Intermediate Adjusting Module For A Scaling Machine

Abstract

A device for scaling cut-out cardboard blanks (2, 2′) includes the high-speed (1.4V) ejection element (I) of a cutting machine and low-speed (V′) receiving element. The device is characterized in that it is provided with an intermediate adjusting module (II) whose at least blank-driving speed is adjustable and which is arranged between the ejection element (I) and the receiving element (III).

Description

The present invention concerns a device intended to allow the high speed overlapping of printed, cut out cardboard blanks.

It is known that machines for printing and cutting out cardboard blanks are required to operate at increasingly higher speeds, and designers of these machines are faced with multiple technical problems regarding both the printing and the overlapped transfer of these cardboard blanks.

With respect to overlapping, it is known that the printed blanks are assembled, after cutting, so as to form a fish scale i.e. they are caused partly to overlap one another. To do so, the blanks derived from a cutting module of a printing machine with determined nominal speed are transferred towards an ejector module which accelerates the blanks so that they separate. The blanks are then delivered to a receiver module travelling at a lower speed, so that they come to overlap partly the blanks previously deposited on the conveyor of a receiver module.

On machines whose nominal speed is in the region of 200 m/min, the transfer of cardboard blanks from the ejector module to the receiver module takes place without any particular difficulty. However, if much higher speeds are required, in the order of 350 m/min for example, more or less random phenomena occur which disturb the proper stacking arrangement of the blanks. It is therefore not possible to arrange each blank on a preceding blank with sufficient accuracy and repeatability to avoid certain problems.

It is known that an incident blank which comes to superimpose itself over a preceding blank, or receiving blank, is presented so that it has a certain angle of incidence thereto, causing the forward edge of the incident blank to slide over the surface of the receiver blank, already in flat position, over a certain distance which represents the stagger distance of the blanks, or overlap. However, it is known that some cut out cardboard blanks, particularly for packaging, are of complex shapes having some portions which are intended to project outwardly e.g. securing flaps, which means that at a certain moment during the sliding movement, the forward edge of the incident blank catches in one these projecting portions of the receiving blank, thereby causing a disorder which most often requires the immediate stopping of the conveyor line.

It is therefore essential, if it is desired to avoid the above-mentioned potential risk, to be able to position the incident flap precisely and repetitively on the receiving blank before any such risk of catching.

Also if the blanks carry fragile coatings such as some paint or gold finishes, the arrival of an incident blank at a relatively high speed and at a certain incidence on a receiving blank may produce a mark on the latter. Additionally, it is known that the incident blanks are received between two components having the same peripheral speed i.e. a lower conveyor belt and an upper “overlapping wheel”. It has been ascertained however that when the speed of the incident blank is much higher than the peripheral speed of the overlapping wheel, this leaves a mark on the blank. It will be appreciated that these different marks are detrimental to the quality of the blanks, and they may simply have to be discarded. It is therefore of prime importance to use means which are capable of maintaining the integrity of the cardboard blanks.

Also, it is known that the transfer between the ejector module and the receiver module is made at a certain angle of incidence between their directions, which is fixed in prior art machines. It has been ascertained however, under the present invention, that in order to apply a maximum nominal speed to the machine this angle needs to be adjusted in relation to a certain number of constituent parameters of the cardboard blank such as its length, its rigidity and its thickness in particular.

The purpose of the present invention is therefore to propose a device with which it is possible to overcome these drawbacks and to meet these new necessities, in particular to achieve precise, repetitive positioning of the incident blanks on the receiving blanks in machines with high nominal speed whilst avoiding deterioration of the incident blanks during their transfer.

The subject-matter of the present invention is therefore a device to achieve overlapping of cut-out cardboard blanks comprising high-speed ejector means of a cutting and/or printing machine and low-speed receiver means, characterized in that, arranged between the ejector means and the receiver means, it comprises an intermediate adjustment module of which at least the driving speed of the blanks cab be adjusted.

According to one advantageous embodiment, the intermediate adjustment module preferably comprises applicator means able to fold down the rear cart of a cardboard blank after it exits the ejector module and to lower it down to a level lower than the level of arrival of the following blank. In this manner, this following blank is sure to find the way clear when it arrives at the intermediate adjustment module. These applicator means may for example comprise an air stream blowing air onto to the rear part of the blanks, or they may use mechanical means, in particular a rotating element provided with a cam-forming portion which comes to bear on each rear part of the blank accompanying the latter positive fashion over at least part of its travel distance.

Preferably, the pathway of the cardboard blanks delivered at the exit of the ejector module forms an angle of incidence with the pathway of these blanks in the intermediate adjustment module. The intermediate adjustment module advantageously comprises means to adjust this angle of incidence.

The mean rate of travel of the blanks in the intermediate adjustment module is for example approximately the average of the speed of the incident blanks leaving the ejector module and the speed of the receiver module. If the nominal travel speed V of the machine at the exit of the ejector module is 1.4V for example, and the travel speed V″ in the receiver module is 0.1V, the travel speed V′ in the intermediate module is in the order of 0.6V. In relation to the desired extent of overlap, the user therefore has the possibility to adjust the value of the speed either side of this average speed.

