EP1872871A1

EP1872871A1 - Method and apparatus for loading and unloading containers in a mail processing system

Info

Publication number: EP1872871A1
Application number: EP06013583A
Authority: EP
Inventors: Peter Berdelle-Hilge
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2006-06-30
Filing date: 2006-06-30
Publication date: 2008-01-02
Anticipated expiration: 2026-06-30
Also published as: EP1872871B1; ATE413236T1; DE602006003543D1

Abstract

A mail processing system has a conveyor system (12) with a first level (12a) and a second level (12b) and configured to convey mail containers. An elevator installation (10) is coupled to receive and output mail containers from and to the conveyor system (12), wherein the elevator installation (10) includes tablets (16) configured to move along a closed loop extending along first and second sides of the elevator installation (10) . On each side a predetermined number of tablets extends between a top end and a bottom end of the elevator installation (10). A carousel carrier (14) is coupled to receive and output mail containers from and to the elevator installation (10). The carousel carrier (14) has a vertical column of a predetermined number of platforms arranged between a top end and a bottom end of the carousel carrier (14), wherein the number of tablets is the same as the number of platforms.

Description

Background of the Invention

The various embodiments described herein relate generally to a mail processing system. More particularly, these embodiments relate to a method and apparatus for loading and unloading containers in such a system.
Each day postal services process mail items for delivery to millions of individual domestic addresses. As used throughout this application, mail items refer to letters, magazines, books and other such flat items. Before mail carriers begin to walk through or drive through their delivery routes, a mail processing system at a processing site sorts all mail items for the carriers and prepares the sorted mail items for delivery to a multitude of domestic addresses. A carrier's responsibility includes putting all of these mail items into an appropriate sequence for efficient delivery to the domestic addresses.
The mail processing system is highly automated to handle the amount of daily mail items. Some mail processing systems may include a delivery point packaging (DPP) system that, for example, separates the mail items, reads their destination addresses and groups the mail items based upon their respective destination addresses. An exemplary DPP system is an automatic casing system which may comprise two U-shaped casing towers arranged side by side. Each tower carries, on a given member of levels, vertical oriented slots. The slots may be grouped in containers or pods wherein most or all mail for a delivery point is inserted. The insertion may be effected by autonomous moving vehicles . Each of the vehicles may carry one piece of mail. Each of the two casing towers may be further connected to two loading points. Each loading point may further be connected to one or more feeders via a conveyor system. After the mail is appropriately sorted, the mail needs to be extracted. The containers are transported to extracting stations where carousel-like apparatuses are used to exchange full containers with empty containers.

Summary of Certain Inventive Aspects

A general aspect of a mail processing system is to operate as efficient and reliable as possible and as inexpensive as possible. One parameter that influences efficiency, reliability, and operating costs is the operational speed at the extraction stations. The unloading of full mail containers from the various levels of the processing system and the loading of empty containers to these levels may be done using a lift, which vertically connects the levels at the extraction stations. However, a lift has a limited capacity due to idle strokes and a limited operational speed. There is, therefore, a need for an improved technique for loading and unloading containers.
Accordingly, one aspect involves a method of loading and unloading mail containers in a mail processing system having a conveyor system with a first level and a second level, an elevator installation and a carousel carrier. A predetermined number of first mail containers is fed from the first level of the conveyor to a predetermined number of platforms of the elevator installation, wherein the predetermined number of first mail containers is the same as the predetermined number of tablets. The first mail containers are simultaneously transferred to a predetermined number of platforms of the carousel carrier, wherein the predetermined number of platforms is the same as the predetermined number of tablets.
Another aspect involves a mail processing system having a conveyor with a first level and a second level and configured to convey mail containers. An elevator installation is coupled to receive and output mail containers from and to the conveyor, wherein the elevator installation includes tablets configured to move along a closed loop extending along first and second sides of the elevator installation. On each side a predetermined number of tablets extends between a top end and a bottom end of the elevator installation. A carousel carrier is coupled to receive and output mail containers from and to the elevator installation. The carousel carrier has a vertical column of a predetermined number of platforms arranged between a top end and a bottom end of the carousel carrier, wherein the number of tablets is the same as the number of platforms.

Brief Description 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. In the following list of figures:

Figure 1 depicts a schematic overview of one embodiment of a mail processing system;
Figure 2 is a schematic illustration of a first embodiment of a method of loading and unloading containers used in the system of Figure 1; and
Figure 3 is a schematic illustration of a second embodiment of a method of loading and unloading containers used in the system of Figure 1.

