Abstract:
A rotary press comprises a press frame and a rotor arranged thereon. The rotor has a die plate, an upper punch receiver receiving upper punches, a lower punch receiver receiving lower punches, an upper cam that guides the upper punches, and a lower cam that guides the lower punches. A rotor drive can drive the rotor rotationally. Within at least one dosing station, material is filled into receivers of the die plate for pressing. An upper pressing station has an upper pressing roller and a lower pressing station has a lower pressing roller. Coupling means couples at least one drive that operates the rotary press to the rotor such that, with movement of the at least one drive, the rotor is raised out of its operating position and into a removal position where the rotor can be removed out of the press frame in a lateral direction.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to German patent application no. 10 2014 106 405.4, filed May 7, 2014, and German patent application no. 10 2014 113 211.4, filed Sep. 12, 2014, each of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     The invention relates to a rotary press. 
     BACKGROUND 
     A rotary press may comprise a press frame and a rotor arranged thereon having a die plate, an upper punch receiver for receiving a plurality of upper punches, a lower punch receiver for receiving a plurality of lower punches, an upper cam for carrying upper cam elements for guiding the upper punches, and a lower cam for carrying lower cam elements for guiding the lower punches. A rotor drive can drive the rotor rotationally. Material to be pressed is filled into receivers of the die plate at one or more dosing stations. At least one upper pressing station has at least one upper pressing roller, and at least one lower pressing station has at least one lower pressing roller. 
     SUMMARY 
     With rotary presses it is occasionally necessary to remove the rotor out of the press frame for maintenance or changing operating parameters. In an arrangement as described above, the rotor must be lifted from the rotor shaft connected to the rotor drive. Then, the rotor can be removed laterally from the press frame. Separate lifting equipment (e.g., a lift truck) that has drives and transmission suitable for lifting the rotor is used. This is time-consuming, which impacts the availability of the rotary press. Furthermore, this lifting equipment is expensive with respect to cost and required space. It has only limited cleaning possibilities and to some extent requires additional media that must be provided and maintained, for example for supplying hydraulics. 
     In contrast, the teachings herein provide a rotary press where the rotor can be removed from the press frame in a simple manner. 
     For a rotary press as described herein, coupling means is provided with which at least one drive of the rotary press, used for operating the rotary press, can be coupled to the rotor in such a manner that with a movement of the at least one drive, the rotor is raised out of its operating position occupied for producing pressings. The rotor is raised into a removal position. The rotor can be removed from the removal position out of the press frame in a lateral direction. 
     The die plate of the rotor has recesses in which the powder filled in the dosing station is pressed into pressings, in particular tablets. The die plate can be comprised of ring segments or be integrally annular. The rotary press comprises, in particular, a plurality of upper punches received in the upper punch receiver rotating with the rotor, and a plurality of lower punches received in the lower punch receiver rotating with the rotor. The upper and lower punches interact with the recesses in the die plate for producing the pressings. The rotary press additionally comprises, in particular, upper cam elements for guiding the upper punches held at the upper cam, and lower cam elements for guiding the lower punches held at the lower cam. 
     The coupling means may be provided via which a drive of the rotary press that is otherwise present and used for operating the rotary press can be used for lifting the rotor into the removal position thereof. The coupling means couples this drive to the rotor. In the removal position, the rotor can be lifted from the rotor shaft connected to the rotor drive such that it can be removed out of the press frame in the lateral direction, for example using an appropriate removal device. Here, however, no lifting forces must be exerted by the removal device for lifting the rotor. Accordingly, this removal device does not require a lift drive. Also by means of the coupling means, the rotor can also be lowered out of the removal position thereof into the operating position thereof, using the drive for the rotary press that is already used and present for operation. This can occur without attaching additional components to the drive. 
     The upper drives of the rotary press and/or lower drives can be used for raising, or respectively lowering, the rotor. In a particularly advantageous manner, for lateral removal of the rotor, the movements of stations of the rotary press into a parked position that are required anyway can be used, thereby resulting in additional time savings and thus an increase of the availability of the rotary press. In this way, the set-up of a separate lifting device is omitted. Cleaning is facilitated because no additional drive parts are required in the press space. In addition, the maintenance of additional equipment, in particular an external lift device, is omitted. The costs are reduced and the operation is facilitated because the rotor can be moved into the removal position thereof completely automatically without manual intervention. 
     According to one design, the at least one drive that can be coupled by the coupling means to the rotor for operating the rotary press can be at least one dosing station drive that serves for adjusting the height of the at least one dosing station. 
