Dispenser for mixes

Abstract

A mix dispenser (14) comprises a hopper (24) with a top opening (26) for filling the hopper with a predetermined amount of mix and a bottom opening (28). The dispenser comprises a conveyor (30) which forms the bottom of said hopper (24) and is designed to extract the mix from the hopper (24) and convey it towards an end from where it falls into a mould. The dispenser is characterized in that said conveyor (30) comprises a supporting meshwork (32) made of a material resistant to the vapours of solvents such as styrene and operated by an electric motor (34). Furthermore a plant comprising such as dispenser is also described.

Claims

1. A mix dispenser comprising a hopper with a top opening for filling the hopper with a predetermined amount of mix and a bottom opening, said dispenser further comprising a conveyor which forms a bottom of said hopper and is configured to extract the mix from the hopper and convey the mix towards an end from where the mix falls into a mould; characterized in that said conveyor comprises a supporting meshwork operated by an electric motor, said supporting meshwork being lined with a plastic film; and wherein the plastic film is adaptive to the meshwork so as to form, inside meshes of the meshwork, corresponding trays in which the mix is arranged.

2. The mix dispenser according to claim 1, characterized in that said supporting meshwork is made of a material resistant to vapours of solvents.

3. The mix dispenser according to claim 2, characterized in that said supporting meshwork is made of metal.

4. The mix dispenser according to claim 3, characterized in that the metal supporting meshwork is formed with flat strips folded onto themselves to form elements with a substantially undulating progression, said elements being fixed in pairs by means of pins, perpendicularly oriented relative to a direction of folding, and in a vicinity of the element pairs so that relative rotation of the element pairs along axes of the pins is possible.

5. The mix dispenser according to claim 2, characterized in that said supporting meshwork is made of a material resistant to vapours of styrene which are present in the mix in which a polyester resin is used.

6. The mix dispenser according to claim 1, characterized in that the supporting meshwork is inclined forward with an inclination of between 5 and 15 relative to horizontal.

7. The mix dispenser according to claim 1, characterized in that the conveyor further comprises at least one cog wheel for driving the supporting meshwork.

8. The mix dispenser according to claim 7, characterized in that the at least one cog wheel is keyed onto a shaft and is rotated by means of the electric motor.

9. The mix dispenser according to claim 7, characterized in that the conveyor comprises a plurality of cog wheels which are equidistant from each other.

10. The mix dispenser according to claim 7, characterized in that said conveyor comprises a series of idle wheels at an end opposite to the at least one cog wheel that is rotated by means of the electric motor.

11. The mix dispenser according to claim 1, characterized in that a supporting surface onto which the mix discharged from the hopper is poured comprises the plastic film placed on said supporting meshwork so as to in turn line said supporting meshwork.

12. The mix dispenser according to claim 11, characterized in that the plastic film is made of polypropylene or polyethylene.

13. The mix dispenser according to claim 11, characterized in further comprising a feed roller for the plastic film and a recovery roller.

14. The mix dispenser according to claim 1, characterized in that the meshwork so as to support the mix is formed of plastic film.

15. The mix dispenser according to claim 14, characterized in that a size of the meshwork is 10 mm.

16. The mix dispenser according to claim 1, characterized in that a size of the meshwork so as to support the mix ranges between 8 and 12 mm.

17. A plant for production of slabs from stone or stone-like material and a binder, comprising a mix dispenser according to claim 1.

Description

(1) The advantages and characteristic features of the present invention will emerge more clearly from the detailed description below of a number of examples of embodiment provided by way of a non-limiting example, with reference to the attached drawings in which:

(2) FIG. 1 shows a schematic side view of a plant according to the present invention;

(3) FIG. 2 shows a schematic side view of a dispenser according to the present invention;

(4) FIG. 3 shows a schematic side view of a portion of the dispenser according to FIG. 2;

(5) FIG. 4 illustrates an example of operation of a portion of a dispenser according to the present invention;

(6) FIG. 5 shows a view, on larger scale, of a detail of FIG. 4; and

(7) FIG. 6 shows a schematic perspective view of a portion of a dispenser according to the present invention;

(8) In FIG. 1 the reference number 12 denotes a plant for the production of slabs consisting of stone or stone-like material and an organic or inorganic binder.

(9) The plant 12 comprises a mix dispenser 14, a mould or temporary support 16 and means for relative movement of mix dispenser 14 and support 16.

(10) In accordance with a possible embodiment of the present invention, the relative movement means may comprise a carriage 18 which is operated by a motor (not shown) and provided with wheels 20 (two for each of the two sides) which travel on respective rails 22. The motor may be of the variable-speed type for adjusting the quantity of material dispensed, as will become clear from the continuation of the description.

(11) The mix dispenser 14, as can be seen in FIG. 2, comprises a hopper 24 provided with a top opening 26 and a bottom opening 28.

(12) The top opening 26 is used to fill the hopper with a predetermined amount of mix in a manner known per se to the person skilled in the art.

(13) The hopper 24 may be provided with a shaped wall 230, of the type described further above with reference to the relevant prior art.

