Technical field

The present invention concerns a bin lift arrangement in a bin storage system.

Background

The Applicant's already known AutoStore system is a storage system comprising a three-dimensional storage grid structure wherein storage bins are stacked on top of each other to a certain height. Such a prior art system is shown in fig. 1. The storage system 10 comprises a grid structure 20 constructed as aluminium columns interconnected by top rails. Between the columns, vertical compartments are defined, in which the storage bins 30 may be stacked vertically above each other. A number of vehicles 40, or robot vehicles, are arranged on the top rails and may move horizontally on top of the storage grid. Each vehicle is equipped with a lift for picking up, carrying, and placing storage bins 30 that are stored in the storage grid.

The system also comprises picking and/or supply stations 60, where one or several product items are picked out from the storage bin 30 or where one or several product items are filled into the storage bin 30. When a product item stored in a storage bin is to be picked from the storage grid, the robot vehicle is arranged to pick up the storage bin containing that product type and then transport it to a bin lift device 50. The bin lift device is transporting the storage bin to the picking and/or supply station 60, where the item of the product type is retrieved from the storage bin. The storage bin with the remaining product items is thereafter returned to the storage grid by means of a bin lift device and a robot vehicle.

The same procedure is used for supplying product items into the storage grid. First, items are supplied into a storage bin at a picking and/or supply station. The bin lift device is then lifting the storage bin up to the upper level where a robot vehicle is transporting the storage bin into its correct position within the storage grid.

A storage control and communication system is used to monitor inventory, to keep track of the location of respective storage bins (within storage grid and/or during transport), the content of each storage bins etc. Further, the storage control and communication system may also comprise, or may be provided in communication with, a control system for controlling the robot vehicles to pick a desired storage bin and to deliver it at the desired location at the desired time - without colliding with other vehicles. It has been found that relatively long time is used by the storage system to transport storage bins from the top of the grid and to the picking and/or supply stations. In addition, in the system of fig. 1, a single bin lift device is used for transport of the storage bin, both from the top level of the storage grid to the picking and/or supply station as well as from the picking and/or supply station to the top level. This solution put restrictions on the speed at which storage bins may be transported to and from the storage grid and the picking/supply station. For example, a vehicle 40 will have to postpone loading a second storage bin into the bin lift device 50 until the operator is finished with the present storage bin and it is returned to the top level. Hence, the operating time of the vehicle is not as efficient as possible.

The present invention provides a more time efficient storage system. Another object is to improve the ergonomic operation of the picking and/or supply station.

Summary of the invention

The present invention is defined by the appended claims and in the following:

In a first aspect, the present invention provides a picking/supply station assembly for a storage system, the storage system comprising a grid structure of storage columns having a top level, each storage column being arranged to accommodate a vertical stack of storage bins, at least one vehicle arranged to move horizontally at the top level of the grid structure and able to retrieve a storage bin from a storage cell at the top level of the grid structure and to deliver the storage bin to the picking/supply station assembly, wherein the picking/supply station assembly comprises a first bin lift device, a second bin lift device and a picking/supply station, wherein the first bin lift device is arrangeable to receive a storage bin from the at least one vehicle at the top level of the grid structure and deliver the storage bin to the picking/supply station;

the picking/supply station comprises a bin transport assembly arranged to move the storage bin from the first bin lift device to the second bin lift device; and

the second bin lift device is arranged to receive the storage bin from the bin transport assembly and is arrangeable to convey the storage bin to the top level of the grid structure.

In an embodiment of the picking/supply station assembly, the bin transport assembly comprises a conveyor system operably connected to the first bin lift device and the second bin lift device. The conveyor system arranged to move a storage bin in a substantially horizontal direction between the first and the second bin lift device.

In an embodiment of the picking/supply station assembly, the conveyor system comprises multiple conveyor units arranged to transport a storage bin from the first bin lift device to the second bin lift device via the picking/supply station. The multiple conveyor units are arranged adjacent to each other, such that a storage bin may be transferred from one conveyor unit to an adjacent conveyor unit.

