Pipetting device with movable pipetting channel and increased storage distance

Description

[0001] The present invention relates to a pipetting device having a guide frame with a first linear guide rail and with a second linear guide rail according to the preamble of claim 1.

[0002] Such a pipetting device of the generic type is known, for example, from EP 2 410 342 A2. This document discloses a guide frame with a total of four parallel linear guide rails, with two of the four guide rails apparently serving to guide the displacement movement of a pipetting channel along the imaginary displacement axis.

[0003] The four known guide rails are grouped into two pairs, whereby the guide rails grouped into a pair are closer together than the guide rails of different groups.

[0004] The four guide rails of the known pipetting device lie in one plane and are identically aligned. On each of the four guide rails, the bearing components movably guided thereon are arranged on the side facing the pipetting channel, which facilitates the attachment of the disclosed plurality of pipetting channels.

[0005] Without it being expressly disclosed in EP 2 410 342 A2, it can be assumed that each pipetting channel is guided on a guide rail from each pair group and that further along the displacement axis, adjacent pipetting channels are displaceably guided on different guide rails.

[0006] With pipetting devices of this type, the fundamental problem is to design the individual pipetting channels as slim as possible, so that the dispensing openings or the channel axes of directly adjacent pipetting channels along the displacement axis are spaced no more than 9 mm apart. This makes the individual pipetting channels very slim in the direction of the displacement axis compared to their dimensions along the channel axis, which are many times larger than their dimensions along the displacement axis.As a rule, the dimension of the bearing components along the displacement axis is larger than the rectified dimension of the pipetting channels themselves, which makes the use of more than two guide rails necessary in order to be able to bring pipetting channels directly adjacent along the displacement axis closer to each other to the required 9 mm, despite the large dimension of the bearing components along the displacement axis compared to their own dimension.

[0007] The slim dimensions of a pipetting channel along the displacement axis, but expansive along the channel axis, lead to problems with the movable mounting of the pipetting channels, as the distance between the bearing components orthogonal to the displacement axis is very large compared to their bearing length along the displacement axis. During operation, acceleration of the pipetting channel along the displacement axis can result in acceleration moments acting around a moment axis orthogonal to both the channel axis and the displacement axis, leading to dynamic bearing forces that must be supported by the bearing components. In this case, even when using bearing components guided by rolling elements on the respective linear guide rails, the known pipetting device can experience short-term movement disturbances, for example due to jamming, so that the operation of the pipetting device is either disrupted or has to run more slowly than desired.

[0008] JP 2003-028884 A discloses a pipetting device having a plurality of pipetting channels. The pipetting channels are arranged at nodes of a scissor mechanism clamped between two base plates. As the base plates approach each other, the scissor mechanism is stretched against its preload, increasing the distance between all pipetting channels, the so-called "pipetting channel pitch." Removing the base plates contracts the correspondingly preloaded scissor mechanism, reducing the pipetting channel pitch.

[0009] The pipetting device described in JP 2003-028884 A is gripped by a movement device and moved by it parallel and orthogonal to a working plane in which containers to be pipetted are arranged.

[0010] From WO 2014 / 041113 A1, a pipetting device is known, having four parallel guide rails running along the displacement axis, wherein each of four pipetting channels directly following one another along the displacement axis is displaceably mounted on a different guide rail.

[0011] JP 2007-003339 A discloses a pipetting device with four parallel guide rails running along the displacement axis and with a plurality of pipetting channels. The four guide rails run along the edges of a cuboid extending along the displacement axis. Two guide rails are positioned exactly one above the other along the channel axis. Two other guide rails are positioned exactly opposite each other along an offset axis orthogonal to both the displacement axis and the channel axes. A pipetting channel is always guided along two guide rails positioned exactly one above the other along the channel axis for movement along the displacement axis. Pipetting channels immediately adjacent along the displacement axis are mounted on different pairs of guide rails spaced apart from one another along the offset axis.The pipetting channel pitch of pipetting channels of a guide rail pair can be changed by a scissor mechanism.

[0012] Another pipetting device with individually drivable pipetting channels is known from JP 2004-069664 A.

[0013] The object of the present invention is to improve the pipetting device mentioned at the outset in such a way that the disadvantages described above are reduced or even eliminated.

[0014] This object is achieved according to the present invention by a pipetting device having all the features of claim 1.

[0015] By changing the arrangement of the bearing components that can be displaced along the displacement axis with one and the same pipetting channel, such that these two bearing components are spaced apart along the displacement axis, a greater bearing length in the direction of the displacement axis is achieved on the pipetting channel bearing than is the case with previously known bearings, in which the two bearing components supporting one and the same pipetting channel are always arranged at the same position along the displacement axis. This increased bearing length avoids disruptive "drawer jamming," which is common when operating drawers that are short in the opening direction but wide in relation to the opening direction. Such drawers often jam repeatedly during an extension or insertion movement.

[0016] Although the guide frame of the pipetting device according to the invention is designed to be longer along the displacement axis by approximately the distance between the first and second bearing components than the actual usable displacement path of the pipetting channel along the displacement axis, this slightly larger installation space requirement is more than offset by the higher accelerations and displacement speeds along the displacement axis made possible by the improved mounting of the pipetting channel. The pipetting channel can thus be strongly accelerated and moved at high speed along the displacement axis, which leads to a significant productivity advantage over the operating life of the pipetting device. In principle, the first and / or second bearing components of the present invention can be a bearing component mounted displaceably along the displacement axis by means of a sliding bearing on the linear guide rail.For reasons of particularly low friction, it is preferred to mount the first and / or the second bearing component on the linear guide rail with rolling elements, for example by means of a recirculating ball bearing.

[0017] A linear guide rail within the meaning of the present invention is any component that guides a bearing component for movement along the displacement axis. Preferably, the first and / or second bearing component engages around the linear guide rail, so that the first and / or second bearing component preferably rides on the linear guide rail associated with the respective bearing component. Alternatively, however, the linear guide rail can also engage around the bearing component associated with it, so that the bearing component can be movably guided in a groove of the linear guide rail, for example, if the bearing component is not intended to protrude beyond the linear guide rail orthogonally to the displacement axis due to available installation space.

[0018] To reduce the number of different components required to manufacture the pipetting device, the first and second bearing components are preferably identical bearing components and are designed essentially identically. The same applies to the linear guide rails guiding the bearing components. These, too, are preferably designed essentially identically.

