Patent Description:
The members <NUM>, <NUM> may typically be made of metal, e.g. extruded aluminium profiles.

The framework structure <NUM> of the automated storage and retrieval system <NUM> comprises a rail system <NUM> arranged in a grid pattern (i.e. a rail grid) across the top of framework structure <NUM>, on which rail system <NUM> a plurality of container handling vehicles <NUM>,<NUM> are operated to raise storage containers <NUM> from, and lower storage containers <NUM> into, the storage columns <NUM>, and also to transport the storage containers <NUM> above the storage columns <NUM>. The horizontal extent of one of the grid cells <NUM> constituting the grid pattern is marked by thick lines.

The rail system <NUM> (or rail grid) comprises a first set of parallel rails <NUM> arranged to guide movement of the container handling vehicles <NUM>,<NUM> in a first direction X across the top of the frame structure <NUM>, and a second set of parallel rails <NUM> arranged perpendicular to the first set of rails <NUM> to guide movement of the container handling vehicles <NUM>,<NUM> in a second direction Y which is perpendicular to the first direction X. Commonly, at least one of the sets of rails <NUM>,<NUM> is made up of dual-track rails allowing two container handling vehicles to pass each other on neighbouring grid cells <NUM> Dual-track rails are disclosed in for instance <CIT> and <CIT>.

Each prior art container handling vehicle <NUM>,<NUM> also comprises a container lifting assembly <NUM> (shown in <FIG>) for vertical transportation of storage containers <NUM>, e.g. raising a storage container <NUM> from, and lowering a storage container <NUM> into, a storage column <NUM>. The container lifting assembly <NUM> comprises a lifting frame <NUM> having one or more gripping/engaging devices <NUM> adapted to engage a storage container <NUM> and guide pins <NUM> for correct positioning of the lifting frame <NUM> relative to the storage container <NUM>. The lifting frame <NUM> can be lowered from the vehicle <NUM>,<NUM> by lifting bands <NUM> so that the position of the lifting frame with respect to the vehicle <NUM>,<NUM> can be adjusted in a third direction Z which is orthogonal the first direction X and the second direction Y.

The lifting frame <NUM> (not shown) of the container handling vehicle <NUM> in <FIG> is located within a cavity of the vehicle body 201a.

The storage volume of the framework structure <NUM> has often been referred to as a grid <NUM>, where the possible storage positions within this grid are referred to as storage cells. Each storage column may be identified by a position in an X- and Y-direction, while each storage cell may be identified by a container number in the X-, Y and Z-direction.

The storage space may comprise a cavity arranged centrally within the vehicle body 201a as shown in <FIG> and as described in e.g. <CIT>, <FIG> shows an alternative configuration of a container handling vehicle <NUM> with a cantilever construction. Such a vehicle is described in detail in e.g. <CIT>, The central cavity container handling vehicles <NUM> shown in <FIG> may have a footprint that covers an area with dimensions in the X and Y directions which is generally equal to the lateral extent of a storage column <NUM>, e.g. as is described in <CIT>, The term 'lateral' used herein may mean 'horizontal'.

<CIT>, illustrates a typical configuration of rail system <NUM> comprising rails and parallel tracks in both X and Y directions.

The access station may typically be a picking or a stocking station where product items are removed from or positioned into the storage containers <NUM>. In a picking or a stocking station, the storage containers <NUM> are normally not removed from the automated storage and retrieval system <NUM> but are returned into the framework structure <NUM> again once accessed. A port can also be used for transferring storage containers to another storage facility (e.g. to another framework structure or to another automated storage and retrieval system), to a transport vehicle (e.g. a train or a lorry), or to a production facility.

The conveyor system may be arranged to transfer storage containers <NUM> between different framework structures, e.g. as is described in <CIT>,.

When a storage container <NUM> is to be stored in one of the columns <NUM>, one of the container handling vehicles <NUM>,<NUM> is instructed to pick up the storage container <NUM> from the pick-up port column <NUM> and transport it to a location above the storage column <NUM> where it is to be stored. After any storage containers positioned at or above the target position within the storage column stack <NUM> have been removed, the container handling vehicle <NUM>,<NUM> positions the storage container <NUM> at the desired position. The removed storage containers may then be lowered back into the storage column <NUM> or relocated to other storage columns.

