Rotor assembly for laboratory centrifuge.

Abstract

The present invention relates to a rotor assembly equipped with a cover, intended to equip laboratory apparatus of the centrifuge type, mainly with a vertical rotation axis, characterized in that the rotor is crossed from one side to the other by an axial orifice and offers no possibility of connection with the drive motor shaft of the centrifuge. A lock assembly is associated with this rotor, comprising in particular a part placed at the interface between the rotor and the drive motor shaft, having external shapes capable of cooperating in rotation with said rotor and internal shapes capable of cooperating in rotation with said drive motor shaft. The lock assembly also comprises means of fixing with the rotor, means of fixing with the motor shaft and possibly a sealed cover.The present invention also comprises the centrifuge equipped with this rotor, equipped with means for recognizing whether said rotor is correctly locked and not allowing the centrifugation cycle to start if so. Figure for abstract: Figure 2.

Description

Title of the invention: Rotor assembly for laboratory centrifuge. TECHNICAL FIELD TO WHICH THE INVENTION RELATES

[0001] The present invention relates to a rotor assembly equipped with a cover, intended to equip laboratory devices of the centrifuge type, mainly with a vertical rotation axis. TECHNOLOGICAL BACKGROUND

[0002] Centrifugation allows the separation of constituents of very variable size and mass contained in a liquid sample, from molecules to whole cells. These samples can be contaminated and / or contaminating and must be kept in their containers.

[0003] These centrifugation techniques are conventionally implemented using laboratory centrifuges which comprise a chamber containing two rotating parts, namely: - A drive motor shaft, associated with motor means for its rotational maneuver, and; - A rotor, intended to be mounted on said motor shaft and intended to receive the containers in which the liquid samples to be centrifuged are returned. Some rotors are said to be "open" when the chamber intended to receive the containers is left open to the air. Others are "closed" by a cover, in particular when the user wants to limit the risk of propagation of contaminated agents and / or contaminants which may constitute the sample to be centrifuged, in the event of breakage of a container.

[0004] In a conventional manner, these two rotating parts are provided with complementary assembly means for the removable mounting of the rotor on the free end of the drive motor shaft. These assembly means comprise: - A centering and rotation locking means, such as for example a conical connection, splines, a key or other rotation stop means. Traditionally, these rotation locking means consist of a male part carried by the drive motor shaft and a female part carried by the rotor body, and; - A translational locking means such as a nut, or a system that can be manipulated without tools, such as that described in patent EP2799148.

[0005] It will then be understood that a rotor thus conventionally produced can be placed on the drive motor shaft, locked in rotation but not in translation. As soon as therefore, nothing prevents the user of a centrifuge from launching a centrifugation program (the rotation of the drive motor shaft and therefore of the rotor placed on it) even if said rotor is not correctly locked on the drive motor shaft. This possibility constitutes a danger for users because the rotor is not locked axially (in translation), it can become detached from the motor shaft and cause an accident with destruction of the centrifuge and breakage of the containers releasing the potentially pathogenic sample into the atmosphere. The use of a "closed" rotor, i.e. equipped with a sealed cover should make it possible, if not to respond to the risk stated above of starting the rotation of a rotor without it being effectively locked in translation, to limit the risks of accidental propagation of samples.Unfortunately, the known systems do not guarantee the correct locking and therefore the correct sealing of the covers on the rotors when the rotation of the said rotor is started.

[0006] For example, patents US6063018, WO8304379, US5897482, EP3132855, EP3132854, US7311652, EP2024097 ... are known, all of which describe a rotor cover and its fixing means which is at best associated with the axial locking of the rotor on the drive motor shaft (e.g. WO9407606), but for which the means for centering and / or driving the rotor body in rotation are made either directly in the rotor body or in a fixed and immovable part of the rotor body.

[0007] These proposals do not always guarantee that the cover is kept correctly closed when manipulating the rotor locking means on the centrifuge drive motor shaft.

