GB2488382A - Improved Flushing Apparatus and Method - Google Patents

Abstract

The invention relates to a flushing apparatus for use in emptying a cistern in order to flush a sanitary apparatus such as a toilet, and in particular the invention relates to a valve 700 and valve assembly of the flushing apparatus. The valve comprises an inlet 704, an outlet 706, a control member 712, a valve chamber 710, and a sub chamber 716. The control member is operable to open and close the outlet. A valve chamber connects the inlet to the outlet, wherein the valve chamber acts on one side of the control member so that pressure within the valve chamber acts to urge the control member to an open position. A sub chamber is arranged on an opposed side of the control member to that of the valve chamber so that pressure within the sub chamber acts to close the control member. The sub chamber has an entrance 714 and an exit 718, the entrance being arranged to be open to the inlet when the control member is open and closed to the inlet when the control member is closed by a closure member 720. The closure member is moved from a sealed position with the exit to an un sealed position by a solenoid.

Description

Improved Flushing Apparatus and Method Thereof The present invention relates to a flushing apparatus for use in emptying a cistern in order to flush a sanitary apparatus such as a toilet. In particular, the present invention relates to an improved valve and valve assembly of the flushing apparatus.

A typical set up of a sanitary apparatus is shown in Figure 1. A toilet 10 is flushed by emptying water from a cistern 12. The cistern 12 is located above the toilet so that the water can be emptied from the cistern to flush the toilet under gravity and via passage 14. The cistern can be easily accessible or hidden as shown in Figure 1. A flushing apparatus 20 controls exit of water from the cistern 12. Once a flush has been activated, the cistern 12 is filled from a water source such as a mains inlet pipe 14. A float valve 18 is generally used to open the inlet pipe 14 in order to replenish the cistern 12.

A number of flushing apparatus 20 are known. For instance, it is know to use a valve such as a siphon to control the discharge of water from the cistern 12. The operation of a siphon is well known. Known single flush siphons are activated by depressing an activation mechanism 30 (commonly a handle, though an infra-red activation mechanism is shown in Figure 1). In single flush siphons, the entire cistern 12 is emptied of water. Since, depending on the flushing requirements of a particular user, it is not always necessary to discharge a full cistern, this is uneconomical and wasteful. Thus, dual flush siphons were developed. Dual flush siphons have a long and short flush capacity. Dual flush siphons are known with default long or short flushes. Here, the default flush is selected by depressing and releasing the activation mechanism whereas the other flush is selected by depressing and holding down the activation mechanism. For instance, in default long flush siphons, the short flush capacity is selected by holding down the handle in order to break the siphonic affect before the cistern has been fully emptied. However, it is still necessary to open the inlet pipe 18 only once the siphonic action has stopped. Thus there is a delay whilst the cistern is re-filled before the toilet can be flushed again.

EP 0651838 discloses a flushing apparatus comprising an electronic valve. Here the electronic valve comprises a valve housing having a lower, hollow portion provided with inlets to allow water ingress. The lower portion of the valve housing seals about the aperture from the cistern. A piston is operable within the valve housing to open and close the inlets to the valve housing. A head of the piston has a magnetic solenoid pin mounted thereon. Sealed within an upper area of the valve housing is an electrically operated solenoid. Thus the solenoid can be activated to attract the magnetic solenoid pin in order to raise the piston and open the inlets, thereby flushing the toilet.

With the valve being electrically operated, the flush can be activated by an infra red detector switch (shown as 30 in Figure 1) or a simple push-button. However, infrared detector switches can be unreliable. For instance, if a lens covering the detector becomes dirty or becomes dulled by abrasive cleaning products, inaccurate sensing or false activations can result. Furthermore, highly reflective clothing can cause the infrared sensor to trigger from further away than anticipated. EP 0651838 discloses providing two switches, each with its own associated variable timer, in order to hold open the piston for a pre-determined time. It will be appreciated that the time the piston is held open determines the amount of water that is flushed from the cistern.

Thus, a dual flush facility can be provided.

In EP 0651838 the solenoid directly activates the piston. Thus the solenoid is often housed beneath the level of water within the cistern. Consequently the solenoid is required to be waterproof. Also, it has been found that in order to provide sufficient force to lift the piston, the solenoid needs to be relatively large. This can lead to slow and noisy operation. This is because the solenoid can take some time to recover after operation. The size also means that the unit needs to be powered by mains electricity.

It is an aim of the present invention to attempt to overcome at least one of the above or other disadvantages. It is a further aim to provide an activation mechanism and valve that operates reliably, particularly for high use applications such as public toilets.

It is a further aim to provide an activation mechanism and valve that can be flushed repeatedly without having to wait in between flushes to activate the flush again. It is a further aim to provide an activation mechanism and valve that operates with reduced noise and with greater user-control over the length of flush.

According to the present invention there is provided an apparatus and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

According to a first aspect there is provided a flushing valve for flushing a cistern. The flushing valve comprises a housing and a piston. The housing is able to be secured to an outlet of a cistern. The piston is moveable relative to the housing between a non-flush and a flush position. In a preferred embodiment, the flushing valve includes a fluid conduit that extends between an upper region of the cistern and the outlet of the cistern. Relative movement of the piston and body does not close the fluid conduit. Advantageously, the fluid conduit provides an automatic overflow.

