Abstract:
A dual quantity flushing valve mechanism comprising a housing having a base fitting for attachment to a water outlet of a toilet cistern, an overflow tube axially displaceable within the housing and having a bottom portion extending substantially coaxial within the housing, a top portion parallel to the bottom portion and extending outside of the housing, and an intermediate, inclined portion extending between the top portion and the bottom and projecting through the housing, with a seal disc fitted at a bottom of the bottom portion for sealing engagement of the water outlet. The mechanism further comprising an internal float coaxial over the bottom portion of the overflow tube, has an axial displacement restrictor articulated thereto and an external float fixed to the overflow tube, an operating mechanism fitted within the housing, for axial displacement of the overflow tube, however with selective axial displacement of the internal float responsive to a operating a long flush actuator or a short flush actuator, articulated with said operating mechanism.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to toilet cistern flushing valve mechanisms, and particularly to dual quantity flushing valve mechanisms.  
       BACKGROUND OF THE INVENTION  
       [0002]     Due to increasing population and limited resources of fresh water supply, conservation of water is becoming important. A significant source of water consumption, in the domestic arena is the water used in flushing toilets. It is well appreciated that in some cases a full volume flush is not required to clean out a toilet bowl.  
         [0003]     Thus, there has been an increase in recent years in demand and development of toilets fitted with a dual cistern flushing mechanism, such that the amount of water used for each flush is determined by the individual, allowing consumption of less water during certain flush cycles. In fact, some countries have regulated this matter and it is mandatory that each cistern be fitted with a dual flushing mechanism.  
         [0004]     Various dual flush mechanisms have been developed over the years for the purpose of providing the option of a full or long flush cycle for solid waste, or a short or partial flush cycle for liquid waste.  
         [0005]     One type of dual flush mechanisms comprises a single operating actuator, a first activation thereof opens the valve to flush the toilet bowl and a second activation is required to cease operation thereof, namely to shut water flow to the toilet bowl.  
         [0006]     The more popular type of dual flushing mechanisms, typically comprises two different flush cycles achieved by the flush valve being adapted for two positions, whereby each cycle is activated by a separate knob or handle. The two positions may be at different heights with respect to the bottom of the closet&#39;s tank. The actuation of the knob linked to an upper valve position will produce a short or partial flush, while the actuation of a lower valve position will produce a long or full flush. The length of the flush cycle is a function of the height of the flush valve with respect to the closet&#39;s bottom wall. The higher the valve is from the closet&#39;s bottom wall, the smaller the volume of water that will be discharged. Accordingly, the flushing of liquid waste, for example, requires the pressing of the upper flush valve position operating knob since only a small amount of water is required for the flushing, while the flushing of solid waste requires the pressing of the knob linked to the lower flushing valve position whereby a longer flush or a larger volume of flush water is produced. In this way, water conservation is ensured.  
         [0007]     It is an object of the present invention to provide a dual flush mechanism of simple construction, and which may be adjusted to adapt to different designs of toilet cisterns, i.e. the height of the mechanism is adjustable to accommodate the variation in tank size.  
       SUMMARY OF THE INVENTION  
       [0008]     According to the present invention there is provided a toilet cistern flushing valve of compact size, rendering it suitable for installation in cisterns of different configurations, e.g. substantially large or small cisterns, with long/short flush actuators of different configurations (push buttons, levers, etc.)  
         [0009]     The invention thus calls for a dual quantity flushing valve mechanism comprising: 
        a housing having a base fitting for attachment to a water outlet of a toilet cistern;     an overflow tube axially displaceable within the housing and having a bottom portion extending substantially coaxial within the housing, a top portion parallel to said bottom portion and extending outside of the housing, and an intermediate, inclined portion extending between the top portion and the bottom and projecting through the housing, there being a seal disc fitted at a bottom of the bottom portion for sealing engagement of the water outlet;     an internal float coaxial over the bottom portion of the overflow tube, having an axial displacement restrictor articulated thereto;     an external float fixed to the overflow tube; and     an operating mechanism fitted within the housing, for axial displacement of the overflow tube, however with selective axial displacement of the internal float responsive to a operating a long flush actuator or a short flush actuator, articulated with said operating mechanism.        