The prior art container-handling vehicles comprises a rechargeable battery for driving the vehicle and operating the lifting device. The battery of the container-handling vehicle is recharged at a charging station. Commonly, the vehicle and the charging station features a pin and socket interface. A pin <NUM> for coupling to a socket of a charging station is shown on the prior art container-handling vehicle <NUM> in <FIG>. The battery of the prior art container-handling vehicle <NUM> is recharged by moving the vehicle towards the charging station, such that the pin <NUM> is inserted into a corresponding socket on the charging station. When the battery is charged, the vehicle is moved away from the charging station to disconnect the pin/pin from the socket. During charging the prior art container-handling vehicle <NUM> and the charging station occupies three adjacent grid cells upon the rail grid <NUM>. Although functioning well, the solution is quite service intensive due to wear caused by minor misalignments between the pin/pin and socket during connection. The misalignments may for instance be caused by small height differences of the rail grid <NUM>.

Further, the wheels of the prior art vehicles do not have brakes, and to keep a container-handling vehicle in close contact with the charging station during charging, the wheels arranged to move in the direction of the charging station are powered to push the vehicle against the charging station. A disadvantage of this solution is that an amount of power is used also during charging.

<CIT> describes an automated storage and retrieval system, a storage container handling vehicle and a method for operating such a system. The system comprises one or more vehicle configured to lift and move storage containers stacked in the system. Each vehicle comprises a storage container lifting device, a drive system with a wheel arrangement configured to drive and maneuver the vehicle along the track system, abase onto which the wheel arrangement is connected, a rotational part rotationally connected via a swivel device to the base and a rotational drive system for rotating the rotational part relative to the base.

In view of the above, the aim of the present invention is to provide a storage system having a charging system, and a method for operating such a charging system, that solves or at least mitigates one or more of the problems related to the charging systems of the prior art storage and retrieval systems.

The present invention is defined by appended claims <NUM>, <NUM> and <NUM>. Optional features of the present invention are provided in the dependent claims and below.

In a first aspect, the present invention provides a storage system according to claim <NUM>.

Each of the two resiliently mounted charge-receiving or charge-providing elements may move elastically independent of each other.

The resiliently mounted charge-providing or charge-receiving elements are biased into the neutral position by a resilient assembly.

The elastic movement is relative to any of the sidewall and the support structure.

In an embodiment of the storage system, each of the charge-providing elements is resiliently mounted to the support structure and configured to allow independent elastic movement of the charge-providing element from a neutral position in a direction perpendicular to the connection direction during coupling of the charge-providing and charge-receiving elements.

In an embodiment of the storage system, each of the charge-providing elements is mounted to the support structure via a resilient assembly, the resilient assembly is configured to allow elastic movement of the charge-providing element in a vertical plane being perpendicular to the connection direction.

In an embodiment of the storage system, each of the charge-receiving elements is mounted to the vehicle framework via a resilient assembly, the resilient assembly is configured to allow elastic movement of the charge-receiving element in a vertical plane being perpendicular to the connection direction.

In other words, the vertical plane being perpendicular to the connection direction is a vertical plane perpendicular to one of the two perpendicular directions in which the container handling vehicle may move upon the rail grid. The respective charge-receiving elements or charge-providing elements extend in a direction perpendicular to the vertical plane.

In an embodiment of the storage system, each of the resiliently mounted charge-providing elements and/or each of the resiliently mounted charge-receiving elements has a horizontal centreline, and the horizontal centreline is perpendicular to the vertical plane during the elastic movement of the charge-providing element and/or the charge-receiving element.

In an embodiment of the storage system, each of the two charge-receiving elements and the two charge-providing elements are arranged on opposite sides of a vertical centre plane of the container handling vehicle and the charging station, respectively, the vertical centre plane extending in the connection direction.

In an embodiment of the storage system, the resilient assembly is configured to prevent movement of the charge-providing elements along the connection direction, i.e. the charge-providing elements are fixed relative to the connection direction.