In addition to the flushing valve having a housing and a piston, the piston being moveable relative to the housing between a non-flush position and a flush position; and wherein the flushing valve includes a fluid conduit that extends between an upper aperture and a lower aperture, in use, the upper aperture being in fluid communication with an upper region of the cistern and the lower aperture being in fluid communication with the outlet in both the flushing and non flush position of the piston, the first aspect further includes, a holder for holding material within the fluid conduit, the holder being arranged so that, in use, the material is stowed substantially dry when the piston is in the non-flush position, put substantially immersed in fluid when the cistern is flushed.

In the exemplary embodiments the piston and housing are substantially hollow.

Preferably, an upper aperture and a lower aperture of the fluid conduit are moveably secured to each other. Thus, advantageously, the height of the overflow can be adjusted. In the exemplary embodiments, the piston includes two parts. One of the parts is an extension part. The two parts are telescopically linked so as to move the upper and lower apertures towards and away from each other. That is the flushing valve includes an extension part that is moveable relative to the piston in order to raise or lower the upper aperture.

The holder is located such that the material is stowed substantially dry when the piston is in the non-flush position and substantially immersed when the piston is opened. The holder may be secured fast to the body. In the exemplary embodiments the housing comprises a tubular part having a shelf. Here the tubular part is arranged co-axially with the piston. Preferably, the shelf is permeable to fluid. The holder may be arranged to hold tablets and more preferably sized so as to receive a plurality of tablets. To induce immersion of the material in the fluid, it is advantageous if the tubular part includes at least one aperture. Here, the at least one aperture may be formed in the circumferential face in order to allow fluid to circulate within the tubular part when the cistern is flushed.

The flushing valve of the first aspect may be arranged to be moved from the non-flush position to the flushing position by a supply of pressurised fluid. Moreover, flushing the valve may form part of a valve assembly comprising the flushing valve and a control means. The control means having a first operable valve for supplying pressurised fluid to act on the piston in order to cause movement from the non-flush position to the flushing position. Furthermore, the flushing valve may form part of a cistern including flushing apparatus. Here the flushing apparatus comprises a valve assembly and an activation mechanism, wherein the flushing valve assembly comprises the valve and a control means. The activation mechanism being operable to activate the first operable valve of the control means to supply pressurised fluid to the valve.

According to a second aspect, there is therefore provided a method of sanitising a cistern, the method comprising placing material within a holder of a valve such that the material is stowed substantially dry when the flushing valve is in a non-flushing position, the method comprising causing the material to become substantially immersed in fluid when the flushing valve is in a flushing position, wherein the immersion causes the fluid to be sanitised.

According to a further aspect there is provided a flushing valve for flushing a cistern.

The flushing valve comprises a housing and a piston. The housing is able to be secured to an outlet of a cistern. The piston is moveable relative to the housing between a non-flush and a flush position. The piston is moved from the non-flushing position by providing pressurised fluid to one side only of a part of an area of the piston that seals with the housing. The pressurised fluid is provided through an inlet.

Consequently the flushing valve is hydraulically operated. Advantageously the speed of operation, power consumption and noise level are all improved. A valve is provided having the flushing valve and a control means. The control means includes a first operable valve for supplying the pressurised fluid and a second operable valve. The second operable valve is arranged to refill a cistern after the flushing valve is opened.

The first and second operable valves are supplied by a common reservoir of pressurised fluid. The Second operable valve includes a delayed activation. That is, the second operable valve opens automatically when the flushing valve is opened but after a delay in time. Thus, the outlet to the cistern is opened for a period of time before the second operable valve is opened in order to replenish the cistern's reservoir.

In an exemplary embodiment, the delayed fill is achieved by a second operable valve comprising a float chamber for mounting within the cistern and a float means arranged within the float chamber. The float means is arranged to automatically control operation of the valve in accordance with the water level within the float chamber.

The float chamber includes an opening through which water may flow both from the cistern to the float chamber and from the float chamber to the cistern. The rate at which fluid drains from the float chamber is set to be slower than the rate at which fluid is discharged from the cistern. Thus the float means does not drop as quick as the cistern level, and importantly, because the float means opens the second operable valve automatically when it drops to a certain level, a delayed fill is achieved.

Preferably, the delay is sufficient to allow a full flush of the cistern before refilling is initiated. That is, preferably, the difference between the rate of drain through the filling valve and from the float chamber is such that a volume of flushing fluid equivelant to a full flush has drained through the filling valve before the float chamber has drained sufficiently to cause the float means to open the second operable valve.

In the exemplary embodiments the piston is sealed to the housing at one location and the housing is sealed to the piston at a second, spaced location. Here, the pressurised fluid is supplied to the sealed space between the two locations.

