EP0832734B1 - Method and apparatus for producing transverse precreases, in particular on envelope blanks - Google Patents

Description

The invention relates to a method and a device for producing transverse prematures on blanks and in particular on envelope blanks with the aid of at least one knife roller and a counter-roller.

The production of one or more transverse breaks on an envelope or the blank of a mailer or the like is in principle associated with particular difficulties when the material is highly inelastic. Although the roughing knife wants to pull the material of the blank into a recess located in or forming in a counter-tool or in a counter-roller, for example paper is not very suitable for this purpose. The material gets out For this reason, during pre-break formation, it is either stretched or, if it does not yield, the blank changes position relative to the cycle of the machine. The usually largely rigid and inelastic blank is therefore usually also performed in a special, complex manner, which is noticeable on the finished product. In the case of envelope cutouts, basically two transverse breaks are required at a distance from one another according to the height of the envelope, which are each produced abruptly. This occurring inaccuracies must then be corrected by switching off the machine by correcting the knife roller by hand. For this purpose and to remedy other disorders, it is customary to store the knife roller pivotally in the machine frame. Elaborate bridge constructions for the swing-away and basically driven knife roller are common here. Also, register-accurate re-engagement of the drive wheel of the knife roller in the drive train of the machine after a fault repair is always consuming. There are also major problems with the unguided spout from the device, especially when blanks with lateral tips.

From GB-A-284 259 it is known to form transverse breaks on envelope blanks. For this purpose, the blanks between a knife roller and a cooperating counter roll are performed, which is covered with a soft peripheral surface in the form of a rubber band, in which the Vorbrechmesser push the blank material, without performing a separating cut. The impressions of the blank material in the rubber band leads, as stated above, to an undesired stretching or a change in position relative to the machine cycle.

From US-A-3 728 918 it is known to pass a blank through a nip between a knife roll and a backing roll, the blank being gripped at its front end by suction openings on the knife roll and thus pulled through the nip. However, the counter roll is a hard roll with a metallic peripheral surface, and the roll knives are cutting knives that form parting cuts, notably for cutting rectangular window chips in the production of window envelopes. Since no transverse pre-fractures are formed, the aforementioned problem of length compensation does not occur in this case.

From US-A-4 504 260, which is based on the delimitation of claims 1 and 2, a device for producing a transverse rupture is known which operates with a knife roller and a counter-roller. The counter roll is provided with a hard peripheral surface and a notch formed therein which extends along a surface line and serves to receive the protruding knife of the knife roll. Accordingly, both rollers must be driven clock accurate. The counter-roller is formed as the cutting vorbewegende transport roller and provided over its entire circumferential length and width with suction openings which fix the blank in its entire front region from the front edge to the notch of the backing roll and thus the transverse rupture of the backing roll. Therefore, a material feed during transverse crushing of the blank could not be taken up easily, which then results when instead of the counter roll, the knife roller causes the blank transport and the radially vorste abrupt cutting knife brings the blank in the area of Quervorbruchs abruptly to a larger effective diameter with an increased peripheral speed.

Further, US-A-2 690 103 discloses a device according to the preamble of claim 1.

The invention is therefore based on the object to provide measures by means of which the said difficulties in the formation of transverse prematures can be avoided.

This object is achieved with the features of claim 1 (method) and with the features of claim 2 (device). Thereafter, it is envisaged that the blank is pulled in the transport direction during the production of the transverse pre-fractures at its front edge and otherwise carried loosely in front of and behind the transverse pre-breakage, so that he is responsible for a Compensation movement during the Vorbruchbildung is free to move.

While the blank was previously clamped on both sides of the knife roller and its counter-tool during the formation of the ridge and a pushing force acts on the blank essentially in the transport direction behind the transverse rupture to be produced, the blank now becomes in front of the ridge formation in the region of its front edge or front edge captured and kept there during transport. The rear end of the blank is no longer held and is therefore able to perform necessary compensating movements when the material must yield in the generation of the transverse pre-cracks in the direction of the registration register leading edge of the blank. The intrinsically disadvantageous material properties, such as e.g. has rigid and inelastic paper, therefore, no longer lead to production difficulties, with the result that it is possible to increase the unit performance of a production machine compared to earlier.

