Abstract:
This lifesaving floatation and breathing device comprises first and second inflatable bags having similar bag volumes, and a mouthpiece communicating with both bags. A pressurized gas cylinder filled with breathable gas is mounted to one of the bags. This pressurized gas cylinder has a gas volume and a gas pressure therein. The device also has an inflator mechanism mounted thereto for transferring the breathable gas from the pressurized gas cylinder into one of the bags. One of the characteristics of the device is that the volume of each bag is a mathematical product of the gas volume inside the cylinder and a ratio of the gas pressure inside the cylinder over atmospheric pressure. Either bags can accept the full content of the cylinder at atmospheric pressure, thereby obviating the need for a pressure regulator or flow control orifice therein.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention pertains to lifesaving floatation devices inflated with respirable gas and having mouthpieces to breathe the gas therein. More particularly, it pertains to a floatation device having two inflatable compartments interconnected together through a valve arrangement that is sequentially positioned to inhale from one compartment and exhale into the other, and to re-breathe the previously-exhaled gas from the other compartment in order to extend the breathing period thereof.  
       BACKGROUND OF THE INVENTION  
       [0002]     A lack of breathing air and a need for floatation are often combined in a same catastrophic event. For example, people trapped inside a submerged vehicle need breathing air to get out of the vehicle and added buoyancy to swim to the shore. Similarly, smoke inhalation and drowning are often combined risks in an air plane crash or in the case of a burning ship. Home owners living near flood plains could also be exposed to smoke inhalation from a house fire due to electrical short circuits caused by rising water, and drowning when evacuating their house during an inundation; Therefore it is believed that a need exists for a lifesaving device offering both floatation and oxygen supply for at least a short period of time.  
         [0003]     Conventional lifesaving devices for use in homes, vehicles, cottages and small crafts are generally limited to containers of breathable gas, gas filters, floatation vests and inflatable rafts. Both a breathing aid and floatation equipment are purchased, stored and maintained separately and therefore, people often neglect to obtain one or the other or both.  
         [0004]     Examples of emergency oxygen or air supply devices of the prior art are described in the following documents. These documents are divided in two groups. The documents in the first group pertain to devices used to filter ambient air delivered to a mouthpiece, and the documents in the second group pertain to devices incorporating a limited supply of breathable gas contained under pressure in a small cylinder. Examples of the devices of the prior art having a filter incorporated therein are as follows: 
    U.S. Pat. No. 4,515,156 issued to N. M. Khudosovtsev et al. on May 7, 1985;     U.S. Pat. No. 6,032,668 issued to C. Y. Chung on Mar. 7, 2000;     CA Patent 2,084,765 issued to L. J. Swann on Nov. 12, 1996.    
 
         [0008]     Examples of breathing devices having a supply of respirable gas included therein are as follows: 
    U.S. Pat. No. 2,831,607 issued to A. J. Berndt on Apr. 22, 1958;     U.S. Pat. No. 4,440,163 issued to G. Spergel on Apr. 3, 1984;     U.S. Pat. No. 5,979,442 issued to R. J. Orr on Nov. 9, 1999;     U.S. Pat. No. 6,412,482 issued to C. D. Rowe on Jul. 2, 2002;    
 
         [0013]     Both the filter and the pressurized cylinder types of breathing devices are advantageous to prevent inhalation of smoke or toxic gases for example for a period of time which is sufficiently long to allow a person to get away from a danger area. In the case of the CA Patent 2,084,765 for example, a supply of breathable air for a period of 10 minutes is suggested. In another example, the U.S. Pat. No. 4,440,163 suggests a supply of respirable air for a period of about 5 minutes.  
         [0014]     In regard to prior art in the field of inflatable lifesaving devices, the following documents represent good examples of floatation equipment that are inflatable by mouth of the user: 
    U.S. Pat. No. 2,742,654 issued to V. H. Hurt on Apr. 24, 1956;     U.S. Pat. No. 5,516,233 issued to W. L. Courtney on May 14, 1996;     U.S. Pat. No. 4,813,899 issued to H. Fujimoto on Mar. 21, 1989.    
