CH712234B1 - Pipetting device with an automatically exchangeable functional component, in particular a filter, and a method for the alignment-free reception of a functional component in a pipetting channel. - Google Patents

Abstract

A pipetting device (10) for aspiration and dispensing of a dosing liquid at a dosing location (DO) by means of a working fluid, with a pipetting channel (22) containing working fluid during normal operation, which from a location further away from the dosing location (DO) along a channel path (K) to a pipetting channel end (24) located at a distance from the dosing location (DO) but closer to the dosing location (DO), a channel end region (43) having the pipetting channel end (24) being designed to contain a functional component (46), such as a filter component, a gas-permeable liquid barrier component and / or a reactive indicator component to be detachably received in the pipetting channel (22), which is characterized in that the channel end region (43) in a state of the pipetting device (10) that is ready for aspiration and / or dispensing as intended Pipetting channel end (24) having first section (40) with a larger channel cross section and a second section (42) with a smaller channel cross-section provided at a distance from the pipetting channel end (24), wherein the first and second sections (42) can be moved along the channel path (K) relative to one another between the operational state and a component release state wherein a free channel volume (44) of a pipetting channel section located in the first section (40) is greater in the operationally ready state than in the component release state.

Description

The present invention relates to a pipetting device for aspiration and dispensing of a dosing liquid at a dosing location by means of a working fluid, with a pipetting channel containing working fluid during normal operation, which from a location further away from the dosing location along a channel path up to a distance from the dosing location, However, the pipetting channel end closer to the metering point runs, wherein a channel end region having the pipetting channel end is designed to releasably receive a functional component, in particular a filter component, a gas-permeable liquid barrier component or a reactive indicator component, in the pipetting channel.

A generic pipetting device is known from WO 01/03835 A1. This shows a pipetting device with a piston-cylinder arrangement, by means of which a pressure of the working fluid can be changed by means of a displacement of the pipetting piston movably guided in the cylinder along the cylinder axis and thus an aspiration or dispensing process can be carried out with the mediation of the working fluid. As a rule, the aspiration process and the dispensing process are controlled in a manner known per se by a targeted change in the pressure of the working fluid compared to the atmospheric pressure prevailing in the external environment of the pipetting device.

In the generic pipetting device, a pipetting tip can be detachably attached to the cylinder of the piston-cylinder arrangement and is usually changed after each dispensing process. In the present application, the term “dosing process” denotes both an aspiration process and a dispensing process.

A piston rod connected to the pipetting piston emerges from the cylinder of the known pipetting device at its axial longitudinal end remote from the dosing location. This can be actuated to change the pressure in the working fluid. At the opposite axial longitudinal end of the cylinder, which is closer to the dosing location, a communication opening is provided in order to be able to communicate a pressure change in the working fluid caused by the displacement of the pipetting piston in the cylinder up to the dosing location.

The generic document further teaches to arrange a liquid barrier in the communication opening of the cylinder, which allows the gaseous working fluid used to pass through, but which blocks the passage of liquids. This can prevent an aspirated dosing liquid from getting into the working space of the piston-cylinder arrangement, which is delimited by the cylinder and piston surface, through splashes, foam formation and the like and thus possibly causing a contamination of dosing liquids that are dosing with the pipetting device after this contaminating dosing will.

The functional component referred to in the generic publication as “barrier means” comprises a tubular support structure and, as a functional element, a membrane which is fastened to the support structure spanning an opening of a through opening of the tubular support structure.

The tubular support structure has two axially successive sections with different outer diameters. The first section, further away from the functional element, is smaller in diameter and its outer diameter dimension is matched to the inner diameter of the communication opening pointing to the dosing location in such a way that this support structure section can be inserted into the communication opening and held there with a friction fit. The section closer to the functional element has a larger outer diameter than the inner diameter of the communication opening in order to prevent the functional component from being able to penetrate completely into the variable-volume working space of the cylinder, from where it can no longer be removed.

The functional element itself, that is, the membrane, is arranged at the free longitudinal end of the support structure with the larger-diameter section.

In the pipetting device known from WO 01/03835 A1, the functional component can be arranged on the pipetting device in such a way that when a pipetting tip is coupled to the pipetting device, regardless of whether a functional component is arranged or not, there is no change in length of the pipetting device and pipette tip formed overall arrangement comes.

However, in the known pipetting device, the pipetting piston is used to throw off the functional component arranged on the cylinder again. On the one hand, this is mechanically disadvantageous for the pipetting piston and, on the other hand, it means a low, but not negligible risk of contamination, since the pipetting piston of the pipetting device, as an essential part of a device for changing pressure in the working fluid, constantly comes into contact with different carrier structures. The purity of the support structure is therefore particularly important, because the pipetting piston is not easily accessible for cleaning.

Another pipetting device is known from JP 4792879 B2, in which a functional component can be arranged on a pipetting channel. The functional element, which is designed to be cylindrical or spherical in this publication, is received in a cylindrical support structure, which in turn has axial sections with different outer diameters.

A smaller-diameter section of the support structure can be inserted along the pipetting channel through the pipetting channel end into the channel end region until a larger-diameter section, the outer diameter of which is greater than the diameter of the pipetting channel at the pipetting channel end, comes to rest on the component having the pipetting channel end.

The spherical functional element known from this publication is arranged in a through channel in the support structure. The longitudinal end of the support structure that points away from the pipetting device as intended serves as the insertion end for detachably securing a disposable pipette tip. The shape of the insertion end of the pipette tip corresponds to the smaller-diameter axial section of the support structure, so that the pipette tip can be inserted either directly into the pipetting device or into the longitudinal end of the functional component remote from the device, more precisely: the support structure of the functional component.

