Patent Publication Number: US-2004040080-A1

Title: Toilet assembly

Description:
FIELD OF INVENTION  
       [0001] The present invention relates to a toilet for the removal of human and other waste. The present invention further relates to a toilet which is resistant to clogging, increases flushing capacity, and delivers the flush water volume with greater energy.  
       BACKGROUND OF INVENTION  
       [0002] Toilets for removing waste products are well known. Typically, toilets incorporate three systems that work together to perform the flushing action. Those systems are (1) the bowl siphon, (2) the flush mechanism, and (3) the refill mechanism. Working in concert, these three systems allow for the flushing function of the toilet.  
       [0003] Siphoning is used to transport fluid and waste from the higher elevation of the bowl to a lower elevation of the wastewater line. The flow channels in a toilet assembly are designed to begin siphoning when the water in the bowl rises above a certain level. The siphon tube itself is an upside down U-shaped tube that draws water from the toilet bowl to the wastewater line. Water is drawn out of the bowl and into the siphon tube when the toilet is flushed. The flushing action is initiated by water entering the bowl through the action of the flush mechanism and the refill mechanism. When flushed, the bowl is quickly filled with water from the tank positioned above, which causes the siphon tube to fill with water, creating a pressure gradient in the tube. The water-filled bowl creates higher pressure at the beginning of the siphon tube, and causes the water and waste to be pushed through the tube and into the wastewater line.  
       [0004] Typically, the tank, positioned over the back of the bowl, contains water that is used to initiate the siphoning from the bowl to the sewage line, as well as refilling the bowl with fresh water. When a user desires to flush the toilet, he pushes down on a flush lever on the outside of the tank, which is connected on the inside of the tank to a movable chain or lever. When the flush lever is depressed, it moves a chain or lever on the inside of the tank which acts to lift and open the flush valve, causing water to flow from the tank and into the bowl, thus initiating the toilet flush.  
       [0005] In many toilet designs, water flows both directly into the bowl and is dispersed into the rim of the toilet bowl. The rim typically has several small holes to allow flow into the bowl. The water releases into the bowl rather quickly, with flow from the tank into the bowl typically lasting approximately two to four seconds. The water flows from the rim, down a channel within the sides of the bowl, into the large hole at the bottom of the toilet, commonly known as the siphon jet. The siphon jet releases most of the water into the siphon tube, initiating the siphon action. The siphoning action draws all the water and waste out of the bowl and into the siphon tube. The waste and water continues through the other end of the U-shaped siphon tube through an area known as the trapway, and is then released into the wastewater line connected at the base of the toilet.  
       [0006] Once the tank is emptied of its contents (fresh water) during the flush, the flush valve closes, and a floating mechanism, which has now dropped in the tank to some residual amount, initiates the opening of the filler valve. The filler valve provides fresh water to both the tank and the bowl through separate flows. Eventually the tank fills with water to a high enough level to cause the float to rise, thus shutting off the filler valve. At this point, the flushing cycle is complete.  
       [0007] However, government agencies have continually demanded that municipal water users reduce the amount of water they use. Much of the focus in recent years has been to reduce the water demand required by toilet flushing operations. In order to illustrate this point, the amount of water used in a toilet for each flush has gradually been reduced by governmental agencies from 7 gallons/flush (prior to the 1950&#39;s), to 5.5 gallons/flush (by the end of the 1960&#39;s), to 3.5 gallons/flush (in the 1980&#39;s). The National Energy Policy Act of 1995 now mandates that toilets sold in the United States can use water in an amount of only 1.6 gallons/flush (6 liters/flush).  
       [0008] In the past, toilet designs have attempted by various methods to comply with this reduced water requirement, but achieving superior flush performance has been difficult. Therefore, it has been found desirable to provide a toilet which assists the flush operation in meeting the mandated water requirements while at the same time providing for an enhanced and superior flushing operation.  
       [0009] In the crowded art of producing a more reliable, more efficient and more powerful 1.6 gallon (6 liter) gravity toilet, one method to more effectively remove waste from the toilet bowl is to increase the hydraulic energy available during the flushing operation. However, the hydraulic energy available is not enhanced by the typical rim wash employed in existing toilets as the water path flows in two opposite directions through the rim of the toilet thus reducing the available energy. It has therefore been found desirable to provide a toilet which increases the hydraulic energy of the rim flush.  
       [0010] Current agency requirements further mandate that the flush lever for the flush valve assembly have a minimum “hold down” time of 1 second without exceeding the aforementioned total water usage or discharge per flush of 1.6 gallons or 6 liters of water. It has been found that the hydraulic performance characteristics of the toilet can be significantly enhanced if water can be evacuated from the water tank in a dumping time of less than 1 second, preferably 0.5-0.6 seconds. Therefore, it has been further found desirable to provide a toilet which releases the effect of the flush lever so that the valve opening can close before the expiration of the mandated minimum “hold down” time of the flush lever (1 second) without exceeding the total water per flush mandate of 1.6 gallons (6 liters).  
       [0011] In the development of the invention of this application, several toilets were examined and tested. Measurements were made to examine flushing capabilities. In order to determine the clogging and unclogging properties of these toilets, various objects were flushed through the toilets, including ping pong balls, thick napkins, floating Polypropylene balls, foam sponges, and floating rubber tubes. These objects were used to simulate various waste sizes and shapes.  
       [0012] All of the tested designs shared some of the same problems, but in varying degrees. First, several of the models had clogging problems. In most of these toilets, this problem could be attributed to an undersized trapway. Second, when there was a significant level of waste in the bowl, several of the designs were not capable of cleaning the bowl in a single flush. Third, several of the toilets used a symmetrical sweeping flow path to deliver flow volume to the rim, which perhaps decreased the efficiency of the toilet. Fourth, the flush-valve in several of the toilets was not capable of providing both a fast and high volume of water delivery from the tank. Finally, many of the toilets produced a considerable amount of noise during flushing. These tests confirmed the desirability of providing a toilet assembly which achieves a maximum trapway but does not alleviate the siphon effect.  
