GB2113633A - An article (e.g. packet) sorting system - Google Patents

Abstract

The system comprises an endless looped track including parallel sidings defining loading bays (300, 301) and further parallel sidings each defining a plurality of serially arranged unloading positions (302, 303, 304, 305). Vehicles for carrying the articles to be sorted travel around the track under computer control, and each vehicle carries onboard means for routing it at track junctions so that it will travel from a loading bay to a selected unloading position in accordance with address instructions supplied when the article is placed in the vehicle at the loading bay. Each vehicle (Fig. 2) may comprise a bin 3 hanging from a wheeled trolley 6 which has a traction motor 7 supplied from distribution rails via collector shoes 12, 13. <IMAGE>

Description

SPECIFICATION Packet sorting proposal INTRODUCTION The present invention is a proposal, submitted in confidence by Flyda Limited, to Plessey Controls Limited, with a view to its joint submission to the Post Office for packet sorting.

Flyda was founded to promote and research automatic passenger transport. A favourable DOI supported feasibility study by UMIST (1979-1980) has led to an ongoing Total Programme there, with promotion assisted by both the DOI and the Department of Transport. Before long it should be seen at British airports and in London. The present proposal is the result of simplification of previous proposals and offers the Post Office a comparatively cheap and technically ideal solution.

DESCRIPTION The following is a description of features of the invention, reference being made to Figs. 1 to 1 4 of the accompanying drawings.

Figure 1 is a front elevation of a packet conveyor, trolley and bin.

Figure 2 is a corresponding transverse section.

Fig. 2 shows the right hand extremity of a tabie 1, upon which packet, not shown, rests while an operator keys in an address extract on a digital unit 2. It is checked against a visual display and the packet placed in a bin 3. Operation of a start button, not shown, moves on the trolley and moves in an empty one. The bin hangs from bearings at 4 and 5, from a wheeled trolley 6.

The trolley 6 comprises a traction motor 7, driven wheels 8 and 9 and trailing wheels 10 and 11. Mains power is supplied by distribution rails each side, through collector shoes 12 and 13.

Support wheels for the trolley run on formed sections 1 4 and 15, carried by frames such as 16, themselves suspended from light beam 1 7. Bins may be provided with doors 31 and 32, electrically released to direct the packet to an outlet upon the correct side of the pitch line. They may subsequently be closed electrically.

A two throw crankshaft 1 8 passes right through the trolley, mounting wheels 1 9 and 20. It is used for routing. Two guide wheel assemblies, axes 21-22 and 23-24 mount horizontal guide wheels, such as 25 and 26, which are offset so that each bears upon one side of the track. The rods mounting them may conveniently be used to suspend the bin.

Communication with the trolley is by wire 27 and inductive pickup 28. In addition, an induction proximity detector 29 detects special holes in the vertical wall of the track, such as that at 30. Such holes are used to indicate the position of the trolley and are designated position markets.

TRACK SELECTION Figures 3 to 5 are diagrammatic end elevations of the trolley and track.

Fig. 4 is the normal position. The trolley is supported from both sides and guided by both horizontal guide wheels. The two throw crankshaft 200 is idle.

Fig. 3 represents the conditions for branching left. The crankshaft has been actuated so that the wheels 201 and 202 engage special vertical guide surfaces, as shown. These are present only in the vicinity of junctions. The horizontal guide wheels force the trolley to the left, and the upper wheel produces one part of a couple which keeps it upright.

Fig. 5 shows the corresponding condition for branching right.

COMPOUND SWITCHING The crankshaft may be operated by an onboard solenoid or pushed bodily by a track mounted guide blade.

Figure 6 shows the on-board solenoid 203, acting through a rocker 204 and a special crank. Only enough friction is present to hold the crankshaft in place after actuation.

Figure 7 shows the alternative means of actuation, when the wheel 201 is engaged by a shaped guide blade mounted directly above the trolley. Blade 205 may be fixed or movable. 206 represents the subsequent position of wheel 201. 228 and 229 are stops.

TURNSTILE Figure 8 is a plan of a star wheel mounted horizontally beside the track, at loading stations. Its spokes engage the lower part of the crankshaft, represented in section by the circle 207.

POWER COLLECTORS Figure 9 is a section through the distribution rail assembly, with an end elevation of the collector shoe. The scale is approximately full size, and the arrow 208 is vertical.

Figure 11 is a side elevation of the collector shoe, from the side of the carbons.

Figure 10 is a view corresponding to Fig. 9, at a "funnel".

Distribution rails 209-211 are engaged by carbons 212-214, which provide three point contact. The weight is carried by carbons 21 5 and 216 engaging earth rail 217, and it is lightly loaded downwards by carbon 218 which engages signal rail 219.

One shoe necessarily leaves the rails at junctions: it is subsequently restored by special funnels, Fig. 10.

