FR3091883A1 - Device for securing the locking of a manhole cover system - Google Patents

Abstract

The invention relates to a device for securing the locking of a system for closing a manhole comprising a frame (2) and a grid (1) of the type locking vis-à-vis the frame (2) by deformation. elastic of a deformable element of said grid (1), the closure system comprising a tool introduction space allowing the introduction of a tool in order to deform the deformable element. The device comprises a lower part (19) and an upper part (21) which can be assembled or disassembled. When the lower part (19) and the upper part (21) are assembled, a space is provided between said lower part (19) and said upper part (21) allowing at least part of the deformable element to be accommodated therein. the grid (1) and / or the frame (2), and the upper part (21) is shaped to fill all or part of the tool insertion space so as to prevent the introduction of a tool therein capable of deforming the deformable element. Figure for the abstract: Fig. 6

Description

Securing device for locking a manhole shutter system

The present invention relates to the field of access to underground and surface infrastructures of all types, and relates in particular to the field of grids allowing the closing of manholes.

To close a manhole, it has long been known to use a grid mounted in a removable or pivoting manner in a frame integral with the roadway. This type of shutter assembly makes it possible in particular to shut off a manhole while allowing the recovery of rainwater, for example.

It is also known to lock the grid elastically in the frame, according to various methods and configurations, by deformation of the grid, for example by deformation of one or more bars of the grid.

In general, the grids with locking device by elastic deformation comprise a locking means, preventing the withdrawal or the tilting of the grid vis-à-vis the frame, based on the capacity that has at least one element of the grid to be elastically deformed, under the effect of a force, vis-à-vis the rest of the grid. The deformation of the deformable element makes it possible to escape when closing the grid to an element forming a stop such as a lug carried by the frame, so that the grid can descend into the frame and rest there. When the force acting on and deforming the deformable element ceases, the latter tends to return to its original configuration (in the absence of force). All or part of the deformable element is then positioned under or lodged in the element forming the abutment of the frame. The opening of the gate is then made impossible by the mechanical interference between the deformable element and the element forming a stop. To reopen the grille, it is necessary to deform the deformable element with the help of a tool and to hold it in a deformed position, so that it escapes from the element forming a stop on the frame.

Numerous documents are known which present grids with a locking device by elastic deformation. The document FR2843139 presents for example a grid whose locking is ensured by an elastic finger. The document FR2716472 discloses a gate whose locking is optimized as to the resistance of the locking device, in that said locking is ensured therein by the deformation of a complete bar.

The tool allowing the deformation of the deformable element can be a lever or a conventional crowbar, while certain known grids are associated with a particular tool (for example of particular shape) to easily deform the elastic deformation element.

Grids with locking device by elastic deformation thus constitute devices for closing a manhole which are simple to implement and which are reliable with respect to an impromptu or accidental opening.

Nevertheless, it may be desirable for some applications to secure the closing and locking of the gate to some degree, or at least to make the opening of the gate more complex. For example, it may be desirable to make a gate installed in the playground of a school impossible for a child or teenager to open. It may also be desirable, for an access grid for example to rainwater drainage pipes, to make it impossible to open the grid without special equipment, whether to prevent access to underground infrastructures or to prevent a gate on the public highway from being opened and left as it is, which would cause a hazard.

The invention thus tends to propose a device making it possible to secure the locking of a locking grid by elastic deformation.

Thus, the invention relates to a device for securing the locking of a shutter system of a manhole, said shutter system comprising a frame and a grid of the locking type vis-à-vis the frame by elastic deformation of a deformable element of said grid, said shutter system comprising a tool introduction space allowing the introduction of a tool in order to deform the deformable element. The device comprises a lower part, an upper part, and connecting means allowing the assembly of the lower part and the upper part or the disassembly of the upper part vis-à-vis the lower part. The device is configured so that, when the lower part and the upper part are assembled, a space is made between said lower part and said upper part allowing at least part of the deformable element of the grid to be accommodated therein and/or or of the frame, the upper part being further shaped to fill all or part of the tool introduction space so as to prevent the introduction therein of a tool capable of deforming the deformable element.

The locking securing device proposed according to the invention is a simple mechanical device. It is based on the idea of locking the gate in the closed position by preventing the introduction in the intended place of a tool allowing leverage on the deformable element, rather than seeking to mechanically block said deformable element.

This mode of operation makes it possible to obtain a simple, compact and efficient device.

