GB2303153A - Valve-discharge apparatus for a cistern - Google Patents

Abstract

Valve Discharge apparatus for a cistern (11) comprises a sealing shuttle (34) movable between a sealing position sealing an outlet (48) and a displaced position in which the sealing shuttle is retracted from the sealing position so as to permit fluid to be discharged from the cistern via the discharge outlet. The shuttle is retracted in response to an increase in air pressure when a valve is actuated to supply pressurised air. Desirably, the air is arranged to be pressurised as the receptacle becomes charged with fluid.

Description

Receptacle Discharge Apparatus The present invention relates to receptacle discharge apparatus, such as, for example, apparatus suitable for discharging water from a plumbing cistern, water tank or the like.

According to the present invention, there is provided discharge apparatus for discharging a receptacle of fluid, the apparatus comprising: (a) sealing means movable between a sealing position in which a discharge outlet provided for the receptacle is substantially sealed to the passage of fluid therethrough, and a displaced position in which the sealing means is displaced from the sealing position thereby permitting fluid to be discharged from the receptacle via the discharge outlet; (b) displacement means arranged to move the sealing means from the sealing position to the displaced position, the displacement means so acting in response to an increase in air pressure; and (c) valve means actuatable to supply pressurised air to operate the displacement means.

It is preferred that the apparatus further comprises pressurisation means arranged to pressurise air for operation of the displacement means. Desirably, the pressurisation means is arranged to pressurise a volume of air as the receptacle becomes charged with fluid.

Advantageously, the pressurisation means comprises an upwardly extending conduit or tube positioned in the interior of the receptacle arranged to contain a column of air which becomes pressurised as the receptacle fills with fluid.

In the context of the present invention, pressurised air should be taken to mean air having a pressure greater than ambient atmospheric.

It is preferred that the displacement means comprises a movable element, movable in response to variation in air pressure acting thereon. The movable element may, for example, be a piston or more preferably a displaceable diaphragm.

The movable element of the displacement means is preferably linked or connected to the sealing means such that movement of the movable element effects corresponding movement of the sealing means. Desirably, the displacement means is arranged to move the sealing means in the axial direction of the discharge outlet. Advantageously, the displacement means is arranged to act so as to retract the sealing means upwardly from the sealing position.

The sealing means preferably comprises a sealing element arranged to seal around an annular shoulder or rim of the discharge outlet.

Actuation of the valve means preferably directs pressurised air to the displacement means, preferably via a tube or conduit which may be flexible.

Preferably, the valve means is arranged to be normally biased to a closed position in which closed position pressurised air is inhibited from leaving the upwardly extending tube or conduit which comprises the pressurisation means.

The invention will now be further described in a specific embodiment, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic sectional representation of a receptacle provided with discharge apparatus according to the invention; Figure 2 is a schematic sectional representation of a part of the discharge apparatus of Figure 1; Figure 3 is a schematic sectional representation of a further part of the discharge apparatus of Figure 1; and Figure 4 is a schematic sectional representation of a preferred embodiment of the part of the discharge apparatus shown in Figure 2.

Referring to the drawings, cistern 11 is of substantially, conventional construction and carries valves 2, 14 in standard locating holes. Conventional ball valve 14 controls the water level in cistern 11 and is of a type well known in the art.

Referring to Figure 3, body 21 of valve 2 has an axial passage 41 provided with seats for sealing member 22 and tappet 25. An angled passage 42 connects axial passage 41 with an axial passage (port A), in cap 23. Sealing member 22 is axially movable within cap 23 against spring 24. Tappet 25 lies between sealing member 22 and pushbutton 26 and has a small axial clearance when at rest. Spring 27 reacting against body 21, holds pushbutton 26 away from tappet 25. Nut 28 secures the valve assembly to cistern 11; reed 29 allows air to flow from body 21 to cap 23 (port A) but restricts flow into body 21 thereby effectively acting as a one-way valve.

Referring to Figure 2, body 31 is secured to cistern 11, and comprises an upper chamber 37 closed by diaphragm 32 (retained by ring 33) and guidance means for a shuttle 34. An annular chamber 39 surrounds the lower portion of body 31 serving to trap air which becomes pressurised in flexible tube 12 as cistern 11 fills with water.

Retractor 35 is driven by diaphragm 32 to lift shuttle 34 when air pressure is ported to chamber 37 to act on the diaphragm 32. Spring 36 holds shuttle 34 in contact with body 31 when at rest. Shuttle 34 is provided with a skirt 38 at its lower end to seal against rim 47 of discharge outlet 48 and has a transverse septum 49 pierced to locate retractor shaft 35a.

Further holes in septum 49 allow excess water to drain away in the event of a malfunction of valve 14.

