EP2822885A1

EP2822885A1 - Automated machine to fold in a zigzag manner and stack a creased tape made of a sufficiently rigid material

Info

Publication number: EP2822885A1
Application number: EP13720014.3A
Authority: EP
Inventors: Giuseppe Capoia
Original assignee: Panotec SRL
Current assignee: Panotec SRL
Priority date: 2012-03-06
Filing date: 2013-03-05
Publication date: 2015-01-14
Anticipated expiration: 2033-03-05
Also published as: ES2574435T3; RU2622333C2; RU2014140233A; US20140378288A1; CA2866487A1; CA2866487C; JP6108184B2; JP2015509473A; ITUD20120036A1; EP2822885B1; WO2013132325A1; CN104520221B; CN104520221A

Abstract

Automated machine to fold in a zigzag manner and stack a creased tape (11) made of a sufficiently rigid material and provided with a plurality of transverse creasings (12) equidistant with respect to each other, comprising feed means (15) suitable to feed the creased tape (11) in a determinate direction of feed toward a folding device (20) of the rotary type suitable to fold it in a zigzag manner and to convey it toward collection means (50). The folding device (20) comprises four parallel pairs of main arms (21-24), having the same length and disposed in a cross, which rotate in a direction of rotation consistent with the direction of feed of the creased tape (11) around a central axis of rotation (Z) perpendicular to the latter, four corresponding parallel pairs of secondary arms (31-34), pivoted to the peripheral ends of the main arms (21-24), toward the inside thereof and rotatable in an opposite direction to the latter, and four folding rods (41-44) pivoted to the peripheral ends of the secondary arms (31-34), so that each of the four folding rods (41-44) is suitable to describe in space a substantially elliptical trajectory (T). The folding rods (41-44) are suitable to intercept the creased tape (11) in correspondence to every two of the transverse creasings (12). The major axis (X) of the trajectory (T) is substantially horizontal and the central stacking axis (W) of the collection means (50) is substantially vertical and parallel to the minor axis (Y) of the trajectory (T).

Description

"AUTOMATED MACHINE TO FOLD IN A ZIGZAG MANNER AND STACK A CREASED TAPE MADE OF A SUFFICIENTLY RIGID MATERIAL" FIELD OF THE INVENTION

The present invention concerns an automated machine to fold in a zigzag manner and stack a tape made of a sufficiently rigid material, that is, with a rigidity so that it does not easily deform, such as for example cardboard, plastic or materials with a thickness and consistency which have similar characteristics of rigidity and provided with a plurality of transverse creasings that are equidistant from each other by a determinate pitch. The machine according to the present invention is applied for example downstream of a continuous production plant of cardboard in sheets of ample width, even more than 3 m, and with high productivity, that is, more than 3.3 m/sec (about 200 m/min).

BACKGROUND OF THE INVENTION

In the field of packing or packaging, folding machines are known, used to fold in a zigzag manner a creased tape, typically made of cardboard, along its creasings and to stack it in a zigzag manner to form suitable stacks of determinate sizes, which are then stored for subsequent workings for packing boxes of different sizes. The distance between two successive creasings is defined as the "pitch" of the tape to be folded, which can be equal to or more than 2,500 mm.

A known folding machine is described in the Italian patent for industrial invention N° 1.374.280 granted to the Applicant on 1 1.02.2008. This known folding machine comprises a folding device with rotating arms suitable to fold each of the segments of the tape with respect to the adjacent one along the transverse creasings, and to stack it toward a collection container. In particular the folding device comprises four parallel pairs of main arms, of the same length and disposed in a cross, which rotate together around a central axis of rotation in a determinate direction, consistent with the direction of feed of the tape to be folded. At the peripheral end of each pair of main arms, and toward the inside thereof, a parallel pair of secondary arms is pivoted, of a lesser length than that of the main arms and rotatable in an opposite direction to that of the latter. Between the peripheral ends of each of the four pairs of secondary arms a folding rod is disposed, parallel to the main axis of rotation and therefore transverse to the direction of feed of the tape to be folded. The secondary arms receive their motion from the main arms with a transmission ratio such that each pair of secondary arms completes two revolutions around their own pins, while the main arms complete one revolution around the central axis. In this way each of the four folding rods describes a substantially elliptical trajectory in space. The length of the main arms and that of the secondary arms and their speeds of rotation are such that each of the folding rods intercepts the tape to be folded every two creasings of the latter, that is every two pitches. In this way, each folding rod lifts the tape to be folded in correspondence to alternate creasings, while the tape itself is lowered in correspondence with the creasings intermediate to those contacted by a folding rod, folding the tape in a zigzag development.

