EP1138454B1 - Apparatus for separating the attachment points connecting the edges of a line of cut - Google Patents

Abstract

The device comprises a frame carrying transporter belts for transporting cut-outs in a plane trajectory and two parallel shafts (10,11) able to rotate either side the trajectory. There are tool supports (19a,19b,20a,20b) on each shaft for shearing the adjacent edges of a cutting line during their displacement. The tool supports have angular and longitudinal positioners (10a,11a).

Description

The present invention relates to a device for breaking attachment points connecting two edges of a cut line on cardboard blanks before being shaped by folding, comprising a frame carrying means for transporting said blanks along a path substantially flat and two parallel shafts rotatably mounted on both sides else of the plane of said trajectory, comprising tools for inducing a shear between the edges adjacent to said cutting line during their displacement, in order to break said attachment points.

When cutting certain cardboard cuttings intended for be folded along fold lines, in particular to form boxes, it is often useful, even necessary, to maintain a liaison between the adjacent edges of at least some of the cutting lines to prevent the cutouts do not cling to each other. These links are generally in the form of point links arranged between the edges of the line of cut and spaced from each other along the cutting line.

When such cuts are introduced into a folder-gluer, it is then necessary to break these links before proceeding folding operations of these cuts.

A neighboring device has already been proposed, for example, in the patent EP 0 680 821. This device is intended to break more especially the fibers of cardboard that can survive accidentally in cuttings different panels are separated by simple cutting lines. However, even if the reasons for the links are here involuntary, the problem to be solved is however quite comparable to that mentioned above.

The solution proposed by the above-mentioned document disadvantages, mainly related to its lack of flexibility, tools for inducing shear to break open fibers being formed on the rotating shafts themselves. As a result, the change of type of cardboard cuttings requires the change of the two trees, leading to an important disassembly operation of the device. Moreover, the pivot axes of these shafts on the frame being fixed, such a device can not practically be used for the same type of box, in this case cigarette packaging, so that the device in question would not be usable for processing cardboard blanks of substantially dimensions different.

Another disadvantage, related to this solution of the prior art lies in that the cardboard blanks must be spaced apart from each other others with very precise distances, otherwise the relative position tools and cuts will vary, there will be a gap between the tools and the parts of cardboard cuttings to be worked, no longer capable of attaining the desired objective and then risking damage to the cardboard cutouts. Gold the maintenance of this precise spacing requires adjustment operations long and painstaking, and productivity is limited by the fact that number of processed cuts per unit length can not be optimized.

The object of the present invention is to remedy, at least in partly to the disadvantages of the above-mentioned device.

For this purpose, this invention relates to a device as defined by claim 1.

The design of this device allows it a great flexibility of use and adaptation to cardboard blanks dimensions likely to vary in important proportions. This new design also makes it easy to adjust the position of the tools, to increase productivity.

La figure 1 est une vue en élévation de cette forme d'exécution, vu du côté gauche par rapport au sens de transport des découpes de carton;

la figure 1a est une vue en élévation de cette forme d'exécution, vu du côté intérieur droit par rapport au sens de transport des découpes de carton;

la figure 2 est une vue en perspective de l'autre côté du dispositif;

la figure 3 est une vue en perspective d'un détail de la figure 1, se rapportant au mécanisme pour rompre les points d'attache proprement dit;

la figure 4 est une vue en perspective agrandie d'un détail de la figure 2;

la figure 5 est une vue en élévation latérale depuis le côté gauche du seul mécanisme de transport de cette forme d'exécution;

la figure 6 est un schéma-bloc d'un asservissement de la position angulaire des outils par rapport à la position des découpes en amont des outils de travail.

Several other features and important advantages of this device will become apparent from the following description and with the aid of the accompanying drawings which illustrate, schematically and by way of example, an embodiment of the device for breaking the points. fastener connecting two edges of a section line object of the present invention.

Figure 1 is an elevational view of this embodiment, seen from the left side with respect to the direction of transport of cardboard blanks;

Figure 1a is an elevational view of this embodiment, seen from the inner right side with respect to the direction of transport of the cardboard blanks;

Figure 2 is a perspective view of the other side of the device;

Figure 3 is a perspective view of a detail of Figure 1, relating to the mechanism for breaking the proper attachment points;

Figure 4 is an enlarged perspective view of a detail of Figure 2;

Figure 5 is a side elevational view from the left side of the single transport mechanism of this embodiment;

Figure 6 is a block diagram of a servo of the angular position of the tools relative to the position of the cuts upstream of the working tools.

