FR2809752A1 - ARTICULATED LID MANHOLE WITH ANTI-THEFT DEVICE FOR EXCAVATING FLOOR - Google Patents

Abstract

To prevent the cover (3) from being removed, a tenon (30) of which is articulated in a cell (10) of the frame (1) of the manhole, in a space in the cell comprised between a lug (303) of the tenon (30 ) which is partially overhung by an edge of the cell and a wall (11) thereof facing the end of the post when the cover is closed, a stopper plate (4) for the post (30) resting on a surface of the frame (1) limits the possibilities of displacement of the cover (3) towards said wall (11) to an insufficient stroke so that the lug (303) ceases to be overhung at least partially by said edge of the cell (10); the cell opens at the base of the frame (1) through an orifice (100) allowing the passage of the plate for its installation in said space. Use: securing against theft, covers for manholes.

Description

The invention relates to manhole covers or a hinged grid form

  mant cover, and more particularly the manholes comprising such a cover

  articulated ring placed on public roads to cover or selectively access

  Avoidance of excavations dug in the ground such as trenches or chimneys to visit underground galleries.

  For security reasons, as for economic reasons,

  ques, it is essential that the covers of manholes located on the public road

  cannot be removed, except, if necessary, by persons

nes empowered.

  To this end, we already know manholes equipped with an em-

  fishing for the removal of the cover purely manually.

  However, most of these devices are visible from the outside when the cover is in the closed position, and can be removed.

using conventional tools.

  There are also known invisible or barely visible anti-theft devices.

  from the outside, but may be dismantled or destroyed relative-

  easily when the cover is put in the open position, which

  is possible without great difficulty when the gaze is devoid of a lock.

  The invention aims to remedy these drawbacks and relates

  to this end a manhole cover to cover or selectively access

  an excavation dug in the ground, comprising a delimited chassis

  both an access to the excavation and a cover adapted to be able to be moved

  in an approximately pivoting movement about an ap-

  approximately horizontal resting in the frame between a position

  closure in which it covers approximately the access and a po-

  sition of opening in abutment in which it releases it substantially, the

  cover and the chassis being provided with means of mutual articulation

  killed by at least one lug of the cover and at least one cell of the chassis having mutual bearing surfaces adapted to cooperate during said approximately pivoting movement, the lug having in the

  region of its free end separated from the wall of the cell which is facing

  opposite when the cover is in the closed position by a space, a

  articulation head comprising at least one lateral lug housed, when the cou-

  vercle rests in the chassis, at least partially under at least one edge of the cell which is overhanging and extends itself in the direction of said wall of the cell at a distance therefrom, look characterized in that 'it comprises, housed in said space, a stop plate for the articulation head, resting on at least one support surface belonging to the chassis, limiting the possibilities of movement of the cover in the direction of said cell wall to one stroke insufficient for the lug to cease to be at least partially overhung by said edge of the cell, and the cell opens to the outside of the chassis by its base so that said space is in communication with the outside of the chassis through a hole

  allowing the passage of the plate for its establishment in this es-

pace.

  Thanks to this structure, the plate can be mounted by the

  under the chassis, the arrangement of the anti-theft device is not very visible, and thus it is extremely difficult to separate the cover from the chassis without damaging

  largely the look, which is impossible with common hand tools.

  The manhole according to the invention may also have one or more of the following characteristics: - the cover comprises a lug having two lateral lugs, and the chassis comprises a cell, the side walls of which are provided with

  bearing surfaces for the post delimiting an edge of the cell which is in sur-

  lead and extends towards the wall of the cell which faces the free end of the post when the cover is in the closed position; - The cover comprises a tenon having two lateral lugs, and the chassis comprises a cell, the side walls of which are provided with at least one bearing surface for the tenon delimiting an edge of the cell which is overhanging and extends towards an inner wall of the cell, the top of which serves as a seat for the cover; The cell has side walls having grooves of

  respective retainers extending against said wall of the cell which is facing

  opposite the free end of the post when the cover is in the closed position

  meture, and the wafer comprises lateral pins mounted sliding in these grooves;

