A System Comprising a Flush Control Mechanism

Abstract

A siphon flush system including a cistern 10 which houses a siphon 12 and a flush control mechanism 14 which has an actuator 143 movable between a standby, a 1st and a 2nd position, wherein the actuat

Description

Field of disclosure

[0001] The present invention relates to a flush valve operable to initiate a part flush and a full flush. Background

[0002] Using flush valves in toilet cisterns to drain a tank of water through a drainage pipe and to subsequently flush a toilet is known. In prior art arrangements, substantial force is required to initiate a flush because component parts are required to be pushed below the water level, which may be difficult for the user.

[0003] In traditional flush valves, there is a rubber seal around an aperture in the bottom of the cistem through which water flows into the toilet bowl, to flush the toilet. The rubber seal is therefore below the water line and is thus prone to degradation due to debris and limescale. Over time, the rubber seal deteriorates and is no longer watertight, thus causing leakage of water. The cost of water wastage from a single toilet can be over £400 per year and it is estimated that 5 to 8% of toilets in the UK leak.

[0004] Accordingly, there is a need in the field for an arrangement which reduces the effort required to initiate a flushing procedure, while allowing control over the amount of water flush and preventing water leakage. Summary of Invention

[0005] According to the present invention, there is provided a system comprising a cistem, a siphon and a flush control mechanism connected to the siphon, wherein the cistern houses the siphon and the flush control mechanism, wherein the flush control mechanism comprises an actuator, wherein the actuator is movable between a standby position, a first position and a second position, wherein the actuator is biased toward the standby position, wherein in the first position a part flush is initiated, and in the second position a full flush is initiated.

[0006] The present invention advantageously provides a flushing system using the siphon effect, which is easily controlled by a user, with minimal effort and force, to achieve a part or full flush. Accordingly, the system has improved accessibility and usability compared to conventional arrangements. The siphon may include a siphon bell having an aperture in the top thereof. Sealing of the aperture in the top of the siphon bell will create a vacuum and initiate the siphon effect. The water in the cistern is below the level of the aperture in the top of the siphon bell, meaning that the structures surrounding the aperture remain substantially dry during use of the flushing system. Consequently, limescale buildup which would cause degradation of those structures is mitigated, thus reducing water leakage. This improves the lifetime of the system, reduces costs and minimises maintenance requirements.

[0007] Preferably, the flush control mechanism comprises a button connected to the actuator, wherein the button can be pressed to cause the actuator to move a first distance to adopt the first position.

[0008] In a preferred arrangement, the button can be pressed to cause the actuator to move a second distance to adopt the second position, wherein the second distance is greater than the first distance, and the actuator is configured to move beyond the first position to adopt the second position.

[0009] Preferably, the flush control mechanism comprises a first button and a second button, wherein the first button and the second button are connected to the actuator, wherein pushing the first button causes the actuator to move to the first position and pressing the second button causes the actuator to move to the second position.

[0010] It is preferred that the actuator is lockable in the first position and wherein the actuator is lockable in the second position.

[0011] Preferably, a part flush is operable to flush approximately 4 L of water.

[0012] Preferably, a full flush is operable to flush approximately 6 L of water.

[0013] In a preferred arrangement, the siphon comprises a siphon bell and a plug, wherein the siphon bell comprises an aperture, wherein the plug is for sealing the aperture and the plug is connected to the actuator, wherein the aperture is unsealed when the actuator is in the standby position, wherein the aperture is sealed by the plug when the actuator is in the first position, and wherein the aperture is sealed by the plug when the actuator is in the second position. Preferably, the aperture is in the top of the siphon bell and above the maximum water level in the cistern. Accordingly, the aperture and surrounding structures remain substantially dry, which mitigates formation of limescale and degradation of the surrounding structures. Leakage of water is reduced, as a result.

[0014] Preferably, the flush control mechanism further comprises a latching mechanism and a water level detector, wherein the latching mechanism is operable to: latch the actuator at the first position when the actuator moves by the first distance from the standby position, and to latch the actuator at the second position when the actuator moves by the second distance from the standby position, wherein the second distance is greater than the first distance.

[0015] It is preferred that the latching mechanism comprises a first latch and a second latch, wherein when the actuator is latched in the first position, the flush control mechanism is operable to de-latch the first latch from the actuator such that it returns to the standby position when the water level detector determines a water level has dropped to a first level, and when the actuator is latched in the second position, the flush control mechanism is operable to de-latch the first and second latches from the actuator when the water level detector determines a water level has dropped to a second level, the second level being further from the plug than the first level.

[0016] In a preferred arrangement, the water level detector comprises a first float and a second float, wherein the first float is connected to the first latch and the second float is connected to the second latch.

[0017] Preferably, the first float is positioned closer to a top of the cistern than the second float.

