EP0382011B1 - Apparatus for attaching without interruption a replacement web to an expiring web - Google Patents

Abstract

A device for the uninterrupted changeover of a plastic band (13, 13') from a first drum having a web (3, 3') of this band to a second drum having a web (3, 3') of the same plastic band (13, 13') comprises, apart from the two drums, a cutting (9, 9') and gluing device (5) and also control means (6) for actuating the various drives. <??>To reduce deficiencies in packages in the package-making machine although said machine is maintained in continuous operation even during the drum changeover, the invention provides that the deflecting rollers (15, 16, 18, 21), guide rollers (8, 8') and pressing rollers (7, 7') are arranged symmetrically so as to be adjustable with respect to a centre line (m) which runs perpendicularly to the connecting line (v) of the axes (4, 4') of the two webs (3, 3'), one pressing roller (7, 7') is in each case displaceable relative to the other, and the displacement drive (31, 31') for this can be controlled by a switch (10, 10') which is actuated as a function of the position of a web- sensing roller (26, 26'). <IMAGE>

Description

The invention relates to a device for the flying change of a first drum with a roll of plastic tape to a second drum with a roll of the same plastic tape, in which in addition to the two drums, a cutting and gluing device and control means for actuating the various drives are provided.

A device of this type is known, for example, from US-A-4 172 564.

The use of the device described here is intended for production machines for plastic packaging made of paper material coated liquid-tight with plastic on both sides. Parallelepipedic packs made from this material are known for the distribution of milk and juices. To cope with the problems associated with mass production, many types of packs are formed from a tube from which the individual packs are produced by transverse sealing. Each of these known packs has, among other things, a longitudinal sealing seam, which e.g. is formed by overlapping one edge of the tubular web over the other end edge and sealing in the overlap area.

The person skilled in the art knows that precisely in the area of a sealing seam, which is formed by overlapping the end edges, a cut edge of the web comes to lie in the interior of the package. The cutting creates an edge that is not covered by plastic, into which liquid can penetrate and destroy the packaging at this point. It is therefore also known to continuously place a cover strip over this plastic-free edge while the pack is in operation. The material of such a known plastic strip or tape is, for example, polyethylene. In practice, it has proven to be advantageous to make this polyethylene strip about 6 mm wide and to weld it in this form as edge protection on the sealing seam.

The person skilled in the art is therefore faced with the problem of using a plastic band for the continuous manufacturing process of the pack - e.g. in the width of 6 mm - continuously fed to the packaging machine. It is of course known to produce such plastic strips separately and to wind them up in large quantities on the hub of drums and to store them in this form. The respective drum is placed in an apparatus in front of the packaging machine, the beginning of the plastic tape is taken from the reel, inserted into the manufacturing machine, and then the operation can begin.

It was always problematic when a first roll was largely used up and the first drum was empty because a relatively long distance and a relatively large amount of packaging passed in the continuous manufacturing operation or packaging was produced, where before the beginning of the Plastic tape of the second full drum packs without edge protection were created because no plastic tape could be fed. It has therefore been considered how to switch as quickly as possible from a first roll of plastic tape to a second roll of the same plastic tape.

The object of the invention is therefore to design a device for the flying change of a first drum with a roll of plastic tape to a second drum, so that the waste of packs in the pack manufacturing machine is reduced, although the manufacturing machine continues continuously during the drum change or roll change becomes.

This object is achieved by a device of the type described in the introduction, in which deflection, guide and pressure rollers are arranged symmetrically to a center line which runs perpendicular to the connecting line of the axes of the two windings, one pressure roller being adjustable relative to the other, whereby the adjustment drive for this is controllable by a switch which is actuated as a function of the position of a winding scanning roller, and wherein at least one deflection roller is designed as a dancer roller and a brake designed as a V-shaped steel bracket is connected to the arm of the dancer roller and to a side plate Drum can be brought into engagement.