       [0013] It is therefore desirable to provide a toilet which allows for quieter flushing and decreased likelihood of clogging, increases flushing capacity, and creates a vortex flushing action by having an asymmetrical jet stream rim flow. This toilet includes a flush valve which minimizes losses of hydraulic force and allows for smooth transition of the water flow from the flush valve to the jet and rim channel supplies.  
       OBJECTS AND SUMMARY OF THE INVENTION  
       [0014] Therefore, it is an advantage of the present invention to provide a toilet which avoids the aforementioned disadvantages of the prior art.  
       [0015] An additional advantage of the present invention is to provide a toilet that is resistant to clogging.  
       [0016] Another advantage of the present invention is to provide a toilet with a flushing mechanism which is capable of cleaning the bowl in a single flush.  
       [0017] A further advantage of the present invention is to create a toilet which is self-cleaning.  
       [0018] A still further advantage of the present invention is to provide a toilet with a relatively silent flushing mechanism.  
       [0019] A yet still further advantage of the present invention is to provide a toilet with a large trapway diameter.  
       [0020] Yet another advantage of the present invention is to provide a toilet with a high discharge rate into the wastewater line.  
       [0021] Still yet another advantage of the present invention is to provide a toilet which has a sweeping flow path to deliver the flush volume to the rim and jet sections with greater energy.  
       [0022] Yet an additional advantage of the present invention is to provide a toilet with a hydraulically tuned direct jet path for greater performance.  
       [0023] It is yet a further advantage of the present invention to provide a toilet which reduces hydraulic losses.  
       [0024] Still another advantage of the present invention is to provide a toilet having an asymmetrical rim path flow resulting in vigorous vortex action.  
       [0025] In accordance with the present invention, a new and improved toilet is provided which includes a toilet bowl assembly having a toilet bowl and a trapway extending from the bottom of the toilet bowl to a sewage line. The toilet bowl has a rim part along an upper perimeter portion that accommodates an asymmetric flow path for flush water. A water tank positioned over the toilet bowl assembly contains water that is used to initiate siphoning from the toilet bowl to the sewage line and refills the toilet bowl with fresh flush water after each flush operation.  
       [0026] This toilet incorporates water supply to the bowl from both a direct jet flow as well as an asymmetrical rim flow. The water flows from the tank through the rim in one direction and is dispersed through one slot halfway around the rim (at the front of the bowl) and another slot at the end of the rim&#39;s path (at the back of the bowl). The water also flows through several other smaller holes distributed evenly along the perimeter of the rim. The water discharged from the two large rim slots is in two powerful streams, thus creating a strong vortex that initiates the flushing action. This water discharge configuration creates a high energy jet. The dispersion from the smaller holes around the perimeter of the bowl serves to wet and clean the bowl.  
       [0027] This toilet includes a trapway with no reductions in cross sectional area. This feature prevents clogging, because any load passing through the trap continues through to the wastewater line. This trapway is also larger than existing trapways, which enhances the toilet&#39;s anti-clogging capacity. This increased trapway size also increases the waste discharge rate at the end of the system into the wastewater line.  
       [0028] Various other advantages, and features of the present invention will become readily apparent from the ensuing detailed description and the novel features will be particularly pointed out in the appended claims.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0029] The following detailed description, given by way of example, will best be understood in conjunction with the accompanying drawings in which:  
     [0030]FIG. 1 is a side elevational view of a preferred embodiment of a toilet in accordance with the teachings of the present invention.  
     [0031]FIG. 2 is a front elevational view of the toilet of FIG. 1.  
     [0032]FIG. 3 is a top elevational view illustrating the flush water flow into the toilet bowl of the toilet of FIG. 1.  
     [0033]FIG. 4 is a front perspective view of a preferred embodiment of a flush valve assembly to be incorporated in the toilet of FIG. 1.  
     [0034]FIG. 5 is a front perspective view of the flush valve assembly of FIG. 4 with the valve opening in its open position.  
     [0035]FIG. 6 is a front exploded view of the flush valve assembly of FIGS.  4 - 5 .  
     [0036]FIG. 7 is a front plan view of the flush valve assembly of FIG. 4.  
     [0037]FIG. 8 is a front sectional view of the flush valve assembly of FIG. 4 with the valve opening in its closed position.  
     [0038]FIG. 9 is a front sectional view of the flush valve assembly of FIG. 5 with the valve opening in its open position.  
     [0039]FIG. 10 is a front perspective view of the trip release mechanism of the flush valve assembly of FIGS.  4 - 5 .  
     [0040]FIG. 11 is a front elevational view of the water valve inlet between the water tank and the toilet bowl of the toilet of FIG. 1.  
     [0041]FIG. 12 is a side elevational view of the water valve inlet of FIG. 11.  
     [0042]FIG. 13 is a side elevational view of the water pathway or conduit leading from the water tank to the toilet bowl in the toilet of FIG. 1.  
     [0043]FIG. 14 is a side elevational view of the bowl rim of the toilet of FIG. 1 and specifically illustrates a water slot provided in the bowl rim through which flush water passes.  
     [0044]FIG. 15 is a side elevational view of the bowl rim of the toilet of FIG. 1 and specifically illustrates the rim holes provided therein through which water passes.  
     [0045]FIG. 16 is a top elevational view illustrating the flush water flow through another preferred embodiment of a rim path for a toilet in accordance with the teachings of the present invention.  
     [0046]FIG. 17 is a side elevational view of the bowl rim of the toilet of FIG. 16 taken along line  17 - 17  of FIG. 16.  
     [0047]FIG. 18 is a top elevational view illustrating the flush water path through another preferred embodiment of a rim path for a toilet in accordance with the teachings of the present invention.  
