Patent Description:
A laboratory automation system comprises a plurality of pre-analytical, analytical and/or postanalytical stations, in which samples, for example blood, saliva, swab and other specimens taken from the human body, are processed. It is generally known to provide various containers, such as test tubes or vials, containing the samples. The test tubes are also referred to as sample tubes. In the context of the application, containers such as test tubes or vials for containing a sample are referred to as sample containers.

<CIT> discloses a laboratory sample distribution system with a transport device comprising a transport plane or driving surface and a plurality of electro-magnetic actuators being stationary arranged below said driving surface, and with a plurality of sample containers comprising a magnetically active device, preferably at least one permanent magnet, wherein said electromagnetic actuators are adapted to move a sample container carrier placed on top of said driving surface by applying a magnetic force to said sample container carrier. The sample container carriers have a retaining area for retaining sample containers, so that sample containers can be placed in an upright or vertical position in the sample container carriers.

Post-published European Application <CIT> shows a module for a laboratory sample distribution system comprising a plurality of electro-magnetic actuators and a transport plane mounted to the plurality of electro-magnetic actuators.

It is the object of the invention to provide a transport device comprising a plurality of electro-magnetic actuators being stationary arranged below a driving surface, which transport device is flexible in design and can be adapted to a large number of different requirements.

This object is solved by a transport device, a laboratory sample distribution system, and a laboratory automation system with the features of claims <NUM>, <NUM> and <NUM>.

According to a first aspect, a transport device with a plurality of electro-magnetic actuators and a driving surface arranged above the actuators is provided, wherein the driving surface is adapted to carry sample container carriers and is tiled comprising a plurality of driving surface modules with driving surface elements, wherein support elements arranged in a grid pattern are provided, and wherein each driving surface module is detachably mounted to a subset of the support elements.

The electro-magnetic actuators are adapted to move a sample container carrier on top of the driving surface in at least two different directions using magnetic forces. It is well known to provide a control device, which is adapted to control the movement of said container carriers on the top of the driving surface by driving the electro-magnetic actuators.

The tiling of the driving surface using driving surface modules allows to detach individual driving surface modules to access actuators arranged below said driving surface module, for example in case of a malfunction or defect of an actuator. The driving surface module in one embodiment is smaller in height than the actuators. The height is chosen in preferred embodiments such that a tilting of the driving surface module for mounting or dismounting a driving surface module to the support elements is possible.

The driving surface module comprises a driving surface element adapted to carry sample container carriers. In one embodiment, sample container carriers are provided with rollers for a movement across the driving surface element or a driving surface pieced together from driving surface elements of neighboring transport device units. In particular embodiments, the sample container carriers are moved slidingly across the driving surface element. For this purpose, the driving surface element is made from or coated with a material having a low sliding friction coefficient, in particular in combination with a material used at a sliding surface of the sample container carrier, as well as high abrasion resistance.

According to one embodiment a sealing cord is provided between adjacent sides of neighboring driving surface elements, wherein in each case driving surface elements of neighboring driving surface modules are forced apart by means of the sealing cord and wherein a maximum distance between said driving surface elements is limited by means of the support element. The sealing cord has two functions. Firstly, by means of the sealing cord a liquid accidently spilled on the driving surface is prevented from reaching the actuators and/or a wiring board arranged below the driving surface. Secondly, by means of the sealing cord together with the support elements a horizontal adjustment of neighboring driving surface modules is achieved. In one embodiment, the driving surface modules are coupled to the support elements with play, wherein the sealing cord forces the driving surface elements of neighboring driving surface modules apart. The support elements and, in particular, mechanical end stops provided at the support elements limit a relative movement of the neighboring driving surface elements away from each other. This allows positioning each driving surface element very accurately. Hence, it is avoided that small misalignments between two neighboring driving surface elements add up and impair an overall alignment of the driving surface modules.

In one embodiment, the driving surface elements are provided with a rim at their bottom side for accommodating said sealing cord. In one embodiment, the rim has no interruption and extends over the entire circumference of the driving surface element. In other elements, the rim is pieced together of rim parts arranged with gaps. In still another embodiment, individual rim elements are provided at the respective sides of the driving surface element. To ensure for a reliable sealing, in some embodiments the sealing cord is mounted to the rim of a first side of a driving surface element and a sealing projection for contacting the sealing cord is provided at the rim of a second side of an adjacent driving surface element. In other words, in each case a sealing cord mounted to one side contacts a sealing projection provided at an adjacent side.

