Device for accessing an underground facility provided with a lock
Patent Information
- Application Number
- PCT/EP2026/058521
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-25
- Filing Date
- 2026-03-25
- Publication Date
- 2026-10-01
Smart Images
Figure EP2026058521_01102026_PF_FP_ABST
Abstract
Description
[0001] Locking of an access device to an underground installation
[0002] TECHNICAL FIELD OF THE INVENTION
[0003]
[0001] The invention relates to the field of access devices to an underground installation, also called roadway manholes, of the type comprising a fixed frame forming an opening giving access to the underground installation and a cover configured to close the opening.
[0004]
[0002] More specifically, the invention relates to a locking system for the lid on the fixed frame, for example to prevent accidental lifting of the lid.
[0005] STATE OF THE ART
[0006]
[0003] Figure 1 represents a known locking system in which an access device 100 comprises a fixed frame 102, a cover 103, shown here in a closed position where it rests on the fixed frame 102, and screws 104. For simplicity, reference will be made only to one screw.
[0007]
[0004] The fixed frame 102 has a through opening 105 and insert 106, provided in the through opening 105 and forming a threaded bore to engage with the threaded part of the screw 104.
[0008]
[0005] The cover 103 is provided with a through hole 107 through which passes the threaded part of the screw 104 and a counterbore 108 to countersink the head of the screw 104.
[0009]
[0006] During the installation of the screws 104, sand, dust, and other impurities can accumulate on the threads of the screw 104 and the threads of the insert 106. This accumulation can make tightening difficult and lead to damage to the threads (cross-threading). In some cases, applying a higher tightening torque to overcome the resistance due to this accumulation can cause the screw 104 to loosen unintentionally.
[0010]
[0007] A method of pouring water on the threads before installation has been proposed, but has proven impractical.
[0011]
[0008] In addition, to ensure effective locking, the access device 100 requires several screws 104, typically at least four, which makes installation and disassembly tedious and time-consuming.
[0012]
[0009] Furthermore, this locking system involves a relatively complex design of the fixed frame 102 and the cover 103, resulting in a costly manufacturing process. STATEMENT OF THE INVENTION
[0013]
[0010] The present invention aims to remedy all or part of the disadvantages of the prior art mentioned above by providing an access device of the same type, which is both convenient to use and simple to manufacture and which allows reliable locking.
[0014]
[0011] To this end, the invention relates, according to a first aspect, to a device for accessing an underground installation comprising:
[0015] - a fixed frame forming an opening for access to the underground installation and comprising an engagement zone,
[0016] - a cover configured to assume a closed position in which it rests on the fixed frame and at least partially obstructs the opening, the cover having an inner face, an outer face opposite the inner face, and a through orifice, and - a locking mechanism for the cover on the fixed frame, attached and having: o an engagement portion configured to engage in the engagement zone of the fixed frame, and
[0017] o a portion of the stop mechanically connected to the engagement portion and configured to face the outer face of the cover so as to prevent its lifting when the engagement portion is engaged in the complementary engagement zone of the fixed frame,
[0018] characterized in that the through orifice is configured to permit the passage of the engagement portion, and in that the engagement portion is configured to engage by snapping into the engagement zone of the fixed frame, whereby, while the cover is in the closed position, the engagement portion can be introduced through the through orifice from the external face of the cover and engage by snapping into the engagement zone, thus locking the cover onto the fixed frame.
[0019]
[0012] The access device according to the invention makes it possible to lock the cover onto the fixed frame simply by inserting the locking member into the through orifice of the cover, when the cover is in the closed position.
[0020]
[0013] The snap-lock engagement only requires applying sufficient force to the locking member to overcome the mechanical resistance due to the elastic deformation of the locking member and / or the fixed frame, which is particularly simple and convenient to implement. For example, locking can be achieved by applying pressure to the locking member with the hand or foot, without requiring any specific tool.
