GB2220049A

GB2220049A - Apparatus for switching off a fluid supply

Info

Publication number: GB2220049A
Application number: GB8908031A
Authority: GB
Inventors: Anthony Kenneth James Lewis
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-04-21
Filing date: 1989-04-10
Publication date: 1989-12-28
Also published as: GB8908031D0; GB8809390D0

Abstract

Apparatus for switching off a fluid supply comprises means 13 for basing an operating element 12 to close a valve 11 and means 16-18 for holding the element 12 in the valve-open position against the bias until the ambient temperature drops below a predetermined level. Preferably the holding means includes a water-filled glass phial 18 which will break when the water freezes. Means may also be provided for manually opening the valve. <IMAGE>

Description

Apparatus for Switching Off a Fluid Supply This invention relates to apparatus for switching off a fluid supply and in particular, but not exclusively, to apparatus for switching off mains water supplies.

Despite the well-known consequences of the water in water supply pipes becoming frozen, many householders and owners of business premises forget to take the precaution of switching off their mains water supply if the premises is to be vacated, and unheated, during the winter months. There are a number of frost protection systems but these tend to be complex and require specialised fitting and are often negated if the mains electricity supply is switched off.

The present invention consists in apparatus for switching off a fluid supply, comprising a valve having an operating element, means for biasing the element to close the valve and means for holding the element, against the action of the biased means, in its open position until the ambient temperature drops below a predetermined level.

In a preferred embodiment the holding means comprise a substantially non-extensible support, the support having two sections interconnected by a connector which breaks the connection when the temperature drops below the predetermined level to allow the operating element to move under the action of the biased means.

For example, the connector may comprise a water-filled container made of a material which will break when the water in the container expands on freezing.

In this example the container may be made of glass and for instance may comprise a glass tube having press-fit caps to close its ends. The support thus may comprise a pair of wires interconnected by the water-filled glass container.

The support may be suspended from an anchor point or may be connected to switch means for raising and lowering the support to move the operating element without affecting the integrity of the connector.

The element may be a lever, in which case the bias means may be constituted by a weight, or in another embodiment the element may be a rack and the bias means may be a spring. In that latter case the valve may be a pivotal ball valve and the ball may be drivingly connected to the rack by pinion teeth.

In any of the embodiments the holding means may allow the bias means to close progressively the valve means when the ambient temperature drops below the predetermined level.

Although the invention has been defined above it is to be understood that it includes any inventive combination of the features set out above or in the following description.

The invention may be performed in various ways and specific embodiments will now be described by way of example, with reference to the accompanying drawings, in which Figure 1 is a schematic view of apparatus for switching off a fluid supply; Figure 2 shows part of an alternative arrangement for such apparatus; Figure 3 is a further schematic view of another embodiment; Figure 4 is a schematic view of a valve for use in the apparatus of Figure 3; Figure 5 is a side view of a connector for use in the apparatus of Figure 3; and Figure 6 is a perspective view of a switch for use in the apparatus in Figure 3.

In Figure 1 a water mains pipe 10 can be opened or closed by a valve 11. The valve is provided with the operating lever 12 which is biased downwardly into its closed position by a weight 13.

The lever is, however, normally retained in the open position (illustrated in Figure 1) by a support, generally indicated at 14, which is anchored on a quick release catch 15. The support consists of two rigid wires 16, 17, which are interconnected by a waterfilled glass phial 18.

In use the valve 11 is normally held open by the support 14, until such time as the water in the phial 18 freezes causing it to break, due to the expansion of the water on freezing. The breaking of the phial 18 releases the lower wire 17 and the lever 12 is rotated downwardly under the action of the weight 13 closing the valve 11 and shuting off the water main 10. By suitably positioning phial 18 it will often be possible to ensure that the valve 11 is closed before any water is in the water system supplied by the main 10 freezes. However, even if some part of the system does freeze, any subsequent loss of water in to the premises will be limited to the water then contained in the system, normally about 40 gallons.

Should a leak in the water system occur for some other reason the quick release catch 15 provides an emergency control for the water main as a user simply has to push the button 19 to release the support 14 and hence close the valve.

Figure 2 shows alternative embodiments in which the lever 12 is supported by a support 14 which comprises a pair of telescopic rods 20, 21. The inner rod 20 is supported within the outer rod 21 on a glass phial 22 and when it bursts the rod 20 can drop downwardly allowing the weight 13 to lower the lever 12.

