Conveyor for packages

The present invention relates to a conveyor for packages. In particular, the invention relates to a conveyor for moving packages which are made from a long web of film. A web of film of this type is sealed in the longitudinal direction, thus creating a tube and this tube is provided with a longitudinal seal. Transverse seals may be provided before, after or during filling of the package. However, it should be understood that the invention also relates to the conveying of other kinds of packages.

In the case of such packages, it is important that the sealing seam or seal which has been produced does indeed seal. If the longitudinal sealing seam, for any reason, does not meet the imposed requirements, then it is important that such package is removed from the conveyor as quickly as possible.

Various kinds of structures have been proposed in the prior art for checking if the longitudinal seal performs satisfactorily while the package is being conveyed. These proposals are either very complicated or very simple. However, the latter have been found to function unsatisfactory.

It is an object of the present invention to provide a conveyor which makes it possible to check packages during transportation thereof and, more particularly, to check if they have sufficient mechanical strength in a direction at right angles to the direction of transport.

In the conveyor described above, this object is achieved in that two spreading members are provided opposite one another in the supporting plane at right angles to the direction of transport, each of which perform a conveying movement in the direction from the centre of the belt to the respective outer side.

According to the present invention, a force is exerted on the underside of the package during transportation in a direction at right angles to the direction of transport from two opposite sides by spreading members. Preferably, the packages, such as bags, are laid down in such a manner that the critical seam is situated at the location of, and preferably between, such spreading members. If such a sealing seam is sufficiently

strong, the action of the spreading members will have no effect and such packages will be conveyed in the direction of transport.

However, if the sealing seam is insufficiently strong or is completely or partially absent, then the application of a load by the spreading members will result in the package being opened (further), resulting in the contents thereof being removed from the package which is a clear indication of the package failing. The force which is applied by the spreading members depends on the weight of the package and the friction acting between the spreading members and the package. It is possible to adjust this very accurately in order to prevent good package from being damaged by the spreading members while at the same time ensuring that the package with minor faults is detected immediately. If desired, a pressure force can be applied to the packages in order to be able to increase the spreading force.

Both the conveyor member and the spreading members may be of any embodiment known in the prior art. Thus, it is possible to embody the conveyor member in the form of two belts which are spaced apart and move in the same direction and to provide the spreading members in the intermediate space. A package then rests on its sides on the conveyor member, in each case consisting of a belt, and is "pulled open" from the centre by means of the spreading members.

According to an advantageous embodiment of the invention, the conveyor member consists of a series of rollers which are spaced apart in the direction of transport. Therein, the axis of rotation of the rollers is substantially at right angles to the direction of transport. Each roller can comprise a number of roller parts, thus providing, on the one hand, sufficient support of the package and, on the other hand, sufficient free space inbetween the supporting plane of the conveyor for removing undesirable parts of material. The spreading members can be embodied in the same manner, i.e. may consist of a rotatably driven part which may, in turn, be composed of a number of rotatably driven disc parts which are spaced apart. The rollers/roller parts and/or spreading member/disc parts may be cylindrical parts. Rotation can take place about the axis thereof, but it is also possible for the rotation to take place about a different point of rotation, as a result of which such rollers/roller parts and spreading members/disc parts,

respectively, also carry out a movement in upward and downward direction in addition to a rotating movement, thus improving the transportation of the packages. It is also possible for the rollers/roller parts and/or spreading members/disc parts to have any other conceivable shape (such as rectangular) instead of a cylindrical shape. As a result of the shape, the engagement with the package can be influenced.

In principle, it is possible to drive the spreading members using different motors (running synchronously). However, according to a further advantageous embodiment of the invention, the spreading members are driven by a common drive.

Underneath the conveyor, there may be arranged collecting means for catching any falling material and sensors which detect any defects so that defective packages are signalled.

As described above, the device according to the present invention can not only be used with bags, but also, for example, with boxes which are glue-sealed in one direction or are sealed in another manner.

The present invention also relates to a method for checking the quality of a package comprising conveying the latter in a first direction and subjecting it to spreading forces in a second and third direction during transportation, wherein said second and third direction being opposite to one another and being at right angles to said first direction, wherein said spreading force being applied by friction between packages and spreading member resulting from the weight of said package.