It is provided that at the beginning of the second, full wrap, which represents the replacement wrap, so to speak, a piece over a length of, for example, 1 to 8 cm, preferably 2 to 6 and particularly preferably 4 cm, a adhesive layer on both flat tops Adhesive tape is applied. If you look at the tape running from the work roll, which is gradually approaching its end of supply, during operation, you can see how this tape over one of the two pressure rollers, which is preferably driven, without contacting the other, second, non-driven, stationary drive roller runs. Between the facing surface points of the two drive rollers there is generally a distance during operation, preferably from 3 to 10 mm, particularly preferably from 6 mm. The start of the tape of the replacement reel begins on the opposite second drive roller and lies, so to speak, ready for use on this second drive roller.

As its name suggests, the winding scanning roller scans the winding around the circumference and thus changes its position during operation until the aforementioned switch is actuated when the first winding has almost ended, which, among other things, acts on the adjustment drive for the pressure roller. At the moment of the control pulse, the stationary pressure roller with the adhesive tape is pressed onto the opposite, rotating pressure roller, so that the beginning of the tape of the replacement roll is glued to the end of the tape of the work roll.

One recognizes the great advantage that the plastic tape can continue to run over this glue point, as with a flying change, because the first roll is now empty, so that the continuous feeding of the further plastic tape comes from the replacement roll, which now becomes the work roll.

It is particularly favorable here if the adhesive device with the pressure rollers also has a cutting device in such a way that at the moment of pressing on the replacement pressure roller on the working side, the continuous tape is at a short distance from the tape point that is just between the pressure rollers just touching each other is cut against the transport direction of the belt. This distance between the mentioned point between the pressure rollers on the one hand and the cutting point in the direction opposite to the running direction of the belt on the other hand is 2 to 15 cm, preferably 30 to 100 mm and particularly preferably 70 mm.

With this arrangement of the cutting device with respect to the adhesive device, in other words the cutting engagement point to the pressure roller gap, it is advantageously achieved that in the running direction of the tape behind the adhesive point with the e.g. 3 cm long adhesive tape only 2 to 5 cm old plastic tape runs in from the first, just idling working roll together with the beginning of the new second roll. In this so-called adhesive area and only in this area, the two plastic tapes lie one on top of the other. The adhesive area can be made very short by a corresponding arrangement of the cutting device with respect to the adhesive device. This has the advantage that, despite the flying change from the first reel to the second reel, practically only so little "edge protection tape" leads to rejects in the packaging production machine that only one or two packages ultimately have a double piece of tape adhesive that jeopardizes the tightness are.

It is therefore particularly advantageous if the impulse for triggering the adjustment drive for the pressure rollers also starts the cutting device.

Furthermore, it is particularly favorable if this impulse triggered by the switch also commands the packaging machine, e.g. eject a certain group of packs as rejects because it can be assumed that the adhesive strip is in this group of packs. In practice it has been shown that ejecting a single pack is sufficient. For safety and tightness reasons, it is preferable to eject three to four packs, because it can then be guaranteed for the ongoing operation of a milk packaging system that the glue point is in the committee.

It does not need to be specifically described here that in a manner known per se to the person skilled in the art the group of packs which are ejected as rejects can be exactly determined in the running production line because the Production speed is specified and thus the distance between the adhesive piece arriving with the plastic tape to the pack, to which the plastic tape is applied with this adhesive piece, is precisely determined.

The pack-making machine can thus continue to run, continuously feed an edge protection strip made of plastic, even though a first storage drum with a plastic band runs empty after a long period of operation and is replaced by a second replacement drum.

In an advantageous further embodiment, the winding scanning roller, which can be guided along the circumference of the winding, is rotatably fastened to a scanning arm arranged symmetrically to the center line with respect to another scanning arm, and the respective scanning arm is attached to an articulated block which can be pivoted about an axis parallel to the winding axis and a switching pan to operate the switch. The machine can be particularly robust and reliable in this way because a scanning arm with roller and control is provided for each drum on the respective side of the center line mentioned. The control is carried out by the angular position of the scanning arm, which, for example, is horizontal at the beginning when the winding is full and an angle of e.g. Has passed through 45 ° until the end position is reached. Due to the construction according to the invention, the hinge block has thus also pivoted about 45 ° about the axis, so that the switching pan carried by it comes into the area of the switch and actuates it after passing through the elbow. It is particularly advantageous if the switching socket can be adjusted with respect to the joint block, because in this way an adjustment to the individual drum sizes can be carried out.

