Method for manufacturing a conveyor or power transmission belt and associated mold

Abstract

The invention relates to a mold (1) for manufacturing a belt comprising: - two end elements (8a, 8b) having at least one notch (9), such that the belt (2) has at each of its longitudinal ends (5a, 5b) at least one tooth (10), said teeth (10) being complementary so as to interlock when the longitudinal ends (5a, 5b) of the belt (2) are joined, and - at least one mold rod (11) arranged to pass through said at least one tooth (10) at the level of the neutral fiber plane of said belt (2). This mold comprises four retaining profiles (13) arranged perpendicular to the side plate (6a, 6b), configured to retain a tension cable (12) extending between the two mold rods (11) in the plane of the neutral fiber of the belt (2) at the level of a principal area (2a) of the belt (2). Figure for the abridged version: Fig. 1

Description

Title of the invention: Method for manufacturing a conveyor or power transmission belt and associated mold. Technical field

[0001] The present invention relates to a method for manufacturing a belt. In particular, the invention makes it possible to manufacture a belt with improved mechanical properties.

[0002] The invention finds a particularly advantageous application for the manufacture of conveyor, lifting, or power transmission belts. Previous technique

[0003] Conveying, lifting or power transmission belts, toothed or not, have many advantages: they are economical, light and quiet, they dampen vibrations, shocks and transmission jolts, they are clean and require no maintenance, thus saving time, they do not derail, they also have a significantly longer lifespan than the classic chain transmission system, while offering similar mechanical performance to that of a chain.

[0004] The belts are commonly reinforced with tension cables made of steel, Kevlar®, carbon, fiberglass or similar.

[0005] Document WO2019 / 162455, filed by the applicant, proposes a power transmission belt comprising continuous cables and a link connecting the ends of the belt to form a closed loop. The presence of this link has the disadvantage of creating unevenness in the belt along its length, and therefore uneven wear over time. Furthermore, the link presents problems related to its weight when the belt is used at high speeds. Finally, this belt, conventionally manufactured by molding, requires the use of a different mold for each belt length.

[0006] Document EP2949965, also filed by the applicant, proposes a belt solution whose ends are attached to a central part by welding. This welding creates a point of weakness on the belt, therefore it is not suitable for use in power transmission. Description of the invention

[0007] The present invention aims to overcome these drawbacks by providing a mold for manufacturing a conveyor or power transmission belt comprising: - at least one side plate, configured to define a lateral edge of said belt, - a lower plate and an upper plate, extending parallel to each other, and configured to define respectively the lower and upper faces of said belt, - two end elements configured to each define a longitudinal end of the belt, each end element having a section comprising at least one notch, so that the belt has at each of its longitudinal ends at least one tooth, said teeth being complementary so as to interlock when the two longitudinal ends of the belt are joined, and - at the notches of each end element, at least one mold shank disposed perpendicular to the side plate, said mold shank being disposed so as to pass through said at least one tooth at the plane of the neutral fiber of said belt.

[0008] The mold according to the invention is particular in that it further comprises at least one retaining profile disposed against the lower plate in the vicinity of one of the end elements, one retaining profile disposed against the lower plate in the vicinity of the other end element, one retaining profile disposed against the upper plate in the vicinity of one of the end elements, and one retaining profile disposed against the upper plate in the vicinity of the other end element, said retaining profiles being disposed perpendicular to the side plate, said retaining profiles being configured to retain at least one cable forming a loop around the two mold rods and extending between the two mold rods in the plane of the neutral fiber of the belt at the level of a main area of ​​the belt extending between the retaining profiles.

[0009] Thanks to these arrangements, a belt can be obtained in which the tension cables are mostly arranged in the plane of the belt's neutral axis, and when the belt is closed by means of a locking rod passing through the loops of these cables, the locking rod is also in the plane of the belt's neutral axis. The mechanical performance of the belt is thus improved, and it can be used, in particular, for power transmission at high speeds. Furthermore, the mold allows for simple and rapid belt manufacturing and offers flexibility in length, thus enabling the use of a single mold for different belt lengths.

