ANTI-SIPHONIC TOILET
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application claims the benefit of and priority to U.S. Provisional Patent
Application No. 611779,944, which was filed on March 13,2013. The foregoing U.S.
provisional patent application is incorporated by reference herein in its entirety.
BACKGROUND
[0002] This applicatiori relates generally to the field oftoilets. More specifically, this
application relates to toilets including improved trapways configured to prevent a toilet, such as a
wash-down toilet, from siphoning during its flush cycle.
[0003] Generally, toilets can be classified into two types based on the function of the flush
cycle, with the first type being a siphonic toilet, and the second type being a wash-down toilet.
In a siphonic toilet, an amount of water is quickly supplied during the flushing cycle to
completely fill the trapway, which is typically S-shaped, with water. Air is removed from the
trapway as it is filled with water, and a siphon is created, which rapidly evacuates any water and
waste from the toilet bowl. The siphoning ends once the water level drops below the inlet of the
passageway, thereby allowing air to be introduced. In a siphonic toilet, typically all of the water
in the bowl is removed during the flush cycle, and therefore there is not enough water left in the
bowl to act as a water barrier to block sewer gases (e.g., back flowing gases). Accordingly, after
the sipho~ei vacuates the bowl, water is added to the bowl to create a water barrier.
[0004] In a wash-down toilet, the trapway is generally not configured to induce a siphon. In a
wash-down toilet, the water level in the toilet bowl is at equilibrium with the height of a weir or
dam. When water is supplied to the toilet bowl during a flushing cycle, waste is carried out of
the bowl by the excess water until the flush cycle is co~npletea nd equilibrium is reached.
However, some wash-down toilets have a tendency for a siphon to occur during the flushing
as a single unitary body with one another or with the two members or the two members and any
additional intermediate members being attached to one another.
100661 Ileferences herein to the positions of elements (e.g., "top," "bottom," "above," "below,"
etc.) are merely used to describe the orientation of various elements in the FIGURES. It should
be noted that the orientation of various elements may differ according to other exemplary
embodimcnts, and that such variations are intended to be encompassed by the present disclosure.
100671 It is important to note that the construction and arrangement of the toilets and trapways
as shown in the various exemplary embodiments is illustrative only. Although only a few
embodiments have been dcscribed in detail in this disclosure, those skilled in the art who review
this disclosure will readily appreciate that many modifications are possible (e.g., variations in
sizes, dimensions, structures, shapes and proportions of the various elements, values of
parameters, mounting arrangements, use of materials, colors, orientations, etc.) without
materially departing from the novel teachings and advantages of the subject matter described
herein. For example, elements shown as integrally formed may be constructed of multiple parts
or elements, the position of elements may be reversed or otherwise varied, and the nature or
number of discrete elements or positions may be altered or varied. The order or sequence of any
process or method steps may be varied or re-sequenced according to alternative embodiments.
[0068] Other substitutions, modifications, changes and omissions may also be made in the
design, operating conditions and arrangement of the various exemplary embodiments without
departing from the scope of the present invention. For example, any element provided in one
embodiment niay be used with any other embodirnent of the application.
cycle. For example, if the water is introduced into the bowl too quickly, then a siphon can be
induced in the trapway.
[0005] Furthermore, wash-down toilets generally are not configured to include a feature that
refills the bowl after the flush cycle, since there is generally water left in the bowl following a
flush cycle, unless siphoning has occurred. As a result, if siphoning occurs during the flush
cycle of such a wash-down toilet, then more water may be pulled from the bowl of the toilet than
may be desired.
[0006] Since adding a refill feature to wash-down toilets is relatively expensive and wastes
water in the event there is no siphoning, there exists a need to prevent siphoning from occurring
during the flush cycle in wash-down toilets without the addition of refill features.
SUMMARY
[0007] One embodiment relates to a wash-down toilet that includes a bowl, a passageway, and
a trapway. The bowl includes a sump. The passageway includes an inlet in fluid communication
with the sump, an outlet provided at a height above the inlet, and a weir. The trapway includes
an inlet, an outlet, and a vent, with the inlet of the trapway being in fluid communication with the
outlet of the passageway and the outlet being in fluid communication with a soil pipe. The vent
is configured to introduce a supply of air into the trapway during a flush cycle to prevent
siphoning.
[0008] The trapway may further include an elbow disposed between the inlet and the outlet of
the trapway. The vent may be provided on an upper portion of the elbow. The vent, if provided
on the upper portion of the elbow, may be located above a centerline of the inlet of the trapway.
[0009] The vent may be configured as a two-way vent, such that the vent is coupled to a
transfer pipe configured to vent sewer gases from the toilet to the transfer pipe in addition to
supplying air to the trapway. Alternatively, the vent may be configured as a one-way vcnt that
prevents fluid from entering the vent. The one-way vent may i~icludea valve that prevents the
fluid from entcring the vent.
