MXPA99001607A - Module having a retaining member for use in a modular conveyor mat - Google Patents

Abstract

Viewed in a conveying direction (12), the module (1) comprises a front side (2)and a rear side (3) having hinge loops (4) extending outwards relative to the module. The hinge loops are such that in two modules succeeding each other in the conveying direction, the hinge loops on the front side of one module can cooperate with the hinge loops on the rear side of the other module and that the hinge loops can be coupled by means of hinge pins extending transversely to the conveying direction. The module further comprises a top side (5), a bottom side (6) and two lateral sides (7,8) located opposite each other transversely to the conveying direction. The module comprises a recess (9) accommodating a retaining member (10), and a closing part of the retaining member is rotatable between a first position in which the closing part can retain a hinge pin received by the hinge loops transversely to the conveying direction and a second position in which the closing part can release a hinge pin received by the hinge loops transversely to the conveying direction. Both in said first and second position of the closing part and in intermediate positions of the closing part, the retaining member is located within boundary faces formed by the top side and the bottom side of the module. The retaining member is connected to the module such that loss of the retaining member is prevented.

Description

MODULE THAT HAS A RETENTION ELEMENT FOR USE IN A MODULAR CONVEYOR MESH Field of the Invention The present invention relates to a module for a modular mesh or conveyor belt, comprising a front side and a rear side having articulation loops extending outwardly relative to the module, such that in two modules which are subsequent each other in a transport direction, the articulation loops on the front side of a module can cooperate with the articulation loops on the rear side of the other module and can be coupled by means of articulation bolts which extend transversely with respect to the transport direction, the module further comprises an upper side, a lower side and two lateral sides located opposite each other transversely with respect to the direction of transport, and at least one recess accommodating a retaining element which is rotatable with respect to to an axis of rotation that extends through the retaining element, so that a part of the of the retaining element is revolving Ref.029548 between a first position in which the closing part can retain an articulation axis received by the articulation loops transversely with respect to the direction of transport and a second position in which the part The closure can release an articulation axis received by the articulation loops transversely with respect to the direction of transport. Such a module is used to compose a mesh or modular conveyor belt. A conventional modular conveyor belt or mesh is constructed from • several modules that follow one another in a transport direction and arranged or distributed collaterally in a transversal manner with respect to the transport direction. Seen in the direction of transport, the modules each have their front and rear sides provided with articulation loops. The articulation loops of the successive modules in the conveying direction cooperate and are coupled by means of articulation bolts which extend transversely with respect to the transport direction. For the retention of the articulation bolts transversely with respect to the transport direction, the modules that are located adjacent to the lateral sides of the mesh or conveyor belt are provided with a retaining element. A module that has a retention element is also referred to as the "end module", while the retention element in the assembled condition is also referred to as the retention mechanism. During the assembly of the mesh or conveyor belt, after two rows of modules succeeding one another in the transport direction have been coupled by means of a hinge shaft, the hinge axis is retained transversely with respect to the direction of transport between the retention elements of two end modules arranged or distributed over the opposite ends of the row of modules. The dismantling of the mesh or band proceeds in the reverse order. It is noted that an end module can comprise several retaining elements, for example when a mesh or conveyor belt comprises only one module, observed transversely with respect to the transport direction. In practice, a large number of requirements are imposed on the retention element of a final module. The operation of the retention element must be simple, that is, it must be possible to carry out the operation without some special indications and / or special tools. In addition, the retention element must not be susceptible to soiling. Furthermore, it should be possible to verify in a simple manner whether the retention element is in a position in which it retains an articulation axis received by the articulation loops. An additional requirement imposed on the retention element is that it does not have to be removed to make possible the adjustment or equipment of the articulation shaft, to reduce the risk that the retention element will be lost. In addition, the retaining element must not be susceptible to wear of the upper, lower and lateral side of the end module. Another important requirement imposed on the retention element is that the retention element must not prevent the assembly / disassembly of the mesh or conveyor belt. In practice it has been proven that it will be difficult to provide an extreme module that satisfies