Tablet press and method for rejecting and sampling tablets

Abstract

The rotary tablet press (1) a compression turret (2) rotating about an axis of rotation (X) and including a die table (3) provided with a number of dies (4) arranged to receive a compression target and produce a tablet (100); a conveying means (5) for conveying the tablets (100) produced by the dies (4) of the die table (3) into an outlet conduit (6); a reject / sampling system (7) configured to selectively direct preformed tablets (100) produced by the die (4) of the die table (3) into a reject conduit (8) or into a sampling conduit (9); The reject / sampling system (7) a first routing means (11) configured to act on individual tablets (100a) to be rejected to direct them from the die table (3) towards the reject conduit (8); a second steering means (12) configured to act on the individual tablets (100b) to be sampled to steer them from the die table (3) towards the sampling conduit (9); The first and second steering means (11, 12) are configured to act on the tablet (100) before it leaves the die table (3).

Description

[Technical field]

[0001] The present invention relates to a press suitable for producing tablets, lozenges and pills for pharmaceutical, food and chemical applications, in particular a rotary press provided with a system for rejecting or sampling the tablets produced, and also to a method for rejecting or sampling the tablets produced in the press. [Background technology]

[0002] Known rotary presses include a compression turret formed by a die table or die plate rotating about a vertical axis and provided with a number of dies, i.e. through cavities, which are angularly distributed along the periphery of the table, equidistant from one another and arranged to receive a supply of powder or granules at dedicated loading points. The turret further includes a number of upper and lower punches, which correspond in pairs to each die and move linearly and vertically coaxially with the dies during rotation of the turret by means of cams and compression rollers.

[0003] The lower punch together with the die forms a suitable seat, or filling chamber, capable of receiving the object to be compressed at the filling point.

[0004] At the subsequent compression station, the upper and lower punches are moved by compression rollers to compress the object introduced into the die, thereby producing a tablet. The tablet is then extracted from the die of the table by the lower punch, appropriately lifted and conveyed in an exit chute corresponding to the exit station. During the rotation of the compression turret, which rotates in a generally continuous motion, the various tablet manufacturing steps are carried out.

[0005] The exit chute is usually equipped with a reject system which diverts produced tablets that do not meet production requirements such as size, hardness, porosity and weight into an appropriate reject conduit. To detect these parameters, for example, the compression force exerted by the punches in the single die, the height of the object fed into the die or the mass of the tablet are measured using microwave sensors or based on magnetic resonance techniques, or the tablet weight is measured directly using electronic scales or load cells.

[0006] The reject system typically includes a movable routing element that is mechanically movable by an electrical or pneumatic actuator into an operative position to direct tablets to be rejected into a reject conduit, with legitimate tablets instead being conveyed into the main conduit of the exit chute mentioned above.

[0007] Similarly, some known presses include a sampling system, typically at the exit chute, that routes a batch or sample of the produced tablets into a sampling conduit, for example for thorough inspection and extensive quality control.

[0008] For this purpose, the sampling system includes a dedicated movable routing element that is mechanically movable by an electrical or pneumatic actuator into an operative position, thereby routing the tablet to be sampled into the appropriate conduit.

[0009] Known reject and sampling systems have the following disadvantages: when the tablet press operates at high speed (i.e. the compression turret rotates at high speed), they perform cumulative reject and sampling, i.e. reject and sample multiple tablets in succession, because when the movable routing element is mechanically actuated at low speed, the routing element cannot select and route tablets one by one, i.e. perform so-called single reject and sample.

[0010] However, single-type sampling is very useful and important because it allows, for example, sampling and analyzing only a particular tablet exiting a press, for example tablets produced by a particular pair of punches out of multiple pairs of (upper and lower) punches, typically to verify whether said particular pair of punches is operating normally.

[0011] US 2010 / 094449 discloses a system for rejecting tablets produced in a rotary press. The system includes a discharge nozzle for separating defective tablets. The discharge nozzle is supplied with compressed gas through a supply line. The supply line has an inlet end for connection to a source of compressed gas and an outlet end in communication with the discharge nozzle. The supply line is provided with a control valve that is controlled by a control unit to open the supply line if a defective tablet is detected by the control unit. The supply line is provided with a sensor located between the control valve and the inlet end of the supply line and suitable for detecting a parameter indicative of gas flow through the control valve, and the control unit is adapted to generate an error signal if the control valve malfunctions.

