GB2284248A

GB2284248A - Fluid level control apparatus

Info

Publication number: GB2284248A
Application number: GB9318851A
Authority: GB
Inventors: John Lewis
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-09-11
Filing date: 1993-09-11
Publication date: 1995-05-31
Also published as: GB9318851D0

Abstract

Apparatus for controlling the maximum permitted fluid level in fluid receptacles comprises an actuation member (9), movable under the influence of pressure resultant upon the depth of the fluid in the receptacle, and a sealing member (13) moved by the above actuation member into a position where the fluid supply (8, 6) to the receptacle is shut off in the event of a supply tap or a float valve fitted to the receptacle not being closed. The actuation member (9) is suitably a disc with a membrane (11), the chamber above the member being vented to atmosphere (at 4) while the chamber under the member communicates (at 2, 3) with the bottom of the receptacle. The apparatus may be mounted inside a toilet cistern and responds to the depth of water in an overflow pipe. <IMAGE>

Description

APPARATUS TO CONTROL FLUID LEVEL IN A REcEPTArTv This invention relates to apparatus for controlling the fluid level in tanks, cisterns, baths, basins and other fluid receptacles.

Fluid levels in many types of receptacles, for example water storage tanks and cisterns are fixed at one level by, for example, a float valve. Other receptacles, for example baths and wash-hand basins,have the water level controlled by the use of taps. Incorrect use of these taps can result in these receptacles being over-filled or indeed overflowing resulting in the use of an excessive amount of water.

It is therefore desirable that means be provided for predetermining the maximum permissable fluid level in a receptacle so that when this maximum level is reached the incoming fluid supply is cut off.

This means to be used either, a. as an alternative to a float valve, b. in conjunction with a float valve to safeguard against float valve failure or c. in applications where a float valve is impractical ie. in baths or wash-hand basins where taps would be used to control the level of water at any desired level up to the pre-set maximum.

I have now devised such an apparatus that enables an adjustable maximum fluid level to be set for any receptacle and that when this maximum level is reached the fluid supply to the receptacle is cut off.

According to the present invention there is provided a) an actuation member moveable against a first biasing force from a first position to a second position under the influence of a "head" of fluid in a fluid receptacle.

b) one or more sealing members moveable against a second biasing force, or forces, from a first position to a second position by the movement of the said actuation member from its first to its second position.

In its, or their, second position the said sealing member,or members, closes off the fluid supply to the fluid receptacle.

Advantageously, the apparatus is provided in a housing, which housing is connectable into the fluid supply pipework to the taps or inlet port of the fluid receptacle and connectable to a conduit provided to sense the depth of fluid in the receptacle.

Typically the apparatus body comprises a sealed lower cylindrical chamber having a vertical axis with one or more sealed cylindrical chambers above it, also having a vertical axis or axes. The lower chamber is the "low pressure" chamber and the upper chamber or chambers is the "high pressure" chamber or chambers The actuation member is typically a disc like piston fitted into the low pressure chamber and sealed within it using a flexible seal. In the non-activiated mode of the apparatus, i.e. when the actuation member is in its first position, the low pressure chamber is at atmospheric pressure.

That portion of it above the actuation member being typically vented into the receptacle's outlet pipe and that portion below the actuation member being vented via a conduit connecting the receptacle to the apparatus body.

The actuation member is biased downwards into its first position. In the event of fluid entering the receptacle fluid will be introduced below the actuation member via the connecting conduit and when sufficient head of fluid builds up in the receptacle the resulting pressure will lift the actuation member into its second position.

The actuation member advantageously is attached to a spindle passing co-axially through it. This spindle provides stability for the actuation member by being supported in bores provided for it in the bottom wall of the low pressure chamber and in the wall between the high and low pressure chambers. Suitable seals are provided at this partion wall to prevent escape of fluid from the high pressure chamber.

Each high pressure chamber is typically of a stepped cylindrical configuration. Having its lower portion of a larger diameter than its top portion.

