Plate for joining two end portions of a conveyor belt, joining device comprising at least one such joining plate, and associated strip of joining plates

Abstract

The invention relates to a joining plate (4) for a joining device (1) of a conveyor belt (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 the joining position and an inner surface (S2) opposite the outer surface (S1) 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 flexible material, having an outer surface forming the outer surface (S1) of the joining plate (4); a reinforcement plate (11) having fastening through-holes rigidly attached to the body; and a plurality of inserts (6) each having a fastening opening associated with one of the fastening holes so as to surround a rim of the fastening hole associated with one side of the reinforcement plate (11) for receiving fastening means (5) for fastening the joining device (1) to the end portions (21, 22), each one of which inserts being at least partially embedded in the body (45); the joining plate (4) being characterised in that the body (45) at least partially covers the fastening openings of the inserts.

Description

Plate for joining two end portions of a conveyor belt, joining device comprising at least one such joining plate and associated strip of joining plates TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates, in general, to the technical field of connecting devices for conveyor belts intended to connect ends of a conveyor belt. For the sake of simplification, the term conveyor belt will, by convention, in the present description, have the meaning of both conveyor belt and belt.

[0002] The invention relates more specifically to a joining plate for connecting two conveyor belt end portions, in particular provided with a textile reinforcement, to a conveyor belt joining device comprising at least one such joining plate, and to an associated strip of joining plates. STATE OF THE PRIOR ART

[0003] We know conveyor belts, also called conveyor belts, used to transport, or convey, different materials or different products, such as coal, ores, industrial or agricultural products. These conveyor belts consist of strips made of a reinforced elastomer, or of a reinforced synthetic material, of an appropriate length and width, the ends of which must be connected together, before assembly, or after assembly, on support and drive devices comprising return rollers and idler rollers. Often these devices also include tensioning members, the purpose of which is to properly tension the conveyor belt.

[0004] Until now, different means have been used to achieve this connection of the ends of the conveyor belts.

[0005] Originally, and still today, vulcanization is used when the strip is made of a reinforced vulcanizable elastomer. After preparation work to create complementary profiles at each end that are applied to each other when the ends are brought together, vulcanization is carried out with the application of heat and pressure as is well known. A variant of vulcanization is cold bonding.

[0006] Another known means of connection consists of the use of generally U-shaped clips cut from metal strip, which clips have upper plates and lower plates connected by knuckles, these clips being fixed in two series astride each of the ends of the conveyor belt to be connected, so that the knuckles project and those of one series can be nested between the knuckles of the other series, a connecting and articulating rod then being passed inside the nested knuckles so as to thus connect the two ends, forming a kind of hinge. The known means used for fixing the clips to the ends of the conveyor belt consist of rod fastening means such as studs, rivets and screws.

[0007] In the more recent past, joining devices have been proposed using flat joining elements generally made of reinforced elastomer or reinforced synthetic material, arranged respectively on one side and on the other side of the ends of the conveyor belt and fixed to said ends which are to be joined. Examples of such joining devices are given in patents EP-0827575-B1 and EP-1163459-B1. These devices comprise an upper joining plate and a lower joining plate, possibly connected by a central part. These lower and upper joining plates have a spacing adapted to engage the respective end of a conveyor belt therein, making it come approximately into abutment against the central part, or in the case where the joining device does not have a central part, against a spacer provided for this purpose during assembly, then removed subsequently.In other words, these joining devices comprise two pairs of fixing wings facing each other, the ends of the conveyor belt being introduced respectively between two. wings of the same pair. The lower and upper parts forming a joining plate on the ends of the conveyor belt are generally fixed by means of rivets, nails, crampons, screw-nut systems, or by cold gluing or flat vulcanization of the wings against the flat outer surfaces of the conveyor belt engaged between the wings.

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

[0009] The extensibility of the frames of this type of joining devices in the longitudinal direction of the conveyor belt is intended to enable the joining devices mounted on the conveyor belts to repeatedly cross, without excessive wear or fatigue which could lead to rapid deterioration, the curved parts of the path of the conveyor belts, namely, the bypass of the drive rollers, the return rollers and the tension rollers. Indeed, during this operation the upper part of the joining devices undergoes a tensile force while their lower part (i.e. the one oriented towards the outer surface of the rollers) undergoes a compressive force, and this, due to the difference in the path of these parts, these paths being directly proportional to the radius of curvature, which varies due to the thickness of the joining devices.

[0010] The constraints being very different between the lower and upper parts, and in order to further improve the wear resistance of these joining devices, the Applicant has improved its product in the past so as to give the upper part greater extensibility than that of the lower part. In this type of conveyor belt joining, the central part has then evolved so as to be separated from the lower and upper plates, this to leave room for the use of independent spacers used at the time of assembly against which the first of the ends of the conveyor belt which is placed in the joining, between the lower and upper plates, abuts, then these spacers are removed before placing the second of the ends of the belt conveyor. In fact, the joining devices were made by molding or injection and had an "H" structure whose lower and upper plates and the central part were formed from a single piece. This required for their manufacture as many molds as thicknesses of conveyor belts encountered in the field, and these joining devices had to be manufactured, therefore, in very small series, which increased the cost price, in manufacturing, storage and distribution.

