ADJUSTABLE INITIAL PRESSURE RAIL FOR ROTARY PRESS HAVING INTEGRATED MEASUREMENT OF THE INITIAL PRESSURE FORCE

Abstract

A rotary press comprising at least one pressing station having each of a vertically-adjustable upper and lower pressure roller, which are mounted by axes in the at least one pressing station. Cam-guided upper punches having punch heads are fed to the upper pressure roller by a control cam and a pull-up cam raises the upper punches to a highest point above a filling device. A vertically-adjustable safety cam is designed to be vertically adjustable in relation to the upper pressure roller. The rotary press may comprise a preliminary pressure cam, which is integrated in a guide block.

Claims

1. A rotary press for the production of single-layered or multilayered tablets, the rotary press comprising: at least one filling device for filling a pressing material into openings of a die plate; at least one filling station; at least one metering station for the lower punches; at least one pressing station; at least one ejection station having a tablet stripper and a tablet discharge chute, wherein the at least one pressing station includes respectively an upper pressure roller and a lower pressure roller and respectively an upper cam track and a lower cam track, wherein the upper and lower cam tracks interact with upper and lower punches, wherein at least one vertically-adjustable upper combination cam, includes a pull-down cam, an upper initial pressure rail, a safety rail, and a pull-up cam arranged below the upper pressure roller, and the lower cam track includes a vertically-adjustable lower initial pressure rail and an integral ejection cam attached below the lower pressure roller.

2. The rotary press as claimed in claim 1, wherein a continuous vertical adjustment of the upper initial pressure rail takes place synchronously with a vertical adjustment of the upper pressure roller.

3. The rotary press as claimed in claim 1, wherein the upper initial pressure rail is arranged set back 0.3-1.0 mm in relation to the upper pressure roller and the lower initial pressure rail is arranged set back 0.3-1.0 mm in relation to the lower pressure roller.

4. The rotary press as claimed in claim 1, wherein the at least one upper combination cam is attached with pivot joints on movable upper transition rails.

5. The rotary press as claimed in claim 4, wherein the movable transition rails are connected to rigid transition rails with ball joints for compensating for angle and length changes.

6. The rotary press as claimed in claim 1, wherein the lower initial pressure rail is provided arranged on a swing arm.

7. The rotary press as claimed in claim 1, wherein a movable lower transition rail is arranged in the lower cam track between a metering cam and the lower initial pressure rail, wherein the movable transition rail includes a pivot joint in a transfer region to the initial pressure rail, and on the opposing side includes a ball joint to compensate for height and length changes.

8. The rotary press as claimed in claim 1, wherein the lower initial pressure rail is adjustable in height manually via a handwheel and/or automatically.

9. The rotary press as claimed in claim 1, wherein the lower initial pressure rail is attachable manually and/or automatically to the lower cam track with fasteners.

10. A use of a rotary press as claimed in claim 1, wherein a vertical adjustment of the upper combination cam is performed manually and/or automatically.

11. The use of the rotary press as claimed in claim 10, wherein a measurement of a distance between the upper initial pressure rail and the upper pressure roller is performed mechanically and/or electronically, wherein a result of the distance measurement is displayed in a touch panel.

12. The use of the rotary press as claimed in claim 10, wherein a null position between the upper initial pressure rail and the upper pressure roller and between the lower initial pressure rail and the lower pressure roller is monitored mechanically and/or electrically.

13. The use of the rotary press as claimed in claim 10, wherein the rotary press is automatically stopped when the upper initial pressure rail is arranged above the upper pressure roller and/or the lower initial pressure rail is arranged above the lower pressure roller.

14. The use of the rotary press as claimed in claim 10, wherein an initial pressing force on the upper initial pressure rail is measured and the initial pressing force is displayed in the touch panel.

15. The use of the rotary press as claimed in claim 1, wherein the initial pressing force is measured with a measurement cell by loading the measurement cell by the lower initial pressure rail.

