Patent Publication Number: US-2002000006-A1

Title: Flush activation system

Description:
RELATED U.S. APPLICATION DATA  
     [0001] Continuation-in-part of Ser. No. 09/608,015, filed Jun. 30, 2000. 
    
    
     
       BACKGROUND OF THE INVENTION  
       FIELD OF THE INVENTION  
       [0002] The subject flush activation system is generally directed to a system for selectively actuating a toilet flush. More specifically, the subject flush activation system is directed to a system which simply, efficiently, and reliably enables the selective activation of various flush modes that respectively consume varying volumes of water.  
       [0003] Water conservation remains a point of universal concern around the World. So significant is the concern in certain regions that severe use restrictions and pervasive equipment/facilities regulations are not uncommon in many jurisdictions.  
       [0004] A source of substantial water consumption, at least in the more modernized regions of the world, remains water-flushed toilet facilities. Given their obvious necessity, curtailing usage does not, in most cases, constitute a viable option towards water conservation. Controlling the means of their usage, however, does constitute a viable and, indeed, advisable option. Accordingly, regulations such as that limiting the maximum volume of water stored within a flush tank at any given time have been widely instituted, especially in the United States.  
       [0005] Beyond such regulations, further controls may be implemented to minimize the volume of water consumed in a particular flush. Depending on the composition and quantity of waste to be removed from a toilet by a given flush, the volume of water required may be selectively varied. Rather than draining the full content of the toilet&#39;s flush tank indiscriminately with every flush; the flush tank&#39;s content may be partially drained where only liquid and/or small amounts of solid waste are to be removed, and more fully drained where greater amounts of solid waste are to be removed. The potential for conserving water by controlling the toilet flush operation in this manner is quite significant, given the far greater frequency with which flushes are typically activated to remove merely liquid waste than to remove both liquid and solid wastes.  
       [0006] In order to realize the enormous potential for water conservation thus available, a flush activation system that is reliable enough in operation yet simple (and inexpensive) enough for quick, convenient installation into existing toilet flush system designs is necessary. Given the inherent operation of commonly employed gravity flow toilets, and the restrictive mechanical (and aesthetic) confines within which their interacting components are disposed, though, attaining a suitable flush activation system remains no trivial matter. The need remains for a sufficiently simple and efficient, yet reliable and easily-installed flush activation system for selectively varying the volume of water drained from a given flush tank by a flush.  
       PRIOR ART  
       [0007] Mechanisms for variably controlling a toilet&#39;s flush are known in the art.  
       [0008] The best prior art known to Applicant includes U.S. Pat. Nos. 5,459,885; 5,206,960; 5,903,391; 5,511,253; 5,450,634; 5,331,690; 5,303,728; 5,205,000; 4,864,665; 4,837,867; 4,080,668; 4,829,605; 4,145,774; 3,981,029; 3,945,056; 3,894,299; 3,839,746; 5,887,292; 5,881,399; 5,699,563; 5,673,440; 5,642,533; 5,555,573; 5,524,297; 5,465,432; 5,319,809; 5,301,373; 5,157,795; 5,005,225; 4,878,256; 4,937,894; 4,651,359; 4,561,131; 4,433,445; 4,172,299; 4,149,283; 4,135,263; 4,096,591; 3,906,554; 3,903,550; 3,877,082; 3,858,250; and, 5,067,180. Such known mechanisms, however, fail to provide the sufficient combination of simplicity, efficiency, reliability and ease of installation for optimum practicability.  
       [0009] U.S. Pat. No. 5,459,885, for instance, discloses a dual flush mechanism for a toilet which enables both full and partial flush actuation. The mechanism employs a flush activation arm coupled by a transverse shaft to a handle. The free end of this flush activation arm is connected to a flush float which, in turn, is connected to a non-buoyant flush valve. A partial flush is effected by pivotally displacing the handle which, in turn, pivotally displaces the flush activation arm such that its free end lifts open the flush valve. The buoyancy of the flush float  26  then maintains the flush valve in this open position until the water level drops below it. At that point, the flush float falls by the force of gravity to permit the closure of the flush valve.  
       [0010] A full flush is effected through additional components which, when activated, blocks the flush activation arm from returning to its rest, or original, orientation. The additional components include a contoured contact plate ( 70 ) coupled to a pivot assembly ( 64 ) from which a rod ( 62 ) formed with a second flush float extends. This contact plate ( 70 ) bears against the terminal end of a control bar ( 40 ) which extends radially from the shaft connecting the handle ( 36 ) and flush activation arm ( 28 ).  