Driving surface modules with driving surface elements having different basic shapes can be assembled to a driving surface. In embodiments of the transport device, the driving surface elements have a tessellating basic shape, in particular a regular polygonal basic shape. In other words, driving surface modules with driving surface elements having the same basic shape are combined to the driving surface. Hence, a system with high flexibility is provided which can be adapted to changing requirements of a laboratory system. The driving surface elements can be coupled at their sides for building a continuous surface.

In embodiments of the transport device, the driving surface elements have a regular polygonal basic shape with three, four or six corners, wherein the support elements are designed as corner supports arranged to support adjacent corners of driving surface elements of neighboring driving surface modules. When using such corner supports the number of support elements can be minimized.

As mentioned above, sealing cords are provided between adjacent sides of neighboring driving surface elements. In alternative or in addition, the corner supports in one embodiment are provided with a liquid trap recess at their center for collecting liquid accidently spilled on the transport surface.

In order to couple the driving surface modules with the support elements, more particular with the corner supports, each driving surface module is provided with connecting structures at the corners of the driving surface element for connecting each corner with an associated corner support. In embodiments of the connecting structures, the connecting structures each comprise at least a connection pins adapted to be inserted into an opening provided at the corner support. The connection pin allow for a simple mounting of the driving surface modules to the corner supports. As mentioned above, in one embodiment the driving surface modules are mounted with play to the support elements. For this purpose, the openings of the corner supports can be designed having a larger diameter than the connection pins, wherein adjacent driving surface elements are forced apart and, thus, the connection pins are forced towards regions of the openings away from a center of the corner support.

In an embodiment, at least one of the connecting structures further comprises at least one snap-fit element. By means of the snap-fit element, the driving surface modules are detachably fixed in position in a vertical direction.

In embodiments at least a subset of the driving surface modules is provided with a sensor board arranged at a bottom side of the driving surface element. When mounting the sensor board to the bottom of the driving surface element, the sensor board is arranged close to the driving surface across which the sample container carriers are moved. The sensor board at least forms part of a device for sensing a presence or position of a sample container carrier moved across the upper side of the driving surface element. In one embodiment, the driving surface element is transparent to IR light, wherein the sensor board can be equipped with multiple IR based reflection light barriers arranged in a grid, and the sample container carriers can be adapted to reflect IR radiation emitted by the light barriers.

For avoiding gaps between adjacent driving surface elements, at least a subset of the driving surface elements can be provided with at least one side having a stepped portion and at least one side having a complementary overhang portion, wherein said overhang portion is adapted to overlap a stepped portion at side of a driving surface element of a neighboring driving surface module. In case the driving surface elements have a regular polygonal basic shape with four or six corners, preferably opposite sides of the driving surface elements are provided with a stepped portion and a complementary overhang portion, respectively.

In embodiments of the driving surface modules, resilient force elements are provided for forcing a stepped portion of a driving surface module against the overhang portion at side of a neighboring driving surface module. By means of the resilient force elements it is ensured that an overhang portion rests on the associated stepped portion, and steps between adjacent driving surface modules are avoided.

The resilient force elements in one embodiment comprise hook-shaped elements provided at a bottom surface of a driving surface element underneath the overhang portion and tongue-shaped elements provided at a bottom surface of a driving surface element underneath the stepped portion.

The transport device in one embodiment is assembled from a plurality of transport device units, each transport device unit comprising a base plate module with a base plate for fixing the transport device unit to a support frame and an actuator module with a plurality of electro-magnetic actuators, which actuator module is supported by the base plate module. In other words, a modular transport device is provided, which can be adapted to various requirements of a laboratory distribution system.

In particular embodiments, each driving surface module is assigned to one transport device unit, wherein each driving surface module is detachably mounted to the base plate module of the assigned transport device unit by means of the support elements.

