Title of Invention

"A MANHOLE COVER"

Abstract

A manhole cover of the type comprising two main parts (1,2) (1) intended to be embedded in the ground and a covering member (2) supported by this frame (1), the latter having, under the conditions of installation, two horizontal bearing surfaces (6A, 6B) arranged in the vicinity of two adjacent corners (4A, 4B) and two sloping bearing surfaces (6C, 6D) located in the vicinity of its other two corners (4C, 4D), these four bearing surfaces (6A, 6B, 6C, 6D) being adapted to co-operate with complementary bearing surfaces (12A, 12B, 12C, 12D) integral with the lower surface of the covering member (2), the sloping bearing surfaces (6C, 6D, 12C, 12D) being inclined downwards in the direction of the horizontal bearing surfaces (6A, 6B, 12A, 12B), and the frame (1) being provided, in opposition to its sloping bearing surfaces (6C, 6D) with, stop means (8, 9; 14A, 14B) which co-operate with complementary stop means (13, ISA, 15B) integral with the covering member (2), characterized in that the stop means (8, 9; 14A, 14B) and the complementary stop means (13, 15A, 15B) are shaped in such a way that, when the covering member is subjected to the action of a vertical external force applied at any point, the stop means of the frame cooperate with the complementary stop the frame co-operate with the complementary stop means in such a way as to cause the covering member to turn, under the influence of the reaction-induced to the right of the stop means by the horizontal reaction component-to the external force to the right of the sloping bearing surfaces, in its plane about the stop means (8, 9; 14A, 14B) of the frame (1) until a position of stable equilibrium is attained in which the covering member (2) rests by its four bearing surfaces (12A, 12B, 12C, 12D) on the corresponding bearing surfaces (6A, 6B, 6C, 6D) of the frame(l).

