Method for manufacturing a belt

Abstract

The invention relates to a method for manufacturing, repairing or modifying a belt (1) for transporting, lifting or transmitting power, the belt (1) comprising at least one cleat (5) and a strip of material (2), the periphery of the strip of material (2) being defined by two opposite faces which are a first face (3a) and a second face (3b) and are connected by two longitudinal edges, the method comprising a step of manufacturing at least one portion of a cleat (5) by depositing successive layers on top of one another on the first face (3a) of the strip of material (2) by a depositing unit (6). This method is characterised in that the angle (7) between the successive layers and the first face (3a) of the strip of material (2) at the cleat (5) is greater than or equal to 10°. The invention also relates to a belt (1) obtained by the method according to the invention.

Description

[0001] DESCRIPTION

[0002] Title: Manufacturing process of a belt

[0003] Technical field

[0004] The present invention relates to a method for manufacturing a belt. The invention makes it possible in particular to manufacture belts comprising cleats that are particularly resistant to the forces experienced during use of the belt.

[0005] The invention finds a particularly advantageous application for the manufacture of conveyor, lifting or power transmission belts.

[0006] Prior art

[0007] Conveyor, lifting or power transmission belts, whether toothed or not, have many advantages: they are economical, light and silent, they absorb vibrations, shocks and transmission jolts, they are clean and require no maintenance, saving time, they do not derail, they also benefit from a significantly longer lifespan than the traditional chain transmission system, while offering mechanical performance similar to that of a chain.

[0008] Some applications require the presence of cleats on one side of the belt. These cleats can be useful for pushing material, in the case of a conveyor belt, for hanging a load in the case of a lifting belt, or for other applications.

[0009] The cleats are usually manufactured separately from the rest of the belt, using various known methods, such as machining or additive manufacturing. In a separate step, they are then integrated into the belt using fastening means, such as gluing, welding, mechanical fastening, etc.

[0010] Publication US 10457003 B2 proposes a method for manufacturing cleats directly on the belt, which avoids the integration step mentioned above. More precisely, it is an additive manufacturing method, in which the cleats are formed by depositing successive layers on the back of the belt, parallel to the back. The disadvantage of this method is that the attachment of the cleats to the belt, as well as the cleats themselves, are not strong enough for all applications, and there is a risk of detachment of the cleat, delamination or shearing of the layers forming the cleat, when the cleat is subjected to significant tensile forces generating shear, as well as, where appropriate, during its deformation when passing over the pulleys.

[0011] Statement of the invention

[0012] The present invention aims to overcome these drawbacks by proposing a method for manufacturing or modifying a conveyor, lifting or power transmission belt, said belt comprising at least one cleat and a strip of material, the strip of material extending in a longitudinal direction, the periphery of said strip of material being defined by two opposite faces, including a first face and a second face, connected by two longitudinal edges, including a first longitudinal edge and a second longitudinal edge, said method comprising a step of manufacturing at least part of a cleat by superimposing successive layers deposited on the first face of said strip of material by a depositing unit.

[0013] This method is particular in that the angle between said successive layers and said first face of the strip of material at said cleat is greater than or equal to Thanks to these provisions, the cleated belt can be manufactured quickly and efficiently, this particularly flexible method making it possible to manufacture cleats customized in terms of their dimensions and materials, the resistance of the cleat from its attachment to the strip of material to tensile and shear forces being improved. This method also makes it possible to repair a belt whose cleat has been torn off or too badly damaged, for example by a machine accident or because of a manufacturing problem. This method makes it easy to manufacture the cleat directly on the existing belt, providing a solid attachment of the cleat to the belt.For example, it is possible to perform a 3D scan of another, undamaged belt cleat and use this scan to create the new cleat.

[0014] The said angle may be greater than or equal to 40°, which further improves the resistance of the cleat and its attachment to the strip of material to tensile and shear forces.

[0015] The said angle may be less than or equal to 75°, which in certain cases ensures that the successive layers forming the cleat can hold by themselves on the strip of material, without the use of additional support while waiting for them to harden.

[0016] Said angle may be greater than or equal to 85°, which allows maximum resistance to the tensile and shear forces of the cleat and its attachment to the strip of material.

[0017] During the step of manufacturing said at least one cleat, the layers can rest at least partially on a printing support, said printing support being able to be removed after at least partial solidification of said cleat, which in certain cases makes it possible to print the cleats at a significant angle relative to the strip of material, and therefore to obtain optimal resistance. When depositing the successive layers, said depositing unit can be moved in a back-and-forth movement parallel to the longitudinal edges of the strip of material, which allows better resistance of the cleat to tensile and shear forces.

