U.S. patent application number 10/042524 was filed with the patent office on 2002-08-22 for sorting system.
Invention is credited to Britton, David Thomas, Lennard, Graham Charles.
Application Number | 20020113365 10/042524 |
Document ID | / |
Family ID | 9906476 |
Filed Date | 2002-08-22 |
United States Patent
Application |
20020113365 |
Kind Code |
A1 |
Britton, David Thomas ; et
al. |
August 22, 2002 |
Sorting system
Abstract
An improved system for sorting mail is described, comprising a
sorting machine which uses information collected about each mail
item, such as address and size or weight, to map its collection
bins to a specified sort order. The sorting machine has, instead of
a small number of large sort bins, a large number of small bins. In
this way, a small number of mailpieces may be allocated to each
bin, for example, each bin may be an individual house or person at
a business address The information about each mail item is achieved
by communicating data to the machine before any mail is processed
through it. The data may be derived from sensors which scan the
mailpiece during the initial phase of the sorting process in
conventional sorting systems, or may be supplied by the producer of
the mail. The data is configured and transmitted electronically
ahead of the physical mail. As the sorting machine is aware of the
number, destination and thickness of each mailpiece, it is possible
to allocate a sufficient space in the relevant sort bin for each
mailpiece. In this way, mail from several sources may be merged as
long as the electronic data is written to the machine in advance.
As each mailpiece is uniquely identified it is possible to allocate
a unique position in the machine to each mailpiece.
Inventors: |
Britton, David Thomas;
(Surrey, GB) ; Lennard, Graham Charles;
(Stockport, GB) |
Correspondence
Address: |
FLYNN, THIEL, BOUTELL & TANIS, P.C.
2026 Rambling Road
Kalamazoo
MI
49008-1699
US
|
Family ID: |
9906476 |
Appl. No.: |
10/042524 |
Filed: |
January 9, 2002 |
Current U.S.
Class: |
271/303 |
Current CPC
Class: |
B07C 3/08 20130101; B07C
3/00 20130101; B07C 3/06 20130101 |
Class at
Publication: |
271/303 |
International
Class: |
B65H 039/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 9, 2001 |
GB |
0100503.2 |
Claims
What is claimed is:
1. An apparatus for sorting a plurality of substantially flat items
for delivery to a plurality of recipients, the apparatus
comprising: means for receiving items to be sorted, a destination
recipient address being associated with each item; a plurality of
sorting bins into which items to be sorted are to be deposited;
guide means, coupled to the means for receiving items and the
sorting bins, for directing received items to the plurality of
sorting bins; means for inputting data relating to the plurality of
items, the data including at least each destination recipient
address; means for inputting data defining a pre-determined
sequence of candidate recipient addresses to which the items will
ultimately be delivered; a control unit for receiving the data
relating to the plurality of the items and the data defining the
pre-determined sequence of recipient addresses, for allocating one
or more sorting bins to recipient addresses in the sequence in
dependence on the data relating to the items, the number of sorting
bins that are allocated to a recipient address being sufficient to
accommodate all items that are associated with that destination
recipient address, and for controlling the guide means to direct
the items to the one or more sorting bins so allocated, and wherein
the control unit only operates the guide means to direct the
received items to the respective sorting bins once it has received
the data for the entire plurality of items to be sorted and can
allocate sufficient sorting bins appropriately.
2. An apparatus according to claim 1 wherein the control unit
allocates the sorting bins such that only those candidate recipient
addresses to which items are to be delivered are allocated one or
more sorting bins.
3. An apparatus according to claim 1 wherein the control unit
allocates the sorting bins such that candidate recipient addresses
that are adjacent in the sequence are allocated adjacent sorting
bins.
4. An apparatus according to claim 1 in which the data relating to
the plurality of items includes data describing the dimensions of
each item, and wherein the control unit uses this data to allocate
one or more sorting bins to a recipient address such that all items
of mail to be delivered to that recipient address can be deposited
in the one or more sorting bins so allocated.
5. An apparatus according to claim 1 wherein the means for
inputting data relating to the items has a terminal at a site
remote from the means for receiving the items to be sorted, the
guide means and the sorting bins; the terminal being connected by a
network to the control means, such that if the items to be sorted
are initially received at the remote site, the data relating to the
items can be collected and transmitted to the control unit before
the items themselves are delivered to the means for receiving items
for sorting into the sorting bins.
6. An apparatus according to claim 1 in which the items to be
sorted are items of mail, and in which the data defining the
sequence in which the items to be sorted comprises the order in
which a mail deliverer completes his route.
7. An apparatus for sorting according to claim 1 in which each
sorting bin further comprises indication means controlled by the
control unit, wherein entering data pertaining to an item to be
sorted into the means for inputting data causes the control unit to
activate the indication means for the allocated sorting bin
allowing an operator to manually place the item into the sorting
bin.
8. A method of sorting a plurality of substantially flat items for
delivery to a plurality of recipients, the method comprising:
providing a plurality of sorting bins into which items to be sorted
are to be deposited; receiving items to be sorted, a destination
recipient address being associated with each item; receiving data
relating to the plurality of items, the data including at least
each destination recipient address; receiving data defining a
pre-determined sequence of candidate recipient addresses to which
the items will ultimately be delivered; allocating, once all of the
data relating to the plurality of items to be sorted has been
received, one or more sorting bins to recipient addresses in the
sequence in dependence on the data relating to the plurality of the
items, the number of sorting bins that are allocated to a recipient
address being sufficient to accommodate all items that are
associated with that destination recipient address; directing, once
the sorting bins have been allocated to the recipient addresses,
the items to the one or more sorting bins allocated to the
recipient address corresponding to the destination recipient
address of the item.
9. A method according to claim 8 wherein only those candidate
recipient addresses to which items are to be delivered are
allocated one or more sorting bins.
10. A method according to claim 8 sorting bins are allocated such
that candidate recipient addresses that are adjacent in the
sequence are allocated adjacent sorting bins.
11. A method according to claim 8 comprising: receiving the items
to be sorted at a site remote to the sorting bins; collecting data
relating to the items at the remote site, the data including at
least recipient address information; and transmitting the data from
the remote site to the site at which the sorting bins are located,
before the items to be sorted are delivered to that site so that
the data can be used to allocate the sorting bins in advance.
12. A method according to claim 8 in which the data relating to the
plurality of items includes data describing the dimensions of each
item, and wherein one or more sorting bins are allocated to a
recipient address such that all items of mail to be delivered to
that recipient address can be deposited in the one or more sorting
bins so allocated.
13. A method according to claim 8 in which the items to be sorted
are items of mail, and in which the data defining the sequence in
which the items to be sorted comprises the order in which a mail
deliverer completes his route.
14. An apparatus for sorting items of mail comprising; first input
means for receiving items of mail; a plurality of sorting bins into
which items to be sorted are to be deposited; first guide means for
carrying items of mail to the plurality of sorting bins; second
guide means for carrying items of mail from said first input means
to said first guide means; a second input conveyor for receiving
items of mail that are larger in size than those received by the
first input means, said second input conveyor being coupled
directly to the first guide means such that the mail that is larger
in size follows a shorter path to the sorting bins than the mail
input received by the first input means.
15. The apparatus of claim 14 wherein the sorting bins are arranged
above the first and second input means and said second guide means
is a substantially vertical conveyor belt.
