Patent Application
20180086017
The invention relates to a rotary press comprising at least one compression roll station mountable on a support plate, and method for attaching and detaching the compression roll station.
It is known that rotary presses comprise a rotatably driven rotor which carries a plurality of stamp pairs, wherein each stamp pair is formed by an upper stamp and a lower stamp which can be adjusted relatively to one another. The rotor comprises a matrix disk in which matrix openings are provided at regular intervals on a circular ring and in which the upper and the lower stamps either cooperate directly or they comprise insert pieces shaped like casings and which are designated as matrices. The material to be processed or, for example, to be pressed to a tablet is filled into these matrices or matrix openings by a filling device. If a stamp pair moves by the rotation of the rotor into the area of the matrix or matrix opening filled in this manner, the two stamps are moved toward one another by control cams and move into the area of a compressing roll station in which they are pressed against one another. As a result, the material in the matrix or in the matrix opening is compressed, for example, to a tablet. After the conclusion of the pressing process, both pressing stamps are moved upward and the tablets are ejected from the matrix opening or the matrix.
The pressing force is transferred according to the method course shown, which is used in particular to produce a so-called single-layer tablet, by the pressure rolls onto the pressing tools, wherein in particular the upper stamp and the lower stamp are designated as pressing tools. For example, rotary presses are known in the prior art in which these pressure rolls are fastened separately from each other, for example, above on the headpiece and below on a support plate in the base of the rotary press. This separate arrangement of the two pressure rolls has the disadvantage that the pressing forces produced during the pressing procedure are transferred directly into the upper as well as into the lower machine housing. The machine housing of the rotatory press consists, for example, of a machine base on which the carrier plate for the lower compression roll is located as well as of a head piece on which the upper compression roll is attached. The headpiece and the machine base are connected to one another, for example, by 2 to 4 corner struts, wherein the headpiece, the corner struts and the support plate in the base of the rotatory press must be manufactured to be very massive and with a high material cost in the separate arrangement of the pressure rolls in order to withstand the pressure forces. This results in a high weight of the rotatory press and in high acquisition costs for a potential purchaser.
Furthermore, it turned out that the machine housing of the rotary presses with a separate positioning of the upper and lower compression roll radiates significant body sound oscillations into the air in the audible range. At rather high speeds of the rotor of the rotary press, sound pressure levels of more than 100 dBA can be produced. These disadvantages are overcome by making available compression roll stations which are in particular suitable for receiving a compression roll pair consisting of an upper and a lower compression roll. Compression roll stations are known in the prior art, for example from the documents DE 197 05 092 C1, DE 197 05 094 C1 and DE 10 2009 020 196 A1.
DE 197 05 092 C1 discloses a compression roll unit for a rotary press, wherein the compression roll unit comprises a frame which can be stopped on the rotary press and which can receive two bearing blocks which for their part receive the compression rolls. The frame is formed from a guide column and the bearing blocks are arranged on upper and lower compression roll receivers which are guided by the guide column and can be adjusted against one another.
DE 197 05 094 C1 discloses a compression roll press which comprises a compression roll unit consisting of a massively constructed guide column with a cylindrical cross section. The compression roll press according to DE 197 05 094 C1 comprises a particular massive bend-resistant and twist-resistant base plate for receiving the rotor, the drive and the compression roll unit, wherein the baseplate is received by an elastic support of a base frame of the rotary press.
In the rotary presses according to DE 197 05 092 C1 and DE 197 05 094 C1 a fastening flange shaped like a truncated cone is fastened inside the lower end of the guide column, wherein a traction anchor is screwed into the fastening flange in which penetrates a neck attachment on the lower end of the fastening flange shaped like a truncated cone which can move inside a an oblong hole introduced into the mass of the baseplate of the rotary tablet press, wherein the cited fastening means is a component of the baseplate. The traction anchor is penetrated underneath the baseplate by a wedge which can be detached by a spindle, wherein these components are constituents of the baseplate.
A rotary press is disclosed in DE 10 2009 020 196 A1 with a compression roll unit which is fastened to a support device, in particular at least to a support plate by a holding device in a detachable manner, wherein the support device comprises several holding devices of the same type. In particular, DE 10 2009 020 196 A1 discloses that the holding devices are constructed in the support plate.
