Patent Application
20150136272
The present invention relates to a dosing device, in particular for powder, and the usefulness thereof is more particularly evident for hazardous products, the dissemination of which must be avoided and which often have to be handled from the outside of an enclosure in which they are confined, such as a glove box, a shielded casing or a shielded cell.
The usual method of dosing consists in progressively pouring out the desired amount of the product, contained firstly in a recipient or a container, into another recipient generally positioned on a balance, in order to be able to stop as soon as the desired amount has been reached. A funnel is often arranged on the second recipient to aid the decanting. This method of dosing is employed for all products to be dosed, including those that have been indicated above and which must be confined in a protective enclosure, the handling then taking place either through the intermediary of a glove fixed to the enclosure and traversing it, or by a remote handling device. It is however obvious that it presents risks of accidents or dosing errors stemming from incorrect tiltings of the original container of the product, too late stoppages of the decanting, or disseminations of the product via accidental projections or by remanence on the funnel. These risks are greater when the powders are compact or sticky, which reduces their ability to flow, whereas the expedients that may be envisaged, such as shaking the container or tapping on it, have an unpredictable efficiency and can also lead to a too sudden acceleration of the flow; or when the containers are heavy; or when the dosing is carried out by a remote handling device or through a glove, thus with reduced address or less good visibility.
Mechanical dosing devices also exist where handling of the original container of the product and the associated vagaries and risks are reduced. The document U.S. Pat. No. 4,836,417 may be cited, in which the powder is poured into a hopper comprising a lower distribution neck. The hopper is positioned on a diaphragm which the neck traverses, and this diaphragm is provided with piezoelectric vibration generators. The vibrations communicated to the diaphragm are transmitted to the mouth so as to shake the powder and to assist the flow of same via the mouth. This device nevertheless does not make it possible to control easily the characteristics of the flow and particularly its flow rate, and it is all the same necessary to take precautions against the dissemination of the product, the neck remaining continually open.
Another document describing a dosing device is WO-A-2008/071 872. The original container of the product comprises a plug at its opening; this plug is provided with an orifice and a mobile mechanism to completely close or open the orifice as necessary and, here again, to vary the flow characteristics. More complicated, but automatable, handling operations are still nevertheless necessary to act on this mechanism for opening the plug, which reduces the interest of this device for uses in a confined enclosure; it has rather been designed for the pharmaceutical industry.
The subject matter of the invention is a dosing device of a different type, remarkable in that it avoids disseminations of products, makes it possible to adjust relatively easily the flow rate, and in that it can be easily and without risk handled remotely, even by rudimentary mechanical means.
In a general form, the invention relates to a dosing device comprising a container having an opening, a plug arranged at the opening of the container and a first orifice and having a mobile mechanism on the first orifice of the plug to open or to close as necessary the plug and thus the dosing device; characterised in that the plug comprises: a first outer part, arranged around a connection to the container, the connection being positioned at the opening of the container, so as to be able to rotate around said connection and further comprising a sealing part also arranged in front of the opening and provided with the first orifice; and a second outer part, arranged in front of the sealing part and comprising a second orifice, being able to rotate with respect to the first outer part so as to give as necessary a superposition of variable surface area, or an absence of superposition, of the second orifice over the first orifice.
A rotation on the second outer part of the plug makes it possible to open it to the desired degree, whereas, since the first outer part of the plug is rotating with respect to the container, this may be rotated to assist the mixing of the contents and the flow of same. The use of simple means of rotation between the container and the parts of the plug enables easy handling, even by rudimentary devices; and the movement, assisting the mixing of the contents of same, of the container may be accomplished continuously throughout the dosing.
The plug may further comprise a connection part, assembled to the container around the opening, having a passage traversing it and leading to the exterior, and also having the connection. With such a construction, the plug is easily removable and may be replaced by a conventional complete sealing plug, which properly confines the product in the container, outside of dosing periods.
The connection part may be assembled to the container by an adjustment of concentric smooth parts, by a screw down nut and a locknut, the screw down nut being borne by one of the container and of the connection part so as to be able to rotate freely, the screw down nut and the locknut being screwed onto a thread established on the other of the container and of the connection part.
This arrangement is very reliable for preventing accidental unscrewings, while again using a rotating movement to realise the assembly or the separation.
It also advantageous that the first outer part comprises a stem extending into the container through the opening, in order, here as well, to accentuate the movement or the mixing of the product.
The connection part is advantageously provided with a circular collar, and the first outer part then comprises an assemblage of two parts clasping together the collar; similarly, the first outer part advantageously comprises a second circular collar, and the second outer part comprises an assemblage of two parts clasping together the second collar. In such constructions, particularly if the assembled parts are screwed down in an adjustable manner and optionally blocked by a locknut, the clearance between these assembled parts and the collars may be adjusted to a quite low value to reduce to almost nothing the amount of product that can interfere therewith through dissemination. This makes it possible to limit the retention, that is to say the amount of powder present inside the mechanism of the dosing system when the container has been emptied.
