AU2011201060A1

AU2011201060A1 - Highways device, in particular manhole, with frame and plug with backward movement relative to the frame to ensure the closed position of the plug in the frame

Info

Publication number: AU2011201060A1
Application number: AU2011201060A
Authority: AU
Inventors: Pascal Lacroix
Original assignee: Norinco SA
Current assignee: Norinco SA
Priority date: 2010-03-15
Filing date: 2011-03-09
Publication date: 2011-09-29
Anticipated expiration: 2031-03-09
Also published as: CO6340181A1; MX2011002768A; NZ591687A; ZA201101931B; CN102191780A; CA2733838A1; ES2394285T3; PL2366835T3; BRPI1101329A2; AU2011201060B2; FR2957367A1; PT2366835E; FR2957367B1; RU2526924C2; EP2366835A1; EG26473A; EP2366835B1; CN102191780B; US20110222964A1; RU2011109668A

Abstract

The present invention relates to a highways device, in particular a manhole, with a frame and plug with backward movement relative to the frame to ensure the closed position of 15 the plug in the frame. According to the invention, one of the ends of the self locking arm (30) of said device is pivotally mounted to the frame (20) able to slide in a fixed guide groove (35) so that the end of the arm (3) can bear on a fixed stop (38) of the 20 frame (1) during tilting of the plug (8) to its closed position of the frame (20) to cause the plug (4) to move backwards and allow the latter to correctly close the opening of said frame. The invention is applicable in the highways field. 25 FIGURE 9. 8b 4 40 43 2 30 20 ' 30 14a 14a (D 5 42 41 37 2 36 3 0i :4

Description

1 AUSTRALIA Patents Act 1990 NORINCO COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Highways device, in particular manhole, with frame and plug with backward movement relative to the frame to ensure the closed position of the plug in the frame The following statement is a full description of this invention including the best method of performing it known to us:- 1A The present invention relates to a highways device, in particular a manhole, comprising a rectangular frame whereof the side walls and ends delimit an opening and at least one plug whereof one side is pivotally mounted relative to an adjacent 5 end wall of the frame by at least one joint hinge. The invention is in particular but not exclusively applicable to manhole covers. In such an application, the frame is durably sealed in the ground and one or several plugs articulated relative to the 10 frame can occupy a lowered position in which the plugs cover the opening formed in said frame or a raised position in which the plugs free the opening of the frame. Each joint hinge of a plug to the frame generally has functional play allowing the plug to be articulated to the frame 15 without difficulty and to fit correctly into the opening of the frame delimited by its four side walls and ends to close said opening. However, each manhole cover plug is very heavy, as it is made from a cast iron-based material, in particular spheroidal. 20 Thus, such plugs are difficult to maneuver during tilting thereof between the closed and open positions of the frame and, moreover, when they occupy their raised open position, they can accidentally tilt to their closed position of the opening of the frame. 25 To resolve this problem, a safety device has already been proposed for each articulated manhole cover plug. Such a device comprises, for each manhole plug, at least one jack to assist with opening and closing the plug pivotally mounted by its ends under the plug and to the frame and a self-locking arm also 30 articulated by its ends between the plug and the frame and making it possible to lock the plug in its upright opening position without a risk of accidental tilting of the plug towards its closed position of the frame opening. However, such a safety device has the drawback that during 35 tilting of the plug to its closed position of the frame opening, 2 the assistance jack exerts a force on the plug pushing it towards the end wall of the frame opposite the joint hinge, the functional play of which risks making the corresponding edge of the plug collide with the upper edge of said end wall, thereby 5 preventing correct closing of the frame opening by the plug and risking damaging both the edge of the plug and the corresponding end wall of the frame. The present invention aims to offset the abovementioned drawback of the known safety devices for plugs of highways 10 devices. To that end, according to the invention, the highways device, in particular manhole, of the type comprising a rectangular frame whereof the side and end walls delimit an opening, at least one plug whereof one side is pivotally mounted 15 relative to an adjacent end wall of the frame via at least one joint hinge having functional play to allow the plug to tilt between an upright position releasing the opening of the frame and a closed position of said opening while bearing on an inner peripheral seating wall of the frame and fitting into the frame, 20 at least one jack to assist with opening or closing the plug pivotally mounted between the plug and the frame, and at least one self-locking arm pivotally mounted between the plug and the frame parallel to the assistance jack and making it possible to lock the plug in its raised position releasing the opening of 25 the frame, is characterized in that the end of the self-locking arm is pivotally mounted to the frame able to slide in a fixed longilinear guiding groove secured to the frame and extending below the seating wall of the frame parallel to said wall so that the end of the self-locking arm can come closer to the 30 other end wall of the frame during tilting of the plug to its closed position of the opening of the frame, in that at least one stop is secured to the frame perpendicular to the other end wall of the frame so that the sliding end of the self-locking arm bears on the stop during tilting of the plug to its closed 35 position of the opening of the frame to cause the plug to 3 withdraw towards the end wall adjacent to the articulated side of the plug and allow the latter to close the opening of the frame. The self-locking arm has a determined length and is 5 pivotally connected to a determined location of the plug so that by bearing by its sliding end on the fixed stop, it keeps the plug in a half-open safety position relative to the frame and the self-locking arm causes the plug to withdraw towards the adjacent end wall of the frame while exerting a relatively high 10 pressure on the plug in its half-open position to bring the plug to its position closing the opening of the frame. According to a first embodiment, the plug assumes the form of a right angled triangle and a single self-locking arm is articulated under the plug near its straight side adjacent to 15 the side articulated to the frame and the corresponding side wall of the frame. In this embodiment, the highways device comprises a second plug in the form of a right angled triangle whereof one of the sides is articulated relative to the other end wall of the frame 20 by at least one joint hinge having a functional play to allow the second plug to tilt between an upright position freeing the opening of the frame and a closed position of said opening while bearing on the inner peripheral seating wall of the frame and fitting into the frame, at least one jack assisting with the 25 opening or closing of the second plug pivotally mounted between said plug and the frame and a single self-locking arm articulated parallel to the assistance jack between the frame and under the second plug near its straight side adjacent to the side articulated to the frame and making it possible to lock 30 said plug in its upright position freeing the opening of the frame, the self-locking arm having its end pivotally mounted to the frame able to slide in a second fixed longilinear guide groove secured to the frame and extending below the seating wall of the frame parallel to said wall so that the end of the self 35 locking arm can come closer to the opposite end wall of the 4 frame during tilting of the second plug to its closed position of the opening of the frame and a second stop being secured to the frame perpendicular to the opposite end wall of the frame so that the sliding end of the self-locking arm bears on the second 5 stop during tilting of the second plug to its closed position of the opening of the frame to cause the second plug to withdraw towards the adjacent end wall at the articulated edge of the second plug and to allow the latter to close the opening of the frame. 10 The two triangulated plugs make it possible to completely cover the opening of the frame in their closed position. According to another embodiment, the plug has a rectangular shape capable of completely covering the opening of the frame in its closed position, a second self-locking arm is pivotally 15 mounted between the plug and the frame parallel to the assistance jack and also making it possible to lock the plug in its upright position releasing the opening of the frame, the second self-locking arm having its end pivotally mounted to the frame being able to slide in a second fixed longilinear guide 20 groove secured to the frame extending below the seating wall of the frame parallel to said wall so that the end of the second self-locking arm can come closer to the other end wall of the frame during tilting of the plug to its closed position of the opening of the frame, a second stop being secured to the frame 25 perpendicular to the other end wall of the frame so that the sliding end of the second self-locking arm bears on the second stop during the tilting of the plug to its closed position of the opening of the frame to cause the plug to withdraw towards the end wall adjacent to the articulated side of the plug and to 30 allow the latter to close the opening of the frame. Each self-locking arm is articulated on one hand by one of its ends under the plug around a transverse axis of the arm and on the other hand by its opposite end sliding around a transverse axis of the arm and engaged through the corresponding 35 guide groove to slide along said groove.

