EP2177668A2

EP2177668A2 - Manhole shaft

Info

Publication number: EP2177668A2
Application number: EP09173064A
Authority: EP
Inventors: Ercole Forlivesi
Original assignee: Elettra Srl
Current assignee: Elettra Srl
Priority date: 2008-10-15
Filing date: 2009-10-14
Publication date: 2010-04-21
Also published as: ITRA20080029U1; EP2177668A3

Abstract

A well for underground infrastructures comprising a substantially annular hollow body (10) delimiting laterally a respective space (5), and a closing device (20) carried by the body (10) and suitable to delimit superiorly the space (5); the body (10) being produced substantially in metal so as to present high breaking load but reduced weight.

Description

The present invention relates to a well for underground infrastructures. More in particular, the present invention relates to a modular well for underground infrastructures. More in particular, the present invention relates to a modular well, which can be used in underground infrastructures for cable telecommunications.

BACKGROUND TO THE INVENTION

In the telecommunication sector the production of underground infrastructures is well known to allow copper cables or optical fibre cables passing below the ground, for instance below sidewalks and/or the road surface. These underground infrastructures comprise usually tubes, designed so as to house inside themselves bundles of telecommunication cables, and underground wells, interconnecting branches of these tubes at regular intervals. In particular, these wells surface from the ground so as to allow access to the respective telecommunication network and to enable update or maintenance operations on this network, such as for example the introduction and/or the replacement of cables.
In more detail, each of these wells comprises a hollow body, in concrete or other type of conglomerate, presenting a substantially parallelepipedal or cylindrical shape. This hollow body presents at least a pair of holes, obtained in the respective lateral surface during the phase of installation of the well and dimensioned to house ends of respective tubes, in such a manner as to allow the introduction of a plurality of telecommunication cables in the well.
It should be noted that the space inside these wells is usually designed so as to contain joints between consecutive branches of these communication cables and, at this end, it houses junction boxes, i.e. connecting elements designed to receive at least two distinct cables and to connect the respective ends thereof electrically or optically.
Lastly, each well presents a metal cover arranged, in use, above the concrete hollow body to limit the respective inner space at the top. In particular, this cover can be selectively opened, through lifting or rotation relative to the concrete hollow body, so as to allow the operators to access the well for installation and/or maintenance operations on the telecommunication network.
It should be noted, at this point, that each of these wells for telecommunications presents extremely significant dimensions and a weight in the order of many quintals. It is therefore clearly apparent that the installation of each well requires both the use of a special transport mean, for example a tractor or a truck, for transporting the well to the installation site, and the use of a truck-mounted crane or a self-propelled winch for the installation operations. Moreover, the side walls of the concrete body must be holed during the operation for installing the well, so as to allow the connection with respective tubes housing the telecommunication cables, which must be connected through the junction box housed, in use, inside the well.
In view of the above description it is clearly apparent that each operation for installing a telecommunication well is particularly onerous and requires long execution times. The use of special means for installing the well furthermore entails high installation costs. Lastly, it should be noted that the execution times, and therefore the installation costs, can significantly increase if the well must be installed in a highly urbanised area, for example below the surface of a road with a lot of traffic or in the centre of a town. In these cases, each installation of a well requires that the vehicular traffic is stopped or deviated for all the duration of the intervention, thus creating discomforts both for the road users and for the company, which desires to install the wells and which will be obliged to coordinate, for prolonged time periods, the operations of installations, with the aid of the vehicular traffic control entities.
Therefore, the problem of installing a telecommunication well in a simple, fast and therefore economical manner, is currently unsolved and represents an interesting challenge for the applicant, that aims at obtaining a well that, although respecting the construction standard requirements for the current underground infrastructures for telecommunications, is however light and not very bulky, and is suitable to be installed manually, without the use of special means.

SUMMARY OF THE PRESENT INVENTION

The present invention relates to a well for underground infrastructures. More in particular, the present invention relates to a modular well for underground infrastructures. More in particular, the present invention relates to a modular well, which can be used in underground structures for telecommunications.
An object of the present invention is to provide a well designed to be integrated in underground infrastructures, preferably infrastructures for telecommunications, and suitable to solve the above mentioned disadvantages. In particular, each well according to the present invention is suitable to satisfy a plurality of requirements that to date have still not been addressed, and therefore suitable to represent a new and original source of economic interest and capable of modifying the current market of the underground infrastructures for civil use.
According to the present invention, a well is provided, whose main characteristics will be described in at least one of the appended claims.
A further object of the present invention is to provide a module, which can be validly used to produce a well designed to be integrated in underground infrastructures.
According to the present invention, a module is provided, whose main characteristics will be described in at least one of the appended claims.
A further object of the present invention is to provide a method, validly usable to install manually a well for telecommunication in a fast and extremely simple manner.
According to the present invention a method is provided for installing a well for telecommunication, and the main characteristics of this method will be described in at least one of the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