Description

[0075] The invention is described in greater detail on the basis of exemplary embodiments and the following figures; in the figures:

[0076] FIG. 1 shows a preferred embodiment of an upper cam track of a rotary press

[0077] FIG. 2 shows a detail of a preferred embodiment of an upper cam track of a rotary press (rear view)

[0078] FIG. 3 shows a preferred embodiment of a lower cam carrier having cam track of a rotary press

[0079] FIG. 1 shows a preferred embodiment of an upper cam track (17) of a rotary press. An upper pressure roller (3) is schematically indicated in FIG. 1. This interacts with the press punches and produce the tablets in the die holes of the die. In particular the upper initial pressure unit (1) is shown in FIG. 1, which preferably consists of the inner initial pressure rail (1.1), the outer initial pressure rail (1.2), and the safety rail (1.3), wherein the upper initial pressure unit (1) is synonymously referred to as a combination cam in terms of the invention. The inner initial pressure rail (1.1) and the outer initial pressure rail (1.2) are preferably embodied to be adjustable. It is preferable in terms of the invention that for this purpose firstly the fastening screws (2.1 and 2.2) are loosened. The position and/or height of the upper initial pressure rail (1) can be set in accordance with the setting and/or position of the upper pressure rollers (3) by an adjustment of the adjustment screw (6), wherein advantageously monitoring of the zero position of the upper pressure roller (3) in relation to the initial pressure rail (1) is performed by a sensor (8). It is furthermore preferable that the actual distance between upper pressure roller (3) and initial pressure rail (1) is performed by means of a gauge (7), in particular a dial gauge, which is also shown in FIG. 1. Furthermore, a mount (4) is shown for the dial gauge, and also a fastening screw (5) for this mount. After completed adjustment of the initial pressure rail (1) in relation to the pressure roller (3), the two screws (2.1 and 2.2) can be tightened again.

[0080] Is furthermore preferable that the cam carrier (17) comprises keys (18) on its inner side, which advantageously enable an axial movement of the initial pressure rails (1.1 and 1.2) in a groove in the cam carrier (17) and advantageously prevent a radial movement of the initial pressure rails (1.1 and 1.2).

[0081] It is preferable in terms of the invention that the safety rail (1.3) is provided arranged between the initial pressure rails (1.1 and 1.2), it is preferably also referred to as a catch rail or integrated safety rail in terms of the invention. It is advantageously arranged below the bottom dead center of one of the upper pressure rollers (3) and thus advantageously replaces a gap in the cam path, which exists in conventional tablet presses between the pull-down cam and the pull-up cam. The gap enables the upper punches to be able to plunge over a greater region of the cam path into the die to transmit the pressing pressure onto the tablet material to be compressed. In conventional presses, in order to prevent the upper punch from plunging excessively deeply into the die in the region below the upper pressure roller (3), a so-called catch cam is typically provided, which is supposed to prevent a placement of the punch heads on the rotor upper part or falling of the pressing punch out of the cam path. However, it has been shown in practice that problems can arise in this design if no pressing material is located in the die and the upper punch was pressed unbraked onto the uncovered lower punch.

[0082] The risk of such mechanical damage to the pressing punches is prevented by the provision of the integrated safety rail (1.3). Since the adjustable initial pressure rail (1.1 and 1.2) is preferably located 0.3 to 1.0 mm behind the pressure roller (3), the upper punch can also only plunge by this amount beyond the pressure roller (3) into the die, whereby touching of the pressing punch surfaces is completely precluded. Advantageously, the outer initial pressure rail (1.2) can also function as a pull-down cam in terms of the invention and is also synonymously referred to as such.

[0083] It is preferable that the inner initial pressure rail (1.1) is provided arranged below an upper pressure roller (3) and can be fastened using two screws (2.1 and 2.2), which are preferably embodied as clamping screws, on the cam carrier (17). It is preferable in terms of the invention that the fastening holes for the screws (2.1 and 2.2) are embodied as oblong holes (2a and 2b), so that advantageously a displaceability of the inner initial pressure rail (1.1) is enabled.

[0084] A transition cam (not shown) can be used to accommodate the upper shafts of the pressing punches, while dies of the die plate are filled by a filling device. The transition cam can preferably be provided arranged between the movable rails (10 and 15), so that the transition cams are preferably each provided arranged between one of the preferably three pressure rollers (3) within the upper cam track (17). The transition rail can comprise a sensor (not shown), which is configured to monitor the sluggishness of the upper punches and the upper punch removal opening. It is preferable that if the rotor rotates counterclockwise, the upper shafts of the pressing punches are fed via preferably movable rails (10) to the upper initial pressure rail (1). At the end of the rails (10), the inner shaft rollers can be transferred after the joint (9), which is preferably formed as a pivot joint, to the pull-down cam of the initial pressure rail (1), where they are preferably pulled downward. A transfer of the shafts to the inner initial pressure rail (1.1) and the outer initial pressure rail (1.2) preferably takes place here, whereupon the shafts are lowered further until a straight region of the initial pressure rails (1.1 and 1.2) is reached.

