US3411622A

US3411622A - Parcel sorting installations

Info

Publication number: US3411622A
Application number: US526503A
Authority: US
Inventors: Dickie William
Original assignee: Post Office
Current assignee: Post Office
Priority date: 1965-02-15
Filing date: 1966-02-10
Publication date: 1968-11-19
Anticipated expiration: 1985-11-19
Also published as: DE1456753A1; DE1456753C3; NL6601938A; GB1136801A; DE1456753B2; SE333120B; CH440789A

Description

W. DICKIE Nov. 19, 1968 PARCEL SORTING INSTALLAT IONS Sheets-Sheet l Filed Feb. l0, 1966 QE mm W/LL/AM DKK/5 INVENTQQ an /gdf M7@ Nov. 19, 1968 w, DlcKlE 3,411,622

PARCEL SORTING INSTALLATIONS Filed Feb. 10. 1966 3 Sheets-Sheet 2 M//LL/Ar D'fKlE,

ATTDRNEY W. DICKIE Nov. 19, 1968 PARCEL SORTING INSTALLATIONS 3 Sheets-Sheet 5 Filed Feb. 10. 1966 INVENTOR. WILLIAM DICK/E United States Patent O 3,411,622 PARCEL SORTING INSTALLATIONS William Dickie, Lancing England, assignor to Her Majestys Postmaster General, London, England Filed Feb. 10, 1966, Ser. No. 526,503 Claims priority, application Great Britain, Feb. 15, 1965, 6,497 65 Claims. (Cl. 209-74) ABSTRACT OF THE DISCLOSURE Parcel sorting apparatus employing a tilted band conveyor. Movement of parcels and packets from the tilted band conveyor to other cross conveyors is controlled by discharge doors which are grouped together for operation in combinations. Each combination of doors controls the discharge to one only of the cross conveyors.

This invention relates to sorting installations for objects such as parcels and has especial reference to installations for sorting postal parcels.

To facilitate the sorting of postal parcels it has been proposed to employ what has become known as a tilted band sorting machine. That machine includes a belt conveyor whose forward run is horizontal but is twisted about its longitudinal centre line to provide a length over which the surface of the forward run belt conveyor is constrained into an inclined position. The .angle of inclination to the horizontal lies between and 38, the value of 37 being found to give satisfactory results. A side plate is fitted adjacent the lower edge of the length over which the forward run is inclined and contains a number of discharge doors which, when opened, permit a parcel on the surface to slide off the latter and through the door. The discharge doors are controlled by a unit into which information is fed concerning the destination of the parcel and which causes a door appropriate to that' information to open as the parcel reaches the door. The length of the door measured along the belt must be sufficient to permit the satisfactory discharge of a parcel of the maximum length which the machine is designed to accept and it has been found that for reasonable belt speeds the door length must be greater than the maximum permitted parcel length. Throughout this specification, the term length when applied to a door is used to mean the length of the door when measured in a direction parallel to the longitudinal centre line of the tilted band.

Where parcels discharged from the tilted brand machine pass directly to sorting positions where further sorting is effected manually, there is normally no difculty in accommodating doors of sutlicient length. However, it is frequently required that the parcels shall be discharged on to belt cross conveyors arranged beneath and with their lengths at right angles to the length of inclined belt, usually in order to aggregate the outputs of several tilted band machines. To minimise the floor space required for such an installation or to permit the largest number of cross conevyors in a given space, they must be of the minimum workable width and must be placed as close together as possible. Further, it has been found that a long parcel turns as it slides through a discharge door and that the leading edge of every parcel discharged from any one discharge door falls within a space whose Width is considerably less than the maximum permitted parcel length. This means that whilst the transverse Width of the cross conveyors can be considerably less than the maximum permitted parcel length, the distance between centres of adjacent cross conveyors must be not less than the length of a discharge door. That requirement severely limits the number of cross conveyors which can be accommodated within a given floor space.

3,411,622 Patented Nov. 19, 1968 ICC It is an object of the present invention to provide a parcel sorting installation to which the above described limitation does not apply.

