GB2342374A

GB2342374A - Drainage channel covers

Info

Publication number: GB2342374A
Application number: GB9819940A
Authority: GB
Inventors: John Howard Monks; Joseph Michael Law
Original assignee: ALLPIPE Ltd
Current assignee: ALLPIPE Ltd
Priority date: 1998-09-15
Filing date: 1998-09-15
Publication date: 2000-04-12
Anticipated expiration: 2018-09-15
Also published as: GB9819940D0; GB2342374B

Abstract

A cover for a drainage channel has a main lid body 10 of a cast concrete material and which is adapted to engage the upper region of the channel, via rebates 11, there being at least one opening 13 through the lid body for the passage of water. A metal grating 18 is secured to the upper surface of the main lid body so as to overlie the water opening. The grating 18 has a plurality of relatively small apertures 19, as compared to the size of the opening 13 through the main lid body 10. The grating is located by upstands 14 and is bolted into position.

Description

DRAINAGE CHANNEL COVERS This invention relates to a drainage channel cover and further relates to a drainage channel whenever fitted with a channel cover of this invention.

A known form of drainage channel cover (or lid) is manufactured from a cast concrete (or cement) material, usually reinforced with a suitable material such as steel bars or glass or other fibres to impart sufficient strength to the concrete. Such a cover is located over surface water drainage channels provided in a paved surface such as a car-park, roadway or the like and has apertures through the cover to permit the free flow of water into the drainage channel.

It is further known to provide cast concrete drainage channel covers with an upper surface having a central region of a pre-determined width (with respect to the length of the channel) and side flanks at a lower level than the top surface of the central region, the water apertures being formed through the central region. When such covers have been laid over a drainage channel the surface covering of the paved area may be run over the side flanks of the covers up to the edges of the central region, to be flush with the top surface of the central region. Such covers have the advantage that irrespective of the width of the drainage channel to be covered, and so also irrespective of the overall width of the channel covers, only the relatively narrow central regions of the covers are exposed, which regions may be of constant width for all covers laid on a given site. This gives a particularly aesthetically leasing appearance for example to a car park, which may have a number of drainage channels laid thereacross, of different sizes.

The apertures through a drainage cover can present a hazard, especially to ladies wearing stiletto-heeled shoes. This is a particular problem in car-parks associated with shopping malls, supermarkets and so on. Consequently, manufacturers of drainage channel covers try to maintain the size of each aperture through a cover as small as possible to minimise the hazard. However, the total area of the apertures must be sufficiently large to permit the free flow of surface water, even under storm conditions, but it is difficult to cast a concrete material so as to have a large number of small openings. If a cover is made in this way, there is a tendency for the concrete material to crumble away around the apertures, especially since it is not possible to furnish the concrete with reinforcing bars around the apertures.

It is a principal aim of the present invention to address the above problems and so provide a drainage channel cover which is able to have sufficient capacity to cope with storm water conditions and yet which minimises the hazard to wearers of stiletto-heeled shoes.

According to the present invention, there is provided a drainage channel cover comprising a main lid body of a cast concrete material and adapted to engage the upper region of a channel, there being at least one opening through the lid body for the passage of water, and a metal grating secured to the upper surface of the main lid body over the at least one opening, which grating has a plurality of relatively small apertures through which surface water may pass to the at least one opening of the main lid body.

With the drainage channel cover of the invention, sufficiently small apertures to minimise the hazard to people walking over an area utilising the covers is achieved by providing a metal grating for the through-flow of water.

It is relatively easy to form in such a grating a plurality of small apertures whereby the combined area of all of those may be sufficient for storm water conditions. The grating is fitted to a cast concrete channel cover which may have therethrough only one, or relatively few, large openings and through which the water may flow to the channel over which the cover is fitted.

In a preferred embodiment of channel cover of this invention, the metal grating is releasably secured to the lid body. In this case, the lid body may define a pair of upstands extending parallel to one another, one to each side of the at least one opening through the lid body, so that the grating is received between the pair of upstands. Each such upstand may comprise a metal flange partially embedded in the concrete material of the lid body and against which an edge of the grating lies. Thus, the spacing between the two upstands should be essentially equal to the width of the grating, whereby the grating is a snug fit therebetween.

