DE3240254A1 - Device for checking that a container has been completely filled with packages of cigarettes - Google Patents

Abstract

To permit checking that a container has been completely filled with packages of cigarettes, for example that a carton has been filled with bundles of 10 packets of cigarettes or that a bundle actually consists of 10 packets of cigarettes, the container passes through a measuring section between at least one radioactive emitter and a radioactive beam detector, for example a scintillation counter; it can be determined from the reduction in the signal measured by the detector which has occurred as the signal passed through the measuring section whether the container is completely full or whether at least one package of cigarettes, i.e. a bundle or a packet of cigarettes, is missing. The widths of the cartons concerned are simultaneously determined by means of light barriers, in such a way that a correlation between the change in the measured signal on the one hand and the width of the carton on the other hand can be made and fault-free recognition of defectively filled cartons is possible.

Description

Facility to check the full

Filling a container with packs of cigarettes Description Die The invention relates to a device for checking the complete filling of Containers with cigarette packs specified in the preamble of claim 1 Genus.

In the cigarette industry, there are generally three different ones Different types of containers, namely the usual cigarette pack, which contains, for example, 20 individual cigarettes, then a bundle of 10 cigarette boxes, the large areas of which are adjacent to each other, the so-called "cigarette sticks", or cardboard boxes that can contain up to 50 containers. These boxes generally have a small, medium or large width.

The cigarettes either leave the production process in containers combined or in boxes with several containers. There must be a completeness check be carried out, i.e. it must be determined whether the container holds the 10 cigarette boxes or the boxes contain the specified number of containers. Be for this purpose currently mainly used scales or capacitive initiators. When weighing a box filled with 50 containers, however, fluctuations the weight of the cigarette and differences in weight due to the different moisture contents of the carton occur that exceed the weight of a container. This procedure works so not exactly enough.

The initiators used to check the completeness have the Disadvantage that it can only be used to check cigarettes that are in metal foils or in paper with metal lischer cover are packed. aside from that the container to be tested must be at an extremely short distance, for example in a distance of 15 mm past the initiator. For this reason Initiators are only suitable for checking completeness in a few cases.

Finally, US Pat. No. 4,116,973 indicates that a complete number check can in principle be carried out with microwaves. However, this measuring method is only suitable if a metal foil or a similar material is present.

The invention is therefore based on the object of a device for checking that containers with cigarette packs are completely full of the specified type, in which the disadvantages mentioned above do not exist appear.

In particular, a device should be proposed that also without the use of metal foils or paper with a metallic coating with high Dissolution accuracy. Works and also when checking containers of different Width enables the correct detection of filling errors.

This is according to the invention by the characterizing part of the claim 1 achieved characteristics.

Appropriate embodiments are compiled in the subclaims.

The advantages achieved with the invention are based in particular on the use of a radiometric density measurement.

Thereby, on one side of the transported, to be checked Container, for example a container or a cardboard box, at least one radioactive Emitters, for example americium 241 or curium 244, and on the other hand a radiation detector, in particular a scintillation counter, is arranged. The detector delivers the impulses corresponding to the arrival of the individual rays, whereby the frequency of the impulses is a measure of the number of incoming radiation particles is. This frequency is converted into a corresponding DC voltage signal.

There is no container between the radiocative rays and Detector, the DC voltage signal has a predetermined 'constant' value, with the given properties of the radioactive emitter essentially of depends on the strength of the radioactive emitter, i.e. determined by a calibration measurement can be.

Now a container runs into the area between the radioactive emitters and detector, it is reduced by the absorption of the radiation particles in the container the frequency of the pulses and thus the DC voltage signal; the The difference between the two DC voltage signals represents a known width of the container is a very precise measure of whether the container is completely filled with containers or cigarette packs are filled or not.

In order to automatically, i.e. without manual setting, also containers of different sizes Width to be able to take into account, are several vertically arranged Light barriers provided, with containers of different widths also different Interrupt light barriers. The evaluation electronics therefore take the number into account and position of the interrupted light barriers on the one hand and the difference in the two DC voltage signals on the other hand, in order to generate an error signal if necessary, which indicates that the container that has just been checked is not sufficiently full.

