DE102022104871A1 - Metering roller and device comprising at least one such metering roller - Google Patents

Abstract

Metering roller (1) for filling a target container (2) with a portion (4) of a powdered product (3) to be metered, comprising a roller body (5) with an outer roller surface (6) and an interior space (7) in which there is a compressed air supply ( 8) and dosing chambers (9) for the dosed uptake and delivery of the powdered product (3), which each form connections between the roller outer surface (6) and the inner space (7), the compressed air supply (8) being set up to flow into the Dosing chambers (9) to generate either a negative pressure or an overpressure, in order to convey the powdered product (3) into the dosing chambers (9) or to discharge it from the dosing chambers (9), the dosing chambers (9) being separated from the interior (7) and the compressed air supply (8) are delimited by filter elements (10) permeable to compressed air, which are clamped between clamping elements (11) and the planar contact surfaces (12) of the roller body (5) surrounding the dosing chambers (9).

Description

The invention relates to the field of automatically operating devices for dosing powdery products with the aid of a so-called dosing roller. The invention is particularly suitable for dosing small amounts of powder in the range, for example, from 0.3 mg to 50 mg. This type of dosing roller is used, for example, for dosing pharmaceutical powders, in particular for inhalation. Another application is the dosing of pure pharmaceutical active ingredients.

A device for dosing powdered products is, for example, from EP 3 608 233 B1 known.

In principle, there is a need to further improve such devices, in particular with regard to the ease of assembly, maintainability, and dosing accuracy. The focus here is on improving the dosing accuracy, where an improvement (increase in accuracy) is fundamentally desired.

The object of the present invention is therefore to further improve devices for dosing powdered product. This object is achieved with the metering roller according to the features of the independent patent claims. Further advantageous configurations of the dosing roller and a device for dosing with such a dosing roller are specified in the dependently formulated patent claims and in the description and in particular also in the description of the figures. It should be pointed out that a person skilled in the art can combine the individual features with one another in a technologically sensible manner and thus arrive at further configurations of the invention.

The invention relates to a metering roller for filling a target container with a portion of a powdered product to be metered, having a roller body with an outer surface of the roller and an interior space in which there is a compressed air supply, as well as metering chambers for metered uptake and dispensing of the powdered product, the respective connections between the outer surface of the roller and the interior, wherein the compressed air supply is set up to selectively generate a negative pressure or an overpressure in the dosing chambers in order to convey the powdery product into the dosing chambers or to discharge it from the dosing chambers, the dosing chambers being supplied by the interior and the compressed air supply with for Compressed air-permeable filter elements are delimited, which are clamped between clamping elements and the dosing chambers surrounding planar contact surfaces of the roller body.

The metering roller is a cylindrical body with a roller outer surface and a roller axis. During the dosing process, the dosing roller is rotated around its axis with one direction of rotation. Dosing chambers are each arranged evenly distributed in circumferential annular areas. There are preferably a number of ring-shaped areas along the axis, in each of which a number of dosing chambers are arranged. In this case, dosing chambers in different ring-shaped areas are each preferably arranged in alignment along the axis. In the embodiment variants shown below, also in the figures, four dosing chambers are arranged in an annular area. However, metering rollers with any deviating numbers of metering chambers are also included here, for example with two to ten metering chambers in each ring-shaped area.

With the dosing chambers, the dosing roller conveys defined subsets from a product supply with the powdered product into a target container. A pickup position and a delivery position denote locations relative to the metering roller. The pick-up position is preferably arranged above the metering roller and the delivery position is arranged below the metering roller. By rotating the dosing roller in the direction of rotation of the roller, dosing chambers each move from the receiving position to the dispensing position. At the pick-up position, the dosing chambers are filled with the powdered product. At the delivery position, the powdered product is delivered to the target container.

The target container is, for example, a capsule and the powdered product, for example a medicament, which is to be filled into the capsule. However, the dosing roller can also be used for a wide variety of other powdered products and target containers.

As used herein, the term "product supply" means any source of the powdered product at the pick-up position. This can be, for example, a funnel running towards the metering roller, which can be filled from above with the powdery product and whose outlet is connected to a metering chamber located at the receiving position. The outlet can be closed by the outer surface of the dosing roller if there is no dosing chamber in the receiving position, for example if the dosing roller was rotated further after a dosing chamber in the receiving position was filled with powdered product.

