In one aspect, the present invention is directed to a toilet flushing system, comprising: a first pump ( 38 ) and piping, for emptying the bend ( 56 ) of the flush toilet from fluids (water and urine) into a drainpipe ( 42 ); a water provider, for providing water for flushing the emptied toilet bowl; and a sensor (such as a foot pedal  24 ), for triggering the operation of emptying the bend and flushing the emptied toilet bowl thereafter; a control unit, for controlling the operation of emptying the bend ( 56 ) and flushing the emptied toilet bowl thereafter by a water quantity of at least the quantity required for sealing the bend; thereby flushing the toilet bowl using less water than in toilet flushing systems of the prior art.

FIELD OF THE INVENTION 
       [0001]    The present invention relates to the field of toilet flushing. More particularly, the invention relates to a toilet flushing system and method. 
       BACKGROUND OF THE INVENTION 
       [0002]    A flush toilet is a toilet that disposes of human waste by using water to flush it through a drainpipe to another location. Modern toilets incorporate a bend (trap) that causes the water in a toilet bowl to be collected, and act as a seal against sewer gases. 
         [0003]    One of the well-known technologies for saving water is using smaller water quantities when flushing liquid waste, in comparison to the quantity used when flushing solid waste. 
         [0004]    It would be highly advantageous to provide a flushing technology requiring less water than in the prior art. 
         [0005]    Other objects and advantages of the invention will become apparent as the description proceeds. 
       SUMMARY OF THE INVENTION 
       [0006]    In one aspect, the present invention is directed to a toilet flushing system, comprising:
       a first pump ( 38 ) and piping, for emptying the bend ( 56 ) of the flush toilet from fluids (water and urine) into a drainpipe ( 42 );   a water provider, for providing water for flushing the emptied toilet bowl; and   a sensor (such as foot pedal  24 ), for triggering the operation of emptying the bend and flushing the emptied toilet bowl thereafter;   a control unit ( 60 ), for controlling the operation of emptying the bend ( 56 ) and flushing the emptied toilet bowl thereafter by a water quantity of at least the quantity required for sealing the bend;   thereby flushing the toilet bowl using less water than in toilet flushing systems of the prior art.       
 
         [0012]    According to one embodiment of the invention, the water provider is a secondary flush tank ( 16 ). 
         [0013]    According to another embodiment of the invention, the secondary flush tank further comprises an inlet for inserting therein disinfectant and/or aromatic odor mask. 
         [0014]    According to one embodiment of the invention, the system further comprises a second pump ( 44 ), for pumping water out of the secondary flush tank ( 16 ), into the toilet bowl ( 14 ). 
         [0015]    According to yet another embodiment of the invention, the system further comprises an arrangement (not illustrated) for connecting therein a container of disinfectant and/or odor mask. 
         [0016]    According to one embodiment of the invention, the water provider is the flush tank ( 12 ) of the toilet. 
         [0017]    The system may further comprise sprayer(s) ( 26 ) for increasing the cleansing effect of flushing the emptied toilet bowl, thereby allowing using less water. 
         [0018]    According to one embodiment of the invention, the water provider is a domestic water source ( 18 ). 
         [0019]    The system may further comprise a facility (such as element  32 ) for preventing blocking the piping by solids. 
         [0020]    According to one embodiment of the invention, the sensor is embodied as a foot pedal ( 24 ). 
         [0021]    According to another embodiment of the invention, the sensor is embodied as a foot switch (not illustrated). 
         [0022]    The control unit may employ a timer for determining the time for emptying the bend, and/or for determining the time for refilling the bend. 
         [0023]    The control unit may employ a second sensor (not illustrated) for determining that the bend is empty. 
         [0024]    According to one embodiment of the invention, the control unit employs a third sensor (not illustrated) for detecting that the bend is sealed. 
         [0025]    In another aspect, the present invention is directed to a toilet flushing method after urinating in a flush toilet, the method comprising the steps of;
       emptying the bend of the flush toilet; and   flushing the bowl of the flush toilet until the bend is sealed.       
