Patent Publication Number: US-2019194923-A1

Title: Cistern assembly

Description:
FIELD OF INVENTION 
     The present invention relates to a flush toilet and urinal systems. The present invention has particular but not exclusive application to a cistern for a flush toilet. 
     BACKGROUND OF THE INVENTION 
     A flush toilet system operates by the rapid passage of water from the cistern to the toilet bowl which then passes to the underground sewer pipes. Water is stored in the cistern. Water is released from the cistern with the actuating of the flushing mechanism. Water passes through a cistern outlet into the bowl. In conventional systems, when water has drained from the cistern, the outlet valve reseals about the outlet and water from the mains water supply refills the cistern. 
     The cistern outlet valve in conventional systems is prone to wear and damage resulting in ineffective sealing and consequent leaking and loss of water to the sewerage system. WO 2009/039561 describes a cistern system comprising a cistern housing and an internal cistern member. Flushing relies on a siphoning mechanism and is activated by tilting the internal cistern member. This simple cistern overcomes the need for a cistern outlet valve and requires a reduced amount of maintenance. 
     The design of the simple cistern system requires the addition of a buoyant latch to assist in overcoming a delay in discharge of water when the internal cistern member is tilted to activate flushing. This results in the need for additional parts and increased complexity and cost. 
     In addition, the cistern requires an operating knob or lever. In one version the operating knob protrudes from the front of the cistern which may cause inconvenience. Furthermore, the requirement for a protruding operating knob does not lend the cistern to application in a concealed (in wall) unit. 
     OBJECT OF THE INVENTION 
     It is an object of the present invention to provide an alternate cistern assembly which overcomes at least in part one or more of the above mentioned disadvantages. 
     SUMMARY OF THE INVENTION 
     The present invention broadly resides in a cistern assembly for a flush toilet including 
     a cistern housing: 
     cistern member pivotally attached within the cistern housing and able to move between pivoted positions through an equilibrium position, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber, the passageway has an internal inlet and a cistern outlet and is shaped to siphon water through the passageway; the internal inlet is positioned substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in one of the pivoted positions; and 
     an actuator associated with the cistern member to pivot the cistern member relative to the cistern housing wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     The cistern housing preferably includes a cistern lid and a cistern base. 
     In another aspect the present invention broadly resides in a cistern assembly for a flush toilet including 
     a cistern housing; 
     a cistern member pivotally attached within the cistern housing and able to move between pivoted positions through an equilibrium position, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber, the passageway has an internal inlet and a cistern outlet and is shaped to siphon the water when the hydrostatic pressure within the passageway is lower than the atmospheric pressure in the chamber thereby drawing water through the passageway; the internal inlet is positioned substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in one of the pivoted positions; and 
     an actuator associated with the cistern member to pivot the cistern member relative to the cistern housing wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     The cistern housing preferably includes a cistern lid and a cistern base. 
     The passageway is preferably substantially U-shaped. 
     The passageway preferably has a first section formed within the chamber and a second section formed outside the chamber. The first section and the second section enable continuous fluid communication between the internal inlet of the passageway and the cistern outlet. 
     Preferably, the first section is formed by an inner side wall and the base wall, and the second section is formed by an outer side wall and the base wall. Where the first section meets with the second section there is a substantially U-shaped portion. 
     The first section, the substantially U-shaped portion and the second section preferably form a continuous channel. Preferably, the first section, the substantially U-shaped portion and the second section have internal dimensions that are substantially the same. 
     Preferably the cistern outlet is substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in the pivoted position. 
     Preferably the internal inlet and the cistern outlet are each substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in the pivoted position. 
     Preferably when the cistern member is in the pivoted position the internal inlet and the cistern outlet are each located substantially at the lowest point of the cistern member and the cistern outlet is substantially adjacent to the exit of the cistern housing. 
     In one embodiment, the inner side wall has an aperture between the chamber and the passageway thereby limiting the volume of water to be discharged. In a preferred alternate embodiment, the inner side wall has a plurality of apertures with removable seals. In this preferred embodiment, the selected seal can be removed or broken to enable the discharge of a defined volume of water. 
     In an alternative embodiment, the inner side wall preferably has a plurality of apertures and the aperture which defines a predetermined volume of water remains open while at least those apertures defining smaller volumes of water are closed with a seal. 
     The chamber preferably stores a predetermined volume of water. The chamber preferably stores a predetermined volume of water via means of a cistern inlet. 
     Preferably, the cistern member has a plurality of passageways to enable different volumes of stored water to be discharged from the chamber. More preferably, the cistern member has two passageways to enable the choice of two different volumes of stored water to be discharged from the chamber. 
     In the embodiment where there are two passageways, a first passageway enables substantially all of the predetermined volume of water to be discharged from the chamber, and a second passageway enables about half of the predetermined volume of water to be discharged from the chamber. In this embodiment, one inner side wall has an aperture enabling only about half the volume of the water to be discharged from the chamber. In this embodiment the aperture is positioned at about midpoint on the second said inner side wall. 
