EP4282394A1 - Metering device for microtablets - Google Patents

Abstract

The invention relates to a dosing device (3) for the volumetric dosing of microtablets (1) or the like and for transferring dosed portions thereof into target containers (2). The dosing device comprises a dosing unit (4) with volumetrically determined dosing chambers (5) and a feed container (6) arranged above the dosing unit (4) in the direction of the weight force. The feed container (6) has an upper filling opening (7), side container walls (8) and a lower container base (9) with transfer openings (10) for transferring the microtablets (1) into the dosing chambers (5). At least one retaining base (11) is arranged in the feed container (6) between the filling opening (7) and the container base (9). The retention base (11) covers the transfer openings (10) in the container base (9), with at least one passage gap (12) for the microtablets (1) being formed on the side of the retention base (11).

Description

The invention relates to a metering device with the features according to the preamble of claim 1.

When dosing pharmaceutical preparations in particular, products in the form of powders, granules, pellets or the like are usually measured volumetrically and fed as a measured unit to a target container, for example in the form of a plug-in capsule. The volumetric dosing can be carried out via roller dosing devices, slide dosing devices or the like, in which volumetrically determined dosing chambers are formed. Above such dosing units there is a feed or intermediate container in which a specific product supply is provided. There are transfer openings in the bottom of the feed container through which the product enters the dosing chambers. The volume of such a dosing chamber specifies the volume of the portion of the product to be measured, which is then transferred from the dosing chamber into the target container.

The dosing process summarized above takes advantage of the fact that the powders, granules or pellets mentioned have a certain flowability as bulk material, so that they flow through the individual components of the dosing device in a manner comparable to a liquid.

In contrast to this, other products such as microtablets are usually not measured by volume, but by number of pieces. Via dosing drums or A predetermined number of microtablets is provided using the dosing wheels and then filled into the capsule or another target container. Accurate dosing is mechanically very demanding. In a multi-lane dosing and filling operation, the mechanical complexity increases with the number of lanes and can only be implemented with great difficulty for a 12-lane operation, for example. However, volumetric dosing, which is in principle much simpler, has so far not been applicable to microtablets because the microtablets as bulk material do not have the required flowability like powders, granules or pellets.

The invention is based on the object of developing a generic volumetric metering device in such a way that it is also suitable for metering microtablets.

This task is solved by a metering device with the features of claim 1.

The invention is initially based on the knowledge that microtablets, due to the pressing process used for their production, have circumferential edges which, when used as bulk material, promote mutual wedging, which reduces flowability. In contrast to this, the individual particles of powders, granules or pellets have, at least to a rough approximation, a spherical shape, which promotes flowability. A further finding according to the invention is that the tendency to wedge cannot be overcome by increasing the flow pressure, but on the contrary, a high flow pressure promotes the formation of product bridges, which in turn interrupt the flow process. Building on this, it is provided according to the invention that at least one retaining base is arranged in the feed container between the filling opening and the container base, the retaining base covering the transfer openings in the container base, and at least one passage gap for the microtablets being formed on the side of the retaining base. Several such retaining floors can be provided between them Passage gaps are formed. A retaining base arranged centrally in the feed container is preferably provided, with two opposing edges of the retaining base being positioned at a distance from adjacent container walls, each forming a passage gap.

The term used here that it is a dosing device for the volumetric dosing of microtablets or the like does not mean that the dosing device is intended exclusively for microtablets, but that it can also be used for this purpose, among other things. This makes it possible to volumetrically dose and fill powder, granules, pellets or even microtablets as bulk material as required using the same dosing device.

The retention base according to the invention ensures that the product refilled from above first hits the retention base and from there passes through the passage gap to the bottom of the feed container. However, the amount of product distributed on the bottom of the feed container is limited by the retention base. The result is a product level that is limited in height and is shielded at the top by the retaining floor against advancing material. The height-limited product level reduces the pressing pressure generated by the product weight, which reduces the tendency to wedge, especially with microtablets. The product, particularly (but not only) in the form of microtablets, has increased flowability due to the reduced weight pressure, which enables trouble-free volumetric dosing.

The retention floor can have any suitable shape and can, for example, be a flat, horizontal plate. The retaining base is preferably provided with at least one inclined surface inclined towards the passage gap. The inclined surface encourages the product to flow through the passage gap to the extent that product quantities are removed from below the retention base by the ongoing dosing operation. The precise maintenance of a desired and predetermined product level is favored. In a further preferred development, the retaining floor is provided with a vertical surface adjacent to the passage gap. The vertical surface, with its lower edge, determines the height of the product level on the bottom of the container, similar to the principle of the birdbath. Regardless of this, the actual floor surface can be positioned in height and angle of inclination so that the subsequent flow behavior and the product level achieved can be adjusted freely and without mutual influence.