According to the present invention, a sorting installation for sorting objects according to the destination of the objects comprises a line of discharge doors, conveying apparatus for moving objects to be sorted past the discharge doors, at least one group of collecting conveyors spaced along the length of the line of discharge doors and disposed beneath the latter with their longitudinal axes crossing the line of discharge doors, and an operating mechanism for opening and closing the doors, each collecting conveyor being allotted a unique combination of doors which control the discharge of objects to that particular collecting conveyor, each combination of doors including one door which is individual to the combination and at least one other door which is common to the combination and to the next adjacent combination.

In one embodiment of the invention each combination of doors consists of a long door individual to the combination and two short doors.

Alternatively, all combinations of doors except the rst and last in the group or in each group of collecting conveyors consist of a long door and two short doors. The rst and last combinations consist of a single long door and a single short door.

In each unique combination of three doors comprising a long door and two short doors, one of the short doors is common to the combination and to the next adjacent upstream combination, whilst the other short door is common to the combination and the next downstream combination. In uniquecombinations of two doors comprising a single long door and a single short door, the short door is common to such cmbination and the next adjacent upstream or downstream combination dependent upon the location of the single long door-two door combination.

The overall length of each combination of discharge doors is suicient to permit the discharge of the longest parcel for which installation is designed, and the length of each short door is equal to that overall length less the distance between centres of the collecting conveyors. The length of the single long doors in those combinations of doors consisting of one long door and one short door is equal to the length of a long door in combinations of one long door and two short doors plus the length of a short door.

The conveying ymeans may comprise a tilted band conveyor to which the discharge doors are fitted to control the discharge of objects from the tilted band conveyor to one or other of the cross conveyors.

The doors :of a combination of doors may be opened simultaneously when an object is to be discharged through that combination or the doors ,may be opened sequentially starting with the upstream door of the combination, the remaining doors opening in squence.

Preferably, the axes of the collecting conveyors, which may be belt conveyors, are at right angles to that of t-he tilted band conveyor. The collecting conveyors may be tted with side plates and a guide surface is tted to the tilted band conveyor to facilitate movement of an object from the latter to a particular collecting conveyor.

By way of example only, an embodiment of the invention suitable for sorting postal parcels will now be described in greater detail with reference to the accompanying drawings of which:

FIG. l is a plan view in diagrammatic form only of part of the embodiment,

FIG. 2 is a section on an enlarged scale on line II-II of FIG. l,

FIG. 3 is a perspective View of a detail of the embodiment of FIG. 1, and

FIG. 4 is a front elevation of part of t-he embodiment, on a slightly larger scale, and FIG. 5 is a view similar to FIG. 4, showing a different set of doors opened, and illustrating diagrammatically the association of suitable control and operating apparatus therewith.

Shown in diagrammatic form only in FIG. l, is part of a tilted band belt conveyor 1 whose forward run 2 passes over twisting devices 3, 4 which turn the run from a horizontal to an inclined orientation and from the latter back to the horizontal position respectively. Between the devices 3, 4, the inclined belt is supported on a bed plate or similar belt carrying surface mounted on a supporting structure 5 (FIG. 2). The inclination of the width of the belt to the horizontal is 37. The direction of movement of the forward run 2 is indicated in FIG. 1 by arrows 6.

Arranged directly beneath the tilted band conveyor 1 is a series of collecting conveyors, also belt conveyors, with their longitudinal axes at right angles to that of the conveyor 1. To avoid obstructions, for example vertical support pillars of the building in which the apparatus is housed, the collecting conveyors are arranged in groups, FIG. l showing a first group comprising conveyors 7 10, and part of a second group comprising conveyors 11 15. The direction of movement of the forward runs of the collecting conveyors will depend upon the general layout and typical directions are shown by `arrows 16. The forward runs of the cross conveyors form the floors of troughs with side walls 17. The first and second groups are spaced apart to accommodate a vertical support pillar 18 as shown in FIGS. l and 4.

