Vacuum maintenance method for a sample crusher

Abstract

Title: Method for maintaining a vacuum for a sample crusher Method for maintaining a vacuum for a sample crusher, comprising a first measurement (400) of a pressure, a placement (401) of a tube, a mounting (402) of a second support on a first support, a vacuum application (403), a second measurement (404) of pressure, a determination (405) of a first pressure difference, a verification (406) of the first pressure difference, if it is greater than a first threshold value, starting (408) the precession drive, a third pressure measurement and a determination (409) of a second pressure difference between the third and the first and / or second measurement, a verification (410) of the second pressure difference, if it is greater than a second threshold value, a continuation (412) of the precession drive, if not a stopping (411) of the precession drive. Figure for abstract: Fig.6.

Description

Title of the invention: Vacuum maintenance method for a sample crusher Technical field

[0001] The present invention relates to the field of sample grinders, more precisely the field of chemical or biological sample grinders, also called homogenizers. The present invention relates in particular to the use of vacuum for a chemical or biological sample grinder. STATE OF THE ART

[0002] There are several systems for grinding or, equivalently, homogenizing chemical or biological samples. These systems are commonly referred to as grinders or homogenizers. These systems generally comprise a support configured to receive, in tube holders, closed tubes containing the samples to be ground.

[0003] The first support is typically driven in precession around a central axis, the axis describing a cone during this movement, inducing a movement of the tubes. The samples are thus subjected to a precession movement.

[0004] The tubes also generally contain balls which, combined with the movement to which the tubes are subjected, allow the sample to be ground.

[0005] In order to keep the tubes in position during the precession movement, there are solutions in which the support receiving the tubes is secured to a drive module comprising a shaft, by clipping or screwing. These solutions prove to be unreliable in practice. The clipping and screwing can come loose during the precession movement. In addition, these solutions make handling the grinding system more complex and time-consuming.

[0006] An object of the present invention is therefore to propose a solution improving the reliability and safety of maintaining biological or chemical samples during their grinding.

[0007] Other objects, features, and advantages of the present invention will become apparent from the following description and accompanying drawings. It is understood that other advantages may be incorporated. SUMMARY

[0008] To achieve this objective, according to a first aspect, a vacuum maintenance method is provided using a sample grinder.

[0009] The crusher comprises a sample holding device comprising a first support and a second support, the second support being configured to be mounted on the first support by defining a closed volume between the first and the second support, at least one of the first and the second support being configured to receive at least one tube, preferably a plurality of tubes, containing a sample, the sample holding device being configured so that the first support and the second support have a first configuration in which the first and second supports are not secured to each other by a vacuum of said volume, and a second configuration in which the first and second supports are secured by a vacuum of said volume, and in the second configuration, the first support is configured to be driven in precession around a main axis and thus drive the second support.

[0010] The crusher further comprises a vacuum module comprising a pump, a pumping circuit configured to connect said volume to the pump, and a pressure sensor configured to measure a pressure in the pumping circuit, the pump and the pressure sensor not being driven during said precession movement.

[0011] Thus, the method according to this first aspect comprises: a first measurement of an initial pressure by the pressure sensor, the sample holding device being in the first configuration, a placement of at least one tube in the sample holding device, a mounting of the second support on the first support, after mounting the second support on the first support, a depression by the depression module of said volume to switch the sample holding device from the first configuration to the second configuration, the depression comprising: a second pressure measurement by the pressure sensor, a determination of a first measured API pressure difference between the second measurement and the first measurement, and a verification of the first measured API pressure difference, comprising, when the first API pressure difference is greater than a first threshold value, switching to a precession drive step, the precession drive of the sample holding device for grinding the sample contained in at least one tube, comprising: at least a third pressure measurement by the pressure sensor, a determination of a maintenance of the depression comprising a determination of at least a second pressure difference measured AP2 between the at least third measurement and the first measurement and / or the second measurement, and a verification of the second measured pressure difference AP2, comprising, • when the second measured pressure difference AP2 is lower than a second threshold value, continued precession training, • when the second measured pressure difference AP2 is greater than the second threshold value, a stop of the precession drive.

[0012] This solution thus makes it possible to monitor over time the depression created between the first and second supports, thereby enabling verification of the tubes being held by one and / or the other of the supports.

[0013] The method firstly allows the state of the depression to be checked, before the start of the precession movement with the aim of grinding the samples. This check thus makes the system more reliable and avoids starting the grinder if the pressure conditions and therefore the conditions for securing the samples are not met. Grinding therefore cannot be started without having a correct connection between the two supports. The risk of damage to the system and / or the samples is thus limited. Likewise, this device ensures optimal protection for the user.

[0014] It also allows in a second stage, after starting the precession movement and therefore during the grinding of samples, to check the depression over time thanks to an iteration of pressure measurement. This verification over time makes it possible to check whether the vacuum is maintained effectively in order to limit the risk of detachment of the second support. It is thus possible to detect a possible detachment and to stop the grinding. The risk of damage to the system and / or the samples is further limited. In addition, the use of pressure difference rather than absolute pressure makes it possible to avoid variations in absolute pressure, for example depending on altitude.

