WO2008023136A1

WO2008023136A1 - System for checking cartons for defects

Info

Publication number: WO2008023136A1
Application number: PCT/GB2006/003175
Authority: WO
Inventors: Jong Myung Lee
Original assignee: British American Tobacco Korea Limited; British American Tobacco (Investments) Limited
Priority date: 2006-08-24
Filing date: 2006-08-24
Publication date: 2008-02-28

Abstract

The invention provides a system for sensing missing and defective packs, comprising: a carton transporting device; sensors (30, 40) mounted on the device; and, a programmable logic controller (PLC) connected to the sensors so that it controls the carton transporting device by receiving the signals from the sensors. The sensors transmit the signals by detecting metal foil in the pack, and the PLC stops the device when the signals received from the sensors are different from the signals received from the carton containing normal packs, thereby detecting missing packs as well as defective packs in the carton.

Description

TITLE OF THE INVENTION

SYSTEM FOR CHECKING CARTONS FOR DEFECTS

BACKGROUND OF THE INVENTION

The invention relates to a system for checking cartons of goods such as cigarettes by using sensors.

Various automated devices are known in the art that insert packs of goods such as cigarettes into a carton and then wrap it. Devices for checking the condition of the individual goods and of their wrapping are also known.

In the field of cigarette packaging, a carton generally contains ten cigarette packs. However, when cigarette packs are inserted into cartons, it may occur that some packs are misaligned, so that only eight or nine cigarette packs are inserted into a carton.

Also, a cigarette pack normally comprises a metal foil, which encloses the cigarettes therein. However, faults occurring during the manufacturing of the cigarette pack may cause the foil to be missing or damaged. Moreover, it may happen that the cigarette pack is dented, crushed, or pressed out of shape, the wrap of the cigarette pack is left open or the packaging material may be damaged or soiled, for example with glue.

SUMMARY OF THE INVENTION

Hence, the present invention is directed towards a system for inspecting whether a pack is missing from a carton or whether a carton contains a defective, incomplete or damaged pack.

According to the present invention a system for sensing metal foil in packs is used to detect a missing pack in a carton, and damaged packs within the carton.

Accordingly, a first aspect of the invention is directed to a system for detecting defects in cartons of packs, comprising: a carton transporting device; sensors past which the cartons are transported; and an electronic control device connected to the sensors to receive signals therefrom wherein the sensors detect metal foil in the packs, and alert the control device when an abnormal signal is received from the sensors.

A second aspect of the invention is directed to a method of detecting defects in cartons of packs, comprising: transporting cartons past a sensor device, generating a signal that varies in response to the disposition of metal foil in the packs; transmitting the signals to a control device; and generating an error signal when the signals received from the sensors are different from the signals generated in response to a carton having normal packs.

An embodiment of the invention provides a system for detecting defects in cartons of cigarette packs comprising: a discharge turret portion formed on a carton transporting device to transport a carton discharged from the turret; sensors mounted on the discharge turret portion; and, a computer system connected to the sensors so that it controls the carton transporting device by receiving the signals from the sensors; wherein, the sensors transmit the signals by detecting a metal foil in the cigarette pack, the PLC stops the device when the signals received from the sensors are different from the signals received from the carton containing normal cigarette packs, thereby detecting the missing pack as well as the defects of the cigarette pack and the carton. The sensors may comprise top sensors mounted above the path of the cartons and bottom sensors mounted below the path of the cartons.

The top sensors and the bottom sensors of the sensors may comprise at least five sensors, respectively. The sensors may be arranged transversely across the path of the carton. There may be at least one sensor for each pack in the carton along the direction transverse to the path of the carton, the sensors having a spacing greater than the width of the packs in the direction transverse to the path of the carton.

The top sensors of the sensors may be aligned with the lid portions of the packs. The sensors may be inductive proximity sensors.

