FR3058707A1 - ELASTOMERIC CONVEYOR BELT, WITH JUNCTION DEVICES FORMING STAPLES - Google Patents

Abstract

The invention relates to a conveyor belt (1) comprising two elastomer layers (11) which sandwich a main reinforcing reinforcement (12). The conveyor belt (1) is delimited by two transverse edges (2) and by two longitudinal edges (3). This conveyor belt (1) comprises two terminal sections (5), adjacent to said transverse edges (2), provided with junction members (6) forming staples for joining said transverse edges (2). The connecting members (6) are secured to said terminal sections (5) by means of fastening means (7) passing through at least said main reinforcing armature (12). Each terminal section (5) comprises a secondary reinforcing armature (13), additional and local, also traversed by the fastening means (7) of said connecting members (6).

Description

Technical field to which the invention relates

The present invention relates to the field of conveyor belts.

It relates more particularly to conveyor belts which have two elastomeric layers sandwiching a main reinforcement frame and whose transverse edges are connected by means of junction members forming staples.

Technological background

Conveyor belts are commonly made of an elastomeric material reinforced by means of a main reinforcing frame.

This main reinforcement is often chosen from textile fibers, metal fibers or any other product providing stability and / or resistance to elongation.

The junction of the two transverse edges of such a conveyor belt is conventionally carried out either by vulcanization or by staples.

The vulcanized junction has the advantage of being very resistant to efforts. But it also has many drawbacks for its implementation (heavy and long vulcanization process, difficulties in detecting deterioration at the junction, etc.).

For their part, the staples consist of joining members which are secured to end sections of the conveyor belt by means of fastening means passing through the main reinforcement frame.

Such staples simplify installation, maintenance and repair operations. They also have the advantage of being installed quickly and easily, without the need for special tools and in all weathers. These staples reduce downtime and increase productivity.

However, the main reinforcing frame is often not suitable for ensuring high resistance to the forces exerted by the means for fixing the staples. Current staple junctions do not therefore have sufficient strength to be used in certain heavy applications (mining industry, quarry, etc.).

There is therefore a need for new conveyor belt structures which would be capable of imparting improved strength when joining with staples.

Object of the invention

In order to remedy the aforementioned drawback of the state of the art, the present invention provides a conveyor belt comprising two elastomeric layers which sandwich a main reinforcement frame.

This conveyor belt is delimited by two transverse edges and by two longitudinal edges.

The conveyor belt comprises two end sections, adjoining said transverse edges, provided with joining members forming staples for joining said transverse edges.

The joining members are secured to said end sections by means of fastening means which pass through at least said main reinforcement frame.

And according to the invention, each terminal section comprises a secondary, additional and local reinforcement reinforcement, also crossed by the means for fixing said junction members.

Such a conveyor belt structure has the advantage of ensuring increased tensile strength in the context of a staple joint, which is similar (or even equivalent) to a vulcanized junction.

Indeed, the secondary reinforcements reinforce the fragility usually encountered with the traditional staple junction, or even by cold or hot vulcanization.

Such a structure is also particularly advantageous for significantly reducing the time required to change the conveyor belt and the associated operating losses.

For mobile machines like concrete crusher / demolition, such a structure allows the user to be autonomous by carrying spare parts on construction sites.

According to a preferred embodiment, each end section of said conveyor belt is composed of an end part of the two elastomer layers which sandwich an end part of the main reinforcing frame. And the secondary reinforcement is integrated into the thickness of said end portion of at least one of the two elastomeric layers.

In this case, preferably, the secondary reinforcing frame comprises at least one fold. The end part of an elastomeric layer comprises, on the one hand, an inner underlay, formed between the main reinforcement and the secondary reinforcement and / or, on the other hand, an outer underlay , covering the secondary reinforcement frame.

Again in this case, the secondary reinforcement frame is advantageously provided between the inner and outer sub-layers.

In general, the connecting members advantageously comprise at least one plate arranged at a terminal section and receiving the fixing means.

In this context, said at least one plate of the junction members is advantageously incorporated in the thickness of the terminal part of at least one of the two elastomeric layers.

