Blank diecutting machine

Abstract

A machine for diecutting blanks and having a feeding station for sheets, a sheet feeder through the machine for the fed sheets, a sheet diecutting station, a stripping station for free waste cut from the sheets, a blanking and delivery station of the blanks, an evacuation station for waste attached to the blanks and a binder sheet inserting device for inserting binder sheets from a storage pile of binder sheets between the blanks during piling up of the blanks. A feeding compartment receives the storage pile of binder sheets. That compartment occupies a volume situated between the evacuation station of waste attached to the blanks and a machine base. A lifting mechanism lifts the storage pile of binder sheets during insertion of the binder sheets between the piled up blanks.

Description

BACKGROUND OF THE INVENTION

The present invention refers to a machine for diecutting blanks in sheets of paper, cardboard or similar material, comprising a sheet feeding station, a feeder, a diecutting station, a waste stripping station, a blanking and delivery station, an evacuation station for waste attached to the blanks and a device for inserting binder sheets between the blanks, as their piling up proceeds, from a storage pile of binder sheets.

This kind of machine is well known in the field of manufacturing cardboard boxes for packaging obtained by folding the blanks along the folding and gluing lines by means of glue flaps formed on the blanks.

Such a machine is described in WO 90/06838.

In order to assure the stability of the blank piles, in spite of a weak seating surface of each pile, binder sheets covering the entire blank piles are inserted each time a determined number of blanks has been piled up. The whole forms a complete pile consisting of a plurality of layers of blank and binder sheet piles.

In view of the number of binder sheets used and their weak thickness, the sheets are stored in a drawer. Since these binder sheets are seized by suction cups which have a vertical stroke that is necessarily limited, the depth of the drawer is restricted to a few centimeters. But this is not a problem regarding the range of the reserve of binder sheets as long as their thickness is weak.

A double evolution, however, can be noted. On the one hand, the machines are increasingly rapid, so that the consumption of binder sheets increases in proportion thus reducing the size of the binder sheet reserve, and on the other hand, in some applications, it would be better to insert substantially thicker binder sheets, which reduces the range of the reserve of binder sheets which a conventional drawer can contain, so that the capacity of this drawer would be deficient for a normal use of the machine. In fact, the machine operator has many tasks to perform. But with a binder sheet drawer that is about 8 cm deep and binder sheets each of several tenths of mm thick and a machine that produces more than 8000 sheets per hour, most of the time an operator would have to fill up the binder sheet storage drawer, and, obviously, that is not practical.

For machine users, it is also important not to substantially modify the machine space requirement, actually not only of the machine but also of the room necessary for loading or unloading the machine. In fact, in a factory it is important to be able to replace a diecutting machine with a new one, which nearly occupies the same surface including the loading and the unloading.

SUMMARY OF THE INVENTION

The object of the present invention is to considerably increase the range or capacity of the binder sheet feeding device while approximately keeping the same space requirement as for previous machines for performing the same blanking and diecutting operations.

To this end, the present invention relates to a machine for diecutting blanks in sheets of paper, cardboard or similar material. The machine has a feeding station for sheets, a sheet feeder for feeding sheets through the machine sheets, a sheet diecutting station, a stripping station for free waste cut from the sheets, a blanking and delivery station of the blanks, an evacuation station for waste attached to the blanks and a binder sheet inserting device for inserting binder sheets from a storage pile of binder sheets between the blanks as piling up of fed blanks proceeds. A feeding compartment, which receives the storage pile of binder sheets occupies a volume situated between the evacuation station of waste attached to the blanks and a machine base. A lifting mechanism lifts the storage pile of binder sheets as insertion of the binder sheets between the piled up blanks proceeds.

Without changing the design nor substantially changing the space requirement of the machine, the invention allows a spectacular increase of the range of the binder sheet reserve, which can possibly almost last the entire work day.

