JP2007521216A - Sheet cushioning device and sheet cushioning method - Google Patents

Abstract

The invention concerns sheet buffering means for placement between paper handling equipment, such as a printer or a paper picker, and paper finishing equipment, for example, equipment for stapling and/or folding, which comprises at least a set of a front pair of rollers with rotating rollers for feeding of a sheet between the rollers and a rear pair of rollers with rotating rollers for feeding of a sheet between the rollers. At least one roller in each pair is driven by a common motor or a motor each, the front driven roller is disengageable by means of a clutch for holding a lead end of a sheet at the same time as the rear driven roller is driven so that the sheet becomes bent between the two pairs of rollers. The rear pair of rollers is stopped when the trail end of the sheet reaches the rear pair of rollers, whereby the sheet may sustain bent until it is desirable to feed it out, which is achieved by starting both of the pairs of rollers. The invention also concerns a method of buffering sheets.

Description

  The present invention is arranged between a paper handling machine (printer, offset press, copier, paper collating machine, etc.) and / or a paper finishing machine (for stapling and / or folding, etc.) The present invention relates to a sheet cushioning device and a sheet cushioning method.

  Copiers and printers are increasingly performing and the number of output sheets per unit time is increasing. Also, a feature that has become common is that, for example, two to eight sheets are output one after another with a pause. For example, three sheets are output one after another with a close interval, and then after a pause, three sheets are output one after another with a close interval.

  A paper finishing device is usually provided after a paper handling device (such as a printer or a paper collator) in the form of editing, stapling, folding, folding processing (such as right-angle folding), bookbinding, or mail insertion. It is. A paper finishing apparatus for processing sheets generally must be capable of paper processing at a sheet speed during successive sheet feeding. This requires very high speed equipment, and such equipment is therefore expensive to manufacture, purchase and maintain due to speed requirements. In order to be able to use a simple and inexpensive device that does not meet the speed requirement, it is necessary to give a time interval to a selected part of the process.

  One attempt to solve the problem is shown in US Pat. No. 5,289,251. The shock absorber includes a number of paper traveling paths and a plurality of pairs of driving rollers. In order to cushion one or more sheets, at a middle stage, a pair of rollers stops feeding the leading edge of the sheet being fed in the forward direction, causing the sheet to bend upward, with the trailing edge of the sheet A special paper traveling path is formed so that the sheet is ejected above the rear roller pair so that the sheet becomes flat. Thereafter, the second sheet is sent to the lower side of the sheet flipped upward, and then the sheets are output together with the sheets slightly shifted.

  Although this shock absorber solves the time problem, it presents several drawbacks. For example, the problem is that printers / copiers and / or other paper handling devices are arranged longitudinally with subsequent paper finishing devices in multiple stages. Today's devices form a very long line and are difficult to install. The cushioning flat sheet described in US Pat. No. 5,289,251 provides cushioning but requires space in this part of the device. In special cases, the customer is virtually unable to incorporate other equipment parts into the processing sequence. Another problem is that it requires a long paper path. Complex paper paths are expensive to manufacture and to incorporate into paper machines. In order to keep this cost low, the paper path must be as short and simple as possible.

  The object of the present invention is to solve these problems, which can be achieved by the sheet cushioning device according to claim 1 and the sheet cushioning method according to claim 9.

  An advantage of the present invention is that the length of the processing sequence can be greatly reduced because the curvature of the sheet (s) is maintained over the entire buffer time. Furthermore, the number of paper travel paths is considerably reduced, and the length and complexity thereof are reduced. This results in simpler and cheaper operating means that are smaller and easier to operate.

  An embodiment of the present invention will be described as an illustrated example.

  FIG. 1 shows a sheet cushioning device intended to cushion a maximum of two sheets 7, which includes an upper cushioning path 11 and a lower cushioning path 12. For the sake of clarity, first, the upper buffer path 11 will be described. Of course, the sheet cushioning device can include only a single buffer path for cushioning a single sheet, if desired.