(14) The mix dispenser 14 also comprises a conveyor 30.

(15) The conveyor 30 comprises a, preferably metallic, solvent-resistant supporting meshwork 32 which is operated by an electric motor 34.

(16) The supporting meshwork 32 forms the bottom of the hopper 24. The supporting meshwork may be inclined forwards with an inclination of between 5 and 15, and preferably about 10 relative to the horizontal.

(17) The meshwork used may be for example the metal meshwork commercially distributed by COSTACURTA under the trade name VICO-TR.

(18) The aforementioned metal meshwork is made using small metal strips (long flat elements). These long flat elements are folded onto themselves to form an element with a substantially undulating progression. These elements are then fixed in pairs by means of pins, perpendicularly relative to the direction of folding, and in the vicinity thereof, so that their relative rotation along the axis of the pins is possible.

(19) This type of conveyor, since it is well-known to the person skilled in the art, will not be described further.

(20) As can be seen from FIGS. 3, 4 and 5, the conveyor 30 also comprises cog wheels 36 for driving the meshwork. In accordance with the embodiment shown in FIG. 6, the conveyor 30 may comprise a plurality of cog wheels 36 which are equidistant from each other. The cog wheels 36 are keyed onto the same shaft and rotated by means of the electric motor 34.

(21) In the embodiment shown in FIG. 6, the cog wheels 36 are fifteen in number and equidistant from each other.

(22) Moreover a series of idle wheels is provided at the opposite end.

(23) The cog wheels 36, which engage directly inside the meshes of the meshwork, ensure a highly uniform advancing movement of the material. FIGS. 3 and 4 and the detail of FIG. 5 illustrate in schematic form how transmission between cog wheel and mesh of the meshwork is performed. From the figures it can also be seen that the return section of the meshwork is pulled by the cog wheels, while the outgoing section, on which the material is supported, is pushed by the cog wheels. The direction of movement is indicated by the arrows 38, 40, 42.

(24) The supporting meshwork 32 is lined with a plastic film 241 such that the mix which is discharged from the hopper 24 is deposited on the plastic film 241. In fact, if the film for supporting the mix were not present, the mix would fall through the meshes of the metal meshwork.

(25) Advantageously, the plastic film 241 may be of the type mentioned with reference to the protective film of the preceding extractor belt.

(26) The plastic film may be made for example of polypropylene or polyethylene.

(27) The size of the meshes is such as to support the mix by means of the plastic film and is of the order of about 10 mm or so. Advantageously, the size of the meshes ranges between 8 and 12 mm.

(28) As can be seen in FIG. 2, the dispenser 14 comprises a feed roller 242 for the plastic film and a recovery roller 243. Advantageously, the feed roller 242 may be positioned above the conveyor, while the recovery roller 243 may be positioned below the conveyor 30.

(29) The advantages which can be achieved with a mix dispenser equipped with a meshwork conveyor are therefore evident.

(30) Firstly, with a meshwork conveyor there is large amount of free area and therefore the conveyor may be easily cleaned.

(31) Moreover, the meshing action between cog wheels and meshes of the meshwork ensures a high degree of operational reliability. In fact, since it is moved by cog wheels (which are also low-cost and reliable), the meshwork remains perfectly centred and also ensures feeding at a controlled speed without the risk of slipping.

(32) It has also been noted that the thin protective film adapts itself to the mesh surface of the meshwork, forming inside each mesh a kind of small tray inside which the mix is arranged. This feature is very important for the production process of the plant since it facilitates greatly regular extraction of the mix (which is normally very viscous), in a continuous manner, from the hopper. Moreover, it thus ensures regular and uniform falling of the mix on top of the tray.

(33) A further advantage consists in the metallic nature of the meshes, which ensures flexibility of use independently of the process temperature.

(34) Moreover, the meshwork conveyor, which is preferably metallic, not only has a lower cost compared to a conventional conveyor belt, but in particular is both mechanically stronger and more resistant to the styrene vapours. As already mentioned, although the protective film is present, owing to the atmosphere charged with styrene vapours, the conveyor is in any case subject to attack by the vapours, but, because of its strong, preferably metallic, structure, it is not affected by said vapours.

(35) The conveyor therefore requires a small number of replacement operations with consequent savings both in terms of cost of the belt itself, but also in particular because the maintenance time and therefore the production downtime is reduced, with obvious advantages from an economic point of view.

(36) The person skilled in the art, in order to satisfy specific requirements, may make modifications to the embodiments described above and/or replace the parts described with equivalent parts, without thereby departing from the scope of the accompanying claims.

(37) For example, the meshwork may also not be metallic and be made of a plastic material. In this case, the advantage arising from the greater mechanical strength of the metal meshwork would be forfeited, but the additional advantage of a greater lightness of said meshwork would be gained. Moreover, the meshwork itself would be manufactured more easily and at a lower cost.

(38) As already mentioned above, although this solution has been developed for Bretonstone resin, it could be applied also to similar technologies, such as those which use cementitious binders (Bretonstone), or to Lapitec technology.