EP0329089A1 - Paper feeding device for a high-speed single sheet processing printer - Google Patents

Abstract

A feeding mechanism (26) removes with frictional engagement a printed or unprinted paper web (12) from a supply roll (10). Single sheets (14) are cut off the paper web (12) using a cutting device (28) and are fed by means of a conveying device (32) to the document feeder of a high-speed printer. A smoothing device (22) connected in front of the cutting device (28) cancels out curves in the paper web (12) as a result of their mounting on the supply roll (10) and smooths out possible unevenness in the paper web (12) by means of the smoothing rollers (40, 42). A perforating device (24) can be used to punch transmission holes into the paper web (12). The individual sheets (14) cut from the paper web (12) are placed by means of an acceleration device (30) to give an overlapping formation onto the conveying device (32). The large storage capacity of the supply roll (10) makes it possible for the high-speed printer to be supplied over lengthy periods with individual sheets (14) from a single supply roll (10) without interrupting the operation. <IMAGE>

Description

The present invention relates to a device for feeding paper to the feed device of a single-sheet high-speed printer according to the preamble of claim 1.

Fast printers such as laser printers and other non-impact printers are characterized by a very high processing speed. If the paper supply now consists of a stack of single sheets, which is accommodated in a stacking shaft, this stack will be dismantled after a short time. This leads to frequent filling of the stacking shaft and thus to corresponding interruptions in the printing process. Furthermore, an operator must be ready to fill the stacking shaft as soon as it is empty. The provision of a second stacking shaft also does not make any significant relief.

To solve these problems, a device of the type mentioned above has now been proposed, in which the paper supply is provided in the form of a paper web folded in a zigzag shape to a stack (DE-OS 33 34 825). The paper web is withdrawn from the stack and gradually fed to an intermittent cutting device which cuts the paper web in the area of the folds. The resulting single sheets are then in a scale formation, in which each sheet is like a tile on the preceding sheet rests, fed to the feeder of the fast printer.

In order to avoid that the fold lines appear on a single sheet, a paper strip containing the latter is cut away in the area of each fold line and is carried away as waste. This paper strip is cut away in two successive cutting operations, which has a delaying effect on the entire working process, in particular because of the intermittent operation of the cutting device. Furthermore, the format of the single sheets is determined by the width of the paper web on the one hand and the spacing of the folding lines to be cut away.

The present invention is based on the object of creating a device of the type mentioned for the reliable provision of single sheets for various types of high-speed printers, which is more efficient than the previously known device and in which practically no paper waste occurs when the single sheets are formed.

According to the invention, this object is achieved by the features of the characterizing part of claim 1.

Because the paper supply is present as a paper web wound into a roll, paper webs can be processed without folding lines, which should be taken into account when cutting the paper web or which have to be cut away. Therefore, a new cut sheet can be cut off with a single cut without the noteworthy paper waste arises.

The distance between two cutting lines remains essentially the same, so that the conditions for a continuous cutting process and thus a continuous feed of the paper web are given. This enables a correspondingly high work performance.

Furthermore, it is possible to change the format of the single sheets without much effort and above all without changing the paper supply roll.

Unperforated paper webs can also be processed from a roll, in which case the paper web is pushed forward by the feed mechanism by frictional engagement.

A smoothing device is preferably provided in which the paper web is smoothed as it passes through. As a result, curvatures in the paper web are reversed, which result from the storage of the paper web on a roll or are formed when the paper web is at a standstill where the paper web is guided over deflection rollers.

In a further preferred embodiment of the device according to the invention, the individual sheets are inserted from below into a stack in front of the feed device of the high-speed printer, from which the take-off device pulls the sheets from above.

Further preferred refinements of the device according to the invention form the subject of claims 6 to 18th

• Fig. 1 in Seitenansicht eine Darstellung einer ersten Ausführungsform einer erfindungsgemässen Vorrichtung,
• Fig. 2 die Vorrichtung gemäss Fig. 1 im Grundriss,
• Fig. 3 in Draufsicht in Richtung des Pfeiles III der Fig.1 die teilweise abgeschnitten dargestellte Fördereinrichtung,
• Fig. 4 einen einer Seitenansicht der Fördereinrichtung entsprechenden Schnitt entlang der Linie IV-IV der Fig. 1,
• Fig. 5 in Seitenansicht die Steuerung des Vorschubme­chanismus der Vorrichtung gemäss Fig. 1, und
• Fig. 6 in Sietenansicht, und
• Fig. 7 im Grundriss eine zweite Ausführungsform einer erfindungsgemässen Vorrichtung.

