WO2008081479A1

WO2008081479A1 - Conveyor apparatus with overlapping conveyor belts for leather, or similar, drying plants, or treatment plants in general, in controlled environments

Info

Publication number: WO2008081479A1
Application number: PCT/IT2006/000878
Authority: WO
Inventors: Vito Marino; Emilio Buttazzi; Riccardo Dini
Original assignee: Vito Marino; Emilio Buttazzi; Riccardo Dini
Priority date: 2006-12-28
Filing date: 2006-12-28
Publication date: 2008-07-10
Also published as: CN101605912A; BRPI0622224A2; TR200904939T1; KR20100014288A

Abstract

A drying or treatment in general plant for leather, or similar products, provides a conveyor apparatus of the type with overlapping conveyor belts in which the products are kept in a flat position between the two belts through their run inside the treatment chamber, between a loading station and an unloading station, thanks to the perfect synchronization of the feeding run of the belts and to the complanation of the transmission chains which combine with the transversal stretching means of the belts. The transmission chains of the two belts are shaped as to allow to easily separate the two belts when they come close to the loading and unloading stations, and then to overlap them again.

Description

CONVEYOR APPARATUS WITH OVERLAPPING CONVEYOR BELTS FOR

LEATHER, OR SIMILAR, DRYING PLANTS. OR TREATMENT PLANTS IN

GENERAL, IN CONTROLLED ENVIRONMENTS.

Field of the Invention

The present invention relates to a leather, or similar conveyor apparatus, for drying or treatment in general plants, in controlled environments.

In particular the invention relates to a conveyor apparatus of a type in which the leathers, or other products, to be conveyed through the treatment chamber, are restrained between overlapping conveyor belts.

Background of the Invention

In the leather, or similar, treatment sector are used drying plants of various types in order to rapidly, and according to specific procedures, dry the leather.

Are known, for instance, plants using artificial blowing heating systems working at atmospheric pressure or in a vacuum-operated atmosphere.

The products are dragged through these plants by means of chain or tape conveyor systems, in which the skins to be dried are moved through the treatment chamber hanged or laying on conveyor belts.

Conveyor apparatus with overlapping belts are also used, where two belts run adjacent one to the other, so that the drying skins proceed laying on the lower belt and they are kept in a flat position by the pressure exerted by the upper belt.

These apparatus keep the skins, or the other products treated, perfectly laid out , in a flat position, during the drying process. But, it is important to avoid mutual creeping between the two overlapping belts, as the products laying between the belts would roll and, remaining in such distorted configuration during drying, they would come out irreparably damaged.

A set of guide rollers keeps these belts longitudinally stretched, guiding them through a specific path inside the drying chamber. Said path is as long as possible, for a given length of the plant, in order to optimize the efficiency of the plant itself, both from an energetic point of view and from a logistic one. Said belts are coupled one on top the other just downstream the loading station, then they perform the same run inside the drying chamber and they separate, keeping different directions, when they get close to the unloading station; at the beginning and ending sections of their run the belts are obviously kept separate to allow the loading and unloading of the transported products. The presence of loading and unloading stations involves a certain complexity of the present mechanical actuators of this type of conveyor belts. It has to be considered, in fact, that the belts are made move thanks to an electric actuator which rotates at least one of the guide rollers, and from this last, by a link chain and gear wheels mounted at the end of each roller, the motion is transmitted and the belts are dragged. Such actuating system rises considerable reliability problems when it has to assure the perfect synchronism in the feeding movement of the two belts in correspondence to the loading and unloading stations; in fact, in such zones, one of the belts has to couple and uncouple with an auxiliary transmission chain which follows a path which is other from the one followed by the main transmission chain. There are other systems for dragging the belts based on the use of wires, instead of link chains, which, for their essence, cannot assure synchronism in the feeding run of the belts because of the slipping between wires and rollers.

You can so sense the need to look for solutions based on the use of overlapping conveyor belts which avoid the mutual creeping between the belts, binding them to move together in every section of their path in a completely reliable way. Summary of the Invention

The main object of the present invention is to provide a leather, or similar conveyor apparatus, for drying or treatment in general plants in which the feeding run of the two belts is made perfectly synchronous in every section of their path. Further object of the present invention is to provide a conveyor apparatus with overlapping conveyor belts for leather, or similar products, which grants a safe and reliable conveyance of the above said products, also thanks to the functionality of the layout of the apparatus. Said objects are attained by a leather, or similar products, conveyor apparatus, for drying or treatment in general plants, in controlled environments, in which said products are carried through the treatment chamber by means of conveyor belts overlapping along a specific section of their path from a loading area and an unloading area of said products, said apparatus being characterized by the fact that each of said conveyor belts is provided with its own couple of transmission chains, one at each side, along the whole length of its path comprising the loading and unloading areas, the transmission chains of said two belts being substantially complanate along the section of path in which the two belts overlap and being, furthermore strictly synchronized each other. The transmission chains are actuated by at least one motor reduction unit acting upon the guide rollers of said chains which gear which couples of gear wheels at the ends of the rollers.

