FR2909074A1 - Powder e.g. organic powder, dosing device for e.g. chemical industry, has reservoir movably mounted with respect to distribution unit such that major part of powder is freely displaced along movement same as that of reservoir - Google Patents

Abstract

The device (1) has a reservoir (2) i.e. bottle, movably mounted with respect to a powder e.g. organic powder, distribution unit (5) such that a major part of powder (4) is freely displaced along a movement same as that of the reservoir without producing obstacles driven at its condensation. The major part of the powder is situated between an internal surface (3I) of a wall of the reservoir and the distribution unit. The distribution unit is formed by a rod that is extended parallel to a co-axial vertical axis (XX'). An independent claim is also included for a powder dosing cap comprising a base.

Description

POWDER DOSING DEVICE The present invention relates to the

  field of powder metering devices that allow the distribution or transfer of a controlled quantity of powdery or granular substances.

  The present invention more particularly relates to a powder metering device comprising a reservoir delimited by a wall having an internal face, said reservoir being intended to contain said powder, and a dispensing member allowing the flow of powder out of said reservoir. through a conduit.

  The present invention also relates to a powder metering cap intended to be attached to a reservoir delimited by a wall having an internal surface and containing powder, such as a bottle, said cap comprising for this purpose a base provided with a means fixing to said reservoir, such as a threaded ring.