  - the side walls have respective insertion grooves

  to introduce the pins into the retaining grooves, one of which

  end opens into this retaining groove and whose opposite end

  opens into a support surface of the socket for the post, a lower edge

  laughing of the wafer being adapted to rest on an internal surface of a gutter carried by at least one wall of the cell;

  - the side walls are provided with respective grooves

  both notches, adapted to cooperate by snap-fastening with notches

  carried by side edges of the plate, and the plate also includes

  Lement a nipple of compressible material allowing the sliding of the wafer between a waiting position and a securing position; the cover has two studs, each having at least one

  lateral lug, and the chassis comprises two cells having a wall ex-

  and support surfaces for a respective tenon, the two cells being separated from each other by a T-shaped partition extending from said outer wall of the chassis towards an inner wall of the chassis, a portion enlarged T-shaped partition having edge regions which extend towards the outer wall and which, when the cover is in the closed position, partially overhang the lugs of the post;

  - the plate has two lateral branches adapted for repositioning

  be on support surfaces belonging to the chassis, these

  support being constituted by the upper part of upper bearing surfaces

  laughs equipping each cell for the support of the respective studs and by a song of the edge regions overhanging on the cells; - The plate has at one end a folded foot;

  - the lower part of the cell is lined with a sealing material -

  is lying. Other characteristics and advantages of the invention will emerge from

  the following description of given embodiments of the invention

  by way of nonlimiting examples and shown in the accompanying drawings in which

  - Figure 1 is a schematic perspective view of a plate

  stop quet equipping a first embodiment of a se-

  lon the invention, - Figure 2 is a schematic section of the region of articulation of a manhole according to the first embodiment, in which the cover is shown during an insertion phase in the frame in the open position at 90 relative to the latter, the stop plate not being in the securing position but in the standby position in the chassis so as to allow the fitting of the cover; - Figure 3 is a schematic section similar to that of Figure

  2 but in which the cover is in the closed position in the frame

  sis; - Figure 4 is a schematic section similar to that of the figures

  2 and 3 but in which the stop plate is in the secure position

  tion in the frame and the cover is in the open position as a stop; - Figure 5 is a schematic section similar to that of Figure 4 but in which the cover is shown during an attempted withdrawal in the open position at 90 relative to the chassis, the stop plate in the secure position preventing removal of the cover; Figure 6 is a schematic section along the line VI-VI of Figure 5, in which the cover is not shown; - Figure 7 is a schematic section corresponding to that of Figure 2, a look according to a second embodiment, a wafer

  of the stopper itself according to a second embodiment being in posi-

  waiting in the chassis so as to allow the fitting of the cover; - Figure 8 is a schematic section similar to that of Figure 7 but in which the abutment plate is in the securing position in the chassis and the cover is shown during an attempted withdrawal in the open position at 90 relative to the chassis, the stop plate preventing this withdrawal; - Figure 9 is a schematic section along the line IX-IX of Figure 8, in which the cover is not shown; - Figure 10 is a schematic section corresponding to those of Figures 2 and 7, a look according to a third embodiment, in the absence of abutment plate;

  - Figure 11 is a schematic section similar to that of Figure

  Figure 10 but in which the cover is in the closed position in the frame, along the line XI-XI of Figure 12; - Figure 12 is a schematic top view corresponding to the section of Figure 11; Figure 13 is a schematic top view of the stop plate according to a third embodiment, intended to be inserted in the manhole frame according to the third embodiment

  - Figure 14 is a schematic section of the plate of the

  Figure 13 along line XIV-XIV of Figure 13; - Figure 15 is a schematic top view similar to that of Figure 12 but in which the stop plate is in the securing position in the chassis; and

  - Figure 16 is a schematic section similar to that of Figure

  gure 11 along line XVI-XVI of FIG. 15, corresponding to this FIG. 15 in which the stop plate is in the securing position

in the chassis.