In the preferred embodiments, the piston is substantially cylindrical. Here, the housing includes a substantially cylindrical receiving portion. The piston seals to the receiving portion at one annular seal and the receiving portion seals to the piston at a second, spaced annular seal. In the exemplary embodiments, the pressurised fluid acts on one side of the part of the piston that seals with the housing. The second, opposed side of the part is not pressurised and is open to the cistern. Thus the piston can be moved simply by turning on and off the source of pressurised fluid.

Preferably the pressurised fluid is supplied through an inlet having an axis of directional flow. It is advantageous if the axis of directional flow is angled to substantially perpendicular to a surface that the pressurised water is directed to. The inlet may be connected to the control means by a fluid passageway.

In the exemplary embodiments, the flushing valve includes a biasing means that aids the gravity induced biasing of the flushing valve towards the non-flush position. Here the biasing means may be a resilient member. The biasing means may act on the piston at one end and on a stop member at the other. The stop member may be moveably secured to the body to give a fixed point for the biasing means to act against. Preferably, the stop member is moveably secured to the body so that the biasing means can be pre-stressed.

It will be appreciated that the previous aspects can be used together or independently.

Also, a valve assembly is provided by the valve of the previous embodiments cooperating with a control means. The control means controls the opening and closing of the valve. The control means includes a first operable valve for supplying the pressurised fluid. Here, preferably, the control means also includes a second operable valve. The second operable valve is arranged to be automatically opened when fluid within the cistern drops below a predetermined level. Preferably, the first and second operable valves are supplied by a common reservoir of pressurised fluid.

The control means may be operated to open and close the first operable valve by any suitable activation mechanism. Preferably, however, the activation mechanism electrically switches the control means. More preferably, the activation mechanism is in accordance with the third embodiment. Here, in accordance with a third embodiment of the present invention there is provided a mechanism for activating a valve assembly for flushing a cistern, the activation mechanism comprising a sensing pad and control circuitry, the sensing pad comprises an area of conducting material and wherein the control circuitry is arranged to monitor the current flowing through the sensing pad, such that the control circuitry can detect the discharge of electricity from an operator through the sensor pad when, in use, an operator moves to be spaced adjacent the sensing pad.

Preferably, the sensing pad is connected to earth. Moreover, the control circuitry may be arranged to open an operable valve of a control means when the control circuitry detects the presence of an operator. Suitably, the control circuitry may include a delay means having a pre-set time delay, wherein the control circuitry opens an operable valve of a control means when the presence of an operator is detected and closes the operable valve once the pre-set time delay has elapsed. Two or more sensing pads may be provided. Here the control circuitry may be arranged to open an operable valve of a control means for a different length of time dependant on whether the first or second sensing pad detects the presence of an operator. Also, each sensing pad may be installed behind a pad and the other side of the pad accessible, in use, by an operator includes an indicator to indicate the presence of a sensing pad.

Here, preferably, the indicator includes an indication of the length of flush associated with the sensing pad behind the indicator.

In a further aspect there is provided an operable valve for opening and closing a fluid inlet. The operable valve is particularly, though not exclusively, suitable for opening and closing the fluid supply to the flushing valve of previous aspects. The operable valve comprises a valve chamber connected an inlet for a source of fluid, and to an outlet. Suitably, the outlet is connected to the flushing valve. A control member is arranged to be moveable between a first, open position and a second, closed position wherein the outlet is open and closed to the inlet respectively. A sub-chamber is provided. The sub-chamber is in communication with the inlet via an entrance such as an aperture, for instance a bleed hole. An exit of the sub-chamber is opened and closed by a moveable closure member. Advantageously, the moveable closure member is moved by an actuator such as a linear actuator, for example a solenoid.

Advantageously, the operable valve controls water supply to the flushing valve even with low inlet pressures. In contrast, if the valve is opened and closed directly by a solenoid, it has been found that at lower water inlet pressures, the valve does not function adequately.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 is a pictorial representation of a known sanitary apparatus; Figure 2 is a pictorial perspective view of a cistern having a valve assembly and activation mechanism of a first embodiment of the present invention; Figures 3-5 are cross-sectional views through the cistern of Figure 2 showing the process steps involved in flushing the cistern; Figures 6 and 7 are cross-sectional views through a piston and housing respectively of a valve; Figure 8 is perspective side elevation view of a flushing valve; Figures 9 and 10 are cross sectional views through a flushing valve with and without a piston extension part; Figures 11 and 12 are cross-sectional side perspective views through a housing and flushing valve respectively showing a tablet holder; Figure 13 is a cross-sectional view of a suitable second operable valve; Figure 14 is a cross-sectional view through an operable valve according to a further aspect; and Figure 15 is a cross-sectional view through a cistern having a valve assembly of an exemplary embodiment including a flushing valve of Figure 8, a first operable valve of Figure 14 and a second operable valve of Figure 13.

Referring to Figure 2, a cistern 100 includes a valve assembly 200 and an activation mechanism 500. The valve assembly 200 comprises a flushing valve 300 and a control means 400. The control means 400 is arranged to control the flushing valve 300 to open and close an outlet in the cistern 100. In use the activation mechanism 500 activates the control means 400 to open and close the flushing valve 300 so that the outlet to the cistern is open for a period, during which flushing occurs.

