Flapper valve for a toilet tank

Abstract

A flapper valve for a toilet tank has an annular flange, a cone and an airflow controlling member. The cone is hollow and protrudes from the bottom of the annular flange. The cone has chamber and a vent defined in the outer periphery of the cone and communicating with the chamber. The airflow controlling member is attached to the cone and corresponds to the vent to make air in the chamber being discharged through the airflow controlling chamber. Accordingly, the discharging rate of the air from the chamber in the cone is adjustable, and the volume of flushing water of the toilet is also adjustable.

What is claimed is:  
     
         1 . A flapper valve for a toilet tank having an overflow pipe and a drain pipe with a top opening, and the flapper valve comprising: 
 an annular flange with a bottom and adapted to pivotally connect to the overflow pipe to close the top opening of the drain pipe;    a hollow cone with a bottom and a periphery protruding from the bottom of the annular flange and having 
 a chamber;  
 an opening defined in the bottom of the cone and communicating with the chamber; and  
 a vent defined in the periphery of the cone and communicating with the chamber; and  
   an airflow controlling member attached to the cone and corresponding to the vent to control airflow discharged from the chamber via the vent.    
     
     
         2 . The flapper valve as claimed in  claim 1 , wherein the airflow controlling member has a tubular body inserted into the vent and a passage defined through the tubular body to communicate with the chamber.  
     
     
         3 . The flapper valve as claimed in  claim 1 , wherein the airflow controlling member has a flat plate pivotally attached to the cone and corresponding to the vent to selectively close part of the vent.  
     
     
         4 . The flapper valve as claimed in  claim 3 , wherein the cone further has a bore defined in the periphery of the cone; and 
 the flat plate of the airflow controlling member has a sub extending from the flat plate and rotatably inserted into the bore in the cone.    
     
     
         5 . The flapper valve as claimed in  claim 1 , wherein the airflow controlling member comprises 
 a plug received in the vent and having a bore defined in the plug and a ventage defined through the plug and communicating with the chamber in the cone; and    a disk moveably mounted on the plug, corresponds to the ventage in the plug and has a shaft moveably inserted into the bore in the plug.