EP2446959A1 - Sample mixing device - Google Patents

Abstract

The device (1) comprises a receiving unit, which has two receiving containers. Each receiving container comprises a support area for receiving a sample container (41 to 44), and a guide unit for the lateral guidance of the sample container. The distance between the support area and the guide unit of the former receiving container is different from a distance between the support area and the guide unit of the latter receiving container.

Description

Technical area

The invention relates to a device for mixing a sample, comprising a receiving device with at least a first and a second container receptacle, wherein each container receptacle comprises a support area for receiving a sample container and a guide device for laterally guiding the sample container.

State of the art

Sample material mixing devices are used, for example, in the laboratory for sample preparation prior to analysis and are known in many variants:

For example, shows the EP 0 853 493 B1 (Dade Behring Inc.) a device for mixing liquids, in particular for an analyzer. A lower part of a container is guided in a circular path while the container is kept stationary or vice versa. A centrifugal force is applied to a horizontal cam so that it pivots outwardly and deflects the centerline of the container from its original vertical orientation. A chemical analyzer includes a carousel with sample containers and a cuvette carousel with cuvettes and multiple cartridges. A sample is moved by means of an arm between the various containers, in particular to the vortex mixer.

The EP 1 393 797 B1 (Hans Heidolph) relates to a shaker with a driven eccentric, which is set in rotation. In the edge region of the eccentric unit, the eccentric unit comprises receptacles for vessels. The receptacles are designed essentially as through openings in support elements, in which the vessels can be introduced. The vessel holder can be designed so that vessels of any shape can be added and arranged in particular circular. The support elements are provided interchangeable.

The mixing devices known from the prior art have the disadvantage that they are only conditionally suitable for optimal mixing of different sample volumes. Typically, however, different volumes are needed for the analysis, depending on various factors, in particular the concentration of the substance to be investigated in the sample. Often, although a concentration of the substance can be reduced by means of a dilution series. However, due to the changing matrix concentration, the analysis result may change. Concentrating the samples can also be problematic. When concentrated, for example, due to too low solubility, certain Substances, especially the substances to be tested fail. Concentrations of suspensions are not only difficult to detect but can also damage sensitive analyzers.

Presentation of the invention

The object of the invention is to provide a device for mixing a sample which belongs to the technical field mentioned above and which is suitable for efficient mixing of different sample volumes.

The solution of the problem is defined by the features of claim 1. According to the invention, a distance between the support region and the guide device of the first container receptacle is different from a distance between the support region and the guide device of the second container receptacle.

This ensures that differently high sample containers are optimally supported in each case in a corresponding container receptacle. Preferably, different height sample containers are held by the guide device in each case proportional to the length of the sample container at about the same height above the support area. Typically, the sample containers are held by the guide device so far up that they can not fall out of the guide device during mixing.

The guide device preferably contacts the sample container over a small area, so that the sample container can not tilt during the mixing. Preferably, the contact surface of the guide device is annular, wherein the sample container during the mixing process at any time in each case only touches a circular arc piece of the ring. Furthermore, the guide device can also have, for example, three suitably arranged contact surfaces which can each contact the sample container at the same height. These may be formed, for example, as radially oriented pins.

The bearing areas of the container receptacles are preferably arranged at vertically different heights with respect to a horizontal plane and contact the same at the bottom, typically at a vertically lowest point of the sample container, or slightly higher, for example in the form of a lateral support in the outside bottom area of the sample container.

Due to the different height arrangement of the support areas of the two container receptacles is achieved that different height sample container, which are inserted into the container receptacles, with respect to a vertical upper area can be flush with each other. The contact areas are dimensioned accordingly to the sample containers. Thus, the insertion and removal of the sample container in and out of the device, in particular in an automated use, simplified. Namely, the automatic chemical analyzer may comprise a transport device which selects a corresponding container receptacle depending on the sample container size and can insert the sample container into it. In an advantageous embodiment, the heights of the bearing areas of the two container receptacles are selected such that an upper edge area of the sample containers comes to lie in each case at the same height. Thus, it is sufficient that the transport device in a vertical plane can each perform the same lowering movement to position the sample container in the receiving device.