     Preferably, the first passageway and the second passageway are located on opposite sides of the cistern member. 
     In one aspect the cistern member preferably has a substantially semi-circular cross-section. 
     The cistern member is preferably pivotally mounted to the cistern housing. 
     The cistern member is preferably pivotal about a vertical axis being the central axis through the centre of the cistern member and pivot point. The cistern member can preferably be rotated in a vertical plane about the pivot point of the cistern member. 
     The cistern member is preferably substantially semi-circular in shape having a center of gravity lower than its pivot point. In an embodiment where the cistern member has a center of gravity lower than its pivot point, the cistern member can preferably right itself returning from an inclined position to an upright position when the cistern member is substantially emptied of water. 
     In a preferred aspect, the cistern member has a substantially flat or substantially convex portion that is substantially symmetrical about the vertical axis of the cistern member when the cistern member is in the upright position. 
     The present invention also provides a cistern assembly for a flush toilet including 
     a cistern housing; 
     a cistern member pivotally attached within the cistern housing, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber; the cistern member has a substantially flat or substantially convex portion that is substantially symmetrical about the vertical axis of the cistern member when the cistern member is in the upright position; the passageway has an internal inlet and a cistern outlet and is shaped to siphon water through the passageway; the internal inlet is positioned substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in the pivoted position; and 
     an actuator associated with the cistern member to pivot the cistern member relative to the cistern housing wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     In a more preferred aspect the base wall of the cistern member has a substantially flat or substantially convex portion. 
     In one aspect the cistern member has a substantially flat portion that is substantially symmetrical about the vertical axis of the cistern member. In another aspect the cistern member has a convex portion that is substantially symmetrical about the vertical axis of the cistern member. In a further aspect the convex portion is substantially arcuate. When the convex portion is substantially arcuate, it may be substantially circular or substantially elliptical. In a yet further aspect the convex portion is facetted or polygonal. 
     In an alternative embodiment the cistern member comprises at least one recessed portion to reduce of the volume of the cistern member below the pivot point of said cistern member. The at least one recessed portion is located substantially symmetrically about the vertical axis when the cistern member is in an upright position. Preferably the recessed portion is located in the back wall, the front wall, or both front and back walls of the cistern member. 
     The present invention also provides a cistern assembly for a flush toilet including 
     a cistern housing; 
     a cistern member pivotally attached within the cistern housing, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber; the cistern member comprises at least one recessed portion to reduce the volume of the cistern member below the pivot point of said cistern member, said at least one recessed portion being located substantially symmetrically about the vertical axis when the cistern member is in an upright position; the passageway has an internal inlet and a cistern outlet and is shaped to siphon water through the passageway; and 
     an actuator associated with the cistern member to pivot the cistern member relative to the cistern housing wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     In one aspect the cistern housing comprises one recessed portion formed on the back wall of the cistern member. In another aspect the cistern housing comprises one recessed portion formed on the front wall of the cistern housing. In a yet further aspect the cistern housing comprises two recessed portions wherein the first of said recessed portions is formed on the back wall of the cistern member and the second of said recessed portions is formed on the front wall of the cistern member. 
     Preferably the recessed portion is substantially wedge shaped wherein the apex of the wedge shape also forms a recessed pivot point for the cistern member to rest on when in position in the cistern housing. In a preferred aspect the cistern member comprises two substantially wedge shaped portions wherein the apex of each of said wedge shapes also forms a recessed pivot point for the cistern member to rest on when in position in the cistern housing. 
     In a preferred aspect, the internal inlet is positioned substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in the pivoted position. 
     The present invention also provides a cistern assembly for a flush toilet including 
     a cistern housing; 
     a cistern member pivotally attached within the cistern housing, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber; the cistern member comprises at least one recessed portion to reduce the volume of the cistern member below the pivot point of said cistern member, said at least one recessed portion being located substantially symmetrically about the vertical axis when the cistern member is in an upright position; the passageway has an internal inlet and a cistern outlet and is shaped to siphon water through the passageway; the internal inlet is positioned substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in the pivoted position; and 
     an actuator associated with the cistern member to pivot the cistern member relative to the cistern housing wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     In a further aspect, the present invention provides a cistern assembly for a flush toilet including 
     a cistern housing; 
     a cistern member pivotally attached within the cistern housing, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber; the cistern member is shaped so that the centre of gravity of the stored water mass is positioned to the pivoted side relative to the vertical axis of the pivot when the cistern member is pivoted; the passageway has an internal inlet and a cistern outlet and is shaped to siphon water through the passageway; and 
     an actuator associated with the cistern member to pivot the cistern member relative to the cistern housing wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     Preferably, the internal inlet is positioned substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in the pivoted position. 
     Preferably, the actuator is a lever that pivots the cistern member relative to the cistern housing. The lever is preferably moveable by about 20 degrees either side of the pivot axis. In other embodiments the actuator is a timed or movement sensor triggered device to flush the toilet or urinal. 
     The actuator means preferably can be positioned to tilt and hold the cistern member in a tilted position. 
