DE102011004091A1 - Method and apparatus for sorting flat objects with gap variation - Google Patents

Abstract

The invention relates to a method and a sorting system for sorting flat objects using a gap changing unit, in particular flat mail items. The sorting system brings the objects in a sequence of objects that are spaced apart from one another. A measuring device measures which one for each object. Value assumes a sorting feature for this object. A selection unit selects a sorting output of the sorting system for each item. If different sorting outputs are selected for two consecutive objects in the sequence, these objects are discharged into the different sorting outputs at a distance from one another. If, however, the same sorting output was selected for these objects (Ps-A, Ps-B), the objects (Ps-A, Ps-B) are pushed together in an overlapping process so that the objects (Ps-A, Ps-B) partially overlap. In this overlapping state, the objects (Ps-A, Ps-B) are discharged into the jointly selected sorting exit (Sf).

Description

The invention relates to a method and an apparatus for sorting flat objects using a gap-changing unit, in particular flat mail items.

A method comprising the features of the preamble of claim 1 and an apparatus having the features of the preamble of claim 7 are made DE 10142331 C1 known.

In DE 10142331 C1 For example, a method and an arrangement are described which are capable of eliminating overlaps in the transport of flat postal items. Such overlap is undesirable and will be eliminated. The mail items are transported upright in a so-called "pinch belt system". Each mail item is temporarily clamped between each two endless conveyor belts, which are guided around rollers with vertical axes of rotation. The mailpieces are from an afferent part 3 at a speed v0 to an acceleration section with two conveyor belts running around the two pulleys 1 and 2 are guided around, transported, cf. 1 , A light barrier Li and measuring means La1, La2 detect the current position of a mail item in the feeding part 3 , In the acceleration section 1 . 2 an undesirable overlap between two mailpieces is eliminated by the one conveyor belt of the acceleration section 1 . 2 is moved at a speed v1 and the second conveyor at a speed v2. 2 shows various situations in which v1 and v2 are set to different values depending on v0 and the lengths of the two mailpieces.

In EP 2065325 A2 For example, an apparatus and method for sorting flat objects, e.g. As mail, described. The device described there has two opening transport paths eT-1, eT-2, which terminate at two different points of interchange SV-1, SV-2 in a main transport path LT. From the main transport path LT, several output transport paths AT-1, AT-2 branch off to a sorting output AB-1, AB-2,... In the second opening transport path eT-2, several objects are transported to the second junction SV-2 where they are pushed together to form a stack of partially overlapping objects. This stack is inserted into the main transport path LT in a sufficiently large gap between the objects in the main transport path LT and then also transported in the main transport path. A subsequent singler Ve-L then singles these items again. Downstream of the separator Ve-L is a camera K. The respective destination address of each mail item is read by a reading device, wherein the reading device evaluates a digital image of the mail item which the camera Ka has generated.

In US 6,366,828 B1 and EP 923997 A2 For example, a method and apparatus for transporting flat mail is described. The device comprises a plurality of feed transport paths ("transport modules 5 with transport paths 5p "), Which in a transport device with a closed conveyor track (" looped transport system 12 "), Cf. 1 , This closed transport facility 12 picks up mail from the delivery transport paths. From the transport facility 12 branch several Wegführ transport paths ("transport modules 20 with transport paths 20p "). The transport device 12 forwards each mail item into a respective removal transport path 20 , To every way-out transport path 20 closes another Wegführ transport path ("transport module 22 with transport path 22p ") at. A lot of mail ("postal objects 3 ") First reaches an overlap generation device (" stream forming device 8th "), Which generates a sequence of partially overlapping mailpieces, cf. 2 , A stack of partially overlapping mail pieces ("lbs") is delivered via a feed transport path 5 , the transportation facility 12 , a routing transport path 20 and another routing transport path 22 to a processing device ("postal processing device 27 ") Transported.

In DE 10 2006 057 776 B3 For example, a method and a device for deflecting flat objects, in particular flat postal items, are described. Two mailpieces to be ejected into a stacker are previously brought into a state in which these mailpieces partially overlap and in this overlapping state are redirected from a main transport path to an output transport path. However, this overlapping state is only produced if the sum of the thicknesses of the two mail items lies below a predetermined thickness barrier. Otherwise, the two objects are spaced apart from each other in the stacking tray. This prevents two oversize postal items from overlapping and diverting.

In DE 19823101 B4 For example, a method and apparatus that detects overlap of two flat mailpieces are described. An endless conveyor belt 4a is about two roles 6a . 6b led around, a another endless conveyor belt 4a around two rolls 6c . 6d , another endless conveyor belt 4c and two roles 6d . 6e , The mailing 10 . 12 be between the conveyor belts 4a . 4c clamped until the respective leading edge on the conveyor belt 4b meets. In addition, the leading edge meets a stop 11 , z. B. a role, whereby the mail item experiences a bending transversely to the previous transport direction. Two overlapping mail pieces hit each other so that the stopper 11 fanning them out and thereby separating them. A detector arrangement with at least one distance sensor 2 detects the impact of the front edge of the mail piece.

