Abstract:
A cold weather breathing device and method. Exhaled air warmed by the lungs of a user is flowed into contact with a heat exchange medium to heat the heat exchange medium. The heat exchange medium is positioned in a hollow body adjacent the chest and under cold weather outer clothing of the user. Upon inhaling, cold outside air is contacted with the heat exchange medium so that the inhaled air is heated by the heat exchange medium.

Description:
BACKGROUND 
     The instant invention relates to breathing devices for use in cold weather and more particularly to such devices that employ a heat exchanger to transfer heat from exhaled air to inhaled air. 
     Cold weather breathing devices for use by persons are known. For example, U.S. Pat. No. 4,062,359 to Geaghan disclosed a device employing a face mask having an exit valve with a flexible/porous tube connected to the face mask so that the tube could be positioned adjacent the chest of the user under the user&#39;s outer clothing. Air, warmed and humidified by the body of the user, was breathed into the tube, to the mask and then into the lungs of the user. When the user exhaled, the exhaled air was vented from the face mask by way of the exit valve. 
     U.S. Pat. No. 4,150,671 to Tiger disclosed a device employing a face mask having a heat exchanger positioned therein so that air breathed into the face mask was warmed by previously exhaled air. U.S. Pat. No. 5,063,923 to Peroni disclosed a device employing a mouthpiece connected to a tube, the tube leading to a collecting vessel for the admission of fresh air and air heated by the body, the collecting vessel to be positioned adjacent the chest of the user under the user&#39;s outer clothing. 
     U.S. Pat. No. 4,461,292 to Montalbano disclosed a device employing a mouthpiece connected to a conduit system connected to a chamber positioned adjacent the chest of the user, the conduit having an exit valve so that body heated air was inhaled from the chamber and then exhaled through the exit valve. U.S. Pat. No. 4,269,183 disclosed a device employing a face mask connected to a heat exchanger positioned at the side of the head of the user so that inhaled air was heated by the heat of the exhaled air. 
     Despite the many and continued advances made in the art of cold weather breathing devices, such devices that employ a face mask are relatively uncomfortable and tend to inhibit the ability of the user to communicate with other persons by voice. Cold weather breathing devices that employ a mouthpiece are more comfortable and the mouthpiece can be temporarily removed for voice communication with other persons. Cold weather breathing devices that exhale air directly to the atmosphere waste the heat of the exhaled air. Cold weather breathing devices that heat inhaled air by heat from exhaled air recover the heat of the exhaled air but position the heat exchanger in a face mask or at the side of the head. It would be an advance in the art of cold weather breathing devices if a device were discovered that was more comfortable to use and positioned a heat exchanger for heating the inhaled air by heat from exhaled air in a better location. 
     SUMMARY OF THE INVENTION 
     The instant invention is a cold weather breathing device employing a mouthpiece connected to a flexible conduit that is connected to a heat exchanger so that inhaled air is heated by exhaled air. The heat exchanger is positioned adjacent the chest under the outer clothing of the user of the device. 
     More specifically, the instant invention is a cold weather breathing device, comprising four elements. The first element is a mouthpiece to be held in the mouth of a user of the device. The second element is a hollow body defined by the walls of the body, the body having a mouth thereinto, the body having an opening therefrom, the body being perforated with an aperture. The third element is a heat exchange conduit having a first end and a second end, the first end of the heat exchange conduit being positioned within the hollow body by way of the aperture, the second end of the heat exchange conduit being positioned outside of the wall of the hollow body, the wall of the hollow body being sealed to the heat exchange conduit at the aperture of the body. The fourth element is a flexible conduit having a first end and a second end, the first end of the flexible conduit being connected to the mouthpiece, the second end of the flexible conduit being connected to the mouth of the hollow body. Air breathed out of the lungs of a user through the mouthpiece flows through the flexible conduit, into the hollow body and then out the opening therefrom thereby heating the portion of the heat exchange conduit positioned within the hollow body. Air that is then breathed into the second end of the heat exchange conduit flows into the hollow body heated by the heated portion of the heat exchange conduit positioned within the hollow body, through the flexible conduit, through the mouthpiece and then into the lungs of the user. 
