DE102004034852B4 - Method and apparatus for inspecting containers for foreign matter - Google Patents

Abstract

Device for testing containers for foreign substances, comprising at least one test head which can be placed on a container, characterized by at least one own gear (5) for moving the sampling head (6a) over a part of the movement of the container (4), essentially with the latter characterized in that the transmission (5) for the sampling head (6a) is connected to the drive for the movement of the containers (4) and a mechanical synchronization device, in particular in the form of a geared transmission element (7) for synchronizing the movement of the containers (4). and the sampling head (6a) is arranged at least over a partial section.

Description

The invention relates to a device for inspecting containers for foreign substances, comprising at least one sampling head which can be placed on a container and a method for inspecting containers for foreign substances, wherein a sampling head is placed on a container.

From the EP 534 096 A2 are a generic method and a generic device for inspecting containers for foreign substances known. In this case, containers, such as bottles, are taken over by a feed conveyor by a transfer circular conveyor and transferred to a survey circular conveyor, from which they are returned to a transfer circular conveyor, which feeds them to a Fortführ conveyor track.

The examination circular conveyor carries a plurality of sampling heads, which accordingly revolve with the examination circular conveyor and the bottles conveyed by the same and are vertically movable up and down relative to these, so as to be sealingly placed on the bottles and released from them again. All sampling heads are connected via a rotary distributor with a common analysis device, by means of which the drawn samples are evaluated.

The known device is complicated in structure and has a high technical and therefore costly effort, since in particular in the given configuration necessarily for each position of a bottle on the circular conveyor and an associated sampling head must be provided. Other known devices for taking gas samples from containers are complicated and usually have a plurality of sampling heads, with a partial lance immersed to near the bottom of the container in this.

A device has been proposed in which the containers are guided under a completely stationary, in no way moved sampling head. Safe, meaningful sampling is not possible.

The invention has for its object to provide a generic device that is structurally simple with high security and reliability of sampling and high examination frequency. The invention is further based on a method that can be carried out in the aforementioned advantages by a structurally simple trained device.

According to the invention, the object is achieved in a device of the type mentioned, by at least one own gear for moving the sampling head over a portion of the movement of the container substantially with this. To achieve the object of the invention, the invention further provides in a method of the type mentioned above, that the sampling head is moved by means of its own drive with the container.

The invention thus provides that the rigid connection between the container transport means and the sampling head for carrying the sampling head over a certain part of the movement of the container is released and at least a separate transmission is provided for the sampling head for Mitbewegung with the containers.

In a merely geared connection between the sampling head and moving means for the container or its drive so a common drive with different gears and translations is provided, while in the former alternative, a separate additional drive (motor) can be provided for the co-movement of the sampling.

In both cases, the invention provides in a further embodiment, a synchronization device for synchronizing the movement of the container and the sampling head at least over a partial route. Accordingly, the movements of the container and the co-movement of the sampling head are synchronized. The movement of the sampling head and container can be synchronized electronically or mechanically. Thus, the invention provides an electronic synchronization device, in particular in a separate drive for the co-movement of the sampling head in a preferred embodiment. Alternatively, in a merely geared connection of the sampling head for driving the transport device for the container, the movement of the container and the co-movement of the sampling head are mechanically synchronized with each other via a transmission.

For this purpose, the device according to the invention has a mechanical synchronization device, in particular in the form of a geared transmission element.

In a further preferred embodiment of the invention it is provided that the sampling head is moved along a portion of the movement of the container by means of an eccentric drive.

Further preferred embodiments of the invention provide that a holding member which is in engagement with an eccentrically disposed on the eccentric cam carries the sampling head, wherein In particular holding part and sampling head are yieldingly connected to each other, wherein holding part and sampling head are preferably connected to one another via a spring, in particular a helical spring, elastically.

In a preferred development may also be provided that the holding part is guided by a guide linkage and in particular the guide linkage is designed such that it imposes a limited angular movement in a narrow angular range to the holding part and thus the sampling head, wherein preferably the angular range less than 10 ° is.

For this purpose, the concrete device according to the invention is provided in a concrete embodiment that in particular the guide linkage comprises a lever which is pivotally connected to a fixed point and is connected at its other end to a holding part holding the guide rod.

In addition, a preferred embodiment of the invention provides that the sampling head carries a compressed air lance through which after placement of the holding head on a container, a blast of compressed air is blown into this.

Finally, the device according to the invention is formed by the fact that in the holding head a sampling line opens, by means of which the gas from the container to a measuring system can be guided, in particular the sampling head by means of at least one own transmission over a portion of the movement of the container moves substantially with this becomes.