Still in this context, the junction members advantageously have a general U shape which comprises, on the one hand, two plates, extending opposite and at a distance from each other, and on the other hand, a connecting portion, intended to receive a hinge pin. The two plates enclose at least one end portion of the main reinforcement and at least one secondary reinforcement.

Still generally, the joining members are advantageously covered by a protective coating.

The invention also provides a method for manufacturing a conveyor belt according to the invention.

This process includes:

- The supply of a conveyor belt comprising two elastomeric layers which sandwich a main reinforcement frame, which conveyor belt is delimited by two transverse edges and by two longitudinal edges, and which conveyor belt comprises two end sections which are adjacent to said edges transverse,

- the disbonding of a terminal part of at least one of the elastomeric layers, at the level of the two terminal sections, to form a transverse step,

- the installation, within said transverse recesses, of at least one raw elastomeric sub-layer and of the secondary reinforcement,

- At the level of the two end sections of the conveyor belt, the vulcanization of said at least one added raw elastomeric sub-layer, which method further comprises a step of fixing the junction members with said end sections, by means of the means fixing through the reinforcements.

Preferably, the step of fixing the junction members is carried out before the vulcanization of the raw elastomeric underlayers added.

Detailed description of an exemplary embodiment

The description which follows with reference to the accompanying drawings, given by way of nonlimiting examples, will make it clear what the invention consists of and how it can be carried out.

In the accompanying drawings:

- Figure 1 is a perspective and partial view of a conveyor belt according to the invention, which shows its two end sections assembled by means of junction members forming staples (in this case a system of articulated staples) ;

- Figure 2 is a schematic sectional representation of Figure 1, along a section plane perpendicular to the surfaces of the conveyor belt, which shows the different reinforcements and the mounting of the connecting members;

- Figures 3 to 7 illustrate the main steps of a process for the manufacture of a conveyor belt according to Figures 1 and 2.

The conveyor belt 1 according to the invention, shown very partially in Figure 1, advantageously consists of a conveyor belt.

This conveyor belt 1 is particularly suitable for heavy applications, for example for building and public works, coal, mining, crushing, sand, recycling, steelworks and wood processing.

This conveyor belt 1 has conventionally in itself an outline of generally rectangular shape, namely:

- two transverse edges 2, assembled with one another to close the conveyor belt 1 and extending here perpendicularly to a longitudinal axis 1 ’, and

- two longitudinal edges 3, extending parallel to the longitudinal axis 1 ’.

This conveyor belt 1 also has two opposite faces 4, at least one of which is adapted to receive the product to be conveyed.

As an indication, the conveyor belt 1 comprises:

- a length (corresponding to the distance separating the two transverse edges 2) which is a function of the weight and / or transport limits,

- a width between 100 and 4000 mm (corresponding to the distance separating the two longitudinal edges 3), and

- a thickness between 5 mm and 50 mm (corresponding to the distance separating the two opposite faces 4).

As shown in Figure 2, the conveyor belt 1 has two elastomeric layers 11 which sandwich at least one main reinforcing frame 12, to form a one-piece assembly.

The elastomer layers 11 are produced from at least one material capable of undergoing elastic deformation, also called "elastic material", chosen from:

- elastomeric materials, for example natural rubber, “synthetic natural” rubber (or synthetic polyisoprene), polybutadiene or styrene-butadiene, or

- plastics or thermoplastic elastomers (TPE), namely for example PVB (polyvinyl butyral), ABS (acrylonitrile butadiene styrene) / SBR (styrene-butadiene), PP (polypropylene) / EPDM (ethylenepropylene-diene monomer), TPU (polyurethane TPE).

The main reinforcement frame 12 advantageously has a rectangular outline, matching the outline of the conveyor belt 1.

The main reinforcing frame 12 is for example chosen from textile fibers, metal fibers or any other product providing stability and / or resistance to elongation.

This main reinforcing frame 12 consists for example of a textile frame serving as reinforcement, advantageously made of a material chosen from nylon, cotton, polyester, polyamide or any other reinforcing textile.

This main reinforcement frame 12 may comprise a single ply, or several plies superimposed on the same material or on different materials.

The conveyor belt 1 has two opposite opposite end sections 5, which are each adjoining one of the two transverse edges 2 and which are assembled with one another by joining members 6.

The joining members 6 in presence are commonly designated by the name of "staples" or "mechanical staples".

