Title of Invention

HIGHWAY DEVICE FOR DOZING INSPECTION CHAMBERS

Abstract

The frame (1) has two horizontal bearing surfaces (6A, 6B) and two sloping bearing surfaces (6C, 6D) which are adapted to cooperate with complementary bearing surfaces (12A, 12B, 12C, 12D) integral with the covering element (2). The sloping bearing surfaces (6C, 6D, 12C, 12D) are inclined downwards in the direction of the horizontal bearing surfaces (6B, 6A, 12B, 12A) and the frame (1) is provided, in the vicinity of each sloping bearing surface (6C, 6D), with an inner projection (7C, 7D) having, facing the corresponding sloping bearing surface (6C, 6D), a lateral counterbearing surface (9C, 9D) which, in plan, is oriented obliquely with respect to the lateral face (8) of the frame adjacent to the two sloping bearing surfaces (6C, 6D), the two counterbearing surfaces (9C, 9D) extending towards the interior of the frame in directions which converge and being intended to cooperate with complementary counterbearing surfaces (13C, 13D) integral with the covering element (2). FIG. 1

Full Text

The present invention relates to a highway device of the type comprising two main 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 corners and two sloping bearing surfaces situated in the vicinity of the two other corners of the frame, these four 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 closing technical pits allowing access to an underground network of telecommunication, television or other cables. It also applies 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 configuration, the cover is in stable equilibrium on 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 the passage of a pedestrian, a cyclist etc., the cover rises at the sloping bearing farthest from the point of application of the load; having lost contact with the frame at this place, the cover then rests on the frame only by the two horizontal bearings and the other sloping 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 disadvantages 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 and in which the frame is provided, in the vicinity of each sloping bearing surface, with an inner projection having, facing the corresponding sloping bearing surface, a lateral counterbearing surface which, in plan, is oriented obliquely with respect to the lateral face of the frame adjacent to the two sloping bearing surfaces, the two counterbearing surfaces extending towards the interior of the frame in directions which converge and being intended to cooperate with complementary counterbearing surfaces integral with the covering element. 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 15° and 45* with respect to the vertical; the counterbearing surfaces of the frame are arranged symmetrically with respect to the median plane perpendicular to the lateral face of the frame adjacent to the two sloping bearing surfaces; the counterbearing surfaces of the frame and the counterbearing surfaces of the covering element are substantially vertical; the counterbearing surfaces of the frame are inclined downwards with an overhang, the angle of inclination with respect to the vertical being less than or equal to that of the sloping bearing surfaces; each of the two counterbearing surfaces of the covering element forms the inner lateral face of a raised bearing integral with the lower face of the covering element, the outer lateral face of the said raised bearing constituting a sloping bearing surface intended to cooperate with the mating sloping bearing surface of the frame; the counterbearing surfaces of the frame extend, in the interior, in the direction of the lateral face of the frame adjacent to the two sloping bearing surfaces and form with this lateral face, in horizontal section, an angle of between approximately 10* and 30'. The subjects of the invention are also a support frame and a covering element, in particular a grate or a cover, for a highway device such as that defined above. Other features and advantages will become apparent on reading the description which follows, given purely by way of example and with reference to the accompanying drawings, in which: Fig. 1 represents diagrammatically, in perspective and before assembly, the two main parts of a highway device in accordance with the invention; Pig. 2 is a sectional view, taken along the line II-II of Fig. 1, of the highway device after assembly of the two main parts. The highway device represented diagrammatically in Figs. 1 and 2 is, for example, a pit trap door which, when installed in a footway (not shown) or in a comparable surface, covers a technical chamber for access to an underground network of cables or the like, the trap door providing the closure of this chamber. This device is composed of two main parts, in particular made of ductile cast iron, namely a fixed support frame 1 and a removable cover 2 which constitutes