EP3840895B1 - Method for selective removal of rippling products - Google Patents

Description

The invention relates to a method for selectively separating out free-flowing products that are conveyed in a conveying direction along a conveying path in a conveying path, the conveyed products being checked in a control section of the conveying path using a checking device, and being in a sorting section arranged downstream along the conveying path the product that does not meet a predeterminable control criterion is separated from the conveyor track with a suction device and discharged by arranging the suction device on the conveyor section and generating a suction stream flowing away from the conveyor track for a predefined suction duration in order to suck the product out of the conveyor track.

Various areas of application are known from practice, in which free-flowing products are conveyed in a packaging along a conveyor line during production or when they are packaged. In many cases, the products are first separated in order to be conveyed one after the other in the conveying direction in a conveying track usually formed by a groove-shaped depression. In this case, the conveyor track can be designed, for example, as a vibrating conveyor to be directed by a continuous Vibration movement to transport the products located in the conveyor track in the conveying direction over the conveying path. A particularly relevant for the pharmaceutical industry application of such a transport of products is the separation and transport of individual tablets or capsules during a manufacturing process or when packaging the tablets or capsules in containers such as bottles or cardboard boxes.

In order to prevent damaged or defective products from being conveyed further and possibly filled into packaging, it is known from practice that suitable methods are used to selectively separate out and remove those products from the conveyor line that do not meet a predetermined control criterion. For example, the individual products can be recorded with a camera and checked for optical deviations from a specified appearance. It is also conceivable that the weight of the individual products is checked with the control device. For many areas of application, it is expedient and advantageous to at least also carry out a check for contamination of the products, in which case the contamination can affect, for example, visual perception, a chemical composition or metallic particles or dirt particles. If an individual product does not meet the specified control criterion, such as a specified appearance or a specified minimum weight, the product in question should be discarded if possible, in order not to be further processed and possibly packaged and delivered.

Various methods for selectively separating out products within such a conveyor section are known from practice. For example, products to be sorted out can be moved out of the conveyor track with a targeted jet of compressed air and excluded from further transport. It is also known to use suitable mechanical devices such as flaps or displaceable deflector plates to displace the products to be sorted out from the conveyor track or from a predetermined conveying path and to exclude them from further conveyance. Such a device is, for example, in JP-A-6275911 shown and described.

It has also proven itself in practice to suck the products to be separated out of the conveyor track with a suction device. For this purpose, a suction pipe is usually brought directly above or next to the conveyor track to the product to be sorted out and a suction flow flowing away from the conveyor track is generated for a predetermined suction duration, with which the product is sucked out of the conveyor track. The extracted product can be fed through the suction pipe to a storage container for rejected products. In contrast to blowing a faulty product out of the conveyor track, sucking off the product with a suction device prevents the separated products or, for example, their abrasion or impurities from being blown out of the conveyor track in a more or less uncontrollable manner will. Such a device is, for example, in EP 2 774 693 A shown and described.

In order to be able to reliably suck off the product to be separated out from the conveyor track, the suction device is regularly operated for a predetermined suction duration, which is sufficient to be able to reliably suck off the product to be separated out out of the conveyor track. However, it has been found that it is often unavoidable that a second product following the product to be sorted out is attracted by the suction flow generated and sucked off by the suction device and accelerated in the direction of the suction device, so that the distance between the following second product increases the preceding first product to be discarded is reduced. In some cases, the distance between the following second product and the preceding first product is too small even before the start of the suction period, or due to an acceleration exerted on the following second product during the suction period, it is so small towards the end of the suction process that the second product is also sucked off or is pulled out of the conveyor track by the suction device and no longer reliably falls back into the conveyor track after the end of the suction period. If the distance between the following second product and the preceding first product is too small or if the second product is accelerated due to the suction process of the first product, there is often not enough time to start the second suction process in good time after the end of the first sowing process , in order to still be able to reliably suck off the following second product. If the suction time is reduced in order to be able to rule out an undesired impairment of the second product following in the conveyor track as far as possible, the suction duration would often have to be specified so short that the first product to be separated out can no longer be reliably sucked off.

It is therefore considered an object of the present invention to design a method for selectively separating products from the conveyor track using a suction device in such a way that a subsequent product that is also to be separated out is reliably sucked off, while a subsequent product that is not is to be sucked off, remains in the conveyor track. This object is achieved according to the invention in that the control device checks whether a product to be separated out is followed by a second product that also does not meet the specified control criterion and therefore also has to be separated out, and that the suction time is extended by a specifiable extension period in order to continue without interruption suck off the following second product from the conveyor track. By adapting and, if necessary, lengthening the suction duration as a function of the subsequent second product, it can be ensured that a second product that is also to be separated out is also reliably suctioned off without the suction process having to be interrupted in the meantime and restarted. It has been shown that with uninterrupted suction, a subsequent product that is also to be sorted out can be suctioned off much more reliably and at the same time the suction duration is increased the suction of the second product can be ended earlier in order to influence a subsequent product that is no longer to be sorted out as little as possible and to impair its transport along the conveyor line as little as possible. The method according to the invention can be used particularly advantageously in the case of a conveyor track designed in the form of a groove.