  The manhole cover manhole which is partially represented on

  the figures is a manhole cover generally made of cast iron, which can be used

  selectively cover a dug gallery access chimney

  in the ground or access this fireplace; this look here is generally

  circular rale but this shape is naturally not limiting.

  The manhole comprises an annular frame 1 delimiting an access 2 to the chimney, the pad 3 and the frame being articulated to one another by means of mutual articulation, so that the pad can be moved in an approximately movement swivel (usually a

  pivoting movement accompanied by a slight sliding of its surfaces

  these bearing on the bearing surfaces of the chassis) around an approximate axis

  horizontally by resting in the chassis between a closed position

  ture in which it approximately covers the access and a position

  opening in abutment in which it substantially releases this access.

  Here, the word "horizontal (e)" means (and will mean throughout the text) "parallel to the plane in which the frame extends" although this plane may be possibly tilted if the gaze is intended to be located on the - face of an inclined floor, and the word "vertical (e)" means "perpendicular to the

  plane in which the chassis extends ".

  In the embodiment of FIGS. 1 to 6, the means of mutual articulation of the pad 3 and of the frame I are respectively a lug 30 of the pad and a cell 10 of the frame, but naturally the

  the number of studs and cells can be greater.

  The cell 10 of the chassis 1 is bounded by a wall 11 which is the external wall of the chassis, and facing it by a wall 12, the

  top, serving as seat for tampon 3, is below the level of the som-

  puts the outer wall 11, the level difference being such that the upper face of the pad is flush with the top of the outer wall 11 when the pad is in the closed position; a seal (not shown)

  is interposed between the top of the wall 12 and the pad. The outer wall

  lower 11 has an edge 111 partially overhanging the cell, the edge of which serves as a stop for the buffer to define an open position as a stop

(figure 4).

  Laterally, the cell 10 is limited by two facing walls 13 in which are defined bearing (and sliding) surfaces for the pad 3 during its approximately pivoting movement which has

  was mentioned above; these surfaces will be described later in more detail.

  tail. On the other hand, the cell 10 is deprived of the bottom and thus opens out by

  its base outside the chassis 1.

  As we have seen, buffer 3, here of generally circular shape, comprises

  door, projecting from its circular outline, a stud 30 adapted for

be inserted into the socket 10.

  For convenience, terms like "high", "low",

  "upper", "lower", "above", "below", "on", "under", used

  to locate certain elements of the buffer will be references to

  the location of these elements when the pad is in the closed position

  ture. The pin 30 has, in its region close to its connection to the generally circular part of the pad 3 which is adapted for

  cover the access 2 in the closed position, a portion 301 of thickness

  pick whose respectively lower and upper setback faces are approximately flat and parallel; on the other hand, in its region where its free end is located, the tenon comprises a head 302 comprising lower and upper regions which extend in excess thickness with respect to the faces of the part 301; the lower region of the head 302 comprises two lugs 303 projecting laterally relative to the lateral faces of the region

  upper head; the lower and upper faces of the pins are ap-

  approximately flat and parallel, except that the underside

  it also has a rounded downward protrusion 304

  die, in the immediate vicinity of the free end of the post. The lower surfaces

  upper and upper as well as the edge surface of the tenon likely to come into contact with the cell 10 during the movement approximately of

  pivoting of the buffer, and in particular those of the lugs, constitute the

bearing faces of the post.

