Exhaust air transfer device for open system underwater diving

Apparatus for use during open system diving to support underwater human respiration. In accordance with various embodiments, an air supply provides a supply of air along a supply conduit. A regulator is adapted for engagement with a diver's mouth to receive air from the supply during an inhale cycle and to direct a mixture of water and exhaust air away from the diver along an exhaust conduit during an exhale cycle. An air/water separator separates the exhaust air from the water in said mixture and directs the separated exhaust air through an exhaust air port. In some embodiments, a one-way stop valve is provided within the air/water separator to prevent back flow. In further embodiments, a bubble diffuser emits the exhaust air as a fine mist of bubbles into the surrounding water.

BACKGROUND

Self-contained, underwater breathing apparatus (SCUBA) equipment is used by professional divers, military personnel, and amateur enthusiasts the world over to survive and maneuver underwater for extended periods of time. Such systems often employ a portable source of pressurized air, such as one or more tanks, and associated regulators, lines, mouthpiece, mask, etc. to enable the diver to comfortably breathe air at depths of 100 feet underwater or more.

A problem often associated with open system SCUBA equipment is the exhaust air breathed out by the diver after each breath. This exhaust air normally exits the regulator assembly adjacent the diver's mouth as a large grouping of bubbles that float upward to the surface (hence, “open system” SCUBA). Depending upon the spatial orientation of the diver, the exhaust bubbles can pass directly adjacent the diver's ear, which can be unpleasantly loud and annoying to the diver and can detract from the serenity that the diver might have otherwise enjoyed in the underwater environment. Bubbles passing in front of the diver's mask can also obscure vision and may in some instances cause a safety risk.

Expansive underwater environments, such as that existing under the surface of an ocean, can often have an “ambient” noise level made up of broad-spectrum “white” noise. While this noise can come from a variety of sources such as surface phenomena (e.g., wind, rain) and undersea animal life, a significant proportion of this white noise can often be attributed to bubbles of gas suspended within the water.

Undersea bubbles can be generated in a variety of ways, such as from the natural aeration provided by waves and currents, gasses from animals and plants, and methane or other gasses emitted into the water from underlying strata. This high frequency white noise often represents a normal background level for undersea life, in much the same way that high frequency noise from overhead UV lights or HVAC conduits are not usually noticed by human workers in an office building.

Noise vibrations can be generated when bubbles are formed, when a group of smaller bubbles coalesce into a larger bubble, and when a larger bubble collapses into a group of smaller bubbles. Bubbles also emit noise vibrations when they reach the water surface and the entrapped gas escapes into the atmosphere. It has been found that different sizes of bubbles produce different frequencies when they collapse, and the collapse of different sizes of bubbles release different levels of energy into the surrounding water.

As an extreme case, the so-called Snapping Shrimp (Alpheus heterochaelis) can hunt prey by snapping a specialized claw shut to collapse a cavitation bubble and release large amounts of energy sufficient to stun or kill a small fish. The energy level is so great that sonoluminescence (light generation) and temperatures of around 5,000 degrees Kelvin are produced during the cavitation event.

It follows that, under normal circumstances, undersea wildlife are largely undisturbed by high-frequency, low energy noise conditions, but may become startled and skittish in the presence of lower-frequency, higher energy noise conditions. Unfortunately, when a human diver exhales through existing regulators, large, quickly forming bubbles are produced, and these bubbles release low-frequency energy of the type that tends to scare off wildlife when the diver approaches. By contrast, it has been observed that free divers and divers using closed-circuit rebreathers in which no bubbles are released can normally approach and get very close to wildlife.

SUMMARY

Accordingly, various embodiments of the present invention are generally directed to an improved exhaust air transfer device for open system underwater diving.

In accordance with some embodiments, an exemplary device comprises an air supply which provides a supply of air along a supply conduit. A regulator is adapted for engagement with a diver's mouth to receive air from the supply conduit during an inhale cycle and to direct a mixture of water and exhaust air away from the diver along an exhaust conduit during an exhale cycle. An air/water separator (AWS) is coupled to the exhaust conduit to separate the exhaust air from the water in said mixture and to direct the separated exhaust air along an exhaust air conduit.