     For removing the rotor, generally the upper pressing stations are moved upward and the lower pressing stations are moved downward, so that the rotor can be removed out of the press frame between the upper and lower pressing rollers. In a particularly advantageous manner, therefore the at least one drive that can be coupled via the coupling means to the rotor for operating the rotary press can be at least one pressing station drive that serves for adjusting the height of the at least one upper and/or at least one lower pressing station. The pressing station drives of the rotary press are capable of applying the forces required for lifting the rotor. The movement of the pressing stations into the respective parked position thereof required anyway for removing the rotor is advantageously also used for raising the rotor into the removal position. With a plurality of upper or a plurality of lower pressing station drives, in particular, all upper pressing station drives and/or all lower pressing station drives can be coupled via the coupling means to the rotor for raising (or lowering) the rotor. 
     The coupling means can comprise at least one tractive element fastened on one side to at least one upper pressing station, in particular to at least one fork plate supporting an upper pressing roller, and on the other side to the rotor, in particular the upper cam or the upper punch receiver of the rotor. At least one tractive element can be fastened in each case to each upper pressing station drive, in particular to each upper fork plate. The tractive elements are then all fastened additionally to the rotor. During a movement of the upper pressing station drive, or respectively the upper pressing station, into the parked position, the tractive elements also move the rotor upward into the removal position. 
     The at least one tractive element can be attached to a support attachment piece arranged at the upper cam. In the removal position of the rotor, a removal arm of a removal device can engage at the support attachment piece for lateral removal of the rotor from the press frame. Such a support attachment piece can be designed mushroom-shaped for example. 
     The at least one tractive element can be releasably fastened to the at least one upper pressing station and/or releasably fastened to the rotor. Further, the at least one tractive element can be at least one pull rod. 
     The coupling means, according to a further design, can comprise at least one push element. The push element may be fastened at one side to at least one lower pressing station, in particular to at least one fork plate supporting a lower pressing roller, and on the other side to the rotor, in particular to the lower cam or the lower punch receiver of the rotor. Further, at least one push element can be attached to each lower pressing station drive if a plurality of lower pressing station drives is present. The push elements are then all attached also to the rotor. In this case, the lower pressing station drives, with an upward movement via the push elements, push the rotor also upward into the removal position thereof. The at least one push element can be at least one push bracket. The high forces are transferred safely via such a push bracket. 
     In turn, the at least one push element can be releasably fastened to the at least one lower pressing station and/or releasably fastened to the rotor. 
     Alternatively, the rotary press comprises a rotor shaft coupled on one side to the rotor drive and on the other side to the rotor, wherein the coupling means comprises a lifting collar, mounted rotatably surrounding the rotor shaft and resting against the rotor, in particular the lower cam or the lower punch receiver of the rotor, and at least one engagement element at the lifting collar that, during rotation of the lifting collar, can be selectively brought into and out of engagement with at least one lower pressing station. With an engagement between the at least one lower pressing station and the at least one engagement element, the lifting collar and thus the rotor are raised by an upward movement of the at least one lower pressing station. By rotating the lifting ring, or respectively the lifting collar, with a plurality of lower pressing station drives, the engagement element or possibly the plurality of engagement elements, can be brought into engagement with all lower pressing station drives, in particular in each case a fork plate of the lower pressing station drives holding the lower drive rollers. 
     According to a further design, the coupling means may comprise a rotatably mounted lifting ring, at which at least one engagement element is provided. Through rotation of the lifting ring, the at least one engagement element can be brought selectively into or out of engagement with the rotor. With an engagement between the rotor and the at least one engagement element, the lifting ring and thus the rotor can be raised through a movement of the at least one lower pressing station. 
     According to a further design, the coupling means may comprise at least one lift lever coupled on one side to at least one lower pressing station drive and on the other side to the rotor, in particular to the lower cam or to the lower punch receiver of the rotor. The rotor, with a downward movement of the at least one lower pressing station by the at least one lower pressing station drive, is raised by the at least one lift lever. In turn, with a plurality of lower pressing station drives, in each case at least one lift lever can be coupled to each lower pressing station drive, in particular in each case to a fork plate of the lower pressing station drive holding the lower pressing roller. The lift levers are then in turn all coupled to the rotor. With this design, a lifting mechanism in the manner of a rocker can be realized using the lifting lever. A downward movement of the lower pressing station drive into the parked position causes a raising of the rotor into the removal position. Due to the lifting mechanism, a transmission ratio can be realized that realizes short movement paths and movement times on the pressing station side. The at least one lifting lever can be coupled to the rotor, via at least one suitable element, for example at least one lifting rod engaging at the rotor, in particular at the lower cam or at the lower punch receiver of the rotor. 