In the pipetting device known from the JP publication, the pipetting piston does not come into contact with the functional element or its support structure, but the length of the overall arrangement of the pipetting device and pipetting tip changes depending on whether the functional component is arranged on the pipetting device or not . This change in length is associated with a change in the dosing location defined by a dosing opening of a coupled pipette tip. This change in the dosing location must be taken into account when operating the pipetting device.

In both known pipetting devices, the functional element of the functional component is always located outside of the pipetting channel defined by the pipetting device, even after the functional component has been arranged on the pipetting device.

A corresponding disadvantage of changing the position of the dosing location relative to the pipetting device depending on whether a functional component is provided or not also applies to the pipetting device known from US 2013/0203089 A1. A functional component with a functional element and a carrier structure carrying the functional element can also be arranged on this pipetting device between the pipetting device and the pipetting tip.

It is therefore the object of the present invention to develop a generic pipetting device in such a way that a functional component in the pipetting channel of the pipetting device - with a given pipette tip - can be arranged without changing the distance between the dosing point from the pipetting channel end and, compared to the generic prior art, with reduced mechanical stress and reduced risk of contamination for the pipetting piston is detachable from the pipetting device.

According to a first aspect of the present invention, this object is achieved by a pipetting device of the type mentioned at the outset, in which the channel end region in a state of the pipetting device that is ready for operation as intended for aspiration and / or dispensing has a first section having the pipetting channel end and a larger channel cross-section comprises a second section with a smaller channel cross-section provided at a distance from the pipetting channel end. The first and the second section can be moved along the channel path relative to one another between the operationally ready state and a component release state. In this case, a free channel volume of a pipetting channel section located in the first section is greater in the operationally ready state than in the component release state.

The functional component can thus be accommodated in the free channel volume of the first section with a larger channel cross section, which also has the pipetting channel end and thus an opening of the pipetting channel closer to the dosing location. The second section with a smaller channel cross-section provided at a distance from the pipetting channel end can limit the penetration depth of the functional component from the pipetting channel end along the channel path into the pipetting channel as a physical barrier.

The pipetting channel of the pipetting device is only defined by those components and component sections that are permanent, d. H. for multiple aspiration and dispensing processes are part of the pipetting device. Components that are coupled or can be coupled to the pipetting device only temporarily for aspiration and subsequent dispensing, such as pipette tips or adapters, are not part of the device's own pipetting channel.

Due to the relative mobility of the two sections to one another, the functional component detachably received in the first section of the channel end area can be removed from the channel end area and discarded. For this purpose, it is provided that the free channel volume of the pipetting channel section located in the first section, in which a functional component can be received in the operationally ready state, is greater in the operationally ready state than in the component released state. In the component release state, the free channel volume available for receiving the functional component in the first section of the channel end area is reduced by the previously performed relative movement of the first and second section of the channel end area in such a way that the reduced free channel volume is no longer sufficient to accommodate the functional component. Thus, in the component release state, either no functional component can be received in the channel end area, or a functional component that has already been received is or is detached from the channel end area.

[0022] The “operational state” of the pipetting device means a state which the pipetting device has as intended immediately before an aspiration or a dispensing of dosing liquid. For the operational state to be present, it does not depend on whether a pipette tip is actually coupled to the pipetting device, although this should not be ruled out. It is essentially decisive that the channel end area is present as it is present immediately before or during an aspiration or dispensation.

[0023] “Dosing location” means that location where the dosing liquid is aspirated or dispensed directly. When the pipette tip is connected, this dosing location is indicated through the dosing opening of the pipette tip. When the pipette tip is not coupled, the dosing location is a location which is located along the imaginary elongated channel path in the channel end area at a distance from the pipetting device, namely at a distance in a direction in which the dosing process will take place. A person skilled in the art will readily see in a pipetting device, even without a pipette tip, in which direction, starting from the end of the pipetting channel, the dispensing point is located. The exact distance of the dosing location from the end of the pipetting channel is not important for determining the subject matter of claim 1.

In the present case, the pipetting channel serves to transmit pressure changes in the working fluid. For this purpose, the pipetting device can comprise a pressure changing device which can be designed as a piston-cylinder device or as a rotating pump or as overpressure and underpressure reservoirs that can be activated and deactivated by valves. To protect the pressure transmission device from undesired contamination, a pipetting channel section is arranged between the channel end area with the two sections mentioned: first and second section, and the pressure change device, which separates the channel end area from the pressure change device.

A filter component, which, for example, removes constituents in the working fluid, can be thought of as a functional component. Such constituents can be aerosols, which can get into the working fluid by evaporation or nebulization of aspirated dosing liquid.

Likewise, the functional component can be a liquid barrier component that allows gaseous working fluid to flow in two opposite directions of flow along the channel path, but forms a flow barrier for liquid.

The functional component can also be an indicator component which, through a reaction, indicates the presence of a chemical substance, as is known, for example, as litmus tests for acids and bases.

In terms of construction, the free channel volume provided for receiving the functional component in the first section of the channel end region can be reduced in that the first and second sections, starting from the operational state, are relative to one another along the channel path with the second section approaching the pipetting channel end in the component -Release state are movable. As a result of this approaching movement, the second section can be introduced into the free duct volume that is present in the operationally ready state and, as the introduction increases, the free duct volume can be reduced.

