IE921005A1 - A cover means for an access or drainage shaft - Google Patents

Abstract

The device comprises a frame (1) and a removable grating (2) which is hinged along an axis X-X of the frame, which grating consists of a series of bars connected in pairs, by at least one tie and running perpendicularly to the hinge axis X-X of the grating (2). The grating (2) furthermore comprises two intermediate bars (19A, 19B) connected to the other bars of the grating by their ends opposite the hinge axis X-X and the free ends of which interact, by elastic bending of the bars (19A, 19B) in the plane of the grating, with means (13, 14), arranged on the frame (1), for holding the grating (2) in the open and closed position. <IMAGE>

Description

The present invention relates to a device for capping an access or drainage shaft constituted by a tilting removable grating resting, when the device is in closed position, in a frame sealed into the ground.

In French Patent Application No. 8,912,938 filed on 29 September 1989 by the Applicant, a process and a device were described for capping a drainage shaft, consisting of a grating articulated in a frame along an axis for pivoting of the grating corresponding to one side of the latter, this grating being provided with bars connected to one another by spacers.

The grating is divided along its pivoting axis into a middle part and two lateral parts connected resiliently to the middle part, one end of the middle part contiguous to the pivoting axis being designed to come and bear against a corresponding surface of the frame exerting a torque opposing the movement of the grating about its pivoting axis.

An arrangement of the type described in the above-mentioned patent ensures that the grating remains blocked so as to avoid an accidental opening of the shaft and also to prevent acts of vandalism during which the grating may be deliberately removed from its frame.

Moreover, it ensures the retaining of the grating in the open position.

The invention aims to improve further the technique described above by creating a capping device in which on the one hand any accidental opening of the grating and on the other hand the inadvertent closure of - 2 the latter when it is in the open position are avoided, this being achieved by means of a resilient action of certain members of the grating.

Its subject is therefore a device for capping an 5 access or drainage shaft comprising a frame and a removable grating articulated along an axis X-X of the frame, constituted by a series of bars connected in pairs by at least one spacer and extending perpendicularly to the axis of articulation X-X of the grating, characterised in that the grating further comprises at least one intermediate bar connected to the other bars of the grating by its end opposite to the axis of articulation X-X and whose free end co-operates by resilient flexion of the bar in the plane of the grating with means for retaining the grating in open and closed positions, arranged on the frame.

The invention will be better understood with the aid of the following description, given solely by way of example, with reference to the accompanying drawings, in which: - Fig. 1 is a plan view of a shaft capping device according to the invention; - Fig. 2 is a cross-section along line 2-2 of Fig. 1; - Fig. 3 is a side view of the capping device showing the grating in open position and in closed position; - Fig. 4 is a plan view of the grating of the capping device according to the invention; IE 92100b - 3 - Fig. 5 is a partial perspective view of the capping device according to the invention showing the means for retaining the grating in open or closed position; and - Fig. 6 is a partial perspective view similar to Fig. 5 showing a variant of the means for retaining the grating.

With reference first of all to Figs. 1 and 2, the capping device according to the invention may be seen to comprise a frame 1 designed to be sealed into the ground, for example into a road surface, at the upper end of a drainage or access shaft (not shown) and an articulated removable grating 2 forming a lid.

The frame 1, seen from above, has a square or rectangular general shape and has a vertical skirt 3, provided at its periphery with a peripheral bearing plate 4 serving for the sealing of the frame and with an inner flange 5 serving as a bearing surface for the grating 2.

Two opposite sides ¢, 7 of the skirt 3 each have, in immediate proximity with a side 8 which is perpendicular to them, a cavity 9 of axis X-X parallel to the side 8, the two cavities 9 being coaxial.

The skirt 3 is terminated by a side 10 opposite and parallel to the side 8.

Each cavity 9 is arranged in the skirt 3 of the frame 1 above the inner flange 5 at approximately midheight between this flange and the top of the skirt 3.

