WO1998050643A1

WO1998050643A1 - Water waste preventer

Info

Publication number: WO1998050643A1
Application number: PCT/GB1998/001311
Authority: WO
Inventors: John Robert Smith
Original assignee: Aw Creative Technologies Limited
Priority date: 1997-05-07
Filing date: 1998-05-06
Publication date: 1998-11-12
Also published as: GB9709227D0; AU7343198A

Abstract

A valve (3) for a toilet cistern including means for substantially preventing water refilling the cistern until substantially all the water in the cistern has been discharged. Preferably the means includes a separate chamber (7) provided within the cistern and a float operated inlet valve (3), the float (1) of which floats on the surface of water contained in the chamber (7). The chamber (7) includes an outlet (8) through which the water is discharged more slowly than water is discharged from the cistern.

Description

WATER WASTE PREVENTER BACKGROUND TO THE INVENTION

Flush toilets include a cistern which holds a volume of water, and an outlet such as a siphon, flap valve or drop valve which is arranged to discharge the volume of water into the toilet bowl. Due to the initial head of water in the cistern, the siphon or other outlet initially discharges the water at a high rate into the toilet bowl to clean the toilet bowl . It is this high rate water discharge that is th emost effective at cleaning the bowl. A float valve, for example a "Torbeck" type valve, is provided to control the refilling of the cistern. The float of the float valve floats on the surface of the water in the cistern, and falls as the water level in the cistern falls. As the float is lowered, an inlet valve is opened allowing the cistern to refill. When the water level in the cistern reaches a predetermined upper level, the height of the float causes the inlet valve to close.

The volume of water required to flush a toilet depends on the size and design of the toilet bowl. The required volume of water for any particular design of toilet bowl is determined empirically from a series of tests, for example those specified in British Standard 7358. The cistern and upper level of the float valve is determined to ensure that the required volume of water is flushed into the toilet bowl .

A problem with the conventional flushing system is that the float valve opens the water inlet as soon as the water level in the cistern falls below the predetermined upper level, which occurs shortly after water starts being discharged from the cistern. Accordingly, water introduced into the cistern after the flushing commences is discharged into the toilet bowl together with the predetermined volume of water contained initially in the cistern. This additional water discharged into the toilet bowl is only discharged at low velocity. Therefore, this additional water introduced into the cistern during flushing is largely wasted.

GB-A-2, 173 , 525 discloses a different type of toilet cistern which comprises a water storage tank and a flush tank. An outlet is provided from the flush tank to the toilet bowl, and an outlet is provided from the water storage tank to the flush tank. A plunger is connected to two valve members, one of which is associated with each outlet. Normally, the outlet between the storage tank and flush tank is open, allowing water from the storage tank to fill the flush tank, and the outlet from the flush tank is closed. On operation of the plunger, the valve member closes the outlet between the storage tank and flush tank, and the outlet from the flush tank is opened, allowing water from the flush tank to be dispensed into the toilet bowl. At this time, no water can enter the flush tank from the storage tank. When the plunger is released, the outlet from the flush tank is closed and the outlet from the storage tank opened to refill the flush tank. Whilst this system prevent the refilling of the flush tank whilst water is being discharged into the toilet bowl, the valve members are purely manually operated by the plunger, and accordingly, early release of the plunger, leads to an insufficient quantity of water being flushed. SUMMARY OF THE PRESENT INVENTION

According to the present invention means suitable for use in a toilet cistern is provided to delay the opening of the water inlet to the cistern until water initially in the cistern has been substantially discharged. As water is only introduced into the cistern after the water initially in the cistern has been substantially discharged, only the water initially in the cistern is discharged into the toilet bowl, and therefore the volume of water used to flush the toilet is accurately controlled. This limits the amount of wasted water.

Preferably the means to delay the opening of the water inlet comprises a chamber including an outlet through which water contained in the chamber drains at a rate slower than the rate at which water is discharged from the cistern, and is arranged so that the float of a float valve floats on the surface of the water in the chamber. In this way, as water is discharged from the cistern into the toilet bowl by flushing the toilet, the water level in the chamber falls at a slower rate than the level of the water in the cistern, and therefore the float is lowered more slowly than if it were floating on the surface of the water in the cistern. In this way, the inlet is not opened as quickly as is the case where the float floats on the surface of the water in the cistern.

Preferably the outlet of the chamber is an orifice. It is advantageous that the rate at which water flows from the chamber is variable, for example by providing a variable size orifice, which may be achieved by providing a plurality of plugs having different diameter through- holes which can be fitted into a fixed aperture, or a plurality of orifices one of more of which may be closed to vary the rate which water is discharged from the chamber.

