Mold for producing a concrete voussoir provided with a mechanism for pivoting at least one side wall
The mechanical pivoting mechanism for cast concrete voussoirs simplifies mold operation and maintenance, addressing reliability and safety issues, and ensuring consistent production quality.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- CBE - GROUP BV
- Filing Date
- 2025-05-27
- Publication Date
- 2026-06-04
AI Technical Summary
Current mold systems for producing cast concrete voussoirs require hydraulic power for opening and closing side walls, leading to reliability issues, increased manpower needs, complex cleaning, and potential accidents, and lack sufficient space for vibrators or maintenance.
A mechanical pivoting mechanism with a support, elongated element, rocker, handling cylinder, and threaded nuts allows manual operation of side walls between folded and inclined positions, eliminating the need for hydraulic power and simplifying the process.
Enhances mold reliability, reduces accidents, simplifies operation, and allows for easier maintenance, while maintaining production quality and throughput without specialized operators.
Smart Images

Figure EP2025064715_04062026_PF_FP_ABST
Abstract
Description
Description Title of the invention: Mold for producing a concrete voussoir equipped with a pivoting mechanism for at least one lateral wall Technical field of the invention
[0001] The present invention relates to a mold for the production of a cast concrete voussoir equipped with at least one hinged side wall. Previous technique
[0002] Tunnel construction relies primarily on the fabrication and installation of numerous cast concrete segments. As a reminder, a segment is a rigid structure, generally curved (at least in one longitudinal direction), which is assembled with other adjacent segments to form an arch with a more or less pronounced curvature. Each of these segments forms a portion (arc segment) of a tunnel's cross-section (circumference), and these sections are joined side-by-side at their respective lateral edges to form a complete or partial ring.The tunnel is thus made up of a longitudinal succession of these rings placed end to end (along the longitudinal sides of the voussoirs / rings), often different from one section to another for various reasons (different shape of the rings according to the terrain, necessary addition of safety or signaling elements on certain rings for which the hooks must be provided, insertion of protection zones / fire shelters, junction with transverse galleries, etc.).
[0003] Currently, voussoir manufacturing molds typically consist of a curved (convex) bottom wall forming the intrados of the voussoir once it has been demolded, side walls, namely two opposing arched longitudinal walls that follow the curve of the intrados and two smaller transverse walls, generally straight and perpendicular to the longitudinal walls, and optionally hinged lids on the transverse walls, defining, with the bottom wall, the longitudinal walls and said transverse walls, an internal volume intended to receive the fluid concrete before it dries and hardens.
[0004] Typically the longitudinal and transverse walls are also articulated with respect to the bottom wall, more precisely via pivots linked to a peripheral structure forming a band, like a hinge, between at least a first folded / closed position, defining the internal volume presented previously, and a second inclined / open position used for demolding the voussoir once the concrete is dry and hardened.
[0005] These side walls are equipped with mechanical articulation devices, most often in the form of extremely simple hydraulic cylinders. The mold is specifically designed for this solution and cannot be operated otherwise. Therefore, a technician must activate the hydraulic circuit to open or close it. A manual or automatic supply of hydraulic power is thus required.
[0006] However, in the event of a hydraulic failure, it is impossible to carry out these opening / closing movements of the side walls of the mold, which can have significant consequences on the production of the voussoirs (productivity, quality).
[0007] This solution also has the disadvantage of requiring a lot of manpower (and preferably more expensive specialized operators), of being insufficiently reliable over time (which impacts the implementation of long production lines and increases the shutdowns of the latter as well as maintenance and scrap), of making the cleaning of molds more complex, and of increasing the risks of accidents for operators on the line.
[0008] Finally, this solution generally does not allow for sufficient space under the mold for the installation of vibrators or for possible maintenance. Presentation of the invention
[0009] The present invention aims to overcome these drawbacks with a completely innovative approach that is very simple and quick to use, and without significant modification of the mold and its accessories, thus guaranteeing better reliability and better quality of the voussoirs obtained, reducing the potential risks of accident and facilitating use (possibility offered to less qualified operators to use it) and industrial maintenance.
