VACUUM ASSIST FLUSH SYSTEM

CROSS-REFERENCE TO RELATED APPLICATION

[0001]This application claims the benefit of U.S. Provisional Application No. 63/426,578, filed Nov. 18, 2022, the entire contents of which is incorporated herein by reference.

FIELD

[0002]The present disclosure relates generally to dual-trap toilets.

BACKGROUND

[0003]Conventional dual-trap toilets comprise a trapway that is configured to trap water in two separate locations. A first upstream trap may located directly downstream of the toilet bowl and may be configured to hold water in the toilet bowl in between flush cycles. A second downstream trap may be located between the first trap and an outlet from the trapway to a drainage pipe. The dual-trap configuration may prevent sewer gases from leaking out of the sewer through drainage pipe while also providing a quieter flush cycle than other flush toilets (e.g., single trap toilets).

SUMMARY

[0004]As discussed above, dual-trap toilets may comprise a trapway configured to trap water in an upstream trap and a downstream trap between flush cycles. Between flush cycles, positively pressurized air may be contained in the trapway between the upstream trap and the downstream trap. The pressurized air in the trapway may be fluidly coupled to pressurized air contained in the toilet tank. When a flush cycle is initiated, water may be discharged from the toilet tank into the toilet bowl, which may cause the pressure of the air in the trapway to drop. This drop in pressure may create a siphon in the trapway that pulls the contents of the toilet bowl into and out of the trapway.

[0005]Once the pressure drops in the trapway to generate the siphon, the air pressure within the trapway may not return to pre-flush levels until the toilet tank has replenished its supply of flush water at the end of the flush cycle. However, increasing the air pressure within the trapway before the end of a flush cycle has been found to result in a quieter, more efficient flush cycles.

[0006]Accordingly, described are dual-trap toilets with air transfer openings in a container of the toilet tank. The air transfer openings may provide a passageway for air to flow to and/or from a vacuum chamber in the toilet tank that provides pressurized air to the trapway. When the toilet tank is filled with water such that a water level in the toilet tank is above the air transfer opening, the flow of air through the air transfer opening may be blocked, and air inside the vacuum chamber may be positively. During a flush cycle, as water exits the toilet tank and the water level drops below the air transfer opening, air may be allowed to flow through the opening into and/or out the vacuum chamber. When the air transfer opening connects the vacuum chamber to atmospheric pressure, vacuum in the vacuum chamber may thus be broken, allowing the vacuum chamber to depressurize and for the trapway to return to atmospheric pressure more quickly following the initiation of a flush cycle. This may reduce total flush water consumption per flush cycle and, in some cases, may result in a quieter flush.

[0007]A toilet assembly according to the present disclosure may comprise a toilet tank to hold flush water, a container positioned in and in flow communication with the toilet tank, the container comprising a vacuum chamber having a closed upper end, an air transfer opening between a region exterior to the vacuum chamber and an interior of the vacuum chamber, a flush valve assembly positioned in the toilet tank, a toilet bowl, a trapway in flow communication with the toilet bowl, and a connecting tube extending from the vacuum chamber of the container to the trapway and providing flow communication between the container and the trapway.

[0008]In some embodiments, when the toilet assembly is between flush cycles, the upper end of the vacuum chamber contains a first portion of pressurized air, the trapway contains a second portion of pressurized air, and a flush water level in the vacuum chamber is above the air transfer opening, preventing flow communication of air between the region exterior to the vacuum chamber and the vacuum chamber.

[0009]In some embodiments, during a flush cycle, the flush water level in the vacuum chamber drops below at least a portion of the air transfer opening, allowing flow communication of air between the region exterior to the vacuum chamber and the vacuum chamber.

[0010]In some embodiments, upon discharging flush water into a flush valve core to initiate a flush cycle, reduced pressure is created in the first portion of pressurized air in the vacuum chamber and the second portion pressurized air in the trapway.

[0011]In some embodiments, the air transfer opening comprises an air transfer tube extending from the region exterior to the vacuum chamber to the interior of the vacuum chamber.

[0012]In some embodiments, the air transfer tube has a diameter between 0.25 inches and 0.5 inches.

[0013]In some embodiments, the air transfer tube extends out of the region exterior to the vacuum chamber, through an upper end wall of the container that bounds the upper end of the vacuum chamber, and into the upper end of the vacuum chamber.

[0014]In some embodiments, the air transfer tube extends from the region exterior to the vacuum chamber, through an inner wall of the container that separates the inner chamber from the vacuum chamber, and into an upper end of the vacuum chamber.

[0015]In some embodiments, the air transfer opening is a slot in a wall of the container that separates the region exterior to the vacuum chamber from the vacuum chamber.

[0016]In some embodiments, the slot is tapered such that an upper portion of the slot is narrower than a lower portion of the slot.

[0017]In some embodiments, a width the upper portion of the air transfer slot is 0.125 inches and a width of the lower portion of the air transfer slot is 0.25 inches.

[0018]In some embodiments, the slot is between 1 and 3 inches in length.

[0019]In some embodiments, the region exterior to the vacuum chamber is an inner chamber of container, wherein an upper end of the inner chamber is open.

[0020]In some embodiments, the flush valve is positioned in the inner chamber.

[0021]In some embodiments, the trapway comprises a sump trap, a first upstream weir, a lower trap, and a second downstream weir.

[0022]In some embodiments, the connecting tube is coupled to the trapway at a position between the sump trap and the lower trap such that, when the toilet assembly is between flush cycles, the second portion of pressurized air in the trapway is contained between the sump trap and the lower trap.

[0023]In some embodiments, the flush valve assembly comprises a valve body extending from a valve inlet to a valve outlet and a valve cover having a seal to enclose the valve inlet.

BRIEF DESCRIPTION OF THE FIGURES

[0024]The following figures show various views and/or associated data for dual-trap toilets, in accordance with some embodiments. The dual-trap toilets shown in the figures may, in some embodiments, have any one or more of the characteristics described herein.

[0025]FIGS. 1A and 1B show perspective views of a dual-trap toilet, in accordance with some embodiments.

[0026]FIG. 2 shows a cross-sectional view of a dual-trap toilet, in accordance with some embodiments.

[0027]FIG. 3 shows a perspective cutaway view of a dual-trap toilet, in accordance with some embodiments.

[0028]FIG. 4 shows a partial cross-sectional view of a dual-trap toilet, in accordance with some embodiments.

[0029]FIGS. 5A-5C show various cutaway and cross-sectional views of a tank of a dual-trap toilet, in accordance with some embodiments.

[0030]FIGS. 6A-6C show distributions of flush water and pressurized air in a tank and a trapway of a dual-trap toilet that is between flush cycles, in accordance with some embodiments.

[0031]FIGS. 7A-7C show distributions of flush water and pressurized air in a tank and a trapway of a dual-trap toilet after a flush cycle has been initiated, in accordance with some embodiments.

[0032]FIGS. 8A-8C show distributions of flush water and pressurized air in a tank and a trapway of a dual-trap toilet during a flush cycle, in accordance with some embodiments.

[0033]FIGS. 9A-9C show distributions of flush water and pressurized air in a tank and a trapway of a dual-trap toilet toward the end of a flush cycle, in accordance with some embodiments.

[0034]FIG. 10 shows an exemplary air transfer tube in a tank of a dual-trap toilet, in accordance with some embodiments.

[0035]FIG. 11A-11B shows an exemplary air transfer slot in a tank of a dual-trap toilet, in accordance with some embodiments.

[0036]FIGS. 12A-12B show an exemplary air transfer port in a tank of a dual-trap toilet, in accordance with some embodiments.

[0037]FIG. 13 shows an exemplary air transfer opening in a tank of a dual-trap toilet, in accordance with some embodiments.

