CA2212234A1 - Method and apparatus for cutting across a paper web - Google Patents
Method and apparatus for cutting across a paper webInfo
- Publication number
- CA2212234A1 CA2212234A1 CA002212234A CA2212234A CA2212234A1 CA 2212234 A1 CA2212234 A1 CA 2212234A1 CA 002212234 A CA002212234 A CA 002212234A CA 2212234 A CA2212234 A CA 2212234A CA 2212234 A1 CA2212234 A1 CA 2212234A1
- Authority
- CA
- Canada
- Prior art keywords
- cutting
- paper web
- feed
- guide plate
- loop
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H20/00—Advancing webs
- B65H20/30—Arrangements for accumulating surplus web
- B65H20/32—Arrangements for accumulating surplus web by making loops
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
- B26D7/00—Details of apparatus for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting
- B26D7/01—Means for holding or positioning work
- B26D7/02—Means for holding or positioning work with clamping means
- B26D7/025—Means for holding or positioning work with clamping means acting upon planar surfaces
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H35/00—Delivering articles from cutting or line-perforating machines; Article or web delivery apparatus incorporating cutting or line-perforating devices, e.g. adhesive tape dispensers
- B65H35/04—Delivering articles from cutting or line-perforating machines; Article or web delivery apparatus incorporating cutting or line-perforating devices, e.g. adhesive tape dispensers from or with transverse cutters or perforators
- B65H35/06—Delivering articles from cutting or line-perforating machines; Article or web delivery apparatus incorporating cutting or line-perforating devices, e.g. adhesive tape dispensers from or with transverse cutters or perforators from or with blade, e.g. shear-blade, cutters or perforators
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2301/00—Handling processes for sheets or webs
- B65H2301/50—Auxiliary process performed during handling process
- B65H2301/51—Modifying a characteristic of handled material
- B65H2301/512—Changing form of handled material
- B65H2301/5121—Bending, buckling, curling, bringing a curvature
- B65H2301/51212—Bending, buckling, curling, bringing a curvature perpendicularly to the direction of displacement of handled material, e.g. forming a loop
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Forests & Forestry (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Advancing Webs (AREA)
- Separation, Sorting, Adjustment, Or Bending Of Sheets To Be Conveyed (AREA)
- Folding Of Thin Sheet-Like Materials, Special Discharging Devices, And Others (AREA)
Abstract
In the process for cutting across a paper web, the paper web is advanced longitudinally for a predetermined length in relation to a stationary cutting tool between two successive cutting steps and stopped during the cutting step.
According to the invention, the paper web is conveyed continuously at constant speed as far as the vicinity of the cutting tool and only the region of the paper web immediately adjacent the cutting tool and lying in front thereof is held during the cutting step. At this stage, during the cutting step, the loop (wave) in the section of the continuously conveyed paper web bulging transversely to the theoretically even direction of advance is stored and the stored section is conveyed after the cutting step to the cutting tool at a speed above the constant speed of advance.
According to the invention, the paper web is conveyed continuously at constant speed as far as the vicinity of the cutting tool and only the region of the paper web immediately adjacent the cutting tool and lying in front thereof is held during the cutting step. At this stage, during the cutting step, the loop (wave) in the section of the continuously conveyed paper web bulging transversely to the theoretically even direction of advance is stored and the stored section is conveyed after the cutting step to the cutting tool at a speed above the constant speed of advance.
Description
Translation of replacement pages annexed to the International Prelimin~ry Fl~mination Report under PCT Article 36. The pages 2/1 to 2/11 and 2/13 to 2/17 replace all of the original pages.
Replacement sheet Apparatus for cutting across a paper web This invention relates to an apparatus for cutting across a paper web, with a stationary cutting tool which has cooperating cutter blades, with a first feeddevice arranged before the cutting tool and which is driven continuously during operation of the apparatus, by means of which the paper web is fed between two successive cutting operations by a prede~e~ ed length each time, with a clamping device provided in the region between the first feed device and the cutting tool and driven synchronously with the latter, by means of which the region of the paper web immediately adjoining and lying before the cutting tool can be clamped fast for the duration of the cutting operation, until the passagebetween the cutter blades is free again, and with a free space provided in the region between the first feed device and the cl~mping device, into which the paper web section continuously fed on by the first feed device during the cutting operation can expand in the form of a loop bowed out transversely relative to the theoretical straight feed direction.