[0021]
[0014] Furthermore, the elastic deformation implemented during the snap-lock engagement is not affected by the presence of dust. In other words, the presence of dust does not impair the locking of the cover onto the fixed frame. The access device therefore ensures reliable locking even in the presence of dust.
[0022]
[0015] Moreover, because the locking mechanism is an added element (independent of the rest of the access device), the cover does not require any specific adaptation, other than the presence of a through hole, and is therefore very simple to manufacture.
[0023]
[0016] The access device according to the invention is therefore convenient to use, simple to manufacture and allows reliable locking of the cover onto the fixed frame.
[0024]
[0017] Locking is understood to mean keeping the cover in place on the fixed frame, preventing it from being lifted when an external force greater than its own weight is exerted.
[0025]
[0018] Preferred, simple, convenient and economical features of the access device according to the invention are presented below.
[0026]
[0019] The engagement portion of the locking member may include a ramp forming an angle of less than 90° with a direction of insertion and extraction of the engagement portion.
[0027]
[0020] The insertion and extraction direction of the engagement portion can be substantially orthogonal to a general extension plane of the cover in its closed position.
[0028]
[0021] Thus, to unlock the lid, it is sufficient to pull on the locking mechanism to overcome the aforementioned mechanical resistance. It is also possible to pull on the lid itself, which will then move the locking mechanism via the stop portion. Unlocking is therefore also very simple to perform.
[0029]
[0022] The smaller this angle, the less effort is required to disengage the engaged portion. However, it is important to maintain sufficient locking force to prevent accidental lifting of the cover. An angle between 10° and 45° has proven to offer a good compromise between ease of unlocking and secure retention of the cover.
[0030]
[0023] The locking member may include an elastic part which is elastically deformed when the engagement portion is engaged in the engagement zone of the fixed frame.
[0031]
[0024] Since the locking member is elastically deformable, it is not necessary for the fixed frame to include an elastically deformable portion to allow engagement by snap-fit. The fixed frame can be very simple to manufacture. Moreover, in case of wear, it is much easier and much less expensive to replace the locking member than the fixed frame.
[0032]
[0025] The locking member may have an overall U-shaped form and may comprise a central connecting arm and two lateral arms extending opposite each other from the central connecting arm, each lateral arm having a ratcheting section extending opposite the ratcheting section of the other lateral arm, the ratcheting sections defining between them a narrowed or widened area of the lateral arms, the central connecting arm forming the stop portion and the ratcheting sections forming the engagement portion.
[0033]
[0026] The term "generally U-shaped" refers to a configuration whose geometry resembles a U, without being strictly limited to a rounded curvature. It can thus include variants such as a V-shaped form, a U-shaped form with straight segments and sharp edges, or even a form with more or less open angles, provided that the whole defines two lateral branches connected by a connecting branch.
[0034]
[0027] Thanks to its overall U-shaped configuration, the stresses due to elastic deformation are distributed between the lateral arms, thereby improving the durability of the locking mechanism. The presence of two lateral arms also provides a double contact area with the frame, reducing the risk of accidental unlocking.
[0035]
[0028] Each ratcheting section can form an inclined ramp which approaches the ratcheting section of the other lateral branch as it moves away from the central connecting branch, each ratcheting section forming an angle of less than 90° with an insertion and extraction direction of the engagement portion.
[0036]
[0029] An angle between 10° and 45° has proven to be advantageous in the case of a locking member with an overall U-shaped form because, in addition to the advantages mentioned above, it allows, in combination with the elastic return force of the lateral branches which tends to bring them closer together, to stress the locking member in the direction of insertion and extraction, which promotes the maintenance of the lock and also the maintenance of the central connecting branch against the external face of the cover.
[0037]
[0030] The central connecting arm can be in the form of a plate and can be held against a bearing area of the outer face of the cover when the engagement portion is engaged in the engagement area of the fixed frame, the bearing area extending in the same plane as the rest of the outer face of the cover.
