WO2015011647A1

WO2015011647A1 - Apparatus for feeding inserts to a tablet press

Info

Publication number: WO2015011647A1
Application number: PCT/IB2014/063316
Authority: WO
Inventors: Frank BÖHM
Original assignee: Kilian Tableting Gmbh
Priority date: 2013-07-25
Filing date: 2014-07-22
Publication date: 2015-01-29
Also published as: DE202013103361U1; EP3024647A1; EP3024647B1; PL3024647T3; ES2846005T3

Abstract

The apparatus according to the invention serves for feeding inserts (cores) (11) from a separating device (12) to a tablet press (13). To this end, the apparatus (10) has an endless conveyor (14) which transports the inserts (11) with an endless, circulating conveying element, such as a conveying belt (15). It is provided according to the invention that the endless conveyor has a first conveyor part (16) and a second conveyor part (17) which can be adjusted linearly relative to the first conveyor part (16) in a direction (18) parallel to the conveying direction (19) of the inserts which are transported by the conveying element, whereby it becomes possible to decouple the second conveyor part from the tablet press and to withdraw it for maintenance purposes, with the result that sufficient working space is produced for maintenance/repair of the tablet press.

Description

APPARATUS FOR FEEDING INSERTS TO A TABLET PRESS

The invention relates to an apparatus for feeding inserts (cores) from a separating device to a tablet press, having an endless conveyor which transports the inserts from the separating device to the tablet press with an endless, circulating conveying element.

Not only single-layer tablets can be produced by way of tablet presses, in particular rotary tablet presses, but rather the tablets can also consist of two or even more layers. Here, what is known as a insert or core, for example a smaller tablet with a specific active ingredient which is to be released with a time delay, is increasingly frequently inserted into the tablets before final pressing. Inserts or cores of this type can also be a small microchip, however, which is activated after the tablet is swallowed and the tablet layers which surround it dissolve, for example upon contact with the gastric acid, and then sends a signal to a signal receiver which is situated outside the body, and it is indicated as a result of this that and when the tablet is swallowed by the patients.

In order to feed cores of this type to the tablet press and to deposit them in the die openings on a tablet layer which has already been pre-pressed there, the cores are accepted from a separating device by means of a suitable feed apparatus and are transferred to the tablet press. An apparatus of this kind of the generic type for feeding inserts is known, for example, from DE 103 21 754 B4. In the said known apparatus, the inserts are deposited in a stationary and separated manner on a driven endless conveyor and are accepted from the latter at the tablet press by means of receiving elements and are transferred to a chain conveyor, the conveying chain of which has, on a part section of its run, an arcuate course which coincides with the pitch circle of the die openings which are provided in the die table.

It is frequently necessary in practice to dismantle the endless conveyor, with the aid of which the inserts are transported to the tablet press, or to move or pivot it away from the tablet press, in order to gain access to the tablet press for maintenance or for repair purposes, in particular in order to clean the core setter, with the aid of which the inserts are accepted from the endless conveyor and are transferred into the die holes in the die tables. After maintenance or repair work of this type, the feed apparatus which conveys the inserts to the tablet press or its endless conveyor then has to first of all be oriented correctly again with respect to the tablet press, in order that the cores which are fed can also be accepted reliably from the core setter. This novel calibration of the apparatus is time- and work-intensive.

It is an object of the invention to provide an apparatus of the type mentioned at the outset, in which the endless conveyor can be removed easily and rapidly from the tablet press for maintenance purposes and, after termination of the maintenance work, can be moved similarly rapidly into its correct position on the tablet press again.

This object is achieved by way of the invention by virtue of the fact that the endless conveyor has a first conveyor part and a second conveyor part which can be adjusted linearly relative to the first conveyor part in a direction parallel to the conveying direction of the inserts which are transported by the conveying element.