[0012] US 2017 / 080662 A1 discloses a rotary tablet press. The tablet press includes a table, which is rotatable about a vertical axis of rotation and is provided with a die having holes, for producing tablets at the holes by means of a punch pair. The press includes at least one filling station, at least one pressing station, and at least one tablet outlet for extracting tablets produced by the rotary press. A reject device is coupled to the outlet, which can feed tablets to a first channel as individual tablets or to a second channel as a flow of tablets, respectively, based on a control signal. To increase the production at the outlet, a weighing device is coupled to the weighing cell, which can feed tablets from the first channel via a feed channel to the weighing device.

[0013] US Patent Application Publication No. 2021 / 221085 discloses a reject chute for a machine for making tablets and a method for selecting tablets made by the machine for making tablets. The reject chute includes a channel through which the produced tablets are guided and / or sorted, the channel being arranged on two sides. The sorting of the tablets is performed using sorting devices arranged in a row. Each sorting device includes two bars, which are preferably designated as a sorting bar and a separating bar. The sorting bar includes a linear drive, which is connected with the separating bar by a vibrating lever. When the sorting bar moves upward from a rest position to a sorting position, the separating bar automatically descends and opens the opening of the sorting channel. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] US Patent Application Publication No. 2010 / 094449 [Patent Document 2] US Patent Application Publication No. 2017 / 080662 [Patent Document 3] US Patent Application Publication No. 2021 / 221085 Summary of the Invention [Problem to be solved by the invention]

[0015] One of the objects of the present invention is to improve known tablet presses, in particular rotary presses, which are provided with a system for rejecting and sampling the tablets produced.

[0016] A further object is to provide a press which is capable of selectively rejecting or sampling produced tablets one by one, accurately and precisely, and in particular of performing single rejection and sampling.

[0017] A further object is to provide a press provided with an efficient and accurate reject / sampling system which is simple and economical to assemble.

[0018] Yet another object is to provide a method for rejecting and sampling tablets produced in a press, and in particular for selectively rejecting or accurately and precisely sampling each tablet produced to achieve single rejection and sampling. [Means for solving the problem]

[0019] A first aspect of the present invention provides a tablet press as claimed in claim 1.

[0020] A second aspect of the invention provides a method for rejecting and sampling tablets in a press as claimed in claim 7. [Brief description of the drawings]

[0021] The invention can be better understood and put into practice with reference to the accompanying drawings, which show exemplary and non-limiting embodiments. [Figure 1] FIG. 1 is a schematic and simplified plan view of a rotary tablet press of the present invention during the production process, the tablet press being provided with a reject / sampling system for the produced tablets. [Diagram 2] FIG. 2 is a partial plan view of the press of FIG. 1 with the reject / sampling system in a sampling operation; [Diagram 3] FIG. 2 is a partial plan view of the press of FIG. 1 with the reject / sampling system in a reject operation. [Figure 4] 2 is a partial plan view of the press of FIG. 1 during a reject operation in the first step of the reject / sampling system conditioning the press; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Figures 1 to 4 show diagrammatically a rotary tablet press 1 according to the invention. The tablet press 1 comprises a compression turret 2 rotating about a rotation axis X, which is in particular vertical, and which comprises a die table 3 provided with a number of dies 4 or through cavities arranged to receive the material to be compressed and to produce tablets 100. The dies 4 are arranged angularly spaced apart from one another along the periphery of the die table 3.

[0023] The press 1 further comprises a number of lower and upper punches, which are of known type and therefore not shown in the figures, corresponding to the respective dies in pairs, and a filling station adapted to fill with the objects a filling cavity formed by the lower closing of the die 4 by the lower punch. Drive means, for example of the cam type, are provided to move the lower punch and / or the upper punch in each die 4 to compress the objects and obtain tablets.