The present invention will now be described in more detail using exemplary embodiments. The drawing shows purely schematically:

• 1 shows a side view of a first embodiment of a device according to the invention,
• 2 shows the device according to FIG. 1 in plan view,
• 3 is a top view in the direction of arrow III in FIG.
• 4 shows a section corresponding to a side view of the conveyor device along the line IV-IV of FIG. 1,
• 5 is a side view of the control of the feed mechanism of the device according to FIG. 1, and
• Fig. 6 in sieten view, and
• Fig. 7 in plan a second embodiment of a device according to the invention.

The device shown in FIGS. 1 to 5 unwinds a non-perforated, printed or unprinted paper web 12 from a supply roll 10, processes these into single sheets 14, which one with its feeding device 16 (see FIG. 3) indicated, non-mechanically working high-speed printer P, for example a laser printer or another non-impact high-performance printer.

The supply roll 10 is rotatably mounted in an unwinding station 18, which is only indicated by a dash-dotted axis cross. The direction of rotation of the supply roll 10 when unwinding the paper web 12 is indicated by the arrow A. From the supply roll 10, the paper web 12 runs over a number of deflection rollers, of which only the deflection roller 20 is shown, through a smoothing device 22 and a perforating device 24 to a feed mechanism 26. The feed mechanism 26 pulls the paper web 12 in the direction of conveyance B from the supply roll 10 and feeds them to a cutting device 28 which cuts the paper web 12 in the transverse direction and feeds the individual sheets 14 thus separated to an accelerating device 30. The acceleration device 30 deposits the cut sheets 14 into a scale formation S on a conveyor device 32, which conveys the scale formation S to the feed device 16 of the high-speed printer P. In the following, these facilities will be described in more detail.

The smoothing device 22 has two guide roller pairs 34, 36 spaced apart from one another in the conveying direction B of the paper web. The paper web 12 is guided through the conveying gap between the two guide rollers of each pair of guide rollers 34, 36. Between the two pairs of guide rollers 34, 36 there is a crowbar 38 with a square cross section in a direction of arrow C. Slidably mounted perpendicular to the plane of the paper web 12. In solid lines, the crowbar 38 is indicated in the rest position and with dash-dotted lines in its lowest working position 38 '. The crowbar 38, which runs parallel to the paper web 12 and at right angles to the conveying direction B, can be brought into contact with an edge on that upper side of the paper web 12 which was located on the supply roll 10. The pretension or curvature which the paper web 12 has received in the supply roll 10 is canceled with the crowbar 38. For this purpose, the diameter of the supply roll 10 is scanned in a manner not shown and the crowbar 38 is transferred from the rest position 38 into the working position 38 'in accordance with the decrease in this diameter.

Following the pair of guide rollers 36, as seen in the conveying direction B, three rotatably mounted smoothing rollers 40, 42 are provided above and below the paper web 12. The upper smoothing rollers 40 are arranged above the paper web 12 stretched between the pair of guide rollers 36 and a further guide roller 44, so that they just touch this stretched paper web 12. These smoothing rollers 40 are arranged parallel to one another at a mutual distance which is greater than the diameter of the smoothing rollers 40. The lower smoothing rollers 42 are mounted on a frame 46 which can be displaced in the direction of arrow D. The lower smoothing rollers 42 are offset with respect to the center of the upper smoothing rollers 40 and, together with the frame 46, are shown in their rest position with solid lines. Dash-dotted and with 46 ′ they are designated in their working position, in which they are located between the upper smoothing rollers 40 and bend the paper web 12 in a meandering shape. As long as the device is in operation, the smoothing rollers 42 are in the working position and smooth out any unevenness in the paper web 12 which, when the device is at a standstill, in the deflection roller 20 or other deflection rollers (not shown in FIG. 1) between the supply roller 10 and the smoothing rollers 40, 42 guided paper web 12 can be embossed. On the other hand, as soon as the device is shut down, the smoothing rollers 42 together with the frame 46 and the crowbar 38 are moved into their rest positions so that they do not impress the pretensions and unevenness on the paper web 12 when the device is stationary.

The perforating device 24 for producing storage holes has a stamping roller 48 arranged above the paper web 12 and a die roller 50 cooperating therewith and arranged below the paper web 12. These two rollers are driven by a drive motor 52 at a peripheral speed which corresponds to the conveying speed v of the paper web 12. On the stamping roller 48, stamps 54 are provided, which can be fastened to the stamping roller 48 in the individual sheets 14, depending on the desired perforation. By removing all of the stamps 54 from the stamping roller 48 or by moving the stamping roller 48 and die roller 50 apart, the punching device 24 can be switched off in order to form single sheets 14 without any perforations in the deposit.

