Abstract:
The method for dispensing dosed amounts of a liquid contained in a storage reservoir connected to a dispensing duct provided with a nozzle for delivering the liquid into a receptacle associated with an indicator, delivering in the form of a signal representative of the value of the amount of liquid present in the receptacle and said duct distant from the nozzle, being associated with a closing mechanism which, by command, closes or releases the passage of the liquid through the duct, including the following steps: a) releasing the passage of the liquid between the reservoir and the nozzle by operating the closing mechanism, so that the liquid can fill the portion of the duct between the closing element and the dispensing nozzle; b) closing the passage of the liquid by operating the closing mechanism to interrupt the liquid flow; c) applying on the liquid column between the closing mechanism and the dispensing nozzle, at least a mechanical pulse of calibrated amplitude and/or intensity, for expelling from the liquid column, a micro-amount of liquid; d) comparing the value shown by the indicator and a predetermined index value C1; e) and repeating steps c) and d).

Description:
TECHNICAL FIELD 
     The invention presented here involves a process for the distribution of one or more liquid(s) contained in one or more container(s), in quantities measured by weight, in the use of which each dose is delivered with a great degree of precision, on the order of 0.5 milligrams, as well as a distribution device and a system for the distribution of one or more liquids to one or more recipient(s). 
     BACKGROUND ART 
     For a large number of activities, among which the following can be cited, without the list being restrictive: perfumes, aromas, cosmetics, fine chemistry, pharmaceutics, coloring agents, dyes and paints, food processing, wines and spirits, etc. it is necessary to make “compositions”, as much in the laboratory for tests or sampling, as in production. These compositions are mixtures of liquid or solid raw materials, according to a formula in a precise dosage. The traditional manual creation of these compositions is long and can rise to many manufacturing errors. Moreover, it is difficult to achieve accuracies on the order of a half-milligram. 
     SUMMARY OF THE INVENTION 
     The invention presented here makes it possible to correct for these disadvantages for compositions of liquid raw materials. It also makes it possible to deliver precise quantities of a unique liquid into many containers. 
     For this purpose, the process for distribution of dosed quantities of a liquid contained in a storage container, connected to a distribution conduit equipped with a nozzle for the discharge of liquid to a container connected to a gauge component that delivers, in the form of a signal, a representative value of the quantity of liquid present in the container, where the conduit, at a distance from the nozzle, is connected to a valve component that, upon command, blocks or opens the passage of the liquid through the conduit, from the container towards the distribution nozzle. The diameter of the distribution nozzle is such that the liquid column in the portion of the conduit between the nozzle and the valve component, when the valve component is blocking the passage of liquid, can be immobilized there under the action, in particular, of surface tension forces. The process is characterized essentially in that it consists in the following functional steps, given in chronological order: 
     a)—open the passage of liquid between the container and the nozzle by acting on the valve component, in a manner such that the liquid can fill the portion of the conduit between the valve component and the distribution nozzle, 
     b)—block the passage of liquid by acting on the valve component, in order to cut off the flow of the liquid, 
     c)—apply on the liquid column, located between the valve component and the distribution nozzle, at least one mechanical impulse having a calibrated amplitude and/or intensity, in order to expel a micro-quantity of liquid from the liquid column, through the distribution nozzle, towards the container, 
     d)—compare the value given by the gauge component to a pre-set reference value C1, representative of the value of the dose to be delivered, a tolerance value ΔC1 associated with the value C1, 
     e) and to repeat the steps c) and d) if the value given by the gauge component is not contained in the tolerance range associated with the reference value C1. 
     According to the preferred embodiment form, the gauge component gives a signal representing the weight of the quantity of liquid in the container. 
     It is necessary to be able to distribute in the container a relatively sizable quantity of liquid while maintaining a precision on the order of a half-milligram. Thus, according to another characteristic of the process according to the invention, during the step a), during which the passage of the liquid between the container and the nozzle is opened and the liquid is also discharged into the container, the value given by the gauge component is continuously compared to a reference value C0, less than the reference value C1, and close to this reference value C1, and the step b) of the process is begun when the value given by the gauge component is equal to the reference value C0, the steps c), d) and e) then being started successively. 
     This device makes it possible to ensure both the speed of the dosage and its precision. 
     According to another characteristic of the invention, the mechanical impulses that must be communicated to the liquid column are applied via the conduit. 
     According to another characteristic of the invention, the mechanical impulses that must be communicated to the liquid column are applied directly to the liquid column. 
     The invention also has the object of a distribution device for the delivery of a liquid in dosed quantities, characterized in that it consists of: 
     a storage container containing the liquid to be distributed, 
     a distribution conduit connected to the container and provided with a nozzle for the discharge of the liquid towards a container connected to a gauge component that delivers, in the form of a signal, a value representing the quantity of the liquid present in the container, 
     a valve component connected to the conduit and placed at a distance from the nozzle, blocking or opening upon command the passage of liquid between the container and the nozzle, the area of the section of passage that determines the nozzle being such that when the valve component blocks the passage, the liquid column present in the portion of the conduit between the nozzle and the valve component is immobilized in this portion, under the notable effect of surface tension forces, 
     an impulse mechanism, located between the valve component and the nozzle for the deliverance of the liquid, in order to communicate to the liquid located between the valve component and the distribution nozzle, at least one mechanically calibrated impulse, under the effect of which a micro-quantity of liquid is expelled from the liquid column. 
     According to one of the embodiment forms, the distribution device consists of a rigid structure consisting of a first drill hole that goes all the way through, into which the conduit enters with a functionally reduced play, this rigid structure consisting of a second drill hole, is preferably straight, opening up on the one side, into the first drill hole that goes all the way through, and on the other side, on one of the sides of the rigid structure, the second drill hole receiving the pulse mechanism. According to this embodiment form, the pulse mechanism acts on the conduit and this conduit, according to another aspect of the invention, is elastically deformable at least in the first drill hole of the rigid structure. 
