Cold weather breathing mask

A lightweight face mask for heating surrounding air to be inhaled by a user, said mask comprising:

• a thin cup-shaped inner shell having a concave inner surface, a convex outer surface and a user abutment portion where said inner and outer surfaces meet, said abutment portion adapted to seal against the user's face around the user's mouth and nose with said concave inner surface defining a user breathing space;
• an outer shell spaced from and surrounding said convex outer surface of said inner shell, said inner and outer shells being joined along said user abutment portion and defining an air preheating chamber there between;
• inlet port means in said outer shell having first valve means for permitting entry of surrounding air into said preheating chamber and for preventing exit of air from said preheating chamber to surrounding air;
• an air passage in said inner shell for passing air between said preheating chamber and said user breathing space;
• air heating means for heating air in said passage passing from said preheating chamber to said user breathing space;
• second valve means in said air passage for permitting air to enter said user breathing space from said preheating chamber and for preventing exit of air from said user breathing space to said preheating chamber;
• channel means in said preheating chamber for directing air entering said preheating chamber through said inlet port means over substantially the entire convex outer surface of said inner shell before passing through said air passage;
• and
• exhaust port means in said inner and outer shells having third valve means for permitting exit of air directly from said breathing space to surrounding air and for preventing entry of surrounding air into said user breathing space.

A lightweight face mask for heating surrounding air to be inhaled by a user, said mask comprising:

• a thin cup-shaped inner shell having a concave inner surface, a convex outer surface and a user abutment portion where said inner and outer surfaces meet, said abutment portion adapted to seal against the user's face around the user's mouth and nose with said concave inner surface defining a user breathing space;
• an outer shell spaced from and surrounding said convex outer surface of said inner shell, said inner and outer shells being joined along said user abutment portion and defining an air preheating chamber there between, said outer shell including a front surface, two side surfaces connected to opposite sides of said front surface, and a bottom surface connected to bottom portions of said front and side surfaces,
• an inlet valve port in said outer shell, said inlet valve port passing through one of said outer shell side surfaces proximate said bottom surface for permitting entry of surrounding air into said preheating chamber and for preventing exit of air from said preheating chamber to surrounding air;
• an air passage in said inner shell for passing air between said preheating chamber and said user breathing space, said air passage being proximate said outer shell bottom surface;
• channel means in said preheating chamber for directing air entering said preheating chamber through said inlet valve port over substantially the entire convex outer surface of said inner shell before passing through said air passage thereby heating the air entering said preheating chamber, said channel means dividing said preheating chamber into a first vertical subchamber in direct communication with said air passage, and a second vertical subchamber, in communication with said inlet valve port, said second vertical subchamber being in communication with said first vertical subchamber only at the ends of said first and second vertical subchambers opposite said outer shell bottom surface, whereby air entering said preheating chamber through said valve port must travel the length of said second vertical subchamber and of said first vertical subchamber in a counter-current flow pattern before entering said air passage;
• and
• exhaust port means in said inner and outer shells having valve means for permitting exit of air directly from said breathing space to surrounding air and for preventing entry of the surrounding air into said user breathing space.