the above requirements. US Pat. No. 5,335,768 discloses a module whose retaining element comprises a pivoting arm between a first position in which it can retain an articulation axis received by the articulation loops transversely with respect to the transport direction because it closes the orifice of articulation, and a second position in which the arm can release an articulation axis received by the articulation loops transversely with respect to the direction of transport because the arm extends outwardly relative to the underside of the module. When the arm extends outward, there is a likelihood that the arm may be damaged, for example when a retaining element of an end or end module of a moving conveyor belt or belt accidentally takes the second position and is struck against a obstacle. This leads to a highly reduced reliability in the operation of the mesh or conveyor belt. In addition, the dismantling of a row of modules of a mesh or conveyor belt already arranged or placed on a slide of the conveyor apparatus, becomes difficult, because the mesh or conveyor in the location of the end or end module must to be lifted first from the slide of the conveyor apparatus to enable the operation of the retention element and / or the slide of the conveyor apparatus must be provided with a space in which the arm in the second position can be accommodated. Disassembly is problematic in particular when the mesh or conveyor belt is in tension. In addition, the underside of the module is provided with a relatively long opening adjacent to the arm, which increases the likelihood that the retention element will be blocked by the entry of the dirt. In addition, the portions of the wall located adjacent to the opening are relatively thin. Consequently, the probability that a part of the wall comes off by breaking when it catches under something, is quite substantial, which reduces the reliability in the operation of the retention element. The object of the invention is to provide a module of the type mentioned in the preamble, which satisfies the above requirements and does not have the above disadvantages. For this purpose, the module according to the invention is characterized in that both the first and second positions of the closing part and the intermediate positions of the closing part, the retaining element is located within the limiting faces or border formed by the upper side and the lower side of the module. Accordingly, it is provided that the retention element is more adequately protected against damage and / or fouling, which increases the reliability of the operation. It is further provided that during the disassembly of a row of modules of a mesh or conveyor belt already placed on a slide of the conveyor, the retainer can be operated without the final module having to be lifted from the slide. of the conveyor apparatus or without having to be otherwise created a space to accommodate the retention element. In another embodiment, the module according to the invention is characterized in that the axis of rotation intersects a central line extending through the articulation loops on the front or rear side of the module, preferably at an angle of between 10 ° and 80 °, more preferably between 15 ° and 75 °. It is therefore provided that an external part of the retaining element in the first position, by its edge, can be completely connected around the lateral side of the module to prevent entry of dirt and, in addition, prevent the situation where the accumulation of dirt around from the external part, prevent positions from being reached through rotation. Furthermore, it is therefore provided that the dimension of the closing part in the radial direction relative to the axis of rotation of the retaining element may be small and therefore that the space required to rotate the closing part between the first position and the second position can also be small, which facilitates the reception of the retaining element within the limiting or boundary faces of the module formed by the upper and lower sides of the module. Furthermore, it is provided that it is possible to transmit the force exerted by the articulation axis to the module both in the axial direction and in the radial direction with respect to the axis of articulation. Further elaborations of the advantageous embodiments of the module according to the invention are described in the subclaims. The invention will be specified hereinafter based on several examples of the embodiments shown in the accompanying drawings. In these drawings: Figure 1 is a perspective, schematic view of an exemplary embodiment of the module according to the invention, with the closure part in its first position; Figure 2 is a schematic, perspective view of the module of Figure 1 with the closure part in its second position; Figure 3 is a schematic, perspective view of the retention element of the module of Figure 1; Figure 4 is a perspective, schematic view of the module of Figure 1, in which the. Retention element has been removed; Figure 5 is a schematic, perspective view of a part of the module of Figure 1, taken along the line V-V; Figure 6 is a schematic perspective bottom view of the module of Figure 4; Figure 7 is a schematic, perspective view of a part of a mesh or conveyor belt having modules according to another embodiment of the invention; Figure 8 is a schematic perspective bottom view of the mesh or conveyor belt of Figure 7, in which the retention element has been removed; Figure 9 shows a section of the module of Figure 8, taken along the line IX-IX; and Figure 10 is a perspective, schematic view of the retaining element of a module of Figure 8.