A roller body preferably forms a kind of basic structure of the metering roller. The roller body is preferably a one-piece body made of metal, for example. The roller body can be a cast part, for example, which has been post-processed, if necessary, using machining processes. The roller body can also be manufactured using other suitable manufacturing processes. An outer surface of the metering roller is preferably formed directly by the roller body. In addition, the roller body has an interior space. The basic shape of the roller body is therefore tubular, with the interior of the roller body not being designed, or at least not completely, with an inner surface which is symmetrical to the axis of the metering roller.

In a preferred embodiment, the metering chambers are designed in the manner of bores, which extend from the outer surface of the roller into the metering roller. The bores preferably extend into the interior of the roller and the dosing chambers thus form passages from the outer surface of the roller into the interior. The size or volume of the bores in the dosing chambers determines the dosing volume or the volume of the subsets to be dosed. All metering chambers of the metering roller are preferably of the same size. The size or volume of the metering chambers depends on their diameter and the depth of the bores, with the depth describing the distance from the outer surface of the roller to a lower end of the metering chambers (preferably at a transition area between the metering chamber and the interior of the roller. The filter element is preferably located at this transition area.

The filter element, which is used in the metering roller, delimits the metering chamber at the bottom or delimits the metering chamber from the interior space or the compressed air supply in the interior space. The filter element is preferably film-like, paper-like or also a textile fabric made of plastic, wire or the like. Solid filters made of plastic or metal can also be used as the filter element. The filter element and in particular the permeability of the filter element is matched to the powdered product and in particular its particle size. In particular, the permeability of the filter element is selected in such a way that particles of the powdery product are reliably retained by the filter element and no powdery product gets into the interior - but at the same time compressed air can flow through the filter element with an acceptable flow resistance, so that the compressed air supply generates an overpressure or a negative pressure can be generated in the dosing chambers.

A (continuous) filter element is preferably not provided for all metering chambers of the metering roller, but the filter element is subdivided for the various metering chambers of the metering roller. For example, a continuous strip of filter material can be used for all metering chambers arranged in a line along the axis of the metering roller, which strip is inserted in a groove (described in more detail below) in the interior. In further preferred embodiment variants, there is a separate filter element for each dosing chamber.

The term "compressed air supply" refers here to components for subjecting the dosing chambers to overpressure or underpressure, which are arranged in the interior of the dosing roller. The compressed air supply includes, in particular, compressed air ducts in the interior of the metering roller. The compressed air supply is preferably part of a compressed air supply system, which also includes components located outside the interior of the metering roller, which interact with the compressed air supply. The compressed air supply system preferably has negative pressure generation and positive pressure generation. The generation of negative pressure acts preferably on dosing chambers that are in the receiving position and generates a negative pressure through the filter element, with which the powdered product is drawn into the dosing chamber and then also held in the dosing chamber during transport during the rotation of the dosing roller. In addition, the compressed air supply system preferably has overpressure generation. The generation of overpressure preferably acts on dosing chambers that are in the dispensing position. The overpressure is transmitted through the filter element into the dosing chamber and conveys the powdered product out of the dosing chamber and into the target container.

In particular, the overpressure generation generates a kind of compressed air blast at the dispensing position on the dosing chamber for transferring the powder into a container. If necessary, the negative pressure provided by the negative pressure generation can also vary during the filling of the dosing chambers at the receiving position and/or during the transport of the partial quantities in the dosing chambers from the receiving position to the dispensing position during the rotation, in order to achieve a particularly advantageous filling of the dosing chamber adapted to the respective situation / To effect promotion of the subset.

The generation of negative pressure and the generation of positive pressure are preferably connected to the dosing chambers through channels that are described in more detail below. If applicable A controller can be provided, which specifies in each case whether the negative pressure generation or the positive pressure generation acts on the respective dosing chamber. The terms “negative pressure” and “overpressure” each refer to an ambient pressure that acts on the metering roller from the outside. A negative pressure is a pressure below the ambient pressure. An overpressure is a pressure above the ambient pressure.

Precise dosing of the partial quantity is preferably carried out in that precisely an intended quantity of powdery product can be sucked into the dosing chambers or held in the dosing chambers by the negative pressure. The precise dosing can also be supported by the fact that during filling or shortly after filling, stripping elements can strip off excess powdery product that protrudes beyond the dosing chamber.