  The bearing surfaces for the post and in particular for the pins 303, of each side wall 13 of the cell 10, succeed one another from the face

  upper part of chassis 1, over part of the height of the cell, and present

  try the same profile on both walls. Each of these side walls thus comprises two successions of bearing surfaces arranged opposite, one on the side of the outer wall 11 and the other on the side of the inner wall 12. At the upper part of the cell 10, the bearing surfaces facing each other are spaced a distance slightly greater than the thickness of the pins

  303 of the tenon 30 in order to allow the insertion of the latter into the socket only

  when the pad is approximately vertical; in

  this upper part, a first bearing surface 131 on the inner wall side

  rieure 12 extends vertically over a few millimeters high, and the surface

  bearing face 132 which succeeds it approaches this wall 12 first

  almost horizontal so as to form an edge of the net cell-

  ment overhanging towards the outer wall 11, then continues substantially vertically to finally come to be attached to this wall

  12; also in the upper part of the cell, the supporting surface

  133 on the outer wall side 11 which first moves away from this wall 11 then plunges vertically for a few millimeters, and the surface

  support 134 which extends it approaches the outer wall 11, in sur-

  lead with a slight downward inclination; the next bearing surface moves away again from the outer wall 11 by forming a curved ramp ending approximately halfway up the cell, at a distance from the inner wall 12 approximately equal to the thickness of the pins 303 ; it is extended over a few millimeters by an approximately vertical terminal surface 136 terminating in the lower part of the cell 10, the base of which opens out from the chassis 1 through an orifice

100.

  Due to the shape of the bearing surfaces, the head 302 may be invisible.

  troduit in the alveolus 10 only when the buffer 3 is approximately

  vertically vertical (Figure 2); when the pins 303 are fully

  below the level of the overhanging edges defined by the bearing surfaces 131, 132, 133, 134 belonging to the cell, the pad can be pivoted to its fully open position at approximately 110 degrees relative to the chassis, in which its part 301 of reduced thickness is in contact against the edge 11 of the overhanging cell, and part of its protrusion 304 is in abutment against the lower part of the bearing surface 132 belonging to the cell on the inner wall side 12, which preferably follows the shape of this

  part of the protrusion 304; it can be noted that there is also a posi-

  stable intermediate safety device (not shown) in which the tam-

  pon 3 is locked in an angular position at approximately 90 degrees from

  port to chassis; in this position, the upper face of the part 301 of the tenon at the point of its connection with the circular part of the pad is in abutment against the upper bearing surface 133 on the outer wall side 11, and the lower face of the part 301 bears against the first vertical bearing surface 131 on the inner wall side 12, while the ends of the pins 303 are inserted between the inner wall 12 and the terminal vertical bearing surface 136; alternatively, the pad can be pivoted to its closed position by raising the bearing surfaces belonging to the lug against the curved ramp 135 of the cell by making the lower surface of the studs 30 bear against the surface d 'upper support 131 interior wall side 12; in this closed position in which the

  pad rests horizontally on its seat, the pins are housed partially-

  and trapped under the overhanging edges of the defined cell 10

  by its bearing surfaces 131, 132, 133, 134 (Figure 3).

  With this structure, the pin 30 of the pad 3 can be removed from the socket 10, and thus the pad can be separated from the frame, when the pad

is approximately vertical.

  To eliminate this possibility, in the space of the cell 10 separate

  the free end of the tenon 30 when the plug is in the closed position

  ture, from the outer wall 11, is housed a stop plate 4 for the

  head (Figure 1), intended to be positioned approximately vertically-

  Lement in the cell against the outer wall 11.

  This plate 4 comprises a body 40 having a slight shape

  bent slightly forming a very obtuse dihedral angle opening towards

  the outer wall 11, the stop of the dihedral extending approximately horizontally

  horizontally and halfway along the wafer; in addition, the upper end part of the plate 4 is folded approximately at a right angle towards the outer wall 11 over a very short length, and the two lateral edges 41 of this folded end part carry two pins

  42 respective cylindrical retaining plate against the outer wall

11.