As a result of the refinement according to the invention, it is possible to withdraw that one of the two conveyor parts, by which the cores are accepted from the core setter during operation of the tablet press, in a more linear manner from the tablet press and in the process to adjust it relative to the other conveyor part, by the two conveyor parts being pushed together. As a result, a sufficiently large amount of space is produced, in order for it to be possible to carry out the necessary maintenance work. After termination of said maintenance work, the two conveyor parts are then pushed apart from one another again relative to one another, the movable one of the two conveyor parts being advanced on the same path by the same amount in the direction of the tablet press, by which it was previously withdrawn in order to gain the access to the tablet press. Complicated adjusting work is therefore no longer required.

In one advantageous development of the invention, the conveying element circulates around both conveyor parts over deflection and/or drive rollers or teeth which are formed on said conveyor parts, a conveying element buffer storage region being provided in a transfer region between the first conveyor part and the second conveyor part. If the two conveyor parts are adjusted relative to one another, that is to say the overall length of the endless conveyor changes, the length of the circulating conveying element can be received in the buffer store if the overall length of the endless conveyor is reduced or can be removed from the buffer store again if the overall length of the endless conveyor is increased, with the result that, independently of the position of the two conveyor parts relative to one another, the circulating conveying element always remains reliably mounted with the required tension.

Furthermore, it has proven advantageous if the first and the second conveyor part are connected to one another by means of a linear guide, for example a sliding guide or a recirculating ball bearing guide, and can be adjusted relative to one another between a first, retracted position and a second, extended position. The first conveyor part is expediently connected in a stationary manner on the separating apparatus, whereas the second conveyor part can be advanced in the direction of the tablet press and can be withdrawn from the latter by the first conveyor part.

Moreover, it has proven expedient if a suction device is provided which is active at least on one part section of the conveying run of the conveying element. The suction device can have, in particular, a vacuum chamber which is configured at the tablet press-side end of the second conveyor part below the conveying run of the then air-permeable conveying element and is connected to a suction line. With the aid of the suction which is generated by the suction device, the inserts are pressed against the conveying element, with the result that the frictional force which acts between the inserts and the conveying element is increased. The inserts thus maintain their position on the conveying element even in the case of high conveying speeds. It is particularly advantageous if the suction line has at least one first line section which is arranged on the first conveyor part and at least one second line section which is arranged on the second conveyor part, which line sections are oriented parallel to the conveying direction, it being possible for the line sections to be displaced into one another with sealing. The suction line can therefore be arranged in the interior of the endless conveyor between the two conveyor parts. If the overall length of the endless conveyor is changed by way of relative displacement of the two conveyor parts with respect to one another, the length of the suction line is then automatically also adapted, by the one line section being pushed into the other line section or being pulled out of the latter again.

The conveying element buffer storage section is defined substantially by two deflection rollers on the two conveyor parts, which deflection rollers are wrapped around by the conveying element. Here, the arrangement is made in such a way that, if the overall length of the endless conveyor is shortened by a defined amount, the active spacing between the two deflection rollers which define the buffer storage section is enlarged by the same amount and, as a result, produces the required buffer storage for the conveying element which would otherwise be too long when the conveyor is pushed in.

The adjustable conveyor part is preferably provided with a coupling and/or centring device at its front, free end, which coupling and/or centring device has, in one simple, preferred refinement of the invention, a guide pin which, in the extended state of the adjustable conveyor part, is enclosed in a pin receptacle which is provided on the tablet press.

The conveyor parts can be capable of being locked to one another in a non-positive and/or positively locking manner in at least one telescopic position relative to one another, for example by way of an index bolt which can be actuated on the one conveyor part transversely with respect to the adjusting direction, and an adapted index opening on the other conveyor part, which index opening is aligned with the index bolt in the telescopic position. The locking capability ensures that the two conveyor parts cannot unintentionally change their relative position with respect to one another.

It is provided in one advantageous development of the invention that the endless conveyor is provided with a monitoring unit, preferably a light barrier, in the transfer region to the tablet press, in particular in the region of the suction device. Here, the arrangement is preferably made in such a way that the monitoring unit is connected at at least one connector and/or supply line, such as an optical fibre, and that a storage or winding device for the connector and/or supply line is provided on the endless conveyor. Here, the storage or winding device can have at least two deflection/storage rollers, the spacing of which from one another is variable. A construction has proven particularly advantageous, in which at least one of the deflection/storage rollers is mounted in a stationary manner on the endless conveyor and at least one other of the deflection/storage rollers is mounted rotatably on a slide element which is arranged displaceably on the endless conveyor and is prestressed by a spring force accumulator. If in each case two deflection/storage rollers are arranged in pairs firstly in a stationary manner and secondly on the slide element, a comparatively great length of the connector and/or supply line can be buffer stored in the storage device in a similar manner to a pulley, even in the case of a small displacement travel of the slide element.