In principle, the pipetting channel can have any shape in the channel end region, including a curved shape. Preferably, however, the pipetting channel is designed at least in the channel end region with the first and second sections in a straight line with a channel axis as a channel path. The channel path thus defines an axial direction. In the case of a curved channel path, the axial direction at one location is defined as a local axial direction by the respective tangent to the channel path.

To avoid undesirable flow obstacles in the pipetting channel section located in the channel end area, in particular due to bends or deflections of flow paths, it is preferred if the pipetting channel sections formed in each case in the first and second section are at least in the operational state, preferably also in the component release state, preferably also in every intermediate position that can be achieved between these states, are coaxial with one another. The coaxiality also facilitates the relative mobility, in particular if the pipetting channel sections in the first and in the second section are coaxial to one another in every intermediate position that can be reached between the operationally ready state and the component release state.

In principle, it can be thought of designing the channel end area as a one-piece channel end area component, in which the relative movement of the first and second sections along the channel path takes place through a deformation of the channel end area component. For example, a channel end area component forming the channel end area can be made of sufficiently flexible plastic, such as silicone plastic and the like. Then not only the relative deformability of the first and second sections while reducing the free channel volume in the first section is easily possible. Rather, the channel end region component can also rest against an inner wall of a pipette tip coupled to the pipetting device and thus contribute to sealing the pipette tip from the outside environment.

In order to ensure the most fully defined relative mobility possible over the entire relative movement path of the first and second section and to be able to further avoid deformation of the two sections during the relative movement, it can be provided according to a preferred development of the present invention that the first section at a first section component and the second section is formed on a second section component formed separately from the first, the section components of the channel end region being displaceable relative to one another along the channel path.

Since a received functional component should be safely received in the channel end region, especially during a dosing process, it is advantageous if the first and the second section are biased relative to one another into the operationally ready state.

In the one-piece solution outlined above, this bias can be based on the intrinsic elasticity of the channel end region component itself, determined essentially by the component shape and the component material of the one-piece channel end region component.

In the alternative solution with different section components, a spring arrangement can be provided between the first and the second section component. This spring arrangement can also be designed in one piece with the first and / or the second section component. In order to be able to obtain a dimension of the channel end region which is as axially short as possible, that is to say along the channel path, the spring arrangement preferably comprises disc springs or is a disc spring arrangement with exclusively disc springs. In this case, the spring arrangement, for example for setting the spring stiffness, can be designed separately from the first and second section components and particularly preferably detachable or replaceable on the pipetting device.

In addition to the first and / or the second section of the channel end region, the pipetting device usually has further movable operating components. Such operational components can be, inter alia, a crimp sleeve as part of a coupling device for the detachable coupling of a pipette tip or a stripping device for stripping off a previously coupled pipette tip. In order to be able to provide such operating components with the required precise mobility, the pipetting device preferably has a device base structure on which at least one operating component, preferably a plurality of operating components, can be provided so that they can be moved relative to the device base structure and possibly also relative to one another.

Since the pipetting device usually has to be brought closer to a container in order to carry out a dispensing process, be it to immerse a coupled pipette tip in a dispensing liquid supply to be aspirated or to lower a pipette tip filled with dispensing liquid into a container, the basic device structure is preferably arranged so that it can be displaced relative to a fixed device frame towards and away from the metering location. For example, the device base structure can be movably guided via a corresponding guide device on the device frame.

The basic device structure should be the origin of a stationary device coordinate system for the pipetting device.

Although it can basically remain open how exactly the relative mobility of the first and second section can be structurally solved, for reasons of increased device stability it is advantageous if the second section, in particular implemented as a second section component, is arranged in a stationary manner relative to the device base structure , and the first section, in particular again implemented as a first section component, is arranged on the device base structure so as to be movable relative to the second section. As a result, the number of components to be arranged movably on the device base structure is also reduced.

[0040] The second section is preferably arranged in a releasable manner on the device base structure by means of a latching engagement or by means of a threaded interlocking engagement.

To avoid misunderstandings in the present application, “releasable” always means the operational and intended releasability, i. H. a solvability that manages without destroying the components.

The functional component can in principle be held in a frictionally locking manner in the pipetting channel section formed in the first section of the channel end region. In order to accommodate the functional component in the channel end area as securely as possible, it can be provided that the pipetting channel has a tapering formation in the first section of the channel end area, in the area of which the clear width of the pipetting channel has a smaller dimension than in one along the channel path between the tapering formation and the region of the pipetting channel located in the second section. The tapering formation can be formed directly at the end of the pipetting channel, that is to say at the mouth of the pipetting channel, for example by a circumferential radial projection which protrudes radially inward from the pipetting channel wall defining the pipetting channel. However, a plurality of projections distributed in the circumferential direction around the pipetting channel path can also suffice. In the first section of the channel end region, the tapering formation is preferably axially closer to the pipetting channel end than in the second section, in order to provide sufficient space between the tapering formation and the second section to accommodate the functional component.

The pipetting device is preferably designed for the detachable coupling of a pipette tip, in particular a disposable pipette tip, which is why the pipetting device preferably has a coupling formation designed for this purpose. The coupling formation is preferably a coupling component assembly formed from a plurality of coupling components.

The first and / or the second section of the channel end region, in particular as a first and / or second section component, can be part of this coupling formation. The second section is preferably part of the coupling formation, this particularly applying to the implementation of the second section by means of a second section component. In this case, the second section component can be designed with sufficient rigidity to also be able to take over functional tasks of the coupling formation. The number of operating components and section components to be provided movably relative to the device base structure can thus be reduced, which increases the reliability of the pipetting device.

