STIRRING APPARATUS FOR A FLASH POINT DETERMINATION APPARATUS COMPRISING A SELECTIVELY REMOVABLE STIRRING DEVICE

Abstract

Stirring device for stirring a sample in a container which is closable by a lid, for a flash point determination test and/or combustion point determination test, wherein the stirring device comprises a stirring unit which may extend at least partially through the lid for stirring the sample which is arranged in the container, a drive unit which is to be arranged at least partially outside of the lid, for driving, in particular rotationally driving, the stirring unit, a coupling unit for coupling the stirring unit with the drive unit, and an actuation unit which, in particular for adjusting the coupling unit, is actuatable such that selectively in a first actuation position, when pulling up the drive unit, the lid is detachable from the container commonly with the stirring device, or in a second actuation position, when pulling up the drive unit, the drive unit is detachable from the container, and the stirring unit and the lid remain at the container.

Claims

1.-24. (canceled)

25. Stirring device for stirring a sample in a container which is closable by a lid for a flash point determination test and/or combustion point determination test, wherein the stirring device comprises: a stirring unit which may extend at least partially through the lid for stirring the sample which is arranged in the container; a drive unit which is to be arranged at least partially outside of the lid, for driving, in particular rotationally driving, the stirring device; a coupling unit for coupling the stirring unit with the drive unit; and an actuation unit which is actuatable, in particular for adjusting the coupling unit, such that selectively: in a first actuation position, when pulling up the drive unit, the lid is detachable from the container commonly with the stirring unit; or in a second actuation position, when pulling up the drive unit, the drive unit is detachable from the container and the stirring unit and the lid remain at the container.

26. Stirring device according to claim 25, wherein the coupling unit comprises a first component which is assigned to the drive unit, in particular connected with the drive unit or integrally formed with the drive unit, and a second component which is assigned to the stirring unit, in particular connected with the stirring unit or integrally formed with the stirring unit.

27. Stirring device according to claim 26, wherein the coupling unit comprises at least one first locking body, in particular at least one first locking ball, and further in particular a first row of locking balls, wherein the at least one first locking body locks the first component with the second component, in particular in a torque-transferring manner, when the actuation unit in the first actuation position acts upon the at least one first locking body; in particular wherein the at least one first locking body remains the first component and the second component unlocked, when the actuation unit is in the second actuation position and releases the at least one first locking body.

28. Stirring device according to claim 26, wherein the coupling unit comprises a carrier for selectively transferring a torque between the first component and the second component, wherein in particular the carrier is provided separately from the stirring unit and the drive unit.

29. Stirring device according to claim 28, wherein the coupling unit comprises at least one second locking body, in particular at least one second locking ball, and further in particular a second row of locking balls, wherein the at least one second locking body acts upon the carrier, in particular in a torque-transferring manner, when the actuation unit in the second actuation position acts upon the at least one second locking body.

30. Stirring device according to claim 29, wherein the at least one second locking body does not act upon the carrier, when the actuation unit is in the first actuation position and releases the at least one second locking body.

31. Stirring device according to claim 26, wherein the second component comprises a tapering outer profile, and the first component comprises a tapering inner profile for receiving the tapering outer profile.

32. Stirring device according to claim 31, wherein the tapering outer profile comprises a, in particular surrounding, indentation for receiving the at least one first locking body.

33. Stirring device according to claim 31, wherein the tapering inner profile comprises a, in particular surrounding, indentation for receiving the at least one second locking body.

34. Stirring device according to claim 29, wherein the second component comprises a central recess for receiving at least a part of the carrier.

35. Stirring device according to claim 25, wherein the actuation unit comprises a sleeve which at least partially surrounds the coupling unit, in particular additionally at least partially surrounding the stirring unit and/or the drive unit.