 
         [0015]     According to some particular embodiments of the present invention, any of the following arrangements may be incorporated in the flushing mechanism: 
        a top end of the top portion may be fitted with a telescopic extension piece, for calibrating overfill water level with the cistern.     the external float may be axially displaceable so as to calibrate the amount of water discharged at a short flush.     the external float is axially displaceable by a rack extending outside of said housing and fixedly attached to the overflow tube.     the external float is articulated to the bottom portion of the overflow tube via a slot formed in the housing.     the operating mechanism comprises a short flush rocker lever and a long flush rocker lever pivotally secured within the housing, said rocker levers being engageable at one end to the respective long flush actuator and the short flush actuator, and an opposite end to the overflow tube, for elevation thereof within the housing, and where said short flush rocker lever is articulated with a barrier member such that pivotal displace of the short flush rocker lever entails pivotal displacement of the barrier into a position for encountering the axial displacement restrictor of the internal float.     the long flush actuator and the short flush actuator are push buttons fitted in a top cover mounted on the housing.     the push buttons are each fitted with a length-adjustable stem for engaging a corresponding rocker lever of the operating mechanism.     the long flush actuator and the short flush actuator are pull levers articulated to lever arms.     upwards axial displacement of the internal float is restricted by a lateral restriction element fitted on the bottom portion of the overflow tube and adapted for engaging a top face of the internal float.     the housing is formed at its bottom with a compartment extending between a base portion and a coaxial sleeve portion, slidingly accommodating the internal float, said compartment fitted at its bottom with an outlet for slow release of water to thereby create a damping effect and impede descent of the internal float.     the size of the outlet is controllable for calibrating the internal float descending rate.     the base fitting is articulated to a base coupler attached in turn to a water outlet of a toilet cistern.        
 
         [0028]     According to another aspect of the invention there is a toilet flushing cistern fitted with a dual quantity flushing valve mechanism as described herein above. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]     In order to understand the invention and to see how it may be carried out in practice, some embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:  
         [0030]      FIG. 1  is a view of the inside of a toilet cistern (sectioned) comprising a flushing valve according to an embodiment of the present invention, the valve illustrated in a full-flush position;  
         [0031]      FIG. 2  is a perspective view of a button-operated flushing valve, in full-flush position, with a portion of the housing and cap sectioned, according to an embodiment of the present invention;  
         [0032]      FIG. 3  is a perspective, exploded view of the button-operated flushing valve;  
         [0033]      FIG. 4  is a top perspective view illustrating the operating mechanism;  
         [0034]      FIG. 5  is an isometric view illustrating a full-flush position of only the internal float and the operating mechanism;  
         [0035]      FIG. 6  is an isometric view illustrating a half-flush position of only the internal float and the operating mechanism  
         [0036]      FIG. 7  is a perspective view of a bottom portion of the housing of the valve according to the invention, formed with a controllable outlet lever; and  
         [0037]      FIG. 8  is a perspective view of an operating mechanism articulated with a lever-operated flushing valve, in accordance with an embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0038]     Attention is first directed to  FIG. 1  of the drawings for understanding the construction and usage of the flushing valve in accordance with the present invention generally designated  10 .  
         [0039]     The flushing valve  10  is disposed within a toilet cistern  12 . The cistern  12  comprises an inlet  14  for water flow entry into the cistern  12 , a float control mechanism  15  coupled to the inlet  14 , for regulating water flow into the cistern  12 . An outlet  16  is disposed at a bottom portion of the cistern  12  and is coupled to a toilet bowl (not shown). An operation mechanism  18  is fitted on the top of the cistern  12  and is articulated to the flushing valve  10  for operation thereof.  