 
         [0028]    According to one embodiment of the invention, the operation of flushing the bowl is carried out using spraying, thereby flushing the emptied toilet bowl more efficiently, thereby enabling obtaining the same cleansing effect with less water. 
         [0029]    The foregoing embodiments of the invention are described and illustrated in conjunction with systems and methods thereof, which are meant to be merely illustrative, and not limiting. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    Embodiments and features of the present invention are described herein in conjunction with the following drawings: 
           [0031]      FIG. 1  schematically illustrates a flush toilet, according to one embodiment of the invention. 
           [0032]      FIG. 2  schematically illustrates the flush toilet of  FIG. 1 , while spraying. 
           [0033]      FIG. 3  schematically illustrates the flush toilet in a situation wherein bend (trap)  56  is filled with water. 
           [0034]    Each of  FIGS. 3 to 5  is a sectional view of a flush toilet, which schematically illustrate a stage in flushing the toilet, according to one embodiment of the invention. 
           [0035]      FIG. 3  schematically illustrates the flush toilet in a situation where bend (trap)  56  is filled with water. 
           [0036]      FIG. 4  schematically illustrates the flush toilet in a situation wherein it is emptied. 
           [0037]      FIG. 5  schematically illustrates the flush toilet in a situation wherein second pump  44  flushes water into bowl  14  using sprayers  26 . For this operation, the pump uses the water of secondary flush tank  16 . 
           [0038]      FIG. 6  is a block diagram schematically illustrating the components and process flow of a flush toilet, according to one embodiment of the invention. 
           [0039]      FIG. 7  is a block diagram schematically illustrating the components and process flow of a simplified flush toilet, according to one embodiment of the invention. 
           [0040]      FIG. 8  schematically illustrates a gear pump that can be used as pumps  38  and  44 . 
       
    
    
       [0041]    It should be understood that the drawings are not necessarily drawn to scale. 
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0042]    The present invention will be understood from the following detailed description of preferred embodiments, which are meant to be descriptive and not limiting. For the sake of brevity, some well-known features, methods, systems, procedures, components, circuits, and so on, are not described in detail. 
         [0043]      FIG. 1  schematically illustrates a flush toilet, according to one embodiment of the invention. 
         [0044]    The flush toilet is marked herein by reference numeral  10 . Reference numeral  14  denotes the bowl of the flush toilet, and reference numeral  12  denotes the flush tank thereof. 
         [0045]    Reference numeral  18  denotes a domestic water source, from which water is supplied to flush tank  12  via pipe  20 . 
         [0046]    The additional visible parts, which characterize embodiments of the present invention, are secondary flush tank  16 , which is provided with water supply from domestic water source  18 , via pipe  22 . A foot pedal  24  is used to trigger flushing of water from secondary flush tank  16 , as will be further detailed hereinafter. 
         [0047]      FIG. 2  schematically illustrates the flush toilet of  FIG. 1 , while spraying. 
         [0048]    According to embodiments of the present invention, the operation of the flush toilet comprises two stages: at the first stage, bend (trap)  56  of the toilet is emptied, and at the second stage, sprayers  26  spray water  54 , refilling the trap. The illustration refers to the second stage. Pipe  28  provides the required water from second pump  44  to sprayers  26 . 
         [0049]    Each of  FIGS. 3 to 5  is a sectional view of a flush toilet, which schematically illustrate a stage in flushing the toilet, according to one embodiment of the invention. 
         [0050]      FIG. 3  schematically illustrates the flush toilet in a situation wherein bend (trap)  56  is filled with water. 
         [0051]    At this stage, standing water  30  in trap  56  is used to seal outlet  62  of bowl  14 , thereby preventing the release of foul air from the sewer. 
         [0052]    At this stage, the user urinates, and then presses foot pedal  24  (not seen in this illustration). As a result, first pump  38  is activated. First pump  38  pumps (draws) the content of bend (trap)  56 , until emptied. The content is pushed by the pump into drainpipe  42 . 
         [0053]      FIG. 4  schematically illustrates the emptied flush toilet. 