The present invention therefore also relates to a pipetting device designed and developed as described above with a pipetting tip that can be detachably coupled to the pipetting device. The pipette tip extends along a pipette tip axis. One of its axial end regions has, as the coupling end region, a counter-coupling formation for releasable coupling to the coupling formation. Its other axial end area opposite the coupling end area has a dosing opening as the dosing end area which defines the dosing location when coupled to the pipetting device.

When the pipetting tip is coupled to the pipetting device, the pipetting channel path in the channel end region and the pipetting tip axis are generally collinear.

A short overall arrangement of pipette device and pipette tip along the channel path or when the pipette tip is coupled along the pipette tip axis can advantageously be obtained in that the coupling end region of the pipette tip, when the pipette tip is coupled to the pipette device, is coaxial to at least part of the Extends channel end region and surrounds it radially on the outside. When the pipette tip is coupled to the pipetting device, the channel end area is then at least partially or even completely in the pipette tip, in particular in its coupling end area. The arrangement of a functional component in the first section of the channel end area thus does not change any length dimension of the overall arrangement formed from the pipetting device and the coupled pipette tip.

The present invention relates to a further pipetting arrangement comprising a pipetting device designed and developed as described above with a functional component designed separately from the pipetting device. The functional component has a contact section, the outer dimension of which is not smaller than the clear width of a pipetting channel section in the first section of the channel end area, this contact section of the functional component coming into contact with an inner wall of the pipetting channel after it has been received in the pipetting channel.

Due to the described contact between the functional component and the inner wall of the pipetting channel, a frictional securing of the position of the functional component in the first section of the channel end area can be ensured. This frictional engagement can be relatively strong due to the radial oversize of the functional component in relation to the clear width of the pipetting channel section in the first section of the channel end area, so that the functional component is firmly seated in the first section of the channel end area. This tight fit of the functional component is possible because the functional component can be pushed out of the first section of the channel end region and thrown off in a mechanically secure manner through the second section.

In order to reliably prevent undesired migration of the functional component along the pipetting channel into the pipetting device, the clear width of the pipetting channel in the second section of the channel end region is preferably sufficiently small, approximately smaller than the outer dimension of the contact section, in order for the functional component to penetrate completely to avoid the pipetting channel in the second section of the channel end area. Partial penetration or protrusion of the functional component into the second section can, however, be entirely possible.

The functional component can be secured in position with relatively low surface pressure along the channel path in the direction of the pipetting device in that a longitudinal end of the second section pointing to the pipetting channel end is complementary to an outer section of the functional component.

Another decisive advantage of the present invention over the prior art is that it allows the functional component to be received in the channel end region of the pipetting channel directly and without intermediate arrangement of a support structure that at least partially surrounds a functional element. By contrast, all of the functional components disclosed in the prior art discussed at the outset have a functional element received in a carrier structure. The production of the functional component that can be used for the present pipetting device is thus made considerably easier.

This development of a generic pipetting device with a support structure-free functional component, which is thus formed by the functional element alone, is so advantageous that separate patent protection is sought as a further development of the generic pipetting device mentioned at the beginning.

Thus, in contrast to the prior art, the functional element itself can be received directly in the pipetting channel.

The functional component is preferably designed in spherical shape, so that it is not necessary to align the functional component in order to receive it in the channel end region.

The term “functional component” denotes both a, in particular spherical, carrier structure with a functional element received therein, as well as a functional element, in particular a spherical, functional element used alone as a functional component.

The pipetting device of the present application can be part of an advantageous pipetting system which, in addition to the pipetting device, comprises a functional component supply and a functional component conveying device. The conveying device is designed to convey a functional component - with or without a support structure, preferably without a support structure as a mere functional element - from the functional component supply to a predetermined readiness position in order to provide the functional component for reception through the channel end region of the pipetting channel of the pipetting device, the functional component in the readiness position can be picked up by the channel end region of the pipetting channel in order to use its intended function. As a result, the detachable reception of a functional component in the pipetting device can be automated in an advantageous manner, which not only increases the process reliability with regard to the successful reception, but also the achievable process hygiene.

In order to ensure that only exactly one functional component is provided for reception by the pipetting device at the standby position and in its vicinity, the pipetting system can have a separating device which separates a plurality of functional components received in the functional component supply between the functional component supply and the supply position.

The separating device can be provided, for example, in a manner known per se at the outlet of the functional component supply, for example in the form of a drawer which only receives a single functional component due to its shape and size and which, when empty, is filled with a functional component in the functional component supply, driven by gravity, and then can be emptied by displacement from the functional component supply out into the functional component conveyor. Other types of separating devices are also known and can be used.

In principle, the functional component conveying device can have an automated gripper, for example in the form of a multi-axis robot, which can pick up a functional component at a point in the functional component supply and deposit it at the ready position. In this case, the functional component conveying device can also be a separating device. However, the effort involved in using a multi-axis robot or comparable automated apparatus to transport individual functional components appears to be inadequate.

The functional component conveyor can be formed simply, but effectively, utilizing gravity only by a channel or generally by a conveyor track with an inclination orthogonal to the direction of gravity in order to accelerate the functional component necessary for the movement from a delivery point of the gravity To effect functional component supply to the supply position.

