Patent Publication Number: US-6704945-B2

Title: Dual inlet flush valve system for gravity operated toilets

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to plumbing installations. More particularly, the invention concerns a dual flush system for a gravity flush toilet having an improved flush control apparatus. 
     2. Reference to Related Art 
     For many decades, household toilets have used a generally rectangular porcelain tank mounted above a porcelain bowl from which about 3.5 to 8 gallons of water are rapidly drained to flush waste from the bowl into a sewer system. One very common toilet design uses a silicon flapper that covers a single drain outlet located at the bottom of the tank. When a flush handle on the outside of the tank is manually depressed, the flapper valve is lifted and a modest pressure head of water in the tank empties through the drain outlet into the bowl. Typically, the flapper valve includes an inverted air chamber so that it initially floats as it is lifted away from the drain outlet. This floating flapper valve permits water to flow into the bowl even if the user immediately releases the flush handle. As the body of water flows through the drain outlet of the tank, it starts the siphoning action in the bowl and flushes the standing water in the bowl along with its waste contents into the sewer line. 
     A method for refilling the bowl and tank is also taught by the prior art. A ball cock valve or toilet tank fill valve mounted in the tank is connected to a pressurized water line in the house. When the tank drains, a float ball connected to the ball cock valve descends. The decent of the float ball opens the ball cock valve and begins the refilling of the tank. 
     When the tank is nearly empty, the flapper valve closes. The tank continues to fill as the float ball connected to the ball cock rises. At the same time, water from the ball cock valve enters an overflow tube to refill the bowl to a normal standing water level. Once the float ball reaches a predetermined height indicating the tank is full, the ball cock valve will close. 
     Water shortages throughout significant portions of the United States have forced major water conservation efforts. Conventional household toilets are wasteful and inefficient since a relatively large quantity of water is used to accomplish every flush. Therefore, various approaches have been employed in regions where water conservation is necessary to reduce water consumption by conventional toilets. 
     These efforts have led to improvements in toilets, such that as little as 1.6 gallons of water is utilized for a standard flush. However, this design is inefficient because while solid waste requires 1.6 gallons of water to accomplish the flush, liquid waste only requires enough water to replace the contaminated water in the bowl to complete the flush. 
     Additional approaches have included lowering the tank level or introducing a brick or dam to decrease the water volume released during each flush. 
     Yet another approach has been the development of a reduced flow (water saving) flapper valve that is designed with a vent in the air chamber portion of the flapper. The typical flush valve assembly (as discussed above) includes a single flapper valve having a normally downward opening air chamber which acts as a float when the flapper is raised off its seat to hold the flapper valve open when water is in the tank. A reduced flow flapper allows air to escape when in the open position allowing a rapid descent of the flapper. Therefore, the inlet is sealed before the entire contents of the tank are emptied into the bowl and the amount of water dispensed during each flush is effectively decreased. This approach has also been generally unsatisfactory because the consequent reduction in water flow into the bowl often results in incomplete flushing of solid waste. Users then flush twice, compounding the waste of water. 
     Still another approach for conserving water in toilets has been the use of multi-level flush valves. These valves comprise one inlet at or near the base of a toilet tank for long (solid waste) flushes and another inlet set at a higher elevation in the tank for short (liquid waste) flushes. Such devices depend on the depth of the water to be consistent within the tanks in which they are installed. However, in view of the variety of toilet designs available, each having a different shape or size tank, this approach is ineffective. 
     Accordingly, it is desirable that an improved dual flush apparatus be available which is simple, effective and adaptable for use in a variety of tank shapes and sizes while adequately providing for both long and short flushes of a toilet, with maximum efficiency for the volume of water used. 
     SUMMARY OF THE INVENTION 
     A dual inlet flush valve system is designed to replace standard flush valves and handles without the need for modification of the toilet tank or bowl. This invention provides the public with a simple and inexpensive device that allows the user to easily manage the amount of water dispensed per each flush while at the same time effectively providing for both solid and liquid waste flushes thus minimizing water consumption. 
