Method of handling parcels by using shuttle carts, nesting racks, and lift trolleys having trays

A method of handling articles in a logistics center uses an unloading zone for unloading the articles arriving at the center and an article stowage zone where the articles are stored in ordered manner, nesting racks coupled to shuttle robot carts, and also trays placed on lift trolleys coupled to the shuttle robot carts, and at least one vertical tray rack for storing the trays loaded with the articles in superposed manner in the stowage zone. If an article is loaded on a nesting rack in the unloading zone, the shuttle robot cart stores the article with the nesting rack in a lower portion of the tray rack.

TECHNICAL FIELD

The invention relates to handling articles in a logistics center, and in particular handling parcels in a parcel sorting logistics center having an unloading zone for unloading the parcels arriving at the center and a parcel stowage zone where the parcels arriving at the center are stored in mutually ordered manner with a view to them leaving the center in an order following a certain sequence, e.g. for them to be delivered by a delivery person.

BACKGROUND ART

A method of handling parcels in a parcel sorting logistics center is disclosed in Patent FR 2 996 788.

In that method, the parcels are moved from the unloading zone to a stowage zone using nesting-type racks on legs, which nesting racks are coupled to shuttle robot carts and are of different formats (heights and widths) so that they are suitable for nesting together by being superposed on one another.

A plurality of nesting racks, each of which is loaded with one parcel can thus be superposed on a segment of the stowage zone, and, as a result, the segment of the stowage zone extends heightwise while occupying only a small footprint on the floor.

SUMMARY OF THE INVENTION

An object of the invention is to make the heightwise storage of the parcels in the stowage zone even denser so as to sort even more parcels at a parcel sorting logistics center.

To this end, the invention provides a method of handling articles in a logistics center having an unloading zone for unloading the articles arriving at the center and an article stowage zone where the articles arriving at the center are stored in mutually ordered manner with a view to them leaving the center in order following a certain sequence, which method consists in moving the articles from the unloading zone to the stowage zone with nesting racks coupled to shuttle robot carts, said method being characterized in that it also uses trays placed on lift trolleys coupled to the shuttle robot carts for moving the articles from the unloading zone to the stowage zone, and at least one vertical tray rack for storing the trays loaded with the articles in superposed manner in the stowage zone, in that if an article is loaded on a nesting rack in the unloading zone, the shuttle robot cart stores the article with the nesting rack in a lower portion of the tray rack, and if an article is loaded on a tray placed on a lift trolley, the shuttle robot cart stores the article with the tray above the nesting rack in an upper portion of the tray rack that is provided with horizontal runners.

The method of the invention may have the following features:the lift trolleys are actuated by shuttle robot carts in such a manner as to position the trays dynamically and heightwise in the tray rack so as to minimize the empty space between two consecutive trays; anda plurality of tray racks are used that are disposed in one or more rows in the stowage zone.

The invention also provides a logistics center for handling parcels, which logistics center comprises a loading/unloading point for loading/unloading the parcels and a stowage zone that is designed for receiving parcels waiting for loading, and that is subdivided into various segments, each of which corresponds to a shipment of said parcels, and racks on legs of the nesting type and of different formats (heights and widths) suitable for nesting by being superposed on one another, and independently self-propelled motor-driven shuttle carts suitable for docking with each rack under the control of a central processing unit, said logistics center being characterized in that it further comprises lift trolleys for carrying trays and suitable for being docked with the shuttle carts, and one or more tray racks in which nesting racks loaded with parcels are stored in the lower portion and trays loaded with parcels are stored in the upper portion, above the nesting racks.

In particular, the tray rack(s) are wheeled, and the wheeled tray rack(s) are arranged to be docked with and moved by a shuttle cart. Naturally, the invention may extend to articles other than parcels, such as baggage or the like.

DESCRIPTION OF IMPLEMENTATIONS

The invention relates generally to a method of handling articles that are, more particularly in this example, postal parcels to be sorted in a postal sorting logistics center for sorting parcels.

Without going beyond the ambit of the invention, the articles may be baggage and the logistics center may be a place for organizing loading of baggage onto an airplane, for example.

The articles could also be the result of preparing outward orders from a logistics depot, and the center could be a place designed for shipping the orders.

The following description is focused non-limitingly on handling postal parcels in a postal sorting logistics center1.

The logistics center1shown inFIGS. 1 and 2has a platform10provided with unloading and loading points3for unloading and loading the parcels2, which points are accessible to transport means, such as, for example, trucks4for bringing the parcels2and for taking them away.