The part of the flange 5 integral with the side of the skirt 3 has, close to its ends, two apertures - 4 11A, 11B defining between them an intermediate portion each of whose two ends, parallel to the sides 6 and 7 of the skirt, has a chamfered surface 13 directed towards the inside of the frame and diverging from the opposite wall of the corresponding aperture 11A, 11B.

Each end of the intermediate portion 12 of the flange delimited by the apertures 11A, 11B additionally supports a stop 14 projecting towards the top of the frame 1 and integral with the side 8 of the skirt 3.

The arrangement of the chamfered surface 13 and of the stop 14 is clearly apparent in the perspective view of Fig. 5.

Each stop 14 has in cross-section the shape of a right-angled trapezium. It is parallel to the sides 6 and 7 of the frame and consequently to the bars of the grating 2 and has on its side facing the corresponding aperture 11A, 11B a sloping surface or ramp 15 terminating with a horizontal top 16.

The grating 2, of rectangular general shape, is constituted by a series of parallel bars, each bar being connected to the neighbouring bars by at least one spacer.

As may be clearly seen in Fig. 4, the grating comprises two outer bars 17 each having close to one of its ends a pivot 18 designed to come and lodge in one of the cavities 9 of the frame 1, the two pivots 18 being coaxial, of axis Y-Y.

Two intermediate bars 19A, 19B, which are connected by their ends opposite to the axis Y-Y of - 5 articulation of the grating, on the one hand to the outer bars 17 and on the other hand to bars 20 of a central part of the grating, by single spacers 21A, 2IB, comprise each at its free end close to the axis Y-Y a vertical projection 22 directed downwards, whose innermost longitudinal face, that is to say the face closest to the middle of the grating 2, has a sloping surface or ramp 23, the slope of this ramp being identical to that of the corresponding ramp 15 of the associated stop 14. The connecting bars 20 constituting the central part of the grating complete the constitution of the latter.

In order to mount the grating 2 in its frame 1, the grating being presented perpendicularly to the plane of the frame, a pinching of the grating is performed at the free ends of the bars 17, this operation being rendered possible by the natural resilience of the material constituting the grating 2 which is constructed for example of cast steel with spheroidal graphite. The pivots 18 are thus placed facing the cavities 9 of the frame 1 which they enter when the pinching force is released.

Starting from the open position of the grating shown in chain-dotted lines in Fig. 3, in order to close the grating 2, the latter is caused to pivot about its axis of rotation X-X in the direction of the arrow F until the ramps 23 of the intermediate bars 19A, 19B are brought into contact with the chamfered surfaces 13 of the intermediate portion 12 of the flange 5.

When the ramps 23 come into contact with the - 6 chamfered surfaces 13, there is created between the flange 5 and the bars 19A, 19B a torque opposing the continued rotation of the grating 2 thus preventing its inadvertent closure.

In order to overcome this torque, a downward force is applied to the grating 2, the intensity of which causes the ramps 23 to slide along the chamfered surfaces 13 of the intermediate part 12 of the flange 5. This sliding movement causes the resilient separation of the bars 19A, 19B with respect to their normal positions, as shown in chain-dotted lines in Fig. 1, so that the projection 22 of each of the bars 19A, 19B can pivot about the axis X-X owing to the presence of the respective apertures 11A, 11B made in the flange 5 of the frame 1 which allow the corresponding projections 22 to pass .

The separation of the bars 19A, 19B occurs in the plane of the grating 2.

When the grating reaches the closed position, the sloping ramps 23 provided on the projections 22 of the bars 19A, 19B come into contact, because of the resilient coming together of the intermediate bars 19A, 19B, with the sloping ramps 15 of the stops 14 borne by the ends of the intermediate portion 12 of the flange 5 and thus create a torque which opposes the accidental opening of the grating 2.