an element for covering the frame. To facilitate understanding of the invention, the two parts 1, 2 are shown disassembled in Fig. 1, 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 the embedding of the frame in the ground or in a support structure such as concrete for example. Two adjacent corners 4A, 4B of the frame 1 are each equipped with a raised bearing 5A, 5B with an upper bearing surface parallel 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 with a raised bearing 5C, 5D with an upper bearing surface extending, from the top of the skirt 3, towards the base of the frame and in the direction of the raised horizontal bearing 5B, 5A situated opposite, thus defining two sloping bearing surfaces 6C, 6D; the latter are coplanar and form an angle a of between approximately 15° and 45", and preferably of between 20° and 35°, with the vertical. In the vicinity of each raised bearing 5C, 5D, the frame 1 is provided, in the interior, with a projection 7C, 7D which extends, in height, from the base of the frame over approximately three-quarters of the skirt 3 of the frame and which, in plan, extends horizontally in a direction substantially parallel to the lateral face 8 of the frame adjacent to the two raised areas with sloping bearing surface 6C, 6D, each of the two projections 7C, 7D being integral with a side of the frame perpendicular to the said lateral face 8. Each of the two projections 7C, 7D further has, facing the corresponding sloping bearing surface ec, 6D, a lateral counterbearing surface 9C, 9D which, in the example described, is plane and substantially vertical (except for the relief); this counterbearing surface could also be undercut, the angle of inclination with respect to the vertical then being less than or equal to the angle a of inclination of the sloping bearing surfaces 6C, 6D. The two counterbearing surfaces 9C, 9D are arranged symmetrically with respect to the median vertical plane perpendicular to the lateral face 8 of the frame, which forms more generally a plane of symmetry of the frame, and each of them is oriented obliquely with respect to the side of the frame with which the corresponding projection 7C, 7D is integral; each counterbearing surface 9C, 9D is therefore also oriented obliquely with respect to the lateral face 8 of the frame and forms, with respect to the sloping bearing surface 6C, 6D situated opposite, in a horizontal plane, an angle 6 which is between approximately 10° and 30*, and preferably between 15* and 25*. The two counterbearing surfaces 9C, 9D are therefore directed towards the lateral face 8 of the frame and each defining, with the sloping bearing surface 6C, 6D opposite, in horizontal section, a V-shaped profile open towards the exterior of the frame. The advantage of these two counterbearing surfaces 9C, 9D will be explained hereinbelow. The cover 2 essentially comprises a plane sheet 10 of generally square or rectangular shape corresponding to that of the frame l, and of dimensions slightly smaller than the inside dimensions of the skirt 3 of the frame. In the same way as for the frame 1, the cover 2 is provided, in its corners, with four raised bearings HA, 11B, 11C, 11D integral with the lower face of the sheet 10 and intended to cooperate with the four corresponding raised bearings 5A, 5B, 5C, 5D of the frame l. The height of the raised bearings of the cover 2 is such that, when the cover rests on its support frame 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 bearings 11A, 11B of the cover 2 thus each have a horizontal bearing 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, 11D of the cover 2 each have a sloping bearing surface 12C, 12D intended to bear on the corresponding sloping bearing surface 6C, 6D at the frame l. The sloping bearing surfaces 12C, 12D of the cover 2 constitute the outer lateral face of the respective raised bearings l1e, 11D; they are inclined downwards in the direction of the horizontal bearings 11B, 11A situated opposite, and form with respect to the vertical an angle corresponding to the angle of inclination a of the bearing surfaces 6C, 6D of the frame. The inner lateral face of each raised bearing 11C, 11D of the cover 2, that is to say the face directed towards the horizontal bearing surface 125, 12A situated opposite, forms a counterbearing surface 13C, 13D intended to cooperate with the mating counterbearing surface 9C, 9D of the frame 1. The two counterbearing surfaces 13C, 13D of the cover are therefore, in the example described, plane and substantially vertical surfaces; they are oriented obliquely towards the lateral face of the cover adjacent to the two raised bearings 11C, 11D and once again form with this lateral face, in horizontal section, an angle corresponding to the angle 13 of obliquity of the counterbearing surfaces 9C, 9D of the frame. This particular arrangement, comprising on one side of the device