According to a second aspect, a laboratory sample distribution system is provided having a transport device and a plurality of sample container carriers, the sample container carriers each comprising at least one magnetically active device, preferably at least one permanent magnet, and being adapted to carry a sample container containing a sample. The magnetic actuators of the transport device units of the transport device are suitably driven for generating a magnetic field such that a driving force is applied to each of the sample container carriers for transporting the sample container carriers on the surface pieced together of driving surface modules of the units. The distribution system in addition in one embodiment comprises additional conveyor devices for moving a sample container carrier along a defined path.

According to a third aspect, a laboratory automation system with a plurality of pre-analytical, analytical and/or post-analytical stations, and with a distribution system having a transport device and number of sample container carriers is provided.

In the following, an embodiment of the invention will be described in detail with reference to the schematic drawings.

<FIG> schematically shows a top view of an embodiment of a transport device <NUM> build from several, in the embodiment shown twenty transport device units <NUM>. The transport device units <NUM> are fixed to a support frame comprising support bars <NUM>. Each of the transport device units <NUM> shown has a square basic shape allowing building of transport devices <NUM> of various designs by adding additional transport device units <NUM> at either side of already existing units <NUM> and/or removing transport device units <NUM> from the device <NUM> shown in <FIG>. In other embodiments, the transport device units have a different basic shape, for example a triangular basic shape or a hexagonal basic shape. Preferably, all transport device units <NUM> have the same basic shape, wherein the shape is a tessellating shape. However, in specific embodiments, a transport device is composed of transport device units <NUM> having different basic shapes.

<FIG> shows a transport device unit <NUM> for building a transport device <NUM> of <FIG> in an exploded view. <FIG> shows the unit <NUM> of <FIG> in an exploded sectional view. The transport device unit <NUM> comprises three modules, namely a base plate module <NUM> for fixing the transport device unit <NUM> to the support frame, an actuator module <NUM> with a plurality of electro-magnetic actuators <NUM> mounted to a carrier element <NUM>, and a driving surface module <NUM>. Adjacent transport device units <NUM> are connected by means of corner supports <NUM>.

The base plate module <NUM> shown comprises a base plate <NUM> having an essentially square basic shape with four sides and four corners. In the center area of the base plate <NUM>, a recess <NUM> surrounded by walls <NUM> is provided for accommodating a fan <NUM> mounted at the actuator module <NUM> and protruding from a bottom side of the carrier element <NUM>. At the inside of the walls <NUM>, filter elements <NUM> are mounted.

A wiring board <NUM> is mounted to the base plate <NUM> at one corner region thereof. In the embodiment shown, the wiring board <NUM> has an L-shaped basic shape and is arranged directly adjacent to the recess <NUM>.

Neighboring base plate modules <NUM> are coupled to each other. For this purpose, in the embodiment shown at each corner of the base plate module <NUM>, an angled connection bracket <NUM> extending in a vertical direction and perpendicular to a surface area of the base plate <NUM> is provided. Adjacent base plates <NUM>, and thus adjacent base plate modules <NUM>, are connected by means of the corner supports <NUM> attached to two, three or four connection brackets <NUM> of the base plates <NUM> of neighboring transport device units <NUM>. The driving surface module <NUM> is coupled to a top end of the corner supports <NUM> by means of connecting structures <NUM> provided at each of the four corners of the driving surface module <NUM>.

The actuator module <NUM> is supported by the base plate module <NUM>. For this purpose, the base plate module <NUM> and the actuator module <NUM> are provided with cooperating male and female coupling elements. In the embodiment shown, the base plate <NUM> is provided with four receiving openings <NUM>, <NUM> adapted to receive four stands <NUM>, <NUM> provided at the actuator module <NUM>.

For assembling the transport device <NUM> shown in <FIG> from a plurality of transport device units <NUM>, at first a plurality of base plate modules <NUM> is mounted to the support bars <NUM> (see <FIG>), wherein adjacent base plate modules <NUM> are aligned and connected to each other by means of the corner supports <NUM>. Next, a wiring of the transport device units <NUM> can be completed. After the wiring is completed, the actuator modules <NUM> are mounted to the base plate modules <NUM>, wherein the stands <NUM>, <NUM> of the actuator module <NUM> are inserted into the receiving openings <NUM>, <NUM> of the base plate <NUM>. Finally, the driving surface module <NUM> is mounted to the base plate module <NUM> via the corner supports <NUM>, wherein the connecting structures <NUM> of the driving surface module <NUM> are coupled to the corner supports <NUM>.