[0038]
[0031] The bearing area is the area of the cover that abuts against the stop portion of the locking mechanism when the cover is lifted while locked onto the fixed frame. This bearing area is flush with the rest of the outer face of the cover. This is made possible by the plate shape of the central connecting arm, which creates only a slight protrusion compared to the outer face of the cover, thus presenting a low risk of snagging or obstruction that could cause a pedestrian to fall or a vehicle to be struck.
[0032] At least one lateral branch may include a curved end portion, the access device being configured so that, when the engagement portion is introduced into the through orifice, the end portion is brought closer to the rest of the lateral branch by elastically deforming in contact with the walls of the through orifice, and then tends to move away from the rest of the branch by elastic recoil after passing through the through orifice, so as to prevent the withdrawal of the curved end portion.
[0039]
[0033] Thus, the risk of the locking device falling or being lost is reduced.
[0040]
[0034] Each lateral branch has a curved end portion generally in the shape of a U, each end portion comprising a central connecting wing and two lateral wings extending opposite each other from the central connecting wing, namely a first lateral wing by which the end portion is connected to the lateral branch and a second lateral wing having a free end.
[0041]
[0035] The locking mechanism can thus serve as a handle for easily carrying the lid.
[0042]
[0036] The cover may include a pair of separate through holes, each through hole of the pair being configured to allow passage of a ratcheting section of the locking member.
[0043]
[0037] In other words, the two through-holes of each pair are physically separated from each other; that is, they do not form a single continuous opening. This configuration thus allows for a smaller open surface area, limiting the entry of dust or debris.
[0044]
[0038] The frame engagement area may include a lug extending projecting into the opening.
[0045]
[0039] The presence of a lug helps to preserve the robustness of the fixed frame.
[0046]
[0040] The lug may have an upper face facing the cover, a lower face opposite the upper face, and two opposite lateral faces, each connecting the lower face to the upper face and gradually moving away from each other in a direction from the upper face to the lower face, and the access device being configured so that, when the engagement portion is introduced through the through orifice, each ratcheting section slides along a respective lateral face of the lug, with the lateral branches moving away from each other and being elastically deformed, until they pass the lateral face, where the lateral branches come together by elastic return effect and the ratcheting section engages against the lower face of the lug.
[0047]
[0041] Alternatively, the frame engagement area may include an opening provided in a plate, such as a plate forming a support surface for the cover.
[0048]
[0042] The engagement area can thus be made on different types of frames, including on existing frames, for example by a simple cut.
[0043] The plate may have an upper face facing the cover, a lower face opposite the upper face, the opening being delimited by two opposite faces, each connecting the lower face to the upper face and progressively approaching each other in a direction from the upper face to the lower face, the access device being configured so that, when the engagement portion is introduced through the through orifice, the ratcheting section slides along a respective lateral face delimiting the opening, with the lateral branches approaching each other and being elastically deformed, until they pass through the lateral face, where the lateral branches move away from each other by elastic return effect and the ratcheting section engages against the lower face of the plate.
[0049]
[0044] The locking member can be made in one piece.
[0050]
[0045] A one-piece locking element provides better robustness and is simpler to manufacture.
[0051]
[0046] The locking member can be made by bending a flat piece.
[0052]
[0047] This further simplifies the manufacture of the locking mechanism.
[0053]
[0048] It should be noted that the realization of the locking member by folding is identifiable by the presence of visible fold lines, a characteristic radius of curvature and local variations in structure or hardness of the material resulting from the folding.
[0054]
[0049] The cover may have a gripping recess on its external face and configured to allow the passage of a tool to disengage the locking member from the engagement area of the fixed frame.
[0055]
[0050] This simplifies unlocking the cover, particularly when manually grasping the locking mechanism is difficult. It should be noted that, depending on the size of the gripping recess, it may also be possible to insert a finger, allowing the locking mechanism to be disengaged manually.
[0056]
[0051] The cover can be made of composite material.
