EP0648151B1 - Method and device for grading capsules - Google Patents

Abstract

PCT No. PCT/EP93/01534 Sec. 371 Date Jun. 12, 1995 Sec. 102(e) Date Jun. 12, 1995 PCT Filed Jun. 16, 1993 PCT Pub. No. WO94/00249 PCT Pub. Date Jan. 6, 1994Disclosed is an apparatus for sorting capsules of hard or soft gelatin, starch or another material, for faultless and faulty capsules. In the apparatus, capsules are first fed from a supply container holders in a control station, then conveyed in the capsule holders through individual control positions in the control station where they are observed using cameras. The images acquired by the cameras are evaluated to determine production faults in the capsules. The faulty capsules are finally ejected from the control station separately from faultless capsules.

Description

The invention relates to a method and an apparatus for sorting capsules for defect-free and defective capsules, e.g. B. capsules for oral drugs.

Such capsules mainly serve as a casing or container for a powdered or granulated medicament and are taken together with it. These capsules are made of a physiologically safe material, e.g. B. from hard or soft gelatin, from starch or from another material that does not contain the active ingredient of the drug itself. In the following, for example, mostly only gelatin capsules are mentioned. Gelatin capsules are mass-produced in high-performance production processes from gelatin or gelatin solution. A distinction is made between hard gelatin capsules and soft gelatin capsules.

Hard gelatin capsules consist of a hollow upper part (cap) and a hollow lower part (body), which are produced simultaneously on one machine. The capsule parts are temporarily assembled into a finished capsule without filling material, resulting in a small empty oblong container. In order to ensure the quality of the end product, the hard gelatin capsules are manufactured with the highest demands on the dimensional accuracy and cleanliness of the corresponding machine components and the capsule parts produced with them.

Hard gelatin capsules are made in different colors and color combinations, transparent and opaque. The empty hard capsule has a weight of approx. 30 to 130 mg depending on the size.

With regard to further processing, the dimensional accuracy of the hard gelatin capsules is of particular importance. They are passed on to the pharmaceutical industry as empty capsules and filled with the drug here. The empty capsules are separated into upper and lower parts, whereby the lower part takes up the contents and the empty upper part is then replaced. Both capsule halves are firmly and permanently joined together by pressure so that the contents can no longer escape.

The hard gelatin capsules produced on conventional production machines can have defects, such as holes, deformations or blisters, which can cause considerable problems when filling. Any downtimes of the filling machines that may result from this should be avoided. Therefore defective capsules have to be sorted out by the manufacturer.

This sorting process is currently accomplished by manually reading the capsules. The capsules to be sorted fall from a container mounted on a vibrator onto a transparent conveyor belt. The capsules on this conveyor or sorting belt are illuminated from below or from above. One or more people carry out a visual inspection of the capsules and remove the defective capsules from the passing conveyor belt by hand. Each control person sees only about 30 to 40% of the surface of a capsule on a picking belt. A complete control of the quality of the capsule is therefore not possible. In addition, the result of this quality control is significantly influenced by the attention of the respective control person and by their subjective assessment.

DE-A-2 937 335 describes a device for sorting tablets for faultless and defective tablets, the device also appearing suitable for sorting capsules. It has the following features: A control station with various control positions suitable for recording and evaluating the properties of tablets and feed devices suitable for feeding tablets from a storage container to the control station. Cameras and light sources are arranged in the control station at some control positions, which are suitable for all-round viewing of tablets and which are followed by evaluation devices. Finally, ejection devices are provided which serve for the separate ejection of error-free and defective tablets, the device as a whole also appearing to be suitable for processing capsules.

The objects to be sorted are free on a conveyor table, so that precise guidance of the objects is not guaranteed, as a result of which the work result can be impaired. In addition, the known device requires a relatively large amount of space.

GB-A-2 002 512 describes a device for sorting capsules with a control station that works with X-rays, and with a device opposite and therefore far away for feeding capsules from a storage container into tubular capsule holders. In this case, several control positions are not provided, so that a flawless examination of the capsules and thus a flawless work result is not ensured, this known device also requiring a great deal of space.

It is an object of the invention to provide a method and an associated device for sorting capsules for defect-free and defective capsules, in which the problems associated with manual reading of the capsules are eliminated. In particular, the sorting of the capsules is to be carried out without control persons and therefore to be automated, and a perfect work result is to be achieved with a compact device.

The invention describes a method and a device for sorting out defective capsules, wherein the capsules can be viewed all around in a control station in individual control positions by means of cameras. The images recorded by the cameras are evaluated using computer programs to determine production errors. The defective capsules are finally sorted out according to the result of the evaluation.

