Pour-Flush Latrines, Latrine Pans, Latrine Pan Assemblies, and Related Methods

Abstract

The invention described herein includes a pour-flush latrine pan mountable at a surface that includes a collection basin and a flapper. The collection basin has an upper bowl portion that tapers to an outlet extending through a wall of the collection basin at its lower end. The flapper includes a counterbalance device and a coverplate disposed on opposite sides of a pivot. The coverplate has a shape adapted to cover the outlet of the collection basin when the coverplate is engaged against the lower end of the collection basin. The flapper is pivotally mounted against the collection basin such that the coverplate engages against the lower end of the collection basin when a pivotal force attributable to the counterbalance device is greater than a pivotal force applied to the coverplate that engages the lower end of the collection basin. In an embodiment, the shape of the coverplate defines a channel that engages the lower end of the collection basin about its perimeter when the coverplate is engaged against the lower end of the collection basin The invention also includes latrine pan assemblies, latrines and methods that employ the latrine pan.

1 . A pour-flush latrine pan mountable at a surface comprising a collection basin and a flapper,
 the collection basin having an upper bowl portion tapering to an outlet extending through a wall of the collection basin at a lower end of the collection basin,   the flapper comprising a counterbalance device and a coverplate disposed on opposite sides of a pivot,   the coverplate having a shape adapted to cover the outlet of the collection basin when the coverplate is engaged against the lower end of the collection basin,   the flapper being pivotally mounted against the collection basin such that the coverplate engages against the lower end of the collection basin when a pivotal force attributable to the counterbalance device is greater than a pivotal force applied to the coverplate that engages the lower end of the collection basin.   
     
     
         2 . The pour-flush latrine pan of  claim 1 , wherein the shape of the coverplate defines a channel that engages the lower end of the collection basin about at least a portion of its perimeter when the coverplate is engaged against the lower end of the collection basin. 
     
     
         3 . The pour-flush latrine pan of  claim 1 , wherein the shape of the coverplate defines a channel that engages the lower end of the collection basin about its entire perimeter when then coverplate is engaged against the lower end of the collection basin. 
     
     
         4 . The pour-flush latrine pan of  claim 3 , wherein the shape of the coverplate includes a convex portion that extends within the outlet of the collection basin when the coverplate is engaged against the lower end of the collection basin. 
     
     
         5 . The pour-flush latrine pan of  claim 4 , wherein the channel contains a liquid that forms a liquid seal between a first surface of the cover plate and the lower end of the collection basin that prevents or reduces a flow of a sewage gas from a second side of the coverplate to the first side of the coverplate. 
     
     
         6 . The pour-flush latrine pan of  claim 5 , wherein the sewage gas is hydrogen sulfide or ammonia. 
     
     
         7 . The pour-flush latrine pan of  claim 1 , wherein the counterbalance device comprises a container that is filled with a weight material. 
     
     
         8 . The pour-flush latrine pan of  claim 7 , wherein the container has a volumetric dimension that can contain an amount of weight material sufficient to exert a pivotal force upon the flapper that is greater than a pivotal force exerted on the flapper by an average excreta quantity when the average excreta quantity rests upon the coverplate. 
     
     
         9 . The pour-flush latrine pan of  claim 8 , wherein the amount of weight material is selected from about 60 grams, about 85 grams, about 100 grams, about 250 grams, about 500 grams, about 750 grams, about 1000 grams, about 1300 grams and about 1500 grams, and the weight material is cement. 
     
     
         10 . The pour-flush latrine pan of  claim 8 , wherein the container is a hollow cylinder and the weight material is selected from cement, concrete, asphalt, sand, water, stones, pebbles, metal, particulates, and wood. 
     
     
         11 . The pour-flush latrine pan of  claim 1 , wherein the coverplate includes a circumferential rim that extends above the lower end of the collection basin about at least a portion of its perimeter when then coverplate is engaged against the lower end of the collection basin. 
     
     
         12 . The pour-flush latrine pan of  claim 1 , wherein the coverplate includes a circumferential rim that extends above the lower end of the collection basin about its entire perimeter when then coverplate is engaged against the lower end of the collection basin. 
     
     
         13 . The pour-flush latrine pan of  claim 1 , comprising a flange extending around the perimeter of the upper bowl portion. 
     
     
         14 . The pour-flush latrine pan of  claim 1 , wherein the upper bowl portion includes an elongated portion extending radially therefrom. 
     
     
         15 . The pour-flush latrine pan of  claim 14 , wherein the entirety of the interior of the bowl portion tapers downwardly toward the outlet. 
     
     
         16 . The pour-flush latrine pan of  claim 1 , wherein the flapper is pivotally mounted to the exterior of the collection basin. 
     
     
         17 . The pour-flush latrine pan of  claim 1 , wherein the pivot of the flapper is a pair of pins extending laterally away from an extension body of the flapper, the counterbalance device and coverplate being mounted on opposite ends of the flapper body, the pins engaging a pair of aligned holes on a pair of spaced brackets on the exterior of the collection basin. 
     
