EP0087364B1 - Feeder with suction box - Google Patents

Description

The present invention relates to a movable box feeder feeder, more specifically intended to equip the sheet feed magazine with a processing machine, in particular for shaping, of corrugated cardboard boxes.

The mobile suction box feeders, known as “suction feeders”, are very widely used in the industry of corrugated cardboard boxes, and are described in numerous patents, such as for example French patents 1 343 103 and 1 568,091.

All these devices use one or more suction boxes, movable in the longitudinal direction, and the upper part of which is closed by a horizontal plate provided with holes, which transmits the vacuum to the sheet and thus allows, during at least part of the cycle of extraction, to grip the cardboard.

It was found that these known devices were not always satisfactory, in particular in the case of the processing of sheets of hard cardboard. Indeed, it is observed that the plating of the curved sheets on the suction box (es) is often done only partially, so that certain sheets, insufficiently flattened, do not pass under the margin knife, which results in jamming requiring manual intervention by an operator.

To overcome this kind of drawback, it has already been thought of using a device as described in patent FR-A-1 457 486. Such a device, which is of the type 'as described in the preamble of claim 1, uses an auxiliary telescopic suction cup which rises during the advancing phase of the sheet, coming to grip it, and descends during its return phase, which is essential to prevent the elastic edge of the suction cup from turning over when passing under the margin stop, and therefore does not become ineffective at the next aspiration. Such a device has a fairly high cost of production and maintenance, so that a simpler and less expensive solution seems desirable.

• au moins un caisson aspirant animé d'un mouvement longitudinal de va-et-vient et équipé d'une plaque d'aspiration,
• un cadre, ou analogue, en matériau souple, entourant ladite plaque d'aspiration de manière à former avec elle une ventouse creuse, dont les bords souples se situent au-dessus du niveau supérieur de ladite plaque en l'absence de la feuille aspirée, un tel dispositif de marge étant caractérisé par le fait que la ventouse creuse, formée par la plaque d'aspiration et le cadre en matériau souple, est fixe en position verticale par rapport au corps du caisson et que la ventouse creuse précitée est dimensionnée et agencée de façon que, d'une part, les bords souples de ladite ventouse se situent en alignement ou au-dessous du niveau supérieur de la plaque d'aspiration lorsqu'une feuille est aspirée et que, d'autre part, le bord avant souple de ladite ventouse ne vienne pas, dans position la plus reculée du caisson aspirant, en arrière de la butée avant.

The present invention relates to a suction feeder of high efficiency and simple, reliable and inexpensive production. It therefore relates to a margin device intended for feeding sheets to a processing machine where each sheet is taken from below the stack, itself limited by a front stop, said device comprising:

• at least one suction box animated by a longitudinal back and forth movement and equipped with a suction plate,
• a frame, or the like, of flexible material, surrounding said suction plate so as to form with it a hollow suction cup, the flexible edges of which are situated above the upper level of said plate in the absence of the suctioned sheet, such a margin device being characterized in that the hollow suction cup, formed by the suction plate and the frame of flexible material, is fixed in vertical position relative to the body of the box and that the aforementioned hollow suction cup is dimensioned and arranged so that, on the one hand, the flexible edges of said suction cup are in alignment with or below the upper level of the suction plate when a sheet is sucked up and, on the other hand, the flexible front edge of said suction cup does not come, in the most remote position of the suction box, behind the front stop.

• la figure 1 est une vue schématique en coupe longitudinale du margeur de i'inve"ftion
• la figure 2 est une vue en coupe schématique à échelle réduite, selon la direction AA de la figure 1
• la figure 3 est une vue de dessus du cadre souple utilisé pour le margeur de la figure 1, avant installation sur celui-ci
• la figure 4 est une vue perspective du même cadre après sa mise en place sur le margeur de l'invention.

The invention will be better understood with the aid of the following description of a preferred, but nonlimiting example of an embodiment, with reference to the appended drawings in which:

• FIG. 1 is a schematic view in longitudinal section of the feeder of the invention
• Figure 2 is a schematic sectional view on a reduced scale, in the direction AA of Figure 1
• Figure 3 is a top view of the flexible frame used for the feeder of Figure 1, before installation on it
• Figure 4 is a perspective view of the same frame after its implementation on the feeder of the invention.

Referring first to all of Figures 1 and 2, the feeder shown is a feeder very similar to that described in the French patent 1343103 (or US 3,226,108) cited above. It includes in particular a magazine 1, containing the stack 2 of sheets of corrugated cardboard to be extracted one by one from the underside of said stack, and delimited at the rear by a stop 3 adjustable according to the format of the sheets, and at the l 'before by the margin knife 4 defining with the margin table 5 a sufficient space to let pass a sheet of cardboard and only one.

A suction box 6, driven in a longitudinal back-and-forth movement by very conventional means not shown, has the task of removing the bottom sheet from the stack 2 and advancing it under the knife 4 until that the drive rollers 7 located downstream have taken over. For this purpose, the box 6 is connected to a vacuum source, not shown, by means of a pipe 8 and a distribution solenoid valve 9. In an extremely conventional manner, the solenoid valve 9 is controlled so as to that the vacuum is applied to the box 6 during its removal and advancement phase from the bottom sheet of the stack, and is released during the backward phase of said box. Also conventionally, the vacuum is applied to the bottom sheet through a horizontal plate 10 provided with holes 11 and the surface of which advantageously has the shape of sawtooth undulations clearly visible in FIG. 1.