[0008] These proposals do not in any way prevent the user from starting the rotation of the rotor in a centrifuge, because this rotation is possible as long as the rotor is locked in rotation on the drive motor shaft, by any means whatsoever (cone, a key, splines or others) and this even if the rotor is not locked axially. In this case, if the rotor cover is absent or poorly fixed, the sealing of the chamber receiving the samples to be centrifuged is not guaranteed at the time of rotation of said rotor, with a proven risk of propagation of contaminated or contaminating pathogenic samples. SUBJECT OF THE INVENTION

[0009] This is why we propose a rotor assembly and a centrifuge which do not allow the start of a centrifugation cycle in the case of a rotor which is not correctly locked, that is to say both in rotation and axially, on the drive motor axis of a centrifuge, and associated centrifuge.

[0010] In order to remedy the aforementioned risks of the state of the art, the present invention proposes a rotor assembly for a laboratory centrifuge, intended to cooperate with a drive shaft of said laboratory centrifuge.

[0011] The rotor assembly comprises: - A rotor, intended to receive containers (themselves containing samples intended to be centrifuged), and; - A lock assembly, for rotational and axial locking of the rotor

[0012] The rotor comprises: - A chamber in which at least one location is provided which is suitable for receiving a container containing a sample to be centrifuged; - An axial through-orifice, opening into said chamber and intended to be crossed by said drive motor shaft, sufficiently wide to provide no centering or locking, either in rotation or axially, of the rotor on said motor shaft; - An access opening, opening into said chamber for access to said at least one location, and; - An axial locking means capable of cooperating with that installed on the lock assembly, which can be made in the body of the rotor or on an added part secured to the rotor. In the preferred embodiment, we have used an added part fixed by screwing, without possible movement between this part and the rotor after screwing, this axial locking means cooperating with the support takes the form of a coarse thread (at least 8 mm). Note that the axial through hole of the rotor is not limited by this added part in any way whatsoever. - The axial through hole of the rotor is not limited by this locking means in any way.

[0013] The lock assembly comprises: - At least one means of axial locking of the rotor on the drive motor shaft. We are using here the solution proposed in patent EP2799148 without this choice being limiting, a simple nut could also work; - At least one interface inserted into the at least one axial orifice passing through the rotor. The external shapes of this interface are complementary to those of the axial orifice passing through the rotor to be able to be locked in rotation with said rotor. The internal shapes of this interface are complementary to those of the drive motor shaft to be able to be locked in rotation with the drive motor shaft. This interface is secured at least in translation to the axial locking means of the rotor assembly on the drive motor shaft; - At least one support part on which are fixed axially, and free to rotate, the means for axially locking the rotor assembly on the drive motor shaft, and the interface capable of cooperating in rotation with the rotor and the drive motor shaft. This support also comprises at least one axial locking means capable of cooperating with the axial locking means included in the rotor and at least one means of maneuvering it. According to the preferred embodiment, this axial locking means cooperating with the rotor can take the form of a coarse-pitch tapping (at least 8 mm) and the maneuvering means that of a handwheel, both made on the same part. This support only cooperates with the rotor and has no connection with the drive motor shaft. The expected advantages of a coarse pitch (at least 8 mm) are an ergonomic gain, by limiting the angle of rotation of the handwheel to fix or remove the lock assembly from the rotor, and an information gain by obtaining a reduction effect between the possible axial closure defect and the angle of rotation of the handwheel as explained further above, and; - Optionally, to obtain a closed rotor, at least one cover, intended to close the chamber provided in the rotor and at least one compressed seal between the rotor and said at least one cover

[0014] According to the invention, and in the case where the user places the rotor on the drive motor shaft without the lock assembly, he should advantageously notice an abnormal clearance between said motor shaft and said rotor which will encourage him not to initiate a centrifugation cycle.

[0015] However, if it decides, despite the visual alerts described above, to initiate a centrifugation cycle, the centrifuge itself is able to stop the process. Indeed, it is equipped with means capable of monitoring the acceleration of the rotation speed of the drive motor shaft as soon as it is started and of deducing therefrom whether the rotor equipping said centrifuge is, or is not, actually locked on said drive motor shaft, and of ordering, if necessary, the immediate stopping of said drive motor shaft.