Referring to Figure 3, the cistern 100 includes a chamber 110 having an outlet 112.

The flushing valve 300 is assembled to the cistern 100 in order to open and close the outlet 112. The flushing valve 300 comprises a body 310 that is able to be secured fast to the outlet 112 and a piston 320. The piston 320 locates within the body 310 and is sealed thereto. One seal 332 is provided on the piston 320 and another 334 by a close fit to the body 310 creating a sealed space 336. A fluid outlet 338 is provided in communication with the sealed space 336. The piston 320 is moveable between a first position and a second position. In the first position the piston 320 is arranged to seal the outlet 112 (herein the non-flush position). Here, the piston 320 seals against the seal outlet 112. In the second position, the piston 320 is arranged not to seal the outlet 112 which allows water within the cistern to egress through the outlet 112 (herein the flush position). The piston 320 is moved from the first position to the second position by supplying pressurised water to the sealed space 336 through the fluid outlet 338. Consequently, the pressurised water causes the two seals 332, 334 to move apart thereby moving the piston 320 from the first position to the second position. When the supply of pressurised water is stopped, a biasing means biases the piston to return to the first.

Consequently, the flushing valve 300 is moveable between the non-flushing position and the flushing position by pressurised water. Thus the requirement of a solenoid to directly activate the movement of a piston to open and close the cistern's outlet is removed. Moreover, the flushing can be activated in a quiet and responsive manner.

Furthermore, because the flushing operation is activated by simply opening an operable valve in order to supply water through the fluid outlet, the operable valve is able to be a minimal size. Thus, when activated electrically, the operable valve is able to be designed to consume a minimum amount of power. This is environmentally friendly, as well as reducing the maintenance frequency. For instance, when the power to an electrically operated operable valve is supplied via a battery, the battery is able to operate for increased periods before requiring rejuvenation.

The control means 400 includes a first operable valve 410 and a second operable valve 420. The first operable valve 410 is arranged to supply the pressurised water to move the piston 320. As shown, suitably the first operable valve 410 is therefore connected to the fluid outlet 338 by a passageway 412. The second operable valve 420 constantly maintains a desired level of water in the cistern 100. That is, the second valve 420 is arranged to open when water in the cistern 100 drops below a predetermined level and closes again when the water reaches the predetermined level. This is irrespective and independent to the status of the first operable valve 410. Thus, advantageously, there is no need to wait for the cistern 100 to replenish between flushes.

The activation mechanism 500 may be any suitable activation mechanism in order to activate the first operable valve 410. For instance the activation mechanism may comprise one or more switches and communication means. Each switch may be a conventional outlet switch or may be an infra-red switch. However, a particularly preferred non-contact switch is described herein. The communication means may be mechanical or otherwise. In Figure 2, the switch is shown as a sensor 510 and the communication means is shown as an electrical wire 520 for carrying a signal between the sensor 510 and the control means 400, and specifically the first operable valve 410.

The flushing operation of flushing the cistern is now explained with reference to Figures 3 to 5. The valve 300 is shown in Figure 3 in the non-flushing position. Here the biasing means biases the piston so that the piston is arranged to seal the outlet 112. The cistern is filled with flushing fluid, for instance water, via the second operable outlet 420. The flushing apparatus remains in a state of readiness. When the activation mechanism 500 is activated, for instance by an operator triggering the sensor 510 to send a signal along the wire 520, the first operable valve is caused to open for a period of time. Consequently, flushing fluid is allowed to flow along the passageway 412 to exit into the sealed space 336 through the fluid outlet 338, as shown by arrows 150 in Figure 4. Because the flushing fluid is at least slightly pressurised, the flushing fluid causes the two seals 332, 334 to move apart.

Consequently, as shown in Figure 4, the seal 332 is caused to move away from the seal 334. Thus the piston 320 is raised to the flushing position. Flushing fluid from within the cistern 100 is therefore allowed to egress through the outlet 112 as shown by arrows 160. As shown in Figure 5, the cistern is allowed to empty for as long as the first operable valve is maintained open. However, as soon as the level of flushing fluid within the cistern 100 drops below the predetermined level, the second operable outlet is caused to open. Thus the cistern starts filling with flushing fluid immediately, without having to first wait for the selected flush to finish.

It will be appreciated that once the period of time that the first operable valve is opened lapses, the first operable valve closes. The piston 320 is then urged to the non-flushing position by the biasing means and the flush terminated because the piston then closes the outlet 112. However, because the cistern has already been started to be filled, the delay for the next flush is reduced or eliminated.

A particularly suitable flushing control means 400 will now be described.

It is advantageous if the first and second operable valves 410, 420 are supplied by a single supply of flushing fluid such as a single supply of mains water. Here a single flushing fluid supply pipe 114 is provided. As shown, the control means is suitably arranged on the supply pipe 114. Thus, as shown in Figure 2, a fluid splitter 402 such as a t-pipe is provided with the first operable valve 410 being arranged to open and close one branch 404 of the splitter and the second operable valve 420 being arranged to open and close the other branch.