     [0048]FIG. 19 is a side elevational view of the bowl rim of the toilet of FIG. 18 taken along line  19 - 19  of FIG. 18.  
     [0049]FIG. 20 is a side view of the toilet bowl of the toilet of FIG. 1 filled with water.  
     [0050]FIG. 21 is a side elevational view of the siphon and trapway conduits of the toilet of FIG. 1.  
     [0051]FIG. 22 is a side elevational view of another preferred embodiment of a toilet in accordance with the teachings of the present invention.  
     [0052]FIG. 23 is a front elevational view of the toilet of FIG. 22.  
     [0053]FIG. 24 is a top elevational view illustrating the flush wall flow into the toilet bowl of the toilet of FIG. 22.  
     [0054]FIG. 25 is a top elevational view of another preferred embodiment of a plastic insert for the direct jet channel to be used in conjunction with the toilets of FIGS. 1 and 18.  
     [0055]FIG. 26 is a top elevational view of another preferred embodiment of a plastic insert for the direct jet pathway to be used in conjunction with the toilet assembly of the present invention.  
     [0056]FIG. 27 is a side elevational view specifically illustrating water flow through the plastic insert of FIG. 26.  
     [0057]FIG. 28 is a side view specifically illustrating impeded water flow through a direct jet pathway.  
     [0058]FIG. 29 is a chart representing the flush rate of the toilet of FIG. 1 plotting millimeters/second vs. elapsed time. 
    
    
     DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS  
     [0059] Referring now to FIGS.  1 - 3 , a toilet tank in accordance with the teachings of the present invention is illustrated. As will be explained in more detail below, this toilet has a greater energy throughput of the flush water to thereby provide more energy available to remove waste from the toilet bowl. In addition, this toilet permits a toilet to meet governmental agency requirements which mandate a maximum water usage of 1.6 gallons (6 liters) per flush. Further, this toilet improves the flow characteristics of the flow water and flow capacity to provide for not only a more efficient flush but also enhanced cleaning performance and anti-clogging siphoning to assist in waste removal. Moreover, this toilet provides for a quieter and faster flush operation.  
     [0060] As shown in FIGS.  1 - 3 , the toilet  10  includes a water tank  12  which includes a flush valve assembly  14 . The water tank  12 , which is positioned over the back of the toilet bowl  20 , contains water that is used to initiate the siphoning from the bowl to the sewage line, as well as refilling the bowl with fresh water. When a user desires to flush the toilet, the user pushes down on a flush lever  18  on the outside of the water tank which is connected to the flush valve assembly  14  by a movable chain or lever  19 . When the flush lever  18  is depressed, the chain or lever  19  acts to lift open the flush valve opening to be described hereinafter, causing water to flow from the tank  12  and into the toilet bowl  20  thus initiating the toilet flush.  
     [0061] In this toilet, the flush water passes from the water tank  12  to the toilet bowl  20  through a transition pathway  22 , which as will be described in further detail below can be configured as a manifold made of plastic. This transition pathway  22  directs the flush water either into a rim channel  24  provided on top of the toilet bowl  20  or into a direct jet channel  29 . As will be described in more detail below, the flush water flows through the rim channel  24  of the toilet in a path which is asymmetric and unidirectional (see arrows A of FIG. 3). This rim channel  24  includes a plurality of rim openings such as  26   a, b, c  and  d  distributed evenly along the perimeter of the rim channel  24  so that a portion of the flush water in the rim channel  24  flows therethrough and along the sides of the toilet bowl so as to pre-wet the entire perimeter of the toilet bowl and provide a side wall cleaning operation.  
     [0062] In order to increase the flush efficiency and performance of the toilet, a pair of water discharge slots  28   a  and  28   b  are provided in the rim channel  24  so that the flush water passing in the asymmetric path through the rim channel  24  can either be dispensed from the rim channel  24  into the toilet bowl through one of the plurality of rim openings, such as  26   a, b, c  and  d , or through one of the pair of water discharge slots  28   a  and  28   b . These water discharge slots  28   a  and  28   b  discharge flush water directly into the toilet bowl  20  in two water streams (see arrows B &amp; C in FIG. 3) which create a strong vortex action to provide greater siphon energy for waste removal as will be described in greater detail below. As is shown in FIG. 3, one of the pair of water discharge slots  28   a  is provided about halfway around the rim channel  24  and the second of the water discharge slots  28   b  is provided at a back section  29  of the toilet bowl  20 .  
     [0063] During the flush operation as described above, the water flows from the rim openings  26   a, b, c  and  d  down the sides of the bowl or directly into the toilet bowl  20  through the water discharge slots  28   a  and  28   b  toward the large discharge orifice  30  provided at the bottom of the toilet bowl  20  known as the siphon jet. Flush water is also delivered directly into the siphon jet by means of the direct jet channel  29 . The siphon jet releases most of the water into the trapway  40  initiating a siphoning action. The siphoning action draws all the water and waste out of the toilet bowl and into the trapway  40  and is then released into the waste water line connected at the base  31  of the toilet  10 .  
     [0064] Once the tank is emptied of its predetermined volume during the flush, the opening of a filler valve (not shown) is initiated. The filler valve provides fresh water to both the water tank  12  and the toilet bowl  20  through separate flows. Eventually the water tank  12  fills to a water lever to cause a float of the flush valve assembly  14  to rise, thus shutting off the filler valve. The flushing cycle is now completed.  
     [0065] A more detailed description of the components of the toilet  10  of the present invention follows.  
     [0066] As is shown in FIGS. 4 through 6, the flush valve assembly  14  of the present invention includes a valve body  32 , a flush cover member  34  of a predetermined length, and a “trip-release” or “lost-motion” mechanism  36 . The valve assembly  14  allows the water tank to which it is installed to hold a predetermined volume of water and to also serve as a conduit to deliver water to the toilet trapway via the passages within the toilet. The valve body  32  includes a base sleeve portion  38  which is secured to the water tank or water closet by a threaded member  39  provided along the outer peripheral surface  40  of a base support portion  41  thereof.  
