Joint plate for joining two end portions of conveyor belt, joining device comprising at least one such joint plate and associated joint plate strip

Abstract

The invention relates to a joining plate (4) for a joining device (1) of conveyor belts (2) intended to connect two end portions (21, 22) of at least one conveyor belt (2), the joining plate (4) having an outer surface (S1) intended to be flush with a useful surface of the conveyor belt (2) in a joining position and an inner surface (S2) opposite the outer surface (S1), the invention relates to a joining plate (4) for a conveyor belt (2) having an inner surface (21, 22) intended to at least partially cover both end portions (21, 22) of the conveyor belt (2) in a joining position, the joining plate comprising: a body (45) made of a flexible material, the body having an outer surface forming an outer surface (S1) of the joining plate (4); a reinforcing plate (11) having a fastening through-hole, the reinforcing plate being rigidly attached to the main body; and a plurality of inserts (6), each having a fastening opening associated with one of the fastening holes so as to surround an edge of the fastening hole associated with one side of the reinforcing plate (11), the plurality of inserts for receiving fastening means (5) for fastening the joining device (1) to the end portions (21, 22); each of these inserts is at least partially embedded in the body (45); the joining plate (4) is characterized in that the main body (45) at least partially covers the fastening opening of the insert.

Description

Technical Field

[0001] The present invention relates generally to the technical field of joining devices for conveyor belts, the joining devices being intended to connect the ends of conveyor belts.For the sake of simplicity, the term conveyor belt, used conventionally in this specification, will equally mean conveyor belt and belt.

[0002] More specifically, the invention relates to a joining plate for connecting two end portions of a conveyor belt, in particular a joining plate provided with a textile reinforcement, to a joining device for a conveyor belt comprising at least one such joining plate, and to an associated strip of the joining plate. Background Art

[0003] Conveyor belts are known for transporting or conveying various materials or various products, such as coal, ore, industrial or agricultural products. These conveyor belts consist of a belt made of reinforced elastomer or reinforced synthetic material, of suitable length and width, the ends of which must be connected together on supporting and driving devices, including return rollers and idlers, before or after assembly. Usually, these devices also include tensioning members, the purpose of which is to properly tension the conveyor belt.

[0004] To date, various devices have been used to connect the ends of conveyor belts.

[0005] Initially, and even today, when the belt is made of reinforced vulcanizable elastomers, vulcanization is used. As is well known, vulcanization is performed by adding heat and pressure after preparatory work aimed at forming matching profiles in each end, which are pressed together when the ends are brought closer together. An alternative to vulcanization is cold bonding.

[0006] Another known connection device involves the use of fasteners in the general shape of a U and cut from a metal strip, these fasteners comprise an upper plate and a lower plate connected by a joint, wherein these fasteners are fastened in two series that straddle each end of the conveyor belt to be connected so that the joints protrude and so that the joints of one series can be staggered between the joints of the other series, and then the connecting and articulating rods pass inside the staggered joints, thus connecting the two ends by forming a type of hinge. Known means for fastening fasteners to the ends of conveyor belts consist of rod fastening means, such as studs, rivets and screws.

[0007] In the recent past, a joining device using a flat connecting element has been proposed, which is usually made of a reinforced elastomer or a reinforced synthetic material, is arranged on either side of the end of the conveyor belt, and is fastened to the end to be connected. Examples of such joining devices are provided in patents EP-0827575-B1 and EP-1163459-B1. These devices include an upper joining plate and a lower joining plate, which are optionally connected by a central part. These lower joining plates and upper joining plates have a spacing, which is designed to: by making the corresponding end of the conveyor belt roughly against the central part, or even when the joining device does not have a central part, against the spacer provided for this purpose during assembly, and then subsequently removing the spacer, the corresponding end of the conveyor belt is engaged in the spacing. In other words, these joining devices include two pairs of fastening wings facing each other, and the ends of the conveyor belt are introduced between the two wings of the same pair respectively. Fastening the lower and upper parts forming the joining plate to the ends of the conveyor belt is usually carried out with the help of rivets, spikes, studs, nuts, or even by cold bonding or by vulcanizing the wings flat against the flat outer surface of the conveyor belt joined between the wings.

[0008] The joining device is usually made of a flexible and elastic material, for example of vulcanized rubber or of a synthetic material such as polyurethane, in which a reinforcement, usually a textile reinforcement, is embedded which is extensible in the longitudinal reference direction of the conveyor belt.

[0009] The extensibility of the reinforcement for this type of joining device in the longitudinal direction of the conveyor belt is intended to allow the joining device mounted on the conveyor belt to repeatedly pass over the curved parts of the path of the conveyor belt, i.e. the curvature of the drive roller, the return roller and the tensioning roller, without any excessive wear or fatigue that could lead to rapid deterioration. In fact, during this operation, the upper part of the joining device is subjected to tensile forces, while the lower part of the joining device (i.e. the part oriented towards the outer surface of the roller) is subjected to compressive forces, due to the different paths of these parts, which are proportional to the radius of curvature, which varies due to the thickness of the joining device.

[0010] Since the stress is completely different between the lower part and the upper part, and in order to further improve the wear resistance of these joint devices, the applicant has improved their products in the past so as to provide the upper part with greater ductility than the ductility of the lower part. In this type of conveyor belt joint, the central part has been evolved to be separated from the lower plate and the upper plate to leave space for the use of independent spacers, which are used during assembly and the first end of the ends of the conveyor belt placed in the joint abuts against the independent spacers between the lower plate and the upper plate, and then these spacers are removed before the second end of the ends of the conveyor belt is placed. In fact, the joint device is produced by molding or by injection molding and has an H-shaped structure, and the lower plate, the upper plate and the central part of the joint device are formed as a single piece. In order to manufacture the joint device, this will require as many molds as the thickness of the conveyor belt encountered on site, so these joint devices must be manufactured in very small production batches, which increases the cost price of manufacturing, storage and distribution.