[0018] It is preferred that the flush control mechanism comprises a reset mechanism, wherein the reset mechanism is operable to decouple the first latch or the second latch from the actuator when a water level remains above a fixed specified level for a predetermined period of time. It is particularly preferred that the fixed specified level is the first level. The level at which the water remains may be located at a fixed distance from the plug and is closer to the plug than the first water level.

[0019] The reset mechanism is advantageous when a part (or full) flush fails, i.e., when the water level does not descend low enough in the cistern to reset the actuator to its standby position. In such a scenario, the toilet would usually be unusable. The reset mechanism circumvents this problem.

[0020] In a preferred arrangement, the flush control mechanism is operable to decouple the first latch and the second latch from the actuator when a water level remains above the fixed specified level for a predetermined period of time. It is particularly preferred that the fixed specified level is the first level. This is advantageous when a full flush fails.

[0021] Preferably, the reset mechanism is configured to move the actuator to the standby position when the part flush or full flush fails.

[0022] It is preferred that the reset mechanism comprises a reset float housed in a chamber, wherein the chamber comprises a floor and the floor comprises an aperture for restricting fluid flow through the floor.

[0023] Tn 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

[0024] The drawings are included for illustrative purposes only.

[0025] Fig. lisa schematic diagram of a system comprising a flush control mechanism in a standby position.

[0026] Fig. 2 is a schematic diagram of a system comprising a flush control mechanism in a first position, wherein a part flush is initiated.

[0027] Fig. 3 is a schematic diagram of a system comprising a flush control mechanism in a second position, wherein a full flush is initiated.

[0028] Fig. 4 is a schematic diagram of a system comprising a flush control mechanism in a standby position and floats.

[0029] Fig. 5 is a schematic diagram of the system of Fig. 4 in a first position, wherein a part flush is initiated.

[0030] Fig. 6 is a schematic diagram of the system of Fig. 4 in a second position, wherein a full flush is initiated.

[0031] Fig. 7 is a schematic diagram of a system comprising a flush control mechanism and a reset mechanism, wherein a part flush has failed.

[0032] Fig. 8 is a schematic diagram of a system comprising a flush control mechanism and a reset mechanism, wherein a full flush has failed.

[0033] Figs. 9a and 9b show a perspective view of a specific embodiment of a first latch of the flush control mechanism.

[0034] Figs. 9c and 9d show a perspective view of a specific embodiment of a second latch of the flush control mechanism.

[0035] Fig. 9e shows a perspective view of some components of the flush control mechanism, the floats and the reset mechanism.

[0036] Figs. 10a to 10c show cross-sectional views of a specific embodiment of system before flushing (Fig. 10a); once a part flush has been initiated and the water level begins to drop (Fig. 10b); and once a successful part flush has been completed (Fig. 10c). Detailed description

[0037] The present arrangement provides a system comprising a cistern, a siphon and a flush control mechanism connected to the siphon, wherein the cistern houses the siphon and the flush control mechanism, wherein the flush control mechanism comprises an actuator, wherein the actuator is movable between a standby position, a first position and a second position, wherein the actuator is biased toward the standby position, wherein in the first position a part flush is initiated, and in the second position a full flush is initiated.

[0038] Advantageously, a flushing system using the siphon effect is provided, which is easily controlled by a user, with minimal effort and force, to achieve a part or full flush. Accordingly, the system has improved accessibility and usability compared to conventional arrangements. The siphon may include a siphon bell having an aperture in the top thereof. Sealing of the aperture in the top of the siphon bell will create a vacuum and initiate the siphon effect. The water in the cistern is below the level of the aperture in the top of the siphon bell, meaning that the structures surrounding the aperture remain substantially dry during use of the flushing system. Consequently, limescale buildup which would cause degradation of those structures is mitigated, thus reducing water leakage. This improves the lifetime of the system, reduces costs and minimises maintenance requirements.

[0039] Fig. 1 shows a system 100 comprising a cistern 10, a siphon 12 and a flush control mechanism 14 connected to the siphon 12. The system 100 is in the standby / idle position (i.e. a flush has not been initiated). The cistern 10 is configured to contain water and is associated with a predetermined or preferable maximum water level 130. The cistern 10 houses the siphon 12 and the flush control mechanism 14. The siphon 12 includes a siphon bell 121 having an aperture 126 in the top of the siphon bell 121. The siphon bell 121 houses a movable drainage pipe 122, which is open at both ends and is movable (upwards and downwards) with respect to the siphon bell 121, and a flexible seal 123 (e.g. bellows). The flexible seal 123 is attached to the movable drainage pipe 122. The movable drainage pipe 122 is connected to the bottom end of plunger 124, which extends through aperture 126. A plug 128 is attached to the plunger 124 and in the standby position, the aperture 126 is unplugged (i.e. the plug 128 is biased away from aperture 126). There is a drainage aperture 125 at the bottom of the cistern 10 for water to exit the cistern 10 and flush the toilet bowl. In another arrangement, the seal / valve 127 is a deformable rubber membrane and plug 128 acts on the seal / valve 127 to cause the seal / valve 127 to close aperture 126.