 
         [0018]     Although the above inflatable devices have a mouthpiece connected to one or more inflatable bags, each mouthpiece is equipped with a check valve that prevents re-breathing from the bags. These devices are therefore not appropriate for preserving someone&#39;s life in a hazardous situation requiring both floatation and respirable air.  
         [0019]     More relevant prior art devices preceding the present invention consist of floatation vests, each being made of two compartments from which at least one contains respirable air and is equipped with a hose and a mouthpiece for inhaling the air from the bag. These floatation vests are described in the following documents: 
    U.S. Pat. No. 3,866,253 issued to A. J. Sinks et al. on Feb. 18, 1975;     U.S. Pat. No. 3,877,425 issued to W. J. O&#39;Neill on Apr. 15, 1975;     U.S. Pat. No. 4,324,234 issued to S. G. Maness on Apr. 13, 1982.    
 
         [0023]     In the case of U.S. Pat. No. 3,866,253, a diver wearing the vest can inflate one of the compartments by mouth, and where necessary, re-breathe the air from this compartment. The other compartment is inflated by a cartridge of compressed CO 2  gas. The U.S. Pat. No. 4,324,234 suggests a dual-chamber vest wherein one of the chambers is filled with compressed air or breathable gas and the other is filled with CO 2  gas. The document suggests an amount of air sufficient to re-breathe from the bag for a period of 3 to 5 minutes to escape from a danger situation.  
         [0024]     One of the problems associated with a pressurized gas container used in a breathing device is that the discharge of the container into the bag of the device increases the pressure of the breathable gas inside the bag or vest and makes in difficult, at least initially, to control the flow of gas through a mouthpiece. The pressure surge of the discharging cylinder is susceptible of causing a wearer to inadvertently over-breathe or otherwise let escape a substantial amount of gas through the mouthpiece, and to waste a portion of the lifesaving feature of the device. Therefore conventional breathing apparatus using pressurized cylinders have pressure regulators incorporated therein or calibrated orifices to limit the flow of gas to the mouthpiece.  
         [0025]     However, a pressure regulator mounted in a lifesaving breathing device increases the manufacturing cost of the device and is believed to be a determining factor limiting the accessibility of the device to a large number of people. Similarly, the use of an orifice in a breathing device limits the amount of air available to the user at any given time. As the pressure drops in the supply cylinder, the flow of gas also drops across the orifice and to the mouthpiece. This reduction of flow to the mouthpiece could induce a sense of panic to the user.  
         [0026]     On the other hand, when the respirable gas is expanded in a bag at atmospheric pressure, it is estimated that a volume of gas of about 660 cubic inches is required for each minute of breathing time. A bag containing 3 to 5 minutes worth of breathable gas can be seen as a serious encumbrance to get out of a cramped space in a danger situation.  
         [0027]     As such, it may be appreciated that there continues to be a need for a new and improved lifesaving floatation and breathing device having a reasonable volume of breathable air therein and which operates without a pressure regulator or an orifice.  
       SUMMARY OF THE INVENTION  
       [0028]     The floatation and breathing device according to the present invention is inflated from a pressurized cylinder containing breathable gas. The breathable gas is discharged into a bag having an appropriate volume to accept the full content of the cylinder at atmospheric pressure, thereby obviating the need for a pressure regulator or flow control orifice.  
         [0029]     In a broad aspect of the present invention, there is provided a lifesaving floatation and breathing device comprising first and second inflatable bags having similar bag volumes, and a mouthpiece communicating with both bags. A pressurized gas cylinder, or other container, filled with breathable gas is mounted to one of the bags. This pressurized cylinder has a nominal gas volume and a nominal gas pressure therein The device also has an inflator mechanism for transferring the breathable gas from the pressurized gas cylinder into one of the bags. In this device, the volume of each bag corresponds to a mathematical product of the nominal gas volume inside the cylinder and a ratio of the nominal gas pressure inside the cylinder over atmospheric pressure.  