In further embodiments, the exemplary device incorporates a bubble diffuser coupled to the exhaust air conduit which passes the separated exhaust air as a fine mist of bubbles into the surrounding water. The bubble diffuser may be located on the air supply, such as a tank affixed to the back of the diver. The bubble diffuser may be hinged to generally maintain the diffuser within a desired attitude range irrespective of the attitude of the diver. Alternatively, the bubble diffuser may be a “snorkel-type” member that projects upwardly from the air-water separator and away from the diver's face.

These and other features and advantages of various embodiments can be understood from a review of the following detailed description in conjunction with a review of the accompanying drawings.

DETAILED DESCRIPTION

Various embodiments of the present invention are generally directed to an underwater breathing system having specially configured exhaust air transfer characteristics.FIG. 1generally illustrates a human diver100submerged in a body of water102below a surface104thereof. The diver100is represented as engaging in open scuba diving with various accoutrements including a dive mask106and wetsuit108. For ease of reference, the diver will be referred to as a male diver, although such is clearly not limiting.

The diver100employs an underwater breathing system110to provide a self-contained supply of air for the diver to breathe while he remains below the surface104. The exemplary breathing system110incorporates a number of elements which are functionally represented inFIG. 2. These elements include a supply of pressurized air from an air source such as tank112, an associated first stage (stage-1) regulator114, a second stage (stage-2) regulator116, an air/water separator (AWS)118, and a bubble diffuser (bubbler)120. Other arrangements can readily be used.

The stage-1 regulator114is mounted to the tank112and operates to reduce an initial pressure of the compressed air within the tank to a secondary lower pressure. An exemplary initial pressure may be on the order of about 3,000 pounds per square inch, psi, and an exemplary secondary pressure may be on the order of about 150 psi. The tank112and regulator114may be of a conventional type and are strapped to the back of the diver by way of a buoyancy compensator (BC) vest. Other scuba arrangements may readily be used, including the use of an air hose from a source above the surface104.

The stage-2 regulator116takes a substantially conventional configuration except as modified as required to accommodate various aspects of the exemplary system110explained herein. The regulator116is held in the diver's mouth to receive air from the air tank112and stage-1 regulator114.

During normal respiration, the diver breathes in fresh air from the air tank112through the regulator116, and breathes out exhaust air through the regulator116to the downstream elements118and120. Those skilled in the art will appreciate that the regulator generally includes a series of valves which respond to changes in the pressure of the ambient water in relation to the depth of the diver, the pressure exerted by the diver in breathing in fresh air from the tank, and the pressure exerted by the diver in breathing out the spent exhaust air from his lungs.

In the prior art, the spent exhaust air often exits various ports in the body of the regulator adjacent the diver's face, leading to decreased visibility and increased noise. This can be understood with reference toFIG. 3, which is a simplified functional diagram of an exemplary stage-2 regulator116configured as used in the related art. It will be appreciated that various styles and types of regulators are known with a number of additional features and functions not depicted inFIG. 3. Nevertheless,FIG. 3is operable to set forth general features common to typical regulators of the existing art, as well as for regulators adapted for use in the system110ofFIG. 2.

InFIG. 3, the regulator116is shown to have a housing (body)122divided into at least two chambers which are referred to herein as an air chamber124and an exhaust chamber126. The air chamber124is coupled to a mouthpiece128configured for placement in the diver's mouth, and receives air from an air source via an inlet conduit130. A pressure differential actuated air valve132selectively opens to admit a flow of pressurized air into the diver's lungs as the diver inhales. The air valve132is intended to remain closed at all other times. In at least some styles of regulators, the cracking pressure at which this valve opens can be manually adjusted by the diver during operation.

A main valve134is disposed between the air chamber124and the exhaust chamber126. The valve134can take the form of a thin rubber membrane which operates as a one-way check valve. As with the valve132, the valve134opens in a single direction when the diver breathes out so that the exhaust air passes through the air chamber124to the exhaust chamber126, and out an exhaust port (or ports)136directly into the surrounding water.

Because the exhaust chamber126and the port(s)136are open to the surrounding water, these elements are typically full of water except when injected with the exhaust air from the diver's lungs when the diver breathes out. When the pressure of the exhaled air falls below the pressure of the surrounding water, the valve134closes and the valve132opens as the diver takes his next breath. It can be seen fromFIG. 3that the exhaust port is adjacent the mouthpiece128, and hence the exhaust mixture of water and air flowing out the exhaust ports may pass directly adjacent the diver's mask and ears.