[0057]
[0052] Snap-locking is particularly well-suited to a cover made of composite material. On the one hand, it limits localized mechanical stresses that could weaken the material. On the other hand, such a locking mechanism is particularly tolerant of dimensional variations, as it relies on elastic deformation. Indeed, a cover made of composite material is generally manufactured by molding and can therefore exhibit slight dimensional variations from one piece to another.
[0058]
[0053] The fixed frame can be made of composite material.
[0059]
[0054] The access device may include several through-holes distributed around the periphery of the cover, several engagement zones, and several locking members configured to cooperate with at least some of the engagement zones through the through-holes. BRIEF DESCRIPTION OF THE FIGURES
[0060]
[0055] The invention, according to an exemplary embodiment, will be well understood and its advantages will become more apparent upon reading the detailed description that follows, given by way of example and in no way limiting, with reference to the attached drawings.
[0061]
[0056] Figure 1 represents, according to a partial three-dimensional cross-sectional view, a prior art access device.
[0062]
[0057] Figure 2 represents, in perspective view, an access device according to one embodiment of the invention.
[0063]
[0058] Figure 3 is an isolated front view of a locking member of the access device.
[0064]
[0059] Figure 4 is a partial three-dimensional cross-sectional view of the access device, labeled VI-VI in Figure 2, showing in isolation a cover of the device.
[0065]
[0060] Figure 5 is a partial three-dimensional view of a fixed frame of the access device.
[0066]
[0061] Figure 6 is a partial three-dimensional cross-sectional view of the access device, labeled VI-VI in Figure 2, showing the locking of the cover onto the fixed frame via the locking member.
[0067]
[0062] Figure 7 shows, according to a partial three-dimensional view, a variant of the locking member of Figure 2.
[0068] DETAILED DESCRIPTION OF THE INVENTION
[0069]
[0063] As previously stated, the invention relates generally to the locking of a cover of an access device to an underground installation and relates in particular to an access device of the type comprising a fixed frame and a cover.
[0070]
[0064] Underground installations or infrastructure include, in particular, buried water networks, sewers, communication networks, and electrical networks.
[0071]
[0065] The access device, and in particular its cover, can be made of metal, for example ductile iron, or of composite material.
[0072]
[0066] The invention aims to provide a locking system for the cover on the fixed frame by snap-fitting, by means of an added locking member which does not require handling the cover for its placement, or even for its removal.
[0073]
[0067] Snap-fitting is an assembly mechanism in which an elastically deformable element engages with a complementary element by passing through a resistance zone, then returns to its initial position to ensure holding in place, without requiring a tool.
[0074]
[0068] Various embodiments are possible. In particular, the locking member can take various forms.
[0069] Figure 2 represents an access device 1 to an underground installation according to an example of an embodiment of the invention.
[0075]
[0070] The access device comprises a fixed frame 2 forming an opening (not visible) for access to the underground installation, a cover 4 configured to take a closed position, shown in Figure 2, in which it rests on the fixed frame 2 and at least partially closes the opening.
[0076]
[0071] The cover 4 is held in contact with the fixed frame 2 by its own weight.
[0077]
[0072] In the example shown, the cover 4 is a separate element from the fixed frame 2, without any permanent connection between them, such as a joint. It can be lifted and removed freely, independently of the fixed frame 2.
[0078]
[0073] The access device 1 further includes locking members 6 configured to lock the cover 4 onto the fixed frame 2, i.e. to keep the cover in place on the fixed frame, opposing its lifting when an external force greater than its own weight is exerted.
[0079]
[0074] The locking members 6 are configured to pass through the cover 4 and engage by snapping into the fixed frame 2.
[0080]
[0075] In the example shown, the fixed frame 2 and the cover 4 have a rectangular shape, and the locking members 6, here four in number, are arranged at each corner of the cover 4.
[0081]
[0076] Figure 3 shows in isolation a locking member 6 according to an example of an embodiment of the invention.