DETAILED DESCRIPTION

[0038]Dual-trap toilets comprise a trapway that is configured to trap water in two separate locations. In some embodiments, dual-trap toilets may have a trapway including a sump trap, a first upstream weir, a lower trap, and a second downstream weir. A container positioned in the toilet tank may be coupled by a connecting tube that extends between an interior of the container and the trapway. The connecting tube may be coupled to the trapway at a position between the sump trap and the lower trap and may provide flow communication between the container and the trapway. Between flush cycles, the container and the trapway may contain positively pressurized air. Between flush cycles, the positively pressurized air in the trapway may push upwards on water in the sump trap and may result in a larger water spot in the toilet bowl than would be present if not for the positively pressurized air. Between flush cycles, the positively pressurized air in the trapway may push downwards on water in the lower trap, such that a water level in an upstream end of the lower trap may be lower than a water level in a downstream end of the lower trap.

[0039]Upon initiation of a flush cycle, a flush valve seal may lift off of a flush valve inlet to the flush valve to open the flush valve, and flush water may be discharged from the toilet tank and the container through the flush valve and into the toilet bowl. As used herein, the term “flush water” may refer to any water that passes out of a toilet tank (or any subcomponent thereof, such as a container positioned inside a toilet tank, an inner chamber of said container, and/or a vacuum chamber of said container) during a flush cycle. Discharging the flush water during a flush cycle may exert a negative pressure on air in an upper end of the container, connecting tube, and trapway portion between the sump trap and the lower trap. The negative pressure may cause a drop to atmospheric pressure or to partial vacuum. The negative pressure may help create a siphon to pull water and waste through the sump area and into and out of the trapway.

[0040]In some embodiments, during a flush cycle, flush water may exit the tank, a container positioned within the tank, an inner chamber of the container, and/or a vacuum chamber of the container. Water leaving any one or more of said components during a flush cycle may be referred to as “flush water.” In some embodiments, some or all or none of the flush water may flow from the tank (considered separately from the container positioned within the tank) during a flush cycle. In some embodiments, some or all some or all or none of the flush water may flow from the container (considered separately from the tank) during a flush cycle. In some embodiments, some or all some or all or none of the flush water may flow from the vacuum chamber of the container (considered separately from other portions of the container and from the tank) during a flush cycle. In some embodiments, some or all some or all or none of the flush water may flow from the inner chamber of the container (considered separately from other portions of the container and from the tank) during a flush cycle.

[0041]In some embodiments, one or more components of a dual trap toilet may be configured to optimize a ratio of positively pressurized air located in various portions of the toilet between flush cycles. In some embodiments, a first portion of positively pressurized air is located in an upper end of the container in the tank between flush cycles, while a second portion of positively pressurized air is located in the trapway between water in the sump trap and water in the lower trap between flush cycles. (In some embodiments, the second portion of positively pressurized air may also include air located in the connecting tube and/or in an interface portion between the connecting tube and the trapway.)

[0042]A flush cycle may be considered completed upon closing the flush valve and re-filling the toilet tank, sump trap, and lower trap. Upon completion of a flush cycle, new flush water entering the toilet tank may also enter the container via one or more openings positioned in the container wall. Entry of water into the container may compress air into an upper end of the container and may return the air contained in the regions defined by the upper end of the container, the connecting tube, and the trapway portion between a sump trap and a lower trap to atmospheric pressure and/or to a positive pressure above atmospheric pressure.

Dual-Trap Toilets

[0043]Dual-trap toilets comprise a trapway that is configured to trap water in two separate locations. A first, upstream trap may located directly downstream of the toilet bowl and may be configured to hold water in the toilet bowl in between flush cycles. A second, downstream trap may be located between the first trap and an outlet from the trapway to a drainage pipe. The dual-trap configuration may prevent sewer gases from leaking out of the sewer through drainage pipe while also providing a quieter flush cycle than other flush toilets (e.g., single trap toilets).

[0044]FIGS. 1A and 1B show perspective views of a dual-trap toilet, in accordance with some embodiments. Specifically, FIGS. 1A and 1B illustrate perspective views of a dual-trap toilet 100 comprising a toilet bowl 102, a toilet tank 104, and a trapway 106. In some embodiments, toilet bowl 102, toilet tank 104, and trapway 106 may be in flow communication. In some embodiments, as shown in FIG. 1B, toilet 100 may comprise a flush control 108. Flush control 108 may comprise one or more handles, push buttons, levers, chains, position sensors, and/or motion sensors that are configured to initiate a flush cycle when engaged by a user.

[0045]Between flush cycles, toilet bowl 102 may contain a volume of water. In some embodiments, a volume of water contained in toilet bowl 102 between flush cycles may be about 0.5 gallons, about 0.75 gallons, about 1 gallon, about 1.25 gallons, about 1.5 gallons, about 1.75 gallons, about 2 gallons, about 3 gallons, about 4 gallons, or about 5 gallons. In some embodiments, a volume of water contained in toilet bowl 102 between flush cycles may be greater than or equal to 2.5 gallons, 3.5 gallons, 4.5 gallons, 5.5 gallons, 6.5 gallons, 7.5 gallons, or 8.5 gallons. In some embodiments, a volume of water contained in toilet bowl 102 between flush cycles may be less than or equal to 2 gallons, 1.5 gallons, 1 gallon, 0.5 gallons, or 0.1 gallons.

[0046]Toilet tank 104 may be configured to contain flush water. Toilet tank 104 may be configured to fluidly connect to a water supply. In some embodiments, when a flush cycle is initiated, toilet tank 104 may be configured to discharge a volume of contained flush water into toilet bowl 102. Toward the end of a flush cycle, toilet tank 104 may be configured to replenish the discharged volume of water by receiving water from the water supply.

[0047]In some embodiments, when a flush cycle is initiated (e.g., by a user who engages flush control 108), the contents of toilet bowl 102 may be siphoned into trapway 106. Trapway 106 may be configured to fluidly connect to a sewer system (or to one or more drain pipes that connect to a sewer system). During a flush cycle, the siphoned contents of toilet bowl 102 may be directed through trapway 106 and into the sewer system.

[0048]In some embodiments, trapway 106 may comprise a sump trap and a lower trap. The sump trap may be directly downstream of toilet bowl 102 and the lower trap may be downstream of the sump trap. When toilet 100 is between flush cycles, water may collect in both the sump trap and the lower trap. The collection of water in the sump trap and the lower trap may form a series of water seals which prevent leakage of sewer gas out of trapway 106. In some embodiments, between flush cycles, the water that collects in the sump trap may be the volume of water contained in toilet bowl 102, as described above.

[0049]In some embodiments, when toilet 100 is between flush cycles, toilet tank 104 and trapway 106 may be configured to contain positively pressurized air. The positively pressurized air contained in trapway 106 may be contained between a sump trap and a lower trap and may exert upward pressure on water collected in the sump trap and downward pressure on water collected in the lower trap. In some embodiments, the upward pressure exerted on the water collected in the sump trap by the pressurized air contained in trapway 106 may raise the water level of water contained in toilet bowl 102 between flush cycles. The raised water level of water contained in toilet bowl 102 may reduce or prevent soiling of toilet bowl 102.

[0050]In some embodiments, when a flush cycle is initiated and flush water is discharged from toilet tank 104 into toilet bowl 102, a negative pressure may be exerted on the air contained in toilet tank 104 and the air contained in trapway 106. In some embodiments, the negative pressure may cause the pressure within toilet tank 104 and/or trapway 106 to decrease to atmospheric pressure and/or to a partial vacuum. This decrease in pressure may generate a siphon in trapway 106, thereby causing the contents of toilet bowl 102 to be pulled into and subsequently out of trapway 106.

[0051]In some embodiments, toward the end of a flush cycle, water may again collect in toilet bowl 102 and trapway 106. In some embodiments, upon completion of a flush cycle, toilet tank 104 may be configured to receive new flush water from a water supply. As toilet tank 104 refills with flush water, the air contained in toilet tank 104 may be compressed, thereby increasing the pressure of the air contained in toilet tank 104 and/or the air contained in trapway 106 to atmospheric pressure and/or to a pressure above atmospheric pressure. In some embodiments, when the air contained in toilet tank 104 and/or the air contained in trapway 106 have returned to positively pressurized states, the flush cycle may be completed.