     
         18 . The pour-flush latrine pan of  claim 1 , wherein the pivot of the flapper is at least one hole extending laterally through an elongate body of the flapper, the counterbalance device and coverplate being mounted on opposite ends of the flapper body, each hole engaging a pin extending from the exterior of the collection basin. 
     
     
         19 . The pour-flush latrine pan of  claim 1 , wherein the pivot of the flapper is at least one hole extending laterally through an extension body of the flapper, the counterbalance device and coverplate being mounted on opposite ends of the flapper body, each hole engaging a pin that also engages a pair of aligned holes on a pair of spaced brackets on the exterior of the collection basin. 
     
     
         20 . The pour-flush latrine pan of  claim 1 , installed in a slab such that the upper edge of the upper bowl portion is substantially flush with a surface of the slab. 
     
     
         21 . The pour-flush latrine pan of  claim 1 , wherein the collection basin is manufactured of a material selected from a polymer, a plastic, a composite, a metal, a concrete, a cement, a natural or synthetic stone, a composite, a wood, a fiberglass, a porcelain, a ceramic, gravel, and a clay. 
     
     
         22 . The pour-flush latrine pan of  claim 1 , wherein the flapper is manufactured of a material selected from polymer, a plastic, a composite, a metal, a concrete, a cement, a natural or synthetic stone, a composite, a wood, a fiberglass, a porcelain, a ceramic, gravel, and a clay. 
     
     
         23 . A pour-flush latrine pan assembly for installation into a pour-flush latrine comprising the latrine pan of  claim 1  and a water dispensing vessel. 
     
     
         24 . The assembly of  claim 23  wherein the water dispensing vessel is selected from a bucket, a pail, a spout-bearing vessel, a hose, and an expandable bladder. 
     
     
         25 . The assembly of  claim 23 , wherein the water dispensing vessel has a liquid capacity selected from about 1 liter, about 1.5 liters, about 2 liters and about 3-5 liters. 
     
     
         26 . The assembly of  claim 24 , further comprising written materials. 
     
     
         27 . The pour-flush latrine pan assembly of  claim 26 , wherein the written materials comprise a communication device that provides at least one of (a) instructions for assembly of the pour-flush latrine pan, (b) instructions for installation of the pour-flush latrine pan, (c) instructions for use of the pour-flush latrine pan assembly, and (d) instructions for maintenance of the pour-flush latrine pan assembly. 
     
     
         28 . The pour-flush latrine pan assembly of  claim 27 , wherein the communication device comprises text, a drawing, and a cartoon. 
     
     
         29 . A method of preventing or reducing a flow of a sewage gas from a leach pit comprising installing in a slab the pour-flush latrine pan of  claim 1 . 
     
     
         30 . The method of  claim 29 , wherein the flow of the sewage gas is reduced by at least 50% as compared to a conventional open leach pit. 
     
     
         31 . The method of  claim 30 , wherein the sewage gas is hydrogen sulfide or ammonia. 
     
     
         32 . A method of reducing the incidence of adverse health effects caused by sewage gas exposure in a latrine-using individual comprising installing over a leach pit the pour-flush latrine pan of  claim 1 . 
     
     
         33 . The method of  claim 32 , wherein the adverse health effect is chosen from mucus membrane irritation, sore throat, cough, shortness of breath, respiratory ailments, fluid accumulation in the lungs, fatigue, pneumonia, loss of appetite, headaches, irritability, poor memory, dizziness, loss of consciousness and death. 
     
     
         34 . A method of installing a pour-flush latrine comprising fitting the pour-flush latrine pan of  claim 1  in fluid communication with a leach pit. 
     
     
         35 . The method of  claim 34 , wherein the outlet of the collection basin and the leach pit are separated by at least one meter. 
     
     
         36 . The method of  claim 34 , wherein the pour-flush latrine pan is fitted into a cement slab. 
     
     
         37 . The method of  claim 34 , wherein the cement slab contains a footbed on either side of the collection basin to facilitate delivery of a bowel movement as near as possible to the outlet of the basin. 
     
     
         38 . A pour-flush latrine comprising a leach pit in fluid communication with the latrine pan of  claim 1 . 
     
     
         39 . The latrine of  claim 38 , sited in a public sanitation facility. 
     
     
         40 . The latrine of  claim 38 , sited in a family residence. 
     
     
         41 . A method of sustainably and hygienically removing human excreta from human contact comprising
 providing a latrine of  claim 38 ;   delivering to the coverplate of the latrine pan a bowel movement of a user, wherein the bowel movement rest upon a first surface of the coverplate;   applying to the bowel movement-bearing coverplate a water stream such that the pivotal force exerted on the coverplate exceeds the pivotal force exerted on the counterbalance device causing the coverplate to become disengaged from the lower end of the basin such that the coverplate and the lower end are spaced apart sufficiently and the bowel movement is released from the surface of the cover plate, descending downwardly towards the leach pit;   
       wherein upon release of the bowel movement, the coverplate re-engages against the lower end of the collection basin and a liquid seal is formed between the first surface of the coverplate and the lower end of the collection basin. 
     
     
         42 . The method of  claim 41 , wherein the water stream is applied by manually pouring water into the collection basin using a water dispensing vessel.