In the example shown, there are three unloading points3disposed side-by-side, each combined with a loading point3.

Naturally, the unloading points3may be dissociated from the loading points3, and/or there may be a larger number of them, and/or they may be disposed in a configuration other than the configuration shown.

In particular, the platform10includes a stowage zone11designed to receive parcels2that are unloaded and that are waiting to be loaded.

This stowage zone11is subdivided into a plurality of segments12, and into two segments12in the example shown inFIGS. 1 and 2.

In accordance with the invention, nesting-type racks5, lift trolleys5′ having trays, and shuttle robot carts6are used to move the parcels from the unloading point3to the stowage zone11.

In addition, the trays50′ provided for the lift trolleys5′ are stored in one or more tray racks as shown inFIG. 9.

The center1of the invention includes a parking zone13in which empty racks5are stored. The zone13also serves to store lift trolleys5′ and trays50′ for said lift trolleys.

The racks5are shown in detail inFIGS. 5 to 8. They are on legs and of the nesting type. Each rack5has a tray50adapted in size to carry a single parcel2. The tray50is secured to a frame carried by wheels51. The frame has two vertical members52that are secured at their bottom ends to two horizontal members53that are mutually parallel and that are provided with wheels51.

The racks5are of mutually different heights and widths. In the example shown, the racks5thus have three different formats (height-width pairs): small format, medium format, and large format.

In addition, under the tray50, the frame does not have any cross-member interconnecting the vertical members52or the horizontal members53. Thus, and as shown inFIGS. 7 and 8, a rack5of small format or of medium format can fit under a rack5of medium format or of large format, under which it can be stowed.

It is thus possible to stow racks5of different formats at the same place. In the example, shown, three racks5, each having a respective one of the three formats that is different from the other two, can be stowed at the same location, nested and superposed relative to one another.

In addition, the shuttle robot carts (or motor-driven shuttle carts) described below are designed to be suitable for fitting under all of the racks5, regardless of the format of each rack5.

When they are not being stored in the parking zone13, the racks5can be waiting in the stowage zone11or be traveling around the platform10.

In the example shown, the racks5are intrinsically movable by means of their wheels51.

The shuttle carts6of the center are, for example, stored in the parking zone13with the racks5or in any other parking zone or maintenance zone. When they are not being stored, the shuttle carts6are traveling around the platform10. The width of the shuttle cart6is less than the distance between the horizontal members53of the rack5of small format.

Thus, and as shown inFIGS. 6 and 7, the shuttle cart6can fit between the horizontal members53of each rack5, regardless of whether or not said rack is carrying a parcel2, and regardless of its format.

As shown in detail inFIGS. 5 to 8, each shuttle cart6has a motor unit60carried by driven wheels61controlled by a monitoring and control central processing unit7that is described below.

The motor unit60also has arms62that are extensible laterally from the motor unit60and that are caused to be deployed by the monitoring and control central processing unit7.

Said arms62are provided with grasping means63(visible to some extent inFIG. 6) suitable for fastening onto the horizontal members53of the racks5.

These grasping means63are, for example, magnetic means that co-operate with metal horizontal members53of the racks5.

In addition, the arms62can be deployed above the horizontal members53and over a length sufficient to reach the horizontal members53of the rack5of large format. Thus, the arms62can accommodate the various widths of the racks5and can dock with a single rack5or with a plurality of racks5of different formats simultaneously. Each shuttle cart6is independently self-propelled and is provided with positioning sensors, a power supply, and a computer enabling it, in particular, to optimize its movements and to avoid collisions with obstacles and with other shuttle carts6. The shuttle carts6are individually controlled remotely by the monitoring and control central processing unit7shown diagrammatically inFIGS. 1 and 2, and operation of which is described below.

In accordance with the invention, the center further includes lift trolleys5′ that carry trays50′.FIG. 11shows such a lift trolley5′ that, in this example, comprises a frame carried by wheels51′. The frame has two vertical members52′ that are upwardly telescopic (as shown by the arrows F) and that are secured at their bottom ends to two horizontal members53′ that are mutually parallel and that are provided with wheels51′.

Each telescopic member52′ may, for example, be made up of a plurality of parallel bars that slide one in the other to generate the telescopic effect.

The free ends of the vertical members52′ are arranged to carry a removable tray50′ in flat manner. Said free ends may, for example, be designed to form a horizontal fork that passes under the tray50′.