Full Text

The present invention relates to a highway device of the type compiising two mair. parts having, in plan, a generally square or rectangular shape, namely a fixed frame intended to be embedded in the ground and a covering element, in particular a cover or a grate, supported by this frame which, in the installation conditions, has two horizontal bearing surfaces arranged in the vicinity of two adjacent comers and two sloping bearing surfaces situated in the vicinity of the two other corners of the frame, iihese fox bearing surfaces being adapted to cooperate with complementary bearing surfaces integral with the lower face of the covering element. The invention applies in particular to devices for closing inspection chambers of a water network such as roadway or footway manholes, or to devices for capping drains such as highway grates. A highway device of this type is known from the document DE-1104447 in which the two sloping bearing surfaces are inclined downwards and inclined towards one another, In this configuratiori,, the cover is in stable equilibrium or. its support frame only when it is subjected to its own weight or when it is subjected to a vertical load which is exerted inside a triangle of equilibrium defined approximately by the two corners in which the horizontal bearings are situated and by the middle of the opposite side, In contrast, when a load is applied outside this triangle of equilibrium, in particular upon ihe passage of a pedestrian., a cyclist etc.5 the cover rises at tie sloping bearing farthest from the point of application of the load; having lost contact with the frarr .e at this plase, the cover then rests on tie frame only by the two horizontal bearings and the other sic ping bearing. This results in a disequilibrium of the cover which causes wobbling, the cover then banging against the frame upon the passage of pedestrians or vehicles and thus generating an undesirable noise. The object of the present invention is therefore to overcome these diszidvantages and to ensure that, whatever the point of application of the load on the covering element, the latter always rests on the four bearing surfaces of the frame, so as to prevent any wobbling phenomenon. To this end. the subject of the invention is a highway device of the above-mentioned type in which the sloping bearing surfaces are inclined downwards in the direction of the horizontal bearing surfaces sind in which the frame is provided, opposite its sloping bearing surfaces, with stop moans which, when the covering clement is subjected to this action of a vertical force applied at any point, cooperate with complementary stop means integral with the covering clement so as to cause the latter to turn about the said stop means of the frame until a position of stable equilibrium hi which the covering element rests by its four bearing surfaces on the coirssponding bearing surfaces of the frame is attained. The highway device according to the invention may include one or more of the following features: the sloping bearing surfaces of the frame and the cooperating sloping bearing surfaces of the covering element have a common inclination of between approximately 20° and 60' with respect to the horizontal; at each of the main parts, the stop means are arranged midway between the horizontal tearing surfaces, the said meao comprising a substantially vertical projection integral with one of the parts Which is adapted to engage, at least partially, in a substantially vertical recess farmed in a raised stop integral with the other part; tie projection has the shape of a right triangular prism, one of the edges of which is intended to engage in a notch in the shape of a triangular prism defined by the recess of the corresponding raised stop; the projection has a convex profile intended to cooperate with a concave profile of the associated recess; the projection has the shape of a right triangular prism, one olfthe edges of which is intended to cooperate with a concave profile of the associated recess; the recess defines a notch in the shape of a right triangular prism adapted to cooperate with a convex profile of the associated projection; die stop means integral with the frame comprise two vertical or overhanging downwardly inclined faces which are arranged symmetrically with respect to the median plane perpendicular to the lateral faes of the frame adjacent: to the two horizontal bearing surfaces, and which extend obliquely with respect to this lateral face, the said faces being intended to cooperate v/ith two complementary facss integral with the covering element; each oblique face of the frame foims an angle of between 2C° and 60° v/ith the said lateral face; the two horizontal bearing surfaces of the frame are triangular and each have, towards the interior of the foime, an oblique side with a vertical or overhanging downwardly inclined face, thus delimiting two oblique faces which constitute the stop meEJis at the frame. The subjects of the invention are also a support frame and a covering clement, in particular a graU: or a cover, for a highway device such as that defined above. The invention will be better understood on reading the description which follcws, given purely by way of example and with reference to the accompanying drawings, in which: Fig. 1 represents diagrammsitically, in perspective and before assembly, the two main parts of a highway device in accordance with the invention; Fig. 2 is a diagrammatic representation analogous to Fig. 1 of