In DE 10 2004 012 378 B3 and US 7,687,737 B2 For example, a method and apparatus for sorting flat mail items is described. After separation, the mail items pass through a "transport segment 8th ". A switch 11 splits the stream of mail onto a normal transport path 10 and a "short cut 9 " on. Subsequently, the streams are brought together again and go through a "first transport unit 6 "And a subsequent" second transport unit 7 ". Subsequently, the stream of mail is divided again, by a switch 3 to two segments X, Y of sorting terminals L-X1,..., L-Xm, and L-Y1,..., L-Yn, cf. 1 , Each mail item reaches a previously selected sorting endpoint. Between two successive mailings, an individual gap is made before these mail pieces make the switch 3 reach by means of the two transport units 6 . 7 ". The gap depends on the distances that the two mail items have to travel to their respective sorting endpoints.

In DE 3723259 C2 a stacker for letters will be described. The letters are transported upright. A switch W splits a stream of mail onto a main conveyor line 2 and a secondary conveyor line 3 on, with the secondary conveyor line 3 is longer than the main conveyor line 2 , The two conveyor lines 2 . 3 meet again at a junction V. In union point V begins a further conveyor line 4 , see. 1 and 2 , A subsequent letter B2 reaches a leading letter B1 in the union point V, so that the two letters are transported overlapping.

The invention has for its object to provide a method having the features of the preamble of claim 1 and an apparatus having the features of the preamble of claim 7 - seen in the transport direction in which the objects are transported - less transport route and therefore less space need.

The object is achieved by a method having the features of claim 1 and a device having the features of claim 7. Advantageous embodiments are specified in the subclaims.

The invention sorts flat objects. Each item to be sorted extends in each item level.

The default is a sorting feature. This sorting feature takes a value for each item to be sorted. The articles should be sorted according to these sorting feature values.

The items are sorted by a sorting system according to the solution. This sorting system includes several sorting outputs and a measuring device.

The items to be sorted are placed in a sequence of items. Each two successive objects of this sequence are spaced from each other, d. H. there is a gap between them. This item sequence goes through the sorting system.

• – Das Messgerät misst, welchen Wert das Sortiermerkmal für diesen Gegenstand annimmt.
• – Die Sortieranlage wählt einen Sortierausgang für diesen Gegenstand aus. Diese Auswahl wird abhängig vom für diesen Gegenstand gemessenen Sortiermerkmals-Wert getroffen.
• – Die Sortieranlage transportiert den Gegenstand zum ausgewählten Sortierausgang.
• – Die Sortieranlage schleust den Gegenstand in den ausgewählten Sortierausgang aus.

The following steps are automatically performed for each item to be sorted:

• - The meter measures what value the sorting feature takes on this item.
• The sorting system selects a sorting output for this object. This selection is made depending on the sorting feature value measured for that item.
• The sorting system transports the item to the selected sorting output.
• - The sorting system discharges the item into the selected sorting output.

For at least one pair of at least two items occurring consecutively in sequence, a test step is performed. It is possible that a pair consists of more than two items. It is also possible that a test step is carried out in each case for several pairs of objects.

In each item pair checking step, it is checked whether the sorting system has selected the same sorting output for all the items of this item pair or has selected at least two different sorting outputs. Then, when the same sorting output has been selected for all the items of the item pair, an overlapping operation is performed on the items of the item pair. If, on the other hand, the sorting system has selected different sorting outputs for two consecutive objects, these two objects are transported at a distance from one another to these different selected sorting outputs and discharged into these different sorting outputs.

• – Der vorauslaufende Gegenstand wird zeitweise mit einer geringeren Geschwindigkeit und/oder über einen längeren Transportweg als der nachfolgende Gegenstand transportiert.
• – Dies wird so lange durchgeführt, bis die beiden aufeinander folgenden Gegenstände sich wenigstens teilweise überlappen und sich hierbei in einem Überlappungsbereich berühren. Die Überlappung wird – gesehen in eine Betrachtungsrichtung senkrecht auf die Gegenstände – hergestellt.

Each overlapping operation for a pair of at least two objects that follow each other in sequence comprises the following steps:

• - The leading object is temporarily transported at a lower speed and / or over a longer transport path than the subsequent object.
• - This is done until the two consecutive objects overlap at least partially, touching each other in an overlap area. The overlap is made as seen in a viewing direction perpendicular to the objects.

After the overlapping operation is completed, the two objects are transported in a state of partial overlap up to this matching sorting exit selected for both items and discharged into this common sorting exit.

Each article is transported during transport to the selected sorting exit in a transport direction which, for most of the time, is approximately at the article level of that article. The overlapping process causes the two objects, which are pushed together in an overlapping process, seen in the transport direction after overlapping less transport distance and therefore occupy less space than before the overlap. Therefore, the overlap saves space and increases the throughput of items through the sorting system. This overlapping is performed only if the same sorting output has been selected for several immediately consecutive items. Two overlapping objects often can not be transported in overlapping state into different sorting outputs.

The objects are transported in the overlapping state to the common sorting exit. This allows the advantages of the small footprint and the higher throughput for these items can be achieved. Because the objects arrive overlapping in the sorting exit, the risk is reduced that the now discharged items or the previously discharged in this sorting output items are bent or otherwise damaged in the common sorting output when discharging.