     In one preferment, the actuator means includes a lever pivotally mounted to the cistern housing and pivots with the cistern member. 
     In a preferred embodiment, the lever portion also includes a transverse pin for use as a latch to abut against the surface of a latch guide. The latch guide preferably extends as a linear flange across the underside of a cistern lid. Preferably the latch guide includes two flanges extending longitudinally either side of an elongate lid aperture. The lever portion extends through the elongate lid aperture and serves as a handle to tilt the cistern member. The lever portion is preferably captured by one or more member guides which are fixed to the side wall of the cistern member. 
     In another preferred embodiment the actuator means includes a handle means for moving the cistern member relative to the cistern housing. 
     The handle means preferably includes a button that extends from the cistern member side wall. The button preferably extends through a slot in the cistern housing. The button is preferably attached to or integral with the cistern member. 
     In another preferred form, the actuator means includes a lever pivotally mounted to the cistern housing and pivots with the cistern member. 
     The cistern member and other features are similar to those discussed with aspects of the invention. 
     The cistern lid preferably has one or more guide flanges located on an underside of the lid. 
     The one or more guide flanges preferably have a substantially arcuate shape. 
     More preferably, the one or more guide flanges have a concave shape. 
     Each of the one or more guide flanges preferably have at least one abutment side for retaining the latch or latch portion. 
     In one embodiment, the lid has an opening through which extends the handle member. 
     In another embodiment, the cistern base has an opening through which a button can extend. Each of the openings is preferably an arcuate slot. 
     In the embodiment where the lid has the opening for the handle member, the one or more guide flanges are positioned substantially along the periphery or adjacent the periphery of the opening. 
     Preferably, there are two guide flanges and each one of the guide flanges is located on a longitudinal side of the arcuate slot. 
     The actuation means are preferably magnetic actuation means. 
     In another aspect the present invention broadly resides in a cistern assembly for a flush toilet including 
     a cistern housing, 
     a cistern member pivotally attached within the cistern housing, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber, the passageway has an internal inlet and a cistern outlet and is shaped to siphon water through the passageway; and 
     magnetic actuation means associated with the cistern member to pivot the cistern member relative to the cistern housing, the magnetic actuation means comprises a plurality of magnets associated with the cistern member and the cistern housing, wherein the plurality of magnets are arranged relative to each other so that the magnetic fields of at least one magnet of said plurality of magnets on the cistern member interacts with at least one magnet of said plurality of magnets on the cistern housing when actuated to initiate pivoting of the cistern member; wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     In another aspect the present invention broadly resides in a cistern assembly for a flush toilet including 
     a cistern housing; 
     a cistern member pivotally attached within the cistern housing, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber, the passageway has an internal inlet and a cistern outlet and is shaped to siphon the water when the hydrostatic pressure within the passageway is lower than the atmospheric pressure in the chamber thereby drawing water through the passageway; and 
     magnetic actuation means associated with the cistern member to pivot the cistern member relative to the cistern housing, the magnetic actuation means comprises a plurality of magnets associated with the cistern member and the cistern housing, wherein the plurality of magnets are arranged relative to each other to enable the magnetic fields of at least one magnet of said plurality of magnets on the cistern member to interact with at least one magnet of said plurality of magnets on the cistern housing when actuated to initiate pivoting of the cistern member; wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     Preferably, the magnetic actuation means moves the cistern member by about 20 degrees in a transverse direction relative to the pivot axis. 
     Preferably the plurality of magnets associated with the cistern member and cistern housing are arranged relative to each other to enable the magnetic field of at least one magnet of said plurality of magnets on the cistern member to interact by magnetic repulsion with the magnetic field of at least one similarly polarized magnet of said plurality of magnets associated with the cistern housing when actuated to initiate pivoting of the cistern member. 
     More preferably the plurality of magnets associated with the cistern member and cistern housing are arranged relative to each other to enable the magnetic field of at least one magnet of said plurality of magnets on the cistern member to interact by magnetic repulsion with at least one similarly polarized magnet of said plurality of magnets on the cistern housing to initiate pivoting when actuated; with subsequent or concurrent magnetic attraction of the magnetic field of at least one magnet of said plurality of magnets on the cistern housing with the magnetic field of at least one oppositely polarized magnet of said plurality of magnets on the cistern member to initiate pivoting of the cistern member. 
     In a preferred aspect the plurality of magnets are arranged so that pivoting of the cistern member is initiated by magnetic repulsion between the magnetic field of a first magnet on the cistern housing and the magnetic field of a second similarly polarized magnet on the cistern member, with subsequent or concurrent magnetic attraction between the magnetic field of said first magnet and the magnetic field of an oppositely polarized third magnet on the cistern member. 
     Preferably the plurality of magnets associated with the cistern member and cistern housing are arranged relative to each other so that, on actuation, pivoting of the cistern housing is initiated by magnetic repulsion between the magnetic field of a first magnet on the cistern housing and the magnetic field of a second similarly polarized magnet located on the cistern member; the resulting pivoting bringing the magnetic field of an oppositely polarized third magnet into attractive magnetic interaction with the magnetic field of said first magnet to increase the degree of pivoting of the cistern member. 