An adjustment mechanism may be provided to permit the diver to adjust the setpoint, or “cracking pressure” at which the valve132opens during inhaling. Such adjustments may be made by the diver by turning a spring biased knob (not separately shown). Generally, a higher cracking pressure requires the diver to exert greater force in inhaling to open the valve and allow the supply air to enter the air chamber124, whereas a lower cracking pressure allows the diver to inhale air with less effort.

As will be appreciated by those skilled in the art, the valve134generally closes in relation to the pressure differential between the exhaust chamber126and the air chamber124; that is, the system uses water pressure in the exhaust chamber126to close the valve134at the conclusion of each exhale cycle.

In some embodiments the valve134is characterized as a thin-film, disc shaped elastomeric membrane with a central portion rigidly affixed to a central dividing wall138of the housing that separates the respective chambers124,126. A circumferentially extending outer portion of the membrane covers one or more ports (not shown) that extend through the dividing wall.

This outer portion of the membrane is displaced away from the central wall138when the pressure in the air chamber124is greater than that of the exhaust chamber126, thereby allowing the air to flow through said ports to the exhaust chamber126. When the water pressure exceeds the pressure of the exhausted air, the water pressure in the exhaust chamber pushes this outer portion of the valve134into a water-tight sealing engagement against said wall138, thereby closing off the fluidic communication between the respective chambers124,126. It will be appreciated that other valve configurations can readily be utilized.

A free-flow condition can arise if there is insufficient pressure differential to close the valve134before valve132opens. In a free-flow condition, air from the inlet conduit130will pass directly through the respective valves132,134and out the port(s)136. A free-flow condition can be remedied by increasing the setpoint pressure of valve132. However, during such free-flow conditions large volumes of the stored air can escape to the surrounding water, reducing the available supply of air for use by the diver.

FIG. 4shows the regulator116ofFIG. 3configured for use in the system110ofFIGS. 1 and 2in accordance with some embodiments. InFIG. 4, a suitable adapter140matingly seals the port(s)136so that the exhaust air from the exhaust chamber passes along the adapter to the air/water separator118. While the adapter140is shown to have substantial length inFIG. 4, this is merely for purposes of illustration; it is contemplated that the adapter140will be relatively short so that the air/water separator118is as close to the regulator116as practical, and is maintained close to the elevational depth of the main check valve134. In some embodiments the adapter140is configured to mate with an existing regulator body122, whereas in other embodiments the configuration of the regulator body is modified to integrally incorporate the adapter140.

The air/water separator118includes a housing (body)142that defines an interior air/water separator chamber144. An inlet port145receives the exhaust mixture of water and air from the adapter140and injects the same into the chamber144. Although not shown inFIG. 4, the chamber144can be configured with appropriate baffle surfaces such that agitation takes place in the flow of the inlet air/water mixture. The exhaust air from the inlet mixture exits through an exhaust air exit port146, and the exhaust water exists through one or more exhaust water exit ports148. The air exit port146transmits the exhaust air to the bubble diffuser120(FIGS. 1-2) in a manner explained below.

The water exit port148is in fluidic communication with the surrounding water. This allows a two-way flow of water between the surrounding water and the separator chamber144, as well as with the adapter140and the exhaust chamber126in the regulator116. It is contemplated that during an exhale operation, water may be directed from the chamber144to flow out into the surrounding water, and water may flow back into the chamber144at the conclusion of each exhale operation. Although not shown inFIG. 4, adjustment mechanisms can be provided to regulate the effective port size of the port(s)148to adjust the flow of water therethrough.

In some embodiments, the top of the inlet port145is nominally aligned with the bottom of the air outlet port146, which extends into the interior chamber144a selected distance as shown. This provides an air entrapment region147that surrounds the outlet port146and retains a volume of pressurized exhaust air. The entrapped air may cause the level of water within the chamber144to normally reach a steady state level between exhale cycles that is substantially level with the port146, as shown.