     According to another characteristic of the invention, the pulse mechanism consists of a pushrod that can be moved crosswise relative to the conduit and mounted to slide in the second drill hole at least by its front part, in order to make it possible to act by the free end of the front part, by pushing on the conduit This pushrod can be manually maneuvered, but preferably, in a manner so that the impulses communicated can be perfectly calibrated, the impulse mechanism also consists of an operating mechanism fitted to move the pushrod by a brief movement of translation towards the conduit, and this is done according to a specified and perfectly controlled amplitude and acceleration. This operating mechanism, designed to act together with the free end of the rear part of the shaft, can be integrated with the structure of the device, but according to an advantageous aspect of the invention leading to a simplification, this mechanism for operating the pushrod is external to the structure and is independent of it. 
     The valve component can be arranged over the portion of the conduit located between the structure and the container or even be connected to the nozzle discharge of the container, but according to an advantageous aspect of the invention, the structure of the distributor device, upstream from the second drill hole considering the direction of flow of the liquid in the conduit, is provided with a third drill hole, preferably straight, opening on the one side into the first drill hole that goes through and on the other side, on one of the sides of the rigid structure, the third drill hole receiving the valve component. 
     According to another characteristic of the invention, the valve component consists of a mounted shaft, at least with its front part in the third drill hole, coming into blocking position with the open end of its front part pinching the soft conduit. The internal passage of the conduit thus becomes blocked by the flattening of the wall of the conduit on itself. 
     The operation of the shaft can be done manually, but preferably according to another aspect of the invention, the valve component consists of a mechanism for operating the shaft designed to cooperate with the rear part of this shaft, this operating mechanism being preferably outside of the rigid structure. 
     Preferably, according to another aspect of the invention, the shaft is threaded and the third drill hole is tapped in order to receive the shaft when it is screwed in. In screwing the shaft for adjustment of the degree of recess of the shaft in the tapped hole and in the conduit, it is possible to adjust the degree of throttling of the conduit by the shaft, and thus the section of the passage at the level of the valve component, and as a result, the flow rate of the liquid. 
     For its manipulation by the operating mechanism, the shaft, along the open end of its rear part, is equipped with a keyway, which acts together with the formed fitting and the torque transmission and the rotating movement, the drive endpiece in rotational, motorized drive with the operating mechanism. According to a preferred embodiment form, the operating mechanism of the shaft of the valve component is equipped with a drive instrument at the output shaft of which the drive endpiece is coupled. 
     In the embodiment form described above, the impulse mechanism and the valve component act on the wall of the conduit. 
     According to another embodiment form, the distribution device according to the invention is remarkable notably in that the conduit consists of an upstream section connected to the storage container and a downstream section having an open end from which the distribution nozzle is formed and that the valve component is a slide valve of a normally closed type, to which is connected on one side the upstream section of the conduit and on the other side, the downstream section of the conduit, the aforementioned valve consisting of a valve body in which a housing is formed that consists of an upstream section and a downstream section which are in communication with each other via an intermediate section having a cylindrical form, at the opening of which, in the upstream part of the housing, a valve seat is formed, against which a valve that is mounted so that it is mobile in the upstream part of the housing, can rest in a blocking position. This upstream part of the housing is in contact with the upstream section of the conduit by a drill hole formed in the valve body. The downstream section of the conduit is in turn in contact with the intermediate part of the housing through a second drill hole formed in the valve body. The valve body is provided with a third drill hole that passes through it along an axis perpendicular to the valve seat and opening into the downstream part of the housing, where in this drill hole a shaft for operating the valve is placed. The shaft is connected to an operating mechanism and the valve is connected to an impulse mechanism. 
     According to another characteristic of the invention, the material constituting the seat has a greater hardness than that of the constituent material of the valve seat. This makes it possible to perform the automatic run-in of the valve seat and to improve impermeability. 
     According to another characteristic of the invention, an aspiration mechanism is provided to bring back, by aspiration into the upstream part of the conduit, the drops of liquid present at the level of the distribution nozzle and in particular, before the application of impulses on a liquid column. This device, in preventing the liquid drops from falling inadvertently into the container, guarantees dosages that are precise and can be reproduced with the same degree of precision. 
     In the preferred embodiment form, the aspiration mechanism consists of a piston mounted in a cylinder bore made in the valve body. The cylinder bore being in communication with the upstream part of the housing and the piston being connected to an operating mechanism. Advantageously, according to another aspect of the invention, the piston and the operating mechanism constitute the impulse mechanism. 
     According to a particularly advantageous embodiment form, the piston is formed around the activation shaft of the valve and is fixed to this shaft; the operating mechanism of the piston constitutes the operating mechanism of the shaft; the shaft and the valve are not bound to each other and the shaft is mobilized by its operating mechanism in a resting position such that it is isolated from the valve in one of its operating positions where, in operating by pushing on the valve, it supports this valve in isolation from its seat, the value of the isolation between the valve and the seat is thus the value of the flow rate of the liquid, depending on the operating position obtained by the operating shaft. 
     Thus, in selecting the operating position that the shaft must reach, and in controlling this position, it is possible to select the value of the flow rate of the liquid across the slide valve and to perfectly control this value. 
     According to another characteristic of the invention, the operating mechanism of the impulse and actuation mechanism of the valve component consists of a cam and of a driving instrument for driving the cam, this cam being fixed on the rotating output shaft of the drive instrument. 
     The invention presented here also has as an object, a system for delivering in an automatic manner, precise quantities of one or more liquids to one or more container(s) characterized essentially in that it is equipped with at least one distribution device as previously defined. 
