Abstract:
The present invention provides an improved top mounted toilet flush valve and a method for installing the flush valve that can be readily adapted to the tank profile of a wide variety of gravity operated flush toilets. More specifically, in accordance with the objectives of the present invention, there is provided a flush valve having an overflow tube that is adjustable in height and a method for adjusting the overflow tube.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to plumbing fixtures. More particularly, it relates to a flush valve that includes a height-adjustable overflow tube to allow for proper setting of the overflow tube in relation to the height of the water contained within a toilet tank, which height varies between products and designs.  
       BACKGROUND OF THE INVENTION  
       [0002]     A conventional gravity operated flush toilet has several basic components. The china components include a porcelain bowl and a porcelain tank mounted on top of the bowl. The bowl and tank may either be separate pieces or may be molded as a single unitary piece of china. The plumbing components of a conventional gravity operated flush toilet include a fill valve in the tank that is connected to a water supply line, a flush valve mounted in a hole in the bottom wall of the tank that communicates with the bowl, a flapper valve that normally closes the flush valve, and a lever or push button on the outer wall of the tank that is connected with a chain or other mechanical linkage for momentarily lifting of the flapper valve. This allows water stored in the tank to flow rapidly through the flush valve into the bowl to carry waste along with the water through a trap connected to the underside of the bowl and into a waste pipe connected to a sewer line, septic tank or other waste reservoir.  
         [0003]     Conventional flush valves for gravity operated toilets are generally cylindrical and provide a round valve seat for the flapper valve. They are secured in a drain hole in the bottom wall of the toilet tank from underneath the bottom wall. Typically a large nut is screwed over a male threaded lower portion of the cylindrical flush valve body, on the underside of the bottom wall of the tank. Extending upwardly from the flush valve body is a cylindrical overflow tube. The purpose of the overflow tube is to ensure that a proper water level is maintained within the toilet tank. Ideally, the inlet of the overflow tube is set at a point where it is slightly above normal water level but below the bottom of the flush lever nut that is located on a vertical wall of the tank for actuation of the flushing cycle.  
         [0004]     In the United States, there are two basic markets for toilet flush valves, namely, the original equipment manufacturer (OEM) market and the after-installation market. The former consists of large toilet manufacturers that assemble and sell complete gravity operated flush toilets including flush valves. The latter consists of hardware and plumbing supply stores that sell to plumbers and home owners for repair and replacement in toilets already installed in residences.  
         [0005]     Every gravity operated flush toilet has an optimum fill level that ensures that enough water is in the tank for proper flushing without wasting water or risking incomplete waste carry out. For many years, gravity operated flush toilets in the United States had tanks with capacities of three and one-half, five gallons, or more. More recently, the Environmental Protection Agency (EPA) has mandated that low water consumption toilets be installed in all new construction and during all re-models, with a maximum water usage of 1.6 gallons per flush. Both the older high volume gravity operated flush toilets and the newer low volume gravity operated flush toilets come in a wide range of tank configurations with different optimum fill levels. Because of this, installation of after-installation market flush valves, which are manufactured in a pre-determined height to accommodate the deepest tank depth likely to be found, typically requires the installer to hand cut the overflow tube of the flush valve to fit. In the experience of this inventor, it would be unduly expensive to manufacture a variety of different overflow valves, each having an overflow tube of different height, to satisfy the configurations of the various gravity operated flush toilets manufactured in the United States and abroad. It is, therefore, advantageous to provide an after-installation flush valve having an adjustable overflow tube that permits plumbers and do-it-yourself homeowners to install the flush valve and to quickly, easily, and without tools, adjust the height of its overflow tube as necessary.  
       SUMMARY OF THE INVENTION  
       [0006]     Accordingly, a primary objective of the device of the present invention is to provide an improved flush valve for the after market that can be readily adapted to the tank profile of a wide variety of gravity operated flush toilets. A further object of the invention is to provide an increase in the surface area of the opening of the overflow tube by flaring the upper end of the overflow tube such that the overflow tube permits 10 or more gallons/minute. It is an additional object of the present invention to provide a clip mechanism that cooperates with a plurality of ribs on the flared end of the overflow tube. In accordance with the aforementioned objectives of the present invention, there is provided a flush valve having an overflow tube that is adjustable in height. The foregoing and other features of the apparatus of the present invention will be apparent from the detailed description that follows. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is front elevational view of the flush valve with an adjustable overflow tube of the present invention shown installed in a toilet tank.  