Because the overlap is performed after the grading feature values have been measured, the step of having to singulate the articles after the overlapping process is saved. Such singling would be required if the overlapping process were performed before singulation, but the respective sorting feature value can only be measured by a single item.

In order to decide whether to overlap two immediately consecutive items or not, it is necessary to know the sort outputs selected for these items. This in turn requires that the sorting feature values of these items be measured prior to testing and decision.

In addition, the overlapping is performed only when the same sorting output has been selected for several immediately consecutive items. If, on the other hand, two different sorting outputs have been selected for two directly successive objects, no overlapping process is carried out. As a result, the step is saved, the items therefore to separate again to auszuschleusen the re-spaced items in different sorting outputs.

The sorting system preferably has a conveying device with a first conveying element and a second conveying element. These two conveying elements are capable of trapping an object between them. At least one conveying element is movably arranged, so that the distance between the Both conveyor elements can be enlarged and reduced again. This refinement makes it possible to perform an overlapping operation in a space-saving manner and with a relatively simple mechanism.

In one embodiment, the overlapping process comprises the step of delaying the preceding object and of transporting the subsequent object at the same speed. This embodiment eliminates an acceleration step and an additional transport path and is therefore the easiest to implement.

In another embodiment, the subsequent object is accelerated while the leading object is transported at a constant speed. This leads to a particularly high throughput.

In a third embodiment, the leading object is transported via a secondary transport path, the subsequent article via a main transport path. The sub-transport path is longer than the main transport path. This embodiment makes it possible to transport both objects at a constant speed.

In one embodiment, at least three objects immediately following one another are then brought into an overlapping state if the same sorting output has been selected for all three objects. For this purpose, a first overlapping process for the first article and the second article and then a second overlapping process for the second article and the third object are performed. The first item and the third item do not necessarily overlap.

In the following the invention will be described with reference to an embodiment. Showing:

1 schematically the sorting system used,

2 a section of the transport device with the gap changing unit before performing an overlapping operation,

3 the arrangement of 2 at the moment when the leading mail piece is clamped between the first endless conveyor belt and the movably mounted pinch roller of the gap changing unit,

4 the arrangement of 3 at the moment when the leading edge of the leading mail piece has reached the slot between the second endless conveyor belt and the fixedly mounted pinch roller of the gap changing unit,

5 the arrangement of 4 at the moment when the subsequent mail item has reached the leading mail item, so that the overlapping starts,

6 the arrangement of 5 at the moment when the delay of the leading mail piece is completed,

7 the arrangement of 6 at the moment the desired overlap is established,

8th the arrangement of 7 at the moment when the subsequent mailpiece has left the gap changing unit, and

9 a stacking tray into which the two overlapping mailpieces are ejected.

In the exemplary embodiment, the invention is used to transport and sort flat postal items (standard letters, large letters, postcards and the like). Each item of mail is provided with a respective identification of a destination to which this item of mail is to be transported. This tag is applied to the mailpiece in a human-readable form and / or in a machine-readable form. Each mail item extends in an article plane and has - as viewed in the transport direction - a leading edge and a trailing edge.

• – eine Zuführ-Einrichtung ZE („feeder”) mit einem Vereinzeler („singulator”),
• – ein Messgerät mit einer Kamera Ka und mit einer Bildauswerteeinheit Bae,
• – ein weiteres Messgerät MGer, welches die Dicke und die Biegesteifigkeit einer Postsendung zu messen vermag,
• – eine Transport-Einrichtung mit einer Lückenverdnderungs-Einheit LVE,
• – eine Auswahleinheit AE,
• – eine Ausschleus-Einrichtung Aus-E und
• – mehrere Sortierausgänge SAus.1, SAus.2, ....

The invention is used in a sorting system. 1 schematically shows the sorting system used in plan view. This sorting plant has the following components:

• A feeder ZE with a singulator,
• A measuring device with a camera Ka and with an image evaluation unit Bae,
• A further measuring device MGer, which is able to measure the thickness and the bending stiffness of a mail item,
• A transport device with a gap-reduction unit LVE,
• A selection unit AE,
• - An ejection facility Aus-E and
• - several sorting outputs SAus.1, SAus.2, ....

The mail items to be sorted are fed to the feeder ZE. The singler singles the incoming mail. A stream of upright and spaced mailpieces is transported through the sorting system up to the sorting outlets SAus.1, SAus.2, ....

• – Die Kamera Ka erzeugt jeweils ein rechnerverfügbares Abbild Abb von der Oberfläche der Postsendung. Dieses Abbild zeigt die Zielpunkt-Kennzeichnung auf der Postsendung.
• – Die Bildauswerteeinheit Bae entziffert die Zielpunkt-Angaben im Abbild Abb. Die Zielpunkt-Angaben fungieren im Ausführungsbeispiel als der Sortiermerkmals-Wert des zu sortierenden Gegenstands (hier: der Postsendung).
• – Die Transport-Einrichtung TE transportiert die Postsendung weiter bis zur Ausschleus-Einrichtung Aus-E, während die Bildauswerteeinheit Bae die Zielpunkt-Kennzeichnung entziffert.
• – Die Auswahleinheit AE wählt einen Sortierausgang für die Postsendung aus. Hierfür verwendet die Auswahleinheit AE die entzifferte Zielpunkt-Kennzeichnung sowie einen rechnerverfügbaren Sortierplan, der jeder auftretenden Zielpunkt-Kennzeichnung jeweils einen Sortierausgang zuordnet. Dieser sortierplan ist im Datenspeicher DSp abgespeichert. In der Regel ist mehreren Zielpunkt-Kennzeichnungen derselbe Sortierausgang zugeordnet, weil es deutlich mehr Zielpunkt-Kennzeichnungen als Sortierausgänge gibt.
• – Die Ausschleus-Einrichtung Aus-E schleust die Postsendung in den ausgewählten Sortierausgang aus.