16. The apparatus of claim 14 wherein the second input means is a
conveyor belt capable of receiving items of mail that are at least
C4 or equivalent in size.
17. The apparatus of claim 14 wherein the second input means is a
singulater capable of singulating items of mail that are at least
C4 or equivalent in size.
18. An apparatus for sorting items comprising: a plurality of
collection bins, each having an opening which may receive an item
of mail, arranged in one or more rows; a diverter blade connected
to each collection bin, and having a closed position in which it
covers the opening to the collection bin to prevent an item of mail
from entering; means for supporting items of mail flowing across
the top of the diverter blades of each collection bin in a row; and
a control unit for controlling a diverter blade to direct an item
of mail from the items of mailing flowing across the top of the
diverter blades into a pre-designated collection bin; wherein each
collection bin is provided with a gently curved guide plate which
slopes from being substantially horizontal at the opening of the
collection bin to being near vertical at the base of the collection
bin.
19. The apparatus of claim 18 in which a region of the curved guide
plate which comes into contact with a sorted, item as the item
enters the collection bin is provided with means to slow the item's
descent into the collection bin.
20. The apparatus of claim 19 in which the means to slow an item's
descent is a braking material disposed on the surface of the curved
guide plate.
21. The apparatus of claim 18 in which the collection bins are
formed by the space between two adjacent curved guide plates.
22. The apparatus of claim 21 further comprising an output conveyor
for carrying sorted items away from the collection bins, the output
conveyor having an upper surface; wherein the output conveyor is
positioned below the curved guide plates of the collection bins
such that an item of mail directed into the collection bin comes to
rest between the curved guide plates and against the upper surface
of the output conveyor.
23. The apparatus of claim 22 comprising means for raising the
curved guide plates of all of the collection bins such that the
items of mail in the collection bins are output onto the upper
surface of the output conveyor in the order into which they had
been sorted.
24. Apparatus for deflecting an item of mail into a collection bin
comprising: a plurality of collection bins, each having an opening
which may receive an item of mail, arranged in one or more rows; a
diverter blade connected to each collection bin, and having a
closed position in which it covers the opening to the collection
bin to prevent an item of mail from entering; means for supporting
items of mail flowing across the top of the diverter blades of each
collection bin in a row; and a control unit for controlling a
diverter blade to direct an item of mail from the flow into a
pre-designated collection bin; wherein the diverter blade comprises
a substantially flat plate having a cut out section into which a
portion of an adjacent diverter plate may be received, such that
the length of the diverter plates may be longer than the separation
between collecting bins.
25. The apparatus of claim 24 wherein the diverter blade is
connected to the collection bin at a pivot, the cut out section
being disposed at the edge of the flat plate of the diverter blade
closest to the pivot and receiving the leading edge of the
converter blade of the collection bin behind it in the row.
26. The apparatus of claim 25 wherein the leading edge of the
diverter blade is provided with a protruding section of narrower
width than the flat plate, the protruding section angling down near
its tip to form a flange which interlocks with the cut out section
of the diverter blade forward of it in the row of collection bins
when the diverter blade is in the closed position.
27. The apparatus of claim 24 wherein the diverter blades
corresponding to each collection bin are mounted on a rotatable
axle such that rotation of the axle causes the diverter blade to
rotate, the axle being controlled by the control means to rotate
and cause the diverter to direct an item of mail from the flow of
items of mail into a collection bin; and wherein the means for
supporting items of mail flowing across the top of the diverter
blades is a plurality of rollers mounted on the axles such that
they is may rotate freely and independently of the axle.
28. An apparatus for transporting mail comprising: a number of
surface rollers forming a surface across which the mail is
transported; a conveyor belt positioned above the surface rollers
such that mail held between the conveyor and the rollers is
transported along the surface formed by the rollers; wherein the
surface rollers are arranged to form a convex surface whereby
tension is created in the conveyor belt to ensure that mail is kept
substantially in contact with the convex surface.
29. The apparatus of claim 28 further comprising: a control unit; a
plurality of collecting bins disposed under the surface formed by
the rollers; and a diverter blade connected to each of the
collecting bins underneath and disposed in between the rollers on
the surface, the diverter blade having a first position
substantially planar with the surface and a second position above
the surface where it intercepts the mail being transported along
the surface to direct it into the collecting bin to which the
diverted blade is attached; wherein the control unit may control
the diverter blades to direct mail to pre-designated collecting
bins.
30. An apparatus for sorting items comprising: first and second
means for inputting items to be sorted; separate first and second
arrays of sorting bins for receiving the items in the sort; guide
means for directing the items to be sorted to a predesignated sort
bin in one of the first or second arrays of sort bins; and control
means for operating the guide means; wherein the control means
instructs the guide means to direct items such that items received
at either of the first or second input means may be directed to a
sort bin in either of the first or second array of sorting
bins.
31. An apparatus for sorting substantially flat items, comprising:
input means for receiving items to be sorted; a plurality of
moveable divider plates, the space between two moveable divider
plates forming a sorting bin for receiving the items following
sorting; conveyor means to direct the items from the input means to
a pre-designated sort bin; control means to operate the conveyor
means such that the items are directed to a pre-designated sorting
bin and are sorted into a pre-designated order across the sorting
bins; and an output conveyor disposed underneath the plurality of
sorting bins to receive sorted items; wherein when sorting has been
completed across the sorting bins, the moveable divider plates are
raised together causing the items within the sorting bin to fall
onto the output conveyor belt such that the order into which they
had been sorted is retained.
32. The apparatus of claim 31 in which the moveable divider plates
are fixed to an upper pivot near such that when they are raised
they rotate around the pivot.
33. The apparatus of claim 31 comprising guide means proximate the
entrance to a sorting bin which angles the items within the sorting
bin such that the substantially flat surface of the item is
non-horizontal with respect to the output conveyor belt.
34. The apparatus of claim 31 wherein the moveable divider plates
are curved such that an item falling down the curved surface of a
divider plate is angled to adopt an orientation in which the
substantially flat surface of the item is non-horizontal to the
output conveyor belt.
35. The apparatus of claim 31 wherein the moveable divider plates
are positioned such that the bottom item within the sorting bin
comes to rest on the upper surface of the output conveyor belt.
36. A method of sorting substantially flat items, comprising;
providing a sorting apparatus comprising input means for receiving
items to be sorted; a plurality of moveable divider plates, the
space between two moveable divider plates forming a sorting bin for
receiving the items following sorting; conveyor means to direct the
items from the input means to a pre-designated sort bin; control
means to operate the conveyor means such that the items are
directed to a pre-designated sorting bin and are sorted into a
pre-designated order across the sorting bins; and an output
conveyor disposed underneath the plurality of sorting bins to
receive sorted items; inputting items to be sorted into the input
means; operating the apparatus to sort the items into
pre-designated sorting bins; and raising the moveable divider
plates together, when sorting has been completed, causing the items
within the sorting bin to fall out onto the output conveyor belt
such that the order into which they had been sorted is
retained.
37. The method of claim 36 in which the moveable divider plates are
fixed to a pivot near to their top such that when they are raised
they rotate around the pivot.
38. The method of claim 36 wherein the sorting apparatus comprises
guide means proximate the entrance to a sorting bin which angles
the items within the sorting bin such that the substantially flat
surface of the item is non-horizontal with respect to the output
conveyor belt.