         [0008]      FIG. 2  is an enlarged front exploded elevational view of the flush valve illustrated in  FIG. 1 .  
         [0009]      FIG. 3  is top perspective view of the valve body of the flush valve of the present invention.  
         [0010]      FIG. 3A  is a cross-sectional view of the valve body of the flush valve along line A-A of  FIG. 3B .  
         [0011]      FIG. 3B  is a top elevational view of the valve body of the flush valve.  
         [0012]      FIG. 3C  is a side elevational view of the valve body of the flush valve.  
         [0013]      FIG. 3D  is a top elevational view of the valve body of the flush valve.  
         [0014]      FIG. 3E  is a front elevational view of the valve body of the flush valve.  
         [0015]      FIG. 3F  is a cross-sectional view of the valve body of the flush valve along line B-B of  FIG. 3C . 
     
    
     DETAILED DESCRIPTION  
       [0016]     Referring now to the drawings in detail, wherein like-numbered elements refer to like elements throughout,  FIG. 1  illustrates the flush valve  1  of the present invention as it would be installed in a toilet tank  31 . Specifically,  FIG. 1  shows a toilet tank  31  mountable to the rearward portion of a toilet seat (toilet seat is shown in phantom view). The toilet tank  31  is mounted to the toilet seat using mounting bolts  47  and the flush valve  1  is inserted through the drainhole  7  of the toilet tank  31  into the toilet seat.  FIG. 1  also shows the water level  49  in a toilet tank  31 , which is below the top of the overflow tube  15 . In normal operation, to flush the toilet, the lever on the outside of the toilet tank  31  would be moved, typically downwardly, thus actuating the lever  25  in the toilet tank  31  and lifting the flapper chain  27  and flapper valve  21 , thereby emptying the contents of the toilet tank  31  and flushing the toilet. After a flush occurs, the flapper valve  21  closes permitting the toilet to fill. Normally, the flow of water into the toilet is governed by a toilet fill valve or ballcock (not shown). In the event the toilet fill valve malfunctions and fails to shut off the flow of water to the toilet tank  31 , the overflow tube  15  provides an outlet for the excess water in the tank by providing passage down the overflow tubes,  15 ,  11  (i.e. the upper tube  15  and lower tube  11 ) and through the passage through the valve body  9 .  
         [0017]      FIG. 2  shows an exploded view of the assembly of the adjustable-height flush valve  1 . Referring back to  FIG. 1 , and starting from the base of the toilet and moving upwardly, items that may be included in the commercial embodiment of the replacement flush valve include a sponge gasket  3 , a mounting nut  5 , a chipboard washer  23  between the toilet tank  31  and the mounting nut  5 , and a rubber seal  29  between the valve body  9  and the toilet tank  31 .  
         [0018]     The washer  23  is a donut-shaped piece of elastomeric material which is both resilient and deformable. Suitable materials for the washer  23  include, but are not limited to, chipboard or polyethylene. The chipboard washer  23  is used to reduce the friction between the mounting nut  5  and the toilet tank  31 , making it easier to tighten the mounting nut  5  by hand.  
         [0019]     The valve body  9  is formed with a passage (not shown) adjacent to the aperture  39 . The valve body  9  includes flapper valve mounts  35  situated on either side of the valve body  9  for mounting the rubber flapper valve  21 . The flapper valve  21  also includes a flapper chain eyelet  37 . The flapper chain eyelet  37  permits attachment of a flapper chain  27 , attached to lever  25 . The rubber flapper valve  21  covers the aperture  39  in the valve body  9  when the toilet is not being flushed. The lever  25  is actuated by the toilet handle (not pictured) to pull the flapper chain  27  and open the flapper valve  21  and evacuate the contents of the toilet tank  31 , thus flushing the toilet.  