5 Each guide groove comprises, at its end opposite the corresponding stop, a notch for receiving the sliding axis of the self-locking arm to lock the plug in its upright position releasing the opening of the frame. 5 Preferably, the two self-locking arms are the same length, are arranged in two planes perpendicular to the plane of the opening edge of the frame, and are articulated by two of their ends under the plug around two coaxial axes and by their other two ends opposite the frame around two coaxial axes. 10 Advantageously, the device comprises two coaxial joint hinges of the plug to the frame spaced apart from each other parallel to the adjacent end wall of the frame. Each joint hinge comprises a cylindrical axis parallel to the adjacent end wall of the frame supported by a clevis secured 15 to the corresponding part of the seating wall of the frame and two lugs forming knuckles secured to the plug and arranged between the two branches of the clevis while being passed through by the cylindrical axis, the lugs forming knuckles having an orifice with dimensions larger than the diameter of 20 the cylindrical axis to allow movement with play of the plug relative to the cylindrical axis. Each stop can be adjusted in the direction perpendicular to the corresponding end wall. Advantageously, said device comprises at least one 25 elastically deformable means fastened to the seating wall protruding therefrom close to the end wall of the frame opposite the end wall adjacent to the joint hinge and capable of facilitating opening of the plug from its closed position of the frame. 30 The assistance jack is articulated on an axis secured to a platen below the seating wall of the frame. The invention will be better understood, and other aims, features, details, and advantages thereof will appear more clearly in the following explanatory description provided in 35 reference to the appended drawings, provided solely as an 6 example illustrating two embodiments of the invention and in which: - figure 1 is a top view of a manhole according to a first embodiment of the invention where the plug is in its closed 5 position of the frame; - figure 2 is a cross-sectional view along line II-II of figure 1; - figure 3 is an enlarged view of the part circled in III of figure 2; 10 - figure 4 is an enlarged view of the part circled in IV in figure 2; - figure 5 is a cross-sectional view along line V-V of figure 1 and showing the plug in the half-open position relative to the frame; 15 - figure 6 is an enlarged view of the part circled in VI in figure 5; - figure 7 is a perspective view of the plug of the manhole in its raised position releasing the opening of the frame; - figure 8 is an enlarged view of the part circled in VIII 20 of figure 7; - figure 9 is a perspective view along arrow IX of figure 7; - figure 10 is an enlarged view of the part circled in X in figure 9; 25 - figure 11 is a perspective bottom view of the manhole cover whereof the plug is in its closed position of the frame of said manhole; - figure 12 is an enlarged view of the part circled in XII in figure 11; 30 - figure 13 is an enlarged perspective view of the part circled in XIII in figure 7; and - figure 14 is a perspective view of a second embodiment of the manhole cover according to the invention with two plugs triangulated and articulated to the frame of said manhole.