     The at least one pressing station drive can be a spindle drive. Spindle drives can transfer high forces in a precise manner. They typically have in each case a spindle and a spindle nut, wherein the spindle or the spindle nut are generally driven rotationally by an electric motor. The spindle or the spindle nut is thereby moved axially. The lift lever is then coupled to, in each case, the axially moving component, namely the spindle, or respectively the spindle nut. For instance, the spindle of each of the lower pressing station may drive, then actuate the lift mechanism via the lift lever, which engages at the rotor and raises, or respectively lowers, the rotor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Example embodiments of the invention are explained in the following in more detail using the drawings in which: 
         FIG. 1  is a perspective view of a part of a rotary press according to a first exemplary embodiment of the teachings herein; 
         FIG. 2  is a partially transparent, perspective view of a part of a rotary press according to a second exemplary embodiment of the teachings herein; 
         FIG. 3  is a perspective view of a part of a rotary press according to a third exemplary embodiment of the teachings herein; 
         FIG. 4  is a perspective view along with an enlarged sectional representation of a part of a rotary press according to a fourth exemplary embodiment of the teachings herein; 
         FIG. 5  is a perspective view along with an enlarged sectional representation of a part of a rotary press according to a fifth exemplary embodiment of the teachings herein; and 
         FIG. 6  is a partially transparent, perspective representation of a part of a rotary press according to a sixth exemplary embodiment of the teachings herein. 
     
    
    
     The same reference numbers refer to the same objects in the figures unless indicated otherwise. 
     DETAILED DESCRIPTION 
       FIG. 1  shows an upper carrier plate  10  and a lower carrier plate  12  of a press frame of a rotary press. A rotor  16  of the rotary press is arranged on a rotor shaft  14  connected to a rotor drive. The rotor  16  comprises a die plate  18  and an upper punch receiver  20  for receiving a plurality of upper punches and a lower punch receiver  22  for receiving a plurality of lower punches. Additionally, the rotor  16  comprises an upper cam  24  for carrying upper cam elements for guiding the upper punches, and a lower cam  26  for carrying lower cam elements for guiding the lower punches. 
     The rotary press further comprises two pairs of upper pressing stations and two pairs of lower pressing stations. The two upper pressing stations each comprise an upper pre-pressing station having an upper pre-pressing guide housing  28 . The two lower pressing stations each comprise a lower pre-pressing station having a lower pre-pressing guide housing  30 . Additionally, the upper pressing stations each have an upper main pressing station with an upper main pressing station guide housing  32 . The two lower pressing stations likewise each comprise a lower main pressing station with a lower main pressing guide housing  34 . The upper pressing stations each further comprise an upper pre-pressing roller  35  and an upper main pressing roller  36 . Similarly, the lower pressing stations each have a lower pre-pressing roller  37  and a lower main pressing roller  38 . The pressing rollers  35 ,  36 ,  37 ,  38  are each held by an upper fork plate  40 , or respectively a lower fork plate  42 . The elements thus far have been used in some known rotary presses. 
     As seen in  FIG. 1 , pull rods  44  are attached with one end to each of the upper fork plates  40  supporting the upper main pressing rollers  36 , which are attached at the other end to the upper cam  24  of the rotor  16 . Thus, a total of four pull rods  44  are provided, of which only two can be seen in  FIG. 1 . The upper and lower pressing stations of the rotary press each comprise an upper, or respectively lower pressing station drive, each comprising an upper drive motor  46 , or respectively a lower drive motor  48 , seen in  FIG. 2 . The drive motors  46 ,  48  act on the upper and lower pressing stations via gears  50 ,  52 , respectively. For reasons of clarity, the pressing station drives are not shown in  FIGS. 1 and 3 to 5 . The upper and lower pressing stations can be moved upward and downward, respectively, via the upper and lower pressing station drives.  FIG. 1  shows the rotor  16  in the operating position thereof, in which it produces pressings. The rotor  16  can now be raised, through upward movement of the upper pressing station drives and thus the upper pressing stations via the pull rods  44 , into the removal position thereof, in which it can be removed laterally out of the press frame, for example by means of a removal device. In order to have sufficient space for removing the rotor, the lower pressing stations can simultaneously be moved downward into a parked position by means of their pressing station drives. Thus, in a simple manner, the upward movement in this case of the upper pressing station drives into their parked position is used to simultaneously lift the rotor  16  into the removal position thereof. 
       FIG. 2  shows a further example embodiment of a rotary press according to the teachings herein. The rotary press shown in  FIG. 2  corresponds largely to the rotary press shown in  FIG. 1  but differs in that instead of the pull rods  44  attached at the upper cam  24 , pull rods  54  are provided each of which is attached at one side to the upper fork plates  40  of the upper pressing stations and on the other side to a central support attachment piece  56  on the upper cam  24 . This support attachment piece  56  can be formed mushroom-shaped for example, and serves to engage a removal device for lateral removal of the rotor  16 , in the removal position thereof, out of the press frame. Such a mushroom-shaped attachment piece  56  can be seen for example in  FIG. 3 . The attachment piece  56  can be provided with all example embodiments. In addition, the rotor  16  shown in the example in  FIG. 2  is raised into the removal position thereof by an upward movement of the upper pressing station drives, as was explained already with reference to  FIG. 1 . 