  The present invention finally relates to a rod-type powder distribution member intended to be mounted on a tank delimited by a wall having an internal surface and containing powder, such as a bottle, in order to allow the dosage of said powder, said dispensing member comprising a conduit arranged to allow the flow of the powder out of the reservoir when said dispensing member is mounted on said reservoir.  In many industrial applications, and especially in the pharmaceutical, food or chemical industries, it is frequently necessary to proceed to the dosing of ingredients or reagents in powder or granular form.  B60337 / FR 2909074 2 For this purpose, it is known to use powder metering devices which comprise a reservoir in which said powder is stored and which communicates with a distribution chamber, generally forming a hopper, in which a movable member of pallet type or worm 5 pushes the powder under stress to an outlet port.  Although they show generally satisfactory results in terms of simplicity of manufacture and powder distribution, the known devices nevertheless suffer from considerable drawbacks related to the mechanical stresses exerted by worms or pallets on the powder to be dosed. .  First, such constraints are likely to cause the compacting of said powder and the formation of aggregates whose presence is detrimental to the proper functioning of the device.  Indeed, such aggregates form a mass of agglomerated material substantially greater than that of a single grain and capable of being distributed at one time (when said aggregate is discharged as a whole), which tends to increase randomly the elemental amount of powder that the device is likely to distribute, that is to say, to degrade the accuracy of the distribution.  However, the lack of precision in the assay may be particularly problematic when the quantities of powder involved are infinitesimal, of the order of a milligram to a few tens of milligrams, and / or when it is desired to prepare a mixture respecting strict stoichiometric conditions.  This is particularly the case in chemical libraries, in which it is systematically sought to minimize the consumption of reagents necessary for the development of new compounds.  Next, the accumulation of agglomerated powder within the metering device is likely to lead to the occlusion of the latter and to the failure of the distribution process.  Finally, certain powders, in particular organic powders, are particularly fragile and sensitive to the mechanical stresses that are exerted on them.  In particular the compressive or shearing forces caused for example by scraping, settling, grinding or shaking are sometimes capable of degrading the constituent molecules of the powder grains, thus causing the powder to lose all or part of its properties. physical and / or chemical.  The objects assigned to the present invention therefore aim to propose a novel powder metering device which does not have the abovementioned drawbacks and which improves the efficiency and the accuracy of the distribution of powdery or granular materials, in particular for the dosing of small amounts of powder, while preserving the intrinsic qualities of said powder.  Another object of the invention is to provide a new powder metering device whose structure is particularly simple and compact. Another object of the invention is to propose a novel powder metering device whose operation is reproducible and cheap.  Another object of the invention is to provide a new powder metering cap for efficient and precise distribution of said powder while preserving the qualities of the latter.  Finally, another object of the invention is to propose a new rod-type powder distribution member which facilitates the dispensing of said B60337 / FR 2909074 4 powder and improves its efficiency and accuracy while preserving the qualities of said powder. .  The objects assigned to the invention are achieved by means of a powder metering device comprising a reservoir delimited by a wall having an internal face, said reservoir being intended to contain said powder, as well as a dispenser member allowing the flow of the powder out of said tank through a conduit, said device being characterized in that said reservoir is movably mounted with respect to said dispensing member and arranged with respect to said denier so that most of the powder 10 located between the inner face of the tank wall and the dispenser member is free to move substantially in the same movement as the tank without encountering an obstacle likely to lead to its compaction.  The objects assigned to the invention are also achieved by means of a powder metering cap intended to be attached to a reservoir delimited by a wall having an internal surface and containing powder, such as a bottle, said plug comprising for this purpose a base provided with a fixing means to said tank, such as a threaded ring, said cap being characterized in that said base is designed to be mounted movably on a dispensing member allowing the flow of the powder out of said reservoir through a conduit so that, once said base fixed to said reservoir and mounted on the dispensing member, the reservoir and the base can be moved jointly relative to said dispensing member, while most of the powder located between the inner face of the wall of said reservoir and said dispensing member is free to move substantially in accordance with the same movement as the tank without encountering any obstacle likely to lead to its compaction.  860337 / FR 2909074 5 The objects assigned to the invention. are finally achieved by means of a rod-type powder distribution member intended to be mounted on a tank delimited by a wall having an internal surface and containing powder, such as a bottle, in order to allow said powder to be dosed, said dispensing member comprising a conduit arranged to allow the powder to flow out of the reservoir when said dispenser member is mounted on said reservoir, said dispensing member being characterized in that it is arranged on the one hand to be movably mounted relative to the reservoir so that the latter can be moved with respect to said dispenser member, and on the other hand to sufficiently clear the space between itself and the inner face of the wall of said tank so that most of the powder in said space is free to move substantially in the same movement as the tank without encounter obstacles likely to lead to compaction.  Other objects, features and advantages of the invention will appear better on reading the description which follows, as well as with the aid of the accompanying drawings provided for purely illustrative and non-limiting purposes, among which: FIG. a schematic perspective view of an alternative powder metering device according to the invention.  - Figure 2 illustrates, in a perspective view, an alternative embodiment of a powder dispenser member according to the invention.  FIG. 3 illustrates, in a projected front view, a part of the powder distribution member of FIG. 2.  FIG. 4 illustrates, in a side view of the powder distribution member portion of FIG. 3.  