[0010] Accordingly, in a first aspect, the present invention relates to a mold for producing a cast concrete voussoir comprising at least: - a curved bottom wall, called the intrados, surrounded by opposing longitudinal side walls and opposing transverse side walls, at least one of said side walls being hinged with respect to said bottom wall, the set of side walls defining, once erected with respect to the bottom wall and brought close to each other, an internal molding volume intended to be filled with fluid concrete, and - a mechanical mechanism for pivoting the side wall relative to the bottom wall from a first folded / closed position to a second inclined / open position, and vice versa, characterized in that the mechanical pivoting mechanism comprises at least: - a support attached to the mold, - an elongated element connected to the hinged side wall via a connecting member and having an external thread, - a rocker connected in an articulated manner to said support at the level of a first pivot, - a handling cylinder fixed to the support and comprising a movable rod linearly connected in an articulated manner to said rocker at the level of a second pivot of the latter, and - a first threaded nut engaging with the external thread of the elongated element and connected in an articulated manner to said rocker, - said cylinder rod being movable in translation between at least a first retracted position in which the cylinder exerts a tensile force on the rocker so as to rotate the latter around the first pivot in a first direction of rotation in order to pull on the element extended by means of the first tapped articulated nut to bring the side wall into its folded / closed position and a second extended position in which the cylinder exerts a pushing force on the rocker so as to rotate the latter around the first pivot in a second opposite direction of rotation in order to push the extended element by means of the first tapped articulated nut to bring said side wall into its inclined / open position.
[0011] The invention is implemented according to the embodiments and variants set out below, which are to be considered individually or in any technically feasible combination.
[0012] Advantageously, the pivoting rocker is connected to a locking means to clamp it in the first position so that the rotation of the elongated element inside the first tapped articulated nut in a first direction of rotation causes the displacement of said elongated element in a first direction relative to the rocker so as to bring the side wall into the open position and, conversely, the rotation of the elongated element inside the first tapped articulated nut in a second opposite direction of rotation causes the displacement of said elongated element in a second opposite direction relative to the rocker so as to bring the side wall into the closed position.
[0013] More specifically, the means of locking the tilt in the first position is constituted by the rod of the cylinder placed in its retracted position.
[0014] According to one embodiment, the means for locking the rocker in the first position comprises a rod penetrating on the one hand into at least one orifice of the rocker and on the other hand into at least one orifice of a plate of the mold support so that the rod of the cylinder is disconnectable from said rocker at the level of the second pivot or can be removed, making the rocker independent of the cylinder.
[0015] According to a preferred embodiment of the present invention, a manipulator is fixed to the elongated element, opposite the first threaded articulated nut, so that said elongated rod is directly manipulated by an operator manually or with the aid of a external tool so as to rotate it relative to the first tapped articulated nut in a first direction of rotation or in an opposite direction to tilt the side wall in question.
[0016] Preferably, the manipulating element is a nut welded to the elongated element.
[0017] Advantageously, the linking member between the elongated element and the side wall comprises a second threaded nut articulated on said side wall surrounded on one side by a locking fork (29a) and on the other side by a stop.
[0018] According to a particularly interesting aspect of the present invention, all the side walls are equipped with a mechanical pivoting mechanism.
[0019] According to an advantageous feature of the present invention, the side wall is equipped with at least one stop means positioning said side wall, in the closed position of the latter, relative to the other adjacent side walls.
[0020] Specifically, the stop means comprises at least one threaded rod linked to the wall considered movable in translation and a seat integral with the support and against which said threaded rod bears in the folded / closed position of the lateral wall considered.
[0021] Preferably, the mold includes, at each of its corners, means for securely locking the walls together in the folded / closed position, and comprising: - a second cylinder mounted on a given side wall and equipped with a linearly movable rod, - a clamping flange mounted pivoting at the free end of the rod of the second cylinder and around a pivot of the wall in question, - a lock attached to a wall adjacent to the wall in question and which can be either engaged with the flange in a retracted position of the rod of the second cylinder or released from said lock in the extended position of said rod of the cylinder.