     To achieve this, a flush valve system has been developed that is designed to utilize standard size flapper valves, seals and retainer nuts that are readily available at most plumbing retailers. It is preferably constructed of a single housing unit having at least two inlets affixed near the base of the tank fluidly connecting a single outlet. A flush handle assembly includes at least two handles mechanically connected to and at least two linkages. Both linkages pass through a sleeve assembly, which mounts in the standard mount hole provided on conventional gravity flush toilet tanks to provide effective control for the dual inlet flush valve. The inlets are sealed with a primary and a secondary flapper valve that are preferably connected by a chain or other link to the at least two linkages. The first (primary) flapper is preferably a reduced flow (water saving) flapper for use in flushing of liquid waste. The second (secondary) flapper is preferably a standard flapper for use in flushing solid waste or a combination of liquid and solid waste. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A better understanding of the present invention will be had upon review of the detailed description of the preferred embodiment in connection with the drawings wherein like reference numerals refers to like parts throughout the drawings and wherein: 
     FIG.  1 . is a cross-sectional view of a standard toilet tank including a preferred embodiment of an apparatus constructed in accordance with the present invention installed and connected to a conventional fill valve; 
     FIG.  2 . is a cross-sectional view of the valve portion of an apparatus constructed in accordance with the present invention showing its various components; 
     FIG.  3 . is a cross-sectional view of a valve portion of an apparatus constructed in accordance with the present invention; 
     FIG.  4 . shows a front view of the valve portion of an apparatus constructed in accordance with the present invention with flappers, seal and retainer nut installed; 
     FIG.  5 . shows a side view of the valve portion of an apparatus constructed in accordance with the present invention with the flappers, seal and retainer nut installed; 
     FIG.  6 . shows a top view of the handle portion of an apparatus constructed in accordance with the present invention; 
     FIG.  7 . shows a rear view of the handle portion of an apparatus constructed in accordance with of the present invention; 
     FIG.  8 . shows a front view of the handle portion of an apparatus constructed in accordance with of the present invention; and, 
     FIG.  9 . shows a cross-sectional view of the handle portion of an apparatus constructed in accordance with the present invention; 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
     Referring now to FIGS. 1 through 9, and as best seen in FIG. 1, there is shown a cross-sectional view of an apparatus “A” constructed in accordance with the present invention positioned in a standard toilet tank  10 . Preferably, the invention includes a housing  12  having at least two inlets  14   a  and  14   b  fluidly connecting at least one outlet  13 . The inlets  14   a  and  14   b  are respectively sealed with a primary  16  and a secondary  18  flapper. Preferably, the primary flapper  16  is a reduced flow (water saving) flapper for use in flushing liquid waste. The secondary flapper  18  is preferably a full flow (standard) flapper for use in flushing solid waste or solid waste in combination with liquid waste. 
     Referring now to FIGS. 1-3, an overflow tube  20  is attached to the housing  12  that preferably extends upwardly to above water level. Preferably, the flappers  16  and  18  are pivotably connected to a flapper mount pin  22  provided on the overflow tube  20 . Pivoting of either the primary  16  or secondary  18  flapper, or both of them, about the pin  22  orients the air chambers “C” of the flapper generally outward and opens its respective inlet  14   a  or  14   b . Water is thus permitted to flow through the inlet  14   a  or  14   b  and the outlet  13  into the bowl even if the user immediately releases a handle connected to the flapper  16 . 
     Still referring to FIG.  1 . and as best seen in FIGS. 6 through 8, there is shown a handle assembly “H” rotatably affixed on the outside of the tank  10 . The assembly “H” preferably includes a primary  24  and a secondary  26  handle respectively connected to a primary  28  and a secondary  30  linkage. Preferably, the chains  32   a  and  32   b  connect the primary linkage  28  with the primary flapper  16  and secondary linkage  30  with the secondary flapper  18 . As seen in FIG. 6, the primary handle  24  is preferably disposed below and extends outwardly from the tank  10  beyond the secondary handle  26 . 
     Referring now to FIGS. 6,  7  and  9 , the linkages  28  and  30  pass through a sleeve assembly  34  mounted in a standard mount hole provided on the conventional gravity flush toilet tanks and are secured by a retainer nut  38 . Preferably, the primary linkage  28  passes through an aperture  40  defined in the center of the secondary linkage  30 . The flush linkages  28  and  30  extend out into the tank at staggered lengths so that they can be positioned over the flappers  16  and  18 . The chains  32   a  and  32   b  are mounted to the linkages at holes  42   a  and  42   b  provided respectively on the linkages  28  and  30 . 
     In operation, the handles  24  and  26  with linkages  28  and  30  work as levers. As the primary handle  24  is depressed, the attached linkage  28  rises and pulls, via the chain  32   a , the primary flapper  16  upward to initiate a flush. As secondary handle  26  is depressed, the attached linkage  30  rises and pulls, via the chain  32   b , the secondary flapper  18  upward to initiate a flush. Notably, in the preferred embodiment, the placement of the secondary handle  26  above the primary handle  24  results in the activation of the primary flush system whenever the secondary flush system is activated. However, it is anticipated that handles may be realigned (e.g., mounted in opposed fashion or in a non-overlapping arrangement) to permit greater selectivity in flushing. Alternatively, through modification of the linkages, a single standard flush handle may be used to operate the dual flush valve. 
     Preferably, a primary flush is initiated, when the handle  24  connected to the primary flapper  16  is depressed. This action causes the flapper  16  to rise up off its seal allowing tank water to drain through the inlet  14   a  of the housing  12 , out the outlet  13  and then into the bowl. As the flapper  16  is preferably a reduced flow flapper, it descends to reseal inlet much more quickly than its standard counterpart but still permits a sufficient amount of water to produce a (short) liquid waste flush. 
     Preferably, a secondary flush is initiated when the handle  26  connected to the secondary flapper  18  is depressed. This action raises the flapper  18  up off its seal allowing tank water to drain through inlet  14   b  of the housing  12 , out the outlet  13  and then into the bowl. As the flapper  18  is a standard type, it will stay open until the tank water drains to the point where the flapper is pulled down to its seal, thus producing a (long) solid waste flush. 
     A fill tube “F” which is well known in the art, connects to an overflow inlet and includes a ball cock valve or toilet fill valve to refill the bowl with standing water providing a trap seal and completing each flush. 
     Having thus described this preferred embodiment of the present invention, it is anticipated that various other embodiments will be become apparent to those having skill in the art that do not depart from the scope of the present invention.