The apparatus comprises, for each of the two conveyor belts, transversal stretching means apt to engage with longitudinal guiding bars running externally with respect to the chains, or apt to engage with the chains themselves which, in this case, are kept firmly in their mutual position with respect to the belts by means of guiding members made of a self-lubricating material engaging with the internal side of the chain links. In the sections of the path in which the chains are complanate, the transversal stretching means of one of the belts engage in notches or grooves of the other belts chain links, so binding even more the movement of the chains connected to one belt to the movement of the chains connected to the other belt.

The advantages coming from the apparatus of the invention are immediately clear in relation to its great handiness and easiness of manufacturing.

In fact, the presence of a couple of chains, permanently connected to each belt along the whole path, allow to force the two belts to move forward together so avoiding problems that may raise in the loading and unloading areas. In such areas, the two belts run a different path so that also the paths of the chains connected to the belts are no more complanate.

In said areas, the transversal stretching means belonging to the first belt easily disengage the chains of the second belt, and vice versa. The stretching means belonging to one belt keep bound, even in said sections of the path, to the chains of that belt, so granting a proper stretching of the belt in every section of the path. This feature, together with the fact that in every section of the path, but the loading and unloading areas, the chains dragging the belts are exactly complanate, and furthermore the presence, at the ends of each roller, of a gear wheel for each chain, assure a perfect synchronism of the run of the two belts and, simultaneously, assure that the products laying between the belts move forward in a perfectly flat shape. Brief Description of the Drawings

For a better understanding of the characteristics and the advantages of the present invention, embodiments will now be described by way of examples with reference to the accompanying drawings, in which: - figure 1 shows a sketched side view of a leather, or similar, conveyor apparatus according to the invention;

- figure 2 shows a sketched front view of the apparatus of fig.1;

- figure 3 shows a detail of the view of fig.1 relating to the loading and unloading stations of skins, or similar products, of the apparatus of fig.1;

- figure 4 shows a detail, in perspective view, still relating to the loading and unloading area of the skins, of the apparatus of fig.1;

- figure 5 shows a further perspective view relating, in particular, to an end of the guide rollers of the apparatus of fig.1; - figure 6 shows a detailed view of an end of a guide roller placed in the loading and unloading area shown in fig.4;

- figure 7 shows a perspective view, in detail, similar to the view of fig.5 but referring to a different embodiment of the invention;

- figure 8 shows a sketched side view of the embodiment of fig.7; - figures 9 and 10 show section views obtained by the section plane A-A of fig.8.

Description of Preferred Embodiments

Referring to fig.1 is shown as a whole with 10 a conveyor apparatus with overlapping belts, for drying plants for leather or similar products.

To a frame, comprising pillars, 11, and crossbars, 12, arranged to form substantially the shape of a box, is fixed a set of guide rollers, 13, that stretch two conveyor belts,

14, 15, having a net structure, or made in a porous material, which belts, thanks to the arrangement of the rollers, are dragged into the tunnel or drying chamber according to a path consisting in subsequent layers.

By means of a loading station, 16, and an unloading station, 17, the skins, or the other products to be dried, are inserted in the conveyor apparatus and then taken from at the and of the drying process.

The two belts run the following path.

Taking as a reference roller 18 as starting point, the first belt, 14, goes over roller 19, then, after running along all the guide rollers, 13, inside the drying chamber, gets roller 24 at the unloading station, 17, and, finally, reaches the starting point (roller 18).

The second belt, 15, still starring from roller 18, crosses, just like the first belt, roller 19, then runs all the rollers 13 inside the drying chamber and gets, crossing the unloading station, 17, roller 20, and from this one is returned to roller 21, then it goes back, along the perimeter of the drying chamber cross the rollers 22 and 23, to finally reach the starting point (roller 18).

The conveyor belts run therefore overlapped along almost all their path, from roller 18 to roller 24, taking different ways after this last and meeting again at roller 18. The belts are dragged thanks to the presence of a motor reduction unit, not shown in figure, geared to one of the guide rollers 13. As you can see in the detail of figure 4, at the ends of the rollers are mounted gear wheels, 25, which gear with transmission chains which run parallel the belts, from roller to roller, transmitting the torque to the rollers themselves.

Two chains, 26, one per side, are joined to the belt 14, running parallel the belt along all its path; two more chains, 27, one per side, are joined to the belt 15, these too running parallel the belt along all its path.