  To retain the abutment plate 4 against the outer wall 11, each of the side walls 13 of the cell has a groove 137 extending approximately vertically in the cell against the outer wall 11, adapted to receive a respective journal 42 to slide. wafer 4; to allow the introduction of the pin 42 in this groove 137, each side wall of the cell further comprises a groove 138 slightly inclined upward towards the outer wall 11, one end of which opens into the vertical groove 137 and of which the opposite end opens into the surface forming a curved ramp 135 of the cell 10. To support the abutment plate 4, the outer wall 11 of the chassis 1 comprises a gutter 112 extending in the cell 10 in the direction of the inner wall 12, below the level of the lower end

  of the approximately vertical bearing surface 136.

  The support plate 4 is thus capable of taking two positions.

  tions, namely a security position against theft, or anti-theft position, and a waiting position in which it is placed before being put in

security position.

  More precisely, before the tampon is put in place, the support plate 4 is introduced into the cavity 10 through the top of the chassis, or even from below the latter, the orifice 100 of the base of the cell 10 having sufficiently large dimensions to allow passage of the plate 4 to the space of the cell where the plate must be put in place, the two pins 42 are made to slide in the inclined grooves 138, and they are lowers to the bottom of the vertical grooves 137; the body 40 of the plate 4 is then in abutment against the external surface of the gutter

  112 (Figures 2 and 3). The tampon can then be put in place and possibly-

  ment withdrawn; when the pad is in place in any position, the

  tenon 30 practically perfectly hides the insert and also prevents

  che it to escape from the cell 10. To put the support plate 4 in service, the pad 3 is placed in the open position either in the intermediate stable position at 90 degrees or in the position of total opening at 110 degrees, and the plate is pushed from bottom to top until its bottom edge can be introduced into the support gutter 112 and falls back against

  the internal surface of this support gutter. In this position, the

  quette 4 fits into the housing and offers practically no grip, which

makes it virtually inaccessible.

  Under these conditions, the plate 4 limits the possibilities of displacement

  cementation of the buffer 3 in particular in the direction of the outer wall 11 of

  the alveolus 10 at an insufficient stroke for the lug to cease to be overhang-

  opened at least partially by at least one edge overhanging the cell

  ; it is therefore impossible to remove the tampon.

  In summary, this structure allows the buffer to be dismantled during the installation period (for example to seal the chassis), it is prohibited to remove the buffer after installation and commissioning of the wafer, allows the wafer to be integrated into the chassis from the origin in a captive way, and

  makes the board inaccessible and non-removable after it has been put into service.

  In the embodiment of Figures 7 to 9, the buffer 3 is ap-

  approximately identical to that of the embodiments of FIGS. 1 to

  6; therefore, its description will not be repeated; it is the same for the most

  large part of chassis 1; in fact, as it is mainly the shape of the plate 4 of FIGS. 7 to 9 which is different from that of FIGS. 1 to 6, the differences in the frame 1 relate essentially to the means provided for retaining the plate 4 and supporting it ; also, only the wafer 4 and these means will now be described; the elements of the second embodiment corresponding to elements of the first carry

  the same reference numbers, especially on the drawings.

  The plate 4 has in its central part a body 40 presented

  both a general planar shape; like the brochure of the embodiment

  tion of Figures 1 to 6, its upper end part is folded approximately

  tively at right angles to the outer wall 11 over a very short length, and the two lateral edges 41 of this folded end portion carry two respective cylindrical pins 42 for retaining the

  plate against the outer wall 11; furthermore, its lower end portion

  is folded at right angles to the opposite direction from the upper end

  lower, to form a foot 43 perpendicular to the body 40. In addition, the face of the abutment plate 4 which is adapted to come opposite the wall

  outer 11 carries two guide pads 44 extending laterally res-

  pectively on either side of the side edges of the plate; each of these lateral edges also carries, slightly above the level of the pad 44, a catch notch 45 with inclined ramp, projecting from the edge. The

  plate 4 also carries a stud 46 made of very com- plete elastomer material

  pressible, the end of which is generally conical, fixed approximately

  in the center of the body 40 and protruding from the surface of the body which is

  intended to be vis-à-vis the outer wall 11.