[0018] When depositing successive layers, said depositing unit is moved in a back-and-forth movement perpendicular to the longitudinal edges of the strip of material, which allows a more homogeneous distribution of the forces undergone by the cleat over the width of the belt.

[0019] The belt may have, on its second face, separate notches of regular pitch to form a notched face arranged to engage a notched pulley, which allows the belt to be used for different applications.

[0020] During the step of manufacturing at least one cleat, said strip of material can be supported at least in part, at the level of said cleat, by a toothed pulley, which allows the cleat, during subsequent use of the belt, to undergo less stress when passing at the level of a pulley.

[0021] Said at least one cleat may comprise:

[0022] - two end elements made of a first material, in contact with the first face of said strip of material, located at the two ends of said cleat in the longitudinal direction of the strip of material,

[0023] - a central element made of a second material, in contact with the first face of said strip of material, located between the two end elements, said first material being more flexible than said second material after solidification, which allows absorption of forces by the end elements when the cleat passes over a pulley, this absorption not resulting in significant wear, the rigidity of the central element allowing the cleat to perform its function, for example pushing or lifting, by limiting its deformations.

[0024] The present invention also relates to a conveyor, lifting or power transmission belt, comprising at least one cleat and a strip of material, the strip of material extending in a longitudinal direction, the periphery of said strip of material being defined by two opposite faces, including a first face and a second face, connected by two longitudinal edges, including a first longitudinal edge and a second longitudinal edge, said cleat comprising a superposition of layers arranged on the first face of said strip of material,

[0025] This belt is particular in that the angle between said successive layers and said first face of the strip of material at said cleat is greater than or equal to 10°.

[0026] Thanks to these provisions, the cleated belt can be manufactured quickly and efficiently, this particularly flexible process allowing the manufacture of cleats customized in terms of their dimensions and materials, the resistance of the cleat from its attachment to the material strip to tensile and shear forces being improved.

[0027] Brief description of the drawings

[0028] The present invention and its advantages will become more apparent from the following description of several embodiments given by way of non-limiting examples, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a section of a belt being manufactured according to one embodiment of the invention, the printing angle being 45°, Figure 2 is a side view of the belt section of Fig. 1, Figure 3 is a side view of a belt being manufactured according to one embodiment of the invention in which a printing medium is used, the printing angle being 45°, Figure 4 is a side view of a section of a belt being manufactured according to one embodiment of the invention in which a printing medium is used, the printing angle being 60°,Figure 5 is a side view of a section of a belt being manufactured according to an embodiment of the invention in which a printing medium is not used, the printing angle being 60°, Figure 6 is a side view of a section of a belt being manufactured according to an embodiment of the invention in which a printing medium is used, the printing angle being 90°, Figure 7 is a side view of a section of a belt being manufactured according to an embodiment of the invention in which a printing medium is not used, the printing angle being 90°, Figure 8 is a side view of a belt section manufactured according to an embodiment of the invention in which the cleat comprises a central element and two end elements, Figure 9 is a perspective view of the belt section of Fig. 8,Figure 10 is a side view of a belt section manufactured according to an embodiment of the invention in which the cleat comprises a central element and two end elements, said section being curved to rest on a not shown toothed pulley, Figure 11 is a perspective view of the belt section of Fig. 10, Figure 12 is a side view of a belt section manufactured according to an embodiment of the invention, in which the printing angle is 45°, and the depositing unit is moved in a back and forth movement perpendicular to the longitudinal edges of the web of material, Figure 13 is a perspective view of the belt section of Fig. 12, Figure 14 is a side view of a belt section manufactured according to an embodiment of the invention, in which the printing angle is 45°, the belt section being supported by a pulley,Figure 15 is a perspective view of the belt section of Fig. 14.,

[0029] Description of the embodiments

[0030] In the illustrated embodiments, identical elements or parts bear the same reference numbers. Furthermore, terms which have a relative meaning, such as vertical, horizontal, right, left, front, rear, above, below, etc. must be interpreted under normal conditions of use of the invention, and as shown in the figures. Furthermore, the geometric positions indicated in the description and the claims, such as “perpendicular”, “parallel”, “symmetrical” are not limited to the strict sense defined in geometry, but extend to geometric positions which are close, that is to say which accept a certain tolerance in the technical field considered, without influence on the result obtained. This tolerance is notably introduced by the adverb “substantially”, without this term necessarily being repeated before each adjective.