     According to another characteristic, the system according to the invention consists of a first support assembly on which are mounted several distribution devices and a second support assembly, on which the driving instrument(s) of the operating mechanisms is or are mounted, the aforementioned system consisting of more or less one container for liquid(s), at least one gauge component showing the quantity of liquid in this container, this component is fitted to emit a signal representative of this quantity to another programmable unit for the calculation and control, according to the data of a pre-set program, of the drive instrument(s) of the operating mechanism(s) of the valve component and the impulse mechanism of each distribution device. 
     According to another characteristic of the invention, the support assemblies are mobile relative to each other and at least one of the two support assemblies is mobilized relative to the other by a driving instrument controlled by a control and command unit in order to be positioned relative to each other, the driving instrument(s), and the operating shafts of the selected distribution device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other advantages, goals and characteristics of the invention appear in reading the description of a preferred embodiment form, given as an guideline example, in referring to the attached drawings in which: 
     FIG. 1 is a longitudinal sectional view of a distribution device according to a first embodiment form, 
     FIG. 2 is a longitudinal sectional view of a distribution device according to a second embodiment form, 
     FIG. 3 is a sectional view, according to a vertical plane, of a system equipped with distribution devices according to the preferred embodiment form, 
     FIG. 4 is a sectional view along the line AA of FIG. 3, 
     FIG. 5 is a sectional view along a vertical plane, of a system equipped with the distribution devices according to the second embodiment form, 
     FIGS. 6 and 7 are views of a system according to an embodiment form. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in the distribution device  1 ,  2  according to the invention, a storage container  3  contains liquid to be distributed in dosed quantities, consisting of a nozzle for discharging a liquid, to which a distribution conduit  4  is attached in any known way. The distribution conduit  4  is provided at its free end with a nozzle  5  for the discharge of the liquid to a container  6  connected to a gauge component  7  which transmits in the form of a signal, a representative value of the quantity of liquid present in the container  6 . The distribution device consists of, in addition, a valve component  8  connected to the conduit and placed at a distance from the nozzle  5 , blocking or opening the passage of liquid into the conduit between the container  3  and the nozzle  5  on command. This nozzle, having a circular form, determines a circular passage section whose clearance area value is equal to or less than the value necessary in order to ensure that when the valve component is in position blocking the passage liquid, the immobilization of the liquid column in the portion of the conduit includes between the nozzle and the valve component. This immobilization is essentially due to the surface tension forces. The diameter of the nozzle will be a function of the physical characteristics of the liquid to be distributed and thus notably a function of its viscosity. Between the valve component and the nozzle for discharging the liquid, the distribution device is equipped with an impulse mechanism  9  in order to communicate to the liquid column located between the valve component  8  and the distribution nozzle  5 , at least one mechanical impulse calibrated under the effect of which a micro-quantity of liquid is expelled from the liquid column. This impulse mechanism is only activated after the closing of the section of the liquid passage by the valve component  8 . For a dosage of a determined quantity of liquid, the functioning of the device is the following: the valve component  8  is placed first in the open position of the internal passage of the conduit in a manner so that the liquid can flow from the container  3  to the container  6 . The quantity of liquid required being reached to within a drop or a fraction of a drop, and the valve being placed in the blocking position of the internal passage of the conduit, the shocks or impulses, transmitted by the impulse mechanism  9  directly or indirectly to the liquid column contained between the valve component  8  and the nozzle  5 , make it possible to expel micro-quantities of the liquid contained in this column. As a function of the liquid viscosity, of the size of the discharge nozzle  5 , and of the impulse energy, the quantity delivered by these impacts can be precisely determined, and in a repeatable manner by calibration. Thus, the quantity required can be precisely obtained. 
     The liquid container  3 , the valve component  8 , the impulse mechanism  9 , the gauge component  7  and the container  6  are carried by the appropriate supports. 
     The container  3  for liquid storage, of a known type, can be located at a distance from the valve component or even near to it. This container will be provided with a cover for blocking and protecting the internal volume that it contains. This container can be placed to a higher height level with regard to the one of the valve component  8  to allow a gravitational flow of liquid or even at a level lower in connection with a mechanism for propulsion of the liquid towards the valve component  8 . This mechanism can consist of a volume of compressed gas introduced in the upper part of the container in order to exert a pressure on the liquid contents. In the case of the drawing, the cover will ensure a perfect impermeable closing and will be provided with a drill hole that goes through, in which will be fixed a connection nozzle of a conduit connected to a source of gas under pressure. This gas is to be selected in a manner such that a chemical reaction can not occur with the liquid contained in the container. 
     The gauge component  7 , according to the preferred embodiment form, is of the type of those that are fitted to transmit a signal representing a weight value. The gauge component will be or will consist of a weight sensor placed under the container to give a signal representing the weight value of the container and the quantity of liquid contained in the container. Judiciously, the signal emitted will be an electric signal of the analog or digital type in order to allow the treatment of the signal by a command and control unit  10  that can be connected to distribution device  1 ,  2  in order to command and control the functioning according to the instructions of a pre-set program based on the user&#39;s requirements. The gauge component  7  in the preferred embodiment form is a precision scale suited to produce the signal mentioned above and to transmit it to the command and control unit  10  to which it is connected by an appropriate electrical line. This precision scale can be provided with a display component in a form understandable to the user, having the weight value of the liquid introduced into the container. This scale will be provided with a horizontal support on which the container will rest for the purpose of measuring the weight of the liquid contained in it. 
     As a variation, the gauge component will be one of the type of those fitted to directly deliver a signal representing the height of the liquid in the container then convertible by the unit  10  into the weight value or volumetric value. 
     In FIG. 1, a distribution device according to a first embodiment form. 
