Laboratory apparatus

Abstract

A laboratory device, in particular for shaking and/or mixing substances, comprises a base unit, that comprises a drive apparatus, and a pivot unit, that is pivotably connected to the base unit by means of a bearing element about axes oriented perpendicular to a central axis of the base unit. The drive apparatus comprises an arrangement of magnetic elements at an inner side of a roll-off surface of the base unit and a control apparatus that is configured to control the arrangement of magnetic elements for generating a peripheral magnetic field along a closed path at an outer side of the roll-off surface to drive the roll-off section of the pivot unit by means of magnetic attraction and/or repulsion to make a rolling-off along said path.

Claims

1. A laboratory device, comprising: a base unit and a pivot unit that is pivotably connected to the base unit by means of a bearing element about axes oriented perpendicular to a central axis of the base unit, wherein the base unit comprises a drive apparatus to drive the pivot unit to make a tumbling movement about the central axis, wherein the drive apparatus comprises an arrangement of magnetic elements at an inner side of a roll-off surface of the base unit and a control apparatus; and wherein the pivot unit has a peripheral roll-off section, with the control apparatus being configured to control the arrangement of magnetic elements for generating a magnetic field running around along a closed path at an outer side of the roll-of surface to drive the roll-off section of the pivot unit by at least one of magnetically attracting and magnetically repulsing the roll-off section of the pivot unit to make the roll-off section of the pivot unit roll off along said path at the outer side of the roll-off surface of the base unit.

2. The laboratory device of claim 1, wherein the laboratory device is configured to shake and/or mix substances.

3. The laboratory device of claim 1, wherein the pivot unit is blocked against a rotation about the central axis.

4. The laboratory device of claim 3, wherein the pivot unit is blocked by the bearing element against a rotation about the central axis.

5. The laboratory device of claim 1, wherein the magnetic elements are controllable electromagnets.

6. The laboratory device of claim 1, wherein the arrangement of magnetic elements comprises at least three magnetic elements.

7. The laboratory device of claim 6, wherein the at least three magnetic elements are arranged along a circular path and/or equidistantly from one another.

8. The laboratory device of claim 6, wherein the arrangement of magnetic elements comprises at least four and at most eight magnetic elements.

9. The laboratory device of claim 1, wherein the roll-off section is circular.

10. The laboratory device of claim 1, wherein the control apparatus is configured to control the arrangement of magnetic elements for generating a uniformly peripheral magnetic field.

11. The laboratory device of claim 1, wherein the control apparatus is configured to control microsteps.

12. The laboratory device of claim 1, wherein the base unit is bounded in the direction toward the pivot unit by a wall element at which an attachment element is arranged that projects in the direction toward the pivot unit with respect to the wall element; and wherein the roll-off surface is formed at the attachment element.

13. The laboratory device of claim 1, wherein the pivot element comprises a reception section configured to receive substances and a base portion; and wherein the base portion projects in the direction toward the base unit with respect to the reception section and comprises the roll-off section.

14. The laboratory device of claim 1, wherein the laboratory device is configured such that a spacing of the pivot unit from the base unit can be variably fixed.

15. The laboratory device of claim 1, wherein the roll-off surface of at least one of the base unit and the roll-off section of the pivot unit is configured as at least one of changeable and replaceable.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described in more detail in the following only by way of example with reference to the drawings.

(2) FIG. 1 shows in a simplified schematic representation an embodiment of a laboratory device in accordance with the invention at eight points in time consecutive in time during a tumbling movement;

(3) FIG. 2 shows a first embodiment of a laboratory device in accordance with the invention in a schematic cross-section;

(4) FIG. 3 shows a second embodiment of a laboratory device in accordance with the invention in a schematic cross-section; and

(5) FIG. 4 shows a third embodiment of a laboratory device in accordance with the invention in a schematic cross-section.

