DE3240254C2 - Device for checking that a container is completely filled with cigarette packets - Google Patents

Abstract

To check the full filling of a container with cigarette packs, for example a cardboard box with bundles of 10 cigarette packets or a bundle with these 10 cigarette packets, the container runs through a measuring section between at least one radioactive emitter and a detector for radioactive rays, for example a scintillation counter; From the reduction in the measuring signal of the detector when passing through the measuring section, it can be seen whether the container is completely full or at least one cigarette pack, that is to say a container or a cigarette box, is missing. At the same time, the widths of the respective cartons are determined via light barriers, so that a correlation between the change in the measurement signal on the one hand and the width of the carton on the other hand is brought about and incorrectly filled cartons can be correctly identified.

Description

characterized in that

f) at least one vertically arranged light barrier (48, 49; 50, 51; 52, 53) for detecting the horizontal width of a container (16) is provided that

g) each light barrier (48, 49; 50, 51; 52, 53) a level (60, 62, 64) of the output signal of the detector (20) assigned to the corresponding width when the container (16) is completely filled is, and that

h) the level associated with the width of the container (16) together with the output signal of the Detector (20) is given to a comparator (16), the output signal for detection of completely or not completely filled containers (16) is used.

2. Device according to claim 1, characterized in that when checking cardboard boxes (16) from several containers with cigarette packs depending on the size of the boxes up to six radioactive emitters (18) and six associated detectors (20) are provided.

3. Device according to one of claims 1 or 2, characterized in that as a radioactive emitter a radiator (18), in particular americium 241 or Curium 244 is used.

4. Device according to one of claims 1 to 3, characterized in that the detectors (20) Scintillation counters can be used.

5. Device according to one of claims 1 to 4, characterized in that the radioactive (s) Radiator (18) and the (the ^ detector (s) (20) are arranged in a rectangular shielding frame (17).

6. Device according to one of claims 1 to 5, characterized by one at the output of the Detector (20) connected frequency / voltage converter (26) for the formation of the measurement signal.

7. Device according to claim 6, characterized in that after a change in the measurement signal the actual value is stored and compared with the following measurement signal.

8. Device according to claim 7, characterized

indicates that an incorrectly filled container (16) is recognized when the comparison is above a predetermined Time span delivers a positive or negative deviation

3. Device according to one of claims 5 to 8, characterized in that several radioactive emitters (18) arranged vertically one above the other are attached to a vertical column, which via a pneumatic twist lock (25) with spring-loaded Return is fixed in the shielding frame (17).

10. Device according to one of claims 6 to 9, characterized in that the evaluation is digital, in particular via a microprocessor

The invention relates to a device for checking that a container has been completely filled with cigarette packs of the type specified in the preamble of claim 1.
Cigarettes leave the usual production process either in bundles or in boxes with several bundles. A completeness check must be carried out, ie it must be determined whether the respective container contains the specified number of cigarettes. Scales or capacitive initiators are currently used for this purpose. When weighing a carton filled with 50 containers, however, fluctuations in the weight of the cigarette and the various moisture contents of the carton can cause weight differences that exceed the weight of a container. So this procedure does not work precisely enough.

In addition, the initiators used to check for completeness have the disadvantage that they only result in cigarettes can be checked, which are packed in metal foil or in paper with a metallic coating. Furthermore, the container to be tested must be at an extremely short distance, for example at a distance of 15 mm past the initiator. In practice this is usually not possible, like this that these initiators are only suitable for checking completeness in a few cases.

Furthermore, it is pointed out in US-PS 41 16 973 that a completeness check in principle with Microwaves can be carried out. However, this measuring method is only suitable if a Metal foil or similar material is present.

Furthermore, from US-PS 37 96 873 a device for checking the complete filling of a container with a material with a given weight with a radioactive emitter on one side of a conveyor line and a radioactive emitter on the opposite Side a detector assigned to the radioactive emitter are arranged. From the reduction of the Output signal of the detector when a container passes between the radioactive emitter and the Detector, the filled mass can be determined.

A device for checking that a container is completely filled with cigarette packs Specified genus is finally from US-PS 30 84 797 or the article »level control and -Steuerung mit radioactive isotopes «, published in the journal» Atompraxis «, 1959, issue 2 (Febr.), P. 59-66 and has a funding facility for the

filled container, at least one radioactive emitter arranged on one side of the conveyor line, at least one detector assigned to the radioactive emitter for the emitted rays on the other side of the conveyor line, a switching arrangement for determining the filling level of the container from the Reduction in the output signal of the detector when a container passes between the radioactive one Emitter and the detector as well as light barriers for detecting the front in the transport direction of the container or rear ends of the container. Thereby the weakening of the radioactive rays is caused by the filling of the container for scanning fill levels, for monitoring fill limits and for continuous Display and control of fill levels used

In the cigarette industry, in general three different types of containers are used, namely the usual cigarette pack, for example Contains 20 individual cigarettes, furthermore a container of 10 cigarette packs, the large ones Surfaces are adjacent to each other, the so-called »cigarette sticks«, or cardboard boxes that hold up to 50 containers may contain. These respective containers generally have different widths.