[0015] It is therefore understood that the method allows for reliability and security in maintaining samples to be ground, both initially before grinding and during grinding. BRIEF DESCRIPTION OF THE FIGURES

[0016] The aims, objects, as well as the characteristics and advantages of the invention will emerge more clearly from the detailed description of an embodiment thereof which is illustrated by the following accompanying drawings in which:

[0017] [Fig.l] [Fig.l] represents an overall view of a sample crusher, according to an exemplary embodiment.

[0018] [Fig.2A] Figures 2A and 2B show two cross-sectional views of the holding device of a sample crusher according to two embodiments.

[0019] [Fig.2B]

[0020] [Fig.3A] Figures 3A and 3B show two bottom views of two embodiments of a second support of a holding device.

[0021] [Fig.3B]

[0022] [Fig.4] [Fig.4] represents a diagram of the vacuum module used to carry out the method, according to an exemplary embodiment.

[0023] [Fig.5] [Fig.5] represents a connection between the holding device and the vacuum module, according to an exemplary embodiment.

[0024] [Fig.6] [Fig.6] represents a schematic view of steps of the vacuum maintenance method according to an exemplary embodiment.

[0025] [Fig.7] [Fig.7] is a graph illustrating the flow rate of the pump of the vacuum module, as a function of the pressure, according to an exemplary embodiment.

[0026] The drawings are given as examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily on the scale of practical applications. DETAILED DESCRIPTION

[0027] Before beginning a detailed review of embodiments of the invention, optional features which may possibly be used in combination or alternatively are set out below.

[0028] According to an example when verifying the first measured pressure difference, the first measured pressure difference is considered greater than the first threshold value if a ratio between a first setpoint pressure difference and the first measured pressure difference is less than 1.7, preferably 1.5.

[0029] According to one example, when verifying the second measured pressure difference, the second measured pressure difference is considered greater than the second threshold value if a ratio between a second setpoint pressure difference and the second measured pressure difference is less than 1.7, preferably 1.5.

[0030] This threshold value allows sufficient decompression to keep the second support in place during depression, thus keeping the tubes firmly in place during grinding.

[0031] According to one example, when verifying the first measured pressure difference and when determining whether the depression is maintained, the first and second measured pressure differences are greater than or equal to 500 mbar in absolute value to respectively initiate and continue the precession training.

[0032] According to one example, when verifying the first measured pressure difference and when determining whether to maintain the depression, the first and second setpoint pressure differences are greater than or equal to 850 mbar in absolute value to respectively initiate and continue the precession drive.

[0033] These values ​​are the optimal values ​​to allow the grinder to carry out a complete grinding cycle for a grinder positioned up to an altitude of 2,000 m (meters) and a weight for the entire rack, tubes and samples of between 100 g (grams) and 500 g.

[0034] According to one example, the precession drive comprises several third pressure measurements by the pressure sensor, each resulting in the determination of a maintenance of the depression comprising the determination of at least a second measured pressure difference between the third measurement and the first measurement and the second measurement, and the verification of the second measured pressure difference.

[0035] According to one example, the precession drive comprises several third pressure measurements by the pressure sensor, each resulting in the determination of a maintenance of the depression comprising the determination of at least a second measured pressure difference between the third measurement and the first measurement or the second measurement, and the verification of the second measured pressure difference.

[0036] This pressure measurement iteration makes it possible to determine over time whether the depression is sufficient to continue the precessional movement or not.

[0037] According to an example, in which the pumping circuit comprises at least a first movable part secured to the sample holding device and at least a second part not being driven during said precession movement, preferably the second part is fixed, the first movable part being connected to the second part by a connecting member so that the precession drive of the sample holding device comprises a precession movement of the first movable part permitted, relative to the second part, by the connecting member. The connecting member thus allows a mechanical and pneumatic connection between a movable holding device and a vacuum module, the elements of which are not all driven in precession.The distinction between a moving part and a fixed part also makes it possible to prevent at least one part of the vacuum device from undergoing too much movement and not correctly carrying out the vacuum, the reliability and safety of the crusher are then increased.

[0038] According to one example, the second part of the pumping circuit is offset from the volume to be evacuated by means of the first movable part, the pump and the pressure sensor being mounted on said second part.

[0039] According to one example, during precession training, the pump and the pressure sensor are fixed. The elements allowing the depression and the pressure control are not driven in precession, thus ensuring reliability of the data because they are not subject to any movement.

[0040] According to one example, the enclosed volume is delimited at least in part, preferably entirely, by an upper surface of the first support, and a lower surface of the second support, the upper surface and the lower surface being of complementary shape and at least partly conical, and the mounting of the second support on the first support comprises the arrangement of the lower surface of the second support on the upper surface of the first support. The complementary shape between the two supports allows both guidance when placing the second support on the first support for optimal placement, but also allows them to fit together advantageously so that the vacuum holding works.

[0041] According to one example, during the vacuum application, reliefs positioned in the closed volume on one of the lower surface of the second support and the upper surface of the first support come into contact with the other of the lower surface of the second support and the upper surface of the first support. The reliefs thus make it possible to improve the speed of the vacuum application while increasing the rigidity of the supports. In addition, the reliefs allow for more punctual and distributed contact between the supports.