In the following description, when referring to the side left and right side of the device, it is in relation to the direction of transport of cardboard cutouts, indicated by an arrow F. The device illustrated by the 1-3 shows a frame formed essentially of two vertical parts, left and right, respectively 1 and 2, kept apart from each other by several spacers 3.

Two cradles, one upper 4a, the other lower 5a, are associated at the left part 1 of the frame and two other cradles, upper 4b, lower 5b are associated with the right part 2 of the frame. Each of these cradles 4a, 5a, is pivotally mounted on the left part 1 of the frame by a pivot axis 6, respectively 7. Each of the cradles 4b, 5b is pivotally mounted on the part 2 of the frame by a pivot axis 8, respectively 9. The two upper cradles 4a, 4b carry a first tool shaft 10, while the two lower cradles 5a, 5b carry a second tool-holding shaft 11.

The two upper cradles 4a, 4b are associated with a device 12 with worm, acting on two connecting rods 12a, 12b connected to ends of the respective cradles 4a, 4b opposite the pivoting shafts 6, 8 and intended to rotate these upper cradles 4a, 4b around these pivoting axes 6, 8. Another similar adjustment device 13 makes it possible to rotating the lower cradles 5a, 5b around the pivot axes 7, 9, through two connecting rods 13a, 13b.

Each tool shaft 10, 11 is integral with an engine synchronous training M1, M2 respectively. Tool shafts 10, 11 are kinematically connected to shafts 14, respectively 15, coaxial to the pivot axes 8, 9 of the cradles 4b, 5b, by toothed belts 16, respectively 17. The shafts 14, 15 pass through the straight part 2 of the frame, as can be seen in Figure 2, to extend on both sides of this right part 2.

The outer portions of the shafts 14, 15 are connected kinematically by a notched belt 18 on both sides, so that the angular positions of the two tool shafts 10, 11 are constantly synchronous. To obtain this result one of the motors M1, M2 must be enslaved to the other. In this example, it is the motor M1 which is slaved to the motor M2. The servo device will be described in relation with FIG. 6.

Each tool shaft 10, 11 is provided with a keyway 10a, 11a for the angular positioning of annular tool holders 19a, 19b, 20a, 20b. These tool holders always go in pairs and face each other, the tools of a tool support 19a secured to the upper tool shaft 10 cooperating with the tools of the tool support 19b, secured to the tool shaft lower 11.

These annular tool holders 19a, 19b, 20a, 20b are illustrated in FIG. larger scale in Figure 4. Only one of them 19b, will be described here in detail, to the extent that they are all identical. This tool support 19b has a discoidal ring 21 in the form of a circular sector, the angular opening of which is sized to allow the passage of one of the tool shafts 10, 11. The disc rings 21 of two tool supports 19a, 19b of the same pair are intended to be coplanar, that is, they will be positioned to occupy the same axial positions along their tool shafts respective, 10, 11.

The disc ring 21 is integral with a first half collar of clamping 22 of diameter corresponding to that of said tool shafts 10, 11, provided with an internal groove 22a intended to cooperate with one of the grooves key 10a, 11a of the tool shafts 10, 11. A second half collar of clamping 23 of diameter corresponding to that of said tool-holding shafts 10, 11, connected to the first half-clamp 22 by two clamping screws 24, 25, makes it possible to axially immobilize the tool support 19b along the tool-holding shaft 11 by clamping this shaft between the two half-clamps 22, 23.

The disc ring 21 has a positioning protrusion annular 21a, pierced with a plurality of coaxial arcuate openings 26 to the disc ring 21. A similar annular positioning protrusion and of the same diameter as the projection 21a (not visible) is formed on the other face of the discoidal ring 21. Different tools 27 to break the attachment points connecting two edges of a cut line of a cardboard cut are positioned angularly along these annular projections with hooves 27a in which is formed a groove of positioning 27b for engaging with the annular projection 21a.