EP 2 065 176 A2 discloses a frame comprising several platforms for receiving and storing different stations of a rotary press and several supports. The supports are attached in pairs to the frame, wherein the frame is fastened on a base platform. The supports are not constructed like columns and do not directly contain the compression roll receptacles but rather surround the entire inner construction of the rotary press like a frame. The base platform is constructed to be less massive than the massive base plates of DE 197 05 092 C1, DE 197 05 094 C1 and DE 10 2009 020 196 A1. The supports are attached to the base platform by lower supports as holding devices, wherein the lower supports are provided with damping elements. The latter are arranged to lie between the base platform and the supports. In particular, no recesses in the thin base platform are disclosed in EP 2 065 176 A2 with which the lower supports cooperate.
EP 2 110 231 discloses a modularly constructed rotary tablet press, wherein individual modules can be changed and/or removed inside the rotary tablet press. The rotary tablet press comprises, for example, two filling stations, two dosing stations and two compression stations, wherein a filling shoe of the filling stations comprises an agitation wing for thoroughly mixing the material to be compressed and finished, pressed tablets are removed by an ejector from the pressing area of the matrix.
The compression roll stations known from the prior art comprise, for example, carrier columns which are present arranged outside of the partial circle of the rotatable rotor of the rotary press. The carrier columns contain guidance and adjustment means in their interior for the upper and the lower compression roll as well as path measuring and pressure measuring systems. The compression rolls are located in a working position of the pressure roll station exactly on a partial rotor circle so that the upper compression roll acts on the upper stamp head and the lower compression roll acts on the lower stamp head. If the rotor with the compression tools is rotating, the latter are drawn by the torque applied by the rotary drive through the upper and the lower compression rolls of the stationary compression roll station, as a result of which the pressing force is transferred from the compression rolls by the stamp heads onto the material to be compressed in the matrix and in this manner a solid tablet is preferably produced from the loose material to be pressed.
Modern rotary presses are distinguished in that starting from a base arrangement for producing single-layer tablets by the addition of appropriate additional modules, a retrofitting of the base press can take place in that even two-layer tablets, three-layer tablets or even jacket core tablets can be pressed. These additional modules can be, for example, compression stations or preliminary pressing stations.
In addition, it turned out that the quality of one-layer tablets can be improved if a ventilation of the material to be pressed takes place in a so-called preliminary pressing station before the actual tablet production by the compressing of the material located in the matrix or in the matrix opening. It turned out that it is desirable for the user of a rotary press that the individual compression stations can be arranged inside the rotary press at different positions and that a more rapid and simpler rearrangement and changing of position of the individual compression stations should be possible in order to ensure a flexible use of the rotary press in different operating states.
It is customary in conventional rotary presses known in the prior art that the carrier plate of the rotary press comprises a plurality of recesses, wherein each of these recesses is equipped with a tightening device with which a compression station can be fastened at the position given by the recess (cf., for example DE 197 05 092 C1, DE 197 05 094 C1 or DE 10 2009 020 196 A1). Furthermore, it is known that such tightening devices present in recesses of a carrier plate are expensive components in a rotary press. It is unsatisfactory in the fastening systems previously known in the prior art that as a rule more tightening devices are present in the carrier plate than actually documented compression station positions. As a consequence, tightening devices are disadvantageously kept which as a rule are not all used at the same time. This unnecessarily makes the so-called multi-functional rotary presses more expensive on account of the greater number of tightening devices in comparison to the visited tightening positions.
Starting from this prior art, the problem of the present invention consists in making available a rotary press and methods for fastening and loosening a compression roll station of a rotary press which does not have the deficiencies and disadvantages of the prior art and in particular make possible an economical, low-maintenance fastening of compression roll stations which are easy to operate at different positions on the carrier plate of a rotary press.
The problem is solved according to the invention by a rotary press, in particular for producing tablets, with at least one compression roll station, wherein the at least one compression roll station comprises a holding device and a carrier plate of the rotary press comprises at least one recess for receiving the holding device of the compression roll station. It was totally surprising that a compression roll station can be made available which comprises a holding device in such a manner that, in particular, only as many holding devices have to be made available for the operation of a rotary press as compression stations used. This is advantageously achieved in that the holding device is a component of the compression roll station and is integrated in it.