     A magnet associated with the cistern housing or cistern member may be attached to or integral with the walls of the cistern housing or cistern member. A magnet may be associated with the inside or outside of a wall. 
     Suitable magnets include permanent magnets or electromagnets. 
     A permanent magnet may be substituted by a ferromagnetic metal strip capable of being magnetized in the presence of a magnetic field. 
     Electromagnets are activated by electric current, and include solenoids or solenoid coils connected to an electrical circuit. Suitably the electrical circuit may have a low voltage direct current source. Suitably, the electromagnet and electrical circuit are configured to allow the electromagnet to be energized by activation of control means, for example, an electrical rocker switch or a touch pad. 
     A combination of both permanent magnets and electromagnets may be employed. 
     When a magnet is associated with the cistern member, it is preferably a permanent magnet. Alternatively the cistern member may be fitted with at least one ferromagnetic metal strip. In one aspect, a magnet associated with the cistern member is associated with the upper wall of the cistern member. In another aspect a magnet is associated with the side wall of the cistern member. 
     Preferably the pivoting of the cistern member is initiated by operation of an actuator magnet associated with the cistern housing. 
     In one aspect, the actuator magnet is a permanent magnet associated with the cistern housing to allow it to be moved towards at least one magnet associated with the cistern member to enable the magnetic fields to interact to initiate pivoting of the cistern member within the cistern housing. Suitably the actuator magnet is moved by a sliding or pushing action. In one aspect the actuator magnet is integral with or attached to a push button associated with the cistern housing. Alternatively the actuator magnet is integral with or attached to a sliding mechanism associated with the cistern housing. 
     In a preferred embodiment the actuator magnet is an electromagnet associated with the cistern housing, and connected to an electrical circuit to allow it to be energized to enable it to interact with the magnetic field of at least one magnet associated with the cistern housing to initiate pivoting of said cistern member. The electromagnet may be activated by an electrical rocker switch or a touch pad in the electrical system. Preferably the actuator means is configured to allow remote activation. 
     In one aspect the actuator magnet is positioned so that, on activation, its magnetic field interacts with the magnetic field of a similarly polarized magnet associated with the cistern member to initiate pivoting of the cistern housing by magnetic repulsion. In a preferred aspect the actuator magnet is arranged to enable its magnetic field to interact with the magnetic fields of a plurality of magnets associated with the cistern member. Preferably the actuator magnet is positioned such that, on activation, the said actuator magnet is moved towards a similarly polarized first magnet associated with the cistern housing to initiate pivoting of the cistern housing by repulsion between the magnetic fields of the actuator magnet and the first magnet, said pivoting subsequently allows the magnetic field of the actuator magnet to interact with a second magnet associated with the cistern member having an oppositely polarized magnetic field to allow the pivoting to continue through attractive interaction between the magnetic fields of the actuator magnet and the second magnet. 
     In another aspect the present invention broadly resides in a cistern assembly for a flush toilet including 
     a cistern housing; 
     a cistern member pivotally attached within the cistern housing, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber, the passageway has an internal inlet and a cistern outlet and is shaped to siphon water through the passageway; the internal inlet is positioned substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in the pivoted position; and 
     magnetic actuation means associated with the cistern member to pivot the cistern member relative to the cistern housing, the magnetic actuation means comprises a plurality of magnets associated with the cistern member and the cistern housing, wherein the plurality of magnets are arranged relative to each other so that the magnetic fields of at least one magnet of said plurality of magnets on the cistern member interacts with at least one magnet of said plurality of magnets on the cistern housing when actuated to initiate pivoting of the cistern member; wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     The present invention also provides a cistern assembly for a flush toilet including 
     a cistern housing; 
     a cistern member pivotally attached within the cistern housing, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber; the cistern member has a substantially flat or substantially convex portion that is symmetrical about the vertical axis of the cistern member, the passageway has an internal inlet and a cistern outlet and is shaped to siphon water through the passageway; the internal inlet is positioned substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in the pivoted position; and 
     magnetic actuation means associated with the cistern member to pivot the cistern member relative to the cistern housing, the magnetic actuation means comprises a plurality of magnets associated with the cistern member and the cistern housing, wherein the plurality of magnets are arranged relative to each other so that the magnetic fields of at least one magnet of said plurality of magnets on the cistern member interacts with at least one magnet of said plurality of magnets on the cistern housing when actuated to initiate pivoting of the cistern member; wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     In another aspect the present invention broadly resides in a cistern assembly for a flush toilet including 
     a cistern housing; 
     a cistern member pivotally attached within the cistern housing, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber; the cistern member comprises at least one recessed portion to reduce the volume of the cistern member below the pivot point of said cistern member, said at least one recessed portion being located substantially symmetrically about the vertical axis when the cistern member is in an upright position; the passageway has an internal inlet and a cistern outlet and is shaped to siphon water through the passageway; and 
     magnetic actuation means associated with the cistern member to pivot the cistern member relative to the cistern housing, the magnetic actuation means comprises a plurality of magnets associated with the cistern member and the cistern housing, wherein the plurality of magnets are arranged relative to each other so that the magnetic fields of at least one magnet of said plurality of magnets on the cistern member interacts with at least one magnet of said plurality of magnets on the cistern housing when actuated to initiate pivoting of the cistern member; wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     Preferably the internal inlet is positioned substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in the pivoted position. 