-A-

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention and to show how the same may be carried into effect reference is now made by way of example to the accompanying drawings in which:

Figure 1 is a perspective view showing a device for transferring a carton containing cigarette packs on which sensors are mounted according to an embodiment of the invention;

Figure 2 shows the arrangement of sensors according to one example of the invention;

Figure 3 shows the arrangement of sensors according to a further example; and

Figure 4 shows a system operated according to an embodiment of the invention.

DETAILED DESCRIPTION

For a better understanding of the invention, together with other objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims taken in conjunction with the above-described drawings.

The invention relates to a system wherein during the process when cartons containing packs are being transported along a path through a transporting section 18 between a top surface 14 and a bottom surface 16 of the discharge turret portion 10 of a packaging machine, a sensing unit comprising detectors or sensors 30, 40 is disposed on the discharge turret portion 10 in the transporting device, the signals produced by the sensors are transmitted to a PLC (programmable logic controller), and then the device can be stopped when the PLC determines that the transmitted signals are abnormal. Abnormal signals are produced in the event that one or more packs are damaged or missing from the carton. Figure 1 represents a discharge turret portion 10 that supplies cartons containing cigarette packs within a cigarette transporting system. The discharge turret portion 10 consists of a top surface 14 and a bottom surface 16, and the sensors 30, 40 are mounted thereon. The carton is supplied from a turret 12 at the right side in Figure 1 and is transported through the transporting section between the top surface 14 and the bottom surface 16 of the discharge turret portion 10. The sensors 30, 40 detect the top and bottom portions of the moving carton 60. The sensors transmit the detected signals to the PLC 70, and the PLC controls the transporting device by processing the signals. Processing of the signals can generate an error signal or an abnormal signal in the event that a defect is detected in the carton or a pack in the carton, and the PLC can control the system accordingly in response to the error signal.

The detectors or sensors may be proximity sensors. A proximity sensor determines whether an object is close to the sensor prior to contacting with the object, i.e., without contact. In other words, a proximity sensor can detect an object that is close to it, within the proximity range of the sensor. One or more inductive proximity sensors may be used among the proximity sensors. An inductive proximity sensor is utilized for detecting the surface of a metal and the theory of the function is that the oscillating signals decrease as the metallic object comes nearer. Thus, an inductive proximity sensor can detect when a metal foil, such as that used inside cigarette packs, is near.

Examples of suitable inductive proximity sensors include model Nos. IA12ASNO4POM1 (sensing distance: about 3-4 mm) and IAO8BSN26POM5 (sensing distance: about 2-3 mm) made by CARLO VAVAZZI INDUSTRI. As seen in Figure 1, the sensors are arranged on the top surface 14 and bottom surface 16 of the discharge turret 10, respectively. For example, a top sensor 30 such as IA12ASNO4POM1 may be disposed on the top surface 14 of the discharge turret portion 10) and a bottom sensor 40 such as IAO8BSN26POM5 may be disposed on the bottom surface 16 of the discharge turret portion 10. The top sensor 30 senses the upper row of cigarette packs inside the carton and the bottom sensor 40 senses the lower row of cigarette packs inside the carton.

More than one top sensor and one bottom sensor may be used. For example, if the carton contains an upper row of packs and a lower row of packs, the carton may travel through the transporting section with the rows arranged transversely to the direction of travel, and a top row of sensors and a bottom row of sensors may be provided, also arranged transversely to the direction of travel. If the number of sensors in a row matches the number of packs in a row in a normally filled carton, each sensor detects one pack, and the processing of the signals is simplified. For other numbers of sensors, and/or for cartons travelling with rows aligned along the direction of travel, more complex signal processing may be needed to distinguish between a signal produced from a normal carton and a signal produced from an abnormal or defective carton. For cartons containing two rows of five packs of cigarettes, each set of sensors may comprises five or more sensors installed on the top and bottom surfaces, respectively.

Hereinafter, the method for using sensors, including inductive proximity sensors, will be described below in detail.