The connecting means may comprise at least one screw, a screw head of which rests on the upper part and one thread of which engages in a corresponding thread of the lower part when the upper part and the lower part are assembled. For example, the lower part may comprise a nut forming said corresponding thread of the lower part.

The head of the at least one screw may comprise an imprint, said imprint being hexagonal, square, triangular, or of complex shape not corresponding to a common geometric shape, so that said screw can only be actuated by using a tool of shape corresponding to said imprint.

Alternatively, the connecting means may include a key lock.

Depending on the level of security desired, the connecting means making it possible to couple the lower part and the upper part can be more or less complex to operate in order to allow disassembly and separation of the lower part and the upper part, in order to remove the upper to authorize the installation of a tool allowing the unlocking of the grid and its opening.

When the lower part and the upper part are linked by screws, the more or less common imprint of the head of the screws will determine the level of security, due to the complexity of removing the upper part to be able to unlock the grid.

Thus, a hex drive screw, which is common in many assemblies, simply prevents opening by a person with only an object to pry, but is weak security. A more complex footprint goes a long way to limiting the ability to open the gate to authorized personnel. In an extreme case, a key lock makes it possible to limit access only to people with the corresponding key.

The invention also relates to an assembly comprising a system for closing access to a manhole, said closing system comprising a frame and a grid of the locking type vis-à-vis the frame by elastic deformation of a deformable element of said grid, said obturation system comprising a tool introduction space allowing the introduction of a tool in order to deform the deformable element, the assembly further comprising a device for securing the locking as previously described.

The frame may include a housing for receiving the lower part of the locking securing device, said housing being shaped so that said lower part fits therein.

The reception housing of the lower part can in particular be located under an abutment carried by the frame and intended to interfere with the deformable element of the grid.

The deformable element of the grid can be a deformable bar comprising two ends and forming an edge of the grid, the two ends of the deformable bar being connected to the rest of the grid and a central part of the deformable bar having a recess forming, between the deformable bar and the frame, the tool introduction space allowing the introduction of a tool to deform the said deformable bar, this tool introduction space being partly filled by the upper part of the securing device of the locking so as to prevent the introduction of a tool into said tool insertion space when the upper part and the lower part of the locking securing device are assembled.

The deformable bar may include a lug which is housed under the abutment carried by the frame when the grid is in the frame in a closed position, and the lug of the grid and the abutment of the frame are clamped between said lower part and said part superior.

The closure system configuration described above proves to be particularly suitable for the application of a locking securing device as previously described.

Other features and advantages of the invention will appear further in the description below.

In the accompanying drawings, given by way of non-limiting examples:

FIG. 1 represents, according to a schematic three-dimensional view, a system for closing a manhole comprising a frame and a grid, to which the invention can be applied, the grid being in the open position;

FIG. 2 represents the system of FIG. 1, according to the same schematic view in three dimensions, the gate being in the closed position;

Figure 3 shows the frame of the system of Figures 1 and 2;

FIG. 4 represents the frame of FIG. 3 in which a lower part of a locking securing device according to one embodiment of the invention is placed;

FIG. 5 shows, in a partial three-dimensional view, the system of FIGS. 1 and 2, the gate being in the closed position, and a lower part of a locking securing device according to one embodiment of the invention being put in place ;

FIG. 6 shows, according to a view similar to that of FIG. 5, the system of FIGS. 1 and 2, the gate being in the closed position and a locking securing device according to one embodiment of the invention being put in place to prevent the gate from opening;

FIG. 7 represents, according to a three-dimensional view similar to those of FIGS. 1 and 2, the system for closing off a manhole of FIGS. 1 and 2, the grid being in the closed position, and a locking device conforming to the embodiment of the invention of Figure 6 being set up to prevent the opening of the gate;

FIG. 8 represents, according to a three-dimensional view similar to that of FIG. 5, the gate being in the closed position, and a lower part of a locking securing device according to an alternative embodiment of the invention being placed in place.

Figure 1 shows a shutter assembly of a manhole on which the invention can be implemented to secure the locking. The shutter assembly comprises a grid 1 and a frame 2. The grid 1 is hingedly mounted in the frame 2, so as to be able to assume an open position illustrated in figure 1, or a closed position illustrated in figure 2 In the open position of the grid 1 and of the shutter system, access to the manhole is possible. In the closed position, the manhole is closed off so that access to it is impossible.

The frame 2 is intended to be mounted integral with the element in which a manhole is formed, for example a roadway.