[0082]
[0077] The locking member 6 has an engagement portion 12 configured to engage by snapping into the fixed frame 2 and a stop portion 14 mechanically connected to the engagement portion 12 and configured to come opposite the cover 4 so as to prevent its lifting when the engagement portion 12 is engaged by snapping into the fixed frame 2.
[0083]
[0078] In the example shown, the locking member 6 has an overall U-shaped form and comprises a central connecting arm 14 and two lateral arms 16 extending opposite each other from the central connecting arm 14.
[0084]
[0079] The lateral branches 16 each have a ratcheting section 17 and a guide section 18 extending from the ratcheting section 17, with the ratcheting section 17 being between the guide section 18 and the central connecting branch 14.
[0085]
[0080] In this example, the central connecting arm 14 forms the stop portion and the ratcheting sections 17 form the engagement portion 12.
[0081] The ratcheting sections 17 are opposite each other and define between them a narrowed area 20 of the lateral arms 16, in which the spacing between the lateral arms 16 is reduced.
[0086]
[0082] Each snap-in section 17 forms an inclined ramp which approaches the snap-in section 17 of the other lateral branch 16 as it moves away from the central connecting branch 14.
[0087]
[0083] In other words, on the same branch 16, the ratcheting section 17 is inclined in a first direction and the guide section 18 is inclined in a second direction opposite to the first direction.
[0088]
[0084] It should be noted that the locking member 6 is here made in one piece and is shaped by folding a flat piece. The central connecting arm 14 is thus in the shape of a plate.
[0089]
[0085] Figure 4 represents the lid 4 taken in isolation.
[0090]
[0086] The cover has an inner face 23 intended to be turned towards the fixed frame when the cover is in the closed position, shown in Figure 2, an outer face 24 opposite the inner face 23, and several pairs of through holes 26 opening onto both the inner face 23 and the outer face 24.
[0091]
[0087] The inner face 23 and the outer face 24 are generally flat.
[0092]
[0088] The cover 4 here has patterns 27 projecting from the outer face 24 to limit the risk of slipping of a user walking on the cover.
[0093]
[0089] Each through orifice 26 of the same pair is configured to allow the passage of a respective snap-in section of a locking member.
[0094]
[0090] The through holes 26 can be dimensioned to allow passage with or without deformation of the snap-in section.
[0095]
[0091] In the example shown, the cover 4 has four pairs of through holes 26, but only one pair is visible in Figure 4.
[0096]
[0092] The through orifices 26 of each pair are here formed by two rectangular slits extending at a distance and parallel to each other.
[0097]
[0093] The external face 24 of the cover has bearing areas 28 configured each to come into contact with the stop portion of a locking member when the cover is lifted while locked onto the fixed frame.
[0098]
[0094] In the example shown, the external face 24 has four bearing areas 28 and each bearing area 28 extends between the through holes 26 of a pair.
[0099]
[0095] Each support zone 28 extends in the same plane, that is to say, is at the same level as the rest of the external face 24. Each support zone 28 is moreover here coincided with the rest of the external face 24.
[0096] The internal face 23 of the cover 4 further includes a gripping recess 29 configured to allow the passage of a tool to disengage the locking member of the fixed frame.
[0100]
[0097] The gripping recess extends across the bearing area and an area directly adjacent to the bearing area to facilitate the insertion of the tool between the outer face and the central connecting arm of the locking member.
[0101]
[0098] Figure 5 represents the fixed frame 2 taken in isolation.
[0102]
[0099] The fixed frame Leti 2 has a bearing surface 31 configured to support the cover 4 in its closed position and engagement zones 32 each configured to engage by snapping with a locking member.
[0103]
[0100] In the example shown, the fixed frame 2 has four engagement zones 32 (but only one engagement zone is visible in Figure 5) and each engagement zone 32 has a lug 33 extending outward into the opening 30 formed by the fixed frame 2.
[0104]
[0101] The lug 33 has an upper face 34 facing towards the cover 4, an lower face 35 opposite the upper face 34, and two opposite lateral faces 36, each connecting the upper face 34 to the lower face 35 and gradually moving away from each other in a direction from the upper face 34 to the lower face 35.
