POSTAL MATTER SORTING METHOD AND SYSTEM

Abstract: A letter sorting machine (LSM) system of the invention has a plurality of LSMs, each having a feeder (1), a reader (4), horizontal convey paths (8a, 8b, 8c), bins (10) with a push-out mechanism (7), an elevator mechanism (17), a separating mechanism (26) for separating the postal matter from the trays, a destination label printer (28), and a bundling machine (73). These LSMs are connected to a centralized system controller (77). The centralized system controller (77) has a computer (91) and a magnetic disk (97) for storing a schedule for determining the mode of each LSM. The computer (91) reads out the schedule table from the magnetic disk (97) and controls the modes of the LSMs for performing the primary or secondary sortation according to the kinds and amount of the postal matter to be sorted.

Description: The present invention relates to a postal matter sorting method and system for sorting postal matter with a postal code (corresponding to a zip code). Various automatic processing machines for postal matter have been recently developed along with simplification of works in post offices. One of the machines is a letter sorting machine (LSM) or apparatus with an automatic postal code reader. In Japan, the postal code is expressed by upper three digits and lower two supplementary digits separated by a hyphen therefrom. In each post office, the postal matter are classified for about 1000 destination areas according to the upper three digits. Therefore, in order to classify or sort postal matter, a great number of bins corresponding to the destination areas must be prepared on the shelf part of the LSM. However, the bins can hardly be mounted in the LSM due to the size of the LSM and the installation space. Conventionally, a sorting shelf having about 70 boxes thereon has been used and manual sortation has been performed. Each postal matter is primarily sorted into the bins of the shelf corresponding to some areas of the upper three digits of the postal code, and corresponding to 13 groups of adjacent areas. A technique for applying the primary and secondary sortations to LSMs has been considered. However, if LSMs are separately arranged for primary sortation and secondary sortations of each group, the efficiency of operating LSMs is lowered, resulting in high cost. Document DE-A-1,574,143 discloses a letter sorting machine system comprising a plurality of letter sorting machines for automatic sorting of postal matter. In this letter sorting machine system some of the machines are set up for a primary sortation and some are working in a secondary sortation mode. The letter sorting machine system itself could be connected to and controlled by a data processing unit. Document DE-A-1 574 564 discloses a postal matter sorting machine wherein at least one of several sorting apparatuses may operate alternately in a primary or secondary sorting mode. Further, prior art documents "Encyclopedia of Computer Science", 1976, Van Nostrand Reinhold Company, USA, 135 West 50th Street, New York, NY 10020, Manufacturing Systems: pages 28 and 29 and exhibit 8, page 30, and "Encyclopedia of Computer Science and Technology", Volume 13, 1979, Marcel Dekker, Inc., USA, 270 Madison Avenue, New York, New York 10016, Scheduling: pages 58-78, and Steinbuch, wober : Taschenbuch der Informatik, Vol.III, 1974, pages 131-138, 189 disclose the general concept of schedule tables and scheduling which is the process of deciding which of a given set of operations get performed, and when, on a given set of machines. An assignment over time of operations to machines is called a schedule, and in many situations, such as manufacturing, the process of scheduling involves substantial computation so it is natural for the scheduling procedure to be implemented on a computer. It is an object of the present invention to provide a postal matter sorting method for a letter sorting system comprising a plurality of sorting apparatuses with automatic postal code reader, said method having an improved efficiency by effectively performing primary and secondary sortations of the postal matter. The present invention provides a postal matter sorting method as specified in claim 1. The present invention provides also a postal matter sorting system for carrying out the method of claim 1, as specified in claim 6. Other objects and features of the present invention will be apparent from the following description taken in connection with the accompanying drawings in which: Fig. 1 is a schematic perspective view of an LSM as part of a LSM system; Fig. 2 is a schematic perspective view of the overall arrangement of the LSM system which has a plurality of LSMs shown in Fig. 1; Fig. 3 is a flow chart for explaining primary sortation and secondary sortation of the postal matter in the LSM system shown in Fig. 2; Fig. 4 is a block diagram of a centralized system controller and microcomputers connected thereto of