In an embodiment of the storage system, each of the charge-providing elements features a flange, and the resilient assembly comprises a sprung frame that is positioned within a recess in the support structure, the sprung frame being arranged to engage portions of the flange, in order to suspend the charge-providing element, the sprung frame being configured to permit elastic movement of the charge-providing element in the vertical plane.

In an embodiment of the storage system, each of the charge-receiving elements features a flange, and the resilient assembly comprises a sprung frame that is positioned within a recess in the vehicle framework, the sprung frame being arranged to engage portions of the flange, in order to suspend the charge-receiving element, the sprung frame being configured to permit elastic movement of the charge-receiving element in the vertical plane.

In an embodiment of the storage system, each of the charge-providing elements and/or each of the charge-receiving elements may features flange, and may be resiliently mounted via a sprung frame, the sprung frame arranged to engage portions of the flange, in order to suspend the charge-providing element and/or the charge-receiving element, the sprung frame being configured to permit elastic movement of the charge-providing element and/or the charge-receiving element in the vertical plane.

The vertical plane may alternatively be defined as the plane in which the flange is arranged.

In an embodiment of the storage system, the sprung frame comprises a plurality of springs mounted to permit elastic movement of the charge-providing element in at least two perpendicular directions of the vertical plane.

In an embodiment of the storage system, the sprung frame comprises a plurality of springs mounted to permit elastic movement of the charge-receiving element in at least two perpendicular directions of the vertical plane.

In an embodiment of the storage system, each of the charge-providing elements is resiliently mounted to the support structure via a sprung frame, the sprung frame comprising a plurality of springs mounted to permit elastic movement of the charge-providing element in at least two perpendicular directions of the vertical plane.

In an embodiment of the storage system, each of the charge-receiving elements is resiliently mounted to the vehicle framework via a sprung frame, the sprung frame comprising a plurality of springs mounted to permit elastic movement of the charge-providing element in at least two perpendicular directions of the vertical plane.

In an embodiment of the storage system, the plurality of springs may be mounted evenly about a periphery of a flange of the charge-providing element or the charge-receiving element.

In an embodiment of the storage system the sprung frame comprises a plurality of leaf springs arranged as a convex polygon around the flange of the charge-providing element or the charge-receiving element. Each leaf spring may be arranged along a respective side of a convex polygon. The convex polygon may be a regular convex polygon.

In an embodiment of the storage system, the sprung frame may comprise four leaf springs arranged as a square around the flange of the charge-providing element or the charge-receiving element.

In an embodiment of the storage system, the sprung frame may comprise a plurality of coil springs evenly arranged around the flange of the charge-providing element or the charge-receiving element.

In an embodiment of the storage system, the elastic movement in the vertical plane is limited through contact of the springs with a portion of the recess.

In an embodiment of the storage system, the flange is clamped within the recess in the support structure to prevent movement of the flange along the connection direction.

In an embodiment of the storage system, the flange is clamped within the recess in the vehicle framework to prevent movement of the flange along the connection direction.

In an embodiment of the storage system, the recess in the support structure is closed in part by a plate element arranged to retain the resilient assembly within the recess and to prevent movement of the flange along the connection direction. In other words, the plate element ensures that the flange may not move in the connection direction as well as the opposite direction, relative to the support structure i.e. the flange may not move in a direction perpendicular to the vertical plane.

In an embodiment of the storage system, the recess in vehicle framework is closed in part by a plate element arranged to retain the resilient assembly within the recess and to prevent movement of the flange along the connection direction. In other words, the plate element ensures that the flange may not move in the connection direction as well as the opposite direction, relative to the vehicle framework, i.e. the flange may not move in a direction perpendicular to the vertical plane.

The plate element may be in any suitable form, e.g. depending on the circumference of the recess, such as ring-shaped or square. The plate element may feature a through hole for a connecting end of the charge-providing element or charge-receiving element.

In an embodiment of the storage system the plate element is fixed to the support structure or vehicle framework with removable fasteners, the fasteners allowing the plate element to be removed to facilitate replacement of a charge-providing element or a charge-receiving element.

In an embodiment of the storage system, each of the charge-providing elements comprises a socket or a pin, and each of the charge-receiving elements comprises a corresponding pin or socket, and a centreline of the pin and of the socket is arranged to extend along the connection direction during coupling.

The pin and the socket may be termed a pin electrode and a socket electrode.