When positioning in the receiving device, the transport device guides the sample container via the corresponding container receptacle. The transport device can be connected to a computing unit, which can choose the appropriate sample taking due to the size of the sample container. This can be done, for example, by manual input or automatically. For example, the transport device can grip the sample container on the circumference and determine its size on the basis of the diameter of the sample container so that the transport device itself can determine which container receptacle has to be actuated. For this purpose, the arithmetic unit to control the movement, in particular the way of gripper jaws of a gripping device, to derive the diameter of the To determine sample container. However, this requires that over the diameter of the sample container, the size of the same clearly determinable. Typically, however, sample containers of known sizes are used by means of the device, whereby detection of the same by the gripper can be dispensed with.

The sample container is guided over the corresponding container receptacle, lowered into this and then released. The release can take place in a vertical position in which the sample container does not touch, in particular just barely, the support region of the container receptacle. This prevents the transport device from damaging the sample container due to positioning inaccuracies. Alternatively, the support area can also be equipped with a resilient material, which can be compressed when parking the sample container. This tolerances of positioning inaccuracy can be added. Typically, the support region has a concave shape, so that the sample container can be stably held.

The automatic analyzer can be embodied as a chromatograph, in particular as a gas (GC) or liquid chromatograph (LC, HPLC), ion chromatograph (IC, EC) or as another measuring device known to the person skilled in the art of instrumental analysis. The transport device can be designed as an autosampler.

Of course, more than two container receptacles may be provided. In a preferred embodiment, the receiving device comprises four container receptacles, but also three or more than four container receptacles can be provided.

The sample is typically liquid or the main component of the sample is liquid. Since the sample is mixed, suspensions or emulsions, which may possibly be converted into solutions by mixing, can also be mixed by means of the device.

However, it will be clear to those skilled in the art that the device can also be used independently of an automatic chemical analyzer. The transfer of the sample container between the device and the analyzer can also be done by hand respectively. However, the device can also be used for applications other than sample preparation for chemical analysis. Anyone skilled in the art is familiar with any number of fields of application in which a sample must be mixed.

Preferably, a relative movement between the container receptacles and the guide device is executable in an operating state. During operation of the device, in a preferred embodiment, the receptacles of the sample containers move substantially in a horizontal plane, while the guide devices remain stationary. Preferably, the receptacles have a fixed position relative to one another, so that during operation the two receptacles each have the same distance from one another and the same orientation in the horizontal plane. Thus, a sample container inserted into the container receptacle, in particular a vertically lower region of the sample container, can be set in motion. The movement is preferably cyclical and forms a closed path, so that a mixing of the sample material in the sample container is achieved by the non-constant accelerations, which inter alia act on the sample material.

In principle, the movement of the support areas can also take place in a non-horizontal plane; in particular, a movement path on an inclined plane or as a free spatial movement path (similar to a roller coaster) is also conceivable.

Alternatively, in stationary support areas and the guide devices are set in motion.

The receiving device preferably comprises a movable base body on which at least two container receptacles are formed as recesses in the base body. For this purpose, the recesses may be arranged at different heights. The base body can be formed in one piece. It is also possible to provide inserts with which the height of the support surfaces can be varied (see below).

The base body preferably comprises at least one pedestal forming a container receptacle. This can be used in the production in a simple manner

Sample containers corresponding individual receiving device are prepared by one or more different pedestals are assembled in appropriate combination with the base body. This is particularly advantageous when, for example, two or more different sample container sizes are used in a laboratory. The base body is preferably guided against rotation, so that it can not perform any rotational movement during the mixing process. Thus, the container receptacles in the operation of the device in the horizontal plane in each case the same orientation (for example, direction north). For this purpose, the base body is preferably forcibly guided via a cam control.

