AU740793B2 - Overflow outlet - Google Patents

Description

1

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: RODNEY GEORGE WADE 06.

00 9 Actual Inventor: Address for Service: Invention Title: RODNEY GEORGE WADE CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

OVERFLOW OUTLET Details of Associated Provisional Application: No. PP5320 filed 19 August 1998 The following statement is a full description of this invention, including the best method of performing it known to me: OVERFLOW OUTLET BACKGROUND OF THE INVENTION This invention relates to overflow outlets and is particularly concerned with overflow outlets for water storage tanks.

There are a number of problems with conventional overflow outlets and also in the way in which they are installed. There are two main methods for installation which depend on the design of the storage tank. For a typical cylindrical walled tank, a hole is drilled in its sidewall, approximately 50mm from the top, and an appropriately sized 450 bend is inserted so that the outer end is hard up against the sidewall. Silicone 15 is then smeared around the fitting on the inside of the tank to form a seal and to prevent the fitting from coming out.

One problem with this installation is that the flange on the exteriorly projecting female end of the fitting has only a 1 or 2mm step and if the hole is not accurately drilled, the fitting can end up inside the tank when any pressure is applied to it as for instance, when an overflow pipe or other attachment is being 25 installed.

Another problem with the conventional installation is that for "one piece" storage tanks, fitting is time consuming and awkward as the installer must enter the tank by way of an access hole to apply the silicone seal. A still further problem is that for the majority of water storage tanks which are manufactured form polyethylene, silicone does not adhere very well to the polyethylene and leakage will eventually occur around the fitting.

The other main method of installation is that which occurs at the place of manufacture rather than the place where the water storage tank is to be used. These are the so-called "one piece" tanks. Here the outlets typically comprise a flat-flanged fitting which is installed to the wall of the tank on the outside using screws. Such outlets protrude to such an extent that they impede the transportation of the tank and are often broken off or damaged during transport.

A further disadvantage of all such installations is that the maximum capacity of the storage tank cannot be utilized as no matter how close to the top of the sidewall the outlet fitting is installed, there will always be a region equivalent to that occupied by the diameter of the outlet fitting, and the space under 15 the domed top, which the water cannot occupy. This can be quite a significant volume. For instance, for a standard 20,000 litre tank having a 90mm outlet and 120mm riser, the holding capacity which cannot be utilized amounts to approximately 1,400 litres of water.

OBJECT OF THE INVENTION It is therefore an object of the invention to provide an overflow outlet which addresses the above problems and/or provides the public with a useful alternative.

SUMMARY OF THE INVENTION According to one aspect of the present invention there is provided an overflow outlet fitting for a storage tank, said overflow outlet comprising a 900 bend having a male end and a female end, characterized in that offset from the female end, on the exterior circumference thereof, is a plurality of lugs which are wedge-shaped in cross-sectional profile, and further characterized in that between the lugs and the female end of the bend is an exterior circumferential flange, wherein the lugs and the flange define therebetween a region in which a wall of a storage tank can be captured when the fitting is inserted into a commensurate opening in the wall, male end first.

According to another aspect of the present invention there is provided a method for installing the overflow outlet fitting defined above, which method comprises the steps of: forming a hole in the top of the storage tank wall which is of the same diameter as the male end of the fitting, optionally inserting a gasket seal against the flange on the fitting, between the flange and the lugs, 15 placing the fitting into the hole, male end first, rotating the fitting until the uppermost lug comes into contact with the storage tank wall, and forcing the fitting further into the hole to force the lugs through the hole until the wall of the storage tank meets the flange and is retained by the lugs and the flange.

S* DETAILED DESCRIPTION OF THE INVENTION The wedge-shaped lugs are preferably formed with a plurality of parallel serrations on their outwardly facing surfaces. These serrations will tend to cut a shallow groove in the side wall of the tank upon insertion so that the lugs will lock therein to ensure that the fitting is held tight irrespective of varying wall thicknesses of the tank which guarantees a water tight seal at all times even with the varying expansion rates between different plastics materials from which the tank and fitting may be fabricated.

The length of the male section of the fitting can be extended using available fittings, or can be shortened by cutting; thereby setting the uppermost level of water required to be held in the storage tank.

If necessary, the circumferential flange on the female end of the fitting can be formed to such a size that it can provide a region in which screws can be inserted should additional fixing to the tank wall be required.

The number of lugs formed on the surface of the fitting will generally vary from 2 to 6 with the preferred number being 4. In the case of 4 lugs, the *5 lugs will be evenly spaced with those located at 12 15 o'clock and 6 o'clock having a top separation from the flange of 7mm and a bottom separation of 4mm, and the lugs located at 9 o'clock and 3 o'clock having a top separation of 7mm and a bottom separation of 4mm.