       [0011] When the control bar ( 40 ) is displaced during a partial flush responsive simply to a pivotal displacement of the handle ( 36 ), its tip remains thus engaged with the contact plate ( 70 ). When the control bar ( 40 ) is displaced during a full flush responsive to both an axial and a pivotal displacement of the handle ( 36 ), though, its tip proceeds to disengage from the contact plate ( 70 ), freeing that contact plate ( 70 ) for displacement beyond that tip. At that point, the rod ( 62 ) and the second flush float ( 60 ) which had been retained in the vertical orientation are freed to swing together upward, causing a laterally extended portion of the contact plate ( 70 ) to bear against and support a bottom edge of the control bar ( 40 ). This then maintains the shaft ( 38 ) and the flush activation arm ( 28 ) from returning to their non-activated orientations until the water level within the tank ( 12 ) drops sufficiently below the second flush float ( 60 ). It is only after the water level falls to a sufficiently low level that the rod ( 62 ) and second flush float ( 60 ) return to their vertical, or rest, position—to concurrently permit the contact plate&#39;s return to its original position.  
       [0012] A number of significant drawbacks are readily apparent in this mechanism. Perhaps the most significant is the fact that the mechanism demands a high degree of precision in its implementation. For example, the rod ( 62 ) must return fully to its vertical position before the contact plate ( 70 ) may disengage the bottom edge of the control bar ( 40 ), then re-engage the tip thereof. That is, the partial flush actuation function cannot be used again until and unless the rod ( 62 ) is permitted to return to its fully vertical position. This affords very little tolerance in such things as the length of the chains linking the flush valve ( 16 ) and the flush activation arm ( 28 ) (via the float  26 ). If even a slight bit of slack is present in these chains, for example, the slack may be sufficient to permit the flush valve&#39;s premature closure (before the water level has dropped enough for the second flush float ( 60 ) to descend to the point where it places the rod ( 62 ) in its fully vertical orientation). With the flush valve ( 16 ) closed, water would again begin filling the tank ( 12 ), again urging the second flush float ( 60 ) and rod ( 62 ) away from that fully vertical position, back to its activating position. Hence, the partial flush actuation function cannot be used again after the initial occurrence of it a full flush without manual intervention by a user, and all subsequent flushes remain exclusively full flushes.  
       [0013] Another drawback is found in the frictional engagement of the control bar ( 40 ) against the contact plate ( 70 ).  
       [0014] The cumulative effects of such frictional engagement repetitively occurring over an extended period of use would eventually lead to pronounced erosion in the engaging surfaces. Consequently, both the smooth operation and the structural integrity would be severely compromised.  
       [0015] Yet another drawback may be found in the relative complexity of the required motion for actuating a full flush. The concurrent pushing and turning of the handle  36  that is necessary may prohibitively difficult to some users.  
       SUMMARY OF THE INVENTION  
       [0016] It is therefore a primary object of the present invention to provide a flush activation system incorporating a mechanism operable during one or more flush modes to reciprocally displace in stable manner between active and inactive positions for respectively effecting the opening and closing of a given flush tank&#39;s flush mode.  
       [0017] It is another object of the present invention to provide a flush activation system actuable in a first mode to effect a flush that consumes a first volume of water stored in a given flush tank, and actuable in at least one additional mode to effect a flush that consumes a second volume of water.  
       [0018] It is another object of the present invention to provide a flush activation system that is simple in configuration yet operates efficiently and reliably.  
       [0019] It is yet another object of the present invention to provide a flush activation system tolerant in operation to a substantial degree of imprecision in the implementation of various components.  
       [0020] These and other objects are attained by a flush activation system formed in accordance with the present invention. The subject flush activation system is operable to control the drainage of water from a toilet flush tank during a flush. The system preferably comprises, generally: a partial flush mechanism independently actuable to initiate and terminate the drainage from the flush tank of a first volume of water; a full flush mechanism actuable to initiate and terminate the drainage from the flush tank of a second volume of water greater than the first volume of water; and, an actuation assembly coupled to the partial and full flush mechanisms for the selective actuation thereof. The partial flush mechanism operates to maintain the drainage of water at least until the water level within the flush tank drops beyond a first predetermined water level during a flush.  