In variants or in combination, the base body itself can take over the function of container receptacles. Depending on the size of the container, the pedestal can be dispensed with. The device may be such that a largest sample container can be used without the use of a pedestal.

Preferably, the pedestal is replaceable formed and in particular in a recess of the base body can be arranged. This ensures that the user, depending on the sample containers used, the or the pedestals can replace themselves. Depending on the sample container size can also be dispensed with a pedestal, since the recesses in the base body are suitable both as a container receptacle, as well as a receptacle for the pedestals. This results in a modular design of the recording device. For example, a vendor may provide a set of different pedestals with the device or offer them as accessories so that the user can quickly and inexpensively adapt the device to the respective sample containers. Preferably, the pedestals on a circular cylindrical shape, of course, other forms are conceivable. For this purpose, the pedestals preferably have an external thread in a lower region, which can interact with an internal thread of the base body. Preferably, the thread axially has a slightly conical shape, so that a pedestal is positively and non-positively held in the base body and thus does not dissolve in a mixing process from the base body. In order to achieve the necessary torque to the pedestal can have at right angles to the axis of rotation of the circular cylinder two parallel flats, whereby the pedestal by means of a corresponding open-end wrench can be screwed in the base body. Next, a bayonet lock can be provided for fixing. A variety of other suitable techniques for fixing the pedestals on the base body are familiar to those skilled in the art.

In variants, the pedestals can also be dispensed with. In this case, the base body may be equipped with the corresponding container receptacles.

The container receptacles are preferably displaceable in an eccentric translational orbital movement. Particularly preferably, the container receptacles are displaceable in a circular eccentric translational orbital movement, but also an elliptical or other orbital movements would be conceivable. However, a circular path is technically the easiest to implement and during the mixing process, the sample containers are better managed. The movement of the container receptacles are thus guided substantially on a circular path, wherein the orientation of the container receptacles is in each case constant, that is, the container receptacles preferably do not perform rotation about its own axis as a partial movement during the mixing process. This ensures that a centrifugal force on the sample in the sample container during the mixing process is not constant, but steadily changes. Thus, a largely optimal mixing of the sample is achieved.

In variants, the container receptacles can also be arranged radially on an eccentrically rotating disk.

Preferably, the receiving device comprises a diaphragm (50) with openings forming the guide devices for holding the sample containers (41-44) in a region lying over the support areas. Preferably, the diaphragm is arranged stationary over the support areas. The aperture is preferably formed as a horizontally oriented plate with circular openings. The sample containers are guided during insertion through the openings on the support area. When inserted, the containers are guided from the edge region of the openings at an upper region of the sample containers. The openings may for this purpose have a diameter in the region of the diameter of the sample container, but preferably a diameter of the openings is slightly larger than a diameter of the sample container. The openings have the Sample containers corresponding diameter, that is, the openings do not all have the same diameter. Accordingly, the aperture can also be made interchangeable, so that it can be adapted to the sample container sizes.

During the mixing process, the sample container is now offset by the container receptacle in an eccentric translational orbital movement, wherein an upper portion of the sample container is held by the opening of the aperture substantially stationary. Thus, an axis of the sample container describes a conical shell during the mixing process, whereby the mixing of the sample can be further optimized. The bearing areas of the container receptacles preferably have a concave shape, so that the bottom of the sample container remains in contact with the support area during the mixing process. If, for example, the sample containers have a hemispherical shape in a lower region, then the concave shape of the contact region has, for example, a spherical cap shape with a slightly larger radius, the spherical cap representing at most one hemisphere. In an alternative embodiment, the sample containers may have at the bottom a central, axially downwardly projecting pin, which can be inserted in a passport-shaped manner into an opening in the support area. In addition, a force and / or positive connection of the pin may be provided with the opening. This ensures that the sample container is held during the mixing process in the support area.

In variants can be dispensed with the aperture. In this case, the bearing areas of the container receptacles may have a shape in which the sample containers are received to a substantial extent and can not get out of the container receptacle during the mixing process. However, an axis of a sample container would essentially describe a cylinder jacket during the mixing process.

