IE901196L

IE901196L - Manhole cover

Info

Publication number: IE901196L
Application number: IE901196A
Authority: IE
Inventors: Jeanclaude Hauer; Patrice Vauthier
Original assignee: Pont A Mousson
Priority date: 1989-04-03
Filing date: 1990-04-02
Publication date: 1990-10-03
Also published as: NO901468D0; FR2645189B1; NO177504C; EP0391825B1; DE69001635D1; GR3007912T3; NO901468L; ATE89628T1; IE63446B1; FR2645189A1; NO177504B; ES2036161T1; DE69001635T2; EP0391825A1; DK0391825T3; ES2036161T3

Abstract

Hinged road manhole consisting of a frame (1) and of a cover (2), the frame being equipped with at least one receptacle having an upwardly directed orifice opening out towards the inside of the frame (1), each receptacle being intended for interacting with a pivot (19), of which the transverse dimension perpendicular to the cover is smaller than that of the orifice of the receptacle and of which the transverse dimension parallel to the cover is larger than that of the orifice of the receptacle. The bottom of each receptacle has a hole opening out over its entire length and of a dimension slightly larger than the transverse dimension of the pivots (19) perpendicular to the cover, allowing each pivot (19) to penetrate into the hole when the cover forms an angle of 90 DEG in relation to its closing position. <IMAGE>

Description

63446 The present invention relates to a manhole cover which is provided with a hinge means connecting, in a removable manner, the plug to the frame and enabling the plug to be raised with respect to the frame by pivoting about the hinge means, the plug 5 being locked in the open position.

Thus, manhole covers which have a tilting plug and are mounted on at least one hinge and to this end have at least one pivot lug projecting laterally are known from the document FR-A-2 613 742. Each pivot lug engages in a respective receiver 10 with which the frame is eguipped.

Such a manhole cover is opened by pivoting the plug about the hinge means until the plug goes past its vertical position and each pivot lug abuts against the retaining lips with which each hinge is equipped. The plug in the open position thus forms 15 an angle u£ about 105 to 110° with respect to its closed position and remains in this position under the effect of its own weight.

There is a risk of this type of manhole cover, in certain constructions, shutting inopportunely under the effect for example of a very strong gust of wind or a passer-by's 20 carelessness, in particular in the case of particularly light plugs.

Indeed, the plug only needs to be pivoted by 15 to 20° for it to go past its vertical position and to shut forcefully under the effect of its own weight.

Since manhole covers cover inspection shafts, the plug, for elementary safety reasons, must not close inopportunely.

It is known to use means for locking the plug by the insertion, for example, of blocks or locking bars.

Such means, although they lock the plug effectively in the 30 open position, are, however, cumbersome for the user. Indeed, it is necessary to equip oneself with blocks or locking bars and position them after opening the plug. Because of a certain degree of complacency, the user very often omits the operation of locking.

The present invention relates to a manhole cover provided with a hinge means which makes it possible to overcome these disadvantages. 2 The present invention relates more particularly to a hinged manhole cover formed by a frame and a plug, the frame being equipped with at least one receiver which is open towards the top and which opens towards the interior of the frame, each receiver 5 being intended to cooperate with a pivot lug with which the plug is equipped and which projects beyond the periphery of the said plug, the transverse dimension of the said pivot lug perpendicular to the plug being smaller than that of the opening towards the top of the receiver, while its transverse dimension 10 parallel to the plug is larger than that of the opening of the receiver, in which the base of each receiver, defined in the conditions of installation of the frame, has a hole which opens over its whole length, of a dimension which is slightly larger than the transverse dimension perpendicular to the plug of the 15 pivot lugs, enabling each pivot lug to penetrate into the hole when the plug is at an angle of 90° with respect to its closed position.

Other features and advantages will emerge in the course of the following description, which is given solely by way of 20 example and with reference to the attached drawings, in which: - Fig. 1 is a plan view of part of a manhole cover frame according to the invention; - Fig. 2 is a partial view, in radial section, on the line II-II in Fig. 1; - Fig. 3 is a partial view, in radial section, showing the hinge, the plug being in the closed position; and - Fig. 4 is a partial view, in radial section, showing the hinge, the plug being in the open position locked at 90°.

The manhole cover according to the invention is formed by 30 a frame 1 and a plug 2.

The frame 1 has, in known manner, an inner projection 3 covered for example by a sound-absorbing gasket 4 of elastomer.

In the example embodiment illustrated in Fig. 1, the manhole cover is circular.

In the thickness of the frame 1 there is provided at least one receiver 5 which is open towards the top in the upper face of the frame 1 and opens towards the interior of the said frame. 3 In the description, we shall only speak of a frame which is equipped with a single receiver 5.

In the example embodiment illustrated, the receiver 5 has the general shape of a T, as seen in plan view. A part 6 of the 5 said receiver located towards the interior and forming the leg of the T has a depth which is less than the rest of the receiver. The width of the first half 7 of the part 6 which adjoins the projection 3 is greater than that of the second half 8.

A part 9, located towards the exterior, forms the crossbar 10 of the T. It has two distinct zones: a first zone 10 which adjoins the part 6 having, in radial section, a substantially circular contour and whereof the ends are overhung by unchamfered lips 11 which frame a free space 10 which extends the part 6; and a second zone 12 located outermost, which has the same 15 longitudinal dimension as the zone 10, and having an opening 13 towards the top over its whole length.

The base of the receiver 5, at the level of the zone 10, has, over its whole length, a hole 14 which opens out, then has a depth which decreases as far as the external wall 15 of the 20 frame, and is overhung towards its upper end by a lip 16 which is equipped with a chamfer 24.

