EP1715963A1

EP1715963A1 - System and method for sorting postal articles using flatbed sorter

Info

Publication number: EP1715963A1
Application number: EP05707263A
Authority: EP
Inventors: Armin Zimmermann
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2004-02-09
Filing date: 2005-02-08
Publication date: 2006-11-02
Anticipated expiration: 2025-02-08
Also published as: EP1715963B1; DE602005005955T2; CN1917968A; JP2007520342A; WO2005075116A1; DE602005005955D1

Abstract

A system for sorting postal articles includes a plurality of postal article feeders (2, 4). A delay line (18) receives postal articles from one of the feeders (2, 4), and a delivery line (16) receives postal articles from another of the feeders (2, 4). Each one of a plurality of towers (10, 12, 14) has a plurality of destination compartments (20) arranged to receive the postal articles from the delay line (18) and the delivery line (16). The destination compartments (20) move laterally with respect to the towers (10, 12, 149. A plurality of trays (24, 26) receives the postal articles from the delivery and delay lines (16, 18) and delivers the postal articles to select destination compartments (20).

Description

System and Method for Sorting Postal Articles Using Flatbed Sorter

Cross Reference to Related Applications The present application claims priority to provisional patent application serial number 60/542,295 filed on February 9, 2004, which is herein incorporated by reference.

Background of the Invention The various embodiments described herein relate to a system and method for sorting articles within a mail processing system.

Each day, a country's postal service processes articles for delivery to millions of individual domestic addresses. As used throughout the application, articles and mail or postal articles refer to mail items, magazines, books and other such essentially flat items. Before mail carriers begin to walk through or drive through their delivery routes, a mail processing system at a postal service's processing site sorts all articles for the carriers and packages the sorted articles for each domestic address. A carrier's responsibility includes putting all of these articles into an appropriate sequence for efficient delivery to the domestic addresses.

The mail processing system is highly automated to handle the amount of daily articles. For example, it includes a delivery point packaging (DPP) system that separates the articles, reads their destination addresses and groups the articles based upon their respective destination addresses. One example of a DPP system includes an arrangement of a multitude of individual compartments or slots for individual articles. Feeders insert the articles into a transport system at loading points. At this point, the destination address of an article is known and the transport system transports the article along a delivery path to a slot that is pre-assigned to the destination address of that article.

Summary of Certain Inventive Aspects A general aspect of a mail processing system is to operate it as efficient and reliable as possible and as inexpensive as possible to the postal service. One parameter that influences efficiency and operating costs is the number of delivery passes necessary to deliver the articles to the compartments assigned to particular delivery addresses. Reducing the number delivery passes improves efficiency and reliability and reduces operating cost. It is, therefore, an objective to provide a mail processing system that allows operation with a minimum number of delivery passes.

Accordingly, one aspect involves a system for sorting postal articles that includes a plurality of postal article feeders. A delay line receives postal articles from one of the feeders, and a delivery line receives postal articles from another of the feeders. Each one of a plurality of towers has a plurality of destination compartments arranged to receive the postal articles from the delay line and the delivery line. The destination compartments move laterally with respect to the towers. Further, a plurality of trays receives the postal articles from the delivery and delay lines and delivers the postal articles to select destination compartments.

Another aspect involves a method of sorting postal articles. A first feeder is operated to insert a first stream of postal articles into a delivery line at a predetermined first rate, and a second feeder is operated to insert a second stream of postal articles into a delay line at a predetermined second rate. The postal articles are loaded from the delivery line and the delay line onto a plurality of trays. The trays move on a rail system along a plurality of destination compartments arranged to selectively receive the postal articles from the delay line and the delivery line. The first and second rates are selected to provide for a predetermined throughput of the rail system. To empty the destination compartments, the destination compartments move with respect to the trays.

Brief Description of the Several Views of the Drawings These and other aspects, advantages and novel features of the embodiments described herein will become apparent upon reading the following detailed description and upon reference to the accompanying drawings. In the drawings, same elements have the same reference numerals. Figure 1 shows a schematic overview of one embodiment of a mail processing system; Figure 2 illustrates a cross sectional view of an embodiment of a sorter section of the mail processing system; Figure 3 illustrates a side view of the sorter section of Figure 2; Figure 4 illustrates one embodiment of a vertical diverter coupled to a frame of the mail processing system; and Figures 5 - 7 illustrate various options for operating and arranging the feeders of the mail processing system.

