EP1054759B1 - Device for peeling off cut out cardboard blanks - Google Patents

Description

The present invention relates to machines for rotary cutting of cardboard blanks of the type described in EP-A-0 493 229, which serves as a basis for the preamble of claim 1 and concerns more particularly improvements to the devices ensuring the shelling of the cut blanks.

We know that once the rotary blank cutting of cardboard carried out, that this was carried out between a cutting cylinder and a counter cylinder (SK process, either "Single Knife") or between two cutting cylinders (TK process, or "Twin Knife"), it is necessary to separate the falls, or "peels", from the rest of the blank.

Separation can be achieved by a so-called integrated shelling operation. To do this, one of the cutting cylinders, usually the cylinder counterpart, has sharp elements, such as spikes, which cross the shell, so that at during the rotation, the latter is driven by the pins which ensures its separation from the rest of the blank. Combs between the teeth through which the pins pass then ensure the extraction of the preserved hulls by the pins.

This separation can also be achieved by shelling means distinct from the cutting means which consist of a specific shelling module which is arranged downstream of the cutting means. Usually this shelling module consists of two respective series of discs arranged opposite one above the other, between which the cut blank. One of this series of discs, usually the lower discs, is provided with spikes which, as before, pass through the shell to enter holes provided in the cylinder cutting, so that during rotation the shell is separated from the rest of the cut blank and driven by the pins, as described above.

We understand that to ensure the extraction of the peeled once it is maintained by the pins, combs must have an anterior end extremely fine which must imperatively be placed at the closer to the cylinder carrying the pins. The realization of such a module is therefore extremely delicate since, if the combs are too far from the cylinder or the disc carrying the pins, we will cause a jam, and if these same combs are too close together we will risk them deteriorate or wear them which at the same time will decrease their effectiveness.

We know from US-A-2,888,860 a hull offset device consisting of a stud cylindrical screwed into the cylinder and which is provided with its center of a nipple which, during its rotation is forced into the shell by a brush rotary, tearing off the hull thus embedded in the nipple being provided by another rotary brush. Such means of extracting the shell can be used in rotary cutters low rotation speed, but when you want implement high flow machines it's better to use combs as well as exposed previously. Now, with such means allowing to separate the shell from the surface of the cylinder, it it is not possible to use combs since the significant difference required by the width of the base cylindrical would cause jams.

The object of the present invention is to remedy these disadvantages by proposing a device for shelling with pins, the constitution is such that it is no longer necessary, to avoid jamming, that the front edge of the combs is fine and that it is placed near the cylinder or the disk.

The subject of the present invention is therefore a device according to claim 1.

Under these conditions the teeth of the combs intended to extract the shell from the elements of gripping can come as close as possible to these the latter thus avoiding any risk of jamming.

In one embodiment of the invention, the rotary elements consist of discs and areas sharp gripping elements are formed from of planar elements which are fixed on the base faces of them. These gripping elements can also be fixed against a side face of a shoulder circular discs.

In another embodiment of the invention the gripping elements consist of a threaded cylindrical part which is surmounted by a flat itself surmounted by a point constituting the area sharp and it includes a fixing lock nut, the threaded part intended to be screwed into a hole threaded of the rotary element and to be locked on it in a position such that the base of the point is at a distance from the external surface of the cylinder equal to at minus once the thickness of the blank.

The part of the gripping element included between the base and the base of the sharp area forms a flat whose width, (or dimension in the direction of the axis of rotation of the gripping elements), is equal to that of the sharp area.

The device according to the present invention thus allows the hull to be removed from the rotary element carrying the gripping elements, which facilitates the introduction of the comb between these two elements. In these conditions on the one hand it facilitates the realization of means of separating the shell and on the other hand avoids jams.

We will describe below, by way of example not limiting, an embodiment of this invention, with reference to the attached drawing in which:

Figures 1a and 1b are schematic views of two shelling means implemented according to the prior art.

Figure 1c is a partial plan view of a comb.

Figure 1d is a sectional view of the comb shown in Figure 1c along the line Id-Id of it.

Figure 2 is a schematic front view of a separate shelling device.

Figure 3 is a partial side view at more large scale of the shelling device shown in figure 2.

Figure 4 is a sectional view along the line IV-IV of the device shown in Figure 3.

Figure 5 is a sectional side view partial of a device according to the invention, in progress extraction by combs, of a maintained shell by gripping elements.

Figure 6 is a front view of two cylinders one of which is provided with removable gripping elements and adjustable according to a second form of implementation of the invention.

Figure 7 is a radial sectional view partial on a larger scale of the second mode of implementation work shown in Figure 6.

Figure 7a is a top view of the device shown in Figure 7, the upper comb being shown in dotted lines.

