U.S. patent number 3,573,748 [Application Number 04/801,685] was granted by the patent office on 1971-04-06 for postal system.
This patent grant is currently assigned to International Business Machines Corporation. Invention is credited to William M. Holme.
United States Patent |
3,573,748 |
Holme |
April 6, 1971 |
POSTAL SYSTEM
Abstract
A machine for sorting and gathering together articles of like
distribution, such as letter mail, which is randomly positioned in
a supply source. Each article, being in a respective one of a
plurality of categories, is initially sorted by destination or
alternatively reclassified to be sorted by dispatch as the machine
approaches capacity, so as to provide continuous sorting. Storage
means for tallying inventories, and code generating means are
included, as well as dynamic program control and physical means for
supply source enrichment, tying, and labeling.
Inventors: |
Holme; William M. (Falls
Church, VA) |
Assignee: |
International Business Machines
Corporation (Armonk, NY)
|
Family
ID: |
25181792 |
Appl.
No.: |
04/801,685 |
Filed: |
February 24, 1969 |
Current U.S.
Class: |
209/584 |
Current CPC
Class: |
B65H
39/043 (20130101); B07C 3/02 (20130101) |
Current International
Class: |
B07C
3/02 (20060101); G06f 015/46 () |
Field of
Search: |
;340/172.5
;235/157,151.1,151.11 ;214/11 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Zache; Raulfe B.
Claims
I claim:
1. A machine for sorting articles by collecting them from randomly
positioned locations from at least one of a plurality of supply
sources, each article being in a respective one of a plurality of
destination categories comprising:
first generating means station for generating an address code
representing the address of each of said articles;
a primary sort means comprising a plurality of temporary holding
slots;
depositing means for depositing each article in selected respective
one of said slots;
first discharge means for discharging from said slots the articles
contained therein;
collecting means for collecting and labeling the articles
discharged by said first discharge means;
tying means for selectively tying said articles collected by said
collecting means;
collection stations for storage of those of said articles not
selectively tied by said tying means;
a control computer, said control computer further comprising:
a means for keeping a first running inventory of the number of
articles in each address code by slot location and a first running
count of the extent to which said plurality of sorting slots is
occupied,
a second generating means for generating a destination sort code,
said destination sort code capable of activating through said
computer, said first discharge means to discharge from said
plurality of sorting slots all articles of a given destination
category, in response to said means for keeping a first running
inventory and said first running count said destination sort code
being generated when less than an arbitrarily designated number of
said plurality of sorting slots is occupied,
third generating means for generating a dispatch sort code, said
dispatch sort code capable of activating through the computer said
first discharge means to discharge from said plurality of sorting
slots articles of different destination categories, in response to
said means for keeping a first running inventory and first running
count, said dispatch sort code being generated when more than an
arbitrarily designated number of said plurality of sorting slots is
occupied,
and first control and switching means responsive to said means for
keeping a first running count and said arbitrarily designated
number of said plurality of sorting slots filled at a given
time,
said control computer operatively connected:
to said first generating means station for receiving the address
codes representing the destination of said articles from said first
generating means station,
to said depositing means for controlling the deposit of said
articles of like address codes in the same ones of said slots,
to said first discharge means to control the release of said first
discharge means for discharging said articles from said slots,
to said collection means for controlling said collection means to
accept said articles discharged from said slots by said first
discharge means,
to said tying means for controlling said tying means to selectively
tie said articles in bundles and selectively pass the remainder of
said articles into said collection stations,
whereby articles deposited by said depositing means in one of a
plurality of temporary holding sorting slots are discharged from
said slot by said first discharge means under the control of said
control computer and is carried by said collection means to a tying
means where predetermined quantities of articles having identical
codes are tied and diverted from the sorting machine.
2. The machine of claim 1 wherein said collecting means comprises
an endless conveyor having compartments thereon, positioned to
travel beneath said slots.
3. The machine of claim 2 wherein each of said compartments
comprises:
means for retaining articles contained therein as said conveyor
belt traverses an underside path; and
means for discharging from said compartments articles contained
therein.
Description
FIELD OF THE INVENTION
Means to convey a number of articles or masses of material and
deliver a predetermined article or mass to a predetermined point,
as a delivery station, according to the will of the operator, there
being a plurality of stations, and whereby any article may be
delivered to any station at the will of the operator under his
control at a control station.
BACKGROUND OF THE INVENTION
Sorting systems become increasingly complex as the random mix and
number of articles to be sorted increases, as well as the variety
of destinations or categories into which these articles are to be
sorted, and the distribution network complexity for handling is
increased. To illustrate, mail deposited at a local post office may
be in package or letter form. It is initially deposited into a
postal box containing similar packages or letters randomly
positioned in that box, where each of those articles may ultimately
go to any one of some 33,000 post office locations in the United
States prior to ultimate delivery to the addressed recipient.
