Rotary press

A rotary press wherein the dosage drive and the compression roller drive have identical installation means, the stand has an upper and a lower accommodation platform and the accommodation platforms have identical accommodation means for the installation means on the sides facing each other, which are in a coincident arrangement with respect to each other.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not applicable.

BACKGROUND OF THE INVENTION

Rotary presses serve for the manufacture of tablets above all, in the pharmaceutical field for instance. However, they can be used everywhere where articles pressed from powder material are desired, for instance in the field of candies and foodstuffs, for washing agents and so on.

The basic construction of a rotary press is always the same. It has a rotor, which is driven around a vertical axis by a suitable drive motor. The rotor contains an upper and a lower punch guide, which receive upper and lower punches, respectively. The punches co-operate with bores of a die plate, which is arranged between the punch guides. Material which is to be compressed is supplied to the die bores, and heads of the upper and lower punches, respectively, co-operate with compression rollers in compression stations in order to press the compression material in the die bores together. The compression material is fed into the die bores via a suitable filling station. Outside of the compression stations, the punch heads are guided by suitable radial cam sections. For instance, a radial filling cam section is associated to the filling station, which provides that the lower punches project into the die bores for a preset extent in the region of the filling station. This extent determines the filling volume, and with this also the weight of the pressed tablet. In the strip-off region, in which the compressed tablets are stripped off from the upper side of the die plate, a radial cam provides that the lower punches are lifted so far that the pressed articles can be captured and shoved off by the stripping device. Furthermore, a corresponding radial cam section provides for the upper punches that sufficient space remains for the filling station for filling in compression material again.

Such a rotary press is commonly known. For instance, it is made reference to DE 10 2004 040 163 A1, the entire contents of which is incorporated herein by reference.

It is further known to form single layer or multilayer compressed articles with the described rotary press. For the single layer compressed article, one filling- and dosage station and one pre-compression and one main compression station are usually provided, each at a time with an upper and a lower compression roller. In a rotary press for producing two-layer tablets, only one compression station is usually used for the compression of the first layer. Subsequently, the material for the second layer is filled in with the aid of a second filling- and dosage station. The definite pressing together of the two layers takes then place by a pre-compression station and a main compression station. When three or more layers are formed into a tablet, the sequential arrangement of filling- and dosage stations and compression stations is correspondingly continued.

However, it is also known to increase the production capacity with single layer pressed articles in that two or more filling- and dosage stations are provided, to each one of which at least one compression station is arranged downstream. In this way, the production capacity can be doubled or multiplied at equal rotational speed of the rotary press.

The user of a rotary press decides which kind of rotary press is necessary or optimum for his/her production. When he/she produces single layer tablets in small batches, he/she will chose a relatively small rotary press, which has only one filling- and dosage station and two compression stations. When he/she desires to produce greater batches, according to the conditions he/she will prefer a rotary press which has two filling- and dosage stations, each one with two compression stations at a time. With such a rotary press, even a double layer tablet can be produced, when it is suitably remodelled. When the user desires to produce very large batches or three-layer tablets, he/she will provide three filling- and dosage stations, each one with two compression stations at a time. For each one of the described kinds of rotary presses, the stand has to be dimensioned correspondingly, and the press manufacturer has to provide different construction series for the rotary presses in order to fulfil the different user requirements.

The present invention is based on the objective to provide a rotary press which fulfils the different user requirements with a minimal expenditure of production and which can be remodelled to another usage form with little expense, even retroactively.

BRIEF SUMMARY OF THE INVENTION

In the rotary press according to the invention, the stand has an upper and a lower accommodation platform. The at least one dosage drive and the at least one compression roller drive have identical installation means. The accommodation platforms have identical accommodation means for the installation means on the sides facing each other. Thus, it is irrelevant whether a dosage drive or a compression roller drive is fixed on an accommodation means of a platform. With two or more compression stations and filling- and dosage stations, either a single layer tablet or a two layer or a multilayer tablet can be produced with an identically formed platform, for instance.

Preferably, the pitch circles of the lower and the upper accommodation platform on which the filling- and dosage stations and the compression stations are arranged have the same diameter.

The rotary press according to the present invention can be used for small batches, but however, by building in further filling- and dosage and compression stations, it can also be used for the production of single layer tablets in big batches. In addition, it may be remodelled for two layer tablets or for three layer tablets, when accommodation means for three dosage stations and four compression stations are provided on the platform.