Between two consecutive containers passing through the facility short-term "light gaps" occur, which are generated as error signals by the evaluation electronics would be recognized. Also the occasional, irregular hit of the Radiation trilches can be used as an error signal, i.e. not sufficient as a signal for one filled container. For this purpose a time discrimination is used carried out in order to eliminate and ensure the sources of error mentioned, that the mentioned equipment errors are suppressed and only real error signals are registered will.

A version realized as a prototype provided reproducibility of signals of less than 1%, which is the reasonable signal error tolerance was about - 7%.

To optimize adjustability, the containers should be so through the beam path are driven that in the direction of the beam no more than two containers are arranged side by side; this can lead to a mistake in the event of faulty packaging of logarithmic 50% (for two containers arranged side by side) or 100% (for a single container) can be measured. This results in the greatest possible "Good / bad distance.

Because tobacco on the one hand and filter material on the other hand are different Output signals of the detector and thus different signal levels should deliver the irradiated cigarettes either in their longitudinal axis of the beam axis during transport correspond or stand with their longitudinal axis perpendicular to the transport surface, so Stand or hang in relation to filters / tobacco.

However, the cigarettes are lying horizontally in their longitudinal axis Moved parallel to the conveying direction, alternating filters are created in the measurement signal and tobacco-derived, swaying darkness; shouldn't these fluctuations are interpreted as error signals, the signal tolerance must be correspondingly more generous can be set.

The limit of error can be further reduced if necessary and thus the establishment can be made even more sensitive if the transport speed the container is reduced. Because proportional to the reduction in the transport speed the ripple of the measurement signal also decreases, which makes the evaluation even more precise.

If necessary, the device can have an automatic ejection device downstream, the not completely filled container from the actual Production line ejects.

The commonly used, commercially available radioactive Radiators have a half-life of 450 years, so that there is a loss of intensity every year results in less than 0.16%; however, this loss of intensity is caused by sample signal storage automatically balanced for each new container type.

The or the radioactive emitters are expediently in one Fastened cylinder, which rotated about its vertical axis with respect to an outer cylinder can be.

This cylinder is in a shielding frame so that the radioactive rays after rotation of the cylinder, for example by means of a pneumatic Rotary lock, towards which the outer cylinder is directed, i.e. the radioactive one Radiation can no longer penetrate the shielding frame and thus otherwise switched off device no longer forms a source of danger.

The invention is illustrated below using an exemplary embodiment explained in more detail with reference to the accompanying schematic drawings. 1 shows a schematic, perspective view of the basic structure of a Device for checking that a container is completely filled with cigarette packs, 2 shows a schematic representation of the mechanical part and the evaluation electronics of the device, FIG. 3 shows the signal curves for a perfectly filled container for six radioactive emitters and six detectors, and FIG. 4 shows the signal curves for a container with a missing container for six radioactive emitters and six Detectors.

As can be seen in Fig. 1, a carton 16, for example Contains 50 packs of 10 cigarette boxes each, by means of a conveyor 12 with conveyor rollers 14 through a generally through the reference sign 10 indicated device for checking the complete filling of the carton 16 led; this device 10 can be a carton or package completeness check perform and has a rectangular shielding frame 17, the conveyor 12 and the actual objects to be measured, that is to say the cardboard boxes 16, surrounds in the according to FIG Representation in Fig. 1 right strut of the shielding frame 17 are six radioactive Radiators 18 arranged vertically one above the other; than commercially available radioactive Americium 241 or Curium 244 are available.

In the strut on the left as shown in FIG. 1 there are six scintillation counters 20 assigned to the individual radioactive emitters 18 and are connected to evaluation electronics 24 via a line 22.