[0052]FIG. 2 shows a cross-sectional view of a dual-trap toilet, in accordance with some embodiments. Specifically, FIG. 2 illustrates a cross-sectional view of a toilet 200 comprising a toilet bowl 202, a toilet tank 204, a trapway 206, and a flush control 208. In some embodiments, toilet bowl 202, toilet tank 204, trapway 206, and/or flush control 208 may include features of toilet bowl 102, toilet tank 104, trapway 106, and/or flush control 108 shown in FIG. 1A and/or FIG. 1B.

[0053]In some embodiments, a container 218 and a flush valve 224 may be positioned within toilet tank 204. Container 218 and flush valve 224 may be in flow communication with toilet tank 204. In some embodiments, container 218 may have an irregular toroidal structure that defines a vacuum chamber, an inner chamber, and an outer region in toilet tank 204 that is external to and surrounds both container 218 and the central cavity region. In some embodiments, flush valve 224 may be positioned in the inner chamber defined by container 218 such that container 218 encircles flush valve 224.

[0054]Between flush cycles, toilet tank 204 may be configured to contain flush water. In some embodiments, between flush cycles, a first volume of flush water may be contained the outer region in toilet tank 204 that is external to and surrounds container 218 and the central cavity region defined by the structure of container 218. In some embodiments, between flush cycles, a second volume of flush water may be contained in an inner chamber defined by the structure of container 218. In some embodiments, between flush cycles, a third volume of flush water may be contained in a vacuum chamber contained within the internal irregular annular region of container 218.

[0055]In some embodiments, toilet bowl 202 may be fluidly connected to toilet tank 204 via a fluid pathway 222. Flush valve 224 may be in flow communication with fluid pathway 222 which may, in turn, be in flow communication with toilet bowl 202. In some embodiments, a flush valve gasket 210 may be positioned at an interface between flush valve 224 and fluid pathway 222. Flush valve gasket 210 may form a mechanical seal between flush valve 224 and fluid pathway 222 in order to prevent flush water and/or air from leaking out of toilet tank 204 and into toilet bowl 202 between flush cycles (i.e., to prevent water and/or air leakage from toilet tank 204 when flush valve 224 is closed).

[0056]In some embodiments, fluid pathway 222 may be in flow communication with a rim channel 236 that encircles the rim of toilet bowl 202. In some embodiments, during a flush cycle, a portion of flush water may be transmitted from toilet tank 204, through fluid pathway 222, and into rim channel 236. In some embodiments, the flush water may then be transmitted into toilet bowl 202 from rim channel 236 through one or more rim outlets.

[0057]In some embodiments, the portion of flush water transmitted from toilet tank 204, through fluid pathway 222, and into rim channel 236 may be less than or equal to 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.6, 4.8, or 5 liters. In some embodiments, the portion of flush water transmitted from toilet tank 204, through fluid pathway 222, and into rim channel 236 may be greater than or equal to 1, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.6, 4.8, or 5 liters. The portion of flush water transmitted from toilet tank 204, through fluid pathway 222, and into rim channel 236 may be between about 0.5-2 liters, about 1-3 liters, about 1-4 liters, or about 1-5 liters.

[0058]In some embodiments, less than 50% of the total volume of flush water delivered from toilet tank 204 to toilet bowl 202 during a flush cycle may be transmitted through rim channel 236. In some embodiments, greater than 50% of the total volume of flush water delivered from toilet tank 204 to toilet bowl 202 during a flush cycle may be transmitted through rim channel 235.

[0059]In some embodiments, a lower portion of toilet bowl 202, referred to hereinafter as sump area 214a, may be in flow communication with a first upstream portion 214u of trapway 206 through a trapway inlet 207. The first upstream portion 214u of trapway 206, sump area 214a of toilet bowl 202, and a first downstream portion 214d of trapway 206 may together form a sump trap 214. Between flush cycles, water may be contained in sump trap 214.

[0060]In some embodiments, fluid pathway 222 may be in flow communication with a jet channel 238. Jet channel may be adjacent to an upstream end of trapway 206. In some embodiments, jet channel 238 may be fluidically coupled to sump trap 214 via a jet hole 240. In some embodiments, during a flush cycle, a portion of flush water may be transmitted from toilet tank 204, through fluid pathway 222, and into jet channel 238. In some embodiments, the flush water that is transmitted into jet channel 238 may be transferred into sump trap 214 through jet hole 240 in order to generate a siphon in toilet 200. In some embodiments, the flush water that is transmitted into jet channel 238 may be transferred into sump trap 214 through jet hole 240 at the end of the flush cycle to refill sump trap 214.

[0061]In some embodiments, the ratio of the volume of flush water transmitted through rim channel 236 during a flush cycle to the volume of flush water transmitted through jet hole 240 during a flush cycle may be approximately 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, or 1:7. Optionally, the ratio of the volume of flush water transmitted through rim channel 236 during a flush cycle to the volume of flush water transmitted through jet hole 240 during a flush cycle may be less than or equal to 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, or 1:7. Alternatively, the ratio of the volume of flush water transmitted through rim channel 236 during a flush cycle to the volume of flush water transmitted through jet hole 240 during a flush cycle may be greater than or equal to 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, or 1:7.

[0062]In some embodiments, trapway 206 may comprise a first upstream weir 226 configured to contain the water that collects in sump trap 214. First upstream weir 226 may be a high point of a lower wall of trapway 206 downstream of the first downstream portion 214u of trapway 206 and may be positioned above a highest point of trapway inlet 207. In some embodiments, first upstream weir 226 may be positioned above the highest point of toilet bowl 202—trapway 206 interface by an offset distance of about 0.5 inches, about 1 inch, about 1.5 inches, about 2 inches, about 2.5 inches, or about 3 inches. In some embodiments, first upstream weir 226 may be positioned above the highest point of toilet bowl 202—trapway 206 interface by an offset distance greater than or equal to 2 inches, 2.5 inches, 3 inches, 3.5 inches, or 4 inches. In some embodiments, first upstream weir 226 may be positioned above the highest point of toilet bowl 202—trapway 206 interface by an offset distance less than or equal to 6 inches, 5.5 inches, 5 inches, 4.5 inches, or 4 inches.

[0063]Trapway 206 may be configured to fluidly connect to a sewer system via a trapway outlet 220. As a result, sewer gases may enter trapway 206 through trapway outlet 220. In some embodiments, the water that is contained in and sump trap 214 between flush cycles may form a water seal in toilet bowl 202. The water seal may prevent sewer gases which may have entered trapway 206 from leaking out of toilet bowl 202. Between flush cycles, the water seal in toilet bowl 202 may be vertically lower than first upstream weir 226. In some embodiments, a vertical distance between the water seal in toilet bowl 202 and first upstream weir 226 may be about 0.1 inches, about 0.2 inches, about 0.3 inches, about 0.4 inches, or about 0.5 inches. In some embodiments, a vertical distance between the water seal in toilet bowl 202 and first upstream weir 226 may be greater than or equal to 0.2 inches, 0.5 inches, 0.8 inches, or 1 inch. In some embodiments, a vertical distance between the water seal in toilet bowl 202 and first upstream weir 226 may be less than or equal to 2 inches, 1.8 inches, 1.5 inches, or 1.2 inches.

[0064]In some embodiments, trapway 206 may comprise a lower trap 216 positioned downstream of first upstream weir 226 between a second upstream portion 216u of trapway 206 and a second downstream portion 216d of trapway 206. Between flush cycles, water may collect in lower trap 216. In some embodiments, the water contained in lower trap 216 may form water seal which may form a second barrier against sewer gases which may enter trapway 206 via trapway outlet 220. In some embodiments, the downstream water seal of the pair of water seals may be vertically higher than an upstream water seal of the pair of water seals. In some embodiments, trapway 206 may comprise a second downstream weir 228 configured to contain water in lower trap 216. Second downstream weir 228 may be a high point of a lower wall of trapway 206 downstream of the second downstream portion 216d of trapway 206.

[0065]In some embodiments, container 218 may house a connecting tube 230 configured to provide flow communication between container 218 and trapway 206. Connecting tube 230 may extend from an interior region of container 218 into trapway 206. In some embodiments, connecting tube 230 may be coupled to trapway 206 at a position between sump trap 214 and lower trap 216. In some embodiments, a trapway-tank interface 212 may be positioned between sump trap 214 and lower trap 216 and may be configured to couple to connecting tube 230. In some embodiments, connecting tube 230 may comprise a backflow preventer.

