Patent Publication Number: US-6981285-B2

Title: Toilet and method of operation

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation of U.S. patent application Ser. No. 10/258,156 filed Oct. 18, 2002 now U.S. Pat No. 6,883,188, which is a 371 of PCT/US01/44102 filed Nov. 27, 2001 which claims priority of U.S. Provisional Patent Application No. 60/253,113 filed Nov. 28, 2000. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to toilets and, more particularly, to a toilet and toilet system that is particularly suitable for a boat, recreational vehicle (RV), bus or the like. 
   The toilet according to the present invention may either be of the vacuum type (such as generally shown in U.S. Pat. No. 5,621,924, the disclosure of which is hereby incorporated by reference), or the drop through type. 
   There currently exist in the marine and RV industries, vacuum toilets and gravity drop toilets that are foot pedal or lever operated. These are manually operated toilets where a flush valve is opened by the operator and remains open as long as the operator activates the pedal or lever. In the vacuum toilet, if the flush valve is open for too short a period of time, insufficient water may accompany the waste, which may increase the possibility of the system plugging. A short duration flush also limits the amount of vacuum utilized in the flush and reduces the force that macerates the waste, which also increases the possibility of the system plugging. If the flush valve is open for an extended period of time, then excessive water is utilized. Additionally, if a second flush cycle is activated before the full level of vacuum is restored, the reduced level of vacuum may not have sufficient force to macerate the sewage, and system plugging may result. 
   In gravity drop toilets, if the flush valve is open for too short a period of time, then repeated opening of the flush valve may be required to clear the toilet bowl. If the flush valve is open for an extended period of time, then excessive water is utilized and it increases the possibility that malodor from the holding tank may enter the bathroom via the flush valve. 
   Since these toilets are manually operated, the timing between the flush valve and water valve is fixed and allows only one residual water lever. While “dry camping” or in rough seas, a lower level of residual water is desirable. When water is plentiful or in calm seas, a higher level of residual water may be desired. 
   SUMMARY OF THE INVENTION 
   The toilet and toilet system of the present invention generally includes a flush lever assembly for either activating a flush cycle or activating an add water cycle, a base assembly including components of an electrically-operated flush valve, and an electronic assembly incorporating a microprocessor controller that controls operation of the system. The components are housed within a one-piece bowl/base combination formed entirely of china. The dimensions and materials of the toilet mimic those of a conventional residential toilet. 
   In operation, a flush lever of the flush lever assembly is displaceable from a neutral position toward either a “flush” position or an “add water” position. Each respective position activates an operation cycle under the control of the microprocessor controller. 
   In the “add water” cycle, the controller opens a water inlet valve to add water to the bowl. Time limits may be set for the cycle based on a water level, which is selectable by the operator. In the “flush” cycle, the controller opens the water inlet valve and an electrically operated flush valve to effect a flushing operation. The flush valve is generally held open for a set period of time and subsequently closed. The water valve is held open for a period of time that is dependent upon a refill level selected by the operator. 
   With the present invention, the operator initiates the flush cycle but does not control the duration. The flush cycle is controlled by the logic implemented by the microprocessor. The water valve is independently controlled from the flush valve. Water starts to flow into the bowl before the flush valve is opened, and the flush valve is opened for an optimum time period. As a consequence, the quality of the flush is improved. 
   A second flush before full vacuum is restored is prevented. Additionally, the microprocessor may monitor the vacuum level and prevents the second flush even if the flush lever is activated. 
   The operator may be provided with a choice of three residual water levels via a selection switch to match the current residual water requirements. 
   In an exemplary embodiment of the invention, a toilet suitable for a boat, recreational vehicle, bus or the like is provided with a base assembly including an electrically-operated flush valve that opens and closes a passage to a waste receiving area. A flush lever assembly includes a flush lever displaceable from a neutral position toward one of a “flush” position and an “add water” position, the flush lever initiating a flush cycle in the “flush” position and initiating an add water cycle in the “add water” position. A controller communicates with a water inlet valve, the flush valve and the flush lever assembly. The controller opens and closes the water inlet valve and controls a position of the flush valve in accordance with a position of the flush lever. In a preferred embodiment, the flush valve is a ball valve. 