In subsequent processing of printed paper webs, e.g. co~ ulel~ output, the paper web has to be cut off into individual paper sheets with a printed form height, which can lie between 3" and 12" for example. There exist automatic cutting machines for this purpose which are equipped with cutting tools which can cut off the perforated edges of the paper web or divide this in the lon~ih~ n~l direction, in addition to a cutting tool which serves to cut across the paper web. Such an automatic cutting machine which has previously been found outst~nding in practice is described in the brochure of BOWE SYSTEC
AG, D-86135 Augsburg, "Schneideautomat B~WE 310" [BOWE 310 automatic cutting machine, 3/94]. This automatic cutting m~chine handles Replacement sheet fan-folded printed paper webs. It comprises a cutting tool consisting of a stationary cutter blade and a cutter blade which moves up and down for the transverse cutting. A first feed device is arranged ahead of this cutting tool, formed as a so-called tractor. This consists of two endless transport belts arranged parallel to one another, which have pins eng~ging in perforations at the two edges of the paper web. This known automatic cutting m~chine operates according to the start-stop principle. While the cutter blades are o separated from one another and the passage therebetween is freed, the tractor feeds the paper web on by a length corresponding each time to the format height. Then the tractor stops and the cutter blades of the cutting tool performthe cutting operation. As soon as the passage between the cutter blades is free again, the tractor is started up again. Although the cutting rate of this known automatic cutting machine is already pretty high at about 27,000 cuts per hour with a printed form height of 3" (= 7.5 cuts/s), it no longer matches future requirements. Modern data processing installahons operate with laser p~ lels with such a high speed that the known automatic cutting m~çhine would no longer be able to cut up on-line the paper web printed by the laser, i.e. at theoutput of the printer with a speed corresponding to the operating speed of the printer. The operating speed of the known automatic cutting m~chines c~nnot be increased substantially. This is imposed by the start-stop principle of the system. The paper web has to be brought to a standstill before each cut and be accelerated again after each cut from stationary up to the full feed speed, and this more than 30,000 times per hour. The forces of acceleration acting on the paper web at still greater cutting rates are so large CA 022l2234 l997-08-Ol Replacement sheet 2l3 that the edge perforations can tear off and if the paper web is provided with 5 transverse perforations, it tears at the transverse perforations.
An apparatus for cutting across a paper web of the kind initially recited is known from DE-A 3 131 101, in which a second feed device is provided before the clamping device, consisting of a continuously driven upper feed roller and alower feed roller which can be pressed on the upper feed roller from below and o can be lowered away from ~e upper feed roller. The lowering movement of the lower feed roller is effected synchronously with the drive of the clamping device or the cutter blade, in a manner such that, before a cut the paper web isfirst clamped fast in the clamping device and at the same time the lower feed roller is lowered. The paper web thus comes to a standstill and the second feed 15 device also no longer acts on the paper web. Since the first feed device feeds continuously, the paper web jams up and a loop h~n~ing freely downwards forms between the first and second feed devices. The cutting across is effected by means of the cutting tool during the clamping of the paper web. After completion of the cut the clamping is removed and the lower feed roller is 20 pressed against the upper feed roller of the second feed device. Since this operates with higher feed speed than the first feed device, the loop formed during the cutting across is pulled flat again. However, it has been found that the loop formation no longer takes place in an orderly and reproducible m~nner at higher paper feed speeds above 0.5 m/sec. and correspondingly a higher 25 cutting frequency. As a result of the chaotic conditions in the Replacement sheet loop formation, cutting inaccuracies above all result in relation to the length of 5 the sheets of paper which are cut off, which lie outside the predelelmined tolerances. Moreover a substantial amount of noise occurs from the rapid sequence of loop formation and pulling the loop flat.
The invention is therefore based on the object of providing an apparatus for cutting across a paper web of the kind initially referred to, in which a high o cutting accuracy is obtained even at very high paper feed speeds and a high cutting frequency, while the burden of noise is at the same time substantially reduced.
This is achieved according to the invention in that a guide plate is provided between the first feed device and the clamping device, in that the 15 guide plate is provided with a plurality of openings and in that the space above the guide plate is enclosed by a damping hood, which is spaced from the loop.
The damping hood leads in combination with the guide plate provided with openings to a great cutting accuracy even at very high paper feed speeds and high cutting frequencies. Even with paper feed speeds above 0.8 m/sec.
20 and a cutting frequency of more than 10 cuts/sec., cutting accuracies in the tenth of a millimeter range with a tolerance of ~0.3 mm are obtained. This is attributable to the fact that the defined and constant air pressure conditions exist inside the damping hood, which isolate the loop from ambient effects, such as air ~ lellls, heat effects and the like during the loop formation.
25 Moreover vibrations of the loop are damped and through this Replacement sheet ordered, reproducible loop formation is ensured. In this connection, the 5 arrangement of the guide plate provided with openings is also of importance.
The guide plate ensures that the loop can only form in one direction, upwards, while the openings assume decisive importance. Thus, during the whirling out of the loop, air can enter rapidly into the space between the loop and the guideplate but in particular the air can escape rapidly from this space again when the o loop is pulled flat again by the second feed device, after completion of the cutting operation. The invention makes it possible to increase the cutting rate to about 80,000 cuts per hour with a printed form height of 3 ". Thanks to the highcutting rate it is possible to carry out the cutting across on-line at the output of a laser printer, which contributes further advantages.
15 Advantageous emborliment~ of the invention are characterized in the dependent claims.
The invention will be explained below in more detail, with refel-ellce to several embodiments shown in the drawings, in which:
Figure 1 is a longitudinal section of the apparatus for cutting across a 20 paper web, Figure 2 is a partial lon~ 1in~1 section of this apparatus in the region of the loop formation to a larger scale, Figure 3 is a partial plan view in the direction III in Figure 2.