Finally, it is also advantageous if the deflection and/or drive rollers or teeth are cantilever-mounted on the conveyor parts in such a way that they project in the direction of the respectively other conveyor part. The cantilever mounting of the rollers or gearwheels makes maintenance work on the conveying element particularly simple, in particular also the replacement of a conveying belt.

Further features and advantages of the invention result from the following description and the drawing, in which one preferred embodiment of the invention will be explained in greater detail using one example. In the drawing:

Fig. 1 shows an apparatus according to the invention with an extended endless conveyor in a perspective illustration,

Fig. 2 shows the object of Fig. 1 with a retracted endless conveyor,

Fig. 3 shows the object of Fig. 1 with the omission of a cover of the first conveyor part of the endless conveyor,

Fig. 4 shows the endless conveyor of the apparatus according to the invention in a retracted state, in a side view and partially in section,

Fig. 5 shows the object of Fig. 4 in the extended state,

Fig. 6 shows a detailed illustration of the suction device of the apparatus according to the invention in section,

Fig. 7 shows the apparatus according to the invention in the region of its connection on a rotary tablet press, in a plan view,

Fig. 8 shows the object of Fig. 6 in a section along the line VII-VII,

Fig. 9 shows the storage and winding device of a connector and supply line for a monitoring device in the transfer region between the tablet press and endless conveyor, in a simplified side view with an extended second conveyor part, and

Fig. 10 shows the object of Fig. 9 with a retracted second conveyor part.

The apparatus which is shown in the drawings and is denoted in its entirety by 10 serves to feed inserts 11 (cores) which are to be arranged in the interior of a pressed tablet from a separating device 12 to a rotary tablet press 13.

To this end, the apparatus 10 has an endless conveyor 14 which is connected on the separating device 12 with an endless, circulating conveying element 15 which, in the preferred exemplary embodiment which is shown and described, is a narrow, air-permeable belt which transports the inserts 11 which lie on it from the separating device to the tablet press, as will still be described in detail in the following text.

The endless conveyor 14 is formed substantially from a first conveyor part 16, which is connected in a stationary manner on the separating device, and a second conveyor part 17 which can be adjusted linearly relative to the first conveyor part 16 in a direction 18 parallel to the conveying direction 19 of the inserts 11 which are transported by the conveying element 15. Fig. 1 shows the endless conveyor 14 in a state, in which the second conveyor part 17 is situated in an extended position, in which a guide pin 21 of a coupling and centring device 22, which guide pin 21 is arranged at the free, tablet press-side end 20 of the second conveyor part 17, is enclosed in a pin receptacle 23 which is provided on the tablet press 13, which, although it cannot be seen in Fig. 1 since the tablet press is not also shown there, can be seen clearly in Fig. 8.

Fig. 2 shows the endless conveyor 14 in a retracted position of the second conveyor part 17, that is to say a state, in which the second conveyor part is pulled away as far as possible from the tablet press and therefore reaches with its rear end 24 practically as far as just in front of the housing of the separating device 12. This linear adjustability of the two conveyor parts 16, 17 relative to one another provides a sufficiently large amount of space in a particularly advantageous way for the access to the tablet press 13 if it is necessary to maintain or repair the latter, for example in order to clean the core setter unit which is denoted in its entirety by 25 in Figs 7 and 8, to accept individual cores 11 from the conveying element 15 of the endless conveyor 14 by way of the rotating setter wheel 26 of said core setter unit, and to transfer them into the dies 27 of the press, as is known in rotary tablet presses. As a result of the withdrawal of the second conveyor part 17 in the direction of the separating device, a sufficiently wide passage is produced between the tablet press and the endless conveyor, which passage provides the clearance which is required for maintenance and repair purposes of this type. When the work is concluded, the second conveyor part is again advanced linearly relative to the first conveyor part and then passes with its free front end 20, assisted by the coupling and centring device 22, exactly into the correct position relative to the core setter of the tablet press again without further adjusting work, with the result that further tablet production can be started again without delay.