The metering device advantageously has a first shaking drive, which acts at least on the retaining base and in particular on the structural unit consisting of the feed container and the retaining base. By choosing a suitable vibration form and vibration intensity, fluidization of the product can be brought about in such a way that it flows in the desired amount onto the underside of the retention base and that it is distributed with sufficient uniformity on the container base in order to flow from there through the transfer openings into the dosing chambers reach.

The dosing unit can be designed in any suitable form of a volumetric doser. The dosing unit is preferably designed as a slide dosing device with a dosing slide and with a sliding drive acting on the dosing slide, the sliding drive also being designed as a shaking drive for the dosing slide. The sliding drive therefore performs a dual function. On the one hand, it carries out the dosing process by moving the dosing slide back and forth. On the other hand, it causes fluidization of the incoming product by means of an oscillating shaking movement of the metering slide, so that it is ensured that the metering chambers are completely filled with the product in a reproducible quantity.

The same applies to a transfer element of the dosing unit for transferring the dosed subsets of the microtablets from the dosing chambers into the target containers: The dosing unit advantageously comprises a second shaking drive acting on the transfer element, which is caused by the fluidization of the from the dosing chambers escaping product ensures that it reaches the target container without interruption. For this purpose, it has proven to be expedient that the second vibrating drive is formed by a pneumatic vibration exciter attached to the transfer element, the transfer element being suspended elastically and resiliently in the effective direction of the pneumatic vibration exciter. An effective vibration excitation with easily adjustable parameters is achieved with little mechanical effort.

Fig. 1

in schematischer Querschnittsdarstellung eine erfindungsgemäß ausgeführte volumetrische Dosiervorrichtung mit einem Zufuhrbehälter und mit einem im Zufuhrbehälter angeordneten Rückhalteboden, und

Fig. 2

in schematischer Längsschnittdarstellung das Übergabeelement nach Fig. 1 mit Einzelheiten eines eigenen pneumatischen Schwingungserregers.

An exemplary embodiment of the invention is explained in more detail below with reference to the drawing. Show it

Fig. 1

in a schematic cross-sectional representation of a volumetric metering device designed according to the invention with a feed container and with a retaining base arranged in the feed container, and

Fig. 2

The transfer element is shown in a schematic longitudinal section Fig. 1 with details of our own pneumatic vibration exciter.

Fig. 1 shows a schematic cross-sectional representation of a dosing device 3 designed according to the invention for the volumetric dosing of bulk material, particularly from the field of pharmacy or nutritional supplements. Such bulk material is powder, granules, pellets, microtablets 1 or the like. In the exemplary embodiment shown, the dosing device is equally designed for the dosing of pellets and of microtablets 1 that are less flowable than bulk material, although for the sake of simplicity reference will only be made to the microtablets 1 below. In addition to the actual dosing of the microtablets 1, i.e. the volumetric dimension of partial amounts thereof, the dosing device 3 also transfers these dosed partial amounts into the target container 2. The open lower part of a plug-in capsule, which is located in a capsule segment of a capsule filling machine, is shown here as an example as the target container 2. However, it can also be other target containers such as sachets, stick packs or the like.

The metering device 3 comprises a metering unit 4 and a feed container 6 arranged above the metering unit 4 in the direction of the weight force. The metering unit 4 is designed as a slide metering device with a metering slide 16 and with a transfer element 18 positioned immediately below. Pairs of metering chambers 5 with a fixed volume are formed in the metering slide 16. In the middle below there is a transfer channel 22 in the transfer element 18. The metering unit 4 also includes a sliding drive 17, which is only indicated schematically, which acts on the metering slide 16 to generate a cyclic back and forth movement in the horizontal direction corresponding to a double arrow 24 relative to the spatially im Essential fixed transfer element 18 acts. A servo drive is used as a sliding drive. The direction of the back and forth movement corresponds to the direction of distance between the two dosing chambers 5 forming a pair. The amplitude of the back and forth movement is equal to the distance mentioned, the movement being adjusted in such a way that one of the two dosing chambers 5 alternates Coverage is brought with the transfer channel 22 of the fixed transfer element 18.