In an embodiment of the storage system, the centreline of the pin or socket of the resiliently mounted charge-providing element or the resiliently mounted charge-receiving element extends along the connection direction during the elastic movement.

In an embodiment of the storage system, the resiliently mounted charge-providing element or the resiliently mounted charge-receiving element comprises a pin or a socket having a centreline extending in a direction being perpendicular to the vertical plane during the elastic movement.

In an embodiment of the storage system, a centreline of the pin or the socket of the resiliently mounted charge-providing element or the resiliently mounted charge-receiving element extends in a direction perpendicular to the vertical plane during the elastic movement.

By keeping the centerline of the pin or socket perpendicular to the vertical plane during the elastic movement, mechanical wear of the pin or socket is minimized by avoiding pivotal movement of the pin or socket away from the connection direction during coupling.

In an embodiment of the storage system, the pin is accommodated in a guide sleeve having an open end with a flared portion, the flared portion is configured to guide the accommodated pin into alignment with a corresponding socket during coupling.

In an embodiment of the storage system, the socket is accommodated in a guide sleeve having an open end with a flared portion, the flared portion is configured to guide the accommodated socket into alignment with a corresponding pin during coupling.

In an embodiment of the storage system, the flared portion may be configured to guide the accommodated pin or socket into alignment with a corresponding socket or pin before the accommodated pin or socket is in contact with the corresponding socket or pin.

In an embodiment of the storage system, the flared portion may extend beyond the accommodated pin or socket. In other words, the flared portion may extend beyond a connecting end of the accommodated pin or socket, such that the flared portion may interact with a corresponding socket or pin before the corresponding socket or pin couples with the accommodated pin or socket.

In an embodiment of the storage system, the guide sleeve forms an annular space around the pin or socket, and the corresponding socket or pin is accommodated in a protective sleeve, and the flared portion is configured to guide the protective sleeve into the annular space during coupling.

In an embodiment of the storage system, the guide sleeve and/or the protective sleeve comprises a flange.

In an embodiment, the storage system comprises a framework structure featuring multiple storage columns, in which storage containers may be stored stacked on top of one another in vertical stacks, and the rail grid is arranged at a top level of the framework structure,
wherein the container handling vehicle comprises a container lifting assembly and a cantilevered section, the cantilevered section extends laterally from an upper portion of the sidewall at the same side as the charge-receiving elements, the container lifting assembly comprises a lifting frame and a plurality of lifting bands, the lifting frame is for releasable connection to a storage container and is suspended from the cantilevered section by the lifting bands, such that the lifting frame may be raised or lowered relative to the cantilevered section; wherein the lowest level of the lifting frame, when raised in an upper position, is higher than an upper level of the charging station, such that the cantilevered section may be positioned above the charging station during charging of the container handling vehicle.

In an embodiment of the storage system, the rail grid forms a plurality of grid cells, and the container handling vehicle and the charging station occupies an area equal to or less than two adjacent grid cells when the charge-receiving elements are coupled with the corresponding charge-providing elements.

In an embodiment of the storage system, the first set of wheels is displaceable in a vertical direction between a first position, wherein the first set of wheels may move the container vehicle in a first direction, a second position, wherein the first and the second set of wheels are in contact with the rail grid, and a third position wherein the second set of wheels may move the container vehicle in a second direction perpendicular to the first direction.

In a second aspect, the present invention provides a container handling vehicle according to claim <NUM>.

The open end of the guide sleeve may face away from the container handling vehicle. The flared portion may have an inner surface having a circumference increasing in the direction in which the open end faces. The pin may have a horizontal centreline.

In an embodiment of the container handling vehicle, the flared portion may extend beyond the accommodated pin. In other words, the flared portion may extend beyond a connecting end of the accommodated pin, such that the flared portion may interact with a corresponding socket of a charging station before the socket couples with the accommodated pin.

The lifting frame may be raised or lowered in front of the charge-receiving elements.

In a third aspect, the present invention provides a charging station according to claim <NUM>.

In other words, the resilient assembly is configured to allow elastic movement of the charge-providing element in a vertical plane during which movement the centerline of the pin or socket is perpendicular to the vertical plane.