[0011] This problem, namely that of the multiplicity of molds and molded products having to cope with the varied thicknesses of conveyor belts, has been resolved in particular by producing, as explained above, the joining devices in three separate parts: a part constituting upper left and right wings forming a single piece, a part constituting lower left and right wings forming a single piece, and an intermediate part, corresponding to the middle bar of the "H" profile, this intermediate part forming a spacer. In such a configuration, it becomes possible to manufacture the two lower and upper plates separately and each is configured so as to be adapted to the forces they undergo (compression / tensile forces) and the associated constraints.For example, the lower plate is arranged to withstand without damage the passage over drive rollers, return rollers and tension rollers, driving or returning the conveyor belt at the ends of which is mounted the relevant joining device, the lower plate coming directly into contact with these belt drive members. The upper plate is in direct contact with the various materials or products transported on the conveyor belt. Furthermore, the upper plate is also generally swept by scrapers.

[0012] In any event, extensibility has become a predominant characteristic in the design of such a joining plate with a view to obtaining a joining device sufficiently flexible and elastic to withstand without damage the passage over drive rollers and over return rollers while having a tensile strength making it capable of resisting without damage all the forces to which it is subjected. These characteristics of extensibility and resistance to such forces of the junction plate are provided both by the flexible and elastic material (vulcanized rubber, synthetic material such as polyurethane) forming the junction plate and by the reinforcement integrated into it, providing both extensibility in the longitudinal direction of the conveyor belt and resistance adapted to withstand the greatest tensile forces undergone by the conveyor belt.

[0013] Despite the progress made regarding the extensibility of such a joining plate, the Applicant is constantly developing its product in order to increase the flexibility and improve the dynamic behavior of a joining device. It has been observed that the fastening means (such as screws or rivets) securing the joining plates have a significant impact on the rigidity of the joining plates, and more generally of the joining device. This constraint is all the more important in certain applications, such as for so-called heavily coated conveyor belts. Indeed, to improve the abrasion resistance and increase the service life of the conveyor belt, it is known that a conveyor belt is configured so that the layer of flexible and elastic material covering the reinforcement above, for example a textile reinforcement, is thicker than the layer of flexible and elastic material located under said reinforcement.In other words, the reinforcement is not located centrally in the thickness of the belt but off-centered towards the face of the conveyor belt coming directly into contact with the conveyor belt drive members. For this type of application, the fastening means of the joining plates of a given joining device each pass through one of the joining plates, one of the end portions of the conveyor belt and then the other of the joining plates. The length of the fastening elements is constrained by the thickness of the joining plates together with the end portion, in particular to ensure that the fastening means are correctly housed in the inserts incorporated at least partly in the upper and lower plates.The consequence of such a constraint is the presence of as many fixing interfaces as there are fixing elements on the external surfaces of the associated junction plate, interfaces representing areas which become conducive to the appearance of defects in the material of the junction plate, for example cracks. Furthermore, the mobility of the fixing means during the passage of conveyor belt return members implies a stress. increased mechanical stress on the upper junction plate material which is also a source of premature wear. STATEMENT OF THE INVENTION

[0014] The invention aims to remedy all or part of the drawbacks of the state of the art by proposing in particular a solution making it possible to improve the flexibility of the junction devices while further improving their structural strength to improve their lifespan, and thus further limit maintenance operations.

[0015] To this end, according to a first aspect of the invention, a joining plate is proposed for a conveyor belt joining device intended to connect two end portions of at least one conveyor belt, the joining plate having an outer surface to be flush, i.e. level, with a useful surface of the conveyor belt in the joining position and an inner surface opposite the outer surface, and intended to at least partially cover the two end portions of the conveyor belt in the joining position, the joining plate comprising: a body made of flexible material, having an outer surface forming the outer surface of the joining plate; a frame plate having through fixing holes, integral with the body;and a plurality of inserts embedded at least partly in the body and each having a fixing opening associated with one of the fixing holes so as to surround a rim of the associated fixing hole on one side of the reinforcement plate, to receive means for fixing the joining device with the end portions; the joining plate being remarkable in that the body at least partly covers the fixing openings of the inserts.;

[0016] Thanks to such a combination of characteristics, the joining plate is thus devoid of inserts and / or fixing elements in an upper part consisting only of the body of the joining plate, which gives it increased flexibility and better dynamic behavior, in particular when passing drive members and return members, such as rollers of a transport trolley or a conveyor. In this way, whatever the total thickness of the joining plate adapted to a given joining operation, it is possible to limit the impact of the fixing elements on the flexibility of the joining. The length of the fixing elements of a joining device comprising such a joining plate being thus independent of the thickness of the joining plate, the rigidity of the joining plate can be limited.

[0017] According to one embodiment, the body has a minimum thickness measured between the outer surface and the inserts, greater than or equal to a distance equal to a height of the associated inserts. Preferably, this minimum thickness is at least a few millimeters.

[0018] According to one embodiment, the joining plate has an outer surface constituted by an outer surface of the body and an inner surface opposite the outer surface and constituted by an inner surface of the body and / or of the reinforcement plate, the outer surface and the inner surface being equidistant from each other on either side of a median plane of the joining plate, the reinforcement and the inserts being positioned on the inner side of the joining plate relative to the median plane, for example between the median plane and the inner surface.

