ROBERT K GRAY
Broker in Pittsburgh, PA

4090511, May 23, 1978

Mar 23, 1977

5/780409

Robert Elder Gray - Pittsburgh PA

Mine Safety Appliances Company - Pittsburgh PA

A62B 700

128147

A valve housing has a mouth port in one side and a vent opening in its opposite side, with another opening between them for connection to a carbon dioxide removing and oxygen generating canister. Around the mouth port inside the housing is a valve seat, toward which a valve member is urged by a spring to normally close the valve. Surrounding the valve member and spring is a bellows that has an open end secured to the housing around the vent opening to thereby expose the inside of the bellows to the pressure of water or other liquid in which the valve may be submerged. Connected to the outer end of the mouthport is a mouthpiece adapted to be held in the mouth of a user, and encircling the mouthpiece is a ring that is connected with the valve member for movement with it. The ring normally is so positioned on the mouthpiece that it must be moved toward the housing to permit the mouthpiece to be held in the mouth with the lips against the ring to thereby hold the valve open, but if the mouthpiece is removed from the mouth the spring and fluid pressure inside the bellows will close the valve.

4007758, Feb 15, 1977

Jan 14, 1976

5/648915

Robert E. Gray - Pittsburgh PA
Leslie F. Boord - Elizabeth PA

Mine Safety Appliances Company - Pittsburgh PA

F16K 1720

137472

A chamber in a valve case has an inlet port of exhaled air in one of its end walls. Spaced inwardly from the side wall of the chamber is a valve seat surrounding the inlet port and engaged by one side of a sealing member, the opposite side of which is engaged by a rigid disc secured to a valve stem that extends through the port and into guiding means for the stem. The diameter of the disc is nearly as great as the diameter of the chamber. A spring in the case is compressed between the disc and the other end wall of the valve chamber for pressing the sealing member against the seat. The disc is spaced from the ported wall of the chamber far enough for the marginal portion of the disc that extends laterally out beyond the sealing member to be inclined toward the ported wall but spaced from it. The side wall of the chamber is provided with exhaust slots extending around the disc and having inner walls adjacent the ported wall lying in a plane substantially coinciding with the plane in which lies the edge of the disc, and the space between the valve seat and the side wall of the case is always open to the slots.