In order to ensure that the functional component comes to rest in the ready position at precisely the ready position even with only gravity-driven movement, it can be provided that the pipetting system has an arrangement formation at the ready position which is designed to provide at least one functional component relative to the channel end region to be arranged in a surface arranged at an angle to the channel path in the channel end area in the ready position. The orthogonal surface is preferably a plane orthogonal to the channel path or a cone with a large opening angle of preferably more than 75 °, particularly preferably more than 80 °, half the opening angle of the cone. For example, the arrangement formation can be a depression in which the movement of the functional component ends in the ready position. Especially in the case of the preferred use of spherical functional components, the arrangement formation can be surrounded by a conical surface in order to ensure that the functional component always reaches the ready position. The opening angle is large in order to allow the first section of the end of the channel with the end of the pipetting channel to be sufficiently approximated to the surface arranged at an angle to the channel path in order to introduce the functional component sufficiently deep into the pipetting channel section located in the first section.

The conical surface around the standby position thus serves as a type of feed funnel for feeding functional components to the standby position.

For the orderly disposal of used functional components, the pipetting system can have a disposal container for receiving used functional components, the disposal container having a container inlet with an inlet opening. The inlet opening preferably has a greater clear width than the functional component which can be thrown into the discharge container. An edge of the container inlet surrounding the inlet opening can be contacted by the channel end region, in particular by its first section. The dropping container and in particular the edge surrounding its inlet opening must be sufficiently stable that when the dropping container is contacted by the channel end area of the pipetting device, the relative movement of the first and second section can be triggered by relative movement of the device base structure of the pipetting device and the dropping container along the channel path Discard functional component.

In principle, any section of the pipetting device can be contacted with the edge of the container surrounding the inlet opening; To keep the pipetting system low.

WO 01/03835 A1 also discloses a generic method for the detachable arrangement of a functional component, such as a filter component, a gas-permeable liquid barrier component and / or a reactive indicator component, in a channel end region of a pipetting channel of a pipetting device, in particular one as described above configured pipetting device, particularly preferably as part of a pipetting system, the method comprising the following steps: Provision of a functional component at a provision position, Moving the pipetting device to a standby position in which the course of a section of the pipetting channel located in the channel end area and reaching up to the pipetting channel end, intended to be extended towards the standby position, surrounds or intersects the standby position, Moving the channel end region from the standby position along the imaginary extended course to the standby position and thereby Introducing the functional component through the pipetting channel end into the section of the pipetting channel located in the channel end region.

A great advantage of the present invention over the technical teaching known from the generic WO 01/03835 A1 is that by using the spherical functional component, preferably formed by the functional element alone, an alignment of the functional component before insertion, in particular pressing , the same can be omitted through the pipetting channel end in the channel end area. The supply of functional components from a functional component supply to a supply position where the functional component is picked up by the pipetting device can be considerably simplified as a result. The process of picking up the functional component can run faster and more reliably, since there is no alignment process as a source of error.

The present invention will be explained in more detail below with reference to the accompanying drawings. It shows: FIG. 1 a schematic longitudinal sectional view of a pipetting device according to the invention of the present invention in a pipetting system, FIG. 2 a schematic longitudinal sectional view of the pipetting device from FIG. 1 with the pipetting tip coupled to it, and FIG. 3 a schematic longitudinal sectional view of the pipetting device from FIGS. 1 and 2 immediately after it has been dropped of a functional component.

In FIG. 1, an embodiment according to the invention of a pipetting device of the present application is designated generally by 10. The pipetting device 10 is part of a pipetting system 12 which, in addition to the pipetting device 10, has a functional component supply 14, a separating device 16 and a functional component conveying device 18.

The pipetting device 10 has a device basic structure 20, which forms a basic structure of the pipetting device 10, on which operational components movable relative to the device basic structure 20 and also relative to one another can be provided.

A pipetting channel 22 is formed in the device base structure 20, which extends along a channel path K, which is straight in the exemplary embodiment, as far as a pipetting channel end 24.

The imaginary channel path K extended beyond the pipetting channel end 24 would run to a theoretical dosing location DO at which the pipetting device 10 could currently aspirate or dispense dosing liquid.

The pipetting device 10 as a whole can be displaced along the channel path K relative to a device frame, not shown in FIGS. 1 to 3, in order to be approached and removed from a dosing location DO.

On the device base structure, a crimp sleeve 26 can be provided as an operational component, which can be movable relative to the device base structure 20 along the channel path K in order to axially compress an elastic sealing and locking ring 28 and thereby radially outward its outer diameter from the channel path K away to enlarge (see Figure 2). A pinch plate 30 can be provided between the pinch sleeve 26 and the sealing and locking ring 28 in order to be able to introduce force in the circumferential direction around the channel path K with the most uniform surface pressure possible into the sealing and locking ring 28.

A component 32 is fixed in place relative to the device base structure 20, in the illustrated embodiment by screwing it into the device base structure 20. On the one hand, a part of the pipetting channel 22 is formed on the component 32. On the other hand, an abutment 34 fixed to the basic structure can be formed thereon, against which the sealing and locking ring 28 is deformed by the movement of the crimp sleeve 26. The component 32 is a second section component in the sense of the introduction to the description.

On the component 32, a mounting component 36 is arranged, which is movable relative to the component 32 along the channel path K. In the intended, operationally ready state shown in FIG. 1, in which the pipetting device 10 is ready for dosing, i.e. for aspiration or dispensing, of a dosing liquid if a pipetting tip were coupled to it, the holding component 36 is located in its relative to the component 32 an axial end position. In this, the holding component 36 is pretensioned relative to the component 32 by a spring arrangement 38 which, in order to avoid unnecessarily high numbers of components, is preferably supported on the side of the abutment 34 facing away from the ring 28. The abutment 34 is preferably formed in one piece with the component 32, for example by injection molding. The support member 36 is a first section component in the sense of the Besch frictionein line.