[0085] It is preferable that the upper initial pressure unit (1) and the initial pressure rails (1.1 and 1.2) are embodied to be vertically adjustable in relation to the pressure rollers (3). This vertical adjustment can advantageously take place manually or automatically. It represents a particular advantage of the invention that an optimum position of the initial pressure rail (1, 1.1, 1.2) in relation to the bottom dead center of the pressure roller (3) can thus be set independently of the setting and/or position of the upper pressure rollers (3).

[0086] FIG. 1 furthermore shows the preferably movable, i.e., embodied as adjustable, transition rails (10 and 15), and also the preferably rigid transition rails (12), wherein the rigid transition rails (12) are preferably provided arranged so that they advantageously enable a transition of the upper shafts of the pressing punches over the filling devices of the tablet press. It is preferable in terms of the invention to refer to the transition rail (10) synonymously as an inlet rail and the transition rail (15) as an outlet rail. FIG. 1 shows that the movable transition rails (10 and 15) for guiding the upper shafts between filling device and upper pressure roller (3) are preferably provided arranged between the preferably rigid transition rails (12) and the initial pressure unit (1).

[0087] In this case, the preferred movable design of the transition rails (10 and 15) represents a significant advantage in relation to conventional tablet presses, since due to the mobility of the transition rails (10 and 15), a transition of the upper shafts from the preferably rigidly formed transition rails (12), which are fixedly fastened on the cam carrier, to the vertically-adjustable initial pressure rails (1.1 and 1.2) is enabled.

[0088] It is particularly preferable in terms of the invention if the preferably movably designed transition rails (10 and 15) compensate and/or overcome the height differences resulting due to the vertical adjustability between the preferably rigidly formed transition rails (12) and the vertically-adjustable initial pressure rails (1.1 and 1.2). This is advantageously ensured by the provision of joints (9 and 14), which according to FIG. 1 are provided arranged at the transfer point between the inlet rail (10) and the initial pressure rail (1) or at the transfer point between the initial pressure rail (1) and the outlet rail (15), respectively, and are preferably designed as pivot joints. Due to the preferably movable design of the transition rails (10, 15), a length compensation is required, which is preferably performed in relation to the preferably rigid transition rails (12) by means of further joints (11), wherein these joints are preferably referred to as compensation joints and are formed as ball joints. Jamming of the inlet rail (10) and the outlet rail (15) is particularly effectively avoided by the provision of the joints (9, 11, 14), whereby a smooth sequence of the tablet production process is promoted.

[0089] A further advantage of the invention is that the shafts can be axially guided by means of rollers, wherein due to the in particular one-sided vertical adjustability of the transition rails (10 and 15), jamming of the inner guide rollers of the shafts within the cam carrier (17) and/or its components is surprisingly effectively prevented. This is advantageously to be attributed to the fact that in contrast to conventional head-guided pressing punch shafts, a large amount of head freedom for the movement of the shafts does not have to be provided, whereby in particular the risk of severe mechanical damage due to jamming of the shafts can be substantially reduced. The advantages mentioned here for the preferably movable transition rails (10 and 15) each also apply to the transition rails (10 and 15) preferably attached between other pressure rollers (3) in the cam track.

[0090] FIG. 1 shows a detail of an upper cam carrier (17), which can comprise three pressure rollers (3), for example. However, the invention is not restricted to such cam carriers, but rather can be used in particular in single, double, and triple presses, wherein the number of the pressure rollers (3) can vary.

[0091] FIG. 2 shows a detail of one preferred embodiment of an upper cam track (17) of a rotary press. In particular, a detailed view of a rear view of a preferred cam track (17) is illustrated in FIG. 2, i.e., a view as can be displayed out of the inner region of the tablet press, for example.

[0092] FIG. 3 shows a detail of a preferred embodiment of a lower cam carrier (17) having cam track of a rotary press. In particular, the location of the lower pressure roller (23) within the cam track of the cam carrier (19) is schematically shown. The preferred embodiment of the lower cam track (19) shown in FIG. 3 advantageously enables the measurement of the initial pressure force and thus substantially contributes to the quality management within the tablet production process. The lower initial pressure station preferably comprises a lower initial pressure rail (24), which is preferably provided fastened using two screws on a preferably stable swing arm (27), wherein the swing arm (27) is preferably rotatably designed and can be fastened by means of a bolt (27a) on a plate (29).