<FIG> shows the base plate <NUM> of the base plate module <NUM> in a top view. <FIG> shows the base plate module <NUM> in a top view mounted to a support bar <NUM>.

As can be seen in <FIG>, close to its center the surface area of the base plate <NUM> is provided with four rhombic apertures <NUM> each adapted to receive a fastening bolt <NUM> (see <FIG>) equipped with a washer <NUM> and a rhombic slot nut <NUM>, which rhombic slot nut <NUM> is schematically shown in <FIG>. The slot nut <NUM> can be mounted to the fastening bolt <NUM> and inserted from above into a groove of the support bar <NUM> passing through the rhombic apertures <NUM>. This allows for an easy mounting, wherein the fastening bolt <NUM> can be tightened after all base plate modules <NUM> of a transport device are aligned to each other.

As shown in <FIG>, the surface area of the base plate <NUM> is provided with receiving slits <NUM> on the internal side of the walls <NUM> surrounding the recess <NUM>. The receiving slits <NUM> allow for a mounting of filter elements <NUM> (see <FIG> and <FIG>) from below, in case the support bar <NUM> does not hinder an access to the receiving slit <NUM>. In case access to the receiving slit <NUM> from below is hindered by the support bar <NUM> as in the case of the receiving slits <NUM> on the left and the right in <FIG>, the filter element <NUM> can be mounted from above.

To one corner of the base plate <NUM>, in the orientation shown in <FIG> to the upper right corner, a wiring board <NUM> is mounted. The wiring board <NUM> is mounted to the base plate <NUM> by means of screws <NUM> (see <FIG>). For this purpose, as shown in <FIG>, the base plate <NUM> is provided with threaded holes <NUM> for receiving the screws <NUM>. As shown in <FIG>, in the embodiment shown an earth or ground cable <NUM> of the wiring board <NUM> is connected to the fastening bolt <NUM>, and the fastening bolt <NUM> is used for a grounding of the wiring board <NUM>.

The base plate module <NUM> serves as a mounting platform for mounting the actuator module <NUM> and the driving surface module <NUM>.

The actuator module <NUM> is mounted to the base plate module <NUM> by means of stands <NUM>, <NUM> (see <FIG>) serving as male coupling elements to be inserted into receiving openings <NUM>, <NUM> provided at the base plate <NUM>. As best seen in <FIG>, the receiving openings <NUM>, <NUM> adapted to receive the stands <NUM>, <NUM> differ in design for providing a mechanical coding or keying system not having rotational symmetry. Thereby it is ensured that the actuator module <NUM> can only be mounted in one particular orientation to the base plate module <NUM>. In the embodiment shown, two receiving openings <NUM> have a U-shaped design, whereas the other two receiving openings <NUM> have a T-shaped design. Each receiving opening <NUM>, <NUM> is arranged at a center of one of the sides of the base plate <NUM> between two corners. In other embodiments, a keying structure is provided by arranging at least one of the receiving openings <NUM>, <NUM> and the corresponding stand <NUM>, <NUM> offset from a center closer to one corner.

As explained above, the base plates <NUM> of adjacent transport device units <NUM> are coupled and aligned using corner supports <NUM> (see <FIG>) attached to the connection brackets <NUM> at adjacent corners of the base plates <NUM>. In the embodiment shown, each connection bracket <NUM> is provided with two longitudinal grooves <NUM> at its two legs, which longitudinal grooves <NUM> extend parallel to the two adjoining sides and perpendicular to a surface area of the base plate <NUM>. A coupling element can be inserted into the grooves from above.

<FIG> shows a filter element <NUM> of the base plate module <NUM> of <FIG> in a side view. As can be seen in <FIG>, the filter element <NUM> has mirror symmetry allowing a mounting of the filter element <NUM> in four different orientations. The filter element <NUM> is provided with snap-fit connectors <NUM> for detachably securing the filter element <NUM> in position at the base plate <NUM> of the base plate module <NUM>. If required, the filter element <NUM> can be removed and cleaned or replaced. In case access to the filter element <NUM> is possible from below, such a removal and/or replacement is possible without disassembling the transport device unit <NUM>.