With the known devices, the complete filling of such different containers not check, since the intensity of the rays falling on the respective detectors depends, among other things, on the Width of the respective container depends, so even with correctly filled containers accordingly different Output signals of the detectors can result.

The invention is therefore based on the object of providing a device for checking the complete To fill a container with cigarette packs of the specified type, which also applies to containers with different widths enable the correct detection of filling errors.

This object is achieved according to the invention by what is stated in the characterizing part of claim 1 Features solved.

Expedient embodiments are defined by the features of the subclaims.

The advantages achieved by the invention are based on the fact that by using an additional optisehen Measuring device a correlation between the output signal of the detector on the one hand and the width of the each to be checked container on the other hand is possible, so when evaluating the output signal of the Detector also the respective width of the container is taken into account, so that any filling errors also occur Immediately detect containers of different widths.

The evaluation electronics therefore take into account the number and position of the interrupted light barriers on the one hand and the difference in the output signals of the detector, on the other hand, to an error signal, if any to generate, which indicates that the container just checked is not sufficiently filled.

Brief »light gaps« occur between two consecutive containers passing through the facility that would be recognized as error signals by the evaluation electronics. Even the sometimes occurring Irregular impact of the ray particles can be seen as an error signal, i.e. as a signal for one not sufficiently filled container. For this purpose, time discrimination is carried out, to eliminate the sources of error mentioned and to ensure that the mentioned apparatus Errors are suppressed and only genuine error signals are registered.

A version realized as a prototype provided reproducibility of the signals of more than 99%, whereby the acceptable signal error tolerance was approximately ± 7%.

To optimize the adjustability, the containers should be moved through the beam path in such a way that no more than two containers are arranged next to one another in the direction of the jet; this can result in faulty Packaging an error 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«.

Since tobacco on the one hand and filter material on the other hand have different output signals from the detector and In order to provide different signal levels, the irradiated cigarettes should either be transported in their longitudinal axis corresponds to the beam axis or their longitudinal axis is perpendicular to the transport surface, So stand or hang in relation to filters / tobacco.

However, if the cigarettes are moved horizontally in their longitudinal axis parallel to the conveying direction, alternating, fluctuating dark values originating from the filter and tobacco arise in the measurement signal; should If these fluctuations are not interpreted as error signals, the signal tolerance must correspond accordingly be set more generously.

The limit of error can be further reduced if necessary, making the facility even more sensitive when the transport speed of the containers is reduced. Because proportional to the reduction the transport speed also decreases the ripple of the measurement signal, whereby the evaluation becomes even more precise.

If necessary, the device can be followed by an automatic ejection device, which is not ejects completely filled containers from the actual production line.

The commonly used, commercially available radioactive emitters have a half-life of 450 years, so that there is an intensity loss of less than 0.16% per year; this loss of intensity however, it is automatically compensated for every new container type by storing the sample signal.

The radioactive emitter or emitters are expediently attached in a cylinder that is around his vertical axis can be rotated relative to an outer cylinder. This cylinder is in a Shielding frame, so that the radioactive rays after rotation of the cylinder, for example by means of a pneumatic screw cap, towards which the outer cylinder is directed, i.e. the radioactive radiation can no longer get out of the shielding frame and thus when the device is otherwise switched off no longer forms a source of danger.

The invention is described below using an exemplary embodiment with reference to the enclosed, schematic drawings explained in more detail. Show it

F i g. 1 is a schematic, perspective view of the basic structure of a device for checking the complete filling of a container with cigarette packs,

F i g. 2 a schematic representation of the mechanical part and the evaluation electronics of the device,
F i g. 3 the signal curves for an error-free bus

container for six radioactive emitters and six detectors, and

F i g. 4 the signal curves for a container with a missing container for six radioactive emitters and six detectors.

