FR3129413A1 - Device for access to an underground infrastructure comprising a holding leg in the half-open position - Google Patents

Abstract

The invention relates to an access device (1) to an underground installation, comprising a frame (2) forming an opening and a seating surface (5) for the cover (3), the cover (3) being mounted pivoting with respect to said frame (2), the cover having an upper face and a lower face opposite to said upper face, the cover (3) being able to assume a closed position in which it rests on the seat surface (5), the access device comprising a holding leg (7) which comprises an end portion (10) in the form of a hook. The holding leg (7) is positioned entirely under the underside (8) of the lid (3) and is fixed to said lid (3). It is pivotable along an axis substantially orthogonal to the underside (8) of the lid (3), so that it can be positioned: - either in an angular holding position in which the lid (3) can be brought from the closed position to a half-open position in which the end portion (10) of the holding leg (7) mechanically interferes with the frame (2) and prevents any opening beyond said half-open position;- either in an angular release position , in which the cover (3) can be brought from the closed position to an open position in which the opening of the frame is unobstructed, without the holding leg (7) interfering mechanically with the frame (2). The invention also relates to a method for obtaining such a device, based on a pre-existing device. Figure for abstract: Fig. 1

Description

Device for access to an underground infrastructure comprising a holding leg in the half-open position

The present invention relates to the field of access devices to underground networks and more generally to underground installations. These access devices can allow visual control of an installation or allow access for a man.

Access devices thus concern both "manholes" and "manholes" in this document.

Underground facilities or infrastructure include water networks, sewers, communication networks, and underground electrical networks.

Access devices have one or more covers, also called buffers or hatches, which can be hinged to a frame.

Access devices to underground installations, and in particular their covers, are often made of metal, generally ductile iron. This type of material offers good resistance to loads applied to the access device, and also offers the advantage of having a relatively low production cost. Alternatively, plastic materials, in particular composite materials comprising appropriate reinforcements, can be used.

These devices allow access to underground infrastructures, and they secure them. In particular, they prevent a person from falling into the entrances they cover.

Although some covers may be provided with a lock, the covers of such access devices are generally kept closed, resting on the frames to which they are linked, under the effect of their own weight.

Despite this weight, certain events can cause an unexpected opening of such an access device. In particular, in the event of flooding of the underground structure with which the access device is associated, water can rise at high pressure and open the cover of the access device. The lid can thus be open, and remain so after the water has finished escaping.

In some extreme situations, the cover can be pushed out of its frame.

The danger of a person falling into the underground infrastructure is then significant, or even of the person being sucked in in the event of water reflux in the underground infrastructure.

This dangerous situation must therefore be avoided. Some legislation also provides, in certain cases, that access devices must be configured to ensure that they remain closed or that they return to a closed position after such an overflow.

However, it is not always desirable to provide the lid of an access device to an underground infrastructure with a lock that keeps it closed. If the cover does not allow the overflow of water, or more generally the release of a significant overpressure which occurs in the underground infrastructure, significant damage can be caused in the infrastructure, and an uncontrolled release of the water and/or pressure may occur at an undesired location.

In the context of protection against the consequences of underground explosions, document US8714867 discloses a manhole cover comprising a device which allows the cover to be lifted, but not expelled, when an underground explosion causing high overpressure occurs. product. This device is based on one or more holding legs, one of which is fixed through the lid, and rigidly held vis-à-vis the latter by means of a screw which fixes, on the upper surface of the cover, a holding leg plate.

This device, although effective, nevertheless has some disadvantages. In particular, when it is desired to fully open the access device, in order for example to allow an operator to enter the underground infrastructure, it is necessary to dismantle the leg fixed through the cover. In doing so, there is a risk of falling and/or losing the leg or the screw that holds it when opening the cover. Furthermore, once the lid is open, the leg and its retaining screw must be stored, with in particular the risk of leaving the screw on the road, which constitutes a danger for vehicles and pedestrians passing nearby.

The present invention aims to solve all or part of the drawbacks mentioned above.

The invention thus relates to a device for access to an underground installation, comprising a frame forming an opening for access to the underground installation and forming a seating surface for the cover.

