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RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/843,605 filed on Jul. 8, 2013. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to a system to mete an amount of a fluid, such as a treating or cleaning fluid, and dispense the fluid to a desired location. The meting system utilizes hydraulic and air pressure equalization in another fluid system having a liquid substance that has a cyclical or intermittent rise and fall in volume or level, such as a toilet tank, to mete the amount of fluid. 
         [0004]    2. Description of Related Art 
         [0005]    There are numerous known devices for dispensing an amount of fluid to a desired location. Many of these devices rely on mechanical or electrical components to dispense the fluid, including electrical pumping systems, mechanical pumping systems, and rotating feeder systems. Failure of these devices can result from malfunction of the moving parts or disruption of power. Many different applications benefit from periodic dispensing of treating or cleaning fluids, such as toilets and septic systems, swimming pools and spas, industrial cooling towers, and insect control systems. For example, relatively complex spraying devices are commercially available for automatically spraying a cleaning fluid into a toilet bowl. These devices have the disadvantage of requiring a power source and having moving parts that are more susceptible to malfunction. Other devices that do not require power, but still involve moving parts, are also known. For example, U.S. Pat. No. 4,896,382 discloses a device that sits on the bottom of a toilet tank and has a float device to regulate air flow when the toilet is flushed to dispense cleaning solution. 
         [0006]    Other devices, such as that disclosed in U.S. Pat. No. 3,769,640, do not have moving parts or require power, but are designed for use with solid cleaning chemicals that slowly dissolve upon contact with the water in the toilet tank. The use of solid chemicals dissolved in water may result in varying concentrations of the resulting solution being dispensed. Additionally, many of these types of devices dispense the cleaning fluid directly into the toilet tank, where cleaning is not particularly needed and where the corrosive nature of some cleaning products may damage the internal components of the tank, when it is most desirable to dispense to the toilet bowl where cleaning is desired. It is desirable to have a simple apparatus without moving parts or requiring a power source for operation, to dispense an amount of such cleaning or treating fluids with greater ability to control the concentration of the cleaning or treating fluid in the fluid or water source to which it is dispensed and ability to dispense the cleaning or treating fluid directly to an area to be treated, such as a toilet bowl. 
       SUMMARY OF THE INVENTION 
       [0007]    A non-mechanical, non-electrical system according to the invention allows a known or pre-determined amount of cleaning or treating fluid to be dispensed to achieve a given concentration in the fluid or water source being treated. The system is useful in fluid tanks, reservoirs, and fluctuating hydraulic fluid systems, such as a toilet tank, having cyclical or intermittent changes in liquid volume and corresponding changes in gas (usually air) volume. One preferred embodiment of the invention comprises a set of chambers connected together by tubing, one chamber holding a cleaning or treating fluid and the other having a liquid or water level that changes with the changing volume of liquid or water in the fluid tank. Through hydraulic and air pressure equalization, an amount of cleaning or treating fluid is dispensed each time the volume in the fluid tank changes. 
         [0008]    According to another preferred embodiment, a second tube connects the chamber holding the cleaning or treating fluid to a desired dispensing location, which is most preferably located remotely from the fluid tank in which the apparatus is used. For example, the second tube may dispense the cleaning or treating fluid directly into a toilet bowl after a flush and as the bowl is filling, which allows for greater residence time of the cleaning or treating fluid within the bowl between flushes and prevents contact between the cleaning or treating fluid and the internal components of the toilet tank, which may cause corrosion or otherwise be damaging to those internal components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The system of the invention is further described and explained in relation to the following drawings wherein: 
           [0010]      FIG. 1  is a perspective view of one embodiment of a chemical meting system according to the invention; and 
           [0011]      FIG. 2  is cross-sectional view of the system of  FIG. 1 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0012]    Referring to  FIGS. 1-2 , one preferred embodiment of a meting apparatus  10  for use in a tank holding a variable volume of liquid and gas (air) is depicted. Meting apparatus  10  preferably comprises a first chamber  12  connected to a second chamber  14  by tubing  20 . The first chamber  12  is a hydraulic equalization chamber. The second chamber  14  is a chemical meting chamber and holds an initial volume of cleaning or treating fluid. References herein to a cleaning or treating or treatment fluid or solution or the like include any substance that provides a cleaning, treating, disinfecting, or air freshening effect at a desired dispensing location and may include chemicals and/or biological (such as bacterial) components. First chamber  12  preferably comprises a first valve  16  and second valve  18 . Tubing  20  is connected to second valve  18 . Tubing  22  is connected to second chamber  14  by outlet port  34 , with its other end being directed to a desired location for dispensing an amount of cleaning or treating fluid from second chamber  14 . 