the LSM system of the present invention; Fig. 5 shows an example of a schedule table which is stored in a magnetic disk of the centralized system controller shown in Fig. 4 and which indicates control operation of each line; Fig. 6 shows an example of a code-bin assignment table for specifying pocket numbers according to postal code numbers of the postal matter; and Fig. 7 is a flow chart for explaining how the operation schedule of the LSM system of the present invention is made. Referring to Fig. 1, a group of postal matter A such as post cards and letters are set upright in a feeder 1. The postal matter A are sequentially picked up by a pickup 2 from the frontmost mail. The postal matter A are then read by ε reader 4 which is arranged on a convey path 3. Thus, postal codes on the postal matter A are read. The postal matter A are then selectively supplied to sortation convey paths 6a, 6b, 6c and 6d which are vertically arranged in a gate mechanism, 5 in accordance with the results obtained by the reader 4. The postal matter A are then supplied to horizontal convey paths 8a, 8b and 8c of a sorter 7 with an automatic pickup function or a discharge bin 9. A plurality of bins 10 are disposed on the side of the rear surfaces of the horizontal convey paths 8a, 8b and 8c of the sorter 7. Each of the postal matter A fed to the horizontal convey path 8a, 8b or 8c is stacked in a predetermined one of the bins 10 in accordance with the results obtained by the reader 4. When a proper amount of postal matter A is stacked in one of the bins 10, or when a compulsory push-out switch (not shown) is depressed, a pickup mechanism, for example, a push-out mechanism (not shown) of the stacker 10 is operated and pushes out the postal matter A within the bin 10 against the rear surface of the sorter 7. A tray circulating unit 14 with horizontal convey paths 13a, 13b and 13c for trays arranged vertically in three stages in correspondance with the bins 10 is disposed on the rear surface of the sorter 7. The postal matter A pushed out from the respective bins 10 are placed on trays 15 which are sequentially intermittently transferred on the horizontal convey paths 13a, 13b and 13c. An elevator mechanism 17 is arranged at the terminal end side of the paths 13a, 13b and 13c. The elevator mechanism 17 intermittently circulates tray tables 16 to sequentially vertically oppose them to horizontal convey paths 13a, 13b and 13c. The elevator mechanism 17 receives the trays 15 with the postal matter A stacked thereon (may be empty) delivered from the horizontal convey paths 13a, 13b and 13c. The elevator mechanism 17 then carries the trays 15 to the separator of the separating mechanism 18 for separating the postal matter A from the trays. Push-out plates 19 for pushing out the postal matter A and pull-in plate 20 for pulling in the trays 15 reciprocate at the separating mechanism 18. During the forward movement, the push-out plates 19 push out the postal matter A on the trays 15 towards the front to place them on facers 23 of a facer unit 22 at the initial end of a convey line 21. During the backward movement, the pull-in plates 20 pull the empty trays 15 backward to place them at the initial end of a tray return path 24 of the tray circulating unit 14. The postal matter A supplied to the convey line 21 are transferred by a facer convey unit 25 constituting the convey line 21. During the conveying operation, the back side of the postal matter in the direction of their movement and one end thereof in the direction perpendicular thereto are faced. The faced postal matter A are then transferred on another convey line 27 by a transfer mechanism 26 extending perpendicularly to the convey line 21. A destination label 29 is attached on the uppermost one of the postal matter A by a destination label printer 28 facing the convey line 27. The postal matter A with the destination card attached thereon are then supplied for bundling to a bundling machine 30 arranged at the terminal end of the convey line 27. Meanwhile, the trays 15 placed on the tray return path 24 by the separating mechanism 18 are transferred to the side of an elevator mechanism 31 at the initial ends of the horizontal convey paths 8a, 8b and 8c. The trays 15 are then placed on tray tables 32 of the elevator mechanism 31 by a tray transfer mechanism (not shown) facing the terminal end of the tray return path 24. The elevator mechanism 31 intermittently circulates the tray tables 32 so that the tray tables 32 may sequentially face the initial ends of the horizontal convey paths 13a, 13b and 13c in the order named. The trays 15 facing the initial ends of the horizontal convey paths 13a, 13b and 13c are pushed by a push mechanism (not shown) and the trays 15 on the horizontal convey paths 13a, 13b and 13c are conveyed by one pitch. The tray 15 at the temrinal end is placed on the tray table 16 of the elevator mechanism 17. The overall system is controlled by a control section 