A method according to the invention for sorting capsules is described in claim 1. Claims 2 to 7 characterize further developments of this method. A device according to the invention for sorting capsules is described in claim 8. Developments of this sorting device are described in claims 9 to 23.

The automated, electronic sorting method according to the invention and the associated device enable complete control of the capsules on the basis of the all-round view. Since human inadequacies are eliminated, the result of the sorting process is significantly improved. Capsule producers can therefore meet the quality requirements of the pharmaceutical industry as capsule buyers.

The sorting method and the sorting device according to the invention can be used, for example, for sorting out defective, empty, pre-closed or filled, closed hard gelatin capsules. Furthermore, can the invention can also be used for sorting out soft gelatin capsules, capsules made of starch or other materials, and tablets, coated tablets and lozenges.

Fig. 1

ist eine schematische Ansicht einer Sortiereinrichtung mit einer Kontrollstation von oben;

Fig. 2

ist eine Seitenansicht, zum Teil im Schnitt, einer Kontrollposition der Sortiereinrichtung;

Fig. 3

ist eine Seitenansicht der Kontrollposition aus Fig. 2 im Schnitt;

Fig. 4

ist eine Ansicht im Schnitt entlang der Linie A-A aus Fig. 3;

Fig. 5

ist eine Ansicht einer anderen Kontrollposition der Sortiereinrichtung von oben;

Fig. 6

ist eine Seitenansicht im Schnitt entlang der Linie B-B aus Fig. 5.

An embodiment of the invention, which serves to sort out transparent or opaque empty, pre-sealed hard gelatin capsules, is described in detail below with reference to the drawings.

Fig. 1

is a schematic view of a sorting device with a control station from above;

Fig. 2

is a side view, partly in section, a control position of the sorting device;

Fig. 3

is a side view of the control position of Figure 2 in section.

Fig. 4

is a sectional view taken along line AA of Fig. 3;

Fig. 5

is a top view of another control position of the sorter;

Fig. 6

5 is a sectional side view taken along line BB of FIG. 5.

The device for sorting gelatin capsules by defect-free capsules 2 and defective capsules 3 consists of at least one control station 5, which has different control positions 10, 20, 30, 40, 50, 60 for recording and evaluating the properties of the capsules 2, 3. In the control positions, the capsules 2, 3 are held by capsule holders 70. Furthermore, the sorting device has feed devices 90 through which the capsules 2, 3 pass from a storage container 80 into the capsule holders 70, as well as ejection devices 51, 61, through which the error-free capsules 2 are ejected from the control station 5 separately from the defective capsules 3 .

One capsule 2, 3 is held in a capsule holder 70 and is conveyed through six control positions 10, 20, 30, 40, 50, 60 in the control station 5. At the first control position 10 in the control station 5, the capsules 2, 3 are provided in the capsule holders 70. For this purpose, the capsules are removed from the storage container 80 and arranged in the feed device 90 on a guide track 7 in rows of capsules lying one behind the other in a traffic jam. The feed device 90 consists of a downward-pointing tube 91 which is fastened with its upper end to a base plate 81 of the storage container 80. Driven by a stepper motor, the base plate 81 rotates relative to the fixed housing 83 of the storage container 80, as a result of which the capsules 2, 3 reach the tube 91 from the storage container via holes 82 in the base plate 81.

The feed device 90 has two locking bolts 92, 93 connected in series, which are mechanically controlled via guides in such a way that they are lifted one after the other. The first locking pin 92 serves to build up the capsules 2, 3 in the tube 91, while the second locking pin 93 separates the capsules 2, 3 from the jam into the capsule holder 70. The locking bolts thus enable only one capsule to be located in the capsule holder. If several capsules were in a capsule holder at the same time, problems would arise in the further course of the control process. In particular, the capsules could jam at the end of the control station 5 when ejected.

The capsule holder 70 is attached to the outer, lower end of the feeder 90. It consists of a U-shaped, trapezoidal upwardly open rail 71 which has on its underside a slot 72 with pointed edges running in the conveying direction of the capsules 2, 3, on which the capsules fit. At its outer end, the capsule holder 70 has a tip, for example in the form of a grub screw, for supporting the capsules.

After the capsules 2, 3 are provided in the capsule holders 70 at the first control position 10 in the control station 5, the capsules in the capsule holders 70 are conveyed through the following control positions 20, 30, 40, 50, 60. In order to check the capsules for production errors, 5 cameras 21, 31, 32, 33 and light sources 22, 34 are arranged at the second and third control positions 20, 30 in the control station for a complete all-round view of the capsules. A separate image processing computer program is provided for each camera 21, 31, 32, 33, which electronically evaluates the captured image and uses this to determine the nature of the capsules. Since capsules of different colors are to be checked, a color recognition is included in the computer program.