The filter element thus forms (starting from the outer surface of the roller) a lower closure of the dosing chamber and a delimitation of the dosing chamber from the compressed air supply described. The filter element is of great importance for the accuracy of the dosing because the filter element ultimately limits the depth or the height of the dosing chambers and thus also defines the volume of the dosing chambers.

As will be described in more detail below with reference to the figures, which represent the prior art, increased inaccuracies in the metered subsets can occur, in particular due to a curved shape of the filter element.

For this reason, planar contact surfaces are provided on the dosing roller. “Flat” contact surfaces here mean contact surfaces that are flat in a technical sense (compared to the curvature of the outer surface of the metering roller). During the manufacture of the roller body, the planar contact surfaces are produced, for example, with a tool which, because of its tool design, produces a planar surface. This can be, for example, a rotating milling tool with a tool axis which is aligned perpendicularly to the contact surface, with the milling tool preferably having a flat end face.

The planar contact surface can ensure that the filter element inserted into the metering roller itself is also planar (i.e. runs in one plane) and in particular is not curved (e.g. is shaped to follow an inner cylindrical surface of the metering roller).

In addition, it can be achieved that the filter element is braced between two flat surfaces. In this way, an increased uniformity of the bracing and, as a result, also an improved sealing can be achieved.

In particular, membrane effects of the filter element can be avoided when filling and/or emptying the dosing chamber. The term "membrane effect" here means a deformation of the filter element under the influence of media (the powdered product and/or the compressed air) that cause a change in the volume of the dosing chamber.

It has been found that such membrane effects are particularly dependent on the curvature of the contact surface and the resulting curvature of the filter element, with both curvatures resulting from a curved inner surface of a metering roller designed with a roller tube. In particular, it has also been found that such membrane effects can turn out very differently in different metering chambers of a metering roller due to very small geometric deviations of the metering roller in the area of the metering chamber. The more different the membrane effects on individual dosing chambers, the poorer the dosing accuracy of the dosing roller. The fluctuation range of the partial quantities of the powdery product dosed with the dosing roller is greater.

The dosing roller preferably has clamping elements with which the filter elements are clamped on the planar contact surfaces. Preferably, the clamping elements in the area of the dosing chambers each also have a planar contact surface, so that a uniform clamping of the filter elements on the contact surfaces is possible by means of the clamping elements.

It is particularly advantageous if the interior of the roller body has a central area and grooves extending from the central area to the outer surface of the roller, with the dosing chambers each forming connections between a base of the grooves and the outer surface of the roller and the planar contact surfaces on the base of the grooves surrounding the dosing chambers .

The roller body described here differs from a roller tube and has a more complex shape in its interior with a central area from which grooves with a groove base (bottom) extend. The base is preferably flat or planar. The grooves are made, for example, from the inside (starting from the central area) in the roller body by spark erosion. The reason is preferably the flat contact surface.

Particularly in the case of metering rollers for very small metering volumes (very small partial amounts), the design of the roller body described here makes it possible to achieve high metering accuracy and at the same time to provide a very stable construction of the metering roller. For very small partial quantities, the depth of a dosing chamber must not be too great because very small diameters of dosing chambers are also difficult to implement or have other disadvantages (especially when filling/emptying the dosing chambers). For this reason, roller tubes that have been customary up to now have had to have very small wall thicknesses for very small dosing chambers, which impairs the stability of the roller tubes. The rolling body described here is only partially thin-walled (in the area of the grooves or the base of the grooves) and otherwise relatively thick-walled. The roller body therefore has significantly increased stability compared to a roller tube.

A width of the grooves is preferably greater than a diameter of the dosing chambers, so that around the dosing chambers a respective area of the base forms the planar contact surface. The dosing chambers preferably each extend from the center of the grooves.

It is also advantageous if the grooves each form guides for the clamping elements.

The clamping elements preferably have a width that corresponds to the width of the grooves minus a fitting clearance, so that the clamping elements are guided radially in the grooves and can be moved outwards along the (radial) guide. This simplifies the assembly (in particular the positioning) of the clamping elements in the roller body. In addition, it is achieved that the clamping elements are guided evenly towards the filter elements. As a result, the tensioning of the filter elements is improved (in particular made more uniform).