Preferably, each conveyor unit is arranged to accommodate a single storage bin on top. Each conveyor unit may comprise any suitable arrangement of belt(s), chain(s) and/or rollers well known in the art of conveyor systems.

In an embodiment of the picking/supply station assembly, a conveyor unit is arranged in each of the first bin lift device and the second bin lift device, and the conveyor unit in the first bin lift device is able to transport a storage bin out of the first bin lift device, and the conveyor unit in the second bin lift device is able to transport a storage bin into the second bin lift device. The conveyor units of the first bin lift device and the second bin lift device are at the same level. In an embodiment of the picking/supply station assembly, the picking/supply station comprises a work surface arranged above the bin transport assembly and/or the conveyor system, the work surface having at least one picking/supply opening allowing access to a storage bin arranged on the bin transport assembly and/or the conveyor system. Preferably, the bin transport assembly and/or the conveyor system comprises a conveyor unit arranged below the at least one opening. In a further embodiment, the work surface, and at least the conveyor unit arranged below the opening, is inclined in a direction towards an operator. In a further embodiment, the work surface comprises at least two picking/supply openings. In an embodiment of the picking/supply station assembly, the picking/supply station comprises sidewalls enclosing the bin transport assembly and/or the conveyor system, such that a storage bin may only be accessed via the at least one

picking/supply opening in the work surface, during use. In an embodiment of the picking/supply station assembly, the bin transport assembly and/or conveyor system comprises a weighing cell for weighing a storage bin. The weighing cell is preferably arranged below the at least one picking/supply opening in the work surface. The weighing cell is preferably connected to a single conveyor unit. In an embodiment of the picking/supply station assembly, the picking/supply station comprises a height adjustment system arranged such that the height of the work surface and/or the level of a storage bin arranged below the work surface, may be adjusted.

In an embodiment of the picking/supply station assembly, the first bin lift device comprises a first lower storage bin port for delivery of the storage bin to the picking/supply station, and the second bin lift device comprises a second lower storage bin port for receiving the storage bin from the bin transport assembly.

In an embodiment of the picking/supply station assembly, the first lower storage bin port and the second lower storage bin port face each other; preferably, the bin transport assembly comprises at least three conveyor units, each conveyor unit having a horizontal upper surface. Having the lower storage bin ports facing each other provides a picking/supply station assembly having a minimal space requirement. Further, the picking/supply station assembly may be integrated in a vertical side wall of a storage system without changing the footprint of the storage system or storage system grid. These effects are particularly important when a storage system is installed in a space restricted location, since it allows for a maximum size of an installed storage system grid.

In an embodiment of the picking/supply station assembly, the first lower storage bin port and the second lower storage bin port face in the same direction, and the bin transport assembly comprises a linear conveyor system comprising at least three conveyor units having an upper surface inclined in the direction which the lower storage bin ports face; the conveyor units are adjacent, e.g. a first, a second (or middle) and a third conveyor unit, each conveyor unit having an upper surface inclined in the direction which the lower storage bin ports face. The at least three adjacent conveyor units are arranged in a direction being perpendicular to the direction in which the first lower storage bin port and the second lower storage bin port face. The first conveyor unit arranged to receive a storage bin from the first lower storage bin port, optionally via a conveyor unit having a horizontal upper surface, and the second conveyor unit arranged to move a storage bin to the second lower storage bin port, optionally via a conveyor unit having a horizontal upper surface. Preferably, the first and third conveyor unit are conveyor crosses able to change the transport direction of a storage bin from a first direction in which the first lower storage bin port and the second lower storage bin port face to a second direction being perpendicular to the first direction. Having the lower storage bin ports facing in the same direction allows for a simple construction of a

picking/supply station assembly with improved ergonomics for an operator. In an embodiment of the picking/supply station assembly, each of the first bin lift device and the second bin lift device comprises two parallel storage bin lifting arms, which may move in a vertical direction between the top level of the storage system and a lowermost position, the lowermost position being at a level below a conveyor unit arranged in each of the first bin lift device and the second bin lift device, and the two parallel storage bin lifting arms are arranged at a distance from each other larger than the width of the conveyor unit, such that the storage bin lifting arms may pass the conveyor unit while a storage bin. If a storage bin is arranged on the storage bin lifting arms when passing a conveyor unit in a downwards direction, the storage bin is transferred to the conveyor unit.

