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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     The present application is a continuation of U.S. application Ser. No. 12/620,021, filed Nov. 17, 2009, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The present invention relates to plumbing fixtures such as toilets and bidets which have a trapway extending from a lower outlet of their main bowl. In particular, it relates to automated outlet flush valves used therewith, and methods of positioning and calibrating actuators therefor. 
     Toilets are known which have a pivotable outlet flush valve between the bowl&#39;s lower outlet and a trapway extending therefrom towards the sewer system. See e.g. U.S. patent application publication 2008/0072372. As described in that publication, the pivot valve can be linked to an automated control system so as to control toilet flushing via that means. 
     However, using this type of system currently has a number of drawbacks. For one thing, the motor or other actuator system for the pivot valve is typically positioned so as to project laterally out from the trapway in a way that disrupts aesthetics, or uses up desirable lateral space. For another, motor systems attached thereto may present surfaces that can undesirably snag other items (e.g. during cleaning). 
     Moreover, when such pivotable flush valves are repetitively driven between hard stop open and closed positioned by motors, the life of the seal and motor assembly can be compromised absent use of more expensive materials. This can create maintenance issues, and/or undesirably increase the cost of the product to the consumer. 
     Hence, there is a need for improvements to address the above issues. 
     SUMMARY 
     One aspect of the present invention provides a plumbing fixture having a bowl with a lower opening. The lower opening is in selective communication with a trapway. The trapway has an upwardly extending leg linked to a downwardly extending leg, in switchback fashion. There is a space outside the trapway between the bowl and upwardly extending leg. 
     A flush valve is positioned between the lower opening and a portion of the trapway for controlling flow from the bowl through the trapway. The plumbing fixture further includes a valve actuator having a motor that is positioned at least in part in said space. There is also a linkage connected to the motor to be driven thereby. The valve actuator is also connected to the flush valve so that during a flushing cycle it can controllably move the flush valve between a first position in which the flush valve prevents fluid removal from the bowl via the trapway and a second, open position where fluid in the bowl is permitted to evacuate from the bowl through the trapway. 
     In preferred aspects of the present invention: 
     (a) the linkage may be a belt drive; 
     (b) the linkage may be at least in part located on a lateral side of the trapway; and/or 
     (c) the linkage may pivot the flush valve. 
     To control pivoting of the flush valve, a controller is placed in electrical communication with the motor. The controller defines a limited range of pivoting of the flush valve between a seal position and an open position. The controller establishes this limited range at least in part by identifying a high resistance seal position and then setting an operational seal position at a lower resistance seal position adjacent to the high resistance seal position. The controller also preferably establishes this limited range in part by identifying a high resistance open position and then setting an operational open position at a lower resistance open position adjacent to the high resistance open position. 
     According to another aspect of the present invention there is provided a method of setting up a plumbing fixture of the type described above. The method includes establishing a limited range of pivoting of the flush valve at least in part by identifying a high resistance sealing position and then setting an operational sealing position at a lower resistance sealing position adjacent to the high resistance sealing point. The method may further include establishing said limited range in part by also identifying a high resistance open position and then setting an operational open position at a lower resistance position adjacent to the high resistance open position. 
     To do this the motor may be run to pivot the flush valve in a first direction until the flush valve encounters a first obstacle (e.g. the valve seat), thereby defining a first calibration position. The motor may then be reversed to pivot the flush valve in a second direction until the flush valve encounters a second obstacle (e.g. a full open stop surface), thereby defining a second calibration position. 
     The amount of motor operation required to pivot the flush valve between said first and second calibration positions is determined from that movement. An operational sealing position is then defined between the calibration positions, but still at a position where the flush valve firmly contacts the valve seat (albeit with somewhat less force). For example, the system can count the number of motor pulses required to pivot the flush valve between the first and second calibration positions and use that number to help define the sealing position. For example, if 390 pulses were needed to move from the hard seal to the full open position, the system might define the operational seal as 388 back towards the hard seal from the full open. It might then define the less full open operational open position as 386 back from the operational seal position. 
     Hence, this patent provides more compact assemblies for plumbing fixtures having automated flush valves. By placing the motor of the valve actuator in the space between the bowl and a leg of the trapway, and developing a linkage which essentially parallels a lateral aspect of the fixture, the design is more aesthetically pleasing, it presents less risk of undesirably snagging items, and it uses up less space. 
     Further, by employing the methods of setting up the actuator/flush valve, maintenance issues are reduced and the use of higher cost materials is not required. 