[0022] According to a particular feature of the present invention, the secure locking means (further comprises means for positioning two adjacent walls in their respective folded / closed positions) comprising, on the one hand, at least some initial abutment sections integral with a first lateral wall considered, cooperating with second abutment sections integral with an adjacent wall
[0023] In particular, the two stop parts respectively have cooperating support seats in the shape of male and female cones.
[0024] According to a complementary aspect, the lock is mounted on a threaded rod movable in translation by means of an operating member (46) so as to vary the position of said lock relative to the side wall to which it is connected. Brief description of the figures
[0025] Other advantages, purposes and features of the present invention will become apparent from the following description, given for explanatory purposes only and not as a limitation, with reference to the accompanying drawings, in which:
[0026] [Fig. 1] Figure 1 is a perspective view of a mold for manufacturing a voussoir with side walls in an inclined / open position,
[0027] [Fig. 2] Figure 2 is a side view of Figure 1,
[0028] [Fig. 3] Figure 3 is a perspective view from below the mold,
[0029] [Fig. 4] Figure 4 is a perspective view of a vertical section of the mold showing mechanisms for closing / opening longitudinal and lateral walls by pivoting,
[0030] [Fig. 5] Figure 5 is a detailed view of the opening / closing mechanisms of a longitudinal wall of the mold,
[0031] [Fig. 6] Figure 6 is a cross-sectional front view of the mold with its walls in an inclined / open position,
[0032] [Fig. 7] Figure 7 is a front cross-sectional view of the mold with its side walls in the folded / closed position.
[0033] [Fig. 8] Figure 8 is a side detail view of the assisted closing / opening means in the inclined / open position of the corresponding wall,
[0034] [Fig. 9] Figure 9 is a perspective view of Figure 8 with some elements masked,
[0035] [Fig. 10] Figure 10 is a side detail view of assisted opening / closing mechanisms in the folded / closed position of the corresponding wall,
[0036] [Fig. 11] Figure 11 is a perspective view of Figure 10 with some elements masked.
[0037] [Fig. 12] Figure 12 is a side detail view of manual opening / closing mechanisms in the open position of the corresponding wall,
[0038] [Fig. 13] Figure 13 is a perspective view of Figure 12 with some elements masked.
[0039] [Fig. 14] Figure 14 is a detailed view of assisted locking means for a longitudinal wall on a transverse wall in the inclined / open position of said walls,
[0040] [Fig. 15] Figure 15 is a view similar to Figure 14 in the folded / closed position of said walls.
[0041] [Fig. 16] Figure 16 is a detailed view of means for manually locking a longitudinal wall onto a transverse wall in the inclined / open position of said walls,
[0042] [Fig. 17] Figure 17 is a view similar to Figure 16 in the folded / closed position of said walls. Description of the implementation methods
[0043] Firstly, the present description is given without limitation, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment described and / or represented.
[0044] It should also be noted from the outset that the figures are not necessarily to scale, without this hindering their understanding.
[0045] Finally, identical, similar or technically equivalent parts present in different figures carry the same numerical references in order to facilitate the transition from one figure to another.
[0046] Figure 1 is a top perspective view of a mold 1 for the manufacture of voussoirs according to the present invention.
[0047] As can also be seen in figures 2 to 5, the mold 1 typically includes a curved (convex) bottom wall 11 intended, once the concrete has been poured and dried / hardened, to form the intrados of the voussoir (not shown), a first pair of longitudinal side walls 12 and a second pair of transverse side walls 13 (also called "cheeks"), each of the side walls of these two pairs being movable (for example by lateral tilting outwards) on a lower frame 5 around respective axes 14 and 15 between a folded / closed position delimiting an internal volume having a closed perimeter and an inclined / open position allowing in particular the removal of the voussoir once the concrete has dried and hardened.
[0048] Hinged hinged upper side flaps relative to the transverse side walls 13 can also be provided to locally cover the internal volume of the mold 1 and delimit an open central area for pouring fluid concrete through a hopper (not shown).
[0049] The mold 1 also includes, attached to a fixed peripheral belting structure 2 mounted on the lower frame 5, a mechanism 20 for tilting the longitudinal side walls 12, a mechanism 20 for tilting the transverse side walls 13, means 40 for securely locking the side walls together once they have been brought together, and means for manually manipulating some of said tilting and securing means.