         [0054]      FIG. 5  schematically illustrates the flush toilet in a situation wherein second pump  44  flushes  64  water from secondary flush tank  16 , into bowl  14 , via sprayers  26 . 
         [0055]    The water quantity used for spraying should be at least the quantity required for refilling bend  56 . This can be adjusted by setting a control unit  60  that controls the operation of second pump  44 . The control unit may be a circuit, integrated circuit, chip, and so on. It may also comprise a timer. For example, the timer may be used for counting N seconds for activating the first pump to empty the bend, and for M seconds for flushing the toilet. 
         [0056]    Thus, the timer is used as an alternative to a sensor for sensing that the toilet bend is emptied, and that the quantity of water flushed into the bowl is adequate to seal the bend. 
         [0057]    The water quantity in secondary flush tank  16  is retained at a certain level by a faucet  50  connected to a water source, and a float  48  that controls the tap to get closed when the water in the flush tank passes beyond a certain level. This mechanism is common in retaining the water level in flush tanks. 
         [0058]      FIG. 6  is a block diagram schematically illustrating the components and process flow of a flush toilet, according to one embodiment of the invention. 
         [0059]    From the process aspect, the following steps are carried out: 
         [0060]    Step (A): After urinating, the user presses foot pedal  24 . Control unit  60  senses the event of pressing foot pedal  24 , and operates as follows: 
         [0061]    Step (B): The content of bend (trap)  56  is pumped by first pump  38  into drainpipe  42 . 
         [0062]    Step (C): The second pump  44  is activated to flush toilet bowl  14 . The flushed water refills bend (trap)  56 . 
         [0063]    The point that characterizes the operation of this embodiment of the invention in comparison to the prior art is the quantity of the flushed water in step (C). This quantity is at least the quantity required for sealing bend (trap)  56 . This quantity is less than the quantity of water used for “full” flushing or “half” flushing of a common toilet bowl (i.e., flushing after urinating in common flush toilets). The lesser quantity is adequate since the bend (trap) of the toilet bowl is emptied before flushing, and therefore the flushing only washes up the bowl, and seals the bend (trap). 
         [0064]    As such, using the present invention results in less water for flushing a flush toilet in comparison to any flushing mechanism of the prior art. 
         [0065]    An additional advantage of the present invention is the fact that the user does not have to touch the flushing handle, as in a common flush toilet. 
         [0066]    Since foot pedal  24  is used only as a sensor for indicating that the user has activated the flushing process, the pedal can be replaced by a switch attached to the floor. The mechanism of a switch is much simpler and more reliable than the mechanism of the pedal. 
         [0067]    The secondary flush tank  16  is only an example. Actually, the water of the “main” flush tank  12  may be used as well. 
         [0068]      FIG. 7  is a block diagram schematically illustrating the components and process flow of a simplified flush toilet, according to one embodiment of the invention. 
         [0069]    According to this embodiment of the invention, only one pump is used: first pump  38 . Second pump  44  is replaced by a solenoid  58 , which is a simpler component. Furthermore, there is no use of a secondary flush tank. 
         [0070]    Using this system, the following steps are carried out: 
         [0071]    Step (A): After urinating, the user presses foot pedal  24 . Control unit  60  senses the event of pressing foot pedal  24 , and operates as follows: 
         [0072]    Step (B): The content of bend (trap)  56  is pumped by first pump  38  into drainpipe  42 . 
         [0073]    Step (C): Control unit  60  activates solenoid  58  that enables/disables water from a domestic water source  18  (illustrated in  FIG. 1 ) to flush toilet bowl  14 . The flushed water refills bend (trap)  56 . 
         [0074]    The absence of a second pump  44  may reflect the way the flushing is carried out, since water pressure from the water source may not be adequate to generate the necessary spray for flushing the toilet bowl. On the other hand, this way the mechanism is simpler, as neither secondary flush tank or second pump are required. 
         [0075]    Sprayers  26  enable utilizing the flushed water more efficiently, thereby enabling obtaining the same cleaning effect by lesser quantity of water. 