This considerable increase of the storage volume of binder sheets without increase of the space requirement of the machine is due to the use of a volume situated beneath the evacuation station for waste attached to the blanks. This volume was relatively badly used by various other components of the machine mechanism such as compressed air pumps, lubrication aggregate, electric board. These can be placed in other parts of the machine without taking up supplementary space.

Owing to the volume thus gained, it is possible to arrange a real compartment for housing the binder sheet pile as well as a lifting mechanism. This allows permanently positioning the upper surface of the pile within reach of the suctions cups for inserting the binder sheets into the blank piles. As a result, the same binder sheet inserting mechanism can be used as the one used with the conventional drawer.

Due to this feature, not only is the mechanism for inserting binder sheets the same, but also two versions of the same machine are possible, one with a conventional drawer, for users not requiring a binder sheet storage of higher capacity, the other with a compartment occupying the volume between the evacuation station for waste attached to the blanks and the machine base, for users wanting to increase the range of the binder sheet loading station.

Advantageously, the loading can be realized through an opening arranged in the transverse sidewall of the machine housing situated at the output end of the machine, by means of pallets and pallet stackers, as is also realized the feeding of sheets to be diecut and the unloading of blanks.

Preferably, this opening is closed with a safety door. Opening of the door causes the machine to stop. This door advantageously has a window for checking the height of the binder sheets by the operator.

Preferably, the ascending movement of the binder sheet pile is controlled by a servo system that detects the upper level of the pile, as is also controlled the sheet feeding pile.

Further features and advantages of this invention will become evident from the reading of the following description and from the enclosed drawings illustrating, schematically and by way of example, an embodiment of the machine for diecutting blanks of the present invention.

BRIEF DESCRIPTION OF THE DRAWING(S)

FIG. 1 is a side elevational view very schematically showing this embodiment;

FIG. 2 is a perspective view of the storage compartment of the binder sheet pile without the housing surrounding the machine;

FIG. 3 is a partial plan view of the lifting mechanism arranged in the storage compartment of the binder sheet pile of FIG. 2;

FIG. 4 is a perspective view similar to the view of FIG. 2, showing the housing surrounding the storage compartment.

DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 very schematically shows various working stations of a machine for diecutting blanks of the present invention. The feeding station of sheets 1 to be diecut, of cardboard, paper or other material having similar characteristics, comprises a pile of sheets 1 put on a pallet. A known lifting mechanism, not shown since it is not necessary for the understanding of the present invention, lifts the pile 1 as the consumption of sheets proceeds, so as to hold the top of this pile 1 within reach of a feeding device (not shown) of these sheets.

This feeding device successively brings the sheets on a feed table 3 where they are aligned for the subsequent diecutting operation.

A conveying device 4 for these sheets comprises, in known manner, two chains forming two endless loops, respectively arranged on both sides of the machine. Gripper bars extending between the chains are adapted to seize the leading edges of the sheets to be diecut, for conveying them in successive steps with intermediate stops in order to carry out the operations, from one station to the other of the machine.

The feed table 3 is followed by a diecutting station 5 of the blanks and a stripping station 6 of waste which is not attached to the blanks. In order to maintain the various blanks attached to one another, some sheet portions, particularly the leading edge seized by the grippers of the gripper bar, or even a cardboard rack formed between the blanks, are attached to the blanks by bridges. Thus, at the output of the waste stripping station 6, only the blanks and the sheet portions attached to the blanks remain.

Next comes the delivery station of blanks 7 which comprises a blanking station (not shown) and where the blanks 7 are piled up on as many piles as there are diecut blanks in a sheet 1. Obviously, the smaller are the blanks 7, the weaker is the stability of the piles. For that reason binder sheets 8 are necessarily arranged. They often consist of waste papers covering all the piles of blanks 7 and which are inserted at regular intervals.