Replacement sheet 2l6 The apparatus for cutting across a paper web according to the embodiment shown in Figures 1 and 2 comprises a cutting tool 1 with a 5 stationary cutter blade 2 and a cutter blade 3 which can move up and down. A
first feed device 4 is provided, spaced before the cutting tool 1 and is in the form of a so-called tractor in this embodiment. The tractor consists of two conveyor belts S arranged parallel to one another, whose pins 6 engage in perforations at the two sides of the paper web 7. The feed device 4 is driven o continuously with a peripheral speed Vl, which corresponds for example to the discharge rate of a preceding laser printer, not sho~n. In the region between the feed device 4 and the cutting tool 1 there is provided a clamping device 8 driven synchronously with the latter. This clamping device 8 is preferably arranged in the vicinity of the cutting tool 1, i.e. its distance from the cutting 15 tool 1 is smaller than its distance from the feed device 4.
Replacement sheet 2l7 In between the clamping device 8, which will be described in more detail below, and the cutting tool 1 a second continuously driven feed device 9 is s preferably arranged directly adjoining the cutting tool, with its feed speed (=
peripheral speed) V2 greater than the feed speed Vl of the first feed device 4.
A third feed device 10 is advantageously provided after the cuffing tool 1 and is also continuously driven, namely with a feed speed V2 which corresponds to the feed speed V2 of the second feed device 9.
o The clamping device 8 comprises two jaws 11 which are spaced from one another in the transverse direction of the paper web 7 and of which only one is shown in the drawing. These jaws 11 cooperate with a stationary bed 12. Each jaw 11 is disposed on one end (the lower) of plunger 13 movable transverse to the feed direction A of the paper web 7, the other (upper) end carrying a roller14 which cooperates with a cam disc 15. The cam disc 15 can be driven in synchronism with the cutting tool 1. To this end a common belt drive is provided. The belt drive also drives the movable cutter blade 12. The drive of the belt drive is advantageously effected continuously but it can also be The drive speed n of the belt drive is so adjustable in relation to the feed speed Vl of the first feed device 4 that Replacement sheet a cut always takes place when the paper web 7 has been moved on by the feed device 4 by a length corresponding to the desired format height (= printe~ form 5 height) relative to the cutting tool 1.
The second feed device 9 and the third feed device 10 advantageously each comprise a continuously drivable feed roller 20 and 21 respectively and at least one pressure roller 22, 23 axially parallel thereto, which bear under elastic bias 24 on the feed rollers 20 and 21 respectively. The elastic bias 24 is o preferably adjustable. The drive of the two feed rollers 20, 21 can be effected by a third motor for example. This third motor imparts a feed speed V2 to the feed rollers 20, 21 which is four times as larges as the feed speed Vl of the first feed device 4 for example.
Furthermore a bowing out device 25 is provided between the first feed 15 device 4 and the clamping device 9 [8], which exerts a force P directed transversely relative to the feed direction A at least intçrrnitt~ntly. If the feed direction A runs substantially horizontally, as is the case in the embodiment shown in Figures 1 and 2, tbe force P should be di~ected u~wardly. This has the advantage that the advance of the paper web section 7a stored during the 20 cutting operation is also assisted by gravity after the release of the clamping device 8, as will be described in more detail below.
In order to generate the force P in the first place there can be provided a guide plate 26, which Replacement sheet 2l9 is bowed out transversely to the feed direction A relative to a plane E-E
tangential to the feed elements 5 of the first feed device 4 and the clamping 5 elements 11, 12 of the clamping device 8. In the embodiment shown the bowing out 26a is upwards.
The manner of operation of the apparatus described above is as follows:
During the operation of the apparatus, the first feed device 4 is driven continuously with a feed speed Vl and the second and third feed devices 9 and 10 respectively are driven continuously with a greater feed speed V2. The movable cutter blade 3 can also be driven continuously, so that a cutting operation and freeing the passage between the cutter blades 2 and 3 take place alternately. While the latter case applies the clamping device 8 is also opened,so that the paper web 7 is moved on in the direction A by the feed devices 4 15 and 9 and also by the feed device 10 with greater format heights. As soon as the paper web has moved relative to the cutting tool 1 by the set format height,the cam disc 15 presses the plunger 13 down, so that the paper web is clamped fast between Replacement sheet 2/lO
the jaws 11 and the stationary bed 12. The feed rollers 20, 21 of the second - feed device 9 and the third feed device 10 carry on tllrnin~. The movable cutter 5 blade 3 moves down and cuts off a paper sheet 7b of the desired format height,which is moved on irnmediately by the third feed device 10. The feed rollers 20, 21 have a smooth, steel surface and the elastic bias 24 is so chosen that the feed rollers 20, 21 can continue to turn during the clamping of the paper web, without ~m~ging this.
While the paper web is held fast by the clamping device 8 for the duration of the cutting operation, the first feed device 4 feeds the paper web on continuously. This paper web section which is fed on is stored in the form of a loop 7a bowed out transversely upwards relative to the theoretical straight feeddirection A. The bowing out is promoted by the bowed out guide plate 26 and 15 it is therefore ensured that the bowing out talces place in a predetermined direction, namely upwards. During the bowing out a stress develops in the loop 7a, like in a kinked rod. When the passage between the cutter blades 2, 3 becomes free again on completion of the cutting operation, the clamping device 8 also opens, in that the region lSa of the cam disc 15 comes into the range of 20 the roller 14. As soon as the clamping device 8 has opened, the second feed device 9 feeds on the end of the paper web adjoining the cutting device 1 with a feed speed V2, which is higher than the feed speed Vl of the first feed device4.