Whilst any known operable valve that is able to start and stop a supply of fluid to the fluid outlet 338 upon activation by an activation mechanism can be employed as the first operable valve 410, the first operable valve is suitably shown as comprising a known solenoid valve. Here the solenoid valve is activated to open on activation by a control mechanism. The operable valve may be arranged to close once the control mechanism has been released. Thus the length of time the operable valve 410 is open is dependant on the length of time a user holds or depresses or otherwise activates the activation mechanism. Thus a push and hold flush facility is provided so that the user can determine the exact length of time of flush. Alternatively, the operable valve may be arranged to open for a set time once the activation mechanism has been triggered. For instance, suitably, the control means 400 includes a delay means. Here the delay means automatically closes the operable valve 410 after a set time. Thus the length of flush may be irrelevant to whether a user continues to activate the activation mechanism following the start of the flush. It will be appreciated therefore that the activation mechanism may include two or more switches or sensors, with each switch or sensor being associated with a different time delay in order to provide a dual flush facility or even a multiple flush facility.

Additionally, one of the two or more activations may be arranged to be a push and hold flush activation.

Whilst a valve directly operated by a solenoid is able to be used as a first operable valve, it has been found that such valves have a problem opening and closing consistently when the water inlet pressure drops. Consequently, a particularly suitable first operable valve is explained in relation to Figure 14. Here the operable valve is generally indicated by reference 700 and is an equilibrium valve. The operable valve 700 includes a valve housing 702 that defines a water inlet 704 and a water outlet 706. The inlet 704 and outlet 706 are separated by a valve chamber 710 A control member 712 is arranged to be moveable from a first open position to a second closed position. In Figure 14, the control member is shown in the closed position. With reference to Figure 14, and by way of example only, the control member 712 is moveable to the right to move to an open position. In the open position, fluid flows from the inlet to the outlet. In the closed position, the control member 712 forms a seal to prevent water escaping the valve chamber 710 and the operable valve is therefore closed.

The control member 712 is not directly operable by a solenoid. Rather, an entrance, such as a bleed hole 714 is provided to a sub-chamber 716. The bleed hole 714 is opened when the control member 712 moves to an open position and closed when the control member is in the closed position. When opened, the bleed hole provides an entrance for the inlet fluid to enter the sub-chamber 716. The sub-chamber is arranged on the opposite side of the control member as opposed to the valve chamber. Here, the sub-chamber is arranged to act on a greater area of the control member than the valve chamber. Consequently, if the sub-chamber were closed to have a fixed volume, and liquid having an equal pressure supplied to the valve chamber and sub-chamber, the pressure would act to close the control member.

The sub-chamber has an exit 718. The exit is opened and closed by a closure member 720. The closure member 720 is moved to and from a sealed arrangement with the exit by an actuator that is suitably a linear actuator, for instance a solenoid. It will be appreciated that when opened, the exit 718 allows the fluid within the sub-chamber 716 to vent and therefore prevents a pressure build up. Consequently, the fluid in the back of the control member 712 drops and the valve opens. When the exit 718 is closed, the pressure re-establishes on the back of the control member and the valve closes.

Because the solenoid operates to open and close the sub chamber's exit to the equilibrium valve 700 rather than directly to open and close a closure between the inlet and outlet, it has been found that the valve is operable consistently independently to the inlet water pressure. In contrast, the performance of valves directly operated by solenoids reduce at low inlet fluid pressures.

Again, any known valve that can be arranged to open once a volume of fluid within the cistern drops below a set volume and remains open until the volume rises above a predetermined volume, can be used as the second operable valve 420. However, as shown in the Figures, a particularly suitable operable valve is shown as being a float valve. Here a float 422 is associated with a closure member 424. The float 422 is arranged to rise and fall with the water level in the cistern 100. Suitably the closure member 424 is pivotally assembled with respect to an aperture. Thus, as the volume of flushing fluid within the cistern 100 drops, the float also drops. This allows the closure member 424 to pivot away from a sealing engagement with the aperture and therefore the second operable valve is open. When the volume of flushing fluid within the cistern 100 recovers, the float is caused to rise and therefore pivot the closure member to seal against the aperture. The second operable valve 420 is therefore closed.

A particularly suitable flushing valve 300 will now be described.

As shown in Figure 3, preferably the piston has a fluid conduit 340 that extends from one end of the piston to the other. That is, in an upper end of the piston there is provided an entrance 342 to the fluid conduit and in a lower end there is provided an exit 344 to the fluid conduit. When the valve 300 is secured to a cistern in use, the entrance is arranged in fluid communication with an upper area of the cistern 100 and the exit 344 is arranged in fluid communication with the outlet 112 even when the piston is in the non-flush position. Thus, advantageously an integral overflow facility is provided. This is because, if for any reason the second valve of the control means does not close when the water within the cistern 100 fills above the predetermined level, the water level in the cistern will continue to rise. However, once the water level rises above the entrance 342 to the fluid conduit 340, the water is automatically drained down the outlet 112. Thus, a separate overflow drain is not required.