Detailed Description of Certain Inventive Embodiments Figure 1 shows a schematic illustration of one embodiment of a mail processing system to provide for a general overview of a mail processing system. The illustration depicts basic flows and functional relationships within the system. These basic flows and functional relationships include sections for feeding articles, routing the articles and sorting the articles. These flows and relationships represent some of the main functional features of the system. Those of ordinary skill in the art of mail processing systems will appreciate that the system includes a variety of other functional features. A more detailed description of one embodiment of the system and its structural components follows.

Briefly, the feeding section separates individual articles from batches of mail to identify their individual destination addresses. For that purpose, the feeding section includes in one embodiment feeders 2, 4 and optical character readers (OCR) or bar code readers, or a combination of these readers. After successful identification of the destination addresses, the feeder section hands the articles to the routing section. The routing section includes an infrastructure that transports the articles according to their destination addresses to the sorting section. The infrastructure of the routing section includes, among other elements, vertical diverters 6, 7, 8. The sorting section is associated with the routing section to receive the articles and includes a predetermined number of towers 10, 12, 14 that have a plurality of compartments 20 for the articles. In one embodiment, each compartment 20 is assigned to an individual destination address. Once the articles are delivered to the compartments 20 a transport mechanism transfers the articles from the compartments 20 to containers that receive packaged articles, for example, on a per destination address basis. In one embodiment, the feeder 2 inputs letters to the system and the feeder 4 other flat items. Hence, the feeders 2, 4 generate two separate streams of articles. The feeders 2, 4 may be conventional feeders whose structure and operation are known to those of ordinary skill in the art of mail processing systems. The feeder 2 is coupled to a delivery line 16 to receive letters from the feeder 2. The delivery line 16 includes switches 16a, 16b to deliver a letter to one of the three towers 10, 12, 14. The feeder 4 is coupled to a delay line 18 to receive flat items from the feeder 4. The delay line 18 includes switches 18a, 18b, 18c to deliver a flat item to one of the towers 10, 12, 14. In one embodiment, the delivery line 16 receives the letters from the feeder 2 at a throughput of about 3 letters per second, and is a pinch belt system, for example, running at a velocity of about 3 m/s. In that embodiment, a delay line is not coupled to the feeder 2 because letters are typically bar-coded making the destination address immediately available.

In the illustrated embodiment, the delay line 18 is a U-channel that functions as a storage section for the flat articles. The delay line 18 receives the flat articles at a throughput of about one letter per second and provides for a time delay configured to allow the system to perform the optical character reading. In this exemplary embodiment, the throughput ratio of letters to other flats is 3:1. If the delay line 18 runs at a velocity of about 0,5 m/s and a delay time of about 30 s is desired, the delay line 18 may have a length of about 15 m before reaching the first switch 18a. Further, the switches 18a, 18b, 18c are U-channel switches. The U-channel of the delay line 18 and the switches 18a, 18b, 18c provide that the flat articles are transported in a substantially upright (vertical) position leaning against the legs of the "U". At output ends of the switches 18a, 18b, 18c, devices may be inserted into the transport path to bring the flat articles into a desired position (e.g., by turning or twisting) for further handling. It is contemplated that in one embodiment a central controller monitors and controls the mail processing system. Among other functions, the central controller controls the operational speeds and throughputs of the feeders 2, 4, the operation of the delivery line 16 and the delay line 18 and the operation and position of the switches 16a, 16b, 18a, 18b, 18c. Further, the central controller is configured to handle rejected articles and to re-feed them or, if necessary, to send them to a manual feeder. As shown in Figure 1 , each tower 10, 12, 14 includes two frames 10a, 10b,

12a, 12b, 14a, 14b, wherein each has a predetermined number of levels and compartments 20 configured to move laterally with respect to the frames 10a, 10b, 12a, 12b, 14a, 14b. It is contemplated that the top view of Figure 1 shows only one of the towers' levels that have substantially identical structures. Further, in each tower 10, 12, 14, a rail system 22 couples the two frames 10a, 10b, 12a, 12b, 14a, 14b and operates on a per level basis. For each level there are trays 24, 26 configured to move on the rail system 22 in front of the compartments 20 and along a closed loop, for example, at a velocity of about 1 ,4 m/s. The rail system 22 may have a length of about 56 m per level and tower 10, 12, 14. In one embodiment, about 40 trays 24, 26 may move counter-clockwise per level and tower 10, 12, 14. The compartments 20 of each level can be reached by the trays 24, 26 for delivery of an article.