         [0030]     Therefore when the gas from the pressurized cylinder is transferred into the bag, this gas is easily breathable at atmospheric pressure. Also, the exhaled gas which still contains a substantial amount of oxygen is stored in the second bag for eventually re-breathing it. The buoyancy of the device is thereby maintained and the breathing period of the original breathable gas cylinder is substantially increased.  
         [0031]     In another aspect of the present invention, there is provided a selector valve in communication with the mouthpiece, and hoses or conduits between the selector valve and each of the bags. The selector valve has a pair of check valves mounted therein communicating with the hoses or conduits and the mouthpiece to control a gas flow in the mouthpiece to and from the bags. The check valves are mounted inside a circular dial, in opposite air-flow orientations relative to each other. The dial is movable relative to the base of the selector valve from a first position to a second position. In the first position, the check valves allow inhaling oxygen gas from the first bag and exhaling into the second bag. In the second position, the check valves allow the re-breathing of the previously exhaled gas, and exhaling in the first bag. Although the oxygen content in the first exhaled gas is somewhat reduced, it is believed to be appropriate for re-breathing again in a life threatening situation.  
         [0032]     It will be appreciated that when the first-inhaled gas is rich in oxygen, the position of the selector valve can be inverted several times, to allow re-breathing gas from the inflated bag and to exhale and inflate the other bag, until the exhaled gas reaches a minimum breathable oxygen content.  
         [0033]     In another aspect of the present invention, each bag has the shape of a horseshoe having a first end and a second end. The pressurized cylinder has means to introduce the breathable gas in the first end of the first bag and the selector valve is in communication with the other end of that same bag. Because of these opposite mountings, a pressure surge inside the bag when the gas from the cylinder is introduced into the bag all at once has negligible effect on the gas pressure at the mouthpiece.  
         [0034]     In yet another aspect of the present invention, there is provided a floatation and breathing device comprising a front bag and a rear bag each having an upper end and a lower end, and a mouthpiece mounted to the upper ends. The bags share a common membrane and jointly define the shape of a pillow. In this embodiment, the pressurized cylinder has means to introduce the breathable gas in the lower end of the front bag. Again, the pressure surge from discharging the pressurized cylinder inside one of the bags has little effect on the gas pressure at the mouthpiece. Furthermore, the pressure surge caused by the discharging of the gas cylinder into one of the bags when the bags are in a folded form, helps to expand the bags from their folded form.  
         [0035]     This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiments thereof in connection with the attached drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0036]     Two embodiments of the present invention are illustrated in the accompanying drawings, in which like numerals denote like parts throughout the several views, and in which:  
         [0037]      FIG. 1  is a perspective front and side view of the floatation and breathing device according to the first preferred embodiment of the present invention, worn by a user;  
         [0038]      FIG. 2  is a front view of the first preferred floatation and breathing device;  
         [0039]      FIG. 3  is a side view of the first preferred floatation and breathing device, showing the front bag in a deflated mode and the rear bag in an inflated mode;  
         [0040]      FIG. 4  is a front view of the rear bag of the first preferred floatation and breathing device as seen when separated from the front bag;  
         [0041]      FIG. 5  is a front view of the mouthpiece, the extensible hose and selector valve mountable to the first preferred embodiment of the preferred invention;  
         [0042]      FIG. 6  is a front view of the selector valve shown in  FIG. 5  without the extensible hose and mouthpiece;  
         [0043]      FIG. 7  is a side view of the selector valve shown in  FIG. 6 ;  
         [0044]      FIG. 8  is an enlarged diametrical cross-section of the selector valve illustrated in  FIGS. 5-7 , as seen along line  8 - 8  in  FIG. 6 ;  
         [0045]      FIG. 9  is an enlarged diametrical cross-section view of a check valve used in the selector valve of the first and second preferred embodiments of the present invention;  
         [0046]      FIG. 10  is a front view of the floatation and breathing device according to the second preferred embodiment of the present invention;  
         [0047]      FIG. 11  is a cross-section view of the selector valve used in the second preferred embodiment;  
         [0048]      FIG. 12  illustrates the floatation and breathing device according to the second preferred embodiment in a folded mode. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0049]     While this invention is susceptible of embodiment in many different forms, there are shown in the drawings and will be described in details herein two specific embodiments, with the understanding that the present disclosure is to be considered as an example of the principles of the invention and is not intended to limit the invention to the embodiments illustrated and described.  
