Underwater breathing apparatus

Claim 1

A DIVING APPARATUS OF THE CLASS DESCRIBED WHICH INCLUDES: BREATHING MEANS; INHALATION AND AN EXHALATION CHECK VALVES CONNECTED TO SAID BREATHING MEANS; A CARBON DIOXIDE ABSORBENT CANISTER CONNECTED TO SAID EXHALATION CHECK VALVE; AN OXYGEN SOURCE; A FIRST DEMAND REGULATOR VALVE ATTACHED TO SAID OXYGEN SOURCE; AN AIR SOURCE; A SECOND DEMAND REGULATOR VALVE CONNECTED TO SAID AIR SOURCE AND TO SAID INHALATION CHECK VALVE; AND A PRESSURE RESPONSIVE CONTROL MEANS FOR ADDING OXYGEN TO THE GAS EXHALED INTO SAID BREATHING MEANS AND PASSING THROUGH SAID PRESSURE RESPONSIVE CONTROL MEANS DURING THE USE OF SAID DIVING APPARATUS SO AS TO PROVIDE SUFFICIENT OXYGEN TO SAID EXHALED GAS TO BRING THE COMPOSITION OF SAID EXHALED GAS SUPPILED TO SAID BREATHING MEANS THROUGH SAID INHALATION CHECK VALVE BACK TO ITS INITIAL PERCENTAGE COMPOSITION BY VOLUME, SAID PRESSURE RESPONSIVE CONTROL MEANS HAVING INLET MEANS CONNECTED TO SAID CANISTER AND TO SAID FIRST DEMAND REGULATOR VALVE, AND SAID PRESSURE RESPONSIVE CONTROL MEANS ALSO HAVING OUTLET MEANS CONNECTED TO SAID INHALATION VALVE, SAID PRESSURE RESPONSIVE CONTROL MEANS BEING RESPONSIVE TO THE AMBIENT PRESSURE SURROUNDING SAID APPARATUS AND THE QUANTITY OF GAS PASSING THROUGH SAID CANISTER. SO AS TO OBTAIN OXYGEN FROM SAID OXYGEN SOURCE IN ACCORDANCE WITH THE MASS OF CARBON DIOXIDE ABSORBED BY SAID CANISTER SO THAT SAID OXYGEN OBTAINED FROM SAID OXYGNE SOURCE AND SAID GAS PASSING THROUGH SAID CANISTER MAY BE INHALED THROUGH SAID INHALATION CHECK VALVE FROM SAID PRESSURE RESPONSIVE CONTROL MEANS ALONG WITH AIR FROM SAID AIR SOURCE AS REQUIRED BY THE USER OF SAID APPARATUS.