     [0067] The valve body  32  also includes a first cylindrical tube member  46  which extends vertically from the base sleeve portion  38 . In order to properly seal the valve body  32  to the water tank, a sealing member or washer  42  is fitted over the threaded member  39  so as to abut against an annular flange surface  43  of the base sleeve portion  38 . A seal bearing  44  is threaded on the threaded member  39  so as to securely position the sealing member  42  between the annular flange member  43  and the sealing member  44 .  
     [0068] The flush valve cover or closure component  34  is coaxially and slidably mounted with respect to the valve body  32  so that a valve opening  50  is created between the valve body  32  and the flush valve cover  34  when the flush valve cover  34  is removed from the valve body  32 . The flush valve cover  34  is slidably movable between a first rest position, wherein the flush valve cover  34  is seated on an annular valve seat  52  of the base sleeve portion  38  of the valve body  32  so that water cannot pass through the valve opening  50  (see FIGS. 4 and 8), and a second position, wherein the flush valve cover  34  is removed from the annular valve seat  52  of the base sleeve portion  38  of the valve body  32  so that water can pass through the valve opening  50  (see FIGS. 5 and 9). The closed position of the valve opening  50  prevents the flow of flush water into the valve opening until the valve is activated, by means of a flush lever  18 . The open position of the valve opening  50  allows the flow of flush water to enter the valve opening and proceed into passages within the toilet to which the water tank is attached.  
     [0069] As is set forth below, the flush valve assembly  14  of the present invention achieves a greater energy throughput of the flush water, which in turn generates more energy available to remove waste from the toilet bowl. In order to obtain this advantageous result, the base sleeve portion  38  of the vent tube includes a radiused inlet  58  which has a diameter a which is approximately 4.5 inches with a radius b of ¾″ (see FIG. 7) incorporated onto the leading edge  58   a  of the inlet.  
     [0070] As a result, the radiused inlet  58  of the base sleeve portion  18  creates a discharge coefficient of the valve opening of 0.95. The discharge coefficient is the ratio between the actual flow area of the opening area and the static opening area. In practice, the higher the discharge coefficient of the opening, the greater the hydraulic energy of the water passing through the opening. Without providing a radiused inlet at the valve opening with a lead-in angle as in the present invention, the discharge coefficient of the typical prior valve opening is approximately 0.6. Accordingly, the throughput energy of the flush water passing through the valve opening of the flush valve assembly  14  of the toilet of the present invention is greater than the throughput energy of the flush water passing through existing valve assemblies of the prior art as discussed above. As a result of the radiused inlet  58  of the base sleeve portion  38  of the valve body  32  as described above, the flow characteristics of the flush water and flow capacity of the flush valve assembly incorporated in the toilet of the present invention are improved. Therefore, more energy is generated in the flush water passing through this flush valve assembly to remove waste in the toilet bowl.  
     [0071] In order to accommodate unrestricted overflow into the water tank, the flush valve cover  34  includes a funneled inlet  59  at the flush water inlet orifice  60 . This funneled inlet has a predetermined lead-angle β to the horizontal axis of the flush valve cover (see FIG. 7).  
     [0072] As shown in the figures, especially FIG. 4, flush valve cover  34  may include an upper portion  34 ′, a lower portion  34 ″, and a portion  34 ′″ located therebetween which may be a stepped or an inclined portion. The diameter of upper portion  34 ′ may be smaller than the diameter of lower portion  34 ″. Additionally, the annular sealing member  64  provided along the bottom surface of the flush valve cover  34  has a diameter which may be larger than that of the lower portion  34 ″.  
     [0073] The inclined portion  34 ″″ and the diameter of annular sealing member  64  may be designed and/or selected so as to enable a force to be exerted on the flush valve cover  34  during a filing operation which is sufficient to pull the flush valve cover  34  down and cause a proper seal to be formed. Such force may be the minimum force necessary to pull the flush valve cover  34  down and provide the proper seal. Additionally, the diameter of the lower portion  34 ″ is selected so as to provide a desired buoyancy of the flush valve cover  34 . Such buoyancy may affect the time period in which the flush valve cover  34  remains opened.  
     [0074] Thus, the flush valve cover  34  may provide a desired buoyancy and enable a minimum pulling force to be applied thereto while providing a proper sealing condition when the flush valve cover is moved to its first rest position. Furthermore, the flow characteristics of the flush water and flow capacity of the flush valve assembly  14  of the present invention are also enhanced by reducing the pulling force necessary to close and properly seal the valve opening  50  when the flush valve cover  34  is moved from its second upper position to its first rest position.  
     [0075] In accordance therewith, in the flush valve assembly  14  incorporated in the toilet of the present invention, an annular valve seat  52  is provided downstream of the radiused inlet  58  in the flush water discharge opening  61 . As best shown in FIGS. 6 and 7, the annular sealing member  64  is provided along the outer circumferential surface  63  of the flush valve cover  34  which rests in the indented annular valve seat  52  when the flush valve cover  34  is in its first rest position  
     [0076] In order to properly guide and align the flush valve cover  34  with respect to the valve body  32  when the flush valve cover  34  is moved between its first rest and second upper position, the flush valve cover  34  includes a second inner cylindrical tube member  68  secured to the inner peripheral surface of an inner downwardly depending vertical wall member  70  of the flush valve cover  34  by means of a plurality of radially disposed web members (not shown) bridging the second tube member  68  between the inner wall member  70  and the second cylindrical tube member  68 . The second cylindrical tube member  68  is fitted over the first cylindrical tube member  46  of the valve body  32  so that the flush valve cover  34  is properly guided and accurately aligned with the valve body  32  when the flush valve cover  34  is moved between its first rest position and second upper position.  