[0024] The press 1 further comprises a conveying means 5 and a reject / sampling system 7. The conveying means 5 is for conveying tablets 100 produced by the dies 4 of the die table 3 into an outlet conduit 6. The reject / sampling system 7 is configured to selectively route preformed tablets 100 produced by the dies 4 into a reject conduit 8 or into a sampling conduit 9.

[0025] In particular, the reject / sampling system 7 comprises a first routing means 11 and a second routing means 12. The first routing means 11 is configured to act on individual tablets 100a to be rejected, to route them from the die table 3 towards the reject conduit 8. The second routing means 12 is separate from the first routing means 11 and is configured to act on individual tablets 100b to be sampled, to route them from the die table 3 towards the sampling conduit 9. More precisely, the first and second routing means 11, 12 are configured to act on one tablet at a time, to perform the rejection or sampling of the individual tablets.

[0026] In the illustrated embodiment, the first and second routing means 11, 12 each comprise a compressed air supply device of known type suitable for emitting a respective blow or jet of compressed air capable of impinging on one tablet 100a to be rejected at a time and directing one tablet 100b to be sampled at a time as the tablets are extracted from each of the dies 4 of the die table 3.

[0027] The outlet conduit 6 receives the tablet 100 extracted from the die 4 (eg, by appropriately raising the lower punch) and is, for example, disposed approximately radially of the die table 3 .

[0028] The conveying means 5 includes a shaped, curved guide element 15 which is configured to contact the tablet 100 extracted from the die 4 and slide over the upper surface of the die table 3 to guide the tablet 100 into the exit conduit 6.

[0029] The reject conduit 8 and the sampling conduit 9 are arranged side by side and parallel to the outlet conduit 6 and extend from the die table 3. The reject conduit 8 is arranged, for example, between the sampling conduit 9 and the outlet conduit 6. The reject conduit 8, the sampling conduit 9 and the outlet conduit 6 are inclined downwards, for example, to allow tablets to easily slide down by gravity.

[0030] The first path determination means 11 is positioned above the die table 3 and upstream of the outlet conduit 6 with respect to the forward direction of the tablets exiting the die 4, and in particular, faces the mouth of the reject conduit 8 so as to direct each of the tablets 100a to be rejected extracted from the die 4 into the reject conduit 8.

[0031] Similarly, the second path determining means 12 is positioned above the die table 3 and upstream of the outlet conduit 6, particularly opposite the mouth of the sampling conduit 9, so as to direct each of the tablets 100b to be sampled extracted from the die 4 and push them into the sampling conduit 9.

[0032] In particular, the second path determination means 12 is arranged on the die table 3 and upstream of the first path determination means 11 with respect to the advance direction of the tablet.

[0033] The press 1 may further comprise sensor means arranged adjacent the first trajectory determination means 11 and the second trajectory determination means 12 and configured to detect the passage, and in particular the presence, of a tablet 100 in front of the first trajectory determination means 11 and the second trajectory determination means 12.

[0034] A control unit 10 is provided. The control unit 10 is connected to the first routing means 11 and the second routing means 12 and is configured to selectively activate the routing means 11 or the second routing means 12 when a tablet to be rejected or a tablet to be sampled is on the die table 3 and arrives before the first routing means 11 or the second routing means 12.

[0035] The control unit 10 is, for example, a control unit that controls the operation of the entire press 1. For example, the control unit 10 may be connected to sensor means suitable for detecting the compression force exerted by the punch inside the die 4 and / or other parameters of the tablets 100, such as size, hardness, porosity, weight, etc., that enable the control unit 10 to identify manufactured tablets 100 that do not meet production requirements, i.e. tablets 100a that should be rejected.

[0036] In particular, the control unit 10 identifies tablets 100a to be rejected and the dies 4 of the die table 3 which contain the tablets 100a to be rejected so that the control unit 10 can identify such tablets as they exit the die table 3 and route them into the reject conduit 8 or into the sampling conduit 9 by the reject / sampling system 7.

[0037] The reject / sampling system 7 further includes a third routing means 13 configured to route a certain number of rejected tablets 100a from the outlet conduit 6 towards the reject conduit 8, for example during an initial step of adjusting the press 1, when the produced tablets do not yet meet production requirements.