36. Stirring device according to claim 35, comprising at least one of the following features: wherein the sleeve is configured axially displaceable for transferring between the first actuation position and the second actuation position, in particular such that the sleeve, for transferring from the first actuation position to the second actuation position, is to be displaced away from the stirring unit, and for transferring from the second actuation position to the first actuation position, is to be displaced towards the stirring unit; wherein the sleeve comprises at least one inner protrusion for acting upon the at least one first locking body and/or the at least one second locking body and/or the coupling unit.

37. Stirring device according to claim 25, wherein the actuation unit is configured for a manual, in particular one-handed, actuation by a user.

38. Stirring device according to claim 26, wherein the coupling unit comprises at least one locking body which is in particular loadable with a biasing force, for, in particular torque-transferring, locking the first component with the second component; wherein the actuation unit comprises at least one actuation element, in particular at least one actuation screw, wherein the at least one actuation element is configured for locking the at least one locking body by attaching the at least one locking body to at least one of the first component and the second component in the first actuation position, and for unlocking the at least one locking body by removing the at least one locking body from the first component and/or the second component in the second actuation position.

39. Stirring device according to claim 26, wherein the actuation unit comprises a locking unit which, in particular manually by a user or alternatively in an automatized manner, may be brought selectively in the first actuation position or in the second actuation position, in particular is displaceable between the first actuation position and the second actuation position.

40. Stirring device according to claim 25, wherein the coupling unit and the actuation unit are configured in a cooperating manner, such that: both in the first actuation position and in the second actuation position, a transfer of torque from the drive unit to the stirring unit is enabled; and in the first actuation position, the drive unit and the stirring unit are coupled with each other in an axially undetachable manner, and in the second actuation position, the drive unit and the stirring unit are decoupled from each other in an axially detachable manner.

41. Flash Point determination apparatus, in particular also configured for a combustion point determination, wherein the flash point determination apparatus comprises: a container for receiving a sample to be examined; a lid for closing the container; and a stirring device according to claim 25 for stirring the sample in the container which is closable by the lid.

42. Flash point determination apparatus according to claim 41, comprising at least one of the following features: a tempering unit for tempering the sample which is arranged in the container; an ignition device for igniting the sample which is arranged in the container; wherein the stirring unit is fixedly attached to the lid.

43. Method for stirring a sample in a container which is closed by a lid for a flash point determination test and/or combustion point determination test, wherein the method comprises: at least partially guiding a stirring unit through the lid into the sample in the container for stirring the sample; driving, in particular rotationally driving, the stirring unit by a drive unit which is at least partially arranged outside of the lid, for stirring the sample by the stirring unit; coupling the stirring unit with the drive unit by a coupling unit; and actuating an actuation unit, in particular for adjusting the coupling unit, such that selectively: in a first actuation position, when pulling up the drive unit, the lid is detached from the container commonly with the stirring unit; or in a second actuation position, when pulling up the drive unit, the drive unit is detached from the container, and the stirring unit and the lid remain at the container.

44. Method according to claim 43, wherein the method comprises one-handedly actuating the actuation unit for adjusting the coupling unit by a user.

Description

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0053] In the following, exemplary embodiments of the present invention are described in detail with reference to the following figures.

[0054] FIG. 1 shows a cross-sectional view of a flash point determination apparatus according to an exemplary embodiment of the invention.

[0055] FIG. 2 shows a cross-sectional view of a part of a flash point determination apparatus according to another exemplary embodiment of the invention in a first actuation position.

[0056] FIG. 3 shows a cross-sectional view of the part of the flash point determination apparatus according to FIG. 2 in a second actuation position.

[0057] FIG. 4 shows an explosion view of a coupling unit of the flash point determination apparatus according to FIG. 2 and FIG. 3.

[0058] FIG. 5 shows a three-dimensional view of the flash point determination apparatus corresponding to FIG. 2 to FIG. 4.

[0059] FIG. 6 shows a cross-sectional view of a flash point determination apparatus according to another exemplary embodiment of the invention in a mounted state.