In the sense of the present invention the concept “compression roll column” or “compression roll station” denotes one of various station types in the area of rotary tablet presses, in particular those in whose active area the compressing of the usually powdery material to solid pellets, for example, tablets, takes place. Compression roll stations are preferably constructed like columns or have guidance profiles, wherein the columns or profiles used can receive the preferably two compression rolls. It is preferred that the pressing force for producing the pellets is transferred by the compression rolls onto the pressing tools and therefore onto the material to the compressed, wherein in particular the upper stamp and the lower stamp are designated as pressing tools.
It is preferred that compression roll stations are present arranged on a carrier plate of the rotary press, wherein such compression roll stations are known in the prior art which are fastened on the carrier plate by holding devices which are components of the carrier plates. It was completely surprising that a compression roll column can be made available with the present invention which ensures a good stability and an especially reliable operation of the compression roll station, wherein in the compression roll station of the invention the holding device for the fastening on the carrier plate is a component of the compression roll station and is not present inside the carrier plate.
It is preferred that the holding device according to the invention is a tightening device for fixing the compression roll station in recesses in the carrier plate of the rotary press. At least individual components of the holding device or the entire holding device can preferably be moved in a vertical direction along an imaginary central axis inside the compression roll station. As a result, in the sense of the invention a high-and-low movement or an up-and-down movement of the holding device or of its component is preferably carried out. As a result, it is advantageously made available that the holding device can be present, for example, completely or partially inside the compression roll station. If the holding device is completely present inside the compression roll station, the compression roll column is preferably closed flush downwardly so that no components project outwardly. This advantageously makes possible a shifting or a movement of the compression roll station on the carrier plates of the rotary press.
Furthermore, it is preferred that the holding device is present arranged in a production position at least partially in the recesses of the carrier plate. In the sense of this invention a production position is preferably the position in which the compression roll station assumes when the rotary press is operated in order to manufacture, for example, tablets. The holding device lies preferably in a rotor replacement position completely inside the compression roll station, wherein such a position of the compression roll station is designated as the rotor replacement position which the compression roll assumes if a rotor replacement of the rotary press is taking place. It is required for this that compression roll stations can be moved and/or shifted on the carrier plate. This is advantageously achieved in that the holding device of the invention is completely present inside the compression roll station so that advantageously no components of the holding device project out of the compression roll station.
The invention differs from that which was previously technically customary by making available a rotary press in which the holding device for the fastening of the compression roll station on a carrier plate of the rotary press is a component of the compression roll station, because the professional world previously started from the fact that holding devices had to be a component of the carrier plate. It was completely surprising that a compression roll station can be made available which has so much free volume in the lower area facing the carrier plate and a holding device can be received preferably completely inside the lower area of the compression roll station.
Furthermore, it is preferred that the recesses of the carrier plate are formed by openings and/or bores whose diameters correspond to the diameter of the holding device of the compression roll stations. In particular, the recesses are suitable for receiving the holding device of the compression roll station. In the fastening mechanisms known in the prior art for compression roll stations the fastening means, for example, tightening devices, are is a rule inside the recesses within the carrier plate of the rotary press. This is in particular a disadvantage because these tightening devices provided in the carrier plates of the rotary press are expensive to construct and/or require their own media supply lines.
It turned out that the media supplying of the tightening devices, when they are provided inside a compression roll station, surprisingly take place by the already present connections of the compression roll station.
In another preferred embodiment of the invention the holding device comprises locking elements which form in their entirety an annular locking unit with a variable diameter. It is preferred that the locking element preferably comprises 2 to 20 locking units. The selection of this number is not an arbitrary selection but rather corresponds to the result of previous tests which showed that a locking unit with preferably 2 to 20 locking elements is surprisingly especially simple to manufacture and contributes to the stability of the fastening of the compression roll station on the carrier plate which was not to be expected.
