Underwater oxygen supply system

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 (or "octopus") 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.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention pertains to a self-contained underwater breathing apparatus 
(SCUBA) and more particularly to a device that is capable of supplying 
various oxygen/air mixtures to a diver in distress whether the diver is 
below or above the surface of the water. 
2. General Background 
The sport of underwater diving is enjoyed by both amateurs and 
professionals alike. With the advent of diving computers, the duration and 
depth of each dive are more accurately assessed thereby permitting 
sufficiently longer "bottom time" than was previously available using 
standard Navy Dive Tables. Unfortunately, however, because of this 
increase in "bottom time", the diver is subject to a greater risk of 
incurring decompression sickness and/or air embolism. This risk increases 
should the diver also be overweight, out of shape, smoke, or have other 
health problems. 
Decompression sickness, or the "bends", results from an increase of 
nitrogen gas bubbles in the blood stream as a consequence of breathing 
pressurized air. It is important for these pressurized gas bubbles to be 
removed from the blood stream before the diver surfaces. If they are not 
removed, their expansion in the diver's tissue upon surfacing can result 
in symptoms ranging from mild discomfort in the joints to complete 
incapacitation. If this occurs, it becomes extremely important for the 
diver to be re-pressurized, such as in a decompression tank or chamber, so 
that as much of the pressurized nitrogen can be removed as possible. 
Unfortunately, however, relocation of the diver to such a decompression 
tank or chamber is time consuming thereby causing the stricken diver much 
discomfort. Also, by the time such a tank is located, permanent physical 
damage to the diver may have already occurred. Furthermore, even though it 
is becoming more common for large dive boats to be outfitted with such 
decompression tanks, just by bringing the diver to the surface will 
increase the diver's pain, discomfort, and possibility of injury. 
Air embolism is caused by the rupture of lung tissue due to the rapid 
expansion of pressurized air should the diver surface too quickly. It is 
vitally important for the diver to fully exhale during surfacing so as to 
remove all such pressurized air from the lungs before any damage can 
occur. Thus, divers must surface at a rate sufficient enough to remove as 
much pressurized air from the body's tissue as possible. Consequently, it 
has become normal operating procedure for divers to surface in stages, 
staying at one level for a certain period of time before moving on to the 
next level, so as to give the body time to rid itself of any lingering gas 
bubbles. 
It has been found that supplying a diver suffering from the bends with 100% 
oxygen helps reduce and/or eliminate the pressurized nitrogen gas bubbles. 
Additionally, 100% oxygen has also been found useful in resuscitation 
techniques for both drowning victims as well as those with lung damage. In 
fact, SCUBA instructors and dive boats are now frequently coming equipped 
with an emergency oxygen tank for just this purpose. 
In the event a diver in distress is brought to the surface, oxygen must be 
supplied as quickly as possible. Generally, the oxygen tanks on the dive 
ship are not immediately available and their connecting mouthpiece is 
either stored with the tank or elsewhere. Thus, precious time may be 
wasted assembling the necessary apparatus before oxygen can be made 
available to the diver in distress. 
Despite all the precautions taken, divers still contact the bends and 
become disabled via air embolism. Also, just by bringing the distressed 
diver to the surface can result in sever injury even though the dive boat 
contains all the currently available safety features. It is thus an object 
of the present invention to provide a means of supplying emergency oxygen 
to a diver in distress either above or below the surface of the water as 
needed. A further object of the invention is the ability to supply either 
100% oxygen, a mixture of air/oxygen, or 100% air to the diver in distress 
as may be required. Thus, by being able to supply 100% oxygen to a diver 
in distress before surfacing, the magnitude and consequence of contacting 
the bends and/or air embolism is significantly reduced. Still another 
object of the present invention is to provide a means of supplying 
emergency gas directly to a face mask placed over the diver in distress or 
fitted to an unconscious victim. Yet another object of the present 
invention is the ability to supply such gas mixture below the surface of 
the water without endangering the rescuing diver or requiring his/her 
mouthpiece removal. These and other objects and advantages of this 
invention will become obvious upon further investigation. 
SUMMARY OF THE PRESENT INVENTION 
The preferred embodiment of the apparatus of the present invention solves 
the aforementioned problems in a straightforward and simple manner. What 
is disclosed is an underwater breathing apparatus having a pressurized air 
tank, a primary breathing apparatus, and a separate secondary breathing 
apparatus with mouthpiece. The improvement consists of securing a separate 
pressurized oxygen tank to the air tank and connecting a first conduit to 
the air tank and a separate second conduit to the oxygen tank. A gas 
mixing valve couples to both of these conduits and is located intermediate 
the secondary breathing apparatus and these conduits. This gas mixing 
valve is configured with a selector switch for selectively supplying 
either pressurized air from the air tank, pressurized oxygen from the 
oxygen tank, or a pressurized air/oxygen mixture to the secondary 
breathing apparatus. Additionally the gas mixing valve contains an 
internal mixing chamber for combining the pressurized air and the 
pressurized oxygen therein prior to delivering this air/oxygen mixture to 
the secondary breathing apparatus. Check valves are also incorporated 
within this gas mixing valve to prevent any backflow through the gas 
mixing valve.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring initially to FIG. 1, 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 "octopus") 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 FIGS. 2 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. 
FIG. 4 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. 
FIG. 5 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. FIG. 6 illustrates the setting wherein 100% air is supplied 
exit passageway 56 while FIG. 7 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 FIG. 8, 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'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.