Manhole head assembly for manhole column

Abstract

A manhole head assembly for mounting a cover on a manhole column is disclosed. The manhole head assembly comprises a support member having a top portion made of a grindable material and a bottom portion shaped and sized to rest on the manhole column. The top and bottom portions form an inner shoulder sized and shaped to receive the cover. The manhole head assembly further comprises at least one removable spacer adapted to be disposed between the shoulder and the cover for adjusting the height thereof.

Description

[0001] The present application claims the benefit of priority of provisional application No. 60/270,197 filed Feb. 22, 2001.

FIELD OF THE INVENTION

[0002] The present invention relates to manhole head assemblies for mounting a cover on a manhole column. More particularly, it concerns a manhole head assembly which can easily be levelled to be flush with the surface level of the surrounding pavement.

BACKGROUND OF THE INVENTION

[0003] Conventional manholes for draining water or allowing access to a person having to work in the manhole, have many drawbacks, usually caused by the freezing and thawing of the ground surrounding the manhole assembly or by the vibrations caused by the passage of heavy vehicles thereon. Indeed, in regions where varying temperature occurs, a separation between the surrounding pavement and the manhole is often seen resulting in the projection of the manhole cover. This situation may be troublesome for road maintenance during winter, i.e. for the use of snowplows. Another drawback is commonly seen with the use of conventional manholes which comprise metallic parts. Indeed, the contact of these metallic parts with each other may be very noisy.

[0004] In the art, several adjustable manhole head assemblies have been proposed to correct these problems. Examples of such manhole head assemblies are shown in U.S. Pat. Nos. 4,188,151; 4,187,647; 5,044,818; 5,470,172; 5,564,855; 5,956,905; and 6,161,984.

[0005] While these manhole head assemblies have resulted in the advancement within the present field, most of these prior art manhole head assemblies are, nevertheless very hard to rehabilitate.

[0006] There is thus presently a need for an improved manhole head assembly which will at least reduce one or more of these drawbacks.

SUMMARY OF THE INVENTION

[0007] It is therefore an object of the present invention to provide an improved manhole head assembly for mounting a cover on a manhole column.

[0008] In accordance with the invention, that object is achieved with a manhole head assembly for mounting a cover on a manhole column, the manhole head assembly comprising:

[0009] a support member having a top portion made of a grindable material and a bottom portion shaped and sized to rest on the manhole column, the portions forming an inner shoulder sized and shaped to receive the cover; and

[0010] at least one removable spacer adapted to be disposed between the shoulder and the cover for adjusting the height thereof.

[0011] The present invention is also directed to a manhole column comprising:

[0012] rims stacked over one another; and

[0013] a manhole head assembly for mounting a cover on the manhole column as defined above.

[0014] The present invention also proposes a method for levelling off a manhole column as defined above, the method comprising the steps of:

[0015] a) grinding down the top portion of the support member approximately to surface level of surrounding pavement; and

[0016] b) adjusting the height of the cover approximately to the level of the top portion obtained in step a) by placing a desired number of spacer between the shoulder and the cover.

[0017] A manhole head assembly for mounting a cover on the manhole column according to the present invention proposes innovative features that makes it very easy to be levelled flush with the surrounding pavement. Furthermore, the head assembly of the present invention can be readily and easily repaired on the spot.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention and its advantages will be more easily understood after reading the following non-restrictive description of a preferred embodiment thereof, made with reference to the following drawings wherein:

[0019] FIG. 1 is an exploded cross-sectional side view of a manhole column with a manhole head assembly according to a preferred embodiment of the invention.

[0020] FIG. 2 is a perspective exploded view of the manhole head assembly shown in FIG. 1.

[0021] FIG. 3 is another perspective exploded view of the manhole head assembly shown in FIG. 1.

[0022] FIG. 4 is a side view of the manhole column of FIG. 1, showing the cover and the spacers before installation on the manhole head assembly.

[0023] FIG. 5 is the same view as FIG. 4, showing now the cover installed on the manhole head assembly.

[0024] FIG. 6 is a side view of the manhole column of FIG. 1, showing the cover installed on the manhole head assembly in a sloped environment.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0025] The present invention is directed to a manhole head assembly for mounting a cover on a manhole column. It will be understood that the manhole head assembly of the present invention is suitable for use with many types of manhole column know in the art. For instance, the manhole head assembly of the present invention is advantageously suitable for use with manholes for sours and for electrical lines.

[0026] Referring to FIG. 1, a manhole column (10) according to a preferred embodiment of the invention is illustrated. The manhole column (10) comprises rims (12) stacked one over the other. In order to improve the water tightness of the column (10) and to reduce harmful results of vibrations, it may be advantageous to use rings (50) of impermeable and cushioning material adapted to be disposed between each rim (12). Although, such rings (50) may be made of any material known to one skilled in the art, the present invention preferably contemplates employing rings (50) made of a material comprising epoxy, quartz and urethane. The manhole column (10) further comprises a manhole head assembly (14) for mounting a cover (16) on the same (14). For safety reasons, one may find advantageous to lock the cover (16) to the manhole head assembly (14). In such a case, the use of bolts (4) as shown in FIG. 1, or any other type of locking mechanism known in the art will suffice.

[0027] Now turning also to FIGS. 2 and 3, the manhole head assembly (14) comprises a support member (18) having a top portion (20) made of a grindable material and a bottom portion (22) shaped and sized to rest on the upper rim (12) of the manhole column (10). The portions (20, 22) form an inner shoulder (24) sized and shaped to receive the cover (16). According to a preferred embodiment of the invention, the support member (18), the top (20) and bottom (22) portions have an annular shape.