By allowing the rate at which water is discharged from the chamber to be varied, the point at which the water inlet to the cistern is opened can be controlled. It is important to be able to vary the point at which the water inlet to the cistern is opened during the flushing of the toilet depending on the frequency of use of the toilet. For public toilets which are flushed frequently, the refilling of the cistern should begin early in the flushing, whereas for domestic toilets which are flushed less frequently it is not necessary to begin refilling the cistern as early, and therefore a greater water saving is possible.

Advantageously, the height of the chamber with respect to the bottom of the cistern is variable. This allows further control of when the water inlet to the cistern is opened. In this case, the chamber may be mounted on a vertical guide, and include a means to releasably secure the chamber to the guide, for example in the form of a threaded fastener such as a fly nut. In this case, it is beneficial that the chamber is also horizontally movable with respect to the vertical guide to allow the float to be positioned centrally within the chamber. It is preferred that the chamber can be fitted to an existing valve in a toilet cistern to allow for existing cisterns to be modified to give the advantages to the present invention.

BRIEF DESCRIPTION OF THE DRAWING

The present invention will now be described in accordance with the accompanying figure which shows a cross-sectional view of an inlet valve for a toilet cistern incorporating the present invention.

DETAILED DESCRIPTION OF A PREFERRED EXAMPLE

A conventional "Torbeck" water inlet valve for use in a toilet cistern comprises a float 1 connected to a support bar 2, which is connected to a seal (not shown) closing a water inlet 3. In use, as the water level on which the float 1 floats falls, the float is lowered, causing the support bar 2 to pivot downwards, thereby opening the water inlet 3 to allow water to refill the cistern in which the valve is provided. In accordance with the present invention as shown in the Figure, a vertical guide 4 is fixed relative to the water inlet by a support 5 mounted on the inlet pipe 3. A float chamber 7 is mounted on the vertical guide by an adjustable bracket 6. The vertical and horizontal position of the chamber is adjusted by releasing a threaded fly nut 9 to adjust the bracket 6. The float chamber 7 includes an outlet aperture 8. One of a number of plugs, each with a different size through-hole, is plugged into the outlet aperture 8 to vary the effective size of the outlet 8. In use, the toilet cistern contains a fixed volume of water which is determined to be that required to flush the toilet bowl. The chamber 7 contains part of that water. The float 1 floats on the surface of the water in the float chamber 7 at such a height that the inlet 3 is sealed, thereby prevent additional water being introduced into the cistern. When the toilet is flushed, water within the cistern is discharged, for example by a siphon or through a flap or drop valve, into the toilet bowl. As the water level in the cistern falls, water from within the chamber 7 is discharged through the outlet 8 into the cistern, causing the water level in the float chamber 7 to fall. As the water level in the chamber 7 falls, the float 1 is lowered. When the water level reaches a predetermined lower level, the horizontal bar 2 will be at such an angle that the seal over the water inlet opens allowing water from the inlet to refill the cistern. As the outlet 8 has a small diameter, the rate at which the water in the float chamber 7 is discharged into the cistern is much slower than the rate at which the water is discharged from the cistern into the toilet bowl. Therefore, the water inlet 3 is not opened until much later compared to a conventional apparatus due to the slower rate at which the water level in the float chamber 7 falls than that in the cistern.

Claims

1. A means suitable for use in a toilet cistern automatically to control the opening of the water inlet to the cistern until water initially in the cistern has been substantially discharged.

2. A means according to claim 1, comprising a chamber (7) including an outlet (8) through which water contained in a chamber (7) drains at a rate slower than the rate at which water is discharged from the cistern, and is arranged so that, in use, the float (1) of a float valve floats on the surface of the water in the chamber (7) .

3. A means according to claim 2, in which the outlet of the chamber is an orifice (8) .

4. A means according to claim 1 or 2 , in which the rate at which water flows from the chamber (7) is variable.

5. A means according to claim 4, in which the flow rate is varied by providing a variable size orifice (8) .

6. A means according to claim 5, in which the size of the orifice (8) is varied by providing a plurality of plugs having different diameter through-holes which can be fitted into a fixed aperture, or by providing a plurality of orifices one of more of which may be closed to vary the rate which water is discharged from the chamber (7) .

7. A means according to any one of claims 2 to 6 , in which variable means (4,69) are provided to vary the height of the chamber with (7) respect to the bottom of a cistern.

8. A means according to claim 7, in which the chamber (7) is mounted on a vertical guide (9) , and includes a means (6) to releasably secure the chamber (7) at locations along the vertical guide (9) .

9. A means according to claim 7 or 8 , in which the chamber (7) is also horizontally movable with respect to the vertical guide (9) to allow the float (1) to be positioned centrally within the chamber (7) .

10. A toilet cister including a means in accordance with any one of the preceding claims, and a float operated water inlet valve (3) , the float (1) of the water inlet valve (30) co-operating with the means to control the opening of the water inlet valve (3) .