IE903496A1 - A device for capping a discharge shaft - Google Patents

Abstract

The apparatus consists of a grille (3) articulated in a frame along an axis for pivoting of the grille (3) corresponding to one of the sides of the latter, this grille (3) being fitted with bars (18) connected together by cross members (19), and in which the grille is divided, along its pivotal axis, into a middle portion (Z1) and two lateral portions (Z2) elastically connected to the middle portion (Z1), one end of the middle portion (Z1), contiguous to the pivotal axis, being intended to bear against a corresponding surface of the frame exerting a moment opposing the movement of the grille (3) about its pivotal axis. <IMAGE>

Description

The present invention relates to a process and a device for capping a discharge shaft, consisting of a tilting removable grating which, when the device is in the closed position, rests in a frame bedded in the ground.

The subject of the present invention is, more particularly a capping device of the abovementioned type which exhibits a locking of the tilting removable grating in its frame.

In fact, in such capping devices, the grating must be locked perfectly, on the one hand to avoid an accidental opening of the discharge shaft and on the other hand to prevent acts of vandalism during which the grating can deliberately removed from its frame.

For example, the document FR 1,249,110 makes known a rectangular tilting removable grating having two coaxial lateral pivots allowing this grating to pivot about one of its sides, these pivots engaging in receptacles provided in the frame.

In this device, the locking is obtained by means of a finger which is mounted rotatably on the grating and the position of which in relation to the frame determines the closing of the discharge shaft.

Although this device makes it possible to lock the grating effectively in its frame, thus avoiding an accidental opening of the discharge shaft, it nevertheless has disadvantages of three kinds.

In the first place, it requires the use of an additional movable part, namely the rotary finger, which, in addition to the increase in the production cost which it entails, is liable to become jammed and therefore no longer allow a subsequent locking or release.

In the second place, it does not make it possible 5 to prevent a deliberate opening by unauthorized persons since a simple spanner for actuating the finger is sufficient.

Finally, once the grating is in the open position and therefore vertical, it can close again inopportunely, this being of real danger to the operator.

The object of the present invention is, therefore, to solve the problems mentioned above.

The subject of the present invention is, more particularly, a process for capping a discharge shaft, consisting of a grating articulated in a frame with respect to a pivot axis of the grating corresponding to one of the sides of the latter, this grating being equipped with bars connected to one another by means of spacers, in which process the grating is divided with respect to its pivot axis into a middle part and two lateral parts connected elastically to the middle part, one end of the middle part adjacent to the pivot axis being intended to come to bear against a corresponding surface of the frame, at the same time exerting a torque opposing the movement of the grating about its pivot axis.

The characteristics and advantages will emerge from the following description made with reference to the drawings which are given purely by way of non-limiting example and in which: - Fig. 1 shows a diagrammatic sectional view of a device for capping a discharge shaft, - Fig. 2 shows a plan view of the frame of the device according to the invention, - Fig. 3 shows a plan view of the grating of the device according to the invention, - Fig. 4 shows a detail of the device according to the invention, - Fig. 5 shows an alternative version of the device according to the invention, - Fig. 6 illustrates the operating principle of the device according to the invention.

The device according to the invention, as shown 15 in Fig. 1, consists of a frame 1 bedded in the ground, for example in a road surface, at the upper end of a discharge shaft 2, and of an articulated removable grating 3 forming a cover.

According to the exemplary embodiment illus20 trated, the frame 1 and the grating 3 have a general rectangular shape, as seen in a plan view.

The frame 1 possesses a rectangular vertical skirt 4 equipped, on its periphery, with a peripheral bearing sill 5 serving for the bedding of the frame and, on its inner face, with a rim 6 serving as a bearing surface for the grating 3.

Two opposite lateral faces 7, 8 of the skirt 4 each possess, in the immediate vicinity of a lateral face of the skirt 4 perpendicular to the two faces 7, 8, a cavity 10 of axis X-X parallel to the perpendicular lateral face 9, the two cavities 10 of the opposite lateral faces 7, 8 being coaxial.

The skirt 4 terminates in a lateral face 11 opposite and parallel to the lateral face 9.

Each cavity 10 is formed in the skirt 4 of the frame above the bearing rim 6 approximately at mid-height between this bearing rim 6 and the top of the skirt 4.

Preferably, the distance between each cavity 10 and the perpendicular lateral face 9 is equal to the distance between each cavity 10 and the bearing rim 6.

The grating 3 is intended to be mounted in the frame 1. More particularly, it is intended to come to rest in the skirt 4 by being placed on the bearing rim 6.