     In another embodiment, the instant invention is a method for breathing more comfortably in cold weather, comprising the steps of: (a) exhaling air warmed by the lungs into contact with a heat exchange medium to heat the heat exchange medium, the heat exchange medium being positioned adjacent the chest and under cold weather outer clothing; (b) inhaling air from contact with the heat exchange medium so that the inhaled air is heated by the heat exchange medium. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of a device according to the teachings of instant invention showing a flexible conduit connected at one end to a mouthpiece and at the other end to a hollow body; 
     FIG. 2 is a side view of the device shown in FIG. 1; 
     FIG. 3 is a side cross-sectional view of the mouthpiece and upper end of the flexible conduit of FIG.  1  and further showing thermal insulation positioned on and around the flexible conduit; 
     FIG. 4 is a front view of a person wearing a jacket and using the device shown in FIG. 1; 
     FIG. 5 is a front view of a person wearing a cold weather jump suit incorporating the device shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIGS. 1 and 2, therein is shown a front view and side view, respectively, of a breathing device  10  according to the teachings of the instant invention. The device  10  has a mouthpiece  11  to be held in the mouth of a user of the device and a hollow body  12  defined by the walls  13  of the body, the body  12  having a mouth  14  thereinto and an opening  15  therefrom. The body  12  is perforated with an aperture  16 . The device also includes a heat exchange conduit  17  having a first end and a second end. The first end  18  of the heat exchange conduit is positioned within the hollow body  12  by way of the aperture  16 . The second end of the heat exchange conduit  19  is positioned outside of the hollow body  12 . The wall  13  of the hollow body  12  is sealed to the heat exchange conduit  17  at the aperture  16  of the body  12 . Perforated spacers  20  are used to position the heat exchange conduit  17  in the hollow body  12 . The design of the mouthpiece  11  is important for the comfort of the user of the device  10 . The mouthpiece should be designed, with regard, for example, to thickness and size, for maximum comfort of the user. Most preferably, several different sizes and types of mouthpiece are available to the user so that the most appropriate type can be selected. 
     Preferably, the inside diameter of the mouth  14  is larger than the outside diameter of the heat exchange conduit  17  so that during construction of the device  10 , the second end  19  of the heat exchange conduit  17  can be inserted through the mouth  14 , through the perforated spacers  20  and then through the aperture  16 . Preferably, the body  12  is made of plastic and molded in two halves that are then joined together. Preferably, the body  12 , the spacers  20  and the heat exchange conduit  17  are constructed of plasticized polyvinyl chloride. However, of course, the heat exchange conduit  17  can be made of other materials such as corrugated copper tubing. Preferably, the outside diameter of the heat exchange conduit  17  is slightly larger than the inside diameter of the aperture  16  so that the heat exchange conduit  17  is sealed to the aperture  16  by an interference fit. Alternatively, the heat exchange conduit  17  can be molded integrally with the body  12 . Preferably, the mouthpiece  11  is disposable and made of, injection molded polyethylene. The body  12  can be constructed of plastic film, such as polyethylene film. 
     The device  10  also includes a flexible conduit  21  having a first end  22  and a second end  23 . Preferably, the flexible conduit  21  is made of rubber. The first end  22  of the flexible conduit  21  is connected to the mouthpiece  11 . The second end of the flexible conduit  21  is connected to the mouth  14  of the hollow body  12  so that air breathed out of the lungs of a user through the mouthpiece  11  flows through the flexible conduit  21 , into the hollow body  12  and then out the opening  15  therefrom thereby heating the portion of the heat exchange conduit positioned within the hollow body and so that air then breathed into the second end  19  of the heat exchange conduit  17  flows into the hollow body heated by the heated portion of the heat exchange conduit positioned within the hollow body  12  and then flows through the flexible conduit  21 , through the mouthpiece  11  and into the lungs of the user. Preferably, at least one half of the heat of the exhaled air is transferred to the portion of the heat exchange conduit  17  positioned within the hollow body  12 . More preferably, at least two thirds of the heat of the exhaled air is transferred to the portion of the heat exchange conduit  17  positioned within the hollow body  12 . Most preferably, at least three quarters of the heat of the exhaled air is transferred to the portion of the heat exchange conduit  17  positioned within the hollow body  12   
     The efficiency of the device  10  is significantly improved if a first check valve  24  is positioned in and sealed to the heat exchange conduit  17  and if a second check valve  25  is positioned in and sealed to the walls of the body adjacent the opening therefrom to prevent back flow of air through the heat exchange conduit  17  when the user exhales through the device and to prevent backflow of air through the opening  15  of the body  12  when the user inhales air through the device, respectively. Preferably, the first check valve  24  and the second check valve  25  comprise a thin flap of rubber as is well known in the art of breathing devices. 