33. The LSM system incorporates a plurality (5 in the embodiment shown in Fig. 2) of LSMs as described above. The configuration of a LSM system according to an embodiment will now be described with reference to Figs. 2 and 3. The postal matter collected from mailboxes are placed in cases (not shown) which arethen aligned on a case conveyor 51. In operation, the cases are conveyed to a case dumper 53. The postal matter are dumped out of the cases by the case dumper 53 and are automatically conveyed to a rough culling table 55 shown in Fig. 1. The operator removes the postal matter which are not suitable for automatic sortation, such as oversized postal matter and rolls. The removed items are conveyed to a manual cancelling table (not shown) by a belt conveyor 57. The remaining postal matter are conveyed to one of hoppers of culler/facer/cancellers (CFCs) 61 by a pan conveyor 59. Each CFC 61 automatically rejects items which are not suitable for automatic sortation such as too thin or too thick items, stift items, or items containing hard objects. The rejected items are transferred to the manual cancelling table mentioned above. On the other hand, the postal matter which may be subjected to automatic sortation are faced and stamped and regular postal matter thereof are directly transferred to letter sorting machines (LSMs) 63, while special postal matter are stacked on local stackers of the CFCs 61. The regular postal matter which are faced and stamped are automatically supplied one by one to the LSM 63 through an arch transport 66 and a coupler 67. At the LSM 63, the optical character reader (OCR) detects the postal codes on the postal matter which are handwritten or printed. Then the postal matter are stacked on stackers 10 having automatic push-out mechanisms. Those which require secondary sortation are stacked on one of six terminal stackers 69. The postal matter which need not be processed by the CFC are placed in cases on another case conveyor 52 which is different from the case conveyor 51 for the postal matter collected from other post offices. These postal matter include those which have been accepted at the post offices and are faced or those which have been bundled at the other post offices and have been transported. In operation, these cases are lowered to positions near the LSM feeder, and the postal matter are fed to the LSM feeder. The OCR detects the postal codes on the postal matter which are handwritten or printed. Then, the postal matter are stacked on the bins 10 with automatic push-out mechanisms which are one of the sortation terminals or are stacked on one of the six terminal stackers 69 for secondary sortation. The postal matter which have been completely sorted by primary sortation are transferred to the bins 10 with the automatic push-out mechanisms. When substantial amounts of the postal matter are stacked on the bins 10, the postal matter are horizontally pushed to the back and are placed on the trays 15 which are sequentially circulated on the horizontal convey paths 13a, 13b and 13c. The postal matter are then transferred to a label printer 71 through the horizontal convey paths 13a, 13b and 13c, the elevator mechanism 17, and the separating mechanism 18. The postal matter with labels printed thereon from the label printer 71 are supplied to bundling machines 30 and are bundled crosswise with plastic tape. The bundles of postal matter are output to a bundle conveyor 75. As shown in Figs. 2 and 3, this embodiment has five sorter lines. The first through third sorter lines have CFCs and are capable of sorting the postal matter which have been collected from the mailboxes as well as those which have been accepted at the post offices and those which have been transported from other post offices. The fourth sorter line does not have a CFC and is capable of sorting only the postal matter which have been accepted at the postal offices and which have been transported from other post offices. The fifth sorter line does not have a CFC and is not connected to the secondary sortation terminal stacker. Therefore, the fifth sorter line is capable of only sorting the postal matter which have been transported from other post offices (the destination specifying areas of these postal matter have been used in the primary sortation so as not to subject them to the secondary sortation). Although the secondary sortation may be performed at any of the sorter lines, the fifth sorter line is mainly used for the secondary sortation. This is because the fifth sorter line is close to the terminal stackers 69 as shown in Fig. 3 and it is capable of only sorting the postal matters which have been subjected to the primary sortation at other post offices. The postal matter which must be subjected to the secondary sortation are roughly classified according to six destination areas based on the readout results of the OCR and are transferred to the terminal stackers 69 near the LSMs 63 through overhead