Chemical breathing apparatus with alarm device

Claim 2

In a chemical breathing apparatus with an electrically actuated alarm device for use by a human and adapted to supply life-sustaining gases to the respiratory tract of the human who is operating in a gaseous environment, a canister adapted to be carried by the human, said canister containing at least one chemical sorbent through which gases to be treated in the canister must pass, a face piece adapted to be placed over the face of the wearer and having communication with the respiratory tract of the wearer, means forming a fluid flow passage between the canister and the face piece so that treated gases which are treated by the canister can travel to the face piece to be utilized by the wearer, electrode means in contact with the chemical sorbent in the canister and being in the form of spaced apart electrodes, one of said electrodes being positioned only in the upper portion of the chemical sorbent so that the chemical sorbent disposed generally in the upper one-half portion of the canister presents a high resistance between the electrodes, signalling means connected in series with the electrodes and means for applying a potential to the electrodes to give an indication when the resistance of the chemical sorbent between the electrodes is substantially reduced to thereby give an indication of the remaining effective life of the canister.

Claim 3

A breathing apparatus as in claim 1 wherein said signalling means includes a lamp mounted on the breathing apparatus in a position where it can be readily viewed by the wearer of the apparatus.

Claim 4

A breathing apparatus as in claim 1 wherein said canister is of the filter type and is adapted to be opened to the atmosphere to permit atmospheric air to be drawn into the canister to be treated so that it can be utilized by the wearer.

Claim 5

A breathing apparatus as in claim 1 wherein said chemical sorbent is provided for generating oxygen and wherein said means establishing communication between the canister and the face piece include means for introducing exhaled air into the canister where it is recirculated through the canister to remove the carbon dioxide and to introduce oxygen so that the exhaled air can be reused by the wearer.

Claim 6

A breathing apparatus as in claim 1 together with means for testing said alarm device to see whether or not it is operative.

Claim 7

A breathing apparatus as in claim 1 wherein at lwats two different chemical materials are utilized and in which chemical sorbents are disposed in layers in the canister and wherein said first named electrode is disposed in one of said layers.

Claim 8

A breathing apparatus as in claim 1 wherein said alarm device is readily detachable. 8 In a chemical breathing apparatus with an electrically actuated alarm device for use by a human and adapted to supply life sustaining gases to the respiratory tract of the human who is operating in a gaseous environment, a canister adapted to be carried by the human, said canister containing at least one chemical sorbent through which gases to be treated in the canister must pass, a face piece adapted to be placed over the face of the wearer and having communication with the respiratory tract of the wearer, means forming a fluid flow passage between the canister and the face piece so that treated gases which are treated by the canister can travel to the face piece to be utilized by the wearer, electrode means in contact with the chemical sorbent in the canister and being in the form of spaced apart electrodes, one of said electrodes being positioned only in the upper portion of the chemical sorbent so that the chemical sorbent presents a high resistance between the electrodes, signalling means connected in series with the electrodes and direct current power supply means for applying a potential to the electrodes to give an indication when the resistance of the chemical sorbent between the electrodes is substantially reduced to thereby give an indication of the remaining effective life of the canister.

Claim 9

A chemical breathing apparatus as in claim 8 wherein said direct current power supply means is in the form of a battery.

Claim 10

In a chemical breathing apparatus with an electrically actuated alarm device for use by a human and adapted to supply life-sustaining gases to the respiratory tract of the human who is operating in a gaseous environment, a canister adapted to be carried by the human, said canister containing at least one chemical sorbEnt through which gases to be treated in the canister must pass, a face piece adapted to be placed over the face of the wearer and having communication with the respiratory tract of the wearer, means forming a fluid flow passage between the canister and the face piece so that treated gases which are treated by the canister can travel to the face piece to be utilized by the wearer, electrode means in contact with the chemical sorbent in the canister and being in the form of spaced apart electrodes so that the chemical sorbent presents a high resistance between the electrodes, signalling means connected in series with the electrodes and means for applying a potential to the electrodes to give an indication when the resistance of the chemical sorbent between the electrodes is substantially reduced to thereby give an indication of the remaining effective life of the canister, said electrode means being in the form of one electrode extending into the chemical sorbent and the other electrode being in the form of a body with the chemical sorbent disposed in the body.

Claim 11

In a chemical breathing apparatus with an electrically actuated alarm device for use by a human and adapted to supply life-sustaining gases to the respiratory tract of the human who is operating in a gaseous environment, a canister adapted to be carried by the human, said canister containing at least one chemical sorbEnt through which gases to be treated in the canister must pass, a face piece adapted to be placed over the face of the wearer and having communication with the respiratory tract of the wearer, means forming a fluid flow passage between the canister and the face piece so that treated gases which are treated by the canister can travel to the face piece to be utilized by the wearer, electrode means in contact with the chemical sorbent in the canister and being in the form of spaced apart electrodes so that the chemical sorbent presents a high resistance between the electrodes, signalling means connected in series with the electrodes and means for applying a potential to the electrodes to give an indication when the resistance of the chemical sorbent between the electrodes is substantially reduced to thereby give an indication of the remaining effective life of the canister, said electrode means being in the form of one electrode extending into the chemical sorbent and the other electrode being in the form of a body with the chemical sorbent disposed in the body.

Claim 12

A breathing apparatus as in claim 10 wherein said first named electrode is in the form of a screen-like element disposed in the chemical sorbent.

Claim 13

A breathing apparatus as in claim 10 wherein said first named electrode makes electrical contact with two spaced layers.

Claim 14

A breathing apparatus as in claim 12 wherein said first named electrode is in the form of a pair of spaced, generally parallel screen-like members which are connected in parallel and which are disposed in separate spaced layers.