GB2244793A - A float controlled valve - Google Patents

Abstract

A float-controlled valve for a cistern (12) comprises a valve housing (13) formed with inlet and outlet ports (29, 30), a ball closure member (22) having a through-passage (23) housed between compressible annular seals, (31, 32) so as to be rotatable between an open position, and a closed position, and a control arm (25) connected to the closure member (22) and carrying a float member (26). Both the position of the float member (26) on the control arm (25) and the compression of the annular seals (31, 32) can be varied. The closure member may also be cylindrical or conical in shape. <IMAGE>

Description

A FLOAT-CONTROLLED VALVE The present invention relates generally to floatcontrolled valves, and particularly to a float-controlled valve suitable for controlling the inlet to a cistern or like such container.

Traditionally, the inlet to a cistern is controlled by a float-operated shutter valve having a conical valve seat into contact with which a valve shutter having a conically-tapered operating end can be moved by a lever mechanism controlled by a float arm pivoted to the lever mechanism and having a buoyant ball float at its free end.

Such known float-controlled valves have the disadvantage that, because the float needle is forced against the conical valve seat in opposition to the flow of liquid through the valve, the force of the liquid opposes the closure of the valve and increases the valve closing force to a point where the length of the lever arm required to apply the necessary moment to close the valve, and the size of the float necessary to achieve the required turning force of the lever are both relatively great.

this traditional design, which has been substantially unmodified for many years, results in the necessity to form cisterns of certain minimum sizes and a certain minimum width in order to achieve the necessary forces for satisfactory valve closure. In many circumstances, however, it would be convenient to be able to design the cistern shape differently, especially to be able to reduce the width of the cistern for design considerations.

The present invention seeks to provide a float-controlled valve in which the closing force is not dependent on the force of the liquid through the valve, and which, moreover, is substantially less than that of a conventional taper valve so that the physical dimensions of the float and the length of a float arm can both be made substantially smaller whilst nevertheless still generating sufficient force for satisfactory and certain closure of the valve when the liquid level in the cistern reaches the required value.

Accordingly, the present invention provides a floatcontrolled valve for a cistern or like such container, comprising a valve housing with an inlet port, an outlet port and a cavity formed with a valve seat, a valve shutter member having a through-passage cooperatingly housed in the valve seat for rotation between an open position, in which the through-passage provides communication between the inlet port and the outlet port, and a closed position in which communication between the inlet port and the outlet port is cut off, and a control arm connected to the shutter member and carrying a float member, the control arm being arranged to rotate the shutter member between said positions as the height of the float member varies with variation of the liquid level in the cistern in use. The valve shutter member is preferably spherical.

The present invention further provides a float-controlled valve for a cistern or like such container, comprising a valve housing with an inlet port, an outlet port and an at least partly-spherical seating for a valve shutter member having a corresponding part-spherical outer shape and a passage therethrough, the said valve shutter member being turnable about an axis and the said passage therein communicating with the inlet port and the outlet port when the valve shutter member is in a first orientation or range of orientations about the said axis, and which intercepts communication between the inlet port and the outlet port when the valve shutter member is in a second orientation about the said axis, and a control arm for controlling the orientation of the valve shutter member about the said axis, the said control arm having a buoyant member secured thereto whereby to cause the arm and the said valve shutter member to turn about the said axis as the level of liquid within the cistern varies.

Because a spherical valve shutter member can turn about its axis to bring the passage therethrough into alignment with the inlet and outlet ports, or to move it out of alignment therewith, without making a substantial difference to the turning force required, and in particular without requiring that the force closing the valve be maintained as in the case of a conventional taper valve, it can be arranged that the force required to close the valve is very much lower than that required to close the conventional valve.

It will be understood herein that reference to a partspherical valve or valve seat will also comprehend a valve in which the valve seat and valve shutter member are of cylindrical or part-cylindrical form, the essential requirement being that the cross-section of the valve seat and valve shutter member, in a direction transverse that of the flow path, should be circular or part-circular.

Any body, including a conical body having a circular section could, therefore, be used in such a valve.