[0019] The median plane of the junction plate delimits an upper half of the junction plate located on the side of the outer surface of said junction plate relative to the median plane of a lower half of the junction plate located on the side of the inner surface of said junction plate relative to the median plane, the distance separating the outer surface and the inner surface of the body delimiting a thickness of the junction plate.

[0020] According to one embodiment, the reinforcement plate and the inserts are housed on the side of the lower half of the junction plate relative to the median plane, at least in part, or even entirely, in the lower half of the junction plate relative to its thickness, on the side of the inner surface.

[0021] The thickness of the junction plate is therefore delimited by the distance between the outer and inner surfaces of said plate. The lower half of the thickness here designates the "lower half" of the associated junction plate, and in particular of the body of the junction plate. In contrast, the upper half of the junction plate, and in particular of the body of the junction plate, is located above the lower half.

[0022] Thanks to such a combination of characteristics, the junction plate is thus free of inserts and / or fixing elements in its upper half, further improving its extensibility in this area most stressed by the passage of drive and return members.

[0023] According to one embodiment, the reinforcement plate is housed in the body and extends at a constant distance from the outer surface. The reinforcement plate may be fully housed in the body so that the inner surface of the joining plate consists simply of an inner surface of the body itself. Alternatively, the reinforcement plate may be positioned flush with the inner surface of the joining plate, which then consists of an inner surface of the joining plate, or even of the body as well.

[0024] According to one embodiment, the reinforcement plate is textile, that is to say that it comprises, preferably consists of, at least one layer, or even a plurality of layers, of textile. The reinforcement plate, or reinforcement, thus forms a woven reinforcement improving the resistance of the junction plate to tensile forces.

[0025] According to one embodiment, the body is formed from an elastomeric material, preferably rubber, and has an extensibility of between 15% and 40%, preferably between 20% and 30%.

[0026] According to one embodiment, the body of the junction plate has orifices extending from the inner surface of the body into the lower half of the junction plate, the orifices being configured to partially house the fixing means. These orifices at right angles to each of the inserts are each opening out at least on the side of the inner surface of the junction plate but they can remain located in the lower half of the plate. In this configuration, an upper part of the junction plate carrying the outer surface, preferably its upper half, can be devoid of orifices. This reduces the number of areas conducive to the appearance of defects, for example cracks. The dynamic behavior of the junction plate and of the entire device is thus improved.

[0027] According to one embodiment, the body of the junction plate comprises through-holes, extending from the outer surface of the body of the junction plate towards the inner surface of the junction plate, the holes being configured to be each passed through by one of the fixing means. Preferably, the through-holes are cylindrical. Such through-holes are located in line with each of the inserts and thus each provide a function of a passageway for the fixing means to pass towards the associated insert.

[0028] According to one embodiment, a diameter of each through-hole is configured so as to be strictly less than a diameter of the fastening openings of the associated insert so that the body partially covers said fastening openings of the inserts. Thanks to the elasticity of the material constituting the body of the junction plate, it appears that each orifice is configured to deform elastically when one of the fastening elements passes or is introduced through it, the associated orifice being delimited by the body of the junction plate and then returns to its initial shape once the fastening element has been removed, by when the plate and the device are assembled in the junction position and each fastening element cooperates with the associated insert.In practice, and contrary to popular belief, resistance tests have shown that the fixing elements do not cause premature wear due to possible friction with the body of the junction plate.

[0029] According to one embodiment, each of the through holes is coaxial with one of the fixing openings of one of the associated inserts of the junction plate. Preferably each of the through holes is also coaxial with the associated fixing hole of the armature plate.

[0030] According to another aspect of the invention, it relates to a connecting device for a conveyor belt intended to connect two end portions of at least one conveyor belt, the connecting device being remarkable in that it comprises at least one connecting plate as described above.

[0031] According to one embodiment, the conveyor belt joining device comprises a first joining plate according to one of the above embodiments and a second plate comprising a plurality of inserts, the two plates being configured to each cover a separate side of the ends of the conveyor belt so that said conveyor belt is arranged between the two joining plates in the joining position, the first and second joining plates being fixed together by fixing means arranged to penetrate at least partially respectively one joining plate among the first and second joining plates, one of the ends of the conveyor belt and then the other joining plate among the first and second joining plates.

[0032] According to one embodiment, a thickness of the first junction plate is greater than or equal to, preferably strictly greater than, a thickness of the second junction plate of the junction device, preferably greater than or equal to twice the thickness of the second junction plate, more preferably greater than or equal to three times the thickness of the second junction plate. In the jargon of the technical field, such a configuration is referred to as a so-called "heavy-coated" plate. In such a configuration, the heavy coating is carried on the upper junction plate of the junction device.

[0033] According to one embodiment, the fixing means comprise rod fixing means, preferably of the screw type, the fixing means each preferably comprising a head configured to cooperate with a portion of the inserts and an anchoring section, preferably provided with a thread, configured to cooperate with another portion of said inserts. In alternative and / or complementary configurations, the fixing means may comprise rivets.

[0034] According to one embodiment, the inserts configured to each cooperate with a head of the fixing means each comprise a washer pierced with the associated fixing opening bordered by a cup capable of housing the head of the fixing means.

