depending on the case, to choose to cooperate the tooling with projecting strips, or to have it cooperate with recessed strips, these two types of strips being able to constitute working strips in the sense of the present invention.

Advantageously, the working strip is removably mounted on the counter-tooling.

This removable assembly makes it easy to change a used working band and replace it with a new working band.

Advantageously, the drive means are capable of driving the sheets at a substantially constant drive speed in the treatment zone and the machine comprises means for controlling the rotational drive of the carrier shafts able to control the rotational drive. said carrier shafts so that, at least at the moment when the tool and the working strip cooperate with a sheet for the treatment of the latter, the tooling is driven with a processing speed whose tangential component is equal to said drive speed and the working band is located opposite this tool.

Thus, advantageously, the machine comprises means for determining information relating to the position of a sheet in the treatment area and it comprises a control unit able, according to this information, to control the rotational drive of the first and second carrier shafts so that, for the treatment of this sheet, the tool is in contact with a predetermined region of the sheet and is driven by a processing speed whose tangential component is equal to said speed of drive, while the working strip is in contact with said determined region, but on the other side of the sheet relative to the tooling.

Advantageously, the means for controlling the rotational drive of the carrier shafts are able to control this rotation drive so that, at least at the moment when the tooling and the working band cooperate with a sheet for the treatment of the latter. , the tooling and the working band are each driven by a processing speed whose tangential component is equal to said drive speed.

According to one variant, the first carrier shaft is a multi-tool carrier shaft capable of carrying at least first and second angularly spaced tools and the control unit is able to control the rotational drive of said multi-tool carrier shaft according to a cycle comprising a treatment phase by the first tool, wherein said first tool is in contact with a first determined region of a sheet located in the machine processing zone and is animated with a tangential speed equal to the driving speed of this sheet, a positioning phase during which the multi-tool carrier shaft is driven to position the second tool in a situation of treating a second predetermined region of the sheet and a treatment phase by the second tool, wherein the second tool is in contact with said second region and is driven by a tangential speed equal to the drive speed.

In this case, advantageously, the control unit is able to control the driving of the second carrier shaft so that, during a cycle, the first and second tools of the first bearing shaft cooperate with two working bands. distinct.

Advantageously, the first and second carrier shafts are each driven by a motor, the motor of the second carrier shaft being controlled as a slave with respect to the motor of the first shaft.

The invention will be better understood and its advantages will appear better on reading the detailed description which follows, of an embodiment shown by way of non-limiting example.

• la figure 1 est une vue d'une machine conforme à l'invention en coupe dans un plan vertical ;
• la figure 2 montre le flanc d'un emballage après son traitement par la machine ;
• la figure 3 montre, en coupe dans son épaisseur, la structure d'une feuille dans laquelle peut être réalisé un tel flanc ;
• la figure 4 est une vue synoptique en perspective des principaux organes de la machine, avec le principe de leur commande ; et
• les figures 5 à 8 montrent la conformation d'un contre-outillage, dans des coupes transversales à l'axe de l'arbre porteur de ce dernier.

The description refers to the accompanying drawings, in which:

• Figure 1 is a view of a machine according to the invention in section in a vertical plane;
• Figure 2 shows the side of a package after its treatment by the machine;
• Figure 3 shows, in section in its thickness, the structure of a sheet in which can be made such a sidewall;
• Figure 4 is a schematic perspective view of the main organs of the machine, with the principle of their order; and
• Figures 5 to 8 show the conformation of a counter-tooling in cross sections to the axis of the bearing shaft of the latter.

The machine shown in Figure 1 comprises a feed table 10 on which is disposed a sheet 12 for processing in the machine. This is for example a sheet having a corrugated multilayer structure, cardboard or plastic.

The machine has an input zone E, a treatment zone T and an output zone S sequentially arranged in the direction F of advancement of the sheets. In the input zone E, the sheets are supported by drive means 14 which drive them at a speed constant in the treatment zone T. In the example shown, this zone T comprises two processing units, respectively U1 and U2, arranged one after the other in the direction F. Between these two units, there are drive relay means 16. Drive means 18 are also provided at the output S of the machine.