FIG. 7b is a view in radial section of the device shown in Figure 7 along the line VIIb-VIIb thereof.

FIG. 1a shows a device for rotary blank for cardboard blanks which includes essentially two cylinders, namely a cylinder upper 1, called cutting cylinder, i.e. a cylinder which includes the threads ensuring the cutting of the cardboard, and a lower cylinder 3, said cylinder counterpart, which is smooth, between which is entrained a blank of cardboard to cut 5. In order to ensure the dehulling, i.e. the separation of the residues of cutting, or peeling 5a, of the rest of the blank 5b, this device is provided with integrated shelling means. These means consist of gripping elements, such as spikes 7, which protrude from the external surface of the counterpart cylinder 3, and of cavities complementary 9 provided in the cutting cylinder 1, which are intended to accommodate the spikes 7. The device also includes combs 11 (FIGS. 1c and 1d) which have longitudinal slots 13 which are intended for the passage of points 7.

The blank to be cut 5 is driven in the direction of arrow F between the two cylinders 1 and 3 which perform the cutting operation. Immediately this performed, the tips 7 enter the shell 5a and drag it down, while the rest 5b cut blank continues on. Comb 11 is arranged in such a way that it extracts the peel of the tips 7.

As shown in Figure 1b, it is possible to separate the cutting operation from the operation dehulling (separate hulling). To do this we has, downstream of the cutting means 2, means separate shelling 4. These can be made up of two cylinders, lower 3 'and upper 1 'or a series of discs, which are respectively arranged opposite one another. The operation of such a device is identical to that integrated means described above.

The present invention will be described below in the part of a separate shelling device but it could of course also be implemented in any type of hulling and especially in integrated cutting devices.

The separate shelling device shown schematically in Figures 2 to 4 is essentially consisting of a frame 12 which supports a lower shaft 14 and an upper shaft 14 '. These trees support respective lower 16 and upper 16 'discs, which provide training between them of a cut blank 5 from cutting means not shown. The lower discs 16, as shown in the Figures 3 and 4, are hollowed out on each of their faces of a circular groove 21, so as to form a circular shoulder 18. Opposite lateral flanks 20 of this shoulder 18 serve as support for elements of gripping 22 provided with sharp parts 23 intended for enter shell 5a and train it so to separate it from the rest 5b of the blank 5.

The gripping elements 22 consist of a steel plate which is applied to a lateral blank 20 of the circular shoulder 18 by a screw 28 which passes through a light in an arc of a circle 26 of the plate, light centered on the axis of the rotary element 16, to be screwed into threaded holes 30 of the sidewall 20, with the interposition of a tightening washer 32. The lower part of the plate 22 is in the form of an inverted V so that it is supported in two points on the base 25 of the circular groove 21. In this position, as shown in FIGS. 3 and 4, the upper part of the plate, or base 27, protrudes from the external face of the circular shoulder 18 d ' a value d of the order of a few millimeters, for example 3 millimeters. The base 27 is extended outwards by the sharp part 23 which is in the form of a knife, the faces of which are sharpened in order to improve its penetration into the shell 5a. The threaded holes 30 are provided with angular spacings such that, taking into account the angular difference of the window 26, it is possible to angularly position the sharp part 23 at any point on the periphery of the disc 16. In order to improve this ease of positioning at any point on the periphery of the disc 16 the sharp part 23 will preferably be arranged on one side of the base which will allow, by turning face to face of the wafer to obtain two angular positioning zones of the sharp part 23.

As in the devices of the prior art, and as shown in FIG. 5, the device comprises combs 11 which are arranged near the external periphery of the circular shoulder 18 so that the slots 13 with which they are provided allow the passage of the sharp parts 23 of the plates 22 and of their base 27. The width has slots 13 of the combs 11 will preferably be as close as possible to the thickness of the plates or gripping elements 22.

Under these conditions, the cardboard blank 5 once cut engages between discs 16 and 16 'and the sharp parts 23 of the inserts 22 enter the peels 5a and grips it, tearing off the latter from the rest of the cut blank 5b. The shell 5a is then driven downwards, as well as shown in Figures 1a and 5 and it is located pressed not against the outer face of the shoulder 18 of the disc 16 but against the base 27 of the plates 22. In these conditions there is a space between the surface outer of the circular shoulder 18 and the inner face of the shell 5a. As shown in Figure 5 this space allows easy insertion of the comb 11 between these two elements. This removes the face internal comb of the external face of the shoulder circular 18 allowing greater ease of implementation and a lower cost of realization of the peeling device while completely eliminating risks of jamming which sometimes occur in devices according to the prior art.