DETAILED DESCRIPTION

(6) The laboratory device 11 shown in FIG. 1 is shown schematically in a highly simplified manner and comprises a base unit 13, that is shown as a parallelepiped, and a pivot unit 15, that is shown as a circular disk. A sample 17 is arranged on the pivot unit 15 to illustrate the spatial orientation of the pivot unit 15; said sample is shown as an elongate block that is intended to embody a container having a substance to be mixed. The pivot unit 15 is connected to the base unit 13 via a bearing element 19 (cf. FIGS. 2 to 4) covered by the pivot unit 15 and is pivotable about axes perpendicular to a central axis Z of the base unit 13, but not about the central axis Z. A margin of the pivot unit 15 impacts a roll-off surface 21 that is formed at an upper wall element 23 of the base unit 13 by a pivoting. The margin of the pivot unit 15 forms a roll-off section 25 of the pivot unit 15.

(7) The individual illustrations of FIG. 1 show eight points in time following one another uniformly within a single revolution of a tumbling movement of the pivot unit 15. In this respect, the states shown in the individual representations are periodically run through counter-clockwise. In the different individual representations of FIG. 1, the pivot unit 15 is pivoted in a respective different radial direction with respect to the central axis Z, but with the rotational position of the pivot unit 15 relative to the central axis Z always being the same. This can in particular be recognized by the fact that the sample 17 continuously maintains its radial orientation with respect to the central axis Z. The pivot unit 15 therefore does not carry out any rotational movement.

(8) As can be recognized from the illustrations, the point at which the pivot unit 15 is in contact with the base unit 13 changes continuously during the tumbling movement. The roll-off section 25 of the pivot unit 15 to this extent rolls off at the roll-of surface 21 of the base unit 13.

(9) The laboratory device 11 shown in FIG. 2 is shown in cross-section. A base unit 13 of the laboratory device 11 here has a wall element 23 as an upper boundary. The base unit 13 is bounded by further housing walls 27 toward the other sides. The base unit 13 comprises a drive apparatus 29 in its interior that has an arrangement of magnetic elements 33 that are formed as controllable electromagnets in the form of magnetic coils and that are spatially fixedly arranged in the base unit 13. Overall, the arrangement comprises six magnetic elements 33 that are uniformly arranged along a circular path about the central axis Z and of which only those two are shown that are located in the sectional plane of the illustration. In addition, the drive apparatus 29 has a control apparatus 37 that can control the magnetic elements 33 to generate respective magnetic fields and is only shown schematically.

(10) A bearing element 19 is received in a receiver 39 formed in the wall element 23. The bearing element 19 is substantially cylindrical and has a threaded section 43 that can cooperate with an internal thread (not shown) of the receiver 39 to variably define the position of the bearing element 19 axially to the central axis Z. At the end facing away from the base unit 13, the bearing element 19 has a spherical head 45 at which a pivot unit 15 is pivotably supported. A plate 35 is arranged beneath the magnetic elements 33 to provide, together with the bearing element 19 and the pivot unit 15, a magnetic ring closure for the magnetic field generated by the respective magnetic element 33. The remaining base unit 13 is furthermore shielded with respect to the magnetic fields generates by the magnetic elements 33 by the plate 35.

(11) The pivot unit 15 is substantially configured as a circular disk having a peripheral web section 47 that extends away from the base unit 13 and that serves for the securing of samples (not shown) arranged at the upper side of the pivot unit 15. The circular disk and the web section 47 to this extent form a reception section 49 of the pivot unit 15.

(12) The pivot unit 15 is preferably formed as ferromagnetic at least at its lower side facing the base unit 13 and/or at least along the margin facing away from the central axis Z. The lower outer edge of the pivot unit 15 facing the base unit 13 thus forms a roll-off section 25 of the pivot unit 15.

(13) In the state of the laboratory device 11 shown in FIG. 2, the magnetic element 33 shown at the right is controlled by the control apparatus 37 to generate a magnetic field that passes through the wall element 33 and thus is also presents in a sufficient intensity at the outer side of the wall element 23 oriented toward the pivot unit 15 to be able to magnetically attract the roll-off section 25 of the pivot unit 15 toward the roll-off surface 21 at the wall element 23. The remaining magnetic elements 33 are not controlled to generate a magnetic field at this point in time. The magnetic field has the greatest effect on that region of the roll-off section 25 that is located closest to the magnetic element 33. The pivot unit 15 is therefore pivoted in the direction of this magnetic element 33 so that the roll-off section 25, as shown, contacts a point of said region at the roll-off surface 21.