[0066]FIG. 3 shows a perspective cutaway view of a dual-trap toilet, in accordance with some embodiments. Specifically, FIG. 3 illustrates a cross-sectional view of a toilet 300 comprising a toilet bowl 302, a toilet tank 304, a trapway 306, and a flush control 308. In some embodiments, toilet 300 may include one or more features of toilet 200 shown in FIG. 2 and/or toilet 100 shown in FIGS. 1A and 1B.

[0067]Toilet tank 304 may comprise one or more features of toilet tank 204 of toilet 200 shown in FIG. 2. In some embodiments, toilet tank 304 may be configured to house a container 318, a flush valve 324, and a fill valve 334. Container 318 and flush valve 324 may include one or more features of container 218 and flush valve 224, respectively. Fill valve 334 may be configured to fluidly connect to a water supply in order to facilitate the transmission of flush water from the water supply to toilet tank 304. In some embodiments, fill valve 334 may comprise a backflow preventer.

[0068]In some embodiments, toilet bowl 302 may be fluidly coupled to flush valve 324 via a fluid pathway 322. A flush valve gasket 310 may form a mechanical seal between flush valve 324 and fluid pathway 322 in order to prevent water from leaking out of toilet tank 304 and into toilet bowl 302 in between flush cycles. In some embodiments, fluid pathway 322 may be in flow communication with a rim channel 336 and/or a jet channel 338. Rim channel 336 may include one or more features of rim channel 236 shown in FIG. 2. Jet channel 338 may include one or more features of jet channel 238 shown in FIG. 2.

[0069]In some embodiments, trapway 306 may comprise one or more features of trapway 206 of toilet 200 shown in FIG. 2 and/or trapway 106 of toilet 100 shown in FIGS. 1A and 1B. Trapway 306 may comprise a sump trap 314 (defined by a first upstream portion 314u of trapway 306, a sump area 314a in toilet bowl 302, and a first downstream portion 314d of trapway 306), a first upstream weir 326, a lower trap 316 (positioned between a second upstream portion 316u of trapway 306 and a second downstream portion 316d of trapway 306), and a second downstream weir 328. Trapway 306 may be fluidly coupled to toilet tank 304 via a trapway-tank interface 312. In some embodiments, trapway 306 may comprise an outlet 320 configured to fluidly connect to a drainage pipe into a sewer system.

[0070]FIG. 4 shows a partial cross-sectional view of a dual-trap toilet, in accordance with some embodiments. Specifically, FIG. 4 shows a partial cross-sectional view of a toilet 400. Toilet 400 may comprise a toilet bowl 402 that is fluidly coupled to a toilet tank via a flush valve outlet 404. Toilet bowl 402 may be fluidly coupled to a trapway 410 through a trapway inlet 411. A sump trap 412 may be defined by a first upstream portion 412u, a sump area 412a, and a first downstream portion 412d. A first upstream weir 416 of trapway 402 may be positioned downstream of sump trap 412. A lower trap 414 may be positioned between a second upstream portion 414u and a second downstream portion 414d of trapway 410, and a second downstream weir 418 may be positioned downstream of lower trap 414. Trapway 410 may be fluidly coupled to a toilet tank via a trapway-tank interface 408. In some embodiments, one or more features of toilet 400 may include one or more features of toilet 300 shown in FIG. 3, toilet 200 shown in FIG. 2, and/or toilet 100 shown in FIGS. 1A-1B.

Toilet Tank and Air Transfer Opening

[0071]As described above with reference to FIGS. 1-4, dual-trap toilets may comprise a toilet tank that is configured to contain flush water. The toilet tank may house a container that may be coupled to the trapway by a connecting tube that is configured to provide flow communication between the container and the trapway. The container may be divided into a plurality of chambers. In between flush cycles, the flush water in the toilet tank may be divided between a region of the toilet tank outside of the container and the plurality of chambers within the container. One of the chambers (a “vacuum” chamber) may have a closed upper end and may be configured to contain pressurized air when the toilet is between flush cycles. The pressurized air in the vacuum chamber may have a pressure greater than the ambient pressure of air in the toilet tank. The connecting tube may fluidically couple the upper end of the vacuum chamber to the trapway. As a result of the coupling between the trapway and the upper end of the vacuum chamber, the trapway may also contain pressurized air when the toilet is between flush cycles.

[0072]In addition to the vacuum chamber, the container may comprise an inner chamber that may have an upper end that is open to the toilet tank, allowing air to flow freely between the inner chamber and the region of the tank that is outside of the container. This inner chamber may also house a flush valve that is fluidically coupled to a toilet bowl of the dual-trap toilet. Upon initiation of a flush cycle, a flush valve seal may be lifted from an inlet to the flush valve to open the flush valve, and flush water may be discharged from the toilet tank and the container through the flush valve and into the toilet bowl. The discharging flush water may reduce the pressure of the air contained in the vacuum chamber of the container and air contained in the trapway of the toilet. This reduction in pressure may induce a siphon that pulls the contents of the toilet bowl into the trapway and subsequently into the sewer system.

[0073]As flush water exits the toilet tank, the water level in the vacuum chamber may rapidly drop, and air pressure within the vacuum chamber and within the trapway may drop from positive pressure to negative pressure (e.g., below the ambient pressure of air within the toilet tank). At this point, the siphon in the trapway has already been induced, and mass is flowing from the toilet bowl, through the trapway, and into the sewer system. As the flush continues, the reduced air pressure within the trapway may no longer be required to continue evacuating the contents of the toilet bowl; in fact, after the siphon has been initiated, the reduced air pressure in the trapway may impede the flow through the trapway. In order to maximize flush cycle efficiency, the container may include an air transfer opening between the interior of the vacuum chamber (e.g., the chamber with the closed upper end that contains the pressurized air when the toilet is between flush cycles) and a region that is exterior to the vacuum chamber that provides flow communication of air from the region that is exterior to the vacuum chamber to the upper end of the vacuum chamber after the flush water has been discharged from the toilet tank.

[0074]The air transfer opening may be positioned in a wall of the container that separates the vacuum chamber from a region that is exterior to the vacuum chamber. For instance, the air transfer opening may be positioned on a wall that separates the vacuum chamber from a region of the tank that surrounds the container. Alternatively, the air transfer opening may be a tube that extends from the interior of the vacuum chamber to the interior of the inner chamber. In other examples, the air transfer opening may be a slot in a wall that divides the vacuum chamber from the inner chamber. As the flush water is discharged from the toilet tank and the water level in the toilet tank drops below the air transfer opening, the air transfer opening may be unblocked, and air may flow from the interior of the vacuum chamber, through the air transfer opening, and into the region of the toilet tank that is exterior to the vacuum chamber. As ambient pressure air flows into the upper end of the vacuum chamber, the air pressure within the vacuum chamber may rapidly increase to ambient pressure; since the upper end of the vacuum chamber is coupled to the trapway, the air pressure within the trapway will also rapidly increase to ambient pressure. The increase in air pressure within the trapway may increase the flow rate through the trapway, thereby increasing the efficiency of the flush cycle. Thus, the air transfer opening may allow the first container and the trapway to return to ambient pressure earlier in the flush cycle than it would without the air transfer opening.

[0075]Upon completion of a flush cycle, the flush valve may close, and the toilet tank may re-fill with flush water. As the toilet tank refills, the water level within the vacuum chamber of the container may rise above the air transfer opening, preventing air from flowing into the vacuum chamber. The air pressure within the upper end of the vacuum chamber—and, as a result of the coupling provided by the connecting tube, the air pressure within the trapway—may continue to increase until the toilet tank has replenished its flush water supply. In some embodiments, as the air pressure increases, unwanted gases that are trapped in the trapway may be forced out of the trapway and into the sewer system. Once the toilet tank has replenished its flush water supply, the toilet may return to its between-flush-cycle state.