Any sorting system to handle such a wide distribution of articles
to be sorted must have a capability of being able to sort
individual pieces to form larger handling units going to any
individual location, while simultaneously performing this function
in a manner so that overloading or jamming of the accumulation unit
will not occur. While it is theoretically possible to have a
destination slot, bin, or receptacle for each conceivable
destination or for each of the 33,000 post offices, into which
every article destined for that destination may be deposited,
irrespective of size or shape, as a practical matter the incidence
or probability of an article deposited at any one location being
addressed to certain destinations may be extremely low. This being
so, the economics of the system dictate that fewer sorting slots
than the maximum number of destinations possible be provided in the
physical configuration of the sorting machine, while still
maintaining a capacity for separating to every destination articles
thereto addressed. Thus, it is an object of this invention to
utilize a computer-controlled machine system for separating,
identifying and classifying, sorting, gathering, and rerouting of
articles, particularly mail, in an integrated man-machine
computer-controlled processing system.
A further purpose of this invention is to process any type of
material, not necessarily mail, wherein the number of possible
distributions in a sorting function is very large relative to the
number of sorting separations which may be individually active (or
which may receive a plurality of items during a processing period),
and which is subject to input media containing unpredictable and/or
varying distribution of contents to be sorted, rearranged, and
distributed.
Another more specific object of this invention is to provide a
system for processing of flat mail, small parcels and rolls,
parcels and junk mail, destined for any one of a number of post
office locations.
SUMMARY
These and other objects are met by this invention. Briefly, in one
embodiment, this invention comprises a data storage and processing
means; a primary temporary holding sort means comprising a
plurality of presort buffer temporary storage slots; means for
generating an address code representing the destination category of
each of the articles to be sorted, the address code being stored in
the data storage means; depositing means for depositing each
article in a selected temporary storage slot, arbitrarily and
dynamically selected on the basis of immediate availability, and
identifying the contents of that slot by the article's destination
category; means for discharging from the temporary storage slots
the articles contained therein; and means for keeping a running
inventory of articles in each address code held in temporary
storage slots and a running count of the extent to which each of
the plurality of sorting slots is occupied, the total number of
sorting slots occupied, including the destination category of
objects, held in each of those slots, a running inventory and the
running count being stored in the data storage means; and means for
generating a destination sort code capable of actuating the
discharge means to discharge from the plurality of sorting slots
all articles of a given destination category, in dependency upon
the running inventory and running count, the destination sort code
being operative when less than an arbitrarily designated number of
the plurality of sorting slots is occupied; and means for
generating an alternate dispatch or sort code also capable of
activating the discharge means to discharge from the plurality of
sorting slots articles of different categories, in dependency upon
the running inventory and the running count, the dispatch sort code
being operative when more than an arbitrarily designated number of
the plurality of the temporary storage slots is occupied; and a
program control and switching means for switching operation between
the destination sort code and the dispatch sort code in dependency
upon the arbitrarily designated number of the plurality of sorting
slots being filled. In this manner, the sorting machine is
continually alternating between destination sorting and dispatch
sorting as a function of the number of slots occupied at any given
time and the amount of mail for varying destinations located within
those slots. Further, enrichment means for continually enriching
and thus affecting the randomness of the mail in the supply source
is also provided.
The invention may best be understood in conjunction with the
following drawings and general description.
IN THE DRAWINGS
FIG. 1 is a schematic representation of part of the sorting system
of a prior art system. FIG. 1A is an alternate embodiment of the
system of FIG. 1.
FIG. 2 is a schematic representation of part of a prior art sorting
system, from single letter input to multiletter sorted output.
FIG. 3 is a schematic representation of the sorting system of this
invention from single letter to bundled, tied output of stacks of
sorted mail.
FIG. 4 represents one embodiment of a conveyor belt assembly for
use within the sorting system of FIG. 3.
GENERAL DESCRIPTION
Before describing the system of this invention, it is necessary to
thoroughly understand prior art sorting systems that have attempted
to solve the above problems. One of these is known as the "extended
reach" or "conveyorized" method of sorting.
Referring to FIG. 1, this sorting machine essentially consists of a
conveyor 1, separated into a series of compartments 2; a fixed
proximate number of receptacles 7, and a number of mechanisms 4
along the conveyor length, associated with each receptacle 2, the
mechanisms incorporating a plunger, arm, or other mechanical device
15, capable of pushing or otherwise rejecting mail 6, or other
items, into fixed, adjacent accumulating receptacles 7 so as to
form a stack 8 therein. The essential feature of this system is
that it transports items, such as the mail 6, to a preestablished
fixed distribution point, where it mechanically ejects and/or
releases items into an accumulation receptacle 7 for removal and
further routing. The memory and control system to operate such a
system is described in concurrence with a later prior art system
discussed, the "sweep sort" system.
A widely used alternate of the extended reach system is illustrated
in FIG. 1A, wherein the conveyor consists essentially of a number
of receptacle boxes 9, each compartment 10 of which is capable of
holding one unit 11 to be sorted.
The bottom of each compartment is designed with a trap door 12 such
that its contents may be released, by command of appropriate
control devices, to an appropriate proximate fixed accumulating
receptacle 14 for further disposition.
This method is sometimes referred to as extended reach sorting,
since it mechanically makes it possible to make more separations
then are manually feasible within the physical limitations of human
arm reach.
"Modified extended reach systems" are systems which accomplish more
separations then are possible in one pass through the machine, by
making a primary separation to major categories on the first sort,
then, clearing all accumulation receptacles, and resorting within
one presorted group, through the same or an equivalent machine to a
secondary classification. Thus, for instance, up to 10,000
separations may be made by two sorting separations through a
100-pocket separation machine, employing some means of identifying
the material to be sorted, so that it may be automatically
processed in the second, or any other subsequent operation.
