GB2133902A - Float-operated cistern valve assemblies - Google Patents

Abstract

In order to reduce the noise produced in a cistern valve assembly during the closing of the valve seat, the assembly incorporates a flow regulator comprising a vortex chamber (1) having a tangential inlet (4) for connection to the water supply, and an axial outlet (5) provided in a nozzle portion (24) of an insert (18). The outlet is partitioned by a cruciform flow straightener (9) to reduce cavitation. The opposed walls of the vortex chamber are parallel to prevent the formation of a pure vortex flow. A spring strip 6 may be provided and has the effect of preventing vortex formation at low pressure differential and allowing the flow to go directly from inlet 4 to outlet 5. The strip is progressively deflected by increasing flow to permit a vortex to develop. <IMAGE>

Description

SPECIFICATION Float-operated cistern valve assemblies This invention relates to float-operated cistern valve assemblies of the kind comprising a valve seat controlling flow between a water inlet and an outlet discharging into the cistern, and a valve member adapted to be urged against the seat by a float.

With the usual cistern valves a valve member is progressively urged towards a valve seat by a float as the cistern is filled until finally the valve member engages the seat to terminate filling of the cistern.

A problem with this arrangement is that with the water inlet connected to a mains supply much noise is produced during the latter stage of filling when the valve seat is throttled by the approaching valve member. That stage is inevitably prolonged because the throttling reduces the rate of filling of the cistern.

Although pressure balanced valve members have been employed in order to reduce the noise, the supply passage to the balance chamber can become blocked in use, and such valves tend to fail in the open conditions, which is not desirable.

According to the invention a cistern valve assembly of the kind set forth incorporates a flow regulator comprising a vortex chamber having a chamber inlet and a chamber outlet, the arrangement being such that a substantially vortical flow is produced within the chamber, at least for a range of pressures between the chamber inlet and outlet, the flow regulator being arranged in series with the valve seat.

The flow regulator makes use of one characteristic of the flow within a vortex chamber which is that the flow rate increases at only a very small rate with increasing pressure between the chamber inlet and outlet.

Regulation of the flow by the vortex regulator during the latter stage of closing of the valve seat helps to reduce the noise produced.

The flow regulator is preferably located between the water inlet and the valve seat, but in some cases it may be located between the outlet and the float-operated valve and a discharge opening leading into the cistern.

The vortex chamber is preferably defined by a pair of substantially parallel opposed side walls, and by a substantially cylindrical wall, the chamber inlet leading substantially tangentially into the chamber through the cylindrical wall, with the chamber outlet leaving normally from substantially the centre of one side wall.

In order to produce a pure vortex flow it is usual for the chamber side walls to be spaced closer together with decreasing radius from the chamber outlet, but a pure vortex flow would in many cases present an unacceptably high resistance to flow for a cistern valve assembly, which is why we prefer to use substantially parallel chamber walls.

In applications where a large range of operating pressures is likely to be encountered the flow regulator is preferably provided with means for inhibiting formation of a vortex flow at relatively low operating pressures, so that the flow resistance provided by the vortex flow is generated at higher pressures only.

A convenient method of inhibiting the vortex comprises a resilient member located within the chamber and positioned to inhibit formation of a vortex flow but such that at high pressures acting between the chamber inlet and outlet the resilient member is deflected to lie against a wall of the chamber and permit a substantially vortical flow to develop.

The resilient member preferably comprises a curved strip of resilient material with one end attached to the cylindrical wall of the chamber adjacent to the inlet, so that at high pressures the strip is deflected to lie against the cylindrical wall.

The strip is preferably curved through substantially 1 800 with its free end positioned substantially adjacent to the chamber outlet.

Brass, plastics or other suitable resilient material may be used for the strip.

We have found that cavitation at the centre of the vortex can produce undesirable noise, and in order to reduce this noise we propose the use of a flow straightener in or adjacent to the chamber outlet to inhibit circulatory flow of water at the outlet.

The flow straightener conveniently comprises one or more baffles extending transversely across the chamber outlet.