         [0013]    First chamber  12  and second chamber  14  are preferably cylindrical, but other shapes and varying sizes may be used. Any materials may be used for chambers  12  and  14 , but they should be suitable for contact with the liquid (and gas) in the fluid tank in which apparatus  10  will be used. Additionally, the material for chamber  14  should be suitable for the contact with the cleaning or treating fluid it will hold. An opening  26  is disposed at the lower end of chamber  12  to allow fluid communication between the liquid in the tank, reservoir, or other fluid system in which apparatus  10  is to be located and the interior of chamber  12 . Opening  26  may be the entire lower end of chamber  12  or it may be a smaller opening in or near a bottom surface of chamber  12 . Valves  16  and  18  are disposed on an upper end  30  of chamber  12 , with upper end  30  otherwise being sealed. Valves  16  and  18  are one-way valves. Valve  16  is a check valve that permits gas (usually air) from the tank (not depicted) in which apparatus  10  is used to enter chamber  12 . Valve  18  permits gas from chamber  12  to enter chamber  14 , but prevents backflow of cleaning or treating fluid from chamber  14  into chamber  12  (which is open to the liquid in the tank). Valve  18  is connected to tubing  20  to permit fluid communication of gas from the first chamber  12  to the second chamber  14 . Tubing  20  is most preferably made from rigid tubing material, but other materials may be used. Chamber  14  preferably comprises inlet port  32  to connect to tubing  20  and outlet port  34  to connect to tubing  22 . Either or both of ports  32  and  34  may be separate parts or may be unitarily molded with chamber  14 . Outlet port  34  also connects to tubing  36  that extends to the lower end of chamber  14  so that substantially all of the cleaning or treating fluid may be dispensed over the course of repeated dispensing cycles. 
         [0014]    Chamber  14  may also have a removable closure  24  to allow chamber  14  to be opened and periodically re-filled with cleaning or treating fluid. Closure  24  may have other shapes and may form part of a larger removable lid on chamber  14 . When a larger lid is used, one or both of ports  32  and  34  may be disposed on the lid or unitarily molded as part of the lid. Various configurations for closure  24  (or the alternative lid), such as twist-off, compression, pop top, heat sealed or sonic welded, may be used. Alternatively, apparatus  10  may be packaged and sold with chamber  14  pre-filled with cleaning or treating fluid and designed so that the entire apparatus  10  is disposed of and replaced with a new apparatus  10  when the volume of fluid in chamber  14  is depleted. Alternatively, chamber  14  may be separately packaged and sold as a pre-filled product that is disposed of when the fluid in chamber  14  is depleted at the end of treatment cycle and replaced with a new chamber  14 , with chamber  12  and/or tubing  20  or  22  remaining in the fluid tank for reuse over a number of treatment cycles. Those of ordinary skill in the art will understand the various removable closures that may be added to chamber  14  and/or ports  32  and  34  to seal its contents for shipping and sale until it is time to use apparatus  10 , as well as quick connect fittings that may aid in connecting chamber  14  to the rest of apparatus  10  if chamber  14  is disposed of at the end of a treatment cycle and replaced with another pre-filled chamber to start a new treatment cycle. 