The cover is pivotally mounted with respect to the frame, and has an upper face and a lower face opposite said upper face. The cover can assume a closed position in which it rests on the seat surface of the frame. Furthermore, the access device comprises a holding leg which comprises a hooked end portion. This support leg is positioned entirely under the underside of the lid, and is fixed to said lid. It is pivotable along an axis substantially orthogonal to the underside of the cover, so that the support leg can be positioned:
- either in an angular holding position in which the lid can be brought from the closed position to a half-open position in which the end portion of the holding leg mechanically interferes with the frame and prevents opening of the lid beyond said position ajar;
- Either in an angular release position, in which the cover can be brought from the closed position to an open position in which the opening of the frame is released, without the holding leg interfering mechanically with the frame.

The holding leg being pivotally mounted along an axis perpendicular to the pivoting axis of the cover, the passage from the angular holding position to the angular release position is done by simple pivoting of the leg, without any disassembly being necessary. necessary.

When the leg is in the angular holding position, the cover can only be raised to the half-open position. This allows the release of the pressure established in the underground installation, and for example the overflow of water rising in the manhole covered by the access device. Nevertheless, the ajar position can be adapted, using a leg of suitable length, so that once the overflow is over and/or the pressure in the underground installation has returned to a given pressure, the cover closes by itself. , under the effect of its weight.

When the leg is in the angular release position, the cover can be fully opened, and in particular opened in a stable open position, allowing access to the underground infrastructure.

The holding leg can be rigidly linked to a pin passing through the cover.

In particular, the shaft may comprise a shoulder bearing on the upper face of the lid or in a recess made in said upper face of the lid. The pin may have, on the upper face of the cover, a head adapted to be actuated by an appropriate key.

Such a configuration allows easy passage of the holding leg between the angular holding position and the angular release position. The assembly of the holding leg can be carried out very simply, by bringing said holding leg through the underside of the cover. In addition, a pre-existing cover, equipped with a hole for mounting a lock, can be equipped with a retaining leg in order to form an access device according to one embodiment of the invention. It is thus possible either to use an existing access device model to equip it as original equipment with a support leg, which is interesting in terms of the development costs of the solution but also in terms of logistics (a cover reference alone is enough to offer a solution with a classic lock and a solution with a support leg). It is also possible to retrofit a support leg on a pre-existing access device, instead of the lock fitted to the cover. This makes it possible to adapt an existing access device to new technical or regulatory constraints.

In addition, the surface used on the lid to achieve the attachment of the holding leg is small.

The support leg can for example be rigidly linked to the axis by at least one key. The key(s) secure the support leg to the shaft. This allows the support leg to be rotated from one angular position to another by simple rotation of the axis to which it is linked. The key is also sized to be able to take up the vertical force created by the overpressure present in the underground installation, which translates into a shearing force in the key.

The device may comprise a means for indexing the angular position of the support leg adapted to facilitate the positioning and to retain said support leg in at least two predefined angular positions, corresponding respectively to the angular position of support and the angular position of liberation. Typically, this holding means may comprise an indexing washer. The holding means may comprise means complementary to the indexing washer and an elastic device which tends to hold said complementary means in contact with the indexing washer, or the indexing washer in contact with the complementary means.

This type of angular indexing system is simple and effective. Similar systems are sometimes used on access lid locks to underground infrastructures. The general configuration of an access device in accordance with the present invention allows an adaptation of such an indexing system, which proves to be particularly relevant. Indeed, the transition from the angular holding position of the holding leg (which only allows the opening of the access device to a half-open position) to the angular release position (which allows it to be fully opened) is achieved by a simple change of angular position of the support leg.

In the half-open position, the cover can form an angle with respect to the frame of less than 45°, and preferably between 10° and 30°.

By "vis-à-vis the frame", we obviously mean vis-à-vis the general plan of extension of the frame, which is materialized in particular by the opening it forms.

The opening angle must be sufficient to allow the overflow of a liquid (typically water) through the access device, while remaining small enough to guarantee spontaneous closure of the cover after the overflow (or after a drop pressure in the underground installation with which the access device is associated A fairly small opening also makes it possible to avoid suction into the manhole of a large object or a person.

Advantageously, the holding leg is fixed to the underside of the lid close to an edge of the lid which is opposite to an axis of rotation of the lid with respect to the frame.

This preferential position of the support leg causes the lowest possible force in the support leg and avoids the generation of a tilting torque of the cover.