As you can clearly see in fig.5, inside the drying chamber the chains 26 and 27 are complanate. At the ends of the rollers, 13, are mounted two gear wheels, 25, per side, and they are advantageously made in a single component. At both sides of the belts, uniformly distributed, are fixed transversal stretching means, 28, being, in this embodiment, metal rods, 29, riveted, at one of their ends, to the borders of the belts and mounting, at the other ands, two small wheels, 30, freely rotatable around an axis normal to the axis of the metal rod itself. Said small wheels,

30, engage with longitudinal guiding bars, 31, with the section of a double "C", which run externally with respect to the belt's transmission chains along all the path of the belts themselves.

As shown in fig.5 and in fig.6, close to the rollers, 13, 24, the external guiding bars,

31, are replaced by semicircular guiding components, 32, that have a gap, 33, between them in which slide the rods, 29, of the above said transversal stretching means 28; the same arrangement is adopted close to the other rollers, 18, 19, 20, 21, 22, 23. The alternative embodiment of fig.7, miss the external guiding bars 31 as the conveyor belts 14 and 15 are directly fixed to their respective transmission chains 26, 27, through cotter pins, 40, inserted at the ends of the rods 29' of the stretching means 28' of each belt. In this case the chains 26, 27 are kept in the right position with respect to the belts by sliding means, 41, in polymeric self-lubricating material, which, as you can clearly see in fig.10, comprise lateral protrusions which couple with the internal surfaces of the chain links, the sliding means 41 being firmly fastened to the pillars 11 of the frame of the apparatus.

Both in the arrangement of fig.3 and in the arrangement of fig.7, the rods, 29, of the transversal stretching means of belt 15, pass through specific holes, 34, made in some of the chain links, 35 ,of the transmission chain, 27, combined with said belt. In the same way, also the rods of the stretching means of belt 14 pass through similar holes made in the chain links of chain 26 combined with this second belt. As previously pointed out, along the sections of the path where belts 14 and 15 overlap, the relative chains, 26 and 27, are perfectly complanate, running side by side beside the belts. Such an arrangement is allowed thanks to the fact that the stretching means, 28, integral to belt 14 and passing through the transmission chain 26 of said belt, also pass through the grooves 36 provided in one side of some of the chain links of chain 27 of the other belt, 15, and vice versa, the stretching means integral to this last pass through grooves, 37, provided in one side of the link chains of chain 26 of the first belt, 14.

You can notice that in the embodiment of fig.7 the grooves 36 provided in chain 27 are not strictly necessary as the stretching means 28' integral to belt 14 have not to pass through chain 27, but only chain 26. Nevertheless said grooves 36 are advisable both to avoid possible interference between the ends of the stretching means 28' fixed to chain 26 and chain 27, and to have manufactured a single type of chains 26, 27.

Said grooves, 36 and 37, are shaped so that their lateral sloping surfaces make the stretching means, 28, 28', more easily engage with and disengage from the chains 27 and 26, while, at the same time, the flat surfaces at the bottom of the grooves form stable housings for said stretching means along the section of the path in which the belts overlap and the chains run side by side.

All the above contributes to grant that the two belts, 14, 15, run perfectly synchronized, together with their transmission chains 26, 27, which are joined each other and to the belts in a steady manner along the whole path of the belts themselves. Furthermore, thanks to the grooves provided in some of the chain links of the chains, 26, 27, this last easily engage with and disengage from the stretching means integral to the other belt, in the sections where the belts have to keep different directions in order to allow the product's loading and unloading operations.

The way the apparatus works provides that the skins to be dried, once loaded on belt 14, at the loading station 16, enter the drying chamber and, laying between the two belts, go through the chamber from its upper part to its bottom until they exit and reach the unloading station, 17, where laying on belt 15, they can be taken by a worker or let drop to a box or on a further conveyor belt not part of the apparatus. The separation and following rejoining of the two belts at the loading and unloading areas occur in an automatic and reliable way according to the previously disclosed procedures, just thanks to the specific shape of the links of the transmission chains. The effectiveness and safeness of the above disclosed conveyor system are particularly high as a consequence of its great simplicity and functionality. In fact, It is required only that the transmission chains, 26, 27, are identical and that they both provide links with holes, 34, taking turns with links with grooves, 36, or 37, in order to let the two belts be perfectly complanate and also to grant that the layout and the mutual distance among the various stretching means are optimized for both the conveyor belts. Obviously the above said effectiveness and safeness in the way of working keep valid even in presence of further changes or different embodiments. The layout and mutual arrangement of the various components of the above disclosed treating plant may obviously vary, also comprising the position of the product's loading and unloading stations.