       [0021] The full flush mechanism includes a lever arm pivotally displaceable between opening and closing positions for respectively opening and closing a drain seal of the flush tank. It further includes an activation arm coupled to the lever arm pivotally displaceable between angularly offset active and inactive positions. In the active position, this activation arm maintains the lever arm in the opening position thereof during the drainage of water at least until the water level within the flush tank drops beyond a second predetermined water level defined below the first predetermined water level. The activation arm is preferably biased to displace to its inactive position responsive to the water level dropping below the second predetermined water level. The full flush mechanism further includes at least one float component coupled adjacent a terminal end portion of the activation arm which serves to buoyantly bias the activation arm in orientation at its active and inactive positions in angularly offset manner.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0022]FIG. 1 is a perspective view, partially cut-away, of one embodiment of the flush activation system of the present invention shown installed in a toilet flush tank;  
     [0023]FIG. 2 is a perspective view, partially cut-away, of another embodiment of the flush activation system of the present invention shown installed in a toilet flush tank;  
     [0024]FIG. 3 is an exploded perspective view of a portion of the embodiment shown in FIG. 1;  
     [0025] to FIG. 3A is a perspective view, partially cut-away, of an alternate embodiment of a portion of the flush activation system of the present invention;  
     [0026]FIG. 3B is a perspective view, partially cut-away, of another embodiment of a portion of the flush activation system of the present invention;  
     [0027]FIG. 4 is an illustrative view showing the relative positions of various components during a first mode of operation of the flush activation system of the present invention;  
     [0028]FIG. 5 is an illustrative view showing the relative positions of various components during a second mode of operation of the flush activation system of the present invention;  
     [0029]FIG. 6 is a perspective view of an alternate embodiment of a flush valve assembly that may be employed in the flush activation system of the present invention;  
     [0030]FIG. 7 is a perspective view of another alternate embodiment of a flush valve assembly that may be employed in the flush activation system of the present invention;  
     [0031]FIG. 8 is a perspective view of yet another alternate embodiment of a flush valve assembly that may be employed in the flush activation system of the present invention, shown in its open position;  
     [0032]FIG. 9 is a perspective view of the alternate flush valve assembly embodiment of FIG. 8, shown in its closed position;  
     [0033]FIG. 10 is a perspective view of still another alternate embodiment of a flush valve assembly that may be employed in the flush activation system of the present invention, shown in its open position;  
     [0034]FIG. 11A is a perspective view of an alternate portion of the flush valve assembly embodiment of FIG. 10; and,  
     [0035]FIG. 11B is a perspective view of another alternate portion of the flush valve assembly embodiment of FIG. 10.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0036] Turning now to FIG. 1, there is shown one embodiment of the subject flush activation system  10  installed on a flush tank  1 . System  10  generally includes an actuation assembly  100  for selectively actuating partial or full flush mechanisms which initiate and terminate the drainage from flush tank  1  through a drain of different volumes of water collected therein. Generally, the flush operation in a typical gravity flow toilet is initiated by unsealing a normally sealed drain  2  (FIGS. 4 and 5) of flush tank  1 . The water within tank  1  then begins to drain out into the accompanying toilet bowl (not shown). Once the water level within tank  1  drops to a sufficiently low level, drain  2  is again sealed to permit the tank&#39;s re-filling by a valve-controlled water inlet mechanism (not shown) of any suitable type known in the art.  
     [0037] The partial and full flush mechanisms are implemented in the embodiment shown to include a flush lever assembly  200  displaceable in accordance with a user&#39;s corresponding manipulation of actuation assembly  100 . Flush lever assembly  200  operates responsively upon a partial flush valve assembly  300 , so as to either force open or allow the sealed closure of drain  2 . The full flush mechanism is implemented by further incorporating an auxiliary assembly  400  coupled to at least a portion of flush lever assembly  200  for appropriately controlling the displacement of that flush lever assembly portion when a full flush mode of operation is activated.  
     [0038] Actuation assembly  100  may be of any suitable type known in the art. While structural particularities of the assembly are not important to the present invention, it is preferably adapted to effect at least two different modes of operation responsive to correspondingly distinct manipulations thereof by a user.  
     [0039] In the embodiment shown, actuation assembly  100 , as detailed in the exploded view of FIG. 3, includes first and second handle members  102 ,  104  coaxially disposed in independently displaceable manner to a pivot shaft  106 . The pivotal displacement of first handle member  102  indicated by the bi-directional arrow  103  causes a corresponding rotation of pivot shaft  106  about an axis X. The pivotal displacement of second handle member  104  indicated by the bi-directional arrow  105  causes a corresponding displacement of a polygonal extension  108  thereof about pivot shaft  106  (and about the axis X).  
     [0040] As shown, first and second handle members  102 ,  104  are joined through the wall of flush tank  1  with pivot shaft  6  via a positioning bracket  110 , a washer plate  112 , a fastener  114 , and any other suitable hardware mechanism. Pivot shaft  106  passes through respective openings of the intervening hardware to protrude outward from flush tank  1 . The protruding terminal portion of pivot shaft  106  is then received coaxially through the polygonal extension  108  and a through hole  105  of second handle member  104  before first handle member  102  is securely coupled thereto. Polygonal extension  108  is formed with sufficient length to extend axially through the openings of the intervening hardware (and wall of flush tank  1 ) to protrude inward from the inner wall surface of flush tank  1 . With an appropriately shaped opening formed therein, the auxiliary lever arm  204  (described in following paragraphs) may be securely received upon that protruding portion of polygonal extension  108 .  