For sampling itself, the invention provides in a further development that upon seating of the sampling head on the opening of the container, a blast of compressed air is introduced into the container, whereby gas is expelled from the container to a measuring device, where it can then be analyzed accordingly.

Further advantages and features of the invention will become apparent from the claims and from the following description in which an embodiment of the invention with reference to the drawings is explained in detail. It shows or show:

1 a schematic representation of the device according to the invention in side view;

2a , b a sequence of sampling according to the invention in a schematic representation, wherein 2a the assignment of sampling head of the containers to be tested in the movement phase of the sampling head at 0 ° and 2 B shows the sequence of the actual sampling over the movement phases of 105 ° to 255 °.

3a a guide rod; and

3b the guide rod in a schematic representation.

The device according to the invention 1 has in the illustrated embodiment of 1 one by a wave 2 driven circular conveyor 3 for containers to be examined 4 , here refillable PET bottles (REFPET bottles), on. In the 1 is the movement of the containers 4 essentially perpendicular to the plane of the page.

With the conveyor 3 is geared a gearbox 5 for a sampling device 6 with a sampling head 6a connected to each for sampling on a container 4 is put on.

In the illustrated embodiment, the transmission 5 for driving the sampling device 6 one on a gear disc 5a acting drive belt 7 on. The gear disc 5a is with a wave 8th connected to an unspecified angle gear 9 acts, with its output shaft an eccentric 10 connected with an eccentric to its axis of rotation 10a arranged cams 11 in a recess 12 (shown in dashed lines) of a holding part 13 in the form of a holding block for the sampling head 6a intervenes. The holding part 13 is about a guide rod 14 held and guided.

The guide rod is in the 3a . 3b more precisely in line III-III of the 1 shown.

The guide linkage has a lever 15 on that at a fixed point 16 is hinged pivotally. With his other end he is articulated with a guide rod 16 connected, the firm and rigid with the holding part 13 connected and this at his by the cam 11 caused movement ( 3a and 3b ). The guide linkage becomes the circumference of the cam 11 shown at constant angular velocity. The uneven horizontal movement of the articulation point of the linkage 14 on the holding part 13 is regarding the sampling head 6a largely compensated so that it can follow the movement of the container.

The sampling head 6a is yielding towards the guide rod 16 on the holding part 13 arranged, for example by a coil spring 17 where he is opposite the holding head 13 can also have a certain Angularbeweglichkeit.

Into the sampling head 6a first leads a compressed air lance 18 , whose compressed air supply via a valve 19 is controllable. Furthermore, it opens into the upper area of the sampling head 6 a sampling tube 20 that has a filter 21 , which filters out solid and liquid particles, with a measuring system 22 connected is. Not necessarily, but beneficial, is a suction pump 23 provided in the sampling hose system.

On the the Excenter 10 opposite side of the angle gear 9 there is another output shaft 24 , which at its periphery a Schaltnocke 25 , which have an associated pulse generator 26 the valve 19 in the compressed air lance 18 controls.

The following is particularly with reference to the 2 the function of the device according to the invention and thus the sampling method according to the invention are explained:
The position in which the holding part 13 and thus the sampling head 6a located in its uppermost position, is referred to as 0 ° position, while the position in which the holding part 13 and thus the sampling head 6a pressed down as far as possible, is referred to as 180 ° position. In the 0 ° position, the horizontal assignment of the sampling head 6a and container in the direction of movement of the container such that the sampling head is located approximately in the middle between two opposite containers.

The movement of the container 4 and the parallel component (horizontal component) of the holding part 13 and thus the sampling head 6 are synchronized with each other, in the illustrated embodiment by the described gear and guide linkage, so that both movements in their speed and direction substantially coincide.

A container 4 arrives with its opening below the sampling head 6a in the 90 ° position of the same. At 105 ° surrounds the lower edge of the sampling head 6a just the top of the container 4 , At about 120 °, the seal sets 6b the sampling head on the upper edge of the sampling head 6a on the top of the container. The switching cam also arrives at this movement phase 25 to the pulse generator 26 and thus solves by opening the valve 19 a compressed air pulse through the nozzle of the compressed air lance 18 into the container, whereby the gas in it via the sampling line 20 to the measuring system 22 is directed.

With further movements up to 180 °, the holding block moves 13 further down while the sampling head 6a at a further movement down through the upper edge of the container 4 is prevented. Due to the elastic connection between the sampling head 6a and holding part 13 the latter presses the sampling head 6a firmly against the upper edge of the container.