     In yet another aspect the present invention broadly resides in a cistern assembly for a flush toilet including 
     a cistern housing; 
     a cistern member pivotally attached within the cistern housing, the cistern member has a base wall that forms a chamber to store water and a passageway to discharge water from the chamber; the cistern member has a substantially flat or substantially convex portion that is substantially symmetrical about the vertical axis of the cistern member; the cistern member also comprises at least one recessed portion to reduce the volume of the cistern member below the pivot point of said cistern member, said at least one recessed portion being located substantially symmetrically about the vertical axis when the cistern member is in an upright position; the passageway has an internal inlet and a cistern outlet and is shaped to siphon water through the passageway; and 
     magnetic actuation means associated with the cistern member to pivot the cistern member relative to the cistern housing, the magnetic actuation means comprises a plurality of magnets associated with the cistern member and the cistern housing, wherein the plurality of magnets are arranged relative to each other so that the magnetic fields of at least one magnet of said plurality of magnets on the cistern member interacts with at least one magnet of said plurality of magnets on the cistern housing when actuated to initiate pivoting of the cistern member; wherein when the cistern member is pivoted and the passageway is moved below the water level of the stored water of the chamber, the water is drawn through the passageway to the cistern outlet until air within the chamber enters the passageway preventing further water from being drawn into the passageway. 
     Preferably the internal inlet is positioned substantially on or adjacent to the pivot vertical axis of the cistern member when the cistern member is in the pivoted position. 
     In another aspect the present invention broadly resides in a flush toilet including 
     a cistern assembly as described above; and 
     a toilet bowl wherein the cistern assembly discharges water into the toilet bowl. 
     In yet another aspect the present invention broadly resides in a cistern member as described above. 
     The features and embodiments described above in respect of other aspects of the invention are claimed in respect of the present invention in various forms, combinations and permutations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the present invention can be more readily understood reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein: 
         FIG. 1  is a diagrammatic cross sectional view of a cistern housing and cistern member in a cistern assembly according to a first embodiment of the invention; 
         FIGS. 2A and 2B  show a diagrammatic cross sectional view of a cistern housing according to a first embodiment of the invention at equilibrium before pivoting and during pivoting respectively; 
         FIGS. 3A-3D  show a series of diagrammatic cross sectional views of a cistern housing and cistern member in a cistern assembly according a second embodiment of the invention; 
         FIGS. 4A and 4B  show a diagrammatic cross sectional view of a cistern housing according to a second embodiment of the invention at equilibrium before pivoting and during pivoting of the cistern member respectively; 
         FIGS. 5A and 5B  are diagrammatic views of a cistern member according to a third embodiment of the invention; 
         FIGS. 6A and 6B  show diagrammatic cross sectional views of a cistern member according to a third embodiment of the invention showing the centre of gravity of the water and the pivot of the cistern member before and after actuation; 
         FIG. 7  is a diagrammatic cross sectional view of a cistern housing and cistern member of a cistern assembly according to a further embodiment of the invention showing means for initiating pivoting of the cistern member by magnetic actuation through means of movement of a permanent magnet; 
         FIGS. 8A to 8E  show a series of partial diagrammatic cross sectional views of the upper part of a cistern assembly showing the arrangement and relative polarities of the permanent magnets and the sequence of steps during actuation and flushing; 
         FIG. 9  is a diagrammatic cross sectional view of a cistern housing and cistern member of a cistern assembly according to another embodiment of the invention showing means for pivoting the cistern housing by magnetic actuation through electromagnetic activation; and 
         FIGS. 10A to 10E  show a series of partial diagrammatic cross sectional views of the upper part of the cistern assembly of a further embodiment showing an arrangement of a plurality of electromagnets and permanent magnets, and the sequence of steps during actuation and flushing. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to  FIG. 1  there is shown a cistern assembly  10  comprising a substantially semi-circular basin forming a cistern member  11  in a cistern housing  12  and actuation means (not shown). The basin  11  is pivotally mounted to the cistern housing  12  and the actuation means enable the basin  11  to tilt relative to the cistern housing  12 . The basin  11  can be pivoted about 20 degrees in either direction relative to the cistern housing  12 . 
     The basin  11  forms a chamber  13  defined by the basin base wall  14 . Water from a water supply such as mains water supply fills the chamber  13  to a predetermined volume of water. The volume of water is controlled by a float valve positioned near the water inlet (not shown). The float valve stops the entry of the water when a predetermined water level is reached. 
     The basin  11  has two passageways  15 ,  16  that are located on opposite sides of the basin  11 . Water is stored in the chamber  13  and can be discharged through either one of the two passageways  15 ,  16 . 