[0042] According to one example, the closed volume having a center and being delimited by an external periphery, the reliefs are positioned at regular intervals along a transverse direction extending from the center to the external periphery of the closed volume.

[0043] According to one example, the reliefs are circular in shape and are centered on the center of the enclosed volume.

[0044] According to one example, the enclosed volume has a center and the reliefs are positioned at regular intervals along a radial direction between the center and the external periphery of the enclosed volume. The distribution of the reliefs makes it possible to reduce the force required to maintain the second support on the first if too much deformation is observed during depression.

[0045] According to one example, the reliefs comprise openings, the vacuum creation comprising a circulation of air in the enclosed volume, said circulation being permitted by said openings, with a view to the suction of the air. The reliefs make it possible to stiffen the second support, the openings present in the reliefs allow it to deform during the vacuum creation. In addition, the openings facilitate the “breaking of the vacuum” and a reliability of the vacuum throughout the enclosed volume.

[0046] According to one example, the sample holding device comprises a seal sealing gasket positioned between the first support and the second support, the sealing gasket being elastically deformable, and the vacuuming comprises compression of the gasket between the first support and the second support. The presence of the gasket makes it possible to seal the volume between the first support and the second support so that during vacuuming there is decompression in the volume between the two supports.

[0047] According to one example, during vacuuming, the pump of the vacuuming device has a flow rate greater than or equal to 2 L / min, preferably greater than or equal to 5 L / min, preferably equal to 7.5 L / min. This flow rate makes it possible to increase the speed of vacuuming. In addition, this flow rate makes it possible to compensate for leaks present during movement which may be due to manufacturing tolerances, to deformation of the parts with mechanical stresses, to wear of the seal between the first and second support.

[0048] According to one example, the first support comprises a tube-holder tray comprising at least one opening capable of receiving at least one tube, preferably a plurality of tubes, the placement of the at least one tube in the sample holding device comprising a reception, by the first support, of the at least one tube by insertion into the at least one opening according to a translational movement along the main axis.

[0049] According to one example, at least during precession training, the second support holds the at least one tube in position. Thus, it is the first support which holds the tubes and the second support keeps them closed during vacuuming and precession movement.

[0050] According to one example, the second support comprises a crown comprising elastically deformable holding tabs, and the mounting of the second support on the first support comprises at least partial superposition of the crown with the tube-holder plate comprising the at least one tube, and elastic compression of the holding tabs so as to hold the at least one tube in position. Thus, the holding tabs have sufficient rigidity so as not to deform when the second support is placed on the first support, but are flexible enough to deform in order to keep the tubes closed when the vacuum is applied.

[0051] According to one example, the second support comprises at least one sleeve intended to receive at least one tube closed by a stopper, the sleeve extending along a central axis in a plane substantially perpendicular to the main axis of the first support, and the placement of the at least one tube in the sample holding device comprising a reception of the at least one tube by the second support, by sliding along the central axis of the sleeve.

[0052] Thus, it is the second support which contains the tubes and keeps them in place.

[0053] In the remainder of the description, the term “on” does not necessarily mean “directly on”. Thus, when it is indicated that a part or member A is supported “on” a part or member B, this does not mean that the parts or members A and B are necessarily in direct contact with each other. These parts or members A and B may be either in direct contact or be supported on each other by means of one or more other parts. The same applies to other expressions such as, for example, the expression “A acts on B” which may mean “A acts directly on B” or “A acts on B by means of one or more other parts”.

[0054] The term "solidar" used to describe the connection between two parts means that the two parts are connected / fixed relative to each other, according to all degrees of freedom, unless explicitly specified differently. For example, if it is indicated that two parts are solidar in translation in an X direction, this means that the parts can be movable relative to each other, possibly according to several degrees of freedom, excluding the freedom in translation in the X direction. In other words, if one part is moved in the X direction, the other part performs the same movement.

[0055] In the following detailed description, use may be made of terms such as "horizontal", "vertical", "longitudinal", "transverse", "upper", "lower", "top", "bottom", "front", "rear", "inner", "outer". These terms must be interpreted relatively in relation to the normal position of use of the sample crusher. For example, the notion of "vertical" corresponds to the main extension direction (A1) of the crusher shaft.

[0056] A reference will also be used whose rear / front direction corresponds to the x axis, the transverse or right / left direction corresponds to the y axis and the longitudinal or bottom / top direction corresponds to the z axis.

[0057] The grinding method and the grinder 1 of biological samples are now described according to several exemplary embodiments with reference to the figures.

[0058] Generally, as illustrated by [Fig.l], the crusher 1 comprises a sample holding device 10 designed to carry tubes 2 containing samples 3 to be crushed. The sample holding device 10 is generally driven in precession, by a shaft 40 itself in rotation. The sample holding device 10 is mounted on the crusher 1 via the shaft 40 itself mounted on a frame 42. The holding device 10 and the tubes 2 can be arranged under a cover 41 pivoting between an open position and a closed position.

[0059] In order to maintain the holding device 10 integral with the shaft 40 and maintain the tubes 2, a vacuum can be created by creating a sufficient depression instead of using a screwing or clip system which is less resistant to the movement of precession.

[0060] The vacuum maintenance method according to the invention is carried out in order to make the grinding of sample 3 more reliable. The following paragraphs aim to describe the sample grinder 1 used in the method, according to an exemplary embodiment.