[0011] This problem, namely the problem of the large number of moulds and moulded products required for conveyor belts of various thicknesses, has been solved in particular by producing the joining device as explained above in three separate parts: the part forming the upper left and right wings, forming a single piece; the part forming the lower left and right wings, forming a single piece; and the middle part, corresponding to the central rod of the H-shaped profile, wherein the middle part forms the spacer. In this configuration, the two lower plates and the upper plate can then be made separately and each lower plate and upper plate are configured to be suitable for the forces (compression / tension) to which they are subjected and for the associated stresses. For example, the lower plate is arranged to pass over the driving roller, the return roller and the tensioning roller without undergoing any damage, wherein the rollers drive or return the conveyor belt to the end in which the joining device under consideration is installed, the lower plate being in direct contact with these parts to drive the belt. For its part, the upper plate is in direct contact with the various materials or various products conveyed on the conveyor belt. In addition, the upper plate is usually also swept by a wiper.

[0012] In any case, ductility has become a main feature in the design of such a joining plate, with the aim of obtaining a sufficiently flexible and elastic joining device capable of passing over the drive and return rollers without undergoing any damage, while being provided with a tensile strength that allows the joining device to withstand all the forces to which it is subjected without being damaged. These characteristics of ductility and resistance to such forces are conferred on the joining plate both by the flexible and elastic material (vulcanized rubber, synthetic material such as polyurethane) forming the joining plate and by the reinforcements integrated in the joining device, thus providing both ductility in the longitudinal direction of the conveyor belt and resistance suitable for withstanding the greater tensile forces to which the conveyor belt is subjected.

[0013] Although progress has been made on the ductility of such a joint plate, the applicant is still constantly developing their products to increase flexibility and improve the dynamic performance of the joint device. It has been found that the fastening device (such as a screw or a rivet) that fixes the joint plate significantly affects the stiffness of the joint plate, and generally affects the stiffness of the joint device. This constraint is even more important in some applications, such as for a conveyor belt that is called a high-durability coated conveyor belt. In fact, in order to improve the abrasion resistance and extend the service life of the conveyor belt, the known construction of the conveyor belt involves a flexible and elastic material layer covered on a reinforcement, such as a textile reinforcement, which is thicker than the flexible and elastic material layer located below the reinforcement. In other words, the reinforcement is not located at the center of the thickness of the belt, but is offset towards the face of the conveyor belt that is in direct contact with the components for driving the conveyor belt. For this type of application, the device for fastening the joint plate of a given joint device passes through one of the joint plates, one of the end portions of the conveyor belt, and then passes through another joint plate in the joint plate. The length of the fastening elements is limited by the thickness of the joining plates and the end portions, in particular to ensure that the fastening means are correctly housed in the inserts which are at least partially integrated into the upper and lower plates. As a result of this limitation, there are as many fastening interfaces as there are fastening elements on the outer surface of the associated joining plates, which interfaces represent areas conducive to the appearance of defects, such as cracks, in the material of the joining plates. Furthermore, during the passage of the return part of the conveyor belt, the mobility of the fastening means involves increased mechanical stresses on the material of the upper joining plate, which is also a source of premature wear. Summary of the invention

[0014] The present invention aims to overcome all or some of the drawbacks of the prior art, in particular by proposing a solution for increasing the flexibility of the joining device while further increasing its structural strength in order to extend its operating duration, further limiting any maintenance operations.

[0015] To this end, according to a first aspect of the invention, a joining plate is proposed, which is suitable for a joining device for conveyor belts, the joining device being intended to connect two end portions of at least one conveyor belt, the joining plate having an outer surface and an inner surface opposite the outer surface, the outer surface being intended to be flush with the useful surface of the conveyor belt in the joining position, and the inner surface being intended to at least partially cover the two end portions of the conveyor belt in the joining position, the joining plate comprising:

[0016] - a body made of a flexible material, the body having an outer surface forming an outer surface of the engagement plate;

[0017] a reinforcement plate having fastening through holes, the reinforcement plate being rigidly connected to the body; and

[0018] - a plurality of inserts at least partially embedded in the body, each insert having a fastening opening associated with one of the fastening holes so as to surround the edge of the associated fastening hole on one side of the reinforcing plate, the plurality of inserts being used to adapt the fastening means of the engagement device to the end portion;

[0019] It is worth noting that the body of the joining plate at least partially covers the fastening opening of the insert.

[0020] By virtue of this combination of features, the joining plate is thus free of inserts and / or fastening elements in the upper part formed only by the body of the joining plate, which provides the joining plate with increased flexibility and better dynamic performance, in particular for the passage of drive and return parts, such as rollers of a conveyor carriage or rollers of a conveyor. In this way, the influence of the fastening elements on the flexibility of the joint can be limited, regardless of the total thickness of the joining plate suitable for a determined joining operation. Therefore, in the case where the length of the fastening elements of a joining device comprising such a joining plate is independent of the thickness of the joining plate, the stiffness of the joining plate can be limited.

[0021] According to one embodiment, the body has a minimum thickness measured between the outer surface and the insert, which is greater than or equal to a distance equal to the height of the associated insert. Preferably, this minimum thickness is at least a few millimeters.

[0022] According to one embodiment, the joining plate has an outer surface and an inner surface opposite to the outer surface, the outer surface is formed by the outer surface of the main body, and the inner surface is formed by the inner surface of the main body and / or the inner surface of the reinforcement plate. The outer surface and the inner surface are equidistant from each other on either side of a central plane of the joining plate, and the reinforcement and the insert are positioned on the inner side of the joining plate relative to the central plane, for example between the central plane and the inner surface.

