EP0084510B1 - Circular manhole frame with hinged half-covers - Google Patents

Abstract

A manhole structure comprising a circular frame formed with a pair of diametrically opposite inwardly and upwardly open recesses traversed by respective pivot pins and a further pair of diametrically opposite brackets having inwardly and upwardly open recesses. A pair of semicircular cover heads, each has three radially projecting lugs including a pivot lug engaging a respective one of the pins and a pair of support lugs at opposite ends of the rectilinear edge of the cover half. The pivot lug has a pocket receiving the pin and communicating with a narrow slot whereby the pivot lug is inserted over the pin, the pocket being shaped so that when the cover is swung open, it can be braced between the pin and an edge of the recess. All of the recesses have wedge-forming inclined flanks which engage inclined flanks of the cover halves to support the latter in their closed positions.

Description

The invention relates to a circular manhole cover with articulated half-buffers.

The manholes are, in general, composed of a frame fixed to the roadway and a removable buffer. To access the well closed by the ragard, you must remove the buffer. This operation is inconvenient, regardless of the weight of the tampon. It is the same for the replacement of the buffer in the frame.

Furthermore, to avoid lifting the buffer, when passing over it a heavy vehicle generating a strong vertical suction, as well as to avoid any accident when opening the manhole, the buffers, heavy and massive , wedged by their only weight, are gradually replaced by articulated buffers of the type described in British patent 474,250 and in French patent application 79,06566. The practice shows that it would be desirable, on the one hand, to facilitate the opening and closing maneuvers of the pads by controlling the pivoting movements and, on the other hand, to avoid that the means of articulation can be clogged with earth or other waste penetrating into the viewing gaps and interfering with their operation.

We also know, in particular by American patent 2,997,932, manholes comprising two half-buffers which, each having the shape of an isosceles right triangle, are juxtaposed on the frame by their hypotenuse and are provided, in the extension of this and that of their right angle, of radial legs of trapezoidal section resting on spans of complementary V-shaped section. By this arrangement, each half-pad only rests on the frame at three points, which gives it excellent stability and prevents it from generating noise when heavy vehicles pass.

The aim of the present invention is to provide a manhole cover which, combining the advantages of articulated pads and half-pads resting on three V-shaped surfaces, without however presenting any constructive or use disadvantages, and does not risk to generate noises consecutive to bad ranges on the frame.

This manhole is of the type comprising, articulated on a frame, two half-buffers each having three radial studs, respectively lateral and posterior, the lateral studs being provided at their lower part with corners capable of resting on V-shaped positioning faces made in the ears of the frame.

According to the invention, the horizontal axis of articulation of each half-buffer passes through the posterior ear to which it is integral, while the posterior radial post is provided with an internal housing with cam profile whose profile is determined so , that in the closed position, the horizontal axis is not in contact with the housing, but that during opening, it comes into contact with the housing and it controls the movement of this half-pad, first alone , then on the rest of the movement, in combination with the posterior post of the tampon coming to rest on the posterior wall then on the bottom of the ear.

The shape of the housing for the axis therefore makes it possible to give a stable position to the corresponding half-buffer, both when it is in the open position and when it is in the closed position at rest on the V-shaped bearings.

Advantageously, the angle formed by the faces of each of the V-shaped housings of the ears is a few degrees less than that of the angle formed by the complementary faces of the corresponding tenon.

Thanks to this arrangement, the contact faces of the different spans adjust to each other by matting, which improves the contact and the stability of the half-pad. In addition, when the half-pad is tilted from its open position to its closed position without being retained, the energy which is communicated to it allows these studs to get caught in the V of the frame and thus ensure the locking by jamming of this half-buffer.