In addition, it is advantageous if a clamping mechanism is arranged in the interior space, which is set up to clamp filter elements with the clamping elements in the grooves.

The clamping mechanism is preferably set up to convert an axial clamping movement in the clamping mechanism or of components of the clamping mechanism into a radial outward movement of the clamping elements. For this purpose, the tensioning mechanism can, for example, have conical sliding surfaces on the tensioning mechanism and on the tensioning elements that interact with one another. A reduction in movement preferably also takes place here. A larger axial clamping movement with a smaller force is translated into a smaller radial clamping movement of the clamping elements with a larger force. In variant embodiments, the tensioning mechanism can also function pneumatically, for example by providing a deformable element in the interior. Such a deformable element expands when it is filled with compressed air and it pushes the clamping elements outwards.

It is also advantageous if the clamping elements each contain at least one compressed air channel of the compressed air supply and each have a plurality of branch channels which each provide a compressed air-conducting connection of the compressed air channel to the dosing chambers.

The compressed air channels preferably extend in the direction of the axis of the metering roller along the clamping elements in the clamping elements. The compressed air channels are preferably bores in a longitudinal direction through the clamping elements.

The branch channels branch off from the compressed air channels in each case in the radial direction of the metering roller and open into the metering chambers. The branch channels are preferably formed concentrically to the respective dosing chambers. The branch channels serve to transfer the pressure from the compressed air channels to the dosing chambers.

It is also advantageous if sealing elements can be clamped between the clamping elements and the planar contact surfaces together with the filter elements in such a way that an airtight connection from the branch channels to the dosing chambers is provided.

It is also advantageous if the filter elements are braced between the sealing elements and the planar contact surfaces.

It is also advantageous if the sealing elements consist of an elastic material, have a sealing surface and the filter elements can be clamped between the planar contact surface and the roller body and the sealing surface in such a way that the sealing elements are deformed and in a sealing surface area running annularly around the dosing chamber apply an even sealing force to the filter element.

The roller bodies with the planar contact surfaces and clamping elements are preferably made of a relatively rigid material, for example metal or a hard plastic. Such a material is not or only to a small extent deformed by the forces acting during bracing. The sealing element is preferably flexible compared to the contact surfaces and the tensioning elements. The sealing element is made, for example, from an elastomer (e.g. rubber, caoutchouc, etc.). An improved seal is achieved by an elastic deformation of the sealing element, which can in particular also compensate for manufacturing tolerances of the planar contact surfaces.

The sealing elements are preferably rotationally symmetrical parts which are preferably arranged in the metering roller concentrically to the metering chambers and the branch channels or their axes, but any other profile is also possible. The sealing elements preferably do not have any curvature, which would be required for sealing elements adapted to the shape of the inner surface of a roller tube. The sealing elements are preferably designed to interact with planar contact surfaces and preferably form sealing surfaces that lie in planes and are intended to rest against the filter element, the planar contact surfaces and/or the clamping elements.

It is also advantageous if the sealing elements are fastened to the clamping elements.

In preferred variants, the sealing elements are formed onto the clamping elements. Preferably, the sealing elements are integrally connected to the tensioning elements and, for example, vulcanized onto the tensioning elements. The clamping elements, with the sealing elements formed thereon, are preferably prepared components that can be inserted into grooves in the roller body. By molding the sealing elements onto the clamping elements, it is also possible in particular to achieve precise positioning of the sealing elements relative to the clamping elements. Sealing elements can also be attached to the clamping elements in any other way. For example, sealing elements can be clipped into structures provided for this purpose on the clamping elements.

It is also advantageous if recesses are provided on the clamping elements, into which the sealing elements are inserted.

A recess can in particular be an extension of the branch channel on the side oriented towards the dosing chambers, which forms a bearing surface for the sealing elements. The sealing elements can preferably be formed in the recesses.

A device for filling a powdery product is also to be described here, having at least one dosing roller according to one of the preceding claims for filling the powdery product into the target container. Such a device is described below with reference to the figures.

• 1: eine beschriebene Vorrichtung zum Abfüllen eines pulverförmigen Produktes mit mindestens einer beschriebenen Dosierwalze;
• 2: schematisch einen Querschnitt durch eine Dosierwalze gemäß dem Stand der Technik;
• 3 schematisch einen vergrößerten Ausschnitt aus dem Querschnitt gemäß 2;
• 4: schematisch einen Querschnitt durch eine beschriebene Dosierwalze;
• 5: schematisch einen vergrößerten Ausschnitt aus dem Querschnitt gemäß 4; und
• 6: einen Längsschnitt durch eine beschriebene Dosierwalze.

