Abstract
A method of grouping sheet units, which belong together in sheet groups, a sheet stream comprising two superposed sheet units each by means of a grouping unit, a grouping unit for a sheet handling system, and a sheet handling system that allow a high processing speed and a high cycle efficiency of a sheet handling system are disclosed. A sheet unit can be held back in the grouping unit. Depending on whether the downstream subsequent sheet units transferred into the grouping unit belong to a sheet group, the held-back sheet unit can be released by itself and together with one or together with both downstream subsequent sheet units.
Claims
1. A method of grouping sheet units, which belong together in sheet groups, of a sheet stream comprising two superposed sheet units each, the method comprising: a) transferring the superposed sheet units into a grouping unit; b) transferring the superposed sheet units into a collecting station disposed downstream of the grouping unit if the sheet units transferred into the grouping unit belong to the same sheet group; c) otherwise: transferring a sheet unit into the collecting station and holding the other sheet unit back in the grouping station, with the following provisos: i) transferring the held-back sheet unit into the collecting station if this sheet unit is not part of a sheet group of one of the sheet units to be transferred next into the grouping unit; ii) transferring the held-back sheet unit into the collecting station together with both sheet units to be transferred next into the grouping unit if both sheet units to be transferred next into the grouping unit belong to the sheet group of the held-back sheet unit; iii) otherwise: transferring the held-back sheet unit together with the sheet unit belonging to the same sheet group of the sheet units to be transferred next into the grouping unit and holding the other sheet unit back in the grouping unit and continuing the method with one of the processing steps i) to iii).
2. The method of claim 1, wherein following the processing steps b), i) and ii), the method is continued with processing step a).
3. The method of claim 1, wherein the following applies to the sheet units transferred into the grouping unit as described in processing step c): if a sheet unit is part of the sheet group that was transferred immediately prior thereto into the collecting station: transferring this sheet unit into the collecting station and holding the other sheet unit back in the grouping unit; otherwise: transferring a sheet unit, which is not part of a sheet group of the sheet units to be transferred next into the grouping unit, into the collecting station and holding the other sheet unit back in the grouping unit.
4. The method of claim 1, wherein, depending on the sequence in which the downstream subsequent sheet units are arranged and/or on the arrangement of a sheet unit held back in the grouping unit, the sheet units to be transferred next into the grouping unit are arranged so as to be disposed above or below a sheet unit held back in the grouping unit.
5. The method of claim 1, wherein the grouping unit comprises a suction device, by means of which a sheet unit is held back in the grouping unit.
6. The method of claim 1, wherein the sheet units are marked with an identifier that indicates which sheet group the sheet units belong to, with the identifier being read out prior to the transfer of the sheet units into the grouping unit.
7. The method of claim 1, wherein the superposed sheet units to be transferred into the grouping unit are arranged so as to overlap in the sheet travel direction.
8. The method of claim 7, wherein only the superposed sheet units, which do not belong to the same sheet group, are arranged so as to overlap.
9. The method of claim 1, comprising the discharge of a complete sheet group from the collecting station prior to feeding a new sheet group into the collecting station.
10. A grouping unit for a sheet handling system, the grouping unit comprising: a transporting system for transporting sheet units of a sheet stream comprising two superposed sheet units each from an input of the grouping unit to an output of the grouping unit; and a holding unit, wherein the grouping unit groups the sheet units, which belong together in sheet groups, a sheet unit can be held back in the grouping unit, and the grouping unit is designed to release the held-back sheet unit by itself and to release it together with one of two downstream subsequent sheet units and to release it with both downstream subsequent sheet units.
11. The grouping unit of claim 10, wherein the transporting system comprises a first transporting unit that is disposed upstream of the holding unit and a second transporting unit that is disposed downstream of the holding unit.
12. The grouping unit of claim 11, wherein the first transporting unit and/or the second transporting unit includes pairs of transport rollers that are capable of being driven and that can move relative to each other.
13. The grouping unit of claim 10, wherein the grouping unit on its input side comprises an assigning unit, by means of which the downstream subsequent sheet units can be fed so as to be disposed above or below a sheet unit held back in the holding unit.
14. The grouping unit of claim 13, wherein the assigning unit comprises three superposed rollers, wherein at least one of the rollers is disposed so as to be able to move relative to the other rollers.
15. A sheet handling system comprising: a sheet feeding device for furnishing the sheet stream comprising two superposed sheet units each, the grouping unit of claim 10, and a collecting station disposed downstream of the grouping unit.