This is used to treat sheets to conform so that they can then be folded to form a package. For example, Figure 2 shows a machine-processed side from a solid sheet. This sidewall has cutouts 22 and folds 24 which are arranged transversely to the direction F of advancement of the sheet in the machine. The tools of processing units U1 and U2 located in the treatment zone T of the machine make it possible to practice these cuts and these folds. These tools include cutting tools or knives that form cutouts 22 and push-back tools or pressers that form folds 24.

The sidewall shown in FIG. 2 also comprises folds 26 which are arranged parallel to the direction F and which can be produced by means of pressure rollers which cooperate with the drive means. The sidewall still has specific cutouts, for example orifices 28, which serve to form handles in the package and which are made in one of the units U1 and U2.

The drive means of the machine comprise disk-shaped drive rollers which are rotated. For example, FIG. 1 shows, at the entrance to the machine, lower drive rollers 30 and 32, and upper drive rollers 34 and 36. Similarly, at the output, the drive means 18 comprise lower rollers 38 and 40 and upper rollers 42 and 44. The drive relay means 16 also comprise lower rollers 46 and upper rollers 48. In FIG. 1, the driving means 14 and 18 each comprise two rows of lower and upper pebbles. For simplicity, only one row of rollers has been shown for each of these drive means in FIG. 4.

Thus, FIG. 4 shows, at the entrance to the machine, the lower rollers 30 and the upper rollers 34 respectively mounted on a lower shaft 31 and on an upper shaft 35. Similarly, at the exit, the lower rollers 38 and upper 42 are respectively mounted on two shafts 39 and 43, while the intermediate rollers 46 and 48 of the relay 16 are mounted on two shafts 47 and 49. The drive means are driven by a main drive motor M50. The various aforementioned shafts are driven by this motor, to which they are connected by transmission means such as belts 51.

In general, the drive means may be similar to those described in PCT application WO 02/02305.

Each of the processing units U1 and U2 comprises processing means which themselves comprise a tool and a counter-tooling or counter-part for this tooling.

Thus, the unit U1 comprises a first bearing shaft 52 which carries tools 53 and 53 ', and a second bearing shaft 54 which carries a counter-tooling 56.

Similarly, the unit U2 comprises a first bearing shaft 62 which carries tools 63, and a second bearing shaft 54 'which carries a counter-tooling 56'.

The counter-tooling 56 of the unit U1 has a substantially cylindrical surface having a plurality of working strips 57. These working strips extend parallel to the axis of the shaft 54, that is to say transversely in the direction F. The working strips 57 are offset radially relative to the portions 58 of the surface of the counter-tooling which are adjacent to these bands. In this case, the working strips 57 project on the surface of the counter-tooling.

The counter-tooling 56 'of the unit U2 could be made as the counter-tooling 56 of the unit U1 but, in FIGS. 1 and 4, it was chosen to give it a perfectly cylindrical surface because of the conformation of the tools 63 which are rotary cutting tools whose width, measured along the circumference of the carrier shaft 62 is greater than that of the tools 53 and 53 '.

The strips 57 are advantageously made of a material such as polyurethane, sufficiently flexible to allow the tools to perform their function cooperating with them.

In the unit U1, the tools 53 and 53 'are cutting or discharge knives which, during cutting or delivery operations, can penetrate slightly into the polyurethane of the strips 57.

The shafts 52, 54, 62 and 54 'are arranged transversely to the direction F of advancement of the sheets in the machine, so that the tools cooperate with their respective counter-tools in the plane P of advancement of the sheets in the machine, while the tools and the counter-tools (or, for the counter-tooling 56, the strips 57) are driven tangential velocities, respectively V52, V62, V54 and V54 ', which are parallel to this plane and directed in the direction F of advancement of the leaves. In this case, the first bearing shafts 52 and 62 are arranged above the plane P, while the second bearing shafts 54 and 54 'are disposed below this plane.

We first focus more specifically on the processing unit U1. The first carrier shaft 52 is rotated by a motor M52, for example an asynchronous motor, a brushless motor or, generally speaking, a positioning motor.

As indicated in WO 02/02305, the motor M52 is controlled so that the tool 53, 53 'carried by the shaft 52 is animated, at the moment when it comes into contact with the sheet 12 for the treatment of the latter , a tangential velocity V52 equal to the speed V of advancement of this sheet.