A piston 320 is shown in more detail in Figure 6. Here, the fluid conduit 340 is shown as suitably being provided by forming a substantially hollow or tubular piston. Here the piston is substantially cylindrical about a longitudinal axis. The fluid conduit 340 is formed between an entrance 342 on one distal end and an exit 344 on the opposed distal end. An annular seal 332 is provided about the piston 300 spaced between the distal ends of the piston. The annular seal 332 is sized so as to seal against the inside of the housing. In use the annular seal 332 is preferably arranged to be spaced further from the outlet than the fluid outlet 338. A ring seal 302 may be disposed about the piston 300 in order to seal against the outlet 112. The ring seal 302 aids the closure of the outlet 112. However, it is preferable if the ring seal is provided on the housing or cistern as described herein.

Advantageously, the piston comprises a main part 350 and an extension part 352.

The extension part 352 is telescopically linked to the main part 350. Thus the length of the piston can be varied. That is the distance between the entrance 342 and exit 344 can be set dependant on the height of the required overflow facility can be set for a number of different cisterns. As shown in the Figures, the telescopic part fits within the main part. Here an outside circumferential face of the extension part 352 includes a plurality of spaced annular grooves 354 and the inside diameter of the main part 350 includes a correspondingly sized nibs 356. Thus, in use, interference between the nibs and each of the grooves 354 provides a positive stop to hold the extension part with respect to the main part in a number of different positions. It will be appreciated that the nibs are sized so that a resiliency of the nib is sufficient to allow the two parts to be moved relative to each other to extend or contract the piston 300.

A particularly suitable body 310 of the valve 300 is shown with reference to Figure 7.

The body 310 is substantially cylindrical. One distal end of the body is attachable to the cistern. In the Figures, the body is shown as being arranged to extend away from the outlet substantially vertically. A fluid outlet 338 is provided in the body 310. The fluid outlet is spaced from the distal end and exits the inside of the body above an aperture 346 and internal ring seal 334 that is sized so as to seal against the piston.

The fluid outlet can be arranged to supply fluid at any location. For instance, the fluid outlet 338 may be formed on a radial direction relative to the housing. Alternatively, the fluid outlet 338 may be arranged offset from a radius of the housing. In this case, because the fluid outlet is not directed substantially along the radial direction, and is instead angled thereto, cylindrical flow within the sealed space 336 is encouraged. A pressure relief means is provided between the fluid outlet 338 and the other distal end. The pressure relief means is shown as a series of apertures 350. The apertures increase in size as they move further away from the fluid outlet 338. Suitably, the apertures are shown as angled slots. It is these apertures that allow fluid within the sealed space 336 to be vented in order to allow the piston to be returned to the non-flush position once the first operable valve has been closed. It will be appreciated that in order to allow flushing fluid to exit the outlet until the cistern is substantially emptied, the end of the body attached to the cistern is required to be open. Thus as shown in Figure 7, a distal end 304 that is attached to the cistern is separated from the rest of the body by legs 306. Thus fluid may flow between the legs in order to move from the outside of the body to the outlet. Preferably the legs 306 are angled to the axis of the body. Thus the legs are shaped so as to encourage cyclonic flow through the outlet 112. This is advantageous as it encourages the centre of the outlet to be kept clear and improves the evacuation of the chamber.

As discussed above, whilst a ring seal may be provided on the piston, in order to improve the closure of the outlet, it is preferable if the seal 302 is provided on a removable base that defines the outlet 112. Here, the piston has a diameter greater than the diameter of the outlet. Thus a seal between the piston and outlet is created at least partially between the distal end face of the piston and the removable base.

This is advantageous as the seal 302 is fully supported by the removable base. That is, if the seal 302 was an annular seal on the outside diameter of the piston, the seal would be prone to drooping or wrinkling which reduces the effectiveness of the seal.

A flushing valve 300 is shown in Figure 8. A body 310 includes a fluid outlet 338 having an aperture on an inside face of the housing and arranged, in use between two seals formed on the body and a piston respectively, wherein the piston is arranged to slide relative to the body within a socket of the body 310. When the piston is in a non-flushing position, an end of the piston seals an outlet 112. As shown in Figure 8, the outlet 112 is formed through the cistern by a removable base 130 and seal 131 that is secured to an aperture in the cistern. Thus, as shown in Figure 10 the removable base has a tubular part 132 that extends through the aperture in the cistern. The tubular part has an external thread. A nut part 134 can therefore be tightened on to the thread to hold the removable base and seal 131 fast to the cistern. Thus sealing about the aperture to form the outlet 112. Advantageously, the body 310 of the valve may be secured to the removable base. For instance, the body and removable base 130 may be arranged to interlock in a releasable manner and more preferably in a quick release manner. Consequently, maintenance and repair of the valve can be improved because a new valve can be simply switched in by un-hooking the passageway 412 from the fluid outlet 338 and swapping valve units. Suitably, as shown in Figure 8, the interlocking is formed by at least one pin that extends upwards from the removable base and a corresponding variable sized aperture 138 in a distal end face 304 of the body 310. Thus, the pin and variable sized aperture can interlock by twisting the body about a longitudinal axis of the piston. Here, a head of each pin is caused to protrude through a large part of the variable sized aperture. Once twisted, the head of the pin is arranged over an area of the variable sized aperture having a size smaller than the head of the pin. Thus the body and removable base are secured together. The angle and shape of a plurality of legs that join the distal end face to the portion of the body that provides the chamber can be arranged to provide increased strength during the twisting operation.