[0040] The top end of plunger 124 is connected to the flush control mechanism 14. Specifically, the top end of plunger 124 is pivotally connected to lever 141. Lever 141 is fixedly connected to the bottom end of arm 142, which is curved. The top of arm 142 is pivotally connected to actuator 143, which is part of flush control mechanism 14. Accordingly, lateral motion of actuator 143 causes rotation of arm 142, in turn, the lever 141 rotates around its pivot point causing the vertical motion of plunger 124. In Fig. 1, for example, the plunger 124 is attached to an end of the lever 141. As such, a relatively small rotation of the arm 142 cause by activation of the actuator 143 results in the plunger 124 moving a relatively large distance. Actuator 143 is connected to button 13, which includes a first button 13a and second button 13b. Button 13 is a component part of the flush control mechanism 14. First button 13a is for initiating a part flush and second button 13b is for initiating a full flush.

[0041] The volume of water flushed into a toilet bowl in a part flush is lower than the volume of water flushed into the toilet bowl in a full flush. A part flush causes flushing of approximately 4L of fluid (e.g. water) into a toilet bowl (not shown). A full flush causes flushing of approximately 6L fluid into the toilet bowl. Pressing first button 13a or second button 13b causes the actuator to move in the direction of arrow A (towards the left of Fig. 1) and to interact with first latch 146a or second latch 146b of latching mechanism 146, as described in more detail with respect to Figs. 2 and 3. In Fig. 1, actuator 143 is in the standby position (i.e. the non-flushing position) and is biased toward this position, e.g. by a spring (not shown). Other biasing means may be used, such as a magnetic or a hydraulic or pneumatic piston. Actuator 143 includes a first aperture 144 and a second aperture 145. A locking mechanism, such as an aperture on the actuator 143 can receive first and second latches 146a, 146b. This may be a single aperture that can sequentially collect first and second latches 146a, 146b. In Figs. 1-8, first and second apertures 144, 145 are shown for ease of understanding. Here, first and second apertures 144, 145 can receive first latch 146a and second latch 146b of latching mechanism 146, respectively.

[0042] The flush control mechanism 14 also includes a water level detector 148 for stopping the flush. The water level detector 148 may comprise one or more floats.

[0043] In order to initiate a part-flush, button 13 a is pressed by a user, causing actuator 143 to be pushed in the direction of arrow A, by a distance X. In system 100, distance X is 16 mm, but this distance is dependent on the mechanical components of the system and thus it is not essential that distance X is 16 mm.

[0044] Fig. 2 shows system 100 in a first position, when button 13a has been pressed and a part flush is initiated. In this arrangement, initiation of the part flush is caused by a user pressing button 13a, which causes actuator 143 to move in the direction of arrow A (as shown in Fig. 1) and adopt a first position. The first position is achieved when the first latch 146a of the latching mechanism 146 enters the first aperture 144 of actuator 143, as shown in Fig. 2. The actuator 143 is therefore locked in this first position. This initiates a part-flush (approximately 4L of water to be flushed into the toilet bowl). Movement of actuator 143 in the direction of arrow A causes arm 142 to rotate anticlockwise, which pushes lever 141 downwards (in the direction of arrow B). Downward movement of lever 141 causes plunger 124, and thus plug 128, to move downward, until the plug 128 seals aperture 126. This seals the interior of the siphon bell 121 and creates an effective vacuum to enable the siphon effect to occur. Advantageously, the sealed aperture 126 is above the maximum water level 130. This mitigates degradation and build-up of limescale around the seal / valve 127 around aperture 126, reducing leakage of water and therefore making the system 100 more cost efficient than conventional flushing systems.

[0045] As the movable drainage pipe 122 is attached to the bottom end of plunger 124, downward movement of plunger 124 also causes the movable drainage pipe 122 to move down to a lower position, below the maximum water level 130. Water inside siphon bell 121 therefore starts to rush into the movable drainage pipe via its top opening. The water accelerates downwards, removing air, and creating a depression that drains water from the cistern 10 outside the siphon bell 121. The water leaves the system 100 via drainage aperture 125 and flushes the toilet bowl (not shown) with approximately 4L of water, thereby achieving a part flush.