Detailed Description of Certain Inventive Embodiments

Figure 1 shows a schematic illustration of a top view of one exemplary 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 are represented in Figure 1 through functional blocks for a feeding section FS, a routing area RA, a casing area CA and an extraction area EA. These functional blocks 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 may include a variety of other functional features. Further, it is contemplated that the separation into these functional blocks is arbitrary and that the blocks may be shown in a different arrangement without affecting the principal operation of the system. A more detailed description of one embodiment of the system and its structural components follows.
Briefly, the feeding section FS separates individual mail items from batches to identify their individual destination addresses. For that purpose, the feeding section FS includes in one embodiment feeders 3, 5 and optical character readers (OCR) or bar code readers, or a combination of these readers. After a successful identification of the destination addresses, the feeder section FS hands the mail items to the routing area RA. The routing area RA includes loading points 4, 6 coupled to the feeders 3, 5 and an infrastructure that transports the mail items according to their destination addresses to the casing area CA. The casing area CA is embedded in the routing area RA and includes a predetermined number of casing towers 1 that have slots for the mail items. Each slot represents an individual destination address. Once the mail items are delivered to the slots, extraction and packaging modules 2 in the extraction area EA extract the mail items from the slots and pack the mail items on a per destination address basis.
The various embodiments of the mail processing system described hereinafter relate mainly to the extraction area EA.
Figures 2 and 3 are schematic illustrations of embodiments of a method of loading and unloading containers used in the system of Figure 1. Each one of these figures depicts a first cycle ("Cycle n") with four illustrated states, and a second identical cycle ("Cycle n+1"), of which only the first state is illustrated. For each state, the extraction area is illustrated by means of a two-level conveyor system 12, an elevator installation 10 and a multi-level carousel carrier 14.
The two-level conveyor system 12 has a first level 12a and a second level 12b. Each level 12a, 12b includes a conveyor that is independent from the other conveyor. Each conveyor moves is one direction.
The elevator installation 10 is positioned between the two-level conveyor system 12 and the multi-level carousel carrier 14. The illustrated elevator installation 10 functions similar to an elevator know as "paternoster elevator." Such an elevator has a number of platforms that move along a closed loop. For example, in a building a paternoster elevator moves up on one side and down on the other side. The movement of such an elevator is continuous and passengers board and leave the elevator while the elevator continues to move. The elevator installation 10 may be also configured as a Ferris wheel paternoster elevator.
Accordingly, the elevator installation 10 includes a support structure that rests on a base element. The support structure houses, among other elements, a number of tablets 16 and a power train system 18. The tablets 16 are coupled to the power train system 18 that drives and guides the tablets 16 along a closed vertical loop. A part of the power train system 18 divides the elevator installation 10 in a left side and a right side that are connected at the top and bottom of the elevator installation 10. The tablets 16 on either side move in opposite directions. For example, the tablets 16 on the left side move down, whereas the tablets 16 on the right side move up, or vice versa.
In the illustrated embodiment, the elevator installation 10 is configured so that there are six tablets 16 on each side. Hence, the tablets 16 can transport, for example, twelve containers at any time. It is contemplated that the levels 12a, 12b of the conveyor system 12 are assigned to two tablets 16. In Figures 2 and 3, the first level 12a (top level) is assigned to the uppermost tablet 16 on the left side of the elevator installation 10, whereas the second level 12b (bottom level) is assigned to the lowermost tablet 16. The power train system 18 operates the elevator installation 10, for example, on a step-by-step basis so that each tablet 16 moves up or down one step at a time.
The multi-level carousel carrier 14 has a number of platforms 20 selected to correspond to the number of tablets 16 of the elevator installation 10. The carousel carrier 14 is configured to rotate about a vertical axis 24 on both ends of the carousel, or to move straight along the sides of the carousel. In either position of this process, loading and unloading stations may be positioned in order to transport full containers received from the elevator installation 10 away, and to supply empty containers to the elevator installation 10.
Referring to Figure 2, the top level 12a of the conveyor system 12 provides empty containers to the elevator installation 10, whereas the carousel carrier 14 receives the empty containers and supplies full containers, which the bottom level 12b transports away. It is contemplated that the step-by-step operation mentioned above is independent of whether a lateral or Ferris wheel paternoster elevator is used. In State 1, the tablets 16 of the elevator installation 10 are loaded with containers. Full containers A1-A6 are placed on the tablets 16 on the left side, and empty containers B1-B6 are placed on the right side. An arrow 22 indicates that the empty containers B1-B6 are to be transferred to the carousel carrier 14. Empty platforms 20 of the carousel carrier 14 face the elevator installation 10 and align with its tablets 16. The next group of empty containers (only two containers C1, C2 of a group of six are shown) awaits delivery to the elevator installation 10 on the top level 12a.