     This device consists of a rigid structure  11 , having a parallelepiped shape, attached to an appropriate support. This structure consists of, between its two horizontal upper and lower sides, a first drill hole going through, vertically, having a diameter that is equal to or slightly greater than that of the conduit. The conduit  4  is placed in the drill hole and the drill hole preferably only covers a part of the length of the conduit. The rigid structure  11  is preferably located at a distance from the two ends of the conduit. The wall of the part of the conduit located in the first drill hole is elastically deformable. For reasons of simplification of the embodiment, the assembly of the conduit  4  is made of an elastically deformable material but you could provide a conduit in three sections joined by an impermeable material. The two lateral sections could be made of a rigid material, for example, of metal while the middle section, the section to be placed in the first drill hole, could be made in an elastically deformable material. 
     Thus the part of the conduit housed in the vertical drill hole can deform onto itself, under the action of outside forces, in a non-permanent manner, this deformation being done against internal elastic forces due to the natural elasticity of the material constituting its wall. When these forces are removed, the conduit can resume its initial shape because of these internal elastic forces. The dynamic pressure of the liquid exerted on the inner side of the conduit also contributes to returning the conduit to its initial shape. 
     According to the preferred embodiment, the material used to create the conduit  4  has a base of tetrafluoroethylene as is known under the commercial name “TEFLON”, because of the resistance of this material to chemical agents and to corrosion. 
     Perpendicularly to the first drill hole and in a secant manner to it, the structure of the lower part consists of a second drill hole and in an upper part, of a third drill hole. These second and third horizontal drill holes, opening on one side into the first drill hole and on the other side on a same small lateral vertical side of the structure. In the upper drill hole, the valve component is placed while in the lower drill hole, the impulse mechanism is placed. 
     The valve component consists of a shaft  12  mounted at least by its front part in the third drill hole. This shaft, in blocking position, by the free end of its front part, comes to pinch the flexible conduit and flatten the wall of this conduit onto itself, which leads to blocking the internal passage of the liquid The end of the front part of the shaft  12  is rounded in order to prevent damaging the conduit. In the preferred embodiment form at least the lower part of the shaft is threaded and the upper drill hole, along all of its length, is tapped in order to receive the threaded front part of the shaft  12  when it is screwed in. The rear part of the shaft  12 , outside of the rigid structure  11 , is provided with a head  13 , which when manipulated, allows the adjustment of the degree of recess of the free end of the rear part of the shaft  12  in the conduit  4 . Thus, by this arrangement, between a position of full opening in which the conduit  4  is not deformed by the shaft and a position of complete closing, in which the wall of the conduit is flattened on itself by the shaft, it is possible to pull in and to support the free end of the front part of the shaft in an intermediate position according to the desired degree of throttling and thus the flow rate of the liquid obtained. 
     At the level of the valve component, the continuous opening of the inner section of the passage, by unscrewing the shaft  12 , makes it possible to vary the flow rate in a continuous manner, from a drop-by-drop very slow, to a maximum flow rate, which is a function of the section of the conduit and that of the nozzle  5 , of the liquid viscosity, and of the difference of the height between the level of the liquid in the container and the output nozzle or even of the value of the excess pressure in the container, in the case where this container receives a compressed gas in order to propel the liquid. 
     The head, which forms an annular swelling on the shaft, allows the manual manipulation of the shaft. In addition, the head of the shaft can form a stop for the progression of the shaft in the coming conduit, in a completely closed position, against the rigid structure  11 . 
     Thus, in this position, the shaft will not be able to penetrate any further into the wall of the conduit which eliminates the risks of the perforation of this wall. 
     According to a preferred embodiment form, the valve component also contains a mechanism  13  for an automated activation of the aforementioned shaft  12 . This mechanism  13  is outside of the rigid structure  11  and contains a drive instrument  13   a , for example, a step-by-step electric motor, at the output shaft of which a male drive endpiece  13   b  is coupled which acts together by interlocking of shape and transmission of the couple and the rotational movement with a keyway engraved on the free end of the rear part of the shaft  12  in the axis of the shaft. The drive instrument  13   a  will be driven by the control and command unit  10  and for this purpose, will be connected by a suitable electric line to the unit. 
     As mentioned above, the horizontal lower drill hole receives the impulse mechanism  9 . This impulse mechanism contains a pushrod  14  mounted to slide in the lower drill hole in order to be able to act by pushing radially on the conduit and in this way to communicate a mechanical impulse to the liquid column. The impulse mechanism contains, in addition, outside of the rigid structure  11 , an operating mechanism  15  fitted to move the pushrod  14  along a brief translational movement towards the conduit  4 . The pushrod  14  is mounted by its rear part in the lower drill hole and by its rear part comes outside of the rigid structure  11 . The free end of the front part is rounded in a manner to eliminate any risk of perforation of the conduit under the action of the impulses received. In addition, the amplitude of the path of the pushrod is limited to a value lower than the diameter of the inside passage of the conduit in a manner so that the pushrod can not crush the conduit  4 ; this value can also be less than that of the radius of this passage. 
     In order to limit the amplitude of its path, the pushrod  14  contains, between its front part and its rear part, a flanged form  16  that forms a stop and is placed with this flanged form in a countersinking formed in the rear part of the drill hole. The flanged form  16 , coming to stop against the countersunk base, limits the movement of the drive of the pushrod in the conduit  4 . 
     Here it is noted that the internal elastic forces on the part of the conduit housed in the vertical drill hole are sufficiently sizable in order to push back the pushrod  14  towards its initial position when the impulse has stopped. However, if need be, an elastic return movement instrument, in the form of a spring having non-abutting spirals, can be placed under tension between the flanged form and the countersunk base. 
