Rotary tablet press, and pressure rail as a curved portion in the control curve for punching the rotor in a rotary tablet press.

Abstract

The present invention relates to a rotary tablet press, which comprises a rotor 10, at least one filling station 3, at least one compression station 5, and at least one discharge station 6 distributed along the rotation path of the rotor 10, and a fixed control curve for controlling the movement of an upper punch and a lower punch along the rotation path, the control curve having a plurality of curved portions, at least one curved portion for the lower punch forming a pressure rail at least partially inclined in the rotational direction in the compression station region. The present invention proposes that, in order to improve the compressibility of the raw material into tablets, at least one pressure rail 50 for the lower punch in the compression station 6 has at least a partially curved upper surface 54. The present invention also relates to a pressure rail 50 designed to correspond as a curved portion of the control curve. According to a further inventive concept, it is proposed that in the compression station, a pressure roller is omitted and only a pressure rail is used.

Description

Technical Field

[0001] The present invention relates to a rotary tablet press, comprising a housing, an upper punch guide ring which is disposed in the housing in a drivable manner and has a guide for an upper punch, a lower punch guide ring which has a guide for a lower punch, and a die disk which is disposed between the punch guide rings and has a die for manufacturing tablets or other pellets in the die by means of an upper punch and a lower punch, a rotor; at least one filling station distributed on a rotation path of the rotor for pellets manufactured in the die, at least one compression station, and at least one discharge station; and fixed control curves for the upper punch and the lower punch for controlling the operations of the upper punch and the lower punch along the rotation path, wherein the control curves have a plurality of curve portions distributed on the rotation path, and at least one curve portion for the lower punch forms a pressure rail having a pressure rail body including an upper surface in a compression station region, and the upper surface is designed to at least partially rise between a first position of the upper surface and a second position spaced from the first position by a predetermined arc angle in the circumferential direction of the pressure rail body in the rotation direction.

Background Art

[0002] Rotary tablet presses, or rotary tablet presses, are primarily used to manufacture pellets such as single-layer or multi-layer pharmaceutical tablets and detergent tablets from powdered starting materials. The tablet press features a rotating die disc, which typically contains multiple interchangeable dies, allowing for the production of different tablets / pellets with the same press without changing the die disc. Each die has an upper and lower punch, the vertical movement of which is guided by corresponding guide rings and controlled by fixed control curves or guide slots. To increase the number of dies in the die disc, it is known that the die disc can be composed of multiple segments detachably mounted on the tablet press rotor, with each segment having only a single hole instead of interchangeable dies (this hole determines the size and shape of the tablet produced by the die disc). The rotating path includes at least one filling station, at least one compression station, and at least one discharge station. At the filling station, the material to be pressurized, particularly powder, is filled into the die. In the pressing or compression station, the material is pressurized using upper and lower punches, and in the discharge station, the finished pressurized pellets / tablets are discharged and sent to a downstream station outside the tablet press.

[0003] In many tablet presses, pressure rollers are used in the compression station, and these rollers press the appropriately designed heads of the lower and upper punches to compress the pressurized material, such as powder. In other designs of rotary tablet presses, pressure rails may be additionally used. See, for example, Patent Document 1 (European Patent No. 1600285) or Patent Document 2 (European Patent No. 2313259). In the invention described in Patent Document 2, a pressure rail is used for the lower punch, and its upper surface rises linearly along the rotational direction at a predetermined angle until the upper surface of the pressure rail transitions to a horizontal portion. Pressure rollers are positioned before and after the pressure rail, and the lower punch is provided with rollers to improve the sliding of the lower punch along the pressure rail. In the invention described in Patent Document 1, a pressure holding rail is positioned between the pre-pressure roller and the main pressure roller for both the upper and lower punches. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] European Patent No. 1600285 [Patent Document 2] European Patent No. 2313259 [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of the present invention is to improve the compressibility of raw materials into tablets in a rotary tablet press. [Means for solving the problem]

[0006] To solve this problem, the present invention proposes, according to a first solution concept, that the pressure rail for the lower punch has an upper surface that is at least partially curved between a first position and a second position. In a rotary tablet press equipped with a pressure rail whose upper surface is curved, at least for the lower punch, it is observed that the compression behavior of the raw material is significantly improved by the gradual increase in compressive force caused by the curvature. This compressive force can be specifically adjusted by the curvature of the upper surface, even over a relatively short rotation path. The curvature of the pressure rail can be used or modified to control the pressure gradient of the material to be compressed. At the same time, this enables rapid switching when changing materials or dies.