7 The device according to the invention that will be described applies at least to a plug for a manhole cover, but it is understood that it can be applied to any plug or leaf other than that of a manhole cover. 5 According to the first embodiment shown in figures 1 to 13, the manhole cover comprises a frame 1 with a generally rectangular shape comprising two side walls 2 and two end walls 3 welded to each other and delimiting an opening. Each side 2 and end 3 wall constitutes one of the wings of 10 a profile with an L-shaped transverse section, the other wing 4 of which is fastened on a sub-frame 5 via fastening bolts 6. The wings 4 associated with the side 2 and end 3 walls protrude in the opening of the frame 1 and are arranged in a same plane to constitute a peripheral seating wall 7 of a 15 rectangular plug 8 of the manhole cover when the plug 8 is in its closed position of the opening of the frame 1 while fitting into the opening of said frame 1. The sub-frame 5 is intended to be partially buried in the ground of a road and is made up of a flat rectangular upper 20 frame 9 and a lower underlying skirt 10 assembled together by welding so as to have a T-shaped transverse cross-section. The wing 4 associated with each side 2 and end 3 wall is fastened on the horizontal part forming the head of the T of the sub-frame 5 protruding in the opening of the frame 1 and outside the latter. 25 The sub-frame 5 is also provided with four square legs 11 respectively fastened to the four inner corners of the skirt 10. The plug 8 is pivotally mounted by one of its sides 8a, called rear side, to the adjacent one of the end walls 3, called rear wall, preferably by two joint hinges 12 to allow the plug 8 30 to tilt between an upright released position of the opening of the frame 1 and a completely closed position of the opening of said frame. The two joint hinges 12 are arranged coaxially on the wing 4 associated with the rear wall 3 extending parallel to said 35 rear wall.

8 As better emerges from figure 13, each joint hinge comprises a cylindrical axis 13 parallel to the rear wall and supported by a clevis 14 whereof the two parallel branches 14a are fastened, for example by welding, on the wing 4 5 perpendicular thereto. The cylindrical hinge pin 13 of each hinge 12 passes through the two branches 14a of the support clevis 14 practically without play. Each joint hinge 12 also comprise two lugs forming knuckles 15 secured to the inner face of the plug 8 near the rear edge thereof and arranged parallel 10 between the two branches 14a of the clevis 14 while being passed through by the cylindrical hinge pin 13. As better emerges from figure 4, the orifice 16 made through each lug forming a knuckle 15 has dimensions larger than the diameter of the hinge pin 13 passing through said orifice to 15 constitute a relatively substantial functional play of the joint hinge 12. The orifice 16 is obtained by a cast iron core and assumes the particular form in transverse cross section of figure 4 allowing the plug 8 to tilt between its upright position releasing the opening of the frame 1 and closing said 20 opening without a risk of jamming of the joint hinge 12, while allowing movement of the rear edge 8a of the plug 8 relative to the rear wall 3 as will be seen later. Of course, the orifice 16 can have a different shape and be made up of an oblong hole once said orifice allows the rear edge 25 8a of the plug 8 to move away from or closer to the corresponding rear wall 3 during tilting of the plug 8 between its open and closed positions of the frame 1. Each hinge pin 13 is kept axial to the clevis 14 by at least one elastic ring 14b, in this case two, fastened to each 30 end of the axis 13 outside the corresponding branch 14a of the clevis 14. The two axes 13 of the hinges 12 are arranged coaxially to each other.