With the aid of the present invention, compression stations and filling- and dosage stations can be installed in the rotary press even in an exchangeable manner. Setting up for single layer, two layer and multilayer operation is possible in a simple way with the same machine stand; also remodelling at the user. Through this, the usage flexibility of a rotary press concept is significantly increased. The production expenditure for such a flexible rotary press is relatively small, in particular in the light of the manifold usage possibilities, which are required for one rotary press at a time. For the different kinds of usage described above, the number of press constructions is minimised. For instance, a single layer as well as a multilayer tablet can be formed with one construction, provided the corresponding stations are at hand.

According to one embodiment of the present invention, the lower accommodation platform has seven accommodation means. The accommodation means can be formed by identical receptacle openings in the lower and the upper accommodation platform, respectively.

The radial dosage- and fillings cams, respectively, for the filling- and dosage station, as well as the compression rollers, are adjustable in the height by means of a suitable dosage- or compression roller drive, respectively. According to one embodiment of the present invention, the upper and the lower accommodation platform have cavities, in which are arranged at least one dosage- and at least one compression roller drive, respectively. According to a further embodiment of the present invention, compression roller drive and dosage drive are identical and form a unit with a compression roller and a filling- and dosage station, respectively. Therefore, it is irrelevant in the installation whether a compression station or a filling- and dosage station is installed on an accommodation means of the accommodation platform. No special construction or reassembly of the rotary press is therefore necessary for this purpose in order to design the rotary press in the desired fashion. It is to be understood that the cavities in the accommodation platforms are easily accessible for installation procedures.

As already mentioned, upper and lower punches co-operate with corresponding different radial cam sections outside of the compression stations. The radial cam sections can be installable on the upper and the lower accommodation platform. The assigned radial cam sections can be fixed on sites of the platform which were envisioned previously. In a replacement of a filling- and dosage station by a compression station, the associated radial cam sections may be replaced also, without that an installation possibility on the radial cam carriers has to be provided in advance. The installation possibilities for the changeover of the different radial cam sections are already existing.

DETAILED DESCRIPTION OF THE INVENTION

A rotary press afterFIG. 1has a stand, which has a lower accommodation platform10and an upper accommodation platform12. The platforms10,12are frame-like and contain plural cavities. The accommodation platforms10,12are polygonal in their outline, octagonal in the present case, wherein supports14,16attached on opposing sides at the outside keep the accommodation platforms10,12in the predetermined distance from each other. The supports14,16are supported on lower supports20via damping elements18, which on their part stand on a base platform22. The base platform22stands on the ground via feet24.

The lower accommodation platform10has a central pillar26, on which a rotor28is mounted rotatably around a vertical axis. The rotor28contains an integrated electric drive motor (not shown). The kind of the motor which is built in is disclosed in DE 10 2004 040 163 A1, for instance, the entire contents of which is incorporated herein by reference. The rotor28is composed of an upper and a lower punch guide, which are not separately featured here. The punch guides guide upper punches30and lower punches32in suitable guide bores. The compression punches30,32co-operate with die bores of a die plate36(shown only in an adumbrated manner).

Radial cams are also assigned to the compression punches30,32, which are incorporated in the upper and lower radial cam carriers, respectively, on the accommodation platforms10,12. They are omitted for reasons of better depiction. As can be recognised further, the proper processing region, i.e. the die plate and the greatest part of the punch guides, is sealingly surrounded by a casing38, so that dusty compression material does not arrive in the exterior.

InFIG. 1one recognises that lower compression roller arrangements are installed on the lower accommodation platform10at40or42and44, respectively. The compression rollers46of this compression roller arrangement co-operate with the heads of the lower punches32. Correspondingly, upper compression roller arrangements with a compression roller54are installed on the lower side of the upper accommodation platform12at48,50and52. The compression rollers54co-operate with the heads of the upper punches30which face them. Each compression station is made up of a roller arrangement, for example40and roller46,42and roller46and44and roller46, making up three lower compression stations. The upper compression stations are formed of48,50and52, each combined with a roller54. The coincident pairs of upper and lower compression stations40and48,42and50, and44and54, form three pairs of compression stations. However, even further compression stations may be provided, which are not shown in the present case. Yet, they are indicated with respect to the upper compression rollers at56,58.

InFIG. 1, a dosage- or filling station60is also provided, which is arranged on the lower accommodation platform10. Details of the filling station are not shown.

As can be further seen fromFIG. 1, the lower compression roller arrangements40,42and44as well as the dosage station60are fixed on the accommodation platform10with the aid of suitable plates62. The attachment takes place by screwing for instance.