[0010] The vent may have a cross-sectional size that is smaller than either a cross-sectional
size of the inlet or a cross-sectional size of the outlet of the trapway. The cross-sectional size of
the vent may be smaller than both the cross-sectional size of the inlet ofthe trapway and the
cross-sectional size of the out of the trapway.
[0011] The inlet of the trapway may be coupled to the outlet ofthe passageway through a set of
mating threads.
[0012] Another embodiment relates to a toilet configured to prevent siphoning during its flush
cycle. The toilet includes a bowl having a sump, a passageway, and a trapway. The passageway
includes an inlet that is in fluid communication with the sump, an outlet that is provided at a
height above the inlet, and a weir that is provided at a height above the inlet between the inlet
and outlet in the passageway. The trapway includes an inlet portion that is in fluid
communication with the outlet of the passageway, an outlet portion configured to be in fluid
communication with a soil pipe, and a vent tube that introduces a supply of air into the trapway
at a location between the inlet portion and the outlet portion during a flush cycle to prevent
siphoning. The vent tube is provided above a centerline of a vertical cross-section of the inlet
portion of the trapway.
[0013] The vent tube may be configured having a cross-sectional area that is smaller than a
cross-sectional area of an inlet of the inlet portion. The cross-sectional area of the vent tube may
also be configurcd smaller than a cross-sectional arca of an outlet of the outlet pollion. The
cross-sectional area of the outlet of the outlet portion may be configured smaller than the crosssectional
area of the inlet of the inlet portion.
[0014] The vent tube may be configured as a two-way vent that is coupled to a transfer pipe in
order to vent sewer gases from the toilet (to the transfer pipe). The vent tube may be
cylindrically shaped including a centerline, such that the vent tube extends between a first end
coupled to the trapway and a second end, with the centerline of the first end of the vent tube
located between a centerline of the outlet portion and the inlet of the inlet portion of the trapway
(e.g., in a front-to-back direction of the trapway when cut by a vertical section). The first cnd of
the vent tube may be coupled to a top side of an elbow pollion, which interconnects the inlet
portion and the outlet portion of the trapway.
[0015] Yct another ernbodiinent relates to a method for flushing a wash-down toilet. The
method includes introducing a supply of water into a bowl ofthe toilet to move water and waste
in a sump ofthe bowl through a passageway to a trapway of tlie toilet, the passageway including
an inlet and an outlet, wherein thc outlet is provided at a height that is above the inlet and is in
fluid communication with the trapway; introducing a supply of air into the trapway through a
vent to prevcnt a siphon when the water and waste are flowing through the trapway; passing the
water, waste, and air from the trapway; and providing a remaining volume of water in the sump.
[0016] The vent of the trapway may be provided above a centerline of a vertical cross-section
of an inlet of the trapway, and the vent tube may have a cross-sectional area that is smaller than a
cross-sectional area of the inlet ofthe trapway and a cross-sectional area of an outlet of the
trapway.
[0017] The outlet of the trapway may be fluidly connected to a first pipe and the vent may be
fluidly connected to a second pipe, wherein the vent is a two-way vent, such that gases are
allowed to pass through the trapway and exit the vent into the second pipe. The water, waste,
and air enter the first pipe through the outlet of tlte trapway.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 is an exploded cross-sectional view of a toilet having a trapway coupled
thereto, according to an exemplary embodiment.
[0019] Figure 2 is a front view of an exemplary embodiment ofa trapway for use in a toilet,
such as the toilet of Figure 1.
[0020] Figure 3 is a side view of the trapway of Figure 2.
[0021] Figure 4 is a cross-sectional view of the trapway of Figure 2, taken along line 4-4 of
Figure 2.
[0022] Figure 5 is an enlarged view of the portion ofthe trapway of Figure 3 shown in detail 5.
-5-
[0023] Figure 6 is an enlarged view of the portion of the trapway of Figure 4 shown in detail 6.
100241 Figure 7 is a perspective view of another exemplary embodiment of a trapway for use in
a toilet, such as the toilet of Figure 1.
10025) Figure 8 is a side view of the trapway of Figure 7.
100261 Figure 9 is a front view ofthe trapway of Figure 7.
[0027] Figure 10 is a top view of the trapway of Figure 7.
100281 Figure 1 1 is a cross-sectional view of the trapway of Figure 7, taken along line 1 1-1 1 of
Figure 8.
[0029] Figure 12 is a cross-sectional view of the trapway of Figure 7, taken along line 12-12 of
Figure 9.
[0030] Figure 13 is a detail view of a portion of another exelnplary embodiment of a trapway.
[0031] Figure 14 is a detail view of a portion of another exemplary embodiment of a trapway.
DETAILED DESCRIPTION
[0032] Referring generally to the figures, disclosed herein are toilets, such as wash-down
toilets, having improved trapways, which are configured to prevent or substantially reduce the
likelihood of siphoning during the flush cycle of the toilet. The trapways may prevent siphoning
by having a vent provided on an elbow oftlie trapway. The vent is configured to break the
siphon by introducing air into the trapway, such as during the flush cycle. The vent may be
provided on an upper portion of the elbow that is provided above the centerline of the entrance
(e.g., inlet) of the trapway to prevent the back flow of water and waste into the vent. The vent
may be configured to allow venting of gas (e.g., sewer gases) from the system through the vent.