9 The plug 8 comprises, at each of its four corners, a lug 17 bearing on the peripheral seating wall 7 when the plug 8 is in its closed position of the opening of the frame 1. . The plug 8 is also provided with a lock housing 18 fastened 5 under the plug near its front edge 8b and the bolt 19 of which can be engaged under a strike 20 protruding from the inner face of the front end wall 3 of the frame 1 to lock the plug 8 to the frame 1 as shown in figure 2. The bolt 19 can be actuated to its unlocked position of the strike 20 using a key 21. 10 The manhole cover also comprises two parallel jacks 22 for assisting in opening or closing the plug 8 and pivotally mounted between the plug 8 and the frame 1. More specifically, one end of the body 23 of each assistance jack 22 is articulated on an axis 24 secured to a lug 25 fastened to a plate 26 protruding in 15 the opening of the frame 1 and secured to the inner face of the corresponding skirt wall and the corresponding wing 4 associated with the rear wall 3 so that the hinge pin 24 is arranged below the wing 4 that is part of the seating wall 7 of the frame 1. The other end of the rod 27 of each jack 22 is articulated to an 20 axis 28 secured to the end of a rib 29 protruding from the inner face of the plug 8 perpendicular thereto. The two axes 24 and 28 of each jack 22 are parallel to the hinge pins 13 of the hinges 12. The two jacks 22 are thus respectively arranged in two 25 planes perpendicular to the plane of the opening edge of the frame 1. If applicable, a single assistance jack 22 can be articulated between the plug 8 and the frame 1. The manhole cover also comprises two self-locking arms 30 30 each made up of a flat rigid bar and pivotally mounted between the plug 8 and the frame 1 on either side of the assistance jacks 22 parallel thereto. One end of each self-locking arm 30 is articulated on an axis 31 supported by a lug 32 secured to the inner face of the 35 plug 8 perpendicular thereto and situated close to the 10 corresponding side edge 8c of the plug 8. The two hinge pins 31 articulating the plug 8 to the two self-locking arms 30 are coaxial and parallel to the hinge pins 13 of the hinges 12. As shown, each hinge pin 31 is made up of a threaded shaft of a 5 screw passing through the lug 32 and the end of the arm 30 and the head 33 of which bears on the side face of the lug 32 opposite that on which the end of the self-locking arm 30 bears. The opposite end of each self-locking arm 30 is articulated on an axis 34 that passes through a fixed longilinear guiding 10 groove 35 extending below the wing 4 and parallel thereto that is part of the seating wall 7 associated with the corresponding side wall 2 of the frame 1, this groove 35 also extending perpendicularly from the plane containing the front end wall 3 of the frame 1 over a predetermined distance corresponding to 15 half of the length of the side wall 2. The two axes 34 of the arms 30 are coaxial and parallel to the axes 13 of the joint hinges 12. Each groove 35 is made through a rectangular plate 36 fastened, for example by welding, opposite the corresponding 20 wall part of the skirt 10 of the sub-frame 5 and parallel to said part while allowing a space to remain in which the head 37 of a screw constituting the axis 34 passing through the corresponding end of the self-locking arm 30 is housed. Thus each self-locking arm 30 is arranged in a plane 25 perpendicular to the plane of the opening edge of the frame 1 and situated close to the inner edge of the wing 4 associated with the side wall 2 of the frame 1 so that the two self-locking arms 30 can move in the opening of the of the frame 1 during tilting of the plug 8 between its open and closed positions of 30 said frame. Each of the grooves 35 includes, at its end opposite the front end wall 3 of the frame 1, a notch 37 for receiving the hinge pin 34 when the plug 8 is in its raised or upright position releasing the opening of the frame 1 shown in figure 7 11 so that the two self-locking arms 30 can lock the plug in said raised position. The coaxial hinge pins 31 articulating the two self-locking arms 30 to the plug 8 are situated relative to the front edge 8b 5 of the plug 8 at a distance further than that separating the coaxial hinge pins 28 of the jacks 22 of said front edge. The manhole cover also comprises two stops 38 fastened to the frame 1 while being arranged respectively in the two planes containing the two self-locking arms 30 while protruding in the 10 opening of the frame 1 from the plane containing the front end wall 3 of said frame perpendicular to said plane. More specifically, each stop 38 is fastened to a lug 39 fastened under the horizontal branch part 9 of the T of the sub-frame 5 so that the stop 38 protrudes from two superimposed inner edges 15 of the wing 4 associated with the front end wall 30 and the transverse branch part of the T of the sub-frame 5. Each stop 38 can be adjusted in the direction perpendicular to the plane containing the front end wall 3 of the frame 1. To that end and preferably, each stop 38 comprises a screw 20 whereof the shaft 40 is anchored in its lug 39 and the head 41 protrudes in the opening of the frame 1, and a nut 42 making it possible to lock said shaft 40 in the lug 39. The two jacks 23, the two self-locking arms 30, the two guide grooves 35 of the corresponding ends of the two self 25 locking arms 30, and the two stops 38 are arranged symmetrically to the vertical median plane of the frame 1 parallel to the two side walls 2 of said frame. The manhole cover is lastly provided with at least one means 43 to help with opening the plug 8 when it is in its 30 closed position of the opening of the frame 1. Preferably, two means 43 for assisting with opening the plug 8 are provided and are respectively arranged in the two corners of the frame 1 defined between the front end wall 3 and the two side walls 2 of said frame and opposite the joint hinges 35 12.