[0010] At least the retaining profiles arranged against the top plate can be configured to become an integral part of the belt after demolding, which avoids having a discontinuity in the material of the belt at the location of these retaining profiles, and therefore a point of the belt to be reinforced, which adds steps to the manufacture of the belt, and often does not allow for obtaining satisfactory resistance.

[0011] Said lower plate of the mold can be configured so that the belt has, on its lower face, notches separated by a regular pitch to form a toothed face arranged to mesh with toothed pulleys of a mechanical transmission, said lower plate having, at each spacing between two notches of the belt, a retaining profile, which is a simple and effective means of implementing the invention in the context of manufacturing toothed belts.

[0012] For each mold rod, the distance between said mold rod and the nearest retaining profile of said mold rod may be less than or equal to said pitch, which makes it possible to avoid generating high local rigidity of the belt, and degrading its mechanical performance.

[0013] Said mold may include a means for adjusting the gap between said end elements, which makes it possible to produce belts of different lengths using a single mold.

[0014] The present invention also relates to a method for manufacturing a conveyor or power transmission belt using a mold, according to the invention, said method comprising the following steps: - installation of at least one traction cable in the mold, said traction cable forming at least one loop around two mold rods, each positioned at one of the end elements, so as to extend between said two mold rods, said traction cable being held, at a main area of ​​the belt extending between the retaining profiles, in the plane of the neutral fiber of the belt, by said retaining profiles, - injection of a main material into the mold, - demolding of the belt.

[0015] Thanks to these arrangements, a belt can be obtained in which the tension cables are mostly arranged in the plane of the belt's neutral axis, and when the belt is closed by means of a locking rod passing through the loops of these cables, the locking rod is also in the plane of the belt's neutral axis. The mechanical performance of the belt is thus improved, and it can be used, in particular, for power transmission at high speeds. Furthermore, the mold allows for simple and rapid belt manufacturing and offers flexibility in length, thus enabling the use of a single mold for different belt lengths.

[0016] During the demolding step, at least two retaining profiles positioned against said upper plate can be removed from the mold and can be an integral part of the belt, thus avoiding a discontinuity in the belt material at the location of these retaining profiles, and therefore a point in the belt at strengthening, which adds steps to the belt manufacturing process, and often does not allow for satisfactory strength.

[0017] Said retaining profiles forming an integral part of the belt can be made of said main material, which is a simple and effective means of implementing the invention.

[0018] Said manufacturing process may include the following steps after the demolding step: - transverse alignment of at least two teeth located at the two longitudinal ends of said belt, and - insertion of a locking rod inside said at least two loops located in said at least two teeth to assemble the two longitudinal ends of the belt and form a closed belt, which makes it possible to obtain a closed belt whose mechanical resistance is improved.

[0019] After hardening of the main material, before the demolding step, the process may include the following steps: - opening of the mold to include a textile on the lower and / or upper surface of said belt, - applying pressure and / or heating the mold, in order to fix said textiles to the main material of the belt, This allows certain properties to be given to the surfaces of the belt and / or to modify its aesthetics and / or to increase its resistance.

[0020] The present invention further relates to a method for manufacturing a plurality of secondary belts from a primary belt, comprising the following steps: - manufacturing of said primary belt according to the invention, said primary belt comprising at least one longitudinal channel without a traction core, - cutting said primary belt at the level of said at least one longitudinal channel into a plurality of secondary belts.