In order to protect the carbons, splines on the funnel first engage corresponding splines on the shoe, as shown. Funnel splines 220-223: shoe splines 224-227.

Figures 12 and 13 are plan views showing track pitch lines for a representative installation comprising seven parallel loading stations on line 100-101 and representing 500 outlets situated on both sides of the single eliptical track shown in Fig. 1 3.

Trolleys operate in semi-permanently coupled trains of ten. All have track selection crankshafts and position marker counters.

Also on-board memories operated by address extract keys. The leading trolley has power.

On approaching the sidings, each train is normally switched along line 106 and thence into that loading station where it is most required, by the system computer. They queue between lines 102-103 and 100-1 01, being fed past turnstiles at the loading stations. The track slopes downwards between lines 102-103 and 104-105, to keep traffic closed up.

They queue once more on line 104-105, and are restarted in turn by the system computer, in order to avoid collision. When the operator keys the address extract, this is converted into a number and a symbol representing left or right. These are communicated to the trolley. In passing around the track, each outlet is associated with a position marker, and each vehicle counts these, releasing the door to dump its packet at the appropriate place.

NOTES ON FIGURES 12 and 13.

These approximate to the existing layout, and capacity is limited by the rate at which packets can be discharged from moving vehicles.

Master vehicles have induction motors (online starting) operating at much below rated power and consequently at nearly synchronous speeds. Power frequency and voltage are reduced near loading stations.

For switching, guide blades may be used c.g. at 107, 108 and 109, but at turnouts to loading stations (from 106) on-board solenoids are used. This is proposed as follows: When the address extract is keyed in, each vehicle receives and memorises its delivery commands e.g. "1 35th outlet, right" and then counts the position markers. Master vehicles are identifiable and the system computer governs their entry into loading bays.

Slave vehicles follow their masters.

The power rails are divided so that, once the train is clear of the main line (106), the master vehicle receives reduced frequency for braking. It is then released and coats, downhill, until establishing contact with the leading train. As each vehicle passes the turnstile, both it and the next one moving in receive a traction impulse to move them smartly.

When the last vehicle of each train passes the turnstile, the train coasts under gravity into a hinged boom on the line 104-105.

This boom is automatically raised when restarting.

The computer retains counts of vehicle waiting to load, and may confirm this by interrogation.

When shut down, single phase power could retain memories. Alternatively, all loaded vehicles could first discharge their loads. For storage, they could recirculate, being directed (empty) into loading bays, by the system computer.

Figure 14 is a plan showing track pitch lines for a representative installation comprising ten parallel loading stations on line 300-301 and 500 outlets situated on both sides of ten parallel outlet sidings, between lines 302-303 and 304-305.

Trolleys operate individually. All have traction motors, track selection crankshafts, position marker counters and on-board memories operated by address extract keys. On approaching the sidings, each vehicle is normally switched along the line 306, and thence into that loading station where it is most required, by the system computer. They queue between the lines 307-308 and 300-301, being fed past turnstiles at the loading stations. The track slopes downwards between lines 307-308 and 309-310, to keep traffic closed up.

Most routing is preset, but each vehicle counts position markers for the turnouts leading to the outlets, and selects the right one in accordance with its address extract. It then continues to count position markers corresponding to individual outlets, and drops its load at a station, and to a side, indicated by instructions associated with the address extract.

The track slopes downwards from line 304-305 to line 311-31 2, in order to keep closed up queues of vehicles which form on line 311-312. Such whole queues are started in turn by the system computer, in order to avoid collisions.

Optionally, ascending helices such as 313-314-315-316 lead to upper floor levels. On such upper levels, the track system between lines 300-301 and 306 is reproduced. Either, such traffic may return by junctions such as those on line 317-318, with all loading stations on the lower level, or additional loading levels may be provided on other floors, with suitable intercommunication to distribute trolleys.

322 is a trolley maintenance siding.

NOTES ON FIGURE 14 The layout of Fig. 14 makes full use of the Flyda potential, and limitless variants are possible within the concept represented.

Parallel outlet sidings enable packets to be discharged at an increased total rate, while reducing the speed of vehicles while it is taking place.

A key feature is the availability of suitable very small induction motors (e.g. Parvalux).

These notes supplement those concerning Figs. 12 and 13.

Preset routing is by guide blades, which may or may not be movable.

Hinged booms are provided on lines 309-310, 311-312, to form queues. Additional booms are provided on lines 323-324 and 319-320, in order to prevent stragglers joining a queue while it is moving off.

By-passes are provided at 325 (in case excessive traffic is routed to one siding) and at 321, (to return such traffic without re-loading). The by-passes are implemented by guide blades.

