Air operated fresh air ventilator

Claim 1

AN AIR VENTILATOR COMPRISING A DUCT ADAPTED TO RECEIVE FRESH AIR AND HAVING A PORTION THEREOF PROTRUDING INTO A BUILDING, SAID DUCT HAVING A SUBSTANTIALLY UPRIGHT AXIS, AN INTAKE OPENING OPEN OUT OF SAID DUCT, A FLAP TYPE VALVE TO COVER SAID OPENING, SAID FLAP TYPE VALVE BEING SUSPENDED FROM A SUBSTANTIALLY HORIZONTAL AXIS AND MOVABLE FROM A FIRST GRAVITY HELD POSITION WHEREIN IT SUBSTANTIALLY CLOSES OFF AIR FLOW FROM SAID DUCT TO A SECOND POSITION WHEREIN IT PERMITS AIR FLOW FROM SAID DUCT, SAID FLAP TYPE VALVE HAVING A LOWER END PORTION BENT OUT OF THE PLANE OF THE MAIN PORTION OF THE VALVE AND TOWARD THE DIRECTION OF INCOMING AIR FLOW, AND MEANS TO MOVE SAID VALVE TO AND HOLD IT IN SAID SECOND POSITION, SAID MEANS INCLUDING A STOP MEMBER PIVOTALLY MOUNTED IN SPACED RELATION TO SAID FLAP VALVE AT THE AIR INLET SIDE THEREOF FOR MOVEMENT FROM A FIRST LOCATION SPACED FROM SAID FLAP VALVE TO A SECOND LOCATION WHEREIN AN OUTER END OF SAID STOP MEMBER BEARS AGAINST SAID FLAP VALVE TO MOVE IT AND HOLD IT IN SAID SECOND FLAP VALVE POSITION, A CONTROL LEVER INTEGRAL WITH SAID STOP MEMBER, AND MANUALLY OPERABLE MEANS OPERATIVE ON SAID CONTROL LEVER TO CAUSE SAID STOP MEMBER TO MOVE BETWEEN SAID FIRST AND SECOND LOCATIONS.