Replacement sheet The stored loop 7a is caused to decay by this. The further movement of the paper web section stored in the loop 7a is also promoted by the stress generated5 in the loop, which pushes the free end of the paper web on in the direction ofthe cutting tool 1. The loop 7a cannot expand to the rear because the paper web is constantly fed on by the first feed device 4. In addition to the stress built up in the loop 7a, gravity can also be effective in the embodiment shown, pushing the loop 7a down and thus moving the paper web on in the direction towards o the cutting tool 1. The second feed device 9 therefore only has to move on thesmall paper section 7a stored in the form of the loop, this ollw~-d movement being promoted by the stress built up during the clamping and by gravity.
The holding fast of the paper web can also be effected in another way, for example by clamping pincers which engage the edge of the paper web. What s matters is merely that the clamping device is so driven synchronously with thecutting tool that the clamping device holds the paper web fast during the cutting operation.
[There is no replacement page 2/12 for original page 12, since this was cancelled in its entirety.]
Replacement sheet An important contribution to the increase in the cutting rate is given by the formation of the region in which the loop formation takes place, shown in 5 Figures 2 and 3. It has in fact been ascertained that, with paper feed speeds from about 0.8 m/s (which corresponds to about 38,000 cuts per hour with a printed form height of 3"), unacceptable fluctuations in the cutting accuracy arise. In order to achieve an adequate cutting accuracy in the range of tenths of a millimeter, e.g. in the range +0.3 mm in spite of higher feed speed and higherlO cutting rates, Replacement sheet it is advantageous to make use of the features described below in combination.
The guide plate 26 is bowed upwardly, where the bowing is obtained by a s bend 26b in the guide plate. The guide plate 26 is furthermore provided with aplurality of openings 36, e.g. circular holes. Air can enter rapidly between theloop and the guide plate through these openings 36 during the bowing of the loop but in particular the air can escape rapidly from the space between the loop 7a and the guide plate 26 when the loop is pulled flat again by the second o feed device 9 after completion of the cutting operation. The paper web 7 then comes into contact with the bend 26b. The result of the friction occurring at this place is that the tension exerted on the paper web by the second feed device cannot propagate fully to the first feed device 4.
Furthermore, deflector plates 37, 38 which affect the loop formation are lS provided in the front and rear regions of the guide plate 26, as regarded in the feed direction A of the paper, above the guide plate and inclined oppositely towards one another. These deflector plates 37, 38 are fitted to assist uniform loop formation. The effect of the deflector plates 37, 38 is that the loop formation always takes place at approximately the same place and that the loop 20 does not wander forwards or backwards in the feed direction A. Above all the loop formation is reproducible because of the deflector plates 37, 38. In order to be able to affect the loop formation it is further advantageous for the inclination of each deflector plate 37, 38 relative to the guide plate 26 to be adjustable.
Replacement sheet To this end the deflector plates 37, 38 can each turn about an axis 39, 40 extending transversely to the feed direction A and can be fixed by a device 5 which is not shown.
Furthermore, the space above the guide plate 26 and above the deflector plates 37, 38 is enclosed by an damping hood 41. The damping hood 41 should be arranged a large distance from the loop 7a, so that there is enough air spacebetween the loop 7a and the interior of the damping hood. The damping hood o functions on the one hand as an air chamber which damps the vibrations which occur with the loop formation at high speeds and it serves on the other hand also for sound insulation.
The features used together in the embodiment shown in Figures 2 and 3 lead to stabilization and reproducibility of the loop formation, which 15 experience has shown is a pre-condition for high cutting accuracy at high cutting rates, with tolerances in the range of tenths of a millimeter.
Replacement sheet Apparatus for cutting across a paper web This invention relates to an apparatus for cutting across a paper web, with a stationary cutting tool which has cooperating cutter blades, with a first feeddevice arranged before the cutting tool and which is driven continuously during operation of the apparatus, by means of which the paper web is fed between two successive cutting operations by a prede~e~ ed length each time, with a clamping device provided in the region between the first feed device and the cutting tool and driven synchronously with the latter, by means of which the region of the paper web immediately adjoining and lying before the cutting tool can be clamped fast for the duration of the cutting operation, until the passagebetween the cutter blades is free again, and with a free space provided in the region between the first feed device and the cl~mping device, into which the paper web section continuously fed on by the first feed device during the cutting operation can expand in the form of a loop bowed out transversely relative to the theoretical straight feed direction.