[0035] According to one embodiment, the inserts configured to each cooperate with an anchoring section of the fixing means each comprise a cylindrical tubular part delimiting the associated fixing opening, an internal cylindrical surface of which is capable of cooperating with an anchoring section of the fixing means, the internal cylindrical surface preferably comprising a thread.

[0036] According to one embodiment, the first plate comprises only the threaded inserts configured to cooperate with the threaded anchoring sections of the fixing means. Alternatively, the first junction plate comprises only inserts configured to cooperate with the heads of the fixing means.

[0037] According to one embodiment, the through holes are each coaxial with the fixing openings of each associated pair of inserts of the first plate and the second plate, in the joining position, when the first and second joining plates are in a joining position. Such a configuration allows vertical alignment of the inserts of each pair of inserts associated with a given fixing means to allow its anchoring.

[0038] According to one embodiment, a diameter of the through holes is strictly less than a diameter of the fixing opening of the associated insert, preferably strictly less than an outside diameter of the head of the associated fixing element, preferably strictly less than a nominal diameter of the anchoring section of the associated fixing element, more preferably substantially equal to the thread root diameter of the thread of the anchoring section of the associated fixing element.

[0039] According to another aspect of the invention, it relates to a method of manufacturing a junction plate in accordance with one of the embodiments described above, remarkable in that it comprises at least the following steps: manufacturing a continuous succession of a plurality of joining plates in the form of a strip; and cutting, from said strip thus manufactured, joining plates according to predetermined dimensions.

[0040] Such a manufacturing method is particularly advantageous in that it allows continuous manufacturing of several successive joining plates. Each of the first and second joining plates, intended to constitute the lower and upper joining plates of the joining device, are then cut from an associated strip or portion of strip thus manufactured and specifically adapted to the desired use.

[0041] According to another aspect, the invention also relates to a method for joining a first end portion and a second end portion of a conveyor belt by a conveyor belt joining device as described above comprising a first joining plate according to the invention and a second joining plate, characterized in that it comprises at least: a step of covering by the first joining plate and the second joining plate each on a separate side of the end portions of the conveyor belt so that said conveyor belt is interposed vertically between the two joining plates, said first and second joining plates forming a first pair of wings which is adapted to pinch the first end portion of the conveyor belt and a second pair of wings which is adapted to pinch the second end portion of the conveyor belt;a step of inserting the second end of the conveyor belt between two wings of the second pair of wings, a step of fixing the second end portion of the conveyor belt with the two wings of the second pair of wings between which it is positioned; a step of inserting the first end of the conveyor belt between the two wings of the first pair of wings a step of fixing the first end of the conveyor belt with the two wings of the first pair of wings between which it is positioned. BRIEF DESCRIPTION OF THE FIGURES

[0042] Other characteristics and advantages of the invention will emerge from reading the following description, with reference to the appended figures, which illustrate: figure 1: a plan view of a conveyor belt joining device of the prior art, seen from above figure 2: a longitudinal sectional view along section AA of figure 1 of a joining device, showing exploded views of the various elements that constitute it. figure 3a: a longitudinal sectional view of a conveyor belt joining device according to a first embodiment, showing exploded views of the various elements that constitute it. figure 3b: a longitudinal sectional view of a joining device according to the same embodiment, in an intermediate assembly position. figure 3c: a longitudinal sectional view of a joining device according to the same embodiment, in a joining position.Figure 4a: a longitudinal sectional view of a conveyor belt joining device according to another embodiment of the invention, showing exploded views of the various elements that constitute it. Figure 4b: a longitudinal sectional view of a joining device according to the same embodiment of the invention.

[0043] For clarity, identical or similar elements are identified by identical reference signs throughout the figures.

[0044] In the description and claims, for the sake of clarity, the terminology longitudinal, transverse and vertical will be adopted without limitation with reference to the trihedron X, Y, Z indicated in the figures.

[0045] Additionally, the terms "upper", "lower" and their derivatives refer to the position or orientation of an element or component, such position or orientation being considered when the junction plates are in service configuration and extend in a horizontal plane. DETAILED DESCRIPTION OF EMBODIMENTS

[0046] Figure 1 is a plan view, from above, of a joining device 1 according to the prior art and shows an upper joining plate 4 of a joining device 1. Also visible are heads 5a of the screws 5 which constitute an example of means of assembling the joining devices.

[0047] The cutaways 11a and 11b show two types of textile-type reinforcements, which are woven: in the reinforcement 11a the fabric is arranged in such a way that its weft threads, or its warp threads, are oriented at least approximately in the longitudinal direction of the joining device 1 while in the reinforcement 11b the fabric is arranged in such a way that its weft threads and its warp threads are oblique to the longitudinal direction of the joining device 1.

[0048] We recall that by convention the longitudinal direction X of the joining device 1 corresponds, in the present description, to the longitudinal direction X of the conveyor belt 2, the joining device 1 being mounted on the ends 3 of the conveyor belt 2 which it connects. The transverse direction Y of the joining device 1 is, according to the same convention, the direction perpendicular to the longitudinal direction X. This convention is applied whatever the actual dimensions of the joining device 1 in these two directions.