The light sources 22, 34 in the control positions 20, 30 consist of light-emitting diodes which emit light in a region which is visible to the cameras and which is suitable for illuminating the capsules 2, 3. The cameras in the control stations are essentially arranged on the other side of the capsules, opposite the light source. If a transparent or opaque capsule is checked, the light from the light source shines through it, essentially in the direction of the cameras.

Due to the special arrangement of the light sources and the cameras in the second and third control stations 20, 30, a complete all-round view of the capsules is possible, and any errors that may occur with capsules can be recognized. For example, it can be determined whether the capsule has holes, bubbles, deformations or contaminants at any point. The dome on the upper and lower part of the capsule is also checked for damage. In addition, the The position of the capsule (e.g. upper or lower part), the length and diameter of the upper and lower part of the capsule are determined and the cutting edge of the upper part is checked for irregularities.

The points at which the capsule is supported in the capsule holder 70, i.e. the edges on the slot 72 of the rail 71 and the screw tip at the end of the capsule holder 70, are dimensioned and arranged in such a way that all areas of the capsule are exposed to the light sources 22, 34 X-rayed or illuminated and can be detected by the cameras 21, 31, 32, 33.

In the second control position 20 in the control station 5 (FIGS. 2 to 4), the capsules 2, 3 are viewed by a first camera 21. The camera 21 is arranged under the capsule holder 70, that is, under the feed path 7 of the capsules, so that it sees the capsules from below / behind. A light source 22 is arranged above the capsule holder 70, ie above the feed path 7 and thus opposite the camera 21, which illuminates the capsules 2, 3 from above / in front.

Since the capsules 2, 3 cannot yet be completely captured by the camera 21 in the second control position 20, they are viewed again in the third control position 30 by means of two cameras 31, 32 from other directions (FIGS. 5 and 6). A further light source 34 is provided for illuminating the capsules. The cameras 31, 32 are arranged obliquely above, to the side of the capsule holder 70, that is to say above and to the side of the feed path 7 of the capsules 2, 3, one camera 31 seeing the capsules from the right front and the other camera 32 seeing the capsules from the left front. In addition, a third camera 33 can optionally be arranged directly above the capsule holder, ie above the feed path 7 of the capsules, which is inclined to the other two cameras 31, 32 and the capsules directly from looks up / front. The light source 34 is arranged under the capsule holder, that is, under the feed path 7, and illuminates the capsules from below / behind.

The capsules 2, 3 are conveyed through the control positions 10, 20, 30, 40, 50, 60 in the capsule holders 70, but do not move in relation to the capsule holders 70 themselves. 31, 32, 33 considered. Thus, the capsule 2, 3 does not rotate relative to the cameras, nor do the cameras move around the capsule.

The fourth control position 40 is a waiting position during which the computer program evaluates the images taken in order to determine production errors in the capsules.

The result of the evaluation is converted in the fifth or sixth control position into a separation of the defect-free capsules 2 from the defect capsules 3. For this purpose, a compressed air valve 51 is provided in the fifth control position, which is controlled and activated by the computer program if the corresponding capsule has no errors. The defect-free capsule 2 is thus blown out of the capsule holder 70 by the compressed air valve 51 and taken up by a collecting container. If the computer program has found an error on the capsule, the compressed air valve is not activated in the fifth control position 50. Rather, the capsule passes through this control position and finally reaches the sixth control position 60. Here, a further compressed air valve 61 is provided, which is controlled and activated by the computer program if the capsule has a fault. Defective capsules 3 are thus blown out of the capsule holder 70 at the sixth control position 60 by the compressed air valve 61 and taken up by a collecting container.

In order to ensure correct functioning of the sorting device, the stepper motor runs, which rotates the base plate 81 of the storage container 80 relative to its housing 83, thereby the feed devices 90 with the capsule holders 70 attached to them are moved through the six control positions, synchronously with the cameras at the control positions 20 and 30. Each camera must therefore take a picture of a capsule exactly when it is in the corresponding control position. The camera should not take a picture while the capsule holder moves with the capsule into the next control position.