12 Each means 43 is elastically deformable and protrudes from the seating wall 7 so that it is elastically compressed by the corresponding lug 17 of the plug 8 when the latter is in its closed position of the frame and is locked thereto by the bolt 5 19 and strike 20 assembly. As shown in the figures, each means 43 can be made up of a rod plunger 44 secured to a circular head 45 and a helical compression spring 46 coaxially mounted around the rod 44 bearing on one hand under the head 45 and on the other hand at 10 the bottom of a blind hole 47 made in the thickness of the seating wall part 7 and the underlying part of the head 9 of the T of said frame 5. Thus, in the closed position of the plug 8, each of the two lugs 17 situated near the front edge 8b of the plug 8 bears on 15 the corresponding head 45 of the plunger means 43 to engage it, against the return force of the spring 46, in the blind hole 47 so that the outer face of the head 45 is flush with the upper face of the corresponding part of the seating wall 7. Alternatively, each means 43 making it possible to 20 facilitate opening of the plug 8 can be formed by a cylindrical block in an elastomer material fastened in the corresponding blind hole 47 while protruding from the upper face of the corresponding seating wall part of the frame 1 and able to be elastically compressed by the corresponding lug 17 in the closed 25 position of the plug 8. Of course, it is possible to provide only a single means 43 for helping to open the plug 8 by positioning it in the middle of the seating wall part 7 perpendicular to the front end wall 3 of the frame 1. In this case, the plug 8 would include an 30 additional lug 17 arranged close to the front edge 8b of the plug 8 between the two end lugs 17. The operation of the manhole cover already results from the description thereof provided above and will now be explained from the closed position of the opening of the frame 1 by the 35 plug 8.

13 In that position, the plug 8 is locked in the frame 1 by the bolt 19 of the lock housing 18 engaged under the strike 20 of the frame 1. The two plunger means 43 are then elastically compressed in their respective blind holes 47 by the two lugs 17 5 of the plug 8. To perform the tilting operation of the plug 8 from its closed position to its open position of the frame 1, an operator unlocks the plug 8 from the frame 1 using the key 21 to disengage the bolt 19 from the strike 20. The two means forming 10 the plunger 43 then exert a force on the plug 8 pushing said plug into a half-open position, not shown in the figures, in which the operator can easily grasp the front edge 8b of the plug 8 as needed using a tool, to make it pivot to its upright position releasing the opening of the frame 1 shown in figures 7 15 and 9. Of course, the jacks 22 perform their role of assisting with the opening of the plug 8 and the ends of the self-locking arms 30 slide respectively in the two grooves 35 until their two pivot axes 34 engage in their respective notches 37 to completely safely lock the plug 8 in its raised position 20 releasing the opening of the frame 1. Moreover, the functional play of each of the joint hinges 12 allows movement of the rear edge 8a of the plug 8 relative to the fixed hinge pin 13 to prevent any risk of jamming during assisted tilting of the plug 8 from its closed position to its 25 open position. To tilt the plug 8 from its open position to its closed position of the frame 1, the operator manually disengages the two pivot axes 34 from their respective notches 37 by acting on the self-locking arms 30 to cause the pivoting, assisted by the 30 jacks 22, of the plug 8 towards its closed position. During this tilting, the two axes 34 slide along their respective guide grooves 35 until the lower free ends of the self-locking arms 30 bear respectively on the two stops 38. The two self-locking arms 30 have a same determined length and are 35 pivotally connected to a determined location of the plug 8 so 14 that by bearing on the two stops 38, they keep the plug 8 in the half-open intermediate safety position of figure 5. This half-open safety position will then require the user to tilt the plug 8 to its closed position of the opening of the 5 frame 1 by exerting a significant pressure on the plug obtained by the weight of the operator on said plug. During tilting of the plug 8 from its half-open position of figure 5 to its closed position of figure 1, the stops 38 act on the two self-locking arms 30, which then cause the plug 8 to 10 withdraw towards the rear end wall 3 of the frame 1 owing to the functional play between each pair of plates forming knuckles 15 and the corresponding fixed hinge pin 13 of each of the two joint hinges 12, thereby preventing the front edge 8b of the plug 8 from colliding with the front end wall 3 of the frame 1. 15 In the covering position of the opening of the frame 1 by the plug 8, the two self-locking arms 30 are substantially horizontal considering the manhole cover installed in a road and the two assistance jacks 22 are slightly inclined from top to bottom in the direction of the front end wall 3 of the frame 1. 20 In this way, the plug 8 is correctly fitted into the opening defined by the side 2 and end 3 walls of the frame 1 in its closed position of said frame and is automatically locked to the frame 1 via the bolt 19 engaged under the strike 20. Figure 14 shows another embodiment of the manhole cover 25 according to which two plugs 8 in the form of right angled triangles are articulated to the opposite sides of a rectangular frame 1 between a raised position of the plugs 8 of said figure in which the opening of the frame 1 is released and a completely closed position of the opening of said frame in which the two 30 plugs 8 are fitted into the frame 1 with their hypotenuse walls 8d juxtaposed and extending along a diagonal of the frame 1. Each plug 8 is articulated by one of its straight sides 8a relative to the corresponding so-called end wall 3 of the frame 1 by two joint hinges 12 identical to the joint hinges 12 of the 35 first embodiment of figures 1 to 13. As such, there is no point 15 in explaining the structure of each joint hinge 12 of a triangulated plug 8 relative to the wall 3 of the frame 1, or the manner in which the components of this hinge are fastened to the plug 8 and the corresponding part of the seating wall 7. 5 Each triangulated plug 8 includes, under it at its apex, a lug 17 bearing, in the closed position of the plug, on the seating wall part 7 situated at the corner of the frame 1 defined between the end wall 3 opposite the joint hinges 12 of said plug and the side wall 2 adjacent to the other straight 10 side of the triangulated plug 8 in the closed position of said plug. Although it is not shown by figure 14, the two diagonally opposite corners of the frame 1 in which the two lugs 17 of the two triangulated plugs 8 are respectively housed each comprise a means for helping to open each plug 8 and identical to the means 15 23 described in the first embodiment of the manhole cover. Likewise, one of the two triangulated plugs 8 is equipped with a lock housing 18 having a bolt 19 able to be engaged under a strike, not shown, of the side wall 2 of the frame 1 adjacent to the side or edge 8c of the plug 8 to lock the two plugs 8 to 20 the frame 1 after having first lowered the other plug 8 not equipped with the lock housing 18 and then the plug 8 equipped with the lock housing 18, which locks the other plug 8 in the frame 1 via its hypotenuse wall 8d bearing on a tab 8e of the other plug 8 protruding transversely from its hypotenuse wall 25 8d. Each triangulated plug 8 is also equipped with two jacks 22, only one pair of which is visible for one of the plugs, and which makes it possible to assist with opening and closing the plug 8. The opposite ends of each of the assistance jacks 22 are 30 respectively articulated under the plug 8 and to the frame 1 below hinge pins 13 of the hinges 12 in the same way as each of the assistance jacks 22 of the first embodiment such that there is no point in providing another detailed description thereof. Of course, each plug 8 may include only a single assistance jack 35 22.