       FIG. 3  shows a further example embodiment of a rotary press according to the teachings herein. In this case, the upper carrier plate  10  and the upper pressing stations are not shown for illustrative purposes. Again, the example embodiment shown in  FIG. 3  corresponds largely to the example embodiment of  FIG. 1 . However, instead of the pull rods  44  connected to the upper pressing station in  FIG. 1 , the example embodiment of  FIG. 3  includes a total of four push brackets  58 , of which in each case one side is attached on the lower pre-pressing guide housings  30  and the lower main pressing guide housings  34  of the lower pressing station, and the other side engages at the bottom side of the rotor  16 , in particular at the lower punch receiver  22 . Through a movement of the lower pressing stations, in particular the lower pre-pressing guide housings  30  and the lower main pressing guide housing  34 , the rotor  16  can be moved out of the operating position thereof into the removal position thereof via the push bracket  58 . 
       FIG. 4  shows a further example embodiment of a rotary press according to the teachings herein that corresponds largely to the example embodiment from  FIG. 1 . As in  FIG. 3 , the upper carrier plate  10  and the upper pressing stations are not shown for illustrative purposes. With the example embodiment shown in  FIG. 4 , a lifting ring  60  is mounted rotatably on the lower carrier plate  12 , and engages at the lower cam  26  of the rotor  16  via a plurality of lifting rods  62 . In the example shown, four engagement rods  64  are mounted pivotably at the lifting ring  60 . The engagement rods  64  start from the surface of the lifting ring  60  to extend upward and at the free ends thereof are angled outward. As seen in particular in the enlarged representation  66  in  FIG. 4 , the engagement rods  64  can be brought into engagement with the fork plates  42  of the lower pressing stations by suitable pivoting, in particular they can be pivoted over the upper side of the fork plates  42 . If in this engagement setting, the lower pressing stations are moved upward via the lower pressing station drives, they via the engagement rods  64  take along the lifting ring  60 , which in turn via the lifting rods  62  takes the rotor  16  upward into the removal position. The engagement rods  64  can be brought out of engagement with the fork plates  42  of the lower pressing stations by a corresponding return pivoting. 
       FIG. 5  shows an alternative implementation. This example embodiment corresponds largely to the example embodiment shown in  FIG. 4 . In contrast to  FIG. 4 , however, there is no lifting ring  60  with lifting rods  62  and engagement rods  64 , rather there is a lifting collar  68  surrounding the rotor shaft  14  rotatable manually or by means of a suitable drive. The lifting collar  68  in the example shown has four engagement brackets  70 , which extend outward starting from the upper side of the lifting collar  68 . As seen in  FIG. 5 , again in an enlarged sectional representation  67 , the engagement brackets  70  can be brought into engagement with the fork plates  42  of the lower pressing stations by suitable rotation of the lifting collar  68 , in particular in such a manner that they cover the upper side of the fork plates  42  in a manner similar to the engagement rods  64  provided with the example embodiment of  FIG. 4 . Analogous to the example embodiment of  FIG. 4 , with an upward movement, the lower pressing stations, via the engagement brackets  70 , take along the lifting collar  68  and thus the rotor  16  into the removal position. 
       FIG. 6  shows a further example embodiment, which again corresponds largely to the example embodiment shown in  FIG. 4 . In contrast to the example embodiment of  FIG. 4 , with this example embodiment there is a rotatable lift ring  71 . The lift ring  71  can be rotated both manually and also by means of a suitable drive. With the example embodiment of  FIG. 6 , lift levers  72  are provided coupled on one side to the lower pressing stations and on the other side to the rotor  16 . In the example shown, in each case a spindle  73  of a lower pressing station spindle drive engages at one end one of a lift lever  72 , wherein the spindle  73  and the lift lever  72  are coupled together in an articulated manner. The other end of the lift lever  72  is connected, also in an articulated manner, in each case to a lifting rod  74  acting on the rotatable lift ring  71 . By rotating the lift ring  71 , it can be brought selectively into engagement with the rotor  16  or out of engagement with the rotor  16 . With a downward movement of the lower pressing station drives, in particular the spindles  73 , the lift ring  71  and, with appropriate engagement with the rotor  16 , the rotor  16  move upward into the removal position via the lift levers  72  and the lifting rods  74 . 
     It is understood that with all example embodiments, the rotor can be raised both out of its operating position into its removal position, as well as lowered out of its removal position into its operating position. All coupling means described above between the pressing station drives and the rotor can be permanently provided on the rotary press, or provided temporarily, thus removably, such that they are installed only for a raising or lowering of the rotor on the rotary press.