referring initially to fig1 there is shown typical underwater breathing system 10 . this system 10 incorporates a pressurized air tank 12 and a first stage regulator 14 . connected to first stage regulator 14 is primary breathing apparatus 16 having second stage regulator 18 and mouthpiece 20 designed to supply air to the diver upon demand . second stage regulator 18 can also be adjusted to supply a free - flow of air to the diver if such is desired . a separate pressure gauge 21 is also connected to first stage regulator 14 which is used by the diver to monitor the amount of pressurized air remaining in tank 12 . when the amount of air drops to a certain level , the diver must surface . also connected to first stage regulator 14 is a separate secondary breathing apparatus ( or &# 34 ; octopus &# 34 ;) 22 which incorporates second stage regulator 24 and mouthpiece 26 . second stage regulator 24 is generally free - flowing but it can also be adjusted to supply upon demand if desired . the invention pertains to securing a separate smaller 100 % oxygen tank 28 onto air tank 12 such as by strap 30 or the like . other means of attachment are equally suitable with strap 30 being illustrated merely for descriptive ease . oxygen tank 28 incorporates its own first stage regulator 32 secured to oxygen hose 34 . oxygen hose 34 delivers the stored oxygen to gas mixing valve 36 which is located intermediate first stage regulator 14 and second stage regulator 24 on octopus 22 . gas mixing valve 36 also receives air from tank 12 via air hose 38 . depending upon the setting of gas mixing valve 36 , either 100 % air from tank 12 is delivered to mouthpiece 26 , or 100 % oxygen from tank 28 is delivered to mouthpiece 26 , or a mixture of the two ( such as a 60 / 40 ratio of air / oxygen ) is delivered to mouthpiece 26 . referring now more specifically to fig2 and 3 , gas mixing valve 36 is illustrated in greater detail . as shown , valve 36 is coupled to hoses 34 and 38 by standard threaded couplers 40 . when thusly secured , each hose 34 and 38 delivers its product ( either air 42 or oxygen 44 ) to its respective passageway 46 or 48 within gas mixing valve 36 . each passageway 46 and 48 is connected to both mixing chamber 50 and selector switch 52 . also , each passageway 46 and 48 contain typical check valves 54 therein to prevent any backflow within gas mixing valve 36 . selector switch 52 determines whether air 42 , oxygen 44 , or a mixture of the two flows into exit passageway 56 thereby exiting gas mixing valve 36 and flowing to second stage regulator 24 and then to mouthpiece 26 . in order to accomplish this task , selector switch 52 is configured with a central opening 58 therethrough which couples between exit passageway 58 and either air passageway 46 , oxygen passageway 48 , or mixing chamber passageway 60 . as shown , central opening 58 is configured to couple with either passageway 46 , 48 , or 60 through its side 62 while also connecting with exit passageway 56 through its bottom 64 . selector switch 52 can also be adjusted so as not to connect with any such passageway 46 , 48 , or 60 thereby blocking any flow to exit passageway 56 . depending upon the setting of selector switch 52 , and as indicated above , either air passageway 46 is the only passageway open , or oxygen passageway 48 is the only passageway open , or mixing chamber passageway 60 is the only passageway open , or all three passageways 46 , 48 , and 60 are blocked . selector switch 52 is clearly marked so as to indicate which setting is selected . in this fashion , when gas mixing valve is in use , both the diver in distress and the rescuing diver can readily determine which mixture is being supplied . also , should circumstances warrant it , the mixture being supplied can easily be altered during use as needed . fig4 illustrates the setting wherein mixing chamber passageway 60 is open . at this setting , central opening 58 of selector switch 52 connects to mixing chamber passageway 60 thereby permitting a preset mixture ( such as a 60 %/ 40 % mixture of air / oxygen ) combined in mixing chamber 50 to flow to exit passageway 56 . also shown are check valves 54 just upstream mixing chamber 50 that prevent any back flow through passageways 46 or 48 which supply air 42 and oxygen 44 to mixing chamber 50 . generally , first stage regulators 14 and 32 supply their respective gas at relatively the same pressure so that no great pressure differential will exist between passageways 46 and 48 . fig5 illustrates the setting wherein all three passageways 46 , 48 , and 60 are blocked thereby preventing any air or oxygen from flowing through exit passageway 56 . fig6 illustrates the setting wherein 100 % air is supplied exit passageway 56 while fig7 illustrates the setting wherein 100 % oxygen is supplied exit passageway 56 . thus , whatever mixture is required for the situation at hand , the rescuing diver , or the diver in distress , can select the proper setting on selector switch 52 so as to supply this mixture to mouthpiece 26 on octopus 22 . referring now to fig8 there is shown a typical oxygen mask 66 oftentimes used to supply oxygen to a diver in distress . generally , mask 66 is used on the dive boat , but it can also be used in the water if need be . mask 66 is modified to incorporate adaptor 68 which is configured to fit snugly within mouthpiece 26 of octopus 22 . a pair of tubes 70 provide a channel for supplying the selected breathing medium from mouthpiece 26 to mask 66 . indentations 72 in both sides of adaptor 68 are sized to fit the normal teeth guards ( not shown ) found in most mouthpieces 26 thereby sealing between mouthpiece 26 and mask 66 . also , the projection of tubes 70 into mouthpiece 26 ( when installed ) further insure the delivery of the breathing medium to mask 66 . purge valves 74 on both sides of mask 66 permit the diver in distress to exhale as needed . also , mask 66 may be secured around the diver &# 39 ; s head by straps attached to openings 76 in mask 66 if desired . thus , during use , a diver in distress is fitted with mask 66 in the normal fashion with mask 66 already incorporating adaptor 68 ( such as by being permanently secured thereto ). consequently , the rescuing diver need only insert mouthpiece 26 of his octopus 22 around adaptor 68 and select whether air 42 , oxygen 44 , or a mixture of the two is to be supplied . also , second stage regulator 24 of octopus 22 can be adjusted to cause a free flow of this breathing medium to be forced into mask 66 until no longer needed . alternatively , second stage regulator 24 can be adjusted to supply this breathing medium only upon demand if desired . in any event , the diver in distress is supplied the proper mixture in a timely fashion whether above the surface of the water ( via mask 66 ) or below it ( via mouthpiece 26 ). because many varying and differing embodiments may be made within the scope of the inventive concept herein taught and because many modifications may be made in the embodiment herein detailed in accordance with the descriptive requirement of the law , it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense .
an underwater breathing apparatus capable of supplying either 100 % air , 100 % oxygen , or an air / oxygen mixture to a diver as needed . a selector switch clearly indicates what is being supplied through the separate secondary breathing apparatus of the rescuing diver . also disclosed is a face mask to be placed around the nose and mouth of a diver in distress that is configured with an adaptor which accepts and seals around the mouthpiece of the secondary breathing apparatus . in this fashion , the rescuing diver can supply either air , oxygen , or a mixture of the two to a diver in distress in either a free - flow state or upon demand .