[0061] According to an example, the sample crusher 1 3 comprises a sample holding device 10 illustrated in FIGS. 2A and 2B. The sample holding device 10 comprises a first support 11 and a second support 12. The second support 12 can be mounted on the first support 11. Between the first support 11 and the second 12 mounted on each other, a closed volume 13 is defined.

[0062] At least one of the first 11 and the second 12 supports is more particularly designed to receive at least one tube 2 containing a sample 3. Preferably, at least one of the first 11 and the second 12 supports is designed to accommodate a plurality of tubes 2 containing a sample 3. In the following, it is considered, without limitation, that several tubes 2 are held by the holding device 10.

[0063] According to one example, the sample holding device 10 has two configurations. More particularly, the first support 11 and the second support 12 can have two configurations.

[0064] According to one example, in the first configuration, there is no depression of the volume 13. Thus, the first support 11 and the second support 12 cannot be secured to one another. In the second configuration, there may be depression of the volume 13. Thus, the first support 11 and the second support 12 may be secured to one another.

[0065] In the second configuration, the first support 11 can be driven in precession around a main axis AL. Due to the connection between the supports, the second support 12 can be driven in precession in the second configuration. The sample holding device 10 can thus be driven in precession in the second configuration for the grinding of sample 3. The main axis Al is preferably parallel to the direction in which the shaft 40 extends. Preferably the main axis Al is included in a plane in which the shaft 40 also extends.

[0066] The sample 3 grinder 1 comprises a vacuum module 20 illustrated in [Fig.4]. The vacuum module 20 comprises a pump 21, a pumping circuit 22 and a pressure sensor 23. Thus the vacuum module 20 makes it possible to create a vacuum in the volume 13. The sensor 23 can be connected to a power supply card 230.

[0067] According to one example, the pumping circuit 22 connects the volume 13 to the pump 21. In addition, the pressure sensor 23 can measure the pressure present in the circuit pumping 22. This makes it possible to measure the pressure in the pumping circuit 22 and therefore in the volume 13 and to check that the depression is achieved.

[0068] According to one example, the pump 21 is not driven during the precessional movement. Similarly, according to one example, the pressure sensor 23 is not driven during the precessional movement.

[0069] The method relates to the evacuation of the volume 13 by the vacuum module 20 to move the sample holding device 10 into the second configuration and thus allow a reliable precession movement and limit the risk of losing the second support 12 during the grinding of the sample 3.

[0070] Thus, in order to carry out efficient and safe grinding, the method according to one example comprises a depression of the volume 13 made reliable by an iterative measurement of the pressure in the volume 13 carried out by the pressure sensor 23. The pressure observed by the pressure sensor 23 can then allow a determination of a sufficient depression in order to start and / or continue the precession movement for the grinding of the samples 3.

[0071] The process steps will now be described according to the flowchart shown in [Fig.6]. The order of description of the steps does not imply that the steps described are necessarily carried out in this order.

[0072] According to an example, the first step of the vacuum maintenance method illustrated in [Fig.6], comprises a first measurement 400 of pressure PI by the pressure sensor 23. To do this, the sample maintenance device 10 is in its first configuration and the vacuum module 20 does not create a vacuum in the volume 13.

[0073] According to an example illustrated in [Fig.4], the pumping circuit 22 of the vacuum module 20 comprises a filter 221 and a solenoid valve 220. The solenoid valve 220 can be configured to have two positions. The solenoid valve 220 can have an open position making it possible not to create a vacuum and therefore leaving the sample holding device 10 in the first configuration. The solenoid valve 220 can have a closed position making it possible to create a vacuum passing the sample holding device 10 into the second configuration. Thus, during the first step 400, the solenoid valve can be in the open position.

[0074] The next step of the method comprises a placement 401 of the tubes 2 in the sample holding device 10. The placement of the tubes 2 can be carried out, and in particular depending on the size of the tubes 2, in the first 11 and / or the second 12 supports. In a first embodiment, the tubes 2 are arranged in the first support 11, for example illustrated in [Fig.2B]. This can in particular be done for tubes with a volume less than or equal to 50 mL (milliliters). The placement of the tubes can be produced, according to a second embodiment, in the second support 12, for example illustrated in [Fig.2A] and 3A. This can in particular be done for tubes with a volume greater than or equal to 15 mL, preferably 50 mL.

[0075] The first support 11 may comprise a tube-carrying plate 110. The plate 110 comprises openings 12all. The openings 12all may be intended to receive and support by gravity the tubes along the main axis AL. The openings 12al 1 may have dimensions in x and y at least equal to the dimensions of the tubes 2. The openings 12al 1 may have dimensions in x and y smaller than the dimensions of the caps of the tubes 2.

[0076] According to one example, the second support 12 is configured to receive and hold at least one tube 2. For this, the second support 12 may comprise at least one armhole 1202. The at least one armhole 1202 may then receive a tube 2 by sliding along a central armhole axis A2. The armhole 1202 may extend along the central armhole axis A2. The central axis of the armhole A2 being substantially perpendicular to the main axis AL. The armhole 1202 may comprise a locking module 1202a configured to hold a tube 2. According to one example, the locking module 1202a comprises a jaw, the locking module 1202a being elastically deformable, preferably in flexion, between at least one deployed position allowing the insertion of the tube into the armhole and a rest position in which the jaw is intended to grip the cap of the tube when the tube is inserted into the armhole.The 1202a locking module thus ensures that the tube is held in place in the sleeve during handling of the support as well as during grinding, by gripping the tube cap. This also limits the risk of the cap loosening.