It is also particularly advantageous if the hub of the drums, the axis of the joint blocks, the switch and the adhesive device are attached to a main plate. Although these parts are arranged symmetrically to the above-mentioned center line and are therefore available in pairs, an arrangement is provided on a main plate, which results in a good manufacturing possibility and also better handling; especially when the main plate is pivotable relative to the packaging machine. If the staff wishes to carry out maintenance or repair during operation or during downtimes, the main plate can be swiveled up from the frame of the machine in a simple manner without dismantling the device for the flying change, and the parts installed behind this plate are immediately accessible.

It is expedient if at least one deflection roller is designed as a dancer roller. The transverse sealing through the hose in the packaging production machine creates an intermittent operation, which has the consequence that the plastic band is also intermittently drawn from the supply into the production machine. The dancer role allows a balance between continuous and intermittent.

With this or an additional dancer roll of a different kind, you can also ensure the continuous maintenance of a web of the plastic band guided with moderate tension, if the dancer roll is combined with a brake in such a way that when the plastic band is pulled tight, ie. H. when the tension in the running belt increases, the brake is loosened somewhat. This is achieved in that the dancer roll and the brake are connected to one another via a one-piece holder, which in turn can be pivoted through smaller angles.

A brake designed as a V-shaped steel bracket is connected to the arm of the dancer roll and can be brought into engagement with a side plate of the drum. Such a V-shaped brake is not only easy and inexpensive to manufacture, but it can also be easily attached to an angled one Double arm attached at one end, while the dancer roll is rotatably arranged at the opposite end of the double arm, while a rotating bracket is in the middle where the two levers come together. In this way, the V-bracket follows the movement of the dancer roll in the manner described above. This design and arrangement of the brake is advantageous because the side plate of the drum does not change during operation. The diameter of the disc remains the same despite the rotation of the drum and despite the reduction in the number of wraps on the drum. With one and the same position of the dancer roll and thus also the brake, the braking effect on the drum always remains the same.

It is also expedient if, in the direction of travel of the plastic strip, a cut-off protection is fitted behind the adhesive device. So if for any reason the tension in the plastic belt drops too much on the outlet side, this fuse switches off the belt drive in question, so that malfunctions are advantageously avoided. This cut-off protection can be designed in a particularly advantageous manner so that a roller provided with a certain weight is arranged between two deflection rollers so that this roller is carried by the continuous plastic belt. If the tension in the plastic belt drops very sharply or the belt even tears, then this roller falls down and actuates a switch to interrupt a drive circuit. This switch and also the switch mentioned above can be microswitches, preferably proximity switches. An approximation can be provided or canceled via a switching flag, whereby one or the other switching state of the switch is reached. If the mentioned roller can be rotated about an axis via a pivotable arm, then its path of rotation is a circle. The switching flag connected to this roller as a switch-off safeguard can also be designed in an arc shape in such a way that a switching flag with a partial cylinder surface is provided, which is used for the connection or switching off the relevant proximity switch. The roller can dance during operation with a certain amplitude on the plastic tape running under the roller and with it the switch lug, which is elongated in the direction of movement, so that the proximity switch really only switches off when the roller, which acts as a switch-off protection, has passed through a larger amplitude.

Figur 1

eine Draufsicht auf die Hauptplatte mit den beiden Wickeln und der gesamten Vorrichtung für den fliegenden Wechsel von der einen Wickel zur anderen,

Figur 2

eine Einzelansicht der Klebeeinrichtung und Schneideinrichtung in der Draufsicht auf die Hauptplatte wie in Figur 1,

Figur 3

eine Draufsicht auf die Figur 2 von oben nach unten in Richtung der Ebene der Hauptplatte,

Figur 4

die Abschaltsicherung in der Draufsicht der Figuren 1 und 2,

Figur 5

eine Draufsicht auf die Abschaltsicherung, wenn man in Figur 4 von oben nach unten blickt, also wieder in Blickrichtung der Ebene der Hauptplatte,

Figur 6

eine Einzelansicht der in Figur 1 gezeigten Vorrichtung mit den Gelenkklötzen, den Schaltpfannen und den Mikroschaltern,

Figur 7

eine Ansicht der in Figur 6 gezeigten Teile, jedoch aus der Blickrichtung, wenn man Figur 6 von oben nach unten betrachtet, also in Richtung der Ebene der Hauptplatte, und

Figur 8

eine Schnittansicht durch die Hauptplatte etwa längs der Mittellinie m in Figur 1, aber ohne die Abschaltsicherung und ohne die Gelenkklötze.