     [0041] Pivot shaft  106  includes a polygonal section  107  positioned thereon as shown to remain axially offset from polygonal extension  108  of second handle  104  upon the full assembly of the components shown. Polygonal portion  107  is contoured to securely engage a correspondingly shaped opening formed in a primary lever arm  202  (described in following paragraphs). Polygonal portion  107  is fixedly disposed with the other portions of pivot shaft  106 , such that it displaces angularly about the axis X responsive to the pivotal displacement of first handle member  102 , and thereby serves as a mechanical link for transferring the pivotal displacement of first handle member  102  to primary lever arm  202 .  
     [0042] Flush lever assembly  200  in this embodiment includes a primary lever arm  202  and an auxiliary lever arm  204 . As described in preceding paragraphs, primary lever arm  202  is rigidly coupled at polygonal portion  107  of pivot shaft  106  such that it pivotally displaces with that pivot shaft&#39;s rotation about the axis X, as indicated by the bi-directional arrow  203 . Auxiliary lever arm  204  is rigidly coupled to extension portion  108  such that it displaces pivotally with that extension&#39;s rotation about the axis X, as indicated by the bi-directional arrow  205 .  
     [0043] In the embodiment shown, primary lever arm  202  and auxiliary lever arm  204  are separately and independently displaceable responsive to displacements, respectively, of handle members  102 ,  104 . In alternate embodiments, however, appropriate coupling measures may be incorporated to permit the use of a common flush lever arm in effecting each distinct flush mode activated. In the alternate embodiment shown in FIG. 3A, for instance, primary lever arm  2020  remains commonly displaceable responsive to separate and distinct manipulations of actuation assembly  100 . Auxiliary flush lever arm  204  in that embodiment is replaced by a pivotally displaceable auxiliary member  2040  from which a transverse member  2045  extends to pass beneath primary lever arm  2020  as shown. When auxiliary member  2040  pivotally displaces upward, transverse member  2045  forces a concurrent pivotal displacement upward of primary lever arm  2020 . So long as auxiliary member  2040  remains displaced upwardly, therefore, primary lever arm  2020  remains correspondingly displaced upward.  
     [0044] Other suitable alternate embodiments of the actuation and flush lever assemblies  100 ,  200  may also be employed. One such alternate embodiment is illustrated in FIG. 3B. In that embodiment, a primary lever arm  2420  is again commonly employed in effecting each distinct flush mode that is to be activated. Primary lever arm  2420  is linked to a first handle member  2020  by a pivot shaft  2060  such that it displaces pivotally about the axis thereof responsive to the pivotal displacement of first handle member  2020  in the direction indicated by the arrow  2030 . This would activate a first flush mode.  
     [0045] Pivot shaft  2060  in this embodiment passes through an opening formed in activating arm  2402  which, as in the other embodiments already described, includes an activating float component  404  (not shown) coupled at the bottom end thereof. Pivot shaft  2060  also passes through an opening formed in a second handle member  2040  which is rigidly coupled to activating arm  2402 . Thus, when pivot shaft  2060  is rotated about its axis X with the pivotal displacement of first handle member  2020  (and primary lever arm  2420 ), it causes neither activating arm  2402  nor second handle member  2040  to displace. A second flush mode may nonetheless be activated by pivotally displacing second handle member  2040  in the direction indicated by the arrow  2050 . Such downward displacement of second handle member  2040  causes it to engage a catch flange portion  2025  extending laterally from first handle member  2020 , so as to cause that catch flange portion  2025  and first handle member  2020  to also displace pivotally downward. Accordingly, primary lever arm  2420  is caused to pivotally displace concurrently with activating arm  2402 .  
     [0046] An auxiliary arm  2440  is formed to extend laterally from activating arm  2402 . Auxiliary arm  2440  serves in this embodiment primarily weighting and counterbalancing purposes, so that the proper operation of activating arm  2402  (and activating float component  404  attached thereto) occurs properly as described in following paragraphs with reference to other disclosed embodiments. A weighting mechanism  2450  preferably having a securement fastener  2452  may be provided on auxiliary arm  2440  to provide the arm with weighting adjustability.  
     [0047] Returning to FIG. 1, partial flush valve assembly  300  may, too, be realized through numerous other embodiments, so long as it operates suitably to effect the re-closure/seal of the drain  2  responsive automatically to the water level within the tank  1  dropping below a predetermined intermediate water level. In the embodiment shown, partial flush valve assembly  300  includes a valve member  302  displaceable between open and closed positions over drain  2  for alternatively opening and sealing it for and against the drainage of water therethrough. Valve member  302  is formed in this embodiment with a non-buoyant structure such that it tends toward its closed position absent some restraining measure to prevent such closure.  
