GB2266101A - Overflow fitting for a siphon-discharge W.C. cistern - Google Patents

Abstract

An overflow fitting for a siphon-discharge w.c. cistern wherein the siphon has an aperture at or towards the upper end of its down leg. The fitting comprises a cover 14 which is mounted to cover and seal the aperture. A float 20 is arranged to lift if the water level in the cistern exceeds a predetermined level and is operative on lifting to remove the cover to a position in which it does not seal the aperture. <IMAGE>

Description

SIPKON POR A WC CISTERN AND ATTACHMENT THEREFORE This invention relates to siphons for water closets (WCs).

A WC cistern comprises a tank for storing water which is refilled to a predetermined level by supplying water through a ball valve. A siphon is provided to discharge water from the cistern into the bowl of the WC.

An overflow system is required in order to deal with excess water if the ball valve is faulty and does not cut off the supply when the level of water in the tank is at the predetermined level.

The overflow system usually comprises a pipe taken from an outlet at a high level in the tank through an outside wall of the building where the excess water can overflow safely. Water discharging from such an overflow pipe will give a visual and audible warning that there is a fault in the cistern.

In some installations this arrangement is fairly easy to provide but in a growing number of cases it is not.

Difficulties are met especially when WCs are installed deep within houses and commercial buildings, e.g. office blocks, in positions not near to an external wall. In other cases, difficulties are caused by it being undesirable for aesthetic or technical reasons for the pipe to penetrate the external wall, e.g. a high technology cladding.

There have been proposals to allow the overflow of excess water through the down leg of the siphon into the WC bowl. However, all the prior proposals have required the use of a special siphon.

Against this background, the invention provides an attachment for a siphon of a WC cistern, said siphon having an aperture at or towards the upper end of its down leg, the attachment comprising: a cover; means for mounting the cover removably in a position to cover and seal the aperture; and a float arranged to lift if the water level in the cistern exceeds a predetermined level and operative on lifting to remove the cover to a position in which it does not seal the aperture.

The only modification to a conventional siphon which is necessary in principle, in order to fit such an attachment, is to provide the aperture in the down leg.

This may be made after manufacture, even after installation.

If the ball valve fails and the tank overfills, the float lifts when the water reaches a predetermined level. Lifting the float is operative to remove the cover to a position in which it does not seal the aperture. This enables further water to drain through the aperture into the down pipe and so away through the bowl of the WC.

A problem experienced with some prior proposals is that draining--the excess water through the bowl of the WC may go unnoticed. The majority of leaks through ball valves occur at night when the demand is low and the water pressure is thus higher. The user may thus be asleep during the period when the ball valve is leaking. The traditional overflow pipe through an external wall provides an incentive for the owner or manager of the property to fix the ball valve, since if the overflow is allowed to continue for a long period, unsightly stains and growth appear, even damage to the building can result. When the overflow has been discharged down the WC bowl in prior proposals, however, even if the fault is noticed, there is much less incentive to mend the ball valve.With an attachment embodying the invention, provided that the cover does not return to seal the aperture, the WC cannot be flushed. Manually resetting the attachment each time a flush is required, is thought to provide a strong incentive to the user to mend the ball valve.

In one arrangement, the means for mounting the cover allows the float to slide the cover up the down leg of the siphon to said position in which it does not seal the aperture when the water level in the cistern exceeds said predetermined level. In this arrangement, the float may be made sufficiently buoyant to slide the cover up the down leg but sufficiently light that the cover does not slide back down the down leg. After the attachment has operated, it is thus necessary to close the aperture, e.g. with the user's hand, or to reset the cover over the aperture before a flush cak-be obtained.

The cover may be in the form of a clip which attaches round the down leg of the siphon tube.

Another, preferred arrangement, includes a coupling normally applying a bias to close the cover over the aperture, the float being operative to uncouple the coupling so removing the bias to open the cover from the aperture when the water level exceeds said predetermined level.

Since the coupling is uncoupled so removing the bias which closes the cover over the aperture, this arrangement also requires resetting, or the user's hand to be held across the aperture, before a flush can be obtained.

A further, smaller bias may be provided to open the cover away from the aperture when the closing bias is removed by the coupling becoming uncoupled, so as to ensure positive operation.