Further characteristics and advantages of the well according to the present invention will be more apparent from the description below, set forth with reference to the accompanying drawings, which illustrate some non-limiting examples of embodiment, in which identical or corresponding parts of the device are identified by the same reference numbers. In particular:

figure 1 shows a schematic perspective view of a well according to the present invention;
figure 2 shows an exploded perspective view of a second preferred embodiment of figure 1;
figure 3 illustrates, in enlarged scale, a detail extracted from figure 1; and
figure 4 shows a variant of figure 3.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

In the figure, number 1 indicates, in its entirety, a well, designed to be integrated in underground infrastructures and usable preferably for producing cable communication networks, but also for producing plumbing systems or plants for transporting gas, electricity or sewage.
With reference to figure 1, each well according to the present invention comprises a hollow body 10, which presents a substantially annular shape and delimits laterally a respective inner space 5. In particular, this body 10 is made of metal, preferably ductile cast iron. Furthermore, each well 1 preferably comprises a base 18 coupled to the body 10 and a closing device 20 supported by the body 10 at opposite side from the base 18 and suitable to delimit superiorly the space 5. In particular, as it will be better described hereunder, the closing device 20 can be selectively opened so as to allow the access to the space 5. In use, the space 5 of the well 1 can be used to house portions of respective telecommunication cables and/or junction or branch boxes for these telecommunication cables. It should be noted, in this regard, that each of these telecommunication cables can be produced in any way and can comprise, for example, a plurality of twisted-pair copper or optical fibre wires, without however limiting the generality of the present invention.
With particular reference to figures 1 and 2, the well 1 presents a modular structure and the hollow body 10 comprises at least a module 11 comprising a respective second body, substantially annular, which, for the sake of simplicity, will be indicated with the same number 11. In particular, the body 10 will comprise preferably a plurality of modules 11, whose number will depend both upon the depth of the seat, into which the respective well 1 shall be installed, and upon the number of junction boxes, and therefore of branches of cables, which the respective space 5 shall house in use. Each module 11, as well as the base 18 and the closing device 20, is produced preferably in metal through melting and subsequent moulding, so as to minimise the costs for producing the well 1.
At this point it should be noted that all the modules 11 substantially present the same plan conformation, in such a manner that they can be easily stacked along a given direction D, typically the vertical direction, to produce the respective hollow body 10. More in particular, each module 11 presents a respective first upper edge 11', shaped so as to shape-couple with a second lower edge 11" of a further module 11, so that the coupling between two adjacent modules 11 is stable and releasable only by acting along the given direction D. In more detail, each module 11 presents at least a first abutment element 17" carried projecting along the given direction D by a respective second upper edge 11", and at least a seat 17' obtained in a respective second lower edge 11" and shaped so as to house a respective abutment element 17" carried projecting by a further adjacent module 11. With reference to figures 2 and 3, this abutment element 17" can preferably comprise a linear projection 17" travelling peripherally the respective second edge 11" along the whole extension thereof. It is clearly apparent that the seat 17' will be shaped and dimensioned in a manner substantially complementary to the respective abutment element 17", so as to shape-couple with it and, with particular reference to the above mentioned example of a linear projection 17", it can preferably comprise a groove or rest step 17' obtained in the first edge 11' along the whole extension of the respective inner perimeter. Similarly, also the base 18 can preferably comprise a seat 17' to house an abutment element 17", which projects inferiorly from the adjacent module 11. In any case, independently of the respective conformation, the set of each abutment element 17" and each respective seat 17' can be interpreted as a coupling group 17 suitable, in use, to maintain each module 11 stably aligned along the given direction D with further modules 11 or with a base 18 contiguous with it.
At this point, it should be noted that the hollow body 10 of each well 1 is substantially parallelepipedal-shaped and therefore presents two pairs of respective first and second lateral walls A and B, facing two by two and integrally connected to each other. Similarly, the base 18 and each single module 11 present a substantially rectangular plan conformation; in particular, each module 11 will be delimited by respective third and fourth lateral walls A' and B', which, in use, represent portions of respective first and second walls A and B of the body 10. Therefore, hereunder reference will be made only to a well 1 of parallelepipedal shape, as shown in figures 1 and 2, without however limiting the generality of the present invention, which can therefore relate to wells of any shape, for example to wells of cylindrical or prismatic shape.