     The foregoing and still other advantages of the present invention will appear from the following description. In that description reference is made to the accompanying drawings which form a part hereof and in which there is shown by way of illustration preferred embodiments of the invention. These embodiments do not represent the full scope of the invention. Rather, the claims should be looked to in order to judge the full scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a preferred toilet of the present invention; 
         FIG. 2  is partial cross-sectional view of the toilet of  FIG. 1 ; 
         FIG. 3  is a rear, top, side perspective view of the trapway and the attached valve actuator of  FIG. 1 ; 
         FIG. 4  is a side elevational view of the  FIG. 3  components; 
         FIG. 5  is a top plan view of the  FIG. 3  components; 
         FIG. 6  is an enlarged perspective view of a portion of the  FIG. 3  parts, with a belt drive cover shown removed; 
         FIG. 7  is an enlarged partial cross-sectional view of a part of the  FIG. 4  structure, showing how the parts would appear with the flush valve in the operational seal position; 
         FIG. 8  is a view similar to  FIG. 7 , but showing how the parts would appear when the flush valve is in the operational open position; 
         FIG. 9  is a flow chart of a preferred method of calibrating the actuator/flush valve; and 
         FIG. 10  is a cross-sectional view focusing on the flush valve positioning at various stages of the calibration method. 
     
    
    
     DETAILED DESCRIPTION 
     Referring first to  FIGS. 1 and 2 , a toilet  10  is shown that has a front section  12 , a backpack portion  14 , and a movable lid  16 . The front section  12  includes a bowl  18  extending from an upper rim  20  down to a lower opening  22 , which in turn connects to a trapway  24 . 
     An outlet flush valve  26 , which will be described in more detail below, is positioned between the lower opening  22  of the bowl  18  and the trapway  24  to place the two in selective communication with each other. There is a valve actuator  28  which is linked to the flush valve  26  and controlled by a controller  27  (see  FIG. 6 ). 
     In the most aesthetic forms of the invention there is an outer shroud  30  that envelopes the bowl  18 , the trapway  24 , and the valve actuator  28 . However, this is not required. A large number of other operational components including, but not limited to, a water tank, a battery backup, air circulators, and various electronic components, are housed in the backpack portion  14 . 
     With additional reference to  FIGS. 3-6 , the shape of the trapway  24  is serpentine/switchback. As the trapway  24  extends down from the lower opening  22  and towards a sewer connector  32 , the trapway  24  includes an entry  34  which in a conventional fashion then curves back up behind the bowl  18  to communicate with an upwardly extending leg  36 . 
     Then, the upwardly extending leg  36  then curves downwardly in switchback fashion to communicate with a downwardly extending leg  38 . This creates the usual weir  42  between the upwardly extending leg  36  and the downwardly extending leg  38 . When the toilet  10  is between flush cycles water will collect in the trap above point  40  of  FIG. 2  so as to prevent sewer gases from returning back to the bathroom. 
     It should particularly be appreciated that as shown in  FIG. 2  there is a space  60  outside the trap and bowl formed between the bowl and up leg  36 . This is where various portions of the actuating system are now positioned, as will be discussed below. 
     The preferred flush valve  26  has a generally arcuate sealing surface  44  which is pivotable about an axis of rotation A-A in  FIG. 6 . As best understood from  FIG. 10 , the generally arcuate sealing surface  44 , depending on the pivotal position of the flush valve  26 , can be placed in sealing contact with the valve seat  46  to form a seal between the bowl  18  and the trapway  24 , or alternatively moved sufficiently away from that lip to permit the bowl to evacuate. 
     The preferred valve actuator  28  includes a motor  48  that is in electrical communication with the controller  27 , a first rotatable member  50  attached to the motor  48 , a second rotatable member  52  attached to the flush valve  26 , and a drive belt  54  extending between the first and second rotatable members  50 / 52 . A tensioning element  56  can be located along the drive belt  54  so as to provide improved tensioning force to keep the drive belt  54  in tension. A guard cover  58  is placed around the drive belt  54  and the rotatable members  50  and  52 . 
     While the most preferred drive is a belt drive system, it should be appreciated that other drive systems and/or linkages may also be provided for the valve actuator  28 . For example, a chain and sprocket type drive system might be used. 
     The motor  48  is largely positioned in the space  60 . This presents an extremely compact assembly. However, by doing this, one still needs to translate the motion provided by the motor to movement of the flush valve. This is achieved by the use of the belt drive, which essentially parallels the front-to-back axis of the toilet, albeit on a lateral side of the trap. 
     Referring next to  FIGS. 7 and 8 , the operation of the flush valve  26  is illustrated. In these figures, the flush valve  26  is illustrated in phantom lines. 
     In  FIG. 7  the flush valve  26  is positioned in an operational seal position in which the arcuate sealing surface  44  of the flush valve  26  contacts the lip of the valve seat  46  to form an effective seal between the bowl  18  and the trapway  24 . The flush valve  26  will be located in this position between flush cycles so as to retain a pool of water in the bowl  18 . If the flush valve  26  is not already in this position, then the flush valve  26  can be moved or pivoted to this position by running the motor  48  such that the drive belt  54  is driven in a clockwise manner, relative to the view of the valve actuator  28  is illustrated in  FIG. 7  and as indicated by motion arrows on  FIG. 7 . 