For this, the machine comprises a control unit UC which, according to information relating to the position of a sheet 12 in the treatment zone T, controls the motor M52 by a command line L52. The information relating to the position of the sheet 12 is for example delivered, as and when a sheet in the machine advances, by position sensors such as photocells C1, C2 and C3, which are successively arranged in the forward path of the sheets and which are connected to the control unit UC by information input lines, respectively LC1, LC2 and LC3.

The operation of the means for knowing the position of the sheet is described in more detail in WO 02/02305.

The control unit UC knows the forward speed and the position of the sheet in the machine (it controls the main motor M50 by a command line L50 and checks this speed by an input line LE50 connected to a sensor of speed) and, depending on the parameterization means MP entered in this unit UC to memorize the type of treatment (cutting, folds) to be applied in this or that region of the sheet, it can control the motor M52 to position the tools of the unit U1 at the right place, at the right moment and at the right speed.

In this case, the position of the tools on the carrier shaft 52 is adjustable, as shown in WO 02/02305.

For its part, the second carrier shaft 54 is rotated by a motor M54 which is controlled by the control unit UC, by a control line L54.

In this case, the motors M52 and M54 can be controlled as master-slave.

It is in fact on the basis of the control of the motor M52, and knowing furthermore the position of the working band or bands 57, that the motor M54 is controlled by the unit UC so that the or a working band is opposite a tool 53 or 53 'at the moment when this tool cooperates with the sheet, and is driven by the good speed relative to that of the tool 53.

Preferably, the tangential component V54 of this speed is, like the tangential component V52 of that of the tool 53 or 53 ', equal to the speed V of the sheet.

The control unit UC knows the forward speed of the sheet and controls the speed of the motor M52 accordingly by the line L52. The control unit also knows the position of the working band (s) 57 of the counter-tooling 56 (for example by locating the angular position of the counter-tooling 56 and / or the shaft 52 and by memorizing the the position of the working strip or strips relative to a mark on the surface of the counter-tooling) and, depending on the control it gives to the motor M52, it also controls the motor M54. The control unit UC knows the speed of rotation of the shafts 52 and 54 by speed sensors, which are associated with these shafts and which are connected to this unit by input and speed measurement lines LE52 and LE54. for the shafts 52 and 54 respectively. Depending on the data transmitted to it by these lines, the unit UC can control the motors M52 and M54.

Similarly, for the processing unit U2, the first carrier shaft 62 is rotated by a motor M62 which is controlled by the control unit UC by a command line L62 and whose speed is transmitted to this unit by an input line LE62.

The support shaft 54 'of counter-tooling 56' is rotated by a motor M54 ', itself controlled by the unit UC by a control line L54'. This unit knows the speed of this shaft by a speed measurement input line LE54 'connected to a sensor.

As indicated above, the tangential velocity V52 of the tool 53 or 53 'is equal to the drive speed V when this tool cooperates with a sheet for the treatment of the latter. The motor M52 can be controlled in successive phases, comprising a waiting phase during which the tool is separated from the path of the sheets and a processing phase during which the tool cooperates with these sheets and during which the speed V52 is equal at the speed V. Between the waiting phase and the treatment phase, the M52 engine accelerates very quickly, while it decelerates very quickly after the treatment phase.

In general, the first carrier shaft 52 or 62 of the unit U1 or U2 may be driven in a sequence comprising a positioning phase during which it is driven to position the tool that it carries in a situation of treating a machine. determined region of the sheet and a treatment phase during which the tool is in contact with this determined region, is driven by a tangential speed equal to the drive speed V and cooperates with its counter-tooling 56 or 56 '. When, like counter-tooling 56, the latter has working strips 57, a working band 57 is opposite the tooling during the processing phase and is driven by a tangential velocity V54 which is equal to the speed V.

The shaft 52 may be a multi-tool carrier shaft capable of carrying at least two tools spaced angularly. This is seen in FIG. 1, in which two diametrically opposed tools 53, 53 'are arranged on the shaft 52. The angular spacing of these two tools can be adjusted by adjustment means M which are described in detail in WO 02/02305.