The lower portion of each high pressure chamber is exclusively connected to the incoming fluid supply pipework to the receptacle.

The upper portion of each high pressure chamber is exclusively connected via a conduit to the receptacle inlet port or a tap.

In this way all fluid entering the receptacle passes firstly into the lower portion of each high pressure chamber and then to the inlet port or taps via the upper portion of each high pressure chamber.

Typically a disc like sealing member is positioned within the lower portion of each high pressure chamber and is biased downwards against the top end of a support spindle, or in the case of there being only one high pressure chamber, the top end of the actuation member spindle. The support spindles are in turn supported on the actuation member via a rocking lever. Thus when the actuation and sealing members are in their respective first positions inlet fluid is free to pass through the high pressure chambers into the receptacle.

In the activated mode of the apparatus, i.e. when the water level in the receptacle creates sufficient pressure under the actuation member to lift it to its second position, each sealing member is lifted to its second position shutting off the fluid supply to the receptacle by sealing off the upper portion of the high pressure chamber from the lower portion. The resultant disparity of pressures above and below the sealing member, i.e.

low pressure above the sealing member as a result of the open tap or inlet port and the higher supply pressure below it, ensures that the sealing member is self sealing.

Advantagously the sealing member has a hole through its centre which is covered and sealed when in contact with the top of the actuation member spindle or support spindle.

The mechanism is reset by draining the fluid from the receptacle allowing the actuation member to return to its first position to which it is biased. This will uncover the hole through each sealing member allowing pressures to equalise around the sealing member allowing it to return to its position supported on top of the actuation member spindle or support spindle to which it is biased, thus opening the supply of water to the receptacle.

It is preferred that the biasing means applied to the actuation and the sealing members are their respective weights. Resilient biasing means such as coiled springs are alternatives if the apparatus is installed in a different plane.

The invention will now be further described in specific embodiment by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic sectional view of one embodiment of the invention used to control the maximum permissible fluid level in a receptacle supplied by one tap.

Figure 2 is a sectional view of another embodiment suitable to control the maximum permitted depth of water in a bath supplied by two taps.

It also illustrates one means of adjusting and setting the maximum bath water level.

Figure 3 is a schematic sectional view of another embodiment fitted inside a cistern as a safety mechanism to prevent overflows in the event of a failed float valve.

Referring to Fig 1 the fluid level control apparatus is seen outside a fluid receptacle approximately level with the bottom of the receptacle. The bottom cover 1 is connected to an aperture 3 in the bottom of the receptacle by conduit 2 in such a way that if fluid enters the receptacle it flows, via conduit 2,to below disc 9. The space below disc 9 being sealed by flexible membrane 11. As the fluid level rises in the receptacle, and if the tap controlling the flow of fluid is not closed, the resultant pressure under disc 9 will increase to the point where disc 9 is lifted in the direction of arrow A. It should be noted that to achieve this movement the chamber above disc 9 is maintained at atmospheric pressure at all times by connecting vent 4 to atmosphere, typically via the drain connected to the receptacle.

This movement of disc 9, ie. the actuation member, will lift sealing member 13 into a position where it seals off the top of the high pressure chamber from the bottom. Hence the outlet port 6 is closed off from inlet port 8. The supply of fluid to the tap supplying the receptacle is cut off Once moved into it's sealing position, sealing member 13 is "self sealing" by virtue of the high supply pressure on it's underside and the lower pressure, resulting from the open tap, on it's topside.

Fluid supply to the tap is re-connected when the receptacle is drained sufficiently to reduce the pressure under disc 9 to allow it to return to it's first position, under the influence of it's own weight. This downward movement of disc 9 and it's spindle 10 will uncover hole 14 allowing fluid pressure around sealing member 13 to equalise and hence allowing sealing member 13 to move downwards, under the influence of it's weight, to re-connect the fluid supply to the tap.

Referring to Fig 3 the overflow prevention apparatus is seen in use inside a toilet cistern 10 and positioned adjacent to its bottom wall.