It can be decided whether the packs and/or the cartons are abnormal (defective) by detecting a metal foil contained in each cigarette pack 50 and then transmitting the signals to the PLC. For example, if one or more of the cigarette packs are missing in the carton, at least one sensor of the sensors disposed on the top and bottom surfaces cannot detect any metal foil, thereby recognizing that the pack is missing from the carton.

When manufacturing and packing the cigarette products, the following errors may happen: the lid of the cigarette pack may be folded wrongly; the outer surface of the cigarette pack may be pressed and become dented or broken; glue may leak; the wrap of the cigarette pack or the carton may be overlapped, etc. These errors influence the metal foil so that it is pressed or transformed. If the metal foil in the pack is pressed or transformed, it can be moved out of the sensing range of the sensors so that the sensors are not able to detect the foil. Alternatively, the signals transmitted to the

PLC become different from the signals obtained from normal products with no errors. Therefore, in the event that the cigarette pack or the carton has defects, the defects can be found out by processing signals that the sensors transmit to the PLC.

In other words, the disposition of metal foil within the carton is detected. If a pack is missing, damaged or otherwise defective, the disposition of the foil will be different from the disposition in a carton correctly filled with a full complement of non-defective packs. This different disposition is detected and can be identified.

Referring to the table as shown below, it can be understood that the cigarette pack and the carton may have a wide range of defects. The table indicates data with regard to poor products that were detected during one year using a system in accordance with an embodiment of the invention. It should be understood that various problems that happen during the manufacturing and wrapping of the cigarette products may be solved by the sensing system of the invention. (The numerals in the top row of the table denote numerals that were allocated to manufacturing machines for discrimination.)

- Table showing the defects of the cigarette product detected by the invention -

The sensors 30, 40 may be disposed on the top and bottom surfaces in such a manner that each sensor is located in line with the centreline of the associated pack. This allows a range of defects to be detected. However, if one pack is missing in either of the upper and lower rows and the remaining packs are arranged centrally in that row (i.e. arranged as shown in Figure 3), there is a possibility that the total proper number of packs 50 are regarded as being contained in the carton. Each sensor detects metal foil and sends a normal signal to the PLC, and the defective carton is not detected. To address the above problem, Figure 2 suggests an alternative arrangement of sensors 30, 40. Figures 2 and 3 represent a sectional view of the discharge turret portion 10 taken along line H-II of Figure 1. As illustrated, the sensors except the centre sensor 30 are located in such a manner that they are a little spaced from the centreline of each pack, towards the longitudinal ends of the carton 60. It can be seen from Figure 2 that the sensors 30, 40 are located outwardly of centre lines a-a, b-b, c- c, and d-d of each pack except the central pack. That is, the sensors are spaced a little bit wider than the horizontal width of the pack, or are moved a bit towards the longitudinal ends of the carton from the centre pack. In this way, if a pack is missing as in Figure 3, one of the sensors will not detect any metal foil, and the abnormal carton will be detected.

In these and other embodiments, the top sensors 30 may be located to detect the lid portion of each pack. This is useful because it is mostly at the lid portion of the pack 50 that the metal foil can be missing or the paper be folded. Figure 4 shows the operation of a system according to an embodiment of the invention. As shown, the cigarette carton 60 discharged from the turret 12 is transported along a transporting path in the left arrow direction through the discharge turret portion 10. The sensors 30, 40 disposed on the top and bottom portions are connected to the PLC 70 to transmit signals thereto. The PLC 70 receives signals transmitted from sensors and controls the cigarette manufacturing system by a program contained in the PLC. The PLC can control the system in response to the signals from the sensors.

If a carton 60 having a missing or defective cigarette pack passes through the sensors, the signals transmitted to the PLC 70 will be different from the signals at the time when normal products are passing. Therefore, when a signal sensing metal foil is not transmitted by a sensor, or one or more sensor signals are different from normal signals, the PLC processes the signals via a program in the PLC and may generate error signals for alerting the system to the presence of a defective carton. For example, the error signal may be used to stop the transportation system to allow the defective product to be removed, after which the system is re-started.