In this case, the control unit UC can control the rotational drive of the shaft 52 in a cycle comprising a treatment phase by the first tool 53, in which this tool is in contact a first determined region of a sheet located in the treatment zone T of the machine and is driven by a tangential velocity V52 equal to the speed V, a positioning phase during which the carrier shaft 52 is driven to position the second tool 53 'in a situation of treating a second determined region of the sheet and a treatment phase by the second tool 53' in which it is in contact with the second region of the sheet and is driven by a tangential velocity V52 equal to the velocity V. The positioning phase may comprise a waiting phase or a very rapid rotation phase, according to the angular spacing between the tools 53 and 53 'and the spacing between the regions of the sheet to be successively treated by these tools.

For its part, the second carrier shaft 54 can be controlled to place a working band 57 in a standby situation and animate this band with a tangential speed equal to the speed V when said band is opposite the tool 53 which cooperates with it to treat the leaf in the first aforementioned region. If the shaft 52 has the drive sequence described above, the shaft 54 can experience a new positioning phase in which another working band or the same is placed in a waiting situation, to be then animated by a tangential velocity V54 equal to the speed V so as to cooperate with the tool 53 'to treat the second determined region of the sheet.

As regards the second processing unit U2, in the example shown, the first bearing shaft 62 carries a cylindrical surface 562 which carries a tool 63 able to form cutouts of the type of the cutouts 28 of the sidewall shown in FIG.

The shaft 62 is carried on a movable axis 110 which is supported by a spreader shaft 106, via an eccentric 108. With the aid of a spacer motor M108, this eccentric can be driven in rotation so as to raise or lower the shaft 62 to which it is connected by a system of connecting rods 112 articulated on levers 114. The operation of this system is described in detail in WO 02/02305.

As can be seen in FIG. 3, the sheet 12 has, for example, a multilayer structure with corrugated intermediate layers. It thus comprises an outer layer 12A, an intermediate layer 12B and another outer layer 12C, layers spacing of corrugated material, 13A, 13B being disposed between the layers 12A and 12B on the one hand, and between the layers 12B and 12C on the other hand. FIG. 3 shows the driving direction F of the sheet in the machine, with respect to which grooves 13 'formed by the corrugations 13A and 13B are arranged transversely, such as the folds 24 and the cutouts 22 and 28 of the machine. flank of Figure 2.

For the treatment of the sheet by the unit U1 or U2, the counter-tool cooperates with the layer 12C, while the tool cooperates with the layer 12A. During its movement, it tends to crush the flutes 13 'and to bring the layer 12A of the layer 12C. When the layer 12C can not, too, know a displacement of the same nature, if not of the same degree, it results in the creation of an unsightly fold on this layer 12C.

FIG. 5 shows a first variant for producing the counter-tooling of the machine of the invention. This comprises a hollow support cylinder 155 which can cooperate by its inner periphery with the second carrier shaft 54 in a manner known per se and not shown, for driving the counter-tooling in rotation. On the surface of this hollow cylinder 155 is disposed a coating that cooperates with the tool to perform the treatment of the sheet, by cutting or by forming folds.

In this case, the surface of the counter-tooling has a plurality of treatment strips 157 regularly spaced angularly. It can be seen that the working strips 157 project radially by a distance r with respect to the portions 158 of the surface of the counter-tooling between which they are arranged. In fact, the surfaces of the working strips 157 are centered on a first circle C1, while the surfaces 158 are centered on a second circle C2, the radius of the circle C1 being greater than the distance r to that of the circle C2.

FIG. 5 shows the positions of the blades 153A and 153B of a cutting tool which cooperates with one of the working strips 157 to form a cut-out in the sheet 12 (the latter only being sketched).

It can be seen that the blades 153A and 153B penetrate slightly into the strip 157, which is for example formed of polyurethane. The strips 157 have, for example, the shape of prisms, whose length is parallel to the axis of the hollow cylinder 155, and whose base is substantially trapezoidal. as shown in the drawings. During its processing by the tooling, the sheet rests on the upper face of a strip 157. It is deformed by the application of the tool against its surface, and, as seen in FIG. the fact that the strips 157 project from the portions 158 of the surface of the tooling makes it possible for this deformation of the sheet to take place, for the regions of the latter which are adjacent to the cutting zone, without the pressure of this sheet against the counter-tooling surface. As a result, the creation of permanent folds is avoided.

