Not applicable.
Not applicable.
A typical tablet press is a so-called rotary press. If it is dealt with tablet presses above and below, of course such rotary presses are also meant by which arbitrary other pressed articles can be produced, like in the foodstuff-, washing agent- or other fields, for instance.
The typical construction of a rotary press is to mount a rotor in a stand, wherein the rotor has bores for the guides of upper and lower punches, between which a die plate is arranged with die bores with which the punches co-operate during the circulation of the rotor. The compression punches are actuated by compression rollers in compression stations, and guided outside of the same via control cams.
The rotor is driven by a suitable drive motor. In this context, it has also become known to integrate an electric motor into a rotor, wherein the rotor of the electric motor lies in the outside and is in engagement with the inner wall of the press rotor. The press rotor is mostly formed in one piece. Even the die plate can be formed in one piece with the rotor.
However, from DE 101 59 114, the entire contents of which is incorporated herein by reference, it has also become known to compose the die plate from individual segments. The segments are secured in a suitable way in the rotor. From the cited document, it has also become known to press the segments against an abutment surface of the rotor with the aid of compression set screws.
The present invention is based on the objective to form a tablet press with a segmented die plate, such that preset stressing forces can be applied to the die segments in a simple way.
In the present invention, at least one drive device for the clamping elements is arranged in the stand of the tablet press, with a drive element adjustable in the height, which can be selectively set into engagement with the lower end of the clamping element.
Like in the state of the art, the clamping element is guided through a passage in the rotor, and it can be set into engagement to bear against the bottom side of the assigned die segment. A drive device, which may work electrically, hydraulically or pneumatically, is designed to apply an axial pressing force on the clamping element either directly or indirectly, in order to exert a preset clamping force on the assigned die segment by the clamping element. The drive device is stationarily arranged in the stand, due to which the rotor must be adjusted by a corresponding rotation such that the drive element and the clamping element are aligned with each other when the clamping element is to be actuated.
With the aid of the present invention, the clamping of the die elements can be made to work automatically, and it is not necessary to apply a preset force on the clamping element by an operator, for instance with the aid of a torque wrench. When clamping the segments manually, the operator must apply the necessary clamping or releasing force, respectively, by himself. For this reason it might occur that the necessary tension is not guaranteed. When the tabletting tools are built in, the manual clamping or releasing can be performed only with difficulty or not at all.
Advantageous embodiments of the present invention are indicated in subclaims.
One embodiment of the present invention provides that the rotor is surrounded by a stationary shell, which co-operates sealingly with the rotor and forms a processing space, and that the lower ends of the clamping elements are situated outside of the processing space. The processing space is realised such that it essentially surrounds the rotor, but leaves the upper and the lower regions of the rotor open. Therefore, the processing space is relatively small, but through this it permits to clean all the parts facing the processing space, without that a disassembly of punches or the like is necessary. Therefore, according to a further embodiment it is also advantageous when the clamping elements are sealingly guided into the processing space through the passages. On the contrary, the drive device is situated outside the processing space. In the remodelling, it has therefore not to be worked in a narrow space. Even the portions of the clamping elements facing the processing space can be cleaned in the processing space, along with the cleaning of the processing space, and thus they have not to be disassembled.
Different embodiments are conceivable how to bring the clamping elements axially into abutment with the segments of the die plate. One embodiment of the present invention provides that a spindle drive is assigned to the lower end of the clamping element, and a rotational drive device is provided whose lathe spindle can be coupled with the spindle drive. In this context, it is provided in a further embodiment of the present invention that the drive device is connected to a lifting device in the stand. However, a rotational drive is also conceivable whose lathe spindle is axially adjustable in order to be set into engagement with the spindle drive of the clamping element.
A die plate is made up of plural segments, of five segments for instance. One embodiment provides that two clamping elements are provided for each segment. Through this, uniform clamping of the segments can be obtained, in particular when parallel drive devices are operated at the same time according to a further embodiment of the invention.
In fact, it is conceivable to select the number of the drive devices in the stand to be equal to the number of the clamping elements. The expenditure for this is relatively high. According to one embodiment of the present invention, a smaller number of drive devices can therefore be used also, when a control device for the rotational drive of the rotor is designed such that the rotor can be positioned in preset rotational positions, in order to align the drive element with the clamping element.
Examples of the realisation of the present invention are explained in more detail by means of drawings in the following.
While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated
The rotor 10 receives a die plate which is composed of individual segments 20.
As comes out from
At 32 in
The rotor after
In
In
In
A threaded spindle 66 is screwed centrally into an internally threaded bore 68 of the punch 60. The threaded spindle 66 is supported via a radial flange 70 on the inner step. At the lower end, the threaded spindle 66 has a hexagon head 72, which is situated inside a lower recess 74 of the liner 62.
When the threaded spindle 66 is rotated via the hexagon head 72, the punch 60 is axially shifted through this. In a lateral, radially passing slit 76 of the liner 62, there is a head 78 of a screw 80 which is radially screwed into the punch 60. The head 78 can move axis parallel in the slit 76 to a certain amount; however, it prevents a rotational movement of the punch 60.
In
In
The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.
This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
Number | Date | Country | Kind |
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10 2008 006 045 | Jan 2008 | DE | national |
Number | Name | Date | Kind |
---|---|---|---|
7118367 | Hinzpeter et al. | Oct 2006 | B2 |
7553147 | Kramer | Jun 2009 | B2 |
Number | Date | Country | |
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20090191297 A1 | Jul 2009 | US |