[0031] With reference to the figures, the method according to the invention makes it possible to manufacture or modify a conveyor, lifting or power transmission belt 1. This method makes it possible either to manufacture a new belt, comprising at least one cleat, or to repair an existing belt, or to modify an existing belt. Repair may be necessary in the event of a torn or damaged cleat, which needs to be replaced.

[0032] The belt 1 may constitute a transmission belt, a conveyor belt, a conveyor, a lifting belt or the like. It may be closed in an endless loop, or open. The belt 1 manufactured according to the invention consists of a strip of material 2 of defined length, in which a traction core comprising one or more traction cables may be embedded. The material constituting said strip of material 2 may be chosen from thermoplastic materials and, by way of non-limiting example, polyurethanes (TPU or PU), polyethylenes or polyesters, which combine the elastic properties of elastomers and the mechanical properties of plastics. Thus, the main property of polyurethanes is its excellent resistance to abrasion and wear, which makes it a preferred material for belts in general and synchronous belts in particular, i.e. toothed belts.

[0033] The circumference of the belt 1 comprises two opposite faces, including a first face 3a and a second face 3b, connected by two longitudinal edges, including a first longitudinal edge 4a and a second longitudinal edge 4b.

[0034] In the context of the present invention, a longitudinal direction Y is defined as a direction parallel to the planes formed by the faces 3a, 3b and to the longitudinal edges 4a, 4b of the strip of material 2. This definition remains valid in the case where the faces 3a, 3b are curved, for example when the belt 1 is partially wound around a pulley, an approximation being made by considering that on a longitudinal section of the belt of reduced length the faces 3a, 3b form a plane. A transverse direction X is also defined, perpendicular to the longitudinal direction Y and parallel to the faces 3a, 3b, according to the orthonormal reference frame with reference to FIG. 1.

[0035] The belt 1 comprises at least one cleat 5, and preferably a plurality of cleats 5 distributed along the length of the belt 1 at regular or irregular intervals. In the remainder of the description, the method according to the invention will be described for the manufacture of a cleat 5, without this limiting the invention, the manufacture of additional cleats 5 being able to be carried out by repeating the operations for manufacturing this cleat 5. The term "cleat" refers to any three-dimensional part, whatever the shape, forming a relief on the face 3a of the belt 1, which is opposite the face 3b in contact with the pulleys, rollers, rollers and other members rotating the belt.

[0036] The cleat 5 is manufactured at least partially, preferably entirely, by depositing successive layers, in other words by three-dimensional printing, on the first face 3a of the strip of material 2 by a depositing unit 6.

[0037] In some cases, the cleat 5 comprises one or more prefabricated elements, such as inserts, made for example from a metallic material. To manufacture such a cleat, the deposition of successive layers can be stopped at the appropriate time, then the insert can be placed on the deposited layers, and finally the deposition of the following layers can resume. This makes it possible to very easily produce cleats composed of several materials, and in particular comprising inserts entirely surrounded by the main material of the cleat or partially overmolded.

[0038] The material composing the layers of the cleat 5 can be chosen from thermoplastic materials and, by way of non-limiting example, polyurethanes (TPU or PU), polyethylenes or polyesters, which combine the elastic properties of elastomers and the mechanical properties of plastics. Thus, the main property of polyurethanes is its excellent resistance to abrasion and wear, which makes it a preferred material. The cleat 5 can be made of a material identical to the strip of material 2, or different, for example a material more rigid than that of the strip of material 2.

[0039] In the method according to the invention, the successive layers of the cleat 5 and the first face 3a of the strip of material 2 at the level of the cleat 5 are intersecting, and form a non-zero printing angle 7. The belt being flexible, the first face 3a does not always define a plane allowing the printing angle 7 to be observed. The printing angle 7 is then considered after having brought the first face 3a, at least at the level of the cleat 5, into a plane.

[0040] The fact that the printing angle 7 is non-zero allows a plurality of layers forming the cleat 5 to be in contact with the rest of the belt, which allows for a more solid fixing of the cleat 5 and limits the risks of complete or partial tearing of the cleat 5 when it is subjected to shearing and tensile forces. In addition, the fact that the successive layers are inclined makes it possible to oppose delamination or separation of the layers from each other under the effect of a tensile force.

[0041] The printing angle 7 preferably has a value greater than or equal to 10°, which makes it possible to obtain the advantages of the invention.

[0042] In order to increase the number of layers of the cleat 5 in contact with the material strip 2, it is advantageous to use a high printing angle 7. It is thus possible to use a printing angle 7 greater than or equal to 40°, for example 45°, as illustrated in figs. 1 to 3 and 12 to 15.