     Both passageways  15 ,  16  have an inner section  17  in continuous communication with an outer section  18 . 
     Each inner section  17  is formed by an inner side wall  19 ,  20  and the base wall  14  while each outer section  18  is formed by an outer side wall  21 ,  22  and the base wall  14 . An inner section  17  and an outer section  18  are connected by a U-shaped bend  23  to form a continuous channel. The internal dimensions of the inner section  17 , the outer section  18  and the U-shaped bend  23  are substantially the same to optimize the siphoning action through each passageway  15 ,  16 . Water enters the passageways  15 ,  16  via the internal inlets  24 ,  25  respectively and passes out through the external outlets  26 ,  27 . When in the pivoted position, the internal inlet  24  (on anti-clockwise rotation) or  25  (on clockwise rotation) is substantially located on or adjacent to the vertical axis of the cistern member and at or adjacent to the lowest point of the cistern member  11 . The cistern outlet  26  (on anti-clod-wise rotation) or  27  (on clockwise rotation) is substantially adjacent to the exit  28  located in the lower part of the cistern housing  12 . 
     The basin  11  is tilted within the cistern housing  12  using actuation means (not shown). The basin  11  pivots about a vertical axis  29  being the central axis through the centre of the basin  11 , and the pivot point. The basin  11  can be rotated in a vertical plane about the pivot point of the basin  11 . The actuation means (not shown) can pivot the basin  11  about 20 degrees to either the left or the right of the vertical pivot axis  29 . 
     The basin  11  is substantially semi-circular in shape having a center of gravity  100  lower than its pivot point (as shown in  FIG. 26 ). The basin  11  can right itself returning from a pivoted position to an upright position when the basin  11  is substantially emptied of water. 
     In use, when the basin  11  is tilted within the cistern housing  12  in a clockwise direction (as shown in  FIG. 26 ), the passageway  16  is lowered below the water level of the water stored within the basin  11  a siphoning action is established. The siphoning action draws the water from the chamber  13  into the internal inlet  25  of the passageway  16  and out through the cistern outlet  27 . The water discharged through the cistern outlet  27  flows through the exit  28  in the cistern housing  12  and into the toilet bowl (not shown). 
     The combination of the U-shaped bend  23  and the absence of a bulbous formation located at the U-shaped bend, together with the internal inlets  24  or  25  being located at or adjacent to the lowest point of the cistern member  11  when in the pivoted position helps to prevents the centre of gravity  100  of the water mass moving in the opposite direction from the direction of tilt, thus preventing a delay in initiating the siphon action. This configuration eliminates the need for a buoyant latch. 
     Water is discharged through the passageway  16  until air enters the passageway  16  via internal inlet  25  and breaks the siphoning action. The internal inlet  25  is located near the bottom of the chamber  13 , air enters the passageway  16  when substantially all the stored water is discharged from the chamber  13 . 
     When the water level within the basin  11  reaches a defined point, the float valve (not shown) opens and water enters the basin  11  via the water inlet (not shown) to refill the basin  11  to a predetermined volume. 
     With reference to  FIGS. 3A-3D  there is shown a second embodiment of a cistern assembly  30  comprising a basin forming a cistern member  31  in a cistern housing  12  and actuation means (not shown). The cistern assembly  30  is similar to that described for cistern assembly  10 , except that the basin forming the cistern member  31  has a substantially flat or substantially convex portion that is substantially symmetrical about the vertical axis of the cistern member. 
       FIG. 3A  shows the base wall  32  of the basin forming the cistern member  31  is flattened and is symmetrically positioned about the vertical axis of the cistern member. 
       FIG. 3B  shows the base wall  33  of the basin forming the cistern member  31  forming an inwardly protruding V-shape symmetrically positioned about the vertical axis of the cistern member. 
       FIG. 3C  shows the base wall  34  of the basin forming the cistern member  31  forming an inwardly protruding ramp shape symmetrically positioned about the vertical axis of the cistern member. 
       FIG. 3D  shows the base wall  35  of the basin forming the cistern member  31  forming an inwardly protruding circular or elliptical arcuate shape symmetrically positioned about the vertical axis of the cistern member. 
     The effect of the substantially flat or substantially convex (inwardly protruding) region of the cistern member base wall is to reduce the weight of water located in the region of the base of the cistern member. This affects the distribution of the weight of water contained in the cistern member during pivoting, and is demonstrated with reference to  FIGS. 4A and 4B . When the cistern member  31  is pivoted in an anti-clockwise direction within the cistern housing  12 , the substantially convex base region  35  is rotated to the left side of the vertical axis  29  and the internal inlet  25  and passageway  16  remain to the right side of the vertical axis  29 . The substantially convex base region  35  of the cistern member holds comparatively less water than it would if the base was concave. On pivoting in a clockwise direction, the net centre of gravity of the water  100  moves in the direction of the lowered passageway  16  and internal inlet  25 . The modification of the cistern base wall to form a substantially flat or substantially convex base region removes or reduces the occurrence of vibration of the cistern member  11  on initiation of pivoting of the cistern member  11  within the cistern housing  12 . 