[0019] It should be noted that the identical structural design of a component in this case must be considered separately from the arrangement of structurally identical components relative to one another. As will be explained in more detail below, it is sometimes advantageous for the present invention if components are structurally identical in design, in order to avoid an unnecessarily high number of different components, but are arranged differently relative to one another on the pipetting device or, in particular, on the guide frame.

[0020] Although not absolutely necessary, in order to achieve dynamic bearing forces that are as equal as possible on the two bearing components, it is advantageous if the distance of the first bearing component along the displacement axis from the pipetting channel and the distance of the second bearing component along the displacement axis from the pipetting channel are equal in magnitude. The first bearing component then projects just as far along the displacement axis from the pipetting channel in one direction as the second bearing component does in the opposite direction.

[0021] However, under certain circumstances, for example, when the acceleration force exerted on the pipetting channel by a motion drive acts sufficiently far from the center of gravity of the displaceable pipetting channel and thus generates a dynamic moment, it may be advantageous if the distance of the pipetting channel from one bearing component is greater than from the other component. In this case, a configuration can even be selected in which the pipetting channel is always located at the same location along the displacement axis, i.e., in this case, at the same displacement axis coordinate, as one of the two bearing components, and only the other bearing component is spaced apart from the pipetting channel along the displacement axis.

[0022] According to an advantageous development of the present invention, the first and the second bearing component can be arranged offset from one another along an offset axis that is orthogonal to the displacement axis and different from a distance axis that runs in the direction of the shortest distance between the first and the second linear guide rail.

[0023] This measure again increases a bearing dimension, this time in the direction of the offset axis, by the offset amount, which stabilizes the movable bearing of the pipetting channel on the guide frame along the displacement axis.

[0024] To facilitate the description of the pipetting device according to the invention, its working plane will be used here. The working plane is the plane of a pipetting device on which containers are provided for pipetting operations. Typically, a pipetting channel is movable in a plane parallel to the working plane in order to be able to approach different containers and is movable orthogonally to the working plane in order to be able to enter and exit a provided container. The aforementioned displacement axis is a direction of movement parallel to the working plane. The working plane therefore serves below as the reference plane for describing the pipetting device and the movabilities and extensions realized therein.

[0025] Typically, the pipetting channel projects from the two linear guide rails in a substantially prominent direction. When the pipetting channel accelerates, not only must a dynamic moment about a moment axis orthogonal to the aforementioned displacement axis and parallel to the working plane of the pipetting device be supported by the bearing components, but also a dynamic moment about a second moment axis orthogonal to the working plane. This latter support is improved by the offset described. Jamming or movement disturbances in the movement guidance of the pipetting channel for displacement along the displacement axis caused by the second dynamic moment can thus be minimized or even completely eliminated.

[0026] In this application, the term "dynamics" is primarily understood as the study of forces and moments caused by motion, as well as of movement caused by forces and moments.

[0027] The offset axis is preferably non-parallel to the channel axis. Preferably, the offset axis is orthogonal to the channel axis. The offset axis, the displacement axis, and the channel axis thus preferably form three pairwise orthogonal, linearly independent axes of a Cartesian coordinate system, of which the offset axis and the displacement axis preferably run parallel to the working plane of the pipetting device.

[0028] Since the distance between the bearing components along the displacement axis is more crucial for avoiding an undesirable "drawer effect" along the displacement axis than the offset of the bearing components along the offset axis, the offset between the first and second bearing components along the offset axis is preferably smaller in magnitude than the distance between the first and second bearing components along the displacement axis. In order to limit the additional installation space requirements for the guide frame due to the bearing components arranged at a distance from one another along the offset axis, it is also preferably provided that the distance between the first and second bearing components is smaller in magnitude than the distance between the first and second linear guide rails.

[0029] In order to ensure the above-described advantageous accessibility of any point within the working plane of the pipetting device, a preferred embodiment of the present invention provides for the guide frame to be movable along a travel axis that is non-parallel to both the displacement axis and the channel axis. Preferably, the travel axis is orthogonal to the displacement axis as well as to the channel axis. In this case, the travel axis is parallel to the offset axis.

[0030] The guide frame can therefore itself be mounted so as to be movable relative to a fixture frame on a linear guide device known per se along the travel axis.

[0031] Preferably, a pipetting channel can be driven to move in each of its possible linearly independent directions of movement independently of a movement in the other directions of movement.

[0032] To reduce the number of different components in the pipetting device, the first and second bearing components are preferably identical. However, they are also preferably not provided with identical orientations on the guide frame. The first and second bearing components are preferably either rotated by 180° about a rotation axis orthogonal to the displacement axis and parallel to the working plane of the pipetting device or rotated by 180° about a rotation axis parallel to the displacement axis.

[0033] Thus, for example, one bearing component consisting of the first and second bearing components can be arranged upright on its associated guide rail. The other bearing component can be arranged suspended from the other guide rail assigned to it. In this way, the pipetting channel's bearing can excellently absorb opposing forces, since a bearing component can always be arranged such that the force occurring acts as a compressive force, which pushes the bearing component toward the linear guide rail that guides it. This preferably applies to opposing forces whose direction of action is oriented orthogonally to the working plane mentioned above as the reference plane.

[0034] In order to couple the first and the second bearing component to one another for a common displacement movement along the displacement axis, the pipetting device according to the invention has a holding arrangement which connects the first and the second bearing component to one another and on which the pipetting channel is adjustably received along its channel axis.

[0035] As explained above, the mounting of the pipetting device for movement along the displacement axis enables very high accelerations and movement speeds. To utilize this advantage, the pipetting device preferably has a linear motor drive for the displacement of the pipetting channel. This can be achieved structurally by the guide frame having a stator of a linear motor with a magnet arrangement, and by the mounting arrangement having a rotor of the linear motor with a coil arrangement. The stator with the magnet arrangement also runs along the displacement axis. The coil arrangement can be energized.

[0036] To be as independent of a power supply as possible, the magnet arrangement preferably comprises a series of permanent magnets arranged in succession along the displacement axis with alternating polarity. The permanent magnets are preferably polarized such that one pole points toward the path traversed by the rotor, and the other pole points away from this path.

[0037] To achieve locally high field strengths in the path traversed by the rotor, the magnet arrangement particularly preferably comprises a yoke arrangement in which two parallel rows of permanent magnets running along the displacement axis are arranged at a gap spacing from each other. The rotor of the pipetting channel assigned to this stator moves in the gap formed between the two rows of permanent magnets. In this yoke arrangement, magnetic poles of opposite polarity preferably lie opposite one another in the direction of the gap spacing, so that field lines of the magnet arrangement penetrate the gap traversed by the rotor as orthogonally as possible. Here, too, permanent magnets with alternating pole arrangements are arranged in each of the parallel magnet arrangements.The stator therefore preferably has a U-shaped cross-section in a sectional plane orthogonal to the displacement axis, with one of the two parallel magnet arrangements being arranged on each free leg of the U-profile.