         [0050]     The floatation and breathing device according to the first preferred embodiment is illustrated in FIGS.  1  to  9 . This first preferred floatation and breathing device  20  has the form of a life vest and can be worn by a user. This first preferred embodiment is also referred to herein as the life vest  20 .  
         [0051]     The life vest  20  is made of a front bag  22  and a rear bag  24 . The front bag  22  is separate from the rear bag  24 . The front bag  22  is inflatable with exhaled air by the user, by mean a mouthpiece  26  and a flexible and extensible tube  28 . The rear bag  24  is inflatable with oxygen by means of a high pressure gas cylinder  30  and a manual inflator  32 . Each bag has the shape of a horseshoe with a central hole and two lower ends on opposite sides thereof. The gas cylinder  30  preferably contains a breathable gas mixture having a high oxygen content, such as 90% oxygen for example.  
         [0052]     Referring particularly to FIGS.  1  to  4 , the front bag  22  and the rear bag  24  are retained to each other by central tendons  32  extending around the central hole or the neck of the life vest, and by a pair of side tendons  34  extending from the sides of the life vest. A belt  36  is also provided and is fastened to the lower front end of the life vest  20 . In use, the life vest  20  is worn as a bib and is attached to the waist of the user as illustrated in  FIG. 1 .  
         [0053]     The life vest  20  also comprises a selector valve  40  communicating with both bags  22 ,  24  by way of two hoses. The hose mounted to the front bag  22  is referred to as the exhaled air hose and is labelled  42 . The hose mounted to the rear bag  24  is referred to as the oxygen hose and is labelled  44 . The oxygen hose  44  is mounted at one end of the horseshoe shape on the rear bag  24 , and the pressurized gas cylinder  30  and the manual inflator  32  are mounted at the opposite end of that same bag.  
         [0054]     Each of the hoses  42 ,  44  is mounted to a respective bag using a manifold stem valve  46  such as a stem valve, part no. 830 AOE manufactured by Halkey-Roberts™, in which the valve spring and mechanism have been removed, and a corresponding eye-ring fitting  48  at the end of each hose, enclosing the stem valve  46 . The manual inflator  32  is also mounted to a manifold valve  46  as specified above without modification. The manual inflator  32  is also available from a selection of different inflators manufactured by Halkey-Robert™, or other manufacturers. The preferred inflator  32  is operable by pulling on a handle  50  which is tied to the inflator&#39;s mechanism by a string  52 . The preferred inflator  32  is labelled as part 840 AM. Halkey-Roberts™ is located in St-Petersburg, Fla., USA.  
         [0055]     The high-pressure cylinder  30  has a preferred volume of about 4.85 cubic inches and contains oxygen-rich breathable gas at a pressure of about 2000 psi. Both bags  22 ,  24  have a respective volume of about 660 cubic inches.  
         [0056]     When the breathable gas from the cylinder is released in the rear bag  24 , this bag is inflated to a pressure that is substantially the same as the atmospheric pressure. Therefore, there is no need for a pressure regulator or a flow control orifice to control the flow of gas to the mouthpiece  26 . This breathable gas is readily available for breathing, through the oxygen hose  44  and the selector valve  40 . A volume of 660 cubic inches is believed sufficient to provide breathable gas to a person for a period of about one minute.  
         [0057]     Because the oxygen hose  44  is connected to the rear bag  24  on the opposite side of the manual inflator  32 , the pressure surge created by the sudden release of breathable gas from the high pressure cylinder  30  is partly absorbed in the inflation of the rear bag  24 , and therefore does not cause a significant increase in pressure in the oxygen hose  44  and in the selector valve  40 .  
         [0058]     In use, the life vest  20  may be put on by a user, and the handle  50  is pulled down quickly and firmly to puncture a diaphragm (not shown) in the neck of the high pressure cylinder  30 . The breathable gas is released into the rear bag  24  thereby inflating the rear bag  24 . Using the mouthpiece  26  with the selector valve  40  in an initial position, the user inhales breathable gas from the rear bag  24  and exhales a mixture of oxygen and CO 2  into the front bag  22 . The buoyancy of the life vest  20  is thereby maintained.  