As can be seen in Fig. 2, the radioactive emitters are located 18 in a vertical column 19, which by means of a pneumatic twist lock 25 can be rotated with its inner cylinder. This allows the radioactive Radiator 18 from its working position according to FIG. 2 in which it emits the radioactive rays to direct the scintillation counter 20, bring into a position in which the raradioactive Rays only get into the interior of the outer cylinder, i.e. do not penetrate to the outside can.

In Fig. 2 is an embodiment with four vertically one above the other angeoruneten radioactive emitters 18 shown, the beams each on one associated scintillation counter 20 fall, as by the parallel side by side running dashed lines is indicated.

Below the transport surface of the cardboard boxes 16, for example below the conveyor rollers 14 are photocells 48, 50 and 52, the infrared sources as Infrared receiver included. The ones not shown in detail Infrared transmitters of photocells 48, 50 and 52 direct their radiation onto reflectors 49, 51, 53, which are located in the upper, horizontal strut of the shielding frame 17. From these reflectors 49, 51 and 53, the radiation is directed to the photocell receivers 48, 50 and 52 thrown back.

As an alternative to this embodiment, it goes without saying also possible to replace the reflectors 49, 51 and 53 with light sources; in this In this case, the photocells only contain receivers, i.e. the usual photoelectric ones Converter.

The photocells 48, 50 and 52 form with the associated reflectors 49, 51 and 53 each have a light barrier, which -by the passage of a cardboard box 16 is interrupted.

If, for example, only the photocell 52 responds, so it is The photocell 50 also responds to a narrow cardboard box 16i, so it is around a middle carton 16; and if the photocell 48 also responds, so acts it is a wide cardboard box 16; it is assumed that the boxes 16 each in attachment to the right-hand edge as shown in FIG. 2 will.

In Fig. 2, the output signal of a scintillation counter 20 is closed recognize; it forms a sequence of pulses, the number of which is a measure of the number of represents impinging radioactive particles. This sequence of pulses is carried out by a frequency / voltage converter 26 converted into the corresponding direct voltage, which in turn is proportional to the number of radioactive particles that hit it.

If there is no box 16 in the shielding frame, they will fall emitted radioactive particles unhindered on the associated scintillation counter 20, so that a DC voltage signal is present at the frequency / voltage converter 26, which is to be referred to as "light value" in the following and, for example, 12 V is.

On the one hand, this DC voltage signal is sent to a comparator 36 given and on the other hand led to a circuit 28, the function of which will be explained shall be.

If a carton 16 now enters the device 10 and is located thus in the beam path of the radioactive particles, it is reduced due to the Absorption by the material of the cardboard or the cigarette the number of on the associated scintillation counter 20 hit radioactive particles and thus the Number of pulses so that the DC voltage signal of the frequency / voltage converter 26 to a signal corresponding to the width of the cardboard 16 in the direction of the beam, the so-called "dark value", which is generally 1 to 5 volts. The one with it resulting leading edge, i.e. the reduction of the DC voltage signal from the light value to the dark value is recognized by the circuit 28, which is why hereinafter referred to as "leading edge detector"; to a given time delay T1 after determining the leading edge, the can be specified by the adjustable delay element 30, gives the leading edge detector 28 the pending DC voltage signal, i.e. the existing measured value, to a Instantaneous value memory 32. The delay.

T1 is set so that the given to the instantaneous value memory 32 Measuring signal corresponds approximately to the middle of the first expected cigarette pack, So for the carton inspection a bundle of 10 cigarette boxes or at the container control of a cigarette box.

For this reason, the setting of the delay time 1 is essential, because the delay time T1 depends on the type of container to be checked, namely cardboard or container <de, depends (see the sampling point in Figure 2).

The difference between the measurement signal stored in the instantaneous value memory 32, that is to say the DC voltage signal of the frequency / voltage converter 26 with the current measured value becomes in the course of the further passage of the container through the device 10 compared with the comparison value that can be set in the comparators 36 and 38, and the positive deviation of the current memory difference in a first comparator 36 from the comparison value, and in a second comparator 38 the negative deviation of the AXtuell memory difference with the set comparison value in each case. The comparison value is the maximum permitted level deviation of the density.