[0038] For the synchronous execution of pipetting tasks, the pipetting device preferably has an additional pipetting channel which extends along a further channel axis parallel to the channel axis of the pipetting channel. In order to be able to bring the pipetting channel and the additional pipetting channel as close as possible to one another along the displacement axis, the guide frame preferably has a third and a fourth linear guide rail which run parallel to one another along the displacement axis and are provided at a distance from one another. The third and fourth linear guide rails are different from the first and second linear guide rails, but parallel to them. The additional pipetting channel is then displaceably guided along the displacement axis by a third bearing component on the third linear guide rail and by a fourth bearing component on the fourth linear guide rail.In order to achieve the advantage of stable support described above for the further pipetting channel as well, the third and fourth bearing components are arranged at a distance from each other along the displacement axis.

[0039] In principle, what was said above regarding the pipetting channel also applies mutatis mutandis to the further pipetting channel, with the proviso that the third linear guide rail replaces the first linear guide rail, the fourth linear guide rail replaces the second linear guide rail, the third bearing component replaces the first bearing component and the fourth bearing component replaces the second bearing component.

[0040] Preferably, the distance between the third and fourth bearing components along the displacement axis is equal in magnitude to the distance between the first and second bearing components along the displacement axis. This allows the pipetting channel and the additional pipetting channel to be brought as close to each other as possible, whereby the bearing components along the displacement axis can have a larger dimension than the pipetting channels themselves, since the bearing components of the pipetting channel and the bearing components of the additional pipetting channel are guided on different linear guide rails and thus cannot collide with each other.

[0041] Preferably, all bearing components of the guide frame are identical in construction.

[0042] In order to achieve the same dynamic conditions as possible at the pipetting channel and at the further pipetting channel, the distance between the first and the second guide rail is preferably equal in amount to the distance between the third and the fourth guide rail.

[0043] Likewise, to ensure equal movement and bearing conditions on the pipetting channel and the additional pipetting channel, it is preferable for the distance between the first and third guide rails to be equal in magnitude to the distance between the second and fourth guide rails, and for the distance between the first and fourth guide rails to be equal in magnitude to the distance between the second and third guide rails. This can be easily achieved, for example, by having the first to fourth guide rails form edges of a peripheral surface of a cuboid.In this case, the shortest distance between the first and second linear guide rails is preferably oriented obliquely to the working plane, so that the first and second guide rails, as well as the third and fourth guide rails, if present, are spaced apart from each other in a direction orthogonal to the working plane and also in a direction parallel to the working plane and orthogonal to the displacement axis. A compact arrangement of the guide rails is achieved when the first and fourth linear guide rails, on the one hand, and the third and second linear guide rails, on the other hand, are arranged exactly one below the other in a direction orthogonal to the working plane, and when the first and third linear guide rails, on the one hand, and the second and fourth linear guide rails, on the other hand, are arranged exactly next to each other in a direction parallel to the working plane.This leads to the above-mentioned arrangement of the linear guide rails on the edge lines of a circumferential surface of an imaginary cuboid.

[0044] The distance between the rails arranged one above the other in the direction orthogonal to the working plane is preferably greater than the distance between linear guide rails arranged next to one another parallel to the working plane.

[0045] Analogous to the pipetting channel, the additional pipetting channel can have an additional mounting arrangement that connects the third and fourth bearing components and on which the additional pipetting channel is adjustably mounted along its additional channel axis. This results in essentially equal stiffnesses of the functional units that can be displaced along the displacement axis: the pipetting channel and the additional pipetting channel.

[0046] To facilitate the manufacture and assembly of the pipetting device, the mounting arrangement according to the invention can have a carrier arrangement which connects two bearing components guided on different guide rails. The further mounting arrangement can likewise have a carrier arrangement which connects two bearing components guided on different guide rails. Furthermore, the mounting arrangement and the further mounting arrangement can have an adjustment arrangement which is formed separately from the carrier arrangement and connected thereto for a common displacement movement, on which adjustment arrangement the respective pipetting channel is adjustably received along the channel axis. According to the invention, the carrier arrangement couples the bearing components belonging to a respective pipetting channel to one another and enables the attachment of an adjustment arrangement thereto.

[0047] Since the adjustment arrangements, together with a generally common control device for all functional units: pipetting channel and additional pipetting channel, make a significant contribution to the adjustability of the functional units along the respective channel axis, it is advantageous, especially with regard to the use of a common control device, if the adjustment arrangements of the mounting arrangement and the additional mounting arrangement are essentially identical in design and arranged in an identical orientation relative to the guide frame. Due to the identical design and also the identical orientation relative to the guide frame, the same control algorithms can be used for all adjustment arrangements, for example.

[0048] The support assemblies of the pipetting channel and the additional pipetting channel can also be designed identically, which further reduces the number of different components required to manufacture the pipetting device. It may then be sufficient to arrange the structurally identical support assemblies differently oriented relative to each other for the pipetting channel on the one hand and the additional pipetting channel on the other.

[0049] Preferably, the support arrangements of the support arrangement on the one hand and the further support arrangement on the other hand are relative to each other rotated by 180° about a rotation axis orthogonal to the displacement axis and parallel to the working plane of the pipetting device and / or rotated by 180° about a rotation axis orthogonal to the working plane of the pipetting device This is possible, for example, if the four guide rails, as described above, run along the edges of a cuboid. Then the pipetting channel is located at one pair of diagonally opposite edges of the imaginary cuboid. Linear guide rails and the further pipetting channel on the other pair of diagonally opposite linear guide rails.

[0050] The above definition of the relative arrangement of the support arrangements of the holding arrangement on the one hand and the further holding arrangement on the other hand applies to the extremely preferred case that the four guide rails, as explained above, run along the edges of the circumferential surface of a cuboid and two sides of the circumferential surface of the cuboid are oriented parallel to the working surface and two further sides thereof are oriented orthogonally to the working surface.

