ES2299051T3 - FOLDING MACHINE WITH SUCTION MEANS FOR ZIG-ZAG FOLDING OF A CONTINUOUS BAND MATERIAL AND ASSOCIATED FOLDING PROCEDURE. - Google Patents

Abstract

The folding machine comprises; a pair of counter-rotating folding cylinders ( 1, 3 ), each provided with at least one gripping member ( 43 ) to fold a continuous web material (N) in a zigzag manner; and a cutting member ( 60 ) disposed in front of the folding cylinders to cut the zigzag folded web material and divide it into two piles (M) of folded articles. Each gripping member is a suction member which retains the web material by suction at the level of the respective folding line.

Description

Folding machine with suction means for zig-zag folding of a web material Continuous and associated folding procedure.

Technical field

The present invention relates to a machine press brake to fold a web material along lines folding cross. More particularly, the invention is refers to a folding machine of the type comprising a pair of adjacent counter-rotating folding cylinders with shafts parallel, presenting each of them at least one element of grabbed to hold the web material along some lines transversal and make folds along these lines.

The invention also relates to means to perform the folding of a continuous web material according to transversal zigzag lines.

State of the art

In many folding machines, used in the field of paper transformation to produce, for example, folded paper napkins, a web material is fed continuous, optionally folded along a line longitudinal, to a pair of counter-rotating folding cylinders, arranged adjacent to each other to determine a step by which passes the band material, which have parallel axes. In each cylinder are arranged elements that make the fold in Band material. These elements mentioned above are they have and control in such a way that the band material is zigzag fold, alternately adhering first to one of the two counter-rotating folding cylinders and then the other. The package formed by the material in zigzag folded band It is then cut using a blade and divided into two stacks of paper napkins or similar folded products.

A machine of this type is described, by example in the documents WO-A-9728076, US-A-4,332,583 and WO-A-0162651. In US Pat. Nos. 3,195,882, US No. 3,229,974, US 3,820,774, US 3,689,061 and in German patents 4,446,753 and 429,288 describe others examples of folding machines.

The folding elements of these machines folding machines comprise, arranged in each folding cylinder, a gripping element that seizes the material at each turn of the cylinder in band along a folding line. To enter the Band material in the gripping element, are arranged in the two folding cylinders respective blades or wedges of folded, in angularly alternated positions with respect to gripping elements To make a fold, a folding blade of one of the two folding cylinders and a gripping element of the other folding cylinder in positions angular so that they correspond to each other in the step determined between the two folding cylinders, so that pushes the web material using the folding knife in the inside of the gripping element.

Generally, each of the two cylinders of folding has at least one folding blade and one element of grip, so that for each complete turn of the pair of cylinders at least two folds are made in the material in band.

The presence of folding blades and elements of gripping on the counter-rotating folding cylinders makes these particularly complex machines from a mechanical point of view. In addition, the mechanical action of the folding knife or wedge in the Band material tends to deteriorate it. The folding blades are subject to rapid wear with the consequent costs of maintenance.

Documents US-A-5,356,131; US-A-4,921,235; WO-A-03016184 disclose some folding machines of another type and with a different configuration than those referred to in the present invention.

Objectives and summary of the invention

The objective of the present invention is to manufacture a folding machine, of the aforementioned type, Make it simpler, but at the same time effective and safe.

This and other objectives and advantages, which they will be evident to those skilled in the art through the reading of the following text, are essentially achieved with a folding machine according to independent claim 1.

The continuous web material (generally and preferably tissue paper to produce tissues or napkins and similar) is coupled in this way alternately in one and in the another of the counter-rotating folding cylinders by aspiration, and said aspiration that couples the web material in equidistant surfaces produces the zigzag folding thereof, without the need to use complex mechanical elements to grab the material with corresponding cam mechanisms to control them. This simplifies the machine, also making it effective. and safe.

To facilitate folding and, optionally, get particularly safe operation even at high speeds, according to the invention each of the folding cylinders it is provided with a wedge element in phase with the element of held by the opposite cylinder, to produce a line that facilitates the folded in the web material, at the level of said element of has been. The line that facilitates folding is in substance a type of fold and can be obtained particularly effectively providing, for each wedge element, a corresponding notch produced in the opposite cylinder, associated with the suction grip element.

According to a different aspect, the invention is refers to a procedure to produce folded items from of a continuous web material advantageously and preferably in tissue paper according to independent claim 8.

The attached claims indicate other advantageous features and embodiments of the machine and process according to the invention described with more detail below, referring to an example of embodiment.

