EP0557609B1 - Apparatus for on line controlling of foldable box blanks - Google Patents

Description

The invention relates to a device for on-line control and for the automatic ejection of wrong and / or faulty folding box blanks in the production of folding box cartons according to the preamble of claim 1.

Folding boxes made of cardboard or similar material represent a significant share of the packaging materials on the market in the packaging industry. This is not only based on the food industry with its diverse carton designs or the electrical and electronic industry, but also to a particularly high degree on the pharmaceutical industry. Both those placed in glasses or other airtight containers and those in foil packaging are put on the market Pharmaceuticals are generally available in portions in folding box cartons, the imprints of which are immediately legible or provide information about the contents of the box in coded form.

In accordance with the high number of pieces and the variety with which folding cartons from blanks are used in retail, their multi-stage manufacturing process is highly automated. Frequently, the multi-stage manufacturing process, starting with the printing of the flat template, the punching of the blank over the multiple folding up to the assembly of the box, for example by gluing, is combined in a high-performance online machine line. The high production output and the high quality requirements for the finished products make multiple monitoring systems necessary, which due to manual intervention in the production process are neither economically viable nor technically sensible. Any disruption in only a part of the production would ultimately lead to the entire machine line coming to a standstill and thus to significant losses in production output. Other malfunctions such as misdirection or incorrect gluing and the like lead to high reject rates if the subsequent process is not adequately monitored. The requirements for a large amount of information, such as information about the amount and type of content, the shape and color of coding imprints and the like, are particularly important for folding cartons for the pharmaceutical industry and are largely precisely defined by a large number of laws and government regulations . The optical, mechanical and / or electronic monitoring means that are able to detect defective or incorrect production parameters or product components with as little delay as possible, in order to rectify any errors immediately or to eject faulty products from online production without interrupting production.

For example, optoelectronic bar code readers, glue trace control detectors and similar monitors are integrated into a high-performance folder gluer, which is only part of the automatic production line. This monitors the multiple folding of the flat blank into a six-sided or versatile container and the final gluing for the permanent assembly to the desired container shape in each production step.

The operational reliability of such monitoring systems depends not only on the quality and quantity of the error detection, but also on the necessary removal of missing parts from the given production process.

With the high production frequency that is possible due to automated production, automated fault detection has so far been technically less difficult than eliminating missing parts, in particular the process of ejecting individual production products identified as defective or incorrect from the current production line.

In this context, a so-called rotary ejector in the form of a turntable is known Folding carton gluing machines (DE-C-37 43 728). After a detection detector has identified a wrong or faulty blank, this blank is detected by magnetically controlled switching rollers, taking into account the delay time or the number of boxes between recognition and the passage of the blank to be removed from the rotary ejector, fed to a rotating ejector disk and taken over after being taken along ejected an undetermined angle of rotation in the tangential direction. Since the detection detectors are installed very differently in relation to the ejector in the production process, the delay times between detection and activation of the ejection device must be set according to the respective arrangement. The turntable of the known ejection device is arranged laterally to the conveying path of the blanks and aligned in their plane so that the peripheral region of the disc lies directly below or above the path of movement of the blanks along their conveying path or overlaps them. The blanks run into the folding box gluing machine individually, that is to say at a predetermined distance. The position of the blanks is defined by non-slip engagement between the upper endless belt and the lower endless belt of the conveyor line. The blanks protrude on both sides of the belt conveyor, so that the wrong or faulty blank can be gripped during production by means of the mechanism of the rotary ejector. The gripper is a friction roller that is activated when the wrong blank runs past the rotary plate of the rotary ejector, the edge of the blank onto the plate surface provided with a friction layer presses and pulls out the blank between the two endless belts of the conveyor line. When the friction roller is activated, the continuously rotating turntable thus detects a blank which is recognized as being defective at the moment of passing and converts its linear movement into the rotary movement of the turntable during production. However, this is only ensured if the box is held correctly during its lateral displacement. Otherwise, there can only be an undefined lateral shift without complete removal.