In the known folding machine, the major axis of the elliptical trajectory is substantially transverse to the direction of feed of the tape to be folded, which is inclined by about 25° downward with respect to a horizontal plane, and the collection container has a first part, disposed immediately downstream of the folding device, substantially aligned with the direction of feed of the tape to be folded upstream of the folding device.

This disposition of the folding device and the collection container has however shown a series of drawbacks in the known folding machine, which works on a tape which advances at high speed, in the order of about 3 m/sec; these disadvantages have made the machine not very reliable, because it is subject to frequent interruptions, because of jamming and other functioning anomalies. One purpose of the present invention is to obtain an automated machine which is able to fold in a zigzag manner and stack a creased tape of sufficiently rigid material, which advances at high speed, even more than 3.3 m/sec, which is very reliable and which guarantees continuous functioning, in order to be located, for example, downstream of a continuous production plant of said creased tape.

In the event that the creased tape is cardboard, or a similar or comparable product, the machine according to the present invention must also be able to treat the product which exits still hot and damp from the production plant, without making it less reliable and precise in folding and stacking.

Another purpose of the present invention is to obtain a machine which is able to produce stacks or piles of tape folded in a zigzag manner which can be discharged without needing to stop the work cycle.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claim, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, an automated machine to fold in a zigzag manner and stack a creased tape made of a sufficiently rigid material and provided with a plurality of transverse creasings equidistant from each other, which overcomes the limits of the state of the art and eliminates the defects therein, comprises feed means suitable to feed the creased tape in a determinate direction of feed toward a folding device of the rotary type suitable to fold it in a zigzag manner and to convey it toward collection means; the folding device is of the type which comprises four parallel pairs of main arms, having the same length and disposed in a cross, which rotate in a direction of rotation consistent with the direction of feed of the creased tape around a central axis of rotation orthogonal to the latter, four corresponding parallel pairs of secondary arms, pivoted to the peripheral ends of the main arms, toward the inside thereof and rotatable in the opposite direction to the latter, and four folding rods pivoted to the peripheral ends of the secondary arms, so that each of the four folding rods is suitable to describe in space a substantially elliptical trajectory; the folding rods are suitable to intercept the creased tape in correspondence to every two of its transverse creasings.

In accordance with a characteristic feature of the present invention, which allows the machine to function in an optimum way and not to jam even when the creased tape advances at a very high speed, more than 3.3 m/sec, the major axis of the trajectory is substantially horizontal and the central stacking axis of the collection means is substantially vertical, that is, parallel to the minor axis of the trajectory.

In accordance with a secondary characteristic of the present invention, the feed means comprise a terminal slide positioned in proximity to the folding device so that the direction of feed of the creased tape intersects the trajectory in a fourth quadrant of the latter; moreover the collection means are positioned so that their central stacking axis intersects the trajectory in a second quadrant of the latter, opposite the fourth quadrant with respect to the central axis of rotation of the folding device.

In accordance with another secondary characteristic of the present invention, a horizontal support plane is disposed above the collection means and is suitable to support, temporarily and selectively, the beginning of the stack, also called pre- stack, of the creased tape during the steps of removing the stack previously formed in the collection means.

In accordance with another secondary characteristic of the present invention, there is an interception element disposed between the folding device and the collection means, which element is movable between a first operating position in which it is suitable to intercept the head of the creased tape coming from the feed means, and a second operating position not interfering with the creased tape.

