Storage device for stackable containers

Abstract

A storage device for stackable containers for conveying items, in particular items of luggage in a sorting conveyor system in an airport, includes a lifting conveyor with a container receiving device which can be guided between upper and lower conveying planes for storing at least one container. A conveyor is disposed in the upper conveyor plane for guiding storage containers to a transfer position and a discharge conveyor is disposed in the upper conveyor plane for discharging stored containers from a transfer position. A moving device moves a container from the transfer position to the empty container receiving device or to a container placed on the uppermost part of the container receiving device and moves the most upper container placed on the container receiving device to the transfer position. As a result, empty containers can be received, housed and guided back in a simple and cost effective manner.

Claims

1. A storage device for stackable containers for conveying individual items or items of luggage in a sorting conveyor system in an airport, the storage device comprising: an upper conveying plane and a lower conveying plane; a receiving position and a transfer position; a lifting conveyor having a container receiving device being movable between said upper conveying plane and said lower conveying plane, for storing at least one container; a feed conveyor disposed in said upper conveyor plane for feeding containers to be stored to said receiving position; a discharge conveyor disposed in said upper conveying plane for discharging containers from said transfer position; and a moving device for moving a container from said receiving position onto said empty container receiving device or onto a respective uppermost container deposited on said container receiving device as well as for moving the container deposited uppermost on said container receiving device to said transfer position; said moving device including a carriage configured to move parallel to said upper conveying plane, said carriage located above said container receiving device and having controllable gripper elements configured to engage and lift a container.

2. The storage device according to claim 1, which further comprises a transport device, said container receiving device having a transverse conveyor configured to transfer a stack of stored containers on said lower conveying plane between said container receiving device and said transport device.

3. The storage device according to claim 2, wherein said transport device is a reversible buffer conveyor for dynamic storage of container stacks.

4. The storage device according to claim 2, wherein said transport device is a transport vehicle for transporting container stacks between said lifting conveyor and a stationary container buffer.

5. The storage device according to claim 2, wherein said transverse conveyor is configured to transport a container between said receiving position and said transfer position on said upper conveying plane without said moving device.

6. The storage device according to claim 1, wherein the containers are reversible, said discharge conveyor is formed by said feed conveyor and said transfer position is formed by said receiving position.

7. The storage device according to claim 1, which further comprises a control device for controlling said container receiving device of said lifting conveyor by causing said container receiving device to move a container from said receiving position far enough upwards for the container gripped by said moving device to be deposited on said empty container receiving device or to be stacked on the uppermost container stored on said container receiving device.

8. The storage device according to claim 7, wherein said control device is configured to move said container receiving device upwards far enough to permit the uppermost container to be gripped by said moving device in order to move the uppermost container stored on said container receiving device to said transfer position.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) Further features and advantages of the inventive storage device emerge from the description given below, which relates to the drawings, in which, in schematic diagrams:

(2) FIG. 1 shows an inventive storage device in a side view,

(3) FIG. 2 shows the storage device from FIG. 1 in a view from above and

(4) FIG. 3-10 show the storage device from FIGS. 1 and 2 in a perspective view in different stages of the operation to store containers.