     In  FIG. 8  the flush valve  26  is shown as positioned in the open position in which the arcuate sealing surface  44  of the flush valve  26  has been pivoted to break the seal between the arcuate sealing surface  44  and the lip of the valve seat  46 . The flush valve  26  is typically moved to this position during a flush cycle such that, when the valve is open, the bowl  18  and the trapway  24  are placed in fluid communication with one another. When open, fluid and waste in the bowl  18  will be evacuated through the flush valve  26 , into the trapway  24 , out of the sewer connector  32 , and into an attached sewer line. To move from a sealed position to an opened position, the drive belt  54  may be driven in a counter-clockwise direction relative to the view of the valve actuator  28  shown in  FIG. 8  and as indicated by the motion arrows on  FIG. 8 . 
     Now with reference to  FIGS. 9 and 10 , methods  100  of setting up/calibrating the flush valve  26  are schematically illustrated. A calibration sequence may be run at the factory, or the system may be set up so that periodically it can be rechecked after installation. For example, a sensor could be provided that determines whether the system is leaking water into the trapway between flushes. When that is sensed, a calibration cycle can be run to reset the seal position. 
     However, the major purpose of the calibration system is to set the operational seal and operational open positions slightly away from the full hard stop positions, to reduce wear and thus maintenance problems. According to the methods  100 , at least one, and preferably two, hard stop or high resistance positions are determined, and then at least one, and preferably two, operational positions are determined based thereon. 
     To determine the first hard stop or high resistance position (e.g. the valve seat), the motor  48  is run in a first direction until the flush valve  26  hits the valve seat with high resistance at position  1  according to step  110 . At this point, a first position of reference has been determined which corresponds to one extreme of the pivotal range of the flush valve  26 . 
     Then, the other extreme of the pivotal range of the flush valve may be determined. The motor  48  may be run in the reverse direction from the first direction according to step  112  until the flush valve  26  runs into a second high resistance position at position  2 , corresponding to the full open, according to step  114 . 
     Motor pulses are counted over this distance. For example, during the reversal of the motor  48  according to step  112 , the motor  48  may be “pulsed” to incrementally run the flush valve  26  step-wise over the arcuate path of the flush valve  26 . These pulses may be counted to determine the number of pulses between positions  1  and  2  and to evaluate the equivalent distance therebetween according to step  116 . 
     From this value, a position  3  may be set which is effective for sealing, but not quite as pivoted as for position  1 . This corresponds to an operational sealing position. One may also then set an operational open position  4  which is almost, but not quite as pivoted, as for position  2 , according to step  118 . 
     The operational sealing position is a position that is adjacent the high resistance sealing point at position  1 , but is slightly offset such that it is at a lower resistance. Likewise, the operational open position is a position that is adjacent the high resistance open position at position  2 , but at which again is at a lower resistance. During subsequent actuation of the flush valve  26 , the valve is actuated between positions  3  and  4 , thereby avoiding slamming against the stops. 
     If the motor  48  is using a pulse count to determine the pivotal distance and/or the positions  3  and  4 , then the calculation step  118  may operate according to the following example. As the number of pulses between positions  1  and  2  will be known after step  116 , the positions  3  and  4  which correspond to locations inwardly angularly offset from the high resistance positions of  1  and  2  may be determined according to step  118  using simple arithmetic. 
     For example, the number of pulses from position  2  (the second hard stop) back to position  3  (which may be a pulse away from the first hard stop at position  1 ) may be the counted number of pulses minus one pulse. The number of pulses to then go from position  3  (offset from position  1 ) to position  4  (offset from position  2 ) may be the counted number of pulses from position  1  to position  2  minus two pulses. 
     It should be appreciated that while counting pulses is one way of estimating/evaluating the amount of the pivotal range between two high resistance points and two operational points, that other ways of determining the spatial position of the flush valve  26  may be used such as sensors or non-incremental evaluation means. 
     Thus, plumbing fixtures having compact and aesthetically pleasing valve actuating systems are disclosed. Also disclosed are methods of calibrating movement of flush valves pivoted by such systems to reduce maintenance issues. 
     Also, by reducing the footprint of the actuation mechanism, such toilets can be used in many environments where there previously was not enough space in the bathroom to do so. Alternatively, saving space through the techniques of the present invention may provide extra space for the incorporation of other features with the fixture. 
     While a specific embodiment of the present invention has been shown, various modifications falling within the breadth and scope of the invention will be apparent to one skilled in the art. For example, similar principles could be applied to bidets. Thus, the invention should not be considered limited to just the embodiments of the drawings. Rather, the claims should be looked to in order to understand the full scope of the invention. 
     INDUSTRIAL APPLICABILITY 
     Disclosed are plumbing fixtures having automated bowl outlet flush valves, where the actuator therefor is compactly positioned and linked. Also disclosed are techniques for reducing maintenance problems with flush valves of this type.

Summary:
Plumbing fixtures with a valve actuator for automatically controlling pivoting of a flush valve, and methods of calibrating movement of the flush valve, are disclosed. The motor of the valve actuator may be positioned between the bowl of the fixture and a leg of a trapway to provide compact assembly. A belt drive laterally extending along the trapway links the motor to the flush valve. The method of calibrating includes establishing stop points which are at positions of less resistance than hard stop positions.