GB2161904A - Float-operated valve device - Google Patents

Abstract

A float-operated valve device e.g. for use in a W.C. flushing system, includes a float 9 turnable about a horizontal axis A, and a rotary disc valve (3, 4) closable by turning of the float 9 clockwise about the axis A from a lowered position (Fig. 3) to a raised position (Fig. 2). A rising water level around the float 9 initially produces an upward force upon the float 9 tending to turn the float 9 anti- clockwise but subsequently produces an upward force tending to turn the float 9 clockwise, which latter force increases rapidly as the float 9 begins to turn clockwise. The float includes a weight bias 10. <IMAGE>

Description

SPECIFICATION A float for a float-operated valve device This invention relates to a float for a floatoperated valve devices.

Such valves devices are used to control and maintain the level of liquid in a liquid storage cistern, such as a W.C. flushing cistern or similar apparatus. When the water level in the cistern falls the valve opens and recloses when the liquid level has reached a predetermined level.

Conventional valves are held closed by the float buoyancy acting through a lever or linkage mechanism forcing a sealing member, piston or diaphragm to seal closed against a seat and open as the water level in the cistern falls and reduces the buoyant closing force. In this basic cistern, the valve is continually opening and closing, since it is affected by the slightest change in cistern level and float buoyancy and by changes in the water supply pressure.

Heretofore, valve mechanisms have been developed to improve the performance of such valves, for example, servo-assisted valves which have a small float and therefore a relatively rapid shut-off action after a prolonged fill of full flow. Double float mechanisms and weighted floats are also known. All these mechanisms, however, relate to valves which are directly influenced by the water supply pressure-the higher the pressure the greater the closing force necessary and, conversely, the valves are automatically opened by supply pressure and loss of buoyancy when the cistern water level falls.Another valve mechanism is known which is said to operate in exactly the opposite manner, namely, the valve opens when a weighted float on a lever lifts a seat against the water supply pressure and, conversely, the valve is closed by the water supply pressure aided by a loss of weight as the float is submerged.

It is also known for such valve devices to include rotary disc valves in which a rotary disc formed with ports turns relative to a fixed disc also formed with ports, in order to open and close the valve by bringing the two sets of ports into and out of alignment. The discs may be of ceramic material lubricated by grease. Even with such lubrication, the disc valves can be liable not to operate smoothly, owing to stiction and friction between the discs, particularly when the grease has been worn away by the high-pressure water jets operating for relatively long periods of time from the valve ports as the conventional float slowly closes the valve. Moreover, since, during such closing, the total throughflow crosssectional area of the ports reduces gradually to a minute area, leakage through the ports is still liable to occur.

According to a first aspect of the present invention, there is provided a float-operated valve device, comprising a float chamber, means pivotally mounting the float chamber so that the chamber is turnable about a horizontal axis, a valve closable by turning of said float chamber about said axis in one sense from a lowered position to a raised position, the arrangement being such that a rising liquid level around said float chamber initially produces an upward force upon said float chamber tending to turn said float chamber in said opposite sense but subsequently produces an upward force upon said float chamber tending to turn said float chamber in said one sense, which latter force increases rapidly as said float chamber begins to turn in said one sense.

According to a second aspect of the present invention, there is provided a float for a floatoperated valve, the float comprising a float chamber and means pivotally to mount the float chamber so that the chamber is turnable about a horizontal axis, the float chamber subtending at least a right-angle at said axis.

According to a third aspect of present invention, there is provided a float for a floatoperated valve, the float comprising a float chamber and means pivotally to mount the float chamber on a rotatable valve actuating member, the float chamber having a weight bias remote from its pivot axis and being so shaped in relation to its pivot axis that, in use when the valve is open, a rising liquid level around the float chamber initially rises through levels where the float chamber exerts little moment to overcome said weight bias and subsequently rises through levels where there is a significant increase in said moment, thereby overcoming said weight bias, the float chamber pivoting to close the valve in a smooth but rapid action.

Similarly, when the valve is closed, a falling water level around the float chamber initially falls through levels where the float chamber exerts sufficient moment to maintain the valve closed and subsequently falls through levels where the moment decreases to a stage where the weight bias causes the float chamber to pivot to open the valve in a smooth but rapid action.