[0051] For the far less preferred case where none of the four sides of the peripheral surface of the imaginary cuboid defined by the four linear guide rails is oriented parallel or orthogonal to the work surface, the support assemblies of the mounting assembly on the one hand and the further mounting assembly on the other hand can nevertheless be designed as identical parts if they are arranged rotated by 180° relative to each other about a rotation axis orthogonal to a pair of parallel sides of the peripheral surface of the imaginary cuboid defined by the four linear guide rails. The orientation of the work plane relative to the linear guide rails is then irrelevant.

[0052] The support arrangement preferably has, between connecting formations for connection to the respective bearing components, an arrangement formation for arranging an adjustment arrangement thereon. This arrangement formation is preferably symmetrical such that it is invariant with respect to a rotation of 180° about one of the rotation axes mentioned above in connection with the support arrangements, in order to always enable attachment of an adjustment arrangement in the same orientation relative to the guide frame, regardless of the respective orientation of the support arrangement guided on linear guide rails. Preferably - when considering the fully assembled pipetting device - the distance between two linear guide rails guiding one and the same support arrangement orthogonally to the working plane is smaller than the distance between the connecting formations of the support arrangement for connecting the same to the two bearing components guiding it.This allows, for example, the arrangement of at least one stator of a linear motor displacement drive in the area between two guide rails arranged at a distance from each other in a direction orthogonal to the working plane. Preferably, the at least one stator is arranged within the imaginary cuboid defined by the guide rails.

[0053] In order to be able to drive the additional pipetting channel with high acceleration and speed for movement along the displacement axis, the guide frame preferably comprises an additional stator of an additional linear motor with an additional magnet arrangement. The additional mounting arrangement comprises an additional rotor of the linear motor with an additional coil arrangement. This additional stator also runs along the displacement axis and is arranged orthogonally to the displacement axis at a distance from the aforementioned stator.

[0054] Again, the stator with the magnet arrangement, on the one hand, and the further stator with the further magnet arrangement, on the other hand, are preferably designed essentially identically. In particular, both stators are designed as a yoke with the U-shaped cross-section described above. To facilitate assembly of the pipetting device, the stators are then preferably arranged such that the columns of the stators, each with two opposing rows of magnets, are arranged coplanar. Preferably, the stator and the further stator face each other with the yoke opening and face away from each other with the yoke base.

[0055] Preferably, both the stator and the further stator are arranged in the area between two guide rails arranged at a distance from one another in a direction orthogonal to the working plane, particularly preferably within the imaginary cuboid defined by the guide rails.

[0056] The use of identical parts to form the stator and the further stator is possible, for example, if the stator and the further stator are either rotated by 180° about a rotation axis orthogonal to the displacement axis and parallel to a working plane of the pipetting device on which containers are provided for pipetting operations, or rotated by 180° about a rotation axis parallel to the displacement axis are arranged. This information also applies to the preferred case in which the four linear guide rails define the edges of a circumferential surface of a cuboid, and two sides of the circumferential surface are oriented parallel to the working plane. With any orientation of the circumferential surface, the stator and the further stator can be arranged as identical parts, rotated by 180° relative to one another around a rotation axis orthogonal to a pair of parallel sides of the circumferential surface of the cuboid.

[0057] Both orientations defined by relative rotation relative to each other are possible. Depending on the design of the magnet arrangement of the respective stator or additional stator, the two different relative arrangements are indistinguishable from each other. This applies, for example, if the stator and additional stator are mirror-symmetrical with respect to a longitudinal center plane orthogonal to the direction of travel.

[0058] One problem can be the rotor of the linear motor, which is coupled to the pipetting channel for joint displacement along the displacement axis. The same applies to the further rotor of the further pipetting channel. As a rule, one rotor, like another rotor, has a plurality of coils, preferably at least three coils, which are arranged one after the other along the axis of travel. Although the coils can theoretically overlap at least partially, in order to achieve the thinnest possible rotor it is advantageous if the coils are arranged completely next to one another, i.e., in a fully assembled pipetting device, one after the other along the axis of travel. In this case, however, the dimension of one rotor along the axis of travel is usually larger than the dimension of the pipetting channel coupled to the rotor for joint movement. The same applies to the further pipetting channel.

[0059] To increase the proportion of identical parts in the manufacture of the pipetting device, the rotor with the coil arrangement on the one hand and the further rotor with the further coil arrangement on the other hand are preferably structurally identical. However, in order to avoid a collision of the rotors when the pipetting channel and the further pipetting channel approach each other along the axis of travel due to the dimensions described above, and thus to enable a closer approach of the pipetting channel and the further pipetting channel, the rotor and the further rotor are preferably arranged rotated by 180° relative to each other about an axis of rotation orthogonal to the displacement axis and parallel to the working plane - or more generally about an axis of rotation orthogonal to a pair of parallel sides of the circumferential surface of the cuboid defined by the linear guide rails.

[0060] Preferably, the carrier arrangement thus has a mounting formation for attaching a rotor thereto.

[0061] Since the relative orientation of the rotor and the additional rotor to each other corresponds to the orientation of the support assembly and the additional support assembly, each rotor or each rotor component is preferably mounted identically to a support assembly to facilitate the assembly of the pipetting device according to the invention. The orientation of the support assembly relative to the guide frame then determines whether the mounted rotor component is a rotor or an additional rotor, depending on whether it interacts with the stator or the additional stator to generate an electromagnetic acceleration force.

[0062] Each slider or additional sliders is coupled to different phases of a voltage source via a plurality of electrical lines and is controlled by the aforementioned control device. The control device can be a computer or a programmable logic controller. Because the slider and the additional slider can be powered separately by the control device, the pipetting channel and the additional pipetting channel can be displaced independently of each other along the displacement axis.

[0063] The pipetting device according to the invention described here can have more than just one pipetting channel and can have more than just one further pipetting channel. With an increasing number of functional units in the form of pipetting channels and further pipetting channels, the number of pipetting processes that can be carried out simultaneously increases. Therefore, the pipetting device can preferably have a plurality of functional units in the form of pipetting channels and further pipetting channels. To achieve the best possible proximity of the functional units to one another - an approximation of the channel axes of adjacent functional units of at least 9 mm is desired here - along the axis of travel, with the exception of the end-side functional units, for a plurality of functional units, one pipetting channel is arranged between two further pipetting channels and another pipetting channel is arranged between two pipetting channels.This preferably applies to all other functional units with the exception of the end-side functional units, i.e. with the exception of the first and last pipetting channel or further pipetting channel along the displacement axis, depending on whether the pipetting device has an even or odd number of functional units: pipetting channels and further pipetting channels.