Figure 8 shows the flushing valve assembled. That is the piston 320 is arranged within the body 310. As shown in Figures 9 and 10 a biasing means shown here as suitably comprising a resilient member 360 such as spring, is located about the piston and between the piston and body. One end of the resilient member 360 acts on the piston. The resilient member is shown in the Figures as suitably acting directly on the seal 332. The other end of the resilient member 360 acts on a stop member 370.

The stop member is secured to the body such that it can be arranged to move toward or away from the seal 332. Thus the tension in the resilient member 360 can be adjusted by moving the stop member relative to the seal 332 (i.e. by compressing or relaxing the spring). Suitably, the stop member is connected to the body in a threaded connection. Referring back to Figure 8, the stop member 370 is shown suitably as a tubular part that has an external thread 372 (shown in Figure 10). The external thread 372 engages a number of projections 377 (shown in Figure 7) that extend inwardly from the body 310. The projections are arranged, in use, to engage the thread 372. Consequently, the stop member can be screwed on to the end of the body once the resilient member has been inserted between the piston and body. The stop member obstructs the resilient member 360 from being removed from the body.

Figure 11 shows a preferably body 310. The body is substantially as herein described with reference to Figures 7 to 10. However, the body further includes a tablet holder 500. The tablet holder 500 is arranged to store known cleaning tablets within the piston. This is advantageous because the cleaning tablets are water soluble so can not usually be used in a cistern. However, because, when the piston is in a non-flush ing position, the inside of the piston is drained of water, the tablets can be stored out of water, only becoming immersed when the piston is moved to the flushing position. The tablet holder 500 is shown as suitably comprising a tubular section 502 that is arranged, in use, to extend within the piston 320. A shelf 504 is provided on the tubular section 502. The tubular section 502 is connected fast to the body 310 by legs 506 that extend from an inside rim of the outlet 112 in order not to interfere with the sealing of the piston and aperture. The tubular section 502 is sized so as to receive cleaning tablets (not shown). The shelf 504 includes apertures to allow the tablets to become submerged in fluid once the piston is opened. The submersing can be improved by including apertures 508 in the tubular section. Advantageously, the tubular section 502 extends towards the top of the piston. Thus replacement tablets can be dropped in from the top of the cistern without the need for any disassembly.

Moreover a number of tablets can be inserted into the tubular section at any one time.

Thus the cistern is provided with a tablet holder that allows fragrance and cleaning properties to be conveniently added to the flushing fluid, as well as reducing the build up of uric salts and limescale, which can decrease the chances of blockages.

A particularly suitable activation mechanism comprises a non-contact sensor. The non-contact sensor is activated by sensing the presence of a hand or other body part to a sensing pad. The sensing pad is suitably a large area of conductor. Thus, circuitry can be used to monitor the discharge of electricity through the sensing pad.

The sensing accuracy can be improved by earthing the sensing pad. Thus there is provided a non-contact sensor which uses the differential in capacitance between the earth and the human body to activate the system. Thus the possibility of false activation is reduced. Moreover, hygiene is improved due to the non-contact method.

As explained, the flushing apparatus can be improved by including two or more sensing pads for long and short flushes.

Although the control means has been described above with reference to any known second operable valve, it has been found that when operating with a second operable valve that opens as soon as flushing begins, because the first and second operable valves are supplied from the same fluid source, fluid pressure supplied to the flushing valve by the first operable valve drops when the second operable valve opens. This can cause the first operable valve to inadvertently close. This can lead to an intermittent or insufficient flush. Consequently, it is particularly suitable to provide the second operable valve with a delayed fill. That is, rather than the second operable valve opening once the flushing starts as would be the case with a standard float valve mounted within the cistern, a delay is introduced, for instance by mounting the float within a float chamber wherein the rate of drain from the float chamber is lower than that of the cistern. Here the float chamber is filled as the cistern is filled. For instance referring to Figure 13, the second operable valve 600 may comprise a vertical guide 604 fixed relative to the water inlet by a support 605 mounted on the inlet pipe 603. A float chamber 607 is mounted on the vertical guide by an adjustable bracket 606. The vertical and horizontal position of the chamber is adjusted by releasing a threaded fly nut 609 to adjust the bracket 606. The float chamber 607 includes an outlet aperture 600. One of a number of plugs, each with a different size through-hole, is plugged into the outlet aperture 608, to vary the effective size of the outlet 608.