Detailed description of the invention It is noted that the Figures are only schematic representations of the preferred embodiments and that within the structure of the claims, many other modalities are possible. In the Figures, the identical or similar parts have been designated by the corresponding numerical references. Referring to Figure 1, a module 1 is shown which has a front side 2 and a rear side 3, observed in a transport direction 12 indicated by an arrow. The module 1 has its front side 2 and its rear side 3 provided with articulation loops 4 extending outwardly relative to the module 1. The articulation loops 4 of the two modules succeeding one another in the transport direction 12 they cooperate in such a way that the articulation loops 4 on the rear side 3 of a module 1 which are driven in the transport direction 12 interfere with the articulation loops 4 on the front side 2 of the module 1 which follows in the direction of transport. The cooperative articulation loops 4 can be coupled by means of articulation axes extending transversely to the transport direction (not shown). The coupled modules can be identical or different types. A module provided with a retaining element, for example, may be coupled in the transport direction with respect to a module without the retaining element. The module 1 further comprises an upper side 5, a lower side 6 and two side sides 7 and 8, located opposite to each other transversely with respect to the transport direction. Provided on the side side 7 is a recess 9 which accommodates a retaining element 10 which is rotatable relative to an axis of rotation 11 which extends through the retaining element 10. The retaining element 10 comprises a closing part , which, in Figure 1, is in a first position in which it can retain an articulation axis received by the articulation loops 4 transversely with respect to the transport direction 12. The closure part is designed as a cylindrical element 13 which extends coaxially with respect to the axis of rotation 11 and which also forms an outermost part of the retaining element 10, and which, in the first position of the closing part, is substantially flush with the lateral side 7 of the module 1 in which the retaining element 10 is accommodated. Accordingly, it is thus provided that the probability of damage to the retaining element and / or the impediment to the operation of the retaining element due to fouling during the use of the module, is small. Adjacent to its circumferential edge, the cylindrical element 13 is provided with a notch 14 extending in the longitudinal direction of the axis of rotation. In the first position shown in Figure 1, a hinge axis received by the hinge loops 4 can be retained transversely with respect to the transport direction 12 because the cylindrical element 13 covers a hinge hole 15 of one of the loops of joint 4 at least partially. The horizontal position of the arrow 16 provided on the external side of the cylindrical element 13 indicates that the closing part is in its first position. In the center of arrow 16, the cylindrical element 13 is provided with a slot 17 inside which a screwdriver can be inserted. By means of the screwdriver, the retaining element 10 can be rotated counterclockwise above 90 ° relative to the axis of rotation 11, such that the notch 14 in the cylindrical element 13 corresponds to the orifice of articulation 15 (Figure 2). As a result, the cylindrical element 13 is in a second position in which a hinge axis, received by the hinge loops 4, can be released transversely with respect to the transport direction 12. The vertical position of the arrow 16 then indicates that the cylindrical element 13 is in its second position. It is noted that the closing part may also have. a different form of the cylindrical shape of the element 13 shown in Figure 1. It is further noted that the embodiments in which the retaining element 10 can be rotated above an angle greater than or smaller than 90 ° about the axis of rotation 11 between the first and second positions, are also possible. In addition, the recess 9 can have a different shape and can also be placed elsewhere in the module 1. Referring to Figure 3, the retention element 10 is shown in detail there. The retaining element 10 comprises a cylindrical leg 18 which carries the cylindrical element 13 coaxially with respect to the axis of rotation 11. The cylindrical element 13 comprises an embossed edge 19 cooperating with a corresponding slot 20 in the wall of the recess 9 in the module 1 (Figure 4). It is thus provided that the rotation of the cylindrical element 13 from the first position becomes more difficult, which has a fixing effect. In addition, it has been provided that when the first position is reached, a click or light noise signal is given. Of course, in an analogous manner, the retention element 10 can also be provided with a groove and the recess 9 can be provided with an embossed rim. Provided in a cylindrical part 13 is a cavity 21 to achieve a spring action of the raised edge 19, which further increases the fixing effect. The leg 18 of the retaining element 10 is • provided with a hole 22 that extends over at least a part of the axis of rotation 11 and cooperates with a pin or shaft 23 which extends towards this hole 22 from the wall of the recess 9 (Figure 5). Accordingly, provision is made for the retaining element 10 to be centered during rotation about the axis of rotation 11. In addition, the misalignment of the retaining element 10 relative to the cavity 9 due to the forces exerted on the cylindrical element 13 by an axis of retained articulation, are reduced. Referring again to Figure 3, the retaining element 10 comprises a locking element in the form of a projection 24 fixed to the leg 18 and extending radially outwardly relative to the axis of rotation Il of the retaining