With the exception of the external thread with which the component 32 is screwed into the device base structure 20, the component 32 is preferably rotationally symmetrical with respect to the channel path K.

The mounting component 36 is also preferably rotationally symmetrical with respect to the channel path K.

In the operational state of the pipetting device 10 shown in FIG. 1, a first section 40 of the pipetting channel 22 encompassing the pipetting channel end 24 and extending from it into the pipetting device 10 is formed in the holding component 36. A second section 42 following the first section 40 along the channel path K is formed in the component 32. The diameter of the pipetting channel 22, which is preferably designed to be rotationally symmetrical, is greater in the first section 40 than in the second section 42. The sections 40 and 42 form the channel end region 43, which also includes the pipetting channel end.

In the operationally ready state, the pipetting channel 22 provides a free channel volume 44 in the first section 40, in which a functional component 46, for example a filter component, can be detachably received. In order to be able to hold the functional component 46 securely in the free channel volume 44, the holding component 36 has, at its end region forming the pipetting channel longitudinal end 24, a tapering projection 48 which protrudes from the holding component 36 in a radially inward direction towards the channel path K and thus forms a section of reduced pipetting channel diameter, compared to the pipetting channel diameter in the remaining first section 40.

A functional component 46 is received as follows: A large number of functional components 46 are provided in the functional component supply 14. The separating device 16 provided on the output side of the functional component supply 14 ensures that only exactly one functional component 46 leaves the supply 14 towards the pipetting device 10.

The separating device 16, for example controlled by a control device not shown in Figure 1, outputs a single functional component 46 to the functional component conveyor 18, which is formed in the present case by a channel with a V-cross section, which moved the output and exclusively driven by gravity Functional components 46 leads in a form-fitting manner to the readiness position BP located in the plane of the drawing in FIG. 1. The spherical functional components 46 can roll in the channel 18.

An arrangement formation 50 is provided at the ready position BP, for example in the form of a cup-shaped component with a lateral inlet 52 through which the individual functional components 46 can roll into the arrangement formation 50.

The arrangement formation 50 has a side wall 54 which restricts the radial range of movement of the functional component 46 in the arrangement formation 50 in relation to the channel path K.

A bottom surface 56 adjoins the side wall 54, which is designed as a conical surface with a large cone angle, see half the cone angle α in FIG. 1.

At the ready position BP, the arrangement formation 50 has a depression 58 in which the functional component 46 conveyed into the arrangement formation 50 finally comes to rest.

In FIG. 1, the pipetting device 10 is not only shown in its intended, operationally ready state, but also in a standby position in which it attaches a functional component 46 provided in the standby position BP by simply approaching it along the pipetting channel K in the first section 40 of the pipetting channel 22 can accommodate.

For this purpose, the first section 40 has an axial length along the channel path K, which preferably corresponds to at least half the diameter of the functional component 46. The first section 40 is preferably designed to be axially shorter than the diameter of the functional component 46.

In the standby position of the pipetting device 10, the standby position BP is located in a virtual pipetting channel 22 'which is imagined to be extended beyond the pipetting channel end 24. In the standby position of the pipetting device 10, the channel path K, which is imagined to centrally penetrate the pipetting channel 22, intersects the standby position BP in its extension. For this purpose, too, the channel path K is to be thought of as being extended beyond the pipetting channel end 24 away from the pipetting device 10, as is shown in FIG.

The pipetting device 10 in FIG. 1 can accommodate the functional component 46 by lowering it along the channel path K. In this case, the holding component 36 is slipped over the functional component 46 until it comes into contact with a longitudinal end region 60 of the component 32 that is complementary to the outer shape of the functional component 46.

The spherical functional component 46 is thus pressed into the free channel volume 44 of the holding component 36 or of the pipetting channel 22 in the first section 40. With its equatorial section 61, which is to be determined in relation to the channel path K, it rests against the inner wall of the pipetting channel 22 in the first section 40 and is held there with a friction fit and is also held by the radial projection 48 in the first section 40 of the mounting component 36 (see FIG. 2).

The component 32 has radially outwardly on the abutment 34 to the holding component 36 and thus to the dosing DO protruding apron section 62, which limits the receiving space for the spring assembly 38 radially outward and at the same time as a movement guide for guiding the axial relative movement of the holding component 36 relative is used for component 32.

The components 32 and 36 can be made of plastic or metal. They can be made of different or the same materials.

In FIG. 2, the pipetting device 10 is shown with the pipetting tip 64 coupled to it.

A coupling end region 66 of the pipette tip extends coaxially to the holding component 36 and to at least one section of the component 32 Pipette tip 64 in the pipette tip 64. As a result, a distance between a metering opening, not shown, of the pipette tip 64 from the pipette channel end 24 is always the same regardless of whether a functional component 46 is received in the pipette channel 22 or not.

FIG. 2 also shows a properly operational state of the pipetting device 10. In comparison to FIG Determination of whether the operational state of the pipetting device 10 is present or not, not on. The only decisive factor for this is the relative position of the holding component 36 relative to the component 32. In the exemplary embodiment shown, the squeezing of the ring 28 has no influence on this position.

When the pipette tip 64 is coupled to the pipette device 10, a pipette tip longitudinal axis P coincides with the channel path K, which is intended to be extended beyond the pipette channel end 24. Channel path K and pipette tip longitudinal axis P are therefore collinear.