In an embodiment of the charging station, each of the charge-providing elements is mounted in a recess of the support structure via the resilient assembly.

In an embodiment of the charging station, the resilient assembly comprises a sprung frame being arranged to engage portions of the flange, in order to suspend the charge-providing element, the sprung frame being configured to allow elastic movement of the charge-providing element in the vertical plane. The sprung frame may be positioned within a recess of the support structure.

In an embodiment of the charging station, the resilient assembly or the sprung frame comprises a plurality of springs mounted to permit elastic movement of the charge-providing element in at least two perpendicular directions of the vertical plane.

In an embodiment of the charging station, the resilient assembly or the sprung frame comprises a plurality of leaf springs arranged as a convex polygon around the flange of the charge-providing element. The convex polygon may be regular.

In an embodiment of the charging station, the resilient assembly or the sprung frame comprises four leaf springs arranged as a square around the flange.

In an embodiment of the charging station, the elastic movement in the vertical plane is limited through contact of the sprung frame with a portion of the recess.

In an embodiment of the charging station, the recess may be closed in part by a plate element arranged to retain the resilient assembly within the recess and to prevent movement of the flange along the direction of the horizontal centreline, the plate element features a through hole for a power source charger connecting end of the charge-providing element.

In an embodiment of the charging station, the plate element may be fixed to the support structure with removable fasteners, the fasteners allowing the plate element to be removed to facilitate replacement of the charge-providing element.

In an embodiment of the charging station the centreline of the pin or socket is perpendicular to the vertical plane during the elastic movement.

According to an example which is not claimed, the present application provides a method of charging a container vehicle in a storage system, the storage system comprising a horizontal rail grid and a charging system for charging a rechargeable power source of the container handling vehicle, wherein.

The centreline of each of the charge-providing elements may extend in the horizontal direction during the elastic movement. In other words, the centreline of each of the charge-providing elements does not deviate from the horizontal during the elastic movement.

The first set of wheels may be displaceable in a vertical direction between a first position, wherein the first set of wheels may move the container handling vehicle in a first direction, a second position, wherein the first and the second set of wheels are in contact with the rail grid, and a third position wherein the second set of wheels may move the container vehicle in a second direction perpendicular to the first direction; and the method comprises the step of:.

In a further non-claimed example, the present disclosure provides a method of charging a container handling vehicle in a storage system, the storage system comprising a horizontal rail grid and a charging system for charging a rechargeable power source of the container handling vehicle, wherein.

In a further non-claimed example, the present invention provides a method of charging a container vehicle in a storage system, the storage system comprising a horizontal rail grid and a charging system for charging a rechargeable power source of the container handling vehicle, wherein.

The method may comprise an initial step of moving the container handling vehicle in a horizontal direction perpendicular to the horizontal connection direction, i.e. by using the first set of wheels, into a grid cell in front of and adjacent to a grid cell in which the charging station is arranged.

In the present specification, the terms charge-receiving element and charge-providing element may alternatively be termed charge-receiving electrode and charge-providing electrode. The two charge-receiving elements may provide a positive and negative terminal for the DC power source. The two charge-providing elements provide a corresponding positive and a negative terminal for the DC power source charger. Alternatively, the charge-providing elements may provide AC current, and the container handling vehicle may feature a converter connected between the charge-receiving elements and the power source, such that the AC current is converted to DC current.

Embodiments of the invention is described in detail by reference to the following drawings:.

However, the drawings are not intended to limit the invention to the subject-matter depicted in the drawings.

The present invention concerns a charging system for remotely operated container handling vehicles. The charging system is particularly suitable for container handling vehicles in an automated storage system featuring at least one rail grid, e.g. a rail system <NUM> as discussed for the prior art storage system disclosed in <FIG>.

A storage system featuring an exemplary embodiment of a charging system according to the invention is illustrated in <FIG>.

The storage system features at least one container handling vehicle <NUM>, more usually a plurality of such container handling vehicles <NUM>, a horizontal rail grid <NUM> and a charging system for charging a rechargeable power source <NUM> of the container handling vehicle <NUM>. The rechargeable power source may be any type of suitable battery or supercapacitor.

The rail grid is made up of rails <NUM>,<NUM> arranged in two perpendicular directions forming multiple grid cells <NUM>, see <FIG>.