[0023] The central plane of the joining plate defines an upper half of the joining plate and a lower half of the joining plate, wherein the upper half of the joining plate is located on a side of the outer surface of the joining plate relative to the central plane, and the lower half of the joining plate is located on a side of the inner surface of the joining plate relative to the central plane, wherein the distance separating the outer surface and the inner surface of the body defines the thickness of the joining plate.

[0024] According to one embodiment, the reinforcing plate and the insert are housed on one side of the lower half of the joining plate relative to the median plane, at least partially or even completely in the lower half of the joining plate relative to the thickness of the joining plate, on one side of the inner surface.

[0025] The thickness of a joining plate is therefore defined by the distance between the outer surface and the inner surface of said plate. In this case, the lower half of the thickness refers to the "lower half" of the associated joining plate, and in particular the "lower half" of the body of the joining plate. In contrast, the upper half of the joining plate, and in particular the upper half of the body of the joining plate, is located above the lower half.

[0026] By virtue of this combination of features, the engagement plate is thus free of inserts and / or fastening elements in its upper half, thereby further increasing the ductility of the engagement plate in the region which is subject to the greatest stresses during the passage of the drive and return members.

[0027] According to one embodiment, the reinforcing plate is housed in the body and extends at a constant distance from the outer surface. The reinforcing plate may be housed integrally in the body so that the inner surface of the joining plate is simply formed by the inner surface of the body itself. Alternatively, the reinforcing plate may be positioned flush with the inner surface of the joining plate, which is then formed by the inner surface of the joining plate, or even also by the inner surface of the body.

[0028] According to one embodiment, the reinforcing plate is a textile, i.e., it comprises, preferably is formed of, at least one layer of textile or even multiple layers of textile. Thus, the reinforcing plate or reinforcement forms a woven reinforcement, thereby increasing the resistance of the joint plate to tensile forces.

[0029] According to one embodiment, the body is formed of an elastomeric material, preferably made of rubber, and has an extensibility ranging between 15% and 40%, preferably between 20% and 30%.

[0030] According to one embodiment, the body of the joining plate has holes extending from the inner surface of the body in the lower half of the joining plate, the holes being configured to partially accommodate the fastening means. These holes, which are in line with each of the inserts, are each exposed at least on the side of the inner surface of the joining plate, and these holes can remain in the lower half of the plate. In this configuration, the upper part of the joining plate supporting the outer surface, preferably the upper half of the joining plate, can be free of holes. This reduces the number of areas conducive to the occurrence of defects, such as cracks. Therefore, the dynamic performance of the joining plate and the entire device is improved.

[0031] According to one embodiment, the body of the joining plate comprises through holes extending from the outer surface of the body of the joining plate towards the inner surface of the joining plate, each hole being configured to be passed through by one of the fastening means. Preferably, the through holes are cylindrical. Such through holes are positioned in a straight line with each of the inserts, and thus these through holes each provide a passage function for guiding the fastening means towards the associated insert.

[0032] According to one embodiment, the diameter of each through hole is configured to be strictly smaller than the diameter of the fastening opening of the associated insert, so that the body partially covers said fastening opening of the insert. By virtue of the elasticity of the material forming the body of the joining plate, it appears that each hole is configured to deform elastically when one of the fastening elements, which is delimited by the body of the joining plate, passes through said hole or is introduced into said hole, and then when the plate and the device are assembled in the joining position and each fastening element cooperates with the associated insert, the associated hole returns to its original shape once the fastening element has been removed. In practice, contrary to the generally accepted view, resistance tests have shown that the fastening elements do not cause premature wear due to any friction with the body of the joining plate.

[0033] According to one embodiment, each through hole is coaxial with a fastening opening of an associated insert of the engagement plate. Preferably, each through hole is also coaxial with an associated fastening hole of the reinforcement plate.

[0034] According to another aspect of the invention, the invention relates to a joining device for conveyor belts, the joining device being intended to connect two end portions of at least one conveyor belt, the joining device notably comprising at least one joining plate as described above.

[0035] According to one embodiment, a joining device for a conveyor belt includes a first joining plate and a second plate according to any one of the aforementioned embodiments, the second plate includes a plurality of inserts, the two plates are configured to respectively cover separate sides of the ends of the conveyor belt, so that the conveyor belt is arranged between the two joining plates in the joining position, the first joining plate and the second joining plate are fastened together by a fastening device, and the fastening device is arranged to at least partially penetrate one of the first joining plate and the second joining plate, penetrate one of the ends of the conveyor belt, and then penetrate the other of the first joining plate and the second joining plate.

[0036] According to one embodiment, the thickness of the first joining plate of the joining device is greater than or equal to the thickness of the second joining plate, preferably strictly greater than the thickness of the second joining plate of the joining device, preferably greater than or equal to twice the thickness of the second joining plate, and more preferably greater than or equal to three times the thickness of the second joining plate. According to the technical language of the technical field, this construction is called a "high durability coating" plate. In this construction, the high durability coating is supported on the upper joining plate of the joining device.

[0037] According to one embodiment, the fastening means comprises a rod fastening means, preferably a screw-type rod fastening means, the fastening means each preferably comprising a head configured to cooperate with a portion of the insert and an anchoring section, the head preferably being provided with a thread, the anchoring section being configured to cooperate with another portion of the insert. In an alternative and / or additional configuration, the fastening means may comprise a rivet.

[0038] According to one embodiment, the inserts configured to respectively cooperate with the heads of the fastening means each comprise a washer passed through an associated fastening opening, the associated fastening opening being surrounded by a cup capable of housing the heads of the fastening means.