Further advantages, features and possible applications result from the following description of preferred exemplary embodiments in conjunction with the drawings. Show it:

Figure 1

a plan view of the main plate with the two reels and the entire device for the flying change from one reel to the other,

Figure 2

1 shows a single view of the adhesive device and cutting device in a top view of the main plate as in FIG. 1,

Figure 3

2 shows a top view of FIG. 2 from top to bottom in the direction of the plane of the main plate,

Figure 4

the cut-off protection in the top view of Figures 1 and 2,

Figure 5

4 shows a top view of the cut-off safeguard when one looks from top to bottom in FIG. 4, that is to say again in the direction of view of the plane of the main plate,

Figure 6

1 shows a single view of the device shown in FIG. 1 with the joint blocks, the switching pans and the microswitches,

Figure 7

6 shows a view of the parts shown in FIG. 6, but from the viewing direction when looking at FIG. 6 from top to bottom, ie in the direction of the plane of the main plate, and

Figure 8

a sectional view through the main plate approximately along the center line m in Figure 1, but without the switch-off protection and without the hinge blocks.

The overall view of the device described here in the In the preferred embodiment shown in the figures, one can see from FIG. 1. On a main plate 1 with its center line m, the hub 2 of a first drum (not shown) with the first winding 3 is symmetrical on the left and the differently designed hub 2 'of the second winding 3' is symmetrical on the right. by means of the axes 4, 4 'arranged, which protrude vertically from the plane of the paper and thus also vertically from the main plate 1. The dashed line v connects the axes 4 and 4 'of the winding 3 and 3' and is the connecting line. The distance between the axes 4 and 4 'is so large that even between the full rolls 3 and 3' enough space for a total of 5 adhesive device in the area approximately below the connecting line v and for a control means generally designated 6 in the area above the connecting line v remains.

The adhesive device 5 is shown in more detail in Figures 2 and 3 and consists of the pressure rollers 7, 7 ', the guide rollers 8, 8' and the cutting devices 9, 9 '. The control means 6 shown in more detail in FIGS. 6 and 7 essentially has the microswitches 10, 10 ', the articulated blocks 11, 11' and the switching pans 12, 12 'attached to them.

With dashed lines, the plastic tapes 13, 13 'are indicated, of which the first plastic tape 13 is moved in the direction of travel 14 from the side just designated in Figure 1 as the work wrap 3, while the second plastic tape 13' is shown in the threaded position, however 1 comes from the replacement winding 3 '. It can be seen how the plastic strip 13 is pulled off the first left winding 3 around the first deflection roller 15, which is designed and supported as a dancer roller, first led downwards and then upwards again, held by a second deflection roller 16 and downwards on the cutting device 9 past through the guide roller 8 and past the driven pressure roller 7 into the generally designated 17 cut-off protection. The latter is shown more clearly in FIGS. 4 and 5 on an enlarged scale.

In the area of this switch-off safeguard 17, the plastic band 13 first wraps around the deflection roller 18, passes under the switching roller 19, wraps around the further deflection roller 20 from top to bottom, then the deflection roller 21, which can be rotated on an arm 23 pivotable about the axis 22 (dancer roller) and then runs in the direction of travel 14 obliquely upwards to the two deflecting rollers 24 and 25.

The second plastic belt 13 'initially held in the waiting position runs in an analogous manner from the winding 3', loops around the deflection roller 15 'designed as a dancer roller, then the deflection roller 16' and then runs symmetrically to the belt 13 with respect to the center line m on the cutting device 9 ' over the guide roller 8 'to adhere to the pressure roller 7' held at a distance from the pressure roller 7 '.