For each mail item, the following steps are performed:

• The camera Ka generates in each case a computer-accessible image of the surface of the mailpiece. This image shows the destination mark on the mailpiece.
• The image evaluation unit Bae deciphers the target point information in the image. The target point information functions in the exemplary embodiment as the sorting feature value of the item to be sorted (here: the mail item).
• The transport device TE transports the mail item further to the outfeed device Aus-E, while the image evaluation unit Bae deciphers the destination point identifier.
• The selection unit AE selects a sorting output for the mailpiece. For this purpose, the selection unit AE uses the deciphered destination point identification as well as a computer-available sorting plan, which assigns each sorting output to each target point identification that occurs. This sorting plan is stored in the data memory DSp. As a rule, the same sorting output is assigned to several destination point markings because there are significantly more destination point markings than sorting outputs.
• The ejection device Aus-E discharges the mail item into the selected sorting output.

In each sorting exit, a stack of upright flat mailpieces is formed, the stack leaning against a displaceable stacking support Pa and the lower edges of the stacked mailpieces standing on the floor or on an underfloor conveyor belt of the sorting exit. This stack grows in a stacking direction SR with each further mail item that is discharged into the sorting output. In one embodiment, another item of mail is ejected in such a way that the item of mail strikes the already formed stack St or, if it is the first item of mail, on the stack support Ps at an angle.

In addition, in the exemplary embodiment, the length and the thickness of each mail item are measured. The length is the extension of the mail item in the transport direction and in the item level. The thickness is the maximum extent of the mail item perpendicular to the object plane. The length is preferably measured by means of a light barrier, wherein the transport speed with which the mail item is transported through the light barrier is known or also measured. The thickness is z. B. measured by generating a computer-available image of the mail item from a viewing direction in the article plane and the contour of the mailpiece is measured in this image.

• – Für alle diese Postsendungen der Gruppe hat die Auswahleinheit AE denselben Sortierausgang ausgewählt.
• – Die Gesamt-Länge dieser Postsendungen ist nicht größer als die Maximal-Länge.
• – Die Gesamt-Dicke dieser Postsendungen ist nicht größer als die Gesamt-Maximal-Dicke.
• – Jede einzelne Postsendung ist nicht dicker als die Einzel-Maximal-Dicke.

In the exemplary embodiment, a total maximum thickness, a single maximum thickness and a maximum length are specified. As already stated, a sequence of mutually spaced mail items is transported through the sorting system up to the gap changing unit. Multiple mail items occurring in sequence immediately after one another are pushed together to form a shingled overlapping group of mailpieces, if the following conditions are met cumulatively:

• For all these mail items of the group, the selection unit AE has selected the same sorting output.
• The total length of these mail items is not greater than the maximum length.
• The total thickness of these mail items is not greater than the total maximum thickness.
• - Each individual mail item is not thicker than the single maximum thickness.

Only when the consecutive mailings meet all four of these conditions can the mailpieces be shared as a group of overlapping mailpieces in that common one Eject sorting output. On the other hand, a thicker or longer group can not be reliably removed from the main transport path and redirected into a connection path to the sorting output. An excessively heavy mail piece can not be securely overlapped, in particular because the subsequent mail item, when overlapped, strikes against the preceding and too thick mail item and a jam can occur.

The control unit SE receives measured values from sensors of the sorting installation and automatically makes the decision as to whether an overlapping process is carried out or not for consecutive mailpieces.

In one embodiment, the respective flexural rigidity of each mail item to be sorted is additionally measured. For example, a defined force is exerted in a direction perpendicular to the object plane, and it is measured by which distance the mail item is bent in this case. Or is measured, which force is applied to cause a predetermined deflection of the mailpiece. As a further prerequisite for pushing together a plurality of consecutive mailpieces and ejecting them as a group, it is checked whether the respective bending stiffness of each mail item or also the overall bending stiffness of each immediately consecutive mail item lies below a predetermined barrier.

If a plurality of mail items at a time in the group just described are ejected into a sorting exit and not these mailpieces one after the other, the risk is reduced that a rejected mail item or also a mail item of the already formed stack will be kinked or folded during removal or that one Jam of mailings occurs.

It is possible that a mail item Ps-x is discharged into a sorting output, without overlapping with another mail item. This case occurs when a different sorting output has been selected both for the subsequent mail item and for the preceding mail item than for the mail item Ps-x. This case, namely that the mail item Ps-x is ejected alone, also occurs when, by overlapping Ps-x with the preceding and / or with the subsequent mail item too thick or too long a group or a group too high bending stiffness would be generated.