The comparator 36 thus detects a positive deviation, i.e. a larger dark value, as is the case with the stored, previous one Value indicates an error, i.e. the lack of a cigarette box or

of a container.

The second comparator 38 determines a negative deviation, that is a smaller dark value, as is the case if the stored previous one Value has a good point, and one or more error points follow.

The two deviations are processed into a fault rejection signal, if they exceed an adjustable period of time. This fault rejection signal becomes given to a circuit 40, the mode of operation of which will be explained below.

The described time discrimination with the stored, previous one The measuring signal is required to ensure that there are short-term "bright gaps" between the individual Containers are not interpreted as error signals. It can also be used to Suppress brief error signals that are due to the irregular impact of the radioactive particles are due.

In Fig. 2, the time period T2 is also shown schematically, the is required for the passage of a carton 16 through the device 10, Es Can be seen,. that the time period T1, which is the time for the storage of the measurement signal is defined at the beginning of the throughput time T2 of the cardboard box.

The photocells 48, 50 and 52 are set values 60, 62 and 64 for certain Voltage signals xl, x2 and x3 are assigned, which in turn correspond to the different signal levels for the different container sizes. For example, xl is the Minimum level for wide cartons 16, x2 the minimum level for cartons 16 medium Width and x3 the minimum level for narrow boxes 16.

If, for example, the photocell 52 responds, a switch is activated 58 controlled and leaves the minimum level x3 for the narrow cardboard boxes 16 to one Nigarator 66 through; accordingly, when the photocell 48 or 50 the minimum level xl and x2 via the associated electronic switches 54 and 56 given to the comparator 66, which also has the DC voltage output signal of the frequency / voltage converter 26, that is to say the actual measurement signal, receives.

The minimum levels xl to x3 contain a statement about which DC voltage signal with a completely filled box 16 of the determined width should not be undercut.

From the minimum level xl, x2 or x3 on the one hand and the DC voltage signal of the frequency / voltage converter 26, on the other hand, the comparator 10 transmits a statement whether a continuous container is completely filled or not; to basic values for the measuring signals are specified via the minimum level xl to x3, which can only be exceeded if the container is more than half full and at Falling below this also leads to an error signal. Thus it can be determined whether the container 16 passing through is full, half full or empty.

The output of the comparator 66 and the output of the two comparators 36 and 38 are given to an evaluation circuit 40, which the identified errors are summarized and if an incompletely filled one is found Container 16 emits an output signal via a circuit 42 with an interference filter and an amplifier is fed to a fault signal relay 46; this alarm relay can for example generate an alarm signal or an automatic ejection device directly press that removes the container from the product that is recognized as not completely filled walk removed, for example via a slide that serves as an ejection system.

The response time of this alarm relay, R can be determined by a timer 44 are adjusted, which has a through-delay T3 for the circuit 42 and thus a corresponding delay in the response time of the alarm relay R introduces.

The output signals of this device 10, for example that The output signal of the circuit 40 is described below using an exemplary embodiment with six radioactive emitters 18 arranged one above the other and their associated Scintillation counters 20 will be explained; such a device 10 thus has a total of six channels, so that, for example, cardboard boxes 16 can be checked, in which nine bundles next to each other and six layers of bundles on top of each other contain are.

In Fig. 3, for such a carton 16 with four bundle layers, the Transport direction, the beam direction and the output signals of the six channels shown.

Since this box 16 contains only four bundle layers, are located in the Beam path of the two top scintillation counters 20 no containers, so that the corresponding signals remain at the light level and thus remain unchanged.

With the four lower scintillation counters, the light value is at The entry of the cardboard box 16 is reduced to the dark value, as can be seen on the channels 1 to 4 can be recognized, so that there is a clear indication that the Cardboard boxes results. This carton 16 is completely filled, as can be seen from the uniform Shape of the "recess" in the corresponding DC voltage signals which can recognize channels 1 to 4.