Preferably, in a rest position, a relative position between a support region and an aperture of the diaphragm is determined. During operation of the device, a relative arrangement between a support area and an opening periodically changes. The rest position is now as a unique position of a support area defined to an opening of the aperture. This ensures that the transport device can each lead a sample container in the same orientation in the device respectively refer to the device. In particular, during insertion, it is advantageous that for a transport device, a relative position between the opening of the panel and the corresponding support is unique, so that when inserting the sample container through the opening of the support area is also taken.

Alternatively, the determinate rest position can also be dispensed with. In order to facilitate the positioning of the sample container in this case, the support area can be correspondingly larger.

In the rest position, a center of one of the plurality of openings is preferably arranged in each case perpendicularly above a center of a corresponding support area. In a mixing process, an axis of a sample container thereby describes a shape of an oblique cone with a generatrix line substantially perpendicular to the plane of rotation. Thus, during the operation of the device through the sample container, each angular position between a maximum pivoting and a vertical orientation is taken. The fact that the centers of the opening and the corresponding support area are in the rest position on a vertical axis, it is achieved that the sample container can be inserted vertically into the container receptacles. Thus, in particular the loading and unloading is simplified by the transport device, as for the loading and unloading of the container receptacles, the sample containers can each be guided vertically.

In variants, the support region may have a conical shape and size, which allows a vertical insertion of the sample container on the support area in each position of the recordings. For this purpose, for example, a pedestal having a support area which is at least partially perpendicular in any position below a center of the corresponding opening of the panel. Thus, during insertion of the sample container, in particular after being released by the transport device, the same automatically guided by the conical shape in the stable state, in the middle of the support area.

Preferably, the base body is in the rest position on the orbit. Thus, a particularly simple embodiment of the device is achieved, since the position on the orbit to a certain extent represents a "natural" position of the base body.

In variants, the base body can also assume a centered rest position, from which it is deflected during the mixing process.

Preferably, the device includes a sensor to determine the rest position. The transport device can preferably pick up the signals of the sensor, whereby the coordination of a gripper can be controlled. The sensor may be formed in a manner known to those skilled in the art.

If the rest position with respect to the eccentric movement as a central position in the plane of rotation, that is, if the rest position is clear, can also be dispensed with the sensor.

The device preferably comprises a drive unit. The drive unit can be designed in a conventional manner. For this purpose, the base body can centrally have at the bottom a recess into which a cam, which is rotatably mounted eccentrically in a horizontal plane, can intervene. For this purpose, the nubs can be arranged eccentrically on a rotatably mounted plate. The rotation of the nubs can be done by means of an electric motor via a belt or a gear transmission. Preferably, the drive via a belt, since a belt drive is robust against vibrations due to the possibility of bias. The skilled person is also known to further suitable drive options.

In variants, the device may be driven by an external drive unit.

Preferably, the drive unit is controllable by means of the sensor so that the rest position can be approached. Thus, the gripping of the sample container by a transport device is further simplified.

From the following detailed description and the totality of the claims, further advantageous embodiments and feature combinations of the invention result.

The device preferably comprises a control unit for controlling the drive unit. Thus, depending on the sample material to be mixed, the drive unit can be controlled differently. The rotational frequency of the images of the sample container is controlled or adjusted. Typically, this is a constant rotational frequency set, but it is also conceivable to provide a non-constant rotational frequency, whereby the mixing could be further improved. For example, the drive unit could be controlled so that the rotational frequency continuously changes, performs a vibration overlay to the rotational movement and / or alternately changes the direction of rotation.

Alternatively, a single constant adjustment of the drive unit can be provided.

Brief description of the drawings

• Fig. 1 einen Schrägansicht eines erfindungsgemässen Vorrichtung zur Durchmischung einer Probe;
• Fig. 2a eine Seitenansicht der Vorrichtung in einem ersten Zustand;
• Fig. 2b eine Seitenansicht der Vorrichtung in einem zweiten Zustand mit zur Vertikalen verschenktem Probenbehälter.