• – Für die letzte Postsendung der Gruppe und für die unmittelbar nachfolgende Postsendung wurden verschiedene Sortierausgänge ausgewählt.
• – Falls die bereits gebildete Gruppe um eine weitere Postsendung ergänzt werden würde, so würde eine Gruppe erzeugt werden, die dicker als die vorgegebene Maximal-Dicke oder länger als die vorgegebene Maximal-Länge ist.

In order to form a group with a plurality of mailpieces which partially overlap each other in a shingling manner, an overlapping process is carried out for each two immediately consecutive mailpieces. These overlap operations will be canceled for this group, and a new next-mail check process will begin when at least one of the following conditions is true:

• Various sorting outputs have been selected for the last mail item of the group and for the immediately following mail item.
• - If the group already formed would be supplemented by another mail item, a group would be generated which is thicker than the predetermined maximum thickness or longer than the predetermined maximum length.

The generation of the group and these decision processes are carried out automatically, preferably by a control unit, which receives and evaluates measured values from sensors of the sorting system and controls the transport device of the gap changing unit.

In the following, an overlapping process is described by way of example for two directly consecutive mail items Ps-A, Ps-B, for which the same sorting output has been selected.

• – eine Lichtschranke LS mit einem Sender Sen und einem Empfänger Emp,
• – ein zuführendes Segment mit den beiden Endlos-Förderbändern Fb-z.1, Fb-z.2,
• – die Lückenveränderungs-Einheit LVE und
• – ein wegführendes Segment mit den beiden Endlos-Förderbändern Fb-w.1, Fb-w.2.

2 schematically shows that portion of the transport device in which the overlapping operation is performed. This section includes

• A light barrier LS with a transmitter Sen and a receiver Emp,
• A feeding segment with the two endless conveyor belts Fb-z.1, Fb-z.2,
• The gap changing unit LVE and
• - A wegführendes segment with the two endless conveyor belts Fb-w.1, Fb-w.2.

• – die beiden Endlos-Förderbändern Fb-1.1, Fb.1.2,
• – eine fest montierte Andruckrolle Ro-f und
• – eine beweglich montierte Andruckrolle Ro-b.

The gap changing unit LVE comprises

• - The two endless conveyor belts Fb-1.1, Fb.1.2,
• - A firmly mounted pressure roller Ro-f and
• - A movably mounted pressure roller Ro-b.

Each endless conveyor belt Fb-z.1, Fb-z.2, Fb-1.1, Fb.1.2, Fb-w.1, Fb-w.2 is guided around at least two rollers. In the exemplary embodiment, the driven roller (seen in the transport direction TR) is driven furthest downstream, and the remaining rollers are configured as idler rollers. Thus, each conveyor belt is guided around exactly one driven roller. The drive An-Z.1 rotates the driven roller of the conveyor belt Fb-z.1. The drive An-Z.2 rotates the driven roller of the conveyor belt Fb-Z.2. The drive An-1 rotates the roller Ro-1.1, around which the conveyor belt Fb-1.1 of the gap changing unit LVE is guided. The drive An-2 rotates the roller Ro-1.2, around which the conveyor belt Fb-1.2 of the gap changing unit LVE is guided. The control unit SE drives the drives An-Z.1, An-Z.2, An-1, An-2 of the driven rollers and is able to rotate each driven roller at a predetermined speed. The pressure rollers Ro-b, Ro-f are designed as rollers. In addition, the control unit SE is able to control an actuator St-A, and the actuator St-A changes depending on the control of the distance between the movably mounted pinch roller Ro-b and the conveyor belt Fb-1.1. The distance between the fixed pressure roller Ro-f and the conveyor belt Fb-1.1 remains constant. All rollers are mounted on vertical axles or shafts. The rollers each have an elastic roller body z. B. rubber, so that the rollers can be slightly compressed.

In the situation, the 2 shows, the leading mail piece Ps-A is still clamped by the two endless conveyor belts Fb-z.1, Fb-z.2. The leading edge Vk of the mailpieces Ps-A has reached the conveyor Fb-1.1. The conveyor belt Fb-1.1 deflects this leading edge Vk and continues to transport the mail item Ps-A. The movably mounted pressure roller Ro-b has reached the smallest distance to the conveyor belt Fb-1.1 or had this smallest distance already before.

In the situation, the 3 shows, the mail item Ps-A between the conveyor belt Fb-1.1 and the movable mounted pinch roller Ro-b is clamped and further transported in the transport direction TR. The leading edge Vk of the mail item Ps-A reaches the conveyor belt Fb-1.2. At the same time, the feeding segment with the conveyor belts Fb-z.1, Fb-z.2 conveys the following mail item Ps-B to the gap changing unit LVE.

In the situation of 4 the leading edge Vk of the mail item Ps-A has reached the slot between the fixed pressure roller Ro-f and the conveyor belt Fb-1.2. The mail item Ps-A is contacted on one side by the conveyor belt Fb-1.1 and on the other side by the movably mounted pressure roller Ro-b and the conveyor belt Fb-1.2. In the situations of 2 . 3 and 4 The conveyor belts Fb-z.1, Fb-z.2, Fb-1.1 and Fb-1.2 are still driven at the same speed.