  The sheet 7 is guided to the rear roller pair 13 by the wing body 5. The rear roller pair 13 includes a driven roller 1 and a counter roller 8. The rear roller pair 13 feeds the sheet 7 in the forward direction, so that the sheet 7 reaches the front roller pair 14. The front roller pair 14 includes a driven roller 2 and a counter roller 9.

  When the front end 16 of the sheet 7 reaches at least the biting portion 15 of the front roller pair 14, the front roller pair 14 stops, and the front end 16 of the sheet 7 is held at the biting portion 15 position. Meanwhile, the rear roller pair 13 continues to feed the sheet 7 in the forward direction. As a result, the sheet 7 is curved upward. This is because the guide 6 prevents the sheet from being bent downward.

  The guide 6 is not necessary for correctly guiding the sheet 7 relative to the front roller pair 14, but is necessary for curving it in the desired direction. In order to easily start this curve, it is preferable that the guide 6 is slightly curved upward. If necessary, the driven guide 10 may be provided toward the front roller pair 14. The driven guide does not prevent the sheet 7 from being bent, and prevents the sheet 7 from hitting the driven roller 2 of the front roller pair 14.

  The rear end 18 of the sheet 7 reaches the biting portion 17 between the two rollers 1 and 8, or immediately before that, the rear roller pair 13 also stops, and the curved sheet 7 is held in the sheet cushioning device. become. When the sheet 7 is to be delivered, the front and rear roller pairs 14, 13 begin to move, feeding the sheet 7 to the next paper finishing device. Preferably, these roller pairs are driven at a high speed during their delivery to save additional time.

  It is preferable that the rollers 1 and 2 are driven and the opposing rollers 8 and 9 are only driven, but the opposing rollers 8 and 9 are also driven as required (see FIG. 1). The driven rollers 1 and 2 are each driven by a motor (for example, an electric motor), but it is preferable to drive the rollers 1 and 2 by the same motor 19. At that time, the clutch 22 is provided on the driven roller 2 so that the front roller 2 can be separated from the driving force and stopped when the front end 16 of the sheet 7 is held at a fixed position. The driving force of the motor 19 is transmitted to both the rollers 1 and 2 by the transmission belt 23. The friction brake 30 may be provided so that a rigid sheet does not pass through the front roller pair 14 by its own movement. The roller pairs are spring-biased with respect to each other, and at least the peripheral surface may be provided with a flexible material.

  As seen in FIG. 1, the lower buffer path 12 is in a mirror image relationship with the upper buffer path 11. However, it is conceivable to arrange the upper buffer paths so as to overlap each other or to arrange the lower buffer paths so as to overlap each other as necessary. In that case, the distance between the two travel paths must be increased so that a highly curved seat is accommodated between the two travel paths. Similarly, a larger number of buffer paths can be provided in the same sheet buffer if necessary.

  The wing body 5 can be angled between the different buffer paths 11, 12 in order to guide the seat 7 to the desired buffer paths 11, 12 (more if necessary). It is also preferable to provide two short and simple paper travel paths 20 on each side of the wing body 5. Similarly, it is preferable to provide two short and simple paper travel paths 21 at the exit end 24 of the sheet cushioning device for guidance towards the subsequent paper finishing device.

  In order to control the function of the sheet cushioning device, a signal is required from the subsequent paper finishing device indicating that the sheet 7 is ready to be received. With this signal, the sheet 7 is sent directly through the sheet buffer without being held. If the paper finishing device is not ready (i.e., when processing a large number of sheets 7), the sheet cushioning device is set to the activated state. When a sheet is detected by the inlet sensor 26 provided at the inlet 25 of the sheet cushioning device, the wing body 5 is set to the empty position, and the driven rollers 1 and 2 start to rotate in the selected buffer paths 11 and 12.