In one concept variation, material to be sorted may be identified
in the first separation by machine imprinting, labeling, or machine
readable encoding at an induction station, so that it may be
machine read and processed in the subsequent processing. In another
variation of this concept, the material to be sorted may be
containerized, item identification for sorting purposes encoded
upon such containers, containers sorted through the first machine,
and then distributed to a second similar machine for further
mechanical sorting. The transportation from first to second machine
may be in trays, blocks, or groups of items, or it may be done on a
subsidiary conveyor system for continuous flow from output
receptacle of the first machine to the input station of the second.
In either case, this modified system utilizes the same original
extended reach type of machine concept as above (fixed output
pockets, moving distributing conveyor), adding to it a method of
identifying the material sorted so that it may be subsequently
reprocessed for further distribution, without additional manual
handling of individual originating units.
SWEEP SORT SYSTEM
The prior art sweep sort system offers several theoretical
advantages over the extended reach system. Referring to FIG. 2, the
system consists essentially of individual induction stations 21, an
online computer control system 22, holding receptacles 23, and a
conveyor system 26. The holding receptacles 23 are fixed in
position over or otherwise proximate to the conveyor 26, and are
divided into individual separate compartments 24, each of which
incorporates a trapdoor 25, capable of being quickly and remotely
opened upon command from computer 22 to a discharge activating
means, not shown. The conveyor system 26 is discretely zoned
longitudinally along its system, so that each designated section 27
may accumulate material, as indicated at 28. The position of each
section 27 on the conveyor, relative to the fixed receptacle 24
along the system, is known at all times by a computer register
system which dynamically advances the position of the conveyor belt
in its register, as it moves. The clock in the computer which
controls this advancement is in turn set synchronized to the
conveyor itself, by suitable, electronic, mechanical, or
photoelectric pulse triggering devices, well known in the art.
In operation, an operator at induction station 21 reads the address
of a piece of mail 21a presented, and keys a memorized sort
disposition code for this address into the keyboard 29. This
information is transmitted to the computer system 22 via a direct
wire or radio link. The computer 22 refers to its memory to
determine which compartment of the holding receptacle 23 is
unoccupied, assigns the sort disposition code of the item being
sorted to its data storage record for that individual receptacle,
and issues a command to a mechanical transport system (not shown)
to deposit the mail into that particular receptacle.
In this way, mail is classified, presorted and moved into open
available fixed receptacles, under control of the computer which
determines this routing, and retains in memory the desired ultimate
disposition of every unit to be sorted. This function is repeated
for any desired number of induction stations along the length of
the conveyor 26, as required by rate and volume requirements of the
system.
Concurrently, the computer accumulates and reviews, in a separate
assigned memory storage within the computer, the number of pieces
of mail for each different sort category deposited in the storage
receptacles, throughout the entire system, as well as their
locations. Whenever enough pieces of mail have accumulated
throughout the system to make a bundle large enough to tie, the
computer dynamically assigns a moving belt section 27 to that
destination and commences a routine which compares the address of
that belt section with the address of mail in each induction
receptacle, as the conveyor belt moves under it.
The location of any such dynamically assigned conveyor section,
moving along the conveyor under the induction storage receptacles
24 is known relative to the individual holding receptacles 24, on a
real time basis, by the computer system, which advances conveyor
section 27 assignments through its registers in synchronization
with the physical movement of the conveyor 26. The computer clock
is controlled by signals from the conveyor as it moves.
As an assigned section 27 on the conveyor 26 moves under an
induction storage receptacle compartment 24, which holds a piece of
mail for section 27's now-assigned destination, the computer
transmits a control signal to a solenoid mechanism, for example,
which releases trapdoor 25 for that compartment. This permits the
contents of that compartment 24 to fall down into the advancing
conveyor section 27. As conveyor 26 advances under all of the
induction storage units, it thus accumulates and groups mail for
specific destinations on its separately assigned belt sections for
discharge and disposition in sorted categories at the end of the
conveyor system.
Concurrently, as the induction holding receptacles 24 release their
contents, the computer clears its storage of any assignment of mail
to the same, closes and resets the trapdoor, and thereby makes that
receptacle available for assignment to, and use by, another piece
of mail.
A feature of this system is that any given induction station
receptacle 24 may be assigned to and used by only one piece of mail
at a time; conveyorized sections 27 are assigned to only one
destination at a time, but hold multiple pieces of mail. The
assignments of destination addresses to both induction receptacles
24 and conveyor sections 27, are dynamic, being reassigned on a
real time, online basis by the computer system. The input
compartments are fixed, the output belt sections are moving.
This is exactly opposite to the extended reach sorter system,
wherein the input receptacles are conveyorized and moving; and
output compartments are fixed, both physically and as to
destination of contents.
The purpose of this sweep sort system is to provide a means of
handling a larger number of output distributions than is possible
with a fixed pocket extended reach type of sorter, and to permit
complete processing and distribution of the mail without multiple
handlings.
Each of the three general systems outlined above contains intrinsic
shortcomings, for processing and distribution of mail.