     [0048] Partial flush assembly  300  also includes in this embodiment a buoyant float component  304  connected to valve member  302  by a chain or other suitable link member  306 , and to primary flush lever arm  202  by a chain or other suitable link member  308 . Float component  304 , which may be formed with any suitable configuration and composition known in the art, provides a buoyancy great enough to prevent the closure of valve member  302  once drainage of water from tank  1  has been initiated, but low enough to avoid disturbing valve member  302  from its closed position. As illustrated in FIG. 4, when a partial flush mode is activated by accordingly displacing first handle member  102 , the resulting pivotal displacement of primary lever arm  202  in the upward direction  203  draws valve member  302  upward to its open position (via link member  308 , float component  304 , and link member  306 ). Immediately, drainage of the water contained in flush tank  1  commences through drain  2 , as indicated by the directional arrows  20 . Even if handle member  102  is released by the user (to allow the return of primary lever arm  202  to its original position), the buoyancy of the water-submerged float component  304  retains valve member  302  in its open position as long as the water in flush tank  1  remains at a water level  22  above a first predetermined water level  24 . When the water level drops beyond that first predetermined water level  24 , float component  304  no longer remains submerged; hence, it falls by the force of gravity with the water level. This then permits valve member  302  to fall and close under the weight of the water upon it.  
     [0049] Turning back to FIG. 1, the full flush mechanism of system  10  incorporates an auxiliary assembly  400  shown in the given embodiment to include an activating arm  402  preferably extending downward from a proximal end portion of auxiliary lever arm  204 . Auxiliary assembly  400  further includes an activating float component  404  coupled at a suitable point adjacent a terminal end portion of activating arm  402 . Activating arm  402  and activating float component  404  are together pivotally displaceable with auxiliary lever arm  204 , as indicated by the bi-directional arrow  403 , between an inactive position and an active position (shown in FIG. 5). Much like float component  304 , activating float component  404  may be formed with any suitable configuration and composition known in the art to yield a buoyancy sufficient for the requirements of the given application.  
     [0050] When a second flush mode is activated by the user&#39;s appropriate manipulation of second handle member  104 , auxiliary flush lever arm  204  and activating arm  402  are pivotally displaced, preferably as a unit, such that auxiliary lever arm  204  draws valve member  302 , via link member  310 , upward to its open position. Numerous other structural configurations of activating arm  402 , auxiliary flush lever arm  204 , and/or measures for their coupling are readily conceivable.  
     [0051] The open position of valve member  302  permits water to drain, as indicated by the directional arrows  40 ; and, the water level within tank  1  begins immediately to drop. Meanwhile, activating float component  404 —which, in its inactive position (prior to the given flush activation), had been located on one side of a vertical orientation reference  406  to buoyantly bias activating arm  402  in angular orientation away therefrom (in the clockwise direction in the view as shown)—is now located in the active position, as shown, on an opposing side of the vertical orientation reference  406 . Activating float component  404 , there, also buoyantly biases activating arm  402  angularly away from the vertical orientation reference  406 , but in an angular direction opposite that at its inactive position (or in the counter-clockwise direction in the view as shown).  
     [0052] As the water level in tank  1  drops with the drainage of water therefrom, the buoyant bias of activating float  404  retains auxiliary lever arm  204  in its upwardly displaced position to, in turn, maintain valve member  302  in its opened position. This condition remains so long as activating float component  404  remains substantially submerged. As the water level in flush tank  1  drops beyond the first predetermined water level  24 , first float component  304  weighs downward via link member  308  upon primary lever arm  202 . This, however, remains ineffectual to the disposition of auxiliary lever arm  204 .  
     [0053] As the water level drop continues beyond a second predetermined water level  44 , activating float component  404  is eventually left no longer submerged. Consequently, activating float component  404  and activating arm  402  are permitted to swing by force of gravity much like a pendulum to and angularly beyond the vertical orientation reference  406 , as indicated by the directional arrow  408 . The concurrent displacement of auxiliary lever arm  204  pivotally downward with activating arm  402 , as indicated by the directional arrow  206 , sufficiently releases valve member  302  for closure. As the water thereafter fills tank  1  and the water level again begins to rise, activating float component  404  gradually becomes submerged once again to buoyantly urge activating arm  402  angularly away from the vertical orientation reference  406  (in the clockwise direction). Thus, activating float component  404  again biases activating arm  402  to remain in its inactive position.  
     [0054] Note that in the embodiment shown, activating arm  402  is rigidly connected to auxiliary lever arm  204  to be angularly offset therefrom by a predetermined angle a. The resulting configuration aids in biasing the structure to return pivotally to its inactive position (whereby activating float component  404  and activating arm  402  are disposed as shown in FIG. 4). The actual value of the offset angle a may be set in accordance with the particular requirements of the given application. Depending on the requirements, for instance, the angle may be acute as shown or may even be obtuse (not shown).  