In subsequent processing of printed paper webs, e.g. co~ ulel~ output, the paper web has to be cut off into individual paper sheets with a printed form height, which can lie between 3" and 12" for example. There exist automatic cutting machines for this purpose which are equipped with cutting tools which can cut off the perforated edges of the paper web or divide this in the lon~ih~ n~l direction, in addition to a cutting tool which serves to cut across the paper web. Such an automatic cutting machine which has previously been found outst~nding in practice is described in the brochure of BOWE SYSTEC
AG, D-86135 Augsburg, "Schneideautomat B~WE 310" [BOWE 310 automatic cutting machine, 3/94]. This automatic cutting m~chine handles Replacement sheet fan-folded printed paper webs. It comprises a cutting tool consisting of a stationary cutter blade and a cutter blade which moves up and down for the transverse cutting. A first feed device is arranged ahead of this cutting tool, formed as a so-called tractor. This consists of two endless transport belts arranged parallel to one another, which have pins eng~ging in perforations at the two edges of the paper web. This known automatic cutting m~chine operates according to the start-stop principle. While the cutter blades are o separated from one another and the passage therebetween is freed, the tractor feeds the paper web on by a length corresponding each time to the format height. Then the tractor stops and the cutter blades of the cutting tool performthe cutting operation. As soon as the passage between the cutter blades is free again, the tractor is started up again. Although the cutting rate of this known automatic cutting machine is already pretty high at about 27,000 cuts per hour with a printed form height of 3" (= 7.5 cuts/s), it no longer matches future requirements. Modern data processing installahons operate with laser p~ lels with such a high speed that the known automatic cutting m~çhine would no longer be able to cut up on-line the paper web printed by the laser, i.e. at theoutput of the printer with a speed corresponding to the operating speed of the printer. The operating speed of the known automatic cutting m~chines c~nnot be increased substantially. This is imposed by the start-stop principle of the system. The paper web has to be brought to a standstill before each cut and be accelerated again after each cut from stationary up to the full feed speed, and this more than 30,000 times per hour. The forces of acceleration acting on the paper web at still greater cutting rates are so large CA 022l2234 l997-08-Ol Replacement sheet 2l3 that the edge perforations can tear off and if the paper web is provided with 5 transverse perforations, it tears at the transverse perforations.
An apparatus for cutting across a paper web of the kind initially recited is known from DE-A 3 131 101, in which a second feed device is provided before the clamping device, consisting of a continuously driven upper feed roller and alower feed roller which can be pressed on the upper feed roller from below and o can be lowered away from ~e upper feed roller. The lowering movement of the lower feed roller is effected synchronously with the drive of the clamping device or the cutter blade, in a manner such that, before a cut the paper web isfirst clamped fast in the clamping device and at the same time the lower feed roller is lowered. The paper web thus comes to a standstill and the second feed 15 device also no longer acts on the paper web. Since the first feed device feeds continuously, the paper web jams up and a loop h~n~ing freely downwards forms between the first and second feed devices. The cutting across is effected by means of the cutting tool during the clamping of the paper web. After completion of the cut the clamping is removed and the lower feed roller is 20 pressed against the upper feed roller of the second feed device. Since this operates with higher feed speed than the first feed device, the loop formed during the cutting across is pulled flat again. However, it has been found that the loop formation no longer takes place in an orderly and reproducible m~nner at higher paper feed speeds above 0.5 m/sec. and correspondingly a higher 25 cutting frequency. As a result of the chaotic conditions in the Replacement sheet loop formation, cutting inaccuracies above all result in relation to the length of 5 the sheets of paper which are cut off, which lie outside the predelelmined tolerances. Moreover a substantial amount of noise occurs from the rapid sequence of loop formation and pulling the loop flat.
The invention is therefore based on the object of providing an apparatus for cutting across a paper web of the kind initially referred to, in which a high o cutting accuracy is obtained even at very high paper feed speeds and a high cutting frequency, while the burden of noise is at the same time substantially reduced.
This is achieved according to the invention in that a guide plate is provided between the first feed device and the clamping device, in that the 15 guide plate is provided with a plurality of openings and in that the space above the guide plate is enclosed by a damping hood, which is spaced from the loop.
The damping hood leads in combination with the guide plate provided with openings to a great cutting accuracy even at very high paper feed speeds and high cutting frequencies. Even with paper feed speeds above 0.8 m/sec.
20 and a cutting frequency of more than 10 cuts/sec., cutting accuracies in the tenth of a millimeter range with a tolerance of ~0.3 mm are obtained. This is attributable to the fact that the defined and constant air pressure conditions exist inside the damping hood, which isolate the loop from ambient effects, such as air ~ lellls, heat effects and the like during the loop formation.
25 Moreover vibrations of the loop are damped and through this Replacement sheet ordered, reproducible loop formation is ensured. In this connection, the 5 arrangement of the guide plate provided with openings is also of importance.
The guide plate ensures that the loop can only form in one direction, upwards, while the openings assume decisive importance. Thus, during the whirling out of the loop, air can enter rapidly into the space between the loop and the guideplate but in particular the air can escape rapidly from this space again when the o loop is pulled flat again by the second feed device, after completion of the cutting operation. The invention makes it possible to increase the cutting rate to about 80,000 cuts per hour with a printed form height of 3 ". Thanks to the highcutting rate it is possible to carry out the cutting across on-line at the output of a laser printer, which contributes further advantages.