The circumference of the respective roll 3 is scanned by a roll scanning roller 26 on one or 26 'on the opposite side. The winding scanning roller 26 is rotatably attached to a scanning arm 27 or 27 ', which is connected via clamping and screwing to the mentioned joint block 11 or 11'. In Figure 1 and partially broken off in Figure 6, the scanning arm 27 (27 ′) is shown in the extended position and also in a further position shown partly in broken lines, with the broken position of the scanning arm 27 on the left side of FIG. 1 being a larger angle of e.g. 45 ° has passed as the right scanning arm 27 ', which has reached an angle of only about 25 to 30 ° with respect to the horizontal position, which is shown in dashed lines on the right side, to reach the position which is shown with solid lines.

From Figure 1 you can also see the hinge angles 28, 28 'and 29, 29', which are attached to the machine frame (28, 28 ') or on the main plate (29, 29'), so that the main plate 1 against the not machine frame shown can pivot about this hinge bracket 28, 29. This pivoting movement can be supported by a gas pressure spring, not shown, which is connected to the main plate 1 at the point shown at 30 on the left in FIG.

From Figure 1 also shows the adjustment drive in the form of the two pneumatic short-stroke cylinders 31, 31 ', which are attached to angles 32, 32' attached to the main plate 1 and control movable levers 33, 33 ', actuate and in the longitudinal direction of these levers 33, 33 'move, at the ends of the cylinders 31, 31' opposite the pressure rollers 7, 7 'are rotatably arranged. In Figure 3 you can see that the movable lever 33, 33 'are on the upper (rear) side of the main plate 1, while the pressure rollers 7, 7' are on the front, where the plastic band 13, 13 'over the guide rollers 16, 16 'runs. From Figure 3 you can also see the distance a, in which the tape 13 or 13 'extends from the main plate 1. This distance lies when viewing FIG. 1 in the direction of the paper plane, i.e. the guide rollers 16, 16 'are arranged at a distance a in front of the main plate 1.

This creates space for the arrangement of the individual parts of the control means generally designated 6.

From FIG. 1, one can also see the deflection roller 15 designed as a dancer roller (only the left side is described), which is rotatably attached to a lever 35, to which in turn a second lever 36 is firmly connected at an angle, both of which thus consist of one Consist of pieces and at their inner end about the common axis 37 are pivotable in both directions. At the outer ends of the lever 35 already described, the deflection roller 15 and the other lever 36, the brake 38 are attached, which is designed as a V-shaped steel bracket.

The deflection roller 15 at the end of the first lever 35, the course of which can also be seen in cross section in FIG. 8, can run against a Z-shaped bracket 40 according to the illustration in FIG. 1, which ensures that the lever 35 about the pivot point 37 are not rotated further in the counterclockwise direction but are locked in the position shown in FIG. 1. The respective lower leg of the V-shaped brake 38 runs against the disc, not shown, next to the winding 3 and is in continuous engagement with the circumference thereof to a greater or lesser extent. In Figure 1, the brake 38 is shown as if it were tangent to the circumference of the winding 3. In fact, it is not in engagement with the winding 3 but with the disc of the drum. The same naturally also applies to the other brake 38 '.

FIG. 2 shows the adhesive device, designated as a whole by 5, in the front view and in FIG. 3 in the top view on a larger scale for clarification. In the direction of travel 14 of the plastic band 13 one can see the cutting blade 40 (or right 40 ') of the cutting device 9 or 9' with the holder 41, 41 'for the cutting device 9, 9', which is provided behind the upper deflection roller 16. that with the movement of the pressure roller 7 'from the position shown in solid lines in Figure 2 to the left pressed, shown in broken lines position the cutting device 9 also comes into operation. Corresponding block units 42 ensure the suitable attachment of the rollers 7, 8 and the like.

The cut-off protection 17 is shown in FIGS. 4 and 5. The switching roller 19 is rotatably mounted on an arm 45 about the axis 46, regardless of the mounting of the deflection roller 18, which has the same axis of rotation 46. On this arm 45, the switching flag 47 is attached in the shape of a partial cylinder, which comes into functional engagement with the proximity switch 48 and thereby triggers its switching function. Should the band 13 shown in FIG. 4 tear, then the switching roller 19 with the switching flag 47 falls down in the direction of the arrow 49, the switching flag 47 moves away from the effective range of the proximity switch 48, which consequently opens the drive circuit and switches off the drives.