39. The method of claim 36 wherein the moveable divider plates are
curved such that an item falling down the curved surface of a
divider plate is angled to adopt an orientation in which the
substantially flat surface of the item is non-horizontal to the
output conveyor belt.
40. The method of claim 36 wherein the moveable divider plates are
positioned such that the bottom item within the sorting bin comes
to rest on the upper surface of the output conveyor belt.
Description
TECHNICAL BACKGROUND TO THE INVENTION
[0001] This application relates to an improved method and apparatus
for sorting items, and in particular to an improved method and
apparatus for sorting items of mail.
[0002] Sorting machines for organizing papers or documents into a
predetermined order, based on some input information, are well
known. Such machines are essential in the operation of postal
delivery services, for example, in which incoming items of mail or
`mailpieces`, received in no particular order, are sorted and
placed in collecting bins according to the address to which they
should be delivered.
[0003] Conventional postal sorting machines sort the mailpieces
using the postal code of the address to which the mailpiece is to
be delivered. Each new mailpiece received at a mail delivery centre
is scanned by a visual recognition system in order to retrieve the
postal code information of the delivery address. This information
is then converted into a machine-readable code which is printed on
the mailpiece. If the postal code is missing or, for some reason,
cannot be read by the visual recognition system, the mailpiece will
be passed to an operator who can manually enter the relevant postal
code for printing as a machine-readable code. After the mailpieces
have been coded they are sorted into batches corresponding to the
delivery area. They are then sent to the mail delivery centre
corresponding to the mailpiece address for sorting and
delivery.
[0004] To sequence sort mail in the order that it would be
delivered by a delivery person, most conventional sorting machines
require that a single mailpiece be sorted more than once in order
for it to arrive at the correct final collecting bin. Such sorting
machines are known as multipass sorting machines.
[0005] In a first passe the machine sorts each mailpiece in a batch
of mail into collecting bins according only to the first digit or
digits of the mailpiece's machine-readable postal code. The mail
then has to be collected from the bins and re-input into the
sorting machine for a second pass, which then sorts the mailpieces
by the next digit or digits of the machine-readable code. Each
subsequent pass of the mailpieces through the machine refines the
sort until finally they are placed into the correct collecting
bins. Some sorting machines require four passes of the mailpieces
for sorting to be completed.
[0006] A simple example of a multipass sorting process is shown in
FIG. 1. In this example, the address information of each mailpiece
is represented by a three digit number in the same way that
addresses are usually represented by a postal code.
[0007] The mail is input into the machine in no particular order.
The first pass of the machine sorts the mail according to the last
digit into three sort bins. The first bin contains all mailpieces
with an address that ends with the digit `1`, the second sort bin
contains all mailpieces with an address that ends with the digit
`2` and the third sort bin contains all mailpieces with an address
that ends with the digit `3`. The order of the mailpieces within
the sort bins is illustrated by a table in FIG. 1.
[0008] The mailpieces are then retrieved from the sortbins and
re-input for a second pass in the exact order in which they were
extracted. In conventional sorting machines, the bottom of each
sorting bin is pulled away to release the mail onto a conveyor
below for recollection.
[0009] This means that the first mailpiece to come out of the
machine following the first pass is mailpiece `123`, then working
up through sort bin 3, mailpieces `213` and `333` followed by the
bottom-most mailpiece in sort bin 2 and so on.
[0010] The extracted mailpieces are then sorted into bins according
to the second digit of the address. As a result, all mailpieces
with `1` as the middle digit of the address are placed in bin 1;
all mailpieces with `2` as the middle digit of the address are
placed in bin 2 and all mailpieces with `3` as the middle digit of
the address are placed in bin 3. Within each sorting bin the
mailpieces are now in order with respect to the last two digits of
the address, as illustrated by table b shown in FIG. 1.
[0011] Once again, the mailpieces are removed from the sorting bins
from the bottom of the leading sorting bin (in this case, bin 3).
The first mailpiece to come out of the machine is mailpiece `333`
followed by `132`, `231`, `123`, `222` and so on.
[0012] Preserving the order in which they were extracted, the
mailpieces are then re-input into the machine for a third and final
pass in which they are sorted according to the first digit of the
address. As a result, the mailpieces are now ordered within each
sorting bin with respect to all three digits of the address, as
illustrated in table c shown in FIG. 1.
[0013] The mailpieces may then be extracted from the sorting bins
in a convenient order for the mail delivery worker to deliver
during his routes that is `333` first so that it is at the bottom
of the sorted pile, followed by `321`, `312`, `231`, `222`, `213`,
`132`, `123` and finally `111`.
[0014] From this example, it can be seen that multipass sorting
machines require that between passes the order of the mailpieces is
not disrupted; mailpieces must be re-input into the machine for a
subsequent pass in the exact order in which they have been output
from the preceding pass, otherwise the mailpieces will not be
correctly sorted.
[0015] Also, to sort a single batch of mailpieces using a multipass
sorting machine requires the mail to be input up to four times, and
thus takes more time than would be necessary if the mail could be
sorted in a single pass. A known multipass sorting machine is the
Siemens SPACS machine which can input or `singulate` 48,000
mailpieces per hour, but, since the sorting process requires three
passes of a mailpiece, can effectively sort only approximately
15,000 mailpieces per hour.
[0016] Mailpieces sorted in this way pass along the conveyors and
guide wheels of a multipass sorting machine more than once and are
therefore subject to increased wear and tear.
[0017] Multipass sorting machines are therefore designed to
`singulate` mailpieces at faster and faster speeds to compensate
for the much lower sorting speed. `Singulating` is the term used to
describe the separation of a single mailpiece from a stack of
mailpieces to be input into the sorting machine. These `faster`
machines tend to be more complex and so more difficult to maintain
and adjust. Thus, it is necessary to have technically trained
operators present to ensure that the machine is running
optimally.
SUMMARY OF THE INVENTION
[0018] The invention is defined in the appended claims to which
reference should now be made.
[0019] The preferred system allows items of mail or mailpieces to
be sorted exactly to an order which may be specified in a single
pass of the sorting machine. Mail can therefore be sorted by the
machine quickly and with less wear and tear than known multipass
sorting machines.
[0020] Mail that is not correctly sorted in the single pass can be
reinserted to be sorted again, or can be manually placed into the
correct sorting bin.
[0021] The preferred sorting machine has the ability to merge
mailpieces of different sizes and those which originate from
different sources, such as public collection boxes and mailing
houses.