Brief description of the drawings

The invention will be better understood from the description and attached drawing, which show an example of form of non-limiting embodiment of the invention. In particular, in the He drew:

Figure 1 is a plan view of a machine incorporating the invention;

Figure 2 is a front view of the folding cylinders of the machine;

Figure 3 is a plan view by III-III of Figure 2;

Figure 4 is a longitudinal section of one of folding cylinders;

Figure 5 is a cross section V-V schematic of figure 2 of the two folding cylinders;

Figures 6A and 6B are extensions, in two subsequent positions of the gripping elements of one of the folding cylinders at the point where the folded web material begins to separate from the folding cylinder;

Figure 7 is a section by VII-VII of Figure 2;

Figure 8 is an enlarged section longitudinal of the suction zone of one of the cylinders of creased;

Figure 9 is a planar detail of the flange for mounting the suction unit; Y

Figure 10 is an enlarged local section according to an orthogonal plane to the axes of rotation of the cylinders of folded at the level of the folding zone, at the moment when form the fold in the web material.

Detailed description of the preferred embodiments of the invention

Referring initially to Figure 1, The folding machine features a pair of folding cylinders 1 and 3 which rotate according to arrows f1 and f3 around the respective vertical rotation shafts 1A and 3A, arranged parallel and separated from each other so that the two folding cylinders 1, 3 are adjacent to each other at the level of step 5. The cylinder of folding 1 is supported by means of pins 1C and 1D (figure 2) on corresponding supports 7, 9. The folding cylinder 3 It is similarly supported by the 3C and 3D pins on the supports 11 and 13.

The two folding cylinders 1 and 3 are made turn in opposite directions (arrows f1 and f3 in figures 1, 5 and 7) by means of a cogwheel 14 that meshes with a wheel serrated 15 keyed in the shaft of the folding cylinder 1, and that in turn gears with a cogwheel 17 keyed in the tree of the folding cylinder 3.

At the upper end of the cylinder shaft 1C of folding 1 an eccentric 19 is mounted which, by means of a coupling rod 21, provides an alternative movement to an oscillating arm 23 (see figures 2 and 3). Swing arm 23 is keyed in a vertical shaft 25, parallel to the axes of the two folding cylinders 1, 3 and supports in solidarity with the same three shaped bars 26 that are introduced into some corresponding annular grooves 27 of the folding cylinder 1 (see in particular figure 2).

Articulated to swing arm 23, at the end opposite to which the coupling rod 21 is articulated, is arranged another coupling rod 29, whose opposite end is articulated in a support 31 keyed in a tree 33, parallel to the tree 25. Solidarity with tree 33 three bars are arranged 35, analogous to bars 26, which are introduced into corresponding grooves 37 provided in the folding cylinder 3. The number of bars 26, 35 may vary depending on the height of the folding cylinders 1, 3.

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As can be seen in particular in the section of figure 5 and, limited to the folding cylinder 3, in the section of figure 4, has been practiced inside each one folding cylinders 1, 3, a longitudinal seat or cavity, indicated in general for both cylinders by the number of reference 41. The two cavities 41 are symmetrical with each other such as can be seen in particular in figure 5 and the cylinders folding are in phase with each other so that the cavities are in diametrically opposite positions.

The cavities 41 appear on the surface cylindrical of each of the two folding cylinders 1, 3. In each of the two seats or cavities of each folding cylinder 1, 3 is a gripping element, designated in general by reference number 43, which is used to grab and fold the N-band material fed to step 5 between the two folding cylinders 1, 3. The two gripping elements 43 are symmetrical with each other and only one will be described below of them in detail, making particular reference to the figure Four.

The gripping element 43 is composed essentially by a block that has a series of holes interns 45 (arranged in the example represented in four rows parallel to the axis of the folding cylinder). The holes appear on an essentially flat interior or rear surface 47 of the block 43 and on an essentially cylindrical outer surface 49 arranged level with the cylindrical surface of the respective folding cylinder 3 (or 1). The cylindrical surface 49 is interrupted at the level of the grooves 37 (or 27) of the cylinders of folding 1 and 3 and at the level of said annular grooves it presents recessed surfaces 51, to allow the bars to pass 26, 35.

The seat 41 of the two cylinders 1 and 3 is coupled with a suction duct 53 extending coaxially to the axis of rotation of the respective cylinder and appears on the upper front surface thereof, in which (as is described below) is supported for a certain angle of rotation of the respective cylinder in communication with a pipe of aspiration. In this way, there is an aspiration for the holes 45 of each block 43, for a predetermined angle, whose end, as shown in more detail below, is temporarily retain the web material to be folded to along a cross fold line.

On the cylindrical front surface 49 of each block 43, a notch 55 has been performed (see an enlargement  in figure 10), in which a wedge 57, produced in a insert 59 arranged in the opposite cylinder. Such as it can be seen in figure 5, in each of the two cylinders of folded 1, 3 block 43 and insert 59 are arranged in diametrically opposite positions, so that during the rotation of the two cylinders 1, 3 in step 5, each notch 55 of block 43 mounted on one of the two cylinders corresponds to wedge 57 of insert 59 mounted on the other cylinder.