Now according to the invention, in the plate 12 forming the upper periphery of the body of the box 6 is cut an opening 13, of rectangular shape for example, so as to form a bottomless bowl whose edges form, with the upper face 14 of the periphery 12, an acute angle a, advantageously of the order of 45 degrees, as it appears clearly in FIGS. 1 and 2.

The edges of the suction plate 10 are cut so as to have a shape complementary to that of the edges 13 of the perimeter plate 12.

The plate 10 is intended to be screwed onto the body of the box 6 using the screws 16, fitting tightly into the bottomless bowl 13. Between the two is placed a flat and thin continuous seal 17 made of flexible material, frankly overhanging the edges of the bowl 13 and in extension therewith, as can be seen in the drawings, so as to form, with the suction plate 10, a suction cup with edges 26 raised upwards and forming an angle acute has with the horizontal.

In the embodiment described, the seal 17 is formed from a flat frame 18, shown in Figure 3, provided with a central opening at the four corners of which slots are cut at 45 degrees 20. Many materials flexible, going from the metallic sheet to the elastomer, can be used for the constitution of the gasket 17. The Applicant has found that excellent results are obtained by using the sheet with belts, conventionally constituted of a woven nylon fabric on which a sheet of plastic material is glued, and mounting the seal 17 so that the fabric is located upwards, that is to say looks towards the stack 2, or towards the interior of the suction cup (10-17) of the invention.

As can be seen in FIGS. 1, 2 and above all 4, the fact of screwing the plate 10 on the periphery 12, with the seal 17 between them, causes the center of the frame 18 to sink into the opening 13 and raising its edges at the angle a, so as to form, with the plate 10, a bowl with flexible edges.

Furthermore, the thickness of the suction plate 10 and that of the flexible frame 17 are determined relative to the periphery 12 so that the upper face 21 of the plate 10 is located above the upper face 14 of the periphery 12, with a difference in height at least equal to the thickness of the frame 17. In this way, the flexible frame 17 will never have to support the weight of the stack 2.

The operation of the device of the invention is as follows: when the vacuum is applied to a curved sheet 22, the leak is limited by the edges of the flexible frame 17, and the assembly (10-17) behaves like a hollow suction cup positively sucking the sheet 22 and straightening it at 23 while the frame 17 is folded over the periphery 12 as seen in FIG. 1. The straightened sheet 23 can therefore be driven forward by the advance of the box 6, then be taken over by the driving rollers 7.

• - le bord arrière du cadre souple 17 ne vienne jamais, en position la plus avancée du caisson 6, plus loin que le bord avant de la pile de feuilles 2, pour éviter tout risque de retournement de l'arrière du cadre 17 dans la phase de recul du caisson, ce qui rendrait le dispositif inefficace pour la suite des opérations ;
• - le bord avant du cadre souple 17 ne vienne jamais, en position la plus reculée du caisson, en deçà du couteau de marge 4 pour éviter, dans le cas où l'on arrête l'introduction des feuilles, tout risque de retournement de l'avant du cadre 17 dans la phase d'avancée du caisson, ce qui endommagerait le cadre 17 à la longue.

It goes without saying that to ensure proper operation of the device, the assembly is dimensioned and arranged so that:

• - The rear edge of the flexible frame 17 never comes, in the most advanced position of the box 6, further than the front edge of the stack of sheets 2, to avoid any risk of the rear of the frame 17 overturning during the phase recoil of the box, which would make the device ineffective for further operations;
• - The front edge of the flexible frame 17 never comes, in the most remote position of the box, below the margin knife 4 to avoid, in the event that the introduction of the sheets is stopped, any risk of overturning the 'front of the frame 17 in the advance phase of the box, which would damage the frame 17 in the long run.

Claims (4)

1. Pile feeder device for feeding sheets of material of a processing machine wherein each sheet is removed from the bottom of the pile (2), the said pile itself being limited by a front abutment (4), the said device comprising :

a. At least one suction chamber (6) actuated by a reciprocal longitudinal movement and provided with an suction plate (10).

b. A frame (17), or the like, made of flexible material, which surrounds the said suction plate (10) so as to form a hollow vent therewith, of which the flexible edges (26) are arranged above the upper level (21) of the said plate when no sheet of material is sucked in, characterised in that the hollow vent, which is formed by the suction plate (10) and frame (17) made of flexible material, is secured in a vertical position relative to the body of the chamber and that the above- mentioned hollow vent is dimensioned and arranged in such a way that, on the one hand, the flexible edges of the said vent are in alignment or are above the upper level (21) of the suction plate (10) when a sheet (22, 23) is sucked in and that, on the other hand, the flexible front edge of the said vent does not move behind the front abutment (4) when the suction chamber (6) is in the fully retracted position.

2. Pile feeder device according to claim 1, characterised in that the hollow vent is dimensioned and arranged in such a way that when the suction chamber (6) is in the forwardmost position, the flexible rear edge of the said vent remains downstream of the pile (2).

3. Pile feeder device according to claim 1, characterised in that the said thin frame comprises a coating made of plastics material or the like, which is stuck onto cloth, for example woven nylon.

4. Pile feeder device according to claim 3, characterised in that the said thin frame is mounted so that the side made of cloth is orientated upwards.

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