The feed container 6 has a lower container base 9, which is surrounded by side container walls 8. The feed container 6 is closed at the top by an optional lid, in which a filling opening 7 is formed. However, it can also be expedient to do without the lid, in which case the filling opening 7 is formed by the upper open side of the feed container 6. The filling material or the bulk material, here the filling of microtablets 1, passes through the upper filling opening into the feed container 6 and comes to rest on the container bottom 9.

A pair of transfer openings 10 is formed in the container base 9 for each pair of dosing chambers 5. The distance within a pair of transfer openings 10 is coordinated with the movement stroke of the metering slide 16 in such a way that a metering chamber 5 of the metering slide 16 alternately overlaps with a transfer opening 10 in the container base 9. A subset of the microtablets arrive here 1 from the feed container 6 through the transfer opening 10 into the respective dosing chamber 5 and fills it. The volume of the dosing chamber 5 specifies the portion of the microtablets 1 to be measured or dosed. As a result of a movement stroke of the dosing slide 16 in accordance with the double arrow 24, the dosing chamber 5, which is completely filled with microtablets 1, now comes into contact with the transfer channel 22 in the transfer element 18. The subset of microtablets 1 located in the dosing chamber 5 and thereby volumetrically measured now falls downwards out of the Dosing chamber 5 out and passes through the transfer channel 22 into the target container 2. With the same movement stroke of the dosing slide 16, the other dosing chamber 5 is brought into overlap with the other transfer opening 10, so that this other dosing chamber 5 is in the manner described above with microtablets 1 fills while the first dosing chamber 5 is emptied through the transfer channel 22. As a result of a subsequent, opposite lifting movement, the second metering chamber 5 is emptied through the transfer channel 22 into an assigned target container 2, while the first metering chamber 5 is filled again. Due to the cyclic back and forth movement of the dosing slide 16, one of the two dosing chambers 5 is alternately filled with microtablets 1, while the other dosing chamber 5 of a pair of them is emptied into the associated target container 2. In brief, microtablets 1 or the like are dosed volumetrically and the dosed portions thereof are transferred into assigned target containers 2.

The method and function of the device as described above require that the bulk material to be filled has a sufficient degree of flowability, which is not easily the case with some bulk materials and in particular with microtablets. To support the desired flowability, according to the invention, at least one, here precisely one, retaining base 11 is arranged in the feed container 6 between the filling opening 7 and the container bottom 9. In the vertical or weight direction, the retaining base 11 covers the transfer openings 10 in the container base 9. On the side of the retaining base 11 there is at least one passage gap 12 for the microtablets 1. In the preferred exemplary embodiment shown, the retaining base 11 is arranged centrally in relation to the lateral direction, i.e. in the middle of the feed container 6, so that two opposite edges of the retaining base 11 are positioned at a distance from the respective adjacent container walls 8. As a result of these distances, there is a passage gap 12 on both sides of the retention base.

In the preferred embodiment shown, the retaining floor 11 is provided with at least one inclined surface 13 inclined towards the passage gap 12 and with a vertical surface 14 adjacent to the passage gap 12. Due to the presence of two passage gaps 12, the retaining base 11 is designed here in a mirror-symmetrical manner with a total of two inclined surfaces 13 and a total of two vertical surfaces 14, one inclined surface 13 being inclined towards the respective passage gap 12, and one vertical surface 14 being inclined towards the respective passage gap 12 adjacent. The vertical surfaces 14 adjoin outer side edges of the inclined surfaces 13 and end in the direction of the weight force downwards in lower edges 20.

Bulk material in the form of microtablets 1 fed from above through the filling opening 7 does not fall directly onto the container base 9, but first hits the retention base 11. Supported by the inclined surfaces 13, the microtablets 1 "flow" laterally to the respective passage gap 12 and pass through there on the container bottom 9. The microtablets 1 are distributed on the container bottom 9 to form a product level 21. The height of the product level 21 is determined by the height or vertical position of the lower edges 20, without microtablets 1 refilled from above weighing on it. The height of the retaining floor 11 or its lower edges 20 is adjusted in such a way that, compared to the absence of a retaining floor 11, a product level 21 that is reduced in height and does not vary is achieved. As a result, there is a constant and reduced weight force pressure within the product bed distributed on the container base 9, which allows the microtablets to flow as desired.