• Figure 1 en est une vue partielle en perspective, l'une des demi-tampons étant en position d'ouverture, l'autre en position de fermeture,
• Figure 2 est une vue partielle de côté montrant, en coupe et à échelle agrandie, une forme d'exécution du logement ménagé dans le cadre pour recevoir le tenon d'articulation,
• Figure 3 est une vue partielle de côté montrant, à échelle agrandie, le logement réalisé dans le tenon d'articulation,
• Figures 4 à 8 sont des vues partielles de côté en coupe montrant, pour différentes positions d'un demi-tampon articulé, les zones de contact du logement du tenon d'articulation avec l'axe de l'oreille.

Other characteristics and advantages will emerge from the description which follows with reference to the appended schematic drawing representing, by way of nonlimiting example, an embodiment of this manhole cover.

• FIG. 1 is a partial perspective view thereof, one of the half-pads being in the open position, the other in the closed position,
• FIG. 2 is a partial side view showing, in section and on an enlarged scale, an embodiment of the housing provided in the frame for receiving the hinge pin,
• FIG. 3 is a partial side view showing, on an enlarged scale, the housing produced in the hinge pin,
• Figures 4 to 8 are partial side views in section showing, for different positions of an articulated half-pad, the contact zones of the housing of the hinge pin with the axis of the ear.

As shown in Figure 1, this circular manhole is composed of a frame (2) and two half-buffers (3a-3b) having, in plan view from above, a semi-circular shape. Each pad is provided with three radial studs, namely: a rear articulation stud (4) and two lateral positioning studs (5). The longitudinal axis of the hinge pin (4) is perpendicular to the straight edge (6) of the corresponding half-pad, while the longitudinal axes of the two positioning pins (5) are substantially parallel to this straight edge. The two positioning pins (4) are arranged in posterior radial lugs (7) of the frame (2). These two ears are diametrically opposite. As for the positioning studs (5), they penetrate into ears (8), also diametrically opposite and substantially offset by 90 ° relative to wearing to those (7). Each ear (8) is arranged so as to simultaneously receive the positioning pins (5) of the two half-manholes.

The positioning pins (5) are provided with contact and positioning faces capable of cooperating with complementary faces formed in the corresponding ear (8). In the embodiment shown, these contact and positioning faces (9a-9b) form a wedge (9) capable of penetrating into the V-shaped housing (10) formed in the corresponding ear (8). Similarly, the hinge pin (7) 'is provided at its base with two inclined lateral faces (12) giving it a truncated V shape. These faces are intended to cooperate with inclined faces (13) delimiting a V in the bottom of the corresponding ear (7).

The angle formed by the faces of each of the V-shaped housings (10) of the ears (8), as well as that formed by the faces (13) of the ears (7), has a value which is a few degrees lower than that of the angle formed by the complementary faces, respectively (9a-9b) and (12), of the corresponding studs. This arrangement allows the contact faces to form by themselves by matting and thus improves the stability of the gaze. Furthermore, it makes it possible to obtain a wedging effect contributing to keeping the half-buffers in the closed position, even when a heavy vehicle passes over the manhole.

The articulation of each articulation pin (4) on the frame (2) is ensured by an axis (14), horizontal, and passing through said ear to which it is integral. This axis can be attached or come from molding with the frame. This axis crosses transversely a housing (15) of the stud (4), housing whose internal wall has a cam-shaped profile whose usefulness will be specified below. The housing (115) communicates with the outside by a transverse groove (16) formed in its rear part and the opposite faces of which are separated by a distance (D) at least equal to that (d) separating two flat (14a), parallel and vertical, made on the axis (14). This arrangement makes it possible to remove the half-pads if necessary, but also to easily replace them if they are damaged or partially broken.

As shown in more detail in Figure 4 and in order not to disturb the stability of each half-buffer provided by its three V-shaped surfaces and, above all, not to disturb the V-shaped range of the hinge pin (4 ) in the bottom of the ear (7), the wall of the housing (15) is arranged so as not to come into contact with the axis (14).