In one embodiment, each frame 10a, 10b, 12a, 12b, 14a, 14b has 15 levels, and the compartments 20 of each level are arranged in double-deep rows, for example, each row having between a few dozen and several hundred compartments, for example 168. The compartments 20 are next to each other, for example, with a horizontal pitch of about 300 mm and a length of about 400 mm. The 15 levels may have a vertical distance from each other of about 150 mm and a total active height of about 2,25 m. Assuming in each frame 10a, 10b, 12a, 12b, 14a, 14b two or more levels are assigned to one mail carrier, for example, three levels per mail carrier, there are several hundred compartments 20 assigned to one mail carrier. In that example, each frame 10a, 10b, 12a, 12b, 14a, 14b may serve five mail carriers. The mail articles reach the various levels of the towers 10, 12, 14 selectively through the vertical diverters 6, 7, 8 coupled between the switches 18a, 18b, 18c and described in more detail with reference to Figure 4. Figure 2 illustrates a cross sectional view of an embodiment of a frame 10a of the mail processing system. The cross sectional view shows the 15 levels of the frame 10a, the compartments 20 in double-deep arrangement and the rail system 22. Further, in the illustrated embodiment, a carrier 25 is configured to receive three trays 24 and to transport the trays 24 along the rail system 22 to the compartments 20. However, it is contemplated that, instead of using a carrier 25, the system may be configured so that each tray 24 moves independently on the rail system 22. For illustrative purposes, Figure 2 shows a flat article on each tray 24. It is contemplated that the other frames 10b, 12a, 12b, 14a, 14b have essentially the same structure. Each carrier 25 is configured to move independently on the rail system 22 and to stop in front of the compartment 20 assigned to the flat article's destination address. Each tray 24 may move with respect to the carrier 25 to deposit the flat article into a compartment 20 of the first or second row. For example, the flat article may be pushed or dropped into the compartment 20. Further, a telescopic arm may transfer the flat article from the tray 24 to the compartment 20. The compartment 20 may have a slip off device, or any other suitable device to hold the flat article within the compartment 20.

Figure 3 illustrates a side view of one (e.g., frame 14b) of the frames 10a - 14b shown in Figure 1. For ease of reference, the levels are numbered. Each of the 15 levels includes a conveyor belt system. The conveyor belt is cleated so that the space between two cleats forms one of the compartments 20. Further, Figure 3 shows a tray 24 (level 10) positioned next to a compartment 20, compartments 20 containing mail articles (levels 6 and 10), and high volume containers 29 (e.g., 5 containers). It is contemplated that the containers 29 can be reached by the trays 24 and that the containers 29 may be assigned, for example, to companies that receive a substantial amount of mail. As shown in Figure 3, the containers 29 are positioned on the right-hand side of the frame 14b. In one embodiment, the mail processing system waits until all compartments 20 are filled, or all mail articles of the present batch of mail have been sorted, and then activates the conveyor belt system to move the compartments 20 laterally with respect to the rail system 22, for example, from right to left. It is contemplated that the system operates the conveyor belt system of one level independent from the belt system of the other levels.

With the compartments 20 moving from right to left, the articles leave the sorting section at the left-hand side of the frame 14b, as shown in Figure 3.

Accordingly, emptying of the compartments 20 occurs at or near the left-hand side of the frame 14b. The process of emptying the compartments 20 may include packaging the content of each compartment 20, for example, by shrink-wrapping, bagging, or band-wrapping the mail articles. Figure 3 illustrates in level 6 a series of wrapped packages at the left-hand side of the frame 14b. The packages may then be stacked in a container for sorted mail.

Figure 4 illustrates one embodiment of the vertical diverter 6 coupled to the frame 10a of the mail processing system. The vertical diverter 6 is coupled to receive flat articles from the switch 18c. A system of interconnected switches 30 and sections 32 are configured to selectively divert a flat article to reach one of the available (15) levels of the frame 10a. In one embodiment, the switches 30 and sections 32 are based on a flat belt system that drops the flat articles at the desired level onto a tray 24. The belt system and the trays 24 are arranged so that an appropriate angle of inclination exists that assists dropping the flat articles onto the trays 24. In addition, a stop or hold-down mechanism may be provided to assist loading the trays 24.