  To retain the abutment plate 4 against the outer wall 11, each of the side walls 13 of the cell has a groove 137 extending approximately vertically in the cell against the outer wall 11 and opening out of the chassis 1 to the orifice level

  of the base of the cell 10, adapted to receive a sliding movement

  rillon 42 and a pad 44 for guiding the wafer; the outer wall 11 also includes a groove 139 guiding the sliding in the vertical direction of the free end of the stud 46 at the same time as the plate; in addition, the edge 140 on the inner wall side 12 of each of the grooves 137 has notches 141 with an inclined ramp for housing the notch

  corresponding snap 45 of the plate 4 when the latter is in position

  waiting position and when it is in the safety position, and thus the sup-

  wear when it is in one or other of these two positions.

  The pins 42 of the stop plate 4 being inserted in the

  approximately vertical groove 137 by its lower end at the level

  calf of the base orifice 100, to pass from the low standby position (FIG. 7) in which the snap notches 45 are engaged in the corresponding notches, to the high securing position (FIG. 8), it suffices to slide the plate upwards by sliding the inclined ramps of the notches 45 along the inclined ramps of the notches 141 and compressing the elastomer block 46 to allow the release of the notches from the notches, then driving the plate 4 upwards up to the securing position in which the notches 45 are again engaged with notches 141; during this operation, the pad 3 is either in the stable open position at about 90 degrees or in the position

total opening at 110 degrees.

  With this embodiment, it is possible to return from the posi-

  securing in which it is impossible to withdraw the buffer at the standby position in which withdrawal is authorized, but this operation is difficult. To make it impossible, simply drown the lower part of the cell in a sealing material such as sealing concrete

  to prevent any downward movement of the stop plate 4.

  In the embodiment of FIGS. 10 to 16, the means of mutual articulation of the pad 3 and of the frame 1 are respectively two pins 30 of the pad and two cells 10 of the frame; the organs of

  this embodiment corresponding to organs already described in the pre-

  these forms bear the same numerical references.

  The cells 10 are limited by an outer wall 11 and to their

  upper part by an inner wall 12 of the chassis as before-

  is lying; on the other hand, as the two cells are separated from each other by a partition extending in T from the outer wall 11 in the direction of the inner wall 12, they are limited laterally on one side by a wall 13 as previously, while on the opposite side, the side wall of the upper part of the cells is this T-shaped partition 15. The bearing surfaces belonging to the frame 1 are formed in each cell by planar upper surfaces 113 lateral to the outer wall 11 inclined downwards towards the interior of the chassis 1, extended in the same direction by curved surfaces

  114 itself extended by horizontal surfaces 115.

  It can be noted that the T-shaped partition 15 does not extend to the bottom of the cells 10, so that these are in communication with one another under the material bridge constituted by the partition 15; we can

  also note that in each cell 10, facing the sail region

  in the direction of the side wall 13, of the widest part of the wall

  its 15 in T, the outer wall 11 descends approximately vertical-

  ment to the base of the frame 1, the bearing surfaces 113, 114, 115 for the tenon 30 interrupting laterally at the right of the free end of this projecting region; it follows that the two cells 10 pass through the frame right through and open at the base thereof in their region extending between the outer wall 11 and the vertical of the projecting region

  laterally of the widest part of the partition 15, by holes

  pective 100, and that the two orifices 100 are in communication with each other under the partition 15 in T. The tenons 30, at their free end, comprise at the end a head 302 having an external shape in portion of cylinder s 'extending over an arc of circumference of the order of 180 degrees. The cylindrical surfaces of

  heads constitute bearing surfaces of the studs.