Fitted into the bottom of the body of the apparatus 3 is fitted a threaded connector 11. The bottom threaded portion of connector 11 passes through the bottom wall of cistern 10 to which it is clamped by locknut 12. The inlet water supply to cistern 10 is connected to connector 11.

Ducting within the apparatus body 3 feeds the inlet water into that portion of the high pressure chamber that contains the sealing member 8. As drawn the inlet water can pass through the high pressure chamber to the inlet float valve 9 via ducting and conduits.

This is the normal mode of operation of the cistern i.e. the float valve 9 allows the cistern to refill after use and maintains its water at the correct level.

In the event of float valve 9 failing and the cistern water level rising then overflow water will flow into overflow pipe 2 before overflowing from the cistern.

Overflow water flowing into overflow pipe 2 is ducted to the underside of actuation member 5. As the head of water builds up in pipe 2 water pressure increases under actuation member 5 to the point where it lifts actuation member 5 into it's second position.

As decribed under Fig 1 the supply of water to the float valve is thus closed off. This prevents the cistern overflowing onto the floor.

Following the repair of float valve 9 the water supply to float valve 9 is reconnected as follows: 1. The overflow water is drained from overflow pipe 2. In the configuration shown in Fig l this is done by unscrewing the overflow pipe 2 from apparatus body 3.

2. The removal of pressure from below actuation member 5 allows it to return to its first position as drawn, under its own weight.

3. The return of actuation member 5 and spindle 7 to their first positions will uncover the small hole through sealing member 8.

4. The uncovering of the small hole through sealing member 8 will allow the pressure around sealing member 8 to equalise allowing it to move downwards under its own weight, thus reopening the water supply to float valve 9.

Claims

CLAIMS.

1. Apparatus to control the level of the fluid in a receptacle, which apparatus comprises: a) an actuation member movable against a first biasing force from a first position to a second position under the influence of a "head" of fluid in a fluid receptacle.

b) one or more sealing members moveable against a second biasing force, or forces, from a first position to a second position by the movement of the said actuation member from it's first to it's second position.

In it's, or their, second position the said sealing member, or members, closes off the fluid supply to the fluid receptacle.

2. Apparatus according to claim 1 wherein first and second biasing means are typically the weights of the actuation and sealing members but may be resilient means such as coiled springs if preferable.

3. Apparatus according to any preceeding claim wherein a housing for the apparatus is provided, the housing being connectable into the incoming fluid supply line and connectable to a conduit provided to sense the fluid level in the receptacle.

4. Apparatus according to any preceeding claim wherein the actuation member is a disc like piston fixed to a spindle passing co-axially through it and arranged to be movable under the influence of a "head" of fluid pressure.

5. Apparatus according to any preceeding claim wherein each sealing member is a disk like member arranged to be moved to a position where it closes off a fluid supply by the movement of the actuation member.

6. Apparatus according to any preceeding claim wherein each sealing member is provided with a "self energising" sealing effect by the resultant difference in pressure on each side of the sealing member when moved into its sealing position.

7. Apparatus according to any preceeding claim wherein each sealing member is provided with a hole through it such that that portion of the spindle against which it rests seals off that hole against the flow of fluid.

8. Apparatus according to any preceeding claim wherein the actuation member moves freely back to its first position, under the influence of its biasing means, when the fluid is drained from the receptacle.

9. Apparatus according to any preceeding claim wherein movement of the actuation member, and it's associated spindle or spindles, away from each closed sealing member uncovers the hole through each sealing member allowing pressure to equalise around the sealing member and hence allowing it to return to its position against the end of it's support spindle under the influence of its biasing means.

10. Apparatus according to claim 6, wherein the actuation member is a flexible diaphram.

11. Apparatus according to claim 7, wherein the sealing member is a flexible diaphram.

12. Apparatus according to any preceeding claims wherein that space above the actuation member is vented to atmosphere typically via the receptacle drain pipe.

13. Apparatus substantially as herein described with reference to the accompanying drawings.