U.S. patent application number 13/053329 was filed with the patent office on 2011-07-14 for mail sorter system and method for moving trays of mail to dispatch in delivery order.
This patent application is currently assigned to LOCKHEED MARTIN CORPORATION. Invention is credited to Denis J. STEMMLE.
Application Number | 20110170990 13/053329 |
Document ID | / |
Family ID | 39301179 |
Filed Date | 2011-07-14 |
United States Patent
Application |
20110170990 |
Kind Code |
A1 |
STEMMLE; Denis J. |
July 14, 2011 |
MAIL SORTER SYSTEM AND METHOD FOR MOVING TRAYS OF MAIL TO DISPATCH
IN DELIVERY ORDER
Abstract
A sorter, method, and software product are provided for sorting
mail pieces. The mail pieces are fed into a sorter, sorted, and
then deposited into mail trays. The mail trays are then moved from
the deposit area to a dispatch area, in the order they will be
loaded into a truck. That order is preferably the same as the order
in which the containers received the mail pieces.
Inventors: |
STEMMLE; Denis J.;
(Stratford, CT) |
Assignee: |
LOCKHEED MARTIN CORPORATION
Bethesda
MD
|
Family ID: |
39301179 |
Appl. No.: |
13/053329 |
Filed: |
March 22, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11544184 |
Oct 6, 2006 |
7947916 |
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13053329 |
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Current U.S.
Class: |
414/222.01 ;
414/806 |
Current CPC
Class: |
B07C 3/008 20130101;
Y10S 209/90 20130101 |
Class at
Publication: |
414/222.01 ;
414/806 |
International
Class: |
B07C 3/00 20060101
B07C003/00 |
Claims
1. A method for sorting mail pieces comprising: feeding mail pieces
into a sorting system; sorting mail pieces to large batches in a
first location in the sorting system; sorting each large batch one
at a time into smaller batches in a second location in the sorter
system; sorting each smaller batch one at a time to delivery
sequence; and unloading the sorted mail pieces into mail trays.
2. The method of claim 1, wherein: said mail trays comprise a queue
of mail trays for a plurality of mail routes; and the sorting each
smaller batch one at a time to delivery sequence comprises sorting
the mail pieces to delivery sequence, said delivery sequence
further comprising a sequence of said plurality of mail routes.
3. The method of claim 1, further comprising: loading the mail
trays, in said delivery sequence, onto at least one dispatch truck
for delivering the containers to the plurality of delivery offices
along a delivery route of the at least one dispatch truck; wherein,
between said sorting each smaller batch one at a time to delivery
sequence and said loading the mail trays onto at least one dispatch
truck, said method includes no sorting of said mail trays.
4. A mail sorting system for sorting mail pieces, comprising: at
least one feeder module configured to feed the mail pieces into the
sorting system; at least one deposit module configured to place the
mail pieces into containers; and at least one moving module,
configured to move the containers from the at least one deposit
module to at least one dispatch area, substantially in a loading
order in which the containers will be loaded into at least one
vehicle for convenient unloading at respective unloading locations
of each of the at least one vehicle, wherein the containers are
mail trays or other devices for carrying a plurality of the mail
pieces.
5. The mail sorting system of claim 4, wherein the loading order is
substantially equivalent to a deposit order in which the containers
received the mail pieces.
6. The mail sorting system of claim 4, wherein the at least one
vehicle is equipped to deliver the containers to the respective
unloading locations along a route of each of the at least one
vehicle.
7. The mail sorting system of claim 6: wherein the sorting system
is configured to sort the mail pieces for one of the at least one
vehicle so that the mail pieces that will be unloaded at a first
one of the unloading locations are deposited by the deposit module
into a first set of at least one of the containers, and so that the
mail pieces that will be subsequently unloaded at a second one of
the unloading locations are deposited by the deposit module into a
second set of at least one of the containers, and wherein the
second set precedes the first set in the loading order.
8. The mail sorting system of claim 6, wherein the unloading at the
unloading locations is in substantially reverse order from the
loading order.
9. The mail sorting system of claim 7, further comprising at least
one batch sorting module and at least one delivery sequence sorting
module, wherein the at least one batch sorting module is configured
to sort the mail pieces prior to sorting by the at least one
delivery sequence sorting module, and wherein the at least one
batch sorting module is configured to sort the mail pieces into an
order calculated to ensure that the second set will precede the
first set.