[0022] The sorting machine according to the preferred embodiment of
the present invention has, instead of a small number of large sort
bins, a large number of small bins. In this way, a small number of
mailpieces may be allocated to each bin, for example, each bin may
be an individual house or person at a business address. The
mailpieces are routed to the bin using prior knowledge. This is
achieved by communicating data to the machine before any mailpieces
are processed through it. Some of this data is derived from
machines which scan the mailpiece during the initial phase of the
sorting process in present conventional sorting systems. Data can
also be derived from the mailpiece producer. The producer may
supply relevant data related to the mail they have generated. This
data is configured and transmitted electronically ahead of the
physical mail. The electronic data may typically include
information of destination, addressee, the mailpiece physical
dimensions, mailpiece weight and thickness, This data is then used
to map the sorting bins of the machine in accordance with the mail
about to be processed. As the sorting machine is aware of the
number, destination and thickness of each mailpiece, it is possible
to allocate a sufficient space in the relevant bin for each
mailpiece in the machine. In this way, mail from several sources
may be merged as long as the electronic data is written to the
machine in advance. As each mailpiece is uniquely identified it is
possible to allocate to it a unique position in the machine in
advance of its input.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] A preferred embodiment of the invention will now be
described in more detail and with reference to the drawings in
which:
[0024] FIG. 1 illustrates the order of mailpieces within sorting
bins at each stage of an example known multipass sorting
operation;
[0025] FIG. 2 is a schematic illustration of the preferred sorting
system according to an embodiment of the invention;
[0026] FIG. 3 is an illustration of the input means of the
preferred sorting machine;
[0027] FIG. 4 is a simplified side view of the sorting machine;
[0028] FIG. 5 is an enlarged view of the sorting bins provided on a
sorting deck of the sorting machine shown in both `sorting`
position and `output` position;
[0029] FIG. 6a shows a three dimensional top view of a preferred
diverter plate used in the preferred embodiment of the sorting
machine;
[0030] FIG. 6b shows a three dimensional bottom view of the
preferred diverter plate shown in FIG. 6a;
[0031] FIG. 7a shows a top view of an array of the diverter blades
shown in FIGS. 6a and 6b as arranged in the preferred embodiment of
the sorting machine;
[0032] FIG. 7b shows a longitudinal cross-section through the array
of diverter blades along line 7-7 in FIG. 7a, when all diverter
plates are closed;
[0033] FIG. 7c shows a longitudinal cross-section through the array
of diverter blades along line 7-7 in FIG. 7a when the central
diverter plate is open;
[0034] FIG. 7d shows the mounting spindle on which the sorting bin
guide plates are suspended;
[0035] FIG. 8a shows a top view of the solenoid arrangement for
deflecting the diverter blades of the preferred sorting
machine;
[0036] FIG. 8b shows a side view of the solenoid arrangement of
FIG. 8a; and
[0037] FIG. 8c shows two views of the front of solenoid arrangement
shown in FIGS. 8a and 8b in a resting and activated position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] The preferred embodiment of the invention is a system
comprising a sorting machine control system and sorting machine
which enables mailpieces to be sorted into a predetermined order in
just a single pass or working cycle of the machine. Since
mailpieces need to be input into the machine only once, the sorting
process is much faster. In addition, the condition of the mail
after sorting is likely to be better than that of known multipass
sorting machines as only one pass is needed to sort. The novel
design of the collecting bins in conjunction with a wide conveyor
transport system, allows mailpieces of a wide range of sizes to be
handled by the sorting machine.
[0039] The preferred embodiment of the single pass sorting machine
will now be described in detail with reference to FIGS. 2 to 8.
[0040] FIG. 2 is a schematic illustration of a preferred system 100
embodying the invention. The system is divided into four main
sections; the first of these represents the collection and
cataloguing of mail at local receiving sections and is shown in the
top left of the diagram comprising components 102 to 128; the
second section, shown next to the first in the top right corner of
the diagram and comprising components 104 to 136, represents the
generation of items of mail by an external mail producer. The third
section, shown below the first two sections comprising components
140 to 144, represents the transmission of the mail and mail
information from the local receiving office and external mail
producer to a local delivery office. The local delivery office
forms the fourth section of the system and comprises components 150
to 152.
[0041] The components making up each of these sections will now be
described in more detail.
[0042] The top left corner section illustrates the reception and
indexing of mail in a typical letter sorting office or local mail
receiving office. Mail 102 is received from posting points in the
local area, taken to the receiving office and input into the local
sorting machine 110. Local sorting machine comprises means 112 for
receiving mail, means 114 for scanning the mail address
information, means 116 for determining the characteristics, such as
size and weight, of each piece of mail, means 118 for printing tag
or route information on an item of mail, and means 120 for
receiving items of mail sorted according to the destination
delivery office. In the preferred embodiment, an OCR (Optical
Character Recognition) Scanner is used as scanning means 112. `Tag`
information in this context means a unique identifier for that
particular item of mails whereas `route information` means an
identifier for the address to which the mail piece is destined.
[0043] Mail 102 received at the input device 112 of the sorting
machine 110 is caused, during the sorting process, to pass in turn
through each of the different means or parts mentioned above. Each
of these parts is controlled by a Machine Control system 126 which
additionally receives the addressing information and characteristic
information for each item of mail sorted.
[0044] Machine Control System 126 is also connected to means 124
for manually entering the address information into the control
system if this information cannot be extracted through the scanning
means 114. The address information and characteristics of each mail
item are transmitted by the control system to Outward Office
Computer System 128.
[0045] Once sorting of the mail has been completed at the local
receiving office, the mail is delivered by transport means 142 to
the delivery office illustrated in the bottom-most section of FIG.
2. Also, the address information and characteristics of each
mailpiece delivered to that delivery office are transmitted by
Outward Office Computer System 128 via Network 140, to the Computer
System 150 of the delivery office.
[0046] FIG. 2 also shows in the top right corner example production
of mail by external mail producers. Customer data 104 is entered
into the computer system 130 of the mail producer. The computer
system 130 is connected to printing machines 132 which it instructs
to produce the mail or letter to be sent to customers specified in
the customer data 104. The printing machines are also instructed to
produce addressed and possibly tag encoded envelopes for each
customer letter. The letters and envelopes are passed to means 134
for combining the letters and corresponding envelopes to be sent
out as mail. The printing machines and document inserting machine
communicate with Outward Customer Communication System 136 to pass
on mail information about the mail pieces sent out. This mail is
then delivered by transport means 144 to a pre-designated delivery
office which serves the addresses of the mail sent out. The address
information and characteristics, such as size and weight, of all
mail sent out are maintained by Customer Computer System 136, which
once the mail has been sent out transmits this information, via
Network 140, to the Computer System 150 of the pre-designated
delivery office.
[0047] The delivery office itself comprises a computer system 150
connected to Network 140 for receiving mail information and for
programming sorting machine control system 152 which controls one
or more sorting machines 154 (not shown in FIG. 2) at the delivery
office to sort the mail into the correct order for a mail delivery
worker to deliver the mail to the addresses on his route. Route
information may be entered onto the delivery office computer system
so that the sort order may be determined.
[0048] The preferred sorting machine for use with the preferred
system will next be described with reference to FIGS. 3 to 6.
[0049] FIG. 3 shows a top view of the `singulaters` used to input
mail for sorting into the sorting machine and the bottom deck of
the sorting machine 154. A first `singulater` 210, comprises
conveyor belt housing 212 and input conveyor belt 214. Conveyor
belt housing 212 has an input end 216 at which mailpieces can be
loaded onto input conveyor 214. A person loading the mail onto the
conveyor may stand at the input end of the conveyor or behind the
long side of the conveyor housing to place mail for input along the
length of the conveyor. Situated at the other end of the conveyor
housing 212, are barrier 218 and feed conveyor 224, mounted on
first and second feed conveyor guide wheels 220 and 222. First
guide wheel 220 is situated approximately on the central axis of
the input conveyor 214. The direction of travel of feed conveyor
224 is disposed perpendicular to input conveyor 214 and is adjacent
to, barrier 218, disposed between first guide wheel 220 and input
conveyor housing 212.
[0050] The end of the feed conveyor 224 distant to the input
conveyor 214 abuts twin feed conveyors 251 and 252 which are
disposed adjacent one another and which themselves abut a control
portion of main conveyor assembly 255.
[0051] The main conveyor assembly 255 is supported on the bottom or
input deck 250 of the sorting machine 154, and stretches
longitudinally along its length.