At 180 ° reached, as I said, the holding part 13 its lowest position and thus exerts the greatest pressure on the sampling head 6a out.

The sample is analyzed in the measuring system, preferably spectroscopically by means of UV or IR light or by means of microwave radiation, although other methods of measurement, such as mass spectrometry or the so-called TOF technique (Time of Flight) can be used, with an ionization of the container 4 expelled gas and accelerating the gas molecules in the electric field is carried out and the gas species are determined over a predetermined distance devoted flight times.

With the further movement beyond the 180 ° position also raises the holding block 13 back from the container 4 and thus triggers the sampling head 6a from the container opening, wherein at the latest 270 ° of the sampling head 6a the top of the container 4 completely free, allowing the container through the conveyor 2 can be freely promoted while the holding block 13 and thus the sampling head 6 be returned to the 0 ° position and reach again after lowering into the 90 ° position on the opening of the next container so that it can be removed in the manner described gas for examination.

LIST OF REFERENCE NUMBERS

1

contraption

2

wave

3

circular conveyor

4

container

5

transmission

5a

gear wheel

6

sampling equipment

6a

sampling head

6b

poetry

7

pulse

7

drive belt

8th

wave

9

angle gear

10

eccentric

10a

axis of rotation

11

cam

12

recess

13

holding part

14

guide linkage

15

lever

16

guide rod

16a

benchmark

17

coil spring

18

Compressed air lance

19

Valve

20

sample tube

21

filter

22

measuring system

23

suction pump

24

output shaft

25

switch cam

26

pulse

Claims (16)

Apparatus for inspecting containers for foreign substances, comprising at least one test head which can be placed on a container, characterized by at least one own transmission ( 5 ) to move the sampling head ( 6a ) over a portion of the movement of the container ( 4 ), essentially with this, characterized in that the transmission ( 5 ) for the sampling head ( 6a ) with the drive for the movement of the container ( 4 ) and a mechanical synchronization device, in particular in the form of a geared transmission element ( 7 ) for synchronizing the movement of the containers ( 4 ) and the sampling head ( 6a ) is arranged at least over a section. Apparatus according to claim 1, characterized by a separate drive for the movement of the container ( 4 ) corresponding movement of the sampling head ( 6 ). Device according to one of the preceding claims, characterized in that one in engagement with an eccentric on the eccentric ( 10 ) arranged cam ( 11 ) standing holding part ( 13 ) the sampling head ( 6a ) wearing. Apparatus according to claim 3, characterized in that holding part ( 12 ) and sampling head ( 6a ) are yielding to each other. Apparatus according to claim 4, characterized in that holding part ( 13 ) and sampling head ( 6a ) via a spring ( 7 ), preferably a coil spring are elastically connected to each other. Apparatus according to claim 4 or 5, characterized in that holding part ( 13 ) by a guide rod ( 14 ) is guided. Apparatus according to claim 6, characterized in that the guide rod ( 14 ) is designed such that it the holding part ( 13 ) and thus the sampling head ( 6a ) imposes a limited angular movement in a narrow angular range. Apparatus according to claim 7, characterized in that the angular range is less than 10 °. Device according to one of claims 5 to 8, characterized in that the guide rod a lever ( 15 ) at a fixed point ( 16 ) is articulated pivotally and with its other end with a holding part ( 13 ) holding guide rod ( 16 ) connected is. Device according to one of the preceding claims, characterized in that the sampling head ( 6a ) a compressed air lance ( 18 ), by the after mounting of the holding head ( 6a ) on a container ( 4 ) A compressed air blast is inflatable in this. Device according to one of the preceding claims, characterized in that in the holding head of a sampling line ( 20 ), by means of which from the container ( 4 ) to a measuring system ( 22 ) is feasible. A method for examining containers for foreign substances, wherein a sampling head is placed on a container, characterized in that the sampling head is moved by means of at least one of its own transmission over a portion of the movement of the container substantially with the latter, the sampling head via a transmission through the Drive for the movement of the container is moved, wherein movements of the container and co-movement of the sampling head are synchronized with each other mechanically via the transmission. A method according to claim 12, characterized in that the sampling head is moved in accordance with the movement of the container by means of an eccentric drive over a partial distance. Method according to one of claims 12 to 13, characterized in that the sampling head is pressed elastically against an opening of the container. Method according to one of claims 12 to 14, characterized in that upon seating of the sampling head on an opening of the container in this an air pressure shock is introduced, through which gas is expelled from the container. A method according to claim 15, characterized in that the gas expelled from the container is analyzed.

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