10. The mail sorting system of claim 7, further comprising at least
one batch sorting module and at least one delivery sequence sorting
module, wherein the at least one batch sorting module is configured
to sort the mail pieces prior to sorting by the at least one
delivery sequence sorting module, and wherein the mail sorting
system further comprises a controller configured to selectively
move mail pieces, that were previously sorted by the at least one
batch sorting module, to the at least one sort to delivery sequence
module in an order calculated to ensure that the second set will
precede the first set.
11. The mail sorting system of claim 6, further comprising: a sort
to relatively large batch module, which is configured to sort the
mail pieces into a plurality of relatively large batches; a
plurality of storage areas configured to store the relatively large
batches; a processor configured to determine a preferred order in
which the containers will be unloaded from the at least one vehicle
at the unloading locations; a conveying module configured to convey
the mail pieces from each of the plurality of storage areas in a
selected order that is associated with the preferred order for
unloading the containers from the at least one vehicle; and a sort
to smaller batch module configured to sort the mail pieces conveyed
from each of the plurality of storage areas, to relatively small
batches that are smaller than the large batches; wherein the
deposit module is further configured to place the relatively small
batches into the containers in a specified order that is
substantially equivalent to said loading order and is in the
preferred order.
12. The mail sorter of claim 4, further comprising: a plurality of
large capacity modules configured to sort mail pieces to relatively
large batches, and store the relatively large batches in large
capacity storage areas; a plurality of small batch storage areas;
at least one sort to delivery sequence module; a sorter controller
for controlling a sequence of operation; wherein the sequence of
operation comprises loading unsorted mail into the mail sorter and
sorting it into the relatively large batches which are then stored
in the large capacity storage areas, selectively moving each of the
relatively large batches from the large batch storage areas in the
loading order in which the containers will preferably be loaded
onto the at least one vehicle for delivery along a respective
route, sorting each selected one of the relatively large batches
into relatively small batches that are smaller than the relatively
large batches, storing the relatively small batches in the
plurality of small batch storage areas in an order associated with
delivery sequence, moving each of the relatively small batches from
the small batch storage areas to the sort to delivery sequence
module for sorting each of the relatively small batches to delivery
sequence, unloading each of the relatively small batches that have
been sorted to delivery sequence into the containers, and
delivering the containers to a dispatch area in the loading order
in which they are to be loaded onto the vehicles.
13. The mail sorting system of claim 4: wherein said convenient
unloading comprises unloading of the containers at the unloading
stations according to a delivery sequence of mail routes.
14. The mail sorting system of claim 13: wherein said moving module
is structured and arranged to move the containers from the at least
one deposit module to the at least one dispatch area, substantially
in said loading order, without subsequent sorting of the
containers.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional application of U.S.
application Ser. No. 11/544,184, filed on Oct. 6, 2006, the
contents of which are incorporated by reference herein in their
entirety.
TECHNICAL FIELD
[0002] The present invention relates generally to mail sorting, and
more particularly to sorting mail into trays.
BACKGROUND OF THE INVENTION
[0003] In centralized postal sorting centers, mail is typically
passed through automated sorting systems multiple times. After the
last pass through the sorters, the mail must be placed in mail
trays and eventually loaded onto trucks by a deadline for
dispatching the mail in the trucks to the correct delivery offices.
Each truck will typically take mail trays to several different
delivery offices, and each of the delivery offices is then
responsible for taking the mail to particular final destinations
along multiple different mail routes.
[0004] Typically, 20 to 40 pieces of various types of sorting
equipment are used within a centralized postal sorting center.
Often, the mail destined for a single delivery office might be
sorted on several types of sorters in different locations
throughout the sorting center. After the last pass on each of the
sorters, the trays of sorted mail must then themselves be sorted,
in order to ensure that all the mail destined for the same
destination is loaded in an intelligent order onto the trucks going
to that destination.