[0052] A second singulater 230, identical to the first 210, lies
behind the first singulater but adjacent to the input deck 250. The
second singulater similarly comprises conveyor belt 234 supported
by conveyor belt housing 232 with input end 236, barrier 238, and
feed conveyor belt 244 mounted on first and second conveyor rollers
240 and 242.
[0053] The end of the feed conveyor belt 244 distant to the input
conveyor 234 abuts twin feed conveyors 253 and 254 disposed
adjacent one another and which together about the end of main
conveyor assembly 255.
[0054] The main conveyor assembly 255 is a series of conveyor belts
mounted on guide wheels 256 which acts to draw mail from the
singulater feed conveyors 251, 252 and 253 and 254 along the input
deck to a pair of vertical feed conveyors 210 and 280.
[0055] Referring to FIG. 3, it will be appreciated that mailpieces
once they have entered the main conveyor assembly are carried
leftwards to vertical feed conveyors 270 and 280 at which point the
mailpieces are carried in a direction up and out of the page.
[0056] The preferred sorting machine is provided with two
singulaters and two arrays of sorting bins, disposed on either side
of the machine, and served independently by one of the two vertical
feed conveyors 270 or 280. This arrangement allows the sorting
machine to be used flexibly, allowing for example, a single
singulater and array of sortbins to be allocated to a one sort
while the other singulater and array of sort bins are allocated to
another sort; alternatively, both singulaters and arrays of sort
bins may be allocated to the same sort for faster processing.
Possible uses of the machine will be described in more detail
later.
[0057] In order to direct mail from either singulater to either of
the vertical conveyors 270 and 280 and thus to either side of the
machine, the main conveyor assembly 255 is provided with two sets
of readers 262, 264 and diverters 266 and 268. The readers 262, 264
scan each mailpiece that passes through for the machine readable
address information or post code printed on the mailpiece, and
notifies the controlling computer system that the mailpiece has
been received and read by that particular reader, at that
particular time. The controlling computer system may then operate
the appropriate diverter 266 or 268 to direct the mail to the
allocated side of the machine and the allocated sort bin.
[0058] Reference will now be made to FIG. 4 which shows the
preferred embodiment of the sorting machine 154 in a side view.
[0059] It will be seen from FIG. 4 that the singulating apparatus
shown in a top view in FIG. 3 comprises the bottom-most layer 250
of the sorting machine. The conveyor belt assembly 255 and
singulaters 210 and 230 shown in FIG. 3 are not shown in FIG. 4 to
avoid complicating the diagram.
[0060] The preferred sorting machine shown in FIG. 4 comprises
input deck 250 and one or more sorting decks 300 comprising input
conveyors 302, an output conveyor 304 and an array of collecting or
sorting bins 306. Only one sorting deck 300 is shown in FIG. 4 for
the sake of simplicity, but others could be provided either above
or below that shown to provide a larger array of sorting bins.
[0061] Mail is passed to the input conveyor of sorting deck 300 by
the vertical conveyor assembly 290. This will be understood to
comprise vertical feed conveyors 270 and 280 shown in FIG. 3. Each
of these conveyors comprises a belt 292 borne on rollers 294 and
296, and acts to carry mail from the input deck 250 to the top
sorting deck 300. Vertical conveyor assembly 290 may also contain
diverters 298 to divert mailpieces to subsequent sorting decks if
these are provided.
[0062] Referring next to FIGS. 5 to 8 the structure of the sorting
deck will be described in more detail.
[0063] FIG. 5 shows an enlarged view of the array of collecting
bins 306 shown in FIG. 4. It will be seen from this figure that the
sorting bins 306 comprise a curved plate 308 which hangs suspended
from the upper surface of the sorting deck 300 on which input
conveyor 302 is mounted. Input conveyors 302 are borne on rollers
303. The upper surface of the sorting deck will be described in
more detail later with reference to FIGS. 6 to 8.
[0064] Mailpieces are transported to input conveyors 302 of the
sort deck by vertical conveyor assembly 290 pass along the
conveyor, from left to right in FIG. 5, and are deflected into a
pre-designated sort bin 306 by the control system of the sorting
machine. The mailpiece falls down the underside of the curved plate
308 or guide in front of it until it comes to rest against output
conveyor belt 304 which stops its fall and keeps the mailpiece
upright within the sorting bin. The curvature of plate 308 means
that any subsequent mailpieces deflected into the bin may slot
neatly behind the mailpiece in front of it. This helps to keep the
mailpieces in the sorting bin neatly stacked and in the order in
which they entered the bin.
[0065] The curvature of the curved plate or guide 308 causes the
mailpiece to deform and thus partly absorb the energy in it. The
region of the guide which meets the leading edge of the mailpiece
is provided with a material 309 that acts as a break. The braking
action that it provides reduces the speed with which the mailpiece
meets the stationary output conveyor and allows the mailpiece to
come to rest in a more controlled manner.
[0066] The array of sorting bins 310 shown to the right of FIG. 5
are identical in structure and shape to the array of sorting bins
306 but are shown in a raised position. The sorting bins may be
raised from their rest position by pulling the bottom of each
sorting bin guide plate 308 rightwards by means of an actuator
connected to pins 312. Raising the sorting bin guide plates 308
allows the mail contained therein to fall out onto the output
conveyor belt 304. The output conveyor belt carries the mailpieces
towards the output end of the sorting machine, shown on the right
in FIG. 4, where they may be collected for delivery.
[0067] Although only two arrays of sort bins are shown in FIGS. 4
and 5 it will be appreciated that the sorting machine is modular in
design and may comprise one or more arrays of sorting bins
depending on the specified requirements of the machine user. These
will need to be given during machine installation. Only two arrays
are shown in FIG. 4, in modules 1 and 2, to avoid complicating the
diagram; the arrays of sorting bins in modules 3, 4 and x have been
omitted. `X` is intended to indicate an arbitrary module meaning
that the sorting machine shown in FIG. 4 may also be more than five
modules in length. The number of sort bins per module may also be
determined by the requirements of the user, as for the number of
modules and the number of sorting decks per module.
[0068] Referring now to FIGS. 6 to 8, the mechanism for diverting a
mailpiece from the input conveyor 302 to a pre-designated sorting
bin 306 will next be described.
[0069] A mailpiece is deflected into a sorting bin 306 using
diverter blades 320 of the type shown in FIGS. 6a and 6b.
[0070] Diverter blade 320 comprises a substantially flat plate 322
which curves a round at one edge to join back on itself forming a
loop. Formed integral to the loop and extending slightly beyond the
edges of the plate is sleeve 340. The sleeve is hollow and receives
a spindle of smaller diameter 360, not shown in FIGS. 6a or 6b, by
which the diverter blade is caused to rotate. Plate 322 is provided
with a cut away section 330 at the curving edge with a shape that
matches the profile of the leading edge 326, 328 of the diverter
blade 322.
[0071] Briefly referring to FIGS. 7a and 7b it will be seen that
the diverter blades are arranged adjacent to one another in rows,
one row behind another. This arrangement of diverter plates forms
the top of the sorting deck over which the mailpieces pass and
under which the sort bins are disposed. The mailpieces are driven
along the sorting deck by means of input conveyors 302 positioned
between the diverter blades. The cut away section of one diverter
plate receives the leading edge of the diverter blade plate in the
row directly behind it in an interlocking arrangement so that both
diverter plates form a horizontal surface for mailpieces to slide
over. The interlocking arrangement allows the diverter blade to be
long, advantageously providing a gentler deflecting gradient to a
mailpiece when the blade is raised, while allowing the sort bins to
be placed closer together reducing the overall space
requirements.
