# US 9,752,311 B2 · Anti-siphonic toilet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,311 B2 - Document ID: US9752311B2 - Status: Granted - Kind: B2 - Application number: 14/207,166 - Filed: 2014-03-12 - Published: 2014-09-18 - Granted: 2017-09-05 - Earliest claimed: 2013-03-13 - Assignees: Kohler Co. - Applicants: Kohler Co. - Inventors: Robert S. Davis; Thomas M. Spankowski; Lachlan A. Stewart, III - Web page: https://patentgrep.com/patent/US9752311B2 ## CPC - E03D 11/02: Water-closet bowls (auxiliary chambers with connections to flushing water for bowl-cleaning utensils E03D9/06; modified for using upwardly-directed sprays E03D9/08; seats or covers A47K13/00 ){; Bowls with a double odour seal optionally with provisions for a good siphonic action; siphons as part of the bowl (parts or details of bowls E03D11/13)} - E03D: WATER-CLOSETS OR URINALS WITH FLUSHING DEVICES; FLUSHING VALVES THEREFOR ## Abstract A wash-down toilet including 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. ## Claims ### Claim 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; 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 configured to be in fluid communication with a soil pipe; and a supply of air provided from an air supply to the trapway by way of the vent; wherein the vent introduces the supply of air into the trapway during a flush cycle to prevent siphoning; and wherein the vent is configured as a one-way vent that prevents fluid from entering the vent from the trapway. ### Claim 2 (depends on 1) The wash-down toilet of claim 1, wherein the trapway further includes an elbow disposed between the inlet and the outlet of the trapway. ### Claim 3 (depends on 2) The wash-down toilet of claim 2, wherein the vent is provided on an upper portion of the elbow. ### Claim 4 (depends on 3) 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. ### Claim 5 (depends on 1) The wash-down toilet of claim 1, wherein the one-way vent includes a valve to prevent the fluid from entering the vent. ### Claim 6 (depends on 4) 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. ### Claim 7 (depends on 6) The wash-down toilet of claim 6, 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. ### Claim 8 (depends on 1) 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. ### Claim 9 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; 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 positioned between the inlet portion and the outlet portion the vent tube configured as a one-way vent that prevents fluid from entering the vent tube from the trapway; and a supply of air provided from an air supply to the trapway through the vent tube; wherein the supply of air is fed to the trapway during a flush cycle to prevent siphoning; and wherein the vent tube is provided above a centerline of a vertical cross-section of the inlet portion of the trapway. ### Claim 10 (depends on 9) The toilet of claim 9, 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. ### Claim 11 (depends on 10) The toilet of claim 10, 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. ### Claim 12 (depends on 11) The toilet of claim 11, 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. ### Claim 13 (depends on 9) The toilet of claim 9, 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. ### Claim 14 (depends on 9) The toilet of claim 9, wherein a 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. ### Claim 15 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. ### Claim 16 (depends on 15) The method of claim 15, 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. ### Claim 17 (depends on 16) The method of claim 16, wherein the outlet of the trapway is fluidly connected to a first pipe and the vent is fluidly connected to a second pipe. ### Claim 18 (depends on 15) The method of claim 15, 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. ### Claim 19 (depends on 18) The method of claim 18, wherein gases are not passed through the second pipe while the water, waste, and air are passing from the trapway. ### Claim 20 (depends on 15) The method of claim 15, wherein the vent is a one-way vent, such that the supply of air passes from the vent to the trapway, but gases do not pass from the trapway through the vent. ### Claim 21 (depends on 15) The method of claim 15, further comprising preventing gases from passing from the trapway through the vent.