[0105]
[0102] In other words, the ergot 33 has a trapezoidal shape in section.
[0106]
[0103] The lateral faces 36 of the lug 33 are configured to be opposite the through holes 26 of the same pair of the cover 4 when it is in its closed position, so that by introducing an object through a through hole 26 perpendicular to a general plane of extension of the cover 4, this object comes into contact with one of the lateral faces 36 of the lug 33.
[0107]
[0104] The fixed frame here includes a peripheral rim 38 configured to position and hold the cover 4 in a determined position where the through holes 26 are aligned with the lateral faces 36 of the lug 33.
[0108]
[0105] The locking of the cover 4 onto the fixed frame 2 by means of the locking member 6 will now be described with reference to figure 6.
[0109]
[0106] The cover 4 is first placed in the closed position where its inner face rests on the bearing surface of the fixed frame 2 and at least partially closes the opening. In this position, each through-hole 26 of the same pair is opposite (or aligned) with a respective lateral face 36 of a lug 33. This alignment is ensured by the peripheral rim of the fixed frame which forces the cover into a specific position.
[0110]
[0107] The snap-in sections 17 are then introduced into the through holes 26 of the same pair from the outer face of the cover 4 (or from outside the access device) according to an insertion and extraction direction, represented by the axis F in Figure 6, in a direction going from the outer face of the cover 4 towards its inner face (we speak of the insertion direction for simplicity).
[0111]
[0108] During the introduction, the ratcheting section 17 of each lateral branch slides along a respective lateral face 36 of the lug, with the lateral branches moving away from each other and being elastically deformed, until they pass the lateral face 36, where the lateral branches come together again by elastic return effect and each ratcheting section 17 engages against the lower face 35 of the lug 33.
[0112]
[0109] It will be noted that each guide section 18 prevents a free end of the lateral branch from getting stuck during insertion, in particular between the cover 4 and the lug 33 in the event of a slight gap between them, or if the upper face of the lug protrudes laterally so as to be slightly opposite the through orifice 26.
[0113]
[0110] It will also be noted that due to the angle a between the ramp formed by the ratcheting section and the insertion direction F and the elastic return of the lateral branches (which tends to bring them closer together), the locking member 6 is stressed in the insertion direction F, which promotes the maintenance of the locking and also the maintenance of the central connecting branch against the external face of the cover 4.
[0114]
[0111] In the example shown, the insertion direction F is orthogonal to the general plane of the cover 4 and the angle α between the ramp formed by each snap-in section 17 and this direction F is approximately 20°. This angle allows the snap-in sections 17 to be easily disengaged from the lug 33.
[0115]
[0112] Thus, to unlock the cover 4 from the fixed frame 2, the locking member 6 is moved along the insertion and extraction direction F, but in the opposite direction (referred to as the extraction direction for simplicity). This can be done by moving the central connecting arm away from the cover 4, either manually or by means of a tool inserted into the gripping recess. It is also possible to move the cover 4 away from the fixed frame 2 by lifting it with sufficient force to disengage the ratcheting sections 17 from the lug 33.
[0116]
[0113] The access device 1 thus makes it possible to lock the cover 4 onto the fixed frame 2 simply by inserting the locking members 6 into the through holes 26 of the cover 4, when the latter is in the closed position, represented in figure 2.
[0117]
[0114] The snap-on engagement only requires applying sufficient force to the locking member to overcome the mechanical resistance due to the elastic deformation of the locking member 6, which is particularly simple and convenient to implement. For example, locking can be achieved by applying pressure to each locking member 6 with the hand or foot, without requiring any special tools.
[0115] Furthermore, the elastic deformation induced during snap-on engagement is unaffected by the presence of dust. In other words, the presence of dust does not impair the locking of the cover 4 onto the fixed frame 2. The access device 1 therefore ensures reliable locking even in the presence of dust.