FIG. 4 shows a carton 16 similar to FIG. 3 with four on top of one another arranged bundle layers, with one bundle in the upper, fourth bundle layer absent, while the other layers are complete.

Since this box 16 contains only four layers of bundles, the DC voltage signals remain in the upper channels 5 and 6 at the light value and thus constant.

The three lower bundle layers are completely filled, so that the same reduction in the DC voltage signal from the light value to the dark value as in the case of the completely filled carton according to FIG. 3.

In the channel 4 occurs first the usual, through the penetration of the Cardboard boxes 16 in the test section caused reduction of the measurement signal from the Light value to dark value. Now comes the area where the container is missing and if there is only air in the beam path, the absorption is reduced in comparison with areas with containers, i.e. the dark value increases again for a short time to the light value, as indicated by the tip in channel 4. Afterward If the measurement signal falls back to the dark value, there is now again the absorption noticeable through the following containers.

The characteristic shape according to channel 4 can therefore be used immediately recognize that a container is missing approximately in the middle of this container.

After the device 10 has been appropriately calibrated, it can turn off to the Measurement signal can also be derived from the lack of a cigarette pack in a container.

Claims (14)

Device for checking that a container is completely full with cigarette packs Claims 1 \ facility for checking the complete Filling a container with cigarette pods a) with a conveyor for the filled container, b) with a measuring device for the degree of filling, and c) with an evaluation device for the output signal of the measuring device, characterized by d) at least one radioactive one arranged on one side of the conveyor line Radiator (18), through e) at least one associated with the radioactive radiator (18) Detector (20) for the emitted beams on the other side of the conveyor line, and by f) a switching arrangement for determining the degree of filling from the reduction the output signal of the detector (20) when passing through a container (16) between to the radioactive emitter (18) and the detector (20). 2. Device according to claim 1, characterized in that the Checking of containers from several cigarette packs a radioactive emitter (18) and a detector (20) are provided. ¢ 3. Device according to claim 1, characterized characterized in that when checking cardboard boxes (16) from several containers with Cigarette packs up to six radioactive, depending on the size of the boxes Radiators (18) and six associated detectors (20) are provided. 4. Device according to one of claims 1 to 3, characterized in that that as a radioactive emitter an a-emitter (18), in particular americium 241 or Curium 244 is used. 5. Device according to one of claims 1 to 4, characterized in that that scintillation counters are used as detectors (20). 6. Device according to one of claims 1 to 5, characterized in that that the radioactive emitter (18) and the detector (s) (20) in one rectangular shielding frame (17) are arranged. 7. Device according to one of claims 1 to 6, characterized by at least one vertically arranged light barrier (48, 49; 50, 51; 52, 53) for Detection of the horizontal width of a container (16), as well as that in the transport direction of the container (16) at the front or rear ends of the container. 8. Device according to claim 7, characterized in that that each light barrier (48, 49; 50, 51, 52, 53) a level (60, 62, 64) of the output signal of the detector (20) with a completely filled container (16) the corresponding Width is assigned. 9. Device according to claim 8, characterized in that the the Width of the container (16) associated level together with the output signal of the Detector (20) is given to a comparator (66), the output signal for Detection of completely or not completely filled containers (16) is used. 10. Device according to one of claims 1 to 9, characterized by a frequency / voltage converter connected to the output of the detector (20) (26) for the formation of the measurement signal. 11. Device according to claim 10, characterized in that according to a change in the measurement signal, the actual value is stored and with the following measurement signal is compared. 12. Device according to claim 11, characterized in that a incorrectly filled container (16) is recognized when the comparison is made over a specified Time span delivers a positive or negative deviation. 13. Device according to one of claims 6 to 12, characterized in that that several, vertically one above the other arranged radioactive emitters (18) on one vertical column are attached, which via a pneumatic rotary lock (25) is fastened with spring-loaded return in the shielding frame (17). 14. Device according to one of claims 7 to 13, characterized marked, that the evaluation takes place digitally, in particular via a microprocessor.