[0021] Thanks to these provisions, several belts with the advantages detailed above can be manufactured quickly, in a reduced number of manufacturing steps. Brief description of the drawings

[0022] 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:

[0023] [Fig.1] [Fig.1] is a top view of a mold according to a preferred embodiment of the invention,

[0024] [Fig.2] [Fig.2] is a side view of the mold of [Fig.1],

[0025] [Fig.3] [Fig.3] is an enlarged view of a detail of [Fig.2],

[0026] [Fig.4] [Fig.4] is a top view of a belt manufactured by a process of manufacturing corresponding to a preferred embodiment of the invention,

[0027] [Fig.5] [Fig.5] is a side view of the belt of [Fig.4],

[0028] [Fig.6] [Fig.6] is an enlarged view of a detail of [Fig.5],

[0029] [Fig.7] [Fig.7] is a perspective view of the belt of [Fig.4], and

[0030] [Fig.8] [Fig.8] is a perspective view of the longitudinal ends of the belt of the [Fig.4], assembled together to form a closed belt. Description of the implementation methods

[0031] In the illustrated embodiments, identical elements or parts bear the same reference numbers. Furthermore, terms with a relative meaning, such as vertical, horizontal, right, left, front, back, above, below, etc., should be interpreted under normal conditions of use of the invention, as shown in the figures. The X, Y, and Z axes are defined by an orthonormal coordinate system illustrated in [Fig. 1]. Moreover, the geometric positions indicated in the description and claims, such as "perpendicular," "parallel," and "symmetrical," are not limited to the strict sense defined in geometry, but extend to geometric positions that are close, that is, that allow a certain tolerance within the technical field considered, without affecting the result obtained.This tolerance is notably introduced by the adverb "sensible", without this term necessarily being repeated before each adjective.

[0032] With reference to the figures, the mold 1 according to the invention makes it possible to manufacture a conveyor belt 2 or a power transmission belt.

[0033] The circumference of the belt 2, illustrated by way of example in Figures 4 to 8, comprises two opposite faces, including a lower face 3a and an upper face 3b, connected by two longitudinal edges, including a first lateral edge 4a and a second lateral edge 4b. The belt 2 also comprises two longitudinal ends 5a, 5b, which can be joined together to form a closed belt 2.

[0034] The main material of the belt 2 can be chosen from thermoplastic materials and, by way of non-limiting example, from polyurethanes (TPU or PU), polyethylenes, polyesters, or even rubber (for example of type EPDM for Ethylene Propylene Diene Monomer, or CR for chloroprene), which combine the elastic properties of elastomers and the mechanical properties of plastics.

[0035] The mold 1 comprises at least one side plate 6a, optionally two side plates 6a, 6b, parallel to each other, and whose dimensions and shape are configured to define the side edges 4a, 4b of the belt 2. The side plates 6a, 6b are on the [Fig.1] perpendicular to the X axis.

[0036] The mold 1 also includes a lower plate 7a and an upper plate 7b, the dimensions and shape of which are configured to define the lower face 3a and upper face 3b of the belt 2. The lower plate 7a and upper plate 7b are parallel to each other and perpendicular to the side plates 6a, 6b. The lower plate 7a and upper plate 7b are, in [Fig. 1], perpendicular to the Z-axis.

[0037] The mold 1 further comprises two end elements 8a, 8b, whose dimensions and shape are configured to define the longitudinal ends 5a, 5b of the belt 2. The end elements 8a, 8b are not planar, but they extend mainly along a plane perpendicular to the side plates 6a, 6b, 7a, 7b, that is to say along a plane perpendicular, on the [Fig.1], to the Y axis.

[0038] The end elements 8a, 8b have a cross-section comprising at least one notch 9. The notches 9 allow teeth 10 to be formed at the longitudinal ends 5a, 5b of the belt 2. The teeth 10 of the two longitudinal ends 5a, 5b have complementary shapes, so that the teeth 10 of the longitudinal ends 5a, 5b can interlock with each other when the two longitudinal ends 5a, 5b are joined together, to form a closed belt 2 with continuity of material on its lower face 3a and upper face 3b. This interlocking is illustrated by way of example in [Fig. 8].