a highway device according to a second embodiment of the invention. The highway device represented diairammat'cally in Fig. 1 is a footway manhole installed in a footway (not shown), or a comparable surface such as a floor of a parking area for example, where it permits the inspection of an underground water network, for which it provides the closure, It is composed of two main parts made of ductile cast iron, namely a fixed support frame 1 and a removable cover 2 which constitutes an element tor covering the frame. To facilitate understanding of the invention, the two parts 1, 2 are shown disassembled, in a position in which the cover 2 is ready to be mounted on its support frame 1. The frame 1 has, in plan, a generally square or rectangular shape .and has a vertical skirt 3 provided at its base with a peripheral sole piece (not shown) intended for embedding the frame in the ground or in a support structure such-as concrete for example. Two adjacent comers 4A, 4B of the frame 1 are each equipped with, a raised bearing 5 A, SB with an upper bearing surface pEtrallel to the plane of the frame, thus defining two horizontal bearing surfaces 6A, 6B. The latter are'coplanar and are situated roughly halfway up the skirt 3. The two other corners 4C, 4D of the frame are each equipped witla a raised bearing 5C, 5D with em upper bearing surface extending, from a region close to.the top of the skirt 3, towards the base of the frame and in the direction of the raised horizontal bearing 5A. 5B dtuated opposite, thus defining two sloping bearing surfaces 6C, 6D; the latter are coplanar and form an angle a of between approximately 20° and 60° with the horizontal. Midway between the two raised horizontal bearing surfaces 6A, 6B, the lateral face 7 of the frtime adjacent to these two raised bearings 5A, 5B has, on the inside, a raised stop 8 integral with the skirt 3, in which stop a substantially vertical recess 9 is formed. This recess 9 has the shape of a V which is open towards the interior of the frame, thus defining a notch in the shape of a right triangular prism. The advantage of this recessed raised stop 8 will be explained liereinbdow. The cover 2 essentially comprises a plane sheet 10 of generally square or rectangular shape and of dimensions slightly smaller than the inside dimensions of the skin 3 of the frame 1. In the sjrne way as for the frame 1:) the cover 2 is provided, in its comers, with foui raised beauugs 11A, 1 ID. 11C, 1 ID integral with the lower race of the sheet 10 and intended to coojrarate with the four corresponding raised bearings 5 A, 5B, 5C, 5D of the frame 1. The height of the raised bearings of the cover 2 is such that, when the cover rests on its support fhime 1, the upper face of the sheet 10 of the cover is flush with the upper edge of the skirt 3 of the frame. Two adjacent raised besurings 11 A, 11B of the cover 2 thus each have a horizontal bear.ng surface 12A, 12B intended to come into contact with the complementary- horizontal bearing surface 6A, 6B of the frame, while the two other raised bearings 11C, 1 ID of the cover 2 each have a sloping bearing surface 12C, 12D intended to beai on the corresponding sloping bearing surface 6C, 6D at the frame 1. The sloping bearing surfaces 12C, 12D of the cover 2 are likewise inclined downwards in the direction of the respective! horizontal bearings 11 A, 11B situated opposite, and form with the horizontal an angle corresponding to the angle of inclination a of the sloping bearing surfaces 6C, 6D of the frame. Midway between the two raised bearings 11 A, 11B with horizontal bearing surface, the covsr 2 has a stop means 13 projecting vertically downwards; the latter is intended to cooperate with the recess 9 of the raised stop 8 of the frame 1, In the example described, this projection 13 thus lias the shape of a right triangular prism, one of the edges of which is intended to engage in the complementary prismatic recess 9 at the frame 1. This particular arrangement, comprising on one side of the device cooperating «1npir»e hearing surfaces inclined downwards in the direction of the opposite ijide where corrssponding and complementary stop m This system functions such that, under ihe action of a vertical external force applied at any point, the cover 2 is desiabiliasu -fifOfii bearing on-three points and searches for the fourth bearing point This is so because the load which is exerted on the cover 2 first of ail brings the latter into contact with three of the four bearings of the. frame 1, the two raised bearings with horizontal, tearing surface 6A, ntal component and a vertical component The horizontal component of the reaction at "&s sloping raised bearing induces the participation of the stop 8, the reaction of which :.s directionally incapable of creating a state: of equilibrium without thsi complementary participation of the second sloping raised bearing, thereby making it possible to arrive at a system of equilibrium of three forcss in horizontal projection. To this end, the median vertical projection 13 of the cover 2 and the recess 9 of the raised stop 8 of the frame with which the projection 13 cooperates behave in the manner of an articulated hinge by allowing a slight rotation of the cover 2 in its plane and about the raised stop 8. Thus, under the action of the vertical force, the cover 2 is earned to pivot about the raised stop 8 against which it bears by way cf the projection 13 until it conies into contact with the second sloping raised bearing of the frame 