   The flush valve is preferably displaceable between a sealed position and a full open position, wherein the controller controls the position of the flush valve through a programmed cycle from the sealed position to the full open position and back to the sealed position in accordance with the signal from the flush lever. In this context, the flush valve may include an open limit switch that detects when the flush valve is in the full open position and a closed limit switch that detects when the flush valve is in the sealed position. The flush valve may be mounted on a valve shaft with the flush valve further including a first cam lobe that engages the open limit switch when the flush valve is in the full open position and a second cam lobe that engages the closed limit switch when the flush valve is in the sealed position. 
   Additionally, the flush valve may further include a valve motor controlled by the controller and having a motor output shaft, a follower lever coupled with the valve shaft, and a cam lever engaging the follower lever at one end and the motor output shaft at an opposite end. 
   Preferably, the programmed cycle carried out by the controller opens the flush valve for a predetermined period of time during the flush cycle. In this context, the programmed cycle carried out by the controller may stage the opening of the flush valve. That is, the controller may begin opening the flush valve for a first predetermined period of time such as 0.1 seconds, then stop opening the flush valve for a second predetermined period of time such as 0.2 seconds, then continue opening until the flush valve reaches the full open position. 
   The flush lever assembly preferably includes an add water/flush switch coupled with the flush lever. The flush lever closes flush contacts of the add water/flush switch in the “flush” position and closes the add water contacts of the add water/flush switch in the “add water” position. The flush lever assembly may additionally include a water level switch communicating with the controller that enables the operator to select a water level in the toilet. Preferably, the water level switch includes a low position, a normal position, and a high position. In this context, the controller opens the water inlet valve during the flush cycle for a time that is based on the position of the water level switch. In a similar context, the controller limits a time of the add water cycle based on a position of the water level switch. The flush lever assembly may also include a mode switch that enables operator selection between the normal mode and a service mode. 
   In another exemplary embodiment of the invention, a flush valve assembly is provided for the toilet. The flush valve assembly includes an electrically-operated flush valve for opening and closing a passage to a waste receiving area. A controller communicates with a water inlet valve and the flush valve and serves to open and close the water inlet valve while controlling the position of the flush valve in accordance with a position of a flush actuating mechanism. 
   In yet another exemplary embodiment of the invention, a method of operating a toilet suitable for a boat, recreational vehicle, bus or the like includes the steps of (a) detecting a position of a flush lever in a flush lever assembly, and (b) controlling a water inlet valve and an electrically-operated flush valve that opens and closes a passage to a waste receiving area in accordance with a position of the flush lever by initiating a flush cycle in a “flush” position and initiating an add water cycle in an “add water” position. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other aspects and advantages of the present invention will be described in detail with reference to the accompanying drawings, in which: 
       FIG. 1  is a side view of an exemplary toilet according to the invention; 
       FIG. 2  is a top view of the toilet shown in  FIG. 1 ; 
       FIG. 3  is a front view of the toilet shown in  FIG. 1 ; 
       FIG. 4  is a detailed perspective view of a preferred embodiment of the flush lever assembly for the toilet of  FIGS. 1–3 ; 
       FIGS. 5–7  are perspective views of a preferred embodiment of a base assembly provided within a bowl and base combination of the toilet of  FIGS. 1–3 ; 
       FIGS. 8A and 8B  show an electrical schematic showing the interconnections between a microprocessor and various other components of a preferred electrical system used in the toilet and with the toilet system of  FIGS. 1–7 ; and 
       FIGS. 9A and 9B  are exemplary timing charts showing the operation of the toilet according to the present invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIGS. 1–3  show an exemplary toilet  10  (either vacuum or drop through) according to the invention having a substantially all china one-piece combination bowl and base  11 , with a conventional toilet seat  12  and cover  13  associated therewith. In exterior appearance, the toilet  10  generally resembles conventional toilets found in homes, businesses and the like. The toilet  10  includes a flush lever assembly  15  associated therewith incorporating an actuating lever  16 . An exemplary form of the flush lever assembly  15  is shown in more detail in  FIG. 4 . 
