GB2223771A

GB2223771A - Overflow fitting for a siphon-discharge W.C. cistern

Info

Publication number: GB2223771A
Application number: GB8922860A
Authority: GB
Inventors: Karim Malekottodjary
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-10-11
Filing date: 1989-10-11
Publication date: 1990-04-18
Also published as: GB8823818D0; GB8922860D0

Abstract

A flushing cistern (10) comprising a water outlet pipe (20) and means (16) for causing water to flow through the outlet pipe, characterised in that an internal overflow pipe (22) is connected to the water outlet pipe within the cistern, the upper portion (24) of the overflow pipe being adjacent the top of the cistern. The upper portion may be a cup-like receptacle and carry a ball (26) whereby to seal the overflow except when the water level rises beyond a predetermined limit. <IMAGE>

Description

FLUSHING CISTERN This invention relates to flushing cisterns especially for WC's.

Flushing cisterns in this country are normally provided with an external overflow so that, in the event of a faulty ball valve supply arrangement resulting in overfilling of the- cistern, the water can escape. It is common to use an overflow pipe passing through an outside wall of the building. However in large buildings such as hotels, office blocks and the like, WC's are not always located in rooms adjacent outside walls and the long overflow pipes which would be necessary to provide external escape of water are inconvenient.

The invention seeks to provide an internal overflow system for use with flushing cisterns.

According to the present invention there is provided a flushing cistern comprising a water outlet pipe and means for causing water to flow through the outlet pipe, characterised in that an internal overflow pipe is connected to the water outlet pipe within the cistern, the upper portion of the overflow pipe being adjacent the top of the cistern.

Preferably the upper portion of the overflow pipe is also fitted with a valve, such as a ball valve. The latter may conveniently comprise a ball fitted in the top of the overflow pipe which has been opened out into a cup shaped receptacle to receive the ball. The ball will be of a material less dense than water so that it will float free of the overflow inlet should the water level rise above it. The ball should nevertheless preferably be large enough and therefore heavy enough to resist the initial surge of pressure when the cistern is flushed.

By connecting the overflow pipe to the water outlet pipe, should the cistern overfill and activate the overflow, the excess water will be deposited in the lavatory pan and the fact that this is occurring will be obvious to a user. Nevertheless, should further visual indication of an overflow situation be required other means can be employed. For example, a 'flag' in the top or lid of the cistern may be located over the overflow ball valve so as to provide a visual indication when the ball valve is opening the overflow inlet. Alternatively, a material containing a dye, for example one of the coloured tablets of material provided for fitting in a WC cistern to disinfect and colour the water, may be located within the overflow pipe such that the coloured water will only be visible in the toilet pan when an overflow occurs.

Preferably, however, a means is provided to prevent the air-tight re-sealing of the valve after actuation. This means that the valve must be manually re-set in the event of of an overflow or the syphon will not operate to flush the toilet pan. This not only alerts the user, but the inconvenience involved encourages prompt attention to the cause of the overflow, e.g. a worn washer, and thus discourages wastage of water.

The invention will be described further, by way of example, with reference to the accompanying drawing, in which the sole figure is a diagrammatic sectional view of a flushing cistern in accordance with the invention.

Referring to the drawing, a cistern generally designated 10 has a lid 12 and is adapted to be filled with water for use with a WC.

The water inlet and ball-cock are omitted for clarity. The normal water level is indicated at 14.

As is common with such flush cisterns, a syphonic flush arrangement comprising a piston 16 within a cylinder 18 is connected to a water outlet pipe 20 such that actuation of the piston 16 by means of an external handle or chain causes the pipe 20 to fill and, by syphonic action, to continue to drain water from the cistern till the latter is empty and air enters the cylinder 18. At this stage the piston 16 returns to its lowermost position, as shown in the drawing, and the cistern 10 refills with water to the level 14 ready for the next actuation.

Normally such a cistern would be provided with an external overflow as indicated at 20 externally of the cistern.