A. the extended reach type of sorter is practically limited in
number of separations it can make, economically and physically.
1. Beyond a certain number of separations, the utilization of
pockets for less active destinations becomes so light, that it is
not economical to make machine provision for such sorts.
2. Physical size also becomes a limitation where too many
separations are attempted, relative to the throughput capability of
the machine.
3. Because of limitation 1, this type of sorting requires multiple
handlings in order to obtain the required number of separations.
For example, current post office machines accomplish from 150--300
separations in each pass; whereas 3--4,000 distinct post office
tie-out separations (out of a total of 33,000 different post
offices) is not uncommon for a major postal processing center.
4. No provision is made for clearing the output of the machine from
its sorting pockets. The system thus requires manual support at the
output end, and processing is not fully mechanized.
5. Because of the uneven and extreme activity volumes of different
post offices, the fixed output pocket type of sorter tends to fill
up its pockets for very active destinations extremely fast. This
creates jamming, and/or severe problems in clearing the machine; or
requires manpower in excess of the work content that orderly
removal would otherwise indicate.
B. the modified extended reach systems attempt to overcome the
shortcomings of A, by using smaller (less separation) machines,
adding a means of encoding the mail (or a unit mail container) for
subsequent handling. By using machines with less separations, the
machine utilization per pocket is more efficient, which permits
mechanized sweeping and removal means. By employing a system for
encoding and machine reading of the mail, for subsequent handlings,
the added cost of manually reading and keying the mail for
subsequent handlings, after the first, may be largely mechanized,
at optimum machine rates, reducing the disadvantages of multiple
handlings, as appear in the basic extended reach systems.
Nevertheless, these configurations still retain, in reduced degree,
the basic disadvantages of any extended reach system. The basic
disadvantages are as follows:
1. The system essentially addresses the input and sorting problem,
but not the one of disposing of the mail after it has been
sorted.
2. The reduced cost of lesser pocket machines is offset by added
cost of sweeping mechanisms to clear and stack machine output,
where high-speed automatic machines are desired. The cost of such
machines appears to increase in throughput rate.
3. It does require multiple handlings. As contrasted to manual
sorting, which requires 3+ handlings per piece on outgoing
separation, this system requires almost as many average handlings
per piece (machine or manual).
4. In addition to the added machine cost, this system necessarily
requires a costly system to either imprint and machine read the
mail, or handle and process special containers.
C. computer simulation studies of the sweep sorting type of system
have shown this system not to be feasible, as was proposed.
Specifically, those studies indicated that because there are many
very low volume mail destinations, the input holding receptacle
units tended to fill up all storage receptacles, faster than
accumulation and release of mail for specific destinations would
clear the machine. That is, in a multiple operator input system,
the number of pieces for a given low volume destination, as
processed into the entire system by a number of different operators
within any short given period of time, do not build up fast enough
for the system to release them, before all holding receptacle
compartments are filled up at some input stations.
Conversely, on the very high activity level destinations, a number
of input receptacle compartments for a few of the very highest
volume destinations tend to fill up faster than they are emptied,
even though the dynamic sweeping system constantly reassigns
conveyor sweeping to those destinations.
Thus, it was found that a 20-compartment input receptacle system
tended to jam itself out of operation in 20--30 minutes;
50-compartment receptacle systems in an hour to an hour and a half;
etc. The analysis ultimately concluded that the number of input
holding compartments necessary to insure unjammed, continuous
operation of the system was economically unfeasible.
THE INVENTION
The machine of this invention is designed to address the following
situation. Quantities of mail on a continuing basis are delivered
to a local post office from various pickup stations. This mail is
introduced into a series of bins from which it will be introduced
into the machine to be described. Bundled mail leaves any
particular post office only at certain times and along certain
routes, inherent in the function of that post office. For example,
a post office may ship mail by truck 10 times daily to 10 separate
locations along 10 separate routes; it may ship mail by air four
times daily along four separate routes; it may ship mail by train
12 times daily along four different routes.
It is desired that mail be sorted in such a manner that whatever
mail has been sorted to a given point at a given time be removed
from the rest of the mail being sorted or yet to be sorted so that
it may be shipped via the train, air, or motor route on schedule.
Thus, the mail must be kept in motion and moving toward its
ultimate destination with the least amount of delay within the post
office. The route that the air, motor, or rail carrier will take is
the dispatch along which it runs. Those locations or destinations
along which the carrier will stop or may discharge mail are
destinations along the dispatch. It is always desired to keep the
mail moving whether it be to a destination or along a dispatch so
that it may ultimately reach a destination in the least amount of
time. While these terms will be described in greater detail later
in conjunction with the operation of the machine, it should be kept
in mind that this machine is designed as a real time system. The
computer, which is a basic part of the machine to be described,
will be continually checking a real time clock against the
departure schedules of the motor, air, or rail carrier, as well as
the particular route of the carrier against the articles being
processed through the machine at any one time.
Present mail sorting, which lacks the computerized mechanization,
as disclosed herein, separates mail on a geographical or numerical
basis. That is, mail which is not sorted direct to a post office
destination, is sorted to a secondary "scheme," which could be a
state, for instance. The invention disclosed herein is capable of
either geographical or dispatch sorting for secondary
separation.
