Technical field

The present invention relates to a flush valve for use in a toilet cistern, utilising the siphon effect.

Background

Making use of the siphon effect in toilet cisterns to drain a tank of water through a drainage pipe to flush a toilet is well known in the art. It is advantageous in that once the siphon effect is activated, the movement of water from the tank will continue naturally under the water’s own weight until the siphon is broken.

US 2002/108169 A1 discloses a siphon flush apparatus comprising a discharge conduct, and a sliding conduct fixedly attached to a flow-directing element. Floating means are affixed to the flow-directing element which keeps it afloat at the water level in the cistern, and the top of sliding conduct above the water level. When a user pushes down the flow-directing element, the top of the sliding conduct drops below the water level, allowing water to flow thereinto, causing a siphon effect to drain the water from the main bulk of the cistern, up the interior of the flow directing element, and down the interior of the sliding conduct and the discharge conduct, and into a discharge aperture of the cistern, hence flushing the toilet. After flushing, the siphon effect is broken, the water is refilled in the cistern; because of the floating means, once the pushing force is removed, the sliding conduct and flow directing means are biased to return to the original position with the sliding conduct above water level, where air within the flow-directing element prevents water from going into the sliding conduct.

However, in this arrangement, it would require substantial force to initiate the siphon effect, since the sliding conduct needs to be pushed below the water level, against the upward force caused by the floating means, which is added to the mass of the entire flow-directing element to which the sliding conduct is attached. For a human operator, this may be inconvenient or tricky, particularly for the old or infirm. For a motorised system, it may consume power at a rate that is unsustainable by a battery, necessitating connecting the system to the power mains, which is often undesirable close to drainage systems present in a bathroom. Accordingly, there is a need in the field for an arrangement which reduces significantly the effort or power required to initiate the siphon flushing procedure.

Summary of the invention

In accordance with an aspect of the invention herein described, there is disclosed a flush valve for use in a cistern containing liquid, said flush valve comprising siphon bell, and a drainage pipe comprising a movable portion movable with respect to the siphon bell between a standby position and a flush position, wherein, in the standby position, said movable portion prevents liquid in the cistern from entering the draining pipe, and wherein, in the flush position, said movable portion allows the liquid to enter the drainage pipe, and the draining pipe and the siphon bell collectively create a siphon effect to cause the liquid to be flushed from the cistern. As a result of this arrangement, there is no need to provide a floating means attached to the drainage pipe, advantageously avoiding having to push a float down into the liquid, against the upward force caused by the float (as in US 2002/108169 Al), to cause the water level to rise above the top of the pipe to initiate the siphon effect.

Preferably, the siphon bell is stationary or fixed. Advantageously, this reduces the number and mass of the components to be moved when activating a flush.

Preferably, the siphon bell is an envelope disposed above the drainage pipe.

Preferably, the moveable portion of the drainage pipe is moveable by an actuating means, which may go through an orifice in the siphon bell. The orifice is preferably at the top of the siphon bell.

In one aspect, the actuating means comprises a motor. Advantageously this can be of significant assistance to a user who is not physically strong when triggering a flush. Preferably, the motor is connected to the moveable portion of the draining pipe by a rod, and the rod goes through the orifice in the siphon bell. Preferably, the actuating means also comprises a plugging means to seal the orifice when the moveable portion is in the flush position, in order to provide an effective vacuum within the siphon bell to allow the siphon effect to take place.

Preferably, the actuating means is powered by a battery. This advantageously avoids complications of having mains electrical circuitry in proximity to a water tank and moisture.

Preferably, the moveable portion is operable to move or slide coaxially with respect to the drainage pipe, wherein the standby position is an upper position, and the flush position is a lower position.

Preferably, the flush valve further comprises adjusting means for adjusting the standby position and/or the flush position of the moveable portion with respect to the drainage pipe. This advantageously improves flexibility for use in different cisterns, for example when the flush valve is to be retrofitted.