[0060] FIG. 7 shows a three-dimensional view of the flash point determination apparatus according to FIG. 6 in a demounted state.

[0061] Same or similar components in different figures are provided with the same reference numbers.

[0062] Before, referring to the figures, exemplary embodiments of the invention are described, some general aspects of the invention and the basic technologies shall be explained:

[0063] According to an exemplary embodiment of the invention, a flash point determination apparatus and/or a flash point measurement technique may be provided, which provide possibilities to actively decide, before the measurement, if a container lid or crucible lid shall be co-lifted from a head and/or the part of the apparatus in which the drive device is arranged, or shall remain on the container or crucible after the end of the measurement.

[0064] A conventional embodiment couples the head with the sample insert at each placing on the crucible, and consequently remains coupled. In other conventional embodiments, the head and the sample insert remain always decoupled. After the end of the test, the lid is always co-transported with the head and is brought in a tilted position. In this case, sample residues may move from the agitator in the direction of a lid opening and may additionally contaminate the lid. Decoupling the crucible lid with a movement of a hand (as according to an exemplary embodiment of the invention) is not possible, since, additionally to elaborately releasing the coupling, also all connected cables (in particular ignition cables, detector cables, etc.) have to be separately disconnected, before the lid can be released from the flash point determination apparatus.

[0065] Another conventional embodiment does not enable a detachment of the lid at all. The component is fixedly connected with the head.

[0066] By the cooperation of the coupling unit and the actuation unit of a stirring device according to an exemplary embodiment of the invention, in particular the following advantages may be achieved:

[0067] When selecting a first actuation position for causing a co-transport of the crucible lid after the end of the test, a simple, rapid cleaning of the lid without a complete demounting may be achieved. In particular, the lid may be positioned in a hanging manner after the end of the measurement. Then, the stirring unit is freely accessible for wiping off the sample residues. By a simple movement of a hand, the lid may be completely removed from the flash point determination apparatus, if desired.

[0068] When selecting another second actuation position for remaining the crucible lid on the crucible, the sample may be effectively protected against contamination. Furthermore, the environment may be protected against sample vapors, until a removal of the sample insert from the flash point determination apparatus is actively performed. For example, a measurement may be started in a supervised manner, may be finished in a non-supervised manner, and a decision for the removal of the sample insert is performed only later (hours later, for example). The environment and the sample remain protected.

[0069] FIG. 1 shows a cross-sectional view of a flash point determination apparatus 140 according to an exemplary embodiment of the invention, by which a flash point determination or a combustion point determination may be selectively performed.

[0070] The flash point determination apparatus 140 comprises a crucible or container 104 for receiving a liquid sample 106 to be examined (for example diesel). A lid 102 which is detachable from the container 104 serves for closing the container 104 during the measurement.

[0071] A stirring device 100 is provided in the container 104 which is closable by the lid 102 for stirring the sample 106.

[0072] The container 104 is thermally coupled with a tempering unit 142 for tempering (in particular heating) the sample 106 which is arranged in the container 104, wherein the thermal coupling may be performed directly or indirectly via an air gap which is not shown here between the tempering unit 142 and the container 104. By the tempering unit 142, the sample 106 may be brought to a desired temperature.

[0073] Furthermore, an ignition device 144 for igniting the gas-air-sample-mixture which is formed above the sample 106 is inserted in the container 104.

[0074] According to FIG. 1, a stirring unit 108 of the stirring device 100 may be fixedly attached at the lid 102.

[0075] Said stirring unit 100 of the flash point determination apparatus 140 serves for stirring the sample 106 which is filled in the container 104 which is closed by the detachable lid 102. For a flash point determination test and/or a combustion point determination test, it may be desirable or required, to stir the sample 106, For this purpose, the stirring device 100 comprises a stirring unit 108 in an, according to FIG. 1, lower region of the stirring device 100. For stirring the sample 106 which is arranged in the container 104, the stirring unit 108 extends at least partially through the lid 102, i.e. is arranged partially above and partially below the lid 102.