In State 2, the empty containers B1-B6 have been transferred to the platforms 20 of the carousel carrier 14. The carousel carrier 14 is activated to rotate about the axis 24 to transport the empty containers B1-B6 away, as indicated by an arrow 28. The tablets 16 on the right side of the elevator installation 10 are empty. Further, the elevator installation 10 is activated to transport the tablets 16 counterclockwise, as indicated by an arrow 26. The tablets 16 on the left side move downwards, wherein each time a tablet 16 reaches the bottom level 12 a full container is transferred to the bottom level 12b of the conveyor system 12, as indicated by an arrow 32. With the tablets 16 moving counterclockwise, empty tablets 16 are transported from the right to the left side and become available for loading with empty containers C1, C2, as indicated by an arrow 30.
In State 3, the tablets 16 of the right side of the elevator installation 10 have been loaded with empty containers C1-C6, while the bottom level 12b of the conveyor system 12 transports the full containers A1-A6 away. The tablets 16 of the right side are empty. The platforms 20 of the carousel carrier 14 are loaded with full containers D1-D6, which await transfer to the tablets 16 on the right side, as indicated by an arrow 34.
In State 4, the tablets 16 of the left side of the elevator installation 10 are loaded with empty containers C1-C6. The tablets 16 of the right side carry now the full containers D1-D6. Subsequently, the elevator installation 10 turns about a vertical axis 38, as indicated by an arrow 36, for example, counterclockwise by about 180°. The system is now available for the next cycle.
In State 1 of the next cycle (Cycle n+1), the tablets 16 of the left side of the elevator installation 10 (after the turn in State 4) are loaded with the full containers D1-D6, whereas the tablets 16 of the right side carry now the empty containers C1-C6. Similar to State 1 of the previous cycle (Cycle n), the top level 12a of the conveyor system 12 supplies empty containers E1, E2 for transfer to the elevator installation 10.
In the embodiment of Figure 2, the orientation of the containers changes by 180° during the loading or unloading process due to the turning of the elevator installation 10 in State 4. For illustrative purposes, each container includes an orientation mark 17. For example, in State 4 the orientation marks 17 of the containers D1-D6 point to the right, whereas they point to the left in State 1 of Cycle n+1. The elevator installation 10 may be a lateral or a Ferris wheel paternoster elevator. If the orientation of the mail container should be unchanged, the elevator installation 10 is a Ferris wheel paternoster elevator that may not turn around a vertical axis, as shown in Figure 3.
In Figure 3, as mentioned above, the extraction area is illustrated by means of a two-level conveyor system 12, an elevator installation 10 and a multi-level carousel carrier 14. The two-level conveyor system 12 and the carousel carrier 14 correspond to the ones described with reference to Figure 2.
In State 1, the tablets 16 of the elevator installation 10 are loaded with containers. Empty containers A1-A6 are placed on the tablets 16 on the left side, whereas the bottom level 12b of the conveyor system 12 transports full containers B1, B2 away. The tablets 16 on the right side of the elevator installation 10. are empty. An arrow 40 indicates that the empty containers A1-A6 are to be transferred through the elevator installation 10 to the carousel carrier 14. Empty platforms 20 of the carousel carrier 14 face the elevator installation 10 and align with its tablets 16. The next group of empty containers (only two containers C1, C2 of a group of six are shown) awaits delivery to the elevator installation 10.
In State 2, the empty containers A1-A6 have been transferred to the platforms 20 of the carousel carrier 14. The carousel carrier 14 is activated to rotate about the axis 24 to transport the empty containers A1-A6 away, as indicated by an arrow 28. The tablets 16 on both sides of the elevator installation 10 are empty.
In State 3, the platforms 20 of the carousel carrier 14 carry full containers D1-D6, which await transfer to the tablets 16 on the right side, as indicated by an arrow 42.
In State 4, the full containers D1-D6 have been transferred to the tablets 16 on the right side and from there through the elevator installation 10 to the left side. The elevator installation 10 is activated to rotate counterclockwise, as indicated by an arrow 44. The full containers D1-D1 are now on the left side of the elevator installation 10 and move downwards, wherein each time a tablet 16 reaches the bottom level 12b a full container is transferred to the bottom level 12b of the conveyor system 12, as indicated by an arrow 46. with the tablets 16 moving counterclockwise, empty tablets 16 are transported from the right to the left side and become available for loading with empty containers B1, B2, as indicated by an arrow 48. The system is now available for the next cycle.
In State 1 of the next cycle (Cycle n+1), the tablets 16 of the left side of the elevator installation 10 are loaded with the empty containers B1-B6, whereas the tablets 16 of the right side are empty. Similar to State 1 of the previous cycle (Cycle n), the top level 12a of the conveyor system 12 supplies empty containers E1, E2 for transfer to the elevator installation 10.
It is apparent that there has been disclosed an apparatus and method for loading and unloading containers that fully satisfy the objects, means, and advantages set forth hereinbefore. For example, the embodiments allow continuous operation of the elevator installation that avoids any idle strokes necessary in conventional lifts. Further, the use of an elevator installation that has the same number of tablets as the carousel has platforms provides the highest number of simultaneously loaded or unloaded containers, and, therefore, maximum performance. The use of the elevator installation avoids transporting containers over top.