16. The sheet handling system of claim 15, wherein the sheet feeding device comprises a sheet cutting device for furnishing two sheet units arranged side by side.
17. The sheet handling system of claim 15, wherein a merging unit for assembling the sheet units one on top of the other is disposed downstream of the sheet feeding device, with the merging unit being designed to release the superposed sheet units in an overlapping arrangement.
18. The grouping unit of claim 10, wherein the holding unit comprises a suction device.
19. A grouping unit for a sheet handling system, the grouping unit comprising: a transporting system for transporting sheet units of a sheet stream consisting of two sheet units each from an input of the grouping unit to an output of the grouping unit; and a holding unit, wherein the grouping unit groups the sheet units, which belong together in sheet groups, a sheet unit can be held back in the grouping unit, the grouping unit is designed to release the held-back sheet unit by itself and to release it together with one of two downstream subsequent sheet units and to release it with both downstream subsequent sheet units, and the holding unit comprises a suction device.
20. The grouping unit of claim 19, wherein the suction device comprises a lower suction plate and an upper suction plate, with the sheet stream being routed between the lower suction plate and the upper suction plate.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The disclosure will be described based on the practical examples below with reference to the accompanying drawings. The drawings show:
(2) FIGS. 1A to 1C: a portion of a method for grouping sheet units belonging to specific sheet groups in a grouping unit in a first possible constellation of the sheet units belonging to sheet groups;
(3) FIGS. 2A to 2D: a portion of a method for grouping sheet units belonging to specific sheet groups in a grouping unit in a second possible constellation of the sheet units belonging to sheet groups;
(4) FIGS. 3A to 3E: a portion of a method for grouping sheet units belonging to specific sheet groups in a grouping unit in a third possible constellation of the sheet units belonging to sheet groups;
(5) FIGS. 4A to 4E: a portion of a method for grouping sheet units belonging to specific sheet groups in a grouping unit in a fourth possible constellation of the sheet units belonging to sheet groups;
(6) FIG. 5: an overview of the configuration of a sheet handling system;
(7) FIG. 6: an embodiment of a grouping unit;
(8) FIGS. 7A to 7D: an example of a portion of the operating cycle of the grouping unit of FIG. 6.
DETAILED DESCRIPTION
(9) To explain the method according to the present disclosure, FIGS. 1 to 4 show four portions of the method for grouping sheet units belonging to specific sheet groups in a grouping unit in possible constellations of the sheet units belonging to sheet groups. By way of an example, FIGS. 1 to 4 also show individual processing steps that are carried out when grouping the sheet units in the grouping unit and the subsequent transfer into a collecting station. The letters A, B, C, D of the individual sheet units indicate that these sheet units belong to a sheet group. Sheet units with identical letters belong to a shared sheet group. The hatched sheet units shown in FIGS. 1 to 4 indicate that, although these sheet units belong to a specific sheet group, they are not directly relevant to the description of the scenario described in the respective figures. Arrow P denotes the direction of the sheet stream, i.e., the sheet travel direction.
(10) FIG. 1A shows the base situation of a first constellation of sheet units that are arranged one on top of the other and that are to be transferred into the grouping unit. The sheet units to be transferred into the grouping unit are both part of the sheet group A. As shown in FIG. 1B, the sheet units are transferred together into the grouping unit. As FIG. 1C shows, the sheet units are being transferred together into the collecting station while the downstream subsequent sheet units are being transferred into the grouping unit.
(11) FIG. 2A shows the base situation of a second constellation of sheet units that are arranged one on top of the other and that are to be transferred into the grouping unit. The sheet units to be transferred into the grouping unit belong to the different sheet groups A and B. As shown in FIG. 2B, the sheet units are transferred together into the grouping unit. The downstream subsequent sheet units to be transferred into the grouping unit are neither part of the sheet group A nor part of the sheet group B, but part of the sheet groups C and C/D (sheet group C or D). As shown in FIG. 2C, the sheet unit belonging to the sheet group A is transferred into the collecting station, and the sheet unit belonging to the sheet group B is held back in the grouping unit. Subsequently, the sheet unit B that has been held back in the grouping unit is transferred into the collecting station, and, as shown in FIG. 2D, the sheet unit belonging to the sheet group A has already been discharged from the collecting station. Only once the sheet group B has been transferred into the collecting station will the downstream subsequent sheet units C, C/D be transferred into the grouping unit.