As can be seen best using Figs 4 and 5, the conveying element 15 runs around both conveyor parts 16, 17 over deflection rollers 28 which are formed on the latter and around a drive roller 29 which is driven by a geared motor 30. In order that the endless conveying belt 15 does not become slack during the withdrawal of the second conveyor part 17 in the direction of the separating device 12, a conveying element buffer storage section 31 is provided between the two conveyor parts 16, 17, which conveying element buffer storage section 31 is defined substantially by two of the deflection rollers, namely the deflection rollers 28a and 28b, the deflection roller 28a being situated on the first conveyor part and the deflection roller 28b being situated on the second conveyor part, with the result that their spacing from one another is increased during retraction of the second conveyor part in the direction of the separating device 12 (Fig. 4) and is reduced during extension (Fig. 5). The two deflection rollers 28a, b are wrapped around by the conveying belt 15, whereby the lower overall length of the endless conveyor 14 in the retracted state of the second conveyor part 17 is compensated for by the length of the conveying element 15.

If Fig. 3 is now addressed which shows the conveyor 14 in the region of the first conveyor part 16 without an otherwise usually present cover 32 (cf. Figs 1, 2), it can be seen that the two conveyor parts 16, 17 are connected by means of a linear guide 33 such that they can be displaced relative to one another, the linear guide in the present exemplary embodiment being a recirculating ball bearing guide which ensures particularly smooth and exact extension and retraction of the second conveyor part 17. In Figs 1 to 3, furthermore, 34 denotes an index bolt which is a constituent part of a locking device, by way of which the two conveyor parts can be locked to one another in a non-positive and/or positively locking manner in the extended telescopic position (Fig. 1) or the retracted position (Fig. 2), in order to prevent unintentional displacement of the conveyor parts 16, 17 relative to one another. To this end, the index bolt 34 which is arranged on a side wall 35 of the second conveyor part 17 by means of a holding flange such that it can be displaced transversely with respect to the adjusting direction 18 of said conveyor part 17 interacts with index openings which are arranged on the first conveyor part 16 and of which merely one can be seen in Fig. 3 at 36. In order to release the locking action, for example in order for it to be possible to transfer the second conveyor part 17 from its telescopic position which is shown in Figs 1 and 3 into the retracted position which is shown in Fig. 2, the index bolt is gripped at its gripping knob which can be seen easily in the drawings and, for example, is pulled out to a certain extent counter to the action of a spring, with the result that the front end (not visible in the drawings) of the index bolt is pulled out of the index opening which is concealed by the side wall 35 in the drawings, and therefore does not (any longer) block a movement of the conveyor part 17 in the longitudinal direction 18. As soon as the second conveyor part has withdrawn completely in the direction of the separating device 12, the index bolt 34 then passes into alignment with the rear index opening 36 (visible in Fig. 3), into which it can then be enclosed or inserted for locking purposes.

In order that the cores 11 which are fed from the endless conveyor 14 to the tablet press 13 remain lying on the conveying element reliably in the transfer region between the conveyor and the tablet press, in which transfer region the cores are accepted by the setter wheel, until said acceptance, the apparatus according to the invention is provided with a suction device 42 in the region of the core setter 25 in a part section 40 of the upper conveying run 41 of the conveying element 15. At the tablet press-side end 20 of the second conveyor part 17 below the conveying run 41 of the conveying belt 15 which is air-permeable as has already been mentioned, said suction device 42 has a vacuum chamber 43 which is connected to a suction line 44. By way of said suction line, a vacuum is generated in the vacuum chamber, as a result of which suction is produced through the air-permeable conveying belt 15, which suction causes the cores 11 which lie on the conveying run of the conveying belt to be pressed against said conveying belt. The suction line 44 which is arranged in the interior of the endless conveyor 14 has a first line section 45 which is arranged on the first conveyor part 16 and a second line section 46 which is arranged in the interior of the second conveyor part 17, the arrangement being made in such a way that both line sections 45, 46 run parallel to the conveying direction 19 and can be displaced into one another with sealing 47. As a consequence, the second line section 46 can be pushed into the first line section 45 during the withdrawal of the second conveyor part 17 away from the tablet press 13 and toward the separating device 12, with the result that the length of the suction line 44 is adapted automatically during the withdrawal movement of the second conveyor part to that projecting length of the endless conveyor 14 which is then reduced.