The center1may be equipped with a plurality of lift trolleys5′ and with a multitude of trays50′ that are of the same dimension, that are interchangeable, and that may be stored in the parking zone13. As shown inFIG. 11, the horizontal members53′ of the frame of a lift trolley5′ are spaced apart from each other so that a shuttle cart6can dock with them in the same way as with a nesting rack5. The spacing between the horizontal uprights may be smaller than the spacing provided between two horizontal members53of the smallest nesting rack.

The vertical members52′ of a lift trolley5′ may be deployed by an electric or hydraulic transmission that is controlled from the shuttle cart6docking with the lift trolley.

The center1of the invention further includes an identification zone14(visible inFIG. 1) at which the unloaded parcels2are identified. The identification may be performed in contactless manner, e.g. by reading a bar code on the parcel. The bar code may be a parcel identifier that identifies the parcel and that is recorded in a memory of a database in correspondence with other information on the parcel, such as a delivery address, three-dimensional (3D) characteristics (height, width, and length), a weight, etc.

The format of the rack5carrying the parcel2may also be detected at this identification zone14, or determined earlier by any suitable means. In addition, the racks5may also be identified uniquely. The identity of each rack5, in addition to its format, may then be detected at said identification zone14.

The center1of the invention includes a monitoring and control central processing unit7suitable for supervising operation of the center1and in particular for remotely controlling the movements of the shuttle carts6. Said unit7uses the database relating to the characteristics of the parcels. The central processing unit7is also suitable for receiving information relating to identifying the racks5used, to the destinations of the parcels2, and to the positioning of each shuttle cart6. Having the movements of the shuttle carts6managed by the central processing unit7makes it possible to optimize their traffic and to avoid any collision.

The central processing unit7has a sorting plan for sorting the parcels for shipping them, which plan distributes the parcels in the stowage zone11both over the segments12and heightwise with the nesting racks and the tray racks12′.

On the basis of the sorting information collected in the identification zone14on the destinations of the unloaded parcels2, the central processing unit7organizes the stowage of the racks5in the segments12of the stowage zone11and also the superposition of the trays above the racks5in the tray rack(s)12′.

Once all of the parcels2have been stowed and sequenced in the stowage zone11, the central processing unit7organizes recovery of them following an ordered sequence so as to optimize, for example, the loading of the trucks4with a view to delivering the parcels in said ordered sequence.

The center1of the invention may include a service zone15at which the parcels2may, optionally, be weighed, labeled, or repaired. As described in detail below, the parcels2are conveyed to the service zone15by being carried by a rack5that is motor-driven by a shuttle cart6, or by a lift trolley5′ having a tray50′ and that is motor-driven by a shuttle cart6. A security inspection of the parcels2may also be performed at the service zone15.

The center1of the invention makes it possible to implement the method of handling parcels2that is described below, while optimizing the stowage in the stowage zone11, and while optimizing the loading of the parcels2in the trucks4with a view to delivering them.

The handling method of the invention starts with the arrival of a parcel2, e.g. brought by a truck4and unloaded at one of the unloading points3.

Arrival of the truck4can be detected automatically by any known means, or indicated by the handling employee, e.g. by means of a switch (not shown) provided for this purpose at the unloading point3.

As indicated byFIG. 3, the process starts at100. The parcel2is identified and its identification code is transmitted to the central processing unit7.

After this identification, the unit7detects at101whether the parcel2is a parcel of the type to be placed on a nesting rack or a parcel to be placed on a tray of a lift trolley. Other information may be retrieved such as the dimensions of the parcel (height, width, length), weight, delivery address, etc.

In accordance with the invention, the nesting racks are reserved for heavy parcels or for very voluminous parcels, e.g. having a height greater than 20 centimeters (cm). The smaller and lighter other parcels are moved by lift trolley.

In accordance with the invention, the small parcels placed on trays50′ moved by lift trolley are stored in the upper portion of a tray rack12′ as shown inFIG. 9, while the large parcels on nesting racks are stored on the floor, and possibly in the lower portion of a tray rack.

FIG. 9shows a tray rack12′ with, in the upper portion, a superposition of runners60′ that are spaced apart at a small pitch and that are without trays.FIG. 9also shows three trays50′ with three small parcels2and that are superposed in the upper portion of the tray rack12′.