[0005] The average sorting center in the United States Postal
Service (USPS) system sorts the mail for about 713 routes, and
delivers it to 35 delivery offices, each of which have an average
of 20 routes of mail to be delivered. Typically, 60,000 trays of
sorted mail must all be sorted and put on the correct trucks at the
average sorting center. Trays of mail from various sorter systems
(i.e., letter sorters and flats sorters, as well as mail that is
manually sorted such as non-machineable mail and newspapers) must
be collected together in the same place before they are loaded onto
the correct trucks, and/or while they are loaded onto the correct
trucks.
[0006] Most sorting centers have invested in substantial equipment
to transport, store, and retrieve the trays of mail in support of
the sorting operations. But often, the final operation of sorting
the trays of mail to get them all on the right trucks is a manual
operation. In average-sized sorting centers, dozens of workers are
required for several hours to sort the trays of mail and get them
onto the right trucks on time.
[0007] At the most advanced postal services (i.e. "posts") in the
world, typically 20 to 40 workers spend several hours sorting the
trays for dispatch manually. In Denmark, an automated tray sorting
system has been installed to queue up the trays in front of the
correct trucks. That Danish system includes miles of transports,
switching networks, and tray label readers to create queues of
trays with a common destination. Such a system accepts loaded trays
from multiple sorters in the sorting center, transports the trays
to a dispatch area, and moves each tray through a series of
switches down multiple sidings leading to truck loading areas. Only
a few of these systems have been installed around the world because
the expense of the automated tray sorting equipment is prohibitive,
and it takes many years to pay for itself in labor savings.
[0008] Occasionally a tray of mail is loaded onto the wrong truck,
so it is sent to the wrong delivery office. Because the deadlines
are tight, often such errors are not discovered in time to recover,
and it can therefore be very difficult to get the mail to the right
place and delivered on the same day as the error was made. So, the
service performance of the post is negatively affected by such
occasional errors.
[0009] What is needed is a way to deliver the mail trays from the
sorters to the trucks in exactly the order they are to be loaded
onto the trucks. This would have the benefit of reducing the labor
hours of the tray sorting staff, as well as reducing the errors of
loading trays onto the wrong trucks. And, such a system would have
the same benefits as automated tray sorting equipment, but without
the prohibitive expense.
[0010] Examples of such a clamp-based system can be found in
International Application WO 2006/063204 filed 7 Dec. 2005 titled
"System and Method for Full Escort Mixed Mail Sorter Using Clamps"
and can also be found in U.S. Provisional Application Ser. No.
11/519,630 filed 12 Sep. 2006 titled "Sorter, Method, and Software
Product for a Two-Step and One-Pass Sorting Algorithm," which are
both incorporated herein by reference in their entirety. The
concepts of macro-sorting are described, for example, in U.S.
Provisional Application No. 60/669,340 filed 5 Apr. 2005, titled
"Macro Sorting System and Method" which also is incorporated herein
by reference in its entirety.
SUMMARY OF THE INVENTION
[0011] The present invention overcomes the disadvantages of the
prior art by providing the output from sorting system(s) in a
sorting center as a queue of trays full of mail. The trays are in
substantially an order in which the trays need to be loaded onto
trucks. An advantage of the foregoing is that the trays do not need
to be sorted. The only labor requirement is taking the trays from
the queue in the same order in which they arrived, and loading them
onto the trucks for delivery to the delivery offices.
[0012] The present invention unloads mail from the sorter in
exactly the order in which it needs to be loaded on the trucks,
which reduces the tray sorting labor and expense, by eliminating
the need to sort filled mail trays to insure that each tray ends up
on the correct dispatch truck. Additionally, this system eliminates
the need for high rise tray storage and retrieval systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The accompanying drawings illustrate presently various
embodiments of the invention, and assist in explaining the
principles of the invention.
[0014] FIG. 1 is a flow chart showing a method according to an
embodiment of the present invention.
[0015] FIG. 2 is a flow chart showing a further method according to
an embodiment of the present invention.
[0016] FIG. 3 is a block diagram showing a mail sorter according to
an embodiment of the present invention.
[0017] FIG. 4 shows an address sorting module according to an
embodiment of the present invention.
[0018] FIG. 5 shows a batch sorting module according to an
embodiment of the present invention.
[0019] FIG. 6 shows a route storage module, according to an
embodiment of the present invention.
[0020] FIG. 7 shows a triple bank sorter according to an embodiment
of the present invention.
DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
[0021] An embodiment of the present invention will now be
described. It is to be understood that this description is for
purposes of illustration only, and is not meant to limit the scope
of the claimed invention.