<FIG> shows the wiring board <NUM> of the base plate module <NUM> of <FIG> in a perspective view. As can be seen in <FIG>, the wiring board <NUM> is provided with a board-to-board connector <NUM> for electrically connecting the wiring board <NUM> and the actuator module <NUM> (see <FIG>), more particular for electrically connecting the wiring board <NUM> and an actuator module wiring board <NUM> (see <FIG>). In order to ensure a correct alignment of the wiring board <NUM> and the actuator module <NUM>, two centering pins <NUM> are provided, which are received in corresponding centering holes (<NUM>, see <FIG>) at the actuator module <NUM>. In order to avoid an overdetermined mechanical system, the wiring board <NUM> is float-mounted to the base plate <NUM> of the base plate module <NUM>. For this purpose, in the embodiment shown, the wiring board <NUM> is provided with through holes <NUM> for the fixation screws <NUM> (see <FIG>), which through holes <NUM> are larger in diameter than the fixation screws <NUM>. Hence, the wiring board <NUM> is mounted moveably within limits by means of the fixation screws <NUM> to the base plate <NUM>.

<FIG> show the actuator module <NUM> with the carrier element <NUM> and the actuators <NUM> in a perspective view from above and from below, respectively. <FIG> shows the actuator module <NUM> in a different orientation than <FIG> and wherein the actuators <NUM> are removed. <FIG> shows an electro-magnetic actuator <NUM> of the actuator module <NUM>.

The actuator module <NUM> has an essentially square basic shape with four equal sides and four corners. It is adapted to be mounted to the base plate module <NUM> by means of the stands <NUM>, <NUM> inserted into receiving openings <NUM>, <NUM> (see <FIG>). As mentioned above, the carrier element <NUM> is provided with four stands <NUM>, <NUM> adapted to be inserted into four receiving openings <NUM>, <NUM> of the base plate module <NUM> (see <FIG>). The receiving openings <NUM>, <NUM> as well as the corresponding stands <NUM>, <NUM> differ in design for providing a mechanical coding not having rotational symmetry. In the embodiment shown, two stands <NUM> have a U-shaped cross-section, whereas the other two stands <NUM> have a T-shaped cross-section. Each stand <NUM>, <NUM> is arranged at a center of one of the sides of the carrier element <NUM>.

The actuator module <NUM> comprises an actuator module wiring board <NUM> provided with contact pins <NUM> accessible via a bottom surface <NUM> of the carrier element <NUM>. The contact pins <NUM> are adapted to connect with the board-to-board connector <NUM> (see <FIG>) of the wiring board <NUM>. In order to ensure for a correct alignment of the contact pins <NUM> and the board-to-board connector <NUM> of the wiring board <NUM>, two centering holes <NUM> are provided at the bottom surface <NUM> as well as at the actuator module wiring board <NUM>. The centering holes <NUM> are adapted for receiving the centering pins <NUM> of the wiring board <NUM> for aligning the contact pins <NUM> of the actuator module wiring board <NUM> with the board-to-board connector <NUM>.

The actuators <NUM> are electrically and mechanically connected to the actuator module wiring board <NUM>. For this purpose, as best seen in <FIG>, the actuator module wiring board <NUM> is equipped with a plurality of sockets <NUM> adapted to receive contact pins <NUM> provided at the actuators <NUM> (see <FIG>). In order to facilitate a mounting of the actuators <NUM> to the actuator module <NUM>, in the embodiment shown the actuator module <NUM> comprises a grid structure <NUM> made of a magnetically conductive material, in particular a metal, comprising a plurality of bearing pins <NUM>. The bearing pins <NUM> are adapted to receive one actuator <NUM> each, wherein the actuators <NUM> are provided with corresponding cores <NUM>.

At a bottom side of the actuator module <NUM>, the fan <NUM> is provided. The length of the stands <NUM>, <NUM> exceeds the distance over which the fan <NUM> protrudes from the bottom surface <NUM> such that when placing the actuator module <NUM> on a planar surface, for example during transport, for storage and/or for an assembly, the distal ends of the stands <NUM>, <NUM> contact this planar surface and the fan <NUM> is distanced from the planar surface. Hence, it is possible to mount the fan <NUM> directly to the actuator module wiring board <NUM>.