According to the exemplary embodiment illustrated in Fig. 1, therefore, it has a general rectangular shape, two opposite sides 12, 13 being intended to confront the opposite lateral faces 7, 8 of the skirt 4, a side 14 perpendicular to these two sides 12, 13 being intended to confront the perpendicular lateral face 9 of the skirt 4, and a fourth side 15 opposite the side 14 terminating this grating 3 and being intended to confront the face 11 of the skirt 4.

The two sides 12 and 13 of this grating 3 each consist of a lateral bar 16, one end 161 of which is equipped at mid-height, on an outer lateral face of said bar, with a pivot 17 of horizontal axis Y-Y coinciding, when the grating 3 is mounted in the frame 1, with the horizontal axis X-X of the cavities 10 of the skirt 4, these cavities 10 of the frame 1 being intended to receive the pivots 17 of the grating 3 which can thus pivot about the axis X-X.

Between these two lateral bars 16, the grating 3 5 consists of a series of bars 18 which are parallel in the exemplary embodiment illustrated, each bar 18 being connected to an adjacent bar by means of at least one spacer 19.

As can be seen in Fig. 3, each lateral bar 16 is 10 itself connected to the bar 18 adjacent to it by means of at least one spacer 19.

The bars 18 consist of an upper face 20 defining the upper surface of the grating 3 and of a lower face 21 intended to come into contact, at one end 22 or 23 respectively of the bars 18, with the bearing rim 6 in its zone adjacent to the lateral face, 9 or 11 respectively, of the skirt 4.

As can be seen in Fig. 4, with the grating 3 being intended to be movable in rotation about the axis X-X of the frame 1 and with the lateral bars 16, at their end 161, and the bars 18, at their end 22, being in the immediate vicinity of the bearing rim 6 and of the lateral face 9 of the skirt 4, there is a theoretical cylindrical surface S of axis X-X and of radius R in relation to the axis X-X of the frame 1, such that any part P of the grating 3, the volume of which will project beyond this theoretical surface S, will, during the rotation of this grating 3 about the axis X-X of the frame 1, come into contact either with the bearing rim 6, as shown, or with the skirt 4.

As can be seen in Fig. 4, the radius R corresponds to the minimum distance between the axis X-X of the cavities 10 and the frame 1.

If this part P of the grating 3 is connected to the rest of the grating 3 in a completely rigid manner, the rotation can then no longer continue, the grating 3 being trapped in the cavities 10 of the frame 1 by means of its pivots 17.

It is precisely a characteristic of the present invention to produce a grating 3 consisting, with respect to the axis Y-Y of this grating 3, of a middle zone Z1 and of two lateral zones Z2, the middle zone Z1 possessing at least one part P located on the side 14 of the grating 3 projecting beyond this theoretical surface S, the middle zone Z1 being connected elastically to the lateral zones Z2 of the grating 3 by means of spacers 191 not located on the axis X-X and performing the function of torsion bars, the grating 3 being in one piece and the natural elasticity of the component material of the grating 3, for example nodular graphite iron, being sufficient.

Thus, when this part P comes into contact with the frame 1, the middle zone Z1 supporting this part P being connected elastically to the rest of the grating 3, a torque opposing the rotation of the grating 3 is generated.

As can be seen in Fig. 6, taking C to be the tangent point of the surface S with the frame 1 and taking F to be the direction of rotation for opening of the grating 3, with a part Pl of the middle zone Z1 of the grating 3 touching the frame 1 at a point Cl located downstream of the point C in the direction of rotation F, and with a part P2 of the middle zone Z1 of a grating 3 touching the frame 1 at a point C2 located upstream of the point C in the direction of rotation F, it appears clearly that a grating 3 equipped with a profile of the type Pl will, at the outset, be free to rotate until the profile Pl comes into contact with the frame 1, whereas a grating 3 equipped with a profile of the type P2 will immediately have this profile P2 oppose the rotation of the grating 3 about the axis X-X.

Moreover, for each profile Pl and P2, there are three characteristic points M, Ml and M2, the point M corresponding to the point of the profile Pl or P2 furthest away from the axis X-X, and the points Ml and M2 corresponding to the two points of intersection of the profile Pl or P2 with the surface S. 0 It will be seen that, as regards a grating 3 equipped with a profile P2, as described in Fig. 6, the point M2 coincides with the point C.

A grating 3 equipped with a middle zone Z1 having a profile of the type P2 is described in Fig. 5.

