Storage system

1. A storage system comprising a storage grid structure having a top rail grid upon which container handling vehicles work to store and retrieve storage containers in and from storage columns beneath the top rail grid,

wherein the storage system comprises multiple transfer rails forming a horizontal transfer rail grid arranged at a level below the top rail grid, at least one transport vehicle operating on the transfer rail grid, a picking/stocking station for picking/stocking items between a storage container and a packaging box, a dedicated transport vehicle operating between the picking/stocking station and the transfer rail grid, and an unloading/loading assembly for unloading/loading packaging boxes containing such items, the picking/stocking station is operatively connected to a transfer column of the storage grid structure, such that a storage container is transferred by the dedicated transport vehicle between the picking/stocking station and the storage column, and the transport vehicle is arranged to move upon the transfer rail grid in two perpendicular directions and comprises a carrier platform, wherein the transfer rail grid is arranged to allow access for the transport vehicle to transport one or more packaging boxes at a time between the picking/stocking station and the unloading/loading assembly.

2. A storage system according to claim 1 , wherein the carrier platform is for supporting a pallet on which the one or more packaging boxes may be arranged.

3. A storage system according to claim 1 , wherein the transport vehicle has a wheel arrangement comprising a first set of wheels enabling movement of the transport vehicle in a first direction and a second set of wheels enabling movement of the transport vehicle in a second direction perpendicular to the first direction, and each set of wheels comprises at least two pairs of wheels arranged on opposite sides of the transport vehicle.

4. A storage system according to claim 1 , wherein the carrier platform comprises a conveyor assembly arranged to move an item arranged on the carrier platform in a horizontal direction off the transport vehicle.

5. A storage system according to claim 1 , wherein the transport vehicle comprises at least two adjacently connected wheel base units upon which the carrier platform is arranged, and each wheel base unit features a wheel arrangement, wherein a first set of wheels enable movement of the transport vehicle in the first direction upon the transfer rail grid and a second set of wheels enable movement in the second direction, and each set of wheels comprises two pairs of wheels arranged on opposite sides of the wheel base unit.

6. A storage system according to claim 5 , wherein each wheel base unit has a horizontal periphery fitting within the horizontal area defined by a grid cell of the transfer rail grid.

7. A storage system according to claim 5 , wherein the transport vehicle comprises four connected wheel base units, preferably connected in a two by two configuration.

8. A storage system according to claim 1 , wherein the carrier platform has a footprint of four storage containers arranged in a two by two configuration.

9. A storage system according to claim 1 , wherein at least the transfer rails extending in one of two perpendicular directions of the transfer rail grid are dual-track rails, such that the transport vehicle may pass another transport vehicle upon an adjacent grid cell of the transfer rail grid when moving in the one direction.

10. A storage system according to claim 1 , wherein the transport vehicle comprising at least two adjacently connected wheel base units, the carrier platform supported upon the wheel base units, and each wheel base unit features a wheel arrangement having a first set of wheels enabling lateral movement of the transport vehicle in a first direction upon a rail grid and a second set of wheels enabling lateral movement of the transport vehicle in a second direction being perpendicular to the first direction.

11. A storage system according to claim 10 , wherein the carrier platform comprises a conveyor assembly able to move an item arranged on the carrier platform in a horizontal direction.

12. A method of transporting items out a storage system, comprising the steps of:

retrieving at least one item from a storage container arranged in a picking/supply station via a dedicated transport vehicle;

loading the item onto a transport vehicle from the dedicated transport vehicle;

moving the transport vehicle to a unloading/loading assembly; and

retrieving the item from the transport vehicle by use of the unloading/loading assembly,

wherein the picking/supply station is operatively connected to a storage column, such that the storage container is transferred by the dedicated transport vehicle between the picking/stocking station and the storage column.

13. A method of transporting items into a storage system, comprising the steps of:

supplying at least one item to a transport vehicle by use of a unloading/loading assembly,

moving the transport vehicle from the unloading/loading assembly to a dedicated transport vehicle,

transfer the item to the dedicated transport vehicle from the transport vehicle,

moving the dedicated transport vehicle to a picking/supply station,

retrieving the item from the dedicated transport vehicle, and

loading the item into a storage container arranged in the picking/supply station,

wherein the picking/supply station is operatively connected to a storage column, such that the storage container is transferred by the dedicated transport vehicle between the picking/supply station and the storage column.