         [0020]     The valve body  9  also has a first length of overflow tube  11  and a second length of overflow tube  15 . The first length  11  may be an integral part of the valve body  9  or may be a separate part that attaches to the valve body  9 . The first length of overflow tube  11  has been shown in  FIG. 2  as a separate part. In this case, the overflow tube  11  would fit into the complimentary aperture of the passage through the valve body  9 . A simple press fit would be acceptable, although other types of retaining means could also be used. Water entering the upper end of the overflow tube  15  can flow through the passage to the drain hole  7  while the flapper valve  21  is in its closed position sealing the central aperture  39 . In a first embodiment, an adjustable overflow tube  15  fits into the first overflow tube  11  and the top of the first overflow tube  15  is externally threaded  33 . A locknut  13  having complimentary internal threads (not shown) threads onto the threaded portion  33  of the first overflow tube  11 . The first overflow tube  11  also includes an internal retaining ring (not pictured), which is merely a narrowing of the inside of the overflow tube  11  so as to provide a “catch” or retaining means for the adjustable overflow tube  15 .  
         [0021]     The second, or adjustable overflow tube  15  has a notched bottom  41  and a retaining ring  43 . The retaining ring  43  is intended to “catch” the retaining ring on the inside of the first overflow tube  11  such that the adjustable overflow tube  15  cannot easily be pulled out of the first overflow tube  11 .  
         [0022]     Additionally, the adjustable overflow tube  15  of the present invention has one end having a notched appearance  41 . The notches  41  provide a degree of flexibility in the overflow tube  15  which permits the user of the of the overflow tube  15  to insert it into the first overflow tube  11  and move it within the tube so as to adjust the height of the overflow tube  15 . When the adjustable overflow tube  15  is located at the desired height, the locknut  13  is tightened. Tightening or turning the locknut clockwise locknut  13  compresses the radial seal  12  against the outside of the overflow tube  15 , thus locking the overflow tube  15  to the first overflow tube  11  to hold the adjustable overflow tube  15  in relative position to the first overflow tube  11 .  
         [0023]     The upper end of the adjustable overflow tube  15  is flared  51  such that it provides a larger surface area to admit water in the event of an overflow of water. Additionally, the upper end of the overflow tube provides a gap  49  in the flared overflow tube  15  that provides a latching point for the refill tube clip  19 , discussed below. The gap  49  provides, in general, a flat surface  53  interrupted by a ridge  55 . The ridge provides a surface for attaching the refill tube clip  19 .  
         [0024]     Preferably, the various parts of the flush valve  9  and the overflow tubes  11 ,  15  are injection molded using a suitable plastic such as ABS (Trademark) plastic or glass filled polypropylene. However, none of the above materials are considered a limitation of the invention. A wide variety of other suitable, durable and low cost materials for injection molding are also available.  
         [0025]     The present invention also provides a method for fitting any sized toilet tank  31  with a universal flush valve  1  having an adjustable height overflow tube  15 . In general, the water supply to the toilet should be turned off and the toilet tank  31  should be emptied. Secondly, the tank should be unbolted form the toilet bowl. Continuing, the existing flush valve should be removed and the new flush valve installed. First a rubber seal  29  is placed over the threaded end of the valve body  9 . The threaded end of the valve body  9  is then inserted through the drainhole  7  in the toilet tank  31 . A friction reducing washer  23  is then placed over the threaded end of the valve body  9  and a mounting nut  5  is threaded onto the valve body  9  to secure the valve body  9  to the toilet tank  21 . A sponge gasket  3  is then placed over the mounting nut  5 . The toilet tank  31  is then reattached to the bowl. Importantly, the height of the adjustable overflow tube  15  is then adjusted relative to the toilet tank. To adjust the height of the flush valve overflow tube  15 , loosen the locknut  13  and extend the adjustable overflow tube  15  to the appropriate level. Next, tighten the locknut  13  and attach the refill tube  17  to the top of the adjustable overflow tube  15  using the refill tube clip  19 . The refill tube clip  19  can take a variety of forms, but in one particular embodiment features a plurality of prongs which extend downwardly on the inside and the outside of the overflow tube  15  in the gap  49  of the flare  51  of the overflow tube  15 . The prongs on the outside of the overflow tube  15  further have a notch slightly larger than the ridge  55  in the gap  49  such that the clip  19  is securely attached to the overflow tube  15 .  
         [0026]     Although the foregoing has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the construction and the arrangement of components, some of which have been alluded to, may be resorted to without departing from the spirit and scope of the invention as it is described.  
         [0027]     From the foregoing detailed description of the illustrative embodiment of the invention set forth herein, it will be apparent that there has been provided a new, useful and uncomplicated toilet flush valve having a variably adjustable overflow tube.