The mounting and then the functioning of the device according to the invention will now be described.

To mount a grating 3 equipped, for example, with a profile Pl, as described in Fig. 4 and Fig. 6, in the frame 1, a pinching of the grating 3 is carried out in the region of the ends 161 of the lateral bars 16.

This is made possible by the fact that the grating is divided into three zones, the middle zone Z1 being connected elastically to the two lateral zones Z2, the elastic connection simply being made by means of a spacer.

Thus, the pivots 17 of the grating 3 are placed opposite the orifices 10 of the frame 1 into which they penetrate.

During this operation, the grating 3 is vertical.

Once the grating 3 has been placed vertically in the frame 1, it is set in rotation about the axis X-X of the frame 1, until the part P of the middle zone Z1 comes into contact with the frame 1 either in the region of the bearing rim 6 or in the region of the face 9 of the skirt at the contact point Ml corresponding to the intersection of the curve S with the profile of the part P.

From this moment, the middle zone Zl, as a result of the torsion of the spacers 191 connecting it to the lateral zones Z2, moves away from the plane defined by the two lateral zones Z2, thus generating a torque which opposes the closing of the grating, the part P rubbing against the corresponding surface of the frame 1 against which it bears .

With the grating 3 continuing to rotate, if sufficient force is exerted on it a torque opposing the rotation of the grating 3 will be generated, until the contact point of the part P with the frame 1 corresponds to the above-defined point M corresponding to the maximum torque. The torque subsequently decreases again as far as the point M2. From this moment, there is no longer any contact between the part P of the zone Z1 and the frame 1.

When the grating 3 is to be opened, the same phenomenon occurs, this time at the point M2.

In fact, the grating 3 rotates freely until the point M2 of the middle zone Zl comes into contact with the frame 1. From this moment and until the contact point Ml is reached, a torque opposing the rotation of the grating 3 will be generated, thus opposing the opening of the grating 3.

In an alternative embodiment of the invention, the grating 3 is prestressed. Thus the grating, bearing on the corresponding surfaces of the frame 1, has a middle zone Zl bearing with its part P on the bearing rim 6, this bearing being effected such that the spacers 191 connecting the middle zone Zl to the two lateral zones Z2 experience torsion, at the same time exerting a torque which, from the outset when the grating 3 rests on the frame 1, opposes the rotation of the grating 3.

The device according to the invention for capping a discharge shaft thereby makes it possible, on the one hand, to lock the grating in its frame in the closed position and, on the other hand, to avoid inopportune closing when the grating is in the vertical posi-

Claims (5)

1. Process for capping a discharge shaft, consisting of a grating (3) articulated in a frame (1) with respect to a pivot axis of the grating (3) corresponding to one of the sides of the latter, this grating (3) being equipped with bars (18) connected to one another by means of spacers (19), characterized in that the grating (3) is divided with respect to its pivot axis into a middle part (Zl) and two lateral parts (Z2) connected elastically to the middle part (Zl), one end of the middle part (Zl) adjacent to the pivot axis being intended to come to bear against a corresponding surface of the frame (1), at the same time exerting a torque opposing the movement of the grating (3) about its pivot axis.

2. Process according to Claim 1, characterized in that the grating, bearing on corresponding surfaces of the frame (1), has a middle zone (Zl) bearing on a bearing rim (6) of the frame (1), this bearing being effected such that spacers (191) connecting the middle zone (Zl) to the two lateral zones (Z2) experience torsion, at the same time exerting a torque which, from the outset when the grating (3) rests on the frame (1), opposes the rotation of the grating (3).

3. Device for carrying out the process according to either one of the preceding claims, consisting of a frame (1) and of a removable grating (3) articulated with respect to an axis X-X of the frame and consisting of a series of bars (18), each bar (18) being connected to an adjacent bar by means of at least one spacer (19), characterized in that the grating (3) consists, with respect to an axis Y-Y of this grating (3), of a middle zone (Zl) and of two lateral zones (Z2), the middle zone (Zl) being connected elastically to the lateral zones (Z2) of the grating (3) by means of spacers (191) not located on the axis X-X and performing the function of torsion bars, the middle zone (Zl) possessing, in the vicinity of the axis X-X of the frame (1), a part (P) intended to come to bear against a corresponding surface of the frame (1), at the same time exerting a torque opposing the rotation of the grating (3) about the axis X-X.

4. A process according to claim 1, substantially as hereinbefore described with reference to the accompanying drawings .

5. a device according to claim 3, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.