(14) The control apparatus 37 is configured to control the magnetic elements 33 to generate a magnetic field that runs around at the upper side of the wall element 23. For this purpose, the magnetic field of the magnetic element 33 shown at the right in FIG. 2 is attenuated, whereas the magnetic field of the magnetic element 33 (not shown) following along the circular arrangement of the magnetic elements 33 is simultaneously amplified until the magnetic field has so-to-say migrated onward to this following magnetic element 33. The attenuation of the one field and the amplification of the other field preferably take place such that the current of the one coil is reduced in a sinusoidal form, whereas the current of the other coil is increased in cosine form with the same prefactor and the same argument so that, in accordance with the Pythagorean trigonometric identity, the total force with which the two coils attract the pivot unit 15 remains constant. This routine can be continuously repeated with the respective following magnetic elements 33, whereby the magnetic field at the outer side of the wall element 23 runs around along a closed path that substantially corresponds to the circular arrangement of the magnetic elements beneath the wall element 23 and is therefore itself circular.

(15) The region of greatest magnetic attraction at the roll-off section 25 of the pivot unit 15 also runs around continuously due to the peripheral magnetic field. The pivot unit 15 is therefore pivoted in a peripheral radial direction continuously changing, that is running around the central axis Z, so that the pivot unit 15 carries out a tumbling movement. The roll-of section 25 of the pivot unit 15 here continuously rolls off at the roll-off surface 21 formed at the upper side of the wall element 23.

(16) Due to the geometry of the wall element 23 and of the pivot unit 15 and due to the spacing of the pivot point defined by the center of the spherical head 45 of the bearing element 19 from the wall element 23 and from the pivot unit 15, the angle of inclination of the pivot unit relative to the central axis Z is fixed during the tumbling movement. Since the bearing element 19, howeverdue to the cooperation of the threaded section 43 with the internal thread (not shown) of the receiver 39is fixable at different axial positions with respect to the central axis, the angle of inclination of the tumbling movement can be changed. A greater inclination, for example, results when the bearing element 19 is unscrewed further from the base unit 13 in comparison with the position shown in FIG. 2 since the pivot unit 15 then has to be pivoted more until the roll-off section 25 reaches the roll-off surface 21.

(17) To achieve a particularly uniform tumbling movement and to achieve a magnetic attraction that is at least approximately constant (albeit peripheral) in amount with a circularly peripheral magnetic field, it is favorable if the roll-off section 25 is in turn configured as circular, as in the embodiment shown in FIG. 2, for instance. If the roll-off section 25 is arranged directly at the reception section 49, the reception section 49 has to be suitably configured for the tumbling movement to be achieved, that is, for instance, it must have a circular periphery as in the pivot unit shown in FIG. 2 and substantially formed as a circular disk.

(18) However, to be able to form the reception section 49 independently of the tumbling movement, a base portion 51 that comprises the roll-off section 25 can be formed at the pivot unit 15 as in the embodiment shown in FIG. 3. The base portion 51 can then be configured with respect to the tumbling movement to be achieved, while the reception section 49 can be configured independently thereof only with respect to the reliable reception of samples. The reception section 49 can therefore, for instance, also be formed as a rectangular plate such as is the case in the embodiment shown in FIG. 3 that otherwise substantially corresponds to the embodiment shown in FIG. 2, with the same reference numerals marking mutually corresponding elements.

(19) The base portion 51 is substantially formed as a hollow cylinder that can be arranged at the lower side of the reception section 49 of the pivot unit 15 around the bearing element 19. The base portion 51 can generally be formed in one part with the reception section 49. In the embodiment shown, the base portion 51 and the reception section 49 are, however, formed separately. The base portion 51 is in particular releasably connected to the reception section 49 so that it can be selectively used or replaced with another base portion (not shown). In this respect, the respective base portion 51 is selected such that the base portion 51 impacts the wall element 23 on a pivoting of the pivot unit 15 so that the roll-off section 25 formed at the base portion 51 can cooperate with the roll-off surface 21. As the embodiment shown in FIG. 3 illustrates, the use of such a base portion 51 also permits great inclinations with reception sections 49 whose dimensions exceed those of the base unit 13.