100331 Figure 1 illustrates an exemplary embodiment of a toilet 101 configured as a washdown
toilet. As shown, the toilet 101 includes a pedestal 103, which may be co~nposedo f
vitreous china or any other suitable material, and a trapway 105 (e.g., an external trapway) that is
configured to be coupled to the pedestal I03 in fluid communication therewith in order to
transfer water and waste from the pedestal 103 to a soil pipe 107 (e.g., drain pipe). In other
words, the trapway 105 may be disposed between and in fluid communication with the pedestal
103 and the soil pipe 107. Although Figure I illustrates a rear outlet toilet (e.g., a wall-mounted
toilet), it is noted that the trapways disclosed herein may be used with other types of wash-down
toilets, such as, for example, a floor outlet wash-down toilet.
[0034] As shown, the pedestal 103 includes a rim 130, a bowl 131 having a sump 132, and a
passageway 133 (e.g., an internal trapway). The rim 130 is configured to extend around the bowl
131, and may introduce a supply ofwater into the bowl 131, such as during a flush cycle of the
toilet 101. The supply of water may be introduced into the pedestal 103 through a valve from a
tank, a water source, or any other suitable device that ilitroduces water into the toilet. The bowl
131 may transition (e.g., narrow) into the sump 132 that is provided at the bottom of the bowl
13 1, and the sump 132 may be configured to hold a volume of water 1 I 1 in between flush cycles.
[0035] As shown in Figure I, the passageway 133 includes an inlet 134 and an outlet 135,
where the inlet 134 is configured adjacent to and in fluid communication with the sump 132, and
where the outlet 135 is configured adjacent to and in fluid communication with the trapway 105.
Water and waste enter the inlet 134 ofthe passageway 133 from the sulnp 132 and exit the outlet
135 of the passageway 133 to pass into the trapway 105, which in turn transfers the water and
waste to the soil pipe 107. As shown, the inlet 134 of the passageway 133 is disposed below the
outlet 135 of the passageway 133, such that the passageway 133 includes an angled portion 133a
(e.g., an upleg) that extends upward and rearward along an angle from the inlet 134 to the outlet
135 of the passageway 133. The outlet 135 of the passageway 133 may include a flange 135a
that is configured to be coupled to the inlet of the trapway 105. For example, the flange 135a
may include an inner diameter that is configured to receive the inlet of the trapway 105 to fluidly
couple the passageway 133 and the trapway 105, such as through a threaded connectiotl or other
suitable connection. The outlet 135 and/or the flange 135a ofthe passageway 133 may be
configured to extend in a generally horizontal direction, or may extend in a different direction,
away from the angled portion 133a of the passageway 133. The base ofthe outlet 135 of the
passageway 133 (i.e., where the flange 135a extends from) may be configured to include a
shoulder 136, whicli may have a smaller size (e.g., diameter) relative to the size (e.g., inner
diameter) of the outlet 135 oftlie passageway 133, such that the shoulder 136 may act as a stop
to control how much of the trapway 105 (e.g., inlet ofthe trapway) can be inserted into the outlet
135 of the passageway 133. Thus, an end surface of the inlet of the trapway 105 may contact the
shoulder 136 of the passageway 133 upon coupling the trapway 105 and passageway 133.
[0036] Also shown in Figure 1, the passageway 133 also includes a weir 137 (e.g., a dam) that
is provided adjacent to the flange 135a and is configured to trap a volume ofwater 11 1 in the
sump 132 and in a lower section of the angled portion 133a ofthe passageway 133. The volu~nc
of water 11 1 (as shown in Figure 1 as the water provided below the water level) may form a seal
to prevent or prohibit the back flow of gas (e.g., sewer gases) from the passageway 133 into the
bowl 131. It is noted that the height of the water level may be different (e.g., lower, higher) than
shown in Figure 1, but the water level will be below an apex 138 of the weir 137. The weir 137
may be provided above the inlet 134 of the passageway 133 to form an airtight seal in the
passageway 133, and may be the apex of the bottom of outlet 135 of the passageway 133 (e.g.,
the bottom wall as viewed relative to the centerline of the cross-section cut by a vertical plane, as
shown in Figure 1) to trap water.
[0037] Figures 2-6 illustrate an exemplary embodiment ofa trapway 105 for use in a toilet,
such as the wash-down toilet 101, which is configured to prevent or substantially reduce the
likelihood of siphoning during the flush cycle of the toilet 101. As shown, the trapway 105
includes an inlet 150 (e.g., entrance) and an outlet 151 (e.g., exit) provided at an opposite end of
the trapway 105. The trapway 105 may also include an elbow 152 provided between the inlet
150 and the outlet 151. The trapway 105 may be made from a metal, such as iron (e.g., an iron
pipe material) made through a casting process (e.g., cast iron), or may be made from other
suitable materials, such as a plastic or polymer, or processes.