[0038] The third path determination means 13 includes, for example, a path determination element which can be moved to an operating position A to direct a certain number of tablets 100a to be rejected from the outlet conduit 6 towards the reject conduit 8. In particular, the path determination element 13 is inserted into a wall portion separating the outlet conduit 6 from the reject conduit 8 and rotates in the operating position A. In the operating position A, the path determination element 13 is inserted into the outlet conduit 6 to stop the progress of the tablets 100a to be rejected sliding in the outlet conduit 6 midway and direct the tablets 100a to a certain path.

[0039] The navigation element 13 is rotated by drive means (not shown) of known kind, for example electric or pneumatic drive means.

[0040] The operation of the rotary press 1 of the present invention includes extracting the tablet 100 from the die 4 of the die table 3 and transporting the tablet 100 into the outlet conduit 6 using the guide elements 15 of the transport means 5.

[0041] When a tablet 100a to be rejected, which has been stored by the control unit 10 and extracted from each die 4, moves on the die table 3 and reaches in front of the first path determination means 11, the first path determination means is operated by the control unit 10 to cause the tablet to be rejected to take a path and push it into the reject duct 8.

[0042] Similarly, when a tablet 100b to be sampled, which has been stored by the control unit 10 and extracted from each die 4, moves on the die table 3 and arrives in front of the second path determination means 12, the second path determination means is activated to direct the tablet 100b to be sampled and push it into the sampling conduit 9.

[0043] It should be noted that the first navigating means 11 and the second navigating means 12 act on the tablet 100 before it leaves the die table 3 .

[0044] Thus, the press 1 of the present invention is in particular capable of performing single rejection and sampling by selectively rejecting or sampling the produced tablets individually.

[0045] More precisely, the use of the routing means 11, 12, in particular pneumatic blowing compressed air, allows for a simple and economical reject / sampling system 7 which, by acting on one tablet at a time, is able to perform single rejects and samples of tablets 100 in an accurate and reliable manner, even when the press 1 is operating at high speeds.

[0046] Thus, in the case of sampling, it is possible to selectively sample only preformed tablets, even if they are separated from each other at the die table 3 by other tablets that should not be sampled. For example, it is possible to sample only all tablets produced by a particular pair of compression punches in order to precisely and accurately control their operation.

[0047] The method of the present invention for rejecting and sampling tablets, pills, lozenges, etc. produced by press 1 comprises: - conveying the tablets 100 produced by the dies 4 of the die table 3 of the compression turret 2 of the press 1 into an outlet conduit 6; - using a first routing means 11 to route the tablets 100a produced by the die 4 to be rejected one by one from the die table 3 towards the reject conduit 8; - using a second routing means 12 different from the first routing means 11, the tablets 100b to be sampled produced by the die 4 are routed one by one from the die table 3 towards the sampling conduit 9, The first and second navigation means 11 , 12 act on the tablet 100 before it leaves the die table 3 .

[0048] The steering step for the individual tablets 100a to be rejected is carried out using a jet of compressed air emitted by the first steering means 11.

[0049] The step of navigating the individual tablets 100b to be sampled is carried out using a jet of compressed air emitted by the second navigation means 12.

[0050] According to the method, each step of directing an individual tablet 100a to be rejected and an individual tablet 100b to be sampled is performed when the tablet to be rejected or the tablet to be sampled is on the die table 3 and arrives before the first routing means 11 or the second routing means 12, respectively.

[0051] The method further includes, in particular in the initial step of adjusting the press 1, a step of directing the plurality of tablets 100a to be rejected from the outlet conduit 6 towards the reject conduit 8 using a third routing means 13.

[0052] In particular, the routing elements of the third routing means 13 are used to route the plurality of tablets 100a to be rejected from the outlet conduit 6 towards the reject conduit 8. Thus, the method of the present invention can selectively reject or sample, in an accurate and precise manner, tablets produced by and extracted from the die table 3 of the press 1 one by one, thereby achieving single rejection and sampling.