1, thereby making it possible for the cover 2 to find arid maintain a stable equilibrium. In this position of equilibrium, the horizontal components of the reactions of the bearing of the caver on the sloping bearing surfaces 6C, 6D of the frame are balanced by the horizontal reaction resulting from the contact of the projection 13 agains: the raised stop 8 of the frame 1. The state of stability obtained, in which -the cover 2 rests simultaneously by its four bearing surfaces 12A, 12B, 12C, 12D on the respective bearing surfaces 6A, 6B, 6C, 6D of the frame 1, consequently prevents any wobbling phenomenon. It will be noted that in the embodiment described in Fig, 1 the recess 9 of the raised stop 8 of the frame 1 and the associated projection 13 fit the cover 2 are constructed in the shape of triangular prisms, the complementary V-shaped profiles of which facilitate the articulation of the projection. 13 in the recess 9 serving as a receptacle for it. In a variant, it is possible to envisage other cooperating profiles for the projection 13 and the recess 9, in particular In a further variant, the projection 13 and the recess 9 associated with it may be reversed at the two main parts 1, 2 of the highway device, the projection ihen being integral with the frame while ths corresponding recessed raised stop is made integral with the cover or grate. On the other hand, it may also be advantageous, if it is desired not to have a single position for mounting the cover on the frame and thus to facilitate the task of the operator, more particularly when the highway device is of generally square shape, to pnnide the ends of each lateral face of the frame and of the cover wi'Ji a raised bearing with horizontal bearing surface as well as a raised bearing with a bearing surface inclined downwards and towards the opposite lateral face, and to provide in the middle of each of the lateral faces of the device a cooperating assembly consisting of a projection and a. complementary recessed raised, stop; the cover can. then be mounted on the frame in any one of the four angular positions offset by 90° from one another, while enstiriflg, for each mounting position, the simultaneous contact on four bearLngs of the frame. The embodiment of Fig. 2 differs from that of Fig. 1 by the ijrrangement of the stop means employed at the frame 1 and the cover 2, Each of the two raised bearings 5 A, SB with horizontal bearing surface of the frame 1 has, ir. plan, a triangular shape and has, towards the interior of the frame, a substantially vertical face 14A, 14B oriented obliquely with respect to the lateral face 7 of the frame adjacent to the two raised beatings 5A, 5B. These .wo vertical faces thus define two oblique faces 14A, 14B which constitute the stop means at the frame 1. The two oblique faces 14A, 14B are arranged symmetrically with respect to the median vertical plane perpendiculsac to the lateral face 7 of the frame, and form an angle 6 of betw«en approximately 20° and 60° and preferably equal to 45° with this face 1. Correspondingly, the cover 2 has two oblique vertical faces 15A, 15B which extend the respective horizontal bearing surfaces 12A, 12B downwards and which are adapted to cooperate with the corresponding faces 14A, 14B of the frame 1. of which they constitute complementary stop means. Thus, when the cover 2 is placed on its support frame 1 and a vertical force is applied at any location of the cover, the latter is destabilized from bearing on three points and searches for the founh bearing point This is so because the vertical force which is exerted on the cover 2 first of all brings the latter into contact with the two raised bearings with horizontal bearing surface 6A, 6B of the frame and the raised bearing with inclined bearing surface situated closest to the point of application of the force. This results, at this sloping bearing surface of the frame 1, in a bearing reaction of which the ho;rizontal component is direoed, parallel to one side of the frame, towards the horizontal niised bearing situated opposite. This horizontal reaction, however, cannot be balanced by the horizontal reactions which are exerted perpendicu.arly to each of the oblique faces 14A, 14B of the frame and which are generated by contact of these faces with the associated oblique faces 15A} 15B at the cover 2. To balance these horizontal reactions, it is necessary for the cover 2 to come into contact with the fourth bearing, namely the second sloping raised bearing of the frame, so as to develop thereat a. bearing reaction of which the horizontal component makes it possible to balance the system. The participation of the fourth bearing is obtained then, under the action of the vertical force, by a slight rotation of the cover 2 in the horizontal plane by pivoting about the stop means constituted by the oblique faces 14A, 14B of the frar.ic until the cover 2 is brought into contact with the sloping bearing surface of the frame which was not initially acted upon. A stable state is thus arrived at, in which the cover 2 rests simultaneously by its four bearing surfaces 12A, 12B, 12C, 12D on the complementary beziring surfaces 6A, 6B, 5C, 6D of the frame 1, thereby preventing any wobbling phenomenon. It should be noted that this rotation of the cover 2 in its "plans, which makes it possible for the ^tter to find and maintain a four-point bearing stability on the frame, is mad? possible by virtue of the obliquity of the faces 14A, 14B of the frame and of the complementary faces