In a second aspect, the present invention provides a storage system comprising a picking/supply station assembly according to any of the embodiments of the first aspect, the storage system comprising a grid structure of storage columns having a top level, each storage column being arranged to accommodate a vertical stack of storage bins, at least one vehicle arranged to move horizontally at the top level of the grid structure and able to retrieve a storage bin from a storage column at the top level of the grid structure and to deliver the storage bin to the picking/supply station assembly. Preferably, the first bin lift device and the second bin lift device is integrated in the grid structure of storage columns, i.e. each bin lift device occupies a space substantially equivalent to a storage column.

In a third aspect, the present invention provides a method of transferring an item to and from a storage system featuring a grid structure of storage columns having a top level, each storage column arranged to accommodate a vertical stack of storage bins, comprising the steps of: retrieving a selected storage bin at the top level of the storage system; delivering the storage bin to a top section of a first bin lift device arranged at the top level;

lowering the storage bin towards a picking/supply station using the first bin lift device;

moving the storage bin from the first bin lift device to a picking/supply position of the picking/supply station by using a bin transport assembly; - transferring the item to or from the storage bin;

moving the storage bin from the picking/supply position to a second bin lift device;

lifting the storage bin to a top section of the second bin lift device;

retrieving the storage bin from the top section of the second bin lift device for storage in the storage grid. In an embodiment of the method, the bin transport assembly comprises a conveyor system for moving the storage bin to and from the picking/supply position.

In further embodiments of the method, the first bin lift device, the second bin lift device, the picking/supply station and the bin transport assembly may

advantageously comprise any of the technical features defined in relation to the first and second aspect of the invention.

Short description of the drawings

Embodiments of the present invention are described in detail by reference to the following drawings:

Fig. 1 is a perspective view of a prior art storage system.

Fig. 2 is a perspective view and a side view of a first embodiment of a

picking/supply station assembly according to the invention.

Fig. 3 is a cross-sectional front view of the picking/supply station assembly in fig. 2.

Fig. 4 is a cross-sectional view top view of the picking/supply station assembly in fig. 2. Fig. 5a is a front view of a second embodiment of a picking/supply station assembly according to the invention.

Fig. 5b is a cross-sectional side view of the picking/supply station assembly in fig. 5a.

Fig. 6 is a cross-sectional side view of the picking/supply station assembly in fig. 5a.

Fig. 7 is a cross-sectional front view of the picking/supply station assembly in fig. 5a.

Fig. 8 are perspective views of details of the bin lift device used in the

picking/supply station assembly.

Detailed description of the invention As discussed in the background section, the prior art storage system 10 shown in fig. 1 comprises a grid structure of storage columns 80, each storage column arranged to accommodate a vertical stack of storage bins 30. The grid structure has a top level 20.

A first vehicle 40 is arranged to move at the top level 20 of the grid structure and to receive a storage bin 30 from a storage column at the top level 20. A plurality of such vehicles may be arranged on the top level 20 of the grid structure.