Preferably, the width of the or each working strip is greater than the width of the tool, while being close to this width. Thus the width Lc of a strip 57, measured between two radii R1 and R2 of the hollow cylinder 156, according to the upper face of this strip, is slightly greater than the width Lo of the tooling. This width Lo is measured between the outer faces of the blades 153A and 153B, between two radii of the cylinder 155.

Advantageously, the width Lc is between 1.05 and 2 times the width Lo, preferably between 1.05 and 1.8 times this width Lo.

In the example shown, the counter-tooling 156 comprises a sheet metal plate 160 which is wound on the surface of the hollow cylinder 155 and is fixed on the latter. For example, the two ends 160A and 160B of the sheet metal join in a recess 155 'of the surface of the cylinder 155, in which they are fixed with screws 162. A coating 159, for example polyurethane, is attached to the surface of the sheet metal plate, except in the region of its ends. It is the outer surface of this coating which forms the aforementioned portions 158, in the form of a recessed band. The surface of the covering 159 also has recesses 159 'recessed with respect to the surface 158, in which the working strips 157 can be arranged. For example, these strips are fixed in the recesses by means of double-sided adhesive tapes. . This allows, when a strip 157 is worn, remove it quickly from its slot to have a new band.

In the region of the ends of the sheet metal plate 160, a removable coating strip 159A may be attached, for example by gluing or using double-sided tape. It is thus possible to access the screws 162 to fix the sheet metal plate, then cover these screws by the band 159A.

In FIG. 6, which shows a variant of FIG. 5 according to the enlarged portion VI, the working strips 257 of the counter-tooling 256 are fixed in the same way as the strips 157. They differ from the latter in that they have a rounded outer surface.

This shape gives a homogeneous curvature to the underside of the sheet during its treatment. The prismatic shape of the strips 157 may slightly mark the underside of the sheet along the edges of the prism during processing of this sheet, which is not necessarily unsightly, because the fold or cut made by the tool is perfectly positioned between these light marks.

Moreover, in FIG. 6, the method of fixing the sheet 260 to the surface of the hollow cylinder 155 is slightly different from that of FIG. 5. Indeed, one of the ends 260A of the sheet bears a bracket 264 which on both sides of its spacer wing 264A, carries a cushion of a polyurethane material 266A and 266B, respectively. The bracket is disposed in the recess 155 'of the hollow cylinder 155, its fixing flange 264B being fixed in this recess by means of a screw 162. The cushion 266A rests against one of the sides of the recess 155', while the cushion 266B forms a locking member under which a free space 265 (formed above the fixing wing 264B of the bracket) allows the insertion of a complementary locking member 267A integral with the other end 260B of the sheet metal plate, this locking member being formed by the hooking edge of a strip 267, for example polyurethane secured to the sheet metal plate. This complementary locking member may also be made of a material such as polyurethane. The sheet is thus removable, but when it is fixed on the hollow cylinder 155, its two free ends extending along lines parallel to the axis of this cylinder, are end to end. As in the variant of FIG. 5, a covering 159 is fixed on the sheet metal plate and has housings 159 'in which the working strips 257 can be fixed.

In FIG. 7, the surface of the counter-tooling is also carried by a carrier plate 360, for example fixed on the cylinder of the same However, another method of attachment, for example that of FIG. 6, could also be used.

On this sheet 360 are fixed at least two surface elements 359 which define between them, by their axial edges 359A opposite provided with first retaining surfaces, a housing for a working strip 357, the latter being adapted to be inserted in this housing and having, on its axial edges, the second retaining surfaces adapted to cooperate with said first retaining surfaces.

In this case, the counter-tooling comprises more than two working strips 357 and the number of surface elements 359 is greater than two. In the example shown, the first retaining surfaces formed on the axial edges 359A parallel to the axis of the second bearing shaft are formed by axial grooves 359 'formed by an overhanging portion of the retaining elements 359, between said elements of retained and the outer surface of the sheet 360. On their side, the working strips have tabs 357 'which are inserted into the grooves or grooves 359'.