In accordance with another characteristic of the present invention, cutting means are provided to selectively cut the creased tape even without stopping the functioning of the folding device.

Advantageously, the cutting means comprise two horizontal shutters, opposite each other and each movable between an open position, in which they are retracted with respect to the zone of passage of the creased tape, and an operating position, in which they are suitable to pinch the creased tape so that it can be cut on the fly by a cutting unit mounted on the lower part of one of the two shutters.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 is a schematized perspective view of a folding machine according to the present invention, in an initial operating position;

- fig. 2 is a lateral view of a first enlarged detail of the folding machine in fig. 1 in the initial operating position;

- fig. 3 is a lateral view of the first detail in fig. 2 in a first operating folding position;

- fig. 4 is a lateral view of the first detail in fig. 2 in a second operating folding position;

- fig. 5 is a lateral view of the first detail in fig. 2 in a third operating folding position;

- fig. 6 is a lateral view of the first detail in fig. 2 in a fourth operating folding position;

- fig. 7 is a lateral view of the first detail in fig. 2 in a fifth operating folding position;

- fig. 8 is a lateral view of the first detail in fig. 2 in a sixth operating folding position;

- fig. 9 is a lateral view of the first detail in fig. 2 in a cutting operating position;

- fig. 10 is a lateral view, enlarged, of a second detail of the machine in fig. 1 ;

- fig. 1 1 is a lateral view, partly sectioned and enlarged, of a third detail of the machine in fig. 1 in the cutting operating position of fig. 9;

- fig. 12 is a view of the third detail from XII to XII in fig. 1 1 ;

- fig. 13 is an enlarged view of the third detail from XIII to XIII in fig. 11.

DESCRIPTION OF ONE FORM OF EMBODIMENT OF THE PRESENT

INVENTION

With reference to figs. 1 and 2, a machine 10 according to the present invention is suitable to fold and stack in a zigzag manner a creased tape 1 1 (figs. 2 and 3) made of a material, for example cardboard, with a thickness of about 3 mm to about 8 mm and therefore sufficiently rigid, that is, so that it does not deform easily.

The creased tape 11, by way of example, has a maximum width of about 3,000 mm and is provided with transverse creasings 12 at intervals to each other by a determinate constant pitch P (fig. 4), which can be predetermined and which is indicatively comprised between about 600 mm and about 2,500 mm. In the example embodiment given here the pitch P is 1, 150 mm, which is one of the standard measurements in the field of boxes for packaging.

The machine 10 comprises a fixed metal structure 13 (fig. 1) or frame, in the upper part of which a feed unit 15 is mounted, suitable to feed forward continuously the creased tape 11, arriving for example directly from a production plant of the known type and not shown in the drawings, at a determinate very high speed of advance V, even higher than 3.3 m/sec, which corresponds to more than 200 m/min. In particular, the feed unit 15 comprises, in its end part, a plurality of feed rolls 16 and a comb-shaped terminal slide 18, which is inclined downward by an angle a (fig. 2), adjustable and comprised between about 9° and about 20°, with respect to a horizontal plane and defines the direction of feed of the creased tape 11.

Downstream of the feed unit 15 a folding device 20 (figs. 1 and 2) is disposed, suitable to fold in a zigzag manner the creased tape 11 along its transverse creasings 12 (fig. 3). The folding device 20, which will be described in detail hereafter, is similar to the one described in the above mentioned Italian patent for industrial invention N° 1.374.280, included here in its entirety as a reference, even though it contains new and original technical characteristics compared thereto, which will be shown hereafter and which have solved the technical problems of the known machine in a surprising way.

Below the folding device 20 a collection device 50 (figs. 1, 2, 3 and 10) is disposed, suitable to vertically convey the creased tape 11 folded in a zigzag manner, in order to stack it and form a continuous pile, or stack, with a determinate height, for example 1,000-1,200 mm. The collection device 50 will also be described in detail hereafter.