[0076] Furthermore, the stirring device 100 comprises a drive unit 110 which is arranged outside of the lid 102 according to FIG. 1, for driving the stirring unit 108. The drive unit 100 may comprise a motor (not shown) which rotates a drive shaft of the drive unit 110. By force transfer from the drive unit 110 to the stirring unit 108, also the stirring unit 108 may be set into rotation, whereby the sample 106 is stirred.

[0077] A coupling unit 112 of the stirring device 100 functions selectively and/or selectably for mechanically coupling the stirring unit 108 with the drive unit 110, or for mechanically decoupling the stirring unit 108 from the drive unit 110.

[0078] Moreover, the stirring device 100 contains an actuation unit 114 which is actuatable for adjusting the coupling unit 112 and is displaceable in the vertical direction for this purpose, as illustrated with double arrows. The actuation unit 114 may be selectively brought in a first actuation position, in which, when pulling up the drive unit 110, the lid 102 may be detached from the container 104 commonly with the stirring unit 108. In contrast, in a second actuation position of the actuation unit 114, when pulling up the drive unit 110, the drive unit 110 may be detached from the container 104, whereas the stirring unit 108 and the lid 102 remain at the container 104.

[0079] The flash point determination apparatus 140 which is shown in a sectional view in FIG. 1, which is in particular also configured for a combustion point determination, encompasses the container 104 for receiving the sample 106 to be examined, which is in a liquid state. Furthermore, the flash point determination apparatus 140 encompasses the tempering unit 142 for tempering the sample 106 which is arranged in the container 104. The flash point determination apparatus 140 further encompasses the ignition device 144, which is provided for igniting the gas-air-mixture which is formed above the sample 106. The stirring device 100 serves for stirring the sample 106. Furthermore, a flash point and temperature detector 161 with a temperature probe 159 is provided which protrudes up into the liquid part of the sample 106.

[0080] For the flash point determination and/or combustion point determination, the sample 106 in the container 104 is heated by the tempering unit 142. By the temperature probe 159, the temperature of the sample 106 in the container 104 may be detected. By rotationally driving stirring blades 162 at the end of the stirring unit 108, which end is at the side of the container, the sample 106 may be set into motion. By the ignition unit 144, an ignition may be generated, to determine the flash point or combustion point of the gas-air-mixture which is formed above the sample 106.

[0081] The control of the flash point determination apparatus 140 is performed by a control unit 163 (for example a processor). The control unit 163 controls the drive unit 110, the ignition unit 144, and the tempering unit 142. Furthermore, the control unit 163 may receive and process signals of the flash point and temperature detector 161. Optionally, the control unit 163 may actuate the actuation unit 114, although this action is performed by a user in preferred embodiments.

[0082] In order to adjust, if, when detaching the drive unit 110 from the container 104, the lid 102 may be detached with the stirring unit 108 or not, it is sufficient, that a user displaces the sleeve-type actuation unit 114 upwardly and/or downwardly by hand. If the sleeve 138 is in a first actuation position, a first component 116 of a coupling unit 112, which first component 110 is connected with the drive unit 110, cannot be decoupled from a second component 118 of the coupling unit 112 which is attached at the stirring unit 108. Pulling out the drive unit 110 also pulls the stirring unit 108 with the lid 102 upwardly and enables a cleaning of the agitator. In contrast, when the actuation unit 114 is displaced in the second actuation position by axially displacing the sleeve 138, the first component 116 and the second component 118 are decoupled from each other. In this case, removing the drive unit 110 leaves the stirring unit 108 with the lid 102 at the container 104.