cooperating sloping bearing surfaces inclined downwards in the direction of the opposite side where horizontal bearing surfaces are located, the sloping bearing surfaces being associated with complementary counterbearing surfaces which are mounted in opposition at each of the main parts 1, 2 of the device, thus leads to a four-point static bearing system; in this system, the cover 2 rests simultaneously by its four bearing surfaces 12A, 12B, 12C, 120 on the four associated bearing surfaces 6A, 6B, 6C, 6D of the frame 1, and does so in particular under the action of a load exerted on the cover at any point of the quadrilateral delimited by the four raised bearings 11A, 11B, 11C, 11D situated at the ends of the cover. To be precise, this system functions such that, under the action of a vertical external force applied at any point of the cover, the latter is first of all brought into contact with three of the four bearings of the frame 1, the two raised bearings with horizontal bearing surface 6A, 6B and one of the two raised bearings with inclined bearing surface 6C, 6D, namely that situated closest to the point of application of the load. The vertical force applied to the cover 2, which force is directed downwards, thus initially generates three opposite reactions of the frame l. Two of these reactions, originating from the raised bearings with horizontal bearing surface 6A, 6B, are vertical and directed upwards. The third reaction, perpendicular to the slope of the inclined raised bearing acted upon first, has a horizontal component directed towards the interior of the frame, and a vertical component oriented upwards. This horizontal component then induces the participation of the vertical counterbearing surface situated opposite, which results in a horizontal reaction perpendicular to the said counterbearing surface. The resultant reaction at this first couple, formed by the sloping bearing surface initially acted upon and the counterbearing surface which is associated therewith, then leads to a slight displacement of the cover 2, in the horizontal-projection plane, towards the exterior of the V-shaped profile formed by this first bearing/counterbearing couple, until contact with the second bearing/counterbearing couple situated in the fourth corner of the frame is brought about, this second couple consisting of the sloping bearing surface not initially acted upon and of the counterbearing surface which is associated therewith. A situation of stable equilibrium is thus arrived at, in which the cover 2 rests by its four raised bearings 11A, 11B, 11C, 11D on the four corresponding bearings 5A, 5B7 5C, 5D of the frame 1. In this position of equilibrium, the horizontal resultant of the bearing reactions of the cover at the first bearing/counterbearing couple of the frame is compensated for by the horizontal resultant at the second bearing/counterbearing couple of the frame. Moreover, the vertical force applied to the cover 2 is balanced by the vertical reactions at the two bearings with horizontal surface 6A, 6B of the frame and by the vertical components of the bearing reactions of the cover at the two sloping bearing surfaces 6C, 6D of the frame. The state of stability obtained consequently prevents any wobbling phenomenon of the cover. Furthermore, the preferred embodiment which has just been described ensures not only the stability of the cover when the latter is subjected to a vertical load, but also makes it possible to oppose any horizontal displacement of the cover when the latter is subjected to tangential effects due especially to the braking or acceleration of a vehicle. To be precise, when the cover 2 is subjected to the action of a horizontal force directed perpendicularly to the lateral face 8 of the frame adjacent to the two sloping raised bearings 5C, 5D, the stability of the cover 2 is ensured, depending on the orientation of this force, either by the abutment of the two counterbearing surfaces 13C, 13D of the cover against the mating counterbearing surfaces 9C, 9D of the frame, or by the abutment of the two raised bearings lie, 11D of the cover against the corresponding sloping raised bearings 5C, 5D of the frame. In this latter case, the angle of inclination a is sufficiently pronounced to guarantee that the contact between the inclined surfaces 6C, 6D of the frame and the associated inclined surfaces 12C, 12D of the cover is maintained, thus preventing any horizontal displacement of the cover 2. Now, in the most critical case, when the horizontal force applied to the cover 2 is directed parallel to the lateral face 8 of the frame, one of the two bearing/counterbearing couples of the frame 1 is inevitably acted upon by the corresponding raised bearing 11C, 11D of the cover 2, while only the sloping bearing surface of the other bearing/counterbearing couple of the frame is acted upon. The horizontal force applied to