Claims (27)

1. An article sorting system comprising a track, at least one article-carrying vehicle traversing the track, at least two parallel loading bays and two serial unloading positions on the track, the track including junctions whereby a vehicle may be selectively routed to a particular loading bay or unloading position, and means on-board each vehicle for routing the vehicle at said junctions to cause it to travel to a selected loading bay or unloading position.

2. An article sorting system according to claim 1, wherein each vehicle carries on-board means for detecting when it has reached a selected unloading position.

3. An article sorting system according to claim 2, wherein there are provided fixed trackside position indicators and each vehicle is provided with a proximity detector for detecting said indicators and thus indicating the position of the vehicle.

4. An article sorting system according to any of claims 1 to 3, wherein said on-board routing means comprise a guide wheel movably mounted on the vehicle for selective actuation to engage either of two alternative fixed guide surfaces.

5. An article sorting system according to claim 4, wherein said guide wheel is actuated by an on-board solenoid.

6. An article sorting system according to claim 4 or claim 5, wherein said guide wheel is actuated by a trackside mounted guide blade.

7. An article sorting system according to any of the preceding claims, wherein each loading bay includes a movable trackside member engageable with a part of a vehicle, whereby each vehicle may be stopped at the loading bay, by engagement of said trackside member with the vehicle, and released when required.

8. An article sorting system according to claim 7, wherein said movable trackside member comprises a boom which may be extended across the track to restrain a vehicle.

9. An article sorting system according to claim 7 or claim 8, wherein the track is inclined downwardly towards said movable trackside member, whereby vehicles may coast into engagement with said member or another vehicle previously restrained by said member.

10. An article sorting system according to any of the preceding claims, wherein electrical power is supplied to each vehicle by means of on-board collection shoes co-operating with fixed trackside power lines, and wherein each collection shoe is provided with splines which co-operate with fixed surfaces at each junction in a manner to guide the operative portions of the collection shoe into contact with the power line, so as to protect said operative portions against impact.

11. An article sorting system according to any of the preceding claims, wherein there are provided a plurality of groups of vehicles, each group traversing the track as a semipermanently coupled train.

1 2. An article sorting system according to any of the preceding claims, wherein means are provided for counting the number of vehicles at each loading bay and automatically routing a vehicle to a selected bay in accordance with the requirements for vehicles at the different bays.

1 3. An article sorting system according to any of the preceding claims, wherein means are provided for forming a queue of vehicles at a loading bay whereby the vehicles are successively available for loading.

1 4. An article sorting system according to any of the preceding claims, wherein means are provided for forming a queue of vehicles which have left a loading bay, and before the vehicles pass on to a main portion of the track, whereby the vehicles may be successively passed on to the main portion of the track at selected intervals to prevent interference with vehicles already on the main portion of the track.

1 5. An article sorting system according to any of the preceding claims, comprising means for providing each vehicle, at a loading bay, with an address extract indicative of the unloading position to which the vehicle is to travel, the address extract embodying symbols representing instructions for selectively routing the vehicle at junctions to be traversed between the loading bay and unloading position.

16. An article sorting system according to any of the preceding claims, wherein each vehicle includes a container for articles, the container having an access opening, at least one article discharging door, and means for opening the discharging door.

1 7. An article sorting system according to claim 16, wherein the container has a plurality of article discharging doors selectively openable according to the relative position of the vehicle and an unloading position at which the vehicle is to discharge an article.

1 8. An article sorting system according to claim 1 6 or claim 17, wherein the means for opening the discharge door at an unloading position is under the control of means for sensing the location of the vehicle by detecting fixed trackside markers, so that the door is opened at a preselected unloading position.

1 9. An article sorting system according to any of the preceding claims, wherein means are provided for feeding to a central computer information regarding the identity and location of vehicles, said computer controlling the entry of vehicles into loading bays in accordance with a desired maximum number of vehicles in each bay at a given time.

20. An article sorting system according to claim 19, wherein the computer retains counts of the numbers of vehicles waiting to be loaded.

21. An article sorting system according to claim 1 9 or claim 20, wherein the computer instructs unloaded vehicles to circulate on the track if all loading bays have their full complement of vehicles.

22. An article sorting system according to any of the preceding claims, wherein the track includes a plurality of parallel outlet sidings.

23. An article sorting system according to any of the preceding claims, wherein each vehicle has a tractor motor and can travel over the track independently of other vehicles.

24. An article sorting system according to any of the preceding claims, wherein the routing of vehicles at at least certain junctions of the track is preset.

25. An article sorting system according to any of the preceding claims, wherein the track includes track portions at different levels, further track portions being provided for travel of vehicles between said levels.

26. An article sorting system according to any of the preceding claims, wherein bypasses on the track are implemented by trackside-mounted guide blades.

27. An article sorting system substantially as hereinbefore described with reference to the accompanying drawings.