[0050] In the present case, each longitudinal side wall 12 is equipped with three tilting mechanisms 20 which are regularly distributed along its length, one of these mechanisms 20 being placed in the center while the other two are arranged closer to the corners of the mold 1, as can be seen for example in figures 2 and 3.
[0051] Each transverse side wall 13 is, however, equipped with a single tilting mechanism 20 located in the center of the wall in question, as can be seen for example in figures 2 to 4 and 6.
[0052] The mechanisms 20 for tilting the longitudinal walls 12 and transverse walls 13 are identical in design and operation, so that only the mechanisms 20 associated with the Longitudinal walls 12 will be described in more detail below in relation to figures 6 and 7 and then 8 to 11.
[0053] Thus, each tilting mechanism 20 includes a cylinder 21 linked to the peripheral belting structure 2 and includes a rod 22 that is linearly extendable along a stroke that can reach, in its maximum extension, several tens of centimeters, and preferably about 10 to 20 centimeters depending on the type of mold 1 (dimensions) and the angle of inclination that one wishes to apply to the side walls 12 and 13.
[0054] The free end of the rod 22 has a lower pivot 23 on which is mounted a rocker 24 formed of two parallel metal plates of generally substantially triangular shape. A first articulated nut 27 forming a second pivot is connected to an upper end of the rocker 24. A threaded rod 26 is inserted into the first articulated nut 27, which has an internal thread (not shown but of a conventional type) and can therefore pivot freely relative to the rocker 24. The threaded rod 26 passes through an opening 4 in the peripheral support structure 2 of the mold 1. This threaded rod 26 is also mechanically connected to the side wall via a second articulated nut 28 provided with an internal thread, which second nut 28 is also both pivotally mounted relative to the side wall in question (the longitudinal wall 12 in this case) and also fixed against translation (i.e.in a direction parallel to the threaded rod, more particularly coaxial with the latter) on one side by a fork 29a and on the other side by a stop 29b. Finally, the threaded rod 26 is provided, at a free end opposite the first articulated nut 27, with a welded nut with a hexagonal head 50 whose purpose will be described later.
[0055] As can be seen in Figures 5, 6, and 8 to 9, when the rod 22 of the cylinder 21 is extended, it pivots the rocker 24 along arrow D around a main pivot 25, which has the effect of pushing the threaded rod 26 inside the orifice 4 outwards. Since this threaded rod 26 is engaged with the first articulated nut 27, this has the effect of pivoting the longitudinal side wall 12 around its axis 14 because the second nut articulated 28 pushes against the fork 29a attached to said side wall.
[0056] Conversely, as illustrated in figures 7 and 10 to 11, when the rod 22 of the cylinder 21 is retracted, it pivots the rocker according to the arrow G around its main pivot 25, which has the effect of pulling on the threaded rod 26 inside the orifice 4. This threaded rod 26 being in contact with the first articulated nut 27, this has the effect of pivoting the longitudinal side wall 12 around its axis 14 because the second articulated nut 28 pushes against the stop 29b integral with said side wall 12.
[0057] In the folded / closed position of the longitudinal side wall 12, upper and lower rods 61 bear against corresponding seats 62 attached to the belting structure 2 of the mold 1 in order to act as a stop and to stop the folding / closing movement by pivoting of said side wall 12 around its axis 14, as can be seen in particular in figures 7 and 10 to 11.
[0058] In the open position, illustrated for example by figures 6 and 8 to 9, the rods 61 are clearly away from the seats 62. Note that these rods can be screwed / unscrewed in order to adjust the precise position of the stops thus formed with the seats 62.
[0059] The alternating pivoting movement in one direction or another to open or close the mold 1 is identical for the second transverse side wall 12, but also, with a single tilting mechanism 20, for both transverse side walls 13, around the pivot axis 15 integral with the peripheral belting structure 2 of the mold 1.
[0060] Figures 12 and 13 illustrate a so-called "manual" operating mode for the tilting mechanisms 20, which can therefore be used, for example, when the cylinders 21 are inoperable (pump power failure in the case of hydraulic cylinders or electrical failure in the case of electric cylinders) or when the cylinders 21 and the tilting mechanism 24 are blocked intentionally or unintentionally, and it is still necessary to open or close the side walls 12 and / or 13 of the mold 1.