When cistern 11 fills with water, air in annular chamber 39 and flexible tube 12 becomes pressurised, tube 12 effectively being sealed at port P at its upper end by normally closed valve 2 having sealing ball 22 urged into sealing engagement with its seat by spring 24.

Actuation of the push button 26 moves sealing ball 22 out of engagement with its seat and permits pressurised air to flow around ball 22 via axial passage 41 into angled passage 42 and via reed 29 into flexible tube 13 through port A.

Ported pressurised air from pipe 13 causes the pressure in chamber 37 to increase and diaphragm 32 to rise, thereby raising retractor 35 and hence shuttle 34. As shuttle 34 is raised, the skirt 38 is lifted out of sealing engagement with the annular rim 47 of discharge outlet 48 defined by body 31, thereby permitting water to empty from the cistern 11 via the main discharge outlet pipe 48.

Referring now to Figure 4, in a preferred embodiment, the annular chamber 39a is provided midway along the length of shuttle 34 such that the water level in cistern 11 falls below the level of chamber 39a when the cistern is approximately one half discharged. A one-way clack valve plate 52 is provided adjacent the connection to flexible tube 12 arranged to permit air to be pressurised in tube 12 whilst inhibiting air flow in the reverse direction out of tube 12 into chamber 39a. Clack valve plate 52 is retained loosely by ring 51; suitable shaping of the recess containing clack valve 52 ensures a clear airway for airflow into tube 12. Using the embodiment shown in Figure 4, air pressure is maintained in chamber 37 under diaphragm 32 as long as valve 2 is open.

Valve 2 may be operated to provide a partial discharge of cistern 11 (short flush) or a more complete discharge (full flush). Brief pressure on pushbutton 26 ports pressurised air to chamber 37; pressure rises rapidly under diaphragm 32 lifting shuttle 34 and allowing water to leave cistern 11. The dimensions of reed 29 and the associated passages ensure that on release of pushbutton 26 the pressure decays at such a rate as will allow about half of the cistern's contents to escape before spring 36 overcomes the residual pressure and pushes down shuttle 34 thus ending discharge.

Full discharge occurs when pushbutton 26 is held operated for such time as will allow all of the cistern's contents to escape before collapse of operating pressure shuts off the flow, typically about 4 to 5 seconds.

Claims (14)

Claims:

1. Discharge apparatus for discharging a receptacle of fluid, the apparatus comprising: (a) sealing means movable between a sealing position in which a discharge outlet provided for the receptacle is substantially sealed to the passage of fluid therethrough, and a displaced position in which the sealing means is displaced from the sealing position thereby permitting fluid to be discharged from the receptacle via the discharge outlet; (b) displacement means arranged to move the sealing means from the sealing position to the displaced position, the displacement means so acting in response to an increase in air pressure; and (c) valve means actuatable to supply pressurised air to operate the displacement means.

2. Discharge apparatus according to claim 1, further comprising pressurisation means arranged to pressurise air for operation of the displacement means.

3. Discharge apparatus according to claim 2, wherein the pressurisation means is arranged to pressurise a volume of air as the receptacle becomes charged with fluid.

4. Discharge apparatus according to claim 3, wherein the pressurisation means comprises an upwardly extending conduit or tube positioned in the interior of the receptacle arranged to contain a column of air which becomes pressurised as the receptacle fills with fluid.

5. Discharge apparatus according to any preceding claim, wherein the displacement means comprises a movable element, movable in response to variation in air pressure acting thereon.

6. Discharge apparatus according to claim 5, wherein the movable element comprises a piston or displaceable diaphragm.

7. Discharge apparatus according to claim 5 or claim 6, wherein the movable element of the displacement means is linked or connected to the sealing means such that movement of the movable element effects corresponding movement of the sealing means.

8. Disharge apparatus according to any preceding claim, wherein the displacement means is arranged to move the sealing means in the axial direction of the discharge outlet.

9. Discharge apparatus according to any preceding claim, wherein the displacement means is arranged to act so as to retract the sealing means upwardly from the sealing position.

10. Discharge apparatus according to any preceding claim, wherein the sealing means comprises a sealing element arranged to seal around an annular shoulder or rim of the discharge outlet.

11. Discharge apparatus according to any preceding claim, wherein actuation of the valve means causes pressurised air to be directed to the displacement means.

12. Discharge apparatus according to any preceding claim, wherein the valve means is arranged to be normally biased to a closed position in which closed position pressurised air is inhibited from leaving a tube or conduit which comprises the pressurisation means.

13. Discharge apparatus according to any preceding claim, further comprising resilient biasing means arranged to normally bias the sealing means to the sealing position.

14. Discharge apparatus substantially as herein described with reference to the accompanying drawings.