     When the cistern base wall is substantially concave, momentary vibration of the cistern member  11  may occur on initiating of pivoting due to the movement of the centre of gravity  100  of the cistern member as a result of redistribution of the water mass contained within it. This results from the absence of a sufficient weight of water in the outer section  18  of the passageway  16  on pivoting initially causing the centre of gravity  100  to move away from the direction of pivot and the lowered passageway on inlet. The modification to the shape of the base wall of the cistern member causes the centre of gravity  100  to be moved towards the direction of pivot, resulting in the cistern member being held in a tilted position until water can flow through the internal inlet  25  into the inner section of the passageway  16  and into the outer section  18  of the passageway  16 . The weight of water in the outer section  18  of the passageway  16  then retains the cistern member in a tilted position until the water has emptied out through the cistern outlet  27  and cistern housing exit  28 , and the cistern member  31  rotates back to its original upright position. 
     Furthermore, the flat or inwardly protruding area of the base wall of the cistern member  31  results in a reduction of the space immediately adjacent to the internal inlets  24  and  25  resulting in maximization of the volume of water being removed from the basin  11 . 
       FIGS. 5A, 5B, 6A and 6B  illustrate a basin forming a cistern member  41 .  FIGS. 5A and 5B  show a basin forming a cistern member  41 . Cistern member  41  is intended for use with a cistern housing and actuation means (not shown) to form a cistern assembly  40  according to a third embodiment of the present invention. The cistern member  41  is similar to cistern member  11 , except that the basin forming the cistern member  41  has a substantially wedge shaped recess section  42  located in the back wall or in the front wall, or in both the back wall and front wall, of the basin of the cistern member  41 . The, or each, wedge shaped recess  42  is substantially symmetrical about the vertical axis of symmetry  29  of the cistern member  41  when the cistern member is in the equilibrium position. The, or each, wedge shaped recess  42  has an apex  43  to provide a recessed pivot point for the cistern member  41  to rest on in the cistern housing. 
     Because the front to back dimension of the cistern member  41  is smaller behind the recessed portion or portions  42 , the volume of water located in the region behind the recessed portion or portions  42  is smaller than the volume of water located in the region of a full depth section of the cistern member  41 . When the cistern housing is in its equilibrium (upright) position, the region of reduced volume of water is located symmetrically about the vertical axis, and the cistern housing remains upright and stable. When the cistern member  41  is tilted relative to the cistern housing, the region of reduced volume moves in the opposite direction to the direction of tilt, resulting in the movement of the net centre of gravity  100  of the water mass contained in the basin of cistern housing  41  towards the tilt side thus reducing the resistance to tilting as illustrated in  FIGS. 6A and 6B . 
     With reference to  FIG. 7 , there is shown a fourth embodiment of the present invention.  FIG. 7  shows a cistern assembly  50  comprising a basin forming a cistern member  11  in a cistern housing  12  and magnetic actuation means  52 - 56 . The cistern assembly  50  is similar to that described in cistern assembly  10 , but the pivoting is initiated by magnetic actuation means provided by an arrangement of permanent magnets  52 - 56  associated with the cistern housing  12  and the cistern member  11 . 
     The partial cross sectional views in  FIGS. 8A-8E  show the upper section of a cistern assembly  60  representing further embodiments of the present invention. Cistern assembly  60  comprises a cistern housing  12 , and magnetic actuation means and a basin forming a cistern member  61 . The basin forming the cistern member  61  is similar to any of those described in the above-mentioned Figures. In one embodiment the cistern member  61  is similar to that described by cistern member  11  in  FIG. 1 . In further embodiments the cistern member  61  may be similar to a shaped cistern member defined above as cistern members  31  or  41  in  FIGS. 3-6 . 
     With reference to the  FIGS. 8A to 8E , the figures show the arrangement and relative polarities of the permanent magnets on the upper part of the cistern housing  12  and the upper part of cistern member  61 , and the sequence of steps during flushing.  FIG. 8A  shows the cistern member  61  at equilibrium in the cistern housing  12 . The upper part of the cistern housing  12  is fitted with two permanent magnets  62  and  63  mounted substantially vertically which act as actuator magnets. The upper surface of the cistern member  61  is fitted with two permanent magnets  65  and  66 , and a third permanent magnet  64  centrally located on the upper surface of the cistern member  61 . Permanent magnet  64  is positioned between, and oppositely polarized to, the permanent magnets  65  and  66 . Actuator magnets  62  and  63  on the cistern housing  12  are positioned so that their magnetic fields are similarly polarized with the polarity of the permanent magnets  65  and  66  on the cistern member  61 , and oppositely polarized to magnet  64 .  FIG. 8B  shows the actuation and the resultant pivoting action of the cistern member  61 . Pivoting of the cistern member  61  in the cistern housing  12  is initiated by depressing an actuator magnet  62 , moving it towards the similarly polarized magnet  65  to initiate the pivoting action by repulsion of the similarly polarized magnetic fields of the two magnets.  FIG. 8C  shows a later stage of the pivoting movement, and a further degree of pivoting. The repelling force of the magnetic field of the actuator magnet  62  on the similarly polarized magnet  65  results in the two magnets moving apart and the repulsive force drops off. The rotation of the cistern member  61  brings the magnetic field of the actuator magnet  62  into attractive interaction with oppositely polarized magnet  64  on the cistern member resulting in a further degree of pivoting. The pivoting movement results in establishing the siphoning action to drain the water stored in the basin of the cistern member  61  as described above.  FIG. 8D  shows the cistern member  61  returning to the equilibrium position in the cistern housing after the water has siphoned off.  FIG. 8E  shows the cistern member  61  back in the equilibrium position within the cistern housing  12 . 