[0064] The present invention is explained in more detail below with reference to the accompanying drawings. It shows: Figure 1 shows a roughly schematic perspective view of an embodiment of a pipetting device according to the invention from above and in front, Figure 2 shows the pipetting device of Figure 1 when viewed along the displacement axis, Figure 3 the pipetting device of the Figure 1 and 2 in perspective view, but without paneling, when viewed from above and behind, Figure 4 the pipetting device of Figure 1, but without guide frame, only with linear guide rails and support arrangements and pipetting channels guided thereon by means of bearing components, when viewed along the travel axis, Figure 5 the representation of Figure 4 in perspective view from above and behind and Figure 6 the pipetting device of Figure 3 with alternatively shown linear guide arrangement for moving the pipetting channels also in the direction of the travel axis.

[0065] In the Figures 1 to 6 An embodiment of a pipetting device according to the invention of the present application is generally designated 10.

[0066] The pipetting device 10 comprises a guide frame 12, on which Figure 1The pipetting channels 14 and 16 shown are mounted so as to be movable along a displacement axis VL. The pipetting channels 14 and 16 are essentially identical in construction, so that the following information about a pipetting channel applies to all pipetting channels shown in the present embodiment.

[0067] Pipette tips 18 and 20, respectively, can be releasably received on the pipette channels 14 and 16 in a manner known per se.

[0068] The pipetting channels 14 and 16 extend along respective channel axes K14 and K16, respectively, which are preferably oriented orthogonally to the displacement axis VL.

[0069] On a working plane AE, which in the present embodiment is indicated by a dash-dotted line, containers are usually provided which are not shown in the figures and do not belong to the pipetting device, from which containers liquids are drawn into the pipetting tips 18 and 20 or into which liquids are dispensed from the pipetting tips 18 and 20. For the aspiration or dispensing of liquids, the pressure of a working medium, usually air, is changed in the pipetting channels 14 and 16 in a manner known per se in order to suck liquid into or eject liquid from the respective pipetting tip 18 and / or 20 via the negative pressure or positive pressure thus generated relative to the pressure of the surrounding atmosphere.

[0070] In this example, the working plane AE is parallel to the displacement axis VL and orthogonal to the channel axes K14 and K16.

[0071] The pipetting device 10 can also be arranged to be movable along a travel axis VF which is also parallel to the working plane AE but orthogonal to the displacement axis VL, as is shown for example in Figure 6at the left end of the guide frame 12. The pipetting channels 14 and 16 can then move to any point on the working plane AE within their ranges of motion along the movement axes VL and VF parallel to the working plane AE. In order to avoid colliding with containers provided there when moving parallel to the working plane AE and still be able to immerse themselves in them, the pipetting channels 14 and 16 are adjustable along adjustment axes VS parallel to the respective channel axes K14 and K16. The movement axes VL, VF and VS thus form linearly independent movement axes of a Cartesian coordinate system, so that a dispensing opening 18a of a pipetting tip 18 can move to any point in the movement space spanned by the movement axes VL, VF and VS within the ranges of motion assigned to the respective movement axes. For the dispensing openings of further pipetting tips 20, etc.What has been said for pipette tip 18 applies accordingly.

[0072] The pipetting channel 14—and all other pipetting channels 16, etc.—of the present pipetting device 10 is mounted on the guide frame 12 via a mounting device 22 so as to be displaceable along the displacement axis VL. In the illustrated embodiment, the mounting arrangement 22 comprises a support component 24, which is guided on the guide frame 12 so as to be displaceable along the displacement axis VL, and an adjustment arrangement 26 connected to the support assembly for joint displacement movement along the displacement axis VL. The adjustment arrangement 26 comprises a first component 26a fixed to the support assembly and a second component 26b movable relative to the first component 26a along the adjustment axis VS.The second component 26b can be guided on the first component 26a in a manner known per se for movement along the adjustment axis VS, for example by a linear guide device extending along the adjustment axis VS, and can further be driven for the adjustment movement in a manner known per se, for example by a spindle drive or by a linear motor. The movement drive for the relative movement of the second component 26b relative to the first component 26a along the adjustment axis VS can be accommodated in the first component 26a, and the control system required for this can also be partially or completely accommodated in the first component 26a. The second component 26b can partially or completely comprise the devices required for changing the pressure of the working medium in the associated respective pipetting channel, such as a corresponding control system.The pipetting channel 14 can, for example, have a ferromagnetic and preferably permanently magnetized piston, which is driven by coils 27 concentric with the respective channel axis K14, K16, etc., for movement along the channel axis K14 in a pipetting channel tube. The current supply to the drive coils 27 can be controlled by the controller incorporated in the first component 26a and / or the second component 26b.

[0073] The pipetting channels 14, 16, etc., are driven by linear motors along the displacement axis VL, enabling high accelerations with correspondingly high dynamic reaction forces. The productivity of such pipetting devices is therefore exceptionally high.

[0074] The guide frame 12 therefore has at least one stator 28. More precisely, the guide frame has two stators, namely the stator 28 and another stator 30. Both stators are essentially identical and are merely rotated relative to one another and arranged at a distance from one another. For example, the two stators 28 and 30 can theoretically be interconverted by rotating them 180° around an axis of rotation parallel to the displacement axis VL, or the two stators 28 and 30 can theoretically be interconverted by rotating them 180° around an axis of rotation parallel to the travel axis VF, i.e., around an axis of rotation orthogonal to the displacement axis VL and parallel to the working plane AE. The latter is the case in the illustrated embodiment. It is therefore sufficient to describe the stator 28 below.Its description also applies to the stator 30 under the above symmetry condition (theoretical transfer by rotation about an axis of rotation parallel to the travel axis VF by 180°).

[0075] The stator 28, like the stator 30, is preferably formed integrally with the guide frame, for example, as an extruded plastic profile or as an extruded aluminum profile. The stator 28 and / or the stator 30 can also be formed separately from the guide frame and connected to it with suitable connecting means.

[0076] The stator 28 has a U-shaped cross-section with its two opposing legs 28a and 28b, which are connected by a base 28c. The legs 28a and 28b can be designed as hollow bodies to save weight. A gap 32 is formed between the legs 28a and 28b of the yoke-like stator 28, in which the rotor 34, in this case the pipetting channel 16, runs displaceably along the displacement axis VL.