  Each articulation head 302 has, in the region of its ex-

  free end separated by a space from the wall 11 of the cell which is opposite

  opposite when the pad is in the closed position, a lateral pin 303 in

  projection relative to the lateral face of the articulation head 302 which is facing

opposite the T-shaped partition 15

  The pins 303 have an upper surface in portion of cy-

  lindre extending here on an arc of circumference of about 180 degrees. They

  are positioned so that they are partially overhung, when the drum

  pon is in the closed position, by an edge region 151 of the widest part of the T-shaped partition 15 constituting, as we have seen, an edge wall of each cell 10, which edge region 151 extends in overhang

  towards the outer wall 11.

  The open position in abutment of the pad 3 (not shown), in which the pad makes an angle of about 120 degrees relative to the

  chassis, is defined by the location and inclination of the upper surfaces

  inclined res 113 against which the upper faces of the part 301 of the studs 30 can be pushed back, as well as by the support of the studs on

  the bearing surfaces 115 and lugs against the base of the wall of the partition

  sound 15 which is opposite the outer wall 11.

  With this structure, the pin 30 of the buffer 3 can be introduced

  in cell 10 of frame 1 when the pad is approximately vertical

  cal (Figure 10), and the pad can then be brought into the open position as a stop, into the closed position (Figure 11), or be separated from the chassis by

  approximately vertical position.

  To remove this last possibility, in the space of the cell

  10 separating, when the pad 3 is in the closed position, the bound end

  bre of the tenon 30, of the outer wall 11, is housed a stop plate

* 4 for the head (figures 13 and 14) intended to be positioned approximately-

  vertically in the cell near the outer wall 11 (fig.

res 15 and 16).

  This plate 4 has in its central part a body 40 pre-

  feeling a generally flat shape; the upper part and the lower part of the plate 4 extend approximately at right angles to the interior wall 12; this plate has a notch 47 extending over the entire length of the upper part extending at right angles to the body 40 and over the region of the body which is adjacent to this upper part, so that two lateral branches 48 are defined on either side of the notch 47; the lower end portion extending approximately at a right angle as previously formed a foot 43; preferably, the foot 43 is narrower than the body 40 and that the spacing of the lateral branches 48; to this end, the body 40 can by

  example present an isosceles trapezoid shape.

  To position with relative precision the plate 4 near

  the outer wall 11 and support it when it is in the dry position.

  curation, the flat inclined upper bearing surfaces 113 for the heads 302 of the studs 30 and the pins 303, and the base 481 of a heel of the upper part of the lateral branches 48 of the plate which projects from the body central 40, have the same inclination; similarly, the edge edge 151 of the cell overhanging the pins 303, and the base of the free end 482 of the upper part of the lateral branches 48 of the plate have the same inclination; in addition, the length of this upper part of the branches 48 is such that it can be adjusted between

  this bearing surface 113 and this edge song overhanging 151.

  The plate 4 is put in place from below the chassis 1 through

  towards the orifices 100 in communication with the base thereof, while the pad 3 is in the open position, by raising the plate 4 in the cell to introduce its branches 48 between the tenon 30 and the outer wall 11 and

  then pivoting the base of the body 40 in the direction of the wall 11. The plate

  quette 4 can also be removed, but this operation is difficult, and all the more so for those who do not know the arrangement of the device; this results in a certain inviolability. To definitively prevent the withdrawal of the plate 4, it suffices to fill the lower part of the cell 10 with a sealing material to a level such that the plate can no longer be removed from below the chassis, for example by drowning the foot

  43 of the wafer in this material such as concrete.

  Of course, the invention is not limited to the embodiments described above and shown, and we can provide others without

get out of its frame.