[0118]
[0116] Moreover, because the locking members 6 are added elements (independent of the rest of the access device), the cover 4 does not require any specific adaptation, except for the presence of through holes 26, and is therefore very simple to manufacture.
[0119]
[0117] The access device 1 is therefore convenient to use, simple to manufacture and allows reliable locking of the cover 4 onto the fixed frame 2.
[0120]
[0118] Figure 7 represents a locking member 60 according to an alternative embodiment of the invention.
[0121]
[0119] The locking member 60 differs from the locking member of figure 3 in that each lateral arm 16 has a curved end portion 62.
[0122]
[0120] The end portions 62 are here curved in opposite directions, which here move away from each other.
[0123]
[0121] In addition, here, each curved end portion 62 has an overall U-shaped form.
[0124]
[0122] Each end portion 62 then comprises a central connecting wing 63 and two lateral wings extending opposite each other from the central connecting wing 63, namely a first lateral wing 64 by which the end portion 62 is connected to the lateral branch 16 and a second lateral wing 65 which has a free end 66.
[0125]
[0123] The end portion 62 is configured to admit a first rest configuration and a second configuration in which the first lateral wing 64 and the second lateral wing 65 are brought close together, with the central connecting wing 63 which is elastically deformed.
[0126]
[0124] The access device is configured so that, when the snap-in sections are introduced into the through holes, each end portion 62 passes from its first rest configuration to its second configuration in contact with the walls of the through hole, and then tends to return to its first configuration after passing through the through hole.
[0127]
[0125] Depending on the available space under the cover, the lateral wings 64, 65 can move away from each other without necessarily returning to their initial configuration. However, as the lateral branches move away from each other, the spacing between them becomes greater than the dimensions of the through-hole. Consequently, the free end 66 of the second lateral wing 65 is located facing the inner face of the cover.
[0128]
[0126] Thus, when the locking member is moved in the extraction direction, the ratchet sections are disengaged from the lugs (if they were), and the free end 66 of the end portion 62 comes to rest against the inner face of the lid. The locking member can then serve as a handle for easily carrying the lid.
[0129]
[0127] It should be noted that, thanks to the overall U-shape, the force exerted on the free end 66 is distributed uniformly in the end portion 62, which gives it good mechanical resistance.
[0130]
[0128] Unillustrated variants are shown below.
[0131]
[0129] The cover can be hinged with respect to the fixed frame.
[0132]
[0130] The device may include several covers.
[0133]
[0131] The cover and the fixed frame can have a different shape, for example round.
[0134]
[0132] The fixed frame may have several engagement zones, and only some of them may have a lug. Other zones may be different, and for example have an opening.
[0135]
[0133] The end portion(s) may have a different shape.
[0136]
[0134] More generally, the invention is not limited to the examples described and represented.
Claims
Demands 1. Device for accessing an underground installation comprising: - a fixed frame (2) forming an opening (30) for access to the underground installation and comprising an engagement zone (32), - a cover (4) configured to assume a closed position in which it rests on the fixed frame (2) and at least partially obstructs the opening (30), the cover (4) having an inner face (23), an outer face (24) opposite the inner face (23), and a through orifice (26), and - a locking mechanism (6, 60) for the cover (4) on the fixed frame (2), attached and having: o an engagement portion (12) configured to engage in the engagement zone (32) of the fixed frame (2), and o a stop portion (14) mechanically connected to the engagement portion (12) and configured to come opposite the outer face (24) of the cover (4) so as to prevent its lifting when the engagement portion (12) is engaged in the complementary engagement zone (32) of the fixed frame (2), characterized in that the through orifice (26) is configured to allow the passage of the engagement portion (12), and in that the engagement portion (12) is configured to engage by snapping into the engagement zone (32) of the fixed frame (2), whereby, while the cover (4) is in the closed position, the engagement portion (12) can be introduced through the through orifice (26) from the outer face (24) of the cover (4) and engage by snapping into the engagement zone (32), thus locking the cover (4) onto the fixed frame (2).
