WO1999039056A1

WO1999039056A1 - Water drainage channel

Info

Publication number: WO1999039056A1
Application number: PCT/AU1999/000068
Authority: WO
Inventors: Nigel Nattrass
Original assignee: L.N. Nattrass Trading Pty. Ltd.
Priority date: 1998-01-30
Filing date: 1999-02-01
Publication date: 1999-08-05
Also published as: AUPP157398A0; GB2348913A; GB2348913B; GB0018067D0

Abstract

A surface water drainage channel is moulded from plastics material to have a base (1) and upwardly depending side walls (2) having lands (3) adapted to support the edges of an elongate drain grate. The side walls have outwardly extending flanges (5) to restrain the channel from floating when concrete is poured about the channel. The channel is moulded with portions of reduced thickness forming hinges (6) between the side walls (2) and base (1) enabling the channel to be moulded flat in a simple two-part die with the side walls folded up through 90° before use.

Description

- 1 -

WATER DRAINAGE CHANNEL FIELD OF THE INVENTION This invention relates to a water drainage channel and has been devised particularly though not solely as a surface water drainage channel intended to be located in a poured in-situ concrete situation.

BACKGROUND OF THE INVENTION There are many situations where it is necessary to provide surface water drainage channels in concrete surfaces such as driveways or parking areas or in many industrial situations. It is common to provide water drainage channels by inserting suitable formwork to define a channel before pouring the concrete pad or surface, and then placing metal grating members over the channels so formed to support passing traffic. The formwork may be formed from folded sheet metal or moulded from plastics materials or polymer concrete, and is commonly left in-situ to define the surface of the channel after the concrete has been poured. When forming such surface water drainage channels from lightweight materials such as plastics materials, it is necessary to provide outwardly extending flanges or the like, typically from the side walls of the channel so that a portion of the fluid concrete lies on top of the flange when poured restraining any upward movement of the channel member. This is necessary because a channel is inherently buoyant in recently poured fluid concrete and tends to "float" to the surface of the concrete unless restrained by flanges of this nature. When moulding surface water drainage channels from plastics materials by an injection moulding process it is extremely difficult to provide the necessary protruding flanges on the outer faces of the side walls due to the necessity to be able to "draw" the finished product from the injection moulding die. Such difficulties have been proposed to be overcome by the use of multiple part dies, - 2 - but these are extremely expensive to manufacture and significantly increase the finished cost of the product.

SUMMARY OF THE INVENTION The present invention therefore provides a surface water drainage channel manufactured from a plastics material and comprising in cross-section a base and upwardly depending side walls having lands at their upper edges adapted to support the edges of an elongate drain grate, characterised by the provision of portions of reduced thickness at the junction of the base and the side walls forming deformable hinges in the plastics material enabling the channel to be manufactured by moulding with the side walls substantially parallel to the base member and then hinged upwardly to form a channel section. Preferably the side walls are provided with outwardly protruding elongate flanges extending along the length of the channel .

Alternatively other substantially horizontal projections from the side walls may be provided, adapted to prevent a formed channel from floating in a fluid concrete pour.

Preferably the plastics material is moulded in the area of the deformable hinges to form portions of increased thickness either side of the deformable hinge which are configured to abut one another when the side walls are hinged upwardly to a position substantially perpendicular to the base member .

BRIEF DESCRIPTION OF THE DRAWINGS Notwithstanding any other forms that may fall within its scope, one preferred form of the invention will now be described by way of example only with reference to the accompanying drawings in which : -

Fig. 1 is a diagrammatic perspective view of a portion of surface water drainage channel according to the invention; Fig. 2 is a cross-section to an enlarged scale through the deformable hinge between the base member and side wall of the channel shown in Fig. 1 with the side wall substantially coplanar to the base member; Fig. 3 is a diagrammatic cross-section of the surface water drainage channel shown in Fig. 1 in a substantially flat "as moulded" configuration;