The grid 1 essentially comprises a layer of longitudinal parallel bars 3 formed in one piece, for example from a foundry, with parallel transverse bars 4.

The grid 1 comprises, at one of the ends of the longitudinal bars, a deformable bar 5 which is elastically deformable with respect to the other transverse bars 4. The deformable bar 5 allows the locking of the grid 1 vis-à-vis the frame 2 , as described below.

In the example of a manhole closure assembly represented here, the deformable bar is integral with the rest of the grid 1 by its two ends 6.7 only. Alternatively, the deformable bar could only be secured to the grid by one of its ends.

Between these two ends 6.7, substantially in the middle of the deformable bar 5, is formed a lug 8 intended to be introduced into a notch or to cooperate with an abutment 9 provided in the frame 2.

In the example represented here, the abutment 9 has the shape of a ramp, oriented towards an upper edge 10 of the frame 2, allowing the closing and the locking of the grid 1 under the effect of a significant vertical pressure, which will cause deformation of the deformable bar 5 due to the reaction force of the ramp of the stop 9 on the lug 8. Under sufficient force, the deformable bar 5 deforms sufficiently so that the lug 8 of the deformable bar 8 escapes the stop 9 and passes below the level thereof.

The shutter assembly for a manhole in Figure 1 is shown in Figure 2 in a closed position. The grid 1 is housed inside the frame 2. In particular, the grid 1 rests on a bottom 12 of the frame 2 forming a bearing surface, for example horizontal. In this position, the assembly allows for example the circulation of a pedestrian or a vehicle on grid 1, while allowing for example the recovery of rainwater in the manhole, through grid 1.

In the closed position, the lug 8 is housed under the stop 9. The mechanical interference between the lug 8 and the stop 9 prevents the grid 1 from pivoting with respect to the frame 2 towards its open position. The grid 1 is thus locked vis-à-vis the frame 2, in the closed position.

In order to unlock the grid, a suitable tool must be introduced between the frame 2 and the deformable bar 5. The tool makes it possible to exert on the deformable bar 2 a force making it possible to deform it in the direction of the adjacent transverse bar 11 so as to make the lug 8 come out from under the stop 9. In other words, a force is exerted on the deformable bar 5 so that its lug 5 no longer interferes mechanically with the stop 9 when the grid is pivoted towards its position opened. The force exerted for this purpose can be longitudinal, directed towards the adjacent bar 11. In the embodiment represented here, this force can also be vertical, the conformation of the lug 8 making it possible to cause its deformation in the direction of the adjacent transverse bar 11 when such a vertical force is applied to the deformable bar 5.

The tool making it possible to open the grid 1 must thus be introduced into a tool introduction space 13 provided between the deformable bar 5 and the frame 2. In particular, the tool introduction space 13 can be located directly on either side of the lug 8 and the abutment 9. In the example represented here, a recess of the deformable bar 5 towards the adjacent bar 11 forms the tool insertion space 13, and accommodates the lug 8 which is formed in one piece with said deformable bar 5.

The invention is based on the idea of preventing the unlocking of the grid by preventing the introduction of a tool into the tool introduction space 13.

It should be noted that, although the invention is described in this document in relation to an example of a shutter assembly which constitutes a preferred application, the locking securing device which is the subject of the invention is applicable to any assembly shutter whose grid can be locked by elastic deformation of a deformable element whose unlocking requires the introduction of a suitable tool into a tool introduction space of the assembly. In particular, the invention is applicable to shutter systems whose grid is not hinged to the frame.

Figure 3 shows frame 2 of the manhole cover assembly of Figures 1 and 2.

The frame 2 comprises substantially vertical side walls 14, which extend between a lower face and an upper edge 10. At the level of the lower face, sealing lugs 15 make it possible to immobilize the frame 2, for example in a roadway . The frame 2 is configured to receive a grid 1. Openings 16 make it possible to receive the tilting axis 17 of the grid 1.

The frame 2 represented here remarkably comprises a housing 18 for receiving a locking securing device in accordance with an embodiment of the invention adapted to the frame 2 represented. The housing 18 is formed under the stop 9, in this case in the bottom 12 of the frame 2.

Figure 4 shows the frame of Figure 3 in which a lower part 19 of an adequate locking securing device is put in place. The lower part 19 comprises in particular a lower portion of shape corresponding to the housing 18, so that the lower part 19 fits into the housing 18. Such fitting by shape correspondence can leave a slight clearance between the edges of the housing 18 and the portion of the lower part which fits therein.