Preferably, the flush valve further comprises a flexible membrane or diaphragm enclosing at least a section of the drainage pipe to form a secure seal around said section from the liquid in the cistern when the movable portion is in the standby position. The flexible membrane may be a cylindrical bellows.

Preferably, the flush valve further comprises a mechanical support for fixing a lower end of the draining pipe to a drainage aperture of the cistern.

In accordance with an aspect of the invention herein described, there is disclosed a flush valve for use in a cistern containing a body of water defining a water level, said flush valve comprising a drainage conduit operable to allow water to flush out of the cistern, and a water-guiding element, wherein at least a portion of the draining conduit is movable with respect to the water-guiding element between a first position and a second position wherein, in the first position, said portion of the draining conduit is above the water level and, wherein, in the second position, said portion is below the water level. In accordance with an aspect of the invention herein described, there is disclosed a flush valve for use in a cistern containing a body of water defining a water level, said flush valve comprising a compressible flushing tube operable to switch between an extended configuration and a collapsed configuration, wherein a top opening of the flushing tube is above the water level in the extended configuration and below the water level in the collapsed configuration, and a fixed siphon bell disposed substantially above and around the compressible flushing tube.

Preferably, the water level defined in the cistern is a predetermined maximum water level associated with the cistern.

In accordance with an aspect of the invention herein described, there is disclosed a toilet cistern comprising the flush valve as described, wherein the lower end of the draining pipe of the flush valve is sealably engaged with a drainage aperture of the cistern for flushing.

Preferably, the siphon bell is substantially fixed relative to the cistern.

Preferably, the toilet cistern further comprises a filling valve, associated with a maximum water level, for filling the cistern with water from a mains network, when a water level in the cistern is below the maximum water level.

Preferably, the toilet cistern further comprises an infrared sensor for detecting a trigger to initiate a flushing operation, and/or a computer unit with software to execute one or more timed predefined operations.

In order that the present invention be more readily understood, various aspects of specific embodiments will now be described in conjunction with the attached drawings.

Brief description of the drawings Fig. 1 shows a toilet cistern containing the flush valve apparatus as presently disclosed, in a first configuration.

Fig. 2 shows the flush valve apparatus as presently disclosed, in a second configuration.

Specific embodiments

Various aspects of the invention are described in detail below, with reference to the drawings.

The flush valve assembly 100 as herein disclosed is suitable for use in any standard toilet cistern apparatus or system 10. It makes use of the siphon effect of draining water from one place to another, which will not be described in detail here. It is understood that the toilet cistern is operable to contain a tank or body of water or other liquids 20, and is associated with a predetermined or preferable maximum water level 22, based on which the volume of water is maintained when idle, and based on which the water is filled by a suitable filling mechanism or fill valve 30 activated after a flushing operation is initiated or completed. The filling mechanism may be separate from and operated independently from the flush valve apparatus. The operation of the filling mechanism, which may comprise a fill valve connected to the mains water network, is not detailed here.

The flush valve 100 comprises a drainage pipe 120 and a siphon bell 130.

The siphon bell 130 may also be called a water-guiding element, or an external envelope, for example. In one aspect, it has an open bottom end and a closed upper end (with one or more sealable apertures). It is preferably cylindrical.

The drainage pipe 120 may also be called a drain tube, or draining conduit, for example. It comprises at least a fixed portion 122 and a moveable portion 124 connected to each other. Preferably, the fixed portion 122 is a lower portion of the drainage pipe 120 and the moveable portion 124 is an upper portion of the drainage pipe 120. Preferably, both portions are cylindrical. The moveable portion 124 has an open top end. The fixed portion 122 is stationary with respect to the cistern 10, and in one aspect, a bottom end of the fixed portion is suitable to be attached or engaged to a drainage aperture 110 at the bottom of the interior of the cistern 10 to flush the toilet bowl. A mechanical support, or other means, is provided to ensure this engagement with the drainage aperture 110 is sealed and watertight. In an alternative aspect, the lower portion of the drainage pipe may be formed integrally with the cistern.