As shown in FIG. 1 can be seen, a cardboard box 16, for example 50 containers of 10 cigarette boxes each contains, by means of a conveyor device 12 with conveyor rollers 14 through a generally through the device indicated by the reference numeral 10 for checking that the carton 16 has been completely filled guided; this device 10 can carry out a carton or package completeness check and has a rectangular shielding frame 17, which the conveyor 12 and the actual objects to be measured, so the cardboard boxes 16 surrounds. According to the illustration in FIG. 1 right strut of the shielding frame 17 six radioactive emitters 18 are arranged vertically one above the other; than commercially available radioactive Americium 241 or Curium 244 are available.

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

As shown in FIG. 2 recognizes, are the radioactive emitters 18 in a vertical column 19, which means a pneumatic rotary lock 25 can be rotated with its inner cylinder. With that you can the radioactive emitters 18 from their working position according to FIG. 2, in which they are the radioactive rays too direct the scintillation counter 20 in a position in which the radioactive rays only into the interior of the Outer cylinder get, so can not penetrate to the outside.

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

Below the transport surface of the cardboard boxes 16, so for example below the conveyor rollers 14 are located photocells 48, 50 and 52 that contain infrared sources and infrared receivers. The ones not shown in detail Infrared transmitter of the photocells 48, 50 and 52 direct their radiation on reflectors 49,51,53, which located in the upper, horizontal strut of the shielding frame 17. Of these reflectors 49, 51 and 53 the Siräiilung aiii uic recipient of the PhoiOzelleii 48.50 and 52 thrown back.

As an alternative to this embodiment, it is of course also possible to use the reflectors 49, 51 and to replace 53 with light sources; in this case the photocells only contain receivers, i.e. the usual ones photoelectric converter.

The photocells 48,50 and 52 form with the associated Reflectors 49, 51 and 53 each have a light barrier that passes through a cardboard box 16 is interrupted.

For example, if only the photocell 52 responds, it is a narrow box 16; speaks If the photocell 50 is also on, it is a middle carton 16; and also speaks the photocell 48, it is a wide box 16; it is assumed that the cartons 16 each attached to the as shown in F i g. 2 right margin.

In Fig. 2 shows the output signal of a scintillation counter 20; it forms a series of impulses, the number of which is a measure of the number of radioactive particles striking. This sequence of impulses is converted by a frequency / voltage converter 26 into the corresponding DC voltage, the is in turn proportional to the number of radioactive particles hitting it.

ίο If there is no box 16 in the shielding frame, the emitted radioactive particles fall unhindered onto the associated scintillation counter 20, so that a DC voltage signal is present at the frequency / voltage converter 26, which will be used in the following

is to be called "Heiiweri" and for example 12 V.

This DC voltage signal is given on the one hand to a comparator 36 and on the other hand to a Circuit 28 out, the function of which will be explained.

If a cardboard box 16 now enters the device 10 and is thus in the beam path of the radioactive particles, the number of radioactive particles hitting the associated scintillation counter 20 and thus the number is reduced due to the absorption by the material of the cardboard box or the cigarette of the pulses, so that the DC voltage signal of the frequency / voltage converter 26 drops 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 resulting leading edge, that is, the reduction of the DC voltage signal from the light value to the dark value, is recognized by the circuit 28, which is therefore to be referred to in the following as the “leading edge detector”; At a predetermined time delay 7 * 1 after the detection of the leading edge, which can be specified by the adjustable delay element 30, the leading edge detector 28 sends the pending DC voltage signal, i.e. the existing measured value, to an instantaneous value memory 32. The delay T 1 is set so that the measurement signal given to the instantaneous value memory 32 corresponds approximately to the middle of the first expected cigarette pack, i.e. a bundle of 10 cigarette boxes when checking a box or a cigarette box when checking a box. For this reason, the setting of the delay time T1 is essential, since the delay time Tt depends on the type of container to be checked, namely cardboard box or container (see the AbiäSipüiik'i in Fig. 2).

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

The comparator 36 thus detects a positive deviation, i.e. a greater dark value, such as then is the case if the stored, previous value indicates a fault, i.e. the lack of a cigarette

lcbox or a container.

The second comparator 38 detects a negative deviation, that is to say a smaller dark value like that is the case when the stored previous value has a "good position" and one or more error positions follow.

The two deviations are processed into a fault rejection signal if they are adjustable Exceed time. This fault rejection signal is given to a circuit 40, the mode of operation of which yet to be explained.

The described time discrimination with the stored, A previous measuring signal is necessary so that there are short-term "healing gaps" between the individual Containers are not interpreted as error signals. In addition, this allows short-term error signals suppress, which are due to the irregular impact of the radioactive particles.

In Figure 2, the time Tl is shown still schematically, which is required for the passage of a carton 16 through the device 10 degrees. It can be seen that the time span 7 * 1, which defines the point in time for storing the measurement signal, lies at the beginning of the throughput time 7 "2 of the carton.