It can be understood that, using a lift trolley5′, it is possible to bring a parcel2placed on a tray50′ to a desired height and to insert the tray onto the runners60′ for storage in the tray rack. Inserting the tray50′ into the rack12′ may take place by advancing the lift trolley towards the rack12′ or indeed by a telescopic effect of the fork of the lift trolley. Removing a tray50′ from the rack12may also take place by reversing the lift trolley away from the rack or indeed by a telescopic effect of the fork of the lift trolley.

In accordance with the invention, a tray rack12′ may have a height above the floor of several meters, and thus a high capacity for storing trays50′.

As shown inFIG. 9, the rack has two sides spaced apart by a distance sufficient for a nesting rack of the largest size to be inserted on the floor between said two sides. In the lower portion of the tray rack12′,FIG. 9also shows three nested nesting racks with large parcels that are superposed on one another. With this tray rack and with the nesting racks, the footprint on the floor is optimized.

At102, a nesting rack5is brought by shuttle robot cart to the unloading point3. At103, a large parcel is loaded by the operator onto the nesting rack, and, at104, the shuttle robot cart moves the nesting rack with the parcel2to the stowage zone13. This stowage zone may correspond to the lower portion of a tray rack. The location of the stowage (choice of the segment in the zone13) is computed by the unit7based on the sorting plan and on the characteristics of the parcel. Then at108the shuttle robot cart releases the nesting rack and returns, for example, to the parking zone13.

At105, a lift trolley5′ with an empty tray50′ is brought by shuttle robot cart to the unloading point. At106, a small parcel is placed by the operator on the tray50′. At107, the resulting assembly is brought by the shuttle robot cart to the stowage zone13. On the basis of the sorting plan and of the parameters of the parcel, and also of a history of the storage of the parcels in the tray racks, the shuttle robot cart6, as controlled by the unit7, actuates the lift trolley so as to present the tray50′ dynamically at a height adjusted with a view to inserting it into a rack12′, with space being optimized as a function of the parcel placed immediately below. In particular, the empty space between two trays50′ in a rack is minimized by the unit7. Then, at108, the shuttle robot cart with the lift trolley releases the tray50′ into the rack and returns to the parking zone13.

The process loops back to step100until there are no more parcels to be stowed at109.

As can be understood, the unit7keeps in a memory a distribution of the parcels in the stowage zone11, be it in the segments12or in the tray racks12′.

Once all of the parcels2have been sorted into the stowage zone11, the parcels can be retrieved from said zone and loaded into the trucks with a view to shipping them and delivering them.

The loading can be performed immediately after the process ofFIG. 3or after a waiting time. For this purpose, the central processing unit7assigns a group of shuttle carts6to loading the parcels for each destination into one or more trucks4and organizes and determines a loading sequence in step110inFIG. 4in such a manner that the trucks4are loaded in the delivery sequence for each shipment.

At111, a type of parcel for the current parcel is thus determined by the unit7(large parcel on nesting rack, or small parcel on tray).

At112, it is a large parcel. A shuttle cart takes the nesting rack and brings it to the loading point3. The operator unloads the parcel from the nesting rack at113, and at114the shuttle cart with the nesting rack returns to the parking zone13.

At115, it is a small parcel. A shuttle cart arrives in the stowage zone with a lift trolley. The tray50′ is taken hold of by the fork of the lift trolley (adjusted heightwise) with the small parcel in the rack124. The shuttle cart brings the resulting assembly to the loading point3. The operator unloads the small parcel at117and the shuttle cart goes back to the parking zone13with the lift trolley and the tray. If, at119, there are no more parcels to be loaded onto the truck(s), the process stops. Otherwise, it loops backs to step110.

With this arrangement, each time a tray with a parcel is inserted into a rack, the unit7is suitable for dynamically adjusting the height at which the tray is inserted in order to leave as little space as possible between said tray and the adjacent tray below in the rack. The tray racks may be disposed in rows, i.e. one row per segment. It is possible to have a plurality of rack aisles and also segments without tray racks depending on the particular features of the parcel sorting to be performed. But it can be understood that with this arrangement a high density of vertical storage is obtained for storing the parcels. The tray racks may be wheeled, i.e. they may have wheels like the nesting racks or the lift trolleys. The tray racks may be designed to be docked and moved by the shuttle robot carts, so that any placement in the stowage zone11of the logistics center can be performed by the shuttle robot carts. It is possible for the stowage zone to be reconfigured automatically.

Naturally, the present invention is in no way limited to the above description of one of its implementations, which can undergo modifications without going beyond the ambit of the invention.