As illustrated in Fig. 1, the siphon bell 130 has a radius or size larger than that of the drainage pipe 120, in particular its moveable portion 124, and is disposed over and surrounding a section of the drainage pipe. Preferably, the siphon bell 130 and the drainage pipe 120 are coaxial with each other.

The siphon bell 130 and the moveable portion 124 of the drainage pipe 120 are not rigidly attached to each other. Preferably, the siphon bell 130 is stationary or fixed with respect to the toilet cistern 10, and therefore with respect to the fixed portion 122 of the drainage pipe. The siphon bell may be affixed to the fixed portion of the draining pipe using suitable affixing means.

In an aspect, during operation, the moveable portion 124 of the draining pipe can be caused to move or slide between a first position (a “standby position”), whereby the flush valve 100 is in a first configuration, and a second position (a “flush position”), whereby the flush valve is in a second configuration. The change in position or configuration of the moveable portion 124 relative to the fixed portion 122 of the drainage pipe is unrelated to and independent of the position or configuration of the siphon bell 130, which stays fixed.

Preferably, the moveable portion is moved vertically between the first position which is an upper position, as shown in Fig. 1, and the second position which is a lower position, as shown in Fig. 2. The upper position and lower position may be at a predetermined maximum height and a predetermined minimum height for the moveable portion, respectively. When the level of the water 20 is at a full level 22 in the tank, and the moveable portion 124 of the drainage pipe 120 is in the upper “standby” position (i.e. the flush valve is in the first configuration as shown in Fig. 1), the top opening of the moveable portion is above the water level, and the water inside the siphon bell but outside the draining pipe is prevented from entering the latter. The flush valve and the toilet remain idle.

When the flush valve 100 is activated, the moveable portion is moved down to the lower position and the flush valve enters the second configuration, as shown in Fig. 2, the top opening of the moveable portion is now below the maximum water level 22, and the water inside the siphon bell starts to rush into the draining pipe via said top opening. The water accelerates down, removing air, and creating a depression that drains all the water from the cistern outside the siphon bell, until the cistern is emptied. The water leaves the bottom drainage aperture 110 and flushes the toilet bowl.

The flow of water as described above is illustrated by thick arrows 40 in Fig. 2.

As the flush valve apparatus 100 returns to the idle first configuration, the filling mechanism 30 causes the tank 10 to be refilled with water.

In an optional aspect, the flush valve apparatus includes adjustment means for adjusting the height of the moveable portion in its first and/or second position, to match different water level settings of the cistern, for example.

In an aspect, flexible sealing means 140 is provided to seal a portion of the draining pipe 120. This allows the moveable connection between the bottom end of the moveable portion 124 and the upper end of the fixed portion 122 to be securely sealed from the water in the cistern, and to stop or reduce water dripping. In one example, the flexible sealing means 140 comprises a flexible cylindrical membrane, such as a bellows, comprising one end sealably attached to the moveable portion and the other end sealably attached to the fixed portion. Preferably, it is coaxial to the drainage pipe. In one aspect, each end may be affixed to the respective portion of the drainage pipe 120 by means of a rigid cylindrical cup. The flexible bellows 140 may be made of rubber. Other examples are possible for the flexible sealing means, such as a flexible tube or film.

In one aspect, the moveable portion 124 of the drainage pipe 120 is moved vertically up and down using an actuating means 150. The actuating means 150 may comprise a rigid rod 160 which goes through an orifice or aperture 132 at the top of the siphon bell 130. The orifice may be circular. Preferably, the rod, the moveable portion of the drainage pipe and the orifice are all co-axial.

