GB2102479A

GB2102479A - A man-hole for a road

Info

Publication number: GB2102479A
Application number: GB08218524A
Authority: GB
Inventors: Andre Defrance; Pierre Vigneron
Original assignee: Pont a Mousson SA
Current assignee: Pont a Mousson SA
Priority date: 1981-07-06
Filing date: 1982-06-25
Publication date: 1983-02-02
Also published as: CH648076A5; FR2508953A1; GB2102479B; BE893763A; IT8267854A0; ES266052Y; DE3224655C2; IT1156034B; ES266052U; FR2508953B1; DE3224655A1

Abstract

A man-hole for a road having a frame 7 provided with an inner radial projection 11 and a cover 15 resting on the projection. A resilient sound- proofing gasket 1 of general L-shaped section has an approximately horizontal side 2 interposed between an approximately horizontal peripheral surface of the cover 15 and the upper face of the projection 11. The gasket also as an approximately vertical side 3 interposed with radial clearance between approximately vertical peripheral surface 20 of the cover and the opposite approximately vertical peripheral surface 14 of the frame. The gasket side 3 comprises a localised peripheral radial projection such as lip 6 which is deformed radially when the cover 15 is in position in the frame 7 and ensures positive centering of the cover. <IMAGE>

Description

SPECIFICATION Man-hole for a road This invention relates to a man-hole for a road of the type comprising first and second members, the first member being a frame provided with a radial internal projection, the second member being a cover resting on the projection, a resilient sound-proofing gasket of general L-shaped section comprising an approximately horizontal side and an approximately vertical side, said horizontal side being interposed between an approximately horizontal peripheral surface of the cover and the upper face of the projection of the frame and said vertical side being interposed with radial clearance between opposed approximately vertical peripheral surfaces of the cover and of the frame.

In man-holes of said type, the radial clearance mentioned is necessary in order to guarantee correct seating of the cover despite great manufacturing tolerances. But, owing to this clearance, the cover has restricted radial movement under the effect of travelling loads, which decreases the efficiency of the soundproofing ensured by the gasket and leads to rapid wear of the latter.

An object of the invention is to provide a man-hole capable of being constructed as to reconcile the two contradictory requirements of considerable tolerances and effective centering of the cover.

According to the invention a man-hole for a road of the aforesaid type further comprises said vertical side of the gasket comprising a localized radial projection which is deformed radially when the cover is in position in the frame.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a half-view in axial section of a gasket used in a first embodiment of a man-hole formed according to the invention; Fig. 2 is a similar view of the gasket in Fig. 1 fitted in the frame of the first embodiment of the man-hole; Fig. 3 is a similar view showing said first embodiment with the cover of the man-hole in position; Fig. 4 is a view similar to Fig. 3 of a second embodiment of man-hole formed according to the invention; Fig. 5 is a view similar to Fig. 1 of a gasket used in a third embodiment of man-hole formed according to the invention;; Fig. 6 is a similar view of the gasket in Fig. 5 fitted to the cover of the third embodiment of man-hole, and Fig. 7 is a similar view showing said third embodiment with the cover of the man-hole in position.

The sound-proofing gasket 1 shown in the free state in figure 1 is circular, closed and of constant section. This section is of general inverted L shape, i.e. that it comprises an approximately horizontal side 2 and an approximately vertical side 3 which extends downwards from one end of the side 2. The angle of the L is slightly less than 900.

The free end of the side 2 comprises a rim 4 projecting downwards. The free end of the side 3 comprises a short approximately horizontal arm 5 directed towards the inside of the L and a lip 6 which becomes progressively thinner and extends downwards at an angle of approximately 450, in the opposite direction to that of the arm 5.

The gasket 1 is fitted on a man-hole frame 7 of cast iron constituted by a support plate 8 whereof the inner periphery forms the starting point for an approximately cylindrical skirt 9 extending upwards. Radial ribs 10 ensure strengthening.

Approximately halfway along its length the skirt 9 is provided with an inner flange 1 The latter comprises an upper face 1 2 and lower face 1 3 which are approximately horizontal and an inner surface 14 which has slightly conicity convergent in a downwards direction. A groove 1 2a borders the face 12 on the outside.

The gasket 1 is fitted on the flanges 11 in the manner of a tyre in order to cover it. The rim 4 fits in the groove 1 2a and the sides 2 and 3 and the upper face of the arm 5 bear respectively against the faces 12, 14 and 13. The gasket is kept in position by the rim 4 and by the fact that it was necessary to open the angle of the L up to a value greater than 900 in order to fit it. The lip 6 is in an overhanding position below the flange 11 and partially below the arm 5.

The cover 1 5 (figure 3) comprises a framework 1 6 of cast iron in the general shape of a cup and a concrete filler 17. The framework 16 has a halfsection of S shape constituted by an approximately cylindrical upper skirt 18, an approximately horizontal portion 19, located approximately halfway along its length and an approximately cylindrical lower skirt 20 whereof the outer radius is less than that of the skirt 18 and is comprised between the minimum radius of the side 3 and that of the lip 6 in the fitted state of the gasket.