A device according to the invention for the production of transverse prematures on blanks of predominantly inelastic material further provides that the knife roller has a suction cup with a plurality of circumferentially arranged suction openings, which can be connected to vacuum or suction air. In a further development of the invention, the suction openings are combined into groups and selectively targeted. It is expedient if the suction openings on the circumference of the suction cup to adapt to different Forma te are summarized to axially parallel groups and each row connected to a suction line.

The suction cup has a plurality of axially parallel suction channels for controlling the suction openings, wherein furthermore each axially parallel suction channel can be connected to a arranged in the drive shaft of the knife roller in the axial direction of the vacuum main channel in a freely selectable manner. For this purpose, in addition to a conventional suction air control head at one end of the drive shaft, a suction air-selector ring - preferably in the middle of the knife roller - provided on the one hand arranged in the drive shaft and leading to the vacuum main channel radial bore and on the other hand with an inner peripheral groove and associated with a radial bore the suction channels in the suction cup. With the said features, the inventive method can be carried out.

Further developments and expedient refinements and advantages which result from the invention will become apparent from the dependent claims and the description and the drawings.

Fig. 1:

im Schnitt eine schematische Ansicht von wesentlichen Teilen der Vorrichtung;

Fig. 2:

einen Längsschnitt durch die Messerwalze;

Fig. 3:

einen Schnitt längs der Linie III-III in Fig. 2;

Fig. 4:

einen Schnitt längs der Linie IV-IV in Fig. 2;

Fig. 5:

eine Ansicht längs der Linie V-V in Fig. 2;

Fig. 6:

eine Ansicht längs der Linie VI-VI in Fig. 2 und

Fig. 7:

eine Ansicht längs der Linie VII-VII in Fig. 2.

The invention will be described below with reference to an embodiment, which is illustrated in the drawing. Showing:

Fig. 1:

in section a schematic view of essential parts of the device;

Fig. 2:

a longitudinal section through the knife roller;

3:

a section along the line III-III in Fig. 2;

4:

a section along the line IV-IV in Fig. 2;

Fig. 5:

a view taken along the line VV in Fig. 2;

Fig. 6:

a view along the line VI-VI in Fig. 2 and

Fig. 7:

a view along the line VII-VII in Fig. 2nd

A device 1 for producing one or more transverse pre-breaks 2 on a blank 3 (FIG. 3) comprises a machine frame 4 (FIGS. 1 and 2) and at least one drive 5 for a knife roller 6, which is a counter-tool, in particular in the form of a counter-roller 7 is associated with an elastic sheath. The knife roller 6 is rotatably supported by means of a drive shaft 8 in the machine frame 4. Further, the blank 3 transporting guide roller 9 and the blank 3 further transporting guide roller 10 of the cutter roller 6 are assigned and equipped with controlled suction cups 11 in a basically known manner.

The knife roller 6 has a suction cup 12 with suction openings 13 arranged on the outer circumference. These suction openings 13 are combined into groups and selectively targeted in groups. It can therefore be adjusted with vacuum controllable suction ports 13 to the format of a respective blank to be processed 3.

According to the embodiment shown in the figures, suction openings 13 are combined in the suction cup 12 to axially parallel groups and connected in rows in each case to a suction line 14. For this purpose, the suction cup 12 has a plurality of axially parallel suction channels 15, to which the circumferentially arranged suction openings 13 are connected radially outwardly directly. In addition, each axially parallel suction channel 15 can be connected to a vacuum main channel 16 arranged in the drive shaft 8 of the knife roller 6. For this purpose, a suction air-selecting ring 17, which is fixed according to embodiment approximately in the middle of the knife roller 6 (Fig. 2), for example by means of a screw 18 and ensures the targeted supply of the individual suction channels 15 with negative pressure. For this purpose, the suction air selector ring 17 over a part of its circumference on an inner circumferential groove 19 and a radially outwardly directed radial bore 20, which is respectively associated with the suction channels 15 in the suction cup 12. By adjusting the adjustable suction air selector ring 17, it is possible to connect each of the suction channels 15 shown in FIG. 3 to the prevailing in the vacuum main channel 16 negative pressure, wherein according to embodiment still a radial bore 21 from the vacuum main channel 16 to the inner Circumferential groove 19 leads. The position and shape and shape of the inner circumferential groove 19 is finally chosen so that each suction channel 15 in the suction cup 12 can be reached by adjusting the suction air selector ring 17.