The feed device is located in front of the cutting device 28 mechanism 26, the feed roller pair 56 of which can be driven by means of a further drive motor 58. The feed roller pair 56 acts on both sides of the paper web 12, the force being transmitted to the paper web 12 without transport perforations by friction. By means of the feed mechanism 26, the paper web 12 is drawn off from the rotatably mounted supply roll 10 and fed to the cutting device 28.

The cutting device 28 has a cross cutting device 62 which is driven by means of a further drive motor 60 and a downstream belt conveyor 66 which is operatively connected to it by means of a gear 64. Provided in the cross cutting apparatus 62 is a knife shaft 68 which is rotatably mounted and rotated above the paper web 12 and has two knives 69 and a counter shaft 70 which cooperates therewith and is arranged below the paper web 12 and is also rotatably driven. The belt conveyor 66 has two conveyor belts 72 arranged one above the other, which delimit a common conveying gap and which are driven in the conveying direction B at a speed which is slightly greater than the conveying speed v of the paper web 12. A single sheet separated from the conveying path 12 by means of the cross-cutting device 62 14 is conveyed from the belt conveyor 66 to the downstream acceleration device 30; the leading edge 12 'of the paper web 12 thus formed runs into the conveyor gap formed by the conveyor belts 72 and the section of the paper web 12 between the feed mechanism 26 and the belt conveyor 66 becomes light due to the higher conveyor speed of the conveyor belts 72 stretched so that the separation of the single sheets 14 can be done with a clean cut.

The belt conveyor 66 places the single sheets 14 on a further belt conveyor 74 of the acceleration device 30. At the end of the effective conveyor section of the belt conveyor 74, an acceleration roller 76 is provided above this belt conveyor 74. The belt conveyor 74 and the acceleration roller 76 are driven by a further drive motor 77 in the conveying direction B at a speed v1 which is greater than the conveying speed v of the paper web 12. The individual sheets 14 placed on the belt conveyor 74 reach the conveying gap at the end of the conveying path between the belt conveyor 74 and the accelerating roller 76 and are fed to the conveying device 32 at the conveying speed v1 and conveyed against an angular stop 78.

As can be seen particularly well from FIG. 3, the conveying direction E of the conveying device 32 runs at right angles to the conveying direction B of the paper web 12. This has the consequence that the individual sheets 14 fed in the longitudinal direction of the conveying device 32 have the shorter direction in their transverse direction Side edges running parallel to the conveying direction E, are conveyed further.

As can be seen in particular from FIG. 4, the conveyor device 32 has a belt conveyor 79, the endless belt 80 of which is guided around a deflection roller 82 at the end of the conveyor-effective route. The deflecting roller 82 is moved in the direction by means of a further drive motor 84 of arrow F driven at speed v2. Another belt conveyor 86 surrounds the deflecting roller 82 and the conveying strand of this belt conveyor 86 forms, together with the deflecting roller 82 or the endless belt 80, a conveying gap 88 for the single sheets 14, which encloses the deflecting roller 82 by approximately 180 °. A stop 90 for forming a buffer stack 94 from the individual sheets 14 is provided in the end region of the conveyor section 86 which is effective for conveying. In the example shown in FIG. 4, this stop 90 is formed by the feed device 16 of the high-speed printer. The feed device 16 advantageously belongs to the original equipment of the fast printer.

The single sheets 14 delivered by the acceleration device 30 in the conveying direction B at the speed v1 arrive at the angular stop 78 for precise positioning before they are taken along by the belt conveyor 79 in the direction of the arrow E. The speed v2 of the belt conveyor 78 is matched to the cycle of the individual sheets 14 that are produced such that each individual sheet 14 is placed overlapping on the leading individual sheet 14. The scale formation S thus formed runs into the conveying gap 88 and is guided around the deflection roller 82, which has the consequence that when leaving the conveying gap 88, the initially overlying side of the scale formation S is now underneath and in the conveying direction E 'seen now each individual sheet 14 on the next one. Thus, each individual sheet 14 is pushed under the individual sheets 14 which are in contact with their leading edges at the stop 90, which results in the build-up of the buffer stack 94 from below, from which the feed device 16 of the subtracts top sheet 14 in each case.