The plug 2 has, in known manner, a peripheral annular bearing surface 17 which is intended to bear on the projection 3 which is covered by the gasket 4, and a skirt 18 which projects 25 below its lower face. The skirt 18 bears against the gasket 4 and prevents the plug 2 from being displaced with respect to the frame 1 when the plug 2 is in the closed position.

The plug 2 has as many pivot lugs 19 as the frame has receivers 5. Each pivot lug 19 projects over the periphery of 30 the plug 2.

In the description, we shall only speak of a plug which is equipped with a single pivot lug 19. The transverse dimension perpendicular to the plug 2 of the lugs 19 is smaller than that of the hole 14 in the receiver 5, and the transverse dimension 35 parallel to the plug 2 of the lugs 19 is larger than that of the hole 14 in the receiver 5 of the frame 1.

In the example embodiment, each pivot lug 19 has the general shape of a T dimensioned to cooperate with a receiver 5 of the frame 1.

The pivot lug 19 has a connection part 20 which corresponds to the leg of the T, extends radially and is connected to the plug, and a pivot shaft part 21 which corresponds to the crossbar of the T.

The part 20 has a stop 23 on each side, in its first innermost half which adjoins the plug.

The part 21 has a substantially cylindrical general shape with a diameter smaller than the diameter of the first zone 10 of semi-circular section of the receiver 5 of the frame 1. It has a flat area 22 which is formed longitudinally over its whole length and extends parallel to the main faces of the plug 2.

The transverse dimension of the part 21, perpendicular to the flat area 22, is smaller than the opening 13 towards the top of the receiver 5, and its length is such that the outer faces have a minimum play with the end faces of the receiver in order to enable the plug 2 to pivot freely with respect to the frame 1, but preventing the said plug jamming when it is raised.

When the plug 2 is in the closed position on the frame 1, the pivot lug 19 has no point of contact with the walls of the receiver 5 in order to prevent any noisy crashing of the plug against the frame when a vehicle passes by. In this position, the pivot shaft part 21 extends, at least partly, below the overhanging lips 11 which thus oppose the emergence of the pivot lug 19 from the receiver 5.

When the pivot lug is tilted under the effect of a torque applied at its centre, the pivot lug 19 is lowered into the receiver 5 until the pivot shaft part 21 is vertical. In this position, it descends into the hole 14 opening in the receiver 5. Simultaneously, the stops 23 of the plug 2 slide behind the lips 11 of the frame 1.

The plug 2 is thus locked in the vertical position.

The horizontal force tending to close the plug is opposed by a torque C which is exerted on the one hand against the lips 11 and on the other hand against the wall of the hole 14 in contact with the flat area 22.

In order to close the plug again, all that is necessary is to raise it slightly in order to disengage the pivot lug 19 from the hole 14 and to pivot the plug.

If it is desired to open the plug 2 in order to bring it into a position which is at an angle greater than 90° with respect to its closed position, all that is necessary is to continue the movement.

In fact, due to the chamfer 24 with which the lip 16 of the frame is equipped, the reaction exerted by the said lip is insufficient to oppose complete opening of the plug. The pivot shaft part 21 is returned by way of gravity until it comes to bear against the wall of the zone 10 of the part 6 of the receiver 5 against the lower face of the overhanging lips 11. 6

Claims

1. Hinged manhole cover formed by a frame (1) and a plug (2), the frame being equipped with at least one receiver (5) which has an opening (13) towards the top and which opens towards the 5 interior of the frame (1), each receiver being intended to cooperate with a pivot lug (19) with which the plug (2) is equipped and which projects beyond the periphery of the said plug (2), the transverse dimension of the said pivot lug (19) perpendicular to the plug being smaller than that of the opening 10 (13) of the receiver (5), while its transverse dimension parallel to the plug is larger than that of the opening (13) of the receiver (5), characterized in that the base of each receiver, defined in the conditions of installation of the frame, has a hole (14) which opens over its whole length, of a dimension which 15 is slightly larger than the transverse dimension perpendicular to the plug of the pivot lugs (19), enabling each pivot lug (19) to penetrate into the hole (14) when the plug is at an angle of 90° with respect to its closed position.

2. Manhole cover according to Claim 1, characterized in that 20 the receiver (5) and the pivot lug (19) have the general shape of a T.

3. Manhole cover according to Claim 2, characterized in that a part (6) of the receiver (5) located towards the interior and corresponding to the leg of the T has a first half (7) which 25 adjoins the interior of the frame (1) and has a width which is greater than that of the second half (8).

4. Manhole cover according to one of Claims 2 and 3, characterized in that a part (9) of the receiver (5) corresponding to the crossbar of the T has two distinct zones: 30 a first zone (10) which adjoins the part (6) having, in radial section, a substantially circular contour and whereof the ends are overhung by unchamfered lips (11) which frame a free space which extends the part (6), and a second zone (12) located outermost, which has the same longitudinal dimension as the zone (10).

5. Manhole cover according to Claim 4, characterized in that the zone (12) is overhung towards its upper end by a lip (16) which is equipped with a chamfer (24).

6. Manhole cover according to Claim 1 and 2, characterized in that the pivot lug (19) has a connection part (20) which extends radially and is connected to the plug and a pivot shaft part (21).

7. Manhole cover according to Claim 6, characterized in that the part (20) has a stop (23) on each side, in its first half which adjoins the plug.

8. Manhole cover according to Claim 6, characterized in that the part (21) has a substantially cylindrical general shape and has a flat area (22) which is formed longitudinally over its whole length and extends parallel to the main faces of the plug (2).

9. A hinged manhole cover according to Claim 1, substantially as hereinbefore described with particular reference to and as illustrated in the accompanying drawings. F. R. KELLY & CO., AGENTS FOR THE APPLICANTS