The container handling vehicle <NUM> comprises a vehicle framework <NUM>, a sidewall <NUM> and a first set of wheels 10a and a second set of wheels 10b for moving the container handling vehicle upon the rail grid <NUM> in the rail directions.

The first set of wheels 10a is displaceable in a vertical direction between a first position, wherein the first set of wheels 10a may move the container handling vehicle <NUM> in a first direction X, a second position, wherein the first and the second set of wheels 10a, 10b are in contact with the rail grid, and a third position wherein the second set of wheels 10b may move the container handling vehicle <NUM> in a second direction Y perpendicular to the first direction.

The charging system comprises two separated charge-receiving elements <NUM>,<NUM>,<NUM> arranged on a sidewall <NUM> of the container handling vehicle and connected to the power source <NUM>, and a charging station <NUM> having two separated charge-providing elements <NUM>,<NUM>,<NUM> connected to a power source charger <NUM>. The charge-receiving elements provide a positive and a negative terminal of the DC power source <NUM>, while the charge-providing elements provide a corresponding negative and positive terminal of the DC power source charger <NUM>. In other embodiments, the charge-providing elements may provide AC current, and the container handling vehicle features a converter connected between the charge-receiving elements and the power source <NUM>, such that the AC current is converted to DC current.

In this embodiment, each of the charge-receiving elements features a pin <NUM> and each of the charge-providing elements features a corresponding socket <NUM>. In other embodiments the opposite combination of a pin and socket may be used.

The pins <NUM> are arranged to couple with the corresponding sockets <NUM> when the container handling vehicle is moved in a horizontal connection direction Y' towards and adjacent to the charging station <NUM>, see <FIG>.

In practice, a rail grid <NUM> as described above will commonly have small variations in the level of the individual rails <NUM>,<NUM>. Such variations may lead to minor misalignments between the pins <NUM> and sockets <NUM> during the initial coupling between them and cause premature wear requiring a more frequent replacement of the pins/socket than desired. To minimize the wear, the charging station <NUM> has a support structure <NUM> to which the sockets <NUM> are resiliently mounted. The sockets <NUM> are configured to allow independent elastic movement of each socket <NUM> from a neutral position in a direction perpendicular to the connection direction Y' during coupling of the pins <NUM> and sockets <NUM>. In other words, each of the sockets <NUM> are allowed elastic movement in a vertical plane being perpendicular to the connection direction Y' while keeping a centreline C of the socket <NUM> extending in the connection direction Y'. This arrangement optimizes the alignment of the pins <NUM> and sockets <NUM> during coupling.

Each of the two charge-receiving elements <NUM> and the two charge-providing elements <NUM> are arranged on opposite sides of a vertical centre plane D of the container handling vehicle and the charging station, respectively, see <FIG>. The vertical centre plane D extending in the connection direction Y'. The vertical centre plane D intersects the sidewall <NUM> of the container handling vehicle. In the embodiment of <FIG>, the distance between the two charge-receiving elements <NUM> is more than half the width of the sidewall <NUM>. In alternative embodiments, the distance between the two charge-receiving elements <NUM> is more than a fourth of the width of the sidewall <NUM>. A highly advantageous effect of having the charge-receiving elements <NUM>, and consequently the charge-providing elements <NUM>, separated in this manner is that lateral skewing of the container handling vehicle relative to the connection direction Y' during initial connection to the charging station <NUM> is minimized. The lateral skewing of the inventive container handling vehicle is minimized since the force required to connect with the charging station is more widely distributed than in prior art solution featuring a single composite connector. Lateral skewing may occur due to limited traction of the wheels 10a, 10b allowing the container handling vehicle to move upon the rail grid <NUM>. Minimizing the lateral skewing will ensure a more reliable connection as well as avoid excessive wear of the charge-receiving elements <NUM> and the charge-providing elements <NUM>.