The operating speed of the described device for feeding paper to the single-sheet high-speed printer is adjusted so that the height of the buffer stack 94 remains approximately constant. It is therefore always ensured that enough single sheets 14 are available for the fast printer. However, a start-stop operation is also conceivable, in which the buffer stack 94 is built up to its maximum height and the device is then shut down until the buffer stack 94 has reached a minimum permissible height.

If a printed paper web 12 is processed, the cutting cycle of the cutting device 28 must be matched to the printing. An embodiment of a corresponding synchronization control will now be described with reference to FIG. 5, in which a section of FIG. 1 is shown. This synchronization control 96 has a control unit 98, the output of which is connected to the drive motor 58 for the feed rollers of the feed mechanism 26. A scanner 100 is connected to one input of the control unit 98 and is used to scan markings which are applied to the paper web 12 at regular intervals. Another input of the control unit 98 is connected to a pulse generator 102 which is coupled to the cutting device 28 and which generates signals characterizing the cutting position of the cutter shaft 68 and the counter shaft 70. On the basis of the signals obtained from the scanner 100 and from the pulse generator 102, the control unit 98 generates control signals for the drive motor 58 of the Feed mechanism 26, so that the paper web 12 is advanced at a speed v such that the paper web 12 is inserted into the cutting device 28 in the correct phase and the printing of the paper web 12 is cut accordingly at the correct location.

Some variants of the device shown in FIGS. 1 to 5 are now briefly explained below.

It is also conceivable not to place the individual sheets 14 in the formation S on the conveyor device 32 as shown, but rather without overlapping. This can be achieved by increasing the conveying speed of the conveying device 32 accordingly. In this case, the turning device, that is to say the deflection roller 82, can be dispensed with under certain circumstances.

In Figures 1 to 4 it is shown that the conveying direction E, E 'of the conveyor 32 is perpendicular to the feed direction B of the paper web 12. In such an arrangement, the single sheets 14 are fed to the printer P in a direction that is perpendicular to the longitudinal extension of the paper web 12. If this is not necessary and the individual sheets 14 can also be fed to the printer P in a direction that runs parallel to the longitudinal extent of the paper web 12, the conveying device 32 can also be arranged such that its conveying direction E is parallel to the conveying direction B of the paper web 12 runs. Such an embodiment variant is shown in FIGS. 6 and 7, which correspond to FIGS. 1 and 2.

The embodiment according to FIGS. 6 and 7 corresponds to up to and with belt conveyor 66 of the embodiment according to FIGS. 1 to 5. For this reason, the same reference numbers are used in FIGS. 6 and 7 for the same components as in FIGS. 1 and 2.

In the device shown in FIGS. 6 and 7, the sheets cut by the cutting device 28 are fed by the belt conveyor 66 to a belt conveyor 104 which belongs to the conveyor device 32. This belt conveyor 104, which is driven in rotation by a drive motor denoted by 106, has a conveying direction E which coincides with the feed direction B of the paper web 12. The single sheets taken over by the belt conveyor 104 are inserted at the bottom into a buffer stack 94, from which the feed device 16 pulls the single sheets from above and feeds them into the printer P. The insertion of the single sheets into the buffer stack 94 from below is possible because this buffer stack 94 is not very high and the belt conveyor 104 is designed such that the adhesion between the belt conveyor and the single sheet conveyed by it is greater than the adhesion between the conveyed sheets Single sheet and the overlying sheet of the buffer stack 94.

In the device according to FIGS. 6 and 7, the individual sheets are introduced into the buffer stack 94 by the conveying device 32 without overlapping. Of course, it is also possible, in a manner similar to that described with reference to the exemplary embodiment according to FIGS. 1 to 5, of the individual sheets in scale formation on the Place conveyor 32 and turn this scale formation as described with reference to the first embodiment.

In addition, it is also possible in the variant according to FIGS. 6 and 7 to arrange the belt conveyor 104 such that its conveying direction is perpendicular to the feed direction B of the paper web 12 if the sheets are required to be fed to the printer P in a direction which runs at right angles to the longitudinal extent of the paper web 12.

In both embodiments, two or more of the drive motors 52, 58, 60, 77, 84, 106 can be replaced by a single drive motor, which then possibly drives several assemblies via gears.

The devices described are in principle also able to process paper webs which are not drawn off from a paper supply roll as shown and described, but are instead taken from an endless stack which is formed by a paper web folded in a zigzag shape.