With the method according to the invention, it is no longer necessary to specify the suction duration, during which a first product to be separated out is sucked off, as short as possible with regard to a subsequent second product that is also to be separated out, in order to reliably continue the suction process for the first product after the suction process has ended finish and then start again in order to be able to reliably suck off the second product as well. Rather, the lengthening of the suction process ensures that the following second product is sucked off early and reliably even in the event of an acceleration generated during the suction of the first product in the direction of the suction device.

It is also possible to initially briefly specify the suction duration for sucking off a first product to be separated out and to check with the aid of a suitable controller or regulator whether the first product to be separated out has been sucked off and to extend the suction duration until the first product to be separated out has actually been sucked off.

The lengthening period can be specified in such a way that the subsequent second product is also reliably sucked off the conveyor track undesired influencing of a subsequent third product which is no longer to be separated out is as small as possible.

According to an advantageous embodiment of the idea of the invention, it is provided that the lengthening period is shorter than the suction period. It has been shown that in most cases, and especially with short distances between the products conveyed one after the other along the conveyor line, a subsequent second product is already accelerated by the suction process of the first product and its distance from the first product is reduced, so that with an extension of the suction duration, the accelerated second product is caught earlier by the suction flow and sucked off with the suction device. Depending on the suction power, the lengthening time can be significantly shorter than the suction time and can be, for example, less than 80% or even less than 50% of the suction time.

Under certain conditions, it can also be expedient and advantageous to set the extension time longer than the suction time.

In order to reduce an undesired influence on a subsequent product while a preceding product is being sucked off, one embodiment of the inventive idea can provide for the suction device to be displaced in the conveying direction along the conveying path during the suction period and/or during the extension period. By tracking the suction device to those conveyed in the conveying direction products, the effect of the suction flow on the product in question can be increased and the product can be reliably sucked off, while at the same time an undesired influence on a subsequent product is reduced.

It is also conceivable and optionally possible for the control device to determine a distance between the following second product and the first product along the conveying path and for the lengthening period to be adjusted as a function of the distance determined. In this way, distances of different sizes between the first product to be sucked off and the subsequent second product can be taken into account when specifying the lengthening period. With a greater distance, a somewhat longer extension time is specified, while with a smaller distance, a shorter extension time is sufficient to reliably suck off the subsequent second product from the conveyor track.

It is also conceivable that the control device is arranged in the immediate vicinity of the suction device and that the control device is used to determine a conveying speed of the products conveyed along the conveying path. If the subsequent second product has an increased conveying speed, the lengthening period can also be preset to be shorter than for a subsequent second product whose conveying speed has not yet been increased by the suction flow during the suctioning of the first product.

According to a particularly advantageous embodiment of the inventive concept, it is provided that the Suction device has a suction seal adapted to a cross-sectional area of the conveying track, which during the suction period is displaced into the conveying track at an end of the suction device lying in the conveying direction in order to reduce suction of the suction flow from a section of the conveying track lying in the conveying direction. If the suction device, which usually has a suction pipe ending directly above the conveyor track, is brought up close to the conveyor track during the suction period or is already there, the suction flow sucked off by the suction device is predominantly sucked out of the sections of the conveyor track that are adjacent in both directions. In many cases, the product to be sucked off is still ahead of the suction device in the conveying direction when the suction process begins. By sucking in the suction stream from the section of the conveyor track that follows in the conveying direction, the suction power acting on the product that is still located in a preceding section of the conveyor track is reduced. In order to be able to ensure reliable suction of the product, the suction flow must either be sucked in with a sufficiently high suction power and sucked away from the conveyor track through the suction pipe, or a sufficiently long suction duration must be specified in order to be able to reliably suck in the product and remove it through the suction device .

Due to the sealing according to the invention of the section of the conveyor track lying in the conveying direction, the entire suction stream must be sucked in from the preceding section of the conveyor track, in which the product to be sucked off is located, so that the suction effect is increased on the product during the suction process and the product can be sucked off with a lower suction power of the suction device or with a shorter suction time.