B60337 / FR 2909074 6 - Figures 5A, 5B, 5C and 5D show, in cross-sectional views A-A, various alternative embodiments of the dispensing member illustrated in Figures 2 to 4.  - Figure 6 illustrates, in a longitudinal sectional view, a portion of the device of Figure 1 in a first configuration.  - Figure 7 illustrates, in a cross-sectional view B-B, the section of the device shown in Figure 6.  - Figure 8 illustrates, in a longitudinal sectional view, the part of the device of Figure 6 in a second configuration.  The powder metering device 1 according to the invention, hereinafter device, is intended to carry out the intermittent or continuous distribution of a powder, that is to say a substance or a mixture of pulverulent or granular substances, mineral or organic, according to a predetermined quantity or a fixed mass flow rate.  More specifically, the device 1 according to the invention is preferably adapted to the precise metering of the powder, and in particular to the distribution of amounts of powder less than one gram, and preferably of the order of a few milligrams to a few tens of minutes. milligrams.  The required accuracy can then be up to one hundred micrograms.  According to a particularly preferred embodiment, the device 1 is a precision distributor for chemical libraries, especially those of pharmaceutical laboratories.  As is illustrated in Figures 1, 6 and 8, the powder metering device 1 comprises a reservoir 2 delimited by a wall 3 having an inner face 31, said reservoir. 2 being intended to contain the powder 4 to be dosed.  The tank 2 may in particular be constituted by a plastic bottle.  According to the invention, the device 1 also comprises a dispensing member 5 which allows the flow of the powder 4 out of the tank 2 through a duct 6.  According to an important characteristic of the invention, the tank 2 is mounted movably with respect to said dispensing member 5 and arranged with respect to the latter so that the major part of the powder 4 situated between the inner face 31 of the wall reservoir 2 and the dispensing member 5 is free to move substantially in the same movement as the tank 2 without encountering an obstacle that may lead to its compaction.  Thus, the device 1 according to the invention is advantageously devoid of blades, squeegees, worm or vibrators from mechanically constraining the powder 4.  Said device 1 thus considerably limits the stress imposed on said powder 4 during dispensing.  More particularly, the device 1 according to the invention makes it possible to substantially avoid the shearing and compression of each elemental volume of powder 4 contained in the reservoir against either a solid body distinct from the powder 4 and forming an obstacle, or the rest of the mass of powder 4.  Advantageously, by avoiding physically constraining the powder, the device 1 according to the invention prevents any degradation of it and therefore retains its physical, chemical, aromatic, taste (. . . ) especially for pharmaceutical, chemical or culinary purposes.  In addition, it limits or eliminates the formation of agglomerates detrimental to the accuracy of the assay.  B60337 / FR 2909074 8 Preferably, most of the constituent elements of the reservoir which come into contact with the powder 4, and more particularly the majority of the surfaces of these elements, are arranged to be driven by the same overall movement. , so as to cause the mass of powder 45 substantially according to said overall movement, without constraining the latter, and in particular without compressing it.  As will be described in greater detail hereinafter, the powder 4 tends therefore mainly to accompany the reservoir 2 in its movement, said reservoir thus conferring on the powder a certain amount of movement, transmitted tangentially by adhesion and not by scraping or compression.  Although it is conceivable that the tank 2 can move in one or more translation components, it is preferably rotatably mounted about an axis (X) (').  In addition, although said rotation can be alternated, it will preferably be unidirectional and substantially regular so as to avoid subjecting the powder 4 to jolts and jolts related to the inertial phenomena occurring during the movements of va-and -Comes.  In addition, according to the invention, it is conceivable that the rotational movement is continuous, particularly in the case of a continuous flow distribution whose mass flow rate is to be regulated, or intermittent, especially in the case of spaced distributions in time and / or involving varying amounts of powder metered.  Preferably, the device 1 comprises a motor 7 arranged to drive the reservoir 2 in rotation about its axis (XX ').  In a particularly preferred manner, the motor 7 will consist of an electric stepping motor.  Said motor 7, as well as the tank 2, are preferably supported by a common frame (not shown), said frame being for example provided with a bearing serving as a rotatable support at the neck of the bottle forming said tank 2 .  The transmission between the engine and the tank 2 may be carried out by means of various appropriate mechanical means, for example by a pinion / crown gear meshing system, or by friction, either directly, by pressing a wheel motor against the outer wall of the bottle, or indirectly using a set of wear rings.  Preferably, as shown in Figure 1, the axis (XX ') is substantially vertical.  Thus, the force of gravity can advantageously contribute to the flow of the powder 4 within the device 1 according to the invention.  By substantially vertical, it is indicated that the axis (XX ') forms an angle of 90 +/- 45 with the horizontal.  Of course, other orientations of the axis (XX ') are conceivable without departing from the scope of the invention.  However, the use of spatial qualifiers such as high, low, low, high (etc. ) will now be referenced, for convenience of description and without this constituting a restriction of the invention, a device 1 whose axis (XX ') is oriented substantially vertically, the tank 2 being above duct 6 so that the flow of the powder 4 is generally in the direction of decreasing altitudes (from top to bottom) during distribution.  According to a preferred embodiment, the dispensing member 5 is formed by a rod 10 which extends substantially parallel to the axis (XX ') and 25 which, particularly preferably, is substantially coaxial with said B60337 / FR 2909074 10 axis (XX ').  Thus, the rod 10 may advantageously materialize the axis of rotation of the reservoir.  Preferably, said rod 10 has a substantially cylindrical revolution geometry.  Preferably, as illustrated in FIGS. 1, 6, 7 and 8, the device 1 comprises a sleeve 11 designed to be secured to the reservoir 2 and to grip the lateral surface of the rod 10, forming a bearing 12 .  Said sleeve 11 is preferably made of an elastomer, the hardness of which will be particularly preferably between 45 and 90 Shore A, mounted fitted or even slightly tightened on the rod 10, so as to form a sliding bearing substantially impervious to the powder 4.  Advantageously, it is thus possible to create a pivot connection, or even a pivot connection sliding in a particularly simple and compact manner between the rod 15 and the reservoir 2.  