At this point, with reference to figures 1 to 3, it should be noted that each module 11 presents at least a pair of first through holes 12 obtained in the third and/or fourth lateral walls A' and/or B' and usable, in use, to connect tubes to the well 1 and therefore to introduce branches of telecommunication cables inside the space 5. More in particular, each module 11 preferably presents a pair of first holes 12 for each third or fourth walls A' or B1, so as to allow the insertion of a plurality of branches of telecommunication cables inside the respective well 1, which can therefore act as a concentrating knot of the respective infrastructure. In more detail, with reference to figures 1 to 3, each first hole 12 can present an inner diameter comprised between 70 mm and 140 mm, so as to be dimensioned to coupled with respective tubes that generally present outer diameters of 63 mm or 125 mm, according to the standards currently in force in the construction practice of the underground infrastructures for telecommunications.
Again with reference to figures 1 to 3, it should be noted that each first hole 12 is provided with a respective bush 12', preferably produced in thermoplastic material, for example rubber, and suitable to support stably a closing member 26 for closing the respective first hole 12. Each closing member 26 can economically comprise a tap 26 in plastic material or, preferably, in metal, shaped to couple in a substantially matching manner with the respective bush 12' so as to close the respective first hole 12 substantially in a fluid tight manner. Therefore, the set of each bush 12' and of the respective closing member 26 can be interpreted as a closing group 25, which can be selectively opened/closed for a respective first hole 12.
In use, when a first hole 12 is used to connect the well 1 to a tube of a respective infrastructure for telecommunications, and therefore to allow the introduction of branches of cable inside the space 5, the closing member 26 is removed and a free end of the tube is coupled with the bush 12'. As illustrated above, the first holes 12, and therefore the respective bushes 12', are dimensioned substantially to shape-couple with the tubes generally used in the production of infrastructures for telecommunications, so as to generate a stable and substantially fluid-tight shape-coupling. Furthermore, each bush 12' is made preferably in thermoplastic material and therefore, during the installation of the well 1, it can be heated at a given temperature and therefore substantially welded to an end of a respective tube housing telecommunication cables. Therefore each bush 12' can be also interpreted as a support member 12' suitable, in use, to couple a respective tube with the well 1 in a stable and substantially fluid-tight manner.
At this point, with particular reference to figure 3, it should be noted that each module 11 is provided with a plurality of first coupling members 16 carried by and projecting from, inside the space 5, the respective lateral surface. These first coupling members 16 can preferably present an annular shape and be therefore provided with respective slots, so as to present a double use. In particular, these first coupling members 16 can be used, during phases of installation of the well 1, so as to act as throughs for respective tie rods for installing each module 11 in the respective underground seat. Alternatively, once the body 10 has been completely lowered in the respective inner seat, the first coupling members 16 can be used as fixing elements 16 for fixing bands that are suitable to maintain stably in a given position junction boxes and/or cables housed, in use, inside the space 5. In other words, it is possible to fix junction boxes and/or communication cables in respective given operative positions inside the space 5, by making fixing bands pass in the slots of the first coupling members 16, for example plastic bands with adjustable extension commonly used by electricians and installers.
At this point, again with reference to figure 3, it should be noted that each module 11 presents stiffening elements 30 carried inside the space 5 by the respective lateral surface and arranged at each square angle delimited by a third wall A' and by a respective adjacent fourth wall B'. These stiffening elements 30 rigidly connect each third wall A' of a module 11 to the respective fourth wall B' adjacent thereto, so as to give stiffness to the structure of the module 11 and to prevent deformations thereof that could compromise the alignment of the various modules 11 and the stability of the body 10. At this end, each stiffening element 30 can preferably comprise a bracket 31, rectilinear or substantially right triangle shaped; this bracket 31 is preferably produced in a single piece with the respective module 11 or, alternatively, it can be welded to each respective first and second surfaces A' and B'.
With reference to figure 2, it is possible to note that the well 1 comprises a first rest grille 15' arranged, in use, on the bottom of the space 5 to support branches or surplus of cable and/or each junction box housed inside the body 10 of the well 1. In particular, this first grille 15 rests on the base 18 of the body 10 by means of respective rest tabs 15' shaped so as to maintain the grille 15 lifted from the base 18 in case rainwater, filtered through the closing device 20, accumulates on the bottom of the space 5. At this end the first rest grille 15 is holed so as to allow the rainwater to flow out.