[0076]FIGS. 5A-5C show various cutaway and cross-sectional views of a tank of a dual-trap toilet, in accordance with some embodiments. Specifically, FIGS. 5A-5C show a top-view cutaway (FIG. 5A), a cross-sectional view (FIG. 5B), and a side-view cutaway (FIG. 5C) of a toilet tank 500 of a dual trap toilet. In some embodiments, tank 500 may include one or more features of toilet tank 304 of toilet 300 shown in FIG. 3, toilet tank 204 of toilet 200 shown in FIG. 2, and/or toilet tank 104 of toilet 100 shown in FIGS. 1A-1B.

[0077]Tank 500 may be formed from a tank wall 502. In some embodiments, a flush control 504 may be positioned on tank wall 502. In some embodiments, tank 500 may house a container 506, a fill valve 508, and a flush valve 510. Fill valve 508 may be configured to fluidly couple to a water supply via one or more openings in tank wall 502. Flush valve 510 may be fluidly coupled to a flush valve outlet 520 that fluidly connects to a toilet bowl of the dual-trap toilet. In some embodiments, flush valve 510 may comprise a valve body that extends from a valve inlet to a flush valve outlet 520. In some embodiments, flush valve 510 may comprise a valve cover with a seal 530 configured to enclose the valve outlet 520.

[0078]Flush control 504 may be configured to initiate a flush cycle upon receiving input from a user. Specifically, upon receiving input from a user, flush control 504 may be configured to cause flush valve seal 530 to lift away from valve outlet 520 of flush valve 510 in order to open flush valve 510, thereby causing flush water that is contained in tank 500 to be discharged into the toilet bowl of the dual-trap toilet. Flush water may be discharged from tank 500 through a plurality of openings 532. The discharge of flush water into the toilet bowl may induce a siphon in a trapway of the dual-trap toilet. In some embodiments, when the level of flush water in tank 500 has fallen below a threshold level with respect to flush valve 510 (e.g., below a lower edge of a head of flush valve 510), the siphon may be broken. Upon completion of the flush cycle, flush valve seal 530 may close, and fill valve 508 may open so that the supply of flush water in tank 500 may be replenished. In some embodiments, a flush valve gasket 518 may be positioned between flush valve 510 and flush valve outlet 520 in order to prevent flush water from leaking into the toilet bowl in between flush cycles.

[0079]Container 506 may have an irregular toroidal (i.e., “donut”-shaped) structure defined by an inner wall 514, a continuous side wall 516, and an upper wall 512 that together define a plurality of interior chambers within container 506. These interior chambers may form an irregular annular region and may include a vacuum chamber 522 and an inner chamber 523. Vacuum chamber 522 may be bounded by inner wall 514, continuous side wall 516, and upper wall 512. Inner chamber 523 may be a central cavity region bounded by inner wall 514. Flush valve 510 may be positioned within inner chamber 523.

[0080]Vacuum chamber 522 may be fluidically coupled to inner chamber 523 and to tank 500 through a plurality of openings 536 in a lower end of container 506. In some embodiments, the plurality of openings 536 may comprise at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 openings. In some embodiments, the plurality of openings 536 may comprise between 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, or 14-16 openings.

[0081]Prior to the initiation of a flush cycle, tank 500 (including container 506) may store a total volume of flush water. In some embodiments, the total volume of flush water stored in tank 500 may be about 0.5 gallons, about 0.75 gallons, about 1 gallon, about 1.25 gallons, about 1.5 gallons, about 1.75 gallons, about 2 gallons, about 3 gallons, about 4 gallons, or about 5 gallons. In some embodiments, the total volume of flush water stored in tank 500 may be greater than or equal to 2.5 gallons, 3.5 gallons, 4.5 gallons, 5.5 gallons, 6.5 gallons, 7.5 gallons, or 8.5 gallons. In some embodiments, the total volume of flush water stored in tank 500 may be less than or equal to 2 gallons, 1.5 gallons, 1 gallon, 0.5 gallons, or 0.1 gallons.

[0082]In between flush cycles, a first portion of the total volume of flush water in tank 500 may be stored in a region tank 500 that is exterior to container 506 (i.e., from a region that excludes vacuum chamber 522 and inner chamber 523 of container 506). During a flush cycle, the percentage of flush water flowing from tank 500 (considered separately from the container and/or interior chambers of the container) may be less than or equal to 30%, 25%, 24%, 22%, 20%, 18%, 16%, 15%, or 10%. Optionally, the percentage of flush water flowing from tank 500 (considered separately from the container and/or interior chambers of the container) during a flush cycle may be greater than or equal to 30%, 25%, 24%, 22%, 20%, 18%, 16%, 15%, or 10%. Optionally, the percentage of flush water flowing from tank 500 (considered separately from the container and/or interior chambers of the container) during a flush cycle may be greater than or equal to 16% and less than or equal to 20%. Optionally, the percentage of flush water flowing from tank 500 (considered separately from the container and/or interior chambers of the container) during a flush cycle may be greater than or equal to 14% and less than or equal to 22%. Optionally, the percentage of flush water flowing from tank 500 (considered separately from the container and/or interior chambers of the container) during a flush cycle may be equal to about 18%.

[0083]A second portion of the total volume of flush water in tank 500 may be stored in vacuum chamber 522 when the toilet is between flush cycles. During a flush cycle, less than one third of the flush water may flow from vacuum chamber 522. Optionally, the percentage of flush water flowing from vacuum chamber 522 during a flush cycle may be less than or equal to 40%, 35%, 34%, 32%, 30%, 28%, 26%, 25%, or 20%. Optionally, the percentage of flush water flowing from vacuum chamber 522 during a flush cycle may be greater than or equal to 40%, 35%, 34%, 32%, 30%, 28%, 26%, 25%, or 20%. Optionally, the percentage of flush water flowing from vacuum chamber 522 during a flush cycle may be greater than or equal to 27% and less than or equal to 31%. Optionally, the percentage of flush water flowing from vacuum chamber 522 during a flush cycle may be greater than or equal to 25% and less than or equal to 33%. Optionally, the percentage of flush water flowing from vacuum chamber 522 during a flush cycle may be equal to about 29%.

[0084]A third portion of the total volume of flush water in tank 500 may be stored in inner chamber 523 when the toilet is between flush cycles. During a flush cycle, more than half of the flush water during a flush cycle may flow from inner chamber 523. Optionally, the percentage of flush water flowing from inner chamber 523 during a flush cycle may be greater than or equal to 40%, 45%, 50%, 52%, 54%, 56%, 58%, 60%, 65%, or 70%. Optionally, the percentage of flush water flowing from inner chamber 523 during a flush cycle may be less than or equal to 40%, 45%, 50%, 52%, 54%, 56%, 58%, 60%, 65%, or 70%. Optionally, the percentage of flush water flowing from inner chamber 523 during a flush cycle may be greater than or equal to 54% and less than or equal to 58%. Optionally, the percentage of flush water flowing from inner chamber 523 during a flush cycle may be greater than or equal to 52% and less than or equal to 60%. Optionally, the percentage of flush water flowing from inner chamber 523 during a flush cycle may be equal to about 56%.

[0085]As shown, an upper end 522a of vacuum chamber 522 may be closed off from the interior of tank 500 by upper wall 512 of container 506. This may allow vacuum chamber 522 to contain pressurized air in its upper end 522a when the toilet is between flush cycles. A connecting tube 524 may be positioned within vacuum chamber 522 and may fluidically couple the upper portion 522a of vacuum chamber 522 to the toilet's trapway. As a result, the trapway may also contain pressurized air when the toilet is between flush cycles. Connecting tube 524 may include a connecting tube gasket 526 positioned between a connecting tube outlet 528 and the trapway in order to prevent flush water from leaking out of tank 500 and into the trapway.

[0086]Between flush cycles, the first portion of positively pressurized air contained in vacuum chamber 522 may have a first volume and the second portion of positively pressurized air contained in the trapway may have a second volume. The first volume of pressurized air contained in vacuum chamber 522 may be less than the second volume of pressurized air contained in the trapway. Optionally, the first volume may be less than or equal to half the second volume. In some embodiments, the first volume may be less than or equal to 50%, 40%, 30%, 28%, 26%, 24%, 22%, 20%, 18%, 16%, 14%, 12%, or 10% the second volume. In some embodiments, the first volume may be greater than or equal to 20% and less than or equal to 24%. In some embodiments, the first volume may be greater than or equal to 18% and less than or equal to 26% the second volume. In some embodiments, the first volume may be equal to about 22% the second volume.