[0077] A step of the method, according to an example, comprises the mounting 402 of the second support 12 on the first support 11. The second support 12 making it possible to hold the tubes in position during a following step, it is preferable that it be correctly positioned in order to secure the holding of the tubes 2.

[0078] According to the first embodiment, the second support 12, illustrated in [Fig.3B], comprises a ring 120. The ring 120 comprises holding tabs 1201, preferably arranged on its outer periphery. According to one example, the holding tabs 1201 are positioned at regular radial intervals. Advantageously, the holding tabs 1201 can be positioned opposite the tubes 2 when the second support 12 is mounted 402 on the first support 11. Thus, the positioning of the holding tabs 1201, aligned along an axis substantially parallel to the main axis A1 with the tubes 2, makes it possible to achieve a reliable mounting 402 and secure holding of the tubes 2.

[0079] According to one example, the first 11 and the second 12 support respectively have a lower surface 11a, 12a and an upper surface 11b, 12b. The upper surface 11b of the first support 11 and the lower surface 12a of the second support 12 may be of complementary shape and at least partly conical. Thus, the mounting of the second support 12 on the first support 11 may be guided by the shape of the surfaces and be facilitated. The enclosed volume 13 may be delimited at least in part by the upper surface 11b of the first support 11 and a lower surface 12a of the second support 12.

[0080] According to one example, the lower surface 12a of the second support 12 comprises reliefs 12al illustrated in FIGS. 3a and 3B. This allows at least partial contact of the lower surface 12a of the second support 12 with the upper surface 11b of the first support 11 at the level of these reliefs. This contact can occur as soon as the second support 12 is placed on the first support 11 or during vacuuming.

[0081] A step following the previous step 402 of the method comprises a depression 403 of the volume 13 by the depression module 20 in order to switch the holding device 10 from the first configuration to the second configuration.

[0082] In order to carry out this step, according to one example, the solenoid valve 220 moves from its open position to its closed position. The pump 21 can then be in operation and create a vacuum and therefore a depression zone in the closed volume 13. The pump 21 can have a flow rate greater than or equal to 2 L / min (liters per minute), preferably greater than or equal to 5 L / min, preferably equal to 7.5 L / min. Thus, the flow rate (illustrated in [Fig.7]) of the pump 21 makes it possible to increase the speed of the vacuuming of the volume 13.

[0083] During step 403 of the method, the vacuuming occurs at the level of the closed volume 13. The vacuuming can cause elastic deformation of the second support 12. Thus, the reliefs 12al positioned on the lower surface 12a of the second support 12 come into contact with the upper surface 11b of the first support 11. The reliefs 12al thus make it possible to improve the speed of the vacuuming 403. According to one example, the reliefs 12al are positioned at regular intervals along a transverse direction (y) extending from a center 13a to an external periphery 13b of the closed volume 13. As a result, the holding force is reduced during the deformation of the second support 12 during the vacuuming. According to one example, the reliefs 12al are circular in shape and include openings 12al 1 which allow the passage of air into the closed volume 13.The openings 12al 1 allow air to pass through, making the vacuum more reliable throughout the entire enclosed volume 13 and facilitating the breaking of the vacuum after use.

[0084] According to one example, the vacuum application during step 403 causes the compression of the second support 12 on the first support 11. A seal 14 may be for this present between the first 11 and the second 12 support in order to ensure the sealing of the volume 13 closed by its compression during the vacuum.

[0085] According to one example, the seal 14 is elastically deformable. The seal 14 can thus compress during step 403, when the first support 11 and the second support 12 are secured. In addition, the seal 14 can return to its initial shape when the sample holding device 10 returns to their first configuration. For example, the seal 14 can go from a thickness of approximately 6 mm (millimeters) to a thickness of approximately 3 mm and vice versa.

[0086] Furthermore, during step 403 of the method, according to the first embodiment, the compression of the second support 12 on the first support 11 causes the compression of the holding tabs 1201 on the closed tubes 2. According to one example, the second support 12 is composed of an elastically deformable material, and for example during the compression of the second support 12 on the first support 11. Similarly, the holding tabs 1201 are composed of an elastically deformable material. The holding tabs 1201 can therefore be sufficiently flexible to deform in order to accept manufacturing tolerances and deformation following vacuuming. Thus, the tubes 2 will be kept closed during the entire grinding cycle. According to one example, the second support 12 and therefore the holding tabs 1201 can be made of polymer.The polymer can be POM, and in particular POMc (polyoxymethylene copolymer, from the polyacetal C family) or PX 245 (vacuum-cast polyurethane).