Alternatively, it should be understood that the PLC can be connected to a rejecting device (illustrated as dotted lines in Figure 4) that automatically rejects the carton when the signal detected from the sensors is abnormal. As the rejecting device, any device may be used as long as it is generally used for delivering products.

Hence, according to an embodiment of the invention, as a carton 60 is discharged from the turret 12 and passes through the transporting section 18 of the discharge turret portion 10, the sensors 30, 40 mounted on the top surface 14 and the bottom surface 16 of the discharge turret portion 10 detect the metal foil contained in the cigarette packs 50 of the carton 60 and transmit signals to the PLC 70, and then the PLC controls the system to stop the device or reject the carton if the transmitted signals are different from the normal signals. By the above process, products having defects can be prevented from coming onto the market. The embodiments of the invention described above make it possible to identify and remove defective cartons of cigarette products by detecting cartons with missing cigarette packs, defective packs such as packs with missing foil or damaged foil, or defective cartons. This is achieved by means of the arrangements of sensors described.

The embodiments which have been described herein are but some of several which utilize this invention and are set forth here by way of illustration but not of limitation. It is apparent that many other embodiments which will be readily apparent to those skilled in the art may be made without departing materially from the scope of this invention.

For example, the invention is not limited to a system for detecting defects in cartons containing packs of cigarettes. It can be usefully applied to the detection of defects in other packaging that contains metal or metal foil.

Claims

1. A system for detecting defects in cartons of packs, comprising: a carton transporting device; sensors past which the cartons are transported; and an electronic control device connected to the sensors to receive signals therefrom; wherein the sensors detect metal foil in the packs, and alert the control device when an abnormal signal is received from the sensors.

2. A system according to claim 1 wherein the control device comprises a personal computer system.

3. A system according to claim 1 or claim 2 wherein the control device stops the transportation device when an abnormal signal is received.

4. A system according to any one of claims 1 to 3, wherein the sensors comprise top sensors mounted above the path of the cartons and bottom sensors mounted below the path of the cartons.

5. A system according to claim 4, wherein the top sensors and the bottom sensors of the sensors comprise at least five sensors respectively.

6. A system according to any one of claims 1 to 5, wherein the sensors are arranged transversely across the path of the carton.

7. A system according to claim 6, wherein there is at least one sensor for each pack in the carton along the direction transverse to the path of the carton, and the sensors have a spacing greater than the width of the packs in the direction transverse to the path of the carton.

8. A system according to any one of claims 1 to 7, wherein the sensors are inductive proximity sensors.

9. A method of detecting defects in cartons of packs, comprising: transporting cartons past a sensor device; generating a signal that varies in response to the disposition of metal foil in the packs; transmitting the signals to a control device; and generating an error signal when the signals received from the sensors are different from the signals generated in response to a carton having normal packs.

10. A method according to claim 9, wherein the control device comprises a personal computer system.

11. A method according to claim 9 or claim 10, further comprising stopping the transporting of the cartons when an error signal is generated.

12. A method according to any one of claims 9 to 11, wherein the sensor device comprises top sensors mounted above the path of the cartons and bottom sensors mounted below the path of the cartons.

13. A method according to claim 12, wherein the top sensors and the bottom sensors of the sensors comprise at least five sensors respectively.

14. A method according to any one of claims 9 to 13, wherein the sensors are arranged transversely across the path of the carton.

15. A method according to claim 14, wherein the sensor device comprises at least one sensor for each pack in the carton along the direction transverse to the path of the carton, and the sensors have a spacing greater than the width of the packs in the direction transverse to the path of the carton.

16. A method according to any one of claims 9 to 15, wherein the sensor device comprises one or more inductive proximity sensors.

17. A system for detecting defects in cartons of packs substantially as described herein with reference to the accompanying drawings.

18. A method of detecting defects in cartons of packs substantially as described herein with reference to the accompanying drawings.