It is preferred that the locking elements comprise a circumferential spring. In the tightened state the circumferential spring preferably exerts an inwardly directed force on the locking elements of the locking unit. The direction “inward” preferably means in the sense of the invention that the locking elements are pressed in the direction of a central axis of the compression roll station. This central axis is shown, for example, in
It is especially preferred that the individual locking elements can be moved outward by pressure pins which transfer the up-and-down movement of an actuating rod with a variable diameter onto the locking elements so that the diameter of the locking unit is, for example, enlarged. Furthermore, it is preferred that the individual locking elements of the locking unit cooperate in the extended state with projections inside the recesses of the carrier plates of the rotary press, wherein these projections are preferably designed in such a manner that they make possible a reliable fastening of the compression roll station in the extended state of the locking elements. It is preferred in the sense of the invention that these projections are preferably designated as a clamping collar or clamping flange, wherein the cited concepts are used synonymously.
A recess in the carrier plate preferably comprises such a projection in the upper area facing the compression roll station, wherein the projection preferably represents an area of the recess with a reduced diameter. This area can also be preferably designated in the sense of the invention as a narrow position. A locking unit with a variable diameter can surprisingly be made available which has a diameter in the non-tightened state which is smaller than the diameter of the narrow position, as a result of which the holding device can be introduced in a simple and non-complicated manner into the recess in the carrier plate. Furthermore, it was surprising that after the introduction of the holding device into the recess the diameter of the locking element can be increased by the cooperation of an actuation rod with the locking elements in such a manner that the holding device can no longer be removed, for example, by being pulled upward out of the recess of the carrier plate.
In particular, a stable tightening of the individual locking elements on the inner walls of the recess of the carrier plate is ensured by the preferred enlargement of the diameter of the locking element, as a result of which an especially stable fixing of the compression roll station inside the recess of the carrier plate is achieved which acts in several spatial directions.
In another preferred embodiment of the invention the locking unit is designed to be adjustable in height, wherein the ability to be adjusted in height can be realized by an actuating rod which is arranged in the middle or centrally in the annular locking unit. “Adjustable in height” means in the sense of this invention that the locking unit is designed to be movable in particular in the vertical direction and can be moved up or down. The spatial direction “down” stands in the sense of this invention from the perspective of the compression roll station preferably for a movement of the locking unit in the direction of the carrier plate of the rotary press when the compression roll station is present arranged in a customary manner on the carrier plate of the rotary press. Such a movement is preferably designated in the sense of this invention as a “downward movement” of the locking unit or of the actuating rod. It is especially preferred that the locking unit moves into the recesses of the carrier plate by a downward movement of the holding device.
The spatial direction “upward” preferably designates in the sense of this invention an upward movement of the holding device into the inner space of the compression roll station, that is, preferably in the direction of the compression rolls preferably belonging to the compression roll station. This is especially true when the holding device is present in the recesses of the carrier plate. The movement of the locking unit, that is, its ability to be adjusted in height, is preferably achieved with an actuating rod. The previous comments regarding the spatial directions preferably refer to the compression roll station. It is preferred that from the perspective of the carrier plate the spatial direction “upward” is characterized by a movement in the direction of the compression roll station and/or of the rotary press. Therefore, the upper side of the carrier plates preferably faces the rotary press and the compression roll station.
It is preferred that the actuating rod is arranged in the middle or centrally in the compression roll station. “In the middle” means in the sense of this invention that the actuating shaft is arranged substantially axially symmetrical to a central axis of the compression roll station, wherein the concept “substantially” is not unclear for the average person skilled in the art because he knows that compression roll stations have as a rule a rectangular or circular base surface, wherein a symmetrical axis can be determined in the middle for such basic shapes.
In another preferred embodiment of the invention the activating rod has a diameter which tapers to the bottom end of the activating rod. It is preferred that the actuating rod comprises an upper and a lower area, wherein the upper area has in particular a circular base surface which corresponds to the inside diameter of a compression roll station. It is preferable that the inner area of the compression roll station, which preferably serves to receive the actuating rod and whose diameter preferably corresponds to the diameter of the actuating rod, is preferably formed by a hydraulic cylinder, wherein this hydraulic cylinder preferably comprises a bipartite piston consisting of an inner and of an outer piston. The movement of the actuating rod is preferably realized by at least this hydraulic connection.
Furthermore, it is preferable that the actuating rod consists of a lower area which consists at first of a tapering area and merges at the lower end of the activating rod into an area with a constant radius, wherein this constant radius of the lower area is smaller than the diameter of the actuating rod in the upper area. The design and the shape of actuating rod result in particular from the figures representing the invention.