It will be noted that the ends of the bars 17, 20 of the grating, in contrast to the intermediate bars 19A and 19B, which are situated close to the axis X-X of - 7 rotation of the grating, do not form obstacles to the rotation of the latter owing to the fact that their end surfaces contiguous to the axis X-X have a cylindrical or spherical shape centred on the axis X-X, and having a radius such that, during the rotation of the grating, these ends never come into contact either with the skirt or with the flange 5 of the frame 1.

As far as the intermediate bars 19A, 19B are concerned, the presence of a projection 22 situated at a distance from the axis X-X greater than its radius renders it necessary to provide in the flange 5 the apertures 11A and 11B which avoid blocking of the rotation by contact between the projections 22 and the flange 5 of the frame 1.

In order to open the grating 2, it is necessary to apply to it a lifting force of an intensity such that the torque which it generates is greater than the resistant torque which results from the contact between the ramps 23 of the projections 22 of the intermediate bars 19A and 19B and ramps 15 of the stops 14 integral with the frame 1.

The movement of lifting of the grating 2 causes sliding of the sloping surfaces 23 on the ramps 15 of the stops 14 and thereby a lateral resilient separation of the bars 19A, 19B with respect to their resting positions.

In order to produce this displacement, a bar forming a lever is generally used.

The separation by resilient deformation of the - 8 intermediate bars 19A and 19B is produced in the plane of the grating 2. Then, during the continued rotation of the grating 2, the respective projections 22 of the bars 19A and 19B engage in the respective apertures 11A and 11B of the flange 5 thus allowing the continued rotation of the grating 2 about the axis X-X.

When the grating is brought into its open position, the projections 22, by coming into contact with the chamfered surfaces 13 of the intermediate part 12, once again allow the bars 19A, 19B to come together, by resilient return, into their resting positions, so that the grating is once again blocked against any inadvertent closure movement.

Owing to the positions of the stops 14 of the frame 1 between the intermediate bars 19A, 19B and the respective orientations of the ramps 15 of the stops 14 and 23 of the projections 22, the resilient flexion of the bars is accompanied by a movement of separation of these bars.

It may also be envisaged to dispose the stops integral with the frame 1 on the outside of the intermediate bars and to orientate the ramps of these stops and those of the ends of the intermediate bars so that during the rotation of the grating the resilient flexion of the bars in the plane of the grating is accompanied by a movement of the bars towards one another.

In the embodiment described with reference to Figs. 1 to 5, the intermediate bars which, by resilient deformation in the plane of the grating, ensure the - 9 immobilising of the grating both in open position and in closed position, by co-operating on the one hand with the ramps 15 of the stops 14 borne by the flange 5 and on the other hand with the chamfered surfaces 13 of the inter5 mediate part 12 of the flange, have projections 22 directed downwards which necessitate the provision in the flange 5 of the apertures 11A, 11B for the passage of these projections during the rotation of the grating.

An embodiment can also be imagined in which the 10 intermediate bars do not have any projections, but comprise ends of cylindrical or spherical shape, identical to those of the other bars such as the bars 17 and 20 of the grating.

Such a variant is shown partially in Fig. 6. This 15 Figure shows one of the intermediate bars 29B whose end 30 is of cylindrical shape, of radius R such that when the grating to which the bar 29B belongs is mounted in the frame 1, the axis of the cylindrical surface 30 is merged with the axis X-X of rotation of the grating.

In these conditions, when the grating is displaced in rotation, the end surface of the bar 29B will never come into contact either with the skirt 3 or with the flange 5 of the frame 1.

In this embodiment, there is therefore no point 25 in making apertures in order to allow the passage of any part whatever of the end of the bar 29B during its displacement in rotation.

In order to ensure the blocking of the grating in open position and in closed position, the frame 1 - 10 bears stops 31 which extend over the entire width of the flange 5 parallel with the bars of the grating. Each of these stops 31 comprises a lateral ramp 32 designed to co-operate with a complementary ramp 33 provided on each bar 29B so as to ensure its resilient separation in the plane of the grating during the displacement in rotation of the latter and an end chamfer 34 serving, by cooperation with the corresponding bar 29B, to allow the said bar to return to the resting position when the grating is in open position so as to ensure the blocking of the latter against any inadvertent closure movement.