The rotational movement of the defective blank not only requires certain pressure and friction values, but also a distance between the successive blanks in the conveyor track, which must correspond at least to the difference between the diagonal length of the blank and its width. This places special demands on the separation of the blanks, ie the spacing of the individual blanks from one another, which lead to a reduction in the production output of the entire machine system. In addition, the angle of rotation, over which the defective blank is carried by the rotary plate of the rotary ejector, is not defined, since it depends not only on the size, but also on the surface quality and weight of the blank, which results in very different friction Driving forces and torques can result. The uncontrolled discharge direction that cannot be prevented in this way often causes machine malfunctions, which can lead to a further reduction in the production output of the overall system. The for taking a defective The required frictional connection between the activated friction roller and the turntable over different arc lengths, depending on the dimensioning of the blank, is only ensured for certain dimensioning areas in the blank dimensions and its box thickness, depending on the adjustment of the rotary ejector. It has also been shown that when the production speed is increased along the conveyor line, the blanks between the friction roller and the turntable are not always reliably grasped. Such blanks can then be partially moved and partially rotated from the ongoing production, so that ultimately there are malfunctions which result in the shutdown of the entire automated on-line system.

See also US-A-4 917 659 for an example of a device for automatically ejecting defective blanks.

Finally, reference should be made here to a further known device for sorting out predetermined box blanks from a series of blanks delivered continuously (DE-A-27 09 812), in which defective blanks are ejected vertically upwards from the conveying plane by means of a plunger in order to a belt conveyor - namely a lower and an upper belt conveyor - detected, deflected and transported away in the opposite direction. For this purpose, however, the boxes or similar blanks must be adequately separated in the ejection area, so that it is ensured that subsequent blanks that are not faulty are also accidentally ejected. The conveying capacity in this known device is therefore extremely limited for the purposes of a fully automated high-performance process.

This is where the present invention comes in, which is based on the object of specifying an ejector for at least partially automated on-line production systems for producing folding box cartons from corresponding blanks, in which any swiveling or deflecting or rotating movement of the one to be removed from the production line Cutting is avoided, so that the disadvantages caused thereby are eliminated and the previously required increased demands on the operating personnel of the machines with reliable sorting can be dispensed with.

This object is achieved according to the invention by the features specified in the characterizing part of claim 1.

Advantageous refinements and developments of this task solution result from the subclaims.

Because the ejector according to the invention for blanks in the manufacture of folding box cartons only carries out translatory movements instead of the previously required deflection or pivoting movements with the blanks to be eliminated in each case, the distance between the blanks fed on the linear conveyor line can also be minimized in the scale flow and thus the production speed increase. In particular, in the case of large formats, it is no longer necessary to pay attention to an enlarged distance between the boxes, due to the radian dimension of the ejector. The blank is ejected in a controlled manner with a precisely defined ejection direction and removal speed via a linear conveyor in the given conveyor level. The detection of defective blanks is independent of their thickness, their surface properties as well as their size and weight. An exact and precisely defined ejection of faulty cuts is ensured regardless of their properties. The trouble-free ejection is achieved according to the invention by the synchronization of the speed of the linear conveying path of the blanks along the production line on the one hand and the linear speed of the ejection device which conveys in the plane of the same to the direction of production on the other hand. The coordination of the two speeds with one another is only dependent on the angle defined between the two linear movements in the same plane, as described above. Once the system has been set up, the angle is generally not changed.

Fig. 1

eine schematisierte Draufsicht auf einen Teil der Förderstrecke einer Faltschachtelklebemaschine mit erfindungsgemäßem Linearauswerfer,

Fig. 2

eine Darstellung gemäß Fig. 1 mit zusätzlichem Stößelauswerfer,

Fig. 3

wiederum schematisiert einen vertikalen Längsschnitt durch eine Ausführungsform eines Linearauswerfers mit zugehöriger Förderstrecke, und

Fig. 4

zeigt eine seitliche Draufsicht gemäß Fig. 3 mehr im Detail.

The invention will be explained in more detail below with reference to the accompanying drawings, which only show exemplary embodiments. Show it:

Fig. 1

2 shows a schematic plan view of a part of the conveying path of a folder gluer with a linear ejector according to the invention,

Fig. 2

1 with an additional tappet ejector,

Fig. 3

again schematically shows a vertical longitudinal section through an embodiment of a linear ejector with associated conveyor section, and

Fig. 4

shows a side plan view of FIG. 3 in more detail.