These tools 27 are attached along the annular projections 21a by tightening bolts 28 which pass through the positioning shoes 27a and the openings in an arc of a circle 26 to be screwed into nuts 29, in mesh with the annular projection on the opposite face of the disc ring 21.

As can be seen in Figure 4, some of the tools 27 extends from one side of the median plane of the discoidal ring 21, while the other part of these tools extends to the other side of this same median plane. Thereby, the tools 27 of two tool supports 19a, 19b of the same pair of supports of tools that extend from one side of this median plane and those that extend from the other side of this median plane describe two parallel circular trajectories and adjacent, since the disc rings 21 of the two tool holders 19a, 19b are coplanar.

It can also be observed that the peripheral edges of some of these tools 27 describe larger circular trajectories diameters as the peripheral edges of the other tools 27. The trajectories of smaller diameter of the peripheral edges of the tools 27 are chosen to be substantially tangent with the plane trajectories of the cuts moved by the transport device that will be described later, so that these tools 27 play a supporting role of the cuts. Edges peripherals of the other tools 27, whose trajectories are larger diameters, are set to penetrate the flat trajectory of the cutouts of carton transported by the carrier.

Therefore, when a cutting line formed in a cut of cardboard, passes between these tools 27, parallel to the median planes coplanar disc rings 21 of the tool supports 19a, 19b, the two edges of the cut line of this cardboard cut are subjected to a shear that breaks the junction points that connected these two edges one to the other, since one of the tools 27, describing a circular path extending on one side of the median plane of the disc rings 21, intersects the trajectory plane cuts, while the other tool 27, describing a trajectory circular parallel and adjacent extending from the other side of this median plane, is substantially tangent to the flat trajectory of the cardboard blanks.

The transport mechanism that will now be described is disposed between the left and right parts 2 of the frame. As the situation of this mechanism would make it difficult to see, it is represented separately to facilitate the reading of the drawing. It has a lower part 30 and two upper parts 31a, 31b. The lower part has a band endless conveyor 32 guided by a plurality of rollers 33 and driven by a motor 34. A portion of the rollers 33 are arranged in a plane corresponding to the transport path of the cardboard blanks.

In the center of the transport plan formed by the rollers 33, the strip endless conveyor 32 is guided by a series of rollers 33a, for forming a loop 32a extending below the plane of the trajectory of transport. This loop 32a provides a space corresponding to the size of the tool support 19b carried by the lower tool shaft 11. In FIG. 5, the loop 32a is shown closed, its two ends 32b meeting substantially at the point of tangency of the strip conveyor 32 with the circular path of the tool support 19b.

On each side of this point of tangency, the rollers 33 of carrier defining the lower part of the transport mechanism horizontal are distributed each, symmetrically with respect to this point of tangency, in three sections, a section in which the rollers 33 are mounted on a slideway 35, followed by a section comprising, in this example, two rollers 33b secured to a removable support 36 and finally a section where the rollers 33 are directly mounted on the frame 37 of the transport mechanism 30. Some of the guide rollers 33 of the band conveyor 32 also play the role of tensioners 33c, mounted on mobile supports (not shown), solicited by means mechanical devices (not shown) which tend constantly to maintain the tense conveyor belt. Setting the opening and closing of the loop 32a of the conveyor belt 32 will be explained later.

The two upper parts 31a 31b of the mechanism of transport are arranged in mirror symmetry with respect to the axis connecting the centers of the two tool shafts 19a, 19b. These two parts 31a, 31b being similar, only one of them will be described. Each part 31a, 31b has an endless conveyor belt 38a, 38b guided by rollers 39, a portion of which forms a flat surface parallel to and adjacent to the portion plane formed by the rollers 33 of the lower part 30 of the conveyor. In outside the rollers 39 forming the flat surface, some pebbles play also the role of tensioning rollers 39c, like the rollers 33c of the part lower 30 of the transport mechanism.

The rollers 39 forming the plane transport parts are grouped into a plurality of bogies 40 subjected to pressure means elastics (not shown) for pressing conveyor belts 32 on the one hand and 38a, 38b on the other hand one against the other. A first part these bogies 40 are articulated around horizontal axes parallel to the axes of the rollers 39 on a slide 41. The following bogie is attached to a removable support 42. Finally the following 40 bogies are attached to a fixed support 43. A photoelectric detection cell 44 is arranged to the input of the transport device and is intended to detect the front edge of the each cardboard cut-out arriving in the device to break the points attachment.