While a capsule is viewed by the camera 21 in the second control position 20, the next capsule is already provided in the first control position 10. By further rotation of the capsule holders 70 (in the direction of the arrow in FIG. 1), the first capsule reaches the third control position 30, where it is viewed by the cameras 31, 32, 33, while the second capsule reaches the second control position 20 and is viewed here by the camera 21. A third capsule is already provided in the first control position 10. By further turning the capsule holders 70, the first capsule reaches the control position 40, the second capsule the control position 30, the third capsule the control position 20, while a further capsule is provided in the first control position 10. While the first capsule is in the waiting position in the control position 40, the computer program evaluates the images of the first capsule recorded by the cameras in the previous steps, although the subsequent capsules in the corresponding control positions 20 and 30 are already being viewed by the cameras. The computer program thus enables parallel observation and evaluation of successive capsules.

1 schematically shows six feed devices 90 with the associated control positions 10, 20, 30, 40, 50, 60 only in one quadrant of the circular base plate 81 of the storage container 80. Analogously, this arrangement can be repeated in the other three quadrants of the circular base plate, so that a total of four control stations 5, each with six control positions, are arranged around a storage container 80. If the base plate is dimensioned differently, more or fewer control stations 5 with the respectively associated control positions can be arranged around the storage container 80.

With the arrangement of four control stations shown in this exemplary embodiment, approximately 70,000 capsules per hour can be checked, which corresponds to a typical performance of a gelatin capsule production machine. Accordingly, approximately 17,000 to 18,000 control steps are carried out in each of the four control stations. The number of capsules checked can be increased accordingly by multiplying the control stations.

The described method and the device for sorting empty, pre-sealed hard gelatin capsules can, for example, be connected directly to the capsule production machine. However, an arrangement in other production steps is also conceivable, e.g. B. where heavily opaque or filled hard gelatin capsules or soft gelatin capsules, which are filled and sealed immediately during production, should be checked and sorted out. In the latter cases, the capsule is no longer transparent and can therefore no longer be illuminated by the light sources and the cameras. The cameras and the light sources are then arranged in the control positions such that the capsule body can only be illuminated and viewed from the outside, but that a complete all-round view of the capsule is nevertheless possible. The same applies to the control of tablets, coated tablets, etc.

Claims (23)

1. A method of sorting capsules, in particular gelatin capsules, for sound (2) and defective (3) capsules, with the following steps:

   - feeding the capsules (2, 3) to a control station (5);

   - all round observation of the capsules (2, 3) in individual control positions (10, 20, 30, 40, 50, 60) by means of cameras (21, 31, 32, 33) in the control station (5);

   - evaluation of the images acquired by the cameras (21, 31, 32, 33) by means of computer programs for determining production defects in the capsules (2, 3);

   - conversion of the result of the evaluation to a sorting out of the defective capsules (3);

   - the capsules (2, 3) are being fed into capsule holders (70) at a first control position (10);

   - the capsules (2, 3) in the capsule holders (70) are conveyed through further control positions (20, 30, 40);

   - the capsules (2, 3) are ejected out of the capsule holders (70) at a last control position (50, 60) separated according to sound and defective capsules.
2. Method according to claim 1, characterized in that one capsule (2, 3) at a time is held in a respective capsule holder (70) and in the latter is conveyed through the various control positions (10, 20, 30, 40, 50, 60) in the control station (5).
3. Method according to any one of the preceding claims, characterized in that the step of feeding the capsules (2, 3) includes the following substeps:

   - removal of capsules from a supply container (80) in rows of capsules piled up one behind the other;

   - separation of the capsules individually from the pile-up into the capsule holder (70).
4. Method according to any one of the preceding claims, characterized in that the step of the all round observation of the capsules (2, 3) includes the following substeps:

   - observation of the capsules in a second control position (20) by means of at least one first camera (21);

   - observation of the capsules in a third control position (30) by means of at least one second camera (31, 32, 33);

   - positioning of the capsules in a fourth control position (40) in a waiting position whilst the computer program evaluates the images acquired.
5. Method according to claim 4, characterized in that during the observation the capsules (2, 3) and the cameras (21, 31, 32, 33) are stationary.
6. Method according to any one of the preceding claims, characterized in that the step of converting the result of the evaluation includes the following substeps:

   - ejection of the sound capsules (2) from the capsule holder (70) at a last control position (50);

   - ejection of the defective capsules (3) from the capsule holder (70) at another last control position (60).
7. Method according to claim 6, characterized in that the ejection is effected by blasting out.
8. An apparatus for sorting capsules, in particular gelatin capsules, for sound (2) and defective (3) capsules, with the following features:

   - a control station (5) having various control positions (10, 20, 30, 40, 50, 60) for receiving the capsules (2, 3) and evaluating the properties thereof;

   - feed means (90) for feeding the capsules (2, 3) from a supply container (80) to the control station (5);