As can be seen from the illustrations, cut pieces 4 for the production of folding box cartons are moved at a speed V ₁ in the direction of the arrow in the conveying plane along a conveying path 3 in this exemplary embodiment, lying at a respective distance 5 from one another. The usual production speeds for this are 300 to 600 m / min. The conveyor section 3 consists of a double belt arrangement, that is to say two endless conveyor belts lying one above the other at a close spacing, which rotate at the same speed in the direction of the arrow and hold the individual blanks 4 in a defined manner by friction. To the side and at an acute angle of attack α for the translational movement of the blanks 4 along the conveyor section 3, a fixed rail arrangement 9 with a conveyor belt 6 for removing defective blanks 4 'in the form shown is positioned in the conveying plane, the ejector belt moving in the direction of the arrow the speed V ₂ moves. This gripper mechanism (not shown in more detail in FIG. 1) detects the blank 4 'at the beginning of the linear ejector, which is arranged such that its area 10 adjacent to the conveying path 3 is flush below or above the edge area of the blanks 4, the conveying plane of the linear ejector 6 , 8, 9 lies in the conveyor plane of conveyor section 3. The section overlapping in plan view between the area 10 of the linear ejector 6, 8 9 and the respective edge area of a blank 4 is designed in such a way that no contact disturbances for the blanks 4 can occur along the conveying direction of the on-line system. Only in the event that a blank is recognized as incorrect, defective, incorrect or incorrectly printed by one or more reporting detectors, not shown here, is a gripper mechanism 7, 8 activated at the moment this blank 4 'passes the linear ejector, which blank either indirectly pressed by friction on the area 10 or pushed further onto this area by linear movement until it is carried along in the direction of movement and in the same movement plane of the linear ejector with only translatory movement at the speed V ₂ .

aufeinander abgestimmt sind. Das Transportband 6 des Linearauswerfers läuft also mit höherer Geschwindigkeit um als die durch die Förderstrecke 3 vorgegebene Produktionsgeschwindigkeit, und zwar in Abhängigkeit vom Anstellwinkel α. Damit ergibt sich bei einem Linearauswerfer, der z.B. unter einem Winkel α = 45° zur Förderstrecke 3 seitlich an diese angestellt ist, eine Linear-Auswerfgeschwindigkeit V₂ von $$\frac{{\text{v}}_{\text{1}}}{\text{cos 45°}}\text{=}\frac{\text{1}}{\text{0,707}}\text{= 1,4}$$

For the trouble-free function of the linear ejector according to the invention it is essential that it lies at an acute angle of attack α with respect to the two translational directions of movement described, the direction of transport between the conveying path 3 and that of the linear ejector according to the formula $${\text{V}}_{\text{2nd}}\text{=}\frac{{\text{V}}_{\text{1}}}{\text{cos α}}$$

are coordinated. The conveyor belt 6 of the linear ejector thus rotates at a higher speed than the production speed specified by the conveyor section 3, depending on the angle of attack α. This results in a linear ejection speed V ₂ of a linear ejector, which is positioned laterally at an angle α = 45 ° to the conveyor section 3, for example $$\frac{{\text{v}}_{\text{1}}}{\text{cos 45 °}}\text{=}\frac{\text{1}}{\text{0.707}}\text{= 1.4}$$

In this exemplary embodiment, the ejection speed is thus 1.4 times greater than the conveying speed of the blanks 4 along the production line. This means nothing other than that the so-called projection speed of the ejector onto the conveyor line corresponds to this speed, so that the blank 4 'recognized as defective during the linear lateral extraction from the conveyor line 3 in the conveyor plane or at least approximately in this plane with the speed the conveying path 3 is also moved between its blank lying in front of it in the conveying direction and behind it in the conveying direction, without it experiencing an acceleration or deceleration movement or any deflection movement. The distance 5 of the individual blanks 4 from one another or, if appropriate, a given overlap distance in a stream of blanks can thus be completely independent of the ejection process, by means of which the production processes determining the separation can be minimized.