[0039] The mold 1 further comprises, at each end element 8a, 8b, and more precisely at the slots 9, at least one mold rod 11. The mold rod 11 is arranged perpendicular to the side plates 6a, 6b, that is, along the X-axis. The mold rod 11 is positioned so that, during the formation of the belt 2 in the mold 1, the mold rod 1 passes through the teeth 10 of the belt 2 formed by the slots 9 of the end elements 5a, 5b. Moreover, and for reasons explained below, the mold rod 11 is arranged so as to be included in the plane of the neutral fiber of the belt 2. Since the mold rod 11 is a physical object, it naturally has a thickness and cannot, strictly speaking, be inscribed in a geometric plane.For the purposes of the present invention, the expression "the mold rod 11 is arranged in a plane" means that the mold rod 11 extends mainly along this plane, and very slightly around this plane, over a distance equal to the diameter of the mold rod 11.

[0040] The role of the mold rods 11 is to hold one or more traction cables 12 in the mold 1 before proceeding with the injection of the main material of the belt 2. The traction cable 12 forms loops around the mold rods 11 arranged at the ends of the mold 1, and is thus arranged in the position it will occupy in the belt 2. Preferably, the traction cable 12 is arranged so as to form a loop at each of the teeth 10 of the belt 2.

[0041] The traction cables 12 can be made of steel, Kevlar, or materials offering better mechanical properties such as Vectran or Zylon.

[0042] In the example of Figures 1 and 4, a single traction cable 12 runs the entire width of the belt 2, moving back and forth from one end of the belt 2 to the other. This has the advantage of simplifying the tension adjustment of the traction cable 12. In other embodiments, several traction cables 12 can be used in a single belt.

[0043] Before or after demolding, the mold pins 11 are preferably removed from the teeth 10 of the belt 2, the loops formed by the tension cable 12 being held in place by the material of the teeth 10. The space previously occupied by the mold pins 11 can then be occupied by a belt locking pin, which can pass through the loops of the teeth 10 at both longitudinal ends 5a, 5b of the belt 2 after the teeth 10 at both longitudinal ends 5a, 5b have interlocked with each other. The locking pin is thus located at the plane of the neutral axis of the belt 2, which allows for good mechanical performance, which is particularly relevant for a power transmission belt intended for use at high speeds.

[0044] The mold 1 further comprises at least four retaining profiles 13, of which at least two retaining profiles 13 are arranged against the lower plate 7a, and at least two retaining profiles 13 are arranged against the upper plate 7b. The retaining profiles 13 extend primarily in a direction perpendicular to the side plates 6a, 6b, i.e., along the X-axis of [Fig. 1]. The retaining profiles 13 preferably extend over the entire width of the lower plate 7a, or of the upper plate 7b respectively, along the X-axis. Of the two retaining profiles 13 arranged against the lower plate 7a, one retaining profile 13 is positioned near a first end element 8a, and the other retaining profile 13 is positioned near a second end element 8b.Similarly, on the two retaining profiles 13 arranged against the upper plate 7b, one retaining profile 13 is positioned near a first end element 8a, and the other retaining profile 13 is positioned near a second end element 8b. In this way, the retaining profiles 13 are able to hold, at a main area 2a of the belt 2, located between two end areas 2b of the belt 2, at least one cable 12 extending between the two stems of the mold 11 in the plane of the neutral fiber of the belt 2, as illustrated in [Fig. 5]. The end areas 2b of the belt 2 are therefore the areas located between the retaining profiles 13 and the longitudinal end 5a, 5b of the belt 2. the belt 2 closest to the retaining profile 13. In the case where more than two retaining profiles 13 are arranged against the lower plate 7a or against the lower plate 7b, the two retaining profiles 13 located closest to the longitudinal ends 5a, 5b are to be considered for defining the main area 2a and the end area 2b of the belt 2. In the case where the retaining profile 13 arranged against the lower plate 7a closest to a longitudinal end 5a, 5b is located at a different distance from this longitudinal end 5a, 5b than the distance separating the retaining profile 13 arranged against the upper plate 7b closest to this longitudinal end 5a, 5b, the retaining profile 13 located at a greater distance from the longitudinal end 5a, 5b is to be considered for defining the main area 2a and the end area 2b of belt 2.For example, in the embodiment illustrated in [Fig. 3], the end zone 2b extends from the retaining profile 13 disposed against the upper plate 7b, the retaining profile 13 disposed against the lower plate 7a being closer to the longitudinal end 5a.