Of course, it is quite possible to use other coupling means interposed between the reservoir 2 and the rod 10 such as ball bushings.  The sleeve 11 and / or the rod 10 may also be provided with additional sealing means such as scraping pads of the lip or o-ring type ensuring a tight contact between the periphery of the rod 10 and the inner wall of the sleeve 11.  According to a particularly preferred embodiment illustrated in FIGS. 6, 7 and 8, the duct 6 is formed, at least in part, by the juxtaposition of a part of a groove dug from the lateral surface B60337 / FR 2909074 11 of the.  rod 10, and secondly of the inner wall of the sleeve 11 which comes into contact with said rod 10.  In other words, the duct 6 can advantageously be formed by covering an excavation which opens on the surface of the rod 10 by a conjugate-shaped cover constituted by the inner wall of the sleeve 11.  Preferably, as shown in Figures 6, 7 and 8, the bottom of said groove and the inner wall of the sleeve 11 form the side walls of the duct 6.  A two-part structure as described above advantageously makes it possible to simplify the manufacture of the duct 6, whether the dispensing member 5 is produced by machining or by casting (molding).  Indeed, in the first case, no delicate drilling or tortured forms is necessary, since it is sufficient to make a groove by milling the rod at a lateral approach and then to thread said rod 10, possibly corrected, 15 in the bore of the sleeve 11.  In the second case, no complex core is necessary, opening the cavity on the outside of the rod to easily predict a draft angle.  Furthermore, this constructive arrangement can contribute to improving the fluidity and regularity of the flow of the powder 4 along the duct 6, the surface of the sleeve 11 in contact with the powder present in said duct 6 tending to exert a function conveying by tangential drive of said powder.  As shown in FIGS. 2, 3, 4, 6 and 7, the duct 6 extends from an intake port 14 which communicates with the reservoir 2, and opens onto an outlet port 15. open in the lateral surface of the rod 10.  B60337 / FR 2909074 12 According to a preferred embodiment, said outlet orifice 15 is formed by an elongate recess, oriented substantially along the axis (XX '), and inclined towards the periphery of the rod 10 so as to form a spout pourer.  Thus, the duct 6 may advantageously be extended by a conical recess portion which, when the rod is assembled on the sleeve 11, is to die against the inner wall of said sleeve.  More specifically, the rod 10 is preferably slidably mounted along the axis (XX ') with respect to the sleeve 11 so as to be able to occupy alternately a closed position, illustrated in FIGS. 6 and 7, in which said sleeve 11 covers the outlet orifice 15 and prevents the powder 4 from flowing out of the duct 6, thus, by extension, out of the tank 2, and an open position, illustrated in FIG. 8, in which the outlet orifice emerges at least partially from said sleeve 11 so as to allow the flow of the powder 4 out of the conduit 6.  The use of a conically shaped pouring spout then advantageously makes it possible to adjust the opening of the outlet orifice 15 as a function of the altitude of the rod 10 with respect to the sleeve 11 and more specifically of the position of the spout. pourer relative to the inner wall of said sleeve.  It is remarkable that the use of a bearing formed by a tubular sleeve in which a cylindrical rod 10 cooperates advantageously makes it possible to produce a sliding pivot connection which simultaneously allows, on the one hand, the rotation of the sleeve, and consequently of the reservoir. 2, relative to said rod 10 and on the other hand the sliding of the rod 10 along the axis of rotation (XX ').  According to a preferred embodiment of the invention, the intimate contact between the sleeve 11 and the rod 10 makes it possible to confine the powder 4 in a sealed manner in the reservoir 2 and the duct 6 when the rod 10 is located. 13 in the closed position, so that said powder can be stored durably within the device 1 without being exposed to the atmosphere surrounding it.  In particular, the device 1 considerably limits the exposure of the powder 4 to the water vapor contained in the ambient air, even in the case of prolonged storage (spaced distributions), which makes it particularly suitable for the determination, even episodic, hygroscopic powders that tend to agglomerate in the presence of moisture.  According to a preferred embodiment illustrated in Figures 1, 6 and 8, the sleeve 11 is extended by a skirt 16 located at a short distance from the side surface of the rod 10; towards the outlet orifice 15, so as to limit the centrifugal radial dispersion of the powder grains with respect to the axis (XX ').  In other words, the sleeve 11 preferably comprises on the one hand a bored upper section of narrow section, fitting in contact with the lateral surface of the rod 10 to form the sliding pivot bearing and provide the cover duct 6 in the closed position, and secondly a lower section of enlarged section allowing free evacuation of the powder 4 out of the duct 6 through the outlet orifice 15, and the circulation, in this case, the fall free by gravity, of said powder 4 within the space 20 formed between the rod 10 and the skirt 16.  Said section of widened section thus forms a deflector which tends to retain the powder grains 4 ejected from the duct 6 in the vicinity of the rod 10 and channels the fall of said grains, substantially vertically along said rod 10, to a container 17 for receiving the dose of powder (such as a vial, a cup, or a test tube).  Thus, the device according to the invention makes it possible to avoid powder losses and / or measurement errors (false weighing) related to a random dispersion of the grains around the container 17.  B60337 / FR 2909074 14 According to a preferred embodiment illustrated in Figures 2 to 8, the duct 6 forms within the rod 10 a chamber 20 between an upper wall 20S adjacent to the reservoir 2 and an opposite bottom wall 201, said upper and lower walls 20S, 201 being substantially normal to the axis (XX ').  Indeed, the inventors have found that such a chamber 20 acts as a buffer between the reservoir 2 and the outlet orifice 15 by regulating the flow of the powder 4, and therefore allowed to improve the reproducibility of the assay. and the regularity of the powder flow.  In a particularly preferred manner, the inlet orifice 14 is pierced in the upper wall 20S and the outlet orifice 15 in the lower wall 201, which allows the powder 4 to drop by gravity firstly from the reservoir. 2 to the chamber 20, then to the chamber 20 outside the device through the outlet port 15.  Preferably, as shown in the figures, the upper 20S and lower walls 201 of the chamber 20 are preferably substantially parallel to each other and normal to the axis (XX '), that is to say substantially horizontal.  This geometry is preferred insofar as it provides, on the one hand, good results in terms of reliability and precision of the metering, and, on the other hand, in that it facilitates the machining of the chamber 20.  