The coupling is preferably arranged to be decoupled by relative sliding movement between two coupling members, said coupling members being normally oriented so that said relative movement is in a direction substantially normal to the direction of the bias, said relative movement being induced by operation of the float when the water level exceeds said predetermined level.

Most preferably, the coupling members are arranged to be tilted as the float rises, when the water level exceeds said predetermined level, so that the direction of said relative movement tilts from normal towards alignment with or parallel to the direction of said bias so causing disengagement of said coupling members This arrangement makes the operation of the float very sensitive and thus reliable.

Even more sensitive operation can be obtained by mounting the coupling member for orbital movement.

One of said coupling members may be a tie member to which the float is attached.

The tie member may be a cord, an elastic cord or a spring.

In such an arrangement, the other of said coupling members may have a notch therein through which the tie member passes, said tie member having a stop thereon to prevent the tie member from drawing through the notch so coupling the members. The stop may be provided by a body of the float.

In an alternative arrangement one of the coupling members has a transverse hole therein the other coupling member having a pin for engagement in the hole so coupling the members.

The invention extends to a siphon with the attachment fitted thereto. The attachment may be fitted in manufacture or after manufacture.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of a siphon for the cistern of a WC and modified for use with an attachment embodying the invention; Figu-re-4- i-s iie-viewf-the-siphon- of--Figure 1- showing the attachment in place; Figure 3 is a side view of the siphon of Figure 2, partly broken away, in which the attachment has operated; Figure 4 is an exploded pictorial view of the attachment of Figures 2 and 3; Figure 5 is an assembled pictorial view of the attachment of Figures 2 and 3; Figure 6 is a pictorial view of another attachment embodying the invention; Figure 7 is an exploded pictorial view of a further attachment embodying the invention; Figure 8 is a pictorial view of part of a yet further attachment embodying the invention;; Figure 9 is a pictorial view of part of a yet further attachment embodying the invention; Figure 10 is a plan view partly in section of yet another attachment embodying the invention and fitted to a siphon; Figure 11 is a plan view similar to Figure 10 showing the attachment after operation; Figure 12 is a plan view of another attachment embodying the invention; Figure 13 is a pictorial view of an alternative detail of a coupling member for the embodiments of Figures 6 to 9.

Referring to Figures 1 to 5 of the drawings, a siphon 2 comprises a plastics moulding providing a generally inverted U-shaped passage and having an up leg 4 and a down leg 6. In use, the siphon is installed in a cistern of a WC with the down leg communicating through the bottom of the cistern with a pipe which supplies flushing water from the cistern to the bowl of the WC. The water level is maintained by a ball valve arrangement (not shown) at a level WL, below the join between the up leg 4 and the down leg 6, so that water does not normally flow through the siphon into the WC bowl. A piston arrangement (not shown) in an enlarged section 8 at the bottom of the up leg 4, is operated via a link 10 to lift water to fill the up leg so that water can siphon through the up leg 4 and down leg 6 to flush the WC bowl.When the water level in the cistern falls below the bottom of the up leg 4, air enters the siphon preventing further siphon action and the cistern refills via the ball valve to the level WL.

The siphon illustrated in Figure 1 has a modification which enables it to be used with an attachment embodying the invention. The modification is the provision of an aperture 12 towards the top of the down leg 6. If the ball valve fails, and the level WL of the water in the cistern rises to the level of the aperture 12, water can drain through the aperture and away through the WC bowl. On its own, the aperture would prevent normal siphon action, however, so that the WC could not be flushed.

In order to allow normal flushing of the WC, an attachment 14 is provided. The attachment, which is shown in detail in Figures 4 and 5, comprises a resilient closed cell foam plastics gasket 16 which is secured round the aperture 12. Other suitable materials maybe used in the alternative e.g. silicon rubber. The gasket 16 may be preformed to clip onto the down leg and/or may be provided with a self adhesive coating on one side. A cover in the form of a part cylindrical flexible clip 18 is clipped removably over the gasket 16 to close the aperture. A float 20 is attached to the clip 18 so that if the water rises above the intended level WL, the float lifts the clip which slides up the gasket to uncover the aperture 12. Water is thus able to drain through the aperture and away down the WC bowl.

There will be a degree of friction between the clip and the gasket 18 which the float can be buoyant enough to overcome. A spring could be employed to assist the action (not shown) The float can, on the other hand, also be sufficiently light that the clip does not slide back down the gasket to re-close the aperture in the event that the level drops. The water level could drop because of a fall in water pressure, e.g., when demand increases in the morning.