The working strips are inserted into the recesses formed between two adjacent surface elements 359 by axial displacement of these strips 357, the tongues 357 'being placed in the grooves 359'.

Thus, the working strips 357 are easily removable to be replaced.

In the variant of FIG. 7, the surface elements 359 are themselves removably attached to the carrier plate 360. For example, fastening strips 370 are fixed at regular intervals to the surface of the sheet 360, and the surface elements 359 are retained on these strips.

Thus, in the example shown, the inner faces of the elements 359 each have two axial grooves 371 whose profiles, for example dovetail, are adapted to those of the strips 370. Thus, the surface elements 359 can be fixed on the sheet by snapping, or by an axial displacement of these elements 359 for threading the strips into the grooves 371. axial stop means for determining the final position of the elements 359 may be associated with these strips.

It is thus possible to change the surface elements 359 which could be damaged.

Depending on the type of sheet to be processed by the machine, it is possible to choose to have the tooling cooperate either with the working strips 357 or with the surface elements 359.

It can be seen in FIG. 7 that the working strips 357 of the counter-tooling 356 are set back relative to the adjacent surface elements. FIG. 7 shows the two blades 153A and 153B of a cutting tool which cooperate with one of the working strips 357. In reality, the surfaces of the working strips are presented as the axial groove bottoms of the counter surface. -outillage. To cut or fold, the tool enters one of these grooves, and pushes the sheet towards the bottom of this groove, that is to say to a working strip. As a result, the upper (first in contact with the tool) and the lower (turned on the counter-tooling side) layers both deform to penetrate the aforementioned groove. As a result, the two layers of the sheet are slightly stretched, even if the lower layer, located on the counter-tooling side, is less so than the upper layer. The applicant has found that this provision prevents the formation of folds.

It should be noted that the width Lc of the outer face of the strips 357, measured between two radii of the hollow cylinder 155, is slightly greater than the width Lo of the tool.

FIG. 8 shows the variant of the working strips in the form of projecting elements with respect to the current surface of the counter-tooling 456, but proposes means of removable fastening of these strips which are similar to those of FIG. 7. For example, the sheet 460 is affixed to the surface of the hollow cylinder 155 in the same manner as in FIG. 5. A plurality of surface elements 459 are attached to this sheet such that two adjacent surface members 459 define between the axial edges 459A of the surface elements 459 are provided with first retaining surfaces formed by axial grooves 459 ', in which flanges 457' of the strips 457 are engaged to retain said working strips.

The surface elements 459 can be fixed, for example by gluing or overmolding on the surface of the sheet 460, or they can be removably attached to this sheet, for example by means of double-sided adhesives.

It is arranged for the fixing screws of the sheet on the hollow cylinder 155 to be in a zone formed between two adjacent surface elements 459, an area which can be disengaged when one of the working strips 457 is removed from its surface. housing.

As in the previous figures, depending on the type of sheet to be treated, it is possible to choose whether it is the working strips 457 that cooperate with the tooling, or that they are surface elements 459.

Claims (12)