This system is hermaphroditic: it combines basic unlike elements of
the extended reach and sweep sorting type of systems, in one
unitized continuous flow unit, so as to overcome the limitations
and shortcomings of either of the other systems, including the
modified extended reach method.
Essentially, the system consists of static input modules, similar
to the fixed receptacle compartments of the sweep sorting system,
with the exception that these compartments are so designed that
they may hold a small number of pieces of mail--up to 10 for
example--instead of just one piece only.
The output conveyor is segmented for gathering of discrete
categories of mail along its length, as in the previous sweep sort
machine, but with the additional feature that the belt is
compartmented so that mail may be retained on the conveyor, at the
end of the belt, carried over, around, down, and back under the
conveyor on its return pass, and then released and be directly
sorted to fixed position accumulation pockets underneath.
The machine consists of a plurality of operator input stations,
configured so as to collect, collate, and gather together items
having a like distribution from discrete temporary storage slots at
the same or different input stations into a common category bundle,
and transport them out of the system for disposition. FiG. 3
illustrates this machine, having, for clarity, but a single input
station illustrated. An operator reads mail 32 at station 31,
presented by a machine system not shown, but well known in the
art.
Each station, such as 31, comprises a first generating means for
generating an address code representing the destination category of
each article, here a piece of mail. An address code may be, for
example, the zip code representing the post office destination for
that item; or it may be an alpha-numeric code obtained by
extraction from the full address. Of course, in lieu of the letter,
for example, being read by an operator, it may also be read by a
magnetic or optical sensing means if each letter has been
previously magnetically or optically coded, or by an optical
character reader or other such nonmanual reading means.
Thus in the system shown, an operator at a station, such as 31,
reads the address of the letter and by depressing appropriate keys
on the console of the unit before him, converts the address to an
address code.
The address code, once keyed, is transmitted to computer 56.
Computer 56 comprises a data storage means, capable of storing each
address code along with the address code for each post office. The
computer memory includes, as a directory table, information as to
other major processing centers through which a destination post
office may be further processed, and the dispatches on which it may
be routed.
As in the sweep sort machine, an unassigned open slot 34 in primary
temporary holding sort means 33 is assigned to each address code,
primary temporary holding sort means 33 comprising a plurality of
sorting slots 34. The mail is directed and moved into that sorting
slot 34 upon command by the computer 56 to a depositing means 60
for depositing each letter according to the letter's address code
in a respective one of the slots 34 located at an arbitrarily
selected location. The address code identification of the sorting
slot is retained in computer memory with the exception that if the
address code of that sorting slot has not already been filled with
mail beyond its limited capacity, the next envelope having that
address code will be moved into that sorting slot, rather than into
a new one.
The computer, however, does have means for keeping a first running
inventory of each address code and a first running count of the
extent to which the plurality of sorting slots is occupied, this
first running count and first running inventory being stored in the
storage means of the computer. Thus, at any given moment, the
computer "knows" the address code assigned to each sorting slot,
the number of letters in each slot, and the number of slots
occupied, or conversely, those available to be filled, and their
locations, and the total amount of mail in the entire system for
each address code.
Similar to the sweep sorter concept, moving compartments 37 on
conveyor 36 are dynamically assigned to specific destinations by
the computer from its inventory of mail in the sorting slots, and
its release program, discussed later.
As the moving compartments 37 move under fixed sorting slots 34 in
the different input stations, having a corresponding address code,
the address code match in the computer program causes solenoids,
for example, to be actuated so that the appropriate trapdoors 35
are opened, and mail is accumulated in stacks 38 for transport out
of the system.
The solenoid-trapdoor combination would comprise, as an example, a
first discharge means for discharging from the sorting slots the
letters contained therein. Other release means are, of course,
available.
To this point, to discharge letters from these sorting slots into
the conveyor compartments is required a second generating means, in
the computer, for generating a destination sort code, the
destination sort code capable of activating the first discharge
means to discharge from the plurality of sorting slots all letters
of a given address in dependency upon the first running inventory
and the first running count, the destination sort code being
operative when less than an arbitrarily designated number of the
plurality of sorting slots is occupied.
Thus, up to this point, the machine operation may be described in
summary.
Mail is automatically brought to an initial reading station. An
operator at this station reads the address on the mail. The
operator depresses on the keyboard before him the address code
representing the post office destination of that piece of mail
prior to actual delivery by a mailman to home or office. While zip
code is one means of keying this mail, other means will known in
the art are equally applicable. For the purposes of this
illustration, however, the operator will key the zip code for that
piece of mail. By his action, the operator has now given this piece
of mail, which is in a given destination category, i.e., mail
destined for a given post office, an address code.
This address code is transmitted to a computer. The computer has
storage means for retaining in its memory that that address code
has been transmitted to it, and will record the same in its
inventory record. The computer, in turn, instructs a depositing
means to take that piece of mail and deposit it into one of a
plurality of sorting slots in the primary temporary holding sort
means.
Each slot may hold an arbitrarily designated number of letters, for
example, 10 letters per slot. Each piece of mail having the same
address code is deposited in the same slot until such slot is full.