At each side of each stand <NUM>, <NUM> a guiding groove <NUM> for a removal tool <NUM> (see <FIG>) is provided, as will be explained in more detail with reference to <FIG> below.

<FIG> show the driving surface module <NUM> in a perspective view from above and from below, respectively. <FIG> is a perspective view from below showing a detail of two adjacent driving surface modules <NUM> of <FIG>.

The driving surface module <NUM> is provided with a driving surface element <NUM>. The driving surface element <NUM> in particular is made of a material suitable for slidingly transporting sample carriers (not shown) along the top surface of the driving surface element <NUM>. The driving surface element <NUM> has an essentially square basic shape with four sides of equal length and four corners.

The driving surface module <NUM> is detachably supported by support elements. In the embodiment shown, the driving surface module <NUM> is detachably supported by the corner supports <NUM> (see <FIG>) serving as support element for the driving surface module <NUM>. At the four corners of the driving surface module <NUM>, connecting structures <NUM> are provided for connecting the driving surface module <NUM> via the corner supports <NUM> with the base plate module <NUM> (see <FIG>). The driving surface module <NUM> comprises a sensor board arranged at a bottom side of the driving surface element <NUM>. Hence, the sensor board is positioned close to the driving surface across which sample support carriers (not shown) are transported. The sensor board at least forms part of a device for sensing a presence or position of an individual sample container carrier moved across the upper side of the driving surface element <NUM>. In one embodiment, the driving surface element <NUM> is transparent to IR light, wherein the sensor board can be equipped with multiple IR based reflection light barriers arranged in a grid, and the sample container carriers can be adapted to reflect IR radiation emitted by the light barriers.

When mounting the driving surface module <NUM> to the base plate module <NUM> by means of the corner supports <NUM>, the driving surface module <NUM> is positioned with high accuracy in relation to the base plate module <NUM>.

At each side of the driving surface element <NUM> a rim <NUM> is provided.

The driving surface elements <NUM> of adjacent transport device units <NUM> overlap each other at their side regions. For this purpose, as best seen in <FIG> and <FIG>, at two adjoining sides of each driving surface module <NUM>, a transition between the top surface of the driving surface element <NUM> and the rim <NUM> is provided with a stepped portion <NUM>. At the respective opposing sides of each driving surface module <NUM>, a transition between the top surface of the driving surface element <NUM> and the rim <NUM> is provided with a complementary overhang portion <NUM>. The stepped portion <NUM> and the overhang portion <NUM> are adapted to each other such that the overhang portion <NUM> rests on the stepped portion <NUM> and is supported by the stepped portion <NUM> for a smooth transition between two driving surface modules <NUM>. In other words, adjacent transport device units <NUM> (see <FIG>) are arranged such that in each case a side provided with an overhang portion <NUM> contacts a side provided with a stepped portion <NUM>.

Further, for tolerance compensation in a vertical direction, resilient elements <NUM>, <NUM> are provided underneath the driving surface element <NUM> for forcing the stepped portion <NUM> towards the overhang portion <NUM>. The resilient elements <NUM>, <NUM> in the embodiment shown comprise pairs of hooked-shaped elements <NUM> arranged underneath each overhang portion <NUM>, wherein each pair of hooked-shaped elements <NUM> is interacting with a tongue-shaped element <NUM> provided at sides of the driving surface element <NUM> having a stepped portion <NUM>. The tongue-shaped element <NUM> and the stepped portion <NUM> are arranged between the overhang portion <NUM> and the hooked-shaped elements <NUM>. Hence, wherein the overhang portion <NUM> and the hooked-shaped elements <NUM> form a clamp for forcing the stepped portion <NUM> towards the overhang portion <NUM> and vice versa.