The holding leg may comprise a curved elongated portion, so that, said holding leg being in the angular holding position, when passing between the closed position and the half-open position of the cover, the distance between the frame and said elongated portion remains substantially constant.

This configuration makes it possible to fix the holding leg as close as possible to an edge of the lid, including when said holding leg is long and extends deeply under the lid.

The invention also relates to a method for obtaining such a device by installing, as a retrofit, a support leg on a pre-existing access device.

More specifically, the invention also relates to a method for obtaining an access device to an underground installation, on the basis of a pre-existing access device comprising a frame and a cover mounted pivoting vis-à-vis of said framework,
the cover having an upper face and a lower face opposite said upper face, the cover being able to adopt a closed position in which it rests on the seat surface of the frame, the cover comprising an orifice adapted to receive a latch and in which is mounted the lock or shutter.

The process includes the steps of:
- disassembly of the lock or the shutter, in order to free the orifice of the cover,
- supply of a support leg comprising a hooked end portion,
- positioning of the support leg under the underside of the lid,
- fixing of the holding leg by the orifice of the lid in a pivotable manner along an axis substantially orthogonal to the underside of the lid, so that the holding leg can be positioned:
- either in an angular holding position in which the lid can be brought from the closed position to a half-open position in which the end portion of the holding leg mechanically interferes with the frame and prevents opening of the lid beyond said position ajar;
- Either in an angular release position, in which the cover can be brought from the closed position to an open position in which the opening of the frame is released, without the holding leg interfering mechanically with the frame.

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:
there shows, in a sectional view, a device according to one embodiment of the invention, in a closed position;
there represents, according to a cross-sectional view, the device of the in a so-called ajar position;
there shows, in a partial three-dimensional view, a device according to one embodiment of the invention, the holding leg of the device being in a so-called holding angular position;
there represents, according to a view analogous to that of the , the device of the , the support leg being in a so-called angular release position,
there shows, in a partial three-dimensional view, a device according to one embodiment of the invention.

There represents an example of an access device 1 to an underground installation in accordance with one embodiment of the invention. The access device 1 comprises a frame 2 intended to be fixed in an integral manner to the ground, to a roadway, or to a fixed construction, and a cover 3. The cover 3 can be a hatch, a buffer, or any other element similar cover.

The frame 2 and the cover 3 can be made, for example, of ductile iron or steel.

The cover 3 is mounted articulated, in particular pivoting, vis-à-vis the frame 2 around a pivot axis (A) to allow the cover element 3 to pivot from a closed position to an open position and vice versa. . Hinge 4 shown in is for illustrative purposes only. Many types of joints can be used in order to make the lid 3 pivot, in the context of the present invention.

In the closed position, shown in , the cover 3 closes off the opening of the frame 2. In the open position of the cover, the opening of the frame is unobstructed, which makes it possible to check the underground installation located under the access device 1 and/or to access to a visit or inspection chimney of an underground network.

The device is shown in with its cover 3 in the closed position. In this position, the cover rests on a seating surface 5 of frame 2, formed by a peripheral wall internal to frame 2. A gasket 6 may be provided. The optional seal 6 can make it possible to dampen the shocks or vibrations of the cover 3. It can also, in certain embodiments, improve the seal between the cover 3 and the frame 2.

According to the invention, the access device comprises a holding leg 7. The holding leg 7 extends under a lower face 8 of the cover 3. The lower face 8 of the cover is located on the side of the underground installation at which the access device is associated, when the cover 3 is in the closed position. The lower face 8 is opposite an upper face 9 of the lid 3. The upper face 9 is exposed to the external environment when the lid is in the closed position. The upper face 9 corresponds in particular to the surface of the lid on which it is possible to circulate when the lid is in the closed position.

The support leg 7 is thus located entirely under the cover 3 (that is to say under the lower face 8 when the cover 3 is in the closed position), to which it is fixed. The support leg 7 is an elongated piece, which extends substantially perpendicular to the cover 3, that is to say substantially perpendicular to the lower face 8, along an axis of extension (E).

The support leg is made of a tensile strength material. It can be formed, for example, of cast iron, steel, or even a composite material, depending on the application in question.

The holding leg 7 is fixed to the cover 3 by means ensuring a solid fixing, while allowing rotation of the holding leg along its axis of extension (E), or along an axis close to its axis of extension ( E).