     In the preferred embodiment form, the operating mechanism  15  is made of a drive instrument of the pneumatic or hydraulic valve type, arranged by its shaft relative to the pushrod  14  in axial alignment with the pushrod. This valve, single or double action, is connected to a source of liquid under pressure (air or oil depending on the valve type), through a solenoid valve piloted by the command and control unit  10 . For this purpose, this solenoid valve is connected to the unit  10  by an appropriate electric line. This valve  15  is mounted on an appropriate support. By the end of its shaft, this valve when it is activated in the direction of the movement out of the shaft, will communicate to the pushrod a mechanical impulse axial, under the action of which this pushrod can be displaced by sliding in the lower drill hole and comes to act by pushing radially on the conduit. Immediately afterwards, the valve is activated in the direction of retraction of its shaft. The shaft of the valve can be fixed to the pushrod by a sleeve tube or an articulation but preferably these two components are not connected to each other. 
     As a variation, the operating mechanism can be made of a cam in the form of an eccentric, and by a drive instrument having a rotating output shaft to which the cam is coupled. This motor, which can be a step-by-step electric motor will be positioned on a fitted support of the type having its output shaft vertical and having the cam in the form of an eccentric positioned relative to free end of the rear part of the pushrod  14 . The cam is, in the form of a thick, circular disk, provided along its depth with a drill hole passing through, set eccentrically, by which it will be mounted in fixed attachment on the output shaft of the motor. By its cylindrical surface, in the process of rotation, the cam comes to act by pushing on the pushrod  14 . The drive instrument will be operated by the command and control unit  10  and will be connected to this unit by a suitable electrical line. 
     In FIG. 2, a distribution device  2  is shown according to a second embodiment form. 
     According to this embodiment form, the conduit  4  has an upstream section  4   a  connected to the storage container  3  and a downstream section  4   b  on the free end of which the distribution nozzle  5  is formed. The valve component  8  consists of a slide valve of the normally closed type to which, on one side the upstream section  4   a  of the conduit is connected, and on the other side, the downstream section  4   b  of the conduit is connected. 
     The valve component consists of a valve body in a parallelepiped form, made of a material that is low in its susceptibility to corrosion and suited to resist chemical agents A stainless steel can be used or preferably a synthetic material based on tetrafluoroethylene such as is known under the commercial name “TEFLON”. 
     In the body of the valve, a horizontal, cylindrical housing that goes through it is formed, consisting of an upstream part  17  and a downstream part  18  each in communication with each other by an intermediate part  19  having a cylindrical form, at the opening of which, in the upstream part  17  of the housing, a seat  20  of the valve is formed. The upstream part of the housing is blocked in an impermeable manner by a stopper  22 . This stopper consists of a head extended axially by a threaded cylindrical part placed so that it screws into a female threading formed in the cylindrical part upstream  17  from the housing. By the head, the stopper is moved under pressure towards the side corresponding to the body of the valve. 
     Against the seat  20  of the valve, a valve  21 , that is mounted so that it can move in the upstream part  17  of the cylindrical housing, rests in the blocking position. Advantageously, the valve is made up of a ball made of stainless steel having a polished surface. This ball has a diameter that is slightly less than the diameter of the upstream part  17  of the housing in order to be able to slide freely in the housing while being perfectly guided. To the valve  2 l, is joined an elastic instrument for return-movement  21   a  which fixes its bearing against the seat  20  in blocking position of the valve. This elastic instrument for return-movement  21   a  consists of a spring having non-abutting spirals, mounted in the upstream part  17 , under tension between the blocking ball  21  and the stopper  22 . 
     The upstream part  17 , by a drill hole  23  made in the valve body perpendicularly to the drill hole passing through, is connected to the upstream section  4   a  of the conduit, this conduit being placed by force into the drill hole  23  while the downstream section  4 b of the conduit is itself connected to the intermediate part  19  of the housing through a second drill hole  24  made in the valve body, in a manner perpendicular to the drill hole going through. The section upstream from the conduit will be placed by force into the drill hole  4   b.    
     The opening of the drill hole  23 , in the upstream part  17 , is positioned so that it is only partially blocked by the ball when the ball is resting on its seat. By this arrangement, the pressure of the liquid in the upstream part  17 , when the valve is in the blocking position, ensures, in combination with the spring  21   a , the support of the ball against its seat. In addition, this arrangement ensures the communication of the drill hole  23  with the intermediate part  19  of the housing and this as soon as the ball  21  is lifted off its seat  20 . 
     The valve body, along an axis perpendicular to the seat of the valve, in the axis of the drill hole passing through, is provided with a drill hole passing through, opening into the downstream part of the housing, in which a cylindrical shaft  25  engages for operating the valve  21 . According to a preferred embodiment form, this drill hole passing through is made in a blocking stopper  26  placed by screwing into a threaded cylindrical part that it contains in a female threading made in the downstream part  18  of the housing. This blocking stopper  26  contains a head by which it is moved under pressure against the lateral side corresponding to the valve body. Some impermeable seals in a toroidal shape are arranged around the shaft, in the drill hole passing through the stopper. 
     Outside of the valve body, the shaft  25  acts together with an operating mechanism made up of, for example, a cam  27  in the form of an eccentric and by a drive mechanism  28  for driving the cam, having a rotating output shaft on which the cam  27  is supported. The motor  28  which can be a step-by-step electric motor is positioned on a fitted support of the type such that its output shaft is vertical and that the cam  27  is positioned relative to the free end of the rear part of the shaft  25 . The cam, in the case of a vertical configuration of the output shaft of the motor, has in the form of a thick circular disc, provided along its depth, a drill hole going through it eccentrically, by which it is mounted in fixed attachment to the output shaft of the motor  27 . By its cylindrical surface, during its rotation, the can comes to act by pushing on the shaft  25  in a manner so as to lift the valve from its seat against the action exerted by the elastic mechanism  21   a . The shape of the cam ensures the continuity of the opening of the valve and thus the continuous variation of the flow rate of the liquid and this is done from a drop-by-drop very slowly, to a maximum flow rate. In addition, in order to assure the bearing of the cam in a fixed angular position, it is possible to regulate the level of the flow rate of the liquid through the valve and to maintain this flow rate constant. 