[0046] When the part flush is complete, normally, the water level detector 148 is operable to control the flush control mechanism 14 to unlatch the actuator 143 such that it returns to the standby position (i.e. the position of actuator 143 shown in Fig. 1). Unlatching of the actuator 143 allows the actuator 143 to move back to its original position, along the direction of arrow C, which causes first latch 146a to unlatch from first aperture 144 of actuator 143. This causes the plunger 124 and plug 128 to lift upwards, opening aperture 126 and stopping the vacuum, thus allowing air to enter and break the siphon and therefore stopping the flush. Unlatching of actuator 143 happens when the water level detector 148 determines that a water level has dropped to a first water level / part flush water level 132. The first water level / part flush water level 132 is lower than the maximum water level 130. The water level detector 148 may comprise floats, as discussed below, but is not limited to floats. Any means for determining that a particular water level has been reached can be used, such as a sensor. The return of actuator 143 to the standby position stops the flush. The system 100 is therefore back in the idle / standby position and a user can press button 13 again to initiate a flush. The unlatching process is described in detail later.

[0047] Generally, to achieve the siphon effect, a siphon bell is present inside the cistern. The siphon bell houses a drainage pipe having a top portion. The top portion of the drainage pipe is movable with respect to the siphon bell. The top of the siphon bell includes an aperture. In the standby / idle position (i.e. before the siphon effect / flush is initiated), fluid in the cistern is prevented from entering the drainage pipe, as the movable top portion is above the water line. In the standby / idle position, the aperture in the top of the siphon bell is open.

[0048] A plunger extends through the aperture in the top of the siphon bell and is configured to move upwards and downwards through the aperture. The plunger comprises a plug around its circumference. The bottom end of the plunger is connected to the movable top portion of the drainage pipe. To initiate the siphon / flush, the plunger is moved downward to seal / close the interior of the siphon bell and create an effective vacuum. Simultaneously, the plunger moves the movable top portion downward so that the movable top portion is below the water line. Water can then enter the drainage pipe and the flushing begins.

[0049] To stop the flush and break the siphon, the aperture in the top of the siphon bell is unplugged, i.e., the plug is removed from the aperture so that the aperture is unsealed. This can be achieved by moving the plunger upwards, thereby moving the plug away from the aperture and moving the movable top portion of the drainage pipe above the water line (thus preventing water from entering the drainage pipe).

[0050] Fig. 3 shows system 100 in a second position, wherein second button 13b has been pressed, causing actuator 143 to be pushed in the direction of arrow A, by distance Y. This initiates a full flush (approximately 6 L of water). In system 100, distance Y is 21 mm, but this distance is dependent on the mechanical components and thus it is not essential that distance Y is 21 mm. The second position adopted by the actuator 143 (in the full flush position) is different to the first position adopted by the actuator 143 (in the part flush position). The distance that actuator 143 travels is greater to reach the second position than it is to reach the first position (i.e. distance Y >distance X).

[0051] Upon pressing second button 13b to initiate a full flush, actuator 143 is moved in the direction of arrow A by distance Y. The second position is achieved by the second latch 146b of latching mechanism 146 entering the second aperture 145 of actuator 143. The actuator 143 is thus locked in the second position. Subsequently, the movement of the components of the siphon 12 connected to actuator 143 are as described above for the first position (part flush), as shown in Fig. 2. Movement of actuator 143 in the direction of arrow A causes arm 142 to rotate anticlockwise, which pushes lever 141 downwards (in the direction of arrow B). Downward movement of lever 141 causes plunger 124, and thus plug 128, to move downward, until the plug 128 seals aperture 126. This seals the interior of the siphon bell 121 and creates an effective vacuum to enable the siphon effect to occur. At all times, the sealed aperture 126 is above the maximum water level 130, meaning that the seal / valve 127 is kept substantially dry and thus is less likely to be susceptible to degradation due to limescale. The lifetime of the system is thus maximised and maintenance requirements are minimised.

[0052] As the movable drainage pipe 122 is attached to the bottom end of plunger 124, downward movement of plunger 124 also causes the movable drainage pipe 122 to move down to a lower position, below the maximum water level 130. Water inside siphon bell 121 therefore starts to rush into the movable drainage pipe 122 via its top opening. The water accelerates downwards, removing air, and creating a depression that drains water from the cistern 10 outside the siphon bell 121. The water leaves the system 100 via drainage aperture 125 and flushes the toilet bowl (not shown) with approximately 6L of water, thereby achieving a full flush.

[0053] When the full flush is complete, normally, the water level detector 148 controls the flush control mechanism 14 to unlatch the actuator 143 such that it returns to the standby / idle position (i.e. the position shown in Fig. 1). Unlatching of the actuator 143 requires the actuator to travel in the direction of arrow C, which causes second latch 146b to unlatch from second aperture 145 of actuator 143. This causes the plunger 124 and plug 128 to lift upwards, opening / unsealing aperture 126 and stopping the vacuum, thus allowing air to enter and break the siphon. Unlatching of actuator 143 happens when the water level detector 148 determines that a water level has dropped to a second water level / full flush water level 134. The second water level / full flush water level 134 is lower than the first water level / part flush water level 132. The water level detector 148 may comprise floats, as discussed below, but is not limited to floats. The return of actuator 143 to the standby position stops the flush. The system 100 is therefore back in the idle / standby position and a user can press button 13 again to initiate a flush.