Again with reference to figure 2, the well 1 comprises a second grille 19 supported by the module 11 adjacent to the closing device 20 so as to delimit the space 5 at the top and to protect the content thereof against any infiltration of soil or powder during operations for laying the well 1 or installing and/or maintaining the respective network of telecommunication cables. More in particular, again with reference to figure 2, each second protective grille 19 is carried by the respective module 11 by means of the respective stiffening elements 30, which support stably feet 19' for resting the second grille 19.
With reference to figure 2 again, it should be noted that the well 1 can also comprise an adjusting ring 33 for regulating the position of the closing device 20; this ring 33 is interposed between the closing device 20 and the module 11 adjacent thereto, and is dimensioned so as to allow, during phases of installation of the well 1, the alignment between a substantially planar closing member 21 associated to the closing device 20 and the road surface or the ground surrounding the well 1. This adjusting ring 33 for regulating the position of the closing member 21 is particularly useful when, for example following the reconstruction of the road surface, it is necessary to change the position of the closing device 20 along the given direction D. In particular, it should be noted that, similarly to each module 11, also the adjusting ring 33 presents preferably a first abutment element 17" and a seat 17', so that it can be stacked with each respective module 11 in a stable manner by means of a respective coupling group 17.
At this point, with reference to figure 2, it should be noted that the closing device 20 comprises at least one closing member 21, preferably shaped as a cover 21, and a support frame 22 for supporting this cover 21. In particular, this frame 22 is stably supported by a respective module 11, through the interposition of an adjusting ring 33, as the case may be. In particular, at this end, also the frame 22 can be provided with a respective abutment element 17" so as to couple stably with a respective seat 17' carried at the top by the adjacent module 11 or by the adjusting ring 33. In more detail, the frame 22 presents respective second coupling means 23, which can be used as throughs for tie rods so as to facilitate operations for installing the well 1.
With reference to figure 2 again, it should be noted that the cover 21 is shaped so as substantially to shape-couple with the respective frame 22 and presents respective ribs 27 suitable to give more stiffness to the cover 21. In particular, the cover 21 can preferably present a cavity 21' arranged at opposite side from the frame 22, housing the stiffening ribs 27, and suitable, in use, to contain a portion of the same covering that covers the ground, the sidewalk or the road, below which the well 1 has been installed, so as to minimise undesired effects of discontinuity in this covering. In more detail, the stiffening ribs 27 can be arranged so as to generate a cell structure, preferably of square or rectangular shape, for example to support better a pavement made of cobblestones, tesseras or porphyry cobblestones.
Alternatively, with reference to figure 1, the cover 21 can be hinged to the relative frame 22 so that it can be opened through rotation without the need of being lifted vertically. In particular the cover 21 can comprise, according to its dimensions, a plurality of complementary portions 21', each of which is hinged to the respective frame 22 and can be opened/closed independently of the other portions 21' forming the cover 21. In more detail, again with reference to figure 1, it is possible to note that each portion 21' is preferably triangle-shaped, and that the hinges 28, connecting each portions 21' to the frame 22, are arranged exclusively along two first opposite sides a' of the frame 22 so that, in use, when the closing device 20 is open, the second side b' perpendicular to the first sides a' are free and can be used by the operators to access the space 5 in a practical and safe manner. Furthermore, it should be noted that, in the case in which the cover 21/each portion 21' is hinged to the respective frame 22, the stiffening ribs 27 will be carried inferiorly projecting by the cover 21/portion 21' so as to facilitate each operation of opening the closing device 20 through rotation.
Again with reference to figure 1, the closing device 20 can be provided with a safety lock 29 suitable, in use, to constrain rigidly the cover 21 or each portion 21' to the respective frame 22.