The folding device 20 (figs.1, 2 and 3) comprise four parallel pairs of main arms , respectively 21, 22, 23 and 24, of the same length and disposed in a cross, which are attached to a central bar 25 rotating in a clockwise direction, that is, consistent with the direction of feed of the creased tape 1 1 , around a central axis of rotation Z, by means of an electric motor 30 mounted on the frame 13.

At the peripheral end of each pair of main arms 21, 22, 23 and 24 and toward the inside thereof, a corresponding parallel pair of secondary arms 31, 32, 33 and respectively 34 are pivoted on pins 26, 27, 28 and respectively 29, the secondary arms being shorter than the main arms 21, 22, 23 and 24 and rotatable in an opposite direction to the latter, that is, in an anti-clockwise direction.

Between the peripheral ends of each of the four pairs of secondary arms 31, 32, 33 and 34 a folding rod 41, 42, 43 and respectively 44 is disposed, parallel to the central axis of rotation Z and therefore transverse to the direction of feed of the creased tape 11.

The radius Rl (fig. 2) of the main arms 21, 22, 23 and 24, between the central axis of rotation Z and the axis of each pin 26, 27, 28, and 29 is substantially equal to pitch P, or a little less than it (for example 1,130 mm). Moreover, the peripheral speed of the pins 26-29 is proportional to the speed of advance V of the creased tape 1 1, and in this case, slightly less than it, for example 1/5 less than V. The radius R2 of the secondary arms 31, 32, 33 and 34 is instead less than half the radius Rl and, in this case, about 430 mm.

The secondary arms 31, 32, 33 and 34 receive motion from the rotation of the main arms 21, 22, 23 and 24, by means of two pairs of chains with rolls 36 and 37, engaging with two corresponding pairs of fixed toothed wheels 38 and 39, coaxial to the central axis of rotation Z. The transmission ratio between the pairs of fixed toothed wheels 38 and 39 and those keyed onto the pins 26, 27, 28 and 29 is 2: 1, which means that each pair of secondary arms 31, 32, 33 and 34 completes two revolutions around the respective pins 26, 27, 28 and 29, while the main arms 21, 22, 23 and 24 perform one complete revolution around the central axis of rotation Z. In this way each of the four folding rods 41, 42, 43 and 44 describes a substantially elliptical trajectory T in space. Advantageously the major axis X of the latter is horizontal, or substantially horizontal, while the minor axis Y is vertical, or substantially vertical.

The lower end of the terminal slide 18 is disposed in a position very near to the fourth quadrant of the trajectory T and almost tangent to it, so that the direction of feed of the creased tape 1 1 intersects the trajectory T exactly in the fourth quadrant of the latter.

In consideration of the sizes of the radiuses Rl of the main arms 21, 22, 23 and 24 and R2 of the secondary arms 31, 32, 33 and 34, as well as their peripheral speeds, each of the folding rods 41, 42, 43 and 44 is able to intercept the creased tape 1 1 every two creasings 12 of the latter, that is every two pitches P. In this way, each folding rod 41, 42, 43 and 44 is able to fold the creased tape 1 1, thrusting it toward the outside, in correspondence to alternate creasings 12, while the creased tape 1 1 itself, because of the particular movement of the folding rods 41, 42, 43 and 44 is subjected to folding toward the inside in correspondence to the creasings 12 intermediate to those contacted by each folding rod 41, 42, 43 and 44. Consequently, the creased tape 1 1 can be folded in an alternate direction, assuming the desired zigzag development.

We must point out that, according to an innovative feature of the present invention, the timing of the main arms 21, 22, 23 and 24 with respect to the secondary arms 31, 32, 33 and 34 is essential and decisive to obtain a zigzag folding which is reliable and constant over time, even at high speeds (more than 3 m/sec) and also with very wide creased tapes (wider than 3 m). This timing provides that two opposite folding rods, for example 42 and 44, must be on the major axis X and face toward the outside when the corresponding main arms and opposite secondary arms, for example 22 and 24, respectively 32 and 34, are also aligned with the major axis X, while at the same time the other two folding rods for example 41 and 43 must be on the minor axis Y and face toward the inside, when the corresponding main and secondary arms, for example 21 and 23, respectively 31 and 33, are also aligned with the minor axis Y.