However, it is perfectly conceivable, without departing from the scope of the invention, for the upper and lower walls of the hinge 20 to be one and / or the other inclined, possibly differently from each other, by 25 relative to the axis (XX ').  B60337 / FR 2909074 In addition, the chamber 20 can adopt different shapes, as illustrated by the different cross-sectional views projected along the axis (XX ') of Figures 5A, 5B, 5C and 5D.  Preferably, the section of the chamber 20 projected in a plane normal to the axis (XX ') has a disk portion type circular geometry, as illustrated in FIG. 5A, of the ring portion type, as shown in FIG. 5B, of ascending type, as shown in FIG. 5C, or of neighborhood type, as illustrated in FIG. 5D.  The angular aperture of such circular geometry sections preferably varies substantially between 60 and 270, and more preferably between 90 and 180.  In particular, the variant embodiments illustrated in FIGS. 5B, 5C, 5D have angular apertures close to 180.  According to a particularly preferred embodiment, the chamber 20 extends, as illustrated in FIG. 5A, according to an angular opening disk portion a of between 60 and 180, and still more preferably between 90 and 60.degree. and 120.  It is remarkable that the use of a chamber 20 of circular geometry bordered by a conjugate movable wall of the sleeve 11 contributes to obtaining a smooth lateral tangential drive of the powder contained in said chamber 20, the grains tending by adhesion to adopt a trajectory concentric with that of the inner wall of the sleeve 11 between the inlet orifice 14 and the outlet orifice 15, in a substantially circular movement of the same direction and in the same direction as said sleeve 11.  The position of the outlet orifice 15 within the chamber 20 is subject to variations, provided that said outlet orifice 15 is not located directly opposite the inlet port 14, i.e. laterally offset from the latter, so that the chamber 20 can fulfill its role of flow control of the powder flow 4.  However, particularly preferably, as is illustrated in particular in Figures 2, 3, 4, 5A to 5D and 7, the outlet orifice 15 is formed at the bottom wall 201 of the chamber 20 and said chamber 20 forms a cul-de-sac whose bottom wall 20F is located substantially in line with said outlet orifice 15, in order to guide the powder 4 contained in the chamber 20 towards said outlet orifice 15.  Advantageously, this arrangement makes it possible to limit the risk of a dead zone, in which non-evacuated powder residues could settle and aggregate, in particular around the outlet orifice 15.  More particularly, the bottom wall 20F forms a stop which prevents the powder 4 from passing the outlet 15 and accumulating downstream thereof.  Preferably, as shown in FIG. 2, the bottom wall 20F of the chamber is substantially normal to the lower walls 201 and upper 20S and joins the contour of the outlet orifice 15 at a tangent approach, so as to form in line with it a vertical extension and smooth not offering any catch on the attachment of any powder residues.  It is also conceivable that said bottom wall 20F is slightly rounded or inclined relative to the bottom wall 201.  Furthermore, according to an alternative embodiment not shown, the leading edge 14A of the inlet orifice, formed by a cutout formed in the upper wall 20S of the chamber 20, can be beveled, its edge B60337 / FR The lower side is set back from its upper edge, so as to facilitate the crumbling and the flow of the powder 4 at the inlet of said chamber.  According to a preferred embodiment, the dispensing member 5 5 has a protuberance 21 which protrudes into the reservoir 2 so as to stir the powder 4 in the vicinity of said dispensing member 5 when said powder 4 is driven by the movement of the reservoir 2 .  Preferably, the protrusion 21 forms a fixed stirrer 22 eccentric and / or asymmetrical with respect to the axis of rotation (XX '), as illustrated in particular in FIG. 4.  Thus, said agitator 22 creates an imbalance within the mass of powder 4 when the latter is rotated by the reservoir 2, this shift of local equilibrium resulting in a gentle mixing of the powder 4 which does not create either compaction or electrostatic charge.  Particularly advantageously, such mixing also produces a homogenizing effect which prevents the formation of arches in the tank 2.  In a particularly preferred manner, said fixed stirrer 22 is integral with the rod 10 and has a smooth and regular profile, at least partially rounded, in order to limit the stresses it imposes locally on the powder 4 when it is flows around him.  In particular, as illustrated in Figures 1, 2, 6 and 8, the agitator 22 may be in the form of a cylinder quarter (almost a half-cylinder) which rises vertically in the tank 2, and whose curved surface 22A joins the flat surface 22B forming an edge 22C 25 substantially perpendicular to the inlet orifice 14.  Such an arrangement advantageously makes it possible to free the access to said inlet orifice of a B60337 / FR 2909074 18 part and, on the other hand, to create at this level a slight turbulence in the flow of the powder 4 and thus to facilitate the falling said powder into the chamber 20 through said inlet port 14.  Moreover, the stirrer 22, and more generally the rod 10, can advantageously be made of a conductive material capable of evacuating any electrostatic charges which would be created during the friction of the powder grains against the stirrer 22.  Thus, it is possible to dose powders which tend to electrify and agglomerate under the effect of electrostatic charges.  According to a particularly preferred embodiment illustrated in FIG. 1, the rod 10 is kept immobile in rotation along the axis (XX '), while the reservoir is driven by a non-zero speed rotational movement (in the clockwise in the figure) around this axis.  Such an arrangement advantageously makes it possible, on the one hand, to systematically maintain the pouring spout in the same angular position with respect to the axis (XX '), in line with the container 17, and on the other hand to easily carry out by cabling. the electrical connection to the earth of the rod 10 for the evacuation of any electrostatic charges.  In addition, the fact of engaging a driving means (motor 7) on the ring of the tank 2, which has a diameter much greater than that of the rod 10, advantageously makes it possible to control the movement of said tank 2 by relative to said rod 10, in position as speed, particularly precisely, and in particular much more accurate than if said drive means was associated with the rod 10.  This results in a noticeable gain in dosage resolution, since the smallest amount of spillable powder is finely controlled.  B60337 / FR 2909074 19 As shown in FIG. 1, the device 1 according to the invention can be completed by one or more systems used to control the dosing process.  In particular, the device 1 may comprise measuring means 23, such as a scale, which makes it possible to measure the quantity of powder 4 poured out of the conduit 6 into the receptacle 17 provided for this purpose.  