[0087] After the depression 403, a second pressure measurement P2 is carried out 404 by the pressure sensor 23 in order to determine whether the depression has been carried out correctly and is effective. The second pressure measurement P2 can then be compared to the first pressure measurement PL. To do this, a difference 405 in measured pressure API between the second measurement P2 and the first measurement PI is for example determined by calculation. This difference in measured pressure API can correspond to a subtraction between the two pressure values ​​P2 and PL. However, it is possible to imagine determining a pressure difference by other means such as a ratio or even a variation rate.

[0088] It is then possible, during a following step 406 of the method, to ask whether the first API pressure difference is greater in absolute value than a first threshold value. Thus, the verification of the first measured API pressure difference with respect to a first threshold value makes it possible to determine whether or not the precession movement of the crusher 1 has started.

[0089] According to an example, if this difference is lower, then there is a stoppage of the depression (step 407 in [Fig.6]) because the depression produced in volume 13 is not not sufficient to keep the first support 11 and the second support 12 together.

[0090] According to one example, if this difference is much greater in absolute value than the first threshold value then step 408 can be carried out and the crusher 1 can be driven in precession. Indeed, the depression is then sufficient to allow the first support 11 and the second support 12 to remain integral during the precession drive.

[0091] According to one example, during step 406, the pressure difference may correspond to a ratio between a set pressure difference API' and the first measured pressure difference API. The threshold value may then be less than 1.7, preferably less than 1.5. Thus, the threshold value makes it possible to determine sufficient decompression to keep the second support 12 in place during depression. Similarly, this makes it possible to ensure that the tubes 2 remain closed during grinding and precession training.

[0092] According to one example, an optimal threshold value for a complete cycle for an altitude up to 2000m and a sample 3 between 100g (grams) and 500g corresponds to a ratio between a first measured API pressure difference greater than 500 mbar (millibar) and a first API setpoint pressure difference greater than 850 mbar.

[0093] During step 408, that is to say during the precession drive of the sample holding device 10 for the grinding of the samples 3, the second support 12 is thus driven in precession by the first support 11. In addition, and as illustrated in [Fig.5], according to one example, a mobile part 20a of the vacuum module 20 follows this precession movement thanks to a pneumatic connecting member 24.

[0094] According to one example, the vacuum module 20 comprises a first movable part 20a and a second fixed part 20b. The movable part 20a and the second fixed part 20b can be connected to each other by the pneumatic connecting member 24 configured to allow the movable part 20a to perform a movement independently of the second fixed part 20b. According to an embodiment illustrated in [Fig.5], the pumping circuit 22, and more particularly the connecting member 24, can connect the pump 21 to the closed volume 13 using flexible conduits 240 and coil springs 241. According to another embodiment not illustrated, the pumping circuit 22 can connect the pump 21 to the closed volume 13 by the shaft 40 associated with a rotating joint.

[0095] The second fixed part 20b comprises the pump 21, the pressure sensor 23 and at least partly the pumping circuit 22. The second fixed part 20b can then be moved away from the volume 13 to be evacuated and remains stationary, thus the second fixed part 20b does not follow the precession movement or any other movement. This movement also makes it possible to secure the vacuuming of the volume 13. Indeed, the elements of the second fixed part 20b are thus not subjected to stresses mechanical factors linked to the precession movement, which can cause defects.

[0096] According to one example, during this step, the pump 21 maintains a flow rate of the order of 7.5 l / min making it possible to compensate for leaks present during movement: manufacturing tolerances, deformation of the parts with mechanical constraints, wear of the sealing joint 14 between the first 11 and the second 12 support.

[0097] During precession training, a third pressure measurement P3 is carried out by the pressure sensor 23.

[0098] This third pressure measurement P3 and the determination of at least one second measured pressure difference AP2 (step 409 illustrated in [Fig.6]) can thus make it possible to determine whether or not it is necessary to stop the precessional movement allowing the grinding of the samples 3. In a similar manner to step 406, the second measured pressure difference AP2 can then be determined by taking the difference, for example, between the third pressure measurement P3 and the second pressure measurement P2. According to one example, the second measured pressure difference AP2 can be taken between the third measured pressure measurement P3 and the first pressure measurement PI.

[0099] Thus, the verification of the second measured pressure difference AP2 with respect to a second threshold value makes it possible to determine whether or not it is better to stop the precession movement of the crusher 1. The second threshold value may be equal to or different from the first threshold value.

[0100] According to one example, if this difference is lower, then there is a stoppage of the precession drive (step 411 in [Fig.6]) because the depression created in the volume 13 is not sufficient to keep the first support 11 and the second support 12 together.

[0101] According to one example, if this difference is greater in absolute value than the second threshold value then step 412 can be carried out and the crusher 1 can continue to be driven in precession. Indeed, the depression is then sufficient to allow the first support 11 and the second support 12 to remain integral during the precession drive.

[0102] According to an example, during step 410, the second measured pressure difference AP2 may correspond to a ratio between a second setpoint pressure difference AP2' and the second measured pressure difference AP2. The threshold value may then be less than 1.7, preferably less than 1.5. Thus, the threshold value makes it possible to determine sufficient decompression to keep the second support 12 in place during depression. Similarly, this makes it possible to ensure that the tubes 2 remain closed during grinding and precession training.

[0103] According to one example, an optimal threshold value for a complete cycle for an altitude up to 2000m and a sample 3 between 100g (grams) and 500g corresponds to a ratio between a second measured pressure difference AP2 greater than 500 mbar (millibar) and a second set pressure difference AP2' greater than 850 mbar.