     [0055] It is important that the buoyancy of activating float component  404  be sufficient to bias activating arm  402  in angular orientation away from the vertical orientation reference  406  at both its inactive and active positions (on opposing sides of that reference  406 ), regardless of the mechanical characteristics of the specific components employed. It is also important, however, that the structure to which activating arm  402  and floating component  404  belong be balanced in such manner that activating float  404  tends by the force of gravity thereupon to swing towards its inactive position when it is disposed at or near the vertical orientation reference  406 .  
     [0056] It is noted in this regard that additional measures to enable adjustment of the prevailing structure&#39;s balancing may be employed. An example of such adjustment measures are shown in the alternate embodiment of FIG. 2. As shown in that embodiment, auxiliary lever arm  1204  is formed with a plurality of longitudinally offset coupling holes  1206  formed along a portion of its length. A weighting mechanism  1500  is releasably coupled to one or more of the coupling holes  1206  to appropriately adjust the tendency of auxiliary lever arm  1204  to displace pivotally downward, as indicated by the directional arrow  1205 .  
     [0057] Also in the alternate embodiment of FIG. 2, a plurality of longitudinally offset coupling holes  1208  may be formed in primary lever arm  1202  along a portion of its length. By the selective coupling of link member  308  to one of these coupling holes  1208 , adjustments may be made to adapt to the peculiar configurations of the given tank  1  and the components arranged therein.  
     [0058] The alternate embodiment of FIG. 2 employs an actuation assembly  1000  wherein a single handle member  1020  is commonly employed to activate each of the system&#39;s plurality of flush modes. For instance, handle member  1020  may be linearly displaced by pressing it towards flush tank  1 , as indicated by the bi-directional arrow  1030 , along the axis X. The mechanical coupling components detailed in the exploded view of FIG. 3A then cause responsive to such linear displacement of handle member  1020  the upward pivotal displacement of primary lever arm  1202  (independent of auxiliary lever arm  1204 ) along the path indicated by the bi-directional arrow  203 . Operation of the system in the ensuing flush mode occurs substantially as described in preceding paragraphs with reference to the embodiment of FIG. 1.  
     [0059] Handle member  1020  may also be pivotally displaced about the axis X, as indicated by the bi-directional arrow  1050  to activate a second flush mode. The mechanical coupling of handle member  1020  to auxiliary lever arm  1204  is such that the auxiliary lever arm  1024  is responsively displaced pivotally upward along the path indicated by the bi-directional arrow  1205 . Again, the system&#39;s operation in the ensuing flush mode occurs as described in preceding paragraphs with reference to the embodiment of FIG. 1.  
     [0060] In each of the embodiments disclosed in FIGS. 1 and 2, auxiliary assembly  400  and auxiliary lever arm  204  which cooperatively implement the full flush mechanism is employed in conjunction with a partial flush mechanism. In certain embodiments, however, auxiliary assembly  400  and auxiliary lever arm  204  may be employed without the presence of a partial flush or any other supplemental flush mechanism. The presence of such supplemental flush mechanism is not necessary for the advantageous flush activation control cooperatively enabled as described in preceding paragraphs by auxiliary assembly  400  and auxiliary lever arm  204 .  
     [0061] Referring now to FIG. 6, there is shown an alternate embodiment  3000  of the partial flush valve assembly. As shown, assembly  3000  in this embodiment includes a Mansfield-type valve known in the art having an elongate tubular portion  3022  coaxially coupled in displaceable manner to a post for axial displacement thereon. Valve member  3020  further includes a bottom float portion  3024  having a buoyancy which enables it to remain buoyantly suspended when it is drawn upward to keep open a drain  3  below it. When thus drawn to its open position, valve member  3020  permits water to drain from the tank, as indicated by the directional arrows  3200 .  
     [0062] Normally, due to the buoyancy of its float portion  3024 , valve member  3020  remains suspended in its open position until the water level drops beneath that float portion  3024 , whereupon it descends by force of gravity to cover and seal the drain  3 . In the embodiment shown, however, assembly  3000  is also equipped with a weighting component  3040  coupled to valve member  3020  via a chain or other comparable link member  3060 . When the water level has dropped to a predefined point relative thereto, weighting component  3040  serves to counteract the buoyancy of the valve member&#39;s float portion  3024  and thereby urge the premature descent of valve member  3020  to its closed position before the water level actually drops beneath that float portion  3024 .  