Figs. 3 to 8 show the different operating steps of the folding device 20, which will be described in detail hereafter.

The collection device 50 (fig. 1) comprises a horizontal support plane 51, vertically mobile between two vertical containing sides 52 and 53 (fig. 10) of the fixed structure 13, which define a stacking chamber 54, by means of a second electric motor 55.

The vertical axis W passing through the center of the stacking chamber 54 defines the stacking axis of the collection device 50 and intersects the trajectory T in a second quadrant of the latter, opposite the fourth quadrant of the same trajectory T with respect to the central axis of rotation Z of the folding device 20. A conveyor belt 56 (fig. 1) is mounted on the support plane 51, for example of the rolling shutter type, on which the pile or stack that the creased tape 11 forms after having been folded by the folding device 20 is suitable to rest.

The conveyor belt 56 is selectively drivable by a third electric motor 57 to laterally discharge the pile of creased tape 11 folded in a zigzag manner, when the support plane 51 is in its lowest position (shown with a dotted line in fig. 10). The collection device 50 also comprises, in its upper part, two lateral walls 58 and 59 (fig. 10) disposed opposite one another and on the side where the creasings 12 of the creased tape 11 are when it is folded in a zigzag manner. A motorized mechanism 60 is associated to each of the two lateral walls 58 and 59, able to make them oscillate with respect to corresponding horizontal pins 61.

Three compressed air ejector units 62 (fig. 2), of the known type and not described in detail, are disposed one above the folding device 20, in correspondence to the first quadrant of the trajectory T, about 50 cm therefrom, one inside the interception element 65, and one inside the lateral wall 59 of the collection device 50. The three ejector units 62 are suitable to work in pulses, timed with the angular position of the folding device 20 to promote the folding and stacking of the creased tape 1 1.

Between the folding device 20 and the collection device 50, the machine 10 comprises an interception element 65 (figs. 2 and 3) formed by a series of parallel bars, suitable to act as a first-start plane for the creased tape 11, and mobile between a first operating position, shown in fig. 2, in which it is substantially interposed between the folding device 20 and the collection device 50, in order to intercept the head of the creased tape 1 1 which is arriving from the feed unit 15, and a second operating position, shown in fig. 3, in which it is displaced on one side and in an almost vertical position, in order not to interfere with the creased tape 1 1.

In particular the interception element 65 is attached to an arched structure 66 sliding on rollers 68 mounted rotatable on the fixed structure 13 and is commanded by a pair of fluid-dynamic pistons 69.

Between the interception element 65 and the collection device 50 a comb- shaped horizontal support 70 is disposed, which is suitable to temporarily support the stack of creased tape 1 1 which is forming, during the step of removing the stack previously formed in the collection device 50.

In particular, the horizontal support 70 is mobile both horizontally, by means of a first movement mechanism 71 commanded by a fourth electric motor 72, between a forward position (figs. 2 and 3) and a retracted position (fig. 10), and also vertically, by means of a second movement mechanism 73 commanded by a fifth electric motor 75, between a raised position and a lowered position (both shown with a dotted line in fig. 10). The details of the movement mechanisms 71 and 73 are easily understandable by a person of skill in the art and are not described in detail here. The machine 10 also comprises a cutting device 80 (fig. 10) disposed under the folding device 20 and above the collection device 50, in order to selectively cut the creased tape 1 1, for example when the stack in the collection device 50 has reached a desired height.

In this case, the cutting device 80 (fig. 11) comprises two horizontal shutters 81, 82, opposite each other, ending with two wedges slightly offset with respect to each other and each mobile between an open position (figs. 3 to 8), in which they are retracted with respect to the passage area of the tape 1 1 , and an operating position (fig. 9) in which they pinch the creased tape 1 1 in order to cut it under them.

The cutting device 80 also comprises a cutting unit 83, mounted on the lower part of the shutters 82 (on the right in fig. 2) and in turn comprising a rotating blade 85 (figs. 1 1, 12 and 13) and a counter roller 86 provided with a circumferential groove 88, in which the peripheral edge of the rotating blade 85 is partly housed, and which defines a matrix which facilitates the cutting of the creased tape 1 1.