The suction seal can, for example, be elastic or flexible and be arranged rigidly on the suction device if, according to an optional embodiment of the inventive concept, the suction device is shifted towards the conveyor track during the suction period and is then moved away from the conveyor track again. It is also conceivable that the suction seal consists of a dimensionally stable material and is adapted to a shape of the conveyor track in an end area facing the conveyor track, so that the end area of the suction seal can be displaced into the conveyor track in order to form a mechanical barrier that sealingly separates the section of the conveyor track that follows in the conveying direction and also prevents undesired further conveyance of individual products or individual products from slipping down after a conveyor movement of the conveyor track has been switched off.

The suction device can have a substantially constant distance from the conveyor track both during a suction process and before and after, and only the suction seal can be displaced during a suction process and arranged so as to protrude into the conveyor track. The suction seal can be inserted into the conveyor track together with the suction device or separately from it, for example pneumatically or with magnetic force and optionally supported by a spring device in and then shifted out of the conveyor track. Other actuators or displacement devices are also conceivable in order to displace the suction seal into the conveyor track if necessary and then to displace it out of the conveyor track again.

• Fig. 1 eine schematische Seitenansicht einer Förderstrecke für Produkte mit einer Kontrolleinrichtung und einer nachfolgend angeordneten Saugvorrichtung,
• Fig. 2 eine Schnittansicht durch die in Fig. 1 gezeigte Fördereinrichtung längs der Linie II-II in Fig. 1,
• Fig. 3 wieder eine Seitenansicht einer abweichend zu Fig. 1 ausgestalteten Fördereinrichtung, wobei die Saugvorrichtung eine in die Förderbahn hinein verlagerbare Saugdichtung aufweist, und
• Fig. 4 eine Schnittansicht der in der Fig. 3 gezeigten Förderstrecke längs der Linie IV-IV in Fig. 3.

Exemplary embodiments of the inventive idea are explained in more detail below, which are shown in the drawing. It shows:

• 1 a schematic side view of a conveyor line for products with a control device and a downstream suction device,
• 2 a sectional view through the in 1 shown conveyor along the line II-II in 1 ,
• 3 again a side view of a different to 1 configured conveyor device, wherein the suction device has a suction seal that can be displaced into the conveyor track, and
• 4 a sectional view of in the 3 conveyor section shown along the line IV-IV in 3 .

In the Figures 1 and 2 is a schematic and exemplary representation of a conveying section 1 for conveying free-flowing products 2, 2', 2" such as tablets or capsules in a conveying direction indicated by an arrow 3. The individual products 2, 2', 2" are spaced apart each other in a groove-shaped conveyor track 4. In the conveyor track 4 is It is a vibrating conveyor in which the products 2, 2', 2" located in the conveyor track 4 are thrown forward in the conveying direction 3 by a directed vibration movement of the conveyor track 4 and are thereby displaced and conveyed in the conveying direction 3.

A control device 6 is arranged in a control section 5 of the conveyor section 1, with which the products 2, 2', 2" conveyed past the control device 6 can be checked. If a product 2 conveyed past the control device 6 does not meet a specifiable control criterion, activated during the conveyance of the product 2 in question by a suction device 8 arranged in a subsequent separation section 7 in order to suck off the product 2 then located in the separation section 7 from the conveyor track 4. For this purpose, the suction device 8 has a a suction pipe 10 having a suction opening 9 facing the conveyor track 4. A suitable vacuum generating device can generate a negative pressure in the suction pipe 10, so that during the operation of the suction device 8 a suction flow is sucked in in the vicinity of the suction opening 9 and discharged through the suction pipe 10 ugt will. As soon as the product 2 to be sorted out is in the detection area of the suction flow generated by the suction device 8 and a sufficiently large suction effect is exerted on the product 2, the product is pushed through the suction opening 9 into the suction tube 10 and through the suction tube 10 to a product that is no longer shown Storage container for discarded products 2 sucked.

If the conveying speed of the products 2, 2', 2" in the conveying direction 3 is known, after the detection of a product 2 to be sorted out with the control device 6, the suction device 8 can be activated after a predetermined activation period, which depends on the conveying speed of the in the conveying direction 3 in the Conveyor track 4 moving products 2, 2 ', 2 "and a distance between the control device 6 and the sorting section 7 along the conveyor line 1 depends. It is also conceivable that the entry of a product 2 into the separation section 7 is detected, for example, with the aid of a light barrier or another suitable detector device, and the suction device 8 is activated immediately thereafter. After the suction device has been activated, suction device 8 generates a vacuum for a specified suction duration and generates a suction flow that flows away from conveyor track 4 through suction pipe 10, with which product 2 located in sorting section 7 is suctioned off through suction pipe 10. The suction device is then deactivated again after the specified suction time has elapsed. Depending on the situation, the duration of the suction can also be specified differently and controlled or regulated. It is also possible to change the conveying speed of the products 2, 2', 2'' accordingly instead of changing the suction duration.