5 shows the beginning of the overlapping process for the two mailings Ps-A, Ps-B. The control unit SE reduces the rotational speed of the driven roller Ro-1.2 of the conveyor belt Fb-1.2 from the original speed v0 to a speed v1 with v1 <v0. It is possible that v1 = 0, that is, that the mail item Ps-A is stopped.

• – der Lücke zwischen der Hinterkante der Postsendung Ps-A und der Vorderkante der Postsendung Ps-B, wobei diese Lücke vor dem Beginn des Überlappungsvorgangs gemessen wurde, und
• – einer vorgegebenen Soll-Überlappung als Länge des Überlappungsbereichs zwischen Ps-A und Ps-B gesehen in die Transportrichtung TR.

Preferably, the speed with which the roll Ro-1.2 and thus the conveyor belt Fb-1.2 are rotated and with which the mail item Ps-A is transported, is linearly controlled down from v0 to v1. The speed gradient depends on the following parameters: from

• The gap between the trailing edge of the mail piece Ps-A and the leading edge of the mail piece Ps-B, this gap being measured before the start of the overlapping operation, and
• - A predetermined target overlap as the length of the overlap region between Ps-A and Ps-B seen in the transport direction TR.

The control unit SE also controls the movably mounted pinch roller Ro-b so that the distance between the roller Ro-b and the endless conveyor belt Fb-1.1 is increased. At the same time, the mail item Ps-A is rotating away from the conveyor belt Fb-1.1, which passes through the kinking. Transport path is effected. The increase in the distance between the conveyor belt Fb-1.1 and the pressure roller Ro-b prevents the mail piece Ps-A continues to be caught by the conveyor belt Fb-1.1. Because the conveyor belt Fb-1.1 is rotated at the speed v0 and the conveyor belt Fb-1.2 at the speed v1 <v0, this would cause the mail item Ps-A to be squashed or kinked.

6 shows the continuation of the overlapping process. The mail item Ps-A was delayed to the speed v1. The conveyor belt Fb-1.1 is further rotated at the speed v0 and has deflected the leading edge Vk-B of the subsequent mail item Ps-B. The mail item Ps-B is clamped between the conveyor belts Fb-z.1, Fb-z.2 and is pushed into the gap between the mail item Ps-A and the conveyor belt Fb-1.1.

In the situation of 7 the desired overlap between the mail items Ps-A and Ps-B is established, ie the overlapping area has reached the predetermined length seen in the transport direction TR. The two mail items Ps-A, Ps-B touch each other in this overlapping area. The control unit SE accelerates the conveyor belt Fb-1.2 back to a speed v2. v2 = v0 is possible. The two conveyor belts Fb-w.1 and Fb-w.2 of the leading-out segment are also moved at the speed v2. At the same time, the actuator moves the movably mounted pressure roller Ro-b back to the conveyor belt Fb-1.1.

In the situation of 8th the subsequent mail item Ps-B is no longer caught by the conveyor belts Fb-1.1, Fb-1.2. The conveyor belts Fb-1.1, Fb-1.2, Fb-w.1, Fb-w.2 are all moved at speed v2. The two mail items Ps-A, Ps-B are clamped between the conveyor belts Fb-1.2 and the fixedly mounted pressure roller Ro-f. The leading mail item Ps-A is taken by the conveyor belts Fb-w.1, Fb-w.2.

9 schematically shows a sorting output in the form of a stacking tray Sf. This stacking tray was selected for the mailing Ps-A, Ps-B. The stacking tray has a compartment wall FW, to which the leading edges of the mailpieces abut, a stacking support in the form of a paddle Pa and a guide device FE for the paddle Pa. A switch W discharges the two overlapping mail items Ps-A, Ps-B to the right from the main transport path HT into the stacking tray Sf. The two mail items Ps-A, Ps-B arrive obliquely on an already formed stack St. This stack St grows in the stacking direction SR. The stack support Pa is moved with the growing stack St.

In the embodiment described so far, the rejection device Aus-E is configured such that the sorting outputs SAus.1, SAus.2,... Are arranged to the right of the main transport path HT, as viewed in the transport direction TR, and therefore the mailpieces are moved to the right be removed from the main transport path HT right. Also possible is a different embodiment, in which the sorting outputs SAus.1, SAus.2, ... are arranged to the left of the main transport path HT.