[0038] The inlet 150 of the trapway 105 is configured to be coupled to the outlet 135 ofthe
passageway 133 and in fluid co~n~nunicatiothne rewith. For example, the inlet 150 ofthe
trapway 105 may have an outer surface 153 that is configured to be connected to the outlet 135
of the passageway 133 either dircctly or indirectly through one or ]nore connecting mernbers.
Alternatively, the inlet 150 ofthe trapway 105 may have an inner surface that is co~iliguredt o be
connected to the outlet 135 of the passageway 133. 'I'he inner or outer surface 153 of the inlet
150 of the trapway 105 may include one or more than one annular ribs, threads having helical
shapes, or another feature for fluidly con~iectingth e inlet 150 of the trapway 105 to the
passageway 133. As shown in Figure 3, the outer surface 153 of the trapway 105 at the inlet 150
includes a plurality of ribs I53a that extend concentrically around the trapway in a parallel and
spaced apart manner. As shown in Figure 5, each rib 153a extends away from the outer surface
153 by a distance and includes a curved surface. The distance that each rib 153a extends away
from the outer surface 153 may be tailored to influence, for example, the coupling strength
between the trapway 105 and the pedestal 103.
100391 The outlet 15 1 of the trapway 105 is configured to be coupled to the soil pipe 107 and
in fluid communication therewith. For example, the outlet 151 of the trapway 105 may have an
outer surface 154 that is configured to be connected to the soil pipe 107 either directly or
indirectly through one or more connecting members. Alternatively, the outlet 15 1 of the trapway
105 may have an inner surface that is co~ifiguredto be connected to the soil pipe 107. The inner
or outer surface 154 of the outlet 15 1 of the trapway 105 may include one or more than one
annular ribs, threads, or another suitable feature for co~inectingth e outlet 15 1 of the trapway 105
to the soil pipe 107.
[0040] The inlet 150 of the trapway 105 may be configured having a larger size (e.g. diameter,
cross-section, etc.) relative to the size of the outlet 151 of the trapway 105 andlor the outlet 135
of the passageway 133. According to an exemplary embodiment, an outer diameter Dl of the
inlet 150 of the trapway 105 is 4.6 - 5.0 inches. More preferably, the outer diameter Dl ofthe
inlet 150 is about 4.8 inches. According to an exemplary embodiment, the outer diameter D2 of
the outlet 15 1 of the trapway 105 is 3.15 - 3.55 inches. More preferably, the outer diameter D2
of the outlet 15 1 is about 3.35 inches. According to an exemplary embodiment, the trapway 105
may have a wall thickness of about 0.29 inches (e.g., 0.29 inches * 0.03 inches). Thus, the inlet
150 may have an inner diameter that is 4.02 - 4.42 inches, and the outlet 15 1 may have an inner
diameter that is 2.57 - 2.97 inches. More preferably the itlner diameter of the inlet 150 may be
about 4.22 inches, and the inner diameter of the outlet 151 may be about 2.77 inches. This
change in diameter of the trapway 105 from the inlet 150 to thc outlet 15 1 may help to improve
the flow of water and wastc through the trapway 105, such as by increasing the velocity of the
flow of waste.
[0041] The elbow 152 of the trapway 105, if provided, is located between the inlet 150 and
outlet 151 of the trapway 105 and is configurcd to change the direction ofthe trapway 105 to
redircct the flow of water and waste in thc systcm. As shown in Figures 3 and 4, the elbow 152
is configured having a curved pollion that transitions from a generally horizontal direction at the
inlet 150 to a generally vertical direction at the outlet 15 1. The curved portion of the elbow 152
may be formed by a radius. According to an exemplary embodiment, the radius R1 of the elbow
152 is 2.0 - 2.4 inches. More preferably, radius R1 of the elbow 152 is about 2.2 inches.
According to an exemplary embodiment, the elbow 152 extends for about 90' (ninety degrees),
such as between its ends. In other words, the elbow 152 may be a 90' part. Alternatively, the
curved portion may be formed by a curvature or other suitable shape, which may extend for more
or less than 90".
[0042] The trapway 105 also includes a vent 155 extending away from the trapway 105, such
as in an upward direction. According to an exemplary embodiment, the vent 155 is configured to
act as a two-way exchange for air and gas, where the vent 155 is configured to introduce a
supply of air into the trapway 105 to prevent or prohibit siphoning during a flush cycle, and
where the vent 155 is also configured to allow gases (e.g., sewer gases emitted) to travel into the
trapway 105 and out through the vent 155. For example, the supply of air may be introduced
into the flow of waste through the vent 155 when the waste and water pass through the trapway
105 to prevent siphoning by introducing air (e.g., a pocket of air) into the flow of water and
waste. The vent 155 is not configured to pull air out of the system, such as the flow of waste
during the flush cycle, because doing so would have the tendency to induce siphoning, and the
vent 155 here is configured to prevent the siphoning. The vent 155 may be configured to pull air
out ofthe system after the water and waste pass by the vent 155, such as to vent gases at the end
of the flush cycle.