element 10. projection 24 is provided with the side walls 25, 26 which extend in a V-shaped configuration in the longitudinal direction of the axis of rotation 11 of the retention element 10 and which extend outwardly relative to one another. Provided between the side walls 25, 26 is a slot 35 by which the side walls 25, 26 are elastically movable in a manner related to each other. As the locking element, the projection 24 cooperates with guide means positioned on the edge of the recess 9, such that the axial movement of the retaining element 10 along the axis of rotation 11 is obstructed. Accordingly, the closure part and the blocking element are designed as separate parts of the retaining element. Referring to Figure 5, the guide means are designed as a slide 27 that extends over a circular arc with respect to the axis of rotation i 11, the side walls 28, 29 of such a slide guide the projection 24 ^ in such a way that the slide 27 prevents the axial movement of the retaining element 10 along the rotating reel 11 and joins the rotation of the cylindrical element 13 between the first and second positions. Accordingly, misalignment is provided to be prevented additionally. The module 1 is provided with an opening 30 which is located slightly inward relative to the side side 7 and through which the rebate 27 for the projection 24 of the retention element 10 is accessible. When the retaining element 10 is being inserted into the cavity 9 in the module 1, the projection 24 is pushed through the opening 30, and after the side walls 25, 26 of the projection 24 have passed the opening 30, the they are flexed outwards to cause the projection to be retained in the slide 27. Accordingly, it is provided that in the first and second positions, as well as in the intermediate positions, the retention element 10 is connected to the module 1 and therefore not may be lost. The module 1 further has its lower side 6 provided with an opening 31 through which the projection 24, when located on the slide, is accessible to be depressed from the slide 29 (Figure 6). Accordingly, provision is made for the retaining element 10 to be detached from the module 1 by performing a separate operation. It was noted that similarly to the opening 31, the locking element and the guiding means cooperating therewith can be designed in many different ways, for example as an annular raised edge cooperating with a corresponding annular groove. When a row of modules is being disassembled from a mesh or conveyor belt already placed on a slide of the conveyor apparatus, the retaining element 10 is rotated in the counterclockwise direction by means of a screwdriver placed in the notch 17, from the first position shown in Figure 1 to the second position shown in Figure 2. Subsequently, the hinge axis on the front side of the module can be removed. This can be effected, for example, outside the hinge loops 4 with a second axis or bolt, after the closing part of a retaining element 10 of an opposite module 1 transversely with respect to the transport direction has been brought similarly towards a second open position. By repeating this operation for the row of modules 1 following in the direction of transport 12, a hinge axis placed or distributed through the hinge loops 4 on the rear side 3 of the module 1 can also be removed, after which the row of modules can be removed. The assembly of the row of modules is carried out in the reverse order. It is noted that the process of adjustment and movement from the first position to the second position and vice versa can not only be performed manually, but can also be conveniently automated. Accordingly, in this way, a module 1 having a retaining element 10 was provided which, in the first and second positions of the closing part 13 as well as in the intermediate positions of the closing part, is located within the limiting or border faces constituted by the upper side 5 and the lower side 6 of the module 1. Referring to Figure 7, a part of the conveyor or conveyor 32 is shown there with several modules 1, which follow each other in a transport direction 12, according to another embodiment of the invention. The articulation loops 4 on the front side 2 and the rear side 3 of the modules 1 which follow each other in the transport direction 12 cooperate and are coupled by means of articulation shafts 33 extending through the loops of articulation 4 transversely with respect to the direction of transport 12. The modules 1 have their lateral side 7 provided with recesses 9 substantially cylindrical to receive a retaining element 10 substantially cylindrical. The diameter of the recess 9 corresponds to the diameter of the retaining element 10. The retaining element 10 is received coaxially and rotatably in the recess 9., such that the axis of rotation 11 of the retaining element 10 intersects the center line 36 which extends through the articulation loops 4 of the front side 2 of the module 1 at an angle of 45 °. Accordingly, it is provided that the dimension of the closing part in the radial direction with respect to the axis of rotation of the retaining element can be small and that, consequently, the space necessary to make possible the rotation of the closing part between the first position and the second position can also be small, which facilitates the reception of the retaining element within the limiting faces of the module formed by the upper side and the lower side of the module. Furthermore, it is therefore provided that it is possible to transmit the force exerted by the hinge axis to the module, in the axial direction as well as in the radial direction with respect to the hinge axis. It has been observed that depending on the desired geometry of the module, a larger or smaller angle of intersection can be chosen, and that the retaining element can also be placed anywhere on the module.