A monitoring device 50 is provided for monitoring the reliable conveying of the cores 11 in the transfer region between the conveyor and the tablet press, which monitoring device 50 is formed substantially by a light barrier 51 which is connected to a control and evaluation device (not shown) via an optical fibre 52 which is guided through the interior of the endless conveyor 18. It is monitored with the aid of the light barrier 51 that there are cores 11 in the region of the accumulating section of the conveyor above the vacuum chamber 43 in front of the setter wheel 26 of the tablet press and that they also bear tightly against one another there in every case, in order that the cores 11 are not damaged when accepted by the driver arms of the setter wheel 26. In order that the optical fibre 52 is wound up correctly in the interior of the conveyor and is not damaged during the withdrawal of the second conveyor part 17, a storage and winding device for said connector and supply line is provided, which storage and winding device is denoted in its entirety by 53 in Fig. 3. Figs 9 and 10 show more detail of the storage and winding device 53.

As can be seen in Figs 9 and 10, the storage and winding device 53 has a total of four deflection/storage rollers, of which the rollers 54 and 55 are mounted rotatably on a bearing block 56 which is arranged in a stationary manner in the interior of the first conveyor part 16, whereas the two other deflection rollers 57 and 58 are mounted rotatably on a slide element 59 which can be displaced in the interior of the first conveyor part of the endless conveyor 14 along two guide rods 60. The slide element 59 is prestressed by a spring force accumulator which is formed by a helical tension spring 61. It can be seen from Figs 9 and 10 that the optical fibre 52, on which the light barrier 51 is connected, wraps around the fixed deflection/storage rollers 54, 55 and the movable deflection/storage rollers 57, 58 in each case alternately as in a pulley. The transmission ratio of the storage section which is formed by the four rollers is therefore 4:1, with the result that, during the withdrawal of the second conveyor part 17 away from the tablet press 13 towards the separating device 12 by the entire available displacement travel, the slide element 59 is pulled by precisely one quarter of the entire displacement travel by the tension spring 61 away from the bearing block 56 which is arranged in a stationary manner and, as a result, stores that length of the optical fibre between the four deflection rollers which is not required in the withdrawn state of the second conveyor part.

All the deflection rollers including the drive roller 28 and the deflection rollers 28 are cantilever-mounted on the two conveyor parts 16, 17, with the result that they project freely in the direction of the respectively other conveyor part. As a result, it is readily possible to change both the optical fibre and the conveying element 15, without it being necessary for the endless conveyor 14 to be dismantled to an appreciable extent for this purpose.

The invention is not restricted to the exemplary embodiment which is shown and described, but rather various modifications are conceivable without departing from the scope of the invention. It is thus possible, for example, to produce the telescoping capability of the endless conveyor not only by way of two conveyor parts which can be displaced relative to one another, but rather it is also possible that the endless conveyor consists of more than two conveyor parts, for example of three or four conveyor parts, if it proves necessary that the endless conveyor is adjustable over a relatively large adjustment travel between the separating device and tablet press. Instead of the tension spring 61 which is used in the storage and winding device of the exemplary embodiment which is described, another spring force accumulator, in particular a compression spring, can also be used there.

Claims

1. Apparatus for feeding inserts (cores) from a separating device (12) to a tablet press (13), having an endless conveyor (14) which transports the inserts (11) from the separating device (12) to the tablet press (13) with an endless, circulating conveying element (15), characterized in that the endless conveyor (14) has a first conveyor part (16) and a second conveyor part (17) being adjustable linearly relative to the first conveyor part (16) in a direction (18) parallel to the conveying direction (19) of the inserts (11) which are transportable by means of the conveying element (15).