100431 According to another exemplary embodiment, the vent I55 may bc configured to act as
a one-way exchange for air and/or fluid. For examplc, the vent 155 may include a valvc or other
suitable restricting feature to limit the flow of air (e.g., gas) and/or fluid in one direction. Thus,
the valve may be configured to allow air to pass from the vent 155 into the trapway 105 to
prevcnt siphoning, but may be configured to prevent the flow of air andlor fluid from the
trapway 105 into the vent 155. For example, air may be introduced into the vent 155 via the pipe
109, which may be coupled at the other end to another device, which may influence (c.g., move)
and/or generate the air supplied to the vent 155.
[0044] As shown in Figure I , the vent 155 is configured as a tube (e.g., pipe, etc.) including a
first end 156 and a second end 157. The vent 155 configured as a tube may have unifonn inner
and outer diameters, such that its size remains generally constant from the first end 156 to the
second end 157. Alternatively, the vent 155 may be configured as a tube that varies in size,
either increasing or decreasing in size as it moves from the first end 156 to the second end 157.
Figure 13 illustrates a vent 355 of the trapway 305 that has a decreasing tapered cross-section
moving from its second end 357 to its first end 356. Figure 14 illustrates a vent 455 of the
trapway 405 that has a decreasing tapered cross-section moving from its first end 456 to its
second end 457. The vent 155 may also have an outer diameter D3 that is smaller than the outer
diameters Dl, D2 of the inlet 150 and the outlet 151 of the trapway 105. According to an
exemplary embodiment, the outer diameter D3 of the vent 155 is between 1 - 2 inches. More
preferably, the outer diameter D3 of the vent 155 is about 1.9 inches, which is smaller than the
diameter of the outlet 15 1 of the trapway 105, yet is of adequate size to sufficiently allow an
adequate supply of airlgas exchange therethrough.
[0045] The first end 156 of the vent 155 is located along the trapway 105, such as at an
opening 158 in the elbow 152 of the trapway 105. The second end 157 of the vent 155 is distally
located relative to the first end 156 and may be configured to connect to another component. For
example, the second end I57 may be configured to connect (e.g., fluidly connect) to another pipe
109, which may be configured to transfer gases (e.g., sewer gases) out of the toilet 101, such as
for the two-way vent configuration. The pipe 109 connected to the second end 157 may be
configured to transfer the vented gases out ofthe building in which the toilet 101 is installed.
The second end 157 may include a feature that is configured to facilitate coupling the pipe to the
vent 155. As an example, Figure 6 illustrates a chamfer 157a on the inner edge ofthe second
end 157 of the vent 155, which may help facilitate a pipe that couples to the inner surface (e.g.,
inner diameter) of the second end 157. According to other examples, the feature may be a
chamfer on the outer edge of the second end 157, or may be configured differently than a
chamfer (e.g., a fillet, threads, ribs, etc.).
[0046] As shown, the vent 155 is configured as a generally straight tube. I-fowever, the shape
of the vent 155 may be different than shown. For example, the vent 155 may be curved or may
have any other suitable shape that allows air to be introduced into the elbow 152 ofthe trapway
105 to prevent siphoning during a flush cycle of the toilet 101.
[0047] The vent 155 may be provided on an upper surface 159 (e.g., relative to the centerline
of the inlet portion of the trapway when viewed in cross-section by a vertical cutting plane) of
the elbow 152 of the trapway 105 rearward (e.g., downstream) ofthe inlet 150 ofthe trapway
105. As shown in Figure 4, the vent 155 is located on the upper surface ofthe elbow 152 at a
location that is provided above a centerline CLH of the inlet 150 of the trapway 105. This
location of thc vent 155 may advantageously prevent the flow of water and waste from entering
the vent 155 and passing up through the vent 155, while allowing air to pass through the vent
155 and into the trapway 105, such as to break siphoning, even if a valve is not provided.
[0048] It is noted that the trapway 105 shown is a separate member that is made separately
from the pedestal 103, then coupled to the pedestal 103 (e.g., vitreous pedestal), because it would
be difficult to manufacture the trapway 105 as configured, such as including the vent 155,
without becoming relatively expensive. Moreover, a trapway 105 integrally formed with the
vitreous may be difficult to attach (e.g., connect, couple, etc.) other features thereto, such as
another feature which connects to the vent 155 of the trapway 105. Thus, although the trapways,
as disclosed herein, may be integrally formed with the vitreous, it would be advantageous for at
least the above reasons to form the trapway 105 and pedestal 103 separately.
100491 The toilet 101 may include a seal that is configured to seal the system (e.g., the trapway
105). For example, the toilet 101 may include a first seal that is provided betwcen the outlet 135
of the pedestal 103 and the inlet 150 of the trapway 105 that seals the connection therebetween.