[0077] On the inner sides of the yoke legs 28a and 28b facing each other, a magnet arrangement is arranged, which comprises a series of alternatingly polarized permanent magnets arranged one after the other along the displacement axis VL. Figure 1 only the magnet arrangement 36 of the leg 28a which is further away from the pipetting channels 14 and 16. This magnet arrangement 36 is followed by a further magnet arrangement 37 (see Figure 3) on the leg 28b, in such a way that poles of opposite polarity always lie opposite one another in the width direction of the gap 32. The permanent magnets of the magnet arrangement 36 as well as of the opposite magnet arrangement 37 are arranged such that their polarization direction also points in the direction of the width of the gap 32, i.e. one of the two poles of a permanent magnet is always completely closer to the gap 32 and the other, opposite pole is completely further away from the gap 32. In this way, field lines between the magnet arrangements 36 and 37 of the two stator legs 28a and 28b of the yoke-like stator 28 pass through the gap 32 in the width direction thereof essentially orthogonally, the field direction reversing with each opposing pair of permanent magnets according to the sequence of permanent magnets arranged with alternating polarization along the displacement axis VL.In this way, a highly efficient, dense magnetic field can be achieved, in which the slider 34 can be moved with high precision, very quickly, and with high acceleration. The accuracy of the positioning of the pipetting channels along the displacement axis VL further depends on the pole pitch of the magnet arrangement 36 and the opposing magnet arrangement 37.

[0078] On the side of a stator section of the guide frame 12 facing away from the other stator, an arrangement 38 or 40 with a pair of linear guide rails is arranged. Figure 1 only the upper arrangement 38 is shown in detail, the lower arrangement 40 is only indicated.

[0079] The guide frame 12 can also have a linear scale 42, which serves to detect the position of pipetting channels along the displacement axis VL. The scale 42 is preferably an absolute scale, so that the position of a pipetting channel can be determined directly. However, the use of an incremental scale instead should not be ruled out. The scale 42 is preferably arranged in a mounting formation 44, into which it preferably fits flush. In the example shown, the mounting formation 44 for attaching the linear scale 42 is arranged on the side of the leg 28a of the stator 28 facing away from the magnet arrangement 36. The same applies to the stator 30 under the above-mentioned symmetry condition. However, the mounting formation 44 could just as well be formed on the side of the leg 28b facing away from the magnet arrangements or at another location on the guide frame 12.

[0080] Since pipetting channels guided on the guide frame 12 for displacement along the displacement axis VL cannot overtake each other, the arrangement of only one linear scale in a single mounting formation is sufficient. In the example shown, the guide frame 12 is surrounded by a shell-shaped casing 46 with a C-shaped cross-section. The mechanical connection of the pipetting channels 14, 16, etc., to the sliders 34 and 50, respectively, is established through the slot 48 of the casing 46.

[0081] How particularly good in Figure 5 As can be seen, each pipetting channel is guided on two linear guide rails, one from each rail arrangement 38 and 40. The linear guide rail arrangement 38 has a first linear guide rail 52, on which a bearing component 54 is guided so as to be displaceable only along the displacement axis VL.

[0082] The linear guide rail assembly 40 has a second linear guide rail 56, on which a second bearing component 58 is guided so as to be displaceable only along the displacement axis VL. The bearing components 54 and 58 can, for example, be guide carriages with recirculating ball bearings, which are guided with low friction but precision on their respective guide rails 52 and 56. The pipetting channel 14 is mounted by the first bearing component 54 and the second bearing component 58 for displacement along the displacement axis VL.

[0083] The first linear guide rail arrangement 38 has a third linear guide rail 60, on which a third bearing component 62 is guided so as to be displaceable only along the displacement axis VL. Likewise, the other linear guide rail arrangement 40 has a fourth linear guide rail 64, on which a fourth bearing component 66 is guided so as to be displaceable only along the displacement axis VL. The pipetting channel 16 is guided by the third and fourth bearing components 62 and 66 on the third and fourth linear guide rails 60 and 64, respectively, for displacement along the displacement axis VL.

[0084] The support assembly 24 of the pipetting channel 14 encompasses the first and second linear guide rails 52 and 56, respectively, which, in the arrangement of linear guide rails in the illustrated embodiment, also encompasses the fourth linear guide rail 64. According to the invention, the support assembly 24 of the pipetting channel 14 rigidly connects the first and second bearing components 54 and 58 for joint movement along the displacement axis VL. As shown in Figure 4which shows the guide rail assemblies 38 and 40 with pipetting channels guided thereon viewed along the travel axis VF, there is a distance A along the displacement axis VL between the bearing components 54 and 58, which are connected to the same pipetting channel 14. This allows the guide length of the pipetting channel 14 to be increased along the displacement axis VL without the pipetting channel 14 or the holder assembly 26 associated with it having to be made wider than necessary. The dimensions of the pipetting channel 14 and the holder assembly 26 do not exceed a value of 9 mm in the direction of the displacement axis VL. The distance A between the first and second bearing components 54 and 58 of the pipetting channel 14, on the other hand, is a multiple of the dimensions of the pipetting channel 14 or its holder assembly 26 in the direction of the displacement axis VL.The two bearing components 54 and 58 are equidistant from a plane containing the channel axis K14 of the pipetting channel 14 and orthogonal to the displacement axis VL, but are located on different sides of this plane.

[0085] The mentioned level is due to the perspective of Figure 4 , in which the travel axis VF is orthogonal to the drawing plane, also orthogonal to the drawing plane, so that it coincides with the line of the channel axis K14. The working plane AE is also in Figure 4 orthogonal to the drawing plane.

[0086] Since the linear guide rails 52 and 56 guiding the first and second bearing components 54 and 58 are offset from one another along an offset axis VA coinciding with the travel axis VF, the bearing components 54 and 58 also have an offset along this offset axis VA, which increases the guiding stability of the pipetting channel 14 during its movement along the displacement axis VL.

[0087] In Fig. 2 the offset V along the offset axis VA between the first and second bearing components 54 and 58 is clearly visible. Fig. 2 the displacement axis VL is oriented orthogonally to the drawing plane, as is the working plane AE.

[0088] The bearing components 54, 58, 62 and 66 are identical. The linear guide rails 52, 56, 60 and 64 are also identical to one another. The linear guide rails 52, 56, 60 are larger orthogonally to the displacement axis VL and travel axis VF than along the travel axis VF or offset axis VA. The linear guide rails 52, 56, 60 and 64 thus form the edges of a circumferential surface of a cuboid. The linear guide rails of arrangement 38 on the one hand and the guide rails of arrangement 40 on the other hand are arranged symmetrically in such a way that one arrangement can theoretically be converted into the other arrangement by rotating it 180° around an axis of rotation parallel to the displacement axis VL. Likewise, due to their symmetrical design, the linear guide rails can theoretically be converted into one another by rotating it 180° around an axis of rotation parallel to the travel axis VF.