These junction members 6 are each secured to one of the end sections 5 by means of fixing means 7 which extend in the thickness of said end section 5.

In this case, as illustrated in FIG. 2, each end section 5 of the conveyor belt 1 consists of a laminated structure which consists of:

a terminal part 111 of each of the two elastomeric layers 11, in the form of a rectangular transverse strip, and

- An end portion 121 of the main reinforcement frame 12, also in the form of a rectangular transverse strip, sandwiched between the two aforementioned end portions 111.

To give optimum resistance to this staple junction, each end section 5 of the conveyor belt 1 here has a secondary and additional secondary reinforcement frame 13.

The secondary reinforcement frame 13 is here integrated into the thickness of the terminal part 111 of at least one of the two elastomer layers 11.

In this case, each of the two end portions 111 of a terminal section 5 comprises a secondary reinforcement frame 13. The end portion 121 of the main reinforcement frame 12 is thus located between two secondary reinforcement frames 13.

The secondary reinforcement frame 13 is for example chosen from textile fibers, metal fibers or any other product providing stability and / or resistance to elongation.

This secondary reinforcement reinforcement 13 consists for example of a textile reinforcement serving as reinforcement, advantageously made of a material chosen from nylon, cotton, polyester, polyamide or any other reinforcement textile.

This secondary reinforcement frame 13 may comprise a single ply, or several plies superimposed on the same material or on different materials.

The secondary reinforcement frame 13 is integrated in the terminal part

111 of an elastomer layer 11 so that this end portion 111 comprises several sublayers:

an inner sub-layer 1111, formed between the end portion 121 of the main reinforcement frame 12 and a secondary reinforcement frame 13, and

- an outer sub-layer 1112, covering the secondary reinforcement frame 13.

The secondary reinforcement frame 13 is thus provided and sandwiched between the two aforementioned sub-layers 1111, 1112 of the end portion 111 of the elastomer layer 11.

This secondary reinforcement frame 13 comprises in particular two transverse edges 131, 132 which define its length:

a proximal transverse border 131, extending along one of the transverse borders 2 of the conveyor belt 1, and

- a distal transverse border 132, extending at a distance from this same transverse border 2 of the conveyor belt 1.

Preferably, the length of this secondary reinforcement frame 13 is at least twice as long as the stapling distance (that is to say the distance between the transverse edge 2 of the conveyor belt 1 and the fixing means 7 located remotely).

This technical characteristic aims to ensure optimal anchoring of the secondary reinforcement frame 13 within its terminal part 111.

More preferably, the length of this secondary reinforcement frame 13 corresponds, at most, to half the circumference of the drive drum (not shown).

The junction members 6 here consist of so-called "articulated" staples, that is to say assembled together by means of a hinge pin 8.

In this case, each terminal section 5 comprises several joining members 6, which are juxtaposed and distributed over the length of its transverse border 2.

The joining members 6 of the two opposite transverse edges 2 intersect and are connected by the hinge pin 8 attached to each other.

To this end, each junction member 6 has a general shape of U which comprises:

- two plates 61, extending opposite and at a distance from each other, and

- A connecting portion 62, in an arc, intended to receive the hinge pin 8.

In this case, the two plates 61 enclose the end portion 121 of the main reinforcement frame 12 and also at least part of the two secondary reinforcement frames 13.

More specifically, the plates 61 of a joining member 6 sandwich the two outer sub-layers 1112 of a terminal section 5.

The fastening means 7, equipping the junction members 6, thus pass through the entire thickness of the associated terminal section 5.

In particular, the fixing means 7, for example screws or rivets, pass through the main reinforcing frame 12, but also the secondary reinforcing frames 13. These fixing means 7 also pass through the aforementioned underlays 1111, 1112 here.

This assembly of the fixing means 7, through this multilayer structure of the terminal section 5, confers a significantly increased resistance to tearing for the junction members 6.

For example, it is possible to obtain resistances up to 1400

N / mm.

The plates 61 of a junction member 6 are also advantageously incorporated, or almost incorporated, in the thickness of the terminal section 5 equipped.

For this, the plates 61 are covered by a protective coating 1113 (Figure 2).