[0049] The junction device of figure 1 is composed of three elements: an element forming an upper junction plate 4, an intermediate element 9 located under the middle part of the joining plate 4 which is not visible in Figure 1 other than by the two dotted lines located on either side of the two middle screws 5 delimiting under the upper joining plate 4 the edges of the ends of the conveyor belt 2 to be connected, and an element forming a lower joining plate 4, not visible in Figure 1, which is located under the intermediate element 9 and under the element forming an upper joining plate 4.

[0050] The exploded section of Figure 2 shows successively assembly screws 51 forming fixing means 5, the upper joining plate 4a, inserts 6 incorporated in the upper joining plate 4, the intermediate element 9 comprising an incorporated through-sleeve, arranged vertically along a vertical axis Z, the lower plate 3 comprising threaded inserts 7.

[0051] The inserts 6 arranged to receive the heads 5a of screws 51 are generally in the form of pierced washers 61 comprising a cup capable of housing the heads 5a of the screws 5 intended to pass through the hole in the pierced washers. The central insert 6' is generally in the same way as the inserts 6 but it comprises a central tubular part, the internal cylindrical surface of which is capable of allowing passage, with very little play, for the corresponding screw 5, this screw therefore not being screwed into the insert 6'. The central tubular part of the insert 6' projects from the lower surface of the upper joining plate 4.

[0052] The inserts 7 each comprise a central tubular part whose inner cylindrical surface is tapped and is capable of receiving a screw 51 screwed into the tapping, said central tubular parts protruding from the upper surface of the lower joining plate 4 of the joining device 1. The middle inserts 7' of the lower plate are presented as the inserts 7.

[0053] Figures 3a, 3b and 3c illustrate a joining device 1 according to a first embodiment of the invention. The joining device 1 comprises a first joining plate 4. In this embodiment, the joining device 1 also comprises a second joining plate 4'. These first and second joining plates 4, 4' each have a body 45 made of a flexible material and elastic, for example made of vulcanized rubber, or of a synthetic material such as polyurethane and they comprise a reinforcement plate 11 secured to the body 45 of the associated joining plates 4, 4'. The reinforcement plate 11 is made of one or more layers of textile, so as to form a woven reinforcement. This material constitutes the body of each of these two joining plates 4, 4'. The reinforcement plate 11 comprises through fixing holes each surrounding at least the fixing means 5 in the joining position, or even a given insert.

[0054] The joining plates 4, 4' are configured to each cover a separate side of end portions 21, 22 of a conveyor belt 2 so that the conveyor belt 2 is interposed vertically between the first and second joining plates 4, 4'. The first and second joining plates 4, 4' together form a first pair of wings 40 which clamps the first end portion 21 of the conveyor belt 2 and a second pair of wings 42 which clamps the second end portion 22 of the conveyor belt 2 in a joining position. The two joining plates 4, 4' are fixed together with the end portions 21, 22 of the conveyor belt 2 by fixing means 5 arranged to penetrate at least partially respectively the first upper joining plate 4, the end portions 21, 22 then the second lower joining plate 4'.

[0055] The first joining plate 4 comprises a body 45 made of a flexible and elastic material such as rubber. The first joining plate 4 has an outer surface SI to be flush, that is to say level, with a useful surface of the conveyor belt 2 in the joining position. The outer surface SI is here constituted by an outer surface of the body. The useful surface of the conveyor belt 2 corresponds to the surface of the conveyor belt 2 on which the various conveyed materials or products rest. The first joining plate 4 also has an inner surface S2, opposite the outer surface SI and constituted here by an inner surface of the body and the frame plate 11. The inner surface S2 is intended to cover a separate side of the two end portions 21, 22 of the conveyor belt 2 in the joining position so as to extend astride these two end portions 21, 22.The inner and outer surfaces SI, S2 delimit a thickness E of the associated junction plate 4.

[0056] The thickness E of the first joining plate 4 is greater than a thickness of the second joining plate 4', preferably greater than or equal to twice the thickness of the second joining plate 4', 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-coating" plate. The reinforcement plate 11 of the joining plate 4 is housed inside the body 45 of the joining plate and extends parallel to the outer surface SI.Here the thickness of the second lower joining plate 4' defined, and therefore measured, in a similar manner to that of the first upper joining plate 4, between its outer and inner surfaces in an area without insert, the outer surface this time being flush with an inner surface of the conveyor belt 2 in the joining position intended to come into contact with the return and drive members of said conveyor belt 2 opposite the useful surface of said conveyor belt 2.

[0057] The first joining plate 4 forming the upper joining plate of the joining device further comprises a plurality of inserts 6 for receiving at least a portion of the fixing means 5 of the joining device 1, with at least the end portions 21, 22. These inserts 6 are embedded at least in part in the body 45 and each have a fixing opening associated with one of the fixing holes of the reinforcement plate 11 so as to surround a rim of the associated fixing hole on one side of the reinforcement plate 11, for receiving means 5 of the joining device 1, with at least the end portions 21, 22.