[0016] These means include: - Means for measuring in real time the acceleration of the rotation speed of the drive motor shaft, such as for example a clock associated with a magnet regularly passing in front of a magnetic sensor and modifying the electrical signal leaving this sensor at each passage, each passage in front of the magnetic sensor representing a revolution of the drive motor shaft and deducing therefrom an acceleration between zero and a few hundred revolutions / min; - Means of comparing this acceleration value with reference values, and; - Means of interpreting the difference in values between the observed acceleration and the recorded reference.

[0017] Thus, if the acceleration of the rotational speed of the drive motor shaft in the measuring range is higher than the reference value, the centrifuge deduces that the rotor is not locked in rotation on the motor shaft, it slips, or slides. The centrifuge stops the centrifugation cycle even before the drive motor shaft has reached its set speed.

[0018] On the contrary, if the acceleration of the rotation speed of the drive motor shaft in the measurement range is less than or equal to the reference value, the centrifuge deduces that the rotor is correctly locked on said motor shaft and authorizes the continuity of the centrifugation cycle.

[0019] The present invention further relates to a laboratory centrifuge characterized in that it is equipped with at least one rotor assembly according to the invention.

[0020] The invention will be clearly understood upon reading the following descriptions of particular embodiments including possible covers and seals, without these examples being in any way limiting, with reference to the appended drawings in which:

[0021] [Fig-1] Is a general view, in section and with a slight perspective, of the rotor (1) according to the invention, placed on the drive motor shaft (2), without the lock assembly (3). We see: - The chamber (4) arranged in said rotor (1) and some locations (5) intended to receive the samples to be centrifuged. In this figure the locations are left empty for better readability of the drawing; - In the center of the rotor (1), the axial through orifice (6), crossed by the drive motor shaft (2), without contact between said axial orifice (6) and said drive motor shaft (2), and therefore offering no possibility of centering or locking said rotor (1) on said drive motor shaft (2); - A coarse thread (7) intended to cooperate with said lock assembly (3) not visible in this view. According to the preferred embodiment, this thread is coarse (at least 8mm) and attached to the rotor (1). Note that the axial through hole (6) of the rotor is not limited by this attached part (7) in any way; - The shapes of the drive motor shaft (2) intended to cooperate with the interface (8) not visible in this view.

[0022] [Fig.2] Is a general perspective and sectional view of the rotor (1) and in perspective of the lock assembly (3) next to each other. We can see: - That the axial orifice passing through (6) the rotor (1) and the external shapes (8a) of the interface (8) of the lock assembly (3) have complementary shapes making them suitable for being locked to each other in rotation. In the preferred embodiment, these shapes are grooves; - That the internal shapes (8b) of the interface (8) of the lock assembly (3) have shapes complementary to those of the drive motor shaft (2) (see [Fig.l]) making them suitable for being locked to each other in rotation. In the preferred embodiment, these shapes are grooves. - In this view, the lock assembly (3) is shown without the optional cover (9).

[0023] [Fig.3] Is a general view, in section and with a slight perspective of the assembly lock (3). We can see (from the center outwards): - The interface (8) intended to be inserted into the axial through hole (6) of said rotor (1), not visible in this view. The external shapes (8a) of said interface (8) are complementary to those of said axial through hole (6) of said rotor (1) so that they are locked in rotation when the lock assembly (3) is fixed on said rotor (1, 7) to form the rotor assembly (10). The internal shapes of said interface (8b) are complementary to those of said drive motor shaft (2), not visible in this view, so that they are locked in rotation when the rotor assembly (10) is locked on said drive motor shaft (2); - A locking means (11) of said rotor assembly (10) on said drive motor shaft (2). We have shown here the means described in patent EP2799148, without this solution being limiting. Any other means of locking a rotor on a drive motor shaft can be used in this invention including a simple nut; - A support (12) on which are fixed axially, and free to rotate, the locking means (11) of the rotor assembly (10) on the drive motor shaft (2), and the interface (8) capable of cooperating in rotation with the rotor (1) and the drive motor shaft (2). This support comprises an axial locking means (12a) cooperating with the rotor (1, 7) and a means of maneuvering it (12b). According to the preferred embodiment, this axial locking means (12a) cooperating with the rotor (1, 7) takes the form of a coarse-pitch tapping (12a) (at least 8 mm) and the maneuvering means (12b) that of a flywheel, both made on the same part. This support (12) only cooperates with the rotor (1, 7) and has no connection with the drive motor shaft (2); - The cover (9), optional, intended to close the chamber (4) arranged on the rotor (1), and supporting two seals, the first (13) of which is intended to be compressed radially, and the second (14) of which is intended to be compressed axially between said rotor (1) and said cover (9) closing said chamber (4) when said lock assembly (3) is locked on said rotor (1, 7). This cover (9) is fixed in translation on the support (12) and free to rotate.