Claims

A method of loading and unloading mail containers in a mail processing system having a conveyor system (12) with a first level (12a) and a second level (12b), an elevator installation (10) and a carousel carrier (14), comprising:
feeding a predetermined number of first mail containers from the first level (12a) of the conveyor system (12) to a predetermined number of tablets (16) of the elevator installation (10), wherein the predetermined number of first mail containers is the same as the predetermined number of tablets (16) ; and

transferring the first mail containers simultaneously to predetermined number of platforms (20) of the carousel carrier (14), wherein the predetermined number of platforms (20) is the same as the predetermined number of tablets (16).
The method of Claim 1, wherein feeding the first mail containers includes transferring each first mail container from the first level (12a) to a tablet (16) at an upper end of the elevator installation (10).
The method of Claim 2, further comprising transferring each first mail container from a tablet (16) at a bottom end of the elevator installation (10) to the second level (12b) of the conveyor system (12).
The method of Claim 3, wherein transferring each first mail container from the first level (12a) to a tablet (16) at an upper end, and transferring each first mail container from a tablet (16) at a bottom end of the elevator installation (10) to the second level (12b) occurs contemporaneously.
The method of Claim 4, further comprising activating the elevator installation (10) to transfer each tablet (16) from the upper end to the bottom end.
The method of Claim 5, further comprising transferring the tablets (16) along a closed loop.
The method of any preceding claim, further comprising turning the carousel carrier (14) about a vertical axis or translating the carousel carrier (14) so as to exchange a first vertical column of platforms (20) with a second vertical column of platforms (20).
The method of any preceding claim, further comprising turning the elevator installation (10) about a vertical axis
A mail processing system, comprising:
a conveyor system (12) having a first level (12a) and a second level (12b) and configured to convey mail containers;

an elevator installation (10) coupled to receive and output mail containers from and to the conveyor system (12), wherein the elevator installation (10) includes tablets (16) configured to move along a closed loop extending along first and second sides of the elevator installation (10), wherein on each side a predetermined number of tablets (16) extends between a top end and a bottom end of the elevator installation; and

a carousel carrier (14) coupled to receive and output mail containers from and to the elevator installation (10), wherein the carousel carrier (14) has a vertical column of a predetermined number of platforms (20) arranged between a top end and a bottom end of the carousel carrier (14), wherein the number of tablets (16) is the same as the number of platforms (20).
The system of Claim 8, wherein the first level (12a) of the conveyor system (12) is coupled to feed mail containers to a tablet (16) at the top end of the elevator installation (10), and wherein the second level (12b) of the conveyor system (12) is coupled to receive mail containers from a tablet (16) at the bottom end of the elevator installation (10).
The system of Claim 8 or 9, wherein the carousel carrier (14) is configured to turn about a vertical axis so as to exchange a first vertical column of platforms (20) with a second vertical column of platforms (20).
The system of Claims 8, 9 or 10, wherein the elevator installation (10) is configured to turn about a vertical axis so as to move the first side from facing the conveyor (12) to face the carousel carrier (14).
The system of any one of Claims 9-12, wherein the elevator installation (10) includes a lateral paternoster elevator or a Ferris wheel elevator.