   - in the control station (5) at some control positions (20, 30) there are arranged cameras (21, 31, 32, 33) and light sources (22, 34) for all round observation of the capsules (2, 3) with evaluating devices following thereafter for evaluation of the images acquired by the cameras by means of computer programs for determining production defects in the capsules;

   - ejection means (51, 61) for separate ejection of sound (2) and defective (3) capsules;

   - a plurality of capsule holders (70) for holding the capsules (2, 3) in the control positions (10, 20, 30, 40, 50, 60);

   - in the first control position (10) there are provided means for feeding the capsules (2, 3) into the capsule holders (70);

   - at the last control position (50, 60) means (51, 61) are provided for separate ejection of the sound (2) and the defective (3) capsules from the capsule holders (70).
9. Sorting apparatus according to claim 8, characterized in that for each camera (21, 31, 32, 33) a separate image-processing computer program is provided for electronic evaluation of the acquired image and for determining the properties of the capsules (2, 3).
10. Sorting apparatus according to claim 9, characterized in that the computer program includes a colour identification.
11. Sorting apparatus according to claim 8, characterized in that the light sources (22, 34) consist of light emitting diodes which emit a light in the visible region which is suitable for transillumination of the capsules (2, 3).
12. Sorting apparatus according to any one of claims 8 to 11, characterized in that the control station (5) has six control positions (10, 20, 30, 40, 50, 60), in which

    - in the second control position (20) at least one camera (21) is provided which observes the capsules (2, 3) from one side;

    - in the third control position (30) at least one further camera (31, 32, 33) is provided which observes the capsules (2, 3) from another side; and

    - the fourth control position (40) is a waiting position in which the computer program evaluates the acquired image.
13. Sorting apparatus according to claim 8, characterized in that one capsule (2, 3) at a time is held in each capsule holder (70) which passes through the various control positions (10, 20, 30, 40, 50, 60) in the control station (5).
14. Sorting apparatus according to claim 8, characterized in that the feed means (90) consists of a downwardly directed tube (91) which has blocking means (92, 93) for piling up and separating the capsules (2, 3).
15. Sorting apparatus according to claim 14, characterized in that the capsule holder (70) is secured to the outer end of the feed means (90).
16. Sorting apparatus according to claim 15, characterized in that the capsule holder (70) consists of a U-shaped upwardly open rail (71) which comprises at its lower side a slot (72) which extends in the conveying direction of the capsules (2, 3) and has pointed edges on which the capsules bear and which comprises at its outer end a tip for supporting the capsules (2, 3).
17. Sorting apparatus according to claim 14, characterized in that the feed means (90) is secured with its upper end to a bottom plate (81) of a supply container (80), the bottom plate (81) having holes (82) through which the capsules (2, 3) pass from the supply container (80) into the feed means (90).
18. Sorting apparatus according to claim 17, characterized in that the supply container (80) comprises a stepping motor for turning the bottom plate (81) relatively to the housing (83) of the supply container (80).
19. Sorting apparatus according to any one of claims 8 to 18, characterized in that the stepping motor runs synchronously with the cameras (21, 31, 32, 33).
20. Sorting apparatus according to claim 17, characterized in that on the bottom plate (81) six feed means (90) are provided.
21. Sorting apparatus according to any one of claims 8 to 20, characterized in that in the control station (5)

    - in the second control position (20) beneath the feed path (7) of the capsules (2, 3) a camera (21) is provided which observes the capsules from below/behind, and above the feed path (7) a light source (22) is provided which lies opposite the camera (21) and illuminates the capsules from above/the front;

    - in the third control position (30) at least two cameras (31, 32) and a light source (34) are provided, the cameras (31, 32) being arranged above the feed path (7) of the capsules (2, 3) and the one camera (31) of which observes the capsules from the front right and the other camera (32) observes the capsules from the front left, a third camera (33) possibly being provided above the feed path (7) of the capsules and arranged inclined to the other two cameras (31, 32), observing the capsules directly from above/the front, and the light source (34) is arranged beneath the feed path (7) and illuminates the capsules from below/behind;

    - in the fifth control position (50) a pressurized air valve (51) is provided which blasts the sound capsules (2) out of the capsule holder (70).

    - in the sixth control position (60) a pressurized air valve (61) is provided which blasts the defective capsules (3) out of the capsule holder (70).
22. Sorting apparatus according to any one of claims 8 to 21, characterized in that it comprises a plurality, in particular four, control stations (5).
23. Sorting apparatus according to any one of claims 8 to 22, characterized in that it is directly connected to a production machine for hard gelatin capsules.

Images