The folding machine described above in This report works as follows. When the folding machine is working, a material is fed into N band, optionally folded longitudinally upstream of folding cylinders 1, 3 with systems known per se that are not described in this report, through step 5 (arrow fN, figure 1) between the folding cylinders 1 and 3. In this point is attracted along transverse fold lines alternatively by one or the other of the two gripping elements by suction, consisting of blocks 43 with the corresponding suction holes 45.

Suction is activated through holes 45, for each cylinder 1, 3 before the hole line 45 plus far forward with respect to the direction of rotation of the respective cylinder 1, 3 reaches step 5, so that the Band material is attracted and retained on the surface cylindrical of the respective folding cylinder. The plurality of suction hole lines 45 ensures effective retention of the web material when it passes through step 5 and moves more beyond this point, following the rotation movement of the cylinder.

The aspiration through the holes 45 is maintained until block 43 is in an approximately angular position 45º to 60º more advanced than the position of step 5. In this way, the N-band material, which advances essentially to it peripheral speed than that of folding cylinders 1, 3, due to to suction, continue to adhere to folding cylinder 1 or 3 in which the aspiration has been activated, producing such a fold as shown in figure 5 (in this case the fold is shown formed by cylinder 3). In the position of figure 5 it has interrupted the suction and the folded edge of the web material N is separated from the folding cylinder 3, facilitated therein by the oscillatory movement of the bars 35, said movement being oscillator advantageously synchronized with the angular position of the folding cylinders 1, 3. The fold produced by the element of grip 43 associated with the folding cylinder 3 is designated by reference P.

Continuing rotation in directions opposite of the two folding cylinders 1, 3, when the element of suction grip 43 is in the vicinity of step 5 is activates the aspiration through it to form a fold in the N-band material, analogous to the P-fold produced by the cylinder folding 3.

With the continuous rotation of the cylinders of folding 1, 3 and alternative activation of aspiration by one or another of the two gripping elements 43, a fold is obtained in zigzag in the N-band material. Thus, a package is formed of material P that is fed (figure 1) according to arrow F towards y against a cutting element 60 with an edge parallel to the axes of rotation 1A, 3A of the folding cylinders 1, 3 and arranged in a vertical plane tangent to the two cylinders. The cutting element it can be (in a manner known per se) a fixed or mobile element which divides the P package into two M1, M2 napkin stacks or other folded items, which are fed into the discharge zone of the machine, on which known elements are arranged, which are not described in detail herein, to separate the Individual packages of items with each other.

To facilitate the formation of folds in the level of gripping elements 43 wedges 57 are provided which cooperate with notches 55. These two elements are enter each other at the level of step 5 (figure 10), deforming the N-band material between them. This forms a line that facilitates folding, essentially in the form of a fold. To obtain this effect, it is not necessary that a pressure be exerted particularly high between the two elements 55, 57. However, it is advantageous that the notch 55 is made in a part that can be removed and replaced from block 43. This part that can can be removed advantageously from a material elastically flexible, such as rubber, which can be relatively hard but with greater elasticity than the material of metal of which the remaining part of block 43 is composed. As can be seen in the drawing, for each block 43, the notch 55 is arranged at the level of the row of holes suction 45 farther forward with respect to the direction of rotation of the respective folding cylinder 1 or 3.

For coupling the suction duct 53 of each of the two cylinders 1, 3 to the suction, for example, a pipe connected to a fan, a arrangement of a coupling that cooperates with the surface upper front of each of the two cylinders, indicated by reference 1F for the folding cylinder 1 and by means of the reference 3F for the folding cylinder 3. This arrangement is shows in detail in figures 7, 8 and 9 for the cylinder of folding 3. For folding cylinder 1 a symmetric arrangement

By means of a plate 83 in a material with a low coefficient of friction, a shoe 81 is supported on the 3F front surface of cylinder 3. Shoe 81 is coupled with sliding way to two vertical guide columns 85 fixed in respective sleeves 87. These in turn are fixed in a flange 89 secured in a part 91 of the fixed structure of the machine. Two compression springs 93 (one of which can shown in figure 8) load the shoe 81 against the surface front of the respective folding cylinder 1 or 3.

Flange 89 is shown in a plan view of Figure 9. By reference number 95 two are designated three-hole series of fixing screws 97 of the sleeves 87 to retain guide columns 85. As you can shown in figure 9, flange 89 has two curved grooves 99. In these slots two screws are inserted (one of the which is indicated by reference number 101 in the figure 8) to fix the flange 89 to the structure 91 of the machine. Thank you to the curved grooves 99, loosening the screws 101 can change the angular position of each flange 89 with respect to the axes of the corresponding cylinder 1 or 3. In this way it is possible adjust the angular position of the respective shoe 81.