The drawings used to explain the embodiment show:

• Fig. 1 an oblique view of an inventive device for mixing a sample;
• Fig. 2a a side view of the device in a first state;
• Fig. 2b a side view of the device in a second state with the sample container given away to the vertical.

Basically, the same parts are provided with the same reference numerals in the figures.

Ways to carry out the invention

The FIG. 1 shows a device according to the invention for mixing a sample 1. This comprises a base body 10 with a drive unit, not shown. On the base body 10, a base body 20 is movably mounted. The mounting allows a translatory orbital movement of the base body 20 relative to the stationary base body 10. The base body 20 is thus guided on a circular path without rotation. The base body 20 has four circular cylindrical recesses 21 - 24 on its upper side, wherein the recess 24 in the FIG. 1 is not apparent. The circular cylindrical axes of the recesses 21-24 are arranged in a square. In the recess 21 is a circular cylindrical pedestal 31, which has an external thread in a lower region, whereby this is screwed into the correspondingly shaped internal thread having recess 21 (not shown). The pedestal 31 in turn has a pedestal axially oriented cylindrical recess 31.1, in which a sample container 41 is used. The sample container 41 has an outer diameter, which is smaller than the recess 31.1 of the pedestal 31, so that the sample container 41 can be pivoted in the recess 31.1 in a certain angular range (see below). The recess 22 does not include a pedestal. The sample container 42 is sufficiently high, whereby the recess 22 itself can serve as a support region for the sample container 42. The containers 41 and 42 are arranged flush with each other by means of the pedestal 31 to each other above. Also in the recess 23 no pedestal is provided, since the sample container 43 also has a sufficient height. The sample container 43 protrudes above the sample containers 41 and 42. The sample container 44 is in turn arranged on a pedestal, which is not visible, however, and is also arranged flush with the sample containers 41 and 42 via a top edge. The pedestal corresponds structurally substantially to the pedestal 31 of the sample container 41, wherein the diameter is smaller and it has a greater height than the pedestal 31, since the sample container 44 is smaller than the sample container 41. The pedestals are provided interchangeable, so that the user adapt it to a specific application. As already noted, the recesses in the base body 20 may each have different diameters, so that these are suitable for different diameter sample container 41-44.

The device 1 further comprises an aperture 50, with four openings 51-54. The aperture 50 is held interchangeably in a diaphragm holder 60 and fastened, for example, by means of screws, not shown. The visor holder 60 comprises a rectangular frame 61 as a receptacle for the panel 50, a base plate 62 to which the base 10 is connected, and four abutment 63, which projecting over an upper end respectively perpendicularly downwardly with the corner regions of the frame 61 and a lower end to the base plate 62 are connected.

In the FIG. 1 the openings 51-54 are arranged vertically above the recesses 21-24 of the base body 20 and have the diameters of the recesses 21-24 in approximately proportional diameter. The sample containers 41-44 each protrude at least partially through the corresponding openings 51-54 and are thus kept substantially stationary during a mixing operation in the upper region. The base body 20 is located in the FIG. 1 in the so-called rest position, whereby the sample container 41-44 are each oriented vertically.

A support area, which is formed either as a recess 21-24 of the base body 20 or as a recess 31.1 of a pedestal 31, is formed so that a sample container 41-44 is pivotable in a certain angular range. This angular range depends on the diameter of a sample container 41-44, the dimension of the recess 21-24 or 31.1, the height between the support area to the panel 50 and the maximum deflection of the base body 20 relative to the base body 10. For given boundary conditions, the skilled person can easily determine the dimension (height and diameter) of the recess so that the sample containers 41 - 44 can not tilt during the mixing process.