     [0063] Weighting component  3040  is preferably formed with a body defining a substantially hollow inner compartment. The body is formed with an upper perforated portion  3042  to permit the entry of water into the inner compartment for weighting purposes. Supplementary measures for stabilizing the position and orientation of weighting component  3040  may be employed, such as inserting one or more weighting ballasts (not shown) within the inner compartment and/or forming the body from a dense material. Preferably, the body of weighting component  3040  is also formed with a bottom perforated portion  3044  for the release of water from the inner compartment in a sufficiently gradual manner as to—without prematurely halting the descending closure of valve member  3020 —effectively minimize the weight to be counteracted by auxiliary assembly  400  during a full flush mode of system operation.  
     [0064] In operation, valve member  3020  is drawn upwards by flush lever arm assembly  200 , via a chain or comparable link member  3080 . This occurs regardless of the mode of flush activated. Where a full flush mode has been activated, valve member  3020  will remain in its open position until the water level is permitted to descend by the operation of auxiliary assembly  400 . Where a partial flush mode has been activated, however, valve member  3020  remains in its buoyantly suspended open position only until the water, level initially at  3220 , drops beyond a predetermined intermediate water level  3240 . At that point, weighting component  3040  which had theretofore been substantially submerged in water is no longer submerged and weighs downward upon valve member  3020  sufficiently to overcome the buoyancy of float portion  3024 . Accordingly, valve member  3020  is caused to descend prematurely to its closed position upon drain  3 .  
     [0065] Turning now to FIG. 7, there is shown another alternate embodiment  3500  of the partial flush valve assembly. The operation of this embodiment is similar to that of assembly  3000  shown in FIG. 6. Valve member  3520  in this embodiment is also of a type known in the art, but is formed with a shaft portion  3522  supported by a support structure  3510  to be axially displaceable between open and closed positions over a tank drain  4 . At the bottom end of shaft portion  3522  is formed a buoyant float portion  3524  which, much like float portion  3024  of valve member  3020  in FIG. 6, normally maintains valve member  3520 , upon the activation of a flush, buoyantly suspended in its open position above drain  4  until the water level drops beneath it. Weighting component  3040  is coupled to shaft portion  3522  by link member  3060 , as before, to urge the descent of valve member  3520  to its closed position once the water level drops to the predetermined intermediate water level  3240  during a partial flush mode of operation. Float component  3040  and its contents weigh valve member  3520  sufficiently downward to overcome the buoyancy of float portion  3524 . Of course, once valve member  3520  is fully seated upon drain  4 , the weight of the water upon it prevents its upward displacement.  
     [0066] Referring to FIGS.  8 - 9 , there is shown another partial flush valve assembly  13000  that may be employed in yet another alternate embodiment of the present invention. In this embodiment, assembly  13000  incorporates in place of the separate float component configurations shown in preceding embodiments a float component  13040  formed—preferably in integral manner—to extend downward from a valve member  13020 . Float component  13040  includes a bulbous air trap portion formed by a sidewall  13042  which extends about and defines an air pocket  13044  and a bottom opening  13046  that provides open access thereto. Sidewall  13042  is formed with a perforate hole  13048  preferably situated as shown at an upper part of the bulbous air trap portion  13040  adjacent valve member  13020 .  
     [0067] As indicated by the directional arrow  13050 , valve member  13020  is coupled in angularly displaceable manner to a support bracket  13055  in order that the valve member&#39;s buoyancy may be readily adjusted. As in the embodiments shown in FIGS.  1 - 5 , valve member  13020  may be pulled via a link  13060  to pivotally displace from its closed, or sealing, position over the given tank&#39;s drain  2  to the open position shown. Operation occurs as follows, once the valve member  13020  (and its air trap portion  13040 ) is initially pulled to this open position. Water which had been stored in the tank begins to exit through drain  2 . Both the air trap portion  13040  and valve member  13020  are fully submerged in the tank&#39;s water at this initial stage; and, the air that had been occupying the air trap portion&#39;s air pocket  13044  begins escaping through the perforate hole  13048 . Concurrently, water enters through the bottom opening  13046  to gradually fill the vacated space in air pocket  13044  until the valve member  13020 , by this action, fully descends to its sealing position upon drain  2 . The tank is again sealed at that point against further water drainage, and the water which had been occupying air pocket  13044  just prior to the valve member&#39;s full closure releases freely through the air trap portion&#39;s bottom opening  13046  (since air can then vent freely through perforate opening  13048 ) until the next flush operation is initiated.  
     [0068] During a flush operation, the escape of air from pocket  13044  through perforate hole  13048  occurs most rapidly when that perforate hole  13048  is situated at its highest point as shown in FIG. 8. If it were repositioned by angularly displacing valve member  13020  relative to bracket  13055 , it is offset from the apex of the air trap portion&#39;s tilted orientation. The rate of air escape therethrough diminishes, consequently, with such repositioning. To set to a minimum, then, the volume of the water to be drained from the tank during a flush, valve assembly  13000  would be configured such that perforate through hole  13048  is situated as shown, at or near the tilted orientation apex. To release a greater volume of water from the tank, valve assembly  13000  would be configured such that perforate through hole  13048  is positioned at a point  13048 ′ that is offset from the apex tilted orientation.  