It may be possible indeed to dispense with the weight 13 in this arrangement.

The advantage of these particular systems is that they are very easy to fit and that their operation relates directly to the condition which the system is attempting to detect, i.e. the freezing of water.

However, it will be understood that the release of the support 14 can be achieved in other ways which may for example be operated by temperature detection systems such as thermometers or thermistors. In one construction the catch 15 could be electro-magnetically operated to release the support 14 when the temperature detected adjacent the main 10 falls below a predetermined temperature. Such systems have the disadvantage that they require more specialised fitting and the provision of an electricity supply. Modern rechargeable batteries are capable of providing such a supply for some time after the mains is switched off, but they cannot protect property which is empty for many months.

In an alternative construction, the weight 13 in the Figure 1 arrangement, could be connected to the phial 18, so that it is held above the lever 12. When the phial breaks the weight will flop down past the lever creating a sudden application of force on the lever and hence creating a jolt which is likely to overcome any sticking of the valve 11, which may occur.

Figure 3 shows an alternative arrangement to that shown in Figure 1 although the overall principles are the same. In this case the quick release catch 15 is replaced by a switch 24 and the valve 11 and elements 12, 13 are replaced by an arrangement shown in Figure 4.

Turning to Figure 4 the valve 25 is generally of the form having a pivotal ball 26 mounted on a shaft 27, the ball having a bore (not shown) which can be aligned with or displaced from the pipe 10 to open and close the valve. In this case a pinion 28 is mounted on the shaft 27 to engage a rack 29 which passes through the housing 30 of the valve 25. This rack is actuated open by a compression spring 31, located in a closed sleeve 32, and is connected to the lower wire 17 so that it can be held in its raised position by a switch 24.

In this position the valve is open or on.

As can be seen in Figure 6 the switch 24 comprises a lever 33 pivotally mounted in a housing 34.

One end of the lever projects from the housing to act as the switch handle whilst the other end, which is on the opposite side of the pivot 35, is connected to the upper wire 16. Thus when the handle portion 36 is depressed the other end 37 is raised causing the rack 29 to lift and the ball 26 to rotate opening the valve 24. If the consumer wishes to switch off the water they simply have to lift the handle portion 36 which causes the rack to be lowered and the valve 24 closes.

The switch can be conveniently located at worktop level.

Figure 5 illustrates a preferred construction for the glass phial 18. It will be seen that it consists of a tube 38 closed by two press-fit caps 39, each of which have eyelets for receiving the ends of their respective wires 16, 17. This construction is particularly easy to assemble and removes many of the problems of completely filling a substantially closed container with water, as the upper cap can be positioned when the tube has been filled.

Claims

1. Apparatus for switching off a fluid supply comprising a valve having an operating element, means for biasing the element to close the valve, and means for holding the element, against the action of the bias means, in its open position until the ambient temperature drops below a predetermined level.

2. Apparatus as claimed in Claim 1, wherein the holding means comprises a substantially nonextensible support, the support having two sections interconnected by a connector which breaks the connection when the temperature drops below the predetermined level to allow the operating element to move under the action of the bias means.

3. Apparatus as claimed in Claim 2, wherein the connector comprises a water-filled container made of a material which will break when the water in the container expands on freezing.

4. Apparatus as claimed in Claim 3, wherein the container is substantially made of glass.

5. Apparatus as claimed in Claim 4, wherein the container is a tube with press-fit caps.

6. Apparatus as claimed in any one of Claims 2 to 5, wherein the support is suspended from an anchor point.

7. Apparatus as claimed in any one of Claims 2 to 6, further including switch means for raising and lowering the support to move the operating element without affecting the integrity of the connector.

8. Apparatus as claimed in any one of the preceding claims, wherein the element is a lever and the bias means are constituted by a weight.

9. Apparatus as claimed in any one of the preceding claims, wherein the element is a rack ad the bias means is a spring.

10. Apparatus as claimed in Claim 9, wherein the valve is a ball valve and the ball is drivingly connected to the rack by pinion teeth.

11. Apparatus as claimed in any one of the preceding claims, wherein the holding means allows the bias means to close progressively the valve means when the ambient temperature drops below the predetermined level.

12. Apparatus substantially as hereinbefore described, with reference to the accompanying drawings.