At this point, with particular reference to figure 4, it should be noted that the well 1 can comprise a further annular module 11 provided with at least a pair of second holes 13 obtained in the respective lateral surface and substantially aligned. In particular, this module 11 can preferably contain more than one pair of second holes 13 aligned and obtained in the first or in the second surfaces A' or B'. Each second hole 13 presents a respective aperture 14 obtained in the second lower edge 11" of the respective module 11 so as to allow a lateral access to the respective second hole 13. In particular, each second hole 13 can be preferably shaped as a slot presenting a substantially U-shaped perimeter delimited inferiorly by a respective aperture 14 obtained in the second edge 11". In more detail, each second hole 13 also presents a width comprised between 70 mm and 140 mm so that it can house, in use, any tube presenting an outer diameter substantially standard in the sector of the production of underground infrastructures not only for telecommunications but also, for instance, for water, gas and electricity distribution. It is therefore clearly apparent that the use of the module 11 illustrated in figure 4 allows to install a well 1 without the need of interventions on the tubes of pre-existing underground infrastructures. At this end, each module 11 provided with respective holes 13 can be arranged both below the base 18, thus acting as support module 11 for supporting the body 10, and above the base 18, thus acting as base module 11 of the hollow body 10.
Lastly, it can be advisable to specify that the use of ductile cast iron to produce each module 11 and the closing device 20 allows to obtain wells 1 of class D400, i.e. presenting a breaking load of at least 400kN. This characteristic allows to use the wells 1 according to the present invention practically in any underground infrastructure for civil use and, in particular, it allows to satisfy the law requirements for the installation of wells below the road surface. In particular, it should be noted that a well 1 provided with two mutually superimposed modules 11, as that illustrated in figure 1, can be validly used in applications requiring wells of class D400. In more detail, each module 11 preferably presents dimensions in the order of 76 x 40 x 20 cm so that the body 10, composed by two mutually superimposed modules 11, presents each transverse section according to a plan parallel to a second wall B of substantially square shape (40 x 40 cm), so as to maximise the ratio between the volume of the space 5 and the quantity of metal necessary to produce the body 10.
The use of the well 1 is clearly apparent from the description above and requires no further explanations; however it should be advisable to remember that the present invention also relates to a method validly usable to install a well 1 of the type described above.
In particular, this method comprises first of all the phase of producing at least a module 11 through melting and preferably in ductile cast iron. This phase of producing at least a module 11 is followed, in sequence, by the phases of lowering a base 18, at least a module 11 and a frame 22 in a respective seat provided for the well 1, and by a phase of coupling stably a closing member 21 to the respective frame 22. It should be noted that the overall weight of each single component or module of the well 1 is not greater than 30 kg and therefore each of the phases of lowering a given component of the well 1 in the respective sat can be performed manually and safety also by a single operator. In addition, the phase of lowering a base 18 can be or preceded or followed by a phase of lowering a module 11 provided with respective second holes 13 in such a manner as to house a pre-existing tube inside at least a pair of these second holes 13 reciprocally aligned.
Lastly, the method for installing the well 1 comprises at least a phase of coupling an end of a given tube to a respective first hole 12 by means of a respective bush 21' so as to allow the introduction of telecommunication cables inside the space 5.
At this point it would be advisable to specify some advantages obtained through the use of the well 1 and the application of the respective installation method relative to the prior art, which provides for the installation and the use of wells comprising a hollow body made of concrete.
First of all, with the same dimensions of the inner space 5, the use of a metal body 10 allows to obtain a well 1 presenting the same mechanical properties of stress resistance, but dimensions and weight significantly lower than the prior art; this well 1 can be furthermore transported to the installation site by means of a common car and therefore without the need for special transport means. Just by way of example, it must be considered that the weight of a Class D400 well according to the prior art is comprised between 9 and 11 quintals, whilst the weight of an equivalent well 1 produced in metal according to the teachings of the present invention is of about 200 kg. In addition, as each component of the well 1 is produced in such a manner as to have a weight no greater than 30 kg, it is clearly apparent that it is possible to lower the well 1 in the seat without using a crane or a winch, but simply performing manual installation operations which can be even performed by a single operator without the risk of injuries due to the excessive weight of the components to be installed. Furthermore, the metal modules 11 can be produced with a plurality of first and/or second adequately dimensioned holes 12 and 13, and therefore, contrary to the prior art, it is not necessary to hole concrete blocks during the operation for installing the well. Therefore the use of a well 1 produced substantially in metal allows not only to facilitate respective installation operation, but also to reduce the duration, and therefore the costs, of these operations.
Lastly, it is apparent that modifications and variants can be made to the well 1 described and illustrated herein, without however departing from the protective scope of the present invention.