transport means 79 so as to be subjected to the secondary sortation. At the LSM 63 which has been instructed to perform the secondary sortation, the operator selects one of the six destination modes (A to F) and feeds the postal matter to the LSM. The OCR of the LSM reads the postal codes one by one. The postal matter are sorted into the bins according to the readout results of the OCR and the code-bin assignment table of the selected destination mode. The sorted postal matter are automatically pushed onto the horizontal convey paths 13a, 13b and 13c which convey them to the bundling machine 30 through the label printer 71. The overall system is monitored and controlled by a centralized system controller 77. Fig. 4 is a block diagram of a centralized system controller of the sorting system. A centralized control computer 91 is connected through a process I/O controller 167 to a central computer 93, a bundling conveyor microcomputer 179, a console 101 for instructing the operation of the system, a monitor board 95 for monitoring the ON/OFF state of the system or the operation status of each unit, and a case conveyor microcomputer 181. The centralized control computer 91 is also connected through an I/O device controller 165 to a line printer 99 for printing daily, weekly and monthly reports, a magnetic disk 97 for storing schedule tables, code-bin assignment tables, statistics, control program and so on, a display unit 103 for displaying the amounts of the sorted and rejected postal matters, and a keyboard 105 for inputting data for changing the code-bin assignment tables or schedule tables. As described above, the centralized control computer 91 is connected to the central computer 93 through the process I/O controller 167. When a command signal for retrieval of data on the amount of sorted postal matter has been received from the central computer 93, the centralized control computer 91 acknowledges the central computer 93 the amount of sorted postal matter and the operation status. The centralized control computer 91 is further connected through the I/O device controller 165 to line 1 to line 5 microcomputers 169, 171, 173, 175 and 177; a rough culling table microcomputer 183; a secondary sortation terminal stacker microcomputer 185; and a manual sortation terminal stacker microcomputer 187. The centralized control computer 91 supplies through the I/O device controller 165 to the line 1 to line 5 microcomputers 169, 171, 173, 175 and 177 the operation guide data such as operation start or operation stop signals or code-bin assignment table data. On the other hand, the line 1 to line 5 microcomputers 169, 171, 173, 175 and 177 supply through the I/O device controller 165 to the centralized control computer 91 the amounts of the sorted postal matter in each box, the number of bundles, the amount of postal matter for each postal Code, and the operation status. The rough culling table microcomputer 185 supplies the operation status data to the centralized control computer 91 through the I/O device controller 165. On the other hand, the centralized control computer 91 supplies the operation guide data to the rough culling table microcomputer 183 through the I/O device controller 165. The secondary sortation terminal stacker microcomputer 185 supplies the operation status data and the secondary sortation data to the centralized control computer 91 through the I/O device controller 165. On the other hand, the centralized control computer 91 supplies the operation guide data to the secondary sortation terminal stacker microcomputer 185 through the I/O device controller 165. The manual sortation terminal stacker microcomputer 187 supplies the operation status data to the centralized control computer 91 through the I/O device 165, while the latter supplies the operation guide data to the former through the I/O device controller 165. The case conveyor microcomputer 181 supplies the operation status data to the centralized control computer 91 through the process I/O controller 167. The case conveyor microcomputer 181 supplies the operation status data to the centralized control computer 91 through the process I/O controller 167. Fig. 5 shows an example of a schedule table 121 stored in the magnetic disk 97. According to this schedule table 121, the sorter line 1 (line 1 of the five lines) is started in the primary sortation mode for sorting the postal matter from the other post station at 10:05. At 10:20, the sorter 2 is started in the mode A of the secondary sortation. Fig. 6 shows an example of a code-bin assignment table 123 stored in the magnetic disk 97. For example, the postal matter with the postal code "000" are stacked on the bin 10 of the stage A (bin number A-10). The postal matter of the postal code "001" are stacked on the bin 10 of the stage A (bin number A-11). The postal matter with the postal code "003" are stacked on the bin 10 of the stage B (bin number B-10). The postal matter with the