The present invention is of interest in that the intermediate adjustment module can easily be adapted to existing machines for their improvement, insofar as all that is required is to add the intermediate adjustment module between an ejector module and a receiver module.

Various forms of embodiment of the invention are described below by way of non-limiting examples with reference to the appended drawing in which:

FIG. 1 is a plan view of two cardboard blanks inside the intermediate adjustment module, an incident blank coming to overlap a receiving blank.

FIG. 2 is a schematic view of an ejector module, an intermediate adjustment module, and a receiver module ensuring receipt and overlapping,

FIG. 3 is a schematic view showing the relative position of the cardboard blanks leaving the ejector module, in the intermediate adjustment module and in the receiver module.

FIG. 1 shows can exemplary cardboard blank 2 that is printed and cut out, of length f and intended to form a box, which has a certain peripheral profile P. This blank has scores 4 intended to form fold lines which are subsequently used to put the box together. The cardboard blank 2 also has cut-outs 3 defining tabs 5 which, after folding, are intended to ensure the holding together and coherency of the box.

The overlapping operation consists of casing the blanks to become partly superimposed with a certain overlap R corresponding to the length of the receiving blank 2′ covered by an incident blank 2. In the remainder hereof, it is preferred to refer to the notion of non-overlap NR which, conversely, represents the length of the blank 2′ that is not covered by the incident blank 2. It is to be noted that non-overlap corresponds to a rate of non-overlap δ which corresponds to the percentage length of the blank that is not covered and which is δ=NR/f.

It will be appreciated that during the overlap operation the incident blank 2 slides over the upper surface of the receiving blank 2′, and that if its forward face during this movement should encounter a projecting part of the receiving blank, this will cause an interruption giving rise to a disorder which may require halting of the entire transfer line.

FIG. 2 schematically illustrates a printing and/or cutting out machine which comprises an ejector module I at its exit, an intermediate adjustment module II and a receiver or overlap module III.

The function of the ejector module I is to separate cardboard blanks 2 which have been printed and cut out at the nominal speed V of the machine by printing and cutting modules thereof which are not illustrated in the drawing. To do so, the ejector module I accelerates the blanks 2 by around 40% for example i.e. to bring them up to a speed of 1.4V. As shown FIGS. 2 and 3, the blanks 2 arriving at the exit of the ejector module I are therefore spaced from each other by a distance d. In the prior art these blanks were immediately transferred to the overlap module III.

According to the invention, the blanks 2 are transferred from the ejector module I to the intermediate adjustment module II. For this purpose, the travel plan (or pathway) T1 of the incident blanks 2 leaving the ejector module I, together with the travel plan T2 of the blanks in the intermediate adjustment module T1, forms an angle i of approximately 15°. This allows the forward face of an incident blank 2 to slide over a preceding, or receiver, blank 2′, which already lies in a flat position on the travel plan T2 in the intermediate adjustment module II. The receiving of an incident blank 2 takes place between an upper overlap wheel 6 and a lower conveyor belt 7 which have the same peripheral speed V′ and which block the incident blank 2 by communicating their speed to it.

It will evidently be understood that in relation to the difference existing between the speed of the incident blank 2 (which in the chosen example is 1.4V) and the speed V′ of the receiving blank 2′, the blanks 2, 2′ have a greater or lesser non-overlap NR. For example, if the speed of the receiving blank 2′ is equal to the nominal speed of the machine, i.e. V, the incident blank 2 will come to position itself so that it just touches the receiving blank 2′, (in which case non-overlap will be NR=f, and the rate of non-overlap will be δ=1), and therefore to achieve overlap the speed V′ of the receiving blank 2′ must be slower than said nominal speed V. It will be appreciated that under these conditions, the non-overlap value NR of the receiving blank 2′ by the incident blank 2 can be adjusted by adjusting the speed V′ of blank 2′ in the intermediate adjustment module II.

Also, it is specified that the rate of non-overlap δ is equal to the difference in relative travel speed between the intermediate adjustment module II and the nominal speed V of the machine: δ=V′/V.

According to the invention, the intermediate module II is provided with means which can be used to adjust the speed of travel V′ of the receiving blanks 2′ which allows the rate of non-overlap δ to be adjusted to the desired value.

Therefore, according to the invention, the intermediate adjustment module II ensures several functions. First it allows the speed difference existing between the incident blank 2 and the receiving blank 2′ to be reduced, thereby allowing rigorous positioning of the incident blank on the receiving blank, whilst reducing the influence of random phenomena occurring during the overlap operation, and also avoiding inadvertent marks on the incident blanks.

It subsequently ensures an adjustment function of the rate of non-overlap δ, and therefore allows the incident blank 2 to be brought onto the receiving blank 2′ and to stop overlapping before there is a risk that one of the forward edges of the incident blank 2 comes into contact with a tab of the receiving blank 2′.