[0022] It is possible to scale up a merge and sequence sorter
concept, so that multiple zones of mail can be loaded and sorted to
delivery sequence. FIG. 7, for example, shows a sorter that can
accept unsorted mail destined for between 100 and 250 routes and
sort it all to delivery sequence. The concepts of macro-sorting,
and simultaneously sorting inbound and outbound mail, are described
in U.S. Provisional Application No. 60/669,340 filed 5 Apr. 2005,
titled "Macro Sorting System and Method" which has been
incorporated herein by reference.
[0023] The inbound sorting operations (merging and sequencing) for
these types of sorters can be conducted in three phases. Phase I
involves loading all the mail into the sorter using one or more
infeed stations. Each piece of inbound mail is loaded into a clamp,
transported in face-to-face orientation with respect to other
clamped mail pieces, and sorted into groups of one or more routes
of mail and stored in storage legs in the upper tiers of the
sorter. This could occur over a time period of 21 hours or less.
Phase II starts after all the mail is loaded into the sorter during
phase I, and includes moving individual large batches of mail from
the large batch storage modules to the lowest tier one batch at a
time, and sorting first into smaller batches each containing mail
destined for between 15 to 60 addresses. Each of these smaller
batches are then sorted one at a time to delivery sequence. When
the mail is sorted to sequence, it then enters phase III, during
which it is loaded into trays and sent to dispatch.
[0024] Phases II and III are fully automated. The sorter
systematically moves the mail previously sorted and stored in large
batches consisting of one or more routes during phase I from its
storage location inside the sorter to the lowest tier to conduct
the sort-to-smaller-batch and sort-to-sequence operations. The
large batches of mail are transported one right after another
through the bottom tier, and thereafter stacked into trays and sent
to dispatch. It will be noted that the large batches of mail can be
moved from the large batch storage areas in the upper tiers in any
appropriate order. For the purposes of this invention, the order
will be selected so that mail stored in multiple large storage legs
of the sorter that is destined for common delivery offices (average
of 20 routes of mail in the USPS), will be moved in an
pre-determined sequence.
[0025] For example, in some sorting configurations, mail for two
routes will be stored in each of the large storage areas (storage
legs) of the sorter. Mail destined for one delivery office might
therefore be stored in a total of 10 large storage areas. The mail
from these 10 large storage areas (which may or may not be
co-located in any part of the sorter) will be moved in a sequence
one after another so that all the mail for these 20 routes is moved
through the lowest tier of the sorter in a prescribed order, sorted
to delivery sequence one route at a time, loaded into mail trays
automatically, and transported away from the sorter in a queue of
mail trays with, for example, the sequenced mail for the first
route in the first several trays, followed by the sequenced mail
for the second route in the next several trays, etc, for all 20
routes in order.
[0026] The sorter will then select the mail for the next delivery
office from multiple large storage areas and move that through the
final two phases of the sorting operations. This mail will be
destined for another delivery office, but may need to be loaded on
the same truck. It would not be uncommon, for example, for the mail
from four to ten delivery offices to be loaded onto the same
truck.
[0027] This truck delivery plan will be known in advance, and
programmed into the sorter operating system. So, for example, if
the truck delivery plan involves delivering mail to five delivery
offices, the mail destined for the last delivery office of the
truck delivery route will be unloaded from the sorter (from the
multiple storage areas containing the mail for all the routes for
that last delivery office), through the final sorting stages,
transported to the truck, and loaded first onto the truck. The
sorter would then move the mail destined for the second last stop
on the delivery route through the sorter, into the trays, and
transported to the dispatch area, where it will be loaded onto the
truck in front of the mail destined for the last stop. And so on.
The mail destined for the first stop on the delivery route will be
unloaded from the sorter--in this example--fifth, and loaded onto
the truck last so that it can be unloaded first.
[0028] The sorter will then proceed to process the mail to be
loaded on the next truck, which may deliver mail to seven delivery
offices. Again, the sorter will first move the mail from the large
storage areas destined for the last stop on the delivery route, so
that that mail can be loaded onto the truck first.