In this way, as the diver exhales a breath, the force required by the diver during such exhalation may be relatively low; that is, just enough to lower the water level to uncover the port146, thereby allowing the exhaust air to flow freely from port145to port146and out of the air/water separator118. A slightly greater exhalation force may be required if the chamber144is completely filled with water, since the diver will need to vacate a larger amount of water from the chamber144to establish an atmospheric communication path between the respective ports145,146. Even if the chamber144is completely filled with water, however, it is contemplated that the diver will still be able to exhale easily and without noticeable effort.

Depending on the interior configuration of the chamber144and the orientation of the chamber during operation, at various times the chamber may be substantially filled with air, substantially filled with water, or may hold various respective amounts of air and water. In all cases, easy controlled respiration by the diver will be accommodated.

The air/water separator118can be mounted to the adapter140via a swivel so as to maintain a substantially constant upright vertical orientation irrespective of the orientation of the stage-2 regulator116. In other embodiments, the air/water separator118can be rigidly affixed to the stage-2 regulator so that the orientation of the chamber144is set by the orientation angle of the regulator. It has been found that the air/water separator will function properly in substantially all orientations, even when upside down, as the exhaust air can readily flow out the port(s)148in this latter condition. However, it is contemplated that optimal results may be obtained when the chamber144is oriented along a range from upright vertical to horizontal.

Of particular interest is the flow of the exhaust water through the air/water separator. It will be recalled that the main check valve134opens and closes in relation to the differential pressure between the respective chambers124and126. It is generally desirable that water flow into the exhaust chamber126at the conclusion of each exhale cycle to prevent initiation of a free-flow condition.

The adapter140and air/water separator118can be readily configured such that sufficient water is present to immediately fill the chamber126at the conclusion of each exhale cycle. To further ensure this fluidic flow, in at least some embodiments one-way check valves149may be provisioned in the adapter140. These valves149remain closed when the mixture of water and air pass from the adapter140to the chamber144during an exhale cycle, and then immediately open at the end of each exhale cycle to permit a back flow of water into the exhaust chamber126.

Preliminary test results have indicated that the force required to exhale air from the mouthpiece128and through an air/water separator such as118may be less than that required in a conventional regulator setup as inFIG. 3. In some cases it has been found that differential pressures sufficient to allow free flow in a conventional regulator setup as inFIG. 3do not readily induce free-flow in the configuration ofFIG. 4. Lower cracking pressures at the valve132can thus be used, leading to easier respiration by a diver during operation.

A variety of air/water separator configurations can be employed. Exemplary configurations include cylindrical, spherical, and tortuous path configurations. The relative locations of the inlet146and outlet148can be established to ensure that the exhaust air flows freely regardless of attitude, orientation angle, or relative depths of the regulator116and air/water separator118.

As noted above, the exhaust air during each exhale cycle passes from the air/water separation chamber118through the exhaust air port146to the bubble diffuser120. In some embodiments, the bubble diffuser120is located on the tank112on the diver's back. It will be appreciated that the use of the bubble diffuser with the air/water separator is not necessarily required; for example, in an alternative embodiment a conduit can extend from the air exhaust port148in a direction away from the diver's head and terminate in a one-way check valve. In such case, the exhausted air can exit into the surrounding water without the use of a diffusion structure to form a fine mist151of bubbles.

FIGS. 5-1and5-2generally illustrate the exemplary bubble diffuser120to incorporate a hinge assembly150. The bubbler120can be mounted to the tank112via a circumferentially extending strap152which is shown in cross-section. The strap rigidly secures a first hinge plate154of the hinge assembly150to the tank112. A second hinge plate156can be secured to the underside of the bubbler housing, as shown. An intermediary hinge pin arrangement158facilitates relative rotation of the second hinge plate156with respect to the first hinge plate154, so that the bubbler120is cantilevered at one end and rotates relative to the tank112. In this way, the buoyancy of the bubbler housing and the enclosed air flowing therethrough will generally tend to maintain the bubbler120in a level orientation irrespective of changes in the rotational orientation of the diver.

FIG. 5Ashows an alternative mounting configuration for the bubbler120onto the tank112. The embodiment ofFIG. 5A, and those that follow, can incorporate the hinge assembly150ofFIG. 5as desired. The bubbler120inFIG. 5Aincludes a tab160that extends from the bubbler housing and passes underneath the strap152. Preferably, the bubbler housing is placed at or near the center of gravity of the diver100, thereby having a substantially neutral effect upon diver maneuverability. This placement also locates the mist of bubbles a significant distance from the ears and eyes of the diver.