When the cover 1 5 is in position, its portion 1 9 bears on the side 2 of the gasket. Its upper skirt 1 8 is located opposite the upper part of the skirt 9 of the frame, but without any contact with the latter and its lower skirt 20 is located opposite the flange 11, with a radial clearance with respect to the side 3 of the gasket and deforms the lip 6 radially outwards. The shape of this lip in the inoperative position is shown in dot dash lines in figure 3.

Thus, the lower skirt 20 extends downwards clearly beyond the face 1 3 and its only contact with the gasket is in the vicinity of the free end part of the lip 6.

It is easy to find a material for the gasket 1 and dimensions which make it possible to obtain in this way effective centering and radial retention of the cover during operation. In particular, the gasket may be made from flexible material, for example from natural or synthetic rubber, polyurethane or polyethylene, this gasket being able to be moulded or produced from an extruded sectional member whereof the two ends are joined, in particular heat-welded.

In this respect it should be noted that the compression of the side 2 tends to increase the radial force exerted by the lip 6 on the cover.

The lip 6 absorbs the radial tolerances. In addition, this lip exerts an anti-lifting and thus an anti-rocking effect on the cover, which guarantees a stable support for the cover, even with cast iron members 7 and 1 5 which are rough-cast.

It should also be noted that the downwards elongation of the skirt 20 of the cover, due to the shape and situation of the lip 6. lowers the centre of gravity of the cover, which increases the stability thereof.

The embodiment of figure 4 differs essentially from the preceding embodiment by the fact that in the gasket 1 A, the lip 6 is replaced by a localized internal excess thickness 6A of the side 3A located approximately halfway along its length. When the cover 15, which is the same as previously, is put in position, this part of the side 3A having an excess thickness is compressed radially between the lower skirt 20 of the cover and the surface 14 of the frame, which is the same as previously. The advantages mentioned above are once more obtained, with the exception of lowering the centre of gravity, since the skirt 20 stops in effect approximately at the level of the face 13.

Figures 5 to 7 illustrate one embodiment of the invention in which the gasket 1 3 is supported by the cover 15B.

The gasket 1 B still has a section in the form of an inverted L. The free end of the horizontal sides 2B comprises an upper notch 48, in place of a lower rim. The free end of the descending side 3B has only one lip 6B rising towards the outside at an angle of approximately 450. In the inoperative position. the angle of the L is slightly greater than 900.

The cover 15B is modified with respect to the cover 1 5 of figure 3 in the following manner: the outer end of the portion 1 9B comprises a lower annular projection 21 co-operating with the notch 48 and the lower end of the lower skirt 20B comprises an outer annular projection 22 whereof the upper surface has a back-taper which defines a groove 23 cooperating with the lower point 24 of the side 38 of the gasket.

The gasket 1 B is fitted on the cover 15B in the manner of a tyre by slightly closing the angle of the L. The sides 2B and 3B bear respectively on the regions of the L. The sides 2B and 3B bear respectively on the regions 1 9B and 20B, the notch 4B fits on the projection 21 and the point 24 is housed in the groove 23. The lip 6B thus covers the lower part of the side 38 radially with clearance.

When the cover 15B is placed flat in the frame 7B, which differs from the frame 7 solely by the absence of the groove 1 5, the side 2B bears on the face 12 of the flange 11 B and extends beyond the latter towards the axis of the man-hole. A small radial clearance exists between the upper skirt 1 8 and the skirt 9 of the frame and a greater radial clearance exists between the side 38 of the gasket and the inner face 14 of the flange 11 B.

The only contact between this face and the gasket is with the end of the lip 6B, which is deformed radially towards the inside, whilst however remaining spaced apart radially from the side 38.

The projection 22 of the cover is located clearly below the lower face 13 of the flange 11 B.

The advantages of this embodiment are the same as in figures 1 to 3.

Claims

1. A man-hole for a road comprising first and second members, the first member being a frame provided with an inner radial projection, the second member being a cover resting on the projection, a resilient sound-proofing gasket of general L-shaped section comprising an approximately horizontal side and an approximately vertical side, said horizontal side being interposed between an approximately horizontal peripheral surface of the cover and the upper face of the projection of the frame and said vertical side being interposed with radial clearance between opposed approximately vertical peripheral surfaces of the cover and of the frame, and said vertical side of the gasket comprising a localised radial projection which is deformed radially when the cover is in position in the frame.

2. A man-hole as claimed in claim 1, in which said projection of the gasket is a rim compressed radially between said vertical surfaces of the cover and frame.

3. A man-hole as claimed in claim 1, in which said projection of the gasket is arranged to overhang vertically with respect to a said member which supports the gasket.

4. A man-hole as claimed in claim 3, in which the frame supports the gasket which surrounds the radial projection of the frame, and the projection of the gasket overhangs in the downwards direction with respect to the projection of the frame and cooperates with a lower extension of said vertical surface of the cover.

5. A man-hole as claimed in claim 1, in which the projection of the gasket is a lip covering part of said vertical side of the gasket with clearance and remaining spaced apart from said vertical in the deformed state.

6. A man-hole as claimed in any one of claims 1 to 5, in which the gasket is continuous and has a constant section over the entire periphery of the man-hole.

7. A man-hole for a road, substantially as hereinbefore described with reference to Figs. 1 to 3 or Fig. 4 or Figs. 5 to 7 of the accompanying drawings.