When the gate 1 is closed, as shown in Figure 5, the lower part 19 is covered by the lug 8 of the deformable bar 5. The lower part 19 is thus immobilized vis-à-vis the frame 2. As is well visible in Figure 5, the lower part 19 is provided in the embodiment shown, on either side of the lug 8 of the grid 1 and the abutment 9 of the frame 2, two threaded parts 20. threaded portions 20 each have a thread, so that a screw or other threaded part can be screwed therein. In the partial view shown in Figure 5, one of the threaded portions 20 is cut, thus showing its internal thread.

FIG. 6 represents, according to a view similar to that of FIG. 5, the assembly for closing a manhole, equipped with a locking securing device according to one embodiment of the invention, comprising the lower part 19 , the upper part 21, as well as connecting means 22, in this case screws 23.

In particular, the upper part 21 comprises bores 24 which can be placed opposite the tapped parts 20 of the lower part 19. When the bores 24 are opposite the tapped parts 20, a screw 23 can be placed in position in the bore 24 and screwed into the threaded part 20 to assemble the upper part 21 to the lower part 19. In particular, the screw 23 comprises a threaded part 26 engaged in the threaded part 20. According to one embodiment, described below in referring to Figure 8, the threaded part 20 of the lower part can be formed by an insert nut.

In the exemplary embodiment represented, each screw 23 comprises a screw head 27 able to bear on a bearing surface 28 of the upper part 21. The screw head 27 comprises a recess 29 (female part) of a shape allowing the screw 23 to be screwed or unscrewed only with a tool comprising a head of corresponding shape. In the example represented here, the screw 23 comprises a hexagonal recess 29, with hexagon socket. A hexagonal recessed screw can be screwed or unscrewed using a hexagonal key called an Allen key.

Of course, each screw 23 could have an imprint 29 of different shape. In particular, a less common shape can be chosen to complicate the unscrewing of the screws 23. For example, each screw 23 can have a recess 29 of square, triangular or torx shape.

Apart from these common shapes, the recess 29 can have a complex shape, requiring a tool such as a key of corresponding male shape to screw or unscrew the screw 23.

Of course, the position of the female and male parts of the screw 23 and of the tool can be reversed, that is to say that the head of each screw 23 has a male part instead of the recess 29 , so that each screw 23 must be actuated by a tool having a corresponding female recess. The more complex and uncommon the chosen shape, the more secure is access to the manhole comprising the shutter assembly provided with a locking securing device in accordance with one embodiment of the invention.

The screw head is embedded in the upper part 21, so that it does not protrude from the upper surface 30 of the upper part 21, once the screw is in the screwed position in the lower part 19. Similarly, the upper part 21 is advantageously shaped so that its upper surface 30 is at the level of the upper surface 31 of the grid 1, or at a level slightly lower than the upper face 31 of the grid 1.

According to an embodiment not shown, the connecting means 22 may comprise a key lock, making it possible to prevent the dismantling of the upper part with a high level of security.

The upper part 21 is shaped to fill, at least in part, the tool introduction space 13. The introduction space 13 is thus filled, at least sufficiently to prevent the introduction of a tool adapted to deform the deformable bar 5 in said insertion space 13.

Thus, it is impossible to deform the bar 5 with a view to opening the gate 1 without first removing the upper part 21 of the locking securing device.

The securing device, and in particular the upper part 21, can be made, in addition to metal, of any sufficiently strong material, for example of reinforced plastic material.

FIG. 7 represents a set for closing a manhole, for example a manhole allowing the recovery of rainwater, through the grid 1 in its closed position. The locking of the shutter assembly, obtained by mechanical interference of the deformable bar 5 with the frame 2 (and in particular of the lug of the deformable bar 5 with the abutment of the frame 2), is secured by a device for securing the lock according to the embodiment described with reference to Figures 4 to 6.

In order to open the gate 1 to allow access under said gate 1, it is first necessary to free the insertion space 13 largely closed by the upper part 21 of the locking securing device. To remove said upper part 21, it is necessary to release the connecting means 22 between the lower part 19 and the upper part 21. For example, each screw 23 must be unscrewed using a suitable tool.

It is only once the upper part 21 has been removed that a tool can be introduced to lever the deformable bar 5 and deform it in the direction of the adjacent transverse bar 11.