[0045] Thus the mold 1 comprises at least four retaining profiles: a retaining profile 13 against the lower plate 7a and a profile 13 against the lower plate 7b, near each of the end elements 8a, 8b of the mold 1. The proximity of the ends allows the traction cable 12 to be in the plane of the neutral fiber of the belt 2 over the greatest possible length.

[0046] The retaining profiles 13 ensure that, at the level of the main area 2a of the belt 2, which covers most of the length of the belt 2, the traction cable(s) 12 are in the plane of the neutral fiber of the belt 2. For the purposes of the present invention, the expression "the traction cable 12 is arranged in a plane" means that the traction cable 12 extends mainly along this plane, and very slightly around this plane, over a distance equal to the diameter of the traction cable 12.

[0047] It therefore appears that the retaining profiles 13 must be positioned as close as possible to the end elements 8a, 8b of the mold. In the case of a toothed belt 2, as described below, the distance between the retaining profile 12 and the locking rod 11 is preferably less than or equal to the pitch of the belt 2, the pitch being, for example, between 2 and 20 mm. However, there is a limit imposed by the flow of the main material of the belt 2 into the mold. Indeed, if the retaining profile 13 is located too close to the mold rod 11, the cable 12 forms too large an angle between the main area 2a and the end area 2b of the belt. It is therefore preferable to establish a minimum distance between the mold rod 11 and the main area 2a of the belt 2.

[0048] In a preferred embodiment, at least two retaining profiles 13, for example the retaining profiles 13 arranged against the upper plate 7b, are configured to be an integral part of the belt 2. To achieve this, these retaining profiles 13 are made of a compatible material, or the same material, as the main material of the belt 2 that will be injected into the mold 1. Furthermore, these retaining profiles 13 are held in place relative to the rest of the mold 1 in such a way that they can be easily separated from it during demolding. For example, they can be held between the lower plate 7a, or upper plate 7b respectively, and the tension cable(s) 12, which can perform this function by virtue of their tension. It is also possible to use a temporary adhesive to bond the retaining profiles 13 to the rest of the mold 1. Integrating the retaining profiles 13 into the belt 2 avoids any discontinuity in the surface of the belt 2 at their location.Furthermore, this allows the mold 1 to be used for different lengths of belt 2, the retaining profiles 13 being able to be arranged in the mold 1 at different levels of the plates, and different retaining profiles 13 of different shapes can be used depending on the type of belt 2 which is manufactured.

[0049] It is also possible, within the scope of the present invention, for the retaining profile 13 to remain attached to the mold 1 after the belt 2 has been demolded. In this case, it is, for example, a metal part, or it can be formed by machining in the lower plate 7a and / or upper plate 7b. In this case, after demolding, a hole remains in the surface of the belt 2, which creates a weak point where the transmission cable 12 is exposed. This hole can be filled by adding material, preferably of the same type as the main material, and this filler material can be covered, along with the rest of the belt, by a layer of textile. The filler material can then be fused with the rest of the belt during the textile fixing step, during which the mold is heated and / or pressurized.

[0050] The retaining profile 13 preferably has a constant section over its entire length, which can for example be parallelepiped-shaped or triangular, with a larger attachment surface to the lower plate 7a, respectively upper plate 7b, or even rectangular.

[0051] In the embodiment illustrated in the figures, the mold 1 is configured to manufacture a belt having, on its lower face 3a, notches 14 separated by a regular pitch to form a toothed face arranged to mesh with toothed pulleys of a mechanical transmission. In this case, as illustrated in [Fig. 3], the lower plate 7a may have, at each spacing between two notches of the belt 2, a retaining profile 13. These retaining profiles 13 are therefore an integral part of the mold 1 and are not intended to be integrated into the belt 2. The presence of retaining profiles 13 at each spacing between two notches, allows the lower plate 7a to be used to make different lengths of belt, as will be explained below.