         [0040]     The flushing valve  10  is secured to the outlet  16  via a base coupler  20 . The base coupler  20  has slots  21  formed therein, through which the base coupler  20  is in fluid communication with the cistern  12 . As will be explained in greater detail hereinafter, the flushing valve  10  comprises an annular plug  22 , fitted with an annular seal  23 , extending within the base coupler  20 , adapted for sealing water passage into the outlet  16 , whenever the flushing valve is in its closed position.  
         [0041]     As can further be seen in  FIGS. 2 and 3  there is illustrated a button operated flushing valve  10 , comprising a half-flush mode and a full-flush mode as will be explained hereinafter in detail. The valve  10  comprises a substantially cylindrical housing  32  (which in the drawings is partially concealed to facilitate viewing of the internal components therein). The housing  32  comprises an open top portion  34 , and is formed with a large slot  38 , a small slot  40  and several notches  42  disposed adjacent to the top portion  34 , adapted for fastening different covers thereto, as will be discussed hereinafter. The housing  32  further comprises a bottom portion  43 , formed with a downwardly extending rim  44  for detachably connecting to the base coupler  20 , and a propulsion inlet  48  formed therein (elaborated in connection with  FIG. 7 ).  
         [0042]     The large slot  38  extends from about slightly higher than the middle of the housing  32  to the top portion  34 . The small slot  40  is disposed diametrically opposite to the large slot  38 , extending upwardly from about the middle of the housing  32  a length, for example. However, position of the small slot  40  may differ with respect to the position of the large slot  38 .  
         [0043]     The housing  32  is detachably secured to the base coupler  20  by snap coupling, however it may be secured in other ways, e.g., by threaded coupling, bayonet coupling, etc., and typically the arrangement is such that the housing  32  may be rotatably fixed with respect to the base coupler  20 . The base coupler  20  has an externally threaded tubular bottom portion  50  and is fitted for projecting through an opening formed at a bottom wall of the cistern  12  and is connectable by said threading to outlet pipe  16  which as discussed hereinabove in connection with in  FIG. 1 , is coupled in turn to a toilet bowl (typically via an intermediate pipe segment, not shown).  
         [0044]     A non-linear overflow pipe and float guide  62 , disposed partially within the housing  32 , comprises a bottom portion of the pipe  64  being vertically oriented, disposed coaxially within the housing  32  and being in fluid communication with the tubular bottom portion  50 , an intermediate portion of the pipe  66 , disposed above the first portion  64 , being slanted and protruding upwardly from the housing  32  via the large slot  38  therein, and a top portion of the pipe  68 , disposed above the intermediate portion  66 , being substantially vertically oriented with an open upper end  69 , and accommodating a telescopic extension tube section  70  ( FIG. 3 ) with an open top end  71 , axially displaceable with respect to the top portion of the pipe  68 . The height of the top end  71  determines an overflow level of the cistern  12 , namely the top end  71  determines the maximal water level within the cistern  12  so that in case of a system miscalibration or failure, in which the water level rises above the height of top end  71 , the water may drain through the pipe  62 , and hence the tubular bottom portion  50  into the outlet  16  ( FIG. 1 ).  
         [0045]     As can best be seen in  FIG. 3 , the bottom portion of the pipe  64  may be integrally formed with the annular plug  22  described in  FIG. 1 , supporting the rubber seal disc  23  so as to more effectively seal an axial aperture  52  of the base coupler  20  ( FIG. 2 ). However, for practical manufacturing purposes, the plug  22  may be fitted on a lowermost end of the bottom portion of the pipe  64 .  
         [0046]     The bottom portion  64  of the overflow pipe  62  is further formed with a plurality of laterally projecting wings  72 , and a lateral flange  75  formed integrally therewith, to be described hereinafter.  
         [0047]     The intermediate portion  66  of the pipe  62  is formed with two laterally extending arms  74 , with their extreme edges  78  oriented away from each other (substantially radial), so that the extreme ends  78  are slidingly received within internal axial grooves  76  that extend along an internal wall portion of the housing  32 , whereby the overflow pipe  62  is adapted for axial displacement only within the housing  32 .  