As best seen in <FIG>, in the embodiment shown, a grid-shaped resilient component <NUM> is provided, wherein the resilient elements <NUM>, <NUM> are formed at ends of grid-lines of the grid-shaped resilient component <NUM>. Grid-lines of the grid-shaped resilient component <NUM> are arranged above some of the actuators <NUM> of the actuator module <NUM> (see <FIG>), wherein the grid-lines are provided with recesses <NUM> for receiving upper ends of the actuators <NUM>. The grid-shaped resilient component <NUM> is mounted to the bottom surface of the driving surface element <NUM>. In the embodiment shown, the bottom surface of the driving surface element <NUM> is provided with screw sockets <NUM> for fixing the grid-shaped resilient component <NUM> to the driving surface element <NUM>.

In order to avoid that a liquid accidently spilled on the upper surface of the transport device enters the transport device unit <NUM>, a sealing cord <NUM> is provided. In the embodiment shown, the sealing cord <NUM> extends along two sides of the driving surface element <NUM>, namely the sides provided with the overhang portion <NUM>. The sealing cord <NUM> is mounted at the respective sides to the rim <NUM>. For this purpose, a groove for mounting of the sealing cord <NUM> can be provided. At the respective opposite sides, the rim <NUM> is provided with a sealing projection for contacting the sealing cord <NUM>.

In order to ensure that the driving surface modules <NUM> are mounted in such an orientation that in each case a side having an overhang portion <NUM> contacts a side of a driving surface module <NUM> of an adjacent transport device unit <NUM> having a stepped portion <NUM>, the driving surface element <NUM> has no rotational symmetry and can be mounted only in one orientation.

<FIG> shows a detail XVI of <FIG>, wherein the connecting structure <NUM> for connecting the driving surface module <NUM> with the corner support <NUM> (see <FIG>) is shown in more detail. The connecting structure <NUM> comprises a connection pin <NUM> formed integrally with the driving surface element <NUM>. Further, two snap-fit elements <NUM> are provided, which in the embodiment shown are formed integrally with the grid-shaped component <NUM>.

<FIG> is a perspective view of a corner support <NUM> for connecting adjacent transport device units <NUM> (see <FIG>). The corner support <NUM> in the embodiment shown functions as a cross-shaped connection node for both, a plurality of base plate modules <NUM> and a plurality of driving surface modules <NUM>. As shown in <FIG>, the corner supports <NUM> are arranged at the four corners of the transport device unit <NUM>, wherein the driving surface module <NUM> rests on the four corner supports <NUM>. Each corner support <NUM> is provided with a liquid trap recess <NUM> at its center for collecting liquid accidently spilled on the driving surface.

For connecting and aligning up to four base plate modules <NUM>, four pairs of snap-fit elements <NUM>, <NUM>, <NUM>, <NUM> and four pairs of ribs <NUM>, <NUM>, <NUM>, <NUM> (only partly visible in <FIG>) are provided. The snap-fit elements <NUM>, <NUM>, <NUM>, <NUM> as well as the ribs <NUM>, <NUM>, <NUM>, <NUM> of each pair are arranged at an angle of <NUM>° to each other. The ribs <NUM>, <NUM>, <NUM>, <NUM> are adapted to enter into the longitudinal grooves <NUM> of the connecting bracket <NUM> of the base plate modules <NUM> (see <FIG>) and the snap-fit elements <NUM>, <NUM>, <NUM>, <NUM> are adapted to be snapped to a hook provided at a side of the connecting bracket <NUM> directly adjacent to this longitudinal groove <NUM>. <FIG> shows a bottom view of a corner support <NUM> attached to a base plate <NUM>, wherein ribs <NUM> (not visible in <FIG>) are inserted into longitudinal grooves <NUM> of the connecting bracket <NUM> of the base plate <NUM> and snap-fit elements <NUM> are snapped to the hook provided at the side of the connecting bracket <NUM> directly adjacent to this longitudinal groove <NUM>.