[0029] As shown in FIG. 1, a method 100 according to an embodiment
of the invention begins by feeding 105 mail into a sorter. Then the
mail is sorted 110 so as to ensure trays will be filled in an
appropriate or preferred order for loading the trays on trucks. The
mail pieces are then deposited 115 into trays in such a way that
the order of filling the trays is substantially the order in which
the trays will be loaded onto the trucks. Subsequently, the trays
are moved 130 from the deposit area to a dispatch area, in the
appropriate or preferred order for loading the trays onto trucks.
The trays are then loaded onto the trucks in the order in which
they arrived. Each of the trucks then delivers 135 the respective
trays to several unloading locations. And, the trays are unloaded
140 from each truck in substantially reverse order from the order
in which they were loaded onto the trucks.
[0030] FIG. 2 provides a bit more detail about how the appropriate
or preferred order is determined. According to the method 200 of
FIG. 2, a determination 250 is made (e.g. by a processor) as to a
first set of trayfuls of mail that will eventually be unloaded at a
first unloading location of a truck. Then, a determination 260 is
made as to a second set of trayfuls of mail that will eventually be
unloaded at a second unloading location of the truck. And, a
determination 270 is then made as to a preferred order for filling
the trays, such that the second set will be filled before the first
set. That way, the first set will be loaded onto the truck later
than the second set, so that the first set can be conveniently
removed from the truck earlier than the second set.
[0031] Turning now to the block diagram of FIG. 3, a mail sorting
system 300 is shown. A feeder module 310 is used to feed mail
pieces into the system. As pieces are fed in, information about the
pieces is acquired and stored in a memory 340. The mail pieces
proceed to a sort-to-relatively-large-batch module 320, and from
there to storage areas 330. A processor 350 accesses the
information in the memory 340, in order to determine an appropriate
or preferred order for loading trayfuls of the mail onto trucks,
and the processor 350 ensures that mail pieces are conveyed by a
conveying module 360 from the storage area 330 in a proper order
that will facilitate loading the trayfuls onto the trucks. The
conveying module 360 conveys the mail pieces to a
sort-to-smaller-batch module and/or a sort-to-delivery-sequence
module 370, which then provides the mail pieces to a deposit module
380. The deposit module 380 deposits the mail pieces into the
trays. The trays are then moved by a moving module 390 directly to
a dispatch area 395, without any need for the moving module to
rearrange the trays or otherwise sort the trays, due to the fact
that the sorting has already ensured that the trays will be in a
correct order for dispatch to the trucks.
[0032] Algorithms for implementing this system for moving trays in
proper order for dispatch can be realized using a general purpose
or specific-use computer system, with standard operating system
software conforming to the method described above. The software
product is designed to drive the operation of the particular
hardware of the system. A computer system for implementing this
embodiment includes a CPU processor 350 or controller, comprising a
single processing unit, multiple processing units capable of
parallel operation, or the CPU can be distributed across one or
more processing units in one or more locations, e.g., on a client
and server. The CPU may interact with a memory unit 340 having any
known type of data storage and/or transmission media, including
magnetic media, optical media, random access memory (RAM),
read-only memory (ROM), a data cache, a data object, etc. Moreover,
similar to the CPU, the memory may reside at a single physical
location, comprising one or more types of data storage, or be
distributed across a plurality of physical systems in various
forms.
[0033] For sorting configurations in which sort to delivery
sequence is a functional requirement, an average of five mail
pieces will likely be sorted to each address in embodiments for use
in the United States, and an average of two to three will be sorted
to each address in typical European applications. A sorter module
with 14 to 20 paths between the input side (unsorted mail) and the
sorted side is an appropriate design. FIG. 4 shows an example of
this type of sorting module, which can be referred to as a
sort-to-delivery-sequence module 400.
[0034] As mentioned, this embodiment of the invention includes
batch sorting modules, for sorting large batches to small batches,
as well as address sorting modules for sorting to delivery
sequence. FIG. 4 shows the address sorting module 400. These
address sorting modules may have the following functions and
characteristics, in an embodiment of the invention that utilizes
clamps to hold the mail pieces.
[0035] The address sorting module will accept sequential batches of
clamped mail from the third path 511 of the upstream batch sorting
module 500 shown in FIG. 5, and will also accept information on the
clamp identities and instructions for the disposition of each clamp
(and mail piece) from a master controller or processor. The address
sorting module 400 will read clamp identities as they enter the
sorting module.