The rotating blade 85 and the counter roller 86 are mounted rotatable on a slider 89 sliding on a guide 90 attached to the shutter 82 in a transverse direction to the direction of feed of the creased tape 1 1, that is, in the direction indicated by the arrow A in figs. 12 and 13. The translation motion of the slider 89 from a lateral inactive position (fig. 12), outside the bulk of the creased tape 1 1, as far as an opposite operating end, after having crossed, cutting it, the creased tape 1 1 for its entire length, and back, is carried out by a sixth electric motor 91 by means of a transmission belt 92. The rotation of the rotating blade 85 is on the other hand achieved by the same translation motion of the slider 89, by means of a toothed belt 93, with its heads attached to the shutter 82 and engaging with a toothed pinion 95 (fig. 13) mounted rotatable on the slider 89 coaxial with and solid to the rotating blade 85. Two small rollers 96, also mounted rotatable on the slider 89 and disposed at the sides of the toothed pinion 95, parallel to it, cooperate with the back of the toothed belt 93, thus ensuring that the latter engages with the toothed pinion 95.

The machine 10 as described heretofore functions as follows.

First of all it must be underlined that for a correct functioning of the machine 10 it is essential to synchronize both the angular speed of the main arms 21-24 of the folding device 20 with the speed of advance V of the creased tape 11, and also the angular timing of the main arms 21-24 with the position of the transverse creasings 14, made upstream of the feed unit 15 by any known device and not shown in the drawings, and also the reciprocal timing between the main arms 21- 24 and the secondary arms 31-34 as described above.

When the method to fold the creased tape 11 in a zigzag manner is started, the machine 10 is in the initial operating position shown in figs. 1 and 2, with the interception element 65 in the operating position in order to intercept the head of the creased tape 11 and therefore closing the access to the collection device 50 below, with the horizontal support 70 in a high and forward position, with the shutter 81 (on the left in fig. 2) forward and with the shutter 82 (on the right in fig. 2) retracted.

When the head of the creased tape 11 reaches the interception element 65, the latter is moved by the fluid-dynamic pistons 69 into its inactive position, which corresponds to a first operating folding position, shown in fig. 3, and it remains there until the folding process is ended. The shutter 81 is also retracted, while the horizontal support 70 remains in the forward position and begins to gradually descend, by means of the second movement mechanism 73, as the stack (the pre- stack) of the creased tape 1 1 progressively forms.

In this first operating folding position, the main arm 21 is inclined by an angle β, about 30°, in advance with respect to the minor axis Y of the trajectory T, with the corresponding folding rod 41 ready to intercept the transverse creasing 12 which is arriving from the terminal slide 18.

In a second operating folding position (fig. 4), after a rotation by 15° of the folding device 20 in a clockwise direction, that is, when the angle β is about 15° in advance with respect to the minor axis Y of the trajectory T, the folding rod 41 has just contacted the creased tape 11 and begins to fold it upward in correspondence to the corresponding transverse creasing 12.

The folding device 20, continuing to rotate in a clockwise direction, takes the main arm 21, in sequence, first into a third operating folding position (fig. 5), in which it is aligned with the minor axis Y of the trajectory T, then into a fourth operating folding position (fig. 6), in which angle β is about 15° behind with respect to the minor axis Y of the trajectory T, then into a fifth operating folding position (fig. 7), in which angle β is about 30° behind with respect to the minor axis Y of the trajectory T, and finally into a sixth operating folding position (fig. 8), in which angle β is about 45° behind with respect to the minor axis Y of the trajectory T. It should be noted that in the passage from the second operating folding position to the sixth operating folding position (figs. 4 to 8) the transverse creasing 12 adjacent to the one intercepted by the folding rod 41 is not affected by any element of the folding device 20, and therefore, because of the particular movement of the secondary arms 31-34, the creased tape 11 folds in the opposite direction, thus disposing itself in a zigzag manner.