The corner support <NUM> shown in <FIG> is further provided with four pairs of latch elements <NUM>, <NUM>, <NUM>, <NUM> (only partly visible in <FIG>) for connecting and aligning up to four driving surface modules <NUM>. The latch elements <NUM>, <NUM>, <NUM>, <NUM> of each pair are also arranged at an angle of <NUM>° to each other. Between the two latch elements <NUM>, <NUM>, <NUM>, <NUM> of each pair, an opening <NUM>, <NUM>, <NUM>, <NUM> is provided. <FIG> shows a bottom view of a corner support <NUM>, wherein two connecting structures <NUM> of two adjacent driving surface modules <NUM> are coupled by means of the corner support <NUM>. The connection pin <NUM> of each connecting structure <NUM> is inserted into an opening <NUM>, <NUM> and the snap-fit elements <NUM> of the respective connecting structure <NUM> interlocks with the latch elements <NUM>. <NUM> arranged on either side of the respective opening <NUM>, <NUM>.

As mentioned above, a sealing cord <NUM> is arranged between two adjacent driving surface modules <NUM>.

<FIG> schematically shows a sectional view of two adjacent transfer units with base plate elements <NUM> and driving surface modules <NUM>, which are coupled by means of a corner support <NUM>.

The connection pins <NUM> of each driving surface module <NUM> are inserted into an associated opening <NUM>, <NUM> of a common corner support <NUM>. As schematically shown in <FIG>, the sealing cord <NUM> forces the two driving surface modules <NUM> apart, and hence, the connection pins <NUM> are forced against the edges of the openings <NUM>, <NUM> receiving the connection pins <NUM> as schematically shown by two arrows in <FIG>. This allows for a precise positioning of the adjacent driving surface modules <NUM> with respect to each other. Further, it is avoided that acceptable tolerances between adjacent driving surface modules <NUM> accumulate along the driving surface.

As also shown in <FIG>, the corner support <NUM> also serves to clamp a base plate element <NUM> to an adjacent base plate element <NUM>. For this purpose, in the embodiment shown two parallel ribs <NUM>, <NUM> are inserted into two parallel arranged longitudinal grooves <NUM> of the brackets <NUM> of the adjacent base plate elements <NUM>.

One advantage of the modular system is that the transport device can be easily adapted to changing conditions and/or requirements of a laboratory automation system. Further, malfunctioning transport device units <NUM>, in particular malfunction actuator modules <NUM>, can be easily and quickly replaced. The transport device units <NUM> are arranged tightly at the transport device. For removal of a driving surface module <NUM>, said driving surface module <NUM> can be raised at one side having an overhang portion <NUM> and inclined. An access to the actuator module <NUM> is more challenging. For an easy removal, a removal tool <NUM> is provided.

<FIG> shows the transport device <NUM> upon removal of one actuator module <NUM> of a transport device unit <NUM> using two removal tools <NUM>. <FIG> shows a removal tool <NUM> in a perspective view.

As shown in <FIG>, for a removal of the actuator module <NUM>, at first the driving surface module <NUM> is removed. After the removal the driving surface module <NUM> as shown in <FIG>, two removal tools are inserted at two opposing sides of the actuator module <NUM>.

The removal tool <NUM> is essentially U-shaped with a handle portion <NUM> and two legs <NUM>. The legs <NUM> are adapted for entering into the guiding grooves <NUM> of the actuator module <NUM> (see <FIG>). At the distal ends of the legs <NUM>, engagement hooks <NUM> are provided for engaging with a bottom surface <NUM> of the carrier element <NUM> of the actuator module <NUM> and/or hooks provided in the grooves <NUM> for removing the actuator module <NUM> from the transport device <NUM>.

The removal tool <NUM> is provided with a stop element <NUM> arranged at least essentially in parallel to the handle portion <NUM>. The stop element <NUM> prevents the removal tool <NUM> from being entered too deep into the grooves <NUM>. Hence, an unintentional damaging of the actuator module <NUM> and/or any element arranged below the actuator module <NUM> with the removal tool <NUM> is avoided.

Claim 1:
A transport device with a plurality of electro-magnetic actuators (<NUM>) and a driving surface arranged above the electro-magnetic actuators (<NUM>), which driving surface is adapted to carry sample container carriers, wherein the driving surface is tiled comprising a plurality of driving surface modules (<NUM>) with driving surface elements (<NUM>), wherein support elements arranged in a grid pattern are provided, and wherein each driving surface module (<NUM>) is detachably mounted to a subset of the support elements, so that individual driving surface modules (<NUM>) are detachable to access electro-magnetic actuators (<NUM>) arranged below said individual driving surface modules (<NUM>).