The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a schematic cross-sectional view of a flow regulator in accordance with the invention for use in a float-operated cistern valve assembly and taken on the line 1-1 of Figure 2; Figure 2 is a section on the line 2-2 of Figure 1; Figure 3 is a vertical cross-section of a combined flow regulator and cistern valve assembly in accordance with the invention and showing the cistern valve in the open condition; and Figure 4 is a section on the line 4-4 of Figure 3 of the assembly housing and pedestal.

A vortex chamber 1 is defined by a pair of opposed parallel side wails 2, 2' and by a cylindrical wall 3, the wall 3 being penetrated by a tangential chamber inlet 4 which is connected in use directly to a high pressure mains water supply. An axial chamber outlet 5 extends normally through side wall 2' and is connected in use to the inlet of a conventional float-operated cistern valve, not shown, so that the regulator acts to regulate the flow from the mains supply to the inlet of the cistern valve itself.

The cistern valve may for example be of the well known kind in which a plunger is reciprocated in a valve housing by a lever arm which carries a float, and a diaphragm valve member for engagement with a valve seat is connected between the plunger and the valve housing.

The spacing w of the side walls 2, 2' is typically 3 mm. A resilient brass strip 6 has a width such that it is a sliding fit between side walls 2, 2', and has one end 7 attached to the wall 3 adjacent to the chamber inlet 4. The strip in its free state as shown extends arcuately through slightly more than 1800, such that its free end 8 is substantially adjacent to the chamber outlet 5 and such that its concave side faces the direction of flow from the inlet 4. At low pressure differences between chamber 4 and chamber outlet 5 the strip 6 will be substantially undeflected and will deflect the flow substantially directly from inlet 4 to outlet 5 to prevent the formation of a vortex, but at increasing pressure differentials the strip 6 will be progressively deflected by the flow until it lies against the wall 3 to permit a vortex flow to develop.

A crossed baffle 9 is provided in the entrance to outlet 5 to inhibit circulatory flow and thus cavitation in the centre of chamber 1 and thereby reduce noise.

For convenience of manufacture the housing is preferably made in two parts, a first part of shallow cup shape defining cylindrical wall 3 and outlet 5, and a circular plate for closing the mouth of the cup and to define surface 2. The end 7 of strip 6 may then be received and trapped in a slot in the cup member, to be retained in position on assembly of the plate.

The ratios of the diameters of the inlet and outlet 4 and 5 to the diameter of the chamber 1 determine the pressure/flow characteristics of the regulator, and the precise dimensions for a particular application are best determined by experimentation.

Figures 3 and 4 show a combined flow regulator and cistern valve assembly. A cylindrical housing 11 is formed with a stepped bore 12 and comprises an integral tubular outlet 13 and a water inlet 14, the bore 1 5 of the inlet 14 leading tangentially into a cylindrical vortex chamber 1 6 defined between an end wall 17 of the housing and an insert 1 8. In this construction no spring has been provided in the vortex chamber, since the inlet 1 4 is intended to be supplied with water at mains pressure.

The insert 1 8 comprises a sleeve portion 1 9 which is received in the larger diameter portion 20 of housing bore 12 and abuts the step 21 between bore portion 20 and smaller diameter bore portion 22, and an annular end wall portion 23 from which depends a nozzle portion 24 directed inwardly of the sleeve portion 1 9. End wall portion 23 is received within smaller bore portion 22 and is sealed to the bore wall by an annular seal 25 received in an external annular recess in portion 23.

End wall portion 23 is provided with a planar side face 26 on its side opposing wall 1 7 so as to provide a side face to the vortex chamber 1 6 that is parallel to the opposing planar side face 27 of wall 17.

Sleeve portion 23 is provided with an outlet port 28 which is arranged to be in register with outlet 13 by a keyed connection 29. The radially outer periphery 30 of an elastomeric valve diaphragm 31 is clamped between the outer end of insert 1 8 and the rim of a cup-shaped carrier 32 for an axially extending valve plunger 33. The enlarged inner end 34 of plunger 33 engages with one side of valve member 35 integral with diaphragm 31, the other side of which is adapted to cooperate with an annular valve seat 36 provided by the free end of nozzle portion 24.

Valve member 35 is shaped in known manner at 37 to reduce the noise produced in the final stages of closure of valve seat 36 by valve member 35.