     Referring now to FIG. 3, therein is shown a side cross-sectional view of the mouthpiece  11  and upper end of the flexible conduit  21  of the device  10  of FIG.  1  and further showing thermal insulation  26  positioned on and around the flexible conduit  21 . The use of thermal insulation  26  is preferred to conserve the heat of exhaled air and to inhibit condensation of moisture in the flexible conduit  21 . The thermal insulation  26  is most preferably a tube of knitted yarn such as knitted wool yarn. 
     Referring now to FIG. 4, therein is shown a person  30  using the device  10  shown in FIG. 1 under a jacket  31  with the body  12  of the device  10  being positioned adjacent the chest of the user. It should be understood that the term “chest” is intended to include the abdomen of the user. The body  12  can be simply held in place under the jacket  31  or preferably, the body  12  is attached to the jacket  31 . Alternatively, the body  12  can be carried by the user by the use of suspender straps, not shown, worn under the jacket  31 . It should be understood that the opening  15  can be positioned as shown in FIG. 4, or to the front or rear of the person  30 , or the opening  15  can be positioned under the clothing of the person  30  if desired. Similarly, the end  19  of the heat exchange conduit  17  can be positioned as shown in FIG. 4, or to the front or rear of the person  30 , or the end  19  can be positioned under the clothing of the person  30  if desired. In addition, it may be desirable in some circumstances to place a knitted yarn tube around the heat exchange conduit  17  between the end  19  and the aperture  16  to thermally insulate this end of the heat exchange conduit  17 . 
     Referring now to FIG. 5, therein is shown a person  40  using the device  10  shown in FIG. 1 that has been incorporated into a cold weather jump suit  41 . The embodiment shown in FIG. 5 is highly preferred for use by persons who need to work in extremely cold conditions. Condensation and ice formation can be a problem at the opening  15  in extremely cold conditions. A condensation trap  42  incorporated into the body  12  may be helpful in collecting a portion of such condensation. A dust and/or toxic gas filter, not shown, can be attached to the end  19  of the heat exchange conduit  17  to help protect the user of the device  10  from dust and/or toxic gases or vapors. Again, it should be understood that the opening  15  can be incorporated as shown in FIG. 5, or to the front or rear of the person  40 , or the opening  15  can be positioned under the jump suit of the person  40  if desired. Similarly, the end  19  of the heat exchange conduit  17  can be incorporated as shown in FIG. 5, or to the front or rear of the person  40 , or the end  19  can be positioned under the jump suit of the person  40  if desired. In addition, it may be desirable in some circumstances to place a knitted yarn tube around the heat exchange conduit  17  between the end  19  and the aperture  16  to thermally insulate this end of the heat exchange conduit  17 . 
     In its various embodiments, the device and method of the instant invention can be used by dog sledders, snowmobliers, ice skaters, skiers, firemen, policemen, soldiers, sailors, marines, construction workers, loggers, oil drillers, ice fishermen, commercial fishermen, road workers, mailmen, hunters, infirm persons sensitive to the cold and, in general, any person who works, plays or otherwise needs to breath more comfortably in a cold weather environment. 
     In conclusion, it is readily apparent that although the invention has been described in relation with its preferred embodiments, it should be understood that the instant invention is not limited thereby but is intended to cover all alternatives, modifications and equivalents that are included within the scope of the invention as defined by the following claims.