Drainage channel of flush toilet

Abstract

Disclosed is a flush toilet drainage channel capable of good flushing. The flush toilet drainage channel includes an ascending channel ( 30 ) which communicates with the downstream side of a toilet bowl ( 10 ) and ascends toward the downstream side. The ascending channel ( 30 ) is formed so that a channel bottom ( 33 ) is gradually rendered wider toward a bottom top ( 32 ) thereof located at the downstream side.

1 . A drainage channel of a flush toilet, comprising an ascending channel which communicates with a downstream side of a toilet bowl and ascends toward a downstream side of the drainage channel, wherein the ascending channel is formed so that a channel bottom of the ascending channel is gradually rendered wider toward a bottom top thereof located at the downstream side of the drainage channel. 
     
     
         2 . The drainage channel according to  claim 1 , wherein the bottom top has a substantially horizontal surface extending in a direction perpendicular to a drainage direction of flushing water. 
     
     
         3 . The drainage channel according to  claim 1 , wherein the ascending channel includes an upstream end, a vertical middle, a first region between the upstream end and the vertical middle and a second region between the middle and an upstream side of the bottom top, and the ascending channel has a cross-sectional shape in a direction perpendicular to the, drainage direction of the flushing water;
 in the cross-sectional shape of the ascending channel, the first region includes a first upper region and first lower region both relative to the vertical middle, and the first upper region has a larger flow passage area than the first lower region; and   in the cross-sectional shape of the ascending channel, the second region includes a second upper region and a second lower region both relative to the vertical middle, and the second lower region has a larger flow passage area than the second upper region.   
     
     
         4 . The drainage channel according to  claim 1 , wherein the channel bottom of the ascending channel has a substantially flat surface extending in a/the drainage direction of the flushing water and in a direction perpendicular to the drainage direction. 
     
     
         5 . The drainage channel according to  claim 1 , wherein the ascending channel has a vertical maximum length that is enlarged from the upstream end toward the downstream side in a/the cross-sectional shape of the ascending channel in the direction perpendicular to the drainage direction of the flushing water. 
     
     
         6 . The drainage channel according to  claim 5 , wherein the ascending channel has an upper surface formed into an angled shape such that the upper surface is gradually enlarged from a middle part thereof toward right and left lower parts thereof in the cross-sectional shape of the ascending channel in the direction perpendicular to the drainage direction of the flushing water. 
     
     
         7 . The drainage channel according to  claim 1 , further comprising a descending channel communicating with a downstream side of the ascending channel and descending toward the downstream side of the drainage channel, the descending channel having a ledge extending from the bottom top of the ascending, channel to inwardly protrude along an inner periphery of the descending channel. 
     
     
         8 . The drainage channel according to  claim 7 , wherein the ledge is formed into an inclined surface directed inwardly upward. 
     
     
         9 . The drainage channel according to  claim 7 , wherein the descending channel has a rear surface and the ledge extends, near a middle part of the rear surface of the descending channel. 
     
     
         10 . The drainage channel according to  claim 7 , wherein the ledge descends rearward along the inner peripheral surface of the descending channel. 
     
     
         11 . A drainage channel of a flush toilet, comprising an ascending channel which communicates with a downstream side of a toilet bowl and ascends toward a downstream side of the drainage channel,
 wherein the ascending channel has a cross-sectional shape in a direction perpendicular to the drainage direction of the flushing water; and   in the cross-sectional shape, the ascending channel has a vertical maximum length that is increased from the upstream end toward the downstream side and the upstream end has an inner surface having a larger crosswise dimension than a longitudinal dimension.   
     
     
         12 . The, drainage channel according to  claim 1 , wherein the ascending channel has an upper surface formed into an angled shape such that the upper surface is gradually enlarged from a middle part thereof toward right and left lower parts thereof, in a/the cross-sectional shape of the ascending channel in the direction perpendicular to the drainage direction of the flushing water. 
     
     
         13 . The drainage channel according to  claim 12 , wherein the channel bottom of the ascending channel has rising surfaces rising from right and left ends thereof, and the rising surfaces have maximum heights near an upstream side of the bottom top located at the downstream side of the drainage channel, respectively, in the cross-sectional shape perpendicular to the drainage direction of the flushing water. 
     
     
         14 . The drainage channel according to  claim 12 , wherein the upper surface of the ascending channel is formed into an inclined surface extending from a middle part thereof rightward downward and leftward downward and inwardly swollen, in the cross-sectional shape perpendicular to the drainage direction of the flushing water. 
     
     
         15 . The drainage channel according to  claim 1 , wherein the ascending channel has corners between the channel bottom and the rising surfaces rising from the right and left ends of the channel bottom near the upstream end of the ascending channel respectively;
 the corners are formed into respective rounded surfaces; and   the rounded surface of one of the right and left corners has a larger curvature than the rounded surface of the other corner.   
     
     
         16 . The drainage channel according to  claim 1 , further comprising a pipe-like introduction passage downwardly inclined from a lower end of the toilet bowl toward the upstream end of the ascending channel. 
     
     
         17 . A drainage channel of a flush toilet, comprising a descending channel which communicates with a downstream side of an ascending channel communicating with a downstream side of a toilet bowl and ascending toward a downstream side of the drainage channel, the descending channel descending toward the downstream side, wherein the descending channel has a ledge which extends from a bottom top located at a downstream side of a channel bottom of the ascending channel and is formed so as to inwardly protrude along an inner periphery of the descending channel. 
     
     
         18 . The drainage channel according to  claim 17 , wherein the ledge descends rearward along the inner periphery of the descending channel. 
     
     
         19 . The drainage channel according to  claim 17 , wherein the ledge is formed into an inclined surface directed inwardly upward. 
     
     
         20 . The drainage channel according to  claim 17 , wherein the descending channel has a rear surface and the ledge extends near a middle part of the rear surface of the descending channel. 
     
     
         21 . The drainage channel according to  claim 11 , wherein the ascending channel has an upper surface formed into an angled shape such that the upper surface is gradually enlarged from a middle part thereof toward right and left lower parts thereof, in a/the cross-sectional shape of the ascending channel in the direction perpendicular to the drainage direction of the flushing water. 
     
     
         22 . The drainage channel according to  claim 11 , wherein the ascending channel has corners between the channel bottom and the rising surfaces rising from the right and left ends of the channel bottom near the upstream end of the ascending channel respectively;
 the corners are formed into respective rounded surfaces; and   the rounded surface of one of the right and left corners has a larger curvature than the rounded surface of the other corner.   
     
     
         23 . The drainage channel according to  claim 11 , further comprising pipe-like introduction passage downwardly inclined from a lower end of the toilet bowl toward the upstream end of the ascending channel.