Details of the charge-receiving elements and the charge-providing elements are shown in <FIG>. The socket <NUM> of the charge-providing element is accommodated in a protective sleeve <NUM> having a flange <NUM>. A power charger connecting end <NUM> of the socket <NUM> is connected to the power source charger <NUM>. The pin <NUM> of the charge-receiving element is accommodated in a guide sleeve <NUM> forming an annular space <NUM> around the pin <NUM>. The guide sleeve <NUM> has a flange <NUM>, connected to a vehicle framework <NUM>, and an open end with a flared portion <NUM>. The flared portion <NUM> is configured to guide the protective sleeve <NUM> and the socket <NUM> into the annular space <NUM> during coupling. The guide sleeve <NUM> steers the protective sleeve <NUM> and the socket <NUM> into a correct alignment with the pin <NUM>. The pin <NUM> and socket <NUM> are preferably aligned before contact, or at initial contact, to further minimize wear. To obtain alignment before, or at initial contact, the flared portion <NUM> may advantageously extend beyond the pin <NUM>, such that the protective sleeve <NUM> interacts with the flared portion before the socket <NUM> comes into contact with the pin <NUM>.

Each of the charge-providing elements is resiliently mounted to the support structure <NUM> via the flange <NUM>, see <FIG>. The flange <NUM> is suspended within a recess of the support structure <NUM> by multiple leaf springs 16a (i.e. a resilient assembly) forming a sprung frame. The leaf springs are arranged to engage circumferential portions of the flange <NUM> to allow elastic movement of the flange <NUM> and consequently the socket <NUM> in the vertical plane being perpendicular to the connection direction Y'. In the illustrated embodiment, the sprung frame consists of four leaf springs 16a arranged as a square around the flange. The elastic movement in the vertical plane is limited through contact of the springs 16a with an inner circumference of the recess <NUM>. In other embodiments, the number of leaf springs may be different, e.g. six leaf springs in a hexagonal arrangement, eight leaf springs in an octagonal arrangement etc..

To prevent movement of the flange <NUM> and socket <NUM> along the connection direction Y', i.e. horizontal movement relative to the support structure <NUM>, the flange is clamped within the recess <NUM> by a ring-shaped plate element <NUM>. The plate element features a through hole <NUM> for a power charger connecting end <NUM> of the socket <NUM>. The plate element <NUM> is fixed to the support structure <NUM> with removable fasteners <NUM>. The fasteners allowing the plate element to be removed to facilitate replacement of a socket <NUM>. In other embodiments, the ring-shaped plate element may be replaced by any element suitable for clamping the flange in place to prevent movement of the flange along the connection direction.

The use of leaf springs provides a simple and reliable sprung frame. However, a suitable sprung frame may be obtained by other spring arrangements. The leaf springs may e.g. be replaced by multiple coil springs or a suitable resilient material arranged around the flange <NUM>. An embodiment of a sprung frame featuring coil springs 16b is shown in <FIG>. The sprung frame features four coil springs 16b, each having one end accommodated in holes <NUM> arranged on opposite sides of the flange <NUM>.

The charging station <NUM> is sized to be accommodated within a grid cell <NUM> of the rail grid <NUM>. The charging station <NUM> is mounted by bolts <NUM> to the vertical sides of the parallel rails <NUM> of the grid cell <NUM> via the support structure <NUM>, see <FIG>.

The exemplary container handling vehicle <NUM> used to illustrate the present invention features a cantilevered section <NUM> and a container lifting assembly <NUM> comprising a lifting frame <NUM> similar to the container lifting assembly of the prior art container handling vehicle <NUM> discussed above. In the exemplary container handling vehicle <NUM>, the cantilevered section <NUM> extends laterally from an upper portion of the sidewall <NUM> at the same side as the charge-receiving elements <NUM>. The lowest level of the lifting frame <NUM>, when raised in an upper position, is higher than an upper level of the charging station <NUM>. The positioning of the charge-receiving elements <NUM> allows the cantilevered section <NUM> to be positioned above the charging station <NUM> during charging of the container handling vehicle <NUM>. In this manner, the area of the rail grid <NUM> occupied by a container-handling vehicle and the charging station during charging is minimized, i.e. the occupied area is equal to two grid cells <NUM> or less.

It is noted that the charging system is suitable for any type of container handling vehicle able to carry or transfer a storage container.