At that time, additional pieces of mail having the same address
code are deposited in the next available slot. The computer keeps
track of the number of pieces of mail of each address code in each
slot, the location of those slots, and the number of slots filled
or conversely, the number of slots yet to be filled and thus
available for additional category code sorting.
Each sorting slot has a first discharge means that can be activated
upon command from the computer to discharge, for example, by
gravity, the mail contained in the sorting slot. In this
illustration, a conveyor belt having compartments upon it is
operative and running beneath the primary sort means. A second
generating means, such as a computer program, is operative to
generate a destination sort code within the computer. The
destination sort code is capable of activating the first discharge
means to discharge from the slots those letters for a given
destination category in dependency upon the running inventory and
the running count. The address code is operative when less than a
given number of primary sorting slots are occupied.
The destination sort code will operate in the following manner, for
example. Assume that it is desired that each bundle of mail or each
sort for a given destination category contain no less than a given
number of letters, for example, 50 letters. If each sorting slot
can hold 10 letters, this would require that no discharge take
place from these sorting slots until five of such slots or the
equivalent, were full throughout the system. Thus the computer,
keeping track of the location of each category code within a slot
and the number of slots occupied, would at a given point (50
letters in the sorting slots) clear those slots having the same
address code of the mail contained therein. This is done by
choosing an empty compartment on the moving conveyor and as that
compartment passes beneath the sorting slots, serially triggering
the sorting slot release means upon command from the destination
sort code, thus releasing the mail of a given address code into
that chosen compartment on the conveyor. Thus in the illustration
given, a number of different slots at different locations would
serially discharge mail of the same given address code into the
same conveyor compartment as the compartment moves beneath the
slots.
The empty slots are now available, of course, for mail of other
address codes. Thus, upon command from the computer via the
destination sort code, the primary temporary holding sorting means
is continually emptied as mail is sorted, and continually refilled
by the depositing means via the initial system described. Thus, a
real time dynamic system is in operation.
The sorted mail in the conveyor compartments is conveyed directly
into and through an online automatic tying machine 42 which ties
and labels the mail under computer control. The conveyor unit
performs two other functions as will be described subsequently.
Not all mail is processed in this fashion.
As mail temporarily accumulates in the sorting slots 34, and the
number of available unused sorting slots approaches a critical
minimum number, the computer will determine, by preset programmed
rules, whether or not to release less active address destinations
or address codes, by making smaller bundles for tie-out, or to
activate an alternate routine. In any event, when an arbitrarily
designated number of the plurality of sorting slots is occupied, an
alternate routine takes over.
Initially, the computer program has a constant number which is the
number of pieces of mail desired to be accumulated for a
destination, before mail for that destination is to be released,
swept, and tied out into a bundle.
A second program polls the contents of the different temporary
storage holding receptacle stations. Whenever the contents of any
station approach saturation, such that it will shortly be unable to
receive more mail, the program initiates a modification routine on
the number of pieces of mail required to make a tie-out, reducing
the same in fixed increments, down to 10 letters per bundle, for
example, until the impending bottleneck is released.
As soon as the impending saturation relieved, the program reverts
to the original constant number of pieces for a bundle. If the
program iterates and advances down to 10-letter bundles, without
correcting the situation, the alternative routine is called
out.
Assuming that the latter has become necessary to clear the system,
the computer then searches its stored inventory balance information
for the addresses for all pieces of mail in storage for which there
is only one piece of mail in the temporary storage holding
compartments. For each of these, the address is looked up against a
table, to determine the next dispatch on which each of those pieces
of mail is going out (or to which postal processing center the mail
should be sent for further separation, in an alternative system).
Stored data, as to address disposition of those pieces of mail, in
their respective individual temporary storage holding compartments,
is then updated in memory, to correspond to the new disposition
address, based upon a dispatch or secondary sort scheme
category.
Only those pieces of mail which have an address inventory balance
of one are initially so recategorized in the first iteration, and
processed as described below.
The disposition is determined by a dispatch sort code. This
requires a third generating means, in the computer, for generating
a dispatch sort code, the dispatch sort code also capable, as with
the destination sort code, of activating the first discharge means
to discharge from the plurality of sorting slots articles of
different destination categories, in dependency on the first
running inventory and the first running count, the dispatch sort
code being operative when more than the arbitrarily designated
number of the plurality of sorting slots is occupied. Thus, an
initial and primary difference is that whereas the destination sort
code will cause release of all articles of a given destination
category, the dispatch sort code discharges articles of different
destination categories but the same dispatch category from the
sorting slots. The dispatch is sorted in the following manner.
Where there are an insufficient number of articles to form a
tie-out or bundle for a given destination, and the machine
temporary holding sorting slots become overly occupied, i.e.,
tendency toward full utilization and thus jamming, the dispatch
sort code will cause release into a single moving compartment on
the conveyor of the contents of those sorting slots having
addresses which contain the least number of articles therein, with
a common factor being that while address codes of each set of
articles from each sorting slot is different for each release to a
compartment on the sweeping conveyor, all will ultimately be
delivered to their destinations along the same route or dispatch.