[0061] Thus, in a first scenario where the rod 22 of the cylinder 21 is, for example, fully extended (or fully retracted), the tilting mechanism is therefore locked in a static position, and the side wall in question is open, a technician can directly act on the threaded rod 26 to gradually lower said wall. To do this, the technician can use a tool (pipe or open-end wrench, electric or hydraulic screwdriver, electric drill with a dedicated bit) which they will engage with the nut 50 and turn clockwise. As the nut 50 is fixed to the threaded rod 26, this will cause the latter to rotate in the same direction within the threads of the articulated nuts 28 and 27, which will gradually pivot the side wall in question around its axis of rotation, bringing it closer to the inside of the mold 1.
[0062] Conversely, in a folded / closed position of a given side wall, the technician can use the tool to turn the nut 50, and therefore the threaded rod 26, counterclockwise, which will cause the said wall to rotate / tilt around its axis, gradually moving away from the inside of the mold 1.
[0063] It is even possible to provide means of locking the rocker 24 in a given position, for example by means of a cylindrical rod (not referenced) forming a locking axis passing through on the one hand orifices 24a provided for this purpose in the two plates constituting the rocker 24 and on the other hand orifices 24c of the support plates 24b of the rocker mechanisms 20 (see figures 5 and 8 to 13), which allows on the one hand to carry out the rotation movements of the nut 50 described previously but also to remove if necessary the cylinder 21 and its rod 22 as soon as the rocker 24 remains locked in its position.
[0064] This solution is therefore very simple and quick to use, requires only minor modifications to the mold and its accessories, allows for improved reliability and quality of the resulting voussoirs (less waste), with an improved throughput on the production line (fewer breakdowns, less maintenance), reducing the potential risks of accidents and ease of use (possibility offered to less qualified operators to use it), the addition of vibrators under the bottom of the mold and industrial maintenance.
[0065] The invention also has the major technical advantage of allowing the transition from the folded / closed position to the inclined / open position of each of the walls, and vice versa, without the need to use the jacks, which can therefore be voluntarily disengaged, broken down, or even temporarily removed for maintenance, without significantly slowing down the manufacturing rate of the voussoirs since the line is not stopped during this time and the molds can still be closed and opened manually and used to manufacture parts, without loss of quality and without requiring specialized operators, complex tools or complicated, long or dangerous handling.
[0066] Figures 14 and 15 illustrate the assisted-type secure locking means 40, arranged at the four corners of the mold 1. These assisted locking means comprise, on the one hand, connected to a first lateral wall (a longitudinal wall 12 in this case), a cylinder 41 provided with an extendable rod 41a of a known type, a flange 42 connected to the rod of the cylinder 41 and articulated around a pivot 43, and first stop portions 47, each provided with a female conical seat; and on the other hand, connected to a second lateral wall (a transverse wall 13 in this case), a lock 44, designed to engage with the flange 42 in the folded position of two adjacent walls 12 and 13, a threaded rod 45 supporting said lock 44 and equipped with a welded nut 46, and second stop portions 48, each provided with a cooperating male conical seat, in the position folded down from the said two adjacent walls 12 and 13, with the female conical seat of the first 47 stop parts.In figure 14 in which the side walls 12 and 13 are inclined / open, the rod 41a of the cylinder 41 is extended so that the flange 42 is pivoted backwards around its axis 43.
[0067] As can be seen in Figure 15, when the side walls 12 and 13 are fully folded inwards towards the mold 1, the rod 41a of the cylinder 41 is retracted, which has the effect of rotating the flange 42 towards The front is positioned around its pivot 43 and engages behind the lock 44 to hold the walls securely in place (secure clamping), preventing them from opening outwards. The conical female and male seats of the first parts 47 and second parts 48 of the stop fit into each other, which also allows for ideal centering of the two lateral walls 12 and 13, whose edges are perpendicular to each other.