     [0077] This guiding assembly consisting of the first and second cylindrical tube members  46  and  68 , respectively, also assists in properly sealing the valve opening  50  when the flush valve cover  34  is returned to its first rest position. The guiding assembly assures that the annular sealing member  64  fitted over the flush valve cover  34  is properly seated on the annular valve seat  52  of the valve body  32  in the first rest position of the flush valve cover  34 .  
     [0078] In order to reduce hydraulic losses and further improve flow characteristics of the flush valve assembly  34 , the valve body  32  includes structure to minimize flow resistance. This flow resistance minimization member includes a plurality of tapered web members  72   a ,  72   b ,  72   c  radially disposed between the first cylindrical tube member  46  and an inner peripheral portion  73  of the base sleeve portion  38  of the valve body  32 . As is best shown in FIG. 7, each tapered web member  72   a ,  72   b ,  72   c  is formed of a lower height section  75   a  at an end toward the first cylindrical tube member  46  which increases in height through a tapered section  75   b  until reaching extended height section  75   c  at an end toward the inner peripheral surface  73  of the base sleeve portion  38 . With this design, turbulence of the flush water passing through the valve discharge opening  61  is minimized.  
     [0079] Hydraulic losses can also result if the flush water does not flow in a laminar manner. Laminar flow can be disrupted by backflow of water within the flush valve assembly  14 . In order to reduce backflow of the flush water during the flushing operation, adequate flotation of the flush valve cover  34  must be provided so that the flush water will drain properly.  
     [0080] In order to provide flotation of the flush valve cover  34  when the flush valve cover  34  is moved from its first rest position to its second rest position so as to achieve proper flush water drainage, a flotation cavity  76  is formed between the downwardly depending inner and outer wall members  70  and  78 , respectively, of the flush valve cover  34 .  
     [0081] As in typical flush valve assemblies, the flush valve cover  34  is initially moved from its first rest position, wherein the valve opening  50  is closed, to a second position, wherein the valve opening  50  is opened by means of a flush lever  18 . This flush lever  18  is displaceable by a user between a first rest position and a second position to operatively move the flush valve cover  34  between its first rest position and second upper position. Current agency requirements mandate that the minimum “hold-down” time for the flush lever is one second. However, the longer the valve opening remains open before water is evacuated from the tank, the more energy is dissipated during the flush cycle.  
     [0082] The flush valve assembly of the present invention can achieve closure of the valve opening  50  in less than 1 second, preferably in 0.5-0.6 seconds, to increase the available hydraulic energy of the flush water and thereby ensure a relatively rapid delivery of a predetermined quantity of flush water without exceeding agency requirements. In accordance therewith, the flush valve assembly  14  includes a “trip-release” or “lost-motion” mechanism  36  which, as described below, releases the effect of the flush lever  18  on the flush valve cover  34  when the flush valve cover  34  reaches its second position so as to return the flush valve cover to its first rest position prior to the flush lever  18  returning to its first rest position.  
     [0083] As is shown in the figures, the trip release mechanism  36  includes a cam rod  80 , a pull rod  82  operatively connected to the flush lever at end  82   a  and slidably mounted with respect to the cam rod  80  so that the pull rod  82  and the cam rod  80  are moveable in response to movement of the flush lever. A trip dog assembly  90  is also incorporated in the trip release mechanism  36  which is capable of engaging the flush valve cover  34  when the pull rod  82  and cam rod  80  are moved between a first rest position and a second predetermined position and is capable of disengaging the flush valve cover  34  when the pull rod  82  moves beyond its second predetermined position.  
     [0084] As is best shown in FIGS. 6, 7 and  10 , the pull rod  82  includes a plurality of extension members, such as  77   a  and  77   b , which includes a narrow width section  79   a  gradually increasing in width to a raised width section  79   b . The raised width members  79   b  extend outwardly to an extent such that they can be received within a receiving opening  100   a  formed by the inner peripheral surface of an annularly inclined baffle  100 , to be explained in more detail below. Each of the raised width members  79   b  include an engaging hole  79   c  at a lower end thereof.  
     [0085] The engaging and disengaging members of the trip dog assembly  90  include wing-like retention members  92   a ,  92   b  which are supported in the engaging holes  79   c  of the raised width members  79   b  of the extension members  77   a  and  77   b . As is shown in FIG. 8, the wing-like retention members  92   a ,  92   b  extend outwardly to engage the flush valve cover  34  when the cam rod  80  and the pull rod  82  are moved together between their first position and the second predetermined position so as to move the flush valve cover  34  between its first rest and second positions. Further movement of the cam rod  80  is restricted past this second predetermined position as will be described in further detail below. With the movement of the cam rod  80  so restricted, FIG. 9 illustrates that the wing-like retention members  92   a ,  92   b  retract when the pull rod  82  is moved past the second predetermined position so as to disengage the wing-like retention members  92   a ,  92   b  from the flush valve cover  34  which in turn allows the flush valve cover  34  to return to its first rest position.  
     [0086] More specifically, as shown in FIGS. 6 and 8, in the first rest position of the cam rod  80  and the pull rod  82 , a first catch member  93  of each wing-like retention member  92   a  and  92   b  abuts against a leading inclined surface  94   a  of a central depression cam section  94  of the cam rod  80 . The leading edge  95   a  of a second catch member  95  of the wing-like retention members  92   a ,  92   b  abuts against a reduced diameter section  80   a  of the central depression cam section  94  of the cam rod  80 .  