The support leg has an end part 10 forming a hook. In particular, the hook formed by the end part 10 comprises a bearing surface 11, substantially perpendicular to the axis of extension (E) of the support leg and which faces the lower face 8 of the cover 3.

In the exemplary embodiment shown here, and as clearly visible also at , the holding leg 7 is fixed to the lid 3 via a pin 12. The pin 12 is positioned in a hole formed in the lid 3 (it can be a hole formed for this or a hole initially formed to accommodate a lock). The shaft 12 thus has a portion located on the side of the upper face 9 of the cover. This portion of the shaft 12 can form a head 13, the shape of which allows the shaft to be turned using a tool. The head 13 can thus take various prismatic shapes. It can be for example a hexagonal head or a square head. The head 13 can be housed in a recess 14 formed in the upper face 9 of the lid 3, so that the head 13 does not protrude from the major extension plane of the upper surface 9. The axis 12 has a shoulder 15 coming into support in the recess 14, which blocks the axis 12 in translation. Alternatively, a support washer could be interposed between the cover and the head 13 of the pin, and/or the support of the pin 12 on the cover 3 could be made on the upper surface 9. This makes it possible to prevent the shaft from passing through the orifice of the cover 3, and allows the tensile forces of the shaft to be taken up on a surface of the cover 3.

The support leg 7 is fixed to the axis 12 using any appropriate means ensuring a rigid connection.

For example, pin 12 can be threaded, and the support leg has a threaded well into which pin 12 is screwed. In order to guarantee the maintenance in rotation of the support leg 7 with respect to the axis 12 (so that any rotation of the axis 12 causes an equivalent rotation of the support leg) various devices can be used. A lock nut can be placed on pin 12 and tightened on the support leg. A key 16, transverse to the support leg and crossing the axis 12 can be used. Alternatively, the key 16 can be sized to participate in (or ensure) the maintenance in translation of the support leg 7 vis-à-vis the axis 12. Several keys 16 can be used.

There represents the access device to an underground infrastructure of the , in a half-open position.

Between the closed position and the half-open position, the lid 3 has pivoted around the pivot axis (A) and it is no longer resting on the seat surface 5 of the frame 2. The pivoting of the lid 3 can be caused by the rise of pressurized water from the underground infrastructure, as can typically be the case during a flood, following heavy rains, etc. An increase in pressure in the underground infrastructure, for whatever reason, can also cause such a phenomenon.

In the half-open position, the bearing surface 11 of the end part 10 of the holding leg 7 comes into contact with a corresponding retaining surface 17. It is therefore the half-open position which precisely determines the orientation of the support surface 11, in order to maximize the contact surface between the support surface 11 and the retaining surface 17. Thus, the opening of the cover 3 beyond the ajar position is prevented. In this half-open position, the cover 3 forms an angle α of less than 90° with respect to the frame 2, and in particular with respect to the seat surface 5. This allows the cover to spontaneously return to its position closed when the water or gas pressure in the underground infrastructure falls below a certain threshold that no longer allows it to be kept in the half-open position. In practice, in order to facilitate this return to the closed position but also to avoid creating a large opening in the half-open position while nevertheless allowing an overflow of fluid and/or a release of pressure in the underground infrastructure, the support leg 7 can be dimensioned so that the angle α is between 5° and 60°, for example between 15° and 45°, such as around 30°.

The device that is the subject of the present invention thus fulfills the desired safety function, by a simple means.

Note that the support leg 7, although having an elongated shape along the extension axis (E), is not necessarily straight. In particular, the support leg may have a curved portion. This curvature of the holding leg 7 makes it possible to avoid any mechanical interference of the holding leg with the edge of the frame 2 when the cover passes from the closed position to the half-open position. It makes it possible to optimize the section of the support leg 7. Finally, it makes it possible to facilitate the formation and adaptation to the retaining surface 17 of the support surface 11 of the end part 10 of the support leg 7.

Compared to the solutions known in the state of the art, the object of the present invention has additional advantages which appear in the light of figures 3 and 4.

There shows a device according to one embodiment of the invention, the holding leg 7 of the device being in a so-called holding angular position. The angular holding position of the holding leg also corresponds to the position shown in and at the .