     [0069] The rapid escape of air from air pocket  13044  in the first case would yield a correspondingly rapid closure of valve member  13020 . Conversely, the less rapid escape of air from air pocket  13044  in the second case would yield a correspondingly less rapid closure of valve member  13020 .  
     [0070] Valve assembly  13000  of the embodiment shown includes visual indicia  13022  formed on valve member  13020  for visually guiding a user to precisely adjust its configuration. Such visual indicia includes incrementally offset tick marks which are sequentially numbered from a clearly denoted “MIN” setting to a clearly denoted “MAX” setting. A reference pointer  13057  is formed on bracket  13055 , and the tick mark closest to the “MIN” marker is preferably formed in alignment with perforate through hole  13048 . Rotating valve member  13020  such that tick mark “ 1 ” is aligned with reference pointer  13057  thus aligns perforate through hole  13048  as shown with the apex of air trap portion&#39;s tilted orientation. Alternatively, rotating valve member  13020  along the direction  13050  to align tick mark “ 9 ” with reference pointer  10357  situates perforate through hole  13048  at the point  13048 ′, which is well offset from that apex.  
     [0071] The type of valve assembly  13000  employed in this embodiment is one that is known in the prior art. One such valve assembly that may be incorporated in accordance with the present invention is that provided by FLUIDMASTER of San Juan Capistrano, Calif.  
     [0072] The adjustability of flush volume in such valve assembly types results from varying the position of a through hole for venting the air that would otherwise be trapped within the assembly&#39;s air pocket  13044 . Flush volume adjustability may also be effected by varying another parameter, namely the size of the bottom opening with which the assembly&#39;s air pocket communicates while maintaining without change the relative position and configuration of the venting through hole. The embodiment shown in FIG. 10, for instance, employs a valve assembly  23000  which includes a valve member  23020  that is pivotally displaceable between open and closed positions over the tank&#39;s drain  2  as in the preceding embodiment, but is not angularly displaceable, as was the valve member in that embodiment. Instead, assembly  23000  employs a replaceable attachment  23050  to vary the size of the passage formed through bottom opening  23046  of the assembly&#39;s water trap portion  23040 .  
     [0073] As before, water enters the air pocket  23044  defined by the water trap portion&#39;s sidewall  23042  during operation—as air that had been occupying air pocket  23044  escapes through a perforate through hole  23048  formed in the sidewall  23042 . A plurality of such replaceable attachments  23050  for bottom opening  23046  are provided, each obstructing the bottom opening  23046  by a different extent to define an attachment opening  23052  of distinct size.  
     [0074] Different exemplary ones of such attachments  23050   a,    23050   b  are respectively shown in FIGS. 11A and 11B. Each attachment  23050   a,    23050   b  is characteristically configured with respective attachment openings  23052   a,    23052   b  of corresponding size. The lesser the attachment opening size, the more time it takes for water to enter the air pocket  23044  space vacated by the air escaping through perforate through hole  23048 . Hence, a correspondingly less rapid closure of valve member  23020  occurs, permitting the drainage of a greater volume of tank water during a given flush. Conversely, the greater the attachment opening size, the less time it takes for water to enter the air pocket  23044  space vacated by the air escaping through perforate hole  23048 . Hence, a correspondingly more rapid closure of valve member  23020  to its closed position occurs, permitting a lesser volume of tank water to drain during a given flush.  
     [0075] Valve assembly  23000  is of a type known in the art. Like the alternate valve types shown in FIGS. 6, 7, and  8 - 9  for alternate embodiments of the present invention, the type shown in the embodiments of FIGS.  10 - 11 B may be independently varied apart from the other features disclosed herein for system  10 —to more simply adjust the volume of water released by a flush in a given flush activation system.  
     [0076] Of course, where adjustability of the valve member&#39;s closure is not required, bottom opening  23046  in this embodiment may be maintained at a fixed size and configuration. The venting through hole in the valve assembly of the embodiment shown in FIGS. 8 - 9  may, similarly, be maintained in that case at a fixed position, size, and configuration.  
     [0077] Although this invention has been described in connection with specific forms and embodiments thereof, it will be appreciated that various modifications other than those discussed above may be resorted to without departing from the spirit or scope of the invention. For example, equivalent elements may be substituted for those specifically shown and described, certain features may be used independently of other features, and in certain cases, particular combinations of system components may be interchanged or interposed, all without departing from the spirit or scope of the invention as defined in the appended Claims.