FIG. 5Afurther shows the diffusion structure to include an array of small exhaust apertures162that extend through an upper surface164of the bubbler120. These apertures162permit passage of the air into the surrounding water as the aforementioned mist. Any suitable arrangement of apertures can be used as desired.

FIG. 5Bshows a reversed mounting configuration for the bubbler120onto the tank112. InFIG. 5B, the bubbler120is mounted below the strap152so as to be rotated 180 degrees as compared to the orientation ofFIG. 5A. This arrangement may be suitable for divers who prefer a “higher” placement of the tank to facilitate a more “head down” attitude during diving.

FIG. 5Cprovides a side elevational depiction of the bubbler120in accordance with yet another embodiment. InFIG. 5C, the bubbler housing takes a substantially curvilinear shape to nominally match the cylindrical outer surface of the tank112. A layer of magnetic material166can be used to secure the bubbler120to the tank112. Since many air tanks are made of magnetically permeable metal, the magnetic material166allows ease of placement and subsequent removal of the bubbler at any desired location along the tank, while providing sufficient retention force to ensure the bubbler remains in place during the diving session.

FIG. 5Dshows another alternative arrangement for the bubbler120. InFIG. 5D, the bubbler substantially extends along a linear plane and incorporates a curved support member168to contactingly engage the curvilinearly extending outer surface of the tank112.FIG. 5Eshows the use of individual standoffs170to contactingly engage the tank112.

FIG. 6provides a cross-sectional elevational representation of the interior of the bubbler120in accordance with preferred embodiments. The bubbler120may be formed from suitable materials such as Plexiglas® acrylic glass or injection molded plastic components that are assembled into a final stacked arrangement. An inlet port172accommodates a flow of the exhaust air from the air/water separator118(FIG. 4) via a suitable conduit174. The inlet port172extends through a base plate176to which is mounted to a tub-shaped member178to form a first interior chamber (inlet plenum)180.

A number of spaced apart ports182extend through the tub-shaped member178and accommodate individual one-way check valves184, which may take a similar configuration to that of the main one-way check valve134discussed inFIG. 3. Each port182will be characterized as a second chamber.

An interior cover plate186spans and covers the ports182and includes a number of smaller openings (ports)188in fluidic communication with the larger ports182and valves184. A second tub-shaped member190mates with the interior cover (diffuser) plate186to form a third interior chamber (outlet plenum)192. The second tub-shaped member190may further include an array of multiple spaced apart openings (ports)194, corresponding to the openings162previously depicted inFIGS. 5A-5B.

As further shown inFIG. 6A, the respective openings194may be provisioned with variable length discharge tubes such as196,197and198. These tubes can be intermixed to help maintain bubble separation as the exhaust air exits the outlet plenum192.

It has been found through extensive empirical analysis that providing a succession of chambers can provide significant noise reduction. The embodiment ofFIG. 6generally operates to “form bubbles” three different times in succession as the exhaust air passes through the successive chambers.

As noted above, the exhaled air passes through the conduit174and into the first chamber180. The first chamber180accumulates the exhaust air from the air/water separator118and provides some measure of noise suppression. It will be appreciated that some amount of water may accumulate in the first chamber180from time to time, and at other times, the first chamber180may be full of air only.

The exhaust air passes from the first chamber180, through the valves184into the second chambers182to form relatively large, high energy, low frequency bubbles.

The air from the second chambers182pass through the ports188into the third chamber as a series of relatively small, low energy, higher frequency bubbles. These bubbles then are further reduced by passing through the diffuser plate portion of member190and through the tubes196,197and198into the surrounding water as small, low energy, high frequency bubbles, or mist151. The openings through the tubes196,197and198are sized to permit a backflow of water into the chamber192, and the openings188further allow flow of water into the chambers182. However, the valves184are generally configured to restrict flow of water from the second chambers182into the first chamber180. To the extent that water accumulates in the first chamber180, this water will drain back down the conduit174and into the air/water separator118.