     As a variation, the motor will be positioned such that its output shaft is horizontal. In this configuration, the cam has a cam surface that expands in an oblique manner relative to the axis of rotation. 
     The drive instrument will be controlled by the command and control unit  10  and will be connected to this unit by a suitable electric line. 
     It is noted here that when there is a power cutoff, the return-movement spring  21   a  is sufficiently powerful to push back the assembly made up of the valve, the shaft  25  and the cam, and to move the valve to its seat. Thus, a power cutoff of the drive instrument turns into a closing of the valve. 
     Connected to this device is an aspiration mechanism for moving the liquid drops present at the level of the distribution nozzle  5  by aspiration in the upstream part of the conduit  4   b , and this is notably done before the application of the impulses on the column of liquid. According to the preferred embodiment form, this aspiration mechanism consists of a piston  29  formed around the actuation shaft  25  and attached to the shaft. This piston is mounted to slide in the downstream part  18 , where this part  18  is bored. In this embodiment form, the actuation shaft  25  is not fixed to the valve and an elastic instrument  30  is planned for moving back, as soon as the valve has returned to its seat, of the shaft and the piston to a resting position, i.e. the position the furthest from the seat of the valve. According to this position, the shaft  25  is removed from the valve. In the resting position, the piston  29 , by a conical door  29   a  that it has in its rear part, comes to support against a conical seat  26   a  arranged in the stopper  26  around the drill hole passing through. This arrangement promotes impermeability of the assembly. The elastic instrument  30  is mounted in the downstream part ( 18 ) of the housing, under tension between the piston ( 29 ) and a shoulder ( 19   a ) formed between the part ( 18 ) and the intermediate part ( 19 ). The return movement of the shaft and the piston is done continuously during the return of the cam to an initial angular position where it no longer acts on the shaft  25 . During this return movement to the resting position, the valve being support on its seat, the volume of the encapsulation formed in front of the piston increases continuously and the liquid contained in the section of the conduit  4   b  is aspired to the part  19  of the housing and towards the upstream part  18 . Thus, the liquid drops present at the level of the nozzle  5  are brought back into the section of the conduit  4   b.    
     In this embodiment form, the piston  29  and the actuation mechanism of the shaft of the valve consisting of the impulse mechanism  9 , it is noted that the maximum amplitude value of the movement of the shaft, when the impulses are communicated by the piston to the column of liquid present in the conduit section  4   b  is less than the value of the difference between the shaft and the valve  21 , measured when the valve is resting on its seat and the shaft is in the resting position. Thus, during the application of the impulses on the liquid column, the shaft can not come into contact with the valve  21  which eliminates risks of opening the valve unexpectedly during micro-dosage. 
     It is noted here that the mechanism which is being described presents two zones to know one zone of elevated pressure concerning section  4   a  of the conduit, the drill hole  23  and the upper part  17  of the housing and a lower pressure zone involving the section of the conduit  4   b , the intermediate part  19  of the housing, and the downstream part  18  of the housing. It is noted also that the impermeability of this assembly is primarily ensured in the lowest pressure zone, which is a notable advantage for the reliability of the device. 
     The container  3  of this device can be placed at a distance from the valve body or even immediately adjacent to the valve body, in order to reduce the length of the conduit section and thus the size of the storage volumes. This device is notably applied when the liquid is costly and/or when it must be distributed in a very low quantity. The container  3  can also be directly fitted in the drill hole  23  by its nozzle. 
     The distribution device  2  as has been described can be used in a large number of applications from micro-dosage in the laboratory to the dosage of large quantities of liquid. For production applications, the size of section  4   a ,  4   b  of the conduit can reach without difficulty diameters of 50 mm, or even more. The size of the valve will of course be proportional to the size of the conduit. 
     In FIGS. 3 to  7 , various embodiment forms of a system provided with at least one distribution device  1 ,  2  are shown, as have been described above. This system is designed to deliver in an automatic manner, precise quantities of one or more liquids to one or more container(s)  6  in order to form, for example, mixtures of various liquid products. 
     The installation consists of a first assembly support  31  on which several distribution devices  1 ,  2  are mounted and a second assembly support on which the drive instrument(s)  13   a ,  15 ,  27 ,  28  of the actuation mechanisms is or are mounted. Connected to this system are at least one container  6  of liquid(s), at least one gauge component  7  of the quantity of liquid in the container  3 , which is fitted to transmit a signal that is representative of this quantity to the calculation and command unit  10 , programmably fitted to command and control according to the data of its program, the drive instrument(s) of the actuation mechanism(s) of the valve component and of the impulse mechanism of each distribution device. 
     According to a first embodiment form, the support assemblies  31 ,  32  are mobile relative to each other and at least one of the two support assemblies is mobilized relative to the other by a drive instrument controlled by the calculation and command unit  10  in order to be positioned in relation to the other ones, the drive instruments of the actuation mechanisms and the actuation shaft(s) of the distributor device selected. 
     Always depending on the preferred embodiment form, the distribution devices  1 ,  2  are placed on the first assembly support  31  at a constant interval along a circle circumference and in a radial manner relative to the circle circumference in a manner so as to form a crown. As a variation, these devices can be placed at a constant interval along a straight line or even along a curve if the geometrical restrictions of the implantation and installation site require such a configuration. With a configuration in a straight line, the second assembly support will be movable and will be constituted by a shifted carriage so much in height as to be parallel to the alignment formed by the distribution devices. The movements of this carriage with respect to the distribution devices, as well as its position relative to the distributor selected are steered and controlled by the command and control unit  10 . 
     The distribution devices could also be arranged at a non-constant interval from each other. 
     In the embodiment forms shown in FIGS. 3 to  5 , the second assembly support  32  is arranged in the first one and the shaft(s)  12 ,  14 ,  25  of the actuation mechanism(s) of each distribution component  1 ,  2  is or are horizontal and radial to the crown formed by the distribution devices. 