         [0059]     Both bags  22 ,  24  are made of a flexible, weather-resistant and gas-tight material. A pair of handles  52  are provided on the front bag  22  to allow a user to hold on to the life vest  20  by hand as if it was a pillow for example. The handles  52  are also advantageous to assist a user in squeezing the air out of one of the bags.  
         [0060]     It is known that ambient air contains about 21% oxygen. It is also known that a recommended minimum oxygen content in breathable air is about 15%, because a lower amount could cause hallucinations. It is further known that a person breathing normally consumes about 5% of the oxygen present in ambient air, while a person hyperventilating in a panic situation absorbs only about 3%. Therefore, it is believed that in many circumstances, the air exhaled into the front bag  22  of the life vest  20  still contains oxygen and can be re-breathed again.  
         [0061]     When the breathable gas in the high pressure cylinder  30  is a mixture of gas rich in oxygen, such as 90% oxygen for example, this gas can be re-breathed several times before it reaches the 15% lower limit. Therefore, the selector valve  40  in the life vest  20  according to the first preferred embodiment is rotated half a turn to allow the re-breathing the once-exhaled air and to allow exhaling in the rear bag  24 . The selector valve  40  can be rotated once more to re-breathe the twice-exhaled gas from one bag and exhaled in the other. In other words, the selector valve  40  is rotated as required to breathe from the inflated bag and to exhale and inflate the other bag.  
         [0062]     Referring now to FIGS.  5  to  9 , the operation of the selector valve  40  will be explained in details. The selector valve  40  constitutes a base from which extends the flexible tube  28  leading to the mouthpiece  26 . The selector valve  40  has a cylindrical shape, a base portion  60  and a circular dial  62  to which is mounted the flexible tube  28  and the mouthpiece  26 . The base portion  60  has flat tabs  64  extending therefrom. These tabs  64  are sewn, glued or bonded to the life vest  20  to retain the selector valve  40  to the life vest  20 . A pair of hose nipples  66  extend radially from the base portion  60 . The exhaled air hose  42  and the oxygen hose  44  are mounted to these hose nipples  66 .  
         [0063]     Referring particularly to  FIGS. 8 and 9 , the base portion  60  of the selector valve  40  has a pair of conduits  70 ,  72  therein extending parallel to the axis of the valve  40 . Each conduit  70 ,  72  communicates with one of the hose nipples  66 . These conduits  70 ,  72  are open at their top ends and closed at their bottom ends by a pair of pipe plugs  74 .  
         [0064]     The dial  62  is mounted atop the base portion  60  and is held to the base portion  60  by a snap ring  76  and a stem  78  extending upward from the centre of the base portion  60 . The snap ring  76  is engaged into a groove on the end of the stem  78 . A spring disc  80  is also provided under the snap ring  76  to retain the dial  62  to the base portion  60  with a light pressure.  
         [0065]     The dial  62  has a pair of cavities  84 ,  86  therein in which are respectively mounted an inhale check valve  88  and an exhale check valve  90 . Each of the cavities  84 ,  86  communicates with a respective conduit  92  or  94  extending into the lower end of the flexible tube  28 , and joining the flexible tube  28  to both check valves  88 ,  90 . The dial  62  has a shoulder  96  on its bottom surface and an O-ring  98  circling that shoulder. The shoulder  96  and the O-ring  98  have dimensions to mount into a circular groove  100  in the upper surface of the base portion  60  so to seal the dial  62  to the base portion  60 .  
         [0066]     Each of the check valves  88 ,  90  has a valve seat  110  which is force-fitted into a respective cavity  84  or  86 . A valve stem  112  extends from the valve seat. A valve disc  114  is mounted to the valve stem  112  and is urged against the valve seat  110  by a compression spring  116  fastened to the valve stem  112 . The compression spring  116  is calibrated so that the valve disc  114  opens under a pressure of about between 1-5 psi. The locations of the breathable gas cylinder  30  and of the oxygen hose  44  on opposite sides of the oxygen bag  24 , and the size of the oxygen bag make it unnecessary to use stronger check valves. Consequently, the content of the life vest  20  is breathable without effort.  