[0007] The aforementioned problems can also be solved by a pressure rail as a curved portion of the control curve for punching in the rotor of a rotary tablet press. In this case, the pressure rail has a pressure rail body including an upper surface, the upper surface preferably rises continuously between a first position on the upper surface and a second position separated from the first position by a predetermined arc angle in the arc direction of the pressure rail body. This is because the upper surface is curved between the first and second positions.

[0008] In a particularly advantageous design, the curvature of the upper surface can form a spline, preferably along the entire curvature. Alternatively, the curvature of the upper surface can form a conic section, preferably along the entire curvature. In other alternative designs, the curvature of the upper surface can have multiple radii of curvature, particularly multiple radii of curvature that transition substantially tangentially to each other.

[0009] In all designs of pressure rails for rotary presses or pressure rails equipped in rotary tablet presses, it is particularly advantageous if the local radius of curvature of the upper surface increases continuously from a first position to a second position.

[0010] For convenience, a single pressure rail with a curved top surface is used. Alternatively, the pressure rail for the lower punch may consist of multiple segments. In this design, each segment may have a top surface with a constant radius of curvature, or, in the direction of rotation, subsequent segments may have a larger radius of curvature than preceding segments in the direction of rotation.

[0011] In one of the rotary tablet press designs described above, the upper punch can be assigned a control curve for the upper punch, which includes a pressure rail having a pressure rail body that includes at least a partially horizontal lower surface along the rotation path. In this case, the opposing pressure rail for the upper punch and the pressure rail for the lower punch are preferably arranged along the rotation path, in the pressure station region, such that the curved region of the upper surface of the pressure rail for the lower punch faces the horizontally extending region of the lower surface of the opposing pressure rail for the upper punch.

[0012] According to an alternative design, the control curve for the upper punch may comprise a pressure rail having a pressure rail body including a lower surface, the lower surface curving between a first position on the lower surface and a second position separated from the first position by a predetermined curvature angle in the arc direction of the pressure rail body. By using a pressure rail for the lower punch having a curved upper surface and a pressure rail for the upper punch having a curved lower surface, the compression behavior of the material to be pressurized can be better controlled, thus improving the overall compression behavior and, for example, further increasing the hardness of a tablet. In a pressure rail for the upper punch having a curved lower surface, the curvature of the lower surface may form a spline, preferably along the entire curvature. Alternatively, the curvature of the lower surface may form a conic section, preferably along the entire curvature. According to another alternative design, the curvature of the lower surface may have multiple radii of curvature, preferably multiple radii of curvature that transition substantially tangentially to each other. In this design as well, it is particularly advantageous if the local radius of curvature of the lower surface increases continuously from the first position to the second position.

[0013] In a rotary tablet press, only a single control curve with a pressure rail including a curved upper or lower surface may be used, and this control curve may also work in cooperation with conventional pressure rollers at the main pressurizing station. However, in a particularly preferred design, only pressure rails are used for the upper and lower punches at the main compression station, and no pressure rollers are used. More preferably, at all compression stations, at least one, and possibly all, pressure rails have a curved sliding surface to work with the punches to apply localized pressure.

[0014] The above-mentioned problems are solved in a general rotary press machine according to a second aspect of the present invention, in which only pressure rails are provided at the main pressing stations for the upper and lower punches and each pre-pressing station present, and no pressure rollers are provided, and the pressure rail for the lower punch at the main pressing station has an upper surface that rises at least partially and continuously between a first position and a second position. By compressing the material using only pressure rails that have an upper surface that rises at least partially and linearly or curved, the compressive force on the material can be increased slowly but surely as needed. In this case, the compressive force that gradually increases with the rise of the upper surface can be specifically adjusted by the design of the upper surface of the pressure rail, even for relatively short rotation paths. The design of the upper surface of the pressure rail can be used or modified as appropriate to control the pressure gradient of the material to be compressed. The upper surface of the pressure rail may have portions with different pitch angles, or portions with linear and curved profiles, in order to affect the compressive behavior of the material. This design of the pressure rail at the main pressing station in particular also enables quick switching when changing materials or dies.