[0089] The support assemblies 24 are identically designed for all pipetting channels, but are not arranged identically. The support assembly 24 of the pipetting channel 14 can be converted into a support assembly 24 of the pipetting channel 16 by rotating it 180° about a rotation axis parallel to the travel axis VF, and vice versa. The bearing components connected to the respective support assembly 24 can participate in this rotation.

[0090] Preferably, two pipetting channels directly adjacent to each other along the displacement axis VL are each guided on a different pair of linear guide rails. Thus, the pipetting channel 16 directly adjacent to the pipetting channel 14 along the displacement axis VL is guided on the third linear guide rail 60 and the fourth linear guide rail 64 for movement along the displacement axis VL. Figure 4shows two additional pipetting channels, one adjacent to pipetting channel 16 on the side facing away from pipetting channel 14, and one adjacent to pipetting channel 14 on the side facing away from pipetting channel 16. For all pipetting channels of the pipetting device 10 that are guided displaceably along the displacement axis VL, the condition applies that two pipetting channels directly adjacent to each other along the displacement axis VL are guided on different linear guide rails, with every second pipetting channel always being guided on the same two linear guide rails. This makes it possible to design the bearing components longer in the direction along the displacement axis VL than the pipetting channels they support, which means additional guide length along the displacement axis VL.

[0091] How Figure 5As shown, the rotors 34 and 50 of two rotors directly adjacent along the displacement axis VL are identical in design, but are not arranged identically on the pipetting device 10. These have a narrow attachment section 34a and 50a, respectively, which is no wider in the direction of the displacement axis VL than the desired grid dimension between two channel axes of two directly adjacent pipetting channels that are as close as possible to one another. Furthermore, the rotors 34 and 50 have a coil section 34b and 50b, respectively, in which a coil arrangement is accommodated which, when energized, generates a time-varying magnetic field that interacts with the magnet arrangements of the stators 28 and 30, respectively, and thus causes an acceleration of the respective pipetting channel along the displacement axis VL.The attachment section 34a and the coil section 34b have an L-shape, so that the runners 34 and 50 of two pipetting channels immediately adjacent along the displacement axis VL can complement each other to form a substantially closed rectangle when approaching each other as closely as possible.

[0092] On a support arrangement 24 or on a runner arranged thereon (see runner 50 in Figure 4 ), a sensor 68 can be provided, which interacts with the line scale 42 to determine the position. For reasons of symmetry and the associated simplified assembly and manufacture, the guide frame 12 with the stators 28 and 30 integrally formed thereon is preferably arranged mirror-symmetrically with respect to a plane of symmetry parallel to the working plane AE. Thus, the guide frame has two mounting formations 44 for mounting the line scale 42, of which, however, only one is actually required.

[0093] Figure 2 shows that a support arrangement 24, when viewed along the displacement axis VL, has an E-shaped configuration, the upper and lower legs of which serve to connect to the bearing components, the middle leg of which serves to connect to the respective rotor, and the base connecting the legs of which serves to connect to the adjustment arrangement 26. The middle part of the base connecting the three legs is preferably oriented parallel to the channel axis K of the respective pipetting channel connected to the support arrangement, whereas an upper and a lower region of the base of the support arrangement 24 is inclined with respect to the associated channel axis K in order to be able to effect the distance A of the bearing components connected to the support arrangement 24.

[0094] In Figure 6Firstly, it is shown that the pipetting device does not necessarily require a housing 46 surrounding the guide frame 12. Rather, the guide frame 12 itself can either rest directly on a frame 70 or be guided via a further linear guide arrangement 72 for movement along the travel axis VF. The guide frame 12 can itself be driven by a linear motor or mechanically by a spindle drive for movement along the travel axis VF. Of course, the guide frame 12 can also be designed to be movable with a housing 46 having a linear guide arrangement 72.

[0095] With the present invention, a highly dynamic, extremely fast and precisely movable and thus highly productive pipetting device 10 is achieved.

Claims

1. A pipetting apparatus (10) having a guidance frame (12) with a first linear guidance rail (52) and with a second linear guidance rail (56), the first and the second linear guidance rail (52, 56) proceeding parallel to one another along a displacement axis (VL) and being provided at a distance from one another orthogonally to the displacement axis (VL) , and having a pipetting channel (14) which extends along a channel axis (K14) which is nonparallel, preferably orthogonal, to the displacement axis (VL) channel axis (K14) and which is guided displaceably along the displacement axis (VL) by a first bearing component (54) on the first linear guidance rail (52) and by a second bearing component (58) on the second linear guidance rail (56), wherein the pipetting device (10) has a retaining arrangement (22) for coupling the first and second bearing components (54, 58) for joint displacement movement along the displacement axis (VL), which retaining arrangement connects the first and second bearing components (54, 58) to one another and on which the pipetting channel (14) is adjustably received along its channel axis (K14), wherein the retaining arrangement (22) has a carrier arrangement (24), which rigidly connects the first and the second bearing component (54, 58) to one another for joint movement along the displacement axis (VL), the pipetting device (10) having an adjustment arrangement (26) formed separately from the carrier arrangement (24) and connected to the carrier arrangement (24) for joint displacement movement on which the pipetting channel (14) is received adjustably along the channel axis (K14), characterized in that the first and the second bearing component (54, 58) are arranged at a distance (A) from one another along the displacement axis (VL) in order to increase the guide length of the pipetting channel along the displacement axis (VL), compared with an arrangement of the first and second bearing components (54, 58) at the same position along the displacement axis (VL).

2. The pipetting apparatus (10) according to Claim 1, characterized in that the spacing of the first bearing component (54) from the pipetting channel (14) along the displacement axis (VL), and the spacing of the second bearing component (58) from the pipetting channel (14) along the displacement axis (VL), are of equal magnitude.

3. The pipetting apparatus (10) according to one of Claims 1 or 2, characterized in that the first and the second bearing component (54, 58) are arranged with an offset (V) from one another along an offset axis (VA) that is orthogonal to the displacement axis (VL) and is different from a distance axis that proceeds in the direction of the shortest distance between the first (52) and the second linear guidance rail (56).

4. The pipetting apparatus (10) according to Claim 3, characterized in that the offset axis (VA) is nonparallel, preferably orthogonal, to the channel axis (K14).