The invention will be explained below in more detail with reference to an exemplary embodiment illustrated in the drawing, in which:

Fig. 1 diagrammatically shows the conveyor according to the invention in perspective;

Fig. 2 shows the device from Fig. 1 in top view; Fig. 3 shows the device from Figs. 1 and 2 in side view;

Fig. 4 shows the device according to the invention in front view,

Fig. 5 shows a variant of a transport roller,

Fig. 6 shows a further variant of the transport roller, and

Fig. 7 shows a further variant of the disc parts.

The conveyor according to the present invention is denoted overall by reference numeral 1 in Fig. 1 and Fig. 2. It comprises a frame 2 in which a number of transport rollers 4 are mounted in order to enable transportation in the direction of arrow 3. Each or some of the transport rollers are driven by a drive mechanism 9 using a motor. Such a motor can be incommon for several rollers.

Each transport roller 4 comprises a shaft 5 and a number of roller parts 6 which are spaced apart. As can be seen in particular in Fig. 3, each roller part 6 is of circular embodiment and has a core 8. However, the core of shaft 5 denoted by reference numeral 7 does not coincide with core 8, so that a reciprocating movement is produced in addition to a rotating movement.

A conveyor with such roller parts is generally known in the prior art.

The present invention proposes to provide spreading members. These are denoted by reference numeral 10 and in each case comprise a shaft 11 and 12, respectively, with disc parts 13 and 14, respectively, being arranged at a distance therefrom. These may have any conceivable shape, but are preferably embodied in such a manner that the engagement with the package is optimal. This may be achieved by means of a circular shape. A common drive mechanism 15 (see Fig. 4) is present and the disc parts 13 and 14 are rotated in the direction of arrow 17 and 18, respectively, by means of a transmission 16.

Underneath the frame 2, a tray 19 is provided.

As can be seen in Fig. 4, during transportation in the direction 3, a package 20 completely or partially rests on the disc parts 13, 14. By rotating these in the direction of the arrows 17 and 18, due to the friction resulting from the weight of the package 20 and the friction coefficients of the packages material and the surfaces of the disc parts 13 and 14, respectively, a spreading force will be produced by means of which the bag is pulled open on the underside. As is illustrated, the bag is provided with a longitudinal

seam 21. If this seam 21 is sufficiently strong, the pulling action of the disc parts 13, 14 will have no effect. However, if the seam 21 is not perfect or completely absent, then the package 20 will be opened and the contents thereof will disappear into the tray 19. This can be detected in a simple manner, after which the package in question can be removed.

It will be understood that it is also possible to use such an assembly to check other packages for strength.

Fig. 5 shows a variant of a transport roller which is provided with disc parts having a shape which deviates from the shape shown in the preceding figures.

Fig. 6 shows a further variant of the transport roller. It is provided with disc parts having a shape which also deviates from those shown above.

Fig. 7 shows a variant of parts 13 and 14, respectively, from the previous figures. In this case, the shape is oval. Optionally in combination with the embodiment from Fig.

5, this shape slightly lifts a packages during transportation, as a result of which the engagement in the lateral direction (spreading) is increased. Depending on the type of packages and the strength of the seals to be tested, the shape, dimensions and material properties of the disc parts and transport rollers can be selected.

The embodiment of the disc parts and other associated parts of the assembly depends on the application of the transport roller. If they are used in combination with food products, they have to be compatible with the food. By way of example, food-grade rubber blocks which can be cleaned in a simple manner are mentioned here.

The present invention provides a simple test which yields highly reproducible results and can be achieved with moderate expenditure in terms of construction. It will be understood that the spreading members which are embodied as rollers in this example can also be embodied in other ways. What is essential to the invention is the fact that an opposite force, at right angles to the direction of transport, is exerted on the packages. Obviously, this force does not have to be exactly at right angles to the direction of

transport.

After reading the above description, those skilled in the art will immediately be able to think of variants which are covered by the scope of the attached claims and for which rights are expressly sought.