In a preferred embodiment of the invention the valve housing is made in several parts with at least one compressible annular seal located between two adjacent parts thereof, the annular seal being shaped to define a circular contact region with the valve shutter member.

Preferably the parts of the valve shutter member can be clamped together by a greater or lesser clamping force such that the annular seal, upon compression, is caused to bulge more or less into the cylindrical or spherical cavity constituting the valve seat occupied by the valve shutter member, whereby to adjust the sealing pressure applied thereto and thus the resistance to turning of the valve shutter member.

In the preferred embodiment of the invention the valve housing has a central housing body with two such compressible seals one on either side of the body, held in place by respective end members.

The position of the buoyant member on the control arm of the float valve may itself be adjustable in order to adjust the turning force applied when the level of liquid within the cistern changes and this adjustment, together with the adjustment of the compression of the annular seals, gives a wide range of potential adjustments to suit different circumstances and different cistern configurations.

One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of a float valve formed as a first embodiment of the present invention: Figure 2 is a schematic side view of a second embodiment of the invention: Figure 3 is an enlarged sectional view of the embodiment of Figure 2 illustrating the internal configuration of the valve: Figure 4 is a schematic side view of a third embodiment of the invention: Figure 5 is a view similar to Figure 3 showing the embodiment of Figure 4 in greater detail: and Figure 6 is a sectional view taken on line V - V of Figure 5 but showing only part of the valve.

Referring now to the drawings, Figure 1 illustrates a cistern generally indicating 12 having an inlet valve generally indicated 13 for controlling the flow of liquid through an inlet duct 14 which is secured to a side wall 15 of the cistern 12 by an appropriate clamping fitting 16.

The valve 13, the interior of which is shown in more detail in Figure 3, comprises a main valve body 17 having a part-spherical socket 18 and an auxiliary body 19 also having a part-spherical socket 20 which matches that of the socket 18. The auxiliary body 19 is screw-fitted into the body 17 so that, together, the two part-spherical sockets 18, 20 form a spherical cavity 21 within which is housed a spherical valve shutter member 22 having a transverse passage 23 extending therethrough. The spherical shutter member 22 also has a laterally-extending control stub shaft or spindle 24 with a prismatic end to which is secured one end of a float arm 25 the free end of which is attached to a buoyant body or float 26.As the level of liquid in the cistern 12, identified by the surface line 27, rises, for example, to the broken line position 28 the float 26 is caused to rise to the position shown in broken outline and identified with reference numeral 26' turning the control arm 25 to the position illustrated 25' and thereby causing the spherical valve body 22 to turn through a corresponding angle alpha. When the level in the cistern rises to its maximum desired value the angle alpha increases to a point such that the passage 23 in the valve shutter member 22 is turned to the position illustrated in Figure 3 where it completely intercepts communication between an inlet port 29 of the valve body 17 and an outlet port 30 in the auxiliary valve body 19.

To ensure a seal between the valve seat defined by the part-spherical sockets 18, 20 and the spherical shutter member 22 there are provided two annular compressible seals 31, 32 the degree of compression of which can be adjusted by the degree to which the auxiliary body 19 is screwed into the valve body 17. The seals 31, 32 may be made form a suitable elastomer, possibly impregnated with polytetrafluorethylene or like low-friction material, so that an adequate seal between the valve shutter 22 and the valve seat defined by the two part-spherical sockets 18, 20 is achieved whilst, at the same time, determining the required force to turn the valve shutter 22.

It will be appreciated that, in contrast with known float-controlled cistern valves, the length of the arm 25 and the size of the float 26 can be made very much smaller because the force required to turn the valve shutter member 22 is not dependent on the pressure of liquid in the inlet duct 14 and, in particular, the buoyancy of the float 26 does not have to maintain the valve in its closed position against the liquid pressure.