It will be seen that the present float operates in none of the ways in which the known valve mechanisms described above work. The present float enables the valve to be opened and closed independently of the supply pressure and relies for operation purely on the level of water in the cistern.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which: Figure 1 is a diagrammatic sectional side view of part of a float-operated valve device showing part of a float thereof, Figure 2 is a diagrammatic side view of the float in a raised, or valve-closed, position, Figure 3 is a view similar to Figure 2 but showing the float in a lowered, or valve-open, position, Figure 4 is an exploded side elevation of the device with the float in its raised position, and Figure 5 is an end view of the device with the float in its lowered position.

The drawing shows a float-operated valve device as fitted in a water storage cistern 1 6 and communicating with a water supply 2.

The valve comprises a body 1, two ceramic discs 3 and 4 with grease-lubricated, polished, sliding surfaces and with ports 1 7 which are not aligned when the valve is closed. In the embodiment shown, the disc 3 is fixed and the disc 4 can rotate to open the valve by aligning the ports 1 7.

The disc 4 is rotated by the float, which incudes an actuator 5 connected to the disc 4 and to a cranked arm 7 which is itself connected to a float chamber 9. The valve 1 is closed when the water level in the cistern has risen to a level 11 to cause the float chamber 9 to lift by buoyancy. When the float falls and the ports 1 7 in the discs 3 and 4 are aligned, water can be fed from the supply 2 and can discharge via an outlet 6.

More in detail, the float chamber 9 is attached by the arm 7 to the rotatable valve actuator 5, the arm 7 being substantially Lshaped. The float chamber 9 is substantially elongate in form and is arranged to be placed in an upright position (Figure 2) when the valve is closed, the arm 7 being connected to the float chamber 9 near its upper end. A weight bias 10, which could be a metallic or non-metallic weight or even water, is provided in or on the float chamber 9 at a position spaced from its pivot axis A and also towards the upper end of the float chamber. The float chamber 9 subtends at least a right-angle at the axis A.Moreover, the angular distance a between the raised and lowered positions of the chamber 9 is at least 40 , preferably about 60 . In order to ensure that the relatively small mechanical advantage obtained by the relatively short radius between the chamber 9 and the axis A should nevertheless cause the valve 3, 4 to operate smoothly, the maximum total contact area between the discs 3 and 4 is advantageously 40 mm.2, preferably 30 mm.2, so reducing problems with stiction and friction between the discs.

Figures 2 and 3 show that the float chamber is so shaped in relation to its pivot axis that, in use when the valve is open, as shown in Figure 3, a liquid level rising from the level 1 2 around the float chamber initially rises through levels where the buoyancy of the float chamber initially tends to turn the chamber anticlockwise with the weight bias 10, but against some stop means (not shown), later exerts insufficient clockwise moment to overcome the weight bias 10 and subsequently rises through levels towards the level 11 where there is a significant increase in that moment, thereby overcoming the weight bias 10, the float chamber pivoting to close the valve in a smooth but rapid action.As the weight bias is overcome and the chamber 9 begins to turn, the transfer of the buoyancy from one side of the vertical V through the axis A to the other side thereof rapidly increases that moment so that friction and stiction are easily overcome and the valve rapidly closes; in fact the disc 4 is turned through a significant angle beyond the actual point of closing of the valve, thereby ensuring a significant surface overlap between the discs 3 and 4 to prevent leakage.Similarly, with the valve closed, as shown in Figure 2, a falling water level from the water level 11 around the float chamber initially falls through levels where the float chamber exerts sufficient clockwise moment to maintain the valve closed and subsequently falls through levels where the moment decreases to a stage where the weight bias causes the float chamber 9 to pivot to open the valve in a smooth but rapid action.

The reason that this happens can be explained with reference to Figure 3, where the two shaded areas 1 4 and 1 5 are on either side of the vertical V and represent the buoyancy effect supposing that the water level has reached the level 11.

When the water level in the cistern 1 6 falls to the level 12, the weight bias 10 causes the float chamber 9 to fall thus rotating the disc 4 to align the ports 1 7 thereby opening the valve. The arm 7 is so arranged that the float chamber 9 will always move the same angular displacement a in relation to the line V and so the float will lower to the position shown in Figure 3.