The invention and the technical context of the invention are explained in more detail below with reference to the figures. The figures show preferred exemplary embodiments to which the invention is not restricted. It should be pointed out in particular that the figures and in particular the proportions shown in the figures are only schematic. Show it:

• 1 : a described device for filling a powdery product with at least one metering roller described;
• 2 : a schematic cross section through a metering roller according to the prior art;
• 3 schematically shows an enlarged section of the cross section according to FIG 2 ;
• 4 : schematically a cross section through a metering roller described;
• 5 : schematically shows an enlarged section of the cross section according to FIG 4 ; and
• 6 : a longitudinal section through a metering roller described.

1 shows a device 23 for filling a powdery product, which has a metering roller 1 described. The structure of the device 23 is only an example. The metering roller 1 described can also be used in devices with a different structure. The device 23 has a carousel 31 which is rotated with a carousel direction of rotation 36 and in this way guides capsule holders 38 with capsules 37 held therein through various stations 32 at which processing steps of the capsules 37 take place. Shown here as an example are a loading station 33, in which empty capsules 37 are inserted into a capsule holder 38, a filling station 34, at which the capsules 37 are filled with the powdered product 3, and a removal station 35, at which the filled capsules 37 are provided or removed . Further stations 32 are shown here by way of example, which, however, are not to be explained in more detail here. At least one dosing roller 1 described is provided at the filling station 34, with which a powdered product 3 from a product supply 28 is filled into the capsules 37. Two different degrees of fineness of the powdered product 3 are shown here as an example. The metering roller described is suitable for powdered products 3 with different degrees of fineness.

The 2 and 3 show a metering roller 1 of the prior art in contrast to the metering roller 1 described here according to the invention. The metering roller 1 described here according to the invention is then in the 4 , 5 and 6 explained in more detail. First, the metering roller 1 of the prior art is described here, and based on this, the metering roller according to the present invention is then explained.

The metering roller 1 is formed from a roller tube 39 which has an outer roller surface 6 and in which there are metering chambers 9 distributed around the circumference, in which a metered subset 4 of the powdered product 3 can be received. A plurality of metering chambers 9 are preferably arranged one behind the other along the axis 40 of the metering roller 1, which extends here into the plane of representation. The metering roller 1 can be rotated with a roller direction of rotation 27 in order to convey the subsets 4 of the powdery product 3 located in the metering chambers 9 . Above the metering roller 1 is a product supply 28 of the powdered product 3, which is designed here like a kind of funnel, which feeds the powdered product 3 to the metering chamber 9 located in the receiving position 44.

A dosing chamber 9 is arranged directly below the product store 28 so that the dosing chamber 9 can be filled with the powdered product 3 from the product store 28 . This position on the metering roller 1 is referred to here as the pick-up position 44 . In an interior space 7 of the metering roller 1 there is a compressed air supply 8 with which it is possible to pressurize the metering chambers 9 with compressed air, with an overpressure or an underpressure being able to be provided depending on the situation. A row of dosing chambers 9 arranged one behind the other along the axis 40 is connected to the compressed air supply 8 via a compressed air duct 17 . Branch channels 18 branch off from the compressed air channel 17 to the dosing chambers 9 , which connect the compressed air channel 17 to the dosing chambers 9 in each case. However, the branch channels 18 and the compressed air supply 8 are each separated from the dosing chambers 9 by a filter element 10 . The filter element 10 is permeable to compressed air, but not to the powdered product. The filter element 10 extends along an inner surface 41 of the metering roller 1 or the roller tube 39.

The filter element 10 is braced on the inner surface 41 at each connection point between a dosing chamber 9 and a branch channel 18 in such a way that a compressed air-tight connection between the compressed air supply 8 and the dosing chamber 9 exists. A compressed-air-tight connection means here that compressed air which is intended to flow from the branch channel 18 into the metering chamber 9 also passes completely through the filter element 10 into the metering chamber 9 and does not unintentionally pass into the interior 7 of the metering roller 1. A sealing element 19 is arranged between the filter element 10 and a component with the compressed air channel 17 and the branch channels 18 for this fluid-tight bracing. The component with the compressed air channel 17 is designed as a clamping element 11, which can be pressed outwards with a clamping mechanism 16 (not shown in detail here).