[0054] The unlatching process is now described. Fig. 4 shows a system 400 wherein the flush control mechanism 148 includes a first float 41 and second float 42. The rest of the components are the same as in Figs. 1 to 3. Fig. 4 shows system 400 in the standby / idle position, wherein the actuator 143 is unlatched and the water level in the cistern 10 is at the maximum water level 130. In this arrangement, both floats 41 and 42 are submerged. First float 41 is connected to first latch 146a via linkage 43 and second float 42 is connected to second latch 146b via linkage 44. First latch 146a has a pivot point 45 which it can rotate anticlockwise around, when the weight of first float 41 provides a downward force on first latch 146a. Second latch 146b has a pivot point 46 which it can rotate anticlockwise about, when the weight of second float 42 provides a downward force on second latch 146a. The first float / first latch and second fl oat / second latch systems function independently of each other. In the standby position (when the water is at its maximum level 130), the first float 41 and second float 42, due to being submerged, do not provide a downward force on the first or second latches 146a, 146b and thus do not cause movement of the latches 146a, 146b.

[0055] Fig. 5 shows system 400 when the part flush button 13a is pressed. A siphon is initiated and a part flush starts, causing the water level in the cistern 10 to descend from the maximum water level 130. When the water level in the cistern 10 drops to the first water level / part flush water level 132, float 41 now floats / sits on the surface of the water. This causes the flush control mechanism 148 to re-set the actuator 143 to the standby position, thereby unplugging aperture 126 in the siphon bell 121 and stopping the siphon effect, thus stopping the flush. In Fig. 5, at this point, there is no buoyance to balance the weight of first float 41. Thus, all the weight of first float 41 is applied via linkage 43. This downwards force causes first latch 146a to pivot around pivot point 46 in the anticlockwise direction indicated by arrow D and thus first latch 146a is decoupled from first aperture 144 of actuator 143. This allows actuator 143 to move in the direction of arrow C, back to the standby (i.e. original) position. By doing so, the actuator 143 causes arm 142 to rotate clockwise, which pulls plunger 124 and thus plug 128 upwards, unsealing aperture 126 and thereby allowing air to flow and stop the siphon. The part flush is therefore stopped and the system 400 reverts to the standby position, as shown in Fig. 4.

[0056] Fig. 6 shows system 400 when the full flush button 13b is pressed. A siphon is initiated and a full flush starts, causing the water level in the cistern 10 to drop. When the water level in the cistern 10 drops from the maximum water level 130 to the second water level / full flush water level 134, second float 42 now floats / sits on the surface of the water. First float 41 resides at a level above water level 134 and above second float 42. The dropping of the water to level 134 causes the flush control mechanism 148 to cause the actuator 143 to move back to the standby position (in the direction of arrow C), thereby stopping the flush. As shown in Fig. 6, once the water level is at the second level 134, the first and second floats 41, 42 are both no longer submerged. The weight of the first float 41 via linkage 43 will cause first latch 146a to rotate anticlockwise around its pivot point 46 in the direction of arrow D. At the same time, the weight of float 42 via linkage 44 will cause anticlockwise rotation of second latch 146b around its pivot point 45, thereby unlatching the actuator 143, allowing it to return to the standby position, thereby causing plunger 124 and plug 128 to move upwards, opening aperture 126 and stopping the flush.

[0057] Fig. 7 shows system 500 including a reset mechanism 70. When a part or full flush is initiated (by pressing first or second buttons 13a, 13b), occasionally the water level does not drop far enough to cause the water level detector (e.g. floats) to reset the actuator 143 to the standby position and thus stop the flush. This can occur, for example, if button 13 is pressed too quickly after the previous flush. In that scenario, the part or full flush does not complete and there is inadequate flushing of the toilet. The actuator 143 does not revert to the standby / idle position, meaning that a new flush cannot be initiated. This leaves a toilet bowl unable to be flushed again and thus unusable until maintenance is carried out, as the plug 128 continues to seal the aperture 126 and the vacuum remains.

[0058] Fig. 7 shows a situation wherein the water level in cistern 10 is ‘stuck’ at level 136 (e.g. a fixed specified level) after initiation of a part flush, which is higher up than first level / part flush level 132. Accordingly, the plug 128 continues to seal aperture 126. At water level 136, first float 41 is partly submerged. Due to the buoyancy, the first float 41 is not able to cause the actuator 143 to revert to the original / standby position and stop the flush. The reset mechanism 70 addresses this problem by causing delatching / decoupling of first latch 146a and thus causing the actuator 143 to move back to the standby position and stop the flush. The reset mechanism 70 therefore avoids the need for maintenance of the toilet in the event of an unsuccessful flush.