In the embodiment of the method according to the invention, a product 2' following the preceding first product 2 to be separated out is checked with the control device 6 and it is determined whether the following second Product 2' also does not meet the specified control criterion and should therefore also be discarded, or whether the following second product 2' should be conveyed further along the conveying direction 3 in the conveying track 4. If the following second product 2' is also to be sorted out, the suction device 8 is not deactivated after the suction time has elapsed, but continues to be operated for a predetermined extension time in order to suck off the suction flow through the suction pipe 10 without interruption until the second product 2' to be sorted out is also is sucked out of the conveyor track 4 during the extension period. After the extension period has expired, the suction device 8 is then deactivated.

In principle, it is conceivable that the control device 6 also controls a third product 2" following the second product 2' and, if necessary, the suction device 8 is operated for a further extension period in order to also suck off the third product 2" that follows. This can be continued in the same way as desired until a subsequent product 2 satisfies the control criterion and is no longer to be sucked off, but to be conveyed on.

At the in the Figures 1 and 2 illustrated embodiment variant of the suction device 8 a sucked through the suction opening 9 suction stream is mainly sucked out of the conveyor track 4. It is achieved by an aligned in the conveying direction 3 arrangement of the suction pipe 10 and a suction opening 9 adapted thereto, that a larger proportion of the suction flow sucked in from a Area 11 of the conveyor track 4 preceding the conveying direction 3 is sucked in, while a comparatively smaller proportion of the suction flow is sucked in from a region 12 of the conveyor track 4 following in the conveying direction 3 . At the same time, it cannot be avoided that an often not inconsiderable proportion of the sucked-in suction flow is sucked in from the following area 12 of the conveyor track 4, thereby reducing the suction power acting on the product 2 to be separated, which is located in the preceding area 11 of the conveyor track 4 .

In the Figures 3 and 4 a differently designed suction device 8 is shown. The suction device 8 has a suction seal 13 which can be displaced into the groove-shaped conveyor track 4 and consists of a suitable elastomer material. When the suction device 8 is activated in order to suck off a product 2, 2', the suction seal 13 is moved into the groove-shaped conveyor track 4 at the same time and over the entire suction period and any subsequent extension period and forms a seal for the subsequent area 12 of the conveyor track 4 by the suction stream, which then has to be sucked in predominantly from the preceding area 11 of the conveyor track 4, in which the product 2, 2' to be sucked off is located. As a result, the suction power acting on the product 2, 2' to be sucked off is increased and the product 2, 2' to be sucked off can be reliably sucked off with a lower suction flow generated by the vacuum generating device. In addition, the suction seal 13 forms a barrier that reliably prevents a product 2, 2' to be sucked off from being unintentionally in the conveyor track 4 passes the suction device 8 into the following area 12 of the conveyor track 4 and may no longer be able to be sucked off.

Claims (6)

1. Method for selectively separating out free-flowing products (2, 2', 2'') which are conveyed in a conveying direction (3) along a conveying path (1) in a conveying track (4), wherein the conveyed products (2, 2', 2'') are checked in a monitoring portion (5) of the conveying path

   (1) by means of a monitoring device (6), and wherein in a separating-out portion (7) arranged downstream along the conveying path (1) that product (2, 2') which does not meet a presettable monitoring criterion is separated out and carried away from the conveying track (4) using a suction device (8) in that the suction device (8) is arranged on the conveying path (1) and for a preset suction period a suction flow flowing away out of the conveying track (4) is produced in order to remove the product (2, 2') from the conveying track (4) by suction, characterised in that the monitoring device (5) is used to check whether a second product (2') which likewise does not meet the preset monitoring criterion and therefore is likewise to be separated out succeeds the first product

   (2) which is to be separated out, and in that the suction period is extended by a presettable extension period in order also to remove the subsequent second product (2') by suction from the conveying track (4) without interruption.
2. Method according to claim 1, characterised in that the extension period is shorter than the suction period.
3. Method according to claim 1 or claim 2, characterised in that the suction device (8) during the suction period and/or the extension period is displaced in the conveying direction (3) along the conveying path (1).
4. Method according to one of the preceding claims, characterised in that a distance of the subsequent second product (2') from the first product (2) along the conveying path (1) is determined using the monitoring device (5), and in that the extension period is adapted as a function of the determined distance.
5. Method according to one of the preceding claims, characterised in that the suction device (8) has a suction seal (13) adapted to a cross-sectional area of the conveying track (4), which suction seal during the suction period is displaced into the conveying track (4) at an end, located in the conveying direction (3), of the suction device (8) in order to reduce intake of the suction flow out of a portion of the conveying track (4) which follows in the conveying direction (3).
6. Method according to claim 5, characterised in that the suction device (8) during the suction period is displaced in the direction of the conveying track (4) up to the conveying track (4).

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