15 Advantageous emborliment~ of the invention are characterized in the dependent claims.
The invention will be explained below in more detail, with refel-ellce to several embodiments shown in the drawings, in which:
Figure 1 is a longitudinal section of the apparatus for cutting across a 20 paper web, Figure 2 is a partial lon~ 1in~1 section of this apparatus in the region of the loop formation to a larger scale, Figure 3 is a partial plan view in the direction III in Figure 2.
Replacement sheet 2l6 The apparatus for cutting across a paper web according to the embodiment shown in Figures 1 and 2 comprises a cutting tool 1 with a 5 stationary cutter blade 2 and a cutter blade 3 which can move up and down. A
first feed device 4 is provided, spaced before the cutting tool 1 and is in the form of a so-called tractor in this embodiment. The tractor consists of two conveyor belts S arranged parallel to one another, whose pins 6 engage in perforations at the two sides of the paper web 7. The feed device 4 is driven o continuously with a peripheral speed Vl, which corresponds for example to the discharge rate of a preceding laser printer, not sho~n. In the region between the feed device 4 and the cutting tool 1 there is provided a clamping device 8 driven synchronously with the latter. This clamping device 8 is preferably arranged in the vicinity of the cutting tool 1, i.e. its distance from the cutting 15 tool 1 is smaller than its distance from the feed device 4.
Replacement sheet 2l7 In between the clamping device 8, which will be described in more detail below, and the cutting tool 1 a second continuously driven feed device 9 is s preferably arranged directly adjoining the cutting tool, with its feed speed (=
peripheral speed) V2 greater than the feed speed Vl of the first feed device 4.
A third feed device 10 is advantageously provided after the cuffing tool 1 and is also continuously driven, namely with a feed speed V2 which corresponds to the feed speed V2 of the second feed device 9.
o The clamping device 8 comprises two jaws 11 which are spaced from one another in the transverse direction of the paper web 7 and of which only one is shown in the drawing. These jaws 11 cooperate with a stationary bed 12. Each jaw 11 is disposed on one end (the lower) of plunger 13 movable transverse to the feed direction A of the paper web 7, the other (upper) end carrying a roller14 which cooperates with a cam disc 15. The cam disc 15 can be driven in synchronism with the cutting tool 1. To this end a common belt drive is provided. The belt drive also drives the movable cutter blade 12. The drive of the belt drive is advantageously effected continuously but it can also be The drive speed n of the belt drive is so adjustable in relation to the feed speed Vl of the first feed device 4 that Replacement sheet a cut always takes place when the paper web 7 has been moved on by the feed device 4 by a length corresponding to the desired format height (= printe~ form 5 height) relative to the cutting tool 1.
The second feed device 9 and the third feed device 10 advantageously each comprise a continuously drivable feed roller 20 and 21 respectively and at least one pressure roller 22, 23 axially parallel thereto, which bear under elastic bias 24 on the feed rollers 20 and 21 respectively. The elastic bias 24 is o preferably adjustable. The drive of the two feed rollers 20, 21 can be effected by a third motor for example. This third motor imparts a feed speed V2 to the feed rollers 20, 21 which is four times as larges as the feed speed Vl of the first feed device 4 for example.
Furthermore a bowing out device 25 is provided between the first feed 15 device 4 and the clamping device 9 [8], which exerts a force P directed transversely relative to the feed direction A at least intçrrnitt~ntly. If the feed direction A runs substantially horizontally, as is the case in the embodiment shown in Figures 1 and 2, tbe force P should be di~ected u~wardly. This has the advantage that the advance of the paper web section 7a stored during the 20 cutting operation is also assisted by gravity after the release of the clamping device 8, as will be described in more detail below.
In order to generate the force P in the first place there can be provided a guide plate 26, which Replacement sheet 2l9 is bowed out transversely to the feed direction A relative to a plane E-E
tangential to the feed elements 5 of the first feed device 4 and the clamping 5 elements 11, 12 of the clamping device 8. In the embodiment shown the bowing out 26a is upwards.
The manner of operation of the apparatus described above is as follows:
During the operation of the apparatus, the first feed device 4 is driven continuously with a feed speed Vl and the second and third feed devices 9 and 10 respectively are driven continuously with a greater feed speed V2. The movable cutter blade 3 can also be driven continuously, so that a cutting operation and freeing the passage between the cutter blades 2 and 3 take place alternately. While the latter case applies the clamping device 8 is also opened,so that the paper web 7 is moved on in the direction A by the feed devices 4 15 and 9 and also by the feed device 10 with greater format heights. As soon as the paper web has moved relative to the cutting tool 1 by the set format height,the cam disc 15 presses the plunger 13 down, so that the paper web is clamped fast between Replacement sheet 2/lO
the jaws 11 and the stationary bed 12. The feed rollers 20, 21 of the second - feed device 9 and the third feed device 10 carry on tllrnin~. The movable cutter 5 blade 3 moves down and cuts off a paper sheet 7b of the desired format height,which is moved on irnmediately by the third feed device 10. The feed rollers 20, 21 have a smooth, steel surface and the elastic bias 24 is so chosen that the feed rollers 20, 21 can continue to turn during the clamping of the paper web, without ~m~ging this.
