ELASTIC CONVEYOR BELT WITH CONDUCTING FIBRES FOR THE DISCHARGE OF STATIC ELECTRICITY AND LEATHER PERCHING MACHINE COMPRISING SUCH BELT

Abstract: The invention discloses a conveyor belt realised with elastic fabrics of natural or synthetic fibres having in the weft and/or in the warp fibres of conducting material able to allow the discharge of static electricity accumulated by the belt or by the objects transported by said belt.

Description: ELASTIC CONVOYOR BELT WITH CONDUCTING FIBRES FOR THE DISCHARGE OF STATIC ELECTRICITY AND LEATHER PERCHING MACHINE COMPRISING SUCH BELT The invention relates to an elastic belt conveyor with conducting fibres for the 5 discharge of static electricity. Belt conveyors with elastic fibres realized with natural or synthetic fibres are used in several productive fields, such as in the packaging or in the field of leathers' processing, but also in many other productive environments, to satisfy some production requirements. 10 In the leather sector the perching process is used to give back to tanned leather its elasticity and softness after going through various treatments. The process consists in beating leather repeatedly and casually with metal pegs, as leather moves through the perching machine compressed between two elastic fabrics. 15 In this process, it is obvious that the belt that conveys leather under the perching units must have elastic properties, to endure the repeated actions of vertical beating that the perching units perform on the belt and therefore on leather while it passes transversally before coming out of the machine. Just because of this treatment leather accumulates static electricity due to the 20 friction between the belt and the same leather and this electricity is the cause of a series of drawbacks. One of these is the fact that leathers remain attached to the belt of the perching machine and are discharged with difficulty. Moreover leathers that have accumulated static electricity discharge the same 25 on the people who handle them, that is the operators who take them to pass on to successive treatments. Another drawback can derive from the fact that static electricity of leather is discharged on electronic devices associated with the perching machines, such as stacking units. 30 All these drawbacks remain till now unsolved, for the phenomenon of static electricity is produced just during the perching operation and is therefore unavoidable to eliminate static electricity at the source with the existent technique. Attempts carried out with the aim of discharging static electricity of the belts 35 through the direct contact of the same belts with metallic rollers or with brushes connected to the ground, were not successful because of the high quantity of static electricity produced. What has been heretofore described, is just one of the drawbacks that the known technique cannot solve in the field of transportation of materials with elastic fibres under processing. Actually, there are many sectors, besides tannery, that are registering the above mentioned drawbacks. One of these sectors notably is that of packaging, where films of synthetic materials or cellophane accumulate a large amount of static electricity and provoke several drawbacks with reference to this matter. The purpose of the invention is to eliminate the just mentioned drawbacks. The main objective of the invention is therefore to realize an elastic belt conveyor with intrinsic properties able to eliminate the formation and the accumulation of static electricity both in the belt and in the objects transported by the belt itself. It shall be noted that elastic fabrics with conducting fibres made recently their appearance as an experimental product in the fashion sector where some stylists, on the look for peculiar aesthetical and chromatic effects, tried to realize garments, with stretch or not, with carbon, copper, aluminium, silver or gold fibres. No industrial application is known to the Applicant, above all in the sector of belt conveyors, elasticised fabrics with conducting fibres. The present invention proposes therefore to transfer from the fashion sector to the industrial sector and specifically to that of belt conveyors the technology of elasticised fabrics with fibres made with conducting materials. According to the content of the first claim there is proposed a belt conveyor realized with elasticised fabric of natural or synthetic fibres that is characterised by being provided, in the weft and/or in the warp, with fibres of conducting material able to allow the discharge of static electricity accumulated by the belt or by the objects transported by said belt. The discharge of static electricity will take place through the direct contact of the belt conveyor on the feed rollers of the belt itself, rollers that are connected to the structure of the machine and that, being realised in metallic material, are electrically connected to the ground and therefore suitable to discharge static electricity. As hinted before, an advantageous use of the belt conveyor according to the invention, is in the perching machines that realize the beating of tanned leather through perching units. This kind of beating takes place positioning the leathers like a sandwich between two elastic belts that move in the same direction in a perching machine, substantially one in contact with the other, with the possibility of inserting leathers between these walls in contact. Leathers inserted into this sandwich consisting of these two facing belts are subjected to the action of beating on the part of perching units. It is in this stage, according to the traditional technique and with the currently used belts, the static electricity caused by the friction between the elasticised fabric and the leather is generated and accumulated onto the leathers. By providing, according to the invention, the belt conveyor with fibres of a conducting material such as, carbon, copper, aluminium, titanium or any other conducting fibre, static electricity as soon as it is generated is directly discharged on the cylinders that drive the belt conveyors or on equipments added to this purpose. Thus all the problems connected with the accumulation of static electricity are completely eliminated. Of course, as it was already hinted, the belt conveyor according to the invention can be used with advantage in other industrial activities different from the tanning sector with the same advantages, for this invention actually eliminates the dangerous static electricity, dangerous both for the operators, and also for the possible deterioration of the manufactured articles that accumulate static electricity. With the aim of rendering such conducting fibres, that are added to the already elastic fabric, such as fibres of carbon, copper or aluminium, elastic, a special preparation of the conducting fibres will take place before the weaving process. Such preparation will be performed, for instance, with a special helical winding of the same thread, around a yarn of elastomer to allow the extension during the elastic action of the conducting thread together with the elastic belt, without breaking the conducting thread. Of course other known technologies can be used to give elasticity to the conducting fibres making part of the elastic belt.

Claims: CLAIMS 1 ) Belt conveyor realised with elastic fabrics of natural or synthetic fibres, characterised in that it is provided in the weft and/or in the warp with fibres of conducting material able to allow the discharge of static electricity accumulated by the belt or by the objects transported by said belt. 2) Belt according to claim 1 , characterised in that each conducting yarn of the elastic fabric making part of the belt, is made elastic being helically wound around an elastic yarn, so as to permit the extension during the carrying out of the elastic action of the belt. 3) Use of the conducting elastic belt according to the previous claims for the realisation of belt conveyors for leathers in a perching machine for the softening of tanned leather. 4) Perching machine for the treatment of leathers characterised in that at least one of the two belts between which the leathers are compressed during the perching process presents features of the fabric as claimed in claim 1 or 2.

Inventors: ANTONIAZZI ANTONIO, ANTONIAZZI, ANTONIO
Applicants: ANTONIAZZI ANTONIO, ANTONIAZZI, ANTONIO
Application year: 2000
Main classification: B65G15
IPC codes: B65G15, B65G43, D03D15