[0015] It is particularly advantageous if the upper surface of at least one pressure rail in the pre-pressurizing station also has an upper surface that rises at least partially and continuously between a first position and a second position. According to a modification of one embodiment, the upper surface of the pressure rail for the lower punch in the main pressurizing station may extend to rise linearly between a first position and a second position, and / or the upper surface of at least one pressure rail in the pre-pressurizing station may rise at least partially and linearly between a first position and a second position. The upper surface of the pressure rail for the lower punch in the main pressurizing station may be curved, and / or the upper surface of the pressure rail for the lower punch in at least one pre-pressurizing station may be curved.

[0016] Further features and advantages of the present invention will become apparent from the following description and drawings. In this case, preferred embodiments of the present invention will be described in detail by a greatly simplified schematic example. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic plan view showing a rotary tablet press equipped with stations arranged along a rotation path. [Figure 2] Figure 1 is a schematic exploded view showing the rotation sequence of a rotary tablet press according to the first embodiment, which is equipped with a pressure rail with a curved upper surface. [Figure 3] This is a schematic perspective view showing the pressure rail of the control curve for the main pressurizing station in a rotary tablet press equipped with a pressure rail having a curved upper surface according to the present invention. [Figure 4] This is an exploded view showing the rotation sequence of a rotary tablet press according to a second embodiment, which is equipped with a pressure rail whose upper surface rises linearly. [Modes for carrying out the invention]

[0018] Figure 1 shows a highly simplified plan view of a rotary tablet press (collectively denoted by reference numeral 1) for manufacturing tablets from suitable raw materials such as powder. The rotary tablet press 1 comprises a housing 2 in which a rotor 10 is housed and rotatably supported, and is driveable in the rotational direction R by a drive unit (not shown), as indicated by the arrow. The rotor 10 has a die disc containing die receptacles 14 for a plurality of dies arranged on a pitch circle, as will be described in more detail with reference to Figure 2, within which the powdered raw material is pressed into tablets by cooperating upper punches 12 and lower punches 13. While the rotor 10 rotates in the rotational direction R, the upper punches 12 and lower punches 13 pass through different stations. In the illustrated exemplary embodiment, the rotary tablet press 1 constitutes a monopress or a press for single-layer operation. Along the rotation path of the rotor 10, there is a filling station 3, schematically shown by a filling curve, where powdered material is filled into a die and compressed into a tablet by an appropriate filling element, such as a filling shoe, there is a weighing station 4, there is a compression station 5, and there is a discharge station 6, symbolically shown by a stripping rail. At each of these stations, the upper punch 12 and the lower punch 13 need to be moved to different distances from each other, in which case this movement is controlled throughout the rotation by a control curve in the rotary tablet press 1. Different control curves exist for the upper punch 12 and the lower punch 13, in which case only the control curve 20 for the lower punch 13 is symbolically shown in Figure 1. All control curves 20 are fixedly located within the housing 2 and are divided into different curve sections depending on the station or function of the rotary tablet press 1.

[0019] The symbolic representation in Figure 1 shows a total of four curved sections for the lower punch: namely, the pull-down / filling rail 21, the metering rail 22, the pressure rail 50, and the discharge rail 24. Since each of these rails can also consist of multiple sections, the representation in Figure 1 is merely symbolic.

[0020] Next, referring to FIG. 2, there is shown a developed view of the rotary path of the rotary tablet press 1 in FIG. 1, and the upper punches 12 and the lower punches 13 are shown at different positions along the rotary path. All of the upper punches 12 are guided to be movable by the guide of the upper punch guide ring 15, and the lower punches 13 are guided to be movable by the guide of the lower punch guide ring 16. The upper punch guide ring 15, the die disk 11, and the lower punch guide ring 16 together with the upper punches 12 and the lower punches 13 constitute the main components of the rotor 10. Starting from the left end of FIG. 2 is the filling station, where the lower punch 13 is held at the uppermost moving position by the filling station holding rail 31 from the upper punch 13 by the lowering and filling rail 21. Thereby, as shown in FIG. 2, the powder 18 to be pressed is filled into the die whose lower part is closed by the punch head of the lower punch 13 by the filling element 17, for example, the filling shoe. Since it takes a certain amount of time to fill the die, the filling station extends over a wide angular range in the rotary path. The metering rail 22 for the lower punch 13 is connected to the lowering and filling rail 21 in the rotational direction R, and the lower punch 13 is moved upward by this metering rail 22, so that the filling amount of the material to be pressed is filled as accurately as possible into the die between the head of each lower punch 13 and the upper surface of the die disk 11. The metering rail 22 can be assigned a vibration element in order to improve the filling property of the powdery material into the die whose upper part is open and whose lower part is closed by the pressing head of the lower punch. The filling element 17 can have a metering edge for holding (excess) powdery material in the filling station or in the filling element and preventing it from rotating together with the die disk 11. In the region of the metering rail 22 for the lower punch 13, as shown by the guide rail 32 for the upper punch 12, the downward movement of the upper punch 12 is also started. In this case, the guide rail 32 guides the upper punch 12 obliquely downward and lowers the upper punch 12 until the press head of each upper punch 12 penetrates into the die.

