Patent ID: 8083208

Claim:
A gas rotary valve comprising: a valve body ( 1 ) including an inlet passage ( 11 ) and an outlet passage ( 12 ); a valve core ( 2 ) with a center hole ( 21 ) disposed in said valve body ( 1 ) and being rotatable relatively to said valve body ( 1 ), having a large through hole ( 22 ), a first small through hole ( 23 ) and a second small through hole ( 24 ) which are all disposed on a peripheral surface of said valve core ( 2 ) and communicated with said center hole ( 21 ) respectively; a valve cover ( 3 ) disposed at an end of the valve body ( 1 ); an actuating shaft ( 4 ) for driving said valve core ( 2 ) to rotate in the single direction, a rear end of the actuating shaft going through a center hole ( 31 ) of said valve cover ( 3 ) and inserting into a round inner chamber of said valve cover ( 3 ), a guide pin ( 41 ) radially fixed on the rear end of said actuating shaft ( 4 ), said actuating shaft ( 4 ) being movable inward and outward relatively to said valve cover ( 3 ); wherein a first step ( 3 a ; 3 c ) and a second step ( 3 b ; 3 d ) disposed in distance in the inner chamber of said valve cover ( 3 ) respectively preventing said guide pin ( 41 ) from rotating, the positions of the two steps matching the following condition: at a turn of said guide pin ( 41 ) on said actuating shaft ( 4 ) is stopped by said first step ( 3 a ; 3 c ) said large through hole ( 22 ) on said valve core ( 2 ) communicates with said inlet passage ( 11 ) of the valve body ( 1 ); at the turn of said guide pin ( 41 ) on said actuating shaft ( 4 ) is stopped by said second step ( 3 b ; 3 d ), said second small through hole ( 24 ) on said valve core ( 2 ) communicates with said inlet passage ( 11 ) of the valve body ( 1 ); a regulator positioning pin ( 6 ), a rear end of which being able to enter into the inner chamber of said valve cover ( 3 ), the rear end of said regulator positioning pin ( 6 ) being located between said first step ( 3 a ; 3 c ) and said second step ( 3 b ; 3 d ), the position of the rear end of said regulator positioning pin ( 6 ) matching the following condition: at the turn of said guide pin ( 41 ) on said actuating shaft ( 4 ) is stopped by the rear end ( 61 ) of said regulator positioning pin ( 6 ) said first small through hole ( 23 ) on said valve core ( 2 ) communicates with said inlet passage ( 11 ) of the valve body ( 1 ).