In FIG. 3, the pipetting device 10 of FIGS. 1 and 2 is shown in its component release state. In this state, the holding component 36 is displaced against the pretensioning force of the spring arrangement 38 along the channel path K from the expected metering location DO away to the abutment 34. The spring assembly 38 is therefore compressed. Consequently, the free channel volume 44 in the first section 40 of the channel end region 43 is reduced. This reduction is such that, starting from the pipetting channel end 24, the pipetting channel section located in the first section 40 extends deep into the pipetting device 10 by less than half the diameter of a functional component 46, preferably less than a third of this diameter. As a result, the functional component 46 initially received in the first section 40 of the pipetting channel 22 or the channel end region 43 is released from the pipetting device 10.

For this purpose, the pipetting system 12 shown in FIG. 1 has a dropping container 70. Its inlet opening 72 has a clear width that is larger than the largest diameter of the functional component 46. The inlet opening 72 preferably even has a larger clear width than the free channel volume 44 in the first section 40 of the channel end region 43.

The inlet opening is surrounded by an edge 74, which can be contacted by the end face 76 of the holding component 36. For this purpose, the pipetting device 10 is first moved into a position in which the channel path K is aligned with the entry axis E of the container entry 78 of the discharge container 70. Then the pipetting device 10 is lowered along the channel path K towards the disposal container 70, the end face 76 of the mounting component 36 coming into contact with the edge 74 of the container inlet 78 and, with the continued lowering movement of the pipetting device 10, against the biasing force of the spring arrangement 38 along the channel path K to Abutment 34 is moved towards. When the pipetting device 10 is lifted from the container inlet 78, the holding component 36 is displaced back into the operational state along the channel path K under the action of the force of the spring arrangement 38.

A sliding guide arrangement 80 enclosing the longitudinal end of the component 32 closer to the dosing location is fixedly attached to the component 32 and also moves relative to the holding component 36 when this is moved along the channel path K relative to the component 32.

For reasons of the highest possible rigidity of the container inlet 78 of the discharge container 70, this is preferably designed as a cone or as a cylinder.

The filter component 46 can - detached from the illustrated embodiment - be made from a plastic, for example from a polyolefin such as polypropylene or polyethylene, preferably from polyethylene. The functional component 46 can be sintered or designed as a tangled fiber to achieve a desired gas permeability. It is preferably sintered from a powder material. The pore size in the functional component 46 is preferably in a range from 15 to 50 μm, the proportion by volume of the pore volume in the total volume of the functional component 46 not being less than 35%. With a pressure difference of 50 mbar between the overpressure and the underpressure side in the pipetting channel, a gas flow of approximately 350 to 750 ml / min through the functional component is achieved.

The material forming the filter component 46 can be coated, for example it can be made hydrophobic. It can also be coated with indicator substances that change their color in the presence of predetermined chemical substances.

The functional component 46 is preferably formed solely by a functional element and does not have any housing.

The spherical shape of the functional component 46 impressively shows in FIG. 1 that an alignment of the functional component relative to the pipetting device 10 can be completely dispensed with and the functional component 46 is always ready to be picked up by the pipetting device 10 as soon as it is in the ready position BP Calm has come.

Claims (24)