Preferably, the upper surface of the lid body to each side of the upstand is at a lower level than the upper surface of the grating, so that when the cover is installed over a drainage channel, a surface covering (such as of tarmac) may be applied over the upper surface of the lid body, flush with the upper surface of the grating. In this way, only the grating and the immediately adjacent upstand will be visible once the channel cover has been installed, for example in a car-park, and the width of the gratings may be constant throughout the car park, irrespective of the width of the drainage channels over which the covers are fitted. As mentioned above, this gives an aesthetically pleasing appearance to the overall installation.

Typically, the main lid body is of cast concrete with metal reinforcing bars embedded therein. Alternatively other similar materials could be used such as glass-reinforced cement (GRC). The main lid body may be of rectangular form and so also is the grating of rectangular form but of course of a lesser width. For most drainage channels, the lid body will be of elongate shape, in which case, it is convenient to have two metal gratings arranged end-to-end along the length of the main lid body and extending substantially to the end faces of the lid body whereby a plurality of covers may be laid end-to-end over a drainage channel, with the gratings disposed substantially continuously therealong. Then, the lid body may have one relatively large opening therethrough beneath each grating secured to the body; and the upper surface of the body below the grating may be profile to lead water passing through the grating down into the opening through the lid body.

In the case of a releasable grating, which gives access to the drainage channel therebelow, the grating may be secured to the lid body by means of at least one rotatable fastener having a threaded region below the grating and engagable with a nut furnished in the lid body during the manufacture thereof. Typically, two such fasteners may be provided, one at or adjacent each end of the grating. Other arrangements could be provided, permitting the releasable attachment of the grating to the cast concrete material of the lid body-for example, a fastener having a laterally projecting foot which engages in a slot in the lid body, upon rotation of the fastener.

The lower surface of the lid body may be profile to inter-engage with the upper surface region of the drainage channel with which the cover is used. Typically therefore the lower surface may have rebated side edges which bear on the upper edges of the drainage channel, with the portion between those rebated side edges giving lateral location for the cover.

This invention extends to a drainage channel whenever provided with a channel cover of this invention as described above.

By way of example only, one specific embodiment of drainage channel cover constructed and arranged in accordance with the present invention will now be described in detail, reference being made to the accompanying drawings in which :- Figure 1 is a longitudinal cross section through the cover, with only parts of the grating shown in section; Figure 2 is a transverse cross section through the cover, when installed in a car-park or similar paved area; Figure 3 is a detailed view on an enlarged scale of the upstand provided as a part of the lid body ; and Figures 4 and 5 are respectively plan and side views on a grating used with the cover of Figures 1 and 2.

The drainage channel cover shown in the drawings comprises a main lid body 10 made of a cast concrete material and provided with steel reinforcing bars (not shown) extending both along the length thereof and transversely. The lid body 10 is of elongate rectangular shape and typically may be 1000mm long, the width of the body depending upon the size of the drainage channel with which the cover is to be used. A typical small channel, may have an internal width of 150mm, the overall width of the body then being about 350mm; for a 600mm channel, the overall width of the lid body might be as large as 925mm. The lower surface of the body is profile as shown in Figure 2, and has rebates 11 on each side into which the upper edges of a drainage channel may be received, with lateral location being provided by the central region 12 between the rebates 11, engaging the internal side walls of the channel.

Two relatively large openings 13 are provided through the main body 10, each disposed generally centrally across the body and each disposed with its centre in from one end by approximately one quarter of the length of the overall channel. Each such opening 13 is of generally rectangular shape, but with rounded corners to avoid high stress regions in the cast concrete material.

During manufacture of the lid body, a pair of parallel metal upstands 14 are partially embedded in the concrete, as best seen in Figure 3, to extend for the full length of the lid body. Each upstand 14 has a leg region 15 embedded in the concrete and turned through 90 at its free end 16 to assist retention of the upstand in the concrete. The upper part of each upstand is turned back to lie along itself and defines a foot portion 17, on the side of the upstand nearer the opening 13. The central region of the lid body is provided with two cast-iron gratings 18, each resting along its two long edges on the foot portions 17 of the two upstands, and fitting between the upstanding portions so as to be located laterally on the cover. Each grating 18 has a plurality of slit-like apertures 19 arranged in a generally parallel disposition, laterally of the grating as shown in Figure 4. Fastenings 20 are provided adjacent each end of each grating, each of which fastenings has a head accessible from above the grating and a downwardly projecting shaft 21 threaded at its lower end and engageable in a nut 23 embedded in the cast concrete lid body. The upper surface of the lid body is profile below the gratings, downwardly towards the openings 13, to assist the direction of water flowing through the gratings down through the openings 13.