In the sixth operating folding position of the main arm 21, the main arm 24 adjacent to it is inclined by an angle of 45° in advance with respect to the minor axis Y of the trajectory T, ready to intercept the creased tape 1 1 in proximity to another transverse creasing 12, after another rotation of 15°, when this too will be in the first operating folding position as described above.

It should be noted that every folding rod 41-44, because of its own satellite- type motion, varies its speed with respect to the creased tape 11, so that in a first sector, which begins from the first operating folding position (fig. 3) and ends after a rotation of 90° (position in which the folding rod 42 is in fig. 3), the folding rod 41-44 rotates at a speed substantially equal to the speed of advance V of the creased tape 11, and then progressively diminishes to zero, when it is in its horizontal position between the first and the second quadrant of the trajectory T. Then the speed of the folding rod 41-44 progressively increases until it arrives in a third sector (offset by 180° with respect to the first sector).

In this way, each folding rod 41-44 contacts the creased tape 11 in correspondence to one of its transverse creasings 12, it accompanies it at the same speed V for all of the first sector, then slows down and zeroes its relative speed, and then accelerates to let the creased tape fall, already folded, into the stack below.

As the creased tape 11 gradually folds in a zigzag manner and forms the pre- stack on the horizontal support 70, the latter is lowered so as to bring it into proximity to the support plane 51, which at the beginning was in the maximum raised position shown with a dotted line in fig. 10. The horizontal support 70 is then taken into the retracted position, by means of the first movement mechanism 71, so that the pre- stack just formed rests on the support plane 51 below, which is then moved downward to the lower position, at the base of the collection device 50, shown with a continuous line in fig. 10. In the meantime, to facilitate the formation of the stack, the motorized mechanisms 60 are driven in order to oscillate the lateral walls 58 and 59 with respect to their horizontal pins 61.

When the stack of creased tape 1 1 is completed, the latter is cut, without stopping its advance toward the folding device 20, carrying out a so-called "cut on the fly".

To do this, the two shutters 81 and 82 are made to advance one toward the other and taken to the operating cutting position shown in figs. 9 and 1 1, so that the creased tape 1 1 remains pinched between their wedged ends.

The cutting device 80 is then activated and in particular the electric motor 91, which by means of the transmission belts 92 makes the slider 89 translate transversely to the creased tape 1 1, which is thus held between the counter roller 86 and the rotating blade 85 and cut by the latter in a few seconds. The slider 89, after carrying out the complete outward travel and cutting the creased tape 1 1, is kept in that position, outside the transverse bulk of the creased tape 1 1; the horizontal shutters 81 and 82 are then drawback toward their position shown in fig. 3, in order to immediately allow the normal flow of the creased tape 1 1 toward the collection device 50. The slider 89 is then returned to its initial position (fig. 12), remaining outside the transverse bulk of the creased tape 1 1 for the whole of the return travel.

Once the cutting operation of the creased tape 1 1 has been completed, the conveyor belt 56 is driven (figs. 1 and 10) of the collection device 50 in order to discharge the stack toward conveying means of the known type and not shown in the drawings. During this operation to discharge the stack, the horizontal support 70 is returned to its initial position, at the top and forward (fig. 3), that is, below the creased tape 1 1 which has just been cut, so that the folding cycle described above can be repeated.

Once the discharge of the stack by the conveyor belt 56 has been completed, the support plane 51 is returned to its raised position, to be ready to receive another pre-stack of creased tape 11 which in the meantime is forming on the horizontal support 70, thus ensuring the continuous functioning of the machine 10, without having to stop the folding device 20.