20 The fitting can be easily installed, such as by knocking it in with a hammer, and is of such a size that it does not protrude beyond the widest region of the oo sidewall of most corrugated storage tanks. The fitting can also be factory fitted without risk of dislodgement 25 or damage; is fitted from the exterior of the storage tank; and does not require the tank to be entered for any part of the installation process.

DESCRIPTION OF THE DRAWINGS Figure 1 is a side-on cross-sectional view of an overflow outlet fitting according to the present invention; and Figure 2 is a side-on cross-section view of a water storage tank with the fitting depicted in Figure 1.

DESCRIPTION OF PREFERRED EMBODIMENT A preferred embodiment of the invention will now be described with reference to the accompanying drawings, in both of which like reference numerals refer to like parts.

The overflow outlet fitting, indicated generally at 10, comprises a 90mm 900 hd polyethylene bend having a male end 11 and a female end 12. Four wedge-shaped lugs, two of which are illustrated at 13 and 14, project from the perimeter of the fitting at equispaced locations. These lugs include serrated surfaces 16 for cutting a shallow groove in the tank wall upon insertion.

A flange 17 circumscribes the female end of the fitting and defines a space 18 with the respective lugs for accommodating the side wall 20 of a water storage tank 21 as depicted in Figure 2. Openings, not illustrated, can be provided in the flange wall to facilitate the fixing of the outlet fitting to the wall 20 of the storage tank by screws or the like, should this be necessary for any particular installation.

"CC Installation of the overflow outlet fitting comprises forming a hole in the sidewall 20 of the water 25 storage tank and inserting the fitting, male end first.

If necessary, a gasket (not shown) or a bead of silicone (also not shown) is previously placed around the inner face 22 of the flange to ensure the absolute integrity of the joint when complete.

The fitting is rotated upon insertion to ensure the final orientation with the male end facing upwards as depicted in Figure 2. This rotation causes a grooving of the sidewall of the tank by the serrations 15. The fitting is finally forced home by hitting it with a hammer so as to produce an integral sealing with the water tank. No further sealing is required.

It will be readily apparent from Figure 2 that the fitting enables a higher level of water, depicted by level to be stored in the tank than with a conventional overflow which would have a maximum level depicted by level That is, in a conventional system, the fitting would present a circular opening into the tank and the lowermost level of the opening would determine the level of water in the tank.

The fitting furthermore does not have the installation or transport problems of the previously described known overflows and thereby meets the objects of the invention.

go.co: Whilst the above has been given by way of illustrative example of the invention, many modifications and variation may be made thereto by persons skilled in the art without departing from the broad scope and ambit of the invention as herein set forth.

S o

Claims (7)

1. An overflow outlet fitting for a storage tank, said overflow outlet comprising a 900 bend having a male end and a female end, characterized in that offset from the female end, on the exterior circumference thereof, is a plurality of lugs which are wedge-shaped in cross- sectional profile, and further characterized in that between the lugs and the female end of the bend is an exterior circumferential flange, wherein the lugs and the flange define therebetween a region in which a wall of a storage tank can be captured when the fitting is inserted into a commensurate opening in the wall, male end first.

2. An overflow outlet fitting as claimed in claim 15 i, wherein the lugs are formed with serrations on their outwardly facing surfaces.

3. An overflow outlet fitting as claimed in claim 1 or claim 2, wherein there are from 4 to 6 lugs formed 20 on the fitting.

4. An overflow outlet fitting as claimed in any one of the preceding claims, wherein the lugs are evenly spaced about the fitting.

A method for installing the overflow outlet fitting as defined in any one of the preceding claims, which method comprises the steps of: forming a hole in the top of the storage tank wall which is of the same diameter as the male end of the fitting, optionally inserting a gasket seal against the flange on the fitting, between the flange and the lugs, placing the fitting into the hole, male end first, rotating the fitting until the uppermost lug comes into contact with the storage tank wall, and forcing the fitting further into the hole to force the lugs through the hole until the wall of the storage tank meets the flange and is retained by the lugs and the flange.

6. An overflow outlet fitting for a water storage tank substantially as herein described with reference to the accompanying drawings.

7. A method for installing the overflow outlet fitting as defined in any one of claims 1 to 4 or 6, 15 substantially as herein described with reference to the accompanying drawings. DATED this 16th day of August 1999 ":'RODNEY GEORGE WADE 20 By his Patent Attorneys CULLEN CO. oO*