A cap nut 37 retains the carrier 32 in position in firm engagement with diaphragm periphery 30 which thereby seals the outer end of outlet chamber 38.

Carrier 32 is provided with an integral pivot lug 39 for a float arm, not shown, which carries an abutment acting on plunger 33 to urge plunger 33 inwardly to close seat 36 on lifting of the float.

A cruciform flow straightener 40 is integrally provided in the larger diameter part of nozzle portion 24 for the purpose previously described.

Inlet 14 is provided with an integral plug 41 which is sealingly secured by friction welding in the end 42 of a tubular pedestal 43, and the bore 44 of the plug 41 is made of substantially frustoconical shape to encourage the production of streamline flow in the inlet bore 1 5, thereby to promote a substantially vortical flow in chamber 16.

Outlet 13 leads to a discharge assembly, not shown, which can be of any convenient form such as that disclosed in our Patent Specification No.

2074292A.

It will be appreciated that the provision of the valve seat 36 on the nozzle portion 24 leads to a particularly compact arrangement, and that the use of an insert 18 enables the cost of the assembly to be kept to a minimum.

Since there is no balance chamber in a valve of this kind there is no passage that is likely to become blocked with debris, and the assembly can therefore be made more reliable in operation.

The number of moving parts is kept to a minimum.

Claims (Filed on 19/1/84) 1. A cistern valve assembly of the kind set forth incorporating a flow regulator comprising a vortex chamber having a chamber inlet and a chamber outlet, the arrangement being such that a substantially vortical flow is produced within the chamber, at least for a range of pressures between the chamber inlet and outlet, the flow regulator being arranged in series with the valve seat.

2. An assembly as claimed in claim 1 in which the flow regulator is located between the water inlet and the valve seat.

3. An assembly as claimed in claim 1 or claim 2 in which the vortex chamber is defined by a pair

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. connected between the plunger and the valve housing. The spacing w of the side walls 2, 2' is typically 3 mm. A resilient brass strip 6 has a width such that it is a sliding fit between side walls 2, 2', and has one end 7 attached to the wall 3 adjacent to the chamber inlet 4. The strip in its free state as shown extends arcuately through slightly more than 1800, such that its free end 8 is substantially adjacent to the chamber outlet 5 and such that its concave side faces the direction of flow from the inlet 4. At low pressure differences between chamber 4 and chamber outlet 5 the strip 6 will be substantially undeflected and will deflect the flow substantially directly from inlet 4 to outlet 5 to prevent the formation of a vortex, but at increasing pressure differentials the strip 6 will be progressively deflected by the flow until it lies against the wall 3 to permit a vortex flow to develop. A crossed baffle 9 is provided in the entrance to outlet 5 to inhibit circulatory flow and thus cavitation in the centre of chamber 1 and thereby reduce noise. For convenience of manufacture the housing is preferably made in two parts, a first part of shallow cup shape defining cylindrical wall 3 and outlet 5, and a circular plate for closing the mouth of the cup and to define surface 2. The end 7 of strip 6 may then be received and trapped in a slot in the cup member, to be retained in position on assembly of the plate. The ratios of the diameters of the inlet and outlet 4 and 5 to the diameter of the chamber 1 determine the pressure/flow characteristics of the regulator, and the precise dimensions for a particular application are best determined by experimentation. Figures 3 and 4 show a combined flow regulator and cistern valve assembly. A cylindrical housing 11 is formed with a stepped bore 12 and comprises an integral tubular outlet 13 and a water inlet 14, the bore 1 5 of the inlet 14 leading tangentially into a cylindrical vortex chamber 1 6 defined between an end wall 17 of the housing and an insert 1 8. In this construction no spring has been provided in the vortex chamber, since the inlet 1 4 is intended to be supplied with water at mains pressure. The insert 1 8 comprises a sleeve portion 1 9 which is received in the larger diameter portion 20 of housing bore 12 and abuts the step 21 between bore portion 20 and smaller diameter bore portion 22, and an annular end wall portion 23 from which depends a nozzle portion 24 directed inwardly of the sleeve portion 1 9. End wall portion 23 is received within smaller bore portion 22 and is sealed to the bore wall by an annular seal 25 received in an external annular recess in portion 23. End wall portion 23 is provided with a planar side face 26 on its side opposing wall 1 7 so as to provide a side face to the vortex chamber 1 6 that is parallel to the opposing planar side face 27 of wall 17. Sleeve portion 23 is provided with an outlet port 28 which is arranged to be in register with outlet 13 by a keyed connection 29. The radially outer periphery 30 of an elastomeric valve diaphragm 31 is clamped between the outer end of insert 1 8 and the rim of a cup-shaped carrier 32 for an axially extending valve plunger 33. The enlarged inner end 34 of plunger 33 engages with one side of valve member 35 integral with diaphragm 31, the other side of which is adapted to cooperate with an annular valve seat 36 provided by the free end of nozzle portion 24. Valve member 35 is shaped in known manner at 37 to reduce the noise produced in the final stages of closure of valve seat 36 by valve member 35. A cap nut 37 retains the carrier 32 in position in firm engagement with diaphragm periphery 30 which thereby seals the outer end of outlet chamber 38. Carrier 32 is provided with an integral pivot lug 39 for a float arm, not shown, which carries an abutment acting on plunger 33 to urge plunger 33 inwardly to close seat 36 on lifting of the float. A cruciform flow straightener 40 is integrally provided in the larger diameter part of nozzle portion 24 for the purpose previously described. Inlet 14 is provided with an integral plug 41 which is sealingly secured by friction welding in the end 42 of a tubular pedestal 43, and the bore 44 of the plug 41 is made of substantially frustoconical shape to encourage the production of streamline flow in the inlet bore 1 5, thereby to promote a substantially vortical flow in chamber 16. Outlet 13 leads to a discharge assembly, not shown, which can be of any convenient form such as that disclosed in our Patent Specification No. 2074292A. It will be appreciated that the provision of the valve seat 36 on the nozzle portion 24 leads to a particularly compact arrangement, and that the use of an insert 18 enables the cost of the assembly to be kept to a minimum. Since there is no balance chamber in a valve of this kind there is no passage that is likely to become blocked with debris, and the assembly can therefore be made more reliable in operation. The number of moving parts is kept to a minimum. Claims (Filed on 19/1/84)