The control means 6 is shown in Figures 6 and 7, here the bracket 50 for the proximity switches 10, 10 'with their cables 51, 51', which are guided through the holes 52, 52 'in the main plate 1 behind them with a slope 53 is provided in comparison to the illustration in FIG. 1 in order to be able to arrange a weight flap 54 here, which is guided in the deflection roller 16 and is intended to prevent the plastic band (not shown in FIG. 6) from falling out due to movements, wind or the like.

The pivot blocks 11, 11 'are pivotable about the axes 55, 55', the horizontal position of the spacer arms 27, 27 'being desired for changing the drums and being fixable by a spring-loaded ball lock, as indicated in FIG. 7 by 56, 56'.

In operation, the device according to the invention works so that, starting from the state of Figure 1, the plastic tape 13 in the manner described and shown above in the running direction 14 through the distance between the pressure rollers 7 and 7 'in contact with the left pressure roller 7. When the scanning arm 27 has run down approximately to the hub 2 of the drum or to the last turns of the first winding 3, the switching flag 10 has reached the position shown in dashed lines on the left in FIG. 1 and actuated the proximity switch 10 so that it is one outputs electrical impulse. This pulse controls the pneumatic short-stroke cylinder 31 ', so that the pressure roller 7' with the beginning of the tape with adhesive strips 60, as shown in FIG. 2 on the right with a thick line, presses on the opposite continuous belt 13. The electrical pulse also triggers the cutting of the tape 13 by the left-hand cutting device 9, so that only one tape length of the first plastic tape 13 is continued between two locations together with the new tape 13 '. These two points are on the one hand the point of contact between the two pressure rollers 7, 7 'in the state of compression and on the other hand the point of engagement of the knife 40 of the cutting device 9 when cutting the tape 13th

Then the scanning arm 27 is pivoted into the horizontal position and locked there, the empty drum with the expired roll 3 is removed and replaced by a full new one, which now represents the replacement roll.

Claims (6)

1. An apparatus for a flying change-over from a first drum carrying a roll (3, 3') of synthetic plastics strip (13, 13') to a second drum carrying a roll (3, 3') of the same synthetic plastics strip (13, 13'), in which, in addition to the two drums, a cutting (9, 9') and gluing means (5) as well as control means (6) for actuating the various drives are provided, whereby direction reversing (15, 15', 16, 16', 18, 18', 21, 21') guide (8, 8') and pressure applying rollers (7, 7') are disposed adjustably and symmetrically of a central line (m) which extends at right-angles to the line (v) connecting the axes (4, 4') of the two rolls (3, 3'), in each case one pressure applying roller (7, 7') is adjustable in relation to the other (7, 7'), the adjusting drive (31, 31') for this being controllable by a switch (10, 10') which is actuated as as function of the position of a roll sensing roller (26, 26'), whereby at least one direction-changing roller (15, 15') is constructed as a jockey roller and a brake (38, 38') constructed as a steel bracket bent to a V-shape is connected to the arm (35, 36) of the jockey roller (15) and can be brought into engagement with side plate of the drum.
2. An apparatus according to Claim 1, characterised in that the roll sensing roller (26, 26') which can be guided along the periphery of the roll (3, 3') is rotatably mounted on a sensing arm (27', 27) which is disposed symmetrically with the central line (m) in respect of whichever is the other sensing arm (27, 27') and in that the relevant sensing arm (27, 27') is mounted on an articulating block (11, 11') adapted to pivot about an axis (55, 55') parallel with the roll axis (4, 4') and carries a switching block (12, 12') to actuate the switch (10, 10').
3. An apparatus according to Claim 1 or 2, characterised in that the hub (2) of the drums, the spindles (4, 4') of the articulating blocks (12, 12'), the switch (10, 10') and the gluing means (5) are mounted on a main plate (1).
4. An apparatus according to Claim 3, characterised in that the main plate (1) is pivotable (28, 29, 28', 29') in respect of the package producing machine.
5. An apparatus according to one of Claims 1 to 4, characterised in that viewed in the direction of movement (14) of the synthetic plastics strip (13, 13') there is following the gluing means (5) a switch-off safety device (17).
6. An apparatus according to one of Claims 1 to 5, characterised in that the switching block (12, 12') is adjustable in respect of the articulating block (11, 11').

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