Also, for example, the toilet 101 may include a second seal that is provided between the outlet
15 1 of the trapway 105 and the soil pipe 107 (or other elcment coupled thereto) to seal the
connection therebetween. Also, for example, the toilet 101 may include a third seal that is
configured to seal the connection between the vent 155 and the element coupled thereto, if any
such element is provided. Each scal may be conligured to prevent leaking of fluid andlor air
from the connection, and may be configured using any suitable sealing material having any
suitable shape.
[OOSO] Figures 7-12 illustrate another exemplary embodiment of a trapway 205 for use with a
toilet, such as the wash-down toilet 101. As shown, the trapway 205 includes a body portion
having an inlet 250 (e.g., entrance) and an outlet 251 (e.g., exit) provided at an opposite end of
the trapway 205. The body portion of the trapway 205 may also include an elbow 252 provided
between the inlet 150 and the outlet 151. The inlet 250 of the trapway 205 is configured to be
coupled to an outlet (e.g., the outlet 135) of a passageway of a toilet to be in fluid
com~nunication with the passageway. The outlet 251 of the trapway 205 is configured to be
coupled to the soil pipe 207 to be in fluid communication with the soil pipe 207. The elbow 252
of the trapway 205, if provided between the inlet 250 and outlet 251, is configured to change the
direction of the trapway 205 to redirect the flow of water and waste in the system. As shown, the
elbow 252 is configured having a curved portion that transitions from a generally horizontal
direction at the inlet 250 to a generally vertical direction at the outlet 251. In other words, the
elbow 252 may extend over an angular travel of about 90" (ninety degrees).
[OOSl] The trapway 205 may also include a vent that extends away from the body portion of
the trapway 205, such as in an upward direction. As shown in Figures 7-12, the trapway 205
includes a first vent 255 and a second vent 258. The first vent 255 and second vent 258 may
extend adjacent to one another and away from the body poltion, such as from an upper surface
(e.g., section, portion. etc.) of the body portion. Each vent 255,258 may be provided on an
upper surface (e.g., when viewed in cross-section by a vertical cutting plane), such as an uppcr
surface of the elbow 252, that is rearward (e.g., downstream) of the inlet 250 and above a
centerline of the inlet 250 to advantageously prevent the flow of water and waste from entering
each vent 255,258.
[0052] As shown in Figure 8, the first vent 255 and second vent 258 are configured at an angle
A1 relative to one another when viewed from the front ofthe trapway 205. According to one
example, each of the first vent 255 and the second vent 258 is configured at an angle A2 relative
to vertical, such that the vents extend away from the body portion in a symnletric manner from a
vertical plane. The first and secotid vents 255,258 may extend radially away from the centerline
of the inlet 250 of the body portion at the angle A2. Thus, the first and second vents 255,258
may have a generally V-shape.
[0053] As shown in Figure 9, the first vent 255 includes a first end 256 and a second end 257.
The first end 256 of the first vent 255 is located along the trapway 205, such as at an opening in
the body portion. For example, the first end 256 ofthe first vent 255 may be coupled to the body
portion of the trapway 205, such as the upper surface ofthe elbow 252, to place the first vent 255
and the body portion of the trapway 205 in fluid communication. The second elid 257 of the first
vent 255 is distally located relative to the first end 256 and may be configured to connect to
another component. The second end 257 of the first vent 255 may be closed-off or may be openended.
For example, the second end 257 may include a cap to form a closed seco~ide nd, such as
to prevent flow from the second end 257. Also, for example, the second end 257 may be openended
atid it1 fluid cotnmunication with another element or object, such as a pipe to input a
supply of air into the first vent 255 andlor output gases (e.g., sewer gases) from the toilet to the
pipe,
100541 Also shown in Figure 9, the second vent 258 includes a first end 259 and a second end
260. The first end 259 of the second vent 258 is located along the trapway 205, such as at an
opening in the body portion. For example, the first end 259 of the second vent 258 may be
coupled to the body portion of the trapway 205, such as the upper surface of the elbow 252. The
second end 260 of the second vent 258 is distally located relative to the first end 259 and may be
configured to connect to another co~nponent. The second end 260 of the second vent 258 may be
closed-ended (e.g., closed-om or may be open-ended (e.g., opened). For example, the second
end 260 may include a cap to form a closed second end, such as to prevent flow fro~nth e second
end 260. Also, for example, the second end 260 may be open-ended and in fluid comtnunication
with another element or ob,ject, such as a pipe to input a supply of air into the second vent 258
and/or output gases (e.g., sewer gases) from the toilet to the pipe.
[OOSS] Each vent 255,258 may be configured as a tube, a pipe, or any suitable shape that is
capable of transferring a fluid to and from trapway 205. Each vent 255, 258 luay be configured,
for example, as a generally straight tube, a curved tube, or may have any other suitable shape that
allows a fluid to be transferred through the vent.