(12) FIG. 3A shows the base situation of a third constellation of sheet units that are arranged one on top of the other and that are to be transferred into the grouping unit. The sheet units to be transferred into the grouping unit belong to the different sheet groups A and B. As shown in FIG. 3B, the sheet units are transferred together into the grouping unit. Both downstream subsequent sheet units to be transferred into the grouping unit belong to the sheet group B. As shown in FIG. 3C, the sheet unit belonging to the sheet group A is transferred into the collecting station, and the sheet unit belonging to the sheet group B is held back in the grouping unit. While the sheet unit A is being transferred into the collecting station, the two downstream subsequent sheet units B are transferred into the grouping unit where they are joined to the sheet unit B held therein, as shown in FIG. 3D. As an alternative, a transfer of the two downstream subsequent sheet units B at the same time that the sheet unit A is discharged from the collecting station may be an option as well. As shown in FIG. 3E, the three sheet units belonging to the sheet group B are transferred together into the ready-to-receive collecting station. As the sheet units B are being transferred into the collecting station, the downstream subsequent sheet units are already being transferred into the grouping unit.
(13) FIG. 4A shows the base situation of a fourth constellation of sheet units that are arranged one on top of the other and that are to be transferred into the grouping unit. The sheet units to be transferred into the grouping unit belong to the different sheet groups A and B. As shown FIG. 4B, the sheet units are transferred together into the grouping unit. The downstream subsequent sheet units to be transferred into the grouping unit belong to the sheet groups B and C. As shown in FIG. 4C, the sheet unit belonging to the sheet group A is transferred into the collecting station, and the sheet unit belonging to the sheet group B is held back in the grouping unit. While the sheet unit A is being transferred into the collecting station, the two downstream subsequent sheet units B, C are transferred into the grouping unit where they are joined to the sheet unit B held therein, as shown in FIG. 4D. After and during the discharge of the sheet unit A from the collecting station, the two sheet units belonging to the sheet group B are transferred together into the ready-to-receive collecting station, as shown in FIG. 4E. The sheet unit C is held back in the grouping unit. As the sheet units B are being transferred into the collecting station, the downstream subsequent sheet units, depending on the sheet group they belong to, can be transferred into the grouping unit. If none of the downstream subsequent sheet units is part of the sheet group C, these sheet units will be transferred into the collecting station only after the sheet unit C has been released from the grouping unit.
(14) The diagrams of the individual processing steps shown in FIGS. 1 to 4 outline only the most important steps of the disclosed method. It should be noted in particular that alternative embodiments with respect to the exact time of the transfer of the sheet units into the grouping unit and of the transfer of sheet units from the grouping unit into the collecting station are possible.
(15) By way of an example, FIG. 5 shows an overview of the configuration of a sheet handling system 1. As seen when looking in the sheet travel direction P, the sheet handling system 1 comprises a sheet feeding device 2, a merging unit 3, a grouping unit 4 and a collecting station 5. The sheet feeding device 2 involved is, for example, a combination of a printer not shown in the drawing and a cutting device not specifically shown in the drawing. The sheet feeding device 2 furnishes two sheet units arranged side by side from a paper web. The sheet feeding device 2 further comprises a readout device 6 for reading an identifier of the sheet units that identifies which specific sheet group the sheet units belong to. The information with respect to which sheet group the sheet units belong to is used to control the merging unit 3 and/or the grouping unit 4 and/or the collecting station 5. In the sheet handling system 1 shown by way of an example in FIG. 5, the identifier of the sheet units is read already before the paper web is cut into individual sheet units.
(16) As illustrated in FIG. 5, the sheet units arranged side by side, which sheet units are furnished by the sheet feeding device 2, are transferred into the merging unit 3. The merging unit 3 assembles the side-by-side sheet units one on top of the other, as especially indicated by the arrows seen in FIG. 5. The sheet units can be assembled one on top of the other so as to overlap or be flush with each other. Preferably, the merging unit 3 assembles only the superposed sheet units, which do not belong to the same sheet group, so as to overlap. With respect to whether the arrangement should, or should not, overlap, the merging unit 3 can be controlled based on the read-out identifier of the sheet units. Since only the sheet units that do not belong to a sheet group are assembled so as to overlap, an undesirable delay of the process, which would occur if all of the sheet units were assembled in an overlapping arrangement, is avoided.