In one aspect, the actuating means 150 also comprises a plugging means 162, such as one attached to the actuating rod 160, to seal the orifice 132 when the moveable portion 124 is moved to its lower second position. This is to seal the interior of the siphon bell and provide an effective vacuum to allow the siphon effect to take place, when the water is rushing into the drainage tube 120 following the intended direction 40.

The plug or plugging means 162 may have a frusto-conical shape, and the orifice 132 may have a matching frusto-conical shape, to ensure more secure airtight sealing. The plug may be made of rubber.

At the top of the siphon bell 130, the orifice 132 and the plugging means 162 may be considered as a valve allowing control of air flow, keeping the vacuum when necessary, or allowing air to enter and break the siphon when opened, or to deliver full or part flushing action.

In one preferred aspect, the actuating means 150 may comprise a motor (or motors) 152 connected to the rod 160. The operation of the motor 152 in raising and lowering the moveable portion 124 of the draining tube 120 is not detailed here. The motor may be connected to hardware circuitry for control. The actuating rod 160 may be connected to a system of levers that transmit spinning/rotational action of the motor into linear translation. In one preferable aspect, the motor is electrically connected to and powered by one or more batteries 180. Alternatively, it may be powered by mains electricity.

In one aspect, a user may activate a flushing operation of the toilet valve system via triggering a sensor 170 included in the system, connected to the motor 152 and associated circuitry. An example is an infrared motion sensor, connected to the motor, detecting the coming-and-goings and deliberate gestures of a user.

In an optional aspect, a computer unit with software is included in the flush system to control the movement of the components of the flush assembly, based on a predetermined number of timed events and/or triggers detected by the sensor 170, for example. It may also be used to control the operation of the filling valve.

In an alternative aspect, the system is only partially motorised. In an alternative or additional aspect, the system includes an integrated manual override. In another alternative aspect, no motor is provided and the flush valve assembly is purely mechanical, operated manually by a human user.

In one aspect, the flush valve apparatus as herein disclosed is suitable to be retrofitted on to existing toilets. This may involve providing a motor with a modest-sized battery, rather than connecting it to mains power, which is harder to retrofit. Advantageously, this improves the convenience of retrofit installation without requiring major adaptation of the bathroom or building; it also avoids or reduces complications arising from having mains electricity connections physically close to a tank of water such as a cistern or a generally damp environment such as a bathroom.

Compared to prior arrangements that require a substantial force to operate, such as in US 2002/108169 Al, the flush valve as presently disclosed is especially suited to being powered by battery, as the prior arrangements would necessitate considerable work by the motor, draining the battery power more quickly, making it impractical. More generally, with lighter and smaller components that require less power and effort to operate, the present invention would be especially beneficial for use in hospitals and care homes, for example, where users may not be physically strong and would prefer an easy flush mechanism that is simple to activate, either manually with little physical effort, or via a motorised arrangement that is retrofitable and battery-powered. Advantageously, this is also an energy-saving arrangement.

It should be noted that the present invention is not limited to the above-described example in which a moveable part is lowered with respect to a fixed part of a draining tube. As long as the tube can be altered in terms of its position or configuration, between a first state in which water cannot enter it, and a second state which water can enter it and realise a siphon effect to flush the toilet without an external siphon envelope being substantially moved, the detailed physical components and arrangements provided to achieve this aim can be varied. For example, an alternative arrangement may comprise a pipe or any conduit that may vary in length involving multiple moveable parts. Another alternative arrangement may comprise a single compressible or extendable tube operable to switch between an extended configuration and a collapsed configuration, for example with a collapsible part (such as in a bellows formation) integrally formed in the pipe. Movement of parts is not necessarily limited to vertical motion, but may involve rotations or displacements in other directions, and alignment of multiple apertures to start/stop a flow of water.

The present invention is not to be limited by the above-described aspects and embodiments, and that many variations are within the scope of the appended claims. The various aspects and embodiments may be combined if necessary and appropriate. The drawings serve as exemplary illustrations of the invention only, to aid understanding of the invention.