Just as the suction cup 12 of each suction channel 15 has radially outwardly directed suction ports 13, there is a radially inwardly directed connection opening 22 in each suction channel 15 and is the radial bore 20 in the suction air selector ring 17 assigned. The connection openings 22 of all the suction channels 15, which are not connected to the radial bore 20 of the suction air selector ring 17, are at atmospheric pressure, so that also in the suction channels 15 and their suction 13 there is atmospheric pressure.

The generation of the required negative pressure in the vacuum main channel 16 in the drive shaft 8 takes place in a basically known manner by means of a Saugluf t-control head 25. The drive shaft 8 extends with its vacuum main channel 16 into the control head 25 and carries there a rotationally fixed connected control disk 26. The control disk 26 has a radially directed bore 27 and an axially directed, connected to the bore 27 window 28. In a window 28 facing position is located in the control head 25 also has a window 29 to which the suction line 14 is connected. The front side and the control disk 26 facing window 29 extends in a coordinated manner with the window 28 arcuately such that in the vacuum main channel 16 and correspondingly in one of the suction channels 15, there is a negative pressure, if on the respective suction channel 15 a blank 3 of the Assumption of the guide roller 9 is held until the delivery to the guide roller 10 by suction air from the cutter roller 6 and transported. According to FIG. 1, this is the case over slightly more than 180 °, the axis of the Knife roller 6 is deeper than the axis of the further transporting guide roller 10. The axis of the other guide roller 9 is again slightly higher than that of the guide roller 10th

The attachment of the suction cup 12 and its storage on the drive shaft 8 by means of support rings 30. They are shown in FIG. 2 each axially outside. The suction cup 12 is fixed by means of screws 31 on the circumference of the support rings 30. Conveniently, the support rings 30 are divided for dividing (Fig. 5) and by means of a clamping screw 32 frictionally mounted on the drive shaft 8. For the production of pre-breaks 2 two Vorbrechmesser 33 and 34 are provided according to embodiment. They lie on the circumference of the knife roller 6 in each case outside the suction cup 12 (FIG. 3). The suction cup 12 therefore also extends over only a part of the circumference of the knife roller 6 and, according to the exemplary embodiment, over approximately 120 °. In the area of the other half of the knife roller 6 are the Vorbrechmesser 33 and 34. The suction cup 12 is therefore not burdened by forces resulting from the Vorbruchmessern 33 and 34 respectively.

The one Vorbrechmesser 33 is a fixed on the knife roller 6 knife. The other advance knife 34 is adjustable relative to the roughing knife 33 in the circumferential direction.

As a support for the fixed preset knife 33 serve different support rings 36, 37, 38 and 39. They are mirror images of the suction air selector ring 17 at a distance arranged on the drive shaft 8 and fixed there by means of screws 40 in the axial direction and in the circumferential direction. While the two axially outer support rings 36 of FIG. 6 have a circular circumference and at the same time serve as a drive for the counter roller 7, the support rings 37, 38 and 39 have a basically same cross section as the support ring 38 of FIG. 4, whose outer contour however, deviates from a complete circular shape. Only the non-adjustable in the circumferential direction of the knife roller 6 Vorbrechmesser 33 is located with its terminal block 41 and a fastening screw 42 in a wing-shaped in cross-section projection 43 with a circular outer contour. This wing-shaped projection extends over about 90 °.

The remaining part 44 of the support ring 38 and the support ring 37 and 39 has an annular outer contour 45 which merges gradually at the terminal block 41 and at the other end with a rectangular shoulder 46 in the outer contour 47 of the projection 43.

The outer diameter, which is smaller by the height of the shoulder 46, of the annular part 44 of the support ring 38, 37, 39 serves to create a free space 48 in which the adjustable advance knife 34 is adjustable. Furthermore, in the free space 48 and the suction cup 12, as shown in FIG. 3.

The attachment of the adjustable Vorbrechmessers 34 on the drive shaft 8 by means of support rings 50 and 51, which are also arranged at a distance from each other and a mirror image of the suction air selector ring 17.

The support rings 50 and 51 are slotted as the support rings 30 and on the drive shaft 8 in the circumferential direction adjustable and fastened by means of a clamping screw 52. Over the greater part of their circumference, the support rings 50 and 51 have the same outer diameter as the support rings 37, 38 and 39, and this also applies to projections 53 and 54, which are located on both sides of the slot 55. The projection 54 carries a by means of a screw 57 'attachable terminal block 57 for the Vorbrechmesser 34. From the seat of the terminal block 57 of the projection 54 falls directly into the smaller outer periphery 58 of the support ring 50, 51 from.