[0058] The frame 11 and the inserts 6 are housed in a lower half of the junction plate 4 relative to its thickness E adjoining the inner surface S2, preferably by a vulcanization process. The term "lower half" denotes a part of the junction plate 4 which extends from the inner surface S2 to a median limit equidistant from the inner and outer surfaces SI, S2, this median limit forming a junction plane P of the junction plate 4. The lower half is opposite the "upper half" of the junction plate 4 relative to this median plane P, which upper half is superimposed on the lower half. The upper half of the junction plate 4 is thus constituted by the sole material constituting its body 45 and is strictly devoid of inserts or fixing elements 5, which gives the first joining plate 4 increased flexibility and better dynamic behavior, in particular in contact with drive and return members. This upper part is also the one which undergoes the most elastic deformation when a portion of conveyor belt passes at the level of a return member, offering both significant extensibility in the longitudinal direction of the conveyor belt and suitable resistance to wear, since a thickness of the material of the body 45 located above the reinforcement plate 11 and the inserts 6 is relatively large due to the fact that it is a plate with a strong coating. In particular, the body 45 has a minimum thickness measured between the outer surface SI and the inserts 6, greater than or equal to a distance equal to a height of the associated inserts 6.This ensures a good compromise between elasticity and resistance.

[0059] In the embodiment described with reference to Figures 3a, 3b and 3c, the body 45 comprises through-orifices 47 extending in line with each of the inserts 6 from the inner surface S1 of the body at the level of which they open towards the inner surface S2 of the body 45. These through-orifices 47 of the junction plate 4 have a cylindrical shape and are generally vertically erected. The through-orifices 47 are configured to be traversed in their length by the fixing means 5 of the junction plate 4. The body 45 has an extensibility of between 15% and 40%, preferably between 20% and 30%, so that the through-orifices 47 deform elastically when they are traversed by the fixing elements 5.Here, each through-orifice 47 is oriented so as to be coaxial with a fixing opening of an associated insert 6 of the first junction plate 4 and an associated fixing hole of the reinforcement plate 11. Each through-orifice 47 extends continuously to the fixing opening of the associated insert 6 itself surrounding an associated fixing hole of the reinforcement plate 11. In such a configuration, the through-orifices 47 delimited by the body 45 each provide a function of a passage for supplying the fixing means 5 to the associated insert 6 of the junction plate 4 with which it can cooperate.

[0060] Like the first junction plate 4, the associated second junction plate 4' comprises a plurality of inserts 7, preferably vulcanized.

[0061] The fixing means 5 of the joining device 1 each comprise a head 5a configured to cooperate with a part of the inserts 6, 7 and an anchoring section 5b to cooperate with the other part of the inserts 6, 7.

[0062] Generally, each joining plate 4, 4' of the joining device 1 comprises first interfaces for cooperating with the heads 5a of the fixing means 5 and second interfaces for cooperating with the anchoring sections 5b of the fixing means 5, the second interfaces being distinct from the first interfaces and comprising inserts incorporated at least in part in the associated joining plate 4, 4'. In the embodiment described, the anchoring section 5b is provided with a thread.

[0063] Each fastening means 5 thus locally ensures a fastening of one of the joining plates among the first and second joining plates 4, 4' with the other joining plate among the first and second joining plates 4, 4', while passing through one of the end portions 21, 22 of the conveyor belt 2 interposed between the first and second joining plates 4, 4' in the joining position. Thanks to a pair of a first type of inserts among the inserts 6, 7 and a second type of associated inserts among the inserts 6, 7 of a given fastening means 5, it is possible to maintain the fastening locked.

[0064] In this embodiment, the inserts 6 of the first joining plate 4 form a first part of the inserts of the first interface. They comprise a pierced washer 61 having a cup 62 capable of housing the head 5a of the fixing means 5. When joining the first and second end portions of the conveyor belt 2 together, each screw 5 is inserted through one of the corresponding orifices 47 of the first joining plate 4 until its head 5a is housed in the cup 62 of the washer 61 forming the insert 6. This type of insert is fully embedded in the body 45 of the joining plate.

[0065] The inserts 7 of the second joining plate 4' form a second part of the inserts, of the second interface. They comprise a cylindrical tubular part 73 of which an inner cylindrical surface 74 is capable of cooperating with the anchoring section 5b of the fixing means 5. In the embodiment described, the inner cylindrical surface 74 comprises a thread. When joining the first and second end portions of the conveyor belt 2 together, each screw 5 is inserted through one of the corresponding orifices 47 of the first joining plate 4 until its head 5a is housed in the cup 62 of the washer 61 forming the insert 6 and, concomitantly, the threaded anchoring section 5b passes through the corresponding end portion of the conveyor belt 2 and then comes to be screwed into the thread 74 of the insert 7.This type of insert is partially embedded in the body 45 of the junction plate, at least a portion of the cylindrical tubular part 73 being projecting relative to the interior surface of the associated junction plate.

[0066] In the joining device 1, the through-holes 47 of the joining plate 4 are each coaxial with each associated pair of inserts 6, 7 of the first joining plate 4 and the second joining plate 4'. In the embodiment described, a diameter of the through-holes 47 is strictly less than an outside diameter of the head 5a of the associated fixing element and here strictly less than a diameter of a fixing opening of the associated insert 6 so that the body 45 partly covers the fixing openings of the inserts while ensuring the passage of the rod of the associated fixing element 5. In particular here, the diameter of the through-holes 47 is equal to the thread root diameter of the thread of the anchoring section 5b of the associated fixing element 5.In this way, the screw can be inserted into the insert 6 after passing through the through-hole 47 by screwing into the material of the body 45 which partly covers the fixing openings of the inserts 6. In other words, this allows the fixing element 5 to be screwed into the body 45 delimiting the associated orifice 47. Thus, the through-holes 47 deform elastically when the fixing element 5 is introduced, then return to their initial diameter, at least at the level of the screw head, and have a function of ensuring the passage of the screw by screwing. This also makes it possible to maintain pre-positioned screws in the body of the junction plate 4. The outer surface SI in fact has a. useful surface area greater than that of the prior art where the screw heads come level with this surface of the conveyor belt. In addition, the size of the holes 47 reduces the risk of cracks appearing, which increases the service life of the associated junction plate 4. In practice, it is also noted that the passage of the screw does not create premature wear of the junction plate.