1. Machine for processing sheets for the production of packaging in materials such as cardboard or plastic, comprising driving means (14, 16, 18) able to drive sheets in a drive direction (F) at a substantially constant drive speed (V) through a processing zone (T) located between the entrance (E) and the exit (S) of the machine and processing means comprising a tooling (53, 53') and a counter-tooling (56; 156; 256; 356; 456) respectively borne by a first and by a second rotary support shaft (52, 54), which extend transversely to the drive direction (F), by being disposed facing each other on either side of the path (P) of the sheets, said processing means being designed to provide in these sheets cut-outs (22, 28) and/or folds (24) disposed transversely to the drive direction, the machine comprising means (UC) for controlling the rotating drive of the support shafts (52, 54) and able to control the rotating drive of said support shafts so that, at least at the moment when the tooling (53, 53') and the counter-tooling (56; 156; 256; 356; 456) cooperate with a sheet for making in it the transverse cut-outs or folds, the tooling is moved with a processing speed, the tangential component (V52) of which is equal to said drive speed (L), and the counter-tooling is situated facing to this tooling, characterized in that the counter-tooling (56; 156; 256; 356; 456) has a substantially cylindrical surface having at least one working strip (57; 157; 257; 357; 457) which extends parallel to the axis of the second support shaft and which is radially offset relative to the portions (58; 159; 359; 459) of said surface which are adjacent to this strip, said working strip being designed to cooperate with the tooling to form a cut-out or a fold in a sheet, and in that the first and second support shafts (52, 54) are each driven by a motor (M52, M54), the motor of the second support shaft being controlled as a slave relative to the motor of the first shaft.
2. Machine according to claim 1, characterized in that the surface of the counter-tooling (56; 156; 256; 356; 456) has a plurality of working strips (57; 157; 257; 357; 457) spaced angularly apart.
3. Machine according to claim 2, characterized in that the surface of the counter-tooling (56; 156; 256; 356; 456) has a regular alternation of projecting strips (57; 157; 257; 359; 457) and back step strips (58; 159; 259; 357; 459).
4. Machine according to any one of claims 1 to 3, characterized in that the width (Lc) of the or of each working strip (57 157; 257; 357; 457) is greater than the width (Lo) of the tooling and is between 1.05 to 2 times the width of the tooling.
5. Machine according to any one of claims 1 to 4, characterized in that the working strip (157; 257; 357; 457) is mounted removable on the counter-tooling (56; 156; 256; 356; 456).
6. Machine according to claim 5, characterized in that the surface of the counter-tooling (356; 456) is borne by a support sheet metal (360; 460) on which are fixed at least two surface elements (359; 459), which define between them, by their facing axial edges (359A; 459A) provided with first holding surfaces (359'; 459'), a receptacle for the working strip (357; 457), the latter being able to be inserted in said receptacle and having, on its axial edges, second holding surfaces (357'; 457') able to cooperate with said first holding surfaces.
7. Machine according to claim 6, characterized in that the surface elements (359) are themselves fixed removable on the support plate (360).
8. Machine according to any one of claims 1 to 7, characterized in that it comprises means (C1, C2, C3) for determining an information related to the position of a sheet in the processing zone (T) and in that it comprises a control unit (UC) able, as a function of the information related to the position of a sheet in the processing zone, to control the rotating drive of the first and second support shafts (52, 54) so that, for processing this sheet, the tooling (53, 53') is in contact with a predefined region of the sheet and is moved with a processing speed, the tangential component (V52) of which is equal to said drive speed (V), whereas the working strip (57; 157; 257; 357; 457) is in contact with said defined region, but on the other side of the sheet relative to the tooling.
9. Machine according to any one of claims 1 to 8, characterized in that the means (UC) for controlling the rotating drive of the support shafts are able to control the rotating drive of said support shafts (52; 54) so that, at least at the moment when the tooling (53, 53') and the working strip (57; 157; 257; 357; 457) cooperate with a sheet for the processing of the latter, the tooling and the working strip are each moved with a processing speed, the tangential component (V52, V54) of which is equal to said drive speed (V).
10. Machine according to claim 8 and anyone of claims 1 to 9, characterized in that the first support shaft (52) is a multi-tooled support shaft able to bear at least a first and a second tool (53, 53') spaced angularly apart and in that the control unit (UC) is able to control the rotating drive of said multi-tooled support shaft according to a cycle comprising a processing phase by the first tool, in which said first tool (53) is in contact with a defined first region of a sheet located in the processing zone (T) of the machine and is moved with a tangential speed (V52) equal to the drive speed (V) of this sheet, a positioning phase, during which the multi-tooled support shaft (52) is driven for placing the second tool (53') in a position to process a defined second region of the sheet, and a processing phase performed by the second tool, in which the second tool (53') is in contact with said second region and is moved with a tangential speed (V52) equal to the drive speed (V).
11. Machine according to claims 2 and 10, characterized in that the control unit (UC) is able to control the drive of the second support shaft (54) so that, during a cycle, the first and the second tool (53, 53') of the first support shaft (52) cooperate with two distinctive working strips.
12. Machine according to claim 2 and any one of claims 1 to 11, characterized in that it comprises means (UC) for controlling the rotating drive of the support shafts, which means are able to control this drive for enabling the tooling to cooperate successively with different working strips during the successive processing of several sheets.

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