Compression roller drives for adjusting the compression rollers46,54in the height belong to the compression roller arrangements. For instance, the same are depicted at64for the upper accommodation platform12, and at66and68for the lower accommodation platform10. The installation of these drives takes place in cavities of the accommodation platforms10,12. Even the dosage station60has a drive for the radial dosage cam, which is also housed in a cavity of the accommodation platform10and can be recognised at68.

The attachment of the compression roller arrangements on the accommodation platforms10,12takes place on a pitch circle, wherein both pitch circles can have the same diameter. In addition, the accommodation means on the platforms10and12, respectively, are identical, so that for instance the dosage station60can be set on the position of the compression roller arrangement42,40or44. Vice versa, the compression roller arrangement42can be set on the position of the dosage station60, for instance. In an arrangement or an exchange of the described kind, the associated drives have to be added also, of course. For this reason, the cavities in which the drives64or66or the dosage drive68are accommodated have identical accommodation means, so that only a minimum expenditure for the production, the installation or the replacement is necessary. No particular measures for the respective kind of use have to be taken on the stand. With a predetermined number of accommodation means in the platforms10,12, a number of different applications of the rotary press can be realized.

By means of theFIGS. 2 and 3, the multifunctional usability of the rotary press afterFIG. 1will be explained. InFIG. 2, an accommodation platform10ais shown, which corresponds to the lower accommodation platform10according toFIG. 1, for instance. It is provided with seven identical receptacle openings80, which are situated on a pitch circle82which is concentric to the pitch circle of the die bores, as the same are indicated at84. The receiving bores have an approximately equal distance from each other, and only in the region86they have a greater distance. This region is the stripping region for the compressed articles which are pushed out. It is indicated at70inFIG. 1by a chute.

Each one of the receptacle openings80is suited to accommodate either a lower compression roller drive or a dosage drive. InFIG. 2, the accommodation of dosage drives is indicated with D, and the accommodation of a pre-compression roller drive with1and that of a main compression roller drive with2. One recognises that single layer pressed articles can be produced with the aid of such an arrangement, wherein the production capacity at equal rotational speed of the rotor is twice that of a rotary press which has only one dosage station and two compression stations.

When a double layer tablet is to be produced inFIG. 2, the compression roller2according toFIG. 2is replaced by a dosage station D after the first dosage station D, for instance. Alternatively, the corresponding pre-compression station is omitted. It is to be understood that a three layer tablet can be produced with the arrangement ofFIG. 2also, namely by providing three filling- and dosage stations and four compression stations. It is to be understood that a filling device belongs to a dosage drive too, which must be installed in addition, so that filling- and dosage station are composed of the dosage drive and the filling device.

It is further to be understood that the upper accommodation platform, as indicated inFIG. 1, can also have receptacle openings80, and that in another arrangement of filling- and dosage stations and compression roller arrangements in the lower accommodation platform10a, this leads to a corresponding change of the position of the compression roller arrangements in the upper accommodation platform.

InFIG. 3is indicated a lower accommodation platform10b, which has eleven identical receptacle openings88. Again, they are arranged on a pitch circle82. In the shown case, a five layer tablet is produced. A compression station D is followed by a precompression- and a compression station1and2, respectively. If only a single layer or a two layer tablet is to be produced instead, dosage station and compression roller arrangement have to be arranged correspondingly in order to obtain the desired result.

InFIG. 4, the compression roller46afterFIG. 1is exemplified in a perspective view. It is adjusted in the height by a suitable drive- and gearbox unit100. The unit100has a flange102, which is screwed together with a flange104, a guide106for the compression roller46is attached on the flange104. The flanges102,104are attached to the associated accommodation platform, here the accommodation platform10, in a receptacle opening as shown inFIG. 1,2or3. All the compression rollers as depicted inFIG. 1can be provided with an identical drive- and gearbox unit100and they can form a unit in order to install them in a suitable receptacle opening of the accommodation platform.

Even inFIG. 5, the drive- and gearbox unit100afterFIG. 4is depicted in a perspective view. Its flange102is screwed together with a flange108, which has the same dimensions as the flange104afterFIG. 4. The flange108has a guide110for a radial dosage cam element112, which is attached to a rod114, which is in turn guided in the guide110. The drive- and gearbox unit100can effect a height adjustment of the rod114, and with it of the radial dosage cam element112, in order to adjust the dosage in a not shown filling- and dosage station.

One recognises by means of theFIGS. 4 and 5that the compression rollers and the radial dosage cam elements have identical drive- and gearbox units and that they form a unit with the same, in order to attach them afterFIG. 1in a desired receptacle opening in the platform10or12, respectively.