From the moment the front edge of a cardboard cutout is detected by the cell 44, the exact distance separating this leading edge from tools 27 for breaking the points of attachment, between which the cutting cardboard must pass, is known. This cell 44 delivers a signal that is sent to a microprocessor 45 for regulating the angular position of tool shafts 19a, 19b by adjusting the speed of the motors drive M1, M2 (Figure 6).

This angular position of the tool-holding shafts 19a, 19b is constantly known thanks to two pulse generators G1, G2 associated with the synchronous drive motors M1, M2 respective and transmitting their information to the microprocessor 45. Thus, when the edge before a cut is detected, the microprocessor 45 knows the position angle of the tools 27 on the mounted tool supports 19a, 19b, 20a, 20b on the tool-holder shafts 10 and 11. It also knows the distance between the edge before cutting and the line joining the axes of the tool-holder shafts 10, 11. He can then determine the angular correction to be made. The microprocessor 45 performs this correction by calculating, from the collected data, acceleration or deceleration, as well as how long this correction must be applied to the motors synchronous drive M1, M2, so that the tools 27 are in the desired angular position to perform the points breaking operation binding at the determined location of the carton blank.

The operation and use of the device described are the following:

When the device to break the connecting points of attachment two edges of a cut line is used to treat a new type of cardboard blanks, the first job is to choose the tool holders 19a, 19b, 20a, 20b depending on the size of the cut. The length tool holder device will have to match the length of the measured cut in the direction of its transport F, to which will be added a certain length corresponding to an average spacing between cutouts, the precise adjustment being made by the microprocessor 45 (FIG. 6), following the detection of the leading edge of each cut by the cell 44, as explained above.

Once the diameters of the tool supports have been chosen, angularly position the different tools 27 by fixing them with the help of nuts 29 and bolts 30. Then we will adjust the position of the cradles 4a, 4b, 5a, 5b with respect to the horizontal path of displaced cuts by the conveyor 30, 31a, 31b, using the adjusting devices 12, 13 (Figure 3). This setting allows you to precisely and simultaneously adjust the penetration depth of all tools 27. This represents a gain in time since it is not necessary to perform this tool setting per tool.

The next step is to position and secure the brackets of annular tools 19a, 19b, 20a, 20b on the tool shafts 10, 11. laterally introduced these annular tool holders 19a, 19b, 20a, 20b, thanks to the angular openings of the disc rings 21 in the form of circular sectors, forming these tool holders. The positioning accurate angularity is assured thanks to the internal groove 22a of the half collar of clamping 22 which can be engaged, using a key (not shown) in the keyways 10a, 11a of the tool shafts 10, respectively 11. And before the tightening of the two half-collars tightening 22, 23 by the screws 24, 25, the tool supports 19a, 19b, 20a, 20b will be positioned longitudinally along the tool shafts 10, 11.

It can happen that the axial position of one or the other pair of tool holders 19a, 19b, 20a, 20b on the tool shafts 10, 11, interferes with the transporter mechanism. This problem is solved by device object of the present invention, since the upper parts 31 has, 31b of this carrier may deviate from each other to allow the passage of one of the upper tool supports 19a, 20a, while the 32a loop formed by the guide rollers 33a under the lower part 30 the carrier can open to let one of the tool holders lower 19b, 20b.

To perform this modification of the transporter mechanism, must first remove the two removable supports 36 carrying pebbles 33b, on the lower part 30 and the two removable supports 42 each carrying a bogie 40. Then, it is necessary to slide the slides 35 of the lower part 30, and the slides 41 of the upper parts 31a, 31b, to separate them from each other. The tensioning rollers 33c then make it possible to maintaining the endless conveyor belts 32, 38a, 38b under tension. When useful information about the dimensions of the cuts in particular, will be introduced into the microprocessor 45, the device described will be ready to operate.

It can be seen from the foregoing description that the device object of the invention makes it possible to adapt to a range of dimensions and types of cardboard blanks extremely wide and that the operations of setting are simple to perform. This device not only allows position the tools 27 angularly and longitudinally (or transversely if one refers to the direction of transport F of the cuts), but also to change the diameters of the tool supports 19a, 19b, 20a, 20b to adapt to cuts of different dimensions. The possibility to discard the conveyor belts 32, 38a, 38b to allow position the tool supports 19a, 19b, 20a, 20b in any axial position along the tool shafts 10, 11, depending on the location of the cutting lines on the cuts, as a consequence to allow to work on all the width of the cuts.