[0083] An example for a corresponding mechanical solution is described in more detail in the following with reference to FIG. 2 to FIG. 5:

[0084] FIG. 2 shows a cross-sectional view of a part of a flash point determination apparatus 140 according to an exemplary embodiment of the invention in a first actuation position 197. FIG. 3 shows a cross-sectional view of said part of the flash point determination apparatus 140 according to FIG. 2 in a second actuation position 199. FIG. 4 shows an explosion view of a coupling unit 112 with a carrier 126 of the flash point determination apparatus 140 according to FIG. 2 and FIG. 3, and moreover shows further components (in particular a stirring shaft of a stirring unit 108 and a sleeve 138 of an actuation unit 114). FIG. 5 shows a three-dimensional view of the flash point determination apparatus 140.

[0085] Also according to FIG. 2 to FIG. 5, the stirring device 100 comprises a stirring unit 108, a drive unit 110, a coupling unit 112, and an actuation unit 114 for actuating the coupling unit 112, such that selectively the first actuation position 197 (for detaching the lid 102 with the stirring unit 108 commonly with the drive unit 110) which is shown in FIG. 2, or the second actuation position 199 (for detaching the drive unit 110 without the lid 102 and without the stirring unit 108) which is shown in FIG. 3 may be adjusted.

[0086] As can be seen in FIG. 2 to FIG. 4, the coupling unit 112 has a first component 116 which is assigned to and integrally formed with the drive unit 110, and a second component 118 which is assigned to and integrally formed with the stirring unit 108.

[0087] Moreover, the coupling unit 112 contains first locking bodies 120 which are configured as a surrounding row of first locking balls, which lock the first component 116 with the second component 118 in a torque-transferring manner, when the actuation unit 114 in the first actuation position 197 acts upon the first locking bodies 120. In contrast, the first locking bodies remain the first component 116 and the second component 118 decoupled from each other, when the actuation unit 114 is in the second actuation position 199 and releases the first locking bodies 120.

[0088] In addition, the coupling unit 112 contains a carrier 126 for selectively torque-transferring between the first component 116 and the second component 118 in the second actuation position 199. The carrier 126 is provided separately from the stirring unit 108 and the drive unit 110 in this example. Alternatively, the carrier 126 may also be a part of the stirring unit 108.

[0089] The coupling unit 112 additionally has second locking bodies 122 which are configured as a surrounding row of second locking balls, which may act upon the carrier 126 in a torque-transferring manner, when the actuation unit 114 in the second actuation position 199 acts upon the second locking bodies 122. In contrast, the second locking bodies 122 do not act upon the carrier 126, when the actuation unit 114 is in the first actuation position 197 and releases the second locking balls 122.

[0090] As can be seen in FIG. 2 and FIG. 3, the surrounding row of first locking balls in form of the first locking bodies 120 is below the surrounding row of second locking balls in form of the second locking bodies 122. In other words, the first locking bodies 120 are arranged at the side of the stirrer and the second locking bodies 122 are arranged at the side of the drive.

[0091] As can also be seen in FIG. 2 to FIG. 4, the second component 118 has a drive-sidedly tapering outer profile 128, and the first component 116 also has a drive-sidedly tapering inner profile 130 which is corresponding to it, for receiving the tapering outer profile 128, The tapering outer profile 128 has a surrounding indentation 132 for receiving the first locking body 120. In a corresponding manner, the tapering inner profile 130 has a surrounding indentation 134 for receiving the second locking body 122. Moreover, the second component 118 comprises a central recess 136 for receiving the carrier 126.

[0092] As well recognizable in FIG. 2 and FIG. 3, the actuation unit 114 is configured as a collar or a sleeve 138 which is circumferentially surrounding the coupling unit 112, which collar or sleeve 138 may additionally surround a part of the stirring unit 108 and a part of the drive unit 110. Said sleeve 138 functions for transferring the stirring device 100 between the first actuation position 197 and the second actuation position 199 and is configured axially displaceable for this purpose. For transferring from the first actuation position 197 to the second actuation position 199, the sleeve 138 may be displaced in the direction of the drive unit 110 and/or for transferring from the second actuation position 199 to the first actuation position 197, may be displaced in the direction of the stirring unit 108. The actuation unit 114 is configured for a manual and advantageously one-handed actuation by a user.