As can be seen from Figure 2, moreover, the float 26 which is illustrated in Figure 1 as being a conventional armterminating ball, may be replaced by the float 33 which is adjustable in position along the arm 25. It will be appreciated that in Figure 2 those components which are the same as or fulfil the same function as corresponding components in the embodiment of Figure 1 have been identified with the same reference numerals. The embodiment of Figure 2, therefore, is suitable for use in a wide range of cisterns where the precise closing force can be adjusted by suitably adjusting the position of the float 33 along the arm 25.Once such adjustment has been made, moreover, the part of the arm 25 projecting beyond the float 33 may be removed so that the float valve may be fitted into a very much narrower cistern, for example as identified by the distance D between the side wall 15 and the vertical line in Figure 2 identified by the reference L illustrating the minimum width of cistern which may be designed for use with the float valve of the invention.

It is believed that float valves formed as embodiments of this invention should also help to prevent water hammer in the water delivery system of a building.

Reference is now made to Figures 4 to 6 of the drawings in which a third variant of the invention is shown in greater detail. Components which are similar to those shown in Figures 1 to 3 are again indicated by the same reference numerals and only the differences between this embodiment and those of Figures 1 to 3 will be mentioned below.

It will be seen from Figure 4 that the arrangement of this embodiment is very compact. A ball float 26 is employed which is carried on a straight control arm 25a rather than the cranked arm 25 of the previous embodiments.

Figure 5 of the drawings shows that the main valve body 17 and the auxiliary valve body 19 have sockets 18, 20 which define part cylindrical seats for 34, 35 for the annular seals 31, 32 rather than the part-spherical seats shown in Figure 3. The seats 34, 35 each have a cylindrical circumferential wall 36 and one end wall 37, the other end opening into the valve cavity housing the spherical shutter member 22. The seals 31, 32 are shaped to mate with the seats 34, 35 respectively and have faces 38, 39 facing into the cavity 21 for sealing contact with the shutter member 22.The faces 38, 39 may be part spherical or may be conical and substantially tangential to the surface of the member 22 as shown, the material constituting the seals 31, 32 being resiliently deformable so that, when the auxiliary valve body 19 is screwed into the main body 17, the faces 38, 39 are deformed to contact the member 22 over a greater surface area.

It is also seen in Figure 5 that the spherical shutter member 22 has a through passage 23 which is of larger diameter than the inlet port 29 and the outlet port 30 of the valve body 13, rather than the same diameter as shown schematically in Figure 3. This means that, when the cistern in which the valve is fitted is being refilled and the float 26 rises turning the shutter member 22 gradually from the open position shown in Figure 5 towards its closed position, the flow cross-section through the valve is not reduced as quickly as in the embodiment of Figure 3 and hence the cistern refills more quickly.

Claims (8)

1. A float-controlled valve for a cistern or like such container, comprising a valve housing with an inlet port, an outlet port and a cavity formed with a valve seat, a valve shutter member having a through-passage cooperatingly housed in the valve seat for rotation between an open position, in which the through-passage provides communication between the inlet port and the outlet port, and a closed position in which communication between the inlet port and the outlet port is cut off, and a control arm connected to the shutter member and carrying a float, the control arm being arranged to rotate the shutter member between said positions as the height of the float member varies with variation of the liquid level in the cistern in use.

2. A float-controlled valve as claimed in Claim 1, in which the valve shutter member is spherical.

3. A float-controlled valve as claimed in Claim 1 or Claim 2, in which the valve housing is made in several parts and at least one compressible annular seal is located between one part thereof and the valve shutter member to define a circular contact region with the shutter member.

4. A float-controlled valve as claimed in Claim 3, in which the valve housing has two parts, one formed with the inlet port and the other with the outlet port, and there are two such compressible seals one between each part and the valve shutter member.

5. A float-controlled valve as claimed in Claim 3 or Claim 4, in which the compression force on the or each seal, and thus the resistance of the shutter member to rotation, is adjustable.

6. A float-controlled valve as claimed in any of the preceding Claims, in which the position of the float member is adjustable along the said control arm.

7. A float-controlled valve as claimed in any one of the preceding Claims in which the shutter member throughpassage has a larger flow cross-section than the inlet port and the outlet port.

8. A float-controlled valve for a cistern or like such container substantially as herein described with reference to and as shown in the accompanying drawings.