The device 1 may also comprise a servo-control means 24 designed to control the movement of the tank 2, and in particular to control the speed and / or the angular position of the tank 2 and regulate it by means of the engine 7. function of the data collected by the means of measurement 23.  Said control means 24 may advantageously be computerized so as to be able to manage the assay autonomously from information, such as a mass or mass flow rate, and / or characteristic parameters of the powder, indicated by the user 15 by means of an appropriate interface.  In addition, the servo-control means 24 can also drive a means 25 for adjusting the height of the rod 10 capable of sliding the rod 10 in the sleeve 11 so as to control the opening of the outlet orifice 15.  More particularly, said adjustment means 25 may be provided with a forked gripper arm 26 motorized in vertical translation and adapted to cooperate with the base of the rod 10 by gripping the latter at a groove 27.  Laclite 27 may advantageously comprise one or more flats so that the gripping arm 26 immobilizes the rod 10 in rotation when it is engaged on the latter.  B60337 / FR 2909074 Advantageously, the servo-control means 24 may also include means for detecting operating anomalies, for example capable of sending an error signal back to the user in the event of a powder flow defect. in the container 17, for example when the reservoir 2 is empty or the conduit 6 obstructed.  The servo-control means 24 according to the invention can thus advantageously constitute an automation means able to autonomously govern the distribution of the powder 4 according to a quantity and / or flow instruction determined by the user. , thereby helping to automate the management of the chemical library in which it operates and to save both manpower resources and reagents.  Furthermore, the tank 2 may optionally be associated with an automatic supply means which completes, permanently or periodically, the level of powder contained in said tank so as to compensate for the effects of the distribution.  The present invention also relates as such to a powder dosing cap 30 to be attached to a reservoir 2, such as a bottle, delimited by a wall 3 having an inner face 31 and containing powder 4.  The cap 30 according to the invention comprises for this purpose a base 31 provided with a fixing means to said reservoir, such as a threaded ring.  According to an important characteristic of the invention, said base 31 is designed to be mounted movably on a dispensing member 5 which allows the flow of the powder 4 out of said reservoir 2 through a conduit 6, so that a once said base 31 fixed on said reservoir 2 and mounted on the dispensing member 5, the reservoir 2 and base 31 can be moved jointly relative to said dispensing member 5, while most of the the powder 4 located between the inner face of the wall of the tank 2 and said dispensing member 5 is free to move substantially in the same movement as the tank 2 without encountering any obstacle likely to lead to its compaction.  Preferably, as shown in FIGS. 6, 7 and 8, the plug 30 preferably associates the base 31 with a sleeve 11 as described above, forming a central cylindrical plain bearing intended to accommodate a sliding impervious pivot. the stem 10.  It is remarkable that the sleeve 11 may be associated with a seal, such as a flange 32 intended to be sandwiched between the base 31 and the neck of the bottle forming the tank 2 so as to ensure a tight fastening plug 30 on said tank 2.  It is particularly remarkable that the direction of rotation of the reservoir 2 is preferably chosen so that it corresponds to the screwing direction of the stopper 30 on the vial, that is to say, in the clockwise direction when the stopper 30 has a right screw thread, as shown in FIG. 1.  Thus, it avoids any loosening of the plug during the rotation of the tank 2 for the purpose of powder distribution.  The choice of the direction of rotation can also condition (or conversely, be conditioned by) the geometry of the rod 10 and more particularly the arrangement of the inlet orifice 14 and the outlet orifice 15 relative to the chamber 20 .  Thus, in the embodiments shown in FIGS. 2 to 8, the inlet orifice 14 is located at the top right and the outlet orifice 15 at the bottom left, which corresponds to the direction of movement of the powder 4 when it is driven by a sleeve 11 which is rotated clockwise with respect to the rod 10.  However, it would be perfectly conceivable to use a stopper 30 with a screw thread on the left, to turn the reservoir 2 in the trigonometric direction and to use a rod 10 whose intake orifice 14 would be positioned in position. top left and the outlet 15 at the bottom right, without departing from the scope of the invention.  The present invention finally relates to a powder-like dispensing member 4, of rod type, intended to be mounted on a tank 2 delimited by a wall 3 having an inner face 31 and containing powder 4, such as a bottle, in order to allow the dosing of said powder, said dispensing member 5 having a duct 6 arranged to allow the flow of said powder 4 out of the tank 2 when said dispensing member 5 is mounted on said tank 2.  According to an important characteristic of the invention, said dispenser member 5 is arranged on the one hand to be movably mounted relative to the reservoir 2 so that the latter can be moved with respect to said dispensing member. and secondly to sufficiently clear the space between itself and the inner face of the wall of said tank 2 so that most of the powder 4 in said space is free to move substantially in the same way movement that the tank 2 without encountering an obstacle likely to lead to its compaction.  Preferably, said dispensing member is formed by a rod 10 as described above and illustrated in particular in FIG.  Of course, the device 1 according to the invention, and more particularly the measuring cap 30 can be modular systems that can be sold separately.  In particular, the same device 1 may be provided with a batch of 5 different metering caps 30 adapted to the dosage of various types of powders, depending on the rheological behavior of said powders and the flow rate and / or accuracy sought during the assay.  It is also conceivable to provide such metering plugs separately, for example as spare parts or as a retrofit solution to equip as standard the storage vials of an existing chemical library with a view to using said vials as reservoirs 2 within of a device 1 according to the invention.  In addition, the same cap 30 may for example be provided with a range of several rods 10 (or more sleeves 11) each adapted for the determination of a particular type of powder.  It is indeed conceivable to vary the arrangement and the constituent materials of the plug 30 and the rod 10, and more particularly the dimensions of the chamber 20, the stirrer 22 and the intake orifices 14 and exit 15, depending on various parameters such as particle size, hygroscopic, electrizable, cohesive, or even corrosive character (. . . )