[0104] According to one example, step 413 can be carried out in order to carry out several third pressure measurements Pn by the pressure sensor 23 and to carry out steps 409 and 410 of the method again until the end of the grinding of the samples 3.

[0105] Thus, each of the third pressure measurements Pn can lead to the determination of a maintenance of the depression (step 410) comprising a determination of at least a second measured pressure difference AP2 between a third pressure measurement P3 and the first pressure measurement PI and / or the second pressure measurement P2, and a verification of the second measured pressure difference AP2. This then makes it possible to determine whether the decompression is sufficient over time to continue the precessional movement or not.

[0106] According to one example, stopping the precessional movement causes the grinding of the samples 3 to stop.

[0107] According to one example, the grinding can be stopped by the user at any time and / or can be programmed according to a sample grinding program 3.

[0108] According to one example, the grinding is stopped in the case where the depression is not sufficient or at the end of the grinding program.

[0109] The invention is not limited to the embodiments previously described and extends to all embodiments covered by the invention. Many other variant embodiments are possible, for example by combining previously described characteristics, without departing from the scope of the invention. In particular, many other relative arrangements of the source modules are conceivable, without departing from the scope of the invention. Preferred positions have been described above but many others can be provided. In addition, the characteristics described in relation to one aspect of the invention can be combined with another aspect of the invention. In particular, the method can implement any step implementing a characteristic of the grinder. The grinder can have any characteristic allowing the implementation of a step of the method.

[0110] DIGITAL REFERENCES 1: Sample crusher 10: sample holding device 11: first support 110: plateau lia: lower surface first support 11b: upper surface first support 12: second support 120: crown of the second support 1201: holding tab 1202: armhole 1202a: blocking module 12a: lower surface of second support 12al: reliefs 12a 11: openings 12b: upper surface second support 12bl: drilled screw 13: volume 13a: center of the volume 13b: external perimeter of the volume 14: seal 20: depression module 20a: first mobile part 20b: second fixed part 21: pump 22: pumping circuit 220: solenoid valve 221: filter 23: pressure sensor 230: power supply board 24: pneumatic connecting member 240: flexible conduit 241: coil springs 40: tree 41: hood 42: built 2: tube 3: sample Al: main axis of precession A2: central armhole axis API: First Pressure Difference AP2: second pressure difference API': first set pressure difference AP2': second set pressure difference PI: first pressure measurement second pressure measurement third pressure measurement nth third pressure measurement PI measurement Placement of at least one tube in the holding device Mounting the second bracket on the first bracket Switching on the vacuum device P2 measurement API calculation Is API greater than the threshold value Stop the vacuum, replace the system Starting the crusher motors for precession drive Measurement of P3 and calculation of AP2 Is AP2 above the threshold value? Stop the precession drive, stop the sample crusher Continuation of precession training Return to step 409, Measure Pn until reaching step 411.

Claims

Claims

1. A method of maintaining a vacuum for a sample (3) grinder (1), the grinder (1) comprising: - a sample holding device (10) comprising a first support (11) and a second support (12), the second support (12) being configured to be mounted on the first support (11) by defining a closed volume (13) between the first (11) and the second (12) support, at least one of the first (11) and the second (12) support being configured to receive at least one tube (2), containing a sample (3), the sample holding device (10) being configured so that: • the first support (11) and the second support (12) have a first configuration in which the first (11) and second (12) supports are not secured to each other by a depression of said volume (13), and a second configuration in which the first (11) and second (12) supports are secured by a depression of said volume (13), and • in the second configuration, the first support (11) is configured to be driven in precession around a main axis (Al) and thus drive the second support (12), - a vacuum module (20) comprising a pump (21), a pumping circuit (22) configured to connect said volume (13) to the pump (21), and a pressure sensor (23) configured to measure a pressure in the pumping circuit (22), the pump (21) and the pressure sensor (23) not being driven during said precession movement, the method comprising: - a first measurement (PI) of an initial pressure by the pressure sensor (23), the sample holding device (10) being in the first configuration (400), - a placement (401) of at least one tube (2) in the device sample holder (10), a mounting (402) of the second support (12) on the first support (11), after mounting the second support (12) on the first support (11), a depression (403) by the depression module (20) of said volume (13) to switch the sample holding device (10) from the first configuration to the second configuration, the depression (403) comprising: • a second measurement (P2) of pressure (404) by the pressure sensor (23), • a determination (405) of a first measured pressure difference (API) between the second measurement (P2) and the first measurement (PI), and • a verification (406) of the first measured pressure difference (API), comprising, when the first pressure difference (API) is greater in absolute value than a first threshold value, the transition to a precession drive step (408), the precession drive (408) of the sample holding device (10) for the grinding of the sample (3) contained in the at least one tube (2), comprising: • at least a third measurement (P3) of pressure (409) by the pressure sensor (23), • a determination of a maintenance of the depression (410) comprising a determination of at least a second measured pressure difference (AP2) between the at least third measurement (P3) and the first measurement (PI) and / or the second measurement (P2), and a verification of the second measured pressure difference (AP2), comprising, • when the second measured pressure difference (AP2) is greater in absolute value than a second threshold value, a continuation of the precession drive, • when the second measured pressure difference (AP2) is lower in value absolute at the second threshold value, a stop of the precession drive.