In addition, the metering device 3 includes a first vibrating drive 15, which acts at least on the retaining base 11. In the preferred exemplary embodiment shown, the first vibrating drive 15 acts on the entire assembly consisting of the feed container 6 and the retaining base 11 and causes it to vibrate in accordance with a double arrow 23. In addition, the sliding drive 17 is also designed as a shaking drive for the metering slide 16 and causes the metering slide 16 to vibrate if necessary. The vibration of the feed container 6, retaining base 11 and metering slide 16 is transmitted to the amount of microtablets in contact with it and thereby brings about fluidization or increase in flowability while avoiding wedging and bridging. In conjunction with the effect of the retaining base 11 described above, the vibrating fluidization causes the microtablets 1 present as bulk material to find their way through the passage gap 12, the transfer openings 10 and the dosing chambers 5 into the respective target container 2 due to their weight.

Analogously, the transfer element 18 is also provided with its own, second vibrating drive 19, as shown in Fig. 2 is recognizable. Fig. 2 shows this transfer element 18 Fig. 1 as an individual part in a side, opposite Fig. 1 View rotated through 90° and partially sectioned. First of all, it can be seen that a plurality of transfer channels 22, here for example twelve arranged in a row, are formed in the transfer element 18. Analogously, the metering slide 16 ( Fig. 1 ) a corresponding number of pairs of dosing chambers 5 (not shown). A corresponding number of pairs of transfer openings 10 are also formed in the container bottom 9 of the feed container 6, just as the above-mentioned capsule segment has a corresponding number of receptacles for capsule bases or target containers 2, so that multi-lane, here twelve-lane, parallel operation is possible.

The transfer element 18 is fastened to a spatially fixed base 27 by means of several, here four spring elements 28, in such a way that a lateral spring travel in the direction of a double arrow 25 is possible, while the transfer element 18 is in all other spatial degrees of freedom. The second vibrating drive 19 is designed as a pneumatic vibration exciter and is firmly connected to the transfer element 18. There is an oscillating mass, not shown, in the pneumatic vibration exciter. Compressed air is fed in via a pneumatic connection 26, which causes the oscillating mass to swing sideways in accordance with the double arrow 25. The oscillating movement of the oscillating mass induces an oscillating movement of the transfer element 18 in its elastically resilient bearing in the direction of the double arrow 25, which ensures the fluidization of the material from the dosing chambers 5 ( Fig. 1 ) emerging microtablets 5 as they pass through the transfer channels 22.

Overall, this ensures sufficient and consistent fluidization of the bulk material to be measured for the volumetric dosing process shown, even if products that are difficult to handle, such as microtablets 1, are to be filled as bulk material.

Claims (8)

Dosing device (3) for the volumetric dosing of microtablets (1) or the like and for transferring dosed portions thereof into target containers (2), comprising a dosing unit (4) with volumetrically determined dosing chambers (5) and one in the direction of the weight force above the dosing unit (4 ) arranged feed container (6), the feed container (6) having an upper filling opening (7), side container walls (8) and a lower container base (9) with transfer openings (10) for transferring the microtablets (1) into the dosing chambers (5) having,
characterized in that at least one retaining base (11) is arranged in the feed container (6) between the filling opening (7) and the container base (9), the retaining base (11) covering the transfer openings (10) in the container base (9), and where At least one passage gap (12) for the microtablets (1) is formed on the side of the retaining base (11). Dosing device according to claim 1,
characterized in that a retaining base (11) arranged centrally in the feed container (6) is provided, two opposite edges of the retaining base (11) being positioned at a distance from adjacent container walls (8), each forming a through gap (12). Dosing device according to claim 1 or 2,
characterized in that the retaining base (11) is provided with at least one inclined surface (13) inclined towards the passage gap (12). Dosing device according to one of claims 1 to 3,
characterized in that the retaining base (11) is provided with a vertical surface (14) adjacent to the passage gap (12). Dosing device according to one of claims 1 to 4,
characterized in that the metering device (3) has a first shaking drive (15), which acts at least on the retaining base (11) and in particular on the structural unit consisting of the feed container (6) and the retaining base (11). Dosing device according to one of claims 1 to 5,
characterized in that the dosing unit (4) is designed as a slide doser with a dosing slide (16) and with a sliding drive (17) acting on the dosing slide (16), the sliding drive (17) also being designed as a shaking drive for the dosing slide (16). is. Dosing device according to one of claims 1 to 6,
characterized in that the dosing unit (4) has a transfer element (18) for transferring the dosed partial quantities of the microtablets (1) from the dosing chambers (5) into the target containers (2) and a second vibrating drive (19) acting on the transfer element (18). includes. Dosing device according to claim 7,
characterized in that the second vibrating drive (19) is actuated by a pneumatic vibration exciter attached to the transfer element (18). is formed, wherein the transfer element (18) is suspended elastically in the effective direction of the pneumatic vibration exciter.

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