In the angular holding position of the holding leg 7, the lid 3 can pass from the closed position to the half-open position, and vice versa, but the holding leg 7 mechanically interferes with the frame 2 in the half-open position, preventing the lid from to be more open (as illustrated in ).

To the , the holding leg 7 has been brought into an angular release position. It will be noted that at the , in order to facilitate understanding of the figure, the support leg 7 is not shown cut according to the section plane adopted for the rest of the figure.

Compared to the , the support leg 7 has therefore been brought into the release position by pivoting through 90° (in the example shown here) along its axis of extension (E). The pivoting is obtained by rotational actuation of the head 13 of the axis 12, using a suitable tool, for example a key. The key 16 ensures the locking in rotation of the holding leg 7 vis-à-vis the axis 12, and therefore its concomitant rotation when the axis 12 is turned.

Of course, depending on the configuration of the holding leg 7 and more generally of the access device, the release position is not necessarily at 90° from the holding position.

In the release position, the end part 10 of the support leg, and the support surface 11, are shaped so as not to interfere mechanically with the frame 2 when the cover is opened. It is thus possible to fully open the cover, typically at an angle of 90° or slightly more with respect to frame 2.

Depending on the shape of the support leg and the shape of its end part, the angle between between the angular position of maintenance and the angular position of release is not necessarily 90°. It will also be noted that in the example shown, a rotation of 90° in one direction or the other makes it possible to switch to the angular release position from the angular holding position. Similarly, and by way of example for the embodiment represented, a rotation of 180° also makes it possible to achieve an angular position for releasing the support leg 7.

Thus, while the holding angular position is generally (but not necessarily) unique, several angular release positions can be adopted, at various angles depending on the shape of the holding leg and the configuration of the access device.

In order to help the user to position the support leg in the desired angular position, either to guarantee maintenance in the half-open position in the event of suppression and/or overflow in the underground infrastructure, or to allow the complete opening of the cover, an indexing means can be used.

In the exemplary embodiment shown in Figures 1 to 4, the indexing means is formed of an indexing washer and a complementary element. This type of device proves to be particularly suitable for the present application. An indexing washer is formed of a washer comprising notches or radial extra thicknesses, while the complementary element comprises shapes adapted to cooperate mechanically with the notches or extra thicknesses of the indexing washer. In some cases, the complementary element may be identical to the indexing washer.

For example, in the example shown, an indexing washer 18 is mounted on the shaft 12 and locked in rotation (but not in translation) with respect to the shaft 12. A suitable complementary element is formed by the cover 3, on the underside surrounding the orifice through which the shaft 12 passes through the cover 3. The indexing washer 18 is kept under pressure on the complementary element by an elastic element 19, namely a helical spring in the example shown here.

In addition, due to the force exerted by the elastic element, the shoulder 15 is kept in contact with the cover 3, so that the support leg 7 does not risk vibrating under said cover 3.

Due to the shape correspondence between the surface of the indexing washer 18 and the complementary element, an interlocking occurs between the indexing washer and the complementary element, when the holding leg 7 is in certain desired positions. , corresponding either to an angular holding position, or to an angular release position.

To pass from one angular position to another, it is necessary to overcome the restoring force created by the elastic element and which prevents inadvertent passage from one angular position to another. Obviously a configuration in which the indexing washer 18 is carried by the cover 3 and the complementary means is carried by the axis 12 can be used in the context of the present invention.

Alternatively or in addition to the indexing means described above, a stopper 20 can be used. The stop 20 is formed under the cover 3, projecting from its lower face 8. The stop 20 is configured to mechanically interfere with the holding leg 7 in order to prevent its rotation, in a direction of rotation, beyond a given angular position. This angular position advantageously corresponds to the holding position. The user is thus certain, when the support leg is supported on the stop 20 by rotation of the axis 12, that the support leg 7 is correctly positioned in the support position.

In the example represented here, the holding leg 7 comprises a lug 21 adapted to cooperate with the stop 20.

Of course, a second stop can be provided in order to unequivocally determine an angular position of opening of the support leg.

By using a stopper and an indexing means such as an indexing washer in combination, the stopper makes it possible to guarantee that the support leg is in the desired position (in the angular position of maintenance or in a position of opening), while the indexing washer ensures that the support leg remains in this position.