During charging of the container handling vehicle, the vehicle must be kept stationary relative to the charging station <NUM>. A method of locking the container handling vehicle in place while charging is illustrated in <FIG>. The method requires the charging station <NUM> to be positioned in a grid cell <NUM>' such that full coupling between the pin/socket is only obtained when a pair of wheels of the first set of wheels 10a are positioned within the grid cell <NUM>' of the charging station <NUM>. In this method, the container handling vehicle <NUM> is moved towards the charging station <NUM> in the connection direction Y' until full coupling is obtained. After coupling, the first set of wheels 10a is moved from the third position to the first position. In the first position, the first set of wheels is in contact with a rail side, or sidewall <NUM> of a rail <NUM>, facing the charging station <NUM> and prevents the container handling vehicle <NUM> from moving away from the charging station <NUM>. By having the charging station <NUM> arranged such that the charge-providing elements <NUM> do not extend horizontally beyond the grid cell <NUM>' it is positioned in, a further advantage of the method shown in <FIG> is that the container handling vehicle <NUM> may enter the grid cell <NUM> in front of the charging station from a direction perpendicular to the connection direction Y', i.e. the container handling vehicle may move into the grid cell <NUM> in front of the charging station via the rails <NUM> arranged perpendicular to the connection direction Y'. This feature allows for a highly compact positioning of the charging station <NUM>. For instance, a plurality of charging stations <NUM>',<NUM>" may be arranged at every second grid cell <NUM>' at a side section of the rail grid <NUM>, see <FIG>. In <FIG>, a first container handling vehicle <NUM>' is fully coupled to a first charging station <NUM>'. A second container handling vehicle <NUM>'' is arranged in a grid cell in front of a second charging station <NUM>''. The second container vehicle may move away from the second charging station via the rails <NUM> arranged perpendicular to the connection direction Y' or into coupling with the second charging station <NUM>" by moving in the connection direction Y'.

In an alternative method of locking the container handling vehicle in place while charging, the charging station <NUM> is positioned in a grid cell <NUM> such that full coupling between the pin/socket is obtained before a pair of wheels of the first set of wheels 10a are positioned within the grid cell <NUM> of the charging station <NUM>. In the alternative method, the container handling vehicle <NUM> is moved towards the charging station <NUM> in the connection direction Y' until full coupling is obtained. After coupling, the first set of wheels 10a is moved from the third position to the second position. In the second position, both the first set of wheels and the second set of wheels are in contact with a topside of the rails of the grid cell adjacent to the grid cell of the charging station <NUM> and prevent the container handling vehicle from moving away from the charging station.

Claim 1:
A storage system comprising at least one container handling vehicle (<NUM>), a horizontal rail grid (<NUM>) and a charging system for charging a rechargeable power source (<NUM>) of the container handling vehicle, wherein:
- the container handling vehicle comprises a vehicle framework (<NUM>), a first set of wheels (10a) and a second set of wheels (10b) for moving the container handling vehicle upon the rail grid in two perpendicular directions;
- the charging system comprises two separated charge-receiving elements (<NUM>) arranged on a sidewall (<NUM>) of the container handling vehicle and connected to the power source (<NUM>), and a charging station (<NUM>) comprising a support structure (<NUM>) and two separated charge-providing elements (<NUM>) connected to a power source charger (<NUM>), and the charge-receiving elements (<NUM>) are arranged to couple with the corresponding charge-providing elements (<NUM>) when the container handling vehicle is moved in a horizontal connection direction (Y') towards and adjacent to the charging station;
wherein each of the charge-providing elements (<NUM>) are resiliently mounted to the support structure (<NUM>) and/or wherein each of the charge-receiving elements (<NUM>) are resiliently mounted to the vehicle framework (<NUM>), and
wherein the charge-providing elements (<NUM>) and/or the charge-receiving elements (<NUM>) are configured to allow independent elastic movement of each resiliently mounted charge-providing element and/or each resiliently mounted charge-receiving element from a neutral position in a direction perpendicular to the connection direction during coupling of the charge-providing and charge-receiving elements; and
wherein the two charge-receiving elements (<NUM>) are arranged on opposite sides of a vertical centre plane (D) bisecting the sidewall (<NUM>) of the container handling vehicle, and the distance between the two charge-receiving elements (<NUM>) is more than a fourth of the width of the sidewall (<NUM>).