5. The pipetting apparatus (10) according to Claim 3 or 4, characterized in that the magnitude of the offset (V) between the first and the second bearing component (54, 58) along the offset axis (VA) is less than the spacing (A) between the first and the second bearing component (54, 58) along the displacement axis (VL).

6. The pipetting apparatus (10) according to one of the preceding claims, characterized in that the guidance frame (12) is movable along a movement axis (VF) that is both nonparallel, preferably orthogonal, to the displacement axis (VL) and also nonparallel, preferably orthogonal, to the channel axis (K14), a working plane (AE) of the pipetting apparatus (10), on which containers for pipetting operations are furnished, being parallel both to the displacement axis (VL) and to the movement axis (VF).

7. The pipetting apparatus (10) according to one of the preceding claims, characterized in that the first and the second bearing component (54, 58) are embodied substantially identically and are preferably arranged relative to one another either rotated 180° around a rotation axis that is orthogonal to the displacement axis (VL) and parallel to a working plane (AE) of the pipetting apparatus (10) on which containers for pipetting operations are furnished; or rotated 180° around a rotation axis parallel to the displacement axis (VL).

8. The pipetting apparatus (10) according to one of the preceding claims, characterized in that the guidance frame (12) comprises a stator (28) of a linear motor having a magnet arrangement (36, 37); and the retaining arrangement (22) comprises a rotor (34) of the linear motor having a coil arrangement.

9. The pipetting apparatus (10) according to one of the preceding claims, characterized in that the guidance frame (12) comprises a third and a fourth linear guidance rail (60, 64) that proceed parallel to one another along the displacement axis (VL) and are provided at a distance from one another, the pipetting apparatus (10) comprising a further pipetting channel (16) that extends along a further channel axis (K16) parallel to the channel axis (K14) and is guided displaceably along the displacement axis (VL) with a third bearing component (62) on the third linear guidance rail (60) and with a fourth bearing component (66) on the fourth linear guidance rail (64), the third and the fourth bearing component (62, 66) being arranged with a spacing (A) from one another along the displacement axis (VL).

10. The pipetting apparatus (10) according to Claim 9, characterized in that the distance between the first and the second guidance rail (52, 56) is equal in magnitude to the distance between the third and the fourth guidance rail (60, 64).

11. The pipetting apparatus (10) according to Claim 9 or 10, characterized in that the distance between the first and the third guidance rail (52, 60) is equal in magnitude to the distance between the second and the fourth guidance rail (56; 64); and the distance between the first and fourth guidance rail (52, 64) is equal in magnitude to the distance between the second and the third guidance rail (56, 60).

12. The pipetting apparatus (10) according to one of Claims 9 to 11, characterized in that the further pipetting channel (16) comprises a further retaining arrangement (22) which connects the third and the fourth bearing component (62, 66) to one another and at which the further pipetting channel (16) is received shiftably along its further channel axis (K16).

13. The pipetting apparatus (10) according to Claim 12, characterized in that the retaining arrangement (22) and the further retaining arrangement (22) each comprise a carrier arrangement (24) that connects to one another two bearing components (54, 58, 62, 66) guided on different guidance rails, and comprise a shifting arrangement (26), embodied separately from the carrier arrangement (24) and connected thereto for displacement motion together, on which the respective pipetting channel (14, 16) is received shiftably along the channel axis (K14, K16).

14. The pipetting apparatus (10) according to Claim 13, characterized in that the shifting arrangements (26) of the retaining arrangement (22) and of the further retaining arrangement (22) are embodied substantially identically and are arranged with an identical orientation relative to the guidance frame (12).

15. The pipetting apparatus (10) according to Claim 13 or 14, characterized in that the carrier arrangements (24) of the retaining arrangement (22) and of the further retaining arrangement (22) are embodied substantially identically and are arranged with a different orientation relative to one another.

16. The pipetting apparatus (10) according to Claim 15, characterized in that the carrier arrangements (24) of the retaining arrangement (22) and of the further retaining arrangement (22) are arranged relative to one another rotated 180° around a rotation axis orthogonal to the displacement axis (VL) and parallel to a working plane (AE) of the pipetting apparatus (10) on which containers for pipetting operations are furnished; and / or rotated 180° around a rotation axis orthogonal to the working plane (AE) of the pipetting apparatus (10).

17. The pipetting apparatus (10) according to one of Claims 9 to 16, incorporating Claim 8, characterized in that the guidance frame (12) comprises a further stator (30) of a further linear motor having a further magnet arrangement; and the further retaining arrangement comprises a further rotor (50) of the linear motor having a further coil arrangement.

18. The pipetting apparatus (10) according to Claim 17, characterized in that on the one hand the stator (28) having the magnet arrangement (36), and on the other hand the further stator (30) having the further magnet arrangement, are embodied substantially identically and preferably are arranged in their orientation relative to one another either rotated 180° around a rotation axis that is orthogonal to the displacement axis ((VL) and parallel to a working plane (AE) of the pipetting apparatus (10) on which containers for pipetting operations are furnished; or rotated 180° around a rotation axis parallel to the displacement axis (VL).

19. The pipetting apparatus (10) according to Claim 18, characterized in that on the one hand the rotor (34) having the coil arrangement, and on the other hand the further rotor (50) having the further coil arrangement, are embodied substantially physically identically and are arranged in their orientation relative to one another rotated 180° around a rotation axis that is orthogonal to the displacement axis (VL) and parallel to a working plane (AE) of the pipetting apparatus (10) on which containers for pipetting operations are furnished.

20. The pipetting apparatus (10) according to Claim 19, incorporating Claim 14, characterized in that on the one hand the carrier arrangement (24) of the retaining arrangement (22), and on the other hand the further carrier arrangement (24) of the further retaining arrangement (22), each comprise a rotor (34, 50) and, including that rotor (34, 50), are embodied substantially identically and are arranged in their orientation relative to one another rotated 180° around a rotation axis orthogonal to the displacement axis (VL) and parallel to a working plane (AE) of the pipetting apparatus (10) on which containers for pipetting operations are furnished.

21. The pipetting apparatus (10) according to one of Claims 19 to 20, characterized in that it comprises a plurality of functional units in the form of pipetting channels (14) and further pipetting channels (16), such that along the displacement axis (VL), it is the case for a plurality of functional units with the exception of the end-located functional units, preferably for all the remaining functional units, that one pipetting channel (14) is arranged between two further pipetting channels (16), and one further pipetting channel (16) between two pipetting channels (14).