In another embodiment of the invention the diameter of the locking unit is maximum in a first position in minimum in a second position, wherein the diameter of the locking unit can be varied by an activating rod. As can be seen in
A so-called “unlocked” state is preferably characterized in that the actuating rod is preferably also pressed vertically upward by the upward movement of a pneumatic piston, as a result of which an unlocking of the locking elements is achieved. It is preferable if the locking elements also engage in the unlocked state into the projection of the recess of the carrier plate. The unlocked state is shown, for example, in
The locking elements are preferably relieved by a preferably graduated raising of the actuating rod. For example, it is provided in the first position that the pressure which the locking elements exert, for example, on the inner wall of the recesses in the carrier plate is reduced. In this position the compression roll station can be advantageously rotated about its own axis, wherein a shifting or removal of the compression roll station from the recess can be effectively prevented, for example, in that the locking unit continues to be located below a clamping collar in the recess of the carrier plate. As a result, an undesired sliding off or an undesired change of position of the compression roll station on the carrier plate is surprisingly completely excluded.
A second position in the sense of this invention is preferably present after an upward movement of the actuating rod if the area of the actuating rod is present at the level of the pressure pins which are arranged between the locking elements and the actuating rod, which area has a reduced diameter in comparison to the upper area of the actuating rod. It is preferable that in this second position no direct contact is given between the actuating rod and the pressure pins of the locking elements so that the locking elements are preferably no longer pressed onto the inner walls of the recesses. It is especially preferred that in this position the locking elements are released and pressed by the spring power of the circumferential spring into a position with a minimum diameter. This position is preferably designated in the sense of the present invention as the second position or “released” position of the locking unit. Tests have shown that the compression roll station in this position can move the holding device of the invention in a surprisingly simple manner and without undesired mechanical contacts out of the recesses of the carrier plate. This is advantageously possible because the locking unit in the release state has its minimum diameter which corresponds in particular to the diameter of the narrow position formed by the projection. This state of the locking unit with minimum diameter is preferably designated as the released state and is shown in
In another embodiment of the invention the locking elements of the locking unit lie pressed in the first position on an inside wall of the recess of the carrier plate. It is preferable that the inside walls of the recess are formed by a straight wall. In the first position or spread position of the locking elements the fastening of the compression roll station preferably takes place by the spreading pressure which the locking elements exert on the inner wall of the recess. However, it can also be preferred that the inner wall of the recess is provided, for example with a projection, wherein the inside diameter of the recess in the area of this projection is smaller than in the remaining area of the recess and this projection is also preferably designated in the sense of the invention as a clamping collar or clamping flange. It was completely surprising that an effective fastening of the compression roll station inside the recess is made possible by providing projections inside the recesses.
In another preferred embodiment of the invention the diameter of the locking unit in the second position is smaller than the diameter of the recesses of the carrier plate. It is preferred that the locking elements leave the spread position (first position) based on the spring force exerted by the circumferential spring. As a result, the diameter of the locking unit is advantageously reduced and the locking elements are no longer in contact with the inner wall of the recess. In another preferred embodiment of the invention the holding device is completely present inside the compression roll station. It is preferred that this position is described in the sense of the invention as the “rotor replacement position”. The holding device preferably does not project past the lower closure of the compression roll station, as a result of which the ability to shift and pivot the compression roll station is advantageously ensured. It was completely surprising that a holding device with a locking unit can be designed to be so compact that it can be completely received by the compression roll station and closes flush in the lower area with the compression roll station. This is advantageously achieved by the cooperation and intermeshing of the components of the holding device with the receiving compression roll station, which brings it about that the holding device can be introduced into the limited available space in the compression roll station.
In another preferred embodiment of the invention the movement of the actuating rod takes place hydraulically, pneumatically, mechanically and/or electromechanically. A hydraulic movement can, for example, be transferred by a hydraulic cylinder, wherein a hydraulic cylinder in the sense of the invention is preferably a working cylinder operated with liquid. It is preferred that in the hydraulic cylinder the energy from the hydraulic liquid which is supplied from a hydraulic pressure storage or a hydraulic pump is converted into a readily controllable force acting in a straight line.