the cover is then balanced by the resultant of the horizontal reactions exerted perpendicularly to the sloping bearing surface and perpendicularly to the associated oblique counterbearing surface of the bearing/counterbearing couple acted upon, as well as by the horizontal reaction exerted perpendicularly to the sloping bearing surface acted upon at the other bearing/counterbearing couple. Once again, a stable equilibrium is therefore arrived at, in which the cover 2 rests by its four raised bearings HA, 11B, 11C, 11D on the four corresponding bearings 5A, 5B, 5C, 5D of the frame 1. The solution according to the invention consequently makes it possible, in a simple and economical manner, always to preserve a four-point bearing of the cover on its support frame, thus preventing any wobbling phenomenon. 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 corners (4A, 4B) and two sloping bearing surfaces (6C, 6D) situated in the vicinity of the two other corners (4C, 4D) of the frame, these four bearing surfaces (6A, 6B, 6C, 6D) being adapted to cooperate with complementary bearing surf aces (12A, 12B, 120, 12D) integral with the lower face of the covering element (2), characterized in that the sloping bearing surfaces (6C, 6D, 12C, 12D) are inclined downwards in the direction of the horizontal bearing surfaces (6B, 6A, 12B, 12A) and in that the frame (1) is provided, in the vicinity of each sloping bearing surface (6C, 6D), with an inner projection (7C, 7D) having, facing the corresponding sloping bearing surface (6C, 6D), a lateral counterbearing surface (9C, 9D) which, in plan, is oriented obliquely with respect to the lateral face (8) of the frame adjacent to the two sloping bearing surfaces (6C, 6D), the two counterbearing surfaces (9C, 9D) extending towards the interior of the frame in directions which converge and being intended to cooperate with complementary counterbearing surfaces (13C, 13D) integral with the covering element (2). 2. Highway device according to Claim 1, characterized in that the sloping bearing surfaces (6C, 6D) of the frame (1) and the cooperating sloping bearing surfaces (12C, 12D) of the covering element (2) have a common inclination of between approximately 15 and 45 with respect to the vertical. 3. Highway device according to Claim 1 or 2, characterized in that the counterbearing surfaces (9C, 9D) of the frame (1) are arranged symmetrically with respect to the median plane perpendicular to the lateral face (8) of the frame adjacent to the two sloping bearing surfaces (6C, 60). 4. Highway device according to any one of claims 1 to 3, characterized in that the counterbearing surfaces (9C, 9D) of the frame (1) and the counterbearing surfaces (13C, 13D) of the covering element (2) are substantially vertical. 5. Highway device according to any one of Claims 1 to 3, characterized in that the counterbearing surfaces (9C, 9D) of the frame (1) are inclined downwards with an overhang, the angle of inclination with respect to the vertical being less than or equal to that (a) of the sloping bearing surfaces (6C, 6D). 6. Highway device according to any one of Claims l to 5, characterized in that each of the two counterbearing surfaces (13C, 13D) of the covering element (2) forms the inner lateral face of a raised bearing (l1C, llD) integral with the lower face of the covering element, the outer lateral face of the said raised bearing (l1C, llD) constituting a sloping bearing surface (12C, 12D) intended to cooperate with the mating sloping bearing surface (6C, 6D) of the frame (1). 7. Highway device according to any one of Claims 1 to 6, characterized in that the counterbearing surfaces (9C, 9D) of the frame (1) extend, in the interior, in the direction of the lateral face (8) of the frame adjacent to the two sloping bearing surfaces (6C, 6D) and form with this lateral face, in horizontal section, an angle (6) of between approximately 10* and 30*. 8. Support frame (1) for a highway device according to any one of Claims 1 to 7. 9. Covering element (2), in particular a grate or a cover, for a highway device according to any one of Claims 1 to 7. 10. Highway device substantially as herein described with reference to the accompanying drawings. 11. Support frame for a highway device substantially as herein described with reference to the accompanying drawings. 12. Covering element substantially as herein described with reference to the accompanying drawings.

Documents:

3354-del-1998-abstract.pdf

3354-del-1998-claims.pdf

3354-del-1998-correspondence-others.pdf

3354-del-1998-correspondence-po.pdf

3354-del-1998-description (complete).pdf

3354-del-1998-drawings.pdf

3354-del-1998-form-1.pdf

3354-del-1998-form-13.pdf

3354-del-1998-form-19.pdf

3354-del-1998-form-2.pdf

3354-del-1998-form-3.pdf

3354-del-1998-form-4.pdf

3354-del-1998-form-6.pdf

3354-del-1998-gpa.pdf

3354-del-1998-pct-210.pdf

3354-del-1998-pct-409.pdf