The situation in the area of dosing chamber 9 is in 3 still enlarged. The filter element 10 is braced between the sealing element 19 and the inner surface 41 of the roller tube 39 of the roller. The sealing element 19 is an annular sealing element 19 which is arranged as a continuation of the branch channel 18 . The clamping element 11 presses on the sealing element 19 . The clamping element 11 also provides the compressed air channel 17 and the branch channels 18 .

Based on 2 the use of the metering roller 1 for metering partial quantities 4 of the powdered product 3 will now also be explained. These explanations are based on the use of the metering roller 1 according to the invention (as shown in 4 , 5 and 6 is described) transferrable.

In the 2 dosing chamber 9 located at the top is connected to the product supply 28 . A vacuum generator 24 is connected to the compressed air channel 17 that is connected to this dosing chamber 9 . A subset of the powdered product 3 is drawn from the product supply 28 into the dosing chamber 9 by the negative pressure. Due to the filter element 10, the powdered product 3 stops at a lower end of the dosing chamber 9 and does not get into the compressed air supply (the branch duct 18, the compressed air duct 19, etc.).

The metering roller 1 now rotates in the designated roller direction of rotation 27 until the respective subset 4 of the powdered product 3 is in the lower position. This lower position is referred to as delivery position 45 here. Here, via the compressed air channel 17 and the branch channel 18, an overpressure generation 25 acts on the dosing chamber 9. The overpressure conveys the subset 4 of the powdered product 3 out of the dosing chamber 9 into a target container 2.

There is preferably a controller 26 which controls the described components (vacuum generation 24, overpressure generation 25, direction of rotation 27 of the rollers, etc.). The controller 26 can also be set up mechanically/automatically or electronically, pneumatically or in any other way.

In 3 it can be seen that the inner surface 41 of the roller tube is also curved in the area of the dosing chamber 9 . The filter element 10 and the sealing element 19 follow this curvature. It is also shown here that the surface of the clamping element 11 lying against the sealing element 19 has a curvature adapted to the inner surface 41 . This curvature makes sealing with the sealing element 19 more difficult. For a good seal it is advantageous if the shape of the sealing element 19 is adapted to the shape of the curvature. Such an adapted sealing element 19 has a specified alignment that must be observed when installing such a sealing element 19 . Overall, it is expensive to achieve the desired sealing effect in this embodiment. In addition, the curved shape of the area of the filter element 10 that delimits the dosing chamber 9 favors the deformation of the filter element 10 under the action of the air pressure and the powdered product 3. The curvature of the filter element 10 can, for example, completely or partially turn inwards. This results in a change in the volume of the dosing chambers 9, so that the accuracy of maintaining the subsets 4 provided is impaired or limited. This phenomenon is referred to here as the membrane effect 29 in the 3 is also shown.

The 4 , 5 and 6 now show the metering roller 1 according to the invention in contrast to the previously based on the 2 and 3 described dosing roller of the prior art, with features that have not changed compared to the prior art also refer to the explanations 2 and 3 is referenced.

In the case of the dosing roller 1 according to the invention, the powdered product 3 also travels via the dosing chambers 9 from a product store 28 in a receiving position 44 to the delivery position 45, in which the subsets 4 of the powdered product 3 are delivered to a target container 2 . In the area of the receiving position 44 it is additionally shown here that the dosing of the subsets 4 can be supported by a stripping off of surplus powdery product 3 by means of a stripping element 46 .

The metering roller 1 according to this embodiment has a roller body 5 which, compared to the roller tube 39, has a more complex shape, especially in the interior 7, which takes on more functions within the metering roller 1 than the roller tube 39 in the embodiment according to FIG 4 . Below is mainly on the differences between the metering of the prior art according to the 2 and 3 the dosing roller according to the 4 , 5 and 6 To be received.

The dosing roller according to 4 , 5 and 6 also has the dosing chambers 9 accessible from the roller outer surface 6 for receiving defined subsets 4. The interior space 7, which has a central area 13 and grooves 14 extending outwards away from the central area 13, is designed differently. The central area 13 and the grooves 14 together form a cross section of the inner space 7 which extends along the axis 40 of the metering roller 1 .

