| 摘要 |
A portable emergency oxygen supply which may be carried without difficulty by a user and is safe under all conditions. The supply includes a canister containing oxygen-rich gas at relatively low pressure, the canister having a normally-closed valve which is provided with an actuating switch. The valve output is coupled by a feed tube to the interior of an inflatable bellows which is attached to and communicates with a face mask whereby the user is able to repeatedly inhale and exhale the volume of gas enclosed in the bellows, in the course of which he depletes the oxygen contained therein. The oxygen in the bellows is intermittently replenished by operating the switch so that the available oxygen in the canister is fully utilized.
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