Fig. 4 is a plan view of a section of the channel shown in Fig. 3; Fig. 5 is a side view of the channel shown in Fig. 1; Fig. 6 is a cross-sectional view through the channel showing the use of an assembly handle;

Fig. 7 is a scrap perspective view of the end of the assembly handle shown in Fig. 6; Fig. 8 is a scrap view similar to Fig. 2 but showing an alternative form of integrally moulded "living" hinge construction; and

Fig. 9 is a side view of the assembly handle. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the preferred form of the invention a drainage channel is moulded from plastics material which may be any suitable material but which is typically a structurally foamed polypropylene. The channel, in cross-section, has a substantially planar base member 1 and upwardly depending side walls 2 having lands 3 at the upper edges adapted to support the edges of an elongate drain grate. The lands 3 are typically provided with upwardly extending flanges 4 to locate the grate, the flanges 4 being typically the same depth as the thickness as the grate as can be seen in Fig. 6. The elongate drain grate is typically cast or fabricated from metal such as steel and is typically galvanised before use.

In order to prevent the drainage channel "floating" in fluid poured concrete, the side walls are provided with outwardly extending flanges 5 which will be immersed in the - 4 - concrete so that a portion of the concrete is poured over their upper surfaces . Such flanges keep the channel from floating during a concrete pour and are important in maintaining the upper edges of the grate locating flanges 4 level with the intended surface of the concrete pad during pavement construction.

Although the flanges 5 in Fig. 1 are shown at different heights on either side of the channel, this is for illustrative purposes only to demonstrate that the flange can be lodged in different positions and the flanges in a manufactured channel would typically be at the same height on either side of the channel as shown in Fig. 6. In order to be able to economically manufacture the drainage channel shown in Fig. 1 using an injection moulding process, the corners 6 between the base member 1 and the side walls 2 are formed with a reduced thickness so creating deformable hinges in the plastics material . This enables the channel to be moulded with the side walls substantially parallel to the base member, and typically coplanar with the base member, as shown in Fig. 3.

Fig. 2 is an enlarged cross-section through the hinge of reduced thickness formed between the side wall 2 and the base member 1.

As can be readily seen from Fig. 3, by moulding the drainage channel in this "flat" configuration, it is possible to use a simple two-part die with the necessary "draw" for easy product removal while still making provision for the outwardly extending flanges 5.

In Fig. 8, a further version of the hinge 6 is shown in which enlarged surfaces 7 are provided adjacent the integrally moulded "living" hinge 6 and configured so that the surfaces abut when the side wall 2 is bent upwards through 90° to be substantially perpendicular to the base member 1. This hinge configuration enables the drainage channel to be readily formed to the configuration shown in Fig. 1 without the use of jigs or other aligning apparatus. - 5 -

A hinge of this type when folded up into the channel configuration is shown at 10 in Fig. 6.

It is a further feature of the "flat" manufacture in the configuration shown in Figs. 3 and 4, that large quantities of drainage channel in this form can be packed into a small volume for transportation to the intended usage site.

Although the hinges 6 are preferably located at the junction of the side walls 2 and the base 1, it will be appreciated that the same benefit could be obtained by having upturned side edges in the base with the hinge located at the junction of the upturned side edges and the side walls.

To facilitate the handling of the drainage channel during a concrete pour, and to provide support of the metal grate, assembly handles 8 (Figs. 6, 7 and 9) can be provided having elongate ends 9. The side walls 2 of the drainage channel are provided with horizontally extending slots 11 through which the elongate ends 9 may be inserted when in a horizontal configuration and the assembly handle then rotated to the position shown in Figs. 6 and 7 to retain the assembly handle in the position shown in Fig. 6.

The handle may be provided with a flange 9A spaced from the elongate end 9 by the thickness of side wall 2, to prevent wet concrete entering through the hole in the side wall when the handle is turned ninety degrees to its locked position.

The assembly handle can be moulded from a suitable plastics material and provided with a moulded-in steel nut 8A at its mid-point adapted to receive a bolt to secure the grate to the channel by passing through the channel and into the nut in the handle .