[0021] The metering station 4 or the metering rail 22 is connected to the compression or pressurization station 5 in the rotational direction R, and this station 5, in the rotary tablet press 1, as symbolically shown in FIG. 2, consists only of a single pressure rail 50 for the lower punch 13 and a single opposing pressure rail 33 for the upper punch 12. The opposing pressure rail 33 holds the upper punch 12 in a position where the punch head of the upper punch 12 fully penetrates into the die, and thus the total pressure in the die can be applied to the material to be pressed. In this case, the pressure itself is applied via the lower punch 13 and the pressure rail 50 for moving these lower punches 13, and the pressure rail 50 has an upper surface 54 that is at least partially curved in the rotational direction R, as already clearly shown in FIG. 2. Due to the curved shape of the upper surface 54 of the pressure rail 50, the pressure is applied non-linearly and can be gradually increased by the curved shape.

[0022] In the rotational direction R, behind the pressurization station 5, a discharge rail 24 for the lower punch 13 and a lifting rail 34 for the upper punch 12 are connected, so that the fully compressed tablets are exposed and lifted by the upward movement of the lower punch 13. Thereby, the tablets are moved radially outward from the die table or die disk by the stripping element and are led out of the housing 2 of the tablet press 1 by the stripping element. In this case, as is known, an outlet for the tablets can also be provided, and defective tablets with defects are simultaneously sorted through this outlet.

[0023] In the filling station 3, the metering station 4, and the discharge station 6, the basic structure of the rotary tablet press with the upper punch 12 and the lower punch 13 moved by control curves and appropriate rails is well-known to those skilled in the art, and thus a detailed description is omitted here.

[0024] The innovative aspect of the rotary tablet press 1 according to the present invention lies primarily in the fact that the total pressing force in the tablet press 1 is applied by only one or more pressure rails, and in the embodiment of Figure 2, the pressure rail 50 has a curved upper surface 54. For simplicity, only a single pressure rail 50 for the lower punch 13 and a single opposing pressure rail 33 for the upper punch 12 are shown, but pressure rails and / or opposing pressure rails composed of multiple parts can also be used for corresponding functions. The curvature of the upper surface of the pressure rail 50 can be adjusted according to a desired curve relating to the arc length and pressing force. The opposing pressure rail 33 can also have a curved lower surface to influence the pressing force via the opposing pressure rail. In addition to the curvature of the pressure rail for the lower punch, the opposing pressure rail can have a lower surface that extends obliquely and linearly in the rotational direction to increase the pressing force in the rotational direction via the opposing pressure rail. The curved portion of the upper surface of the pressure rail 50 extends only to a partial region. This is because the upper surface 54 of the pressure rail 50 transitions to a horizontal and straight section, and preferably extends tangentially to this section.

[0025] Figure 3 shows an example of the structure of a corresponding pressure rail 50. The pressure rail 50 has a segmented rail body 51 that is curved in an arc around the axis of rotation according to the curvature of the control curve, and the rail body is provided with retaining holes 52, 53, through which the pressure rail can be fixed to a fixed anchor rod on the housing of the tablet press so as not to move. The upper surface 54 of the pressure rail body 51 is curved to rise continuously from a first position 55 to a second position 56, in this case rising continuously, and preferably rising according to a curve with a changing radius of curvature, such as a spline. In Figure 3, the difference in thickness of the pressure rail body 51 clearly shows this rise of the upper surface 54. The curvature of the upper surface 54 can also form a conic section or a logarithmic section. This curvature can also extend along the entire length of the pressure rail 50, because multiple pressure rails can be arranged in the compression station. In this case, if necessary, only one of these pressure rails may have a corresponding curved upper surface, and the other pressure rails may form curved sections that have other functions in the compression station. Accordingly, the curved portion of the compression station forms a pre-pressurizing station and a main pressurizing station, and if necessary, only one of these pressurizing stations of the compression station has a pressure rail with a curved upper surface, while the other pressure rails have a continuously rising straight upper surface or a straight horizontal upper surface, depending on which path is desired with respect to the pressure applied.