[0043] The printing angle 7 can be further increased to be greater than or equal to 85°, for example 90°, as illustrated in Figs. 6 and 7, which allows the largest possible number of layers forming the cleat 5 to be in contact with the material web 2 and the layers to be perpendicular to the tensile force. In particular, when the cleat 5 is of rectangular section, a printing angle 7 of 90° allows all the layers forming the cleat 5 to be in contact with the material web 2, which results in a particularly strong attachment of the cleat 5 to the material web 2, an ideal solution for maximizing the shear strength of the cleat 5.

[0044] However, the use of a particularly high printing angle 7 may present production difficulties, the successive layers possibly not holding by themselves on the strip of material 2. To avoid this problem, a printing angle 7 less than or equal to 75°, for example 60°, may be chosen, as illustrated in figs. 4 and 5.

[0045] The cleat 5 has for example an elongated shape with a constant rectangular section, extending over the first face 3a of the strip of material in the transverse direction X. Other shapes of cleats 5 are of course possible, the additive manufacturing process making it possible to obtain a wide variety of geometries such as, for example, elongated shapes with a constant trapezoidal or semi-cylindrical section, or a complex shape comprising for example through openings perpendicular or parallel to the first face 3a, or even metal inserts emerging or not from the cleat 5.

[0046] In order to use a large printing angle 7, for example greater than or equal to 60°, during the step of manufacturing the cleat 5, a printing support 8 can be used, as illustrated in FIGS. 3, 4 and 6. During the deposition of the successive layers of the cleat 5, and at least of the first layer(s), these layers rest at least partially on the printing support 8, which makes it possible to hold them in position.

[0047] The printing support 8 may have, in contact with the layers of the cleat 5, a contact surface 8a. The contact surface 8a may be flat, or take another shape depending on the desired shape for the cleat 5, the flat surface 8a forming a mold. After solidification, at least partially, of the cleat 5, when the cleat 5 can stand by itself without the printing support 8, the printing support 8 is removed. The flat surface 8a is therefore preferably made of a material that does not adhere to the material used to form the layers of the cleat 5, for example Teflon, silicone, or any other known non-stick coating.

[0048] In a particular embodiment of the invention, not shown, during the deposition of the successive layers of the cleat 5, the deposition unit 6 is moved in a back-and-forth movement parallel to the longitudinal edges 4a, 4b of the strip of material 2, in the longitudinal direction Y. In this embodiment, whatever the printing angle 7, the layers of the cleat 5 are parallel to the longitudinal direction Y. This allows the interfaces between the layers of the cleat 5 to undergo less tensile force, which in certain applications reduces the risks of detachment of these layers.

[0049] Alternatively, in a preferred embodiment of the invention, illustrated in Figs. 1 to 7 and 12 to 13, during the deposition of the successive layers of the cleat 5, the deposition unit 6 is moved in a back-and-forth movement perpendicular to the longitudinal edges 4a, 4b of the strip of material 2, in the transverse direction X. In this embodiment, whatever the printing angle 7, the layers of the cleat 5 are parallel to the transverse direction X. This allows the forces undergone by the interface between the cleat 5 and the strip of material 5 to be equally distributed over the entire length of the cleat 5, which in certain applications makes it possible to avoid non-uniform wear of the cleat 5 along the transverse direction X.

[0050] As illustrated in fig. 1 and 8 to 11, the belt 1 may comprise, on its second face 3b, notches 9 separated by a regular pitch to form a notched face arranged to mesh with a notched pulley 10 of a mechanical transmission. The notches 9 may be made of the same material as the strip of material 2. In certain embodiments, the notches 9 comprise a finishing layer in a separate material, such as polyamide, which is harder and / or structured, in order to give the notches 9 better resistance to abrasion by reducing the coefficient of friction of contact with a pulley.

[0051] Preferably, when the belt 1 has notches 9, the cleat 5 can be manufactured while the strip of material 2 is supported, at least in part, at the level of the cleat 5, by a toothed pulley 10. The cleat 5 is in this case preferably positioned between two notches 9. This manufacturing method allows that during the subsequent use of the belt 1, the layers of the cleat 5 are formed in order to undergo less shearing forces when they pass at the level of a toothed pulley 10. This arrangement therefore makes it possible to increase the resistance of the cleats 5 over time, while guaranteeing a uniform curvature of the belt 1, even at the level of the cleats 5, a guarantee of precision of the meshing of the belt 1 in a pulley.