   The flush lever assembly  15  includes a shaft that may be rotated in either clockwise (flush) or counterclockwise (add water) directions about an axis (e.g., a substantially horizontal axis) by manipulating the actuating lever  16  to activate components mounted in the housing  19 . In an exemplary embodiment, an electrical switch is mounted at one end of the housing  19  and is actuated to close “add water” contacts or “flush” contacts depending upon the direction in which the shaft  18  is rotated by the lever  16 . Rotation of the shaft  18  causes an actuating lever  21  to be rocked from a neutral central position, against a centering spring bias, to either a “flush” contacts actuating position or an “add water” contacts actuating position. The closing of the “flush” contacts initiates a flush cycle as will be hereinafter described, while the closing of the “add water” contacts initiates an add water cycle as will also be hereinafter described to supply water to the bowl  11  when a flush valve such as a ball valve  33  (see  FIGS. 5–7 ) of the toilet  10  is closed. 
   The housing  20  includes a switching strip  22  extending outwardly therefrom that mounts a low/normal/high residual water level electrical switch  23  and a service mode/normal mode electrical switch  24 . The electrical interconnections between the switches  20 ,  23  and  24  and the rest of the components of the system are shown in  FIG. 8 . 
     FIGS. 5–7  show an exemplary base assembly  30  that may be utilized within the one-piece bowl/base combination  11  of  FIGS. 1–3 , below the interior bottom of the bowl portion thereof. A ring  31  provides bottom support for the assembly  30 , and an upper ring  32  provides a support for a flush valve  33  such as ball valve. The flush valve  33  is coupled to a valve shaft  34  that is driven by a motor  39  through a gearing assembly  40  via first and second levers or links  35 ,  36  interconnected by a pin  37 . The pin  37  is attached to the second lever  36  and slides in a track within the first lever  35  as shown in  FIGS. 5 and 6 . The flush valve  33  is rotated between a sealed position in which a passageway to a waste area is sealed and a full open position that opens a passage to .the waste receiving area. Pivotal movement of the lever  36  to rotate the shaft  34  (and thereby rotate the flush valve  33 ) is effected by rotation of the shaft  38 , which in turn is rotated by the motor  39 , such as a DC electric motor, through the gearing assembly  40 . 
   With particular reference to  FIG. 6 , the valve shaft  34  is preferably provided with a cam  43  mounted thereon, with cam lobes  44  extending radially outwardly therefrom. The lobes  44 , upon rotation of the valve shaft  34 , actuate a closed  45  or open  46  limit switch based on a position of the valve shaft  34 . That is, one cam lobe  44  engages the open limit switch  46  when the flush valve  33  is in the full open position, and the other cam lobe  44  engages the closed limit switch  45  when the flush valve  33  is in the sealed position. 
     FIG. 8  ( 8 A,  8 B) is an electrical schematic that shows the interconnections between the microprocessor inputs  48  and outputs  49  (which are preferably part of a single microprocessor), and other desired electrical components of the system, which are controlled by the microprocessor having the inputs  48  and outputs  49 . The electrical components include a “tank full” switch  51  associated with a conventional holding tank for the toilet system, and a “low vacuum” switch  52  associated with the conventional vacuum tank of the toilet system (when the toilet  10  is a vacuum toilet). The names/functions of the inputs  48  are shown in column  50  in  FIG. 8 , while the names/functions of the outputs  49  are shown in column  53 . In this context, the circuit diagram shown in  FIG. 8  is merely exemplary, and those of ordinary skill in the art may certainly contemplate alternative means for carrying out the microprocessor connections and functions according to the present invention. Thus, aside from the detail discussed above, no further description of the circuit diagram will be provided. 