The end face 34 has a bevel of 45 ° relative to the axis of rotation 11 and form, when the retaining element 10 has been received in the recess 9 in the module, an outermost part of the retaining element 10. In this way , a retaining element 10 has been obtained whose operation is highly insensitive to dirt. Not only is the outermost part of the retaining element in the first position flush with the wall 7 of the module 1, but also, when the edge of the outermost part of the retaining element is connected to the lateral side 7 of the module 1 completely around, the dirt that is possibly located adjacent to the edge can not obstruct, through accumulation, the reach of one of the positions during rotation. Accordingly, the bevel angle preferably corresponds to the angle of intersection between the axis of rotation 11 and the center line 36. Referring to Figure 8, a module 1 of the mesh or conveyor 32 of Figure 7 is shown there, which the retaining element 10 has been removed. Figure 9 shows, in its cross-section, how the recess 9 in the module of Figure 9 is connected to the cavity formed by the hinge hole 15. The recess 9 comprises a guiding means which is designed as a notch 38 and which, in the assembled condition of the retaining element, cooperates with a locking member thereof designated as a sharp disengagement finger 39, to prevent axial movement of the retaining element 10 along the axis of rotation 11 and to limit the rotation of the retaining element about the axis of rotation between the first and second positions. Referring to Figure 10, the closing part of the retaining element 10 is visible there, designed as an embossed edge 40. Located below the raised edge 40 is a recess 41. The operation of the retaining element 10 is as follows. By passing a screwdriver 37 towards the notch 17 in the end face 34 of the retaining element 10, the retaining element 10 can be rotated relative to the axis of rotation 11 over a 90 ° angle in the counterclockwise direction from the first position in which the raised edge 40 is located within the opening formed by the articulation loop 15, to a second position in which the raised edge 40 is located within the recess 9 and the recess 41 corresponds to the cavity formed by the hinge hole 15. Accordingly, a bolt or shaft passed through the hinge loops 4 is retained in the first position and released in the second position. By causing the bevel of the end face 34 to correspond to the angle of intersection between the axis of rotation 11 and the center line through the articulation loops 4, provision is made for the end face 34 in the first position to be substantially flush with the lateral side 7 of the module 1, but in the second position it extends outwardly relative to the lateral side of the module 1. This has the disadvantage that the position of the closing part can be easily detected. Furthermore, due to the bevel of the end face 34, the retention of the articulation axis 33, ie the movement of the closure part from the second position towards the first position, can be automated in a simple manner. It has been found that in this embodiment, too, the retention element can be designed in very different ways, for example as a cylindrical element having two end faces whose bevel extends in parallel. In this case, the retaining element 10 is adjusted between the first position and the second position by rotating it 180 ° relative to the axis of rotation 11. It was further noted that the blocking element and the guiding means cooperating therewith also they can be designed in very different ways, for example as a projection which extends radially outwardly relative to the axis of rotation of the retention element and which cooperates with a cavity provided in the wall of the recess. It was further observed that "mesh or conveyor belt" should also be understood to include a conveyor chain which, transversely with respect to the direction of transport, it is constructed of a single module. With such a mesh or conveyor belt, each module can have both of its lateral sides provided with a retaining element and the dimensions of the modules transversely with respect to the transport direction can vary from a very small amount to a very large amount, depending of the type of the mesh or conveyor belt.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates.