100561 Each vent 255,258 may have uniform cross-sectional shape, such as where its inner and
outer sizes (e.g., diameters) remain generally constant from its first end 256, 259 to its second
end 257, 260. Alternatively, each vent 255, 258 may vary in size, either increasing or decreasing
in size as it moves from its first end 256, 259 to its second end 257,260. For example, each vent
255,258 may have an increasing or decreasing diameter moving from one end to the other end.
Also, for example, one of the vents 255, 258, such as a one-way vent that introduces air into the
body portion ofthe trapway 205, may have a decreasing size from its second end to its first end,
which may increase the flow (e.g., velocity) of the air moving through the vent; and the other of
the vents 255,258, such as a one-way vent that transfers gases from the body portion to the vent,
may have a decreasing size from its first end to its second end, which may increase the flow
(e.g., velocity) ofthe gases moving through the vent.
[0057] Each vent ofthe first and second vents 255,258 may be configured to be closed-ended
or may be open-ended, either in a one-way configuration or in a two-way configuration. The
one-way configured vent allows an exchange of fluid (e.g., air, gases, etc.) in only a single
direction. For example, the one-way vent may be configured to allow a fluid, such as air, to exit
the vent into the body portion of the trapway 205, but prevents any fluid from entering the vent
fiorn the body portion. Also, for example, the one-way vent may be configured to allow fluid,
such as gases, to enter the vent iiom the body portion of thc trapway 205, but prevents any fluid
from exiting the vent into the body portion. Each oac-way vent may include a valve or other
suitable restricting feature to limit the flow of fluid in one direction relative to the vent. T' I' g ure
11 is illustrated to include a valve 270 provided in each of thc vents 255,258. However, as
disclosed herein, each vent 255,258 may be configured without a valve, or a valve 270 may be
provided in one ofthe vents 255,258.
(00581 The two-way configured vent allows an exchange of fluid in at least two directions. In
other words, the two-way vent is configured to allow fluid to both exit the vent (e.g., the vent
255, the vent 258) into the body portion ofthe trapway 205 and enter the vent from the body
portion. For example, the two-way vent may be configured to allow air to enter the body portion
ofthe trapway 205 from the vent, such as during a flush cycle to prevent siphoning, and may
further allow gases to exit the body portion and enter the vent, such as to transfer the gases from
the toilet at the end of a flush.
(0059) According to an exemplary embodiment, one of the first and second vents 255,258 is
configured as a one-way vent that allows fluid, such as air, to enter the body portion of the
trapway 205 from the vent, and the other vent is configured as a one-way vent that allows gases
to exit the body portion into the other vent. Each of the first and second vents 255,258 may
include a valve, which may be configured to openlclose depending on the operation of the toilet.
For example, the valve in the vent (e.g., the first vent 255) that introduces air into the body
portion from the vent may be timed to open during the flush cycle when the water and waste
flow through the body portion to introduce a supply of air (e.g., a pocket of air) into the body
portion to prevent siphoning of the toilet. Also, for example, the valve in the vent (e.g., the
second vent 258) that escapes sewer gases from the body portion to the vent may be timed to be
closed during the flush cycle when the water and waste flow through the body portion and may
be open before and after the period ofthe flush cycle when the water and waste flow through the
body portion of the trapway 205.
[0060] According to another exemplary embodiment, one of the first and second vents 255,
258 is configured as a two-way vent that allows fluid to enterlexit the body portion of the
trapway 205 fro~rt/toth c vent, and the othcr vcnt may be closed-off. This arrange~ncnti lay be
advantageous where an obstacle (e.g., member, structure, element, component, etc.) is positioned
above one of the vents, but not above the other vent, such that one of the vents may be utilized to
vent around the obstacle. Thus, the two-vent trapway 205 may be configured to route the
venting around another structure, and prevent siphoning of the toilet during its flush cycles.
[0061] According to another exemplary embodiment, both ofthe first and second vents 255,
258 may be configured as two-way vents. Thus, both of the first and second vents 255,258 may
be configured to allow fluid to enter the body portion of the trapway 205 from the vent and exit
the body portion to the vent.
100621 It is noted that although specific dimensions have been provided for various features
and elements of ihe toilet, such as the trapway of the toilet, the dimensions provided are
exemplary and are not limiting.
[0063] As utilized herein, the terms "approximately," "about," "substantially", and similar
terms are intended to have a broad meaning in harmony with the common and accepted usage by
those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should
be understood by those of skill in the art who review this disclosure that these terms are intended
to allow a description of certain features described and claimed without restricting the scope of
these features to the precise numerical ranges provided. Accordingly, these terms should be
interpreted as indicating that insubstantial or inconsequential modifications or alterations of the
subject matter described and claimed are considered to be within the scope of the invention as
recited in the appended claims.
[0064] It should be noted that the term "exemplary" as used herein to describe various
embodiments is intended to indicate that such embodiments are possible examples,
representations, andlor illustrations of possible embodinients (and such term is not intended to
connote that such embodiments are necessarily extraordinary or superlative examples).