[0052] The mold 1 preferably includes a means for adjusting the gap between the end elements 8a, 8b. For example, as illustrated in [Fig. 1], one of the end elements 8b can be translationally movable along the side plates 6a, 6b, and lower and upper plates 7a and 7b, along the Y-axis, for example, via a rail system. Thus, a single mold 1 can be used to manufacture belts 2 of different lengths. These arrangements are particularly advantageous when the retaining devices 13 are also configured to be compatible with different belt lengths, for example, when they are, as described above, intended to be an integral part of the belt 2 and / or arranged along the entire length of the lower plate 7a.

[0053] In the example shown, the end element 8b is movable in translation relative to the lower plate 7a, which is configured to form the notches 14 of the belt 2. The end element 8b therefore has a shape corresponding to the notches 14 of the belt, to fit the surface of the lower plate 7a. Adjusting the length of the belt 2 is thus possible in this case with a pitch equal to the pitch of the notches 14.

[0054] In the examples shown, the lower plate 7a is configured to form a notched face, and the upper face 7b is flat. In other embodiments not shown, the mold 1 has flat lower plates 7a and upper plates 7b, and the retaining profiles 13 can all be designed to integrate the belt 2 after demolding.

[0055] The mold 1 preferably includes at least one inlet sprue 15a, through which the main material of the belt 2 is intended to be injected, and optionally an outlet sprue 15b, through which the excess main material can be discharged. The sprues 15a, 15b are preferably contained within at least one of the lower 7a and / or upper 7b plates of the mold. The sprues 15a, 15b preferably extend along the longest dimension of the belt 2, i.e., along the Y-axis. After demolding, the main material that has solidified in the sprues 15a, 15b is preferably cut away from the rest of the belt 2.

[0056] The mold 1 therefore makes it possible to manufacture a belt 2, by being used during a manufacturing process comprising the following steps:

[0057] - placement of at least one traction cable 12 in the mold 1, said cable of traction 12 forming at least one loop around two mold rods 11, each disposed at one of the end elements 8a, 8b, so as to extend between said two mold rods 11, said traction cable 12 being held, at the from a main zone 2a of the belt 2 extending between the retaining profiles 13, in the plane of the neutral fiber of the belt 2, by said retaining profiles 13, - injection of a main material into the mold 1, - demolding of belt 2, some retaining profiles 13 can then be removed from mold 1 in order to become an integral part of belt 2.

[0058] Before demolding, one or more textiles can be applied to the belt 2. These textiles can be used to reinforce the surface strength of the belt 2, or to improve its appearance. To do this, after the main material has solidified, the mold 1 can be opened to insert the required textile layers. The mold 1 is then closed and optionally subjected to pressure and / or heating. The temperature and / or pressure bond the textile to the main material.

[0059] After demolding, the teeth located at the two longitudinal ends can be aligned transversely, i.e., interlocked with each other to form a continuous closed belt. This assembly can then be locked by inserting a locking rod inside the loops formed by the traction cable(s) 12.

[0060] The mold 1 according to the invention can be used to manufacture a plurality of secondary belts from a primary belt. The primary belt is then manufactured during a single cycle of mold operation, and the secondary belts are produced by cutting the primary belt along its length, i.e., along the Y-axis. To do this, it is preferable to provide a longitudinal channel in the belt 2, at the point of the cut, free of a tension cable 12.

[0061] The present invention is 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. Furthermore, the technical features of the various embodiments and variants mentioned above may be combined, in whole or in part.