[0026] Figure 4 shows an alternative embodiment of the rotary tablet press 101. Similar to the embodiment described above, a die disc 111 with a die opening 114, an upper punch guide ring 115 for the upper punch 112, and a lower punch guide ring 113 for the lower punch 112 are provided, and together these constitute the rotor 110 of the rotary tablet press 101. In this case as well, the movement of the upper punch 112 is controlled via rails 131, 132, 133, and 134, and the movement of the lower punch 113 is controlled by the push-down / filling rail 121, the metering rail 122, the pressure rail 150, and the discharge rail 124, and the rotor 110 rotates in the rotational direction R. Similar to the embodiment described above, in this case as well, there are no pressure rollers, and the total pressure is applied only by the pressure rail 150 and the opposing pressure rail 134. However, in this case, the upper surface 154 of the pressure rail 150 is not curved, and rises linearly until the pressure rail 150 changes to a horizontal path.

[0027] Those skilled in the art will be able to conceive of numerous modifications from the above description, and these modifications are included in the appended claims. The illustrated exemplary embodiments are merely symbolic representations of the structure of the rotary tablet press according to the present invention. Each curved section may consist of a plurality of sub-sections and a plurality of corresponding sub-rails. A compression station or pressurizing station may have a plurality of rails, of which at least one pressure rail may function as a pre-pressurizing station and the other rails may function as main pressurizing stations. The dies for manufacturing tablets may also be integrally formed on the die disk. The above exemplary embodiments illustrate a rotary tablet press for single-layer operation. The present invention can also be advantageously used as a double press or a rotary tablet press for multi-layer operation, in which case (at least) two filling stations, two metering stations, and two compression stations are arranged along the rotation path, and in the case of a double press, two discharge stations are provided. In a multi-layer press, a multi-layer tablet or core tablet is manufactured in one rotation using the same pair of punches, and in a double press, two or more tablets are manufactured in one rotation of the rotor using the same pair of punches.

Claims

1. A rotary tablet press, Housing (2), A rotor (10) is drivably disposed within the housing (2) and has an upper punch guide ring (15) having a guide for an upper punch (12), a lower punch guide ring (16) having a guide for a lower punch (13), and a die disc (11) disposed between the punch guide rings (15; 16) and containing a die for manufacturing tablets in the die by the upper punch (12) and the lower punch (13), The rotor (10) has at least one filling station (3), at least one compression station (5), and at least one discharge station (6) distributed along its rotation path, Fixed control curves (20; 31-34) for the upper punch (12) and the lower punch (12) to control the movement of the upper punch (12) and the lower punch (12) along the rotation path, Equipped with, In a rotary tablet press, the control curve has a plurality of curved portions distributed along the rotation path, and at least one curved portion for the lower punch forms a pressure rail in the compression station region having a pressure rail body (51) including an upper surface (54), and the upper surface (54) is designed to rise at least partially in the rotation direction between a first position of the upper surface (54) and a second position separated from the first position by a predetermined arc angle in the arc direction of the pressure rail body, A rotary tablet press, characterized in that the pressure rail (50) for the lower punch in the compression station (6) has an upper surface (54) that is at least partially curved between the first position and the second position.

2. In particular, a pressure rail as a curved portion of a control curve for punching in the rotor of a rotary tablet press according to claim 1, wherein the pressure rail has a pressure rail body (51) including an upper surface (54), and the upper surface (54) preferably rises continuously between a first position (55) on the upper surface and a second position (56) separated from the first position by a predetermined arc angle in the arc direction of the pressure rail body, The upper surface (54) is characterized by being curved between the first position and the second position, wherein the pressure rail is a pressure rail.

3. A rotary tablet press according to claim 1 or a pressure rail according to claim 2, characterized in that the curvature of the upper surface forms a spline, preferably along the entire curvature, or the curvature of the upper surface forms a cone, preferably along the entire curvature.