2 and 3 show, for example, embodiments for possible ejectors of defective blanks 4 'from the conveyor section 3. According to the embodiment of FIG. 2, a plunger 7, which can be moved back and forth in translation in the direction of the double arrow, is activated when one is not The measuring and testing device shown, ie a suitable code reader, has previously recognized a faulty blank 4 'and a Corresponding signal for the actuation of the ram, taking into account the delay time between detection of the error and passing of the faulty blank on the linear ejector. The shown activated, ie extended, position of the plunger 7 is at most only available for a fraction of the length of passage of a blank, calculated to the smallest possible blank length. In the non-activated position, the plunger is withdrawn outside the range of movement of the cutting sequence. The defective blank 4 'which is pushed into the gripper region of the linear ejector by means of the plunger 7 is gripped by the latter and with the increased speed V ₂ , which corresponds to the projection speed taking into account the angle α in the direction of the conveying movement of the speed of the conveying path 3, essentially in the Conveying level remaining, carried along and ejected exactly in the direction of the slide rail 9. The plunger 7 thus pushes the defective blank out of the transport direction so that it inevitably runs into the laterally inclined ejection belt and is slid out of the rail 9 by friction with this belt.

In the embodiment according to FIG. 3, the inlet section 9, ie the section 8 of the ejector belt 6 adjacent to the conveyor section 3, is designed to be pivotable, so that it can be moved in the direction of the blank 4 'and, as shown, away from it. This pivotable section 8 is pivoted downward for the ejection of a defective blank 4 'until it is the blank between itself and the low-friction surface of the slide rails 9 or a corresponding guide plate jammed and thereby pulling the blank out of the conveyor section 3 by means of a force-locking coupling. In this exemplary embodiment, the linear conveyor consists of the endless belt 6 'rotating at the speed V ₂ , which is driven by the motor 11, and the low-friction coated guide rail 9. In the exemplary embodiment according to FIG. 1; 2, the linear conveyor can consist of two endless belts rotating at a close distance from one another, corresponding to the conveyor section 3, which according to FIG. 3 also consists of two endless belts 3 rotating synchronously at a close distance from one another. The endless belts, so to speak, clamp the blanks 4 between them.

Other gripper mechanisms in the area 10 of the linear conveyor and the adjacent conveyor section 3 instead of the plunger 7 or the one-sided gripping conveyor belt 6 'are conceivable.

The use according to the invention of the conveyor belt 6 'which can be folded in the gripping section 8 shown is, however, particularly advantageous because it ensures a seamless transition between the gripper function and the conveying function.

Fig. 4 shows the linear conveyor designed according to the invention in a lateral top view in more detail. The endless belt 6 'which ejects a defective or faulty blank is therefore guided in the region of the pivotable section 8 according to FIG. 3 on the one hand around a folding roller 16 and on the other hand around a deflection roller assigned to the motor 11. The lower run of the discharge belt 6 'is defined in terms of position by means of a plurality of support rollers 21 arranged at a distance from one another. A distance can be set in a defined manner between the lower run and the slide or guide rail 9, the adjustment of which can be carried out as a function of the thickness of the blanks. The surface of the slide rail 9 is treated in such a way that it permits as little friction as possible with the blank, while the surface of the ejection belt 6 'should have the highest possible coefficient of friction compared to the blank to be ejected. The ejecting belt 6 'could advantageously be pre-tensioned via the tensioning roller 20, which is mounted on the free pivotable end of a tensioning lever 14 - in such a way that the folding roller 16 is held in tension in its two positions, namely a lower ejection position (not shown) and the illustrated inactive position is. For this purpose, the folding roller 16 is fixedly connected to a pivot rod 15 by means of the folding lever 13 and can be pivoted together with the latter about a pivot point. The pivoting process takes place by means of an electromagnet 17 via its actuating plunger 22. At the free end of the actuating plunger 22, a plunger roller 24 is mounted, which engages in a fork bearing of the free end of the pivot rod 15. The stroke of the actuating plunger 22 for specifying the passive and the activated position of the folding lever 13 can be precisely specified by loosening a lock nut 18 by means of the adjusting screw 19. With the pivoting movement of the folding lever 13 and thus the folding roller 16 from the shown inactive, ie not ejecting position into a lower active, ie gripping position recognized as defective, the tension of the ejection belt 6 'set with the tensioning roller 20 must be increased above a maximum value to be applied to the output voltage again in the eject position. In the activated ejection position (not shown), the relevant section of the endless belt 6 'lies parallel to the lower guide rail in correspondence with this and is aligned with the entire lower run of the belt.