The FIG. 2a shows a side view of the device 1 according to FIG. 1 , but in a different configuration. In contrast to FIG. 1 is used in the base body 20 only a pedestal 31, which carries the sample container 41. Opposite the FIG. 1 show the FIG. 2a additionally an eccentric drive 70 and a guide element 71, which between the Base body 20 and the main body 10 are arranged. The eccentric drive 70 can set the base body 20 in an eccentric translatory orbital movement, that is, the base body 20 oscillates at a constant orientation on a circular path. The eccentric drive 70 is driven via a belt, not shown, by an electric motor and additionally comprises a sensor for determining the current position. The FIG. 2a shows the device 1 in the rest position, the (single) sample container 41, on the pedestal 31, is oriented vertically and held laterally in the unillustrated opening 51 in an upper region. In this position, typically a sample container 41-44 is inserted or removed. The transfer of the sample containers 41-44 takes place with a transport device, not shown, in particular with a transport arm, which can introduce the sample containers 41-44 vertically through the openings 51-54. After insertion, the mixing operation may begin, whereby the base body 20 guides the lower regions of the sample containers 41-44 in a circular path, while the upper regions of the sample containers 41-44 are held substantially stationary in the openings 51-54.

The FIG. 2b essentially corresponds to the FIG. 2a , but wherein the eccentric 70 has completed half a turn. The sample container 41, which is held over the opening 51 (not shown), is in an inclined position, in particular in the maximum inclined position and is finally returned to the vertical position according to the continuing movement of the base body 20 FIG. 2a recycled.

For the expert it is understood that the embodiment of the device according to the Figures 1 - 3 merely an example of a possible embodiment. The constructive realization can be varied as desired.

In summary, it can be stated that, according to the invention, a device for mixing a sample is created, which is suitable for differently dimensioned sample containers and permits optimal mixing of the sample.

Claims (15)

Device (1) for mixing a sample, in particular for an automatic chemical analyzer, comprising a receiving device with at least one first and one second container receptacle (21-24, 31.1), each receptacle receptacle (21-24, 31.1) having a support region for receiving a Sample container (41-44) and a guide device for lateral guidance of the sample container (41-44), characterized in that a distance between the support area and the guide device of the first container receptacle is different from a distance between the support area and the guide device of the second container receptacle , Device (1) according to claim 1, characterized in that in an operating state, a relative movement between the container receptacles and the guide device is executable. Device (1) according to claim 1 or 2, characterized in that the receiving device comprises a movable base body (20) on which the at least two container receptacles (21-24) are formed as recesses (21-24) in the base body. Device (1) according to claim 3, characterized in that the base body (20) comprises at least one container receptacle (31.1) forming pedestal (31, 32). Device (1) according to claim 4, characterized in that the pedestal (31, 32) formed replaceable and in particular in a recess (21 - 24) of the base body (20) can be arranged. Device (1) according to one of claims 1 to 5, characterized in that the container receptacles (21 - 24, 31.1) are displaceable in an eccentric translational orbital movement. Device (1) according to claim 6, characterized in that the container receptacles (21 - 24, 31.1) are displaceable in a circular eccentric translational orbital movement. Device (1) according to one of claims 1 to 7, characterized in that it comprises a diaphragm (50) with openings forming the guide devices for holding the sample containers (41-44) in a region lying over the support areas. Device (1) according to claim 8, characterized in that in a rest position, a relative position between a support region and an opening (51-54) of the diaphragm (31, 32) is determined. Device (1) according to claim 8 or 9, characterized in that in the rest position, a center of one of the plurality of openings (51-54) are each arranged vertically above a center of one of the plurality of support areas. Device (1) according to one of claims 3 to 10, characterized in that the base body (20) is in the rest position in orbit. Device (1) according to one of claims 9 to 11, characterized in that it comprises a sensor to determine the rest position. Device (1) according to one of claims 1 to 12, characterized in that it comprises a drive unit (70). Device (1) according to claim 12 and 13, characterized in that the drive unit (70) is controllable by means of the sensor so that the rest position can be approached. Device (1) according to claim 13 or 14, characterized in that it comprises a control unit for controlling the drive unit.

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