     [0087] Each of the wing-like retention members  92   a ,  92   b  further include an engagement section  97  which is pivoted to extend outwardly and be thereby repositioned when the cam rod  80  and pull rod  82  are returned to their first rest positions. As the flush lever  18  initially moves the cam rod  80  and the pull rod  82  from their initial rest positions, the first and second catch members  93  and  95  of the wing-like retention members are contained within the central depression cam section  94  of the cam rod  80 . Upon further combined movement of the cam rod  80  and the pull rod  82  due to further depression of the flush lever  18 , the engagement section  97  of each retention member  92   a  and  92   b  is engaged with annularly inclined baffle member  100  (see FIG. 7) extending from an inner peripheral surface  102  of the flush valve cover  34  to raise the flush valve cover  34  from its first rest position, wherein the flush opening  50  is closed, to a second upper position, wherein the flush opening  50  is opened. When the cam rod  80  and the pull rod  82  have been moved to the second predetermined height position upon depression of the flush lever  18 , an extended annular base flange  80   b  provided on a base section  80   c  of the cam rod  80  abuts against an inwardly extending flange  46   a  provided at the top end  46   b  of the first cylindrical tube member  46  of the valve body  32  (see FIG. 9). This restricts further movement of the cam rod  80  with the pull rod  82  as the flush lever  18  is further depressed.  
     [0088] When the pull rod  82  is moved past this second predetermined position by further depression of the flush lever  18 , the pull rod  82  is subjected to additional bias force being applied by a spring member  104  which is fitted over an upper portion of the cam rod  80  and loaded between a central core member  106  of the pull rod  82  (see FIGS. 7 and 10) and a spring knob  108  provided at an upper end of the cam rod  80  (see FIG. 10). Since the cam rod  80  is prevented from further movement, when the pull rod  82  is moved past the second predetermined height position and the biased force begins to be applied thereto, the first and second catch members  93  and  95  ride out of the central depression cam section  94  of the cam rod  80 . This, in turn, causes the wing-like retention members  92   a  and  92   b  to pivot (see FIG. 9) such that the engaging sections  97  of the retention members  92   a  and  92   b  are retracted toward the pull rod  80  and disengaged from the annularly inclined baffle member  100  of the flush valve cover  34 . As a result, since the flush lever  18  is connected to the pull rod  82 , the flush valve cover  34  is no longer under the effect of the flush lever  18 . Since the flush valve cover  34  is unrestrained, the flush valve cover  34  is capable of returning to its first rest position. The pull rod  82  continues its upward movement past the second predetermined position until the central core member  106  abuts against the spring knob  108 . At this point, further movement of the pull rod  82  is restricted.  
     [0089] This flushing operation causes closure of the valve opening in approximately 0.5-0.6 seconds providing a relatively quick flush operation which causes reduced energy dissipation of the flush water during the flushing operation. Even though the flush valve cover  34  returns to its first rest position to close the valve opening  50 , the pull rod  82  continues to move upwardly until the flush lever  18  has complied with its mandatory 1 second “hold-down” time.  
     [0090] In addition, the second cylindrical tube member  68  of the flush valve cover  34  includes an annular extended flange  111  at the upper end thereof (see FIG. 7). When the cam rod  80  and the pull rod  82  are returned to their first rest position in a subsequent flushing operation and the effect of the flush lever is released, the camming surfaces  109  of the retracted wing-like retention members  72   a  and  72   b  abut against the annular extended flange  111  of the second cylindrical tube member  68 . As the camming surfaces ride thereover, the wing-like retention members  92   a ,  92   b  are cammed to an extended engageable position so that the first catch member  93  of each wing-like retention member  92   a  and  92   b  abuts against the leading inclined surface of the central depression cam section  94  of the cam rod  80  and the wing-like retention members  92   a  and  92   b  are pivoted into a position whereby the engaging member  97  is capable of engaging the annularly inclined baffle member  100  of the flush valve cover  34  in a subsequent flush operation.  
     [0091] By including the “trip-release” or “lost-motion” mechanism  36  in combination with the other features set forth above, the flow characteristics of the flush water and flow capacity of the flush valve assembly are improved while at the same time compliance with mandated agency requirements is achieved.  
     [0092]FIG. 11 illustrates a sweep inlet  110  providing a transition between the water tank  12  and the transition pathway  22  so as to maximize throughput energy of the flush water passing into the transition pathway  22  which in turn creates more available energy to remove waste from the toilet bowl. As shown in FIG. 11, the sweep inlet  110  has a radiused port  112  at one end thereof having an inclined leading edge  112   a , similar to the radiused inlet  58  of the base sleeve portion  38  of the flush valve assembly of FIGS.  4 - 9 . The radiused port  112  has a diameter of preferably approximately 4 inches which tapers to a narrowed diameter of 3 inches between the side walls  114   a  and  b . The leading edge  112   a  is inclined to the horizontal axis of the water tank  12  at a lead-in angle α.  
     [0093] As a result of this valve inlet design, the discharge coefficient of the flush valve is increased to approximately 0.95. By increasing the discharge coefficient, the hydraulic energy of the water passing through the flush valve is increased. As a result, the hydraulic losses of the flush water passing from the tank to the rim and jet supply channels are reduced such that more energy is created in the flush water to remove waste in the toilet bowl.  
     [0094]FIG. 12 is another arrangement for a flush valve with improved hydrodynamics. This flush valve embodiment also includes a valve inlet  115  having a radiused port  116  but does not require elevation of the platform for the water tank as in the valve inlet  110  of FIG. 11. Due to the lack of elevation of the platform for the water tank, in order to provide adequate sealing, the valve inlet  115  is made of molded rubber.  
     [0095] The piers of FIGS. 11 and 12 are set forth herein for illustrative purposes. These designs provide for a delivery rate of approximately 7.5 liters/sec. into the transitional pathway  22 . As would be readily known to one skilled in the art, a flush valve cover, such as in the flush valve assembly of FIGS.  4 - 9  can be used in conjunction with either of these valve inlets  110  and  115 . Alternatively, other known flush valve assemblies can be adapted to be used in conjunction with these pier concepts.  