[0072] Referring again to FIGS. 6a and 6b it will be seen that the
leading edge of the preferred diverter blade plate 322 is provided
with a flat jutting out portion 326, of narrower width than plate
322, which angles downwards at its end to form a lip or flange 328.
Jutting out portion 326 and lip 328 are received in the cut out
portion 330 of the preferred diverter blade and make contact with
shoulder 332 and ridge 334 respectively. It will be appreciated
that other designs of cut out portion and leading edge profile may
also be used.
[0073] FIG. 6b shows the underside 324 of the preferred diverter
blade 320. The underside 324 of the plate has a longitudinal spine
336 disposed along its central axis which curves from being narrow
where it joins lip 328 to being thick where it joins the curved
sleeve at the other end of the plate. This curvature forms a gently
sloping deflecting surface 336 which acts to deflect the mailpiece
from its horizontal path along the top of the diverter blade in the
preceding row downwards into a sorting bin when the diverter blade
is raised. Ridge 334 can be seen to be the side of spine 336
opposite to the deflecting surface 338 where the spine passes under
the cut out 330 in the plate 322.
[0074] Referring now to FIGS. 7a and 7b, the arrangement and
operation of the diverter blade assembly will next be
described.
[0075] The diverter blade assembly 350 comprises a number of shafts
or spindles 360 which are supported on the frame of the sorting
deck by pivots 362. Disposed on the spindle 360 are a number of
adjacent diverter blade 320 and roller 364 pairs. In the preferred
embodiment there are three diverter blades with rollers 264 in
between and long rollers 366 at each end.
[0076] The spindle passes through the sleeve 340 of the diverter
blades and is provided with flats which engage in the diverter
blade sleeve so that as the spindle turns the diverter blade is
caused to rotate with the spindle. Neither the flats on the spindle
or the diverter plate sleeve are visible in the drawings. Rollers
364 and 366 on the other hand are freely mounted on the spindle and
rotate as an item of mail passes over them. Input conveyor belts
302 pass over the rows of the diverter assembly 350 in a direction
towards the leading edge of the diverter is blades at positions
above rollers 364,366, that is from the bottom to the top of the
assembly shown in FIG. 7a. Mail is carried in between the input
conveyor belts 302 and the substantially flat surface provided by
the rollers 364 and 366 and closed diverter blades 320. A side view
of the arrangement of closed diverter blades is shown in FIG.
7b.
[0077] FIG. 7b is a cross section through the diverter assembly
shown in FIG. 7a along line 7-7 when all of the diverter plates are
closed. The interlocking configuration of the leading edge profile
326 of the diverter blades and the cut out or recess 330 is clearly
shown. On the scale shown in this figure, the tops 322 of each
diverter blade form a substantially flat surface along which
mailpieces may move. In the preferred embodiment of the diverter
assembly the position of the spindles 360 and the orientation of
the diverter blades 320 is such to introduce a slight convex
curvature into the surface. This curvature is sufficient to ensure
that the tension of the belt running across the top of the surface
rollers 364 and the drive capability of the belting system is
sufficient without the need for additional pressure to be applied
between the belt and the rollers thus enabling positive drive
between belt and mailpiece. In the preferred embodiment the radius
of curvature of the diverter assembly is about 12-16 m over an arc
length of about 1 m.
[0078] The curved plates 308 which form the sorting bins are
suspended from mounting spindles 390 adjacent the spindle on which
the diverter blades and rollers are mounted to form an array of
sorting bins 306 as shown in FIG. 5. The curved plates 308 or
mounting spindles are not however shown in FIGS. 7b or 7c.
[0079] FIG. 7d shows a simple illustration of the mounting spindle
390 on which the curved guide plates 308 of the sort bins are
suspended. One of these spindles 390 is mounted on the frame of the
sorting deck adjacent to each diverter and roller assembly. The
curved plate 308 of the sorting bin hangs vertically down from this
spindle to form one edge of a sort bin.
[0080] If a mailpiece is to be directed to a sorting bin, the
control system of the sorting machine causes the appropriate
spindle 360 to rotate, causing a row of diverter blades 320 to be
opened and adopt the raised position of the central diverter blade
showing in FIG. 7c.
[0081] A mailpiece driven to the right along the top surface of the
diverter assembly by the input conveyor 302 encounters the
deflecting surface 338 on the underside of the raised diverter
blade. The deflecting surface is so shaped to cause the mailpiece
to deform and deflect from linear travel into the sort bin below.
Once the mailpiece has been deflected into the sort bin the
diverter blade is rotated into the closed position.
[0082] The mechanism which causes the spindle 360 to rotate and
open the diverter blades is shown in FIGS. 8a, 8b and 8c.
[0083] FIG. 8a shows the left hand side of the diverter assembly
350 of FIG. 2a in an enlarged view.
[0084] Spindle or shaft 360 is attached to a rotary solenoid 380
via a coupling 370. Solenoid 380 is secured in place on the frame
of the sorting machine by pins 381. The coupling is shaped to
enable the shaft of the roller diverter assembly and the shaft 382
of the rotary solenoid to be coupled by simply inserting each shaft
axially within coupling 370 as shown in FIG. 8b which is side view
of the mechanism shown in FIG. 8a. This is achieved by
incorporating flats on each shaft in the required position to
enable transmission of torque whilst at the same time maintaining
the relative position of one assembly to the other. The opening in
the coupling 370 is shaped to accept the flats on the shaft of the
roller diverter assembly and the shaft of the rotary solenoid. The
coupling is so designed to act as both a means of connecting the
roller diverter assembly to the rotary solenoid and as means of
reacting the load created by the inertia induced by the operation
of the solenoid see FIG. 8b. The need to support this load becomes
more significant in the event of a malfunction at the point of
diversion where a mailpiece becomes jammed at the diverter blade.
In this event much larger forces need to be catered for as the
mailpiece following the jammed piece will be driven into it with
the full power of the level transport system. A method of detecting
such an event is built into the control system. However, in view of
the speed of the machine and the inertia of the transport system it
is not possible to stop the machine instantaneously to avoid more
than one mailpiece in a jam. A torque arm 372 is an integral part
of the coupling moulding which rotates when the rotary solenoid is
initiated. At the point where the solenoid comes to rest the arm
comes into contact with a rigid pin 384 thus reacting the load.
This is shown in the two halves of FIG. 8c; in the left half the
solenoid is not activated and the spindle is undeflected.
Activating the solenoid 380 causes the solenoid shaft 382, coupling
370 and spindle 360 to rotate clockwise to the position shown in
the right hand half of the figure. The angle shown here is about
20.degree..
[0085] The operation of the sorting machine according to the
preferred embodiment of the present invention will next be
described.