Of course, the value whose base exceeds the external face of the discs 16 may vary depending on the different types of application. It will generally greater than the thickness of the blank 5.

Similarly, the gripping elements 22 may be made up of any device other than platelets.

We can, as shown in Figures 6 and 7, use cylindrical elements which will likely to be screwed on the outside of discs like discs 16, but more interesting, on cylinder type elements 31.

Thus, in the embodiment shown in Figure 6 we replaced the lower discs 16 and upper 16 'by cylinders 31 and 31' on which has positioned, in determined places, according to the specific shape of blanks to be cut, pads cylindrical 22 'which are screwed into the cylinder 31.

Specifically, as shown in the Figure 7 the upper face of the cylinder 31 is hollowed out threaded holes 34 and each gripping element 22 'is formed of a threaded part 36 which has at its part upper a flat 38 which is itself surmounted by a cylindrical element 37 of the same diameter as the thickness of the flat and which ends at its upper part by a point 40. The threaded part 36 is screwed into the threaded hole 34 so that the base 27 'is located at the desired distance d from the external surface of the cylinder 31 and that the flat 38 is oriented parallel to the axis of the cylinder 31. The threaded part 36 is held in position by a lock nut 39. The upper face 27 ' of the flat 38 thus constitutes a base which is intended to receive the underside of the shell 5a and to thus moving it away from the external surface of the cylinder, thus allowing the teeth 13 of a comb 11 in passing on either side of flat 38 closest to it as shown in Figure 7a to release easily the shell of the sharp element constituted by the tip 40 without risking jamming.

The operation of such a device is identical to that described above and the proximity of the teeth of the comb 11 with the flat 38 makes it possible to take advantage of the space d to favor, using the combs, the extraction of the shell 5a of the gripping element 22 '.

Claims (8)

1. Device for the rotary cut-out of cardboard blanks (5) between two rollers of which at least one is a cut-out roller, of the type comprising peeling-off means constituted by gripping elements (22, 22') disposed on rotary elements (31), between which the web is entrained and which comprise a sharp-edged zone (23, 40) intended to penetrate in the peel (5a) of the cut-out blank (5), the device comprising a comb in order that, during the rotation of the rotary elements between which the web is entrained, the comb ensures the separation of the peel from the gripping elements, the gripping elements (22, 22') comprising a base (27,28) which projects beyond the outer surface of the rotary elements by a value (d) at least equal to the thickness of the blank, the dimension of the base (27, 38) in the direction of the axis of rotation of the rotary elements (31) being equal to that of the sharp-edged zone, characterized in that the section of the base, seen in the direction of the axis of the rotary element on which the gripping elements are disposed, is greater than that of the sharp-edged zone (23, 40), so that, after penetration of the sharp-edged zone (23, 40) in the peel (5a), the latter is applied against the base (27, 38) which receives the lower face of the peel so as to move it away from the outer surface of the rotary element comprising the gripping elements.
2. Device according to Claim 1, characterized in that the rotary elements are constituted by discs (16, 16') and the sharp-edged elements are formed by planar elements (22) which are fixed on the base faces (20) of these discs.
3. Device according to Claim 2, characterized in that the discs (16) comprise on at least one of their base faces a circular groove (18) against a lateral face (20) of which the gripping elements (22) are fixed.
4. Device according to Claim 3, characterized in that the base of the gripping elements (22) is in the form of an upturned V, allowing it to be in abutment at two points on the rotary element (16).
5. Device according to Claim 3, characterized in that the gripping elements (22) are pierced with slots (26) in the form of arcs of circle, centred on the axis of the rotary elements (16), which are traversed by means (28) for fixing on the lateral face (20).
6. Device according to Claim 5, characterized in that the fixing means are constituted by screws (28) which are placed in threaded holes (30) in the lateral face (20), the angular spacing of the holes (30) and that of the slots (26) being such that it is possible to position the sharp-edged part (23) angularly at any point of the periphery of the disc (16).
7. Device according to Claim 6, characterized in that the sharp-edged zone (23) of the gripping element (22) is disposed on one side of the base, so as to obtain, a turnaround of the gripping element (22) through 180°, a second zone of angular positioning of the sharp-edged zone (23).
8. Device according to Claim 1, characterized in that the gripping elements (22') are constituted by a threaded cylindrical part (36) which is surmounted by a flat portion (38) itself surmounted by a point (40), the threaded part (36) being intended to be screwed in a threaded hole (34) in the rotary element (31) and to be blocked thereon in a position such that the base (27') of the point (40) is at a distance (d) from the outer surface of the roller (31) equal to at least once the thickness of the blank (5), and that the axis (uu') of the flat portion is oriented perpendicularly to the axis of the rotary element (31).

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