[0036] Each address sorting module will have a first path 405 for
transporting clamped unsorted mail, which is either aligned with
the third path of the upstream module when the upstream module is a
batch sort module, or with the first path when the upstream module
is an address sorting module. The input to this first path of the
address sorting module is a batch of clamped mail handed off from
an upstream module, each batch containing mail destined for a
number of addresses not to exceed the number of address sorting
stations. The outputs to this first path of the address sorting
module include fourteen diverter stations (in the present example),
in order to move the mail sideways off the transport, and a means
to hand the partial batches of mail to additional address sorter
modules downstream.
[0037] In the current example, each address sorting module has
fourteen diverter subsystems 410 to move mail from the first mail
path 405 to the fourteen assignable address stations 415. These
diverter subsystems could operate identically to the three diverter
systems designed for the small batch sorting modules (described
later), and preferably have identical components.
[0038] Moreover, each address sorting module will have fourteen
mail storage transports for storing mail destined for each address.
There are two inputs to each of these address storage transports:
the first input is a diverter transport carrying clamps from the
first (batch) mail path, and the second input includes clamps
handed off from an upstream address storage transport. The single
output for each address sorting transport will pass the mail onto
the next address storage transport--which may be the first address
storing transport in the next module. The last address storing
transport will hand the mail off to an output (de-clamping or
stacking) module.
[0039] The storage capacity of each address storage transport may
be a maximum of 10 clamps each holding mail pieces 0.2 inches thick
or less. The capacity will be reduced when the batch being stored
contains thicker mail pieces. The intent of this capacity target is
to accommodate European routes where each address receives an
average of 2.5 mail pieces per day. The 10 pitch storage system
will accommodate heavy mail days of up to 10 of the thinnest pieces
per address, or will accommodate heftier average thickness of each
piece being up to 1.0 inches thick, (or some combination of these
two possibilities.) Note that this storage capacity for each
address station is four times the average mail to be sent to each
address each day.
[0040] As an example, one configuration of the sorter may have a
total of 28 address stations to sort mail previously batched for 25
addresses; these address stations are provided by two address
sorting modules per sorting system, each sorting module having a
14-address sorting capability. Thus, three address stations can be
used as overflow for specific addresses that receive more than the
ten-piece maximum storage capability of the single address
station.
[0041] FIG. 5 shows a small batch sorting module 500 according to
an embodiment of the present invention. The small batch sorting
module will accept a queue of clamped mail from one or more large
batch storage areas, and will also accept information on the clamp
identities and instructions for the disposition of each clamp (and
mail piece) from the master controller or processor.
[0042] Each small batch sorting module will have a first path 505
(i.e. unsorted path) for transporting clamped mail that has not yet
been sorted to small batch; the outputs may include, for example,
three diverter stations to move the mail sideways off the
transport, and a means to hand the unsorted mail off to a sorter
module or an output module downstream.
[0043] Each small batch sorting module will have, for example,
three diverter subsystems 510 to move mail from the unsorted path
505 to respective temporary batch storage stations 512. The
diverter subsystems will have three major sub-components. First, a
diverter subsystem will have a means to move one clamp off the
unsorted mail transport and onto a diverter transport without
disturbing the clamp before or after the diverted clamp on the
unsorted mail transport. The actuator for this mechanism will be
responsive to commands from the module controller. The cycle time
for the diverting mechanism will be sufficient to enable diverting
of either single or adjacent clamps onto the diverting transport.
Second, a diverter subsystem will have a transport for transporting
diverted clamps from the unsorted mail path to the temporary batch
storage area. It is expected that this transport will be positioned
at an angle from the unsorted path such that the component of
velocity parallel to the unsorted path will match the speed of the
unsorted path. Hence, the relative motion between the mail pieces
is limited to mail moving sideways out of the queue of unsorted
mail. Third, a diverter subsystem will have a means to transfer the
clamps from the diverting transport to the batch storage
transport.
[0044] According to this embodiment, each small batch sorting
module will have three (3) temporary batch storage transports (or
stations) for storing batches of mail. There are as many as two
inputs to each batch storage transport: the diverter transport 510
carrying clamps from the unsorted mail path 505, and clamps handed
off from an upstream batch storage transport. Likewise, there are
as many as two outputs for each batch storage transport: an output
514 to the third path/exit transport 511, and an output to a
downstream batch storage transport.