     [0096]FIG. 13 illustrates the transitional pathway or sweep elbow  22  leading from the flush valve assembly of the water tank  12  to the rim channel  24  and direct water channel  29 . As shown in FIG. 13, the radius R of the sweep elbow  22  is at least 3 inches, that is, the radius R must be at least equal to the narrowed diameter of the radiused inlet. At the inlet end  116  of the transitional pathway  22 , the flush valve assembly, such as  14  herein will be fitted with a radiused horn (not shown). The transitional pathway  22  is preferably made of chinaware and thus provides for the smooth transition of the flow of the flush water from the flush valve  12  to the rim channel  24  and the direct water jet channel  29 . Therefore, in conjunction with the flush valve assemblies with radiused inlet as set forth above, a “sweeping” flow path is provided to deliver flush water volume with increased energy to the rim channel  24  and direct jet channel  29 .  
     [0097] As aforementioned, the flush water delivered from the transitional pathway  22  either passes into the rim channel  24  or the direct water jet channel  29  provided at the back section of the toilet bowl. As best shown in FIGS. 1 and 3, the water jet channel  29  is relatively large preferably (1⅝″ diameter) such that a concentrated stream of flush water is directed into the siphon jet  30  at the base of the toilet bowl (see arrow C in FIG. 3). Since this toilet has a single side jet feed, hydraulic losses of the flush water are reduced in comparison to a toilet design having jet ports on both sides of the toilet bowl thereby leading to enhanced flush performance. In the typical flush, 2.6 liters of water passes through the direct jet channel  29 .  
     [0098]FIGS. 1 and 3 illustrate that the flush water flows through the spiral rim channel  24  in an unrestricted supply path which is asymmetric and unidirectional. In order to create balanced flow of the flush water between the rim channel  24  and the direct jet channel  29 , approximately 1.7 liters of water passes through the rim channel  24  during each flush operation. In the preferred embodiment, the rim cross section is approximately 1¼″×1½″.  
     [0099] As described above, the rim channel  24  has two water discharge slots  28   a  and  b , such as the discharge slot shown in FIG. 14. As is shown in FIGS. 1 and 3, one of the discharge slots  28   a  is provided at a front section  117  of the rim channel  24  and has a preferred dimension of approximately 3″×⅝″ and the second discharge slot  28   b  is provided at a rear end section  118  of the rim channel  24  and has a preferred dimension of approximately 4″×1″. The flush water is discharged through the first and second discharge slots  28   a  and  28   b  in two powerful streams to generate a strong vortex action in the sump. This vortex action, in combination with the action of the water jet delivered from the jet channel  29  and the siphon vacuum, leads to a quicker and more complete removal of waste from the toilet bowl as well as provides an efficient bowl cleaning operation.  
     [0100] As is shown in FIGS. 3 and 15, the rim channel  24  also includes a plurality of rim openings, such as  26   a, b, c  and  d . In the preferred embodiment, twenty five rim openings are distributed evenly throughout the whole perimeter of the rim channel  24 . Each of the rim openings  26   a, b, c  and  d  has a diameter of approximately {fraction (7/32)}″ with a pitch of approximately 1½″. The flush water passing through the rim openings  26   a, b, c  and  d  pre-wets the whole perimeter of the toilet bowl  12 . Although energy is dissipated in the flush water passing through the rim openings  26   a, b, c  and  d , this water still contributes additional energy to the creation of a strong vortex in the sump of the toilet bowl to efficiently and quickly remove waste.  
     [0101] In this cleaning process as described above, the sides of the bowls are pre-wetted due to the water passing through the rim openings  26   a, b, c  and  d . In addition, the strong vortex action created by water passing through the siphon jet  29  and the discharge slots  28   a  and  b  efficiently washes the walls of the toilet bowl.  
     [0102]FIG. 16 illustrates in more detail the flush water flow through the rim channel  24 , and more particularly, the side entry of the water flow from the transitional pathway  22 ′ to the rim channel  24 , as shown by arrows D. FIG. 16 further illustrates that a strong vortex action can be achieved if the flush water is discharged from the rim channel  24  into the toilet bowl  20  by concentrated water streams, such as the water streams depicted by arrows E and F. These two streams E and F compensate for each other and create a strong but yet non-turbulent vortex action in the toilet bowl. The two steams E and F are formed by flush water being discharged through the pair of water discharge slots  28   a  and  28   b  provided in the rim channel  24 . FIG. 16 illustrates that one of the discharge slots  28   a  is provided in the middle of the rim channel path at the front of the toilet bowl and the other discharge slot  28   b  is formed at the terminus of the spiral of the rim channel  24 . By providing the second and last discharge slot at the end of the rim channel  24 , water reliably flows in a sufficient amount through the plurality of rim openings, such as  26   a, b, c  and  d  such that the whole perimeter of the toilet bowl is cleared. It has been found that providing two concentrated streams of water, such as water streams E and F, enhances the efficiency of the flush and reduces energy losses.  
     [0103] Moreover, in the design of this toilet, applicants have found that it is advantageous to obtain unrestricted continuation of the water stream after the flush water is discharged from the rim channel  24 . This objective can be achieved by forming a smooth sloped end wall, such as  140  (see FIG. 17) at the back end of the final discharge slot  28   b . If wall  140  was vertical instead of sloped, horizontal water flow is significantly retarded and kinetic energy is lost.  
     [0104]FIGS. 18 and 19 illustrate another preferred embodiment of the configuration of a rim channel  150  for the toilet assembly of the present invention. In this embodiment, the flush water enters the rim channel  150  from the transitional pathway  22 ″ at a side thereof. The flush water flows around the rim channel  150  in the direction of arrows G in FIG. 18 in a path which is asymmetric and unidirectional. Along this path, a first set of rim openings  152   a, b  and  c , preferably three in number, are provided in the middle of the rim channel path at the front of the toilet and a second set of rim openings  154   a, b  and  c  are provided at the end of the spiral rim path. A water discharge slit  156  is also formed in the rim channel  150  after the last of the second set of rim openings  154   c.    