Claims (10)

  1. Manhole cover to cover or selectively access   to an excavation dug in the ground, comprising a frame (1)   delimiting an access (2) to the excavation and a cover (3) suitable for   see being moved in an approximately pivoting movement around an approximately horizontal axis while resting in the chassis between a closed position in which it approximately covers   access and an open position in abutment in which it releases it subs-   as well, the cover (3) and the frame (1) being provided with mutual articulation means constituted by at least one lug (30) of the cover and   at least one cell (10) of the chassis having multiple bearing surfaces   tuel adapted to cooperate during said movement approximately   pivoting, the post having in the region of its free end separated   ree of the wall (11) of the cell which is opposite when the cover is in the closed position by a space, an articulation head (302) comprising at least one lateral lug (303) housed, when the cover (3) rests in the frame (1), at least partially under at least one edge of the cell which is overhanging and extends itself in the direction of said wall (11) of   the socket at a distance therefrom, a look characterized in that it comprises, lo-   gée in said space, a plate (4) of abutment for the articulation head (302), resting on at least one support surface belonging to the frame (1), limiting the possibilities of displacement of the cover (3) in direction of said wall (11) of the cell (10) at an insufficient stroke so that the lug (303) ceases to be overhung at least partially by said edge of the cell, and the cell (10) opens out to the exterior of the chassis (1) by its base so that said space is in communication with the exterior of the chassis by an orifice (100) allowing the passage of the plate (4) for its placement in this space.   2. Manhole according to claim 1, characterized in that the neck   ring (3) comprises a lug (30) having two lateral pins (303), and   the chassis (1) has a cell, the side walls (13) of which are   nies of bearing surfaces (131,132) for the tenon (30) delimiting an edge of the cell which is overhanging and extends in the direction of the wall (11) of   the socket which is opposite the free end of the post (30) when the neck   circle is in the closed position.   3. Manhole according to any one of claims 1 and 2, charac-   terized in that the cover (3) comprises a lug having two lateral lugs (303), and the frame (1) comprises a cell (10) whose walls   lateral (13) are provided with at least one bearing surface (133) for the   no (30) delimiting an edge of the cell which is overhanging and extends in the direction of an inner wall (12) of the cell whose top serves as a seat to the cover (3).   4. Manhole according to one of claims 1 and 3, characterized in that   that the cell has side walls (13) having respective retaining grooves (137) extending against said wall (11) of the cell which is opposite the free end of the stud (30 ) when the cover is in   closed position, and the plate (4) has pins (42) laterally   rails mounted sliding in these grooves.   5. Manhole according to claim 4, characterized in that the pa-   lateral kings (13) have respective insertion grooves (138) for introducing the pins (42) into the retaining grooves (137), one end of which opens into this retaining groove (137) and the opposite end of which opens out in a bearing surface (135) of the socket (10) for the post (30), a lower edge of the plate (4) being adapted to rest on an internal surface of a gutter (112) carried by at   at least one wall (11) of the cell.   6. Manhole according to claim 4, characterized in that the pa-   lateral kings (13) are provided with respective grooves (137) comprising notches (141) adapted to cooperate by snap-fastening with notches (45) carried by lateral edges of the plate (4), and the plate (4) also comprises a stud (46) of compressible material allowing the wafer to slide between a standby position and a position of security.   7. Manhole according to claim 1, characterized in that the cou-   ring (3) comprises two pins (30) each having at least one lateral lug (303), and the frame (1) comprises two cells (10) having an outer wall (11) and bearing surfaces (113, 114 , 115) for a respective tenon, the two cells being separated from each other by a partition   (15) in T extending from said outer wall (11) of the chassis in direct   tion of an inner wall (12) of the chassis, an enlarged part of the T-partition having edge regions (151) which extend in the direction of the outer wall (11) and which, when the cover is in the closed position,   partially overhang the pins (303) of the post (30).   8. Manhole according to claim 7, characterized in that the plate   quette (4) has two lateral branches (48) adapted to rest on support surfaces belonging to the chassis (1), these support surfaces being constituted by the upper part of upper support surfaces (113) equipping each cell (10 ) for the support of the respective tenons (30) and   by a song of the edge regions (151) overhanging on the cells (10).   9. Manhole according to any one of claims 6 and 8, charac-   terized in that the plate (4) has at one end a folded foot (43).   10. Manhole according to any one of claims 1 to 9, charac-   terized in that the lower part of the cell (10) is lined with a material sealing.