Accordingly, the respective chambers180,182and192serve as noise baffling chambers to muffle acoustic noise generated as the exhaust air flows through the bubble diffuser120. It is contemplated that the energy release in chamber182will be further baffled by the air in chamber180and the air and water in chamber192.

The bubbles that pass into the surrounding water will thus have released a substantial amount of energy within the sound chambers and will be close to the ambient bubble energy noise of the water. This will allow the diver to dive with dramatically reduced bubble noise, and allow him to closely approach underwater wildlife without causing a disturbance thereto.

FIGS. 7-12present a number of alternative configurations for the underwater breathing system discussed above. Like reference numerals will generally be used to identify similar components, and a detailed discussion of previously covered features will be omitted for purposes of brevity.

FIG. 7shows a breathing system200with the stage-2 regulator116affixed to a bulb-shaped air/water separator201and a snorkel-type bubbler202. The air/water separator201is generally similar to the separator118and includes an interior one-way check valve (stop valve)206at the exhaust air outlet port146. The snorkel-type bubbler202operates in a manner generally similar to the bubbler120discussed above, but projects above and away from the head of the diver100rather than being attached to the air tank112on the diver's back.

The snorkel-type bubbler202is coupled to the air/water separator200by way of a flexible or rigid conduit208. The conduit may be attached to the strap of the diver's mask (seeFIG. 1) as is commonly employed with conventional snorkels. The snorkel-type bubbler assembly202can take any suitable shape and may have a frusto-conical (tapered) inlet chamber210as shown.

The air/water separator201is shown in greater detail inFIG. 8. The stop valve206sealingly engages the air exhaust port146when the level of water within the chamber144reaches a predetermined level. This prevents the column of exhaust air in the conduit208from re-entering the chamber, thereby reducing the effort required by the diver during the next exhale cycle to introduce the next breath of exhaust air into the air/water separator. The exit conduit208extends vertically as shown inFIG. 7, or can be routed to the side as inFIG. 8. It is contemplated that water from the air chamber in the bubbler and the interconnecting conduit will be able to freely drain back into the air/water separator when the valve is open.

The stop valve206is characterized as a ball valve with a buoyant float212captured within a cage214. Any suitable shape for the float may be used as desired. Other types of check valves can be used, including weighted check valves that rotate within the chamber144to effect sealing of the exit port under different rotational orientations.

An adjustment mechanism216is mounted to a lower extent of the air/water separator201. The adjustment mechanism216includes a user activated knob217which rotates a shroud cover218having apertures219extending therethrough. These apertures219can be controllably aligned relative to the open ports148in the air/water separator housing to regulate a rate of flow of water to/from the chamber144.

FIG. 9shows an alternative breathing system220with a air/water separator222having a substantially s-shaped interior chamber224defined by a medial baffle226. The baffle226divides the interior chamber into upstream and downstream portions228,230. The aforementioned stop valve206is mounted within the upstream portion228as shown, although other locations for the valve can be used. The downstream portion230may be configured to provide an air entrapment region147to temporarily entrap air separated from the inlet mixture prior to flowing to the bubbler.

Various interior sidewall contours operate as flow baffles to facilitate the efficient separation and exit of exhaust air out exhaust air port232and the flow of water out of exhaust water port234. The exhaust water port234includes a one-way check valve236to prevent back flow of water into the downstream portion230. A two-way normally open water flow port238with adjustment mechanism240allows controlled regulation of water into and out of the upstream portion228.FIG. 10shows the air/water separator222ofFIG. 9in greater detail with a side-mounted exit port232.

FIG. 11illustrates another air/water separator250generally similar to the separator201ofFIGS. 7-8. The separator250includes an interior check valve252having a buoyant flapper member254coupled to a swivel ring256by a hinge258. The flapper member is formed from a suitable buoyant material such as a closed cell foam and is configured to form a water-tight seal against the air exit port146when the water in the interior chamber144of the air/water separator250reaches or exceeds a predetermined level. The swivel ring256allows the flapper member254to freely rotate a full 360 degrees around a neck portion260of conduit208that extends into the chamber144. This allows the flapper member254to seal against the outlet port146over a large range of pitch and tilt angles for the separator250. The check valve252is weighted such as by the use of an incorporated weight262adjacent the hinge258to ensure the flapper swivels down as the separator250is manipulated under different operational conditions such as those shown inFIGS. 11A-11D. For reference, orthogonal X, Y and Z axes are represented inFIG. 11.