[0059] The reset mechanism 70 includes a reset float 72 which is housed in chamber 74. Chamber 74 has a top opening 76 (an aperture in the top surface of the chamber 74) and a bottom opening 78 (an aperture in the bottom surface of the chamber). As the water level descends in the cistern 10, so does reset float 72. The speed of the movement of reset float 72 downwards is restricted because the cross-sectional area of bottom opening 78 is small. This restricts fluid flow out of the chamber 74. The reset float 72 will eventually descend (see dashed line version of reset float 72) such that it interacts with lever 71. Interaction between the reset float 72 and the lever 71 causes the first latch 146a to decouple from first aperture 144 of actuator 143 and the second latch 146b to decouple from the actuator 143, and thus enable the actuator 143 to revert to the standby position, thereby lifting plug 128 out of aperture 126 and breaking the siphon. Specifically, the reset mechanism 70 causes first latch 146a to rotate anticlockwise about pivot point 46 to enable the actuator to revert to the standby position.

[0060] The reset mechanism 70 is configured such that reset float 72 does not descend to interact with the lever 71 in a ‘successful’ or ‘normal’ part (or full) flush (i.e., when water levels 132 or 134 are reached), as this would cause premature movement of the actuator 143 back to the standby position, thus unplugging aperture 126 and stopping of the flush. This is achieved by restricting the speed of the reset float 72 downwards in the chamber 74. The bottom opening 78 of chamber 74 has a small cross-sectional area, meaning that fluid flow is restricted therethrough, which slows the movement of reset float 72.

[0061] Fig. 8 shows an arrangement wherein a full flush has been initiated by pressing full flush button 13b, to initiate flushing of approximately 6 L of water into the toilet bowl. As discussed in relation to Fig. 7, occasionally the water level does not drop far enough to cause the water level detector (floats in this arrangement) to reset the actuator 143 to the standby position, meaning that the aperture 126 in the siphon bell 121 remains sealed by plug 128 and the vacuum and siphon effect remains. In that scenario, the full flush does not complete and there is inadequate flushing of the toilet. The actuator 143 does not revert to the standby / idle position, meaning that a new flush cannot be initiated. This leaves a toilet bowl unable to be flushed again and thus unusable, as the plug 128 continues to seal the aperture 126 and the vacuum remains.

[0062] Fig. 8 shows a situation wherein the water level in cistern 10 is ‘stuck’ is at level 136 after initiation of a full flush,. Accordingly, the plug 128 continues to seal aperture 126. At water level 136, second float 42 is completely submerged. Due to the buoyancy, the second float 42 is not able to cause the actuator 143 to revert to the original / standby position and stop the flush. The reset mechanism 70 addresses this problem by causing delatching / decoupling of second latch 146a and thus causing the actuator 143 to move back to the standby position and stop the flush.

[0063] The reset mechanism 70 is the same as shown in Fig. 7 and as described above. As the water level descends in the cistern 10, so does reset float 72. The speed of the movement of reset float 72 downwards is restricted because the cross-sectional area of bottom opening 78 is small. This restricts fluid flow out of the chamber 74. The reset float 72 will eventually descend (see dashed line version of reset float 72) such that it interacts with lever 71. Interaction between the reset float 72 and the lever 71 causes the first and second latches 146a, 146b to rotate anticlockwise about their respective pivot points 46, 45, allowing the second latch 146b to decouple from second aperture 145 of actuator 143 (and / or allowing the first latch 146a to decouple from first aperture 144) and thus enable the actuator 143 to revert to the standby position. This lifts plug 128 out of aperture 126, breaking the siphon. Specific Embodiment

[0064] Figs. 9a to 9d shows a specific embodiment of the latching mechanism 146 when engaged with actuator 143. The first latch 146a is shown in Fig. 9a, wherein it is engaged with an aperture in the actuator 143 at the positions indicated by arrows 92. Here, section 9 of first latch 146a engages with an elongate aperture or trench 10, in actuator 143. In this position, the first latch 146a is locked with actuator 143. In use, this position is arrived at, for example, by the user pressing a part flush button (not shown), causing the actuator 143 to move from a standby / idle position to couple with first latch 146a. The coupling between the actuator 143 and first latch 146a will initiate the siphon effect due to causing movement of component parts of the system which are not shown in Fig 9a, i.e., the engagement will cause sealing of the aperture in the top of the siphon bell.