The folding lever 13 and the rigidly connected to it, but pivotable about a common pivot pivot rod 15 are shown in Fig. 4 with dash-dotted lines in the position in which the ejector belt 6 'can be mounted or removed from the linear ejector without tension. A cover 23 encloses the non-pivotable part of the linear ejector.

The mere, relatively short pivoting movement of the foldable front section of the linear ejector by means of the folding lever 13 when overcoming a maximum continuous tension of the prestressed ejector belt 6 'in the two end positions can be carried out with a high time sequence since inert masses do not occur as a result. As a result of the elasticity of the ejection belt 6 ', the belt tensions which can be optimized for the switching process can be adjusted by means of the tensioning roller 20 and can be readjusted even when the belt is fatigued to a certain extent. The friction-increasing surface coating of the endless belt 6 'is only used during the ejection process of a blank which is recognized as defective, which guarantees its long service life. The electromagnet 17 is designed as a double magnet, ie return spring forces are not required, which leads to an additional reduction in the required switching times. These mechanical measures and the pulsed activation of the two electromagnets with a defined overvoltage (fast excitation) lead to very constant switching times in the ms range. In addition, the switching time is tracked exactly depending on the conveying speed by an electronic compensation circuit.

der Fördergeschwindigkeit darstellt, mit der Relation ${\text{V}}_{\text{1}}{\text{= V}}_{\text{2}}\text{cos α}$

von den tatsächlich gemessenen Werten abweicht.The mutual coordination of the speed V ₂ with which the faulty blanks are ejected and the conveying speed V ₁ takes place via a control circuit by means of actual / setpoint control so that the ejector speed is always a function ${\text{V}}_{\text{2nd}}{\text{= f (V}}_{\text{1}}\text{)}$

represents the conveying speed with the relation ${\text{V}}_{\text{1}}{\text{= V}}_{\text{2nd}}\text{cos α}$

deviates from the actually measured values.

Claims (9)

1. Device for online control and automatic ejection of wrong and/or faulty folding box blanks during the manufacture of folding box cartons by way of suitable folding and gluing processes, with at least one ejector, which is arranged at the side of the conveying path and engageable with the blank and operated via repeater detectors such as code readers or the like and which channels a respective unwanted blank out of a current production along a conveyer path which moves blanks of, if appropriate, different dimensions in close succession or scaled flow, characterised in that the device is a linear ejector (6) which transports approximately in the conveying plane at an acute application angle (α) to the conveying direction, and that the speed (V₁) by which the blanks (4) are moved on the conveying path (3) and the speed (V₂) at which blanks (4') to be channelled out are channelled out by the linear ejector (6) are matched according to the equation $${\text{V}}_{\text{1}}{\text{= V}}_{\text{2}}\text{cos α}$$

   
2. Device according to Claim 1, characterised in that the linear ejector (6) is composed of a belt conveyer, which is aligned with the plane of the conveying path (3) and engageable with blanks (4) within the conveying path (3) with high friction coefficient and a fixed track arrangement with low friction coefficient.
3. Device according to Claim 1, characterised in that the linear ejector comprises a grabbing mechanism in its area (10) adjacent to the conveying path (3).
4. Device according to Claim 1 and 2, characterised in that at least the intake (8) of the belt conveyer, which is positioned adjacent to the conveying path (3), is pivotal whilst performing grabbing functions.
5. Device according to Claim 1, characterised in that the conveying path (3) and/or the linear ejector (6) are composed of two continuous belt conveyers, which are arranged at close proximity on top of each other and which receive the blanks (4, 4') between them.
6. Device according to Claim 1, characterised in that on the side of the conveyer path (3) opposite the grabbing mechanism is provided a pusher (7) which is operationally linked thereto.
7. Device according to Claim 1 to 5, characterised in that the pivotal area (8) as ejector of unwanted blanks (4') and the portion of the linear ejector (Fig. 4) which carries out a defined removal, are reached over by an ejector belt (6')
8. Device according to Claim 1 to 5 and 7, characterised in that the pivotal area (8) is composed of a flap lever (13) with flap roller (16), which is operated by an electro-magnet (17).
9. Device according to Claim 1 to 5, 7 and 8, characterised in that the pretensioning of the ejector belt (6') and the clearance between the belt (6') and the slide track (9) are adjustable.

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