[0039] According to one embodiment, the inserts configured to respectively cooperate with the anchoring sections of the fastening device each comprise a cylindrical tubular portion defining an associated fastening opening, the inner cylindrical surface of the cylindrical tubular portion being capable of cooperating with the anchoring section of the fastening device, the inner cylindrical surface preferably comprising a tapped portion.

[0040] According to one embodiment, the first plate comprises only a tapped insert configured to cooperate with a threaded anchoring section of the fastening device.Alternatively, the first engagement plate comprises only an insert configured to cooperate with a head of the fastening device.

[0041] According to one embodiment, when the first and second engaging plates are in the engaged position, the through hole is coaxial with the fastening opening of each pair of associated inserts of the first and second plates, respectively, in the engaged position. This configuration allows the inserts of each pair of inserts associated with a given fastening device to be vertically aligned so as to allow the inserts to be anchored.

[0042] According to one embodiment, the diameter of the through hole is strictly smaller than the diameter of the fastening opening of the associated insert, preferably strictly smaller than the outer diameter of the head of the associated fastening element, preferably strictly smaller than the nominal diameter of the anchoring section of the associated fastening element, more preferably approximately equal to the thread inner diameter of the thread of the anchoring section of the associated fastening element.

[0043] According to another aspect of the present invention, the present invention relates to a manufacturing method for manufacturing a joining plate according to any one of the embodiments described above, the manufacturing method being characterized by comprising at least the following steps:

[0044] - manufacturing a series of continuous multiple joining plates (4) in the form of strips; and

[0045] - Cutting the joining panels from said produced strips according to predetermined dimensions.

[0046] This manufacturing method is particularly advantageous because it allows the continuous manufacturing of several consecutive joining plates. Each of the first and second joining plates, which are intended to form the lower and upper joining plates of the joining device, is then cut into associated strips or strip portions, which are thus manufactured and specifically adapted to the desired use.

[0047] According to another aspect, the invention also relates to a joining method for joining a first end portion and a second end portion of a conveyor belt using a joining device for a conveyor belt as described above, the joining device comprising a first joining plate and a second joining plate according to the invention, the method being characterized in that it comprises at least the following steps:

[0048] - having a first engaging plate and a second engaging plate each covering a separate side of an end portion of the conveyor belt, so that the conveyor belt is vertically placed between the two engaging plates, the first engaging plate and the second engaging plate forming a first pair of wings and a second pair of wings, the first pair of wings being suitable for clamping the first end portion of the conveyor belt, and the second pair of wings being suitable for clamping the second end portion of the conveyor belt;

[0049] - inserting the second end of the conveyor belt between the two wings of the second pair of wings;

[0050] - fastening a second end portion of the conveyor belt to the two wings of the second pair of wings, the second end portion being positioned between the two wings of the second pair of wings;

[0051] - inserting the first end of the conveyor belt between the two wings of the first pair of wings;

[0052] - Fastening a first end of the conveyor belt to the two wings of the first pair of wings, the first end being positioned between the two wings of the first pair of wings. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Further features and advantages of the present invention will become apparent upon reading the following description made with reference to the accompanying drawings, which show:

[0054] Figure 1 : A plan view of a prior art joining device for a conveyor belt, which is a top view;

[0055] Figure 2 :Joining equipment along Figure 1 A longitudinal cross-sectional view of section AA showing an exploded view of the various components of the bonding device;

[0056] Figure 3a : A longitudinal sectional view of a joining device for a conveyor belt according to a first embodiment, showing an exploded view of the various constituent elements of the joining device;

[0057] Figure 3b : A longitudinal cross-sectional view of a joining device according to the same embodiment, the joining device being in an intermediate assembly position;

[0058] Figure 3c : A longitudinal cross-sectional view of a joining device according to the same embodiment, the joining device being in the joined position;

[0059] Figure 4a: A longitudinal cross-sectional view of a joining device for a conveyor belt according to another embodiment of the present invention, showing an exploded view of various constituent elements of the joining device;

[0060] Figure 4b : A longitudinal sectional view of a joining device according to the same embodiment of the present invention.

[0061] For enhanced clarity, consistent reference numerals are used throughout the drawings to identify consistent or similar elements.

[0062] In the specification and claims, for clarity of the specification and claims, the terms longitudinal, lateral and vertical will be used in a non-limiting manner with reference to the X, Y, Z trihedron shown in the drawings.

[0063] Additionally, the terms "upper," "lower," and their derivatives refer to the position or orientation of an element or component that is considered when the joint plate is in the service configuration and extends in a horizontal plane. DETAILED DESCRIPTION

[0064] Figure 1 is a top plan view of a joining device 1 according to the prior art and shows an upper joining plate 4 of the joining device 1. Also visible are heads 5a of screws 5 which form an example of means for assembling the joining device.

[0065] The cutouts 11a and 11b show two types of textile reinforcements, both types of textile reinforcements are woven: in reinforcement 11a, the fabric is arranged in such a way that the weft threads of the fabric or even the warp threads of the fabric are at least approximately oriented in the longitudinal direction of the joining device 1, while in reinforcement 11b, the fabric is arranged so that the weft threads of the fabric and the warp threads of the fabric are inclined relative to the longitudinal direction of the joining device 1.

[0066] As a reminder, by convention, in this description, the longitudinal direction X of the joining device 1 corresponds to the longitudinal direction X of the conveyor belt 2, wherein the joining device 1 is mounted on the end 3 of the conveyor belt 2 to which the joining device 1 is connected. By the same convention, the transverse direction Y of the joining device 1 is a direction perpendicular to the longitudinal direction X. This convention applies regardless of the effective dimensions of the joining device 1 in these two directions.