         [0067]     In use, the content of the oxygen bag  24  is inhaled first. The dial  62  is rotated half a turn to interchange to positions of the check valves  88  and  90 . Then, the content of the front bag  22  can be re-breathed, while exhaling into the oxygen bag  24 . In extreme situations, as explained before, the dial  62  can be rotated back to its initial position to re-breathe the exhaled gas a second time, and still find in it a quantity of oxygen gas.  
         [0068]     Referring now to  FIGS. 10-12 , the floatation and breathing device according to the second preferred embodiment will be described. The second preferred floatation and breathing device  120  has the shape of a pillow, and is referred to herein as the pillow  120 . This pillow also has a front compartment  122  and a rear compartment  124  separated from each other by a gas-tight membrane  126 . Each of the compartments, also referred to herein as bags for corresponding to the bags in the first preferred embodiment, has a volume sufficiently large to receive 660 cubic inches of gas at atmospheric pressure. Both compartments or bags  122 ,  124  are made of a flexible, weather-resistant and gas-tight material.  
         [0069]     A mouthpiece  26  and a flexible tube  28  are mounted to a selector valve  126  which is bonded to the upper end of the pillow  120 . A high pressure breathable gas cylinder  30 , a manual inflator  32 , and a manifold valve  46  as previously described, are mounted to the bottom end of the pillow  120 . The breathable gas cylinder  30  in this embodiment also contains about 4.85 cubic inches of oxygen-rich breathable gas at a pressure of about 2000 psi. A pair of handles  52  are provided to allow a user to retain the pillow against himself/herself by hand.  
         [0070]     The selector valve  126  is similar in structure to the previously described selector valve  40  except that the base portion  128  thereof has two segments  130 ,  132  extending astride the top end of the pillow, with a conduit  134 ,  136  extending in each segment joining respectively the valve cavities  84 ,  86  to the compartments  122 ,  124 . The base portion  128  of the valve is made of a material which can be vulcanized or otherwise bonded to the material of the pillow  120 .  
         [0071]     The pillow  120  is foldable in half and then in three segments as suggested by the fold lines  140  illustrated in  FIG. 10  to obtain a compact arrangement as illustrated in  FIG. 12 . In the folded mode, the pillow  120  is easily packaged in a pouch (not shown) for example and stowed away. In the folded mode, the mouthpiece  26  and the handle  50  of the manual inflator  32  are clearly visible at one end of the package, and therefore, its use and purpose are self-explanatory.  
         [0072]     Because of the location of the manual inflator  32  on the bottom end of the front face of the pillow  120 , the operation of the manual inflator  32  causes the pillow  120  to unfold and to expand on its own from a folded form. An inscription on the dial  62  reads “½ TURN TO REBREATHE”. This inscription is clearly visible when the pillow  120  is pulled out of its storing pouch, such that a user can understand at a glance the procedure to re-breathe the air from the exhaled air compartment  124  when the oxygen compartment becomes empty.  
         [0073]     As to other manner of usage and operation of the present invention, the same should be apparent from the above description and accompanying drawings, and accordingly further discussion relative to the manner of usage and operation of the invention would be considered repetitious and is not provided.  
         [0074]     While two embodiments of the present invention have been illustrated and described herein above, it will be appreciated by those skilled in the art that various modifications, alternate constructions and equivalents may be employed without departing from the true spirit and scope of the invention. For example, the check valve described and illustrated herein is only one type of check valves available for mounting in the lifesaving devices according to the present invention. Also, it will be understood that although the operation of the lifesaving devices as described herein consists of breathing from one bag and exhaling in the other, the selector valve can be used to inflate both bags, to increase the buoyancy of the device in circumstances where floatation is more important than oxygen supply. Therefore, the above description and the illustrations should not be construed as limiting the scope of the invention which is defined by the appended claims.