Patent ID: 7207332

Claim:
Apparatus for administering a gas to a person or an animal, comprising: a chamber having an inlet; means for supplying the gas under pressure to the chamber inlet; a breathing tube connected to the chamber through a breathing valve, the breathing valve constructed to allow the gas to pass from the chamber to the breathing tube, and to allow exhaled gas in the breathing tube to pass from the breathing tube to outside the apparatus; an aperture through which the gas in the chamber can pass to outside the apparatus; and a safety valve separrate from the breathing valve, the safety valve being urged by a first spring pressure to close the aperture; wherein the safety valve is constructed and arranged to allow the gas in the chamber to escape through the aperture to outside the apparatus as soon as pressure of the gas in the chamber exceeds a threshold value, the threshold value being determined by the first spring pressure; and wherein the first spring pressure is adjustable over a predetermined range.