16 Each of the triangulated plugs 8 is also equipped with a self-locking arm 30 only visible for one of the plugs 8 and identical to each self-locking arm 30 of the first embodiment. Thus, one of the ends of the self-locking arm 30 of each 5 plug 8 is articulated on a pivot axis 31 supported by a lug 32 secured to the inner face of the plug 8 perpendicular thereto and near the inner face of the wall 8f of the plug 8 adjacent to the articulated rear side or edge 8a of the plug 8. The opposite end of the self-locking arm 30 is articulated on an axis able to 10 slide along a guide groove, not shown, and identical to the axis 34 and the guide groove 35 described in the first embodiment for each self-locking arm 30. Thus, the guide groove 35 is made through a rectangular plate identical to the plate 36 of the first embodiment and that is secured perpendicular to and under 15 the seating wall part 7 adjacent to the side wall 2 of the frame 1 situated opposite the wall 8f of the plug 8 when it is in its closed position of the frame 1. Of course, the guide groove of the corresponding end of the self-locking arm 30 of each plug 8 includes, at its end opposite its joint hinges 12, a notch as 20 for the first embodiment making it possible to receive the pivot axis and allowing sliding of the self-locking arm to lock the plug 8 in its raised position releasing the opening of the frame 1. As for each self-locking arm 30 of the first embodiment, 25 the self-locking arm 30 associated with each triangulated plug 8 is arranged in a plane perpendicular to the plane of the opening edge of the frame 1 and is situated close to the inner edge of the seating wall part 7 adjacent to the side wall 2 of the frame 1. 30 The manhole cover of this second embodiment is also equipped with two stops respectively associated with the two triangulated plugs 8. Each of these stops is not shown in figure 14, but is identical to each stop 38 of the first embodiment and is 35 fastened in the same way as in this first embodiment.