This protective coating 1113 is advantageously made of elastomeric material as mentioned above, forming a one-piece assembly with the elastomeric layer 11.

Manufacturing process

A process for the manufacture of such a conveyor belt 1 is illustrated in FIGS. 3 to 7.

Only one of the two terminal sections 5 is shown in Figures 3 to 7; similar operations are implemented on the other of the two terminal sections 5.

This manufacturing process comprises, first of all, the supply of a conveyor belt 1 comprising the two elastomer layers 11 which sandwich said at least one main reinforcement frame 12 (FIG. 3).

The elastomeric layers 11 can be vulcanized (finished product).

An end portion 111 of the two elastomer layers 11 (at the level of each end section 5) is lowered to form a transverse step 115 (FIG. 4).

The transverse recess 115 extends over the entire length of the transverse edge 2, between the two longitudinal edges 3.

This transverse step 115 has a dihedral shape:

a base wall 1151, parallel to the faces 3 of the conveyor belt 1 and to the terminal part 121 of the main reinforcement frame 12, and

- A rear wall 1152, extending from the base wall 1151 to one of the aforementioned faces 4 (advantageously perpendicular to the base wall 1151).

The width of the base wall 1151 corresponds to the distance formed between the transverse edge 2 and the rear wall 1152. This width is equal to, or greater than, the width of the plate 61 of a fixing member 6 (distance between the free end of the plate 61 and the connecting portion 62).

This disbursement step is for example implemented using a grinding wheel with a carbide-tipped disc.

The thickness of this transverse disbursement 115 is advantageously identical over the entire width of the conveyor belt 1. For example, this thickness is between 4 and 15 mm.

Each end part 111 thus comprises a residual elastomer strip 116, defined between the base wall 1151 of the transverse step 115 and the end part 121 of the main reinforcement frame 12.

Within each transverse step 115, a secondary reinforcement frame 13 is then added (FIG. 5).

The secondary reinforcement frame 13 is advantageously deposited on the base wall 1151 of the transverse recess 115, in combination with at least one raw elastomeric sublayer 117 (FIG. 5).

This secondary reinforcement frame 13 has a dimension corresponding, at least approximately, to the surface of the base wall 1151.

For example, in each transverse step 115, two raw elastomeric sublayers 117 are added which sandwich the secondary reinforcement 13.

Alternatively, in each transverse step 115, a single raw elastomeric sublayer 117 is added, covered by the secondary reinforcement 13.

Generally, in this step, the thickness of the terminal section 5 is less than the thickness of the conveyor belt 1, so as to allow integration of the joining members 6 (in particular of its plates 61) in its thickness.

The method according to the invention then comprises a step of positioning and fixing each joining member 6 at its associated terminal section 5 (FIG. 6).

For this, each fixing member 6 is attached so that:

its plates 61 sandwich the two secondary reinforcement frames 13 and said at least one raw elastomeric sublayer 117, and

- the connecting portion 62 protrudes relative to the transverse edge

2.

The fixing step consists of inserting the fixing means 7 through the reinforcing reinforcements 12, 13 (the main reinforcing reinforcement 12 and the secondary reinforcing reinforcements 13), but also through the various elastomeric layers and sublayers 116 , 117.

These fixing means 7 extend between the two plates 61 of the fixing member 6.

The protective coating 1113 is also attached to the joining members 6 (not shown in the figures).

The two end sections 5 of the conveyor belt 1 can finally be subjected to a vulcanization operation.

For example, this vulcanization operation consists in exerting a pressure between 10 and 50 kg / cm ² , combined with heat between 120 and 180 ° C to vulcanize the monobloc assembly.

Following this vulcanization operation, the elastomeric layers and sublayers 116, 117, 1113 form a one-piece assembly, corresponding to a terminal section 5, in which the reinforcing reinforcements 12, 13 are embedded (FIG. 7).

To this end, the raw elastomeric sublayers 117 are joined to the secondary reinforcement frame 13 and to the walls 1151, 1152 delimiting the transverse step 115.

In particular, the residual elastomeric strip 116 solidifies with one of the raw elastomeric sublayers 117 to form the inner sublayer 1111; the other of the raw elastomeric sublayers 117 forms the outer sublayer 1112.