         [0076]    According to one embodiment of the invention, the secondary tank comprises an inlet (not illustrated) for inserting therein a disinfectant, odor mask, and so on. Alternatively, the system may comprise means for connecting therein a container of disinfectant, odor mask, and so on. 
         [0077]      FIG. 8  schematically illustrates a gear pump that can be used as pumps  38  and  44 . 
         [0078]    The pump, which is marked herein by reference numeral  70 , comprises housing  76  having a fluid inlet  72 , and fluid outlet  74 . Two interlaced gears  78  and  78 ′ are disposed in casing  76 . The gaps between the gears and hosing  76  are sealed. An electrical motor rotates the pump. 
         [0079]    As the gears rotate, they separate on the intake side of the pump, creating a void and suction that is filled by fluid. The fluid is carried by the gears to the discharge side of the pump, where the meshing of the gears displaces the fluid. The mechanical clearances are “small”. The tight clearances, along with the speed of rotation, effectively prevent the fluid from leaking backwards. 
         [0080]    The ears may be rotated in the opposite direction, thereby allowing opening jams in pipe  36 , which sucks standing fluid  30  from trap  56 . 
         [0081]    The pumps, solenoid, and control unit use electric power for their operation. The electric power may be provided by batteries or by the domestic electric power supply. 
         [0082]    The invention may be implemented on an existing toilet bowl, and as well can be implemented in a flush toilet designed to include the invention. 
         [0083]    In the figures and/or description herein, the following reference numerals have been mentioned:
       numeral  10  denotes a flush toilet, according to one embodiment of the invention;   numeral  12  denotes a flush tank;   numeral  14  denotes a bowl of a flush toilet;   numeral  16  denotes a secondary flush tank;   numeral  18  denotes a domestic water source;   numeral  20  denotes a pipe through which water is provided from domestic water source  18  to flush tank  12 ;   numeral  22  denotes a pipe through which water is provided from water source  18  to secondary flush tank  16 ;   numeral  24  denotes a foot pedal for activating flushing the toilet from water of the secondary flush tank  16 ;   numeral  26  denotes a sprayer;   numeral  28  denotes a pipe through which water is provided to sprayers  26 ;   numeral  30  denotes standing water in bend (trap)  56 ;   numeral  32  denotes a bend in pipe  36 , for preventing blockage of the pipe;   numeral  34  denotes a sticking facility, for sticking the end of pipe  36  to the bottom of bend (trap)  56 ;   numeral  36  denotes a pipe that pumps the fluids from bend (trap)  56  into drainpipe  42 , and therefrom to drainpipe  42 ;   numeral  38  denotes a first pump for pumping fluids from bend  56 ;   numeral  40  denotes a pipe that pours fluids from bend  56  into drainpipe  42 ;   numeral  42  denotes a drainpipe;   numeral  44  denotes a second pump, for pumping water from secondary flush tank  16 , through sprayers  26 , into bowl  14 ;   numeral  46  denotes the outlet pipe of second pipe  44 ;   numeral  48  denotes a float, for controlling the water level in the secondary flush tank  16 ;   numeral  50  denotes a faucet operated by the arm of float  48 ;   numeral  52  denotes a pipe trough which water is poured from flush tank  12  into toilet bowl  14 ;   numeral  54  denotes sprayed water;   numeral  56  denotes the bend (trap) of toilet  10 ;   numeral  58  denotes a solenoid;   numeral  60  denotes a control unit;   numeral  62  denotes the outlet of flush toilet  10  into drainpipe  42 ;   numeral  64  denotes the water of secondary flush tank  16 ;   numeral  70  denotes a gear pump, that can be used as each of pumps  38  and  44 ;   numeral  72  denotes the inlet of pump  70 ;   numeral  74  denotes the outlet of pump  70 ;   numeral  76  denotes the housing of pump  70 ; and   each of numerals  78  and  78 ′ denotes a gear of pump  70 .       
 
         [0117]    The foregoing description and illustrations of the embodiments of the invention has been presented for the purposes of illustration. It is not intended to be exhaustive or to limit the invention to the above description in any form. 
         [0118]    Any term that has been defined above and used in the claims, should to be interpreted according to this definition.