Thus, once the attachment has operated, the WC cannot be flushed until the aperture has been closed. This could be done by resetting the clip or by the user holding a hand over the aperture. The necessity to perform either action each time it is desired to flush the WC will provide a strong incentive to fix the ball valve.

Another embodiment is shown in Figure 6. Here, the cover-is--in-Ehe---form-of--a--curved-plate-~-22 on the inside of which is mounted a resilient closed cell foam plastics pad 24. The cover plate is shown in Figure 6 as if secured over the aperture by a tie member in the form of a cord 26 which thus biases the cover so that the pad closes the aperture and which, for this purpose, may be elastic. As may be seen from Figure 7, additional or alternative resilience is provided by the plate 22 which is shown in its relaxed state in Figure 7, but flexed as if secured round the down leg in Figure 6. The cord 26 is attached fixedly through holes 28 at one side of the cover plate. On the other side of the cover plate is secured a coupling member in the form of a notched plate 30. A float 32 is secured at the remote end of the cord 26.In use the cover is placed over the aperture (not shown in Figure 6), the cord is passed round the siphon and pulled into the notch 34 in the plate 30.

When the cord is released, the body of the float 32 acts as a stop preventing the cord from drawing thorough the notch 34.

The plate 30 is set so that movement which would uncouple the float 32 from the plate 30 is substantially normal to the cord.

Normally the float 32 is clear of the water similar to the arrangement of Figures 1 to 5. When the water level rises, however, the float lifts clear of the notch uncoupling the float from the plate and allowing the cover plate to open from the aperture in the down leg. Especially when the cord is elastic, or resilience is provided by other means, the sudden release of the cord causes the cover to spring off the down leg. Reliable and positive action is thus ensured and the siphon cannot be operated unless the aperture is covered, e.g., either with the user's had or by resetting the cover plate 22.

The operation of the arrangement can be made more sensitive and thus more reliable by mounting the plate 30 pivotally on the cover plate 22. To this end the plate 30 is shown mounted on the cover plate by a pivot pin 36. The body of the float will be held against the plate 30 by the tension in the cord 26 so that a degree of friction will exist which will need to be overcome before the float can slide against the plate 30. Before the water level has risen sufficiently to overcome such friction, the float will cause the plate to pivot about the pin 36. This aligns the direction in which the float must slide on the plate somewhat with the direction of the bias provided by the cord 26. There is thus a component of the bias acting in addition to the lift provided by the buoyancy of the float, to slide the float on the plate 30 thus to decouple the float from the plate.

An exploded pictorial view of another embodiment is shown in Figure 7. Again, the cover plate 22 is formed at one end 50 to conform to the down pipe, similar to the embodiment of Figure 6, and, the other end 52 of the cover plate is resiliently flexible and, unless bent round the down leg of the siphon, would stick out as shown. The arrangement provides a resilience which facilitates the use of a non-elastic co-rd~~2~6.--AIternatively, a 'spring 54 may replace the cord. As will be seen from Figure 7, the plastics pad 24 is mounted on a straight section of the plate 22. When the device operates, removing the tension of the cord 26, the plate straightens so lifting at least part of the pad clear of the aperture.

Another feature of the arrangement shown in Figure 7 is that the plate 30 is mounted pivotally at one end 64 of an arm 62. The other end 60 of the arm is itself pivotally mounted on the cover plate 22 so that the plate 30 may orbit about the pivot at the end 60 of the arm. The arrangement is intended to provide even more reliable operation since if during many years in which the ball valve worked properly one of the pivots seized, say, due to line encrustation, there is the possibility that the other pivot is still operational. The arrangement also provides the advantage that the float is positioned further from the ball valve.

That advantage can also be obtained with the plate 30 rigidly mounted on the arm 62 as shown in the detail of Figure 13.

In another arrangement, shown in Figure 8 the attachment is extended round both legs of the siphon thereby allowing the float and plate to be positioned adjacent to the up leg of the siphon. The arrangements within some cisterns make this desirable. The pad 24 is not shown in Figure 8. The cover plate could be replaced by a resiliently flexible plastics strip 56 shown in Figure 9.

Again the pad 24 is not shown.

