Pneumatic amplifier air flow regulator for underwater breathing appts. - uses small deflection of valve attached to membrane sensing breathing to displace piston away from air inlet

摘要

The underwater breathing appts. regulator gives smooth flow of air through the diver's mouthpiece. The regulator is incorporated in the mouthpiece and receives air at low pressure from the primary regulator fitted at the air tank outlet. A membrane with water pressure on one side and air connection to the diver's mouth on the other, has a cone attached to its inner surface. Intake of breath reduces pressure underneath the cone so it is forced inwards, displacing levers which tilt and raise a valve through a small distance against weak spring pressure. This allows the low pressure air supply to enter a cylinder coaxial with the valve and to lift a loose fitting piston which slides along the stem of the valve against a larger spring. The bottom of the piston is thus moved clear of the main low pressure inlet and air passes through orifices in the cylinder support to equalise pressure on the membrane and progressively reduce the air supply as the valve is closed and the air escapes around the piston which is restored to the closed position by the spring.