17 Thus, the stop associated with the self-locking arm 30 of the plug 8 with lock housing 18 is arranged in the corner of the sub-frame 5 opposite the joint hinges 12 of said plug protruding in the opening of the frame 1 in a direction perpendicular to 5 the end wall 3 of the other plug substantially in a same plane as that containing the self-locking arm 30 of the lock housing 18 plug. Likewise, the stop associated with the plug 8 not including a lock housing is fastened in the corner of the frame 5 opposite 10 the joint hinges of said plug protruding in the opening of the frame 1 in a direction perpendicular to the end wall 3 of the plug 8 including the lock housing 18 while being situated substantially in the same plane as that going through the self locking arm 30 of the plug 8 not including a lock housing. 15 To bring the two triangulated panels 8 into their open position shown in figure 14 from their closed position of the opening of the frame 1, the operator first unlocks the bolt 19 from its strike 20 using the key, not shown, of the lock housing 18 and the two plunger means exert, on the two lugs 17 of the 20 two plugs 8, respectively, a thrust force bringing their front apex edges 8b of the plugs 8 into a half-open position allowing the operator to grasp and raise, if needed using a tool, first the front edge 8b of the plug 8 with lock housing 18 to make the plug 8 pivot, with assistance from the jacks 22, to its raised 25 position releasing the opening of the frame 1 in which it is completely safely locked by the self-locking arm 30 as for the first embodiment. Then, the operator grasps and raises the front edge 8b of the other triangulated plug 8 to make it pivot, with assistance 30 from the jacks 22, to its raised position completely releasing the opening of the frame 1 to which the plug 8 is locked by the self-locking arm 30 associated therewith. The operations tilting the two plugs 8 to their open position are facilitated by the functional play of the joint 18 hinges 12, which thereby prevent any risk of jamming of each plug during tilting thereof in the open position. To return the two triangulated plugs 8 to their closed position of the frame 1, the operator first disengages the lower 5 end of the self-locking arm 30 from the notch of the corresponding guide groove associated with the plug 8 not including a lock housing and makes said plug tilt towards its closed position with the assistance of jacks associated with said plug until the end of the self-locking arm 13 bears on the 10 corresponding stop to make it possible to immobilize the plug 8 in a half-open safety position as for the plug 8 shown in figure 5 of the first embodiment. Then, the operator mounts the plug 8 to use his own weight to exert a significant force causing the plug 8 to withdraw 15 towards the end wall 3 of the frame 1 owing to the functional play of the joint hinges adjacent to this wall so that the apex of the front edge 8b of the plug is at least partially engaged in the corresponding corner opposite the joint hinges defined by two of the corresponding side 2 and end 3 walls with the lug 17 20 bearing on the plunger means that is partially compressed by the weight of the plug itself. Then, the operator disengages the self-locking arm 30 from the other plug 8 with lock housing from the notch of its associated guide groove and makes the plug tilt towards its 25 closed position with the assistance of jacks 22 until the end of the self-locking arm 30 bears on the corresponding stop so as to immobilize said plug in a half-open safety position. To completely close the plug 8 with the lock housing 18, the operator mounts said plug to use his own weight to exert a 30 substantial force thereon allowing the plug to withdraw towards the corresponding end wall 13 owing to the functional play of its joint hinges 12 and to introduce the apex of the front edge 8 equipped with said plug in the corresponding opposite corner defined between the other side 2 and end 3 walls. The lug 17 of 35 this plug completely pushes in the associated plunger means, 19 which simultaneously causes the other plunger means to be completely pushed in by the lug 17 of the other plug via the action exerted by the lower edge of the hypotenuse wall 8d of the plug 8 with lock housing 18 on the tab 8e of the other plug 5 8 and the two plugs are locked in their position completely closing the opening of the frame 1 via the bolt 19 engaged under its corresponding strike. Alternatively, the two plugs 8 could be brought into their closed position by first tilting the plug 8 without lock housing 10 to its half-open position, then the other plug 8 with lock housing 18 to its half-open position. Then, the operator, using his own weight, exerts a substantial pressure on the plug 8 with lock housing 18 so as to bring its hypotenuse wall 8d on the tab 8e of the other plug 8 to push the lugs 17 into their diagonally 15 opposite respective corners of the frame 1 by compressing the plunger means and make the edges 8a of the two plugs simultaneously withdraw towards the end walls 3 to ensure covering of the frame 1 by the two plugs without their front edges 8b colliding with the walls 3. The two plugs 8 are then 20 locked to the frame 1 via the bolt and strike assembly. The presence of the two stops, the two self-locking arms respectively associated with the two triangulated plugs 8 as well as the functional play of the joint hinges of each of these two plugs to the frame 1 make it possible to ensure the tilting 25 of each plug into the closed and open positions of the frame 1 while preventing the front apex edge 8b of the plug from colliding with the corresponding end wall part of the frame opposite the articulations of the plug. The fact that the frame 1 has been described as being 30 rectangular does not limit the invention to this geometric embodiment, which also encompasses square manhole cover frames.

Claims

1. A highways device, in particular manhole, comprising a rectangular frame whereof the side and end walls delimit 5 an opening, at least one plug whereof one side is pivotally mounted relative to an adjacent end wall of the frame via at least one joint hinge having functional play to allow the plug to tilt between an upright position releasing the opening of the frame and a closed position 10 of said opening while bearing on an inner peripheral seating wall of the frame and fitting into the frame, at least one jack to assist with opening or closing the plug pivotally mounted between the plug and the frame, and at least one self-locking arm pivotally mounted between the 15 plug and the frame parallel to the assistance jack and making it possible to lock the plug in its raised position releasing the opening of the frame, characterized in that the end of the self-locking arm is pivotally mounted to the frame able to slide in a fixed longilinear guiding 20 groove secured to the frame and extending below the seating wall of the frame parallel to said wall so that the end of the self-locking arm can come closer to the other end wall of the frame during tilting of the plug to its closed position of the opening of the frame, in that 25 at least one stop is secured to the frame perpendicular to the other end wall of the frame so that the sliding end of the self-locking arm bears on the stop during tilting of the plug to its closed position of the opening of the frame to cause the plug to withdraw towards the end wall 30 adjacent to the articulated side of the plug and allow the latter to close the opening of the frame.