While the paper web is held fast by the clamping device 8 for the duration of the cutting operation, the first feed device 4 feeds the paper web on continuously. This paper web section which is fed on is stored in the form of a loop 7a bowed out transversely upwards relative to the theoretical straight feeddirection A. The bowing out is promoted by the bowed out guide plate 26 and 15 it is therefore ensured that the bowing out talces place in a predetermined direction, namely upwards. During the bowing out a stress develops in the loop 7a, like in a kinked rod. When the passage between the cutter blades 2, 3 becomes free again on completion of the cutting operation, the clamping device 8 also opens, in that the region lSa of the cam disc 15 comes into the range of 20 the roller 14. As soon as the clamping device 8 has opened, the second feed device 9 feeds on the end of the paper web adjoining the cutting device 1 with a feed speed V2, which is higher than the feed speed Vl of the first feed device4.
Replacement sheet The stored loop 7a is caused to decay by this. The further movement of the paper web section stored in the loop 7a is also promoted by the stress generated5 in the loop, which pushes the free end of the paper web on in the direction ofthe cutting tool 1. The loop 7a cannot expand to the rear because the paper web is constantly fed on by the first feed device 4. In addition to the stress built up in the loop 7a, gravity can also be effective in the embodiment shown, pushing the loop 7a down and thus moving the paper web on in the direction towards o the cutting tool 1. The second feed device 9 therefore only has to move on thesmall paper section 7a stored in the form of the loop, this ollw~-d movement being promoted by the stress built up during the clamping and by gravity.
The holding fast of the paper web can also be effected in another way, for example by clamping pincers which engage the edge of the paper web. What s matters is merely that the clamping device is so driven synchronously with thecutting tool that the clamping device holds the paper web fast during the cutting operation.
[There is no replacement page 2/12 for original page 12, since this was cancelled in its entirety.]
Replacement sheet An important contribution to the increase in the cutting rate is given by the formation of the region in which the loop formation takes place, shown in 5 Figures 2 and 3. It has in fact been ascertained that, with paper feed speeds from about 0.8 m/s (which corresponds to about 38,000 cuts per hour with a printed form height of 3"), unacceptable fluctuations in the cutting accuracy arise. In order to achieve an adequate cutting accuracy in the range of tenths of a millimeter, e.g. in the range +0.3 mm in spite of higher feed speed and higherlO cutting rates, Replacement sheet it is advantageous to make use of the features described below in combination.
The guide plate 26 is bowed upwardly, where the bowing is obtained by a s bend 26b in the guide plate. The guide plate 26 is furthermore provided with aplurality of openings 36, e.g. circular holes. Air can enter rapidly between theloop and the guide plate through these openings 36 during the bowing of the loop but in particular the air can escape rapidly from the space between the loop 7a and the guide plate 26 when the loop is pulled flat again by the second o feed device 9 after completion of the cutting operation. The paper web 7 then comes into contact with the bend 26b. The result of the friction occurring at this place is that the tension exerted on the paper web by the second feed device cannot propagate fully to the first feed device 4.
Furthermore, deflector plates 37, 38 which affect the loop formation are lS provided in the front and rear regions of the guide plate 26, as regarded in the feed direction A of the paper, above the guide plate and inclined oppositely towards one another. These deflector plates 37, 38 are fitted to assist uniform loop formation. The effect of the deflector plates 37, 38 is that the loop formation always takes place at approximately the same place and that the loop 20 does not wander forwards or backwards in the feed direction A. Above all the loop formation is reproducible because of the deflector plates 37, 38. In order to be able to affect the loop formation it is further advantageous for the inclination of each deflector plate 37, 38 relative to the guide plate 26 to be adjustable.
Replacement sheet To this end the deflector plates 37, 38 can each turn about an axis 39, 40 extending transversely to the feed direction A and can be fixed by a device 5 which is not shown.
Furthermore, the space above the guide plate 26 and above the deflector plates 37, 38 is enclosed by an damping hood 41. The damping hood 41 should be arranged a large distance from the loop 7a, so that there is enough air spacebetween the loop 7a and the interior of the damping hood. The damping hood o functions on the one hand as an air chamber which damps the vibrations which occur with the loop formation at high speeds and it serves on the other hand also for sound insulation.
The features used together in the embodiment shown in Figures 2 and 3 lead to stabilization and reproducibility of the loop formation, which 15 experience has shown is a pre-condition for high cutting accuracy at high cutting rates, with tolerances in the range of tenths of a millimeter.
Claims (4)
1. Apparatus for cutting across a paper web (7), with a stationary cutting tool (1) which has cooperating cutter blades (2, 3), with a first feed device (4) arranged before the cutting tool and which is driven continuously during operation of the apparatus, by means of which the paper web is fed between two successive cutting operations by a predetermined length each time, with a clamping device (8) provided in the region between the first feed device (4) and the cutting tool (1) and driven synchronously with the latter, by means of which the region of the paper web (7) immediately adjoining and lying before the cutting tool (1) can be clamped fast for the duration of the cutting operation, until the passage between the cutter blades (2, 3) is free again, and with a free space (30) provided in the region between the first feed device (4) and the clamping device (8), into which the paper web section continuously fed on by the first feed device during the cutting operation can expand in the form of a loop (7a) bowed out transversely relative to the theoretical straight feed direction (A), characterized in that a guide plate (26) is provided between the first feed device (4) and the clamping device (8), in that the guide plate (26) is provided with a plurality of openings (36) and in that the space above the guide plate (26) is enclosed by a damping hood (41), which is spaced from the loop (7a).