[0086] A item of mail or mailpiece for delivery is received by the
local sorting machine 110 of a mail processing centre and is
scanned using known techniques and apparatus, such as OCR Scanner
114, and mail characteristic sensors 116 to determine the address
to which the mailpiece should be delivered and physical information
about the mailpiece such as size and weight. In particular the
thickness of the mailpiece is determined. The address and other
information including size information is obtained from scanner 114
and sensor 116 by machine control system 126 and input into
computer. system 128 where it is given a unique reference number
for identification. The reference number is printed onto the
mailpiece as a machine-readable code using printer 118. The
information describing the mailpiece is then transmitted e.g. via
network connection 140 to the computer system of the delivery
centre 150 and stored in memory. The mailpiece is then sent to the
mail delivery centre dealing with the mail delivery for the area
specified on the address of the mailpiece.
[0087] Mailpieces from mailing houses and companies that bulk
mail-shot are not usually `posted` in the same way as ordinary mail
and so are not necessarily received at a mail receiving centre
where the mailpiece details may be input into the system. Instead
they are sent directly to each mail delivery centre for delivery to
each address in the centre's catchment area. Such mailpieces pose a
problem in conventional mail delivery systems since the amount of
mail cannot be predicted in advance making it necessary to sort
bulk mail and individually directed mail separately.
[0088] The preferred system provides a solution to this problem
however by providing means to enter data about the mailing house's
intended delivery into the system before any mail is received at a
delivery centre. In the system illustrated in FIG. 2, customer data
104 is first entered into the bulk mail producer's computer system
130. This system then controls the printing of mail to be sent out
using printing machine 132 and document inserted 134, and transmits
data about the mail such as address, and size and weight of the
mailpiece to the bulk mail producer's outward computer system 136.
This system then transmits the mail data to the destination
delivery office computer system 150 across network 140. The mail is
carried to the destination delivery office by conventional means
144.
[0089] Thus the delivery office control system 150 knows in advance
of sorting the mail exactly what mail it is to receive from local
receiving offices and from bulk mail producers and can instruct the
sorting machine control system 152 to operate the sorting machine
in the most efficient way. This allows both individually addressed
mail and bulk mail to be integrated and sorted in a single
operation of the machine.
[0090] Once an entire batch of mailpieces has been read into the
system, the sorting control system 152 calculates the order in
which the mailpieces should be arranged according to predetermined
route information entered by a user of the system and the address
information held in memory for each mailpiece. The route
information allows a user to specify the exact order into which
mailpieces should be sorted. This means that the order can be made
to reflect the route walked by individual postal delivery
workers.
[0091] The sorting control system 152 then uses the width and
thickness information collected for each mailpiece and the
addresses of received mail to allocate sorting bins 306 to
accommodate the specified sorting order. Unlike conventional
sorting machines, in which each sorting bin is used consistently to
receive mailpieces with a predetermined postal code or portion of
postal code, the sorting bins of the preferred sorting machine are
allocated in response to the route information entered by the user
and the size information for each mailpiece. Bins need not be
allocated to addresses in the route, for which no mailpieces are
destined. Similarly, if there is a large amount of mail for a
particular address, more than one sorting bin may be allocated to
accommodate the mail.
[0092] Once the delivery walk order is established, the sorting
control system 324 calculates for each position in the delivery
walk order, how many mailpieces will be received, and how many
sorting bins need to be allocated to accommodate those mailpieces.
The result will depend on the thickness of the mailpieces. The
mailpieces deemed to fit in the first sorting bin are then
allocated to the appropriate bin. Next, the control unit performs a
similar calculation for the next position in the walk order. This
process continues until all of the mailpieces have been mapped to a
destination sorting bin.
[0093] The mailpieces are then manually input onto input conveyor
214, and input conveyor 234, to form a stack of mail. The stacks of
mailpieces will comprise mail of all different sizes, weights and
dimensions, although preferably is of C5 size or smaller. C5 is the
maximum size that can typically be accommodated by conventional
input singulaters. Mail of size larger than C5 may be sorted by the
preferred system but cannot be input into the machine while the
singulaters are processing mail of smaller sizes. Mailpieces are
input until the conveyor belts are full or there are no more
mailpieces to input. The input conveyor belts are then turned on
and begin to carry the mail from the conveyor input end 216 and 236
to the ends at which the feed conveyor belt 224 and 244 are
situated. A first mailpiece arriving at the feed conveyor belt 224
of singulater 210 will be pushed against the barrier 218 and the
feed conveyor belt 224 by the action of the input conveyor belt 214
and the mailpieces in the stack behind it. Feed conveyor belt 222,
and all the conveyors in the sorting machine according to the
preferred embodiment of the invention are provided with a surface
that has a high coefficient of friction for `gripping` the surface
of a mailpiece. Feed conveyor belts 224 and 244 are additionally
provided with small holes. A vacuum pump is used in conjunction
with these conveyors to provide a suction which holds the mail to
the conveyor. Feed conveyor belt 224 is caused to rotate by rollers
220 and 224 in a direction away from the input conveyor 214 and
towards the input deck 250 of the sorting machine. A mailpiece
pushed against the surface of the feed conveyor 224, is pulled off
the stack of mailpieces by the action of the conveyor belt motion
and the suction provided by the vacuum pump, and is input into twin
feed conveyors 251 and 252 which support the mailpiece and direct
it to conveyor assembly 255 of the input deck 250. This process is
called `singulating`.
[0094] The conveyor assembly 255 in conjunction with guide rollers
256 carry the mailpiece from the feed conveyor belt 222 to the
vertical feed conveyors 270 and 280. The mailpiece is held
vertically by the conveyor assembly 255 while it is being
conveyed.
[0095] Mailpieces are also singulated at the second singulater 230
and input into the conveyor assembly 255 by feed conveyor belt 244.
First and second singulaters 210 and 230 may operate in tandem with
each other to interlace the mailpieces received from the two feed
conveyors 224 and 244 into a single stream. For this reason it is
preferred that mail of sizes larger than C5 are not input at the
same time as smaller mail as the larger sizes are difficult to
interlace with the smaller mailpieces in an efficient way and
because the force required to singulate larger mail places greater
strain on the singulater feed conveyors. Mail of sizes larger than
C5 can be sorted with the preferred sorting machine and can be
merged in with mail of smaller sizes, but it is preferred that the
larger mail is input in a separate process. In the preferred
embodiment, a dedicated singulater 314 is provided for this.
[0096] Singulater 314 is located adjacent the vertical conveyors
270 and 280. Such a position reduces the path that the larger mail
pieces have to travel, which is advantageous because of their
greater size and the corresponding greater force that is required
to transport them. The mail that is input to the singulater, and
from their to the vertical conveyors, is input in a horizontal
fashion unlike the mail from the first and second singulater which
is input standing on edge and which therefore receives a 90.degree.
twist before passing to the vertical conveyor. The shorter distance
of travel and the fact that the mail does not requiring much
directing or manipulating before it passes to the vertical conveyor
means that the wear and tear on the larger mail items is greatly
reduced.
[0097] Conveyor 314 can singulate items of mail of at least C4 size
which are then sorted and merged with the other smaller items from
the first and second feed conveyors. This means that promotional
material from companies using the mail service to advertise can be
easily merged with regular mail.
[0098] Each mailpiece passing through conveyor assembly 255 is read
by one of the two readers or scanners 262 or 264. First scanner 262
receives mail from singulater 210; second scanner 264 receives mail
from singulater 230. First scanner 262 reads the machine readable
code printed on the mailpiece at the local receiving office or the
bulk mail producer and informs the machine control system 152 of
the mailpiece's location within the sorting machine. Like most
sorting machines the position of the mailpiece within the machine
is tracked by an internal clock. Once the machine control system
knows where a mailpiece is it may operate diverters 266 or 268 to
direct the mail to the correct side of the machine, and then
operate the required diverter plate to direct the mail into the
designation sorting bin at the right time by monitoring how long
has passed since the mailpiece was read in. Known sorting machines
provide correction methods to ensure that the sorting machine's
internal clock is in synchronisation with the expected position of
the mailpiece.