Claims

1. Demands Mold (1) for manufacturing a conveyor or power transmission belt (2) comprising: - at least one side plate (6a, 6b), configured to define a side edge (4a, 4b) of said belt (2), - a lower plate (7a) and an upper plate (7b), extending parallel to each other, and configured to define respectively the lower (3a) and upper (3b) surfaces of said belt (2), - two end elements (8a, 8b) configured to each define a longitudinal end (5a, 5b) of the belt (2), each end element (8a, 8b) having a cross-section comprising at least one notch (9), such that the belt (2) has at each of its longitudinal ends (5a, 5b) at least one tooth (10), said teeth (10) being complementary so as to interlock when the two longitudinal ends (5a, 5b) of the belt (2) are joined, and - at the slots (9) of each end element (8a, 8b), at least one mold rod (11) arranged perpendicular to the side plate (6a, 6b), said mold rod (11) being arranged so as to pass through said at least one tooth (10) at the plane of the neutral fiber of said belt (2), characterized in that it further comprises at least one retaining profile (13) disposed against the lower plate (7a) in the vicinity of one of the end elements (8a), one retaining profile (13) disposed against the lower plate (7a) in the vicinity of the other end element (8b), one retaining profile (13) disposed against the upper plate (7b) in the vicinity of one of the end elements (8a), and one retaining profile (13) disposed against the upper plate (7b) in the vicinity of the other end element (8b), said retaining profiles (13) being disposed perpendicular to the side plate (6a, 6b), said retaining profiles (13) being configured to retain at least one traction cable (12) forming a loop around the two mold rods (11) and extending between the two mold rods (11) in the plane of the neutral axis of the belt (2) at the level of a main zone (2a) of the belt (2) extending between the retaining profiles (13).

2. Mold (1) according to claim 1, characterized in that at least the retaining profiles (13) arranged against the upper plate (7b) are configured to be an integral part of the belt (2) after demolding.

3. Mold (1) according to any one of claims 1 to 2, characterized in that said lower plate (7a) of the mold (1) is configured so that the belt (2) has, on its lower face (3a), notches (14) separated by a regular pitch to form a toothed face arranged to mesh with toothed pulleys of a mechanical transmission, said lower plate (7a) having, at each spacing between two notches (14) of the belt (2), a retaining profile (13).

4. Mold (1) according to claim 3, characterized in that for each mold rod (11), the distance between said mold rod (11) and the retaining profile (13) closest to said mold rod (11) is less than or equal to said pitch.

5. Mold (1) according to any one of claims 1 to 4, comprising a means for adjusting the gap between said end elements (8a, 8b).

6. A method for manufacturing a conveyor or power transmission belt (2) using a mold (1), according to any one of claims 1 to 5, said method comprising the following steps: - placing at least one traction cable (12) in the mold (1), said traction cable (12) forming at least one loop around two mold rods (11) each disposed at one of the end elements (8a, 8b), so as to extend between said two mold rods (12), said traction cable (12) being held, at a principal area (2a) of the belt (2) extending between the retaining profiles (13), in the plane of the neutral fiber of the belt (2), by said retaining profiles (13), - injecting a principal material into the mold (1), - demolding the belt (2).

7. A manufacturing method according to claim 6, characterized in that during the demolding step, at least two retaining profiles (13) arranged against said upper plate (7b) are removed from the mold (1), and are an integral part of the belt (2).

8. A manufacturing method according to any one of claims 6 to 7, characterized in that said retaining profiles (13) forming an integral part of the belt (2) are made of said main material.

9. A manufacturing method according to any one of claims 6 to 8, comprising the following steps after the demolding step: - transverse alignment of the at least two teeth (10) located at the two longitudinal ends (5a, 5b) of said belt (2), and - insertion of a locking rod inside said at least two loops located in said at least two teeth (10) to assemble the two longitudinal ends (5a, 5b) of the belt (2) and form a closed belt.

10. A manufacturing process according to any one of claims 6 to 9, characterized in that after hardening of the main material, before the demolding step, the process comprises the following steps: - opening of the mold (1) in order to include a textile on the lower face (3a) and / or on the upper face (3b) of said belt (2), - pressurizing and / or heating of the mold (1), in order to fix said textiles to the main material of the belt (2).

11. A method for manufacturing a plurality of secondary belts from a primary belt, comprising the following steps: - manufacturing said primary belt (2) according to any one of claims 6 to 10, said primary belt comprising at least one longitudinal channel without a traction core (12), - cutting said primary belt (2) at the level of said at least one longitudinal channel into a plurality of secondary belts.

12. Conveying or power transmission belt (2) manufactured according to a manufacturing process according to any one of claims 6 to 11.

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