(17) After the merging unit 3 has assembled the sheet units one on top of the other, these sheet unit are transferred into the grouping unit 4. The grouping unit 4 is designed such that superposed sheet units of the same sheet group are transported through grouping unit 4 into the collecting station 5. The grouping unit 4 is further designed such that in cases in which the sheet units transferred into the grouping unit 4 do not belong to the same sheet group, first only one of the two sheet units is transferred into the collecting station 5 and the other sheet unit is held back in the grouping unit 4. The grouping unit 4 is designed to release the held-back sheet unit both without and together with one or both of the sheet units next transferred into the grouping unit 4. Whether the held-back sheet unit is released without or together with one or both of the sheet units next transferred into the grouping unit 4 depends on which sheet group of the held-back sheet unit the sheet units next transferred into the grouping unit 4 belong to.
(18) Once all sheet units belonging to a shared sheet group have been transferred into the collecting station 5, the stack formed therefrom is discharged from the collecting station 5. The stack discharged from the collecting station 5 can subsequently be forwarded for further processing, e.g., folding and/or enveloping, to a device disposed downstream of, or connected to, the collecting station 5.
(19) FIG. 6 shows a practical example of a grouping unit 4 according to the disclosure for grouping sheet units that belong together, of a sheet stream consisting of two sheet units each. The sheet stream not shown in the drawing extends substantially in the sheet travel plane E. In this context, the terms ‘above’ and ‘below’ used hereinafter always refer to an element disposed above or below the sheet travel plane E shown in the drawing.
(20) The grouping unit 4 comprises an assigning unit 7 disposed on the input side as seen when looking in the sheet travel direction P, a transporting system with a first transporting unit 8 for transporting the sheet units from the assigning unit 7 into a holding unit 9, and a second transporting unit 10 for transporting the one or three sheet units from the holding unit 9 into the collecting station 5 disposed on the output side but not shown in FIG. 6.
(21) The orderly grouping of the sheet units and the transfer of the sheet units into the grouping unit 4 and from the grouping unit into the collecting station 5 is implemented by the interaction of the assigning unit 7, the transporting units 8, 10 and the holding unit 9, which together control both the holding back of a sheet unit in the grouping unit 4 and the speed at which the sheet units pass through the grouping unit 4.
(22) The assigning unit 7 disposed on the input side of the grouping unit 4 makes it possible to feed the sheet units next to be transferred into the grouping unit 4 above or below a sheet unit that is held back in the holding unit 9. Disposed upstream of the assigning unit 7 is a transport module comprising an upper guide roller 16 and a lower guide roller 17. The transport module serves to feed the sheet units from the merging unit 3 to the assigning unit 7. The sheet units are routed between the upper guide roller 16 and the lower guide roller 17. The upper guide roller 16 is disposed on a spring element 18 that enables a movement of the upper guide roller 16 relative to the lower guide roller 17. The lower guide roller 17 is capable of being driven by a first drive/control unit A. More specifically, the first drive/control unit A makes it possible to control the rotational speed of the lower guide roller 17 and thus the speed of a sheet unit that is to be transferred into the grouping unit 4.
(23) The assigning unit 7 shown in FIG. 6 comprises three superposed rollers that are capable of being driven, i.e., an upper roller 11, a middle roller 12 and a lower roller 13. The upper roller 11 and the lower roller 13 are disposed on a suspension 15 that enables a movement of the upper roller 11 and the lower roller 13 relative to the middle roller 12. The middle roller 12 can be driven by a second drive/control unit B. Depending on the routing of the sheet units between the upper roller 11 and the middle roller 12 or between the middle roller 12 and the lower roller 13, the middle roller 12 is capable of being driven in different directions of rotation. More specifically, the second drive/control unit B makes it possible to also control the rotational speed of the middle roller 12. Depending on whether the sheet units transferred into the grouping unit 4 are to be routed above or below a sheet unit held back in the grouping unit 4, the sheet units transferred into the grouping unit 4 are routed between the upper roller 11 and the middle roller 12 or between the middle roller 12 and the lower roller 13. The assigning unit 7 further comprises a switch 14 that is disposed upstream of the three rollers 11, 12, 13. The switch 14 controls the reliable routing of the sheet units between the upper roller 11 and the middle roller 12 or between the middle roller 12 and the lower roller 13.