[0067] This embodiment allows the splicing device 1 to be mounted from above on a conveyor with as few cavities and roughnesses as possible, thereby limiting damage due to abrasion. The splicing coating can wear in the same way as that of the conveyor belt without affecting the fasteners and inserts. With shorter screws, better dynamic operation is ensured on heavily coated belts.

[0068] Figures 4a and 4b illustrate a joining device 1 according to another embodiment of the invention described which differs from the previous one essentially in that the inserts 6 of the first, upper joining plate 4 form a part of the inserts, here of the second interface, and in that the body 45 of the first, upper joining plate covers completely, and not only in part, the fixing openings of the inserts 6. They comprise a cylindrical tubular part 63 delimiting the fixing opening and of which an internal cylindrical surface 64 is capable of cooperating with the anchoring section 5b of the fixing means. The inserts 7 of the second, lower joining plate 4' form a part of the inserts, here of the first interface. They comprise a pierced washer 71 comprising a cup 72 delimiting the fixing opening and capable of housing the head 5a of the fixing means 5.In the described embodiment, the inner cylindrical surface 74 comprises a thread.

[0069] Here, the orifices 47 are not through and extend 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 which completely covers the fixing openings of the inserts 6. The outer surface SI is thus free of any interface which would represent areas conducive to the appearance of structural defects such as cracks.

[0070] This embodiment allows the splicing device to be mounted from below on a conveyor but allows for a splicing coating without a hole on the face in contact with the materials to be conveyed. This offers an advantage since the coating will be as smooth as the belt coating, and therefore less sensitive to abrasion. The coating thickness can vary depending on the belt coating thickness. In this case, the length of the screws is no longer influenced by the coating thickness. Shorter screws ensure better dynamic operation.

[0071] Naturally, the invention is described in the foregoing by way of example. It is understood that those skilled in the art are able to carry out different variant embodiments of the invention without departing from the scope of the invention.

[0072] It is emphasized that all features, as they emerge for a person skilled in the art from this description, the drawings and the attached claims, even if they have been specifically described only in relation to other specific features, both individually and in any combinations, may be combined with other features or groups of features disclosed herein, provided that this has not been expressly excluded or that technical circumstances make such combinations impossible or meaningless.

Claims

CLAIMS Junction plate (4) for a junction device (1) of a conveyor belt (2) intended to connect two end portions (21, 22) of at least one conveyor belt (2), the junction plate (4) having an outer surface (SI) to be flush with a useful surface of the conveyor belt (2) in the junction position and an inner surface (S2) opposite the outer surface (SI), and intended to at least partially cover the two end portions (21, 22) of the conveyor belt (2) in the junction position, the junction plate comprising: a body (45) made of flexible material, having an outer surface forming the outer surface (SI) of the junction plate (4); a frame plate (11) having through fixing holes, integral with the body, ;and a plurality of inserts (6) embedded at least partly in the body (45) and each having a fixing opening associated with one of the fixing holes so as to surround a rim of the associated fixing hole on one side of the reinforcement plate (11), to receive fixing means (5) of the joining device (1) with the end portions (21, 22);the junction plate (4) being characterized in that the body (45) at least partially covers the fixing openings of the inserts. Junction plate (4) according to the preceding claim, characterized in that the body (45) has a minimum thickness measured between the outer surface (SI) and the inserts (6), greater than or equal to a distance equal to a height of the associated inserts. Junction plate (4) according to claim 1 or 2, characterized in that the junction plate (4) has an outer surface (SI) constituted by an outer surface of the body (45) and an inner surface (S2) opposite the; outer surface (SI) and constituted by an inner surface of the body (45) and / or of the reinforcement plate (11), the outer surface (SI) and the inner surface (S2) being equidistant from each other on either side of a median plane (P) of the joining plate (4), the reinforcement (11) and the inserts (6) being positioned on the inner side of the joining plate relative to the median plane (P), preferably between the median plane and the inner surface (S2).

4. Junction plate (4) according to any one of the preceding claims, characterized in that the reinforcement plate (11) is housed in the body (45) and extends at a constant distance from the outer surface (SI).

5. Junction plate (4) according to any one of the preceding claims, characterized in that the body (45) is formed from an elastomeric material, preferably rubber, and has an extensibility of between 15% and 40%, preferably between 20% and 30%.

6. Junction plate (4) according to any one of the preceding claims, characterized in that the body (45) of the junction plate (4) comprises orifices (47) extending from the inner surface (S2) of the body (45) into the lower half of the junction plate (4), the orifices (47) being configured to partially house the fixing means (5).

