GB2327447A

GB2327447A - Drainage grid assembly

Info

Publication number: GB2327447A
Application number: GB9714924A
Authority: GB
Inventors: Stuart Entwhistle
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-07-16
Filing date: 1997-07-16
Publication date: 1999-01-27
Anticipated expiration: 2017-07-16
Also published as: GB9714924D0; GB2327447B

Abstract

A drainage grid assembly comprises a frame (10) defining an opening and a grid (12) located within the frame (10) as a cover to the opening. At least one hooked element (14) extends from the frame (10) through an aperture (16) of the grid (12) so as to hingedly connect the grid (12) to the frame (10). With this arrangement at least part of the grid (12) cannot be detached or lifted free of the frame (10), but can be pivoted relative thereto to permit access to the opening. The hooked element (14) may be generally U-shaped.

Description

A DRAINAGE GRID ASSEMBLY This invention relates to a drainage grid assembly comprising a frame defining an opening into a drainage system and a grid locating within said frame as a cover to said opening. The purpose of the grid is, self-evidently, to remove the danger which an unprotected opening would present to passing pedestrians and vehicles, while still allowing ready drainage of water from the surrounding area as well as access to the drainage system by way of the opening when the cover is removed.

One widely used type of grid is in the shape of a rectangle with a plurality of elongate slots therethrough, the slots extending parallel with opposing sides of the grid. Around its periphery the grid merely rests on a shoulder provided around the inner edge of the frame defining the opening to which the grid provides a cover. Although such grids are heavy, being formed of cast iron, they can be moved by lifting if access is required to the drainage system, for example for inspection or repair.

Unfortunately, such grids are also a common target for thieves as they have a reasonable scrap value when melted down.

Furthermore, they are proving very expensive to replace since the design is now obsolete so that local authorities tend to replace the entire assembly comprising a frame, which is also of cast iron, attached to a new design of hingedly connected grid. Thus the cost in materials and labour for installation is very considerable.

Another known style of grid is formed in two parts, each of triangular shape and fitting together along their longest sides so as to form a rectangle. Each part is formed with a plurality of elongate slots extending from the apex towards the hypotenuse.

Exactly the same problems arise in connection with theft and replacement of these grids.

An object of the present invention is to provide simple addition to the known grid assembly, of either of the above mentioned styles, which would prevent removal of the grids, yet still allow for access to the opening when required.

According to the invention a drainage grid assembly comprises a frame defining an opening, a grid locating within said frame as a cover to said opening and at least one hooked element extending from the frame and through an aperture of the grid so as hingedly to connect the grid to the frame such that the grid, or at least part of the grid, cannot be detached or lifted free of the frame, but can be pivoted relative thereto to permit access to the opening.

The hooked element may be approximately U-shaped, but that is not essential so long as it suffices to connect the grid to the frame in such a manner that it cannot be detached or lifted free, but can be pivoted relative thereto, as first mentioned.

In most embodiments, the hooked element will comprise a portion extending inwardly from the frame above the grid, a portion extending downwardly through one aperture of the grid, and a portion extending back towards the frame below the grid.

Also, in most embodiments, two such hooked elements will be provided. In this respect, when two such hooked elements are added to the first type of grid assembly mentioned above, they will both be secured to the frame at the same side thereof, for example by welding thereto at spaced locations. On the other hand, in the case of the second type of grid mentioned above, the two hooked elements will generally be located adjacent to opposing corners of the frame, so that each one serves as a retainer/hinge means for respective triangular parts of the complete grid.

The invention will be more readily understood by reference to the accompanying drawing, in which; Fig. 1 is a perspective view of a first drainage grid assembly in accordance with the invention; and Fig. 2 is a comparable view of a second embodiment of a drainage grid assembly in accordance with the present invention.

Referring first to Fig. 1, a grid assembly comprises a frame (10) formed of cast iron, defining an opening to a drainage system, a grid (12) which seats in the mouth of the opening, as a cover thereto, and a pair of hooked elements (14). Both the frame and grid are conventional.

The frame is formed with a shoulder around its inner edge upon which the outer periphery of the grid (12) rests such that the upper surface of the grid is generally flush with the upper surface of the frame (10). To prevent removal of the grid, the two hooked elements (14) are welded onto one side of the frame (10) at spaced locations. Each hooked element (14) is installed so as to extend from the frame (14) and through a respective aperture (16) of the grid so as hingedly to connect the grid (12) to the frame (10). The hooked elements (14) must be of sufficient length and of an appropriate curved or angled configuration to prevent the grid (12) being lifted free from the frame (10) whilst permitting the grid (12) to be raised at one edge (opposite to the edge over which the hooked elements (14) locate) and pivoted to allow access to the opening therebelow.

The grid (12) is shown as having a pair of opposing lugs (18) resting in respective recesses in the frame (10). These facilitated pivoting of the grid (12) (prior to installation of the hooks (14)), but did not prevent removal/theft of the grid (12), as the hooks (14) do. Other versions of grid may not have such lugs.

Referring now to Fig. 2, the grid (22) in this case is formed in two parts, each being triangular and providing one half of the overall rectangular form of the grid. In other words, the grid (22) is split diagonally and the apertures (26) extend from the apex of each triangular part to a diagonal cross piece (28) which abuts the other part.

In other respects, the grid assembly in Fig. 2 is similar to that in Fig. 1, with the frame (20) being of substantially the same form and the two part grid (22) again seating on a shoulder so that it lies with its upper surface substantially flush with the surface of the frame (20).

The positioning of the hooked elements (24), when these are installed to prevent theft of the grid (22), are somewhat different. They are secured, again suitably by means of welding, adjacent the opposing corners of the frame (20) where the apexes of the triangular grid halves are positioned. The two parts of the grid (22) can then each be lifted from the diagonal cross piece (28) and pivoted relative to the hooked element (24) to allow access to the opening therebelow.

Other variations in the details of the grid and the hooked element are possible within the scope of the invention as the foregoing is only illustrative, not limitative.

Claims

1. A drainage grid assembly comprising a frame defining an opening, a grid locating within said frame as a cover to said opening and at least one hooked element extending from the frame and through an aperture of the grid so as hingedly to connect the grid to the frame such that the grid, or at least part of the grid, cannot be detached or lifted free of the frame, but can be pivoted relative thereto to permit access to the opening.

2. An assembly as claimed in claim 1 wherein the hooked element is generally U-shaped.

3. An assembly as claimed in claim 1 or 2 wherein the hooked element comprises a portion extending inwardly from the frame above the grid, a portion extending downwardly through one aperture of the grid, and a portion extending back towards the frame below the grid.

4. A drainage grid assembly substantially as hereinbefore described with reference to and as illustrated by Fig. 1 or Fig. 2 of the accompanying drawing.