A pneumatic cylinder in the sense of the invention is preferably a working cylinder operated by compressed air which is preferably used to pneumatically move the actuating rod. Electrical cylinders are in the sense of the invention preferably adjusting units which are operated by electromotor in which can move a push tube in and out in a linear manner. It is preferred that the drive of an electrical cylinder takes place by an electromotor which is preferably coupled to a transmission. The moving in and out of the push tube preferably takes place by the right-handed rotation or left-handed rotation of the motor. An electrical cylinder can preferably also be provided with a standing tube for guiding and stabilizing the push tube. Electric cylinders are preferably suited for forces of attraction and/or of pressure.
It is advantageous when using the cited cylinder types that their components can be combined in a surprisingly compact manner. Furthermore, the cited cylinders can be integrated into the total construction of the compression roll station in a surprisingly space-saving manner.
It is preferred in the sense of the invention that the movement of the movable components of the holding device is realized by a first and a second hydraulic connection and a pneumatic connection, wherein the pneumatic connection is preferably arranged in the carrier plate of the rotary press. It is preferred that the diameter of the locking unit is then advantageously reduced when the actuating rod is moved upward by the pneumatic connection and the locking elements are no longer held in the spread position. Furthermore, it is preferred that the holding device comprises a hydraulic cylinder with a cylinder bottom and a cylinder cover, wherein the cylinder bottom of the hydraulic cylinder forms the upper closure of the of the holding device, which closure faces the compression roll station, and the cylinder cover closes the compression roll station downward on the side facing the carrier plate.
Furthermore, it is preferred that the holding device comprises a bipartite piston consisting of an inner piston and an outer piston, wherein the inner piston comprises the locking elements, which form in their entirety the circular locking unit with a variable diameter. It is furthermore preferred that the inner piston, the outer piston and the actuating rod of the holding device are constructed to be movable and that the movement of the movable components of the holding device takes place by a first and a second hydraulic connection and a pneumatic connection. It is furthermore preferred that the cylinder bottom comprises a guide for the actuating rod.
Furthermore, it is provided in a preferred embodiment that the holding device comprises at least one pressure spring arranged between the inner and the outer piston and which is capable, on account of the exerted spring pressure, of reducing the diameter of the locking unit in a surprising manner. As a result, the complete receiving of the holding device inside the compression roll station is advantageously made possible. It is furthermore preferred that the holding device comprises plate springs, as a result a non-positive connection of the locking elements to the inner wall of the recess of the carrier plate is achieved.
In another aspect the invention relates to a method for fastening a compression roll station of a rotary press comprising the following steps:
After the termination of this method the locking elements of the locking unit are present in a spread position, wherein the locking elements are pressed against the inner walls of the recesses.
In another aspect the invention relates to a method for loosening a compression roll station of a rotary press, comprising the following steps:
The invention is described in detail using preferred exemplary embodiments and the following figures. In particular, the
As
The locking elements (10) are provided with a circumferential annular spring (11) which exerts a spring force on the locking elements (10). This spring force is directed in particular inward, that is, for example in the direction of the actuating rod (13) centrally arranged inside the compression roll station (1). The spring force has the result that the locking elements (10) move inward, as a result of which the diameter of the locking unit (37) is reduced when the pressure pins (12) are not pressed outward by an actuating rod (13).
The upper closure of the holding device (21) is formed by a cylinder bottom (5). The upper area of the holding device (21), which is not designed to be movable and is in the lower area of a compression roll station (1), comprises hydraulic connections (17, 18) which cooperate with different hydraulic pistons (8, 9). These two hydraulic pistons (8, 9) form an inner (8) and an outer piston (9) of a bipartite hydraulic cylinder (3). Pressure springs (6) are arranged in the transition area between the hydraulic pistons (8, 9). The hydraulic pistons (8, 9) can be moved by the hydraulic connections (17 and 18). The hydraulic cylinder (3) comprises a cylinder cover (4) as the lower closure of the compression roll station (1) and comprises a cylinder bottom (5) as the upper closure of the holding device. Seals (20) close the various work areas inside the hydraulic cylinder (3) against each other.
| Number | Date | Country | Kind |
|---|---|---|---|
| 15161246.2 | Mar 2015 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/056784 | 3/29/2016 | WO | 00 |