[0093] The sleeve 138 is provided with an inner protrusion 195 for acting upon the coupling unit 112. In more detail, the protrusion 195 in the first actuation position 197 may act upon the first locking bodies 120, but not upon the second locking bodies 122. In contrast, the protrusion 195 in the second actuation position 199 may act upon the second locking bodies 122, but not upon the first locking bodies 120.

[0094] The embodiment according to FIG. 2 to FIG. 5 descriptively generates a stirrer coupling of a flash point tester according to Pensky and Pensky-Martens. The flash point determination apparatus 140 contains a stirrer coupling which combines the basic functionality of the stirrer and the user-friendly and flexible option for removing the lid 102 when detaching the stirring device 100 (also denoted as co-transport of the crucible lid). The stirring device 100 contains a coupling unit 112 encompassing a carrier 126 for the torque-transfer. The carrier 126 may be screwed with the stirrer shaft of the stirring unit 108. Alternatively, the carrier 126 may also be integrated in the stirrer shaft. The stirring device 100 is illustrated, respectively as longitudinal sectional view, in a coupled state which corresponds to the first actuation position 197 (see FIG. 2) and a decoupled state which corresponds to the second actuation position 199 (compare FIG. 3) of the drive unit 110 and the stirring unit 108. FIG. 4 shows constituents of the interface and coupling unit 112, respectively.

[0095] A user may perform a manual option choice and may adjust a performed or prevented co-transport of the crucible lid, by only displacing the sleeve 138 of the actuation unit 114 upwardly and downwardly, respectively. A displacement “upwardly” and “downwardly” denotes a displacement in the axial direction. “Up” and “down” denote directions at a point in time, while the flash point determination apparatus 140 is in operation.

[0096] The stirrer coupling may be both completely visibly (see for example FIG. 5) and partially invisibly installed in the flash point determination apparatus 140. Thus, FIG. 5 shows an installation example of the assembly of the stirrer coupling and the stirring device 100, respectively. Preferably, the coupling position is positioned, such that it is easily accessible, to be able to simply activate and deactivate the option of the co-transport of the crucible lid.

[0097] The choice of the option of the co-transport of the crucible lid is performable by one hand in the illustrated example, as soon as the coupling unit 112 is directly attached to the stirring device 100. The outer sleeve 138 may be manually pushed downwardly, i.e. transferred to the first actuation position 197, prior to the start of the flash point measurement. This is performable by one hand. The lower ball row of the first locking bodies 120 of the coupling unit 112 is locked towards the center of rotation by the sleeve 138. Thereby, the placed stirrer shaft is pushed into the cone reception of the coupling unit 112 and the locking bodies 120 are pushed into a cone groove. The generated force-fit between the components 116, 118, 120 of the coupling unit 112 causes a torque-transfer on the stirrer unit 108 and additionally enables a co-transport of the lid 102 of the container 104 by the device head. The coupling remains in this state, until the sleeve 138 is manually pushed upwardly again, i.e. is transferred to the second actuation position 199. In this case, the lower ball row of the first locking bodies 120 is released and the upper ball row of the second locking bodies 122 in turn is locked towards the center of rotation. The torque-transfer is performed as soon as a locked ball abuts against the carrier 126 and transfers the rotational motion to the stirrer shaft. Since the force-fit between the components 116, 118, 120 of the coupling unit 112 is repealed, in this state, the lid 102 of the crucible or container 104 is not co-transported when lifting the head.

[0098] When the sleeve 138 is in the lower position (FIG. 2), the balls of the first locking bodies 120 are pushed into the recess or indentation 132 and the shaft is fixed to the upper part of the flash point determination apparatus 140. The lid 102 is co-transported when displacing upwardly.