An arrangement-shownv n-F-igure 12 has an~acetate outer strip and a closed cell foam plastics inner strip 60 so that any part of the inner strip can be used to close the aperture in the down leg. The notched plate 30 is pivotally mounted on a rigid plate 62 fastened to one end of the strips 58 and 60. At the other end a reinforcing plate 64 receives one end of a cord 66 the other end of which is received by a washer 68. Knots prevent the cord from pulling through the reinforcing plate 64 and the washer 68.

The washer 68 bears on one end of a coil spring 70 through which the cord passes. The other end of the spring bears on the wall of a float 72 through which the cord passes sealingly so that compression of the spring 70 provides tension in the cord 66 when the float 72 and plate 30 are coupled. The spring also serves to tug the strip off the aperture when the attachment activates, thereby overcoming any adhesion which may have developed between the gasket and the surface of the siphon, particularly on the area surrounding the aperture.

A further arrangement is shown in Figures 10 and 11. Here a clamp 74 is fixed to the up leg 4 of the siphon.

A flexible plastics cover plate 22 is fixed to the clamp and in its normal, relaxed, state it has the shape shown in Figure 11. A kink 76 in the plate is provided as a hinge.

The float 70 has a depending leg 78 in which is provided a hole 80. A pin 82 projects from an arm 84 of the clamp. In use the hole 80 is hitched over the pin 82 so that the cord 26 biases the cover plate 22 to the position shown in which the pad 24 closes the aperture 12. If the water level in the tank rises unduly, the float levers the leg 78 off the pin 82 so that the cover plate can relax to its open position shown in Figure 11 and excess water can drain down the down leg 6.

In order that a person investigating the cistern will know what to do when the ball valve fails and the attachment operates, the attachment may provide instructions as to how to repair the ball valve and how to obtain a flush by closing the aperture. The instructions could be displayed on top of the float, for example, or the float being hollow could have a sealed lid so as to contain a sheet of paper printed with instructions. The outside of the float could then display the message "Instructions Inside".

Claims (14)

Claims

1. An attachment for a siphon of a WC cistern, said siphon having an aperture at or towards the upper end of its down leg, the attachment comprising: a cover; means for mounting the cover removably in a position to cover and seal the aperture; and a float arranged to lift if the water level in the cistern exceeds a predetermined level and operative on lifting to remove the cover to a position in which it does not seal the aperture.

2. An attachment as claimed in claim 1, wherein the means for mounting the cover allows the float to slide the cover up the down leg of the siphon to said position in which it does not seal the aperture when the water level in the cistern exceeds said predetermined level.

3. An attachment as claimed in claim 2, in which the cover is in the form of a clip which attaches round the down leg of the siphon tube.

4. An attachment ascTajme in claiin í, including a coupling normally applying a bias to close the cover over the aperture, the float being operative to uncouple the coupling so removing the bias to open the cover from the aperture when the water level exceeds said predetermined level.

5. An attachment as claimed in claim 4, wherein the coupling is arranged to be decoupled by relative sliding movement between two coupling members, said coupling members being normally oriented so that said relative sliding movement is in a direction substantially normal to the direction of the bias, said relative sliding movement being induced by operation of the float when the water level exceeds said predetermined level.

6. An attachment as claimed in claim 5, wherein one of the coupling members is arranged to be tilted as the float rises, when the water level exceeds said predetermined level, so that the direction of said relative sliding movement tilts from normal towards alignment with or parallel to the direction of said bias causing disengagement of said coupling members.

7. An attachment as claimed in claim 6, wherein the tilting coupling member is mounted for orbital movement.

8. An attachment as claimed inany of claims 4 to 7, wherein one of said coupling members is a tie member to which the float is attached.

9. An attachment as claimed in claim 8, wherein the tie member is a cord, an elastic cord or a spring.

10. An attachment as claimed in claim 8 or 9, wherein the other of said coupling members has a notch therein through which the tie member passes, said tie member having a stop thereon to prevent the tie member from drawing through the notch so coupling the members.

11. An attachment as claimed in claim 10, wherein the stop is provided by a body of the float.

12. An attachment as claimed in claim 8 or 9, wherein one of the coupling members has a transverse hole therein the other coupling member having a pin for engagement in the hole so coupling the members.

13. An attachment substantially as hereinbefore described with respect to any of the accompanying drawings.

14. A siphon including an attachment as claimed in any preceding claim.