[0065] The terms "coupled," "connected," and the like as used herein mean the joining of two
members directly or indirectly to one another. Such joining may be stationary (e.g., permanent)
or moveable (e.g., removable or releasable). Such joining may be achieved with the two
members or the two members and any additional intermediate members being integrally formed

CLAIMED:
1.A wash-down toilet, comprising:
a bowl having a sump;
a passageway having an inlet, an outlet provided at a height above the inlet, and a weir, the inlet being in fluid communication with the sump; and
a trapway having an inlet, an outlet, and a vent, the inlet of the trapway being in fluid communication with the outlet of the passageway, the outlet being in fluid communication with a soil pipe;
wherein the vent is configured to introduce a supply of air into the trapway during a flush cycle to prevent siphoning.
2. The wash-down toilet of claim 1, wherein the trapway further includes an elbow disposed between the inlet and the outlet of the trapway.
3. The wash-down toilet of claim 2, wherein the vent is provided on an upper portion of the elbow.
4. The wash-down toilet of claim 3, wherein the vent provided on the upper portion of the elbow is located above a centerline of the inlet of the trapway.
5. The wash-down toilet of claim 4, wherein the vent is configured as a two-way vent, such that the vent is coupled to a transfer pipe configured to vent sewer gases from the toilet to the transfer pipe.
6. The wash-down toilet of claim 4, wherein the vent is configured as a one-way vent that prevents fluid from entering the vent.
7. The wash-down toilet of claim 6, wherein the one-way vent includes a valve to prevent the fluid from entering the vent.
8. The wash-down toilet of claim 4, wherein the vent has a cross-sectional size that is smaller than either a cross-sectional size of the inlet or a cross-sectional size of the outlet of the trapway.

9. The wash-down toilet of claim 8, wherein the cross-sectional size of the vent is smaller than both the cross-sectional size of the inlet of the trapway and the cross-sectional size of the outlet of the trapway.
10. The wash-down toilet of claim 1, wherein the inlet of the trapway is coupled to the outlet of the passageway through a set of mating threads.
11. A toilet configured to prevent siphoning during its flush cycle, comprising:
a bowl having a sump;
a passageway having an inlet in fluid communication with the sump, an outlet provided at a height above the inlet, and a weir provided at a height above the inlet between the inlet and outlet in the passageway; and
a trapway having an inlet portion in fluid communication with the outlet of the passageway, an outlet portion configured to be in fluid communication with a soil pipe, and a vent tube that introduces a supply of air into the trapway at a location between the inlet portion and the outlet portion during a flush cycle to prevent siphoning,
wherein the vent tube is provided above a centerline of a vertical cross-section of the inlet portion of the trapway.
12. The toilet of claim 11, wherein the vent tube has a cross-sectional area that is smaller than a cross-sectional area of an inlet of the inlet portion of the trapway.
13. The toilet of claim 12, wherein the cross-sectional area of the vent tube is smaller than a cross-sectional area of an outlet of the outlet portion of the trapway.
14. The toilet of claim 13, wherein the cross-sectional area of the outlet of the outlet portion of the trapway is smaller than the cross-sectional area of the inlet of the inlet portion of the trapway.
15. The toilet of claim 14, wherein the vent tube is a two-way vent and is coupled to a transfer pipe that vents sewer gases from the toilet.
16. The toilet of claim 11, wherein the vent tube is cylindrically shaped including a centerline, wherein the vent tube extends between a first end coupled to the trapway and a second end, wherein the centerline of the vent tube at the first end is located between a centerline of the outlet portion of the trapway and the inlet of the inlet portion of the trapway.
17. The toilet of claim 11, wherein the first end of the vent tube is coupled to a top side of an elbow portion interconnecting the inlet and outlet portions of the trapway.
18. A method for flushing a wash-down toilet, comprising:
introducing a supply of water into a bowl of the toilet to move water and waste in a sump of the bowl through a passageway to a trapway of the toilet, the passageway including an inlet and an outlet, wherein the outlet is provided at a height that is above the inlet and is in fluid communication with the trapway;
introducing a supply of air into the trapway through a vent to prevent a siphon when the water and waste flow through the trapway;
passing the water, waste, and air from the trapway; and
providing a remaining volume of water in the sump.

19. The method of claim 18, wherein the vent of the trapway is provided above a centerline of a vertical cross-section of an inlet of the trapway, and wherein the vent tube has a cross-sectional area that is smaller than a cross-sectional area of the inlet of the trapway and a cross-sectional area of an outlet of the trapway.
20. The method of claim 19, wherein the outlet of the trapway is fluidly connected to a first pipe and the vent is fluidly connected to a second pipe, wherein the vent is a two-way vent, such that gases are allowed to pass through the trapway and exit the vent into the second pipe, and wherein the water, waste, and air enter the first pipe through the outlet of the trapway.

21. A wash-down toilet, substantially as herein described with reference to accompanying drawings and examples.
22. A toilet configured to prevent siphoning during its flush cycle, substantially as herein described with reference to accompanying drawings and examples.
23. A method for flushing a wash-down toilet, substantially as herein described with reference to accompanying drawings and examples.