Along the lower edge of the inclined belt is a side plate part of which comprises a series of discharge doors each pivotally mounted adjacent that edge as at 19 (FIG. 2) and provided with a powered opening and closing mechanism (not shown). Extending along the length of lthe inclined belt is a guide surface 20 which, in effect, forms a continuation of the belt run 2 and is similarly inclined. The guide surface 20 terminates just above semi-cylindrical surfaces 21 which bridge small gaps between the adjacent side walls 17 of adjacent collecting conveyors. Between the groups of collecting conveyors, the side plate comprises a xed section which bridges the space between the discharge doors of the last cross conveyor in one group and the first cross conveyor in the next group. Thus, FIGS. l and 4 show a fixed section 22 between doors D10 and D11. Fixed

sections

23, 24 `are also included at the beginning and end of the tilted band conveyor over the length of the twisting devices 3 and 4.

The discharge doors are combined together for operation in unique combination of two or three doors each, and in each unique combination there is a long discharge door and at least one short discharge door. Each combination of two doors or three doors controls the disc-barge of parcels from the run 2 to one only of the collecting conveyors and is unique to that one collecting conveyor. For example, the combination of doors controlling the discharge of parcels to collecting conveyor 7 comprises doors D7 and D7/8 of which D7 is a long door and D7/ 8 is a short door. The discharge of parcels to collecting conveyor 8 is controlled by the unique combination of the three doors D7/8, D8 and D8/9. Doors D7/8 and D8/9 are short doors and D8 is a long door. The factors affecting the choice of discharge door lengths will be dealt with later. However, it will be observed that all long doors are of equal length with the exception of doors D7, D10, D11 and D15, i.e. the rst and last doors of each group which are of a length equal to the sum of doors D7/ 8 `and D8, and which may be replaced by a long door and a short door operated together, if desired.

It will be apparent that the long doors are each unique to a single collecting conveyor whilst the short doors are common to adjacent collecting conveyors and that this enables a reduction in the distance between collecting conveyor centres to be obtained `and thus, more collecting conveyors can be accommodated within a given oor space. In FIG. l, long doors bear the reference number of the collecting conveyor to which they are unique whilst the short doors bear the reference numbers of the adjacent collecting conveyors to which the short doors are common.

The upstream edges of all long discharge doors D7, D8, D9, etc. (except the first of each group, e.g. D7 and D11) and the upstream edges of yall xed

sections

22, 23, 24, etc. (except the rst, eg. 23) of side plate are fitted with quadrant plates 25 and FIG. 3 shows one such plate 25 secured to a long door, while FIGS. 4 and 5 show the arrangement and operation of this feature in stations of this feature in stations of the irst group of FIG. 1, and show how each of these quadrant plates 25 is related to the next upstream combination of doors. Thus from FIG. 4, in which the combination of the two doors D9/ 10 and D10, unique to conveyor station 10, is shown operated, it will be seen that the quadrant plate 25 carried by the iixed side plate 22, downstream of this station, is juxtaposed to the downstream end of the downstream door D10 of the operated station and constitutes a parcel guiding wall thereat. Similarly, from FIG. 5, wherein the combination of the three doors D8/9, D9 and D9/10, unique to the conveyor station 9, is shown operated, it will be seen that the quadrant plate 25 carried by the next downstream long door D10 is juxtaposed to the downstream end of the downstream door D9/ 10 of the operated combination, and forms a parcel guiding wall thereat. In addition, it will be noted from FIG. l, and also from FIGS. 4 and 5, that the centre line of each combination of doors lies slightly upstream, with respect to the direction of movement of the upper run 2 of conveyor 1, of its associated collecting conveyor.