         [0048]     A support member  80 , vertically displaceable outside the housing  32 , is attached to the first flange  75 . The support member  80  is in the form of a thin connecting bar, with one surface having a toothed-rack like appearance  84  and another surface further comprising a second flange  82  formed thereon. The second flange  82  is articulated to the first flange  75  and laterally projects through slot  40  formed in the housing  32 . The arrangement is such that vertical displacement of the overflow pipe  62  entails corresponding vertical displacement of the support member  80  and vice versa.  
         [0049]     The support member  80  has mounted thereon an external float  88  (referred to as a “half flush float”, as it is associated with flushing only a partial volume of the cistern  12  as will become apparent hereinafter). The external float  88  may have a buoyant material inserted therein, e.g. foamed material, a water tight space, etc. The external float  88  is slidingly displaceable over a portion of the toothed rack-like surface  84  of the support member  80  and is fitted with a clasp  90  formed in turn with a projection  91 , fitted for engaging with the teeth of the toothed surface  84  so as to calibrate the vertical level of the external float  88 . The arrangement is such that the external float  88  is stationary with respect to the support member  80 , i.e. with respect to the pipe  62 , and is articulated displaceable therewith.  
         [0050]     In this embodiment the button operated flushing valve  10  comprises a top cover  92  articulated to the top portion of the housing  32 , e.g. by snap-type engagement with notches  42  of the housing  32 . The cover  92  comprises in turn a chamber  100  accommodating two push buttons, namely a full flush button  96  and a half-flush button  95 , each having an upper pressing surface  104  and an elongated vertical stem  97  and  98 , respectively, integrally formed therewith and extending downwards through respective openings formed in a bottom wall  102  of the top cover  92 . The full flush button  96  and the half-flush button  95  are each fitted with a coiled spring  99  ( FIG. 3 ) mounted on the respective stem, disposed between the upper surface  104  and the bottom wall  102  of the top cover  92 , for biasing the buttons into their non-depressed position (in  FIGS. 2 and 5  the full flush button  96  is shown in its depressed position and the half-flush button  95  in its elevated position, and in  FIG. 6  vice versa).  
         [0051]     An annular rim  108  of the top cover  92  further comprises a guide member  112 , adapted to slidingly receive and support the support member  80 .  
         [0052]     Referring to FIGS.  4  to  6 , the elongated vertical stems  97  and  98  are each in contact with a lever system  114 , completely disposed within the housing  32 , at a top portion thereof, above the intermediate portion  66  of the pipe  62  ( FIG. 2 ). The lever system  114  comprises a shaft  116 , oriented horizontally, inserted in two notches  47  (one of which is seen in  FIG. 3 ) in the housing  32  (FIGS.  1  to  3 ) such that translational movement is prevented but not rotational movement.  
         [0053]     Mounted on the shaft  116  in a freely rotatable manner there is a first rocker lever  118 , a second rocker lever  120  and a barrier  121 . The center of gravity of the first rocker lever  118  and second rocker lever  120  is such that they normally retain a ready state, namely extend at a substantially horizontal position.  
         [0054]     Both the first rocker lever  118  and the second rocker lever  120  are physically similar though oriented in opposite directions, and each comprises a first end  122 A,  122 B respectively, adapted for contact with the vertical stem  97  and  98 , respectively. The first ends  122 A and  122 B are arced so as to enable continuous and smooth contact with a bottom end of the respective vertical stem  97  and  98 . A second end  123 A and  123 B of each rocker is fitted with a first lateral projection  124 A and  124 B, respectively, and a second lateral protrusion  126 A and  126 B, to be further elaborated on hereinafter.  
         [0055]     In the disclosed embodiment the first rocker lever  118  and the barrier  121  are articulated to one another by a lateral projection  125 , so that rotational movement of the first lever  118  entails the barrier  121  to rotationally displace in the same sense. It is noted however that the barrier  121  is formed with an arresting arm portion  127 , extending shorter than the second end  123 A of the first rocker lever  118 , the reason for which will become apparent hereinafter.  