In the examples which have just been described with reference to the drawings, the grating of the capping device comprises two intermediate bars ensuring, in co-operation with means arranged on the frame, the retaining of the grating in open and closed positions.

It will be understood that it is equally possible for the grating to comprise only a single intermediate bar disposed preferably in the central part of the grating and co-operating with corresponding retaining means provided on the frame.

Claims (9)

1. Device for capping an access or drainage shaft comprising a frame (1) and a removable grating (2) articulated along an axis X-X of the frame, constituted 5 by a series of bars connected in pairs by at least one spacer and extending perpendicularly to the axis of articulation X-X of the grating (2), characterised in that the grating (2) further comprises at least one intermediate bar (19A, 19B; 29B) connected to the other 10 bars of the grating by its end opposite to the axis of articulation X-X and whose free end co-operates by resilient flexion of the bar (19A, 19B; 29B) in the plane of the grating with means (13, 14, 15; 31, 32, 34) for retaining the grating (2) in open and closed positions, 15 arranged on the frame (1).

2. Capping device according to Claim 1, characterised in that the grating comprises outer bars (17) provided at their free ends with pivots (18) engaged, by resilient flexion of the outer bars (17), in 20 corresponding cavities (9) of the frame (1) r two intermediate bars (19A, 19B; 29B) each being connected to one outer bar (17) by a single spacer (21A) and to a bar (20) of a central part of the grating by a single spacer (2IB). 25

3. Capping device according to either of Claims 1 and 2, characterised in that each of the intermediate bars (19A, 19B) of the grating (2) comprises at its free end close to the axis of articulation of the grating in the frame (1) a vertical projection (22) directed - 12 downwards whose inner longitudinal face has a sloping surface or ramp (23) co-operating with a sloping surface (15) of a stop (14) projecting towards the top of the frame (1), secured to the latter and extending parallel 5 to the bars of the grating (2), the said stops (14) forming, in co-operation with the projections (22) of the intermediate bars, means for retaining the grating (2) in closed position.

4. Capping device according to Claim 3, in which the 10 frame (1) is provided with an inner bearing flange (5) for the grating (2) in closed position, characterised in that apertures (11A, 11B) for the passage of the projections (22) of the intermediate bars (19A, 19B) during the rotation of the grating are made in the inner 15 flange (5) of the frame (1).

5. Capping device according to Claim 4, characterised in that the means for retaining the grating (2) in open position comprise chamfered surfaces (13) directed towards the inside of the frame (1), arranged on 20 one of the walls of the apertures (HA, 11B) which delimit an intermediate portion (12) of the flange (5), and diverging respectively from the other of the walls of the corresponding apertures .

6. Capping device according to Claim 5, 25 characterised in that the stops (14) co-operating with the projections (22) are situated along the walls of the apertures (11A, 11B) comprising the said chamfered surfaces (13).

7. Capping device according to either of Claims 1 and 2, characterised in that each of the intermediate bars (29B) of the grating (2) comprises a free end close to the axis of articulation of the grating in the frame (1) of appropriate shape to allow it to turn about the 5 axis of articulation without coming into contact with the frame (1), and in that on the frame (1) are provided stops (31) parallel to the bars of the grating, provided with sloping surfaces (32) co-operating with corresponding sloping surfaces (33) of the intermediate 10 bars (29B) and forming the said means for retaining the grating in closed position.

8. Capping device according to Claim 7, characterised in that each of the stops (31) forming the said means for retaining the grating in closed position 15 comprises a chamfered end surface (34) directed towards the inside of the frame, the chamfered surfaces (34) forming with the ends of the corresponding intermediate bars (29B) the said means for retaining the grating in open position.

9. Capping device according to Claim 1, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.