The end portion 111 of an elastomer layer 11 thus comprises the inner 1111 and outer 1112 sublayers sandwiching the secondary reinforcement 13.

Alternatively, the vulcanization of all of the raw elastomeric layers and sublayers can be carried out before the attachment of the joining members 6. The attachment means 7 are thus put in place after the vulcanization.

The conveyor belt 1 thus obtained can be closed by the establishment of the hinge pin 8 which is attached between the junction members 6 juxtaposed.

Finally, on site or on site, after union by the hinge pin 8, the assembly can be embedded in an elastomeric material (for example a flexible and abrasion-resistant polyurethane), so that the junction becomes invisible, protected from abrasive waste, and does not interfere with scrapers / belt cleaners.

Claims (10)

1. Conveyor belt (1), comprising two elastomeric layers (11) which sandwich a main reinforcement frame (12), which conveyor belt (1) is delimited by two transverse edges (2) and by two longitudinal edges (3 ), which conveyor belt (1) comprises two end sections (5), adjoining said transverse edges (2), provided with joining members (6) forming staples for joining said transverse edges (2), which joining members ( 6) are joined to said end sections (5) by means of fixing means (7) passing through at least said main reinforcement frame (12), characterized in that each end section (5) comprises a secondary reinforcement frame ( 13), additional and local, also traversed by the fixing means (7) of said junction members (6). 2. Conveyor belt, according to claim 1, characterized in that each end section (5) of said conveyor belt (1) consists of an end portion (111) of the two elastomeric layers (11) which sandwich a portion end (121) of the main reinforcement frame (12), and in that the secondary reinforcement frame (13) is integrated into the thickness of said end portion (111) of at least one of the two layers elastomers (11). 3. Conveyor belt, according to claim 2, characterized in that the secondary reinforcement frame (13) comprises at least one ply, and in that the terminal part (111) of an elastomer layer (11) comprises: - an inner sub-layer (1111), formed between the main reinforcement frame (12) and the secondary reinforcement frame (13), and / or - an outer sub-layer (1112), covering the secondary reinforcement frame (13). 4. Conveyor belt according to claim 3, characterized in that the secondary reinforcement frame (13) is formed between the inner (1111) and outer (1112) sub-layers. 5. Conveyor belt according to any one of claims 1 to 4, characterized in that the joining members (6) comprise at least one plate (61) arranged at a terminal section (5) and receiving the means fixing (7). 6. Conveyor belt according to claim 5 in combination with claim 2, characterized in that said at least one plate (61) of the joining members (6) is incorporated in the thickness of the end portion (111) of the 'at least one of the two elastomeric layers (11). 7. Conveyor belt according to any one of claims 5 or 6, characterized in that the joining members (6) have a general shape of U, comprising: - two plates (61), extending opposite and at a distance from each other, and a connecting portion (62), intended to receive a hinge pin (8), and in that the two plates (61) enclose at least one end part (121) of the main reinforcement frame (12) and at least one secondary reinforcement frame (13). 8. Conveyor belt according to any one of claims 1 to 7, characterized in that the joining members (6) are covered by a protective coating (1113). 9. A method for manufacturing a conveyor belt according to any one of claims 1 to 8, characterized in that it comprises: - the supply of a conveyor belt comprising two elastomer layers (11) which sandwich a main reinforcement frame (12), which conveyor belt (1) is delimited by two transverse edges (2) and by two longitudinal edges (3 ), and which conveyor belt (1) comprises two end sections (5) which are adjacent to said transverse edges (2), - the disbonding of an end part (111) of at least one of the elastomer layers (11), at the level of the two end sections (5), to form a transverse step (115), - the installation, within said transverse recesses (115), of at least one raw elastomeric sublayer (117) and of the secondary reinforcement reinforcement (13), - At the level of the two end sections (5) of the conveyor belt (1), the vulcanization of said at least one added raw elastomeric sublayer (117), which method further comprises a step of fixing the joining members (6) with said end sections (5), by the installation of the fixing means (7) through the reinforcing frames (12, 13). 10. A method for manufacturing a conveyor belt according to claim 9, characterized in that the step of fixing the joining members (6) is carried out before the vulcanization of the raw elastomeric sub-layers (117) added . 1/2 Fig. 1 3; 1 111