powders

  to be dosed. Thus, the device 1 according to the invention is likely to be declined and easily adapted to many types and sizes of bottles, as well as many types of powders with very variable rheological properties. In addition, the interchangeability of the constituent parts of the measuring cap 30, as well as the ease of assembly or disassembly thereof, greatly simplify the installation and maintenance operations (cleaning or replacement) of the dispensing cap 30. a device 1 according to the invention.

The operation of a device 1 according to the invention will now be described with reference to the preferred embodiment illustrated in FIGS. 1, 6 and 8. The user first fills a reservoir 2, of the bottle type. using a raw quantity of powder 4 which it wishes to dose accurate amounts.

The user then selects a measuring cap 30 and a rod 10 adapted to the rheological properties of the powder 4 chosen. The user then assembles the plug 30 and the rod 10 by threading the latter into the sleeve 11 provided for this purpose. Then, the user reports the cap 30 on the reservoir 2 by screwing the base 31 of said cap on the threaded neck of the bottle forming said reservoir 2. It is also conceivable that the user first fixes the cap 30 on the vial 2, then only after insert the rod 10 through the sleeve 11 secured to the cap 30. The user then flips the bottle so that the plug 30 is 20 downward. It is then conceivable for the user to carry out manual dosing of the powder 4 by holding the rod 10 with one hand while he is driving the bottle 2 with a rotational movement with respect to the latter. using the other hand. However, the device 1 according to the invention preferably forms an automatic dosing machine adapted to support the reservoir 2 and to drive it in rotation. The user then comes to place the outer ring of the wall of the bottle 2 in contact with his drive system connected to the stepping motor 7. The user then comes to associate the rod 10 with the translational control means 25 by engaging the grasping arm 26 in the groove 27 of said rod 10. Then, the user positions the container 17 under the rod, in line with the outlet orifice 5. He then programs the mass flow instruction and / or quantity of powder to be dosed, as well as possibly the number of dosages to be carried out thanks to the interface of the servo-control means 24. The servo-control means 24 then engages the motor 7 so that it drives in The reservoir 2 in turn rotates substantially identically to the powder 4 it contains, giving the mass of powder as a whole a quantity of motion. In doing so, the powder thus driven moves relative to the dispensing member 5, and more particularly flows along the curved surface 22A of the agitator 22. When the powder passes. the transition marked by the ridge 22C of the agitator, the continuity rupture of the profile causes turbulence in the flow of the powder 4 in the vicinity of the stirrer. This slight stirring which occurs at right of the inlet orifice 14 facilitates the engagement of the powder 4 in the duct 6, which thus drops under the effect of the gravity in the chamber 20. The servo means 24 The adjustment means 25 is then used to lower the rod 10 by exerting traction thereon by means of the gripping arm 26. The rod thus slides from its initial closing position, illustrated in FIG. an open position, illustrated in Figure 8, gradually clearing the spout of the narrow section of the sleeve 11 so as to communicate the conduit 6 with the outside. Once engaged in the chamber 20, the powder 4 tends to be driven by adhesion, as sucked by the tangential rotary movement of the inner wall of the sleeve 11 which comes to conform to the periphery of the chamber 20. The powder 4 is thus progressively conveyed to the outlet port 15. At said exit port 15, it escapes through said outlet by dropping along the spout and then the body of the shaft 10 until it lands in the container 17. When the balance 23 indicates that the quantity of desired powder has been poured into the container 17, that is to say that the setpoint is reached, the control means 24 stops the flow by closing the outlet orifice 15, that is to say by controlling the rise of the rod 10, and by stopping the rotation of the tank 2. B60337 / FR 2909074 27 The undistributed powder which remains in the tank 2 and in the conduit 6 is then preserved away from the surrounding atmosphere e waiting for the next use of the device 1. It is remarkable that depending on the rheological behavior of the powder 4 to be dosed, the dosage regulation can intervene, independently or jointly, on the one hand by adjusting the opening of the outlet orifice 15, that is to say of the section of the spout that emerges from the sleeve 11, and secondly by controlling the rotation of the reservoir 2. For example, in the case of a powder 4 having a sufficiently fluid behavior to flow spontaneously and without difficulty through the conduit 6 under the sole effect of gravity, the flow can be triggered only by the only passage in the open position of the rod 10, independently of the rotation of the tank 2. Table 1 below provides some experimental examples of the precision obtained in series of dosages of small amounts of powders carried out using a device 1 true the invention having the following characteristics: - Rod diameter 10: D = 8 mm Angular chamber opening 20: a = 120 20 Chamber height 20: h = 3 mm Section of the inlet orifice = 3.53 mm 2 Section of the outlet orifice 15 (at the lower surface 201) = 3.14 mm 2 Angular resolution (no) of the rotational control of the flask = 0.6. P1 to P3 powders are considered, by reference to the results obtained with metering devices of the prior art, as easy to dose, the powders P4 to P7 are usually judged as difficult to dose .

For each set of instructions, a series of ten determinations was carried out, the mass of powder poured at each of these dosages being measured by a balance. Table 1 summarizes for each series the minimum value, the maximum value and the average obtained. Powder Dosage (10 measurements performed) Designation _ Properties Setpoint Min. Max. Mean Particle size [mg] [mg] [mg] [mg] [Pm] 2 1.9 2.0 1.94 P1: 20 flows through 5 4, 9 5.0 4.95 Silica grains gravity 10 9.9 10.0 9.94 25 24.9 25.0 24.93 _ 2 1.9 2.2 2.05 P2: 200 to 600 5 4, 9 5,4 5,17 Sucrose 10 10,0 10,6 10,29 25 24,9 25,6 22,93 2 - - - P3: 5 - - - Trichloroiso- 400 to 2000 hygroscopic acid 10 - - - Cyanuric acid 25.0 26.9 25.85 2 1.9 2.7 2, 28 P4: 50 fine 5 4.9 5.6 5.2 and cohesive Plaster 10 9.9 10.5 10.23 25 24, 9 25.6 25.25 2 2.2 2.5 2.39 P5: 45 cohesive and 5.15 5.5 5.34 Electrophilic cellulose 10 9.9 10.5 10.26 24.9 25, 25.18 P6: 2 1.9 2.3 2.16 Intermediate of 20 fine, cohesive, 4.9 5.3, 5.12 hygroscopic synthesis 10 9.9 10.4 10.21 pharmaceutical 24, 9 25.5 25.24 - very fine, 2 1.9 2.1 2 P7. cohesive, 5 4.9 5.1 5.02 Active ingredient 8 to 12 hygroscopic and 10 9.9 10.2 10.01 pharmaceutical electable 25 24.9 25.2 25.06 Table 1: Assay results B60337 / EN Thus, the device 1 according to the invention makes it possible to achieve particularly precise dosages without mechanically constraining the powder, which on the one hand preserves the properties of the latter and on the other hand minimizes the risk of failure of the process. of distribution by limiting the probability of an obstruction due to compaction of the powder. Advantageously, the device according to the invention also makes it possible to substantially reduce the appearance of electrostatic charges and agglomerates within the powder to be dosed, and also limits the formation of arches in the reservoir 2 during dispensing. .

In a particularly advantageous manner, said device effectively and durably preserves the powder from the influence of the external medium by conditioning it in a sealed enclosure outside the distribution phases. In addition, the automation of said device makes it possible to optimize its performance in terms of precision and reproducibility of the dosage, while increasing the availability of the operator who can then devote himself to other tasks. Finally, the simple, compact and modular design of said device makes it possible to envisage its manufacture at a reduced cost, guarantees its adaptation to any type of container and powder to be dosed, and facilitates its implementation as well as its maintenance. B60337 / EN

Claims (11)