Having described the invention as above, property is claimed as contained in the following

Claims (17)

1. A module for a modular mesh or conveyor belt, comprising a front side and a rear side having articulation loops extending outwardly relative to the module, such that in two successive modules in a direction of In this case, the articulation loops on the front side of a module can cooperate with the articulation loops on the rear side of the other module and can be coupled by means of articulation axes extending transversely with respect to the transport direction. The module further comprises an upper side, a lower side and two lateral sides located opposite each other transversely with respect to the direction of transport, and at least one recess accommodating a retaining element which is rotatable relative to an axis of rotation that extends through the retaining element, such that a closing part of the retaining element is rotatable in A first position in which the closing part can retain an articulation axis received by the articulation loops transversely with respect to the direction of transport and a second position in which the closing part can release a joint axis received by the articulation loops transversely with respect to the direction of transport, characterized in that both the first and second positions of the closing part and in the intermediate positions of the closing part, the retaining element is located within the faces constraints formed by the upper side and the lower side of the module.

2. A module according to claim 1, characterized in that at least one recess is provided on a lateral side of the module.

3. A module according to claim 1 or 2, characterized in that an outermost part of the retaining element in the first position of the closing part is substantially flush with the lateral side of the module in which the retaining element has been accommodated.

4. The module according to any of claims 1-3, characterized in that the retaining element comprises a blocking element cooperating with guide means provided in the wall of the recess, in such a way that the axial movement of the retention element as long axis of rotation is prevented.

5. A module according to any of claims 1-4, characterized in that the closing part comprises a cylindrical element extending coaxially with respect to the axis of rotation, such cylindrical element is provided, adjacent to the circumferential edge thereof, with a groove which extends in the longitudinal direction of the axis of rotation, such that in the first position, an articulation axis received by the articulation loops can be retained transversely with respect to the direction of transport covering a joint bore of one. of the articulation loops at least partially, by means of the cylindrical element, and in the second position, an articulation axis received by the articulation loops can be released transversely with respect to the direction of transport through the correspondence at least partial of the groove in the cylindrical element with the hinge hole.

6. A module according to claim 5, characterized in that the cylindrical element and the wall of the recess are provided with an raised rim and a notch cooperating in such a way that the rotation of the cylindrical element from the first position becomes difficult.

7. A module according to any of claims 1-6, characterized in that the retaining element is provided with a hole that extends over at least a part of the axis of rotation and cooperates with a bolt or shaft extending from the wall of the recess towards the hole.

8. A module according to any of claims 4-7, characterized in that the blocking element comprises a projection extending radially outwards with respect to the axis of rotation of the retaining element.

9. A module according to claim 8, characterized in that the guide means comprise a slide that extends over a circular arc with respect to the axis of rotation, whose lateral walls guide the projection in such a way that the slide limits the rotation of the closing part of the retaining element between the first and second positions.

10. A module according to claim 8 or 9, characterized in that the projection is provided with side walls extending in a V-shaped configuration in the longitudinal direction of the axis of rotation of the retaining element and extending elastically outwards. towards the others.

11. A module according to claim 10, characterized in that the module has its lateral side provided with an opening through which the slide for projecting the retention element is accessible.

12. A module according to claim 11, characterized in that the module also has its lower side provided with an opening through which the projection, when located on the slide, is accessible to be depressed from the slide.

13. A module according to any of claims 1-4, characterized in that the axis of rotation intersects a central line through the articulation loops on the front or rear side of the module, preferably at an angle of between 10 ° and 80 °, more preferably between 15 ° and 75 °.

14. A module according to claim 13, characterized in that in the second position of the closing part, a more external part of the retaining element extends outwardly relative to the side face of the module which accommodates the retaining element.

15. A module according to claim 13 or 14, characterized in that the retaining element is substantially cylindrical.

16. A module according to claim 15, characterized in that the retaining element comprises at least one beveled end face forming the outermost part.

17. A modular mesh or conveyor belt, characterized in that it comprises one or more modules according to any of claims 1-16. SUMMARY OF THE INVENTION The present invention relates to a modular mesh or conveyor belt. Observed in a transport direction, the module comprises a front side and a rear side having articulation loops that extend outwardly relative to the module. The articulation loops are such that in the two modules which follow one another in the transport direction, the articulation loops on the front side of one module can cooperate with the articulation loops on the rear side of the other module and such so that the articulation loops can be coupled by means of articulation axes extending transversely with respect to the transport direction. The module further comprises an upper side, a lower side and two lateral sides located opposite to each other transversely with respect to the transport direction. The module comprises a recess which accommodates a retaining element, and a closing part of the retaining element is rotatable between a first position in which the closing part can retain an articulation axis received by the articulation loops transversely with respect to the transport direction and a second position in which the closing part can release an articulation axis received by the articulation loops transversely with respect to the transport direction. In both the first and the second position of the closing part and in the intermediate parts of the closing part, the retaining element is located within the limiting faces formed by the upper side and the lower side of the module. The retention element is connected to the module so that the loss of the retention element is prevented.