The passing of the blanks 2′ from the intermediate adjustment module II to the receiver module III is made in the same manner with a small difference between the respective speeds of these modules (V′=0.6 m/min and V″=0.1 m/min in the example given) which provides a guarantee that positioning will be precise and the new, final rate of non-overlap δ′ will be rigorous.

Preferably, according to the invention, and as illustrated FIG. 2, or the entry side of the intermediate adjustment module II recourse is made to means which can be used to rapidly fold down the rear part of the cardboard blank 2 as soon as it leaves the ejector module I, so that the newly arriving incident blank (this arrival occurring at level N) is unable to enter into collision therewith. These means are illustrated FIG. 2 by arrow F. They may be of any type and may in particular consist of a rotating cam which, when it passes, comes to bear upon the rear part of the blank and accompanies it downwardly in positive fashion until it comes to lie below the level of arrival N of the following blank.

The intermediate adjustment module II can therefore be used:

a) to stabilize and accurately position an incident blank on a receiving blank in a machine with a high nominal speed V.

b) to adjust, precisely, the overlap R (or non-overlap NR) of an incident blank on a receiving blank,

c) to adjust, if necessary, the angle of incidence i of the pathway T1 of the incident blanks 2 and the pathway T2 of the receiving blanks 2′,

d) if the overlap R of the blanks is to be more precise, to reduce the distance d of the blanks leaving the ejector module I and hence the speed of the blanks leaving this module.

Claims

1. Device to overlap cut out cardboard blanks (2, 2′), comprising high speed (1.4V) ejector means (I) of a cutting and/or printing machine and low speed receiver means (V″) characterized in that, arranged between the ejector means (I) and the receiver means (III), it comprises an intermediate adjustment module (II) of which at least the driving speed of the blanks can be adjusted.

2. Device according to claim 1, characterized in that the intermediate adjustment module (II) comprises applicator means (F) able to fold down the rear part of a cardboard blank (2) after it has left the ejector module (I) and to lower it down to a level lower than the arrival level (N) of the following blank.

3. Device according to claim 2, characterized in that the applicator means (F) comprise a rotating element provide with a cam-forming zone which comes to bear upon each rear part of the blank (2) and accompanies the blank positively over at least part of its travel distance.

4. Device according to claim 1 characterized in that the pathway of the cardboard blanks (2) delivered at the exit of the ejector module (I) forms an angle of incidence (i) with the pathway of these blanks in the intermediate adjustment module (II) and the latter comprises means to adjust said angle of incidence (i).

5. Device according to claim 2, characterized in that the angle of incidence is close to 15°.

6. Device according to claim 1, characterized in that the nominal driving speed (V′) of the intermediate module (II) lies approximately mid-way between the difference in exit speeds from the ejector module (I) and the receiver module (III).

7. Device according to claim 1, characterized in that the speed of the blanks from the ejector module is 40% greater than the nominal speed (V) of the machine.

8. Device according to claim 2 characterized in that the pathway of the cardboard blanks (2) delivered at the exit of the ejector module (I) forms an angle of incidence (i) with the pathway of these blanks in the intermediate adjustment module (II) and the latter comprises means to adjust said angle of incidence (i).

9. Device according to claim 3 characterized in that the pathway of the cardboard blanks (2) delivered at the exit of the ejector module (I) forms an angle of incidence (i) with the pathway of these blanks in the intermediate adjustment module (II) and the latter comprises means to adjust said angle of incidence (i).

10. Device according to claim 4, characterized in that the angle of incidence is close to 15°.

11. Device according to claim 2, characterized in that the nominal driving speed (V′) of the intermediate module (II) lies approximately mid-way between the difference in exit speeds from the ejector module (I) and the receiver module (III).

12. Device according to claim 3, characterized in that the nominal driving speed (V′) of the intermediate module (II) lies approximately mid-way between the difference in exit speeds from the ejector module (I) and the receiver module (III).

13. Device according to claim 4, characterized in that the nominal driving speed (V′) of the intermediate module (II) lies approximately mid-way between the difference in exit speeds from the ejector module (I) and the receiver module (III).

14. Device according to claim 5, characterized in that the nominal driving speed (V′) of the intermediate module (II) lies approximately mid-way between the difference in exit speeds from the ejector module (I) and the receiver module (III).

15. Device according to claim 2, characterized in that the speed of the blanks from the ejector module is 40% greater than the nominal speed (V) of the machine.

16. Device according to claim 3, characterized in that the speed of the blanks from the ejector module is 40% greater than the nominal speed (V) of the machine.

17. Device according to claim 4, characterized in that the speed of the blanks from the ejector module is 40% greater than the nominal speed (V) of the machine.

18. Device according to claim 5, characterized in that the speed of the blanks from the ejector module is 40% greater than the nominal speed (V) of the machine.

19. Device according to claim 6, characterized in that the speed of the blanks from the ejector module is 40% greater than the nominal speed (V) of the machine.

20. Device according to claim 11, characterized in that the speed of the blanks from the ejector module is 40% greater than the nominal speed (V) of the machine.