[0065] Fig. 9a also shows first stud 95 which is part of and protrudes from the body of the first latch 146a. Fig. 9b shows screw 93 having a catch 97 which rests on first stud 95. When the screw 93 descends, e.g. due to the weight of a float attached to screw 93 (float not shown), the first latch is caused to rotate about pivot point 99a, therefore disengaging the first latch 146a from actuator 143 and allowing the actuator 143 to move back to its standby position, i.e. the position which the actuator 143 is biased to adopt. In that regard, actuator 143 has a spring holder 91, which can house a spring (not shown) to cause the actuator 143 to be biased toward the standby position.

[0066] The first latch 146a is weighted in the vicinity of section 9, meaning that it is heavier in the region where engagement with the trench 10 occurs, compared to the region of the latch 146a in the vicinity of the first stud 95. Accordingly, the weight of section 9 causes the first latch 146a to drop naturally under gravity into trench 10, when in use. Alternatively, or additionally, compression springs (not shown) may be housed in holes 9a and 9b. This assists engagement of section 9 with trench 10 as the compression springs abut against the top of an internal surface of a housing (not shown).

[0067] Fig. 9c shows engagement between the second latch 146b and the actuator 143, with the point of engagement indicated by arrow 90. In this position, the second latch 146b is locked with actuator 143. Section 11 of second latch 146b engages with the trench 10 in actuator 143. In use, this position is arrived at, for example, by the user pressing a full flush button (not shown), causing the actuator 143 to move from a standby / idle position to couple with second latch 146b. The coupling between the actuator 146 and second latch 146b will initiate the siphon effect due to causing movement of component parts of the system which are not shown in Fig 9c, i.e., the engagement will cause sealing of the aperture in the top of the siphon bell.

[0068] Fig. 9c also shows second stud 94 which is part of and protrudes from the body of the second latch 146b. Fig. 9d shows screw 96 having a catch 98 which rests on second stud 94. When the screw 96 descends, e.g. due to the weight of a float attached to screw 93 (float not shown), the second latch 146b is caused to rotate about pivot point 99b, therefore disengaging the second latch 146b from actuator 143 and allowing the actuator 143 to move back to its standby position, i.e. the position which the actuator 143 is biased to adopt.

[0069] The second latch 146b is also weighted towards its back and is thus heavier in the region where engagement with trench 10 occurs. Alternatively or additionally, hole 9c can house a compression spring (not shown), which in use abuts against an internal surface of a housing (not shown). This assists engagement of the second latch 146b with trench 10.

[0070] Fig. 9e shows components of the flush control mechanism, the water level detector (floats) and the reset mechanism 70. The siphon is not shown. Fig. 9e illustrates how the first latch 146a, second latch 146b and the actuator 143 are positioned relative to each other (in the standby position). In use, as actuator 143 is moved to the first position, it engages section 9 of first latch 146a. If the actuator 143 is moved to the second position, it engages with section 11 of second latch 146b. Thus, in the second position, section 9 of the first latch 146a is no longer engaged with the trench 10 of actuator 143.

[0071] The arrangement of the screws 93, 96 and floats 41 and 42 are also shown. Float 41 is associated with screw 93 and first latch 146a, whereas float 42 is associated with screw 96 and second latch 146b. Screws 93, 96 may be considered linkages between the floats and the relevant latch, as described with respect to Fig. 4. In addition, arm 142 can be seen in Fig. 9e, which is pivotally connected to actuator 143. These components form part of the flush control mechanism 14. The lever, which is normally attached to the bottom end of arm 142 and the plunger attached to the lever having a plug to seal the aperture in the siphon bell are not shown.

[0072] Fig. 9e also shows the reset mechanism 70. Referring also to Figs. 7 and 8, when float 72 engages lever 71, link mechanisms 17a, 17b are caused to pivot to engage stud 18 on first latch 146a and stud 16 on second latch 146b, thus pushing the respective latches out of the elongate aperture / trench 10 and allowing the spring to freely push the actuator 143 back to the standby position.

[0073] Figs. 10a to 10c show cross-sectional views of a specific embodiment of system before flushing (Fig. 10a), once a part flush has been initiated and the water level begins to drop (Fig. 10b) and once a successful part flush has been completed (Fig. 10c). In Fig. 10a, the actuator 143 is biased toward the standby position. The water level is at a maximum water level 130 in the cistern (not shown), wherein float 41, which is associated with first latch 146a, is partly submerged. Float 42, which is associated with second latch 146b, is completely submerged. Fig. 10a further shows the bellows 123 of the siphon mechanism in an expanded state. The bellows 123 are a flexible seal and can move up and down. In the standby / idle position, the bellows 123 are expanded and can be moved downwards upon initiation of a flush. The movable drainage pipe, which would be attached to the bellows 123, is not shown.