Upstream of twisting device 3 is a parcel loading station (not shown) where parcels are loaded manually on to the forward run 2. As each parcel is loaded information is inserted into a control unit 26 (FIG. 5) which stores the information and uses it at the correct moment to actuate an operating mechanism 27 (FIG. 5) to open that group of discharge doors appropriate to the information and to close the doors of the group after the parcel has passed through them unless the succeeding parcel is to follow the same route. The parcel slides on to one of the collecting conveyors which takes it to a bag-filling position or to another sorting station (not shown). A keyboard 28 at the loading station 29 enables an operative who loads the parcel to insert into the control unit information indicative of the parcel destination. The keyed information is stored temporarily and then released to be stored in a memory unit when the parcel passes a predetermined point on the run 2 indicated, for example, by a light beam and photo-electric cell or a flap displaced by the parcel as it passes the point or in some other suitable way (not shown). The stored information is subsequently used to operate the mechanism 27 to open the appropriate combination of doors at the correct moment to permit the parcel to be discharged on to the correct cross conveyor. If the operative realises, before dealing with the next parcel, that he has made an error he may operate a cancel key which will erase the information just stored so that the parcel will proceed to a mis-sort conveyor or station (not shown) as described hereinafter.

All the doors of the unique combination being operated may be opened simultaneously or they may be opened in sequence starting with the upstream door of the combination. Similarly, the doors of such combination may be closed simultaneously or in sequence before the parcel following that just discharged reaches those doors, The doors will however remain open if the following parcel is to be discharged on to the same cross conveyor. If the following parcel is for an immediately adjacent cross conveyor, the short door common to the combinations of doors of the two cross conveyors may be left open as part of the operation of the combination of doors required to be opened for the adjacent cross conveyor.

Since parcels slide olf the tilted band conveyor and over the surface of the opened discharge door and the guide surface 20, these components are made of or faced with material having a low coefficient of friction. The coefficient of friction of the surface of the belt conveyor 1 must, of course, be such that the parcels can be satisfactorily carried along.

The theoretical sorting rate of the installation depends on such factors as (1) speed of belt conveyor 1, (2) time for the discharge doors to open and close, (3) time for parcels to slide free from the surface of run 2 and, (4) dimensions of parcels being dealt with. The lengths of the doors depend on the maximum permitted parcel length, the speed of belt conveyor 1, the time for parcels to slide free of surface 2 and the distance between centres of the collecting conveyors.

The width of a parcel determines the time required for it to fall clear of the surface of run 2. If a parcel being conveyed approaches a combination of open discharge doors it will be seen that before the parcel can commence to slide, the centre of gravity of the parcel must have passed the leading edge of the iirst discharge door in the combination. Thus, it is not necessary to open the doors (or the upstream door of the combination, where the doors are opened in sequence) until the centre of gravity of the average parcel is level with the leading edge of the upstream door of the combination.

The dimensions of postal parcels vary considerably but the British Postal Regulations provide that the length of a parcel shall not exceed 3'6 and that the sum of the length and the girth of the parcel shall not exceed 6. With these dimensions and a tilted band conveyor speed of 180 ft./min. the length of the combination of discharge doors for any one collecting conveyor must be not less than 38". The length of the long discharge doors except the first and last of each group can be calculated by subtracting from the distance between centres of adjacent cross conveyors the length of a short door. The length of a short door is obtained by subtracting from 38 the distance between centres of adjacent cross conveyors. Thus, if the distance between cross conveyor centres is 2'10" each short door is l0" long whilst each long door except the first and last is 2'. The length of the first and last discharge doors of each group is 2'10".

It will be appreciated that one or some of the cross conveyors may be replaced by chutes (not shown) leading to bag-filling stations (not shown) or other sorting stations.

There will be as many cross conveyors or cross conveyors and other stations as required by the lsorting procedure and in most cases there will be an additional missort cross conveyor or station (not shown), just before the twisting device 4, whose discharge doors have been omitted. This additional cross conveyor or station will thus receive any parcel which for any reason has not been ydischarged into one of the preceding cross conveyors or stations. Those parcels may be returned for re-sorting or dealt with in some other appropriate way. To make certain that no parcel reaches device 4, a ploug (not shown) maybe fitted to the tilted band adjacent the additional cross conveyor or station.