Claims

1. A rotary tablet press (1), a compression turret (2) rotating about an axis of rotation (X) and including a die table (3) provided with a number of dies (4) arranged to receive the objects to be compressed and to produce the tablets (100); - conveying means (5) for conveying the tablets (100) produced by the dies (4) of the die table (3) into an outlet conduit (6); a reject / sampling system (7) configured to selectively route preformed tablets (100) produced by the die (4) of the die table (3) into a reject conduit (8) or into a sampling conduit (9), The reject / sampling system (7) comprises: a first routing means (11) configured to act on individual tablets (100a) to be rejected to direct them from said die table (3) towards said reject conduit (8); a second navigation means (12) separate from the first navigation means (11) and configured to act on individual tablets (100b) to be sampled to navigate them from the die table (3) towards the sampling conduit (9); 1. A rotary tablet press (1), characterized in that the first and second path determining means (11, 12) are configured to act on the tablet (100) before it leaves the die table (3).

2. The first path determination means (11) and the second path determination means (12) each include a compressed air supply device; 2. The rotary tablet press (1) of claim 1, wherein the compressed air supply device is adapted to emit compressed air blows capable of striking one rejected tablet (100a) at a time and directing it against one sampled tablet (100b) at a time.

3. Further comprising a control unit (10), The control unit (10) At least, the first route determination means (11) and the second route determination means (12) are connected to the first route determination means (11) and the second route determination means (12), activating the first path determining means (11) when the tablet to be rejected is on the die table (3) and arrives in front of the first path determining means (11); 3. A rotary tablet press (1) as claimed in claim 1 or 2, configured to activate the second routing means (12) when the tablet to be sampled is on the die table (3) and arrives in front of the second routing means (12).

4. The reject / sampling system (7) further comprises a third routing means (13); 4. A rotary tablet press (1) according to claim 1, wherein the third path determination means (13) is configured to direct a certain number of tablets (100a) to be rejected from the outlet conduit (6) towards the reject conduit (8), in particular during a first step of adjusting the tablet press (1).

5. The third route determination means (13) includes a route determination element, 5. The rotary tablet press (1) of claim 4, wherein the path determining element is capable of moving to an operating position (A) to direct the plurality of tablets to be rejected (100a) from the outlet conduit (6) towards the reject conduit (8).

6. 6. The rotary tablet press (1) according to claim 1, wherein the reject conduit (8) and the sampling conduit (9) are arranged side-by-side and parallel to the outlet conduit (6) and extend from the die table (3).

7. 7. A rotary tablet press (1) according to claim 1, wherein the first and second path determining means (11, 12) are arranged above the die table (3) and upstream of the outlet conduit (6) with respect to the advance direction of the tablets.

8. 8. A rotary tablet press (1) according to claim 1, wherein the second path determining means (12) is arranged on the die table (3) and upstream of the first path determining means (11) with respect to the advance direction of the tablets.

9. A method for rejecting and sampling tablets, pills, lozenges, etc. produced by a rotary tablet press (1), comprising: - conveying tablets (100) produced by dies (4) mounted on a die table (3) of a compression turret (2) of said tablet press (1) into an outlet conduit (6); - using a first routing means (11) to route the rejected tablets (100a) produced by said die (4) one by one from said die table (3) towards a reject conduit (8); - using a second navigation means (12) distinct from the first navigation means (11), to navigate the tablets (100b) produced by the die (4) one by one towards a sampling conduit (9), The method of claim 1, wherein the first and second steering means (11, 12) act on the tablet (100) before it leaves the die table (3).

10. 10. The method according to claim 9, wherein the step of steering each of the tablets (100a) to be rejected is performed using compressed air blows emitted by the first steering means (11).

11. 11. The method according to claim 9 or 10, wherein the step of steering the individual tablets (100b) to be sampled is performed using compressed air blows delivered by the second steering means (12).

12. said step of routing each of said tablets (100a) to be rejected is carried out when said tablets to be rejected are on said die table (3) and arrive before said first routing means (11); 12. The method according to claim 9, wherein the step of directing each tablet (100b) to be sampled is performed when the tablet to be sampled is on the die table (3) and arrives in front of the second routing means (12).

13. 13. The method according to any one of claims 9 to 12, further comprising, in particular in an initial step of adjusting the tablet press (1), using a third routing means to route a number of tablets (100a) to be rejected from the outlet conduit (6) towards the reject conduit (8).

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