In the preferred form of the invention, the handle is able to form a securing point for the grate 12 (Fig. 6) by the provision of upwardly extending arms 13 having inwardly protruding barbs 14 at their upper ends. The barbs are - 6 - adapted to engage either side of a central rail 15 in the grate 12 in use, to lock the grate securely in position. Once the assembly handles have been engaged with the channel and rotated to the locked in position shown in Fig. 6, they are used to handle and place the channel. The grate can be engaged at any time, either before or after pouring concrete about the channel .

In this manner the assembly handle not only provides a convenient method of handling an assembled channel but also provides a secure location and retention means for the metal grate.

As a further feature, the lands 3 may incorporate scalloped out portions in their under surfaces at predetermined intervals to leave sections of reduced thickness at intervals along the length of the channel . By scalloping out the section that is immediately under the steel grate in use, concrete can be poured so that it flows into the scalloped out sections to reduce the effect of compression of the structurally foamed plastic when traffic runs over the grate. The scalloped sections are typically 5mm in length every 25mm along the length of the channel and are the total width of the support land 3 underneath the grate .

It is a further feature of the invention that the die used to manufacture the channel in the form shown in Figs.

3 and 4 can be easily adapted by inserting a tool to provide alternative depths of channel enabling different product sizes to be manufactured using the same basic die set. In this manner a water drainage channel can be readily manufactured from injection moulded plastics material in an economical manner while providing a superior product that is inexpensive to transport, lightweight and easy to handle on site and able to withstand the loading imposed by heavy traffic.

Claims

- 7 -CLAIMS : -

1. A surface water drainage channel manufactured from a plastics material and comprising in cross-section a base and upwardly depending side walls having lands at their upper edges adapted to support the edges of an elongate drain grate, characterised by the provision of portions of reduced thickness at the junction of the base and the side walls forming deformable hinges in the plastics material enabling the channel to be manufactured by moulding with the side walls substantially parallel to the base member and then hinged upwardly to form a channel section.

2. A surface water drainage channel as claimed in claim 1 wherein the side walls are provided with outwardly protruding members having at least one upwardly facing surface.

3. A surface water drainage channel as claimed in claim 2 wherein the outwardly protruding members comprise elongate flanges extending along the length of the channel .

4. A surface water drainage channel as claimed in any one of the preceding claims wherein the plastics material is moulded in the area of the deformable hinges to form portions of increased thickness either side of the deformable hinge which are configured to abut one another when the side walls are hinged upwardly to a position substantially perpendicular to the base member.

5. A surface water drainage channel as claimed in any one of claims 1 to 3 wherein the base incorporates upturned side edges with the deformable hinges located at the junction of the upturned side edges and the side walls.

6. A surface water drainage channel as claimed in claim 5 wherein the plastics material is moulded in the area of the deformable hinges to form portions of increased thickness either side of the deformable hinges which are configured to abut one another when the side walls are hinged upwardly to a position substantially parallel to the upturned side edges . - 8 -

7. A surface water drainage channel as claimed in any one of the preceding claims when provided with one or more assembly handles engageable at either end thereof with the side walls of the channel and extending across the channel when so engaged with the side walls hinged upwardly to form the channel section.

8. A surface water drainage channel as claimed in claim 7 wherein the assembly handles are engageable with the side walls of the channel by way of slots in the side walls engageable with elongate protrusions at each end of the handle .

9. A surface water drainage channel as claimed in either claim 7 or claim 8 wherein the handles incorporate engagement means for a grate adapted to be supported on the lands of the channel.

10. A surface water drainage channel as claimed in claim 9 wherein the engagement means comprise a nut engageable with a bolt passing through the grate.

11. A surface water drainage channel as claimed in any one of the preceding claims wherein the lands are moulded with scalloped portions of reduced thickness on their undersides, providing relatively thinner load bearing portions between a grate supported by the lands and an underlying concrete substrate.