1. A cistern valve assembly of the kind set forth incorporating a flow regulator comprising a vortex chamber having a chamber inlet and a chamber outlet, the arrangement being such that a substantially vortical flow is produced within the chamber, at least for a range of pressures between the chamber inlet and outlet, the flow regulator being arranged in series with the valve seat.

2. An assembly as claimed in claim 1 in which the flow regulator is located between the water inlet and the valve seat.

3. An assembly as claimed in claim 1 or claim 2 in which the vortex chamber is defined by a pair

of substantially parallel opposed side walls, and by a substantially cylindrical wall, the chamber inlet leading substantially tangentially into the chamber through the cylindrical wall, with the chamber outlet leaving normally from substantially the centre of one side wall.

4. An assembly as claimed in any of the preceding claims comprising means for inhibiting the formation of a vortex flow at relatively low operating pressures.

5. An assembly as claimed in claim 4 in which the vortex inhibiting means comprises a resilient member located within the chamber and positioned to inhibit formation of a vortex flow but such that as high pressures acting between the chamber inlet and outlet the resilient member is deflected to lie against a wall of the chamber and permit a substantially vortical flow to develop.

6. An assembly as claimed in any of the preceding claims comprising a flow straightener in or adjacent to the chamber outlet so arranged as to inhibit circulatory flow of water at the outlet.

7. An assembly as claimed in claim 6 in which the flow straightener comprises one or more baffles extending transversely across the chamber outlet.

8. An assembly as claimed in any of the preceding claims in which the vortex chamber is defined between a wall of a housing and a removable insert located within the housing, the housing being provided with the chamber inlet, and the chamber outlet being provided in a substantially nozzle-shaped portion of the insert which is directed away from the vortex chamber.

9. An assembly as claimed in claim 8 in which the valve seat is provided on the free end of the nozzle-shaped portion.

10. A cistern valve assembly of the kind set forth and substantially as described with reference to Figures 1 and 2 of the accompanying drawings.

11. A cistern valve assembly of the kind set forth and substantially as described with reference to Figures 3 and 4 of the accompanying drawings.