2. Apparatus according to Claim 1, characterized in that the conveying element (15) is circulatable around both conveyor parts (16, 17) over deflection and/or drive rollers (28, 29) or teeth which are formed on said conveyor parts (16, 17), and in that a conveying element buffer storage section (31) is provided in a transfer region between the first conveyor part (16) and the second conveyor part (17).

3. Apparatus according to Claim 1 or Claim 2, characterized in that the first and the second conveyor part (16, 17) are connected to one another by means of a linear guide (33), for example a sliding guide or a recirculating ball bearing guide, and are adjustable relative to one another between a first, retracted position and a second, extended position.

4. Apparatus according to one of Claims 1 to 3, characterized in that the first conveyor part (16) is connected in a stationary manner on the separating apparatus (12), and in that the second conveyor part (17) is advancable in the direction of the tablet press (13) and is withdrawable from the latter by the first conveyor part (16).

5. Apparatus according to one of Claims 1 to 4, characterized by a suction device (42) which is active on at least one part section (40) of the conveying run (41) of the conveying element.

6. Apparatus according to Claim 5, characterized in that the suction device (42) has a vacuum chamber (43) which is configured at the tablet press-side end (20) of the second conveyor part (17) below the conveying run (41) of the air-permeable conveying element (15) and is connected to a suction line (44).

7. Apparatus according to Claim 6, characterized in that the suction line (44) has at least one first line section (45) which is arranged on the first conveyor part (16) and at least one second line section (46) which is arranged on the second conveyor part (17), which line sections (45, 46) are oriented parallel to the conveying direction (19), with the line sections (45, 46) being displacable into one another with sealing (47).

8. Apparatus according to one of Claims 2 to 7, characterized in that the conveying element buffer storage section (31) is defined substantially by two deflection rollers (28) on the two conveyor parts (16, 17), which deflection rollers (28) are wrapped around by the conveying element (15).

9. Apparatus according to one of Claims 1 to 8, characterized in that the adjustable conveyor part (17) is provided with a coupling and/or centring device (22) at its front, free end (20).

10. Apparatus according to Claim 9, characterized in that the coupling and/or centring device (22) has a guide pin (21) which, in the extended state of the adjustable conveyor part (17), is enclosed in a pin receptacle (23) which is provided on the tablet press (13).

11. Apparatus according to one of Claims 1 to 10, characterized in that the conveyor parts (16, 17) are lockable to one another in a non-positive and/or positively locking manner in at least one telescopic position relative to one another.

12. Apparatus according to Claim 11, characterized by an index bolt (34) being actuable on the one conveyor part (17) transversely with respect to the adjusting direction (18), and an adapted index opening (36) on the other conveyor part (16), which index opening (36) is aligned with the index bolt (34) in the telescopic position.

13. Apparatus according to one of Claims 1 to 12, characterized in that the endless conveyor (15) is provided with a monitoring device (50), preferably a light barrier (51), in the transfer region to the tablet press (13), in particular in the region of the suction device (42).

14. Apparatus according to Claim 13, characterized in that the monitoring device (50) is connected to at least one connector and/or supply line (52), such as an optical fibre, and in that a storage or winding device (53) for the connector and/or supply line (52) is provided on the endless conveyor (14).

15. Apparatus according to Claim 14, characterized in that the storage or winding device (53) has at least two deflection/storage rollers (54, 55, 57, 58), the spacing of which from one another is variable.

16. Apparatus according to Claim 15, characterized in that at least one of the deflection/storage rollers (54, 55) is mounted in a stationary manner on the endless conveyor (14) and at least one other of the deflection/storage rollers (57, 58) is mounted rotatably on a slide element (59) which is arranged displaceably on the endless conveyor (14) and is prestressed by a spring force accumulator (61).

17. Apparatus according to one of Claims 1 to 16, characterized in that the deflection and/or drive rollers (28, 29) or teeth are cantilever-mounted on the conveyor parts (16, 17) in such a way that they project in the direction of the respectively other conveyor part (17, 16).