(20) A further embodiment is shown in FIG. 4 that largely corresponds to the embodiments of the laboratory device 11 shown in FIGS. 2 and 3, with the same reference numerals marking mutually corresponding elements. In the laboratory device 11 in FIG. 4, however, unlike the other embodiments, an attachment element 55 is additionally provided at the wall element 23 of the base unit 13 formed as a plate 53. The attachment element 55 can also be provided when no roll-off element 51 is provided.

(21) In general, the attachment element 55 can be formed as part of the wall element 23 and in particular in one part with the plate 53. In the embodiment shown, the attachment element is formed, however, in a similar manner to the above-named base portion 51, as a separate hollow cylinder and can be placed onto the plate 53 to provide a roll-off surface 21 projecting in the direction toward the pivot unit 15 with respect to the plate 53 for the rolling off of the roll-off section 25 of the pivot unit 15. The roll-off surface 21 can then, as shown, be formed by the front surface of the attachment element 55 that faces the pivot unit 15 and that is a circular surface in the embodiment shown.

(22) The attachment element 55 can here be matched in size and shape to the desired tumbling movement so that the plate 53 can be formed independently thereof. In addition, the attachment element 55 is adapted to the magnetic field generated by the arrangement of the magnetic elements 33 so that the magnetic field in particular runs around along the roll-off surface 21 to a sufficiently high degree to attract the roll-off section 25 of the pivot unit 15 and thus to be able to bring about the tumbling movement of the pivot unit 15. The attachment element 55 can in particular, for instance, be formed with respect to its material and/or its shape such that is promotes the formation of the magnetic field along the roll-off surface 21.

(23) Like the base portion 51 at the remaining pivot unit 15, the attachment element 55 is arranged releasably and replaceably at the remaining base unit 13. The embodiment shown in FIG. 4 can therefore selectively also be operated without an attachment element 55 or without a base portion 51 to generate any respective tumbling movements. If no attachment element 55 or no base portion 51 is present, the (effective) roll-off surface 21 or the (effective) roll-section 25 is formed directly at the wall element 23 or at the reception section 49. The position of the respective currently effective roll-off surface 21 or of the respective currently effective roll-off section 25 can consequently be changed by replacing or removing the respective attachment element 55 or of the respective base portion 51

(24) With the laboratory devices 11 shown in FIGS. 2 to 4, the bearing element 19 cannot only be changed in its axial position, but can rather also be removed from the receiver 39 or can be replaced with another bearing element (not shown). It is, on the one hand, possible in this manner to use the base unit 13 in isolation as a magnetic stirrer in that a stirring vessel having a magnetic stir bar is placed onto the wall element 23 that is then driven to make a stirring movement by the drive apparatus 29. For this purpose, a plug (not shown) can be provided for a flush closing of the receiver 39. It is, on the other hand, possible to replace the pivot unit 15 with another work unit (not shown) which is optionally to be supported in another manner at the base unit 13 and which can be driven selectively alternatively to the pivot unit 15 by the drive apparatus 29 in a magnetic manner to make a working movement. A work unit can, for example, be provided for generating a rocking movement. Furthermore, for instance, the embodiments shown in the Figures can also be driven to make a rocking movement in that e.g. the shown respective work unit 15 is only alternately pivoted in the radial direction shown and in the radial direction opposite thereto. The two magnetic elements 33 shown in the sectional representations can then also be sufficient to drive such a rocking movement.

(25) The described laboratory devices 11 therefore have a particularly high flexibility with respect to their possible use with a configuration simple in construction.

REFERENCE NUMERAL LIST

(26) 11 laboratory device 13 base unit 15 pivot unit 17 sample 19 bearing element 21 roll-off surface 23 wall element 25 roll-off section 27 housing wall 29 drive apparatus 33 magnetic element 35 return plate 37 control apparatus 39 receiver 43 threaded section 45 spherical head 47 web section 49 reception section 51 base portion 53 plate 55 attachment plate Z central axis