[0093] The plate (29) preferably comprises a key (44), which preferably engages in a corresponding groove in the cam carrier (19), wherein advantageously an axial key guide of the plate (29) is enabled, but a radial movement is effectively prevented. It is preferable in terms of the invention that the plate (29) is supported on a wedge (30), which can move axially in two guide rails (42). A star grip (31) and a spindle (31a) advantageously enable adjustability of the wedge to the right or left. Is preferable in terms of the invention that the wedge (30) is moved to the right when the star grip (31) is rotated to the right, wherein the spindle (31a), which is preferably formed by an adjustment spindle, follows this right movement In particular, this adjustment movement preferably results in a preferably parallel raising of the plate (29) and the lower initial pressure rail (24). Similarly, a left rotation of the star grip and the adjustment spindle preferably results in a preferably parallel lowering of the plate (29) and the lower initial pressure rail (24). This particularly convenient design of the adjustability of the lower initial pressure rail (24) is particularly advantageous because the lower initial pressure rail (24) has to be adjusted relatively frequently in practice, since the desired tablet thickness, for example, can be set using the height and/or position setting of the lower initial pressure rail (24). After completion of the adjustment of the lower initial pressure rail (24), the plate (29) can be fastened using a screw (35), for example, by clamping on the cam carrier (19).

[0094] Is preferable in terms of the invention that a null position of the lower initial pressure rail (24) can be monitored using a rocker arm (28) and a limit switch (36), wherein the null point is defined in particular as when the lower initial pressure rail (24) and the top dead center of the lower pressure roller (23) are located at one height with one another. It is particularly preferable in terms of the invention that the lower initial pressure rail (24) is provided arranged, for example, by 0.3 to 1.0 mm behind the top dead center of the lower pressure roller (23), so that the initial pressure is advantageously less than the main pressure. Advantageously, the upper null point sensor (8) and the null point limit switch (36) form a safety device within the tablet press, using which the tablet press can preferably be stopped instantaneously in the event of an incorrect setting of the upper (1) or lower (24) initial pressure rail.

[0095] A further advantage of the preferred embodiment of the lower cam track (19) shown in FIG. 3 is that the height and/or position setting of the lower initial pressure rail (24) can be measured using a spindle (34) and displayed using a gauge (32), preferably a dial gauge.

[0096] The vertical adjustability of the lower initial pressure rail (24) has the result that the position of the lower initial pressure rail (24) changes in relation to the metering cam (21). To ensure a smooth and problem-free transfer of the lower punch shaft between the individual components of the lower cam track (19), the lower transition rails (43) are also movably designed, in particular pivotably and displaceably mounted. The above-mentioned advantages apply similarly with respect to the preferably movably designed transition rails (10 and 15). It is preferable in terms of the invention that the transition rail (43) comprises a joint (25), which is advantageously designed as a pivot joint, in the transition region to the lower initial pressure rail (24).

[0097] At the other end, the transition rail (43) preferably comprises a joint (26), which is preferably designed as a ball (bearing) joint and advantageously enables a rotating and/or sliding movement.

LIST OF REFERENCE SIGNS

[0098] 1 upper initial pressure unit

[0099] 1.1 inner adjustable initial pressure rail

[0100] 1.2 outer adjustable initial pressure rail

[0101] 1.3 safety rail (catch rail)

[0102] 2.1 clamping screw

[0103] 2.2 clamping screw

[0104] 2a oblong hole

[0105] 2b oblong hole

[0106] 3 upper pressure roller

[0107] 4 mount for dial gauge

[0108] 5 fastening screw for 4

[0109] 6 adjustment screw

[0110] 7 dial gauge

[0111] 8 upper null point sensor

[0112] 9 pivot joint

[0113] 10 movable transition rail, inlet rail

[0114] 11 ball joint

[0115] 12 transition rail

[0116] 14 pivot joint

[0117] 15 movable transition rail, outlet rail

[0118] 17 upper cam track

[0119] 18 key

[0120] 19 lower cam carrier with cam track

[0121] 21 metering cam

[0122] 22 adjustment of metering cam

[0123] 23 lower pressure roller

[0124] 24 lower initial pressure rail

[0125] 25 pivot joint

[0126] 26 ball joint

[0127] 27 swing arm for lower initial pressure rail

[0128] 27a bolt

[0129] 28 null point rocker arm

[0130] 29 plate

[0131] 30 wedge

[0132] 31 star grip

[0133] 31a spindle

[0134] 32 dial gauge

[0135] 33 threaded spindle bearing

[0136] 34 screw

[0137] 35 clamping screw

[0138] 36 null point limit switch

[0139] 42 guide rail

[0140] 43 movable transition rail

[0141] 44 key

[0142] 45 roller pins

[0143] 46 ejection cam