2. The device according to claim 1, characterized in that the self-locking arm has a determined length and is 35 pivotally connected to a determined location of the plug so that by bearing by its sliding end on the fixed stop, 21 it keeps the plug in a half-open safety position relative to the frame and in that the self-locking arm causes the plug to withdraw towards the adjacent end wall of the frame while exerting a relatively high pressure on the 5 plug in its half-open position to bring the plug to its position closing the opening of the frame.

3. The device according to claim 1 or 2, characterized in that the plug assumes the form of a right angled 10 triangle and in that a single self-locking arm is articulated under the plug near its straight side adjacent to the side articulated to the frame and the corresponding side wall of the frame. 15

4. The device according to claim 3, characterized in that it comprises a second plug in the form of a right angled triangle whereof one of the sides is articulated relative to the other end wall of the frame by at least one joint hinge having a functional play to allow the 20 second plug to tilt between an upright position freeing the opening of the frame and a closed position of said opening bearing on the inner peripheral seating wall of the frame and fitting into the frame, in that at least one jack assisting with the opening or closing of the second 25 plug is pivotally mounted between said plug and the frame and a single self-locking arm is articulated parallel to the assistance jack between the frame and under the second plug near its straight side adjacent to the side articulated to the frame and making it possible to lock 30 said plug in its upright position freeing the opening of the frame, in that the self-locking arm has its end pivotally mounted to the frame able to slide in a second fixed longilinear guide groove secured to the frame extending below the seating wall of the frame parallel to 35 said wall so that the end of the self-locking arm can come closer to the opposite end wall of the frame during 22 tilting of the second plug to its closed position of the opening of the frame, in that a second stop is secured to the frame perpendicular to the opposite end wall of the frame so that the sliding end of the self-locking arm 5 bears on the second stop during tilting of the second plug to its closed position of the opening of the frame to cause the second plug to withdraw towards the end wall adjacent to the articulated edge of the second plug and to allow the latter to close the opening of the frame. 10

5. The device according to claim 4, characterized in that the two triangulated plugs make it possible to completely cover the opening of the frame in their closed position. 15

6. The device according to claim 1 or 2, characterized in that the plug has a rectangular shape capable of completely covering the opening of the frame in its closed position, in that a second self-locking arm is pivotally 20 mounted between the plug and the frame parallel to the assistance jack and also making it possible to lock the plug in its upright position releasing the opening of the frame, in that the second self-locking arm has its end pivotally mounted to the frame being able to slide in a 25 second fixed longilinear guide groove secured to the frame extending below the seating wall of the frame parallel to said wall so that the end of the second self-locking arm can come closer to the other end wall of the frame during tilting of the plug to its closed position of the opening 30 of the frame, in that a second stop is secured to the frame perpendicular to the other end wall of the frame so that the sliding end of the second self-locking arm bears on the second stop during the tilting of the plug to its closed position of the opening of the frame to cause the 35 plug to withdraw towards the end wall adjacent to the 23 articulated side of the plug and to allow the latter to close the opening of the frame.

7. The device according to one of the preceding claims, 5 characterized in that each self-locking arm is articulated on one hand by one of its ends under the plug around a transverse axis of the arm and on the other hand by its opposite end sliding around a transverse axis of the arm and engaged through the corresponding guide groove to 10 slide along said groove.

8. The device according to claim 7, characterized in that each guide groove comprises, at its end opposite the corresponding stop, a notch for receiving the sliding axis 15 of the self-locking arm to lock the plug in its upright position releasing the opening of the frame.

9. The device according to one of claims 6 to 8, characterized in that the two self-locking arms are the 20 same length, are arranged in two planes perpendicular to the plane of the opening edge of the frame, and are articulated by two of their ends under the plug around two coaxial axes and by their other two ends opposite the frame around two coaxial axes. 25

10. The device according to one of the preceding claims, characterized in that it comprises two coaxial joint hinges of the plug to the frame spaced apart from each other parallel to the adjacent end wall of the frame. 30

11. The device according to one of the preceding claims, characterized in that each joint hinge comprises a cylindrical axis parallel to the adjacent end wall of the frame supported by a clevis secured to the corresponding 35 part of the seating wall of the frame and two lugs forming knuckles secured to the plug arranged between the two 24 branches of the clevis while being passed through by the cylindrical axis, the lugs forming knuckles having an orifice with dimensions larger than the diameter of the cylindrical axis to allow movement with play of the plug 5 relative to the cylindrical axis.

12. The device according to one of the preceding claims, characterized in that each stop is adjustable in the direction perpendicular to the corresponding end wall. 10

13. The device according to one of the preceding claims, characterized in that it comprises at least one elastically deformable means fastened to the seating wall protruding therefrom close to the end wall of the frame 15 opposite the end wall adjacent to the joint hinge and capable of facilitating opening of the plug from its closed position of the frame.

14. The device according to one of the preceding 20 claims, characterized in that the assistance jack is articulated on an axis secured to a platen below the seating wall of the frame.