Figures 5 - 7 illustrate various options for operating and arranging the feeders of the mail processing system. In these exemplary illustrations, the total throughput of the feeders is four articles per second (4/s). Referring to Figure 5, the (letter) feeder 2 operates at a rate of four articles per second (4/s), but leaves a gap after every third article. As such, the feeder 2 inserts letters into the delivery line 16 at a rate of three letters per second (3/s). The feeder 4 operates at a rate of one article per second (1/s) and, as such, inserts a flat item into the delay line 18 at a rate of 1/s. At the rail system 22, the two streams of articles merge into a single stream. That is, once the trays 24, 26 are loaded, they travel at a rate of 4/s. As illustrated in Figure 5, after a series of three trays 26 loaded with letters, a tray 24 with a flat item follows setting a letter to flats ratio of 3:1.

Referring to Figure 6, the (letter) feeder 2 operates at a rate of three articles per second (3/s), and the feeder 4 operates at a rate of one article per second (1/s). Although the letter to flats ratio is 3:1 , as in Figure 5, the two streams cannot be merged to a single stream.

Referring to Figure 7, a feeder 2' is configured to output letters and flat items at a rate of two articles per second (2/s). Similarly, a feeder 4' is configured to output letters and flat items at a rate of two articles per second (2/s). Both feeders 2', 4' leave a gap after each article. At the rail system 22, the two streams of articles merge into a single stream. As illustrated in Figure 7, after one tray loaded with a letter, one tray with a flat item follows setting a letter to flats ratio of 1:1. It is apparent that there has been disclosed a mail processing system and a method of sorting articles within a mail processing system that fully satisfies the objects, means, and advantages set forth hereinbefore. While specific embodiments of the system and method have been described, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description.

Claims

claim:

1. A system for sorting postal articles, comprising: a plurality of postal article feeders (2, 4); a delay line (18) arranged to receive postal articles from one of the feeders (2, 4); a delivery line (16) arranged to receive postal articles from another of the feeders (2, 4); a plurality of towers (10, 12, 14), each including a plurality of destination compartments (20) arranged to receive the postal articles from the delay line (18) and the delivery line (16), the destination compartments (20) being arranged to move laterally with respect to the towers (10, 12, 14); and a plurality of trays (24, 26) arranged to receive the postal articles from the delivery and delay lines (16, 18) and deliver the postal articles to select destination compartments (20).

2. The system of Claim 1, wherein each tower (10, 12, 14) includes a plurality of rows and vertically displaced levels, each level including a predetermined number of destination compartments (20) arranged in a row.

3. The system of Claim 1 , wherein one of the feeders (2, 4) is a flats feeder (4) and the other of the feeders is a letters feeder (2).

4. The system of Claim 3, wherein the delay line (18) comprises a U channel and U channel switches (18a, 18b, 18c) arranged to divert flats and letters to select compartments (20).

5. The system of Claim 3, further comprising a pinch or flat belt system arranged to deposit postal articles from the delay lines (18) into respective trays (24, 26).

6. The system of Claim 1 , further comprising a rail system (22) upon which the trays (24, 26) navigate to and from the destination compartments (20).

7. A method of sorting postal articles, comprising: operating a first feeder (2) to insert a first stream of postal articles into a delivery line (16) at a predetermined first rate; operating a second feeder (4) to insert a second stream of postal articles into a delay line (18) at a predetermined second rate; loading the postal articles from the delivery line (16) and the delay line (18) onto a plurality of trays (24, 26); moving the trays (24, 26) on a rail system (22) along a plurality of destination compartments (20) arranged to selectively receive the postal articles from the delay line (18) and the delivery line (16), wherein the first and second rates are selected to provide for a predetermined throughput of the rail system (22); and moving the destination compartments (20) with respect to the trays (24, 26) to empty the destination compartments (20).

8. The method of Claim 7, further comprising merging the first and second streams of postal articles to a single stream on the rail system (22).

9. The method of Claim 8, wherein the single stream includes postal articles from the first stream and postal articles from the second stream at a ratio of 3:1.

10. The method of Claim 9, wherein the first feeder (2) operates at a rate of four postal articles per second, and the second feeder (4) operates at a rate of one article per second.

11. The method of Claim 8, wherein the single stream includes postal articles from the first stream and postal articles from the second stream at a ratio of 1 :1.

12. The method of Claim 11 , wherein the first feeder (2') operates at a rate of two postal articles per second, and the second feeder (4') operates at a rate of two articles per second.