However, in accordance with the invention, an overflow pipe 22 is provided connected into the water outlet pipe 20 and having an upper end 24 adjacent the top of the cistern lO and in any event above the normal water level 14. In the embodiment described the upper end 24 of the overflow pipe 22 is belled out to form a hemispherical cavity within which sits a ball 26 made of a material less dense than water. Above the ball 26 is a 'flag' 28 freely movable in an orifice 30 in the lid 12 of the cistern.

The flag 28 may be brightly coloured, e.g. fluorescent red.

In use of the device, should the water level rise above its normal point 14 toward the top of the cistern 10 it will cause the ball 26 to lift out of the top 24 of the overflow pipe 22 thereby allowing the excess water to flow through the pipe 22 and the water outlet pipe 20 into the WC pan. It is envisaged that the bore of the overflow pipe 22 will be sufficiently great to cope with the maximum flow of water capable of being provided to the cistern. As the ball 26 rises with the water level it pushes the flag 28 through the lid 24 so that it is clearly visible to the user. However, the water flowing into the pan would be visible in any event.

The overflow of the invention does not interfere with the normal flushing of the cistern except as discussed below. As the piston 16 is initially raised the pressure within the water outlet pipe 20, and thus the overflow 22, momentarily rises. However the weight of the ball 26 is sufficient for it not to be dislodged.

As the water begins to flow down the water outlet 20 a suction effect is created in the pipe 22 tending to draw air into it.

However, this causes the ball 26 to be drawn firmly into the cup 24 thereby sealing the overflow pipe 22 and preventing air from being forced into the water outlet pipe 20.

As described above the ball 26 sits in the cup 24 and provides an air- and water-tight seal in normal operation of the cystern.

The ball is preferably provided with a depression 32 and the cup with a correspondingly shaped projection 34, which therefore mate together when the ball is correctly oriented with respect to the cup. If an overflow occurs, the ball will be raised and moved by the water flow. The depression and projection will then almost always move out of register, and if the piston 16 is actuated lowering the water level, the ball will held out of sealing engagement with the cup by the projection 34. This in turn means that there will be air leaking into the system once the water level has dropped below the base of the cup, and the flush will therefore not operate. The user will need the lift the cystern lid 12 and manually turn the ball 26 untill the depression and projection are in register to allow sealing to take place once again. The inconvenience in this provides a strong incentive for the user to correct the cause of the overflow rather than just allowing the water to run to waste.

If desired the ballcock arm can, e.g. via an extension, rest on the ball 26 adding to its effective weight. However, if the water level should rise beyond its normal level the ballcock will lift as well as the ball 26 allowing it to operate as before.

The device of the invention provides a simple and economical means of eliminating external overflows for flushing cisterns.

Claims

1. A flushing cistern comprising a water outlet pipe and means for causing water to flow through the outlet pipe, characterised in that an internal overflow pipe is connected to the water outlet pipe within the cistern, the upper portion of the overflow pipe being adjacent the top of the cistern.

2. A cistern as claimed in claim in which a portion of the overflow pipe is also fitted with a valve, such as a ball valve.

3. A cistern as claimed in claim 2 in the valve comprises a ball fitted in the top of the overflow pipe which has been opened out into a cup shaped receptacle to receive the ball.

4. A cistern as claimed in claim 3 in which the ball is of a material less dense than water so that it will float free of the overflow inlet should the water level rise above it.

5. A cistern as claimed in claim 4 in which the ball is large enough and therefore heavy enough to resist the initial surge of pressure when the cistern is flushed.

6. A cistern as claimed in any of claims 2 to 5 in which a 'flag' in the top or lid of the cistern may be located over the overflow ball valve so as to provide a visual indication when the ball valve is opening the overflow inlet.

7. A cistern as claimed in any of claims 2 to 6 in which a means is provided to prevent the air-tight re-sealing of the valve after actuation.

8. A cistern as claimed in claim 6 in which the means comprises a depression in the ball and a corresponding projection on the cup so that, when the two are out of register, the ball does not provide an air-tight seal.