Thus, an individual cannot, opportunistically, open access to the manhole by improvising a lever to deform the deformable bar, without having first disassembled the upper part from the lower part of the locking securing device. This secures the locking of gate 1, and avoids certain risks of access to the manhole, or certain risks associated with a gate which would remain open or poorly closed, for example on the public highway. Similarly, in certain places, such as a schoolyard, this limits the risk of unauthorized opening of the gate.

Figure 8 finally shows, according to a view similar to that of Figure 5, a variant of the invention in which the thread of the lower part 19, the thread of which is intended to correspond with the thread of a screw for the assembly of the upper part 21, is carried out using a nut 25 reported. In particular, the nut 25 can be inserted into a cavity of the lower part 19. The realization of a thread in a mechanical part is an expensive operation, so that the present variant comprising an added nut 25 is particularly economical.

The invention thus developed makes it possible to secure the locking of a gate shutter assembly comprising a deformable element. The proposed locking securing device is simple to implement. It is inexpensive. It can be applied to certain grids already installed, if the circumstances require it. Depending on the connection means implemented, the level of locking security can be adapted to the application in question. The proposed device proves to be very effective, and does not require resisting extreme forces, because it does not reside in the idea of opposing the force applied to a deformable element of a grid to prevent its deformation, but on the idea of preventing the installation of a tool used to deform said deformable element.

Claims (10)

Device for securing the locking of a manhole shutter system, said shutter system comprising a frame (2) and a grid (1) of the type locking vis-à-vis the frame (2) by deformation elastic of a deformable element of said grid (1), said closure system comprising a tool introduction space allowing the introduction of a tool in order to deform the deformable element,
characterized in that the device comprises a lower part (19), an upper part (21), and connecting means (22) allowing the assembly of the lower part (19) and the upper part (21) or disassembly of the upper part (21) vis-à-vis the lower part (19),
said device being configured so that, when the lower part (19) and the upper part (21) are assembled, a space is provided between said lower part (19) and said upper part (21) allowing at least one to accommodate therein a part of the deformable element of the grid (1) and / or of the frame (2), the upper part (21) also being shaped to fill all or part of the tool insertion space (13) so as to prevent the introduction of a tool capable of deforming the deformable element. Device according to Claim 1, in which the connecting means (22) comprise at least one screw (23) of which a screw head (27) bears on the upper part (21) and of which a thread is engaged in a corresponding net of the lower part (19) when the upper part (21) and the inner part (19) are assembled. Device according to claim 2, in which the lower part (19) comprises a nut forming said corresponding thread of the lower part (19). Device according to claim 2, wherein the head of the at least one screw has a recess (29), said recess being hexagonal, square, triangular, or of complex shape not corresponding to a common geometric shape, so that said recess screw (23) can only be actuated using a tool of a shape corresponding to said cavity. Device according to Claim 1, in which the connecting means (22) comprise a key lock. Assembly comprising a system for closing off access to a manhole, said closing system comprising a frame (2) and a grid (1) of the type locking vis-à-vis the frame (2) by deformation elastic of a deformable element of said grid (1), said closure system comprising a tool insertion space (13) allowing the introduction of a tool in order to deform the deformable element,
the assembly further comprising a locking securing device according to one of claims 1 to 5. Assembly according to Claim 6, in which the frame (2) comprises a housing (18) for receiving the lower part (19) of the locking securing device, said housing (18) being shaped so that said lower part (19) fits into it. Assembly according to Claim 7, in which the housing (18) for receiving the lower part (19) is located under a stop (9) carried by the frame (2) and intended to interfere with the deformable element of the grid ( 1). Assembly according to one of claims 6 to 8, in which the deformable element of the grid (1) is a deformable bar (5) comprising two ends and forming an edge of the grid (1), the two ends of the deformable bar (5) being linked to the rest of the grid (1) and a central part of the deformable bar (5) having a recess forming, between the deformable bar (5) and the frame (2), the space for the introduction of tool (13) allowing the introduction of a tool to deform said deformable bar (5), this tool insertion space (13) being partly filled by the upper part (21) of the device for securing the locking of so as to prevent the introduction of a tool into said tool insertion space (13) when the upper part (21) and the lower part (19) of the locking securing device are assembled. Assembly according to Claim 9, in which the deformable bar (5) comprises a lug (8) which is housed under the stop (9) carried by the frame (2) when the grid (1) is in the frame (2) in a closed position, and in which the lug (8) of the grid (1) and the stop (9) of the frame (2) are clamped between said lower part (19) and said upper part (21).