[0067] Figure 1 The joining device is composed of the following three elements: an element forming the upper joining plate 4; an intermediate element 9, which is located below the central part of the joining plate 4, and the intermediate element 9 is Figure 1 , except for two imaginary lines, located on either side of the two central screws 5, which delimit the edges of the ends of the conveyor belts 2 to be connected, below the upper joining plate 4; and the elements forming the lower joining plate 4, in Figure 1Not shown in FIG. 1 , the element forming the lower joining plate 4 is located below the intermediate element 9 and below the element forming the upper joining plate 4 .

[0068] Figure 2 The exploded sections show in sequence: the assembly screws 51 forming the fastening device 5; the upper joining plate 4a; the insert 6, which is integrated into the upper joining plate 4; the intermediate element 9, including the integrated through-bushing, which is vertically arranged along the vertical axis Z; and the lower plate 3, including the tapped insert 7.

[0069] The insert 6 arranged to receive the head 5a of the screw 51 is substantially in the form of a perforated washer 61 comprising a cup capable of receiving the head 5a of the screw 5 intended to enter the hole of the perforated washer. The central insert 6' is substantially in the form of the insert 6 and comprises a central tubular portion, the inner cylindrical surface of which is capable of allowing the passage of the corresponding screw 5 with very little clearance, so that the screw is not tightened into the insert 6'. The central tubular portion of the insert 6' protrudes from the lower surface of the upper engaging plate 4.

[0070] The inserts 7 each comprise a central tubular portion, the inner cylindrical surface of which is tapped and capable of receiving a screw 51 which is tightened into the tapping, said central tubular portion protruding from the upper surface of the lower engaging plate 4 of the engaging device 1. The central insert 7' of the lower plate is in the form of an insert 7.

[0071] Figure 3a , Figure 3b and Figure 3c A joining device 1 according to a first embodiment of the present invention is shown. The joining device 1 comprises a first joining plate 4. In this embodiment, the joining device 1 also comprises a second joining plate 4'. The first joining plate 4 and the second joining plate 4' each have a body 45, the body 45 is made of a flexible and elastic material, for example made of vulcanized rubber, or made of a synthetic material such as polyurethane, and the first joining plate 4 and the second joining plate 4' comprise a reinforcement plate 11, which is rigidly connected to the body 45 of the associated joining plates 4, 4'. The reinforcement plate 11 consists of one or more textile layers to form a woven reinforcement. This material forms the body of each of the two joining plates 4, 4'. The reinforcement plate 11 comprises fastening through holes, each of which surrounds at least the fastening device 5 in the joining position, or even also surrounds a given insert.

[0072] The joining plates 4, 4' are configured to cover separate sides of the end portions 21, 22 of the conveyor belt 2, respectively, so that the conveyor belt 2 is vertically placed between the first joining plate 4 and the second joining plate 4'. The first joining plate 4 and the second joining plate 4' together form a first pair of wings 40 and a second pair of wings 42, the first pair of wings 40 clamping the first end portion 21 of the conveyor belt 2, and the second pair of wings 42 clamping the second end portion 22 of the conveyor belt 2 in the joined position. The two joining plates 4, 4' are fastened together with the end portions 21, 22 of the conveyor belt 2 by fastening devices 5, and the fastening devices 5 are respectively arranged to at least partially penetrate the first upper joining plate 4, penetrate the end portions 21, 22, and then penetrate the second lower joining plate 4'.

[0073] The first joining plate 4 comprises a main body 45, which is made of a flexible and elastic material, such as rubber. The first joining plate 4 has an outer surface S1, which is intended to be flush with the useful surface of the conveyor belt 2 at the joining position, i.e. horizontal. The outer surface S1 in this case is formed by the outer surface of the main body. The useful surface of the conveyor belt 2 corresponds to the surface of the conveyor belt 2 on which various conveyed materials or products are placed. The first joining plate 4 also has an inner surface S2, which is opposite to the outer surface S1 and is formed by the inner surface of the main body and the inner surface of the reinforcing plate 11 in this case. The inner surface S2 is intended to cover the separate sides of the two end portions 21, 22 of the conveyor belt 2 at the joining position so as to straddle the two end portions 21, 22. The inner surface S2 and the outer surface S1 define the thickness E of the associated joining plate 4.

[0074] The thickness E of the first joining plate 4 is greater than the thickness of the second joining plate 4', preferably greater than or equal to twice the thickness of the second joining plate 4', and more preferably greater than or equal to three times the thickness of the second joining plate 4'. Such a joining plate 4 is referred to as a "high durability coating" plate. The reinforcing plate 11 of the joining plate 4 is accommodated inside the body 45 of the joining plate and extends parallel to the outer surface S1. In this case, the thickness of the second lower joining plate 4' is defined and measured between the outer surface and the inner surface in the area without inserts of the second lower joining plate 4' in a manner similar to the thickness of the first upper joining plate 4, and the outer surface is flush with the inner surface of the conveyor belt 2 in the joining position, and the inner surface of the conveyor belt 2 is intended to contact the return and drive components of the conveyor belt 2, and the inner surface of the conveyor belt 2 is opposite to the useful surface of the conveyor belt 2.

[0075] The first joining plate 4 forming the upper joining plate of the joining device further comprises a plurality of inserts 6 for at least partially adapting the fastening means 5 of the joining device 1 to at least the end portions 21, 22. These inserts 6 are at least partially embedded in the body 45 and respectively have a fastening opening associated with one of the fastening holes of the reinforcing plate 11 to surround the edge of the associated fastening hole on one side of the reinforcing plate 11 so as to adapt the means 5 of the joining device 1 to at least the end portions 21, 22.

