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[0001]    This application claims priority to and incorporates by reference U.S. Provisional Application Serial No. 60/358,108 filed Feb. 21, 2002. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to plumbing for toilet tanks, and more specifically provides an alarm system that detects and indicates a failure mode in a toilet&#39;s operation while minimizing the alarm&#39;s exposure to water and associated corrosion.  
         BACKGROUND OF THE INVENTION  
         [0003]    In many standard toilet systems, a water reservoir, or tank, is mounted adjacent to and above the bowl. When the toilet is flushed, an exit valve at the bottom of the tank is opened, allowing water from the reservoir to flow into the bowl. While the water level decreases, an inlet valve is opened and replacement water is allowed to flow into the holding tank at a rate typically slower than the rate at which water is exiting the tank. The water leaving the tank enters the bowl, causing the water level in the bowl to increase, which, in turn, causes the water in the bowl to flow over a inverted-U in the bowl exit pipe and drain to the sewer. After the correct amount of water has exited the toilet tank, the exit valve closes stopping the water outflow and the replacement water fills the reservoir. Once the water level in the reservoir has reached a sufficient height, the water inlet valve is closed stopping the inflow of water into the reservoir.  
           [0004]    During normal operation, the valves operate and the water flow begins and ends automatically. However, a failure condition can occur when either the tank exit or inlet valves fail to close properly. If the tank exit valve fails to close correctly, water can continue to flow out of the tank indefinitely until it is noticed and fixed. This can lead to a significant waste of water if not noticed quickly. If this failure occurs when the bowl exit pipe is blocked, the water continuously entering the bowl will cause the bowl to overflow. Another failure occurs if the tank inlet valve fails to close while the tank exit valve closes properly. In this situation, the water level in the tank will cause the tank to overflow, flooding the surrounding area. This can cause significant damage and also waste water if not noticed.  
           [0005]    Some prior art designs have attempted to address these problems, but have required complex mechanical assemblies and/or electrical systems. Prior electrical systems, such as disclosed in Kirby, U.S. Pat. No. 3,984,877, have including electrical components within the tank, subjecting the pieces to water damage and the risk of rust or a short-circuit. Other systems have placed water sensors on the outside of the tank and bowl, but these systems react only after flooding has occurred and, furthermore, do not detect conditions where there is no obstruction in the exit pipe from the bowl. Examples of these systems are Quintana, U.S. Pat. Nos. 6,367,096, 6,178,569, and 6,058,519, and Mankin, U.S. Pat. Nos. 6,052,841 and 5,940,899. Yet other systems disclose annunciators designed to train people in toilet etiquette, such as Maehre, U.S. Pat. No. 6,028,520, but do not provide any warnings for toilet malfunctions.  
           [0006]    Accordingly, there is a need for a reliable and easily installed system to provide a warning of a toilet failure. The present invention addresses these concerns and others.  
         SUMMARY OF THE INVENTION  
         [0007]    Preferred embodiments of the present invention provide a system that is mounted to a toilet tank reservoir that triggers an alarm if a malfunction occurs in either the toilet tank exit or inlet valves. Alternate preferred embodiments and features provide for an alarm that actuates valves to correct a toilet malfunction, while still other preferred embodiments provide for a system that can control the normal operations of the toilet.  
           [0008]    In one preferred embodiment, a buoyant magnetic device floats near the top of the water level in the toilet tank and sensors mounted externally to the tank detect various positions of the buoyant device as the water level increases and decreases. A guide member is used to hold the buoyant device near the side of the tank where the sensors are mounted. The sensors are typically mounted above the normal high water level and below the normal low water level such that they will not be activated by the proximity of the buoyant device unless a malfunction has occurred. Once an unusual water level has been detected by the sensors, an alarm is activated alerting people to the malfunction.  
           [0009]    In an alternate preferred embodiment, when the sensors detect an abnormal water level in the tank, valves are automatically operated to correct the malfunction. In still other preferred embodiments, normal operation of the toilet tank inlet and exit valves are controlled by the sensors and the buoyant magnetic device.  
           [0010]    It is one preferred object of the present invention to provide an easily installed system that activates an alarm after a toilet malfunction is detected. It is an alternate preferred object of the present invention to provide a system that can correct a toilet malfunction or control the normal operations of a toilet.  
           [0011]    Other objects and advantages of preferred embodiments of the present invention shall be apparent from the accompanying drawings and description.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a perspective cut-away view of a toilet reservoir tank with a preferred embodiment of the present invention installed.  
         [0013]    [0013]FIG. 2 is a cut-away view of a preferred embodiment of the present invention.  
         [0014]    [0014]FIG. 3 is a perspective cut-away view of a toilet reservoir tank with an alternate preferred embodiment of the present invention installed.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]    For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations, modifications, and further applications of the principles of the invention being contemplated as would normally occur to one skilled in the art to which the invention relates.  