The structure of the shoe 81 is shown with detail in figures 7 and 8. This presents a main body in the one that has had a lowered seat 103, inside which houses plate 83. The main body of plate 83 of the shoe 81 has a hole with an oblong section 105, which extends parallel to the axis of the folding cylinder 1 and 3. The oblong hole 105 is attached to a side hole 107 connected to a tube of suction 109, connected in turn to a fan or other element suction not shown. The oblong hole 105 extends angularly, corresponding to the rotation angle of cylinder 1 or 3 along which the aspiration is carried out through the holes 45 of block 43.

With this arrangement, when the cylinder of folding 1 or 3 rotates around its axis, an aspiration occurs inside the suction duct 53 throughout the entire rotation of the cylinder in which the conduit of suction 53 with oblong hole 105 made in shoe 81. The possibility of adjusting the angular position of the flange 89 allows the adjustment of the angular positions at which it begins and the suction ends inside the suction duct 53.

It is evident from the description earlier than with the suction system associated with the cylinders  Folders 1, 3 the N-band material is folded (optionally with the help of the fold line that can be produced by wedge 57 cooperating with notch 55) without the need for mechanical fasteners controlled and operated by complex cam systems, as is the case in devices conventional.

In comparison with conventional machines (such as those of the type described in the document WO-A-0162651), the present machine It is therefore much simpler.

It is understood that the drawing shows only one possible embodiment of the invention, which may vary in its forms and dispositions without departing from the scope of the concept on which the invention is based. Any numbers of reference in the appended claims are provided with the sole purpose of facilitating its reading from the description earlier in the present report and the attached drawings and not limit the scope of protection in any way.

Claims (9)

1. Folding machine comprising: a pair of counter-rotating folding cylinders (1, 3), each of which is provided with at least one gripping element (43) to fold a continuous band material (N) into a zigzag; a cutting element (60) arranged in front of said folding cylinders to cut the material into a zigzag folded band and divide it into two piles (M) of folded articles; wherein each gripping element is an aspiration element that retains the web material by aspiration at the level of the respective folding line; and in which each folding cylinder (1, 3) presents a wedge element (57) in phase with the gripping element of the opposite cylinder, to produce a line that facilitates folding in the web material, at the level of said gripping element; characterized because

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every gripping element includes a plurality of rows of holes of aspiration (45); Y

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every wedge element (57) cooperates with a respective notch (55) formed in the opposite cylinder and associated with the element of suction (43) with which said wedge element is in phase, said notch being located at the level of the row of suction holes farther forward with respect to the direction of rotation of the respective folding cylinder.

2. Folding machine according to claim 1, characterized in that said notch is made in an interchangeable insert. 3. Folding machine according to claim 2, characterized in that said interchangeable insert is produced in an elastically flexible material. 4. Folding machine according to one or more of the preceding claims, characterized in that said plurality of rows of suction holes (45) extend parallel to the axes (1A, 3A) of the respective folding cylinder (1, 3). 5. Folding machine according to one or more of claims 1 to 4, characterized in that said suction holes (45) of each folding cylinder are made in a block (43) housed in a seat (41) of the respective folding cylinder ( 1, 3). 6. Folding machine according to one or more of the preceding claims, characterized in that means for synchronizing the aspiration with the angular position of the respective folding cylinder (1, 3) are associated with each of said suction gripping elements (43). . 7. Folding machine according to one or more of the preceding claims, characterized in that with each folding cylinder, oscillating bars (26, 35) are housed in annular grooves (27, 37) of the respective folding cylinder, to produce separation of the folded web material of the folding cylinders. 8. Procedure for producing folded articles (M) from a continuous web material (N) comprising the following steps: feeding the continuous web material at a step (5) defined between two counter-rotating folding cylinders (1, 3 ), each of them being provided with at least one gripping element (43); folding the zigzag web material by means of said folding cylinders, coupling the web material with the gripping elements of one and the other of said folding cylinders alternately; feeding the zigzag folded web material towards a cutting element (60); by means of said cutting element (60), cut the material in a zigzag folded band into two piles of folded articles (M); wherein the web material is retained and folded in said suction folding cylinders; and wherein bending lines are produced mechanically in the web material by means of said two folding cylinders at the level of said gripping elements, which retain the web material by aspiration; characterized in that said fold lines to facilitate folding are produced by the mutual penetration of a wedge element (57) and a notch (55), produced in one and the other of said two folding cylinders, the material being arranged in band (N) between said wedge element (57) and said notch (55); the retention of the web material is driven by a plurality of rows of suction holes (45); and said bending lines are formed at the level of the row of suction holes furthest forward with respect to the direction of the respective folding cylinder. 9. Method according to claim 8, characterized in that said web material is tissue paper.