[0052] In a particular embodiment illustrated in fig. 8 to 11, the cleat 5 comprises a central element 5a, surrounded by two end elements 5b. The end elements 5b and the central element 5a follow one another, each in contact with the strip of material 2, in the longitudinal direction Y. The material of the end elements 5b is more flexible than the material of the central element 5a. Thus, when the cleat 5 passes at the level of a toothed pulley 10, the end elements 5b follow the bending of the belt and absorb the majority of the shear forces. Their relative flexibility then allows them to better absorb these shear forces, not to harm the flexibility of the belt, and to have good resistance over time.The central element 5a, for its part, undergoes less shearing forces when passing at the level of a pulley 10, and has the necessary rigidity for the cleat 5 to be able to perform its function, for example pushing material or lifting.

[0053] The end elements 5b may have a triangular section, or in the form of a weld bead, according to a longitudinal section, which gives them good adhesion to the strip of material 2, their upper part being able to deform easily in the longitudinal direction in the manner of a hinge. Of course, other shapes of end elements 5b can be envisaged, depending on the applications.

[0054] When the cleat is composed of several elements of different materials, it may be provided that at least one of these elements is not produced by depositing successive layers, but that it is for example produced separately, then integrated into the belt by gluing, welding, overmolding, or mechanically. The present invention is of course not limited to the embodiments described but extends to any modification and variant obvious to a person skilled in the art within the limits of the appended claims. In addition, the technical characteristics of the different embodiments and variants mentioned above may be, in whole or for some of them, combined with each other.

Claims

CLAIMS

1. Method of manufacturing, repairing or modifying a conveying, lifting or power transmission belt (1), said belt (1) comprising at least one cleat (5) and a strip of material (2), the strip of material (2) extending in a longitudinal direction (Y), the periphery of said strip of material (2) being defined by two opposite faces, including a first face (3a) and a second face (3b), connected by two longitudinal edges, including a first longitudinal edge (4a) and a second longitudinal edge (4b), said method comprising a step of manufacturing at least part of a cleat (5) by superimposing successive layers deposited on the first face (3a) of said strip of material (2) by a depositing unit (6), characterized in that the angle (7) between said successive layers and said first face (3a) of the strip of material (2) at said cleat (5) is greater than or equal to 10°.

2. A method according to claim 1, wherein said angle (7) is greater than or equal to 40°.

3. Method according to one of claims 1 to 2, wherein said angle (7) is less than or equal to 75°.

4. A method according to claim 1, wherein said angle (7) is greater than or equal to 85°.

5. Method according to one of claims 1 to 4, wherein during the step of manufacturing said at least one cleat (5), the layers rest at least partially on a printing support (8), said printing support (8) being removed after at least partial solidification of said cleat (5).

6. Method according to one of claims 1 to 5, wherein during the deposition of the successive layers, said deposition unit (6) is moved in a back-and-forth movement parallel to the longitudinal edges (4a, 4b) of the strip of material (2).

7. Method according to one of claims 1 to 5, wherein during the deposition of the successive layers, said deposition unit (6) is moved in a back-and-forth movement perpendicular to the longitudinal edges (4a, 4b) of the strip of material (2).

8. Method according to one of claims 1 to 7, in which the belt (1) comprises, on its second face (3b), notches (9) separated by a regular pitch to form a notched face arranged to engage a notched pulley.

9. Method according to claim 8, wherein during the step of manufacturing at least one cleat (5), said strip of material (2) is supported at least in part, at the level of said cleat (5), by a toothed pulley.

10. Method according to one of claims 1 to 9, in which said at least one cleat (5) comprises: - two end elements (5b) made of a first material, in contact with the first face (3a) of said strip of material (2), located at the two ends of said cleat in the longitudinal direction of the strip of material (2), - a central element (5 a) made of a second material, in contact with the first face (3a) of said strip of material (2), located between the two end elements (5b), said first material being more flexible than said second material after solidification.

11. Belt (1) for transport, lifting or power transmission, comprising at least one cleat (5) and a strip of material (2), the strip of material (2) extending in a longitudinal direction (Y), the periphery of said strip of material (2) being defined by two opposite faces, including a first face (3a) and a second face (3b), connected by two longitudinal edges, including a first longitudinal edge (4a) and a second longitudinal edge (4b), said cleat (5) comprising a superposition of layers arranged on the first face (3a) of said strip of material (2), characterized in that the angle (7) between said successive layers and said first face (3a) of the strip of material (2) at said cleat (5) is greater than or equal to 10°.

Images