     FIG. 8  additionally shows, generally at  56 , plugs and sockets associated with the microprocessor input  48 , including pins  57  and sockets  58 , labeled as seen in  FIG. 8  and associated with the names/functions in column  50 ′ corresponding to the names/functions in column  50 . The plugs and sockets shown generally at  60  are associated with the microprocessor outputs  49 , including sockets  61  and pins  62  at the bottom of  FIG. 8  and the names/functions in column  53 ′ correspond to the names/functions in column  53 .  FIG. 8  also shows switches from the flush lever assembly  15  including electrical switch  20 , water level switch  23 , and mode switch  24 . Additionally, limit switches  45  and  46  are also shown. 
   The microprocessor also communicates with a water inlet valve  65  that flows fresh water into the bowl during operation of the toilet system. 
     FIGS. 9A and 9B  show timing charts for operating modes of the toilet system according to the present invention. With reference to  FIG. 9A , a flush cycle is initiated when the flush lever  16  is rotated to close the “flush” contacts of the electrical switch  20 . During the flush cycle, the controller first opens the water inlet valve  65  to allow fresh water to flow into the bowl. As seen in  FIG. 9A , the amount of time that the controller keeps open the water inlet valve depends upon a position of the water level switch  23 . After opening the water valve for a short period of time, such as 2.1 seconds as shown in  FIG. 9A , the controller begins opening the flush valve  33  via the motor  39 . The motor  39  is activated to open the flush valve  33  until one of the cam lobes  44  engages the open limit switch  46 , signifying that the flush valve  33  has reached its full open position. The controller maintains the flush valve  33  in its full open position for a predetermined period of time (about 3 seconds in  FIG. 9A  after reaching the full open position). Subsequently, the motor  39  is driven in a reverse direction to close the flush valve  33  to its sealed position. 
   In a preferred embodiment, the controller effects opening of the flush valve  33  in stages to prevent any splash back of residual water out of the bowl. That is, with continued reference to  FIG. 9A , the controller effects opening the flush valve  33 . for a first predetermined period of time (e.g., 0.1 seconds shown in  FIG. 9A ), then stops opening the flush valve for a second predetermined period of time (e.g., 0.2 seconds shown in  FIG. 9A ), then continues opening until the flush valve  33  reaches its full open position. In this manner, any residual water splash back will contact the flush valve  33  and will not reach the exterior of the bowl. By partially opening the flush valve for a short duration, the vacuum level is reduced during the full opening by controlling the vacuum inlet via the flush valve. Additionally, any splash back will contact the underside of the flush valve and reduce or eliminate an amount that reaches the exterior of the bowl. 
     FIG. 9B  is a timing chart showing “add water” time limits for the add water cycle of the toilet system. The “add water” cycle is initiated when the flush lever  16  is rotated to close “add water” contacts of the electrical switch  20 . When the add water cycle is initiated, the controller effects opening of the water inlet valve  65  to flow water into the bowl. As seen in  FIG. 9B , time limits for the add water cycle vary based on a position of the water level switch  23 . In this manner, for example, if the water level switch  23  is set to a low position, thereby keeping the amount of water in the bowl at a low level, the bowl has additional capacity for the add water cycle, and the add water cycle time limit is higher (e.g., about 9 seconds in  FIG. 9B ). On the other hand, if the water level switch is set in a high position, the bowl has considerably less capacity for the add water cycle, and the add water time limit is significantly shorter (e.g., about 3 seconds in  FIG. 9B ). In a similar context, when the mode switch  24  is set to the service mode, the flush valve  33  is generally held open, and the add water time limit can be considerably longer (e.g., about 15 seconds in  FIG. 9B ). 
   With the system according to the present invention, an efficient operating toilet suitable for a boat, recreational vehicle, bus or the like is provided. A microprocessor controller controls the operation of the system to effect convenient and efficient operation. 
   While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.