Several tilted band conveyors may be used in large installations and they usually feed cross conveyors which are common to all of the tilted band conveyors. In addition the tilted band conveyors may feed manual sorting lpositions.

A sorting installation embodying the invention may be .used to sort objects other than postal parcels. The installation could be used in factories or warehouses where objects for example apparatus, equipment, clothing, tinned goods, have to be sorted for transmission to different destinations. Further, the above described manual insertion of information regarding destinations of objects might be replaced by 'a suitable form of automatic insertion effected by scanning each object and deriving the information from an indication on the object itself.

I claim:

1. A sorting installation for sorting objects according to the destination of the objects comprising a line of discharge doors, conveying apparatus for moving the objects past the discharge doors, at least one group of collecting conveyors spaced along the length of the line of disch-arge doors with their longitudinal axes crossing the line of discharge doors, and an operating mechanism for opening and closing the doors, each collecting conveyor being allotted a unique combination of doors which controlthe discharge of objects to that particular conveyor, each combination of doors comprising one door which is individual to the combination and -at least one other door which is common to the combination and the next adjacent combination.

2. An installation as claimed in claim 1 in which each combination of doors except those of the first and last collecting conveyors of a group of collecting conveyors comprises a long door individual to the combination and two short doors of which one is common to the combination Iand to the next adjacent upstream combination and the other to the combination and the next adjacent downstream combination, the remaining combinations of doors comprising a long door and a short door individual to the combination and a short door common to the combination and the next adjacent combination.

3. An installation as claimed in claim 1 in which each combination of doors except those of the iirst and last collecting conveyors in -a group of collecting conveyors comprises a long door individual to the combination and two short doors of which one is common to the combination and to the next adjacent upstream combination and the other to the, combination and the next downstream combination, whilst the combinations of doors of the first and last collecting conveyors in a groupcomprise one long door individual to the combination and one short door common to the combination and the next adjacent combination.

4. An installation as claimed in claim 2 in which the overall length of every combination of doors is suicient to permit the discharge of the longest object for which the installation is designed, and in which the length of every short door is equal to that overall length less the distance between centres of the collecting conveyors.

5. An installation as claimed in claim 3 in which the overall length of every combination of doors is suicient to permit the discharge of the longest object for which the installation is designed, in which the length of every short door is equal to that overall length less the distance between centres of the collecting conveyors,. and in which the length of each long door in every combination of doors of first and last collecting conveyors in a group is equal to the length of a short door plus the length of the long door of a combination of doors other than a cornbination of doors of the lirst and last collecting conveyors.

6. An installation as claimed in claim 1 in which the conveying means is a tilted band conveyor to which the discharge doors are fitted to control the discharge of objects from the tilted band conveyor to a collecting conveyor.

7. An installation as claimed in claim 6 in which the tilted band conveyor is a belt conveyor part of whose forward run is supported at an angle to the horizontal, the `discharge doors being disposed along the lower edge thereof and in which there is a guide surface extending from that lower edge towards the collecting conveyors for the purpose of guiding objects discharged through the discharge doors.

8. An installation as claimed in claim 7 in which the collecting conveyors are belt conveyors having side walls to contain objects discharged onto the collecting conveyors and in which the guide surface extends to said side walls. v

9. An installation as claimed in claim 1 in which the 7 discharge doors form part of a side plate which includes fixed sections over those parts of its length where discharge doors are not tted and in which the upstream edges of all long discharge doors, except the rst one associated with each group of collecting conveyors, and the upstream edges of all xed sections except the first, are provided with extension plates extending towards the collecting conveyors to facilitate discharge of an article.

10. An installation as claimed in claim 1 in which the centre line of earch combination of doors lies slightly upstream of the longitudinal axis of the associated collecting conveyor.

References Cited UNITED STATES PATENTS Goodell et al. 214-11 Edelman 209-111.7 X

Harrison et al. 198-38 Immesberger 198-38 McWilliams 214-11 X 10 ALLEN N. KNoWLEs, Primary Examiner.