Claims

A module (11) for a well (1) for underground infrastructures; said module (11) comprising a substantially annular body (11) suitable, in use, to delimit laterally at least a portion of an inner space (5) of said well (1); characterised by being produced in a substantially integral manner in metal, so as to present high breaking load but reduced weight.
A module according to claim 1, characterised by presenting at least a pair of first through holes (12), obtained laterally in said substantially annular body (11) and dimensioned so as substantially to shape-couple with respective tubes of said underground infrastructure.
A module according to claim 2, characterised in that at least one said first hole (12) presents a respective inner diameter comprised between 70 mm and 140 mm, so as to couple in a substantially matching manner with said tubes of said underground infrastructure.
A module according to claim 2 or 3, characterised in that each said first hole (12) is provided with a respective bush (12'), suitable to couple said respective first hole (12) with a respective said tube in a substantially fluid-tight manner.
A module according to any one of claims 1 to 4,
characterised by presenting at least a pair of second through holes (13) obtained laterally in said body (11) and substantially aligned; each said second hole (13) presenting a respective aperture (14) obtained in a first edge (11") of said body (11) and being shaped so as to allow a respective lateral insertion of at least a respective given tubular body inside the respective said second hole (12).
A module according to claim 5 characterised in that each said second hole (13) comprises a substantially U-shaped slot presenting a respective width comprised between 70 mm and 140 mm so as to be suitable to house tubes associated to a further given underground infrastructure.
A module according to any one of claims 2 to 6,
characterised by comprising second closing means (25) suitable to seal substantially in a fluid-tight manner each said hole (12, 13) obtained laterally in said substantially annular body (11).
A module according to claim 4 or according to claim 4 and any one of claims 5 to 7, characterised in that said second closing means comprise a closing member (26) for each said hole (12, 13) obtained in the lateral surface of each said module (11); each said closing member (26) being shaped so as to couple in a substantially matching manner with a respective said bush (12').
A module according to any one of the previous claims, characterised by presenting internally coupling means (16) designed to couple respective tie rods so as to allow respective installation operations in order to assembly the respective said well (1).
A module according to any one of the previous claim, characterised by being couplable with at least a further said module (11) along a given direction (D) and by comprising at least an abutment member (17") carried by and projecting from a respective first edge (11") of said substantially annular body (11), and a seat (17') for each said abutment member (17") obtained in a second edge (11') of said body (11) arranged at opposite side relative to said first edge (11"); each said seat (17') being designed so as to shape-couple in a substantially matching manner with a respective said abutment member (17").
A module according to claim 10, characterised in that each said abutment member (17") comprises a linear projection (17") carried peripherally by a said first lower edge (11") of said body (11), and each said seat (17') comprises a rest step (17') or a slit (17') shaped so as to house a respective said linear projection (17") and obtained in a said second upper edge (11') of said substantially annular body (11).
A module according to any one of the previous claims, characterised by presenting a substantially parallelepipedal shape and in that said body (11) is delimited by first and second walls (A', B') facing two by two and connected to each other perpendicularly; stiffening means (30) being arranged to connect rigidly each said first wall (A') with the respective said adjacent second walls (B') so as to prevent deformations of the respective said module (11).
A module according to any one of the previous claims, characterised by being produced integrally in cast iron.
A module according to any one of the previous claim, characterised by having a weight lower than 30 kg so as to allow respective installation operations to be performed manually by a single operator.
A module according to any one of the previous claims, characterised by being produced substantially by means of melting operations so as to reduce the production costs thereof.
A well for underground infrastructure comprising a substantially annular hollow body (10) which delimits laterally a respective space (5) and closing means (20) carried by said body (10) and suitable to delimit superiorly said space (5); characterised in that said body (10) comprises at least a module (11) produced according to any one of the previous claims.
A well according to claim 16 depending upon claim 10 or 11, characterised by comprising coupling means (17) interposed between each pair of two said contiguous modules (11) to connect in a substantially stable and selectively releasable manner these said contiguous modules (11); said coupling means (17) comprising at least a said abutment member (17") and at least a respective said seat (17').
A well according to claim 16 or 17, characterised in that said first closing means (20) comprise a frame (22) supported by said hollow body (10) and at least a closing member (21, 21') carried by said frame (22) to prevent undesired access to said space (5).
A well according to claim 18, characterised in that each said closing member (21, 21') presents respective stiffening ribs (27) so as to give to the closing device (20) a greater compressive strength.
A well according to claim 19, characterised in that each said closing member (21, 21') is hinged to the respective said frame (22) by means of respective hinges (29) so as it can be opened through rotation; each said hinge (29) being arranged at the side of a respective said first wall (A') so that, when each closing member (21, 21') is opened, it is easy to access said space (5) from the side of each said second wall (B') from the side of said first walls (A').
A well according to any one of claims 16 to 20,
characterised by comprising an adjusting ring (33) presenting a given thickness and interposed between said closing device (20) and said hollow body (10) so as to vary selectively a respective reciprocal distance.