The present invention relates to a device for filling storage containers for preforms.

The present invention falls within the sector of plants for processing bottles made of plastic, in particular PET. According to the known production technology, the final form of the bottle is achieved by means of blowing of a preform in a suitable mould. For this purpose the preforms are stored in containers to which they are supplied by means of a conveyor belt.

The transfer from the conveyor belt to the container is performed by means of simple gravity, namely at the end of the conveyor belt the preform falls into the container situated at a variable height underneath the said belt.

The preforms are thus made to fall from above, which may cause scratches and/or dents which are then greatly accentuated by the ensuing blowing operation.

The result is, therefore, a bottle with imperfections which may have negative consequences for the bottle both from an aesthetic and from a functional point of view.

DISCLOSURE OF INVENTION.

The object of the present invention is to eliminate the abovementioned drawbacks and provide a filling device which accompanies the preforms from the conveyor belt to the container, so as to avoid knocks and consequently damage to the said preforms, which may adversely affect the end product.

Said objects are fully achieved by the device for filling storage containers for preforms, according to the present invention, which is characterized by the contents of the claims indicated below.

In particular, the filling device, comprising a conveyor belt for supplying a storage

container to be filled, located underneath the said belt, is characterized in that it comprises at least one accompanying container which is translatable vertically from the height at which the conveyor belt is situated to the height at which the storage container is situated, and vice versa, so as to accompany the preforms, avoiding knocks.

BRIEF DESCRIPTION OF DRAWINGS.

These and other characteristic features will emerge more clearly from the following description of a preferred embodiment illustrated purely by way of a non-limiting example in the accompanying plates of drawings in which: -Figure 1 shows a perspective view of a filling device; -Figures 2,3 and 4 show perspective views of certain details of the device according to Figure 1; -Figure 5 shows a diagram of the plant.

BEST MODE FOR CARRYING OUT THE INVENTION.

With reference to the figures, 1 denotes a container for storing preforms, which is filled by means of a filling device comprising a conveyor belt 2 supplying the storage container to be filled.

The conveyor belt 2 is located at a height which is greater than that of the storage container 1; in an original manner, an accompanying container 3 supported by a frame 4 travels along this height. The accompanying container 3 is in fact free to perform a translatory movement vertically from the height at which the conveyor belt 2 is situated to the height at which the storage container 1 is situated, and vice versa.

The accompanying container 3 is formed by two separate components 5, which are arranged so as to make contact along a line 6 so as to form the said accompanying container. The two components 5 are connected to the frame 4 by means of pins 10 about which they are free to rotate, so that the contact between the two components 5 along the

line 6 may be eliminated by means 7 for relative movement of the said components.

These relative movement means 7 comprise two gear-wheel systems 9 which are fixed to the accompanying container 3 on opposite sides thereof. Each gear wheel 9a is fixed to a component 5 of the accompanying container 3. One of the gear wheels 9a is actuated by a cylinder 7a fixed to the frame 4, while the other wheels are indirectly moved by it.

The frame 4, on which the accompanying container 3 is supported, comprises means 11 for travel of the said frame along a vertical guide 12, comprising a toothed belt 13 meshing with a toothed wheel 14. Moreover, the frame 4 contains a detection device 8 which is able to operate the means 7 for relative movement of the components 5 so as to open the accompanying container 3 when it is located inside the storage container 1.

The travel and correct positioning along the vertical guide 12 is ensured by a plurality of wheels travelling at the front of and along the sides of the said guide.

A safety device 15 may provided, said device comprising a stop 16 fixed to the frame 4 and a plurality of locating elements 17 fixed to the vertical guide 12. In the event of breakage of the travel means 11, the stop 16 locks the frame 4 against one of the locating elements 17.

The filling device described above, owing to the original introduction of the accompanying container 3, is able to accumulate the preforms being supplied on the conveyor belt, accompany them to the storage container 1, place them inside it and travel back up to the conveyor belt for a new load.

When the accompanying container is located at the height of the conveyor belt 2, the two components are closed and make contact along the line 6 so as to receive the preforms supplied by the belt. When the accompanying container 3 has received a load of preforms, the travel means 11 perform the vertical translatory movement of the accompanying container 3 and transport it to the height of the storage container 1.

The accompanying container 3 and the associated frame 4 enter inside the storage container 1; the detection device 8 detects the distance of the bottom of the accompanying container 3 from the bottom of the storage container 1 and stops the travel means 11 so as to leave the accompanying container 3 the space to open.

The cylinder 7a causes opening of the accompanying container 3 by means of rotation of the gear-wheel systems 9; the two components 5 rotate about the pins 10 and separate along the line 6, releasing the contents inside the storage container 1, avoiding knocking.

After it has been emptied, the accompanying container 3 travels upwards again and closes again so as to be able to accept a new load.

As shown in Figure 5, generally the conveyor belt 2 has a T-shape with a section 2a perpendicular to another section 2b performing an alternating movement so as to supply alternately two storage containers 1.

The preforms which are supplied by the first section 2a are channelled onto the second section 2b which is moved alternately in one direction or the other depending on the accompanying container 3 to be filled.

By alternating the movement of the two accompanying containers and synchronising it with the direction of feeding of the second section of the conveyor belt, it is possible to obtain a continuous filling process, since, while one accompanying container discharges its contents into the storage container, the other accompanying container is located at the height of the conveyor belt 2 so as to receive the preforms.