[0076] The reinforcement 11 and the insert 6 are preferably housed by means of a vulcanization method in the lower half of the joining plate 4, which adjoins the inner surface S2 relative to the thickness E of the joining plate 4. The term "lower half" is understood to mean a portion of the joining plate 4 extending from the inner surface S2 to a central limit equidistant from the inner surface S2 and the outer surface S1, which forms a joining plane P of the joining plate 4. The lower half is opposite to the "upper half" of the joining plate 4 relative to this central plane P, which covers the lower half. The upper half of the joining plate 4 is therefore formed by a single constituent material of the body 45 of the joining plate 4 and is strictly free of inserts or fastening elements 5, which gives the first joining plate 4 increased flexibility and better dynamic properties, in particular in contact with the drive and return parts. This upper portion is also the portion that is subjected to the greatest elastic deformation when a portion of the conveyor belt passes on the return part, which upper portion provides both a significant ductility in the longitudinal direction of the conveyor belt and a suitable wear resistance, since the thickness of the material of the body 45 located above the reinforcing plate 11 and the insert 6 is relatively high, since the upper portion is a high-durability coated plate. In particular, the body 45 has a minimum thickness measured between the outer surface S1 and the insert 6, which is greater than or equal to a distance equal to the height of the associated insert 6. This provides a good compromise between elasticity and resistance.

[0077] In reference Figure 3a , Figure 3b and Figure 3cIn the described embodiment, the body 45 comprises a through hole 47, which extends from the inner surface S1 of the body in which the through hole 47 is exposed toward the inner surface S2 of the body 45 in a straight line with each of the inserts 6. These through holes 47 of the joining plate 4 have a cylindrical shape and are usually vertically erected. The through hole 47 is configured to be longitudinally penetrated by the fastening device 5 of the joining plate 4. The ductility of the body 45 ranges between 15% and 40%, preferably between 20% and 30%, so that when the through hole 47 is penetrated by the fastening element 5, the through hole 47 is elastically deformed. In this case, each through hole 47 is oriented to be coaxial with the opening of the associated insert 6 for fastening the first joining plate 4 and the associated fastening hole of the reinforcing plate 11. Each through hole 47 extends continuously to the fastening opening of the associated insert 6, and the fastening opening of the associated insert 6 itself surrounds the associated fastening hole of the reinforcing plate 11. In this configuration, the through holes 47 defined by the body 45 each provide a passage function for guiding the fastening means 5 to the associated insert 6 of the engagement plate 4 with which the through holes 47 can cooperate.

[0078] Like the first joining plate 4 , the associated second joining plate 4 ′ comprises a plurality of inserts 7 , which are preferably vulcanized.

[0079] The fastening means 5 of the engagement device 1 each comprise a head 5a configured to cooperate with a portion of the insert 6 , 7 and an anchoring section 5b for cooperating with another portion of the insert 6 , 7 .

[0080] In general, each joining plate 4, 4' of the joining device 1 comprises a first interface for cooperating with the head 5a of the fastening device 5 and a second interface for cooperating with the anchoring section 5b of the fastening device 5, wherein the second interface is separate from the first interface and comprises an insert at least partially incorporated into the associated joining plate 4, 4'. In the described embodiment, the anchoring section 5b is provided with a thread.

[0081] Thus, each fastening device 5 partially fastens one of the first and second joining plates 4, 4' to the other of the first and second joining plates 4, 4' while passing through one of the end portions 21, 22 of the conveyor belt 2 placed between the first and second joining plates 4, 4' in the joining position. With a given fastening device 5 and an insert of the first type in a pair of inserts 6, 7 and an associated insert of the second type in the inserts 6, 7, the fastener can remain locked.

[0082] In this embodiment, the insert 6 of the first joining plate 4 forms the first part of the insert of the first interface. The insert 6 of the first joining plate 4 comprises a perforated washer 61 comprising a cup 62 capable of receiving the head 5a of the fastening means 5. When the first and second end portions of the conveyor belt 2 are joined together, each screw 5 is inserted through one of the corresponding holes 47 of the first joining plate 4 until the head 5a of each screw 5 is received in the cup 62 of the washer 61 forming the insert 6. This type of insert is completely embedded in the body 45 of the joining plate.

[0083] The insert 7 of the second joining plate 4' forms the second part of the insert of the second interface. The insert 7 of the second joining plate 4' comprises a cylindrical tubular portion 73, the inner cylindrical surface 74 of which is capable of cooperating with the anchoring section 5b of the fastening device 5. In the described embodiment, the inner cylindrical surface 74 comprises a tapping portion. When the first and second end portions of the conveyor belt 2 are joined together, each screw 5 is inserted through one of the corresponding holes 47 of the first joining plate 4 until the head 5a of each screw 5 is accommodated in the cup 62 of the washer 61 forming the insert 6, and at the same time, until the threaded anchoring section 5b passes through the corresponding end portion of the conveyor belt 2 and is then tightened into the tapping portion 74 of the insert 7. This type of insert is partially embedded in the body 45 of the joining plate, wherein at least a portion of the cylindrical tubular portion 73 protrudes from the inner surface of the associated joining plate.