The compressed air supply 8 is in the variant described above according to 2 and 3 and the variant described here according to the 4 , 5 and 6 constructed very similarly with the difference that the clamping elements 11 (which contain the compressed air channels 17 and the branch channels 18) are each guided within the grooves 14 here. Otherwise, the explanation for the 2 and 3 referred. The grooves of the roller body 5 each form a guide for guiding the clamping elements 11 . The clamping elements 11 can be guided in the radial direction in the grooves 14 when the clamping mechanism 16 is actuated in order to clamp the clamping elements 11 outwards.

Otherwise, the compressed air supply 8 essentially has the same functions. A vacuum generator 24 is set up to suck the powdered product 3 into a dosing chamber 9 at a specific position (here in the dosing chamber 9 arranged at the top) by means of a vacuum. The negative pressure generator 24 is also set up to maintain a negative pressure in order to keep the powdered product 3 in the dosing chamber 9 . This happens both in that the negative pressure is transmitted to the metering chamber 9 with the compressed air supply 8 . An overpressure generator 25 is set up to convey the powdered product 3 out of a dosing chamber 9 at a specific position (here the dosing chamber 9 arranged below). This takes place in that the excess pressure is transmitted to the dosing chamber 9 with the compressed air supply 8 . The compressed air supply 8, the negative pressure generator 24 and the positive pressure generator 25 preferably together form a compressed air supply system.

The interaction of the clamping elements 11 with the grooves 14 and the other components is in 5 shown in detail. The 5 shows a section of the display in 4 . to recognize NEN is first the groove 14, which has a 15 base. The base 15 of the groove 14 provides a planar contact surface 12 for the filter element 10 . Contrary to the according 2 and 3 through the inner surface 41 of the roller tube 39 formed curved surface, the planar contact surface 12 is flat. It can, for example, have been produced with a milling head, with which the groove 14 with the base 15 was milled into the roller body 5 . Another possibility for producing grooves 14 is spark erosion. Here, too, the clamping element 11 provides the compressed air channel 17 with the branch channels 18 . The sealing element 19 is preferably inserted into a recess 22 provided for this purpose on the clamping element 11 . The recess 22 can, for example, form a peripheral shoulder on the branch channel 18, in which the sealing element 19 is inserted. The recess 22 ensures an exact position of the sealing element 19 relative to the clamping element 11 .

The filter element 10 is braced between the sealing element 19 and the planar contact surface 12 on the base 15 of the groove 14 . Circumferential sealing surfaces 20 run around the dosing chamber 9 or around the connection from the dosing chamber 9 to the branch channel 18 . The sealing surfaces 20 form sealing surface regions 21 . On the sealing surfaces 20 or the sealing surface areas 21, the filter element 10 and the planar contact surface 12 or the filter element 10 and the sealing element 19 are pressed against one another with a uniform sealing force. A particularly good sealing effect can be achieved in this way. The dosing chamber 9 , the filter element 10 , the sealing surface areas 21 , the sealing element 19 and the branch channel 18 are preferably each formed rotationally symmetrically around a dosing chamber axis 42 of the respective dosing chamber 9 . All elements (in particular the filter elements 10 and the sealing element 19) are preferably designed to be flat. In particular, the filter element 10 is not curved in the position between the planar contact surface 12 and the sealing element 19, but is also flat. Thus, a small deformation of the filter element 10 under the influence of the acting pressure and under the influence of the powdery product 3 can be achieved. In particular, the basis of 3 explained membrane effect 29 can be completely or at least partially avoided.

6 shows a longitudinal section through the inventive, in 4 and 5 metering roller 1 shown in cross section. The roller body 5 with the roller outer surface 6, the metering chambers 9 and the interior 7 with the central region 13 and the grooves 14, which are each cut here, can be seen. It can first be seen that the dosing chambers 9 are arranged one behind the other along the axis 40 in a plurality of ring-shaped areas 43, with each ring-shaped area 43 being assigned to a dosing station that takes the powdery product 3 from a product supply 28 (not shown here) into a target container 2 promotes.