         [0016]    A common toilet design is one that utilizes a water tank to accumulate water before flushing. When a flush cycle is initiated, the tank exit valve is opened, allowing water to flow from the tank to the toilet bowl and across an inverted-U in the exit pipe from the bowl. When the water level in the tank depletes to a predetermined level, a tank inlet valve is opened to allow replacement water to fill the tank. When the water level in the tank depletes to a second preset level, the tank exit valve closes, allowing replacement water flowing through the open tank inlet valve to fill the water tank. When the water level in the tank increases to another preset level, the tank inlet valve is closed, stopping the flow of replacement water into the tank.  
         [0017]    In preferred embodiments of the present invention, an alarm is provided that actuates when a malfunction has occurred in the normal flushing cycle of a toilet. The definition of alarm is intended to include a variety of actuation devices, such as audible signals, visual signals, and automatically actuated valves. In one preferred embodiment, actuation of the alarm results in the transmission of visual and/or audible signals to alert people of the malfunction. In another preferred embodiment, actuation of the alarm results in the actuation of tank inlet and/or exit valves to automatically stop the intake of water into the tank, or the exit of water from the tank, when a malfunction is detected. In a preferred feature, the present invention indicates a malfunction with a magnetically triggered switch which actuates the alarm. Still other preferred embodiments incorporate a timer whereby the alarm, or automatic shutoff, occurs a specified time after the invention detects a particular toilet condition, such as when the water is mostly emptied from the tank.  
         [0018]    Illustrated in FIGS. 1 and 2 is a preferred embodiment of the present invention within a toilet tank. The apparatus includes a guide cylinder  11  having a length designed to be vertically oriented within the tank. Guide cylinder  11  is designed to be set with one end a short distance above tank bottom  12  and extends vertically to above the top of fill line  13 , near the top of the tank. In a preferred embodiment, guide cylinder  11  is approximately ½ inch above tank bottom  12  and extends to approximately 1 inch above fill line  13 , although other cylinder dimensions and placements may also be desirable. Fill line  13  is typically marked on either the inside of the tank or on exit valve support structure  14  and corresponds to the desired water level in the tank. Exit valve support structure  14  is attached to tank exit valve  15  which is designed to seal tank drain port  30  in tank bottom  12 .  
         [0019]    Within guide cylinder  11  is buoyant element  16  with a diameter sized to effectively slide freely within guide cylinder  11 . Within buoyant element  16  is magnet  17 . Some preferred embodiments include more than one magnet  17 , while other preferred embodiments include more than one buoyant element  16 . Buoyant element  16  is preferably buoyant with regard to the water level within guide cylinder  11 , and in one preferred embodiment is encapsulated at both ends. As the level water within the tank rises, buoyant element  16  will rise within guide cylinder  11 . Conversely, as the water level within the tank drops, buoyant element  16  will be lowered. Guide cylinder  11  is preferably held in place by bracket  18 , which is designed to hold guide cylinder  11  in a vertical orientation. Bracket  18  is attached to U-shaped bracket  25  which is mountable over an external wall of the tank.  
         [0020]    A sensor mounting member is mounted externally to the tank substantially parallel to guide cylinder  11  and held in place by attachment to the opposing end of U-shaped bracket  25 . An example sensor mounting member is depicted in sensor mounting rail  24 . Mounted on sensor mounting rail  24  are lower sensing device  20  and upper sensing device  21 . Upper sensor  21  is mounted within upper sled  23  on rail  24 , and lower sensor  20  is mounted within lower sled  22  on rail  24 . Preferably, lower and upper sleds  22  and  23  are adjustable along sensor mounting rail  24 . In one preferred setup, upper sled  23  is positioned at a point approximately ½ inch above water fill line  13  and lower sled  22  is positioned adjacent a point approximately 1 inch from tank bottom  12 . Upper sled  23  should be positioned at a maximum height equal to the top of support structure  14  if support structure  14  includes a spill-over drain. In alternate preferred embodiments, sensors  20  and  21  are independently mountable to the toilet tank by various means, such as, but not limited to, separate rails, friction, glue, suction cups, and hook and loop fasteners.  
         [0021]    Sensors  20  and  21  are electrically connected to an energy source  26 , such as a battery, and audible/visual alarm  27 . In one preferred embodiment, energy source  26  and alarm  27  are mounted within housing  28 . The alarm may be a buzzer, bell, beeper, solid or flashing light, or other standard signaling method. In other embodiments, alarm  27  includes automatically actuated valves. An example of automatically actuated valves is depicted in FIG. 3 wherein tank exit valve actuator  33  (for example a solenoid which opens or closes tank exit valve  15 ) and tank inlet valve  43  are automatically actuated after sensors  20  and  21  detect an appropriate condition for their actuation.  
         [0022]    In operation, buoyant element  16  moves upward and downward with the changing water level in the tank. When magnet  17  is in an appropriate zone or location relative to sensor  20  or  21 , such as adjacent to sensor  20  or  21 , sensor  20  or  21  detects the change in the local magnetic field caused by magnet  17  and activates a circuit which actuates alarm  27 . The plumbing system can then be fixed and/or reset as desired. Alternate preferred embodiments may include other means for detecting the proximity of the buoyant element  16  to sensors  20  and  21 , such as optic, radio, audio, infrared, or motion detection means.  