While the knife roller 6 as shown in Figures 1 and 2 is rotatably mounted and driven in the machine frame 4, the counter roller 7 can be fixed positionally relative to the knife roller 6 on the one hand, as shown in Fig. 1 and on the other hand, it can be swung. In addition, the counter-roller 7 is adjustable, for which purpose at least one thread 60 or a screw bolt is used.

The counter-roller 7 is pivotally mounted together with its bearing block 61 about an axis 62 on the machine frame 4. If necessary, it can be swung downwards in the direction of the arrow (FIG. 1) away from the knife roller 6.

The various figures clearly show that the device 1 is suitable for carrying out the desired working method. With the help of suction air to the suction ports 13 of one of the suction channels 15 namely the blank 3 to be processed is taken over from the guide roller 9 as shown in FIG. 1 and then receives in a circulation in the direction of Arrows in Fig. 1 a pre-break 2, when the fixed preset knife 33 runs over the counter-roller 7. The part 70 of the blank 3 located behind the transverse rupture 2 in the direction of transport is loosely carried along at the time of the formation of the rupture 2, so that a compensation movement through the part 70 during rupture formation is possible. Finally, this also applies to the rear end 71 of the blank 3 in the direction of transport.

Finally, it goes without saying that each blank 3 must be grasped and transported further with the aid of negative pressure or suction air in the region of its front edge 72 (FIG. In the case of an envelope, the edge of his back flap is suitably detected. Such a case is also the device 1 shown in the figures again.

Claims (8)

1. Device to produce raised transverse creases (2) on a pre-cut paper blank (3), and in particular on an envelope blank, by way of a bladed roll (6) generating the raised transverse crease (2), exhibiting a creasing blade (33), being mounted in a machine frame (4) and being fitted with a drive (5), this roll being associated with a backing roll (7), wherein the blank (3) is grasped by way of vacuum at a point ahead of the transverse crease (2) to be created, as seen along the conveyance direction, and is pulled along the direction of conveyance and further wherein the portion (70) of the blank (3) following the transverse crease, as seen in the conveyance direction, is pulled along loosely so that it remains freely to move so as to be able to execute a compensatory motion during the creation of the crease, characterized by

   a) a plurality of vacuum openings (13) being located along the circumferential direction, in a vacuum shell (12) on the bladed roll (6), and

   b) by these being arranged to form parallel groups,

   c) which can be selectively connected, row by row, to a vacuum line (14) and

   d) by the bladed roll (6) exhibiting two creasing blades (33, 34),

   e) wherein the one creasing blade (33) is fixed in position along the circumferential direction and

   f) the other creasing blade (34) is adjustable along the circumferential direction.
2. Device in accordance with Claim 1, characterized by
   the vacuum shell (12) being adjustable in the circumferential direction on the drive shaft (8) for the bladed roll (6).
3. Device in accordance with Claim 1, characterized by
   the vacuum shell (12) exhibiting a plurality of parallel vacuum channels (15), each exhibiting vacuum openings (13) oriented toward the circumference and each parallel vacuum channel (15) being connectable to a main vacuum channel (16) located in the drive shaft (8) of the bladed roll (6).
4. Device in accordance with Claim 1, characterized by
   the backing roll (7) being fixable in relation to the bladed roll (6) and by it being both adjustable and able to be swung away.
5. Device in accordance with Claim 1, characterized by
   the backing roll (7) being driven by the bladed roll.
6. Device in accordance with Claim 1, characterized by
   an adjustable vacuum selector ring (17) being provided, it being associated on the one hand with a radial bore (21) in the drive shaft (8) communicating with the vacuum channel (16) and being associated on the other hand with the vacuum channels (15) in the vacuum shell (12) by way of an inner circumferential depression (19) and a radial bore (20).
7. Device in accordance with Claim 1, characterized by
   the vacuum shell (12) and the creasing blades (33, 34) being located on carrier rings (30, 36 to 39, and 50, 51).
8. Device in accordance with Claim 1, characterized by
   the circumferential surface of the backing roll (7) being formed by an elastic jacket.

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