Claims (18)

1. Device for feeding paper to the feeder (16) of a single sheet (14) processing high-speed printer (P), with a memory (10) for a paper web (12), a feed mechanism (26) for feeding the memory (10) removed Paper web (12) to a cutting device (28) which cuts individual sheets (14) from it by cross cutting the paper web (12) and a conveyor device (32) connected downstream of the cutting device (28) for feeding the single sheets (14) to the fast printer (P) , characterized in that the paper web storage is a supply roll (10) which is rotatably mounted in an unwinding station (18) and is formed by a wound, printed or unprinted paper web (12). 2. Device according to claim 1, characterized in that the paper web (12) on the supply roll (10) is not perforated and the feed mechanism (26) engages with friction on the paper web (12). 3. Device according to claim 1, characterized in that a smoothing device (22) for smoothing the paper web (12) is provided upstream of the feed mechanism (26) and can be brought into action on the paper web (12). 4. The device according to claim 1, characterized in that the cutting device (26) as a continuous driven rotary cutting arrangement is formed and the feed mechanism (26) feeds the paper web (12) continuously. 5. The device according to claim 1, characterized in that in the end region of the conveyor (32) a stop (90) for the leading edges of the supplied single sheets (14) is provided in order to introduce them from below into a buffer stack (94), of which the feed device (16) of the high-speed printer pulls the single sheets (14) from above. 6. The device according to claim 4, characterized in that between the conveying device (32) and the cutting device (26) is arranged the cut single sheets (14) from the latter further conveying device (66) is arranged, the conveying speed is greater than that (v) the feed mechanism (26). 7. The device according to claim 3, characterized in that the smoothing device (22) a between two guides (34, 36) for the paper web (12) arranged, in one direction (C) transverse to the paper web (12) displaceable crushing member (38) which can be brought into abutment on that side of the paper web (12) which is on the outside of the supply roll (10). 8. The device according to claim 3, characterized in that the smoothing device (22) arranged on both sides of the paper web (12) to parallel to the paper web (12) and substantially perpendicular to the conveying direction (B) of the paper web (12) axes rotatably mounted smoothing tion rollers (40, 42) and the smoothing rollers (42) provided on one side of the paper web (12) can be displaced in a direction (D) transverse to the paper web (12) between the smoothing rollers (40) provided on the other side deflect the paper web (12) in a meandering shape. 9. The device according to claim 4, characterized in that the cutting device (28) has a cross-cutting apparatus (62) with a rotatably drivable knife shaft (68) and a counter element (70), preferably a counter roller, between which the paper web (12) passes . 10. The device according to claim 1, characterized in that between the cutting device (28) and the conveying device (32) an acceleration arrangement (30, 66) for the single sheets (14) is provided, the dispensing cycle in such a way to the conveying speed (v2) of the conveying device (32) it is coordinated that the individual sheets (14) delivered by the acceleration arrangement (30, 66) to the conveying device (32) overlap one another in the manner of roof tiles and form a scale formation (S). 11. The device according to claim 10, characterized in that the conveying device (32) has a turning device (82, 86) in order to turn the scale formation (S) in such a way that its underside comes to lie upwards. 12. The apparatus according to claim 11, characterized in that the turning device (82, 86) has a deflection roller (82) and a belt conveyor (86) surrounding the latter, with the deflection roller (82) forming a conveyor nip (88) for the scale formation (S). 13. The apparatus according to claim 12, characterized in that the turning device (82, 86) has a further belt conveyor (79), the endless belt (80) is guided around the deflection roller (82) and on which the acceleration arrangement (30, 66 ) delivered single sheets (14) in scale form (S) come to rest. 14. The apparatus according to claim 1, characterized in that the conveying direction (E) of the conveyor (32) is substantially perpendicular to the conveying direction (B) of the paper web (12). 15. The apparatus according to claim 4, characterized by a feed rate (V) of the feed mechanism (26) regulating control arrangement (96) for adjusting the respective cutting time of the cutting device (28) to the printing on the paper web (12). 16. The apparatus according to claim 15, characterized in that the control arrangement (96) has a control unit (98) which is connected on the output side to the drive (60) of the cutting device (28) and to the input side a scanner (100) for scanning on the Paper web (12) is applied at regular intervals and a signal transmitter arrangement (102) assigned to the cutting device (28) is connected, which generates signals characterizing the cutting position. 17. The apparatus according to claim 6, characterized in that the conveying device (32) has a belt conveyor (104) taking over the individual sheets (14) from the further conveying device (66), the conveying direction (E) of which with the conveying direction (B) of the paper web (12). matches. 18. The apparatus according to claim 1, characterized in that it is removably attachable to a fast printer (P).

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