[0024] [Fig.4] Is a general view, in section, of the rotor assembly (10). It shows: - The lock assembly (3) fixed on said rotor (1,7), here equipped with the optional cover (9); - The interface (8) of the lock assembly (3) inserted into the axial through hole (6) of said rotor (1), and therefore locked in rotation on said rotor by their complementary shapes (see [Fig.2]); - The optional cover (9) closing the chamber (4) fitted on the rotor (1); - The chamber (4) of said rotor (1), obstructed by the optional cover (9) in a sealed manner by the radial compression of the central seal (13) and the axial compression of the peripheral seal (14)

[0025] [Fig.5] Is a general view, in section, of the rotor assembly (10) locked on the drive motor shaft (2). It shows: - The interface (8) of the lock assembly (3) stopped in rotation with the rotor (1) by its external shapes (8a) and with the drive motor shaft (2) by its internal shapes (8b); - The rotor assembly (10) axially locked on the drive motor shaft (2) by means of the locking means (11) on the drive motor shaft (2)

[0026] It will be understood from reading the previous views that the fixing and removal of the lock assembly (3) on the rotor (1, 7) is done via the single part above called support (12) comprising an operating means (12b) and an axial locking means (12a) cooperating with the rotor (1, 7). Once this lock assembly (3) is in place on said rotor (1, 7), the interface (8) and the locking means (11) are found integral with the rotor (1).

[0027] In the case where a cover (9) is present, its freedom of rotation relative to the support (12) makes it possible to free the maneuver of fixing or removing the lock assembly (3) of said rotor (1, 7) from the friction of the seals (13 and 14) on the cover (9) and the rotor (1).

[0028] Once the lock assembly (3) is fixed on said rotor (1, 7), the locking means (11) of the rotor assembly (10) on the motor shaft (2) can be manipulated without risk of involuntarily removing the lock assembly (3) from said rotor, nor of opening, even partially, the cover (9) if it is present.

[0029] [Fig.6] Is an overall view of a rotor (10) equipped with the lock assembly (3), including the optional cover (9). It shows: - The support (12) and its handwheel (12b) used to maneuver the fixing means (12a) of said support (12) on said rotor (1, 7) in the complete fixing position. It can be seen that the window (15a) made on the crown (15) reveals information (16) allowing the user to understand that the lock assembly (3) is correctly fixed on the rotor (1) such as for example a green color, a closed padlock or other.

[0030] In any other angular position of the lock assembly (3) and therefore of the crown (15), the information (16) is no longer visible because it is no longer located directly opposite the window (15a) made on said crown (15). In the preferred embodiment, with a pitch of 8mm to fix the lock assembly (3) on the rotor (1,7), an axial closing defect of l / 10mm results in an angular position defect of 4.5°, sufficient so that said angular defect does not allow the information (16) to be placed facing the window (15a) made on the crown (15).

[0031] [Fig.7] Is a diagram showing 3 curves characterizing the acceleration of the speed of the drive motor shaft (2). The curve placed in the center, called the threshold curve (17), is the reference curve on which the centrifuge is able to determine the correct assembly of the rotor. - The curve placed to the right (18) of the reference curve (17) is characteristic of that of a rotor correctly driven in rotation and therefore, in the context of the present invention, of a rotor correctly equipped with its said lock assembly (3) including the cover (9) in the case where the latter is present. In this first case, the centrifugation cycle will be authorized. - The curve placed to the left (19) of the reference curve (17) is characteristic of that of a rotor which is not driven in rotation and therefore, in the context of the present invention, of a rotor not equipped with its said lock assembly (3), nor with the cover (9) in the case where this is expected. In this last case, the centrifuge will stop the rotation of the drive motor to ensure the safety of users.