ISA, 15B of the cover. It will be noted furthermore that these oblique races 14A, 14B of the frame 1 are not necessarily vertical but may very well, in a variant, be inclined downwards with an overhang. Lastly, the oblique faces HA, 14B of the frame and the complementary oblique faces ISA, 15Ei of the cover may be dissociated from the horizontal bearings and situated, on the lateral face common to these horizontal bearings, at locations arranged symmetrically v/ith respect to the median plane perpendicular to this lateral fat*. We Claims:- 1. Highway device of the type comprising two main parts (1, 2) having, in plan, a generally square or rectangular shape, namely a fixed frame (1) intended to be embedded in the: ground and a covering element (2) supported by this frame (1) -which, in the installation conditions, has two horizontal bearing surfaces (6A, 6B) arranged in the vicinity of two adjacent comers (4A, 4B) and two sloping bearing surfaces (6C, 6D) situ&ed in the vicinity of the two other comers (4C, 4D) of the frame, these four bearing surfaces (6A, 6B, 6C, 6D) being adapted to cooperate with complementary bearing surfaces (12A, 12B, 12C, 12D) integral with the lower face of the covering element (2), characterized in. that the sloping bearing surfaces (6C. 6D, 12C, 12D) ate inclined downwards in the direction of the horizontal bearing surfaces (6A. 6B, 12A, 12B) and in that the frame (1) is provided, opposite its sloping bearing surfaces, (6C, 6D), with stop means (8, 9; 14A, 14B) which, when the covering element (2) is subjected to the action of a vertical forse applied at any point, cooperate with complementaiy stop means (13; ISA. 15B) integral with the covering element (2) so as to cause the Utter to turn about the said stop means (8, 9; 14A, 14B) of the frame (1) until a position, of stable equilibrium in which the covering element (2) rests by its four bearing surfaces (12A, 12B, 12C. 12D) on the corresponding bearing surfaces (6A, 6B, 6C, 6D) of the frame (1) is attained, 2. Highway device according to Claim 1, characterized in that the sloping bearing surfaces (6C3 6D) of the frame (1) and the cooperating sloping bearing surfaces (12C, 12D) 03' the covering dement (2) have a common inclination of between approximately 20° and 60° with respect to the horizontal. 3. Highway device according to Claim 1 or 2, characterized in that, at each of the main parts (1; 2), the stop means (8, 9; 13) are arranged midway between the horizontal bearing surfaces (6A, 6B; 12A, 12B), the said means comprising a substantially vertical projection (13) integral wish one of ihe parts which is adapted to engage, at least jjartially, in a substantially vertical recess (9) formed in a raised stop (8) integral with the other part. 4. Highway device according to Claim 3, characterized in that the projection (13) Lias the shape of a right triangular prism, one of the edges of which is intended to engage in a notch (9) in the shape of a triangular prism defined by the recess of trie corresponding raised stop (8), 5. Highway device according to Claim 3, characteiized ia that the projection has a convex profile intended to cooperate with a concave profile of the associated recess. 6. 13ighway device according to Claim 3, characteiized in that the projection has the shape of a right triangular prism, one of the fjdges of which is intended to cooperate with a concave profile of the associated recess. 7. !Highway device according to Cl;iim 3, characterized, in that the recess defines a notch in the shape of a right triangular prism adapted to cooperate with a convex profile of the associated projection. 8. Highway device according to Claim I or 2, characterized in that the Stop moans integral with the frame (1) comprise two vertical or overhanging downwardly inclined faces {14A, 14B) which are arranged symmetrically with respect to the median plane perpendicular to the lateral face (7) of the iiame (1) adjacent to the two horizontal bemng surfaces (6A, 6B), and which extend obliquely with respect, to this lateral face (7), the said faces (14A. 14B) being intended to cooperate with two complementary faces (ISA, 153) integral with the covering element (2). 9. tlighway device according to Claim 8, characterized in that each oblique face (14A, 14B) of the Same (1) forms an angle of between 20C and 60° wiih the said lateral face (7). 10. Highway device according to Claim 8 or 9, characterised in that the two horizontal bearing surfaces (6A,, 6B) of the frame (1) are trianguhir and towiirds the interior of the frame, an oblique side with a verticjil or overhanging downwardly inclined face, thus delimiting two oblique faces (14A, 14B) which constitute the stop means at the frame (1), 11. Support frame (1) for a highway device according to any one of Claims 1 to 10. 12. Covering element (2), in particular a grate or a cover, for a highway device according to any one of Claims 1 to 10. 13. Highway device substantially as herein described with reference to and as illustrated in the accompanying drawings.

Documents:

589-del-1998-abstract.pdf

589-del-1998-claims.pdf

589-del-1998-correspondence-others.pdf

589-del-1998-correspondence-po.pdf

589-del-1998-description (complete).pdf

589-del-1998-form-1.pdf

589-del-1998-form-13.pdf

589-del-1998-form-19.pdf

589-del-1998-form-2.pdf

589-del-1998-form-3.pdf

589-del-1998-form-4.pdf

589-del-1998-form-6.pdf

589-del-1998-gpa.pdf

589-del-1998-pct-409.pdf

589-del-1998-petition-137.pdf

589-del-1998-petition-138.pdf