At least one bin lift device 50 is arranged in the system to receive a storage bin from a vehicle at the top level 20 and to convey the bin down in a vertical direction to a supply/picking station 60 arranged at the ground floor in the building wherein the storage system is installed. The supply/picking station 60 may also receive storage bins from the operator and deliver them to the bin lift device 50 for return to the top level and further storage in a storage column 80. A first embodiment of a novel supply/picking station assembly suitable for the above discussed storage system 10 is shown in fig. 2. For illustrative purposes, the supply/picking assembly is depicted separate from the storage system 10. The picking/supply station assembly 1 comprises a first bin lift device 2, a second bin lift device 3 and a picking/supply station 18. In use, the first bin lift device 2 is arranged such that it may receive a storage bin 30 from a vehicle 40 at the top level 20 of the grid structure of a storage system 10 and deliver the storage bin to the picking/supply station 18. The picking/supply station 18 features a bin transport assembly 4 arranged to move the storage bin from the first bin lift device 2 to the second bin lift device 3. The second bin lift device 3 is arranged to receive the storage bin from the bin transport assembly 4 and deliver it to the top level of the grid structure. The first and the second bin lift devices comprise a top section 16, 17 at which a storage bin may be received from, or retrieved by, a vehicle 40 at the top level 20. The bin lift devices feature a pair of lifting arms 21 which may move in a vertical direction between the top level of the storage system and the picking/supply station. An expanded drawing of the lifting arms and the rail system 22 on which they travel are shown in fig. 8. Each of the bin lift devices features a lower port 8,9 (i.e. a first and second lower storage bin port) or opening for delivery or supply of the storage bin to the bin transport assembly 4. In the first embodiment the lower ports are facing each other, and the bin transport assembly comprises a linear conveyor system 5. The conveyor system features multiple conveyor units 19a-f. The conveyor units are preferably belt or chain conveyors. A first conveyor unit 19a is arranged in the first bin lift device 2 to move or transport a retrieved storage bin out of the lower port 8. In use, a first storage bin is initially placed on the lifting arms 21 at the top level of the grid and lowered towards the first conveyor unit. The space between the lifting arms are wide enough to allow the first conveyor unit 19a to pass between them. During passing, the first storage bin will remain on the first conveyor unit, while the lifting arms enters their lowermost position. The first storage bin is then transported out of the first lifting device by the first conveyor unit. After exit of the first storage bin from the first bin lift device, the lifting arms may return to the top level for retrieving a second storage bin.

The first storage bin exiting the first bin lift device is then transported via a second and third conveyor unit 19b,c to an opening 12 in the work surface 1 1 of the picking/supply station 18 and an operator may then pick/supply the desired item(s) from the bin. The fourth conveyor unit 19d which is arranged below the opening 12 features, or is connected to, a weighing cell 14 (not shown in this embodiment, see fig. 7 wherein a weighing cell is depicted in connection with a fifth conveyor unit 19e). When the operator is finished with the first storage bin, it is transported via the fifth conveyor unit 19e and onto the sixth conveyor unit 19f arranged in the second bin lift device 3. The second bin lift device may then lift the first storage bin to the top level, wherein a vehicle may retrieve it for storage in the grid. Since the lower ports 8,9 are facing each other, and are interconnected by a linear conveyor system 5, the picking/supply station 18 has a minimal space requirement and may also be integrated in a vertical side wall of the grid structure of a storage system without changing the footprint/periphery 70 of the grid structure. This is particularly important when a storage system is installed in a space restricted location, since it allows for a maximum size of the grid structure of an installed storage system. The disclosed first embodiment may be integrated in a side wall of the grid structure of a prior art storage system as disclosed above, wherein it will occupy the space substantially equivalent to six adjacent storage columns, i.e. the footprint 70 of the storage system is not increased by presence of the picking/supply station. The exact space requirement of the first embodiment is somewhat higher due to the bin lift drive systems 23. A storage column arranged above one of the bin lift drive systems will have a slightly reduced storage capacity, e.g. two or three storage bins less than the remaining storage columns A second embodiment of a picking/supply station according to the invention is shown in figs. 5-7. In this embodiment, the lower ports 8,9 of the first and the second bin lift device do not face each other, but are arranged in the same direction. Consequently, the bin transport assembly 4 may not be a simply linear or straight conveyor system 5 as in the embodiment in figs. 2-4.