7. Junction plate (4) according to any one of the preceding claims, characterized in that the body (45) comprises through orifices (47), extending from the outer surface (SI) of the body (45) of the junction plate (4) towards the inner surface (S2), the orifices (47) being configured to be each crossed by one of the fixing means (5).

8. Junction plate (4) according to the preceding claim, characterized in that each of the through orifices (47) is coaxial with one of the fixing openings of one of the associated inserts (6) of the junction plate (4).

9. Joining device (1) for conveyor belt (2) intended to connect two end portions (21, 22) of at least one conveyor belt (2), characterized in that it comprises at least one junction plate (4) according to any one of the preceding claims.Jointing device (1) for conveyor belt (2) according to the preceding claim, characterized in that it comprises a first jointing plate (4) according to one of claims 1 to 8 and a second plate (4') comprising a plurality of inserts (7), the two plates (4, 4') being configured to each cover a separate side of the ends of the conveyor belt (2) so that said conveyor belt (2) is arranged between the two jointing plates in the jointing position, the first and second jointing plates (4, 4') being fixed together by fixing means (5) arranged to penetrate at least partially respectively one jointing plate among the first and second jointing plates (4, 4'), one of the end portions (21, 22) of the conveyor belt (2) then the other jointing plate among the first and second jointing plates (4, 4').Jointing device (1) according to the preceding claim, characterized in that a thickness (E) of the first jointing plate (4) is greater than or equal to, preferably strictly greater than, a thickness of the second jointing plate (4') of the jointing device (1), preferably greater than or equal to twice the thickness of the second jointing plate (4'), more preferably greater than or equal to three times the thickness of the second jointing plate (4'). Jointing device (1) for conveyor belt (2) according to the preceding claim, characterized in that the fixing means (5) comprise rod fixing means, preferably of the screw type, the fixing means each preferably comprising a head (5a) configured to cooperate with a part of the inserts (6, 7) and an anchoring section (5b), preferably provided with a thread, configured to cooperate with another part of the inserts (6, 7).Jointing device (1) for conveyor belt (2) according to the preceding claim, characterized in that the inserts (6, 7) configured to cooperate with a head (5a) of the fixing means (5) each comprise a washer (61, 71) pierced with the associated fixing opening bordered by a cup (62, 72). capable of housing the head (5a) of the fixing means (5) and the inserts (6, 7) configured to cooperate with an anchoring section (5b) of the fixing means (5) each comprise a cylindrical tubular part (63, 73) delimiting the associated fixing opening of which an internal cylindrical surface (64, 74) is capable of cooperating with the anchoring section (5b) of the fixing means (5), the internal cylindrical surface (64, 74) preferably comprising a thread.

14. Junction device (1) according to the preceding claim, characterized in that the first junction plate (4) comprises only threaded inserts (6) configured to cooperate with the threaded anchor sections (5b) of the fixing means (5).

15. Junction device (1) according to claim 13, characterized in that the first junction plate (4) comprises only inserts (6) configured to cooperate with the heads (5a) of the fixing means (5).

16. Junction device (1) according to any one of claims 10 to 15, the first junction plate (4) being in accordance with claim 7 or 8, characterized in that the through orifices (47) are each coaxial with the fixing openings of each pair of inserts (6, 7) associated with the first junction plate (4) and the second junction plate (4'), in the junction position.

17. Joint device (1) according to any one of claims 10 to 13 and 15, including claim 13, the first joint plate (4) being in accordance with claim 7 or 8, characterized in that a diameter of the through holes (47) is strictly less than a diameter of the fixing opening of the associated insert (6), preferably strictly less than an outside diameter of the head (5a) of the associated fixing element (5), preferably strictly less than a nominal diameter of the anchoring section (5b) of the associated fixing element (5), more preferably substantially equal to the thread root diameter of the thread of the anchoring section (5b) of the associated fixing element (5). Method for manufacturing a joining plate (4) according to any one of claims 1 to 8, characterized in that it comprises at least the following steps: manufacturing a continuous succession of a plurality of joining plates (4) in the form of a strip; and cutting, from said strip thus manufactured, joining plates (4) according to predetermined dimensions. Method for joining a first end portion and a second end portion of a conveyor belt (2) by a joining device (1) for a conveyor belt (2) according to any one of claims 9 to 18 comprising a first joining plate (4) according to any one of claims 1 to 8 and a second joining plate (4'), characterized in that it comprises at least: a step of covering by the first joining plate (4) and the second joining plate (4') each on a separate side of the end portions (21,22) of the conveyor belt (2) such that said conveyor belt is interposed vertically between the two joining plates (4, 4'), said first and second joining plates (4, 4') forming a first pair of wings (40) which is adapted to pinch the first end portion (21) of the conveyor belt (2) and a second pair of wings (42) which is adapted to pinch the second end portion (22) of the conveyor belt (2), > a step of inserting the second end of the conveyor belt (2) between two wings of the second pair of wings (42), a step of fixing the second end portion (22) of the conveyor belt (2) with the two wings of the second pair of wings (42) between which it is positioned, a step of inserting the first end portion (21) of the conveyor belt (2) between the two wings of the first pair of wings (40) a step of fixing the first end portion (21) of the conveyor belt (2) with the two wings of the first pair of wings (40) between which it is positioned.

Images