For example, if a railroad train were to deliver mail from New York
City to Poughkeepsie, N.Y., passing along its route Yonkers, Dobbs
Ferry, Hastings, Tarrytown, Ossining, Peekskill, Cold Spring,
Beacon, and finally terminating at Poughkeepsie, mail destined for
any of those locations to go onto that given train would constitute
the dispatch for such mail. Thus, many destinations lie along a
given dispatch. The dispatch sort code would thus cause clearing of
the least filled slots lying along this dispatch. In
contradistinction, a destination sort code release would release
only mail going to one of those given locations, i.e., Tarrytown or
Ossining, etc.
The code then updates and sets the computer registers for those
sorting slots by a mail processing dispatch number, instead of
destination address, and dynamically assigns conveyorized
compartments 37 to such dispatch number codes, so that mail will
now be accumulated in groups along the conveyor by dispatch, rather
than by destination address.
The system is so programmed that when it becomes necessary to
reassign disposition codes (i.e., from destinations to dispatches),
only those pieces of mail having one piece of mail per address,
throughout the system, are recoded, released, and swept into
dispatch compartments. The computer then reevaluates the storage
condition of the temporary storage holding slots. If the
approaching saturation condition, which previously caused the
reassignment routine to begin has been relieved, the system goes
back to releasing, sweeping, and gathering mail for direct address
destinations only as it had been, previously. If the impending
saturation condition is not relieved by releasing pieces of mail
for which there is only one piece of mail per destination, the
reassignment routine reiterates and searches inventory for all
those pieces of mail for which there are only two pieces per
destination, reassigns their address category to dispatch (or some
other secondary scheme), and releases for gathering and sweeping in
the conveyor compartments, as before. This routine reiterates one
additional piece of mail per destination count for
reclassification, up to 10 pieces of mail for an address, if
necessary, until the approaching saturation utilization of the
temporary holding slots condition has been relieved. No more such
reclassification of address categories is made than necessary to
relieve the filling up of temporary holding slots beyond
unsaturated working capacity; the object of this routine being to
prevent temporary storage slot saturation, by removing the minimum
amount of mail necessary.
Thus, when the number of sorting slots occupied becomes less than
the arbitrarily designated number, a first program control and
switching means in the computer, switches operation from the
dispatch sort code back to the destination sort code for continued
operation.
As the compartments 37 which hold reclassified mail for dispatch or
secondary separation go through the tying, labeling, and bundle
sorter unit 42, the computer program activates an alternative
instruction to the unit 42 which causes it to bypass the tying
operation, and allows the compartment to pass around, under, and
back along the underside of the conveyor.
As such batches of mail return along the underside of the conveyor,
they are held onto the conveyor, until they pass a collection
station 40 which has been assigned to a specific, fixed dispatch
(or secondary separation grouping) by the dispatch sort code via
computer command.
At that point in time, determined by the dynamic computer memory,
which is advancing data in synchronization with the conveyor and
matching the same with correspondingly adjacent collection
stations, the computer program releases a command instruction which
causes the mail so carried to be dropped into its appropriate
dispatch collection station, which may comprise a bin or tray.
Additional means are here present to keep a second running
inventory of each address code within each dispatch, the number of
articles collected in each collection station, the dispatch code
for each collection station and the location of each collection
station. All this is stored in the computer data storage means.
The mail is accumulated in collection stations 40 until the time a
particular dispatch is to be processed or the number of articles in
any given collection station exceeds a predetermined number. This
is done as follows.
The computer, keeping track of the number of articles in any given
collection station and the address codes therein, finds through a
running tally that that collection station contains enough mail
along a given dispatch of the same address code to allow a
secondary sort by address code. Thus the computer will activate
means for reintroducing mail collected in that collection station
into the supply system. This mail then comprises enriched (i.e., a
concentration of mail for a limited number of destinations) rather
than random distribution of mail for 33,000 different post offices
as originally supplied. Additional tie-outs may then be made, by
further sorting, if the computer inventory indicates that the
distribution of mail within that group warrants the same.
However, this being a real time system, there may be insufficient
mail within each destination category to warrant such a sort. As
the time schedule programmed within the computer signals that any
mail to go along the dispatch, as for example from New York City to
Poughkeepsie, must be pouched for delivery to that train by a given
hour, it may call out all mail along that dispatch to be
reintroduced within the unit, sorted into separate sorting slots,
and if these slots still contain insufficient amounts of mail to
warrant a destination sort, the machine will then reassign sorting
instructions to call out a sort to another postal processing center
closer to the destination for such tie-out. In this manner, both
mail to a specific end-point destination, and dispatch (or
secondary scheme) coded mail can be bundled in sufficient time to
meet a carrying means such as the train cited, for prompt deliver.
Of course, as is well known in the post office, dispatch mail goes
to a sectional center post office where the volume of mail for
destinations along the dispatch is greater than at the originating
station, whereby this mail is introduced into the original source
from that post office, destination coded by another machine similar
to that being here described, for ultimate destination delivery.
Thus, the mail from one dispatch is reintroduced into the system
and reprocessed. Since there are only a limited number of
separations on any one dispatch, and this mail has been "enriched"
to the extent that it has already been gathered together into a
limited number of destinations comprising a dispatch, all mail will
be tied out into either a direct destination or a transit post
office destination for further processing. There is no further unit
handling.
The tying and labeling machine 42 includes within its design the
capability of removing all bundles which have been tied and
labeled, from the conveyor. This function may thus be performed
mechanically, as well as manually.