The transversal stretching means, 28, 28', may be differently shaped or they may be made, completely or in part, in a not metallic material. The small wheels, 30, for instance, could be replaced by sliding elements, still apt to engage with longitudinal guiding bars, 31, too differently shaped too.

Also the grooves, 36 and 37, of the links of the transmission chains may be cut according to a different shape, still suitable to facilitate engaging with and disengaging from said stretching means 28, 28'. These ones and more changes may be carried out to the above disclosed conveyor apparatus, always remaining in the ambit of protection of the following claims.

Claims

C L A I M S

1- Leather, or similar products, conveyor apparatus, for drying or treatment in general plants, in controlled environments, in which said products are carried through the treatment chamber by means of conveyor belts overlapping along a specific section of their path from a loading area and an unloading area of said products, said apparatus being characterized in that each of said conveyor belts is provided with at least one transmission chain along the whole length of its path comprising the loading and unloading areas, the transmission chains of said two belts being substantially complanate along the section of path in which the two belts overlap and being, furthermore strictly synchronized each other.

2- Leather, or similar products, conveyor apparatus, for drying plants according to the previous claim characterized in that it comprises transversal stretching means (28, 28') of said belts (14, 15), said stretching means being apt to engage with said transmission chains (26, 27). 3- Conveyor apparatus according to claim 2 characterized in that said transversal stretching means (28') comprise a rod (29') whose one end is fastened to the border of the belt and at its opposite end is inserted a cotter pin (40) apt to allow the connection between the stretching means of a belt and its transmission chain.

4- Conveyor apparatus according to the previous claim characterized in that it comprises sliding means (41) apt to couple with the internal surfaces of the chain links to firmly keep said chains (26, 27) in their respective mutual position with respect to said conveyor belts (14, 15).

5- Conveyor apparatus according to the previous claim characterized in that said sliding means (41) are placed above and under said chains (26, 27), said sliding means being made in a self-lubricating material. 6- Conveyor apparatus according to claim 2 characterized in that said stretching means (28) are apt to couple with guiding bars (31) placed on a same plane with said transmission chains (26, 27), externally disposed with respect to said belts (14, 15).

I- Conveyor apparatus according to the previous claim characterized in that said transversal stretching means (28) comprise a rod (29) whose one end is fastened to the border of the belt and at its opposite end is bound a couple of wheels (30) freely rotating around an axis normal to the axis of said rod (29), said guiding bars (31) being shaped like a double "C" on whose internal surfaces looking towards said belts, said wheels (30) can roll. 8- - Conveyor apparatus according to one of the previous claims characterized in that it comprises a couple of transmission chains for each belt, the chains of each couple of chains being fastened at the two opposite borders of their respective belt by said stretching means (28, 28'). 9- Conveyor apparatus according to the previous claim characterized in that said conveyor belts (14, 15) are longitudinally stretched by guide rollers (13) disposed in order to make said belts move according to a specific path, in particular along parallel layers, inside said treatment chamber, at the ends of said guide rollers being mounted two gear wheels per side, which gear with said transmission chains (26, 27), said two gear wheels at a same side of a guide roller being stably united. 10- Conveyor apparatus according to the previous claim characterized in that said two gears at a same side of a guide roller are a single component.

II- Conveyor apparatus according to claim 8 and followings characterized in that it comprises a first couple of chains (26) bound to transversal stretching means of a first conveyor belt (14), and a second couple of chains (27) bound to transversal stretching means of a second belt (15), said stretching means of the first belt (14) being apt to join said second couple of chains (27), and said stretching means of the second belt (15) being apt to join said first couple of chains (26).

12- Conveyor apparatus according to the previous claim characterized in that each of said transmission chains (26, 27) comprises chain links (35) where are stably connected the transversal stretching means (28, 28') of the conveyor belt combined with that chain, and it also comprises chain links where engage and disengage the transversal stretching means of the conveyor belt not combined with said chain.

13- Conveyor apparatus according to the previous claim characterized in that said chain links (35) to which said transversal stretching means (28, 28') are stably connected comprise through holes where the rods (29, 29') of the stretching means pass through, and that said chain links where the stretching means engage and disengage comprise laterally opened grooves (36, 37) housing the rods (29, 29') of the stretching means in the sections of the path where the belts run overlapped, said stretching means. 14- Conveyor apparatus according to the previous claim characterized in that the laterally opened grooves (37) of said first couple of chains (26) are directed in the opposite direction with respect to the laterally opened grooves (36) of said second couple of chains (27). 15- Conveyor apparatus according to claim 7 characterized in that at the ends of the guide rollers (13, 18, 19, 20, 21, 22, 23) of the conveyor belts, the external guiding bars (31) are replaced by semicircular guiding components (32) that have a gap (33) between them in which can slide the rods (29) of the transversal stretching means (28) of the belts.