Claims

Claims

1. Rotor (1) for a laboratory centrifuge intended to cooperate with a drive shaft of said laboratory centrifuge, characterized in that it comprises: - An axial through-orifice (6), opening into a chamber (4) and intended to be crossed by said drive motor shaft (2), sufficiently wide to offer no centering or locking of the rotor (1) on said motor shaft (2); - An axial locking means (7) capable of cooperating with a fixing means (12a) installed on a lock assembly (3), which can be produced in the body of the rotor (1) or on an attached part and integral with the rotor. This axial locking means (7) cooperates with a support (12) of the lock assembly.

2. Lock assembly (3) intended to cooperate with the rotor according to the preceding claim, lock assembly characterized in that it comprises: - At least one interface (8) inserted into said at least one axial through-orifice (6) of said rotor (1) and whose external shapes (8a) are complementary to the internal shapes of said axial through-orifice (6) of the rotor (1, 7) to lock the 2 parts in rotation; - At least one locking means (11) of the rotor (1) on said drive motor shaft (2) such as for example a nut or any other means; - At least one support part (12) on which said locking means (11) and interface (8) are fixed axially and free to rotate;- At least one fixing means (12a) capable of cooperating with the axial locking means (7) included in the rotor (1) having a reduction effect between a possible axial closing defect and the rotation angle of the operating means (12b), such as a very large pitch thread (at least 8mm); - And, at least one means for operating it (12b).;

3. Lock assembly (3) according to the preceding claim, characterized in that it comprises: - At least one cover (9) closing the chamber (4) arranged on the rotor (1), the latter being fixed in translation and free in rotation on the support part (12) to release the operating means (12b) from fixing or removing the lock assembly (3) of said rotor (1) from the friction of said at least one seal (13,14). - At least one seal (13,14) which is inserted between the rotor (1) and the cover (9) to seal the chamber (4) arranged in the rotor (1);

4. Rotor assembly (10), consisting of a rotor (1) according to claim 1 and a lock assembly (3) according to one of claims 2 to 3, characterized in that it comprises at least one interface (8) whose internal shapes (8b) are complementary to those of the drive motor shaft (2), capable of locking in rotation said rotor assembly (10) with said drive motor shaft (2) of said centrifuge.

5. Rotor assembly (10) according to claim 4, characterized in that the sealing of the chamber (4) arranged in said rotor (1) is ensured by the radial compression of a central seal (13) and the axial compression of a peripheral seal (14) between said rotor (1) and said cover (9) closing said chamber (4) when said lock assembly (3), when equipped with the cover (9), is locked on said rotor (1).

6. Lock assembly (3) according to one of claims 2 or 3 characterized in that it comprises a crown (15) integral with the operating means (12b), equipped with a window (15) capable of not allowing information (16) to appear allowing the user to understand that the lock assembly (3) is correctly fixed on said rotor (1), such as for example a green color, a closed padlock or other. In any other angular position of the lock assembly (3), and therefore of the crown (15), the information (16) is no longer visible.

7. Laboratory centrifuge characterized in that it is equipped with at least one rotor assembly (10) according to one of claims 4 or 5.

8. Laboratory centrifuge intended to be equipped with a rotor assembly (10) according to one of claims 4 or 5, characterized in that it is equipped with means capable of: - Measuring an acceleration value (18, 19) of the rotation speed of the drive motor shaft; - Comparing this value with a reference (17); - Deducing whether the rotor assembly (10) is correctly driven in rotation and therefore that said rotor assembly (10) is correctly equipped with its said lock assembly (3) including the cover (9) if it is present, and allowing the continuity of the centrifugation cycle; - Deduce whether the rotor assembly (10) is not correctly driven in rotation and therefore, that said rotor assembly (10) is not equipped with its said lock assembly (3), nor with the cover (9) in the case where this is expected. In this last case, the centrifuge will stop the rotation of the drive motor.

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