     Preferably, the first assembly support  31  is fixed and the second is mobilized by the drive instrument. You could, however, provide an inverse device i.e. a second fixed assembly support and a first assembly support that is mobile and activated by the drive instrument. 
     In FIGS. 3 and 4, a system equipped with the distribution device  1  according to the first embodiment form is shown. The first assembly support  31  consists of a continuous wall  33 , defining a cylindrical volume in which the second assembly support  32  is housed. This continuous wall receives an upper wall  34  in the form of the circular disk and a lower wall  35  in the form of a circular disk. These upper and lower walls block partly above and partly below the cylindrical volume which delimits the continuous wall  33 . The enclosure formed by the walls  33 ,  34 , and  35  is supported by a suitable underframe, not shown. On the outside cylindrical side of the continuous wall  33 , attached by any mechanism known to the professional, is the rigid structure  11  of each distributor device  1  equipping the system. At the level of each distributor device  1 , the continuous wall  33  is equipped with two drill holes that go through it radially. In one of these drill holes, the shaft  12  of the valve component  8  is placed and in the other one, the pushrod  14  of the impulse mechanism  9 . 
     The second assembly support  32  consists of an enclosure  32   a  forming a parallelepiped caisson, provided with an upper horizontal wall  36  and a lower horizontal wall  37  each equipped along a vertical common axis with a drill hole going through, in which a rotational guide bearing is mounted on a vertical shaft  38  that forms a single piece with the first assembly support  31 , and more precisely, with the walls  33  and  34  of the assembly support  31 . This caisson is arranged in a manner centered relative to the crown formed by the distributor devices  1 . The two upper and lower walls  37 ,  38  are joined to each other by at least two lateral walls  39 ,  40 , diametrically opposed, perpendicular to a same axis secant and perpendicular to the longitudinal axis of the guide shaft  38 . The first of these walls, the wall  39 , along a horizontal axis radial to the guide shaft  38  and radial to the first assembly  31 , is equipped with a drill hole passing through in which a collar is placed that is provided with a bore going through the right polygonal section and expanding along a radial horizontal axis to the guide shaft and radially to the crown formed by the distribution devices. In this bore, a sheath  41  is placed, parallelepiped in shape, that makes up a case having upper  41   a  and lower  41   b  walls, each one provided relative to the other with an opening  41   c  going through the passage of the vertical guide shaft  38 . This shaft receives by attachment, in the sheath  41 , a fixed toothed crown  42  with which it is designed to act together in engaging a toothed pinion  43  supported on the horizontal output shaft of a drive instrument for driving in rotation the second assembly support  32  around the guide shaft  38 . This drive instrument is a single piece with the sheath and is fixed in front of this sheath by any mechanism known to the professional. This drive instrument consists for example of a step-by-step electric motor controlled by the command and control unit  10 . 
     Advantageously, this drive instrument is made of the drive instrument  13   a  of the actuation mechanism  13 . For this purpose, this motor contains a shaft that goes through in order to receive along one of its ends the pinion  43  and along the other end, outside of the enclosure, and relative to the distribution devices, the endpiece  13   b  for coupling to the shaft  12 . 
     The sheath  41  carries outside of the enclosure  32   a  and relative to the distribution devices, the drive instrument  13   a  with the endpiece  13   b  for coupling the valve component  8  while the enclosure  32   a  under the actuation instrument cited above, carries the drive instrument  15  of the actuation mechanism of the impulse mechanism  9 . 
     The drive instrument  13   a  for driving in rotation the second assembly support is steered by the unit  10  so as to displace the actuation mechanisms towards the distribution device selected and to temporarily immobilize them in the axis of the shaft  12  and pushrod  14 . 
     Advantageously to the axis going through the drive instrument  13   a , a coder is connected, of a known type, connected by an appropriate electric line to the control and command unit in order to deliver to the control and command unit a signal representing the angular position of the second assembly in the first. 
     The sheath  41  is mounted to slide in the bore going through the collar, and the openings  41   c  going through, made in the lower and upper walls of the sheath  41  are in an oblong form and oriented in a manner so that their longitudinal axis expands in a manner radially and secant to the longitudinal axis of symmetry of the guide shaft  38 . In addition, at the rear wall of the sheath and at the wall of the enclosure  32   a , an activation instrument  41   d  is attached, of a valve type, under the action of which the sheath  41  is displaced in the bore of the collar either towards the distribution device  2  selected so that the coupling endpiece  13   b  that is carried by the drive instrument  13   a  is coupled to the shaft  12   a  of the valve component  8  and the pinion  43  is uncoupled from the crown  42 , or in the inverse direction so that the coupling endpiece  13   b  is uncoupled from the shaft  12  of the valve component  8  and the pinion  43  is coupled to the toothed crown  42 . 
     Also depending on this type of embodiment, the container  6  and the gauge component  7  of the liquid quantity in this container are fixed with respect to the first assembly support  31  and occupy a lower position coaxial with respect to the crown that forms the distribution devices  1 . The conduits of these devices in the lower part are bent in a manner so as to come to be located by their discharge nozzle  5  above the container  6 . It is noted that the conduit through their lower parts have equal dimensions and are bent along the same angle. This characteristic permits the improvement of the repeatability of the resulting quantities. 
     The system as described can also be use distribution devices  2  according to the second embodiment form. 
     In FIG. 5, a system is shown equipped with distribution devices  2  according to the second embodiment form. 
     The first assembly support  31  consists of a horizontal plate  45  carried by and in a three-dimensional structure formed by the assembly of uprights and traverses arranged according to the edges of a rectangular parallelepiped. This structure receives the fixed walls of the cover defining a parallelepiped volume in which the second assembly support is placed. This volume is provided with an access opening to which a mobile screen, a seal, or even a flap is connected. The horizontal plate  45  receives in attachment the valve body of each distribution device  2  equipping the system. As indicated previously, the valve bodies are arranged at regular interval relative to each other along the circle circumference in a manner so as to form a circular crown and are oriented so that their actuation shaft  25  is radial to the crown formed and is oriented towards the center of this crown and towards the second assembly support  32 . 