Tying and labeling instructions are, of course, received from the
computer, synchronized with the arrival of the conveyor
compartments of the mail to be tied and labeled. This unit,
therefore, has the capability of serving as an induction station to
a connected bundle sorting machine, not shown.
At this station the mail is either bundled, removed, and sorted
into a sack, or the sweeping conveyor system carries it through,
around, and underneath the conveyor system so that it may be
automatically discharged to fixed pocket collection stations
underneath the machine for a second handling.
Just as the sorting slots may become "overutilized" with a tendency
toward jamming, the same is true of the collection stations beneath
the conveyor. Thus, additional means may be provided for allowing
discharge from the collection stations of articles contained
therein, and means for generating an enrichment code, the
enrichment code capable of activating the discharge means to
discharge from the plurality of collection stations all articles of
a given dispatch, in dependency upon the second running inventory
and the number of collection stations occupied, the enrichment code
being operative when an arbitrarily designated number of collection
bins is occupied; and means for generating a station clear code,
the station clear code capable of activating the second discharge
means to discharge from the plurality of collection stations
articles of different dispatches, the station clear code being
operative when more that an arbitrarily designated number of
collection stations is occupied; and second switching means for
switching operation between the enrichment code and station clear
code in dependency upon the arbitrarily designated number of
collection stations being occupied. Thus, the collection bin
storage problem is handled in the same manner as the sorting slots
occupation problem is handled in the primary sort means. In normal
operation, of course, collection bins are continually being emptied
to form enriched mail in the supply source, so that ultimately most
mail may leave via a destination code, i.e., by category code.
Many mechanism are possible for the compartmented conveyor which
permit it to carry mail around its end, and back along underneath,
so as to do direct sorting on its return pass.
One possible means by which this might be accomplished is shown in
FIG. 4. Attached to conveyor 36 (cut away to show detail), the
compartment separators 51 may be constructed with a spring-loaded
hinge 57, so that normally they stand straight out from the
conveyor, as in position B, but when constrained by an interfering
member, they will fold back to form pockets, as in positions A and
C.
In FIG. 4, these pockets incorporate extensions 52a at either or
both sides, upon which small wheels or rollers 52 are mounted.
As the compartments pass around the output end of the conveyor at
C, fixed rails 46, shown in FIG. 3, engage the extending rollers 52
on the top or outer edge of each compartment to fold back around
their spring-loaded, hinged sections 57, in FIG. 4. Thus, any mail
still in the compartment is held in place by that portion of the
compartment which is folded back and becomes the trailing bottom of
an enclosed pocket 44, in FIG. 3, and is shown holding a piece of
mail at 49.
As these compartments are moved from right to left underneath the
conveyor, that portion of the leading wall 51, FIG. 4, which is
articulate, is held in a horizontal position, as a pocket, by the
wheels or rollers 52, as they engage and roll over segmented
sections of tracks 53, adjacent to the conveyor compartments. The
segmented sections of track 53 are mounted in a hinged way at their
forward ends 58, so that they can be externally actuated at ends 59
to pull them out and away from the otherwise continuous, segmented
track (sections 53), illustrated in position B.
Thus, when it is desired to release mail from the pockets, the
computer will actuate a solenoid, not shown, so as to pull the
section of track over the desired sort pocket out of engagement
with its adjoining section of track at one end (B). When this
occurs, there will be no support for the next compartment pocket
moving into position; the spring-loaded compartment wall will
spring down into a vertical position, and contents of the pocket
will be released. Compartments so restored to their original
upright position (now upside down), will retain this position
throughout the remainder of the conveyor cycle, until reset into
pockets by the fixed turn-around track unit 46, at the end of the
conveyor, as shown in FIG. 3, which functions as a cam to close the
pockets.
It will be seen that this system overcomes the obstacles which
prevented the original sweep sort letter sorting machine from being
feasible, as found under simulation, in many ways:
1. By permitting the accumulation of more than one piece of mail
for one destination in an induction receptacle compartment, it
substantially reduces the loss of capacity that occurs when a very
high volume run of mail occurs for one destination at one input
station.
2. By providing a means to remove, sort, and enrich very low
density outgoing mail, using a direct sort feature in addition to
the sweep sort concept, the system can be controlled so that it
will never fill up and stop. At the same time, it continues to make
direct tie-outs of the largest possible number of destinations at
all times, optimizing the tie-out scheme on the basis of current
mail distribution patterns.
3. The end result of this configuration is a system which will
separate and sort the mail in only slightly more than one handling
per unit piece; in a larger post office, only 10--20 percent of the
outgoing mail may require a second handling. This represents a
substantial improvement over any other known mail sorting systems
manual or machine.
4. The portion of mail requiring a second handling is so small that
the function of machine imprinting and coding may not be
required.
5. The system is essentially "continuous flow," i.e. accomplishes
the original objectives the sweep sorter tried but failed to
achieve, and requires substantially less costly mechanical handling
devices than the various existent or proposed extended reach
machines.
While this system has been described primarily with mail sorting in
mind, it is evident that by proper choice of slot sizes, etc.,
other articles besides mail may be sorted. And while particular
means have been described, equivalents are possible, and likely as
technology improves.
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