  1 - Powder metering device (1) comprising a reservoir (2) delimited by a wall (3) having an internal face (31), said reservoir being intended to contain said powder (4), as well as a dispensing member (5) allowing the flow of powder (4) out of said reservoir (2) through a conduit (6), said device being characterized in that said reservoir (2) is movably mounted relative to said dispensing member (5); ) and arranged with respect to the latter so that the majority of the powder (4) located between the inner face (31) of the tank wall (2) and the dispensing member (5) is free to move substantially in the same movement as the tank (2) without encountering an obstacle that may lead to its compaction.   2 - Device according to claim 1 characterized in that the reservoir (2) is rotatably mounted about an axis (XX ').   3 - Device according to claim 2 characterized in that the axis (XX ') is substantially vertical.   4 - Device according to claim 2 or 3 characterized in that the dispensing member (5) is formed by a rod (10) which extends substantially parallel to the axis (XX ').   5 - Device according to claim 4 characterized in that the rod and the axis (XX ') are substantially coaxial.   6 - Device according to claim 4 or 5 characterized in that it comprises a sleeve (11) adapted to be secured to the reservoir (2) and to grip the lateral surface of the rod (10) forming a bearing (12). B60337 / EN 2909074 31   7 - Device according to claim 6 characterized in that the conduit (6) is formed at least in part by the juxtaposition on the one hand of a groove dug from the side surface of the rod (10) and other part of the inner wall of the sleeve (11) which comes into contact with said rod (10). 5   8 - Device according to one of claims 4 to 7 characterized in that the duct (6) extends from an inlet (14) communicating with the reservoir (2) and opens on an outlet port (15) open in the lateral surface of the rod (10).   9 - Device according to claim 8 characterized in that the outlet orifice (15) is formed by an elongate recess oriented substantially along the axis (XX ') and inclined towards the periphery of the rod ('10) so to form a spout.   10 -Dispositif according to claim 6 and one of claims 8 or 9 characterized in that the rod (10) is slidably mounted along the axis (XX ') relative to the sleeve (11) so as to occupy alternately a closed position in which said sleeve (11) covers the outlet (15) and prevents the powder (4) from flowing out of the conduit (6) and an open position in which the exit port (15) emerges at least partially from said sleeve (11) so as to allow the flow of the powder (4) out of the conduit (6). 11 Apparatus according to claims 6 and one of claims 8 to 10 characterized in that the sleeve (11) is extended by a skirt (16) located at a short distance from the lateral surface of the rod (10), vis-a-vis with respect to the outlet orifice (15), so as to limit the centrifugal radial dispersion of the powder grains (4) with respect to the axis (XX '). B60337 / FR 2909074 32 12 - Device according to one of claims 4 to 11 characterized in that the conduit (6) forms within the rod (10) a chamber (20) between an upper wall (20S) adjacent to the reservoir (2) and an opposite bottom wall (201), said upper (20S) and lower (201) walls being substantially normal to the axis (XX '). 13 -Dispositif according to claims 8 and 12 characterized in that the outlet orifice (15) is formed at the bottom wall (201) of the chamber (20) and in that said chamber (20) forms an ass bag-end whose bottom wall (20F) is located substantially in line with said outlet orifice (15) in order to guide the powder (4) contained in the chamber (20) towards the outlet orifice (15). ). 14 -Dispositif according to claim 12 or 13 characterized in that the section of the chamber (20) projected in a plane normal to the axis (XX ') has a circular geometry of disc portion type, ring portion, crescent or quarter, whose angular aperture a is substantially between 60 and 270, and more preferably between 90 and 180. 15 -Dispositif according to one of the preceding claims characterized in that the dispensing member (5) has a protrusion (21) projecting into the reservoir (2) to stir the powder (4) in the vicinity of said organ distribution (5) when said powder (4) is driven by the movement of the reservoir (2). 16 -Dispositif according to claims 2 and 15 characterized in that the protuberance (21) forms a fixed stirrer (22) eccentric and / or 25 asymmetrical with respect to the axis of rotation (XX '). B60337 / FR 2909074 33 17 -Dispositif according to one of the preceding claims characterized in that it comprises a measuring means (23), such as a scale, for measuring the amount of powder (4) spilled out of the conduit (6). 18 -Dispositif according to one of the preceding claims characterized in that it comprises a servo means (24) adapted to control the movement of the reservoir (2). Powder dosing bottle (30) intended to be attached to a tank (2) delimited by a wall (3) having an internal face (31) and containing powder (4), such as a bottle, plug (30) comprising for this purpose a base (31) provided with a fixing means to said reservoir, such as a threaded ring, said plug being characterized in that said base (31) is designed to be mounted to move on a dispensing member (5) allowing the flow of the powder (4) out of said reservoir (2) through a conduit (6), so that once said base (31) is fixed on said reservoir (2) and mounted on the dispensing member (5), the reservoir (2) and the base (31) can be moved jointly relative to said dispensing member (5), while most of the powder (4) ) located between the inner face (31) of the wall of said tank (2) and said dispensing member (5) is free to move cer substantially in the same movement as the tank (2) without encountering an obstacle that may lead to its compaction. Powder-dispensing organ (5), of rod type, intended to be mounted on a reservoir (2) delimited by a wall (3) having an internal face (31) and containing powder (4), such as a bottle, in order to allow the dosing of said powder (4), said dispensing member (5) comprising a conduit (6) arranged to allow the flow of powder (4) out of the tank (2) when said dispensing member (5) is mounted on said tank (2), said dispensing member being characterized in that it is arranged on the one hand to be movably mounted relative to the tank (2). ) so that the latter can be moved with respect to said dispensing member (5), and secondly to sufficiently clear the space between itself and the inner face (31) of the wall of said tank (2) so that the majority of the powder (4) in said space is free to move substantially in the same movement as the tank (2) without encountering any obstacle likely to lead to its compaction. B60337 / EN