         [0015]    In use, apparatus  10  is preferably placed in a tank (not shown) containing a variable volume of liquid and gas (air), such as a toilet tank. During normal use or operations, the tank varies between a substantially pre-set high level and low level of liquid. Opening  26  in chamber  12  should be located in the tank so that it is below the high liquid level in the tank, so that when the tank is at a high level state, liquid from the tank partially fills chamber  12  through opening  26 . However, chamber  12  should be located such that the lower end of valve  18  (disposed inside chamber  12 ) is not submerged when the tank is at the high level state. Similarly, the upper end of valve  16  should be located above the high liquid level in the tank. In the preferred configuration depicted in  FIGS. 1-2 , if the lower end of valve  18  is above the high liquid level then the upper end of valve  16  is also above the high liquid level. Most preferably chamber  12  is located so that opening  26  is located between the high and low liquid levels in the tank. Either or both of chambers  12  or  14  may be pre-marked with a desired location for the where the high liquid level should contact apparatus  10  to make installation of apparatus  10  easier. 
         [0016]    When properly located in the fluid tank, chamber  12  is partially filled with liquid from the tank when in the high level state (such as when the toilet is not being flushed). When the liquid level in the tank drops (such as when the toilet is flushed), the liquid level in chamber  12  also drops and the pressure change causes the space inside chamber  12  between the liquid line and the upper end  30  to fill with gas (usually air) from the tank through valve  16 . It is possible that the liquid level in the tank relative to opening  26  would drop low enough that gas may also enter chamber  12  through opening  26 . That does not interfere with operation of apparatus  10 . When the liquid in the tank rises again, the liquid level in chamber  12  also rises and the pressure causes gas to exit chamber  12  through valve  18 , tubing  20 , and to enter chamber  14 . The air entering chamber  14  displaces the cleaning or treating fluid in chamber  14 , causing it to be dispensed through tubing  36 , outlet port  34 , and tubing  22  to a desired location. When used as a cleaning solution in a toilet tank, tubing  22  preferably dispenses cleaning fluid from chamber  14  directly into the toilet bowl, such as through the refill or overflow tube, rather than into the toilet tank. When used as a treating solution for a septic tank, tubing  22  may dispense the treatment fluid from chamber  14  to a location near the tank flapper so the treatment is flushed from the toilet to the septic tank. 
         [0017]    When the pressure equalizes and the liquid in the tank has returned to (or near) the high level state, no further gas is pushed from chamber  12  to chamber  14  and the dispensing of cleaning or treating fluid stops until the next cycle of volume change in the fluid tank. With minor variations, the same amount of cleaning or treating fluid is dispensed from chamber  14  during each cycle. Those of ordinary skill in the art will understand how the size of the apparatus, the concentration of cleaning or treating fluid in chamber  14 , and/or the operating conditions (such as the variance between the tank&#39;s high and low fluid levels) may be modified to alter the amount/volume of cleaning or treating solution dispensed from chamber  14  during each cycle or to alter the concentration of cleaning or treating fluid finally obtained when the dispensed amount is mixed with other liquid receiving the treatment (such as the water in a toilet bowl). 
         [0018]    Most preferably, tubing  22  delivers the treatment or cleaning fluid to a location for treatment or cleaning outside of the tank in which apparatus  10  is being used. For example, when used in a toilet tank, tubing  22  preferably delivers the treatment or cleaning fluid directly into the refill or overflow tube so that it is discharged into the toilet bowl at the end of a flush (after the tank is emptied or substantially emptied and the bowl is filling), rather than discharging it inside the toilet tank. This provides several benefits for the system in which apparatus  10  is being used. Two of these benefits are longer residence time for the treatment or cleaning fluid within the discharge area that requires treatment (such as the toilet bowl) and reduced product load necessary to achieve the same functional effect (such as cleaning, treating, disinfecting, and/or air freshening), because the treatment or cleaning fluid is not being flushed out of the system as it would if it were discharged into the tank. This allows for more efficient usage of the cleaning or treating fluids, allowing smaller quantities and/or concentrations of active ingredients to be used and providing a cost savings over prior art systems that put the cleaning or treating fluid into the tank. Another benefit is that it eliminates the contact between the chemicals, biologicals, disinfectants or other cleaners that may be part of the treatment or cleaning fluid and the internal components of the tank in which apparatus  10  is used, as the treatment or cleaning fluid may be corrosive or otherwise damaging to the internal components of the system in which apparatus  10  is used. Although there is brief contact with the interior of the refill or overflow tube, the prolonged contact with the other internal components of the tank that occurs with prior art systems that dispense the cleaner or treatment into the tank is avoided. 