[0084] In the joining device 1, the through holes 47 of the joining plates 4 are each coaxial with each pair of associated inserts 6, 7 of the first joining plate 4 and the second joining plate 4'. In the described embodiment, the diameter of the through hole 47 is strictly smaller than the outer diameter of the head 5a of the associated fastening element, and in this case strictly smaller than the diameter of the fastening opening of the associated insert 6, so that the body 45 partially covers the fastening opening of the insert while ensuring the passage of the rod of the associated fastening element 5. In particular, in this case, the diameter of the through hole 47 is equal to the thread inner diameter of the thread of the anchoring section 5b of the associated fastening element 5. In this way, by tightening the screw into the material of the body 45 partially covering the fastening opening of the insert 6, the screw can be inserted into the insert 6 after passing through the through hole 47. In other words, this allows the fastening element 5 to be tightened into the body 45 delimiting the associated hole 47. Thus, when the fastening element 5 is introduced, the through hole 47 deforms elastically, then returns to the initial diameter of the through hole 47 at least on the screw head and performs the function of ensuring the passage of the screw by tightening. This also allows the screw to remain pre-positioned in the body of the joining plate 4. The outer surface S1 actually has a larger useful surface area than that of the prior art, in which the screw head is flush with this surface of the conveyor belt. In addition, the size of the hole 47 reduces the risk of cracks, which increases the service life of the associated joining plate 4. In practice, it has also been noted that the passage of the screw does not cause premature wear of the joining plate.

[0085] This embodiment allows the joint device 1 to be mounted on the conveyor from above, minimizing voids and roughness, so as to limit degradation due to abrasion. The coating of the joint can be worn in the same way as the coating of the conveyor belt, without affecting the fastening elements and inserts. Using shorter threaded fasteners can provide better dynamic operation on high-durability coated belts.

[0086] Figure 4a and Figure 4bA joining device 1 according to another described embodiment of the invention is shown, which essentially differs from the previous embodiments in that the insert 6 of the first upper joining plate 4 forms part of the insert, in this case the second interface, and the body 45 of the first upper joining plate completely and not only partially covers the fastening opening of the insert 6. The insert 6 of the first upper joining plate 4 comprises a cylindrical tubular portion 63, which defines the fastening opening and has an inner cylindrical surface 64, which can cooperate with the anchoring section 5b of the fastening device. The insert 7 of the second lower joining plate 4' forms part of the insert, in this case the first interface. The insert 7 of the second lower joining plate 4' comprises a perforated washer 71, which comprises a cup 72, which defines the fastening opening and can accommodate the head 5a of the fastening device 5. In the described embodiment, the inner cylindrical surface 74 comprises a tapping portion.

[0087] In this case, the hole 47 is not a through hole, but extends from the inner surface S2 of the body 45 into the lower half of the first joining plate 4. In other words, the body 45 completely covers the fastening opening of the insert 6. Therefore, the outer surface S1 does not have any interface that would represent an area conducive to the occurrence of structural defects, such as cracks.

[0088] This embodiment allows the joining device to be mounted on the conveyor from below and allows a non-porous joining coating to be provided on the face in contact with the material to be conveyed. This offers advantages, since the coating will be as smooth as the coating of the belt and therefore less sensitive to abrasion. The coating thickness can vary depending on the coating thickness of the belt. In this case, the length of the screw is no longer affected by the thickness of the coating. Shorter screws ensure better dynamic operation.

[0089] Naturally, the present invention has been described above by way of example. It should be appreciated that those skilled in the art can generate various alternative embodiments of the present invention without departing from the scope of the present invention.

[0090] It should be noted that since all features are set out for a person skilled in the art from the present description, the drawings and the appended claims, even if strictly speaking all features are described only with respect to other determined features both individually and in any combination, all features may be combined with other features or groups of features disclosed herein, as long as this is not explicitly excluded or the technical circumstances make such a combination impossible or meaningless.

Claims

1. A joining plate (4) suitable for a joining device (1) for a conveyor belt (2), the joining device being intended to connect two end portions (21, 22) of at least one conveyor belt (2), the joining plate (4) having an outer surface (S1) and an inner surface (S2) opposite the outer surface (S1), the outer surface being intended to be flush with the useful surface of the conveyor belt (2) in the joining position, the inner surface being intended to at least partially cover the two end portions (21, 22) of the conveyor belt (2) in the joining position, the joining plate comprising: - a body (45) made of a flexible material, said body having an outer surface forming said outer surface (S1) of said engagement plate (4); - a reinforcement plate (11) having fastening through holes, said reinforcement plate being rigidly connected to said body; as well as - a plurality of inserts (6) at least partially embedded in the body (45), each insert having a fastening opening associated with one of the fastening holes so as to surround the edge of the associated fastening hole on one side of the reinforcing plate (11), the plurality of inserts being used to adapt the fastening means (5) of the joining device (1) to the end portions (21, 22); Therein, the body (45) at least partially covers the fastening opening of the insert.

2. A joining plate (4) according to the preceding claim, characterised in that The body (45) has a minimum thickness measured between the outer surface (S1) and the insert (6), the minimum thickness being greater than or equal to a distance equal to the height of the associated insert.

3. The joining plate (4) according to claim 1 or 2, characterized in that The joining plate (4) has an outer surface (S1) and an inner surface (S2) opposite to the outer surface (S1), the outer surface being formed by the outer surface of the main body (45), and the inner surface being formed by the inner surface of the main body (45) and / or the inner surface of the reinforcing plate (11), the outer surface (S1) and the inner surface (S2) being equidistant from each other on either side of a central plane (P) of the joining plate (4), the reinforcement (11) and the insert (6) being positioned on the inner side of the joining plate relative to the central plane (P), preferably between the central plane and the inner surface (S2).

4. A joining plate (4) according to any one of the preceding claims, characterised in that The reinforcing plate (11) is housed in the main body (45) and extends at a constant distance from the outer surface (S1).

5. A joining plate (4) according to any one of the preceding claims, characterised in that The body (45) is formed of an elastomeric material, preferably made of rubber, and has an extensibility ranging between 15% and 40%, preferably between 20% and 30%.

6. A joining plate (4) according to any one of the preceding claims, characterised in that The body (45) of the joining plate (4) comprises a hole (47) extending from the inner surface (S2) of the body (45) in a lower half of the joining plate (4), the hole (47) being configured to partially accommodate the fastening device (5).