Each grating is substantially 500mm long such that two gratings are arranged end to end, over the central region of the 1000mm lid body. Then, when a plurality of bodies are placed end to end, the gratings will run more or less continuously over the drainage channel carrying the covers.

As shown in Figure 2, following installation of the cover over a drainage channel, a final top surface covering may be applied over the area within which the drainage channel has been provided. This top surface covering is shown at 25 in Figure 2, and it can be seen that it is run over the outer region of the lid body, up to the upstand 14, to be flush with the upper surface of the gratings 18. Thus, essentially all that will be visible following completion of the installation are the gratings 18-and these all may be of the same width, irrespective of the width of the underlying lid and also of the underlying drainage channel.

It will be appreciated that the slots 19 through the gratings are relatively narrow, but that the total area of the slots of one grating is relatively large, so permitting the drainage of water even under severe conditions. The total area of the slot-like apertures 19 of one grating may be comparable to the effective area of one of the openings 13, through the lid body, so that adequate drainage may be achieved. Moreover, in view of the relatively narrow width of the apertures 19, the gratings present a minimal hazard to wearers of stiletto-heeled shoes.

Claims

CLAIMS 1. A drainage channe ? cover comprising a main lid body of a cast concrete material and adapted to engage the upper region of a channel, there being at least one opening through the lid body for the passage of water, and a metal grating secured to the upper surface of the main lid body over the at least one opening, which grating has a plurality of relatively small apertures through which surface water may pass to the at least one opening of the main lid body.
2. A drainage channel cover as claimed in claim 1, wherein the metal grating is releasably secured to the main lid body.
3. A drainage channel cover as claimed in claim 2, wherein the lid body defines a pair of upstands extending parallel to one another one to each side of the at least one opening through the lid body, the grating being received between the pair of upstands.
4. A drainage channel cover as claimed in claim 3, wherein each upstand is defined by a metal flange partially embedded in the material of the lid body and against which an edge of the grating lies.
5. A drainage channel cover as claimed in claim 4, wherein each upstand further defines a surface on which the metal grating bears.
6. A drainage channel cover as claimed in any of the preceding claims, wherein the upper surface of the main lid body to each side of the grating is at a lower level than the upper surface of the grating so that when installed over a drainage channel a surface covering may be applied over the upper surface of the lid body, flush with the upper surface of the grating.
7. A drainage channel cover as claimed in any of the preceding claims, wherein the main lid body is of elongate rectangular form, and the grating is also of elongate rectangular form but of a lesser width.
8. A drainage channel cover as claimed in claim 7, wherein two gratings are arranged end-to-end along the length of the main lid body and extending substantially to the end faces of the main lid body whereby a plurality of covers may be laid end-to-end over a drainage channel, with the gratings disposed substantially continuously therealong.
9. A drainage channel cover as claimed in any of the preceding claims, wherein the main lid body defines one relatively large opening therethrough beneath the or each grating secured to the lid body.
10. A drainage channel cover as claimed in claim 9, wherein the upper surface of the lid body below the grating is profile to lead water passing through the grating down into the opening through the lid body.
11. A drainage channel cover as claimed in any of the preceding claims, wherein the grating has a plurality of rectangular openings therethrough all arranged parallel to one another transverse to the length of the lid body.
12. A drainage channel cover as claimed in any of the preceding claims, wherein the grating is secured to the lid body by means of at least one rotatable fastener having a foot region below the grating and engageable with a slot in the lid body upon rotation of the fastener.
13. A drainage channel cover as claimed in any of the preceding claims, wherein the lower surface of the lid body is profile to fit with a drainage channel, with the central portion of the lid body providing lateral location for the lid by engaging the internal side walls of the channel.
14. A drainage channel cover as claimed in any of the preceding claims, and substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.
15. A drainage channel in combination with a channel cover as claimed in any of claims 1 to 13 and received on the upper edges of the side walls of the channel.