1. Pipetting device (10) for aspiration and dispensing of a dosing liquid at a dosing location (DO) by means of a working fluid, with a pipetting channel (22) containing working fluid during normal operation, which from a location further away from the dosing location (DO) along a channel path (K ) extends to a pipetting channel end (24) located at a distance from the dosing location (DO) but closer to the dosing location (DO), a channel end region (43) having the pipetting channel end (24) being designed to contain a functional component (46), in particular a filter component, a gas-permeable liquid barrier component or a reactive indicator component to be detachably received in the pipetting channel (22), characterized in that the channel end region (43) in a state of the pipetting device (10) that is ready for operation as intended for aspiration and / or dispensing has a first section (40) having the pipetting channel end (24) and having a larger channel cross section and a section at a distance from the pipetting channel end (24) provided second section (42) with a smaller channel cross-section, wherein the first and the second section (42) are movable along the channel path (K) relative to one another between the operationally ready state and a component release state, wherein a free channel volume (44) of an im first section (40) located pipetting channel section is larger in the operational state than in the component release state. 2. Pipetting device (10) according to claim 1, characterized in that, starting from the operationally ready state, the first (40) and the second section (42) relative to one another along the channel path (K) with the second section (42) approaching the pipetting channel end (24) and thereby with the introduction of the second section ( 42) can be moved into the free channel volume (44) present in the first section (40) in the component release state. 3. Pipetting device (10) according to claim 1 or 2, characterized in that the pipetting channel sections formed in the first (40) and in the second section (42) are coaxial with each other at least in the operational state, preferably also in the component release state, preferably also in every intermediate position that can be reached between these states. 4. Pipetting device (10) according to one of the preceding claims, characterized in that the first section (40) is formed on a first section component (36) and the second section (42) is formed on a second section component (32) formed separately from the first, the section components (32, 36) relative to one another along the Canal track (K) are relocatable. 5. Pipetting device (10) according to one of the preceding claims, characterized in that the first (40) and the second section (42) are biased into the operational state. 6. pipetting device (10) according to claims 4 and 5, characterized in that a spring arrangement (38) is provided between the first (36) and the second section component (32), preferably a plate spring arrangement (38) for reasons of short dimensions along the channel path (K). 7. Pipetting device (10) according to one of the preceding claims, characterized in that it has a basic device structure (20), preferably a basic device structure (20) which can be displaced relative to a fixed device frame to and away from the metering location (DO), on which at least one operating component (26, 28, 30), preferably a plurality of operational components (26, 28, 30) is provided so as to be movable relative to the device base structure (20), the second section (42), in particular the second section component (32), being arranged in a stationary manner relative to the device base structure (20), in particular is detachably arranged with latching or threaded interlocking engagement. 8. pipetting device (10) according to one of the preceding claims, characterized in that the pipetting channel (22) has a tapering formation (48) in the first section (40) of the channel end area (43), in the area of which the clear width of the pipetting channel (22) has a smaller dimension than in one along the channel path ( K) the region of the pipetting channel (22) which is remote from the tapering formation (48). 9. pipetting device (10) according to one of the preceding claims, characterized in that it has a coupling formation, in particular a coupling component assembly, which is designed to releasably couple a pipetting tip (64) to the pipetting device (10). 10. pipetting device (10) according to claim 9, characterized in that the second section (42), in particular the second section component (32), is part of the coupling formation. 11. Pipetting device (10) according to one of claims 9 or 10, characterized in that it comprises a pipette tip (64) that can be detachably coupled to the coupling formation, the pipette tip extending along a pipette tip axis (P), an axial end region of the pipette tip (64) as the coupling end region (66) being a counter-coupling formation for the detachable coupling to the Has coupling formation and wherein another axial end area of the pipette tip (64) opposite the coupling end area (66) has a dosing opening as the dosing end area which defines the dosing location (DO) when the pipetting tip (64) is coupled to the pipetting device (10). 12. Pipetting device (10) according to claim 11, characterized in that the coupling end region (66) of the pipette tip (64) extends coaxially to at least part of the channel end region (43) in the state coupled to the pipetting device (10) and surrounds it radially on the outside. 13. Pipetting arrangement according to one of the preceding claims, comprising a pipetting device (10) and a functional component (46) formed separately from the pipetting device (10), the functional component (46) having a contact section (61) whose dimensions are not smaller than the clear width of an area of the pipetting channel (22) is in the first section (40) of the channel end area (43), the contact section (61) of the functional component (46) being in contact with the area of the pipetting channel (22) after it has been received in the pipetting channel (22) an inner wall of the pipetting channel (22) arrives. 14. Pipetting arrangement according to claim 13, characterized in that the clear width of the pipetting channel (22) in the second section (42) of the channel end region (43) is sufficiently small to allow the functional component (46) to completely penetrate into the second section (42) of the channel end region (43) Avoid pipetting channel section. 15. Pipetting arrangement according to claim 13 or 14, characterized in that a longitudinal end (60) of the second section (42) pointing towards the pipetting channel end (24) is designed to be complementary to an outer section of the functional component (46). 16. Pipetting arrangement according to one of the preceding claims, characterized in that it has a functional element (46) formed separately from the pipetting device (10) as the functional component (46) which is directly can be received in the channel end region (43) of the pipetting channel (22). 17. Pipetting arrangement according to one of claims 13 to 16, characterized in that the functional component (46) has a spherical shape. 18. Pipetting system (12) with a pipetting arrangement according to claim 17 and further with a functional component supply (14) and a functional component conveying device (18) which is designed to move a functional component (46) from the functional component supply (14) to a predetermined ready position ( BP) to provide the functional component (46) for receiving through the channel end region (43) of the pipetting channel (22), the functional component (46) in the ready position (BP) through the channel end region (43) of the pipetting channel (22) for Use of its intended function can be recorded. 19. Pipetting system (12) according to claim 18, characterized in that it has a separating device (16) which separates a plurality of functional components (46) received in the functional component supply (14) between the functional component supply (14) and the supply position (BP). 20. Pipetting system (12) according to claim 18 or 19, characterized in that it has an arrangement formation (50) at the ready position (BP) which is designed to place a functional component (46) at an angle relative to the channel end region (43) at least in one to the channel path (K) in the channel end region (43) arranged surface (56), in particular plane, to be arranged in the ready position (BP). 21. Pipetting system (12) according to claim 20, characterized in that the arrangement formation (50) has a recess (58) at the ready position (BP). 22. Pipetting system (12) according to one of claims 18 to 21, characterized in that the functional component conveying device (18) has a channel. 23. Pipetting system (12) according to one of claims 18 to 22, characterized in that it has a disposal container (70) for receiving used functional components (46), the disposal container (70) having a container inlet (78) with an inlet opening (72), the inlet opening (72) having a greater internal width than the functional component (46) which can be thrown into the discharge container (70), and wherein an edge (74) of the container inlet (78) surrounding the inlet opening (72) can be contacted by the channel end region (43), in particular by its first section (40). 24. A method for the detachable arrangement of a functional component (46), in particular a filter component, a gas-permeable liquid barrier component or a reactive indicator component, in a channel end region (43) of a pipetting channel (22) of a pipetting device (10) according to claim 17, the method comprising the following steps : - Provision of a functional component (46) at a provision position (BP), - Moving the pipetting device (10) to a standby position, in which the course of a section of the pipetting channel (22) located in the channel end region (43) and reaching up to the pipetting channel end (24) is intended to be extended towards the standby position (BP), the standby position ( BP) surrounds or cuts, - Moving the channel end region (43) from the standby position (BP) along the imaginary extended course to the standby position (BP) and thereby - pressing the functional component (46) through the pipetting channel end (24) into the section of the pipetting channel (22) located in the channel end region (43), characterized in that, due to a spherical configuration of the functional component (46), the method does not have a step of aligning the functional component (46).