[0099] The arrays of sorting bins in the preferred machine are
disposed on the two sides of the machine. Each side is served by a
vertical feed conveyor belt, either 270 or 280, and may be
allocated to the same or different sorts. Diverters 266 and 268
divert the mail received from singulaters 210 and 230 respectively
to the appropriate side of the machine.
[0100] Once a mailpiece has been directed to the appropriate
vertical conveyor belt by the machine control system it is carried
up onto the sorting deck 300 that contains the destination sorting
bin for the mailpiece. The mailpiece may be carried to the top most
sorting deck, or deflected to lower sorting decks by diverters 298
controlled by machine control system 152. The mailpiece travels
along the sorting deck between diverter blade assembly 350 and
input conveyor 302 until the machine control system determines that
it has reached the destination sorting bin. The control system
activates the solenoid 380 to rotate the spindle 360 and diverter
plates 320 just behind the sort bin.
[0101] The mailpiece, travelling along the conveyor on a
substantially flat aspect with its short edge first, in the case of
mail smaller than C5, or with its long side or spine presented
first, in the case of mail greater than C5, makes contact with the
diverter plate and is directed into the destination sorting bin by
means of the sorting bin guide plate 3087.
[0102] The control unit then issues a control signal to the
solenoid 380 causing the spindle and diverter blades to rotate back
to its original position allowing the following mailpieces to flow
past unobstructed. This may be achieved by biasing the spindle with
a spring to remain closed.
[0103] Once all of the mailpieces in a sorting batch have been
directed to the correct destination sorting bins, the control unit
may issue a signal to raise the sorting bin guide plates 308, to
deposit the sorted mailpieces in the sorted order onto the output
conveyor belt 304. The sorted mailpieces can then be output from
the machine ready to be delivered. This represents a considerable
advantage over conventional sorting machines in which sorted
mailpieces are retrieved from the sorting bins by hand.
[0104] The operation of the sorting apparatus has been described
with reference to just one particular way of allocating the sorting
bins. However, other allocation methods are equally possible as
will be described next.
[0105] In the simplest mode of operation the control unit allocates
each sorting bin to an individual position or location in the
sequence, this being an individual address on the postal delivery
worker's route for example. The sorting bins are allocated in the
order that the postal delivery worker encounters the addresses on
his route, so that the mailpieces are output from the sorting
apparatus after just a single pass in the order in which they are
to be delivered. This mode of operation has the drawback that those
addresses for which there is no mail have a sorting bin allocated
to them. Thus, more sorting bins are required for the sort than
will be actually used.
[0106] In an improved mode of operation the control unit processes
the address information for all the items in a sort and only
allocates a sorting bin to those addresses which are to receive
mail and leaves out those that are not to receive mail. In this way
the number of sorting bins that are required to receive the sorted
items may be reduced from that described above.
[0107] In a further improvement to the mode of operation the
control unit uses the data describing the size of each mailpiece in
combination with the address information to allocate a sufficient
number of sorting bins to each position in the sequence, i.e.
address, to receive the sorted mailpieces. Thus, there is no danger
of a sorting bin becoming full and unable to hold any more
mailpieces, as the control unit allocates as many sorting bins as
are required before the sort commences.
[0108] In another possible of operation of the sorting machine, as
described above, the control unit may make use of the size
information and the address information to fit the mailpieces into
the minimum number of sorting bins. The control unit calculates the
order into which the mailpieces are to be sorted and then allocates
as many mailpieces to each sorting bin as will fit, preserving the
order of the mailpieces across the sorting bins. The sorting bins
in this mode of operation are not assigned to a particular position
in the sequence and are used to receive as many consecutive
mailpieces in the order as will fit. Mailpieces for a number of
adjacent addresses may be allocated to the same sorting bin. The
viability of this mode of operation is however dependent on the
order in which the mail is input into the sorting machine as it is
difficult to organise the mailpieces within a sort bin. That is,
mailpieces allocated to the same sort bin will be received at that
mail bin in the order in which they were input into the machine. In
order to use this mode of operation fully, the input order of the
mailpieces must be scanned before the sort bins are allocated. Sort
bins can then be allocated most efficiently.
[0109] The operation of the machine as described above provides a
reliable and flexible way of sorting mailpieces. The exact order of
the sort can be specified, in contrast to conventional sorting
machines which sort by postcode only. Furthermore, mailpieces from
any source, including mailing houses, can be integrated into the
sort, providing data about the mailpieces is received and input
into the system prior to the sort being carried out.
[0110] The preferred system also allows rejected mailpieces, that
is those which for some reason, are not successfully deposited into
a sorting bin to be output from the system and re-input for
sorting. The control unit `knows` which sorting bin the mailpiece
is intended for in advance so that the order in which the
mailpieces are received is entirely irrelevant.
[0111] Mailpieces that are rejected a number of times may also be
manually inserted into the correct sorting bin in the preferred
system. The preferred system makes this possible by providing
indicator lights which correspond to each bin. In order to
determine the intended destination sorting bin for a rejected
mailpiece, a machine operator enters the reference number of the
mailpiece into the computer system 150 and in response the sorting
control unit 152 lights the indicator light corresponding to the
intended destination sorting bin so that the machine operator may
insert the mailpiece by hand.
[0112] The design of the sorting bins and the upper conveyor 302
and guide roller arrangement, which allow mailpieces to be conveyed
horizontally means that the sorting machine can manage mailpieces
with a wide range of sizes and weights. In particular the machine
is able to handle C4 size mail and can easily merge C4 and C5 size
mail in one pass.
[0113] As described earlier, the sorting machine according to the
preferred embodiment has two sides of collecting bins and two
singulaters for inputting mail. This allows the sorting machine to
be operated in up to four modes; dual singulaters operating
separately to produce two streams of mail, each stream of mail
going to each side of the machine and comprising mail from only one
singulater, dual singulaters operating together to produce only one
stream of mail, that stream flowing to both sides of the machine,
one singulater acting alone to produce two streams of mail, one for
each side of the machine, and one singulater operating alone to
produce just one stream of mail which flows to both sides of the
machine.
[0114] Dual singulaters in dual stream mode allows the machine to
run at full capacity. Infeed conveyors 214 and 234 are loaded with
mail and feed each singulater. Each stream of mail from each
singulater is directed to one side of the machine, enabling the
machine to run as two machines that could handle smaller batches of
mail for smaller delivery `walks`. This facility also allows a
considerable amount of machine redundancy due to breakdowns as if,
for example, a singulater were to fail the machine may continue
processing mail with one stream only. In this mode the singulaters
necessarily run at a faster rate than when dual singulaters are
used in a single stream mode.
[0115] Dual singulaters in single stream mode enables mail to flow
to both sides of the machine. In this mode the singulaters will run
at a slower rate.
[0116] A single singulater in dual stream mode processes mail using
one singulater to direct mail to both sides of the machine and may
be used if one of the singulaters is to fail. In this mode, the
singulater will run at the higher speed.
[0117] Finally, a single singulater running a single stream
processes mail using one singulater to direct mail to one side of
the machine.
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