postal code "999" are stacked on the stacker 10 of the stage C (bin number C-5). In this manner, the postal matter are stacked on the predetermined stackers. Several code-bin assignment tables as that described above are prepared for the primary sortation mode, and the secondary sortation modes A to F. Although these schedule tables and code-bin assignment tables are set before the operation of the system, they may be modified by inputting updated data from the keyboard 105. Fig. 7 is a flowchart for explaining the operation of the sorting method. Referring to Fig. 7, in step 131, the amounts of the postal matter are statistically estimated for those in the primary sortation mode which are collected from the mailboxes, those which have been accepted at the post offices, and those which have been transferred from the other post offices, and those which are sorted in the secondary sortation modes A to F. From the estimated amounts of the postal matter, a prospective time for processing these postal matter is computed. In step 133, the number of lines and the starting time of each line are determined through the computation of the arrival times of the postal matter and the departure times thereof. In step 135, modes of the respective lines (primary sortation, secondary sortation, stop modes) and the start and stop times are determined. The operations in steps 131 to 135 are preparatory steps and may be performed before the initialization of the system. When the actual amount of the postal matter exceeds the estimated amount or when an accident happens, steps 131 and thereafter are repeated for readjustment. The centralized control computer 91 reads out the schedule table from the magnetic disk 97 and displays it at the display unit 103. If the current times reaches an execution time (start or stop time) according to the schedule table, this is notified to the operator by lighting the lamp on the console 101 and the buzzing sound. The operation statuses of the CFCs 61, the LSMs 63, the manual sortation terminal stackers, and the secondary sortation terminal stackers are supplied to the centralized control computer 91 through the respective microcomputers controlling these units and through the I/O device controller 165. The centralized control computer 91 displays the received data at the monitor board 95 through the process I/O controller 167. Thus, the operator can determined the instructions to be supplied to each unit while observing the schedule table displayed at the display unit 103 and the operation status displayed at the monitor board 95. When a button on the monitor board 95 corresponding to such an instruction is depressed, the instruction is supplied to the centralized control computer 91 through the process I/O controller which reads out the instruction and supplies the corresponding instruction signal to the corresponding unit through the I/O device controller. Although five lines are used in this embodiment, the present invention is not limited to this.

Claims: A postal matter sorting method which uses a postal matter sorting system in accordance with a schedule table, said sorting system comprising: a plurality of sorting apparatuses having a function of selectively sorting postal matter in accordance with postal codes, each sorting apparatus having a reader (4) for reading destination data applied to written postal matter, a plurality of bins (10) arranged perpendicularly in a plurality of stages for sorting said postal matter and each of which has a pick up mechanism, a gate mechanism (5) for stacking said postal matter in said plurality of bins (10) based on the destination data from said reader (4), and sorting conveyors (6a, 6b, 6c and 6d); a transfer mechanism (26), which sequentially opposes said plurality of bins (10) and which receives stacked postal matter picked up from said plurality of bins (10); a destination label printer (28) for printing a destination label for the stacked postal matter transferred by said transfer mechanism (26); a bundling unit (30) for bundling the stacked matter on which the destination label is applied, and a central system control section (77) which includes said schedule table (121) for determining operation modes of said plurality of sorting apparatuses, and which operates each of said plurality of automatic sorting apparatuses based on said schedule table (121); wherein said schedule table (121) includes as said operating modes a field for designating a primary sorting mode in which the sorting is performed by the upper digits of the postal code and a secondary sorting mode in which the sorting is performed by the lower digits of the postal code, said schedule table further includes a field for the discrimination number of each sorting apparatus and a field for the start time of each sorting apparatus, said sorting method comprising the steps of: (a) estimating the amount of postal matter in said primary and secondary sorting modes and