DESCRIPTION OF THE INVENTION

(5) In accordance with FIGS. 1 and 2 a storage device 1 for stackable containers 2 comprises a lifting conveyor 3 with a movable container receiving device 4 for storing at least one container 2. The container receiving device 4 is able to be moved vertically and continuously between an upper conveyor plane 5 and at least one lower conveyor plane 6 arranged below said upper plane. Arranged in the upper conveyor plane 5 are a feed conveyor 7 for feeding containers 2 to be stored to a receiving position 8 and a discharge conveyor 9 for discharging stored conveyors 2 from a transfer position 10. Likewise arranged in the upper conveyor plane 5 are a receiving conveyor 11 at the receiving position 8 and a transfer conveyor 12 at the transfer position 10, which are borne by two longitudinal supports 15 supported via a support frame 13 on a floor structure 14. The longitudinal supports 15 are aligned horizontally and in parallel to one another. The lifting conveyor 3 is arranged between the receiving position 8 and the transfer position 10 and has vertical struts 16, the lower ends of which stand on the floor structure 14 and the upper ends of which are connected to the longitudinal supports 15. The container receiving device 4 of the lifting conveyor 3 has a transverse conveyor 17, by means of which containers 2 can be accepted on the upper conveying plane 5 by the receiving conveyor 11 or can be transferred to the transfer conveyor 12. On the lower conveying planes 6only one is shown in the exemplary embodiment for reasons of clarity, but a number of lower conveying planes 6 can also be provided at different conveying levelsa lower transfer conveyor 18 is arranged, on which individual or stacked containers 2 are able to be transferred by the transverse conveyor 17 to the lower conveyor plane 6. Not shown in the diagram, but likewise able to be realized, is a further transfer conveyor on the other side of the transverse conveyor 17. Transport means embodied as a reversible buffer conveyor 19 are also arranged on the lower conveying plane 6, which are intended for dynamic storage of stacked containers 2. These can be arranged as continuation of one of the two transfer conveyors 18. Arranged on the longitudinal supports 15 is a moving device 20 for moving a container 2 on the upper conveying plane 5 between receiving position 8, lifting conveyor 3 and transfer position 10. The moving device 20 has a carriage 22 with controllable gripper elements 23 able to be moved by means of a conveyor system 21 in parallel to the upper conveying plane 5. To move a container 2, the gripper elements 23 are able to be engaged with said container, wherein the container 2 is able to be lifted and lowered again when the elements disengage. In accordance with the invention individual containers 2, which if necessary are deposited on the container receiving device 4 of the lifting conveyor 3 or are stacked one above the other, are transported in the upper conveying plane 5. If the stack of containers 2 on the container receiving device 4 has reached a predeterminable number or height, then in accordance with the invention said stack is transported in the lower conveying plane 6, in the dynamic buffer conveyor 19 or by means of transport vehicles not shown in the diagram, into a stationary container buffer.

(6) FIGS. 3 to 10 illustrate the sequence of movement of the empty containers 2 as well as the operating steps carried out for said movement by the inventive storage device 1.

(7) A container 2 separated from the conveyed item of luggage at a sorting end point of a sorting conveyor system of an airport and thus empty is fed to the storage device 1 in accordance with FIG. 3 on the upper conveying plane 5 by means of the feeder conveyor 7. If the container 2 is not to be stored, the receiving device 4 of the lifting conveyor 3 is moved upwards, so that feed conveyor 7, receiving conveyor 11, transverse conveyor 17, transfer conveyor 12 and discharge conveyor 9 are connected after one another and form an end-to-end conveyor path on the upper conveyor plane 5. In this way the empty container 2 can be transported directly from the discharge conveyor 9 in the direction of a loading point, for example in the area of luggage check-in of the airport. In this case the moving device 20 remains inactive in the receiving position 8.

(8) To store empty containers 2, for example during periods of operation in which more empty containers 2 arrive via the feed conveyor 7 than are discharged via the discharge conveyor 9, in accordance with FIG. 4 up to 10 stacks of containers 2 are formed at the container receiving device 4 of the lifting conveyor 3. At the beginning of the stack formation the empty container receiving device 4 of the lifting conveyor 3 is moved upwards, as in FIG. 3. The controller of the storage device 1 stops the container 2 in accordance with FIG. 4, when said container is transported onto the transverse conveyor 17 of the container receiving device 4. Subsequently the container receiving device 4 is transported far enough downwards by the lifting conveyor 3 for the stored container 2 in accordance with FIG. 5 to be lowered below the upper conveying plane 5.