2. Method according to the preceding claim, in which: - when checking (406) the first measured pressure difference (API), the first measured pressure difference (API) is considered greater than the first threshold value if a ratio between a first setpoint pressure difference (API') on the first measured pressure difference (API) is less than 1.7, preferably 1.5 and / or - when checking (410) the second measured pressure difference (AP2), the second measured pressure difference (AP2) is considered greater than the second threshold value if a ratio between a second setpoint pressure difference (AP2') on the second measured pressure difference (AP2) is less than 1.7, preferably 1.5

3. 1.J. Method according to the preceding claim, in which during the verification (406) of the first measured pressure difference (API) and during the determination of a maintenance of the depression (410), the first and second measured pressure differences (API, AP2) are greater than or equal to 500 mbar in absolute value, and the first and second set pressure differences (API', AP2') are greater than or equal to 850 mbar in absolute value, to respectively initiate and continue the precession drive.

4. Method according to any one of the preceding claims, in which the precession drive (408) comprises several (Pn) third pressure measurements (P3) by the pressure sensor (23), each resulting in the determination of a maintenance of the depression (410) comprising the determination of at least one second measured pressure difference (AP2) between the third measurement (P3) and the first measurement (PI) and / or the second measurement (P2), and the verification of the second measured pressure difference (AP2).

5. Method according to any one of the preceding claims, in which the pumping circuit (22) comprises at least a first movable part (20a) integral with the sample holding device (10) and at least a second part 20b not being driven during said precession movement (408), the first movable part (20a) being connected to the second part 20b by a connecting member (24) so ​​that the precession drive (408) of the sample holding device (10) comprises a precession movement of the first movable part (20a) authorized, relative to the second part 20b, by the connecting member (24).

6. Method according to the preceding claim, in which the second part 20b of the pumping circuit (22) is offset from the volume (13) to be evacuated by means of the first movable part (20a), the pump (21) and the pressure sensor (23) being mounted on said second part 20b.

7. Method according to any one of the preceding claims, in which the closed volume (13) is delimited at least in part by an upper surface (11b) of the first support (11), and a lower surface (12a) of the second support (12), the upper surface (11b) and the lower surface (12a) being of complementary shape and at least partly conical, and the mounting (402) of the second support (12) on the first support (11) comprises the arrangement of the lower surface (12a) of the second support (12) on the upper surface (11b) of the first support (11).

8. Method according to any one of the preceding claims, in which, during the depression (403), reliefs (12al) positioned in the closed volume (13) on one of the lower surface (12a) of the second support (12) and the upper surface (11b) of the first support (11) come into contact with the other of the lower surface (12a) of the second support (12) and the upper surface (11b) of the first support (11).

9. Method according to the preceding claim, in which, the closed volume (13) having a center (13a) and being delimited by an external periphery (13b), the reliefs (12al) are positioned at regular intervals along a transverse direction (y) extending from the center (13a) to the external periphery (13b) of the closed volume (13).

10. Method according to any one of the two preceding claims, in which the reliefs (12al) comprise openings (12al 1), the depression (403) comprising a circulation of air in the closed volume (13), said circulation being authorized by said openings (12al 1), with a view to the suction of the air.

11. A method according to any preceding claim, wherein the sample holding device (10) comprises a seal sealing gasket (14) positioned between the first support (11) and the second support (12), the sealing gasket (14) being elastically deformable, and the depression (403) comprises a compression of the gasket (14) between the first support (11) and the second support (12).

12. Method according to any one of the preceding claims, in which during the depression (403), the pump (21) of the depression device (20) has a flow rate greater than or equal to 2 L / min, preferably greater than or equal to 5 L / min, preferably equal to 7.5 L / min.

13. Method according to any one of the preceding claims, in which the first support (11) comprises a tube-holding tray (110) comprising at least one opening capable of receiving at least one tube (2), preferably a plurality of tubes, the placement (401) of the at least one tube (2) in the sample holding device (10) comprising a reception, by the first support (11), of the at least one tube (2) by insertion into the at least one opening according to a translational movement along the main axis (Al).

14. A method according to any preceding claim, wherein, at least during the precession drive (408), the second support (12) holds the at least one tube (2) in position.

15. Method according to the two preceding claims taken in combination, in which the second support (12) comprises a crown (120) comprising elastically deformable holding tabs (1201), and the mounting (402) of the second support (12) on the first support (11) comprises a superposition at least in part of the crown (120) with the tube-holder plate (110) comprising the at least one tube (2), and an elastic compression of the holding tabs (1201) so as to hold the at least one tube (2) in position.

16. Method according to any one of claims 1 to 12 in combination with claim 14, wherein the second support (12) comprises at least one sleeve (1202) intended to receive at least one tube (2) closed by a cap, the sleeve (1202) extending along a central axis (A2) in a plane substantially perpendicular to the main axis (A1) of the first support (11), and the placement (401) of the at least one tube (2) in the sample holding device (10) comprising a reception of the at least one tube (2) by the second support (12), by sliding along the central axis (A2) of the sleeve (1202).

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