         [0023]    In normal operation, the flushing cycle of a toilet is initiated by rotating flushing device  29 . Movement of flushing device  29  causes tank exit valve linkage  31  to lift tank exit valve  15  off of tank drain port  30 , thereby allowing water to flow out of the tank past tank drain port  30  and through a fluid transport member that transports fluid from the tank, or fluid extraction member. Tank exit valve linkage  31  is connected to tank exit valve  15  and is steadied by linkage guide  32 . An example of this type of fluid transport member is depicted in tank drain tube  39 . Thus, the water level in the tank decreases. Inlet valve float  42  floats on the water surface, and when the water level decreases past a preset location, the lowering of inlet valve float  42  causes tank inlet valve  41  to open allowing replacement water to enter the tank through a fluid transport, or supply, member. An example of a fluid transport member is depicted in replacement water supply tube  40 . Replacement water enters the tank at a slower rate than the water exits through the tank drain port, thus, the tank continues to drain despite inlet valve  41  being open. Once the water level has drained until approximately 1 to 2 inches of water remain in the bottom of the tank, tank exit valve  15  (alternately a “flapper” valve) lowers due to gravity, resealing tank drain port  30 . Water entering via replacement water supply tube  40  and through tank inlet valve  41  fills the tank until inlet valve float  42  reaches a predetermined location where it causes inlet valve  41  to close, thereby stopping the addition of water to the tank.  
         [0024]    In a tank exit valve failure, the toilet is flushed and the water in the tank is drained, but for whatever reason, tank exit valve  15  does not close properly with tank drain port  30 . When this occurs, the water level continues to decrease toward tank bottom  12 , thereby causing buoyant element  16  to be lowered to the bottom of the tank adjacent to lower sensor  20 . After lower sensor  20  detects the proximity of buoyant element  16 , alarm  27  is activated.  
         [0025]    In a tank inlet valve failure, tank inlet valve  41  does not shut off when inlet valve float  42  reaches the predetermined position near the top of the tank, but tank exit valve  15  closes properly. Under this condition, the replacement water continues to fill the tank above water fill line  13 , causing buoyant element  16  to float to a position adjacent upper sensor  21 . Magnet  17  in buoyant element  16  activates upper sensor  21 , triggering a visual or audible alarm.  
         [0026]    In a further alternate embodiment, depicted in FIG. 3, alarm  27  includes a system that automatically actuates tank exit valve  15 , tank inlet valve  19  and/or tank inlet valve  43 . The system can utilize various means for operating the valves, such as mechanical or electrical. The automatic actuation of valves can be separate from or in addition to a visual or audible alarm and can be used for normal operations, during a malfunction, or a combination of the two.  
         [0027]    When used to control normal operations, tank inlet valve  43  opens when buoyant element  16  either descends below upper sensor  21  or descends to the location of lower sensor  20 , depending on the specific implementation. Similarly during normal operation, after tank exit valve  15  is opened to begin a flush cycle, tank exit valve  15  closes when buoyant element  16  descends to the location of lower sensor  20 .  
         [0028]    In other preferred embodiments, automatic valve actuation assists to correct a malfunction. For example, during a tank exit valve malfunction in which a buoyant tank exit valve fails to properly close, tank exit valve actuator  33  (for example a solenoid) is actuated to provide a back-up means of closing tank exit valve  15  when lower sensor  20  is sufficiently affected by the proximity of buoyant element  16 . Thus, tank exit valve  15  is forcibly closed and the tank water level is allowed to increase.  
         [0029]    Since different toilet manufacturers will have varying water levels where the tank exit valve and the tank inlet valve are actuated, sensors  20  and  21  are preferably adjustable on sensor mounting rail  24 . Alternately, sensors  20  and  21  can be adjusted to trigger alarm  27  each time the system is cycled to ensure that the cycle was completed correctly or that the energy source, such as a battery, is still charged.  
         [0030]    In an alternate embodiment, a timing mechanism (not depicted) is incorporated into the system whereby the alarm activates after buoyant element  16  has remained within the appropriate zone of activation around either sensor  20  or  21  for a preset time period. In other preferred embodiments, different sensors are associated with different present time periods resulting in different delay times depending on which sensor detects the buoyant element.  
         [0031]    Preferably, the system of the present invention may be manufactured using standard materials and off-the-shelf components, such as extruded or molded plastic pieces, automatically actuated valves, magnets and electrical sensors, with the internal portions being water resistance and all of the electronic circuitry being external to the tank.  
         [0032]    While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

Summary:
The present invention relates to plumbing for toilet tanks, and more specifically provides an alarm system for indicating a failure mode in a toilet tank&#39;s operation. One preferred embodiment of the present invention utilizes a floating magnet and sensors positioned near the top and bottom of the tank which activate an alarm when the magnet becomes sufficiently close to either sensor. The alarm can be audible or visual. In other preferred embodiments, the alarm closes the tank inlet valve or the tank exit valve to control normal operations, or to correct malfunctions.