FIGS. 11A and 11Bshow the separator250in an orientation that is rotated 90 degrees counterclockwise about the Y-axis as compared to the orientation ofFIG. 11. The flapper member254will have swiveled 180 degrees about the Z-axis during this time. InFIG. 11A, the water level within the separator250is sufficiently high to close the flapper member254, whereas the flapper member254is open inFIG. 11B.FIG. 11Bthus represents an exhale event during which the diver is exhaling spent air.

The exhaled air displaces a portion of the water within the chamber through ports148, allowing the flapper member254to move to the open position. It is noted that a portion of the air within the chamber exits through the exposed aperture ports148in bothFIGS. 11A and 11B, forming a small mist of bubbles surrounding the separator250. An elastomeric stopper member264shown inFIG. 11Binsertingly engages the end of the conduit208as shown.

FIGS. 11C and 11Dshow the separator250in an orientation that is rotated 135 degrees clockwise with respect to the orientation ofFIG. 11. As before,FIG. 11Cshows the valve252in a closed position, whereasFIG. 11Dshows the valve252in an open position.

The breathing system as variously embodied herein operates to regulate the respiration of the diver100under different diving conditions. With reference again toFIG. 1, the diver100is shown to be in a normal, substantially horizontal diving attitude with the air/water separator116at a first depth and the bubbler120being at a second, reduced depth. The surrounding water pressure at the air/water separator is denoted as Paws, and the water pressure at the bubbler120is denoted as Pb.

While the elevational depth between these two components may be only a few inches, those skilled in the art will nevertheless recognize that the pressure Pawsmay be significantly greater than the pressure Pb(Paws>Pb). Under these conditions, the exhaust air from the diver100will easily pass through the air/water separator118and bubbler120to the surrounding water, since the exhaust air will normally flow to the lowest available pressure region within the system.

FIG. 12shows the diver100in an upright orientation, such as when the diver is swimming to the surface104at the conclusion of a diving session. Under these circumstances, Pawswill tend to be less than Pb(Pb>Paws). The exhaust air will thus primarily exit the exhaust ports148of the lower pressurized air/water separator118, rather than through the higher pressurized bubbler120. The diver will still be able to breathe easily, and it is contemplated that the exiting bubbles, while adjacent the diver's head, will not obscure the diver's vision as he swims upwardly.

FIG. 13shows the diver in a downward orientation, such as when the diver is beginning a diving session and is maneuvering to a lower depth. As inFIG. 1, the pressure Pawswill tend to be greater than the pressure Pb, and the exhaust air will be directed through the bubbler120to the surrounding water.

Finally,FIG. 14shows the diver in a substantially horizontal, inverted orientation. While uncommon, the diver may choose this orientation for a number of reasons such as to swim under an obstruction or to observe overhead wildlife. As with the orientation ofFIG. 12, Pb>Pawsand the exhaust air will tend to exit the air/water separator118rather than the bubbler120. It is contemplated that the diver's respiration efforts will be otherwise substantially unaffected while in this orientation, and the bubbles will flow upwardly and away from the vicinity of the diver's head.

It will now be appreciated that the various embodiments disclosed herein can provide a number of benefits. The use of a air/water separator as embodied herein generally enables exhaust air to be separated from exhaust water and directed to a suitable location away from the diver's face and ears, while allowing sufficient back flow of water to the exhaust chamber to ensure free-flow conditions are avoided.

While not required, a bubble diffuser can be utilized to break up large volumes of the exhaust air into a smaller mist or array of bubbles, reducing noise that could scare away underwater wild life, and allowing the diver to not be visually or audibly distracted by the exhausted air.

The system as embodied herein can be mounted to an existing stage-2 regulator or can be incorporated into a new regulator design. The size and shape of the air/water separator can vary and can be made relatively small while still providing sufficient chamber space to handle the expected volumes of exhaust air and to provide a sufficient volume of water back to the stage-2 regulator to close the one-way check valve therein. The use of a check valve within the air/water separator can further provide ease of use even when the diver undergoes changes of depth and/or orientation between breaths.