         [0056]     The arrangement is such that at the assembled position, each second lateral protrusion  126 A and  126 B is positioned under an extending arm  74  of the overflow pipe  62 .  
         [0057]     The button valve  10  further comprises a substantially cylindrical internal float  128  concentrically mounted inside the housing  32 , normally disposed at the bottom portion  43  thereof and further being slidingly disposed over the bottom portion  64  of the overflow pipe  62 . However, axial displacement of the internal float  128  in an upwards direction is restricted by the wings  72  of the overflow pipe  62  adapted for engaging a top surface  129  of the internal float  128 . The float  128  may accommodate buoyant material (e.g. foamed material). Furthermore, there is fitted on a top portion of the float a rod  132 , to be discussed hereinafter.  
         [0058]     The internal float  128  is free to move in the axial direction when not restrained by the wings  72 . The wings  72 , biased downwards by the weight of the pipe  62 , serve to ensure the internal float  128  normally remains in the lowest possible position within the housing  32 , sealing the outlet  16  ( FIG. 1 ) from the cistern  12  ( FIG. 1 ).  
         [0059]     The rod  132  is disposed under the barrier  121  such that when the barrier  121  is rotated to a substantially horizontal orientation ( FIGS. 4 and 6 ), the arresting arm portion  127  of the barrier  121  is positioned directly above the rod  132 , preventing further upwards displacement of the rod  132  and the articulated internal float  128 . Additionally, if the barrier  121  is rotated to a substantially vertical orientation, as seen in  FIGS. 1, 2  and  5 , then there is no portion of the barrier  121  above the rod  132 , thus the of the rod  132  and the articulated internal float  128  are free to axially displace upwardly until abutment of the internal float  128  with wings  72 . It is also noteworthy to mention in the normal position the barrier  121  is designed to be in its substantially vertical orientation.  
         [0060]     Before activation of the operation mechanism  18  the normal state of the cistern  12  being at least partially filled with water (not shown), which enters the cistern  12  via the inlet  14 . The water level in the cistern  12  is calibrated to a chosen height by means of the control mechanism  15  which is adapted to detect when the water in the cistern  12  reaches at least a specified level and regulate the flow through the inlet  14  accordingly. The flushing valve  10  being at least partially submerged in the water, having lateral slots allowing water to access the base coupler  20 . The plug  22 , forced downwards by gravity, normally seals the axial aperture  52  thus obstructing the water from entering the outlet  16 .  
         [0061]     During activation of the operation mechanism  18 , the flushing valve  10  may raise the plug  22  allowing the water in the cistern  12  to drain into the outlet  16 . The water in the outlet  16  may be directed into a toilet bowl (not shown) forcing waste (not shown) into a sewer (not shown).  
         [0062]     After the activation of the operation mechanism  18  the plug  22  descends, for reasons that will be explained hereinafter, once again sealing the outlet  16  and restoring the cistern  12  to the “before activation” state described above.  
         [0063]     In a first mode of operation, when a full flush is desired (i.e. substantially the entire amount of water within the cistern), the full flush button  96  is depressed ( FIGS. 1, 2  and  5 ). The coiled spring  99  is thereby compressed and the relevant stem  98  descends into the housing  32  applying a downwards force on the first end  122 B of the second rocker lever  120 , causing it to pivot about shaft  116 . The recoil of the spring  99  causes the button  96  to immediately revert to it&#39;s elevated position ( FIG. 6 ) upon stopping a force applied thereto. However, the rotation of the second lever  120  causes the second lateral protrusion  126 B thereof to elevate the corresponding extending arm  74  of the overflow pipe  62 . The elevation of the pipe  62  entails raising the external float  88  (owing to buoyancy forces), and lifting the annular plug  22 , facilitating full drainage of the cistern  12 . The drainage causes the water level in the cistern  12  to drop below the calibrated water level.  