It is clear that modifications and/or additions of parts may be made to the machine 10 as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of automated machines for folding and stacking in a zigzag manner creased tapes made of a sufficiently rigid material, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

1. Automated machine to fold in a zigzag manner and stack a creased tape (1 1) made of a sufficiently rigid material and provided with a plurality of transverse creasings (12) equidistant with respect to each other, comprising feed means (15) suitable to feed said creased tape (1 1) in a determinate direction of feed toward a folding device (20) of the rotary type suitable to fold it in a zigzag manner and to convey it toward collection means (50), wherein said folding device (20) comprises four parallel pairs of main arms (21-24), having the same length and disposed in a cross, which rotate in a direction of rotation consistent with said direction of feed of said creased tape (1 1) around a central axis of rotation (Z) perpendicular to the latter, four corresponding parallel pairs of secondary arms (31-34), pivoted to the peripheral ends of said main arms (21-24), toward the inside thereof and rotatable in an opposite direction to the latter, and four folding rods (41-44) pivoted to the peripheral ends of said secondary arms (31-34), so that each of said four folding rods (41-44) is suitable to describe in space a substantially elliptical trajectory (T), said folding rods (41-44) being suitable to intercept said creased tape (1 1) in correspondence to every two of said transverse creasings (12), characterized in that the major axis (X) of said trajectory (T) is substantially horizontal and the central stacking axis (W) of said collection means (50) is substantially vertical and parallel to the minor axis (Y) of said trajectory (T).

2. Machine as in claim 1, characterized in that said feed means (15) comprise a terminal slide (18) positioned in proximity to said folding device (20) so that said direction of feed of said creased tape (1 1) intersects said trajectory (T) in a fourth quadrant of the latter, and in that said collection means (50) are positioned so that said central stacking axis (W) intersects said trajectory (T) in a second quadrant of the latter, opposite to said fourth quadrant with respect to said central axis of rotation (Z) of said folding device (20).

3. Machine as in claim 1 or 2, characterized in that said collection means (50) comprise a horizontal support plane (51), vertically movable between two vertical containing sides (52, 53), which define a stacking compartment (54) centered on said central stacking axis (W).

4. Machine as in claim 3, characterized in that a conveyor belt (56) is mounted on said support plane (51) on which the stack which said creased tape (11) is suitable to form after being folded by said folding device (20) is suitable to rest, said conveyor belt (56) being selectively driven to discharge laterally said stack of creased tape (1 1) folded in a zigzag manner, when said support plane (51) is in a lower position.

5. Machine as in claim 3 or 4, characterized in that said collection means (50) also comprise, in the upper part of said stacking compartment (54), two lateral walls (58, 59) disposed opposite one another and on the side in which said creasings (12) of said creased tape (1 1) are found when it is folded in a zigzag manner, and in that a motorized mechanism (60) is associated with each of said two lateral walls (58,59), able to make them oscillate with respect to corresponding horizontal pins (61).

6. Machine as in any claim from 3 to 5, characterized in that a horizontal support (70) is disposed above said collection means (50), suitable to temporarily support the beginning of the stack of said creased tape (1 1) during the removal steps of the previous stack formed in said stacking compartment (54).

7. Machine as in claim 6, characterized in that said horizontal support (70) is movable both horizontally, between a forward position and a retracted position, and also vertically between a raised position and a lowered position.

8. Machine as in any claim hereinbefore, characterized in that between said folding device (20) and said collection means (50) an interception element (65) is disposed, which is movable between a first operating position in which it is suitable to intercept the head of said creased tape (11) coming from said feed means (15), and a second operating position not interfering with said creased tape (1 1).

9. Machine as in any claim hereinbefore, characterized in that it also comprises cutting means (80) disposed between said folding device (20) and said collection means (50) and suitable to selectively cut said creased tape (1 1) even without stopping the functioning of said folding device (20).

10. Machine as in claim 9, characterized in that said cutting means (80) comprise two horizontal shutters (81, 82), opposite each other and each movable between an open position, in which they are retracted with respect to the zone of passage of said creased tape (1 1), and an operating position, in which they are suitable to pinch said creased tape (1 1) so that it can be cut on the fly by a cutting unit (83) mounted on the lower part of one of said two shutters (82).

1 1. Machine as in claim 10, characterized in that said cutting unit (83) comprises a rotary blade (85) and a counter roller (86), which are mounted on a slider (89) selectively sliding in a transverse direction to the direction of feed of said creased tape (1 1) toward said collection means (50).