[0087]Between flush cycles, the positive pressurization of the first portion of pressurized air in the upper end of 522a of vacuum chamber 522 may be equal to the positive pressurization of the second portion of pressurized air in the trapway. Specifically, the positive pressurization of the first portion of pressurized air in the upper end 522a of vacuum chamber 522 may be greater than an ambient air pressure of air inside tank 500. Optionally, between flush cycles, the positive pressurization of the pressurized air in vacuum chamber 522 may be any of about 0.1 cm of water, 0.2 cm of water, 0.3 cm of water, 0.5 cm of water, about 0.8 cm of water, about 1.1 cm of water, about 1.4 cm of water, about 1.7 cm of water, about 2.0 cm of water, about 2.3 cm of water, about 2.6 cm of water, or about 2.9 cm of water, to any of about 3.2 cm of water, about 3.5 cm of water, about 3.8 cm of water, about 4.1 cm of water, about 4.4 cm of water, about 4.7 cm of water, about 5.0 cm of water, or more. Optionally, between flush cycles, the positive pressurization of the pressurized air in vacuum chamber 522 may be greater than or equal to 0.1 cm of water, 0.2 cm of water, 0.3 cm of water, 0.5 cm of water, 0.8 cm of water, 1.1 cm of water, 1.4 cm of water, 1.7 cm of water, 2.0 cm of water, 2.3 cm of water, 2.6 cm of water, or 2.9 cm of water. Optionally, between flush cycles, the positive pressurization of the pressurized air in vacuum chamber 522 may be less than or equal to 3.2 cm of water, 3.5 cm of water, 3.8 cm of water, 4.1 cm of water, 4.4 cm of water, 4.7 cm of water, or 5.0 cm of water. (Note: As used herein, reference to positive pressurization in centimeters of water may refer to pressurization above atmospheric pressure by an amount of additional pressure equal to the given centimeters of water. For example, “positive pressurization of 5 cm of water” may refer to 5 cm of water above atmospheric pressure, or an absolute pressure of about 1.0048 atm.).

[0088]As discussed above, upon initiation of a flush cycle, flush water may be discharged from the toilet tank and the container through flush valve 510 and into the toilet bowl; this discharging flush water may cause the air pressure in the upper end 522a of vacuum chamber 522 to rapidly drop. Since the upper end 522a of vacuum chamber 522 is coupled to the trapway by connecting tube 524, the drop in air pressure in vacuum chamber 522 may cause a drop in air pressure within the trapway which may, in turn induce a siphon in the trapway that pulls the contents of the toilet bowl into the trapway.

[0089]Container 506 may include an air transfer opening 534 (illustrated in FIGS. 5A-5B as an air transfer tube) that extends from the interior of inner chamber 523 to an interior of vacuum chamber 522. When water levels in tank 500 drop below (e.g., below at least an upper edge of) air transfer opening 534, air transfer opening 534 may provide flow communication of air between inner chamber 523 (the upper end 523a of which may be open to tank 500, unlike the upper end 522a of vacuum chamber 522) and vacuum chamber 522. However, between flush cycles, the water levels in vacuum chamber 522 and inner chamber 523 may cover air transfer opening 534, preventing flow communication of air between inner chamber 523 and vacuum chamber 522.

[0090]In some embodiments, air transfer opening 534 may be positioned in inner wall 514 at approximately 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 250, or 250 mm above the bottom of tank 500. In some embodiments, air transfer opening 534 may be positioned between 50-75, 75-100, 100-125, 125-150, 150-175, 175-200, or 200-225 mm above the bottom of tank 500. In some embodiments, air transfer opening 534 may be positioned less than or equal to 125, 150, 175, 200, or 225 mm above the bottom of tank 500. In some embodiments, air transfer opening 534 may be positioned greater than or equal to 125, 150, 175, 200, or 225 mm above the bottom of tank 500.

[0091]FIGS. 6A-6C illustrate exemplary distributions of flush water and pressurized air in tank 500 (as shown in FIGS. 5A-5C) and in trapway 410 (as shown in FIG. 4) of a dual-trap toilet that is between flush cycles. As shown in FIGS. 6A-6B, when the toilet is between flush cycles, flush water in tank 500 may be distributed between vacuum chamber 522, inner chamber 523, and a region of tank 500 that excludes container 506. Specifically, flush water contained in vacuum chamber 522 may be at a first water level 538 within vacuum chamber 522, flush water contained in inner chamber 523 may be at a second water level 540, and flush water in tank 500 (excluding container 506) may be at a third water level 542.

[0092]In some embodiments, flush water level 538 in vacuum chamber 522 may be about 100, about 110, about 120, about 130, about 140, about 150, about 160, about 170, about 180, about 190, about 200, about 210, about 220, about 230, about 240, about 250, about 260, about 260, about 280, about 290, or about 300 mm above the bottom of tank 500. In some embodiments, flush water level 538 in vacuum chamber 522 may be between 210-220, 220-230, 230-240, 240-250, 250-260, or 260-270 mm above the bottom of tank 500. In some embodiments, flush water level 538 in vacuum chamber 522 may be less than or equal to 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, or 255 mm above the bottom of tank 500. In some embodiments, flush water level 538 in vacuum chamber 522 may be greater than or equal to 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, or 255 mm above the bottom of tank 500.

[0093]In some embodiments, flush water level 538 in vacuum chamber 522 may be below flush water level 540 in inner chamber 523 and/or flush water level 542 in tank 500 (excluding container 506). In some embodiments, flush water level 538 in vacuum chamber 522 may be about 5, about 10, about 20, about 30, about 40, or about 50 mm below flush water level 540 in inner chamber 523 and/or flush water level 542 in tank 500 (excluding container 506). In some embodiments, flush water level 538 in vacuum chamber 522 may be at least 5, at least 10, at least 20, at least 30, at least 40, or at least 50 mm below flush water level 540 in inner chamber 523 and/or flush water level 542 in tank 500 (excluding container 506). In some embodiments, flush water level 538 in vacuum chamber 522 may be less than 5, less than 10, less than 20, less than 30, less than 40, or less than 50 mm below flush water level 540 in inner chamber 523 and/or flush water level 542 in tank 500 (excluding container 506).

[0094]In some embodiments, flush water level 540 in inner chamber 523 may be approximately the same as flush water level 542 in tank 500 (excluding container 506). In some embodiments, flush water level 540 in inner chamber 523 may be below or above flush water level 542 in tank 500 (excluding container 506). In some embodiments, flush water level 540 in inner chamber 523 and/or flush water level 542 in tank 500 (excluding container 506) may be about 110, about 120, about 130, about 140, about 150, about 160, about 170, about 180, about 190, about 200, about 210, about 220, about 230, about 240, about 250, about 260, about 270, about 280, about 290, about 300, or about 310 mm above the bottom of tank 500. In some embodiments, flush water level 540 in inner chamber 523 and/or flush water level 542 in tank 500 (excluding container 506) may be between 220-230, 230-240, 240-250, 250-260, 260-270, 270-280, 280-290, 290-300, or 300-310 mm above the bottom of tank 500. In some embodiments, flush water level 540 in inner chamber 523 and/or flush water level 542 in tank 500 (excluding container 506) may be less than or equal to 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, or 280 mm above the bottom of tank 500. In some embodiments, flush water level 540 in inner chamber 523 and/or flush water level 542 in tank 500 (excluding container 506) may be greater than or equal to 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, or 280 mm above the bottom of tank 500.

[0095]The upper end of vacuum chamber 522 may be closed; this may allow vacuum chamber 522 to contain air in the region above water level 538. The air pressure in air contained in vacuum chamber 522 may be greater than an ambient air pressure (P₀) within tank 500. As shown in FIGS. 6B-6C, the upper end of vacuum chamber 522 may be coupled to a region of trapway 410 between sump trap 412 and lower trap 414 by connecting tube 524. Due to the coupling between trapway 410 and vacuum chamber 522, this region may contain air that is also pressurized at a pressure greater than the ambient pressure (P₀) within tank 500.