calculating the time required for processing based on the estimated amount; (b) determining the number and operation status data of automatic sorting apparatuses and the start time of each apparatus from the time of arrival of each piece of postal matter to the departure times of each piece of postal matter; (c) specifying a discrimination number of each automatic sorting apparatus to be operated and specifying a primary or secondary sorting mode of the respective automatic sorting apparatus that is to be operated, and registering the start time in said schedule table, so as both the start time and also the discrimination number are specified in the schedule table that the envisaged operation of the primary and secondary sorting modes are carried out automatically, and (d) permitting said central system control section (77) to determine in response to the amount of said postal matter to be processed and said operation status data the allotment of said primary and secondary sorting modes and number of said automatic sorting apparatuses to be operated. The postal matter sorting method according to claim 1, wherein said central system control section (77) uses a computer (91) connected to said plurality of sorting apparatuses. The postal matter sorting method according to claim 2, wherein said computer (91) uses a magnetic disk (97) which stores the schedules table (121). The postal matter sorting method according to claim 3, wherein said magnetic disk (97) stores data (123) for identification of gate mechanism (5) of said plurality of sorting apparatuses for stacking the postal matter in accordance with the postal code. The postal matter sorting method according to claim 2, wherein said central system control section uses: a magnetic disk (97) connected to said computer (91) and storing the schedule table (121), a console (101) connected to said computer (91) and instructing operation of said plurality of sorting apparatuses, display means (103), connected to said computer (91), for displaying the amount of sorted postal matter and said schedule table (121); keyboard means (105), connected to said computer (91), for inputting instruction data for changing said schedule table (121); and printing means (99), connected to said computer (91), for printing statistics of the postal matter processed. A postal matter sorting system for carrying out the method in claim 1, comprising: a plurality of sorting apparatuses having a function of selectively sorting postal matter in accordance with postal codes, each sorting apparatus having a reader (4) for reading destination data applied to written postal matter, a plurality of bins (10) arranged perpendicularly in a plurality of stages for sorting said postal matter and each of which has a pick up mechanism, a gate mechanism (5) for stacking said postal matter in said plurality of bins (10) based on the destination data from said reader (4), and sorting conveyors (6a, 6b, 6c and 6d); a transfer mechanism (26), which sequentially opposes said plurality of bins (10) and which receives stacked postal matter picked up from said plurality of bins (10); a destination label printer (28) for printing a destination label for the stacked postal matter transferred by said transfer mechanism (26); a bundling unit (30) for bundling the stacked matter on which the destination label is applied; and a central system control section (77) which includes a schedule table (121) for determining operation modes of said plurality of sorting apparatuses, and which operates each of said plurality of automatic sorting apparatuses based on said schedule table (121); characterized in that said central system control section comprises: a computer (91) connected to said plurality of sorting apparatuses for collecting actual system operation status data a magnetic disk (97) connected to said computer (91) and storing the schedule table (121) which includes as said operation modes a field for designating a primary sorting mode in which the sorting is performed by the upper digits of the postal code and a secondary sorting mode in which the sorting is performed by the lower digits of the postal code, said schedule table further includes a field for the discrimination number of each sorting apparatus and a field for the start time of each sorting apparatus; a console (101) connected to said computer (91) and instructing operation of said plurality of sorting apparatuses; display means (103), connected to said computer (91), for displaying the amount of sorted postal matter and said schedule table (121); keyboard means (105), connected to said computer (91), for inputting instruction data for changing said schedule table (121); and printing means (99), connected to said computer (91), for printing statistics of the postal matter processed.

Inventors: HARUKI, KAZUHITO, KOHNO, TAKESHI, NAGASE, YASUO
Applicants: KABUSHIKI KAISHA TOSHIBA
Application year: 1982
Main classification: B07C3
IPC codes: B07C3