The invention thus developed makes it possible to obtain a safety function, namely to allow an overflow of liquid and/or a release of pressure by an access device to an underground infrastructure, for example of the "drain hole" type. man”, while guaranteeing a return of the access device to the closed position when the cause of the opening ceases. Compared to known devices, the device proposed in the invention is simple to implement. In particular, it is possible to equip access devices adapted to receive a lock as original equipment, and/or to replace the lock on existing devices with a holding leg according to the configuration proposed in the invention. In addition, no disassembly is required to fully open the access device cover. There is no risk of losing an item.

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Claims (11)

Access device (1) to an underground installation,
comprising a frame (2) forming an opening for access to the underground installation and forming a seating surface (5) for the cover (3),
the cover (3) being pivotally mounted with respect to said frame (2), the cover having an upper face and a lower face opposite to said upper face,
the cover (3) being able to assume a closed position in which it rests on the seat surface (5) of the frame (2),
the access device comprising a holding leg (7) which comprises a hooked end portion (10),
characterized in that
the holding leg (7) is positioned entirely under the lower face (8) of the lid (3), and is fixed to said lid (3), and
the holding leg (7) is pivotable along an axis substantially orthogonal to the underside (8) of the cover (3), so that the holding leg (7) can be positioned
- either in an angular holding position in which the lid (3) can be brought from the closed position to a half-open position in which the end portion (10) of the holding leg (7) mechanically interferes with the frame (2) and prevents opening of the cover (3) beyond said half-open position;
- either in an angular release position, in which the lid (3) can be brought from the closed position to an open position in which the opening of the frame is free, without the holding leg (7) interfering mechanically with the frame (2). Device according to Claim 1, in which the holding leg (7) is rigidly connected to a pin (12) passing through the cover (3). Device according to Claim 2, in which the pin (12) comprises a shoulder (15) bearing on the upper face (9) of the lid (3) or in a recess (14) formed in the said upper face (9) of the cover (3). Device according to claim 3, in which said pin (12) has, on the upper face (9) of the cover (9), a head (13) adapted to be actuated by a suitable key. Device according to one of Claims 2 to 4, in which the holding leg (7) is rigidly linked to the pin (12) by at least one key (16). Device according to one of the preceding claims comprising means for indexing the angular position of the support leg adapted to facilitate the positioning and to retain the said support leg in at least two predefined angular positions, corresponding respectively to the angular position of maintenance and angular release position. Device according to Claim 6, in which the holding means comprises an indexing washer (18). Device according to Claim 7 comprising a means complementary to the indexing washer (18) and an elastic device (19) which tends to maintain the said complementary means in contact with the indexing washer (18), or the indexing washer (18) in contact with the complementary means. Device according to one of the preceding claims, in which the cover (3) forms, in the ajar position, an angle with respect to the frame (2) of less than 45°, and preferably between 10° and 30°. Device according to one of the preceding claims, in which the holding leg (7) is fixed to the underside (8) of the cover near an edge of the cover which is opposite to a pivot axis (A) of the cover (3) vis-à-vis the frame. Method for obtaining an access device to an underground installation according to one of the preceding claims, on the basis of a pre-existing access device comprising a frame (2) and a lid (3) mounted to pivot -towards said frame (2),
the lid having an upper face and a lower face opposite said upper face,
the cover (3) being able to assume a closed position in which it rests on the seat surface (5) of the frame (2),
the lid comprising an orifice adapted to receive a lock and in which the lock or a shutter is mounted,
the method comprising the steps of:
- disassembly of the lock or the shutter, in order to free the orifice of the cover (3),
- provision of a support leg (7) comprising a hook end portion (10),
- positioning of the support leg under the underside (8) of the cover (3),
- fixing of the holding leg (7) by the orifice of the lid (3) in a pivotable manner along an axis substantially orthogonal to the underside (8) of the lid (3), so that the holding leg (7) can be positioned:
- either in an angular holding position in which the cover (3) can be brought from the closed position to a half-open position in which the end portion (10) of the holding leg (7) mechanically interferes with the frame (2) and prevents opening of the cover (3) beyond said half-open position;
- either in an angular release position, in which the cover (3) can be brought from the closed position to an open position in which the opening of the frame is released, without the holding leg (7) interfering mechanically with the frame (2).