[0068] Conversely, when the operator wishes to cancel the secure clamping effect of the walls 12 and 13 in their folded / closed position, he must first extend the rod 41a from the cylinder 41 from the position in Figure 15, which causes the flange 42 to rotate in the opposite direction around its pivot 43, thus releasing the lock 44 so that the side walls 12 and 13 can again be opened by tilting outwards from the mold 1 (Figure 14).
[0069] Figures 16 and 17 illustrate a so-called manual variant of the secure clamping of the adjacent side walls 12 and 13 in which the rod 41a of the cylinder 41 is for example locked in the retracted position, either voluntarily or following a hydraulic failure of said cylinder.
[0070] In Figure 16, the walls 12 and 13 are in an inclined / open position so that by approaching each other, the flange 42 can pass behind the lock 44. The operator then simply needs to screw the nut 46 clockwise to bring the lock 44 close to the flange 42 and achieve secure clamping, with the female and male conical seats of the first parts 47 and second parts 48 of the stop then penetrating each other.
[0071] Conversely, when the side walls 12 and 13 are in the close / closed position as in Figure 17, and it is desired that the secure clamping be cancelled, the operator turns the nut 46 counterclockwise, which has the effect of moving the lock 44 away from the flange 42, thus allowing the walls 12 and 13 to move into the inclined / open position as in Figure 16.
[0072] As before, this manual solution is particularly practical, easy to use and reliable, eliminating the need for skilled operators and preventing the production line from stopping. for example in the case where there would be a failure of hydraulic supply to the cylinders 41.
[0073] It must be clearly understood that the detailed description of the object of the invention, given solely by way of illustration, does not in any way constitute a limitation, technical equivalents also being included within the scope of the present invention.
[0074] Thus, the welded nut 50 can be replaced by any other mechanical means allowing the threaded rod 26 to be turned manually using a suitable tool inside the articulated nuts 27 and 28 to tilt the side wall in question without the use of the cylinder 21.
[0075] The number of tilting mechanisms 20, their distribution by side wall and their positions can of course vary, in particular according to the dimensions of the mold 1.
[0076] The shape of the rocker can be different as long as it has a main pivot 25 and a pivot 23 for its articulation on the rod 22 of the cylinder 21.
[0077] The fork 29a and the stop 29b can be replaced by a single part used both when the threaded rod 26 is pulled or pushed by the cylinder 21, in particular a fork with its teeth pointing upwards and not oriented towards the inside of the mold / the stop 29b.
Claims
Demands Claim 1. Mold (1) for the production of a cast concrete voussoir comprising at least: - a curved bottom wall (11), called the intrados, surrounded by opposing longitudinal side walls (12) and opposing transverse side walls (13), at least one of said side walls (12; 13) being hinged with respect to said bottom wall (1), the set of side walls (12, 13) defining, once erected with respect to the bottom wall (11) and brought close together, an internal molding volume intended to be filled with fluid concrete, and - a mechanical mechanism (20) for pivoting the side wall (12; 13) relative to the bottom wall (11) from a first folded / closed position to a second inclined / open position, and vice versa, characterized in that the mechanical pivoting mechanism (20) comprises at least: - a support (2) attached to the mold (1), - an elongated element (26) connected to the hinged side wall (12; 13) via a connecting member (28, 29a, 29b) and having an external thread, - a rocker (24) connected in an articulated manner to said support (2) at the level of a first pivot (25), - a handling cylinder (21) fixed to the support (2) and comprising a linearly movable rod (22) articulated to said rocker (24) at a second pivot (23) of the latter, and - a first threaded nut (27) engaging with the external thread of the elongated element (26) and connected in an articulated manner to said rocker (24), - said rod (22) of the cylinder (21) being movable in translation between at least a first retracted position in which the cylinder (21) exerts a pulling force on the rocker (24) so as to rotate the latter around the first pivot (25) in a first direction of rotation in order to pull on the elongated element (26) by means of the first threaded articulated nut (27) to bring the side wall (12; 13) into its folded / closed position and a second extended position in which the cylinder (21) exerts a pushing force on the rocker (24) so as to rotate the latter around the first pivot (25) in a second opposite direction of rotation in order to push the elongated element (26) by means of the first tapped articulated nut (27) to bring said lateral wall (12; 13) into its inclined / open position. Claim 2. Mold (1) according to claim 1, characterized in that the pivoting rocker (24) is connected to a locking means for clamping it in the first position such that the rotation of the elongated element (26) inside the first tapped articulated nut (27) in a first direction of rotation causes the displacement of said elongated element (26) in a first direction relative to the rocker (24) so as to bring the side wall (12; 13) into the open position and, conversely, the rotation of the elongated element (26) inside the first tapped articulated nut (27) in a second opposite direction of rotation causes the displacement of said elongated element (26) in a second opposite direction relative to the rocker (24) so as to bring the side wall (12; 13) into the closed position. Claim 3. Mold (1) according to claim 2, characterized in that the means for locking the rocker (24) in the first position is constituted by the rod (22) of the cylinder (21) placed in its retracted position. Claim 4. Mold (1) according to claim 2, characterized in that the means for locking the rocker (24) in the first position comprises a rod penetrating on the one hand into at least one orifice (24a) of the rocker (24) and on the other hand into at least one orifice (24c) of a plate (24b) of the support (2) of the mold (1) so that the rod (22) of the cylinder (21) is disconnectable from said rocker (24) at the level of the second pivot (23) or can be removed, making the rocker (24) independent of the cylinder (21). Claim 5. Mold (1) according to any one of claims 2 to 4, characterized in that a manipulating member (50) is fixed to the elongated element (26), opposite the first tapped articulated nut (27), so that said elongated rod (26) is directly manipulable by an operator manually or with the aid of an external tool so as to rotate it relative to the first tapped articulated nut (27) in a first direction of rotation or in an opposite direction to tilt the considered side wall (12; 13). Claim 6. Mold (1) according to claim 5, characterized in that the manipulating member is a nut (50) welded to the elongated element (26). Claim 7. Mold (1) according to any one of the preceding claims, characterized in that the connecting member between the elongated element (26) and the lateral wall (12; 13) comprises a second threaded nut (28) articulated on said lateral wall (12; 13) surrounded on one side by a locking fork (29a) and on the other side by a stop (29b). Claim 8. Mold (1) according to any one of the preceding claims, characterized in that the jack (21) for manipulating the rocker (24) is of the hydraulic type. Claim 9. Mold (1) according to any one of the preceding claims, characterized in that all side walls (12, 13) are equipped with a mechanical pivoting mechanism (20). Claim 10. Mold (1) according to any one of the preceding claims, characterized in that the side wall (12; 13) is equipped with at least one stop means (61, 62) positioning said side wall, in the closed position thereof, relative to the other adjacent side walls. Claim 11. Mold (1) according to claim 10, characterized in that the stop means comprises at least one threaded rod (61) linked to the wall considered (12; 13) movable in translation and a seat (62) integral with the support (2) and against which said threaded rod (61) bears in the folded / closed position of the lateral wall considered (12; 13). Claim 12. Mold (1) according to any one of the preceding claims, characterized in that it comprises, at each of its corners, means (40) for securely locking the walls (12; 13) together in the folded / closed position of the latter and comprising: - a second cylinder (41) mounted on a considered side wall (12; 13) and provided with a linearly movable rod, - a clamping flange (42) pivotally mounted at the free end of the rod of the second cylinder (41) and around a pivot (43) of the wall in question (12; 13), - a lock (44) attached to a wall adjacent (13; 12) to the wall in question (12; 13) and capable of being either engaged with the flange (42) in a position retracted from the rod of the second cylinder (41) is released from said lock (44) in the extended position of said rod of the cylinder (41). Claim 13. Mold (1) according to claim 12, characterized in that the secure locking means (40) further comprises means for positioning two adjacent walls in their respective folded / closed position comprising on the one hand at least first stop parts (47) integral with a first lateral wall considered (12; 13) cooperating with second stop parts (48) integral with an adjacent wall (13; 12). Claim 14. Mold according to claim 13, characterized in that the two stop parts (47, 48) respectively comprise cooperating support seats in the form of a male and female cone. Claim 15. Mold (1) according to any one of claims 12 to 14, characterized in that the lock (44) is mounted on a threaded rod (45) movable in translation by means of an operating member (46) so as to vary the position of said lock relative to the side wall (12; 13) to which it is connected.