In use, the toilet cistern contains a fixed volume of fluid which is determined to be that required to flush the toilet bowl. The chamber 607 contains part of that fluid. The float 607 floats on the surface of the fluid in the float chamber 607 at such a height that the inlet 603 is sealed, thereby preventing additional fluid being introduced into the cistern. When the toilet is flushed, fluid within the cistern is discharged into the toilet bowl. As the fluid level in the cistern falls, fluid from within the chamber 607 is discharged through the outlet 608 into the cistern, causing the fluid level in the float chamber 607 to fall. As the fluid level in the chamber 607 falls, the float 601 is lowered. When the fluid level reaches a predetermined lower level, the horizontal bar 602 will be at such an angle that the seal over the fluid inlet opens allowing fluid from the inlet to refill the cistern. As the outlet 608 has a small diameter, the rate at which the fluid in the float chamber 607 is discharged into the cistern is much slower than the rate at which the fluid is discharged from the cistern into the toilet bowl.

Therefore, the fluid inlet 603 is not opened until much later compared to non-delayed valve due to the slower rate at which the fluid level in the float chamber falls that that in the cistern.

Although preferred embodiment(s) of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made without departing from the scope of the invention as defined in the claims.

Claims (17)

1. Claims 1. An operable valve comprising: an inlet; an outlet; a control member operable to open and close the outlet relative to the inlet; a valve chamber connecting the inlet to the outlet, wherein the valve chamber acts on one side of the control member so that pressure within the valve chamber acts to urge the control member to open; a sub-chamber arranged on an opposed side of the control member to that of the valve chamber so that pressure within the sub-chamber acts to close the control member, the sub-chamber having an entrance and an exit, the entrance being arranged to be open to the inlet when the control member is open and closed to the inlet when the control member is closed, and the exit being open and closed by a closure member; wherein the closure member is moved from a sealed position with the exit to an un-sealed position by a solenoid.
2. 2. A valve assembly comprising: a flushing valve for opening and closing an outlet of a cistern, the flushing valve having a housing and a piston, the piston being moveable relative to the housing between a non-flush position and a flush position; and a control means for controlling the flushing valve, the control means having a first operable valve for supplying pressurised fluid to act on the piston in order to cause movement from the non-flush position to the flushing position and a second operable valve that is able to be arranged to automatically open when fluid within the cistern drops below a predetermined level and automatically close when fluid within the cistern rises above a predetermined level, wherein the first operable valve is as claimed in claim 1.
3. 3. The valve assembly of claim 2, wherein the first and second operable valves are supplied by a common source and the second operable valve includes a delayed activation.
4. 4. The valve assembly as claimed in claim 2 or 3 wherein the piston is sealed to the housing at one location and the housing is sealed to the piston at a second, spaced location and the pressurised fluid is supplied to the sealed space between the two locations.
5. 5. The valve assembly of any of Claims 2 to 4 wherein the valve assembly includes a fluid passageway that connects the valve to the control means, the fluid passageway delivering the pressurised fluid.
6. 6. The valve assembly of any of Claims 2 to 5 wherein the piston is biased by a biasing means towards the non-flush position
7. 7. The valve assembly as claimed in Claim 6 wherein the biasing means is a resilient member, and the resilient member acts on the piston at one end and on a stop member at the other, opposed end, the stop member is moveably secured to the body and moving the stop member towards the seals cause the resilient member to be compressed.
8. 8. The valve assembly as claimed in any of Claims 2 to 7 wherein the body includes at least one vent that vents the pressurised fluid from between the two seals when the piston is in the flushing position.
9. 9. The valve assembly as claimed in any of Claims 2 to 8 wherein the body includes a first part and a second part wherein the two parts are releasably engageable, one of the parts houses the piston and the other, in use, is arranged to be fixed fast to the cistern.
10. 10, The valve assembly as claimed in any of Claims 2 to 8 wherein the valve includes a fluid conduit that extends between an upper aperture and a lower aperture, in use, the upper aperture being in fluid communication with an upper region of the cistern and the lower aperture being in fluid communication with the outlet in both the flushing and non flush position of the piston.
11. 11. The valve assembly as claimed in Claim 10 wherein the piston and housing are substantially hollow.
12. 12. The valve assembly as claimed in any of Claims 10 or 11, wherein the valve assembly includes an extension part that is moveable relative to the valve assembly in order to raise or lower the upper aperture.
13. 13. The valve assembly as claimed in any of Claims 10 to 12 wherein the valve assembly includes a holder for holding material within the fluid conduit, the holder being arranged so that, in use, the material is stowed substantially dry when the piston is in the non-flush position, put substantially immersed in fluid when the cistern is flushed.
14. 14. The valve assembly as claimed in any of Claims 2 to 13 wherein the second operable valve comprises a float chamber for mounting within the cistern and a float means arranged within the float chamber, wherein the float means controls the opening and closing of the second operable valve and the float chamber is arranged to drain at a slower rate than fluid through the flushing valve.
15. 15. A cistern including flushing apparatus, the flushing apparatus comprising a valve assembly and an activation mechanism, the valve assembly being as claimed in any of Claims 2 to 14 and the activation mechanism being operable to activate the first operable valve of the control means to supply pressurised fluid to the flushing valve.
16. I 6. A flushing valve or a control means for use in any of Claims 2 to 14.
17. 17. A valve assembly substantially as herein described and with reference to Figures2tol4.