Finally, the detection of the front edges of the cutouts by the cell 44 and the adjustment of the angular position of the tools 27 by the microprocessor 45 allows greater flexibility and gain in the time needed at the setting, since the spacing between the cuts may vary. Adjustment angle of the tools 27 according to variable spacings of the cutouts of Cardboard leads to a productivity gain, since the number of cuts treated per unit length by the device according to the present invention can be increased.

Claims (9)

1. Device for breaking nicks connecting two edges of a cutting line provided on cardboard blanks before they are folded, comprising a frame (1, 2) carrying means (30, 31a, 31b) for conveying said blanks along a substantially planar path, and two parallel shafts (10, 11), rotatably mounted on both sides of the plane of said path, including tools (27) for inducing a shearing between the edges adjacent to said cutting line during their displacement, in order to break said nicks, characterized in that each parallel shaft (10, 11) includes at least one annular tool support (19a, 19b, 20a, 20b) for connecting said shearing tools (27) to said respective shafts (10, 11) and means for angularly (10a, 11a, 22a) and longitudinally (22-25) positioning these annular tool supports (19a, 19b, 20a, 20b) on said respective shafts (10, 11).
2. Device according to claim 1, characterized in that said annular tool supports (19a, 19b, 20a, 20b) include a circular guide track (21a) for the positioning of said tools (27).
3. Device according to any of the preceding claims, characterized in that said annular tool supports (19a, 19b, 20a, 20b) include a discoidal ring (21) in the form of a sector of a circle, having an angular gap sized to allow passage of said tool holder shafts (10, 11), a first half clamping collar (22) of a diameter corresponding to that of said tool holder shafts (10, 11) being fixedly attached to said discoidal ring (21), whereas a second half clamping collar (23) having the same diameter is connected to said first half clamping collar (22) by clamping means (24, 25).
4. Device according to any of the preceding claims, characterized in that said first half clamping collar (22), on the one hand, and said tool holder shafts (10, 11), on the other hand, include key positioning means (22a, 10a, 11a).
5. Device according to claim 1, characterized in that each parallel shaft (10, 11) is connected to the frame (1, 2) by two cradles (4a, 4b, 5a, 5b) mounted on said frame (1, 2) so as to pivot around an axis parallel to said shafts and adapted to occupy a plurality of positions with respect to said planar path, so that said parallel shafts (10, 11) can accommodate annular tool supports (19a, 19b, 20a, 20b) of different diameters.
6. Device according to claim 5, characterized in that the diameter of said annular tool supports (19a, 19b, 20a, 20b) corresponds to a multiple of the length of said cardboard blanks in the direction of transport (F) of these blanks by said conveying means (30, 31a, 31b) plus a determined spacing between said blanks.
7. Device according to any of the preceding claims, characterized in that said parallel shafts (10, 11) are, on the one hand, each fixedly attached to a synchronous drive motor (M1, M2) and, on the other hand, connected to one another by kinematic connection means (14-18), one of said motors (M1, M2) being a main motor, whereas the other is controlled by this main motor.
8. Device according to claim 7, characterized in that it includes means (44) for detecting the passage of the front edge of the cardboard blanks at a determined point of said planar path and means (45) for controlling the speed of said main motor (M2) so that the angular position of said tools (27) coincides with the position of said nicks to be broken.
9. Device according to any of the preceding claims, characterized in that said means (30, 31a, 31b) for conveying said blanks are formed by upper and lower conveyor belts (38a, 38b, 32) respectively, each being divided in two on both sides of a plane containing the axes of rotation of the two tool holder shafts (10, 11), each part (32b) of said conveyor belts (38a, 38b, 32) adjacent to said plane being fixedly attached to support means (35, 41) adapted to be moved parallel to said planar path of said blanks, so as to allow spacing from one another of the said parts of said conveyor belts (38a, 38b, 32) adjacent to said plane for positioning said annular tool supports (19a, 19b, 20a, 20b) between them.

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