The clamping elements 11 are in each case located in the grooves 14 . The clamping elements 11 are clamped in the grooves 14 with the clamping mechanism 16 . The clamping mechanism 16 here has conical sliding surfaces 30, with which an axial clamping movement is converted into a radially acting clamping movement, which pushes the clamping elements 11 outwards. The compressed air channels 17 with the branch channels 18 towards the individual dosing chambers 9 are provided in the clamping elements 11 . The sealing elements 19 provided at the connection from the branch channels 18 to the dosing chambers 9 and the filter element 10 can also be seen.

Reference List

1

dosing roller

2

target container

3

powdered product

4

subset

5

roller body

6

roller outer surface

7

inner space

8th

compressed air supply

9

dosing chamber

10

filter element

11

clamping element

12

flat contact surface

13

central area

14

groove

15

Reason

16

clamping mechanism

17

compressed air duct

18

branch ducts

19

sealing element

20

sealing surface

21

sealing surface area

22

recess

23

contraption

24

vacuum generation

25

overpressure generation

26

steering

27

roller direction

28

product stock

29

membrane effect

30

conical sliding surfaces

31

carousel

32

station

33

loading station

34

filling station

35

extraction station

36

carousel direction of rotation

37

capsule

38

capsule holder

39

roller tube

40

axis

41

inner surface

42

dosing chamber axis

43

annular area

44

recording position

45

delivery position

46

scraper element

QUOTES INCLUDED IN DESCRIPTION

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Patent Literature Cited

• EP 3608233 B1 [0002]

Claims (11)

Metering roller (1) for filling a target container (2) with a portion (4) of a powdered product (3) to be metered, having a roller body (5) with one of the roller outer surfaces (6) and an interior space (7) in which there is a compressed air supply (8) and dosing chambers (9) for the dosed uptake and delivery of the powdered product (3), which each form connections between the roller outer surface (6) and the interior (7), the compressed air supply (8) being set up to the dosing chambers (9) to generate either a negative pressure or an overpressure in order to convey the powdery product into the dosing chambers (9) or to discharge it from the dosing chambers (9), the dosing chambers (9) being supplied by the interior (7) and the compressed air supply (8) are delimited by filter elements (10) permeable to compressed air, which are clamped between clamping elements (11) and planar contact surfaces (12) of the roller body (5) surrounding the dosing chambers (9). Dosing roller (1) after claim 1 , wherein the interior (7) of the roller body (5) has a central area (13) and grooves (14) extending from the central area (13) to the outer surface (6) of the roller, the dosing chambers (9) each having connections between a Form base (15) of the grooves (14) and the roller outer surface (6) and the planar contact surfaces (12) on the base (15) of the grooves (14) surround the dosing chambers (9). Dosing roller (1) after claim 2 , wherein the grooves (14) each form guides for the clamping elements (11). Metering roller (1) according to one of the preceding claims, wherein a tensioning mechanism (16) is arranged in the interior (7) and is designed to tension filter elements (10) with the tensioning elements (11) in the grooves (14). Metering roller (1) according to one of the preceding claims, wherein the clamping elements (11) each contain at least one compressed air duct (17) of the compressed air supply (8) and each have a plurality of branch ducts (18), which each have a compressed air conducting connection of the compressed air duct (17) provide to the dosing chambers (9). Dosing roller (1) after claim 5 wherein sealing elements (19) can be clamped between the clamping elements (11) and the planar contact surfaces (12) together with the filter elements (10) in such a way that an airtight connection from the branch channels (18) to the dosing chambers (9) is provided. Dosing roller (1) after claim 6 , wherein the filter elements (10) are braced between the sealing elements (19) and the planar contact surfaces (12). Dosing roller (1) after claim 6 or 7 wherein the sealing elements (19) consist of an elastic material and have a sealing surface (20) and the filter elements (10) can be clamped between the planar contact surface (12) and the roller body (5) and the sealing surface (20) in such a way that the sealing elements (19) are deformed and apply a uniform sealing force to the filter element (10) in a sealing surface area (21) running annularly around the dosing chamber (9). Metering roller (1) according to one of Claims 6 until 8th , wherein the sealing elements (19) are attached to the clamping elements (11). Metering roller (1) according to one of Claims 6 until 9 , Recesses (22) being provided on the clamping elements (11), in which the sealing elements (19) are inserted. Device (23) for filling a powdery product (3) having at least one dosing roller (1) according to one of the preceding claims for filling the powdery product (3) into the target container (2).

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