     With references to  FIG. 9 , there is shown a fourth embodiment of the present invention.  FIG. 9  shows a cistern assembly  70  comprising a basin forming a cistern member  71  in a cistern housing  12  and magnetic actuation means  72 - 76 ,  78  and  79  in the form of electromagnetic actuation. The cistern assembly  70  is similar to that described in cistern assembly  10 , but the pivoting is initiated by electromagnetic actuation means formed by an arrangement of a plurality of both electromagnets  72 ,  73  and permanent magnets  74 ,  75 ,  76  associated with the cistern housing  12  and the cistern member  71 . 
     The partial cross sectional views in  FIGS. 10A to 10E  show the upper section of a cistern assembly  80  representing further embodiments of the present invention. Cistern assembly  80  comprises a cistern housing  12 , and magnetic actuation means and a basin forming a cistern member  81 . The basin forming the cistern member  81  is similar to those described in the above-mentioned Figures. In one embodiment the cistern member  81  is similar to that described by cistern member  11  in  FIG. 1 . In further embodiments the cistern member  81  may be similar to a shaped cistern member defined above as cistern members  31  or  41  in  FIGS. 3, 4 and 5 . 
     With reference to the  FIGS. 10A to 10E , the figures show the arrangement of magnets on the upper part of the cistern housing  12  and the upper part of cistern member  81 , and the sequence of steps during flushing.  FIG. 10A  shows the cistern member  81  at equilibrium in the cistern housing  12 . The upper part of the cistern housing  2  is fitted with two electromagnets  82  and  83  each attached to electrical circuits and energizing means  88 ,  89  to enable activation of electromagnets  82 ,  83  to allow them to function as actuator magnets. The upper surface of the cistern member  81  is fitted with two similarly polarized permanent magnets  85  and  86 . A third permanent magnet  84  is centrally located on the upper surface of the cistern member  81 . Permanent magnet  84  is positioned between, and oppositely polarized to, the permanent magnets  85  and  86  located at either side of it on the cistern member  81 .  FIG. 10B  shows the actuation of the pivoting movement by activation of energizing means  88  to energize the electromagnet  82  on the cistern housing  12  to create a magnetic field that is similarly polarized to the adjacent permanent magnet  85  located on the cistern member  81 . The repulsion between the similarly polarized magnet fields of the electromagnet  82  on the similarly polarized permanent magnet  85  results in pivoting of the cistern member  81  in the cistern housing  12 .  FIG. 10C  shows a further degree of pivoting of the cistern member  81  within the cistern housing  12 . The pivoting motion causes the actuator electromagnet  82  and the permanent magnet  85  to move apart and the repulsive force between the magnetic fields of the two magnets drops off. The rotation of the cistern member  81  brings the magnetic field of the electromagnet  82  into attractive interaction with the magnetic field of the oppositely polarized permanent magnet  84  on the cistern member  81  resulting in magnetic attraction between electromagnet  82  and magnet  84  to enable a further degree of pivoting. The pivoting movement results in establishing the siphoning action to drain the water stored in the basin of the cistern member  81  as described above.  FIG. 10D  shows the cistern member returning to the equilibrium position in the cistern housing once the stored water has drained from the cistern member  81 .  FIG. 10E  shows the cistern member  81  returned to the equilibrium position within the cistern housing. 
     ADVANTAGES 
     An advantage of the preferred embodiment of the cistern assembly is the provision of a system that is simple to install, and has no moving parts that wear through contact. The improved design of the cistern assembly does not suffer from a delay in initiating the siphoning action after actuation of the pivoting of the cistern member due to control of the movement and location of the centre of gravity of the water mass stored in the basin forming the cistern member. 
     Improved control of the movement and location of the centre of gravity of the stored water mass also results in the reduction of vibration (‘wobble’) of the cistern member following actuation. 
     An advantage of the preferred embodiment of the cistern assembly is the provision of a simple flush system initiated by magnetic interaction. A further advantage of magnetic actuation is the provision of remote activation making it applicable to concealed (in wall) systems. 
     VARIATIONS 
     It will of course be realised that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein set forth. 
     Throughout the description and claims this specification the word “comprise” and variations of that word such as “comprises” and “comprising”, are not intended to exclude other additives, components, integers or steps.