In this variant embodiment, the elements Fb-1.1, Fb-1.2, Ro-b, Ro-f of the gap changing unit LVE and the switch W and the stacking tray Sf are mirror images of the elements in 2 to 8th arranged. Bezuszeichenliste reference numeral importance An-1 Drive for the roll Ro-1.1 An-2 Drive for the role Ro-1.2 An-z.1 Drive for the conveyor belt Fb-z.1 An-T.2 Drive for the conveyor belt Fb-z.2 From E Ausschleus facility Bae image evaluation dsp Data store for the computer-accessible sort plan Emp Receiver of the light barrier LS Fb-1.1, Fb-1.2 Endless conveyor belts of the gap changing unit Fb-w.1, Fb-w.2 Endless conveyor belts of the transporting device's leading segment Fb-z.1, Fb-z.2 Endless conveyor belts of the feeding segment of the transport device FE Guide device for the pile support Pa FW Tray wall of stacking tray Sf HT The main transport path ka camera LVE Gap changing unit, comprising the conveyor belts Fb.1.1 and Fb.1.2 and the pressure rollers Ro-b and Ro-f MGer Measuring device, is able to transport the thickness and bending stiffness of a postal item Pa Stacking support in the form of a paddle Ps-A leading mailing Ps B subsequent mailing Ro-1.1 driven roller around which the conveyor belt Fb-1.1 is guided around Ro-1.2 driven roller, around which the conveyor belt Fb-1.2 is guided Ro-b movably mounted pressure roller of the gap changing unit LVE Ro-f firmly mounted pressure roller of the gap changing unit LVE SAus.1, SAus.2, ... sorting outputs SE control unit Sen Transmitter of the light barrier LS sf sorting output selected for the mailpieces Ps-A, Ps-B in the form of a stacking tray SR Stacking direction into which the stack St in the stacking tray Sf grows St Stack in stacking tray Sf St-A Actuator for the mobile roll Ro-b TE Transport device TR Transport direction, in which the transport device TE transports mail vk Leading edge of the mail piece Ps-A Vc-B Leading edge of the mail piece Ps-B W switch ZE Feeding device with the separator

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10142331 C1 [0002, 0003]
• EP 2065325 A2 [0004]
• US 6366828 B1 [0005]
• EP 923997 A2 [0005]
• DE 102006057776 B3 [0006]
• DE 19823101 B4 [0007]
• DE 102004012378 B3 [0008]
• US 7687737 B2 [0008]
• DE 3723259 C2 [0009]

Claims (8)