The binder sheets 8 are inserted by a known binder sheet inserting device 9. However, contrary to known binder sheet inserting devices, the binder sheets 8 are not stored in a drawer that is a few centimeters deep and which cannot contain a lot of binder sheets, especially when they are thick. In the machine according to the invention, the room situated beneath the binder inserting device 9 is completely occupied by a feeding compartment 10 of binder sheets 8, of high capacity. The binder sheet inserting device 9 is itself situated beneath a waste evacuation station, comprising a waste evacuating apron 11 (FIGS. 1 and 4) for evacuating waste attached to the blanks 7 and which waste has been released when separating the blanks 7 in the blanking station. With this arrangement of the feeding compartment 10 beneath the waste evacuating apron 11 a large space can be occupied without substantially modifying the total space requirement of the machine, since the waste evacuating apron 11 exists anyway.

A conventional binder sheet inserting device 9 uses suction cups for seizing the binder sheets 8 and placing them on a system in order to insert them between the blanks 7 of the various piles. Since the inserting device can seize the binder sheets only if they are at levels varying not more than a few centimeters, the feeding compartment 10 must thus comprise a lifting mechanism 12, like that for the feeding of the sheets to be diecut 1.

The known lifting mechanism 12 comprises a support platform 13, illustrated in FIG. 2 in full lines in lowered position and in dot-and-dash lines in lifted position. The platform 13 carries a pile of binder sheets 8. This platform has four arms 14 arranged at four angles and which laterally project the two lateral sides of this platform 13. Each arm hangs on to the end of a chain 15a, 15b, 15c, 15d. These chains are further engaged in toothed pinions fixedly attached to a shaft 16, which is connected to a drive motor 17 by an endless chain 18. This motor is controlled by the control device of the diecutting machine.

This lifting device 12 further comprises stop means for the positioning of the pile of binder sheets 8 in accordance with their dimensions. To this aim, it comprises a fixed front stop formed by two vertical plates 19 and two movable lateral stops formed by two vertical rules 20a, 20b adjacent to the fixed front stop 19. These movable stops 20a, 20b are engaged with a movement mechanism located on the other side of the fixed front stop 19 and which allows to bring the stops 20a and 20b nearer to or to move them away from one another, so that the space separating them is always centered on the longitudinal median axis of the diecutting machine, in order to maintain the pile of binder sheets 8 centered, whatever the transverse dimension of these binder sheets 8 may be.

This movement mechanism is shown partially in FIG. 2 and completely in FIG. 3. It comprises a control handwheel 21 fixedly attached to a control rod 22. At its other end, this control rod 22 carries a conical pinion 23 engaged with a conical pinion 24 of the actuating means. This means comprises, in this example, a first drive means of the lateral centering stops 20a, 20b formed by a rod 25 which has, in its middle, a pinion engaged with an endless transmission chain 26 (FIG. 2) and adapted to transmit the movement of the control rod 22 to a second drive means of the lateral centering stops 20a, 20b formed by a rod 27, parallel to the first rod 25 and which also has in its middle a pinion for engaging with the endless transmission chain 26.

Each rod 25, 27 of the actuating means comprises two threaded sections 25a, 25b, 27a, 27b (FIG. 3) with respective threads in the reversed direction from one another. The stops 20a, 20b are each engaged with two nuts 28a, 29a, respectively 28b, 29b engaged respectively with the threaded sections 25a, 27a, 25b, 27b. Two horizontal slits 19a (FIG. 2) are machined through the plates of the fixed front stops 19, parallel to the upper actuating rod 25. Two horizontal slits 19b are machined through the same fixed front stops, parallel to the lower actuating rod 27. These slits 19a, 19b enable the linking between the stops 20a, 20b and the nuts 28a, 29a, respectively 28b, 29b, these stops 20a, 20b, on the one hand and these nuts, on the other hand, are respectively situated on both sides of the fixed front stop 19.

This arrangement moves the two movable stops 20a, 20b in the reversed, opposite direction from one another when the control rod 22 is driven in one direction or the other by the control handwheel 21. These stops 20a, 20b move while remaining parallel to one another, coming nearer to or moving away from one another equal amounts but reversed with respect to the longitudinal median axis of the diecutting machine.