[0099] In contrast, when the sleeve 138 is in the upper position (FIG. 3), the balls of the first locking bodies 120 are released and the balls of the second locking bodies 122 are fixed. The latter serves for a force-transfer to the carrier 126 in the center of the flash point determination apparatus 140. In the case of pulling up, the lid 102 remains placed on the container 104. This simply operable, optional co-transport of the lid constitutes a significant advantage of an embodiment of the invention.

[0100] Thus, when the sleeve 138 is in the position according to FIG. 2, by detaching the drive unit 110, also the stirring unit 108 with the lid 102 may be detached from the container 104, to clean the stirring unit 108. In contrast, in the position according to FIG. 3, detaching the drive unit 110 without the co-transport of the stirring unit 108 is enabled. As shown in FIG. 5, for transferring the flash point determination apparatus 140 between both actuation positions 197, 199 according to FIG. 2 and FIG. 3, it is sufficient to displace the sleeve 138 in the axial direction.

[0101] The stirring device 100 which is shown in FIG. 2 to FIG. 5 provides a comfortable operation possibility for a user, since the user, by merely moving the sleeve 138 upwardly and downwardly, may select, if the stirring unit 108 and the drive unit 110 may be commonly detached from the container 104 (operational state according to FIG. 2) or only the drive unit 110 may be detached from the container 104, while the stirring unit 108 remains at the container 104 (operational state according to FIG. 3). This mode of operation is caused by the cooperation of the locking bodies 120, 122 and the carrier 126, wherein it may be acted upon the mentioned component parts by merely vertically displacing the sleeve 138 in a corresponding manner. The lower or first locking bodies 120 which are configured as locking balls cause a force-fit, when the sleeve 138 is displaced downwardly (compare FIG. 2). In this operational state, the lower or second locking bodies 122 are freely movable and functionally without importance. By this torque-coupling, which is also generated in this operational state, between the stirring unit 108 and the drive unit 110, stirring is enabled, wherein the lid 102 is co-transported, when detaching the head of the stirring device 100 and therefore the drive unit 110. When the sleeve 138 is displaced upwardly according to FIG. 3, the upper or second locking bodies 122 are locked and co-transport the nose or the carrier 126. The lower or first locking bodies 120 are functionally without importance in this operational state. Therefore, in the axially decoupled state between the stirring unit 108 and the drive unit 110, a torque-coupling between the stirring unit 108 and the drive unit 110 still remains enabled, and therefore stirring is possible regardless of the axial decoupling between the stirring unit 108 and the drive unit 110. Therefore, both in the decoupled state between the stirring unit 108 and drive unit 110 according to FIG. 3 and in the coupled state between the stirring unit 108 and the drive unit 110 according to FIG. 2, a torque-transfer for stirring is enabled. Descriptively, the upper ball row in form of the second locking bodies 122 causes a form-fit, whereas the lower ball row in form of the first locking bodies 120 serves for a force-fit when stirring. The carrier 126 allows a torque-transfer to the stirring shaft by the second locking bodies 122, when the sleeve 138 is displaced upwardly for co-transporting the carrier 126. When the sleeve 138 is in the lower state, a force-fit may be accomplished by the first locking bodies 120.

[0102] By the described cooperation of the coupling unit 112 and the actuation unit 114, both in the first actuation position 197 and in the second actuation position 199, a transfer of torque from the drive unit 110 to the stirring unit 108 is performed, whereby stirring is enabled in both actuation positions 197, 199. In contrast, only in the first actuation position 197, the drive unit 110 and the stirring unit 108 are coupled with each other in an axially undetachable manner. In contrast, in the second actuation position 199, the drive unit 110 and the stirring unit 108 are decoupled from each other in an axially detachable manner.

[0103] FIG. 6 shows a cross-sectional view of a flash point determination apparatus 140 according to another exemplary embodiment of the invention in a mounted state. FIG. 7 shows a three-dimensional view of the flash point determination apparatus 140 according to FIG. 6 in a demounted state.