         [0064]     Additionally, the upwards motion of the plug  22  forces water into the propulsion inlet  48 , thereby applying additional force propelling the internal float  128  in an upwards direction. The upwards motion of the internal float  128  is halted when the its top surface engages the wings  72 , of the already elevated pipe  62 , the upwards motion of which is halted when the annular plug  22  encounters the bottom base of the housing  32 .  
         [0065]     After the described upward motion has been halted, the pipe  62  and connected components begin to descend, due to gravitational forces, to their original, downward positions. The downwards motion of the pipe  62  is retarded by the external float  88  and the internal float  128  thereby increasing drainage time. The rate of descent is decreased when the buoyant external float  88  contacts the reducing water level, the force of the water on the external float  88  being in the upward direction. Additionally, the descent of the pipe  62  is further retarded by the slow descent of the internal float  128 . The internal float  128  is forced downwards by the wings  72  of the pipe  62 , which are propelled by the weight of the pipe  62 , however, as the water beneath the internal float  128  must exit compartment  45  of the housing  32  via the small propulsion outlet  48  creating a damping effect and thereby impeding the descent of the internal float  128 .  
         [0066]     According to a variation of the invention, disclosed in  FIG. 7 , propulsion outlet  48  may be of controllable section area, e.g. by a manual lever  135  pivotally secured at  131  to the bottom wall of the compartment  125 , governing the section are of the outlet, to thereby govern the descending speed of the overflow pipe  62 .  
         [0067]     Eventually, the pipe  62  resumes the position taken before activation of the flushing valve  10 . The plug  22  thereby seals the outlet  16  allowing the water entering from the inlet  14  to refill the cistern  12  to the calibrated water level.  
         [0068]     Turning now to  FIG. 6 , there is illustrated the lever system  114  with the half-flush button  95  depressed. The operation of the button valve  10  is substantially similar to that described in the previous example, however with the following differences:  
         [0069]     The depression of the half-flush button  95  causes rotation of the second rocker lever  120  and therefore a corresponding pivotal displacement of the articulated barrier  121 . The arresting arm portion  127  of the barrier  121  is thereby rotated to a substantially horizontal orientation. Pivotal displacement of barrier  121  is restricted by a projection  133  extending from the shaft  118 . In the present example the upward motion of the internal float  128  is halted when the rod  132  impacts the arresting arm portion  127  of the barrier  121 . It should be noted that the distance traveled by the internal float  128  is significantly less than in the previous example, associated with a full flush mode, and hence the retardation effect caused thereby will be significantly shorter. Thus there is a shorter drainage period causing the desired half-flush effect. It is noticed that the elevation of the external float  88 , in fact governs the amount of water to be flushed in a ‘half flush’ procedure.  
         [0070]     It is to be appreciated that the design of the system according to the present invention is such that depressing the full flush button  96  and the half-flush button  95  simultaneously, results in activating a half flush mode, as discussed hereinabove.  
         [0071]      FIG. 8  is directed to a modification of the invention, illustrating the activating mechanism generally referred to at  140 , wherein rather than a press button valve there is provided a pull-lever valve. The pull-lever valve  140  differs from the button valve  10  by the replacement of the cover  92  with an alternate cover  142  adapted for pull-levers  144 A and  144 B, associated with the half-flush and full-flush rocker levers  118  and  120 , respectively.  
         [0072]     Each pull-lever  144 A and  144 B is mounted on the relevant lateral protrusions  124 A and  124 B, respectively, and protrudes from the housing  32  upwardly through the alternate cover  142 . In this example each pull-lever  144  has a handle  146  at the upper end thereof. These handles are articulated to lever operators typically fitted on a front wall of a cistern (not shown)  
         [0073]     The operation of the button valve  10  is identical to that of the pull-lever valve  140  except that the respective second end  123 A and  123 B of either the first lever  118  or second lever  120  is pulled in order to create a desired rotational motion and the following chain of effects that are caused.