When one of the half-buffers is operated in the opening direction, it is simultaneously subjected to a translation in the direction of the arrow (20) in FIG. 5 until the axis (14) comes into contact with the rear part of the cam profile of the housing (15), as shown in this figure. From this moment, the pivoting takes place around the lower part of the axis (14) until the rear edge (21) of the post (4) meets the rear wall (22) of the ear (7), as shown in FIG. 5. At this stage, the pivoting is guided by the contact of the edge (21) on the wall (22) until, as shown in FIG. 6, the upper part of the axis (14) comes into contact with the upper profile of the housing (15), then with the front profile (Figure 7) to control the pivoting. As soon as the gaze exceeds the vertical position, it takes an inclined position beyond it, of the order of 18 to 15 °. In this position, as shown in FIG. 8, the tenon (4) is in abutment against the posterior edge (23) of the ear (7) and, by the face of its housing (15), against the posterior flat (14a ) of the axis (14). Thanks to these two contacts, the half-pad occupies a perfectly stable opening position which prevents it from accidentally closing.

It is obvious that, in the closing movement, the different parts of the housing (15) cooperate in reverse with the axis (14). It should however be noted that, at the end of the closing movement, the introduction of the positioning pins (5) into the V's (10), causes the transverse displacement of the half-pad so that the housing (15) occupies the position in which, as shown in Figure 4, its wall is without contact with the axis (14) so as not to disturb the bearing of the inclined faces (12) on those (13) of the ear (7).

As shown in Figure 1, the half-pad (3a) has an opening (25) for the passage of a pointed tool such as the pick of a pickaxe, while the half-pad (3b) is provided with a handle (26) facilitating its lifting.

It should be noted that, thanks to the correct guidance of the tilting ensured by the cooperation of the different parts of the axis (14) with the profile of the housing (15), the closing operation does not require retaining the half-pad, so that it can be carried out very quickly by simple pushing of this half-pad, which, moreover, facilitates the wedging of the positioning pins (5) in the V (10) and the locking of this half-pad .

It follows from the above that, thanks to its structure and, in particular, to the use of two positioning pins and to an articulation pin provided with a cam profile cooperating with the axis of rotation, this manhole cover is very easy to maneuver, both for opening and for closing, ensures the safety of personnel when they are in the open position, without the need for other accessories, and has, in the closed position, excellent stability preventing them to tip over when passing vehicles and, therefore, to generate noise.

In addition, thanks to the total closure of the ears (7) by the corresponding pins (4), the articulation of each half-pad is protected and does not risk being clogged with earth or other waste, such as c 'is the case in other buffers, which guarantees the proper functioning of the buffer over time.

Claims (3)

1. Circular man-hole of the type comprising, pivoted on a frame (3), two halfcovers (3a-3b) each comprising three radial tenons, respectively side and rear tenons, provided at their lower end with wedges (9-12) able to rest on V-shaped positioning faces (10-13) formed in lugs (7-8) of the frame (2), characterised in that the horizontal pivot shaft (14) of each half-cover passes through the rear lug (7) with which it is integral, whereas the rear radial tenon (4) is provided with an internal housing (15) of cam- shaped profile, whereof the profile is determined so that in the closed position, the horizontal shaft (14) is in contact with the housing (15), but during opening, it controls the movement of this half-cover first of all alone, then for the remainder of the movement, in combination with the rear edge of the cover coming to bear against the wall (22) and on the base of the lug (7).

2. Man-hole according to Claim 1, characterised in that the housing (15), provided in the pivot tenon (4) of each half-cover (3a-3b) communicates with the outside by way of a transverse groove (16) provided in its rear part and comprising opposing faces separated by a distance (D) at least equal to the distance (d) separating two parallel and vertical flat portions (14a) formed on the pivot shaft (14).

3. Man-hole according to Claims 1 and 2, characterised in that the angle formed by the faces of each of the V-shaped housings of the lugs (7-8) is several degrees smaller than the angle formed by the complementary faces (12) and (9a-9b) of the corresponding tenon (4-5).

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