A method for sorting flat objects (Ps-A, Ps-B) according to a predetermined sorting feature, wherein each item to be sorted (Ps-A, Ps-B) extends in an object plane, a sorting system is used for sorting used sorting system comprises a plurality of sorting outputs (SAus.1, SAus.2, ...) and the method comprises the steps of - placing the articles to be sorted (Ps-A, Ps-B) in a succession of spaced objects, - this sequence passes through the sorting system, - for each item to be sorted (Ps-A, Ps-B) is measured, which value the given sorting feature for this object (Ps-A, Ps-B) assumes, - depending on the measured sorting feature- Value a sorting output (SAus.1) is selected for the item (Ps-A, Ps-B), - the item (Ps-A, Ps-B) is transported to the selected sorting output (SAus.1) and - the item ( Ps-A, Ps-B) in this selected Sortierau Sgang (SAus.1) is discharged, characterized in that for at least one pair, which consists of at least two consecutive successively in the sequence objects (Ps-A, Ps-B), after measuring the sorting feature values and after the Selecting the sorting outputs for these two items (Ps-A, Ps-B) - checking whether the same sorting output (SAus.1) has been selected for these two items (Ps-A, Ps-B) or two different sorting outputs have been selected, If, for two consecutive objects, different sorting outputs have been selected, these two objects are transported spaced apart from one another to the different sorting outputs and ejected into these sorting outputs, and if the same sorting output is for both articles (Ps-A, Ps-B) (SAus.1) is selected, an overlapping operation is performed, wherein the overlapping process comprises the steps of - the leading object (Ps-A) is transported at a lower speed (v1) and / or over a longer transport path than the subsequent object (Ps-B), until the two objects (Ps-A, Ps-B) are transported - seen in a viewing direction perpendicular to the object planes - at least partially overlapping and touching in an overlap area, and - the two objects (Ps-A, Ps-B) after completion of the overlap operation with at least partial overlap up to that for both Items (Ps-A, Ps-B) selected sorting output (SAus.1) are transported and discharged into this common sorting output (SAus.1). Method according to claim 1, characterized in that the sorting system with a conveyor device - A first conveyor element (Fb-1.1) and A second conveying element (Ro-b) includes, any item transported by this conveyor, - is temporarily trapped during transport between these two conveyor elements (Fb-1.1, Ro-b) and - Is transported in the clamped state of the two conveyor elements (Fb-1.1, Ro-b) and at least one overlapping process comprises the additional steps of When the two conveying elements (Fb-1.1, Ro-b) pinch the leading object (Ps-A), The distance between the two conveying elements (Fb-1.1, Ro-b) is increased in such a way, - That a gap between the leading object (Ps-A) and the first conveying element (Fb-1.1) or between the leading object (Ps-A) and the second conveying element (Ro-b) is produced, - The subsequent object (Ps-B) is pushed into this gap and - the distance between these two conveying elements (Fb-1.1, Ro-b) is reduced again, - So that after this distance reduction, the two at least partially overlapping objects (Ps-A, Ps-B) of both conveyor elements (Fb-1.1, Ro-b) are clamped. A method according to claim 2, characterized in that - the conveying device comprises a third conveying element (Fb-l.2, Ro-f), - the leading object (Ps-A) during a period in which the distance between the first Conveying element (Fb-1.1) and the second conveying element (Ro-b) is increased, - is clamped between the second conveying element (Ro-b) and the third conveying element (Fb-1.2, Ro-f) and - the three conveying elements, the two Transport objects (Ps-A, Ps-B) in such a way that the object plane of the leading object (Ps-A) is rotated in the period of the distance magnification and by this rotation the gap is formed. Method according to one of claims 1 to 3, characterized in that a dimensional barrier is specified and for two immediately consecutive objects (Ps-A, Ps-B) an overlapping operation is performed only if - For both objects (Ps-A, Ps-B), the same sorting output (SAus.1) was selected and also - at least one of the two immediately consecutive objects has an extension - seen in the transport direction - in its object plane, which is smaller than the given dimensional barrier. Method according to one of claims 1 to 4, characterized in that when the same sorting exit (SAus.1) has been selected for a pair of three items to be sorted following in sequence one after another, A first overlapping process is carried out in such a way that after the first overlapping process the first article and the second article of the pair overlap at least partially, A second overlapping operation is performed such that, after the second overlapping operation, the second object and the third object of the pair overlap at least partially, and - The three objects are transported in such a way to the common sorting output and discharged into this common sorting output, - That during transport, the first object and the second object at least partially overlap and - The second object and the third object overlap at least partially. Method according to one of claims 1 to 5, characterized in that a thickness limit is specified and for two immediately successive objects (Ps-A, Ps-B) an overlapping process is executed only if - For both items (Ps-A, Ps-B) the same sorting output (SAusg.1) was selected and also - The sum of the dimensions of the two immediately consecutive objects (Ps-A, Ps-B) - measured in a direction perpendicular to the respective object plane - is less than or equal to the predetermined thickness barrier. Sorting system for sorting flat objects (Ps-A, Ps-B) according to a predetermined sorting feature, each item to be sorted (Ps-A, Ps-B) extending in an object plane, the sorting system - a measuring device (Ka, Bae), - a selection unit (AE), - a transport device (TE), - a discharge device (Aus-E) and - several sorting outputs (SAus.1, SAus.2, ...), the sorting system designed to bring the items to be sorted (Ps-A, Ps-B) in a succession of spaced objects, the transport means (TE) configured to pass this sequence through the sorting unit to the sorting outputs (SAus. 1, SAus.2, ...), the measuring device (Ka, Bae) is designed to measure what value the sorting feature assumes for an item to be sorted, the selection unit (AE) is designed to select a sorting output (SAus.1, SAus.2, ...) for an item to be sorted, the sorting system being designed for each item to be sorted (Ps-A, Ps-B ) to carry out the steps that - the measuring device (Ka, Bae) measures which value the sorting feature for this object (Ps-A, Ps-B) assumes, - the selection unit (AE) depending on the sorting feature value of this object (Ps-) A, Ps-B) selects a sorting output (SAus.1, SAus.2) for this item, - the transport means transports the item (Ps-A, Ps-B) to the selected sorting exit (SAus.1) and - the Outfeed device discharges the object into the selected sorting exit (SAus.1), characterized in that the sorting system comprises an overlap generation device (LVE), the overlap generation device (LVE) being designed for a pair of at least two counters to sort In the sequence immediately following each other (Ps-A, Ps-B), an overlapping operation is performed such that the overlapping process comprises the step of the overlap generating means (LVE) guiding the preceding object (Ps-A) long transported at a lower speed (V1) and / or over a longer transport path than the subsequent object (Ps-B) until the two objects (Ps-A, Ps-B) are in a viewing direction perpendicular to the object Planes - at least partially overlapping and touching each other in an overlap area, the sorting system is configured to check for at least a pair of at least two objects (Ps-A, Ps-B) immediately following each other in the sequence, for either of these Items (Ps-A, Ps-B) the same sorting output has been selected or two different sorting outputs have been selected, the sorting unit is further configured i st, to transport two different contiguous objects, for which different sorting outputs have been selected, spaced apart from one another to the different sorting outputs and to dispose in these sorting exits, the sorting system is further configured for at least one pair of immediately following objects (Ps-A, Ps -B) for which the same sorting output has been selected, - to perform an overlapping operation by means of the overlap-generating means (LVE) and - the two objects (Ps-A, Ps-B) after the overlapping operation has been completed with at least partial overlapping up to to transport the sorting output (SAus.1) selected for both items and to discharge them into this common sorting output (SAus.1). Device according to claim 7, characterized in that the overlap generation device (LVE) includes a conveyor - A first conveyor element (Fb-1.1) and A second conveying element (Ro-b) includes, the overlap generation device (LVE) is designed to handle every item transported by this conveyor device, - temporarily trapped during transport between these two conveyor elements (Fb-1.1, Ro-b) and - To transport in the clamped state of the two conveyor elements (Fb-1.1, Ro-b) and the overlap generation device (LVE) is further configured to perform the additional steps in at least one overlapping process When the two conveying elements (Fb-1.1, Ro-b) pinch the leading object (Ps-A), - To increase the distance between the two conveying elements (Fb-1.1, Ro-b) in such a way A gap is produced between the leading object (Ps-A) and the first conveying element (Fb-1.1) or between the leading object (Ps-A) and the second conveying element (Ro-b), - To push the subsequent object (Ps-B) in this gap and - to reduce the distance between these two conveying elements (Fb-1.1, Ro-b) again, - So that after this distance reduction, the two at least partially overlapping objects (Ps-A, Ps-B) of both conveyor elements (Fb-1.1, Ro-b) are clamped.

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