(24) The first transporting unit 8 shown in FIG. 6 comprises one pair of transport rollers 21, and the second transporting unit 10 comprises four pairs of transport rollers 22, 23, 24, 25. The sheet units are routed between the pairs of transport rollers 21, 22, 23, 24, 25 in the grouping unit 4. The pairs of transport rollers 21, 22, 23, 24, 25 comprise each an upper transport roller and a lower transport roller. Except for the upper transport roller of the pair of transport rollers on the output side that is disposed on a spring element 18′, the upper transport rollers are disposed on a suspension 15. The suspensions 15 and the spring element 18′ make possible a movement of the upper transport rollers relative to the lower transport rollers. More specifically, the suspension 15 allows the upper transport rollers to be moved sufficiently far in, or away from, the direction of the lower transport rollers so that a reliable routing of the one to three sheet units passing through between these transport rollers is ensured. The individual suspensions 15 allow the distance of each respective upper transport roller from the lower transport roller and thus the holding back of the sheet units disposed in between to be controlled. The lower transport roller of the pair of transport rollers 21 of the first transporting unit 8 is connected to the second drive/control unit B, and the lower transport rollers of the pairs of transport rollers 22, 23, 24, 25 of the second transporting unit 10 are connected to a third drive/control unit C. The lower transport rollers are capable of being driven by the drive/control units B, C. The individual lower transport roller (and the middle roller 12 of the assigning unit 7) can preferably be controlled independently of each other by the drive/control units B, C shown. In particular, by means of the drive/control units B, C, the first transporting unit 8 can also be controlled independently of the second transporting unit 10. In addition to the configuration shown, other configurations of the transporting system, for example, transporting units 8, 10 with more or fewer pairs of transport rollers 21, 22, 23, 24, 25, or a different configuration of a suspension 15 of the upper transport rollers are possible.
(25) The holding unit 9 shown in FIG. 6 is a suction device comprising a lower suction plate 19 and an upper suction plate 20. The sheet stream is routed between the lower suction plate 19 and the upper suction plate 20. By applying negative pressure to the lower suction plate 19 and/or the upper suction plate 20, it is possible for the sheet units to be picked up and held by the lower suction plate 19 and/or the upper suction plate 20 and thereby be held back in the holding unit 9.
(26) By way of an example, FIGS. 7A to 7D show a portion of individual phases of sheet units routed in the grouping unit 4 of FIG. 6. For the sake of clarity, the drawings show only shortened versions of the grouping unit 4 of FIG. 6 and only a reduced number of the reference characters. The sheet group a sheet unit belongs to is shown by a broken line and a solid line. For the sake of clarity, the orderly way of routing the sheet units through two of the three rollers 11, 12, 13 of the assigning unit 7 is not shown in the drawing. In the base configuration shown in FIG. 7A, the lower sheet unit belonging to a first sheet group as represented by the broken line was held back in the grouping unit 4 by means of the lower suction plate 19 of the holding unit 9 while the downstream subsequent overlapping sheet units are already being routed so as to be disposed above the held-back sheet unit. As the broken lines indicate, the lower sheet unit of the downstream subsequent sheet units is part of the sheet group of the held-back sheet unit. In contrast, the upper sheet unit identified by a solid line is part of a different sheet group. FIGS. 7A to 7D indicate that the two sheet units represented by the broken lines are discharged and that the sheet unit represented by the solid line is held back by the lower suction plate 19. The arrows indicate movements of the upper transport rollers in the direction of and away from the lower transport roller. Since FIGS. 7A to 7D show only a portion of the individual phases of sheet units routed in the grouping unit 4, not all movements of the upper transport rollers are indicated or sketched in. FIGS. 7A to 7D especially show that the two sheet units represented by the broken lines are discharged via the pairs of transport rollers 22, 23, 24, 25 (which move relative to each other) of the second transporting unit 10. FIG. 7C additionally shows the movement of the upper transport roller of the pair of transport rollers 21 of the first transporting unit 8 in the direction of the lower transport roller. The pair of transport rollers 21 of the first transporting unit 8 (in addition to transporting the sheet unit) allows the sheet unit represented by the solid line to be slowed. As a result, discharging the two sheet units represented by the broken lines and holding back the sheet unit represented by the solid line is facilitated. FIG. 7D indicates that routing the downstream subsequent sheet units, which are to be transferred into the grouping unit 4, between the upper roller 11 and the middle roller 12 of the assigning unit 7 and the resulting routing of the sheet units so as to be disposed above the sheet unit held back in the grouping unit is facilitated by the upper roller 11 of the assigning unit 7, which upper roller is moved away from the middle roller 12.
(27) In addition to the embodiments of the sheet handling system and the grouping unit shown by way of an example, other embodiments are possible, by means of which the method according to the disclosure of grouping sheet units, belonging together in sheet groups, of a sheet stream comprising two superposed sheet units each can be carried out.