[0096]Unlike the upper end of vacuum chamber 522, the upper end of inner chamber 523 may be open to tank 500; as such, air may flow freely between inner chamber 523 and tank 500. Thus, the air pressure in the upper end of inner chamber 523 above water level 540 may be equal to the ambient air pressure (P₀) within tank 500. Between flush cycles, the water level 538 in vacuum chamber 522 and the water level 540 in inner chamber 523 may be above a lower end of the tube that forms air transfer opening 534, preventing air from flowing between vacuum chamber 522 and inner chamber 523 and thus ensuring that the air contained in the upper region of vacuum chamber 522 remains positively pressurized.

[0097]When a flush cycle is initiated, flush water may be rapidly discharged through flush valve 510 into toilet bowl 402, causing the air pressure in vacuum chamber 522 to drop, e.g., below P₀. The drop in air pressure in vacuum chamber 422 may cause a drop in air pressure in trapway 406 which may, in turn, generate a siphon within trapway 406.

[0098]FIGS. 7A-7C show exemplary distributions of flush water and pressurized air in tank 500 and trapway 410 immediately following the initiation of a flush cycle. As shown, the water in vacuum chamber 522 may drop from level 538 (shown in FIGS. 6A-6B) to a level 544, the water level in inner chamber 523 may drop from a level 540 (FIGS. 6A-6B) to a level 546, and the water level in tank 500 (excluding container 506) may drop from a level 544 (FIGS. 6A-6B) to a level 548. At this point in the flush cycle, the air pressure within vacuum chamber 522 may drop below an ambient pressure (P₀) within tank 500. The air pressure within trapway 410 may likewise drop below an ambient pressure within tank 500. However, the water level 546 within vacuum chamber may continue to block air transfer opening 536.

[0099]In some embodiments, flush water level 544 in vacuum chamber 522 may be about 50, about 60, about 70, about 80, about 90, about 100, about 110, about 120, about 130, about 140, about 150, about 160, about 170, about 180, about 190, about 200, about 210, or about 220 the bottom of tank 500. In some embodiments, flush water level 544 in vacuum chamber 522 may be between 140-150, 150-160, 160-170, 170-180, 180-190, 190-200, or 200-210 mm above the bottom of tank 500. In some embodiments, flush water level 544 in vacuum chamber 522 may be less than or equal to 170, 175, 180, 185, 190, 195, 200, or 205 mm above the bottom of tank 500. In some embodiments, flush water level 544 in vacuum chamber 522 may be greater than or equal to 170, 175, 180, 185, 190, 195, 200, or 205 mm above the bottom of tank 500.

[0100]In some embodiments, flush water level 544 in vacuum chamber 522 may be above flush water level 546 in inner chamber 523. In some embodiments, flush water level 544 in vacuum chamber 522 may be about 25, about 50, about 75, about 100, about 125, about 150, about 175, or about 200 mm above flush water level 546 in inner chamber 523. In some embodiments, flush water level 544 in vacuum chamber 522 may be at least 25, at least 50, at least 75, at least 100, at least 125, at least 150, at least 175, or at least 200 mm above flush water level 546 in inner chamber 523. In some embodiments, flush water level 544 in vacuum chamber 522 may be less than 25, less than 50, less than 75, less than 100, less than 125, less than 150, less than 175, or less than 200 mm above flush water level 546 in inner chamber 523.

[0101]In some embodiments, flush water level 546 in inner chamber 523 may be about 10, about 20, about 30, about 40, about 50, about 60, about 70, about 80, about 90, or about 100 mm above the bottom of tank 500. In some embodiments, flush water level 546 in inner chamber 523 may be between 0-20, 20-30, 30-40, 40-50, 50-60, 60-70, 70-80, 80-90, or 90-100 mm above the bottom of tank 500. In some embodiments, flush water level 546 may be less than or equal to 20, 40, 60, 80, or 100 mm above the bottom of tank 500. In some embodiments, flush water level 546 may be greater than or equal to 20, 40, 60, 80, or 100 mm above the bottom of tank 500.

[0102]In some embodiments, flush water level 544 in vacuum chamber 522 may be below flush water level 548 in tank 500 (excluding container 506). In some embodiments, flush water level 544 in vacuum chamber 522 may be about 5, about 10, about 15, about 20, about 25, about 30, about 35, or about 40 mm below flush water level 548 in tank 500 (excluding container 506). In some embodiments, flush water level 544 in vacuum chamber 522 may be at least 5, at least 10, at least 20, at least 25, at least 30, at least 35, or at least 40 mm below flush water level 548 in tank 500 (excluding container 506). In some embodiments, flush water level 544 in vacuum chamber 522 may be less than 5, less than 10, less than 20, less than 25, less than 30, less than 35, or less than 40 mm below flush water level 548 in tank 500 (excluding container 506).

[0103]In some embodiments, flush water level 548 in tank 500 (excluding container 506) may be about 150, about 160, about 170, about 180, about 190, about 200, about 210, about 220, about 230, about 240, about 250, about 260, about 270, about 280, about 290, or about 300 mm above the bottom of tank 500. In some embodiments, flush water level 548 in tank 500 (excluding container 506) may be between 180-190, 190-200, 200-210, 210-220, 220-230, 230-240, or 240-250 mm above the bottom of tank 500. In some embodiments, flush water level 548 in tank 500 (excluding container 506) may be less than or equal to 200, 210, 220, 230, or 240 mm above the bottom of tank 500. In some embodiments, flush water level 548 in tank 500 (excluding container 506) may be greater than or equal to 200, 210, 220, 230, or 240 mm above the bottom of tank 500.

[0104]FIGS. 8A-8C illustrate exemplary distributions of flush water and pressurized air in tank 500 and in trapway 410 during a flush cycle. As the flush cycle progresses the water in vacuum chamber 522 may drop to from level 544 (shown in FIGS. 7A-7B) to a level 550, the water level in inner chamber 523 may drop from a level 546 (FIGS. 7A-7B) to a level 552, and the water level in tank 500 (excluding container 506) may drop from a level 548 (FIGS. 7A-7B) to a level 554. The water level 552 within vacuum chamber may, at this point, be below air transfer opening 534. The unblocking of air transfer opening 534 may allow air to flow from inner chamber 523 to vacuum chamber 522, thereby rapidly returning vacuum chamber 522 (and trapway 406) to P₀.

[0105]FIGS. 9A-9C illustrate exemplary distributions of flush water and pressurized air in tank 500 and in trapway 410 toward the end of a flush cycle, immediately following the closing of the flush valve seal. After the flush valve seal closes, flush water supply in tank 500 may begin to be replenished by refill valve 508, causing the flush water level in inner chamber 523 to rapidly rise from level 552 to a level 558. While water levels in inner chamber 523 may rapidly increase immediately following the closing of the flush valve seal, flush water levels in tank 500 (excluding container 506) and in vacuum chamber 522 may continue to decrease to a level 560 and a level 556, respectively. Meanwhile, air may continue to flow from inner chamber 523, through air transfer opening 534, and into vacuum chamber 522, where it may collect in the upper end. As air collects in vacuum chamber 522, the air pressure within vacuum chamber 522 may rise to the ambient air pressure (P₀) within tank 500.

[0106]In some embodiments, flush water levels in tank 500 may reach levels 556, 558, and 560 in vacuum chamber 522, inner chamber 523, and tank 500 (excluding container 506), respectively, at approximately 0.5, 1, 1.5, 2, 2.5, or 3 seconds following the initiation of a flush cycle. In some embodiments, flush water levels in tank 500 may reach levels 556, 558, and 560 in vacuum chamber 522, inner chamber 523, and tank 500 (excluding container 506), respectively, at less than 0.5, 1, 1.5, 2, 2.5, or 3 seconds following the initiation of a flush cycle. In some embodiments, flush water levels in tank 500 may reach levels 556, 558, and 560 in vacuum chamber 522, inner chamber 523, and tank 500 (excluding container 506), respectively, at more than 0.5, 1, 1.5, 2, 2.5, or 3 seconds following the initiation of a flush cycle.