     [0105] In this embodiment (FIG. 18), the rim openings  152   a, b  and  c  and  154   a, b  and  c  are relatively large and located close to each other. The narrow walls (see  158   a ,  158   b ) between the rim holes provide rigidity in the vertical direction and reduce distortion of the water flow. In total, the combined area of the rim openings  152   a, b , and  c  and  154   a, b  and  c  should be approximately equal to the respective water discharge slots  28   a  and  b  in the embodiment of FIG. 3. By providing two sets of rim openings as shown in FIG. 18, a strong vortex action of the flush water is obtained with an even water level being distributed along the perimeter.  
     [0106] In the rim channel  150  of FIG. 18, unrestricted continuation of the water stream is achieved after the flush water has completed the entire rim path of the rim channel  150  by forming the water discharge slit  156  in a vertical wall  160  of the rim channel  150 . As a result, flush water discharged through the water discharge slit  156  continues to flow in a horizontal direction and consequently does not lose kinetic energy as would result if the flush water impinged upon a vertical wall after complete flow through the rim channel  150 .  
     [0107]FIG. 20 illustrates the configuration of the toilet bowl  20 . FIG. 20 illustrates that the toilet bowl  20  has sufficient depth and is wide enough to have a large enough water spot so as to not collect too much water.  
     [0108] At the completion of the flush process, the flush water and waste material pass through the siphon jet  30  into the trapway  40  which leads to the sewage line. As is shown in FIG. 1, the trapway  40  has a first weir area  162  which connects to a first upwardly inclined trapway section  164 . The length of the first trapway section  164  is minimized such that the standing water in the sump, first weir area  162  and first trapway section  164  is approximately 0.475 liters (see FIG. 21). The first trapway section  164  leads to a downwardly inclined second trapway section  166  which, as shown in FIG. 21, has a slope which is directed to the bowl at an angle of approximately 30°. A second weir area  168  is provided at a discharge end  169  of the second trapway section  166 . The trapway  40  next slopes upwardly in a third trapway section  170  which connects to a generally vertically oriented and downwardly depending fourth trapway section  172  which is connected to the sewage line  31 . In the preferred embodiment, the toilet bowl  20  and trapway  40  store approximately 1.9 liters of water.  
     [0109] In accordance with one of the advantages of the present invention, the trapway  40  has no reduction in cross-section throughout its entire length. In one preferred embodiment, each of the sections of the trapway  40  has a diameter throughout its entire length of up to approximately 2.5 inches. As a result, waste which is less than 2½″ in diameter can pass therethrough without clogging the trapway. Therefore, if any waste material goes into the trapway  40 , it passes therethrough because the trapway  40  has no reduction of cross section. If any clogging takes, place in the toilet  10  of the present invention, the clogging will occur in the sump and can be easily cleaned without cable or plumber assistance. Moreover, due to the lack of reduction in the diameter of the trapway, an anti-clogging cable can easily pass therethrough. Therefore, the trapway design herein provides for outstanding waste removal capacity. Moreover, this trapway design provides for a discharge rate into the sewage line of 4.2 liters/sec.  
     [0110] Therefore, the total water usage per cycle of this toilet is 5.7 liters with 4.5 liters going into flush and 1.2 liters into refill. The amount of fresh residual water in the sump after a flush operation is 0.7 liters.  
     [0111] FIGS.  22 - 24  illustrate another embodiment of a toilet in accordance with the teachings of the present invention which achieves a similar flushing operation to that of FIGS.  1 - 3 . In this embodiment, flush water flows through the rim channel  24   a  (designated by arrow H) and flush water flows through the jet channel  29   a  (designated by arrow I) in opposite directions after being discharged from the transitional pathway  22   a . Although the flush water paths are directed in this manner, hydraulic losses have been found to be minimal.  
     [0112]FIG. 25 illustrates another water flow path for a toilet in accordance with the present invention wherein water flow is directed in the same direction (see arrows J and K) into the rim channel  24   b  and the direct jet channel  29   b . In this embodiment, a portion  176  of the transitional pathway  22   b  is formed of a plastic insert.  
     [0113]FIGS. 26 and 27 illustrate that the transitional pathway and the direct jet pathway are at least in part formed of a plastic insert, such as  180 . A first hole  182  is provided in the plastic insert  180  such that flush water is directed to the rim channel  24 . A second hole  184  is provided at the end of the insert  180  so that flush water can be directed into the base of the bowl. Hydraulic losses, as appear in the water flow path of FIG. 28, are alleviated by providing a smooth channel, the plastic insert  180 , to transfer jet water from the valve inlet  110  to the inlet  184  of the jet channel  29  around the bowl. This smooth non-turbulent flow is enhanced by using plastic, rubber or some other material insert as compared to the more turbulent flow experienced in the water flow path of FIG. 28. By fitting the insert into a finished China toilet, an ease of manufacturing results as well as a more efficient and less expensive assembly.  
     [0114] Accordingly, for those reasons set forth above, a toilet has been designed which achieves a greater energy throughput in comparison to existing toilets to thereby provide more flush water energy to remove waste from the toilet bowl. In addition, the toilet meets governmental agency requirements which mandate a minimum “hold-down” duration of the flush lever of one second and a maximum water usage of 1.6 gallons (6 liters)/flush. Moreover, the toilet of the present invention enhances the flow characteristics and flow capacity of the flush water and provides a flushing operation which is completed in approximately 2.5 seconds (see FIG. 29). Further, the trapway design of the toilet reduces the chances of clogging.  
     [0115] Although the invention has been particularly shown and described with references to certain preferred embodiments, it will be readily appreciated by those or ordinary skill in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention. It is intended that the appended claims be interpreted as including the foregoing as well as various other such changes and modifications.