The photocells 48, 50 and 52 are assigned setting values 60, 62 and 64 for specific voltage signals χ 1, χ 2 and χ 3, which in turn correspond to the different signal levels for the different container sizes. For example, χ 1 is the minimum level for wide cartons 16, χ 2 is the minimum level for cartons 16 of medium width and χ 3 is the minimum level for narrow cartons 16.

For example, if the photocell 52 responds, a switch 58 is activated and lets the minimum level χ 3 for the narrow cardboard boxes 16 through to a comparator 66; Accordingly, when the Pholo cell 48 or 50 is triggered, the minimum level χ 1 and χ 2 are passed via the associated electronic switches 54 and 56 to the comparator 66, which also has the direct voltage output signal of the frequency / voltage converter 26, i.e. the actual Messsigna !, receives.

The minimum levels χ 1 to χ 3 contain a statement as to which DC voltage signal should not fall below the determined width when the carton 16 is completely filled. From the minimum level χ 1, χ 2 or χ 3 on the one hand and the DC voltage signal of the frequency / voltage converter 26 on the other hand, the comparator 10 derives a statement as to whether a container passing through is completely filled or not xi to χ 3 basic values are given for the measuring signals, which can only be exceeded if the container is more than half full and which also lead to an error signal if the value is not reached. This makes it possible to determine whether the container 16 passing through is full, half full or empty.

The output of the comparator 66 and the Output signals of the two comparators 36 and 38 are given to an evaluation circuit 40, which the The detected errors are summarized and an output signal is generated when the container 16 is not completely filled outputs that via a circuit 42 with a noise filter and an amplifier to a fault relay 46 is given; this alarm relay can, for example, generate an alarm signal or one directly Activate the automatic ejection device, which removes the container recognized as not completely full from the Production aisle removed, for example via a slide that serves as an ejection system.

The response time of this alarm relay R can be adjusted by a timer 44, which introduces a switch-on delay Γ3 for the circuit 42 and thus a corresponding delay in the response time of the Störmeidere- R .

The output signals of this device 10, for example the output signal of the circuit 40, should be in the following based on an exemplary embodiment with six radioactive emitters 18 arranged one above the other and their associated scintillation counters 20 will be discussed; such a device 10 thus has a total of six channels so that, for example, cardboard boxes 16 can be checked in which nine containers side by side and six layers of containers are contained on top of each other.

In Fig. 3 are the transport direction and the jet direction for such a carton 16 with four bundle layers as well as the output signals of the six channels are shown.

Since this cardboard box 16 contains only four bundle layers, the two uppermost are in the beam path Scintillation counter 20 does not have a container, so that the corresponding signals are at the light value and thus unchanged stay.

In the case of the four lower scintillation counters, the light value when the carton 16 enters the dark value reduced, as can be seen from channels 1 to 4, so that there is a clear indication for the passage through the cardboard yields. This carton 16 is completely filled, as can be seen from the uniform Can recognize the shape of the »recess« in the corresponding DC voltage signals of channels 1 to 4.

F i g. Figure 4 shows a carton 16 similar to Figure 4. 3 with four layers of bundles arranged one above the other, with however, one package is missing in the upper, fourth package layer, while the other layers are complete.

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

The three lower layers of the container are completely filled, so that there is the same reduction in the DC voltage signal from the light value to the dark value as with the completely filled box F i g. 3 results.

In the channel 4 occurs first the usual, caused by the penetration of the cardboard 16 into the measuring section Reduction of the measurement signal from the light value to the dark value. Now comes the area which the container is missing and in which there is only air, into the jet path, the absorption in the is reduced Comparison with areas with containers, d. that is, the dark value increases again briefly to the light value, like is indicated in channel 4 by the tip. Then the measurement signal drops back to the dark value, because the absorption through the following containers is now again noticeable

From the characteristic shape according to channel 4 it can be seen immediately that this is approximately in the middle A container is missing from the container.

After the device 10 has been appropriately calibrated, the measurement signal can also indicate the absence of a cigarette pack can be derived in a container.

For this purpose 4 sheets of drawings

Claims (1)

Patent claims: 1. Facility to check the full Filling a container with packs of cigarettes a) with a conveyor for the filled containers, b) with at least one radioactive emitter arranged on one side of the conveyor line, c) with at least one detector assigned to the radioactive emitter for the emitted Rays on the other side of the conveyor line, d) with a switching arrangement for determining the filling level of the container from the reduction the output signal of the detector when passing a container between the radioactive Emitter and the detector, and e) with light barriers to detect the front or rear in the transport direction of the container lying ends of the container,