2. Apparatus according to claim 1, characterized in that the guide plate (26) is bowed upwardly relative to a plane (E-E) tangential to the feed elements (5) of the first feed device (4) and the clamping elements (11, 12) of the clamping device (8), transversely relative to the feed direction (A).
3. Apparatus according to claim 1 or 2, characterized in that deflector plates (37, 38) affecting the loop formation are provided in the front and rear regions of the guide plate (26) relative to the paper feed direction (A), above the guide plate and oppositely inclined towards one another.
4. Apparatus according to claim 3, characterized in that the inclination of each deflector plate (37, 38) relative to the guide plate (26) is adjustable.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE29506784.5 | 1995-04-21 | ||
| DE29506784 | 1995-04-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2212234A1 true CA2212234A1 (en) | 1996-10-24 |
Family
ID=8007149
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002212234A Abandoned CA2212234A1 (en) | 1995-04-21 | 1996-04-04 | Method and apparatus for cutting across a paper web |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0822915B1 (en) |
| JP (1) | JPH11503704A (en) |
| CA (1) | CA2212234A1 (en) |
| DE (2) | DE59603008D1 (en) |
| ES (1) | ES2136982T3 (en) |
| WO (1) | WO1996033122A1 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19532487A1 (en) * | 1995-09-02 | 1997-03-06 | Wella Ag | Device and method for transporting and cutting tape material |
| NL1013194C2 (en) * | 1999-10-01 | 2001-04-03 | Aremberg Beheer B V I O | Buffering process for strap material used for handing products involves air pressure exerting force on free part of length of strap material so that loop is formed |
| WO2002016243A2 (en) * | 2000-08-24 | 2002-02-28 | Moore North America, Inc. | Continuous web input guillotine cutter |
| US7124671B2 (en) | 2003-05-06 | 2006-10-24 | Pitney Bowes Inc. | Method and device for reducing web breakage in a web cutter |
| ITTO20030371A1 (en) | 2003-05-20 | 2004-11-21 | Tecnau Srl | CUTTING EQUIPMENT FOR CONTINUOUS MODULES. |
| JP2005001691A (en) | 2003-06-10 | 2005-01-06 | Sii P & S Inc | Heat-activating apparatus for heat-sensitive pressure-sensitive adhesive sheet |
| US20060156876A1 (en) | 2005-01-19 | 2006-07-20 | Pitney Bowes Incorporated | Motion control system and method for a high speed inserter input |
| DE102008006562A1 (en) | 2008-01-29 | 2009-10-15 | Böwe Systec AG | Method and device for transporting paper in a paper handling system from a first transport to a second transport |
| DE102019006046A1 (en) * | 2019-08-27 | 2021-03-04 | Mühlbauer Gmbh & Co. Kg | Device and method for intermittent conveying of a web of material along a conveying direction and for cutting the web of material |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB950654A (en) * | 1961-05-17 | 1964-02-26 | Thompson Jack Evans | Improvements in or relating to the manufacture of sheets from a reel of paper |
| DE3131101C2 (en) * | 1980-09-04 | 1986-03-06 | Vits-Maschinenbau Gmbh, 4018 Langenfeld | Method for cross-cutting a web of material, in particular made of paper, plastic or metal and stacking the cut sheets and device for carrying out the method |
| JPS58140755A (en) * | 1982-02-16 | 1983-08-20 | Fuji Xerox Co Ltd | Copying machine provided with punch mechanism |
| JPS59149265A (en) * | 1983-02-10 | 1984-08-27 | Ricoh Co Ltd | Sheets transport device of recorder |
| JPH04358658A (en) * | 1990-08-28 | 1992-12-11 | Mutoh Ind Ltd | Roll sheet conveying device for recording device |
| EP0825142B1 (en) * | 1993-08-16 | 2002-12-04 | Agfa Corporation | Method and apparatus for buffering media |
-
1996
- 1996-04-04 JP JP8531394A patent/JPH11503704A/en active Pending
- 1996-04-04 CA CA002212234A patent/CA2212234A1/en not_active Abandoned
- 1996-04-04 DE DE59603008T patent/DE59603008D1/en not_active Expired - Fee Related
- 1996-04-04 WO PCT/DE1996/000646 patent/WO1996033122A1/en active IP Right Grant
- 1996-04-04 EP EP96909042A patent/EP0822915B1/en not_active Expired - Lifetime
- 1996-04-04 ES ES96909042T patent/ES2136982T3/en not_active Expired - Lifetime
- 1996-04-18 DE DE29607062U patent/DE29607062U1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH11503704A (en) | 1999-03-30 |
| WO1996033122A1 (en) | 1996-10-24 |
| DE29607062U1 (en) | 1996-06-13 |
| DE59603008D1 (en) | 1999-10-14 |
| ES2136982T3 (en) | 1999-12-01 |
| EP0822915B1 (en) | 1999-09-08 |
| EP0822915A1 (en) | 1998-02-11 |
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| FZDE | Dead |