[0107]In some embodiments, flush water level 556 in vacuum chamber 522 may be about 50, about 60, about 70, about 80, about 90, about 100, about 110, about 120, about 130, about 140, about 150, about 160, about 170, about 180, about 190, about 200, about 210, or about 220 the bottom of tank 500. In some embodiments, flush water level 556 in vacuum chamber 522 may be between 140-150, 150-160, 160-170, 170-180, 180-190, 190-200, or 200-210 mm above the bottom of tank 500. In some embodiments, flush water level 550 in vacuum chamber 556 may be less than or equal to 170, 175, 180, 185, 190, 195, 200, or 205 mm above the bottom of tank 500. In some embodiments, flush water level 556 in vacuum chamber 522 may be greater than or equal to 170, 175, 180, 185, 190, 195, 200, or 205 mm above the bottom of tank 500.

[0108]In some embodiments, flush water level 556 in vacuum chamber 522 may be above flush water level 558 in inner chamber 523. In some embodiments, flush water level 556 in vacuum chamber 522 may be about 10, about 15, about 20, about 25, about 30, about 35, about 40, about 45, about 50, about 55, or about 60 mm above flush water level 558 in inner chamber 523. In some embodiments, flush water level 556 in vacuum chamber 522 may be at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, or at least 80 mm above flush water level 558 in inner chamber 523. In some embodiments, flush water level 556 in vacuum chamber 522 may be less than 10, less than 20, less than 30, less than 40, less than 50, less than 60, less than 70, or less than 80 mm above flush water level 558 in inner chamber 523.

[0109]In some embodiments, flush water level 558 in inner chamber 523 may be about 100, about 110, about 120, about 130, about 140, about 150, about 160, about 170, about 180, or about 190 mm above the bottom of tank 500. In some embodiments, flush water level 558 in inner chamber 523 may be between 100-125, 125-150, 150-175, or 175-200 mm above the bottom of tank 500. In some embodiments, flush water level 558 may be less than or equal to 100, 115, 130, 145, or 160 mm above the bottom of tank 500. In some embodiments, flush water level 558 may be greater than or equal to 100, 115, 130, 145, or 160 mm above the bottom of tank 500.

[0110]In some embodiments, flush water level 556 in vacuum chamber 522 may be below flush water level 560 in tank 500 (excluding container 506). In some embodiments, flush water level 556 in vacuum chamber 522 may be about 5, about 10, about 15, about 20, about 25, about 30, about 35, or about 40 mm below flush water level 560 in tank 500 (excluding container 506). In some embodiments, flush water level 556 in vacuum chamber 522 may be at least 5, at least 10, at least 20, at least 25, at least 30, at least 35, or at least 40 mm below flush water level 560 in tank 500 (excluding container 506). In some embodiments, flush water level 556 in vacuum chamber 522 may be less than 5, less than 10, less than 20, less than 25, less than 30, less than 35, or less than 40 mm below flush water level 560 in tank 500 (excluding container 506).

[0111]In some embodiments, flush water level 560 in tank 500 (excluding container 506) may be about 150, about 160, about 170, about 180, about 190, about 200, about 210, about 220, about 230, about 240, about 250, about 260, about 270, about 280, about 290, or about 300 mm above the bottom of tank 500. In some embodiments, flush water level 560 in tank 500 (excluding container 506) may be between 180-190, 190-200, 200-210, 210-220, 220-230, 230-240, or 240-250 mm above the bottom of tank 500. In some embodiments, flush water level 560 in tank 500 (excluding container 506) may be less than or equal to 200, 210, 220, 230, or 240 mm above the bottom of tank 500. In some embodiments, flush water level 560 in tank 500 (excluding container 506) may be greater than or equal to 200, 210, 220, 230, or 240 mm above the bottom of tank 500.

[0112]As the flush water supply in tank 500 replenishes, water levels in tank 500 may rise from level 560, causing water levels in inner chamber 523 and vacuum chamber 522 to rise past levels 558 and 556, respectively. Subsequently, the water levels in vacuum chamber 522 and inner chamber 523 may rise above air transfer opening 534, causing air flow between inner chamber 523 and vacuum chamber 522 to cease. After air flow between inner chamber 523 and vacuum chamber 522 has stopped, the water level in vacuum chamber 522 may continue to increase, compressing the air contained into the upper end 522a of vacuum chamber 522. This may, in turn, cause air pressure within trapway 410 to continue rising, which may force undesirable gases that may be trapped in trapway 410 out of trapway 410. By the time the flush water has been completely replenished in tank 500, the air pressure in vacuum chamber 522 and trapway 410 may be returned to a pre-flush-cycle pressure level (see FIGS. 6A-6C).

Exemplary Air Transfer Openings

[0113]Air transfer opening 534 may have a variety of implementations and geometries. FIGS. 5A-8B show air transfer opening 534 embodied as a tube that extends from the interior of inner chamber 523, through the inner wall of container 506 that separates inner chamber 523 from vacuum chamber 522 (i.e., inner wall 514 in FIGS. 5A-5B), and into the interior of vacuum chamber 522. Alternatively, air transfer opening 534 may be a tube that extends from the interior of inner chamber 523, out of the open upper end of inner chamber 523, through the upper wall of container 506 that bounds the upper end of vacuum chamber 522 (i.e., upper wall 512 shown in FIGS. 5A-5B), and into vacuum chamber 522, as shown in FIG. 9. An air transfer tube of either configuration may be formed from plastic, metal, glass, or porcelain. Optionally, an air transfer tube may have a diameter greater than or equal to 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, or 0.5 inches. Optionally, an air transfer tube may have a diameter less than or equal to 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, or 0.5 inches.

[0114]Instead of a tube, air transfer opening 534 may be embodied as a slot embedded in inner wall 514 between inner chamber 523 from vacuum chamber 522, as shown in FIGS. 10A-10B. The slot may be tapered such than an upper portion of the slot is narrower than a lower portion of the slot. In some embodiments, a width of the upper portion of the slot may be greater than or equal to 0.100, 0.115, 0.125. 0.135, 0.145, or 0.155 inches. In some embodiments, a width of the upper portion of the slot may be less than or equal to 0.100, 0.115, 0.125. 0.135, 0.145, or 0.155 inches. In some embodiments, a width of the lower portion of the slot may be greater than or equal to 0.10, 0.15, 0.20, 0.25, 0.30, or 0.35 inches. In some embodiments, a width of the lower portion of the slot may be less than or equal to 0.10, 0.15, 0.20, 0.25, 0.30, or 0.35 inches. In some embodiments, rather than an extended rectangular slot, air transfer opening 534 may be embodied as a port (e.g., an approximately square-shaped port) in inner wall 514, as shown in FIGS. 11A-11B. A port of any other suitable shape, e.g., circular, elliptical, or irregular, may be used.

[0115]In some embodiments, air transfer opening 534 may be positioned on an exterior wall of container 506 that bounds vacuum chamber 522. For example, as shown in FIG. 13, air transfer opening 534 may be positioned on continuous side wall 516 of container 506. This air transfer opening may be embodied as a tube (similar to air transfer opening 534 shown in FIGS. 5A-5B or air transfer opening 534 shown in FIG. 9), a slot (similar to air transfer opening 534 shown in FIGS. 10A-10B), or as a port (similar to air transfer opening 534 shown in FIGS. 11A-11B).

[0116]Any one or more characteristics of any of the embodiments (including claims) described, shown, and/or referenced herein may be combined, in whole or in part, with any one or more characteristics of any one or more other embodiments (including claims) described, shown, and/or referenced herein.

[0117]The foregoing description, for the purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the techniques and their practical applications. Others skilled in the art are thereby enabled to best utilize the techniques and various embodiments with various modifications as are suited to the particular use contemplated.

[0118]Although the disclosure and examples have been fully described with reference to the accompanying figures, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the disclosure and examples as defined by the claims. Finally, the entire disclosure of the patents and publications referred to in this application are hereby incorporated herein by reference.