As water enters the cistern 16, the water level 1 2 will rise and give a buoyant effect to the float chamber 9. The first effect will be mainly on the shaded area 14, which, coupled with the weight bias 10, will hold the valve disc 4 in its open position because the float chamber 9 cannot move further anticlockwise. As the water level rises further and approaches the level 11, then more and more buoyancy effect will be created on the side of the shaded area 1 5 which will ultimately overcome the effect of the weight bias 10 and the buoyancy effect on the side of the shaded area 14. The float chamber 9 will then rise smoothly and relatively quickly, thus causing the disc 4 to be rotated to bring the ports 1 7 out of relative alignment with one another, thereby closing the valve. Thus, a rapid refill of the cistern 1 6 is achieved without the prolonged throttle and dripping effect of conventional valves.

The arm 7 is provided with height adjustment holes 8 which can set the predetermined water level 11 and are so arranged that in operation and with adjustment the float chamber 9 always is displaced by the same angular movement thus ensuring the above-described effect of buoyancy on both sides of the float chamber.

Referring to Figs. 4 and 5, which show the device in more detail, a water inlet pipe 1 6 has its horizontal outlet end provided with an O-ring seal 1 7 fitting in the body 1 and retained therein by a U-shaped locking clip 1 8 engaging, through apertures 1 9 formed in the body 1, with diametrically opposite recesses 20 in the outlet end of the pipe 1 6. A water filter 21 is provided between the pipe 1 6 and the body 1. The outlet 6 is connected via a pipe 22 with a downpipe 23 which is of a mesh form to silence the water flow into the cistern. The arm 7 is fastened to the actuator 5 by means of a screw 24 screwed into the end of the actuator 5. Interposed between the arm 7 and the body 1 is a washer 25 formed on one face with a projection 26 which engages with the arm 7 to ensure that the washer turns with the chamber 9, and on its opposite face with a projection 27 which engages in an arcuate slot in the body 1 to provide, at one end of that slot, the aforementioned stop means. The bias 10 consists of a horizontal rod.

Claims (11)

1. A float-operated valve device, comprising a float chamber, means pivotally mounting the float chamber so that the chamber is turnable about a horizontal axis, a valve closable by turning of said float chamber about said axis in one sense from a lowered position to a raised position, the arrangement being such that a rising liquid level around said float chamber initially produces an upward force upon said float chamber tending to turn said float chamber in said opposite sense but subsequently produces an upward force upon said float chamber tending to turn said float chamber in said one sense, which latter force increases rapidly as said float chamber begins to turn in said one sense.

2. A device as claimed in claim 1 and further comprising weight bias of said float chamber and spaced from said axis and tending to turn said float chamber in said opposite sense.

3. A device as claimed in claim 1 or 2, wherein said float chamber is pivotally mounted as aforesaid by way of an arm connected to and protruding from a side of said float chamber.

4. A device as claimed in any preceding claim, wherein the said angular distance between said lowered position and said raised position is at least 40 .

5. A device as claimed in any preceding claim, wherein said float chamber subtends at least a right-angle at said axis.

6. A device as claimed in any preceding claim, wherein said valve comprises a fixed first port and a rotary valve member formed with a second port and connected to said float chamber for turning from an open position which corresponds to said lowered position and in which said first port and said second port are in communication with each other and a closed position which corresponds to said raised position and in which said second port is out of communication with said first port and is spaced significantly from said first port.

7. A device as claimed in any preceding claim, and further comprising means enabling adjustment of the level of said float chamber relative to said valve.

8. A float for a float-operated valve, the float comprising a float chamber and means pivotally to mount the float chamber so that the chamber is turnable about a horizontal axis, the float chamber subtending at least a right-angle at said axis.

9. A float for a float-operated valve, the float comprising a float chamber and means pivotally to mount the float chamber on a rotatable valve actuating member, the float chamber having a weight bias remote from its pivot axis and being so shaped in relation to its pivot axis that, in use when the valve is open, a rising liquid level around the float chamber initially rises through levels where the float chamber exerts little moment to overcome said weight bias and subsequently rises through levels where there is a significant increase in said moment, thereby overcoming said weight bias, the float chamber pivoting to close the valve in a smooth but rapid action.

10. A float-operated valve device, substantially as hereinbefore described with reference to Figs. 1 to 3, or Fig. 4, of the accompanying drawings.

11. A float, substantially as hereinbefore described with reference to Figs. 1 to 3, or Fig. 4, of the accompanying drawings.