[0028] The manhole head assembly (14) further comprises at least one removable spacer (26) adapted to be disposed between the shoulder (24) and the cover (16) for adjusting the height thereof. In other words, and as best viewed in FIG. 5, the level of the cover (16) can be adjusted to be flush with the level of the support member (18) by adding or removing one or more spacers (26). Since the present invention contemplates employing a cover (16) made of any suitable material known in the art, it is thus preferable to use spacers (26) made of a cushioning material such as rubber or a flexible polymer. Thanks to such an arrangement, the noise induced by the contact of the cover (16) with the other parts of the manhole head assembly (14) is greatly reduced.

[0029] As mentioned above, the top portion (20) of the support member (22) is made of a material capable of surface grinding, and that preferably without cracking. According to a preferred embodiment of the invention, such a material is preferably a polymeric cement, most preferably, the material is a polymeric cement comprising epoxy resin mixed with quartz of different sizes. In order to strengthen the support member (18), the polymeric cement is preferably reinforced with a metallic mesh. Furthermore, to facilitate the manufacture of the manhole head assembly (14) of the present invention, the support member (18), as a whole (i.e. top (20) and bottom (22) portions), is preferably made of a polymeric cement.

[0030] As it can be appreciated by viewing FIGS. 4 and 5, a manhole head assembly (14) according to the present invention is easily flush levelled with the surrounding pavement (2) because the top portion (20) of its support member (18) is made of a grindable material. This is achieved by simply removing, by surface grinding with a suitable tool, a given thickness material. Therefore, when a manhole head assembly (14) is protruding with respect to the level of the surrounding pavement (2), for example as a result of frost, it can be simply levelled flush with the pavement by first grinding the top portion (20) thereof and then removing one or more spacers (26), as required, so that the cover (16) and the top portion (20) of the assembly (14) be substantially flush with the surrounding pavement (2).

[0031] When viewing FIGS. 4 and 5, it is clear that the given thickness material removed from the top portion (20) has a substantially uniform thickness in order to level flush the manhole head assembly (14) with the surrounding pavement (2). In such a case, the spacers (26) have also an uniform thickness. However, when the surrounding pavement (2) is in a sloped environment, as shown in FIG. 6, the material to be removed may have a non-uniform thickness. In that case, it may be advantageous to provide one or more spacers (26a) with non-uniform thickness so as to compensate for the sloping surface.

[0032] In this connection and according to another aspect of the invention, a method for levelling off a manhole column (10) as defined above is proposed. The method comprises the steps of:

[0033] a) grinding down the top portion (20) of the support member (18) approximately to surface level of surrounding pavement (2); and

[0034] b) adjusting the height of the cover (16) approximately to the level of the top portion (20) obtained in step a) by placing a desired number of spacer (26) between the shoulder (24) and the cover (16).

[0035] To sum up, the manhole head assembly (14) according to the preferred embodiment described above is believed to overcome many drawbacks of the prior art manhole head assemblies, for example:

[0036] it can be very easily levelled flush with the surrounding pavement (2),

[0037] the polymeric cement used for the support member (18), and also, if desired, for the annular rims (12) of the manhole column (10), is resistant to saline solutions, and is capable of absorbing vibrations;

[0038] it is not noisy, because there are no metallic parts in contact with each other;

[0039] the spacers, which act as a cushioning material, absorb a great part of the noise; and

[0040] because of the material used (viz. a grindable material), the manhole head assembly (14) can be readily and easily repaired on the spot.

[0041] Although the present invention has been explained hereinabove by way of a preferred embodiment thereof, it should be understood that the invention is not limited to this precise embodiment and that various changes and modifications may be effected therein without departing from the scope or spirit of the invention.

Claims

1. A manhole head assembly for mounting a cover on a manhole column, the manhole head assembly comprising:

a support member having a top portion made of a grindable material and a bottom portion shaped and sized to rest on the manhole column, the portions forming an inner shoulder sized and shaped to receive the cover; and

at least one removable spacer adapted to be disposed between the shoulder and the cover for adjusting the height thereof.

2. A manhole head assembly according to claim 1, wherein the support member and the top and bottom portions have an annular shape.

3. A manhole head assembly according to claim 1, wherein the material is a polymeric cement.

4. A manhole head assembly according to claim 3, wherein the polymeric cement comprises epoxy resin mixed with quartz of different sizes.

5. A manhole head assembly according to claim 4, wherein the polymeric cement further comprises a metallic mesh.

6. A manhole head assembly according to claim 1, wherein the support member comprises locking means for locking the cover with respect to the support member.

7. A manhole head assembly according to claim 1, wherein the spacer is made of a cushioning material chosen for the group consisting of rubber and flexible polymer.

8. A manhole column comprising:

rims stacked over one another; and

a manhole head assembly for mounting a cover on the manhole column, the manhole head assembly comprising:

a support member having a top portion made of a grindable material and a bottom portion shaped and sized to rest on the upper rim of the manhole column, the portions forming an inner shoulder sized and shaped to receive the cover; and

at least one removable spacer adapted to be disposed between the shoulder and the cover for adjusting the height thereof.

9. A manhole column according to claim 8, wherein the rims, the support member and the top and bottom portions have an annular shape.

10. A manhole column according to claim 9, further comprising rings made of impermeable and cushioning material, adapted to be disposed between the rims.

11. Method for levelling off a manhole column as defined in claim 8, the method comprising the steps of:

a) grinding down the top portion of the support member approximately to surface level of surrounding pavement; and

b) adjusting the height of the cover approximately to the level of the top portion obtained in step a) by placing a desired number of spacer between the shoulder and the cover.