GB2271364A - Overflow fitting for a siphon-discharge W.C. cistern - Google Patents

Abstract

A w.c. cistern has a siphon unit for discharging water into a flush pipe. Integral with the downpipe of the siphon is a u-shaped tube (14) which constitutes an internal overflow system. <IMAGE>

Description

SYPHONIC OVERFIW This invention relates to an overflow fitted within the toilet cistern.

Overflows for many years are known to comprise of a pipe of certain dimensions, this pipe when fixed to the toilet cistern should terminate if possible through an outside wall. This acts as a warning of ballvalve failure, if water should reach an abnormal level in the cistern. Overflows are designed to cause a hindrance as well as a warning to safeguard against wastage, so easily visible wastage due to overflowing cisterns would be an advantage, wherein normal type overflow arrangements water cannot always be seen due to various problems or complications.

The fixing in of an overflow can also be a costly and time consuming operation especially in larger buildings such as flats or office blocks.

According to the present invention there is provided an early warning system, this comprising of a tube which is joined to the base of the air pLrt of the toilet syphon. This tube is of a larger size than the water inlet, and fitted in such a way that an abnormal water level would pass through the tube down the syphon and into the toilet bowl. If the ballvalve was to stick in 'full bore' position, syphonic action would take place through the tube, emptying the cistern thereof being a hindrance and making normal flushing action impossible.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows in perspective, the cistern in normal operation.

Figure 2 shows the cistern overflowing through the internal tube.

Referring to the drawings a standard type cistern arrangement, with the addition of a tube 14 - fitted to the base of the 'air' part of the syphon 12. The tube 14 then rises to a height between normal fill level 16 and standard overflow height 13, then dips back into water, ending approximately lomrn from cistern 10 base, this so being to prevent air entering into syphon 12 during flushing, thereof not breaking syphonic action.

In order for the tube 14 to work as an overflow, water would have to rise to the level 18, this being the height of the tube invert 19 shown in Fig 2, allowing water to pass through the tube 14 and into the base of the syphon 12 where escaping water would terminate into the toilet bowl. If water was to rise higher, completely submerging tube 14 (due to complete failure of ballvalve 15) then syphonic action would take place emptying the cistern.

Whilst in this mode syphon 12 will not flush, causing a hindrance to user.

Claims (5)

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1. A syphonic overflow consists of a tube which is joined to the base of the 'air' part of the syphon, then rises to a height between normal fill level and standard overflow height to dip back into the water ending approximately lOimn from the base of the cistern.

2. A syphonic overflow as claimed in claim 1 wherein the dipped part of the tube being submerged to act as a 'stop' to counteract the surge of air during flushing, and not breaking syphonic action of syphon.

3. A syphonic overflow as claimed in claim 1 or claim 2 wherein overflowing water would rise over the invert of the tube causing it to become an overflow, diverting water into the toilet bowl.

4. A syphonic overflow as claimed in claim 2 or claim 3 wherein the water being allowed to rise further submerging the tube completely, causing it to become a syphon emptying the cistern.

5. A syphonic overflow substantially as described herein with reference to figures 1 and 2 of the accompanying drawing.