[0074] Fig. 10b shows the system after a part flush has been initiated (e.g. once a user has pressed a part flush button). Actuator 143 has moved toward the left-hand side of Fig. 10b (compared to the position of actuator 143 in Fig. 10a) and will have coupled to latch 146a. This motion causes a plunger having a plug attached thereto, to move downwards and for the plug to seal a hole at the top of siphon bell 121, therefore creating a vacuum and initiating the siphon effect. The plunger, plug and hole in the siphon bell 121 are not shown (but are shown in, e.g., Fig. 1). The bellows 123 are now in a collapsed state, as the siphon has started. At this point, float 41 is still submerged, so the weight of float 41 will not bear down on screw 93 or first stud 95.

[0075] Fig 10c shows the system once a successful part flush has occurred and the water level has dropped in the cistern from maximum water level 130 to first water level / part flush water level 132, which is just below float 41. As shown in Fig. 10c, as float 41 is no longer submerged, the weight of float 41 pulls down on screw 93. Catch 97 of screw 93 thus pulls the first stud 95 of first latch 146a downwards, which in turn causes delatching / decoupling of the first latch 146a from actuator 143. Fig. 10c shows this delatching in progress. Once the delatching completes, the part flush stops and the system returns to the standby position of Fig. 10a, causing the cistern to refill to the maximum water level 130.

[0076] 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.

Claims

1. A system comprising a cistern, a siphon and a flush control mechanism connected to the siphon, wherein the cistern houses the siphon and the flush control mechanism, wherein the flush control mechanism comprises an actuator,wherein the actuator is movable between a standby position, a first position and a second position, wherein the actuator is biased toward the standby position,wherein in the first position a part flush is initiated, and in the second position a full flush is initiated.

2. A system according to claim 1, wherein the flush control mechanism comprises a button connected to the actuator, wherein the button can be pressed to cause the actuator to move a first distance to adopt the first position.

3. A system according to claim 2, wherein the button can be pressed to cause the actuator to move a second distance to adopt the second position, wherein the second distance is greater than the first distance, and the actuator is configured to move beyond the first position to adopt the second position.

4. A system according to claim 1, wherein the flush control mechanism comprises a first button and a second button, wherein the first button and the second button are connected to the actuator, wherein pushing the first button causes the actuator to move to the first position and pressing the second button causes the actuator to move to the second position.

5. A system according to any preceding claim, wherein the actuator is lockable in the first position and wherein the actuator is lockable in the second position.

6. A system according to any preceding claim, wherein the part flush is operable to flush approximately 4 L of water.

7. A system according to any preceding claim, wherein the full flush is operable to flush approximately 6 L of water.

8. A system according to any preceding claim, wherein the siphon comprises a siphon bell and a plug, wherein the siphon bell comprises an aperture, wherein the plug is for sealing the aperture and the plug is connected to the actuator, wherein the aperture is unsealed when the actuator is in the standby position,wherein the aperture is sealed by the plug when the actuator is in the first position,and wherein the aperture is sealed by the plug when the actuator is in the second position.

9. A system according to any preceding claim, wherein:the flush control mechanism further comprises a latching mechanism and a water level detector, wherein the latching mechanism is operable to:latch the actuator at the first position when the actuator moves by the first distance from the standby position, andto latch the actuator at the second position when the actuator moves by the second distance from the standby position, wherein the second distance is greater than the first distance.

10. A system according to claim 9, wherein the latching mechanism comprises a first latch and a second latch,wherein when the actuator is latched in the first position, the flush control mechanism is operable to de-latch the first latch from the actuator such that it returns to the standby position when the water level detector determines a water level has dropped to a first level, andwhen the actuator is latched in the second position, the flush control mechanism is operable to de-latch the first and second latches from the plug when the water level detector determines a water level has dropped to a second level, the second level being further from the plug than the first level.

11. A system according to claim 9 or 10, wherein the water level detector comprises a first float and a second float, wherein the first float is connected to the first latch and the second float is connected to the second latch.

12. A system according to claim 11, wherein the first float is positioned closer to a top of the cistern than the second float.

13. A system according to any preceding claim, wherein the flush control mechanism comprises a reset mechanism, wherein the reset mechanism is operable to decouple the first latch or the second latch from the actuator when a water level remains above a fixed specified level for a predetermined period of time.

14. A system according to claim 13, wherein the flush control mechanism is operable to decouple the first latch and the second latch from the actuator when a water level remains above the fixed specified level for a predetermined period of time.

15. A system according to claim 13 or 14, wherein the reset mechanism is configured to move the actuator to the standby position when the part flush or full flush fails.

16. A system according to any of claims 13 to 15, wherein the reset mechanism comprises a reset float housed in a chamber, wherein the chamber comprises a floor and the floor comprises an aperture for restricting fluid flow through the floor.

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