[0104] According to FIG. 6 and FIG. 7, the coupling unit 112 has locking bodies 124 which are loadable with a biasing force, for torque-transferringly locking the first component 116 with the second component 118. Moreover, the actuation unit 114 according to FIG. 6 and FIG. 7 comprises actuation elements 150 (here configured as actuation screws). These serve for locking the locking bodies 124 by attaching the locking bodies 124 to the first component 116 and the second component 118 in the first actuation position 197, Unlocking the locking bodies 124 is performed by removing the locking bodies 124 from the first component 116 and/or the second component 118 in the second actuation position 199.

[0105] Alternatively, the actuation element 114 may be configured as a locking element 153 with a latch which may be brought in a position by a user, in which it locks the lid and therefore prevents the co-transport of the crucible lid. In this case, the user does not have to actuate any screws.

[0106] Therefore, FIG. 6 and FIG. 7 illustrate an embodiment with an automatic co-transport of the crucible lid, which nevertheless may be switched off or deactivated by the actuation elements 150 and/or the crucible lid locking.

[0107] In such an automatized co-transport of the lid 102 of the container 104, the flash point determination apparatus 140 automatically couples the crucible lid 102 with the drive unit 110. In the illustrated embodiment, the coupling of the head with the sample insert is performed automatically. Furthermore, decoupling the lid 102 may be performed by simply pulling down without the need to additionally unlock and/or move component parts of the coupling. Such a coupling may be realized by a spring-loaded ball row in form of the locking bodies 124 in cooperation with the actuation elements 150, In the automatic co-transport of the crucible lid, said spring-loaded ball row is positioned in the drive shaft. When coupling, the drive shaft pushes in elongated hole grooves of the stirrer shaft and transfers the drive torque to the stirrer. Moreover, thereby, the automatic co-transport of the crucible lid through the device head and/or the part of the device in which the drive unit 110 is located may be enabled. This spring-loaded ball row prevents a slipping out of the stirrer shaft and of the lid 102 and carries them along when displacing the device head upwardly. FIG. 6 in particular shows a cross-section of the coupling for the automatized co-transport of the crucible lid.

[0108] The embodiment according to FIG. 6 and FIG. 7 enables simply connecting the components 116, 118 by inserting the locking bodies 124 and the biasing elements which are configured as coil springs by actuating the actuation element 150 which is configured as actuation screw. When the actuation element 150 is screwed in a receiving opening of the first component 116, a respective locking ball as locking body 124 pushes in a recess of the second component 118. Thereby, the components 116, 118 are locked to each other. Detaching the drive unit 110 then also leads to a co-transport of the stirring unit 108. In contrast, when the actuation element 150 which is configured as actuation screw is not screwed in the reception of the first component 116, the locking ball 124 does not push into the groove of the second component 118. Detaching the drive unit 110 then retains the stirring unit 108 at the container 104.

[0109] FIG. 7 further shows, that in the circumferential direction, the indentation 132 at the second component 118 is configured as a sequence of indentations which are arranged in the circumferential direction with bars which are arranged in between. A locking body 124 which is configured as locking ball may then be inserted into an arbitrary indentation, to connect both components 116, 118 with each other.

[0110] With reference sign 153, an optional locking unit 153 of the actuation unit 114 is illustrated in FIG. 6 and FIG. 7. By an actuation of the locking unit 153 by a user, selectively the lid 102 may be locked at the container 104, to make a co-transport of the crucible lid impossible, or the lid 102 may be unlocked with respect to the container 104, to enable a co-transport of the crucible lid. For example, the locking unit 153 may be configured as a mechanic or magnetic latch.

[0111] Supplementary, it is to be noted that “comprising” does not exclude other elements or steps and “a” or “an” does not exclude a plurality. Furthermore, it is noted, that features or steps which are described with reference to one of the above embodiments, may also be used in combination with other features or steps of other above described embodiments. Reference signs in the claims are not to be construed as limitation.