[0045] The operation of the batch storage transport will be
intermittent; it will advance all mail pieces stored whenever a new
piece has been added from either of the two inputs. The storage
capacity of each batch storage transport may be a maximum of 115
clamps each holding mail pieces 2 mm thick or less. The capacity
will be reduced when the batch being stored contains thicker mail
pieces. The intent of this capacity target is to satisfy two
objectives: first, capacity to hold mail for 25 addresses on
European routes, each address receiving an average of 2.5 mail
pieces per day, the average thickness of each piece being
1.3.times. the standard pitch of 0.2 inches and, second, and
capacity that allows 40% excess capacity for high volume mail
days.
[0046] As mentioned, each small batch sorting module will have a
third path (i.e. batch output path) 511 for advancing clamped mail
past downstream batch storage transports, directly to other modules
down stream such as the address sorting modules or the stacker
modules. The third path transports will accept clamped mail from
any of the three batch storage transports, or from the third path
in an upstream module. The third path will transfer the clamped
mail to the input of the third path on the next downstream module.
The third path speed will be compatible with the rate of
transferring clamped mail onto the transport. Mail will be
transferred to the third path under the following conditions: for
the merge and sequence operation, when the last clamp having
unsorted mail passes the diverter station associated with the batch
storage transport, the clamped mail stored on the batch storage
transport can be transferred to the third path. This empties the
batch storage transport so that the next large batch of mail can be
started down the unsorted mail path. Note the possibility that the
unsorted path may be utilized as (or transformed into) the batch
output path once all of the mail pieces have been diverted from the
unsorted path.
[0047] The first stage of sorting operations involves feeding mail,
measuring one or more of its dimensions, scanning and interpreting
the destination address of each mail piece, and loading it into
clamps--all of which is done in the modules 701 and 702 shown in
FIG. 7. A sorter controller includes a database which stores the
scanned and measured information and associates it with a unique
clamp identifier for the clamp holding the mail piece. The clamped
mail is transported from the feeding modules 701 and 702 to one of
three sorter banks 710, 711, or 712 via clamped mail transport 704.
The two feeding modules and the three sorter banks in FIG. 7 are
shown only as an example, and it will be understood that from one
to eight feeders and from one to 15 sorter banks might be included
in a practical sorting system. The sorter controller commands one
of three diverters on the transport 704 (not shown) to divert each
piece of clamped mail off transport 704 and onto one of three
spiral elevator transports 705, 706, or 707 depending on the sorted
destination of the mail piece. The controller further commands one
of multiple diverter mechanisms in the spiral elevator transports
to divert each clamped mail piece off the spiral elevator transport
and into an appropriate large batch storage area designated to
receive mail destined for a range of adjacent addresses including
the address for each clamped mail pieces diverted thereto. The
diverting mechanisms on transport 704 and spiral elevators 705,
706, and 707 are similar to 510 shown in FIG. 5. In this first
phase of operation, the random order mail pieces are sorted to
large batches containing all the mail destined for addresses on one
or more routes.
[0048] Mail that is initially sorted into large batches, or groups
of one or more routes of mail, is stored in storage legs as shown
in FIG. 6, which are located in the upper tiers of the sorter as
shown in FIG. 7. Subsequently, mail stored in the large storage
modules (see FIG. 6) which are located in the upper tiers of the
sorting system shown in FIG. 7, are transported through multiple
sort-to-small-batch modules shown in FIG. 5, and each small batches
is finally moved through one or more sort-to-address modules as
shown in FIG. 4. The sort-to-small-batch modules and
the-sort-to-address modules are located on the lowest tiers of the
multi-bank sorter system shown in FIG. 7.
[0049] It is to be understood that all of the present figures, and
the accompanying narrative discussions of preferred embodiments, do
not purport to be completely rigorous treatments of the methods and
systems under consideration. A person skilled in the art will
understand that the steps of the present application represent
general cause-and-effect relationships that do not exclude
intermediate interactions of various types, and will further
understand that the various structures and mechanisms described in
this application can be implemented by a variety of different
combinations of hardware and software, and in various
configurations which need not be further elaborated herein.
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