As in the first embodiment, the picking/supply station assembly 1 comprises a first bin lift device 2, a second bin lift device 3 and a picking/supply station 18. In use, the bin lift devices are arranged in connection with a storage system 10 as described for the first embodiment. Each of the bin lift devices features a lower port 8,9 or opening for delivery or supply of the storage bin to the bin transport assembly 4. In the second embodiment, the lower ports are facing in the same direction and the bin transport assembly comprises a conveyor system 5, wherein the direction of the storage bins are changed twice to allow the storage bins to exit the first bin lift device and enter the second bin lift device. The conveyor system features nine conveyor units 19a-i (19h-i are not shown in the figs.) to allow for the transport of the storage bins. The conveyor units are preferably belt or chain conveyors. A first conveyor unit 19a is arranged in the first bin lift device 2 to move or transport a retrieved storage bin out of the lower port 8. In use, a first storage bin is initially placed on the lifting arms 21 at the top level of the grid and lowered towards the first conveyor unit. The space between the lifting arms are wide enough to allow the first conveyor unit 19a to pass between them. During passing, the first storage bin is transferred onto the first conveyor unit, while the lifting arms enters their

lowermost position. The first storage bin is then transported out of the first lifting device by the first conveyor unit 19a. After exit of the first storage bin from the first bin lift device, the lifting arms may return to the top level for retrieving a second storage bin.

The first storage bin exiting the first bin lift device 2 is initially transported in the direction which the lower port is facing via a second and third conveyor unit 19b,c. The third conveyor unit 19c being slightly inclined in a downward direction from the level of the lower port of the first bin lift device or from the level of the second conveyor unit 19a. The position at which the third conveyor unit 19c is arranged comprises a fourth conveyor unit 19d, arranged crosswise to the third conveyor unit. The fourth conveyor unit is able to transport the storage bin in a direction transverse to the initial direction of the storage bin (i.e. the third and fourth conveyor unit constitutes a conveyor cross allowing for a change of transport direction) by lowering or rising the third conveyor unit relative the fourth conveyor unit, such that the fourth conveyor unit is in contact with the storage bin. The first storage bin is then transported via the fourth conveyor unit 19d and a fifth conveyor unit 19e to an opening 12 in the work surface 11 of the picking/supply station 18. An operator may then pick/ supply the desired item(s) from the bin. The fifth conveyor unit 19e which is arranged below the opening 12 features a weighing cell 14. When the operator is finished with the first storage bin, it is transported via a conveyor cross, comprising a sixth conveyor unit 19f and a seventh conveyor unit 19g allowing for a change of direction towards the second bin lift device 3. The third to the seventh conveyor unit are similarly inclined. The inclination provides an improved ergonomic design of the picking/supply station. An eighth and ninth conveyor unit 19h,i (not shown, but corresponding to the first and second conveyor unit moving in the opposite direction) transports the first storage bin into the second bin lift device. The second bin lift device may then lift the first storage bin to the top level, wherein a vehicle may retrieve it for storage in the grid.

Having the lower ports facing in the same direction allows for a simple construction of a picking/supply station assembly with improved operator ergonomics. The inclination/tilting of the storage bins is obtained without the use of any type of tilting mechanism. The disclosed second embodiment may be integrated in a side wall/section of the grid structure of a prior art storage system as disclosed above, wherein it will occupy the space substantially equivalent to two storage columns. The exact space requirement of the two bin lift devices is somewhat higher due to the bin lift drive systems 23. A storage column arranged above one of the bin lift drive systems will have a slightly reduced storage capacity, e.g. two or three storage bins less than the remaining storage columns. Both embodiments may advantageously comprise means for adjusting the height of the opening/work surface, as well as the storage bin arranged below said opening. This may for instance be obtained by having a height adjustment means connected to the conveyor unit below the opening 12, i.e. for adjusting the height of the fourth conveyor unit 19d in the first embodiment or of the fifth conveyor unit 19e in the second embodiment.

The present invention provides numerous advantages in view of the prior art, in addition to the advantages disclosed above. Due to the use of two separate bin lift devices 2,3, one dedicated to deliver and one dedicated to retrieve storage bins to the picking/supply station 18, the present picking/supply station assembly provides a system wherein the vehicles of the storage system and the bin lifts are more efficiently utilized. In addition, the use of multiple separate conveyor units 19 contributes to the efficiency as they allow for queuing/buffering of multiple storage bins 30 in the picking/supply station. Further, the picking/supply station assembly provides an improvement to the work environment as the risk of an operator getting squeezed or trapped between the storage bin and parts of the lifting device or picking/supply station is eliminated.