7. A joining plate (4) according to any one of the preceding claims, characterised in that The body (45) comprises through holes (47) extending from the outer surface (S1) of the body (45) of the joining plate (4) towards the inner surface (S2), each hole (47) being configured to be passed through by one of the fastening means (5).

8. A joining plate (4) according to the preceding claim, characterised in that Each through hole (47) is coaxial with a fastening opening of an associated insert (6) of the joining plate (4).

9. A joining device (1) for conveyor belts (2), the joining device being intended to connect two end sections (21, 22) of at least one conveyor belt (2), characterised in that The joining device comprises at least one joining plate (4) according to any one of the preceding claims.

10. A joining device (1) for a conveyor belt (2) according to the preceding claim, characterised in that The joining device comprises a first joining plate (4) and a second plate (4') according to any one of claims 1 to 8, the second plate comprising a plurality of inserts (7), the two plates (4, 4') being configured to respectively cover separate sides of the ends of the conveyor belt (2), so that the conveyor belt (2) is arranged between the two joining plates in the joining position, the first joining plate (4) and the second joining plate (4') being fastened together by a fastening device (5), the fastening device being arranged to at least partially penetrate one of the first joining plate (4) and the second joining plate (4'), penetrate one of the end portions (21, 22) of the conveyor belt (2), and then penetrate the other of the first joining plate (4) and the second joining plate (4').

11. The joining device (1) according to the preceding claim, characterized in that The thickness (E) of the first joining plate (4) of the joining device (1) is greater than or equal to the thickness of the second joining plate (4'), preferably strictly greater than the thickness of the second joining plate of the joining device, preferably greater than or equal to twice the thickness of the second joining plate (4'), and more preferably greater than or equal to three times the thickness of the second joining plate (4').

12. A joining device (1) for a conveyor belt (2) according to the preceding claim, characterised in that The fastening means (5) comprise rod fastening means, preferably screw-type rod fastening means, each of the fastening means preferably comprising a head (5a) configured to cooperate with a portion of the insert (6, 7) and an anchoring section (5b), the head being preferably provided with a thread, the anchoring section being configured to cooperate with another portion of the insert (6, 7).

13. A joining device (1) for a conveyor belt (2) according to the preceding claim, characterised in that The inserts (6, 7) configured to cooperate with the head (5a) of the fastening device (5) each include a washer (61, 71), which is passed through an associated fastening opening, and the associated fastening opening is surrounded by a cup (62, 72), and the cup is capable of accommodating the head (5a) of the fastening device (5). The inserts (6, 7) configured to cooperate with the anchoring section (5b) of the fastening device (5) each include a cylindrical tubular portion (63, 73), which defines the associated fastening opening, and the inner cylindrical surface (64, 74) of the cylindrical tubular portion is capable of cooperating with the anchoring section (5b) of the fastening device (5), and the inner cylindrical surface (64, 74) preferably includes a tapped portion.

14. The joining device (1) according to the preceding claim, characterized in that The first engagement plate (4) comprises only a tapped insert (6) configured to cooperate with the threaded anchoring section (5b) of the fastening device (5).

15. The joining device (1) according to claim 13, characterized in that The first engaging plate (4) comprises only an insert (6) configured to cooperate with the head (5a) of the fastening device (5).

16. The joining device (1) according to any one of claims 10 to 15, characterized in that Wherein the first joining plate (4) is a joining plate according to claim 7 or 8, the through hole (47) in the joining position is coaxial with the fastening openings of each pair of associated inserts (6, 7) of the first joining plate (4) and the second joining plate (4'), respectively.

17. A joining device (1) according to any one of claims 10 to 13 and 15, characterised in that Comprising a joining device according to claim 13, wherein the first joining plate (4) is a joining plate according to claim 7 or 8, and the diameter of the through hole (47) is strictly smaller than the diameter of the fastening opening of the associated insert (6), preferably strictly smaller than the outer diameter of the head (5a) of the associated fastening element (5), preferably strictly smaller than the nominal diameter of the anchoring section (5b) of the associated fastening element (5), and more preferably approximately equal to the thread inner diameter of the thread of the anchoring section (5b) of the associated fastening element (5).

18. A method for manufacturing a joining plate (4) according to any one of claims 1 to 8, characterized in that: The manufacturing method comprises at least the following steps: - manufacturing a series of continuous multiple joining plates (4) in the form of strips; and - Cutting the joining plates (4) from the produced strip according to predetermined dimensions.

19. A method for joining a first end portion and a second end portion of a conveyor belt (2) using a joining device (1) for a conveyor belt (2) according to any one of claims 9 to 18, the joining device comprising a first joining plate (4) and a second joining plate (4') according to any one of claims 1 to 8, characterized in that The bonding method comprises at least the following steps: - causing the first joining plate (4) and the second joining plate (4') to each cover a separate side of the end portion (21, 22) of the conveyor belt (2), so that the conveyor belt is vertically placed between the two joining plates (4, 4'), the first joining plate (4) and the second joining plate (4') forming a first pair of wings (40) and a second pair of wings (42), the first pair of wings being suitable for clamping the first end portion (21) of the conveyor belt (2), and the second pair of wings being suitable for clamping the second end portion (22) of the conveyor belt (2); - inserting the second end of the conveyor belt (2) between the two wings of the second pair of wings (42); - fastening said second end portion (22) of said conveyor belt (2) to the two wings of said second pair of wings (42), said second end portion being positioned between the two wings of said second pair of wings; - inserting the first end portion (21) of the conveyor belt (2) between the two wings of the first pair of wings (40); - fastening said first end portion (21) of said conveyor belt (2) to the two wings of said first pair of wings (40), said first end portion being positioned between the two wings of said first pair of wings.

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