  When the front sensor 16 of each buffer path detects that the front end 16 of the sheet 7 has reached at least the biting portion 15 between the driven roller 2 and the opposite roller 9, the driven roller 2 is released from the driving force. Thus, the front roller pair 14 stops and the front end 16 of the sheet 7 is held at a predetermined position. The inlet sensor 26 detects immediately or completely when the rear end 18 of the sheet 7 reaches the biting portion 17 between the driven roller 1 and the opposite roller 8, and the motor 19 is cut off. The wing body 5 is then directed to an empty buffer path.

  When the next sheet 7 is fed and the paper finishing device is not ready to accept a new sheet 7, this sheet 7 is similarly held in the sheet buffer. Thereafter, when the paper finishing device is ready to accept a new sheet 7, the roller pairs 13, 14 of each buffer path start to drive together, whereby the sheet 7 is delivered from one buffer path at a time, i.e. They are sent out simultaneously in parallel, or both sheets 7 are sent out in an overlapping intermediate form.

  If necessary, for example, the sheet may be fed as a bundle through the sheet buffer path without performing intermediate holding. This is achieved, for example, by the rollers being spring biased against each other.

  Although the preferred embodiments of the present invention have been described above, those skilled in the art will appreciate that the present invention can be modified within the technical scope described in the claims.

The suitable example of this invention sheet buffering device is shown. Fig. 2 shows driving of a roller in the preferred example of Fig. 1.

Claims (11)

In a sheet cushioning device disposed between a paper handling machine such as a printer or a paper collator and a paper finishing machine (for example, a device for stapling and / or folding),
At least one set of front roller pairs having rotating rollers that feed sheets between the rollers and rear roller pairs having rotating rollers that feed sheets between the rollers, wherein at least one roller in each pair is a common motor, or The front driven rollers driven by the respective motors can be released by the clutch when the rear driven rollers are driven in order to hold the front end of the sheet. The sheet is curved in between, and the back roller pair is stopped when the trailing edge of the sheet reaches the back roller pair, until the sheet is desired to be delivered Is held and the sheet feeding is performed by starting both the roller pairs. Location.   The sheet cushioning device according to claim 1, wherein when the sheet is fed, the roller pair can be driven at a high speed.   The sheet cushioning device according to claim 1, wherein a sensor for detecting a front end position of the sheet is disposed to control driving of the front roller pair.   4. The sheet cushioning device according to claim 1, wherein an entrance sensor for detecting a rear end position of the sheet is disposed to control driving of the rear roller pair.   The sheet cushioning device according to any one of claims 1 to 4, wherein at least two pairs of front and rear roller pairs are disposed to cushion at least two sheets.   The sheet cushioning device according to claim 6, wherein a wing body for guiding a sheet to a desired rear roller pair is disposed in front of the rear roller pair.   The guide member is disposed between the pair of front and rear rollers, and the guide member prevents the sheet from bending in a direction in which the guide member is disposed. The sheet shock absorber described in 1.   The sheet cushioning device according to any one of claims 1 to 7, wherein a friction brake is provided on the front roller pair. In a method of buffering a sheet between a paper handling machine such as a printer or a paper collator and a paper finishing machine (for example, a device for stapling and / or folding),
While the front end of the sheet is fed between the front roller pair and the rear roller pair continues to feed the sheet, at least when the front end of the sheet reaches the biting portion of the front roller pair, the front roller pair is stopped. When the sheet is bent between the two roller pairs, and the trailing edge of the sheet reaches the biting portion of the rear roller pair at the latest, the rear roller pair is stopped and the feeding is desired. And starting the driving of the pair of front and rear rollers.   The sheet cushioning method according to claim 9, wherein the driving of the front and rear roller pairs is faster at the time of feeding than at the time of feeding. The sheet cushioning method according to claim 9 or 10, wherein at least two pairs of front and rear rollers are provided in order to perform cushioning with at least two sheets.

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