     The second support assembly  32  consists of a vertical shaft  46  to which a support arm  47 , is attached in a radial manner. The support arm  47  carries at a distance the shaft  46 , the drive instrument  28  with cam  27  of the impulse mechanism  9  and actuation mechanism of the valve component  8 . The arm extends on both sides of the shaft and carries, in the opposite direction of the motor component  28 , a balance weight. The vertical shaft  46  is placed at its lower end in a guide plate in rotation, fixed to a lower plate  48  that is in one single piece with the first support component  31  and is coupled at its upper end to the vertical output shaft of a drive instrument  49  for driving in rotation, which is fixed by its case to a mount that is a single piece with the first assembly support. This drive instrument, made, for example, by a step-by-step electric motor is connected by an electric line fitted to the control and command unit  10  so that it is steered by the unit  10  and positions as desired the arm  47  and the drive instrument  28  with cam  27  relative to the distribution device selected for distribution of the required amount of liquid in the container  6 . In order to immobilize the arm  47  and the shaft  46  for the time of the distribution of the required quantity of liquid, the body of each distribution device is equipped with an obstructed drill hole open on its upper horizontal side and a pneumatic vertical valve is provided, carried by the arm of the side of its balance weight and intended when it is activated to penetrate by its shaft in the obstructed drill hole of the distributor body diametrically opposed to the one selected. 
     The shaft  46  between the support arm  47  and its upper end is placed in a guide bearing mounted in the drill hole going through the horizontal plate  45  of the first support assembly  31 . The shaft  46  is centered relative to the crown that forms the valve body of the distributors that are oriented so that their shaft  25  expands in a radial manner to the shaft  46  and is turned towards the shaft. 
     The section down from the conduit of each distribution device is fitted in a drill hole going through the support plate ( 45 ) so as to come to be the upstream section ( 4   b ) of the conduit of each distribution device ( 2 ) being placed in a drill hole going through the support plate ( 45 ) so as to come be located, by the distribution nozzle ( 5 ), located, by the distribution nozzle ( 5 ), above a second horizontal support plate  50  placed under the first one and at a distance from the first one, this second support plate being rigidly attached to the drive shaft  46  in a manner to be driven in rotation with the support arm  47 , the container  6  and the gauge component  7  of the liquid quantity in the container being installed on the second plate. The container is positioned with its opening on this plate so that it is in the axis, i.e. is below the discharge nozzle  5  of the distributor device selected to discharge a dosed quantity of liquid contained in the container connected to this distribution device. Advantageously, the position of the plate  50  is adjustable along the axis in order to be able to receive containers having different heights. 
     Preferably, the sections of the conduits  4   b  are all rectilinear, vertical and of equal lengths. These devices make it possible to improve the repeatability of the results of the dosages. 
     Between the plate  50  and the plate  45 , the second assembly support is equipped with a protection plate  51  horizontally fixed to the drive shaft  46 . This plate has a raised peripheral edge and has projecting on its upper side a projection. This projection and the plate have passing straight through them a single vertical drill hole. This drill hole, by rotation of the shaft is carried into the axis of the nozzle  5  of the distributing device selected and allows the flow of the liquid from the nozzle  5  to the container. 
     This plate  51  has the purpose of recovering and holding by its raised edge the residual flows of the liquid and of preventing these flows from coming to contaminate the composition made, or even in the course of its creation and to damage the dosage. 
     Preferably, to the rotating shaft  46  a coder is connected of a known type, connected by an appropriate electric line, to the control and command unit in order to deliver to this unit a signal representing the angular position of the second assembly in the first one. 
     According to another embodiment form of the invention, as can be seen in FIGS. 6 and 7, the two support assemblies  31  ,  32  are fixed relative to each other and the first assembly support receives in attachment to at least one group of two distribution devices  2 , the two distribution devices of the group being arranged in a manner parallel and symmetrical relative to a geometrical vertical plane P and are oriented so that their actuation shafts  25  are turned in the same direction. To this group of distribution devices is connected an actuation mechanism which is appropriate to it, fixed on the second assembly support and consisting of a drive instrument  52  on the output shaft of which a cam  53  is supported. The output shaft of the drive instrument  52  of the actuation mechanism is placed in a vertical manner and the geometrical axis of rotation of this output shaft is placed in the vertical geometrical plane of symmetry P. The cam, supported in rotation on the motor shaft, is intended to be led by one of its cam surfaces by the drive instrument under pressure against the actuation shaft of the impulse mechanism and of the valve of one of the two devices, and by the other cam surface, against the other device. In FIG. 6, you can see that the system consists of several groups of distribution devices and that the two distribution devices of each group are placed side by side. In the case of the figure, the surfaces of the cams are placed according to two vertical planes forming an angle between them. In FIG. 7, you can notice that the installation does not have a single group of distribution devices. These distribution devices are isolated from each other and the surfaces of the cam used are parallel to each other. With one or the other form of the embodiment object of the FIGS. 6 and 7, several containers could be used that are mounted in an immobile manner on a mobile support driven by a drive instrument steered by the command and control unit so as to lead the containers under the discharge nozzles of the distribution devices. To this mobile support, for example, in rotation, a gauge device is connected. These mobile containers can be test tubes, sample tubes, and other containers in which several liquid products are introduced successively. 
     As a variation, a gauge indicator  7  and a container  6  are connected to each group of the system from FIG.  6 . 
     Of course, the invention presented here can receive any adjustments and variations in the range of equivalent techniques, without leaving the frame defined by the following claims.