(1) Field of the Invention
This invention pertains to an air valve of a swimming mask which utilizes the mechanism of springs to regulate the opening and closing of the tube for air circulation on the surface of the water. The presence of the springs will prevent the tube from closing permanently to stop the air inflows. The drainage system of this swimming mask employs a flapper which can drain out any water that comes in from the upper end of the tube.
(2) Description of the Related Art
Representative of the related art known is the U.S. Pat. No. 2,317,236 to C. H. Wilsen et al in which the air intake and outlet valve is a ball valve which is to open or close the flange to prevent water from entering the tube under the surface of the water. In this drainage system, water which may enter the tube will pass through the face to the bottom valve and eventually be purged out through the bottom valve by either submerging the head underneath the water or blowing into the mouthpiece while pressing against the ball valve by hand.
The applicant's swimming mask is imagined according to the human respiratory system around the throat. The biological principle of separating water and air at the pharynx into esophagus and trachea is applied to the design of the protective cover and the air intake and outlet valve on the top part of the plastic tube that is connected with the mask. During swimming, the valve utilizes the springs to open or close the mobile cover depending on the absense or the presence of an external water pressure from the top of the protective cover. This valve will discriminately allow only air to enter into the mask through the plastic tube, thus giving the user a bountiful supply of air. If water enters into the protective cover accidentally, it will be drained out automatically through a hole at the base of the protective cover, preventing it from entering the plastic tube.