4. A rotary tablet press according to claim 1 or a pressure rail according to claim 2, wherein the curvature of the upper surface has a plurality of radii of curvature, preferably a plurality of radii of curvature that transition substantially tangentially to each other.

5. A rotary tablet press according to any one of claims 1, 3, or 4, or a pressure rail according to any one of claims 2 to 4, wherein the local radius of curvature of the upper surface preferably increases continuously from the first position to the second position.

6. A rotary tablet press according to any one of claims 1 to 5, wherein the pressure rail for the lower punch is composed of a plurality of segments, preferably each segment having an upper surface including a certain radius of curvature, and / or, in the direction of rotation, a subsequent segment has a larger radius of curvature than a preceding segment in the direction of rotation.

7. A rotary tablet press according to any one of claims 1 to 6, wherein the control curve for the upper punch comprises a pressure rail (34) having a pressure rail body including a lower surface that extends at least partially horizontally, and the pressure rail (34) for the upper punch and the pressure rail (50) for the lower punch are arranged along the rotation path, in the pressure station (6) region, such that the curved region of the upper surface of the pressure rail (50) for the lower punch (13) faces the horizontally extending region of the lower surface of the opposing pressure rail (34) for the upper punch.

8. A rotary tablet press according to claim 1 or any one of claims 3 to 6, wherein the control curve for the upper punch comprises a pressure rail having a pressure rail body including a lower surface, and the lower surface extends in a curved manner between a first position on the lower surface and a second position separated from the first position by a predetermined curvature angle in the arc direction of the pressure rail body.

9. A rotary tablet press according to claim 8, characterized in that the curvature of the lower surface forms a spline, preferably along the entire curvature, or the curvature of the lower surface forms a cone, preferably along the entire curvature.

10. A rotary tablet press according to claim 8, wherein the curvature of the lower surface has a plurality of radii of curvature, preferably a plurality of radii of curvature that transition substantially tangentially to each other, and the local radius of curvature of the lower surface preferably increases continuously from the first position to the second position.

11. A rotary tablet press according to any one of claims 1 to 10, wherein the compression station comprises a main pressurizing station and preferably at least one pre-pressurizing station, and in all pressurizing stations, only pressure rails are provided for the upper punch and the lower punch, and no pressure rollers are provided.

12. A rotary tablet press, Housing and A rotor (10;110) is drivably disposed within the housing and has an upper punch guide ring (15;115) having a guide for an upper punch (12;112), a lower punch guide ring (16;116) having a guide for a lower punch (13;113), and a die disc (11;111) disposed between the punch guide rings and containing a die for manufacturing tablets in the die by the upper and lower punches, The rotor has at least one filling station (3), at least one compression station (5), and at least one discharge station (6) distributed along its rotation path, A fixed control curve (20) for the upper punch and the lower punch for controlling the movement of the upper punch and the lower punch along the rotation path, Equipped with, In a rotary tablet press, the compression station comprises a main pressurizing station and preferably at least one pre-pressurizing station, the control curve comprises a plurality of curved portions distributed on the rotation path, and at least one curved portion for the lower punch forms a pressure rail in the compression station region having a pressure rail body (51) including an upper surface (54), and the upper surface (54) is designed to rise at least partially in the rotation direction between a first position of the upper surface (54) and a second position separated from the first position by a predetermined arc angle in the arc direction of the pressure rail body, A rotary tablet press, characterized in that the main pressurizing station for the upper punch and the lower punch and each of the pre-pressurizing stations present are provided only with pressure rails (50, 34; 134, 150) and no pressure rollers, and the pressure rail for the lower punch in the main pressurizing station has an upper surface (54; 154) that rises at least partially and continuously between the first position and the second position.

13. A rotary tablet press according to claim 12, characterized in that the upper surface of at least one pressure rail in the pre-pressurizing station has an upper surface that rises at least partially and continuously between a first position and a second position.

14. A rotary tablet press according to claim 12 or 13, characterized in that the upper surface of the pressure rail for the lower punch in the main pressurizing station extends to rise linearly between the first position and the second position, and / or the upper surface of at least one pressure rail in the pre-pressurizing station rises at least partially and linearly between the first position and the second position.

15. A rotary tablet press according to any one of claims 12 to 14, characterized in that the upper surface of the pressure rail is curved for the lower punch in the main pressurizing station.

Images