2. Access device according to claim 1, wherein the locking member (6, 60) includes an elastic part which is elastically deformed when the engagement portion (12) is engaged in the engagement zone (32) of the fixed frame (2).
3. Access device according to claim 1 or 2, wherein the locking member (6, 60) has an overall U-shaped form and comprises a central connecting arm (14) and two lateral arms (16) extending opposite each other from the central connecting arm (14), each lateral arm (16) having a ratcheting section (17) extending opposite the ratcheting section (17) of the other lateral arm (16), the ratcheting sections (17) defining between them a narrowed (20) or widened area of the lateral arms (16), the central connecting arm (14) forming the stop portion (14) and the ratcheting sections (17) forming the engagement portion (12). 4.Access device according to claim 3, wherein each ratcheting section forms an inclined ramp which approaches the ratcheting section (17) of the other lateral branch (16) as it moves away from the central connecting branch (14), each ratcheting section (17) forming an angle of less than 90° with an insertion and extraction direction (F) of the engagement portion (12).
5. Access device according to claim 3 or 4, wherein the central connecting arm (14) is plate-shaped and is held against a bearing area (28) of the outer face (24) of the cover (4) when the engagement portion (12) is engaged in the engagement area (32) of the fixed frame (2), the bearing area (28) extending in the same plane as the rest of the outer face (24) of the cover (4).
6. Access device according to any one of claims 3 to 5, wherein at least one lateral arm (16) has a curved end portion (62), the access device being configured so that, when the engagement portion (12) is introduced into the through orifice (26), the end portion (62) is brought closer to the rest of the lateral arm (16) by elastically deforming in contact with the walls of the through orifice (26), and then tends to move away from the rest of the arm by elastic return effect after passing through the through orifice (26), so as to prevent the withdrawal of the curved end portion (62).
7. Access device according to claim 6, wherein each lateral arm (16) has a curved end portion (62) of overall U-shape, each end portion (62) comprising a central connecting wing (63) and two lateral wings extending opposite each other from the central connecting wing (63), namely a first lateral wing (64) by which the end portion (62) is connected to the lateral arm (16) and a second lateral wing (65) having a free end (66).
8. Access device according to any one of claims 3 to 7, wherein the cover (4) has a pair of separate through holes (26), each through hole (26) of the pair being configured to permit the passage of a ratcheting section (17) of the locking member (6, 60).
9. Access device according to any one of claims 3 to 8, wherein the engagement area (32) of the frame has a lug (33) extending projecting into the opening (30).
10. Access device according to claim 9, in which the lug has an upper face (34) facing the cover (4), a lower face (35) opposite the upper face (34), and two opposing lateral faces (36), each connecting the upper face (34) to the lower face (35) and gradually moving apart from each other in a direction from the upper face (34) to the lower face (35), and the access device being configured so that, when the engagement portion (12) is introduced through the through orifice (26), each latching section (17) slides along a respective lateral face (36) of the lug (33), with the lateral arms (16) moving apart from each other and being elastically deformed, until they pass through the lateral face (36),where the lateral arms (16) are brought closer together by elastic recoil and the ratcheting section (17) engages against the lower face (35) of the lug (33).
11. Access device according to any one of claims 1 to 10, wherein the locking member (6, 60) is made in one piece.
12. Access device according to any one of claims 1 to 11, wherein the locking member (6, 60) is made by folding a flat piece.
13. Access device according to any one of claims 1 to 12, wherein the cover (4) has a gripping recess (29) formed on its external face (24) and configured to allow the passage of a tool to disengage the locking member (6) from the engagement area (32) of the fixed frame (2).
14. Access device according to any one of claims 1 to 13, wherein the cover (4) is made of composite material.
15. Access device according to any one of claims 1 to 14, comprising several through holes (26) distributed around the periphery of the cover (4), several engagement zones (32) and several locking members (6, 60) configured to cooperate with at least some of the engagement zones (32) through the through holes (26).