Aircraft crew member protective breathing apparatus
View Patent ↗A self-contained breathing device for use in fighting fires comprising a hood for covering a wearer's head, a membrane for sealing the hood to create a breathing chamber inside the hood, and a source of oxygen disposed inside the hood. The source of oxygen is connected to the user by a conduit inside of the hood, and another conduit directs user-exhaled carbon dioxide to the source of oxygen. The breathing device includes a visual indicator inside of the hood that reacts to the presence of a gas within the hood and provides visual feedback to the user based on a quantity of the gas present in the hood.
1. A breathing apparatus comprising:
a hood sized to fit over a user's head and having a visor and a sealing membrane to isolate the user's head and define a breathing chamber, and a self-contained oxygen source inside the hood, the self-contained oxygen source located behind the user's head;
a first tube connecting the self-contained oxygen source behind the user's head and terminating at a position above the user's head for delivering oxygen to a breathing area;
a second tube connecting a user's mouth piece to the self-contained oxygen source behind the user's head for carrying carbon dioxide away from the breathing area;
a user's mouth piece connected to a front of the hood including a one-way valve for intake of oxygen from the breathing area and a second one-way valve for expelling carbon dioxide to the second tube;
a transparent viewing window on the hood;
a first internal indicator on the transparent viewing window and facing the user inside the hood that indicates to the user that the self-contained oxygen source behind the user's head is providing a threshold oxygen level inside the breathing chamber at the breathing area; and
a second internal indicator on the transparent viewing window and facing the user inside the hood, that indicates to the user that a threshold carbon dioxide level is not exceeded inside the breathing chamber.
2. The breathing apparatus of claim 1 wherein the self-contained oxygen source comprises a canister containing KO 2 (potassium superoxide) and a starter candle that activates a production of oxygen using NaCIO 3 .