This device also comprises a rear stop 30 formed by a horizontal arm in its rest position, pivotally mounted on a swivelling shaft 31 and sliding on this shaft 31 and on a second shaft 32 (FIG. 2). This rear stop 30 slides manually, and clamping means (not shown) are provided in order to immobilize it in a desired position. This rear stop 30 is further slidably mounted with respect to a detection rod 33 attached to the swivelling shaft 31 by two flanges 34a, 34b. This detection rod is also kinematically attached to the swivelling shaft 31 by the rear stop 30. A detector 35 detects any rotation of the detection rod 33 about the swivelling shaft 31 and thus any lifting of the rear stop 30 from its horizontal rest position, reading while lifting that the pile of binder sheets 8 is not accurately positioned against the fixed front stop 19.

The lifting mechanism 12 of the feeding compartment 10 further comprises a detector 36 for the upper level of the pile of binder sheets 8, which receives a luminous beam 37 issued from a light source 38. When the detector 36 stops receiving the luminous beam because the beam is cut off by the top of the pile of binder sheets 8, the detector emits a signal which allows the drive motor 17 of the lifting mechanism 12 to stop.

As illustrated by FIG. 1, a known retractable support 39 is provided to receive the blanks 7 during the inserting of a binder sheet 8. This retractable support 39 is withdrawn and the blanks accumulated thereon are put on the respective piles during retracting of this support 39.

As shown in FIG. 4, the housing surrounding the machine comprises a door 40 located on the back elevation, or downstream from this housing in the traveling direction of the sheets 1 to be diecut. The door 40 gives access to the feeding compartment 10 and is adapted to allow replacement of an empty pallet with a new pallet carrying a pile of binder sheets 8 on a support platform 13 of the lifting mechanism 12. The door 40 has a window 40a for the machine operator to check where the level of the pile of binder sheets 8 is situated without opening the door 40. Advantageously, this is a safety door which actuates a switch (not shown) for stopping the machine as soon as the door is opened.

Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.

Claims

1. Machine for diecutting blanks in sheets of paper, cardboard or other sheet material, the machine comprising:

a feeding station for the sheets, a sheet feeder for feeding sheets at the station through the machine; a diecutting station operable as the sheet is fed to cut the sheet and create waste, a stripping station for the free waste that has been cut, a blanking and delivery station of the blanks at which the blanks are piled, an evacuation station for waste attached to the blanks, a machine base under the stations of the machine;

a binder sheet inserting device for inserting binder sheets from a storage pile of the binder sheets between successive blanks as the blanks pile up at the delivery station, the inserting device comprising a feeding compartment for receiving the storage pile of binder sheets, the feeding compartment occupying a volume between the evacuation station of waste attached to the blanks and the machine base, and

a lifting mechanism placed and operable for lifting the storage pile of binder sheets during the inserting of the binder sheets between the piled up blanks.

2. Machine according to claim 1, further comprising a housing surrounding the machine, the housing having a transverse wall at a side of the housing downstream in the sheet feeding, a door on the transverse downstream sidewall of the housing and operable to enable access in the housing for positioning of the storage pile of binder sheets in the storage piles in the housing.

3. Machine according to claim 2, wherein the door includes a viewing window.

4. Machine according to claim 2, wherein the door is a safety door operable to cause the machine to stop when opening the door.

5. Machine according to claim 1, wherein the feeding compartment comprises a fixed front stop downstream in the sheet feeding, two movable lateral centering stops at lateral sides of the storage pile, an actuating device comprising two drives for the lateral centering stops, and the drives comprising means for engaging the lateral centering stops and for simultaneously moving the two lateral stops over identical lengths and in the opposite directions from one another.

6. Machine according to claim 5, further comprising a horizontal swivelling shaft, the feeding compartment further comprises a rear stop having a rest position, the rear stop is articulated around a horizontal swivelling shaft; and a detector for detecting swivelling of the rear stop about the swivelling shaft from its rest position.