(9) Each further fed container 2 is transported by means of the feed conveyor 7 and the receiving conveyor 11 in accordance with FIG. 6 up to the receiving position 8. There the gripper elements 23 of the moving device 20 are engaged with the further container 2, through which said container is lifted from the receiving conveyor 11. The carriage 22 of the moving device 20 is now moved up to the lifting conveyor 3, through which the further container 2 is transported in accordance with FIG. 7 to the point at which it is arranged above the first container 2 already lying on the receiving device 4. Now the lifting conveyor 3 moves the container receiving device 4 and thus the first container 2 upwards, while the gripper elements 23 of the moving device 20 are disengaged from the further container 2. In accordance with FIG. 8 the further container 2 comes to rest on the first or respectively uppermost container on the container receiving device 4. In this case the shape of the containers 2 is embodied such that these can form a stable stack when on top of one another. In order, when moving the carriage 22 back into the receiving position 8 in accordance with FIG. 9, to avoid a collision between the gripper elements 23 and the stored containers 2, in such cases neither the container receiving device 4 may be moved downwards nor may the gripper elements 23 be moved into the engagement position. In the meantime a further container 2 not shown in the diagram can already have been fed to the receiving position 8. As soon as the carriage 22 is moved out of the area of the lifting conveyor 3, the lifting conveyor 3 moves the container receiving device 4 downwards far enough for the further, now uppermost container 2 of the stack to be lowered in accordance with FIG. 10 to below the upper conveying plane 5.

(10) After a stack of for example four empty containers 2 is formed, the lifting conveyor 3 moves the container receiving device 4 in accordance with FIG. 1 down to the lower conveying plane 6. The stack of containers 2 is transferred by means of the transverse conveyor 17 and the lower transfer conveyor 19 to transport means. The transport means can be embodied as reversible buffer conveyors 19, which dynamically store stacks of conveyors 2. However the transport means can also be embodied as transport vehicles, which transport stacks of containers 2 to static container bufferssuch as to trestles.

(11) The stack of containers 2 is unstacked in the reverse order of operating steps for forming the stack and storage, only that the uppermost container 2 of the stack is moved by the moving device 20 from the container receiving device 4 to the transfer position 10 and is deposited there on the transfer conveyor 12.

(12) If the containers 2 are embodied reversibly, then in an advantageous manner the transfer conveyor 12 can be dispensed with and can be formed by the receiving conveyor 11 and the discharge conveyor 9 can be dispensed with and can be formed by the feed conveyor 7.

(13) By the inventive separation of individual containers in the upper conveying plane 5 and a number of stacked containers 2 in the lower conveying plane 6 the access to buffer conveyors 19 or container buffers is decoupled. The storage device 1 can operate in accordance with the principle by which the last container 2 deposited on the stack is that container which is taken from the stack when required. This enables movement sequences to be saved or executed in parallel. Thus it is not necessary to lift the entire stack of containers 2 for example in order to be able to insert a further container 2. The carriage 22 is already moving on into the receiving position 8 while the container receiving device 4 is being moved downwards. The performance of an inventive storage device 1 is far higher than with known devices, the costs are only insignificantly higher.

(14) By the decoupling of the individual conveying planes for individual and stacked containers 2, the buffer tracks can also be designed in accordance with the principle that the last container stack stored is that stack which will be the first withdrawn from the buffer track when required. In this case it is a great advantage that the container stacks do not have to be put back into main stream of the material flow, but only move for the period of stacking or unstacking. This leads to significant savings in energy, wear and maintenance effort, especially if the inventive solution is compared with known solutions in which buffer lines are provided for individual containers or in which individual containers circulate permanently in the conveyor system.

(15) A further advantage also lies in the fact that the inventive storage device can be used equally well for stacking and unstacking, since these processes often do not take place at the same time.

(16) Furthermore the inventive storage device is not only suitable for containers for transporting items of luggage, but for individual items of all types, i.e. also for distribution, mail and package logistics.

(17) Depending on the size of the sorting system a number of inventive storage devices 1 can be connected in parallel in order to increase the throughput performance of empty containers or stacks of containers respectively. Likewise storage devices can be connected behind one another in order to increase the storage capacity for stacks of containers. By suitable parallel connection and connection behind one another of inventive storage devices sorting conveyor systems with predetermined throughput performance and storage capacity can be designed.