         [0019]    It is preferred that chambers  12  and  14  be located in close proximity to each other, but that is not necessary provided the tubing  20  is of sufficient length to connect the two chambers. Additionally, the feed source for supplying fluid to refill the tank in which chamber  12  is disposed may be located remotely from the tank and apparatus  10 . The refill fluid may be supplied to the tank by from another tank, pond, lake, municipal water supply or other fluid source by gravity, pump, or other pressurized device. For example, a toilet is typically connected to a pressurized water supply line from a municipal water source. Chambers  12  and  14  may be separate parts or they may be unitarily molded as a single unit. If separate parts, they are preferably supported by a single base or housing unit or are mechanically connected together, such as by strapping, to keep them in close proximity to each other. Apparatus  10  also preferably comprises one or more hanging brackets (no depicted) to allow apparatus  10  to be hung in the fluid tank at the desired level. If chambers  12  and  14  are unitarily molded, mechanically connected or supported by a single base or housing unit, then a single bracket may be used. If they are spaced apart from each other, two brackets may be used. The bracket(s) may have a hook to extend over and hang from the upper lip of the fluid tank, but other attachment or hanging methods may be used as such brackets are well known to those of ordinary skill in the art. As the mechanical parts of many toilet tanks are now standardized, the high water level is generally the same distance from the upper lip of the tank for most toilets, so a standard length hanging bracket may be used for most toilet tank installations. But the hanging bracket may be adjustable in length to accommodate use of apparatus  10  in other types of tanks or in non-standard toilet designs to allow proper placement of apparatus  10  relative to the high liquid level in the tank. 
         [0020]    Apparatus  10  is particularly useful in toilet tanks and in facilities having multiple toilets, such as hotels, entertainment complexes, public restrooms, homes, and restaurants. Apparatus  10  may also be useful in numerous applications involving fluctuating hydraulic fluid systems other than the toilet tank applications described herein. For example, apparatus  10  may be used to mete: saline additive to a fish tank; additives onto bulk RTU tanks for cleaning machinery; cleaning solutions into mop buckets; fuel additives for fuel tanks of various types of machines, military tanks, airplanes, vehicles, motorcycles, boats, trains, mining equipment; chlorine/bromine additive or pH modifiers into swimming pools and spas; liquid foods sources for green houses; anti-freeze additive for automotive windshield washer reservoirs; CIP solutions for food processing/cooking tanks; food/medicinal additives to livestock watering troughs; insecticide solutions to inset control systems; flavor additives to beverage products; treatments for cooling towers; industrial/retail cleaning additives into water for bulk RTU products. References herein to the system in which apparatus  10  is used or located include those systems in which part of apparatus  10  is used or located, as chamber  12  may be located remotely from chamber  14  and references herein to a tank in which chamber  12  or any other part of system  10  are disposed include other structures, such as a reservoir, capable of holding a volume of liquid and include any type of system having a varying volume of liquid and gas. Those of ordinary skill in the art will also appreciate upon reading this specification and the description of preferred embodiments herein that modifications and alterations to the device may be made within the scope of the invention and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventors are legally entitled.

Summary:
A chemical meting system to dispense a known or pre-determined amount of cleaning or treating fluid without requiring any moving mechanical parts or power source, for use in fluid tanks having a volume of liquid periodically varying between a high and low level. The system utilizes the pressure changes created by the varying volume of liquid in the tank to push air from a first chamber into a second chamber containing the cleaning or treating fluid to be dispensed. The volume of air displaces a volume of the fluid to be dispensed. Once the pressure in the first chamber is equalized, the dispensing stops until the next cycle when the volume of liquid in the tank changes.