Another aspect of the invention is a dosing assembly comprising the preceding dosing device, as well as a machine comprising a raising frame itself comprising a support traversed by a vertical boring, the dosing device comprising reliefs resting on the support around the boring, the boring then containing the plug, and the machine further comprises a system for immobilising the plug and a system for rotating the container. And, advantageously, the plug and the boring have first mutually imbricated reliefs which maintain the plug immobilised against rotations; the first reliefs of the plug are placed on the first outer part, the second outer part and a ring delimiting the boring and rotating in the support have second mutually imbricated reliefs that maintain them integral in rotation while enabling the second outer part to rotate with respect to the first outer part; and the dosing device is provided with third reliefs resting on the support around the boring, the plug being flush under the support.
The invention will now be described in its different aspects with reference to the following figures, which represent a purely illustrative illustration thereof:
and
The plug 4 is represented in
The end portion of the connection part 15 is a more or less smooth distribution neck 26 but which nevertheless comprises a collar 27 protruding outwards and around which the first outer part 16 of the plug 4 is installed: the first outer part 16 is mainly composed of two assembled portions 28 and 29, established on either side of the collar 27, overlapping it and joined together by a thread 30; this assemblage makes it possible to install the first outer part 16 around the collar 27 with quite a small clearance in order to thwart the interference of impurities and particularly disseminated materials stemming from the loading of the dosing device 1 or from a later loading while enabling the first outer part 16 to rotate around the connection part 15 and an axis coaxial to the passage 18. A locknut 31 is placed on the thread 30, in order, as previously, to immobilise the assembled portions 28 and 29 at the desired position by jamming them. The rotation of the parts with respect to each other is favoured by the presence of bearings 60.
The second outer part 17 similarly comprises two assembled portions 33 and 34, extending on either side of a second collar 35, itself established on the first outer part 16 of the exterior side; the assembled parts 33, 34 are again joined by a thread 36 and held in place by a locknut 37 established on the thread 36. Here again, an adjustment of the axial clearance between the second collar 35 and the assembled parts 33, 34 is sought in order to thwart the ingress of disseminated materials.
The plug 4 further comprises a stirring rod 42, integral with the first sealing part 38 and which extends to the inside of the passage 18, while occupying a part only of its section up into the container 2, in order to help the mixing of the powder and the flow of same when the container 2 is rotated. The stirring rod 42 (
This dosing device is not used alone in principle, but in cooperation with the machine 5 to form a dosing assembly, the description of which will now be described by means of
The dosing device 1 is turned round and positioned on a support 46 protruding from one side of a frame 47 of the machine 5. The receiving recipient 9 and the balance 10 on which it is positioned are situated under the support 46. The system for rotating 8 comprises a motor 48 mounted on the frame 47, a transmission 49, and a plate 50 rotating in the support 46 around a vertical axis and on which the nut 20 engaged around the cylindrical portion 19 of the part 15 for connecting to the container 2 is positioned. The transmission may consist of a belt stretched between two pulleys, one of which depends on the output shaft of the motor 48 and the other on the plate 50. It is thus possible to make the container 2 and the connection part 15 continually rotate during dosing. Since the support 46 and 50 is traversed completely by a vertical boring 51, the plug 4 is flush under the support 46 and extends immediately above the receiving recipient 9. The boring 51 is formed more precisely through the plate 50 as well as through a socket 52 and a ring 53 which receive respectively the first outer part 16 and the second outer part 17. The socket 52 is fixed with respect to the support 46, but the ring 53 rotates with respect to it, like the plate 50. Bearings, all referenced 54, connect the support 46 to the plate 50 and to the ring 53, and the socket 52 to the same, and thus enable these rotations. The rotation speed being variable, it is possible to carry out the dosing in several steps:
It should be noted that these operations can be fully automated: for this it suffices to replace the stem for adjusting the opening by a second motorisation, commanded by the command-control computer.
The socket 52 comprises a groove 55 receiving a lug 56 of the first outer part 16, and, similarly, the ring 53 comprises a groove 57 receiving a lug of the second outer part 17. Thanks to this arrangement, the first outer part 16 is fixed in rotation and, since the ring 53 is free, it remains normally fixed, but it may be rotated as necessary with the second outer part 17 of the plug 4, in order to adjust according to the needs of opening the dosing device 1. A slug 61 erected on the plate 50 (
An envisaged application for the invention is the dosing of radioactive powders. The dosing devices 1 are consequently shielded in the embodiment actually represented. Dosings of other powders and products in other fluid states are possible.
The plug 4 is normally sufficient hermetic, which makes it possible to handle and tilt the dosing devices 1 without risk. It may nevertheless be replaced if necessary by another plug, not represented, outside of dosing periods. Such a plug would have a connection part similar to the part 19 of the plug 4 present and a continuous sealing part.
An embodiment has been described here where the plug 4 was metal. A plug made of polymer would not be excluded; its shape would be identical, but the number of parts could be reduced and its structure would thus be simplified thanks to the greater facility of constructing parts of more complex shape by moulding and to the possibility of forming assemblages by ratcheting.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1256404 | Jul 2012 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2013/063883 | 7/2/2013 | WO | 00 |
