Sleeping bag

Abstract

For any given thickness of thermal insulation, the usable lower temperature range of a sleeping bag assembly may be extended by constructing it using an inner lining material that in addition to its normal functions of being flexible and capable of retaining insulating materials, is also capable of functioning as a vapor barrier and a radiation barrier. In addition to the standard sleeping bag design approach of incorporating various insulating materials to reduce heat lost by thermal conductivity, the subject disclosure is directed to methods by which heat loss by radiation and evaporation may also be reduced.

1 . A sleeping bag comprising:
 a first half and a second half arranged in opposing relationship with one another from an entrance end to a lower end to define a sleeping compartment therebetween;   said first half and said second half each having an outer shell disposed in facing relationship with an environment of the sleeping bag and an inner shell disposed in facing relationship with said sleeping compartment; and   said inner shell of each of said first and second halves comprised of a polymer film and a low emissivity coating disposed in overlaying relationship with one another to control heat loss from said sleeping compartment due to both evaporation and radiation.   
     
     
         2 . The sleeping bag as set forth in  claim 1 , wherein said low emissivity coating has an emissivity less than 0.1. 
     
     
         3 . The sleeping bag as set forth in  claim 2 , wherein said low emissivity coating is comprised of an aluminized coating. 
     
     
         4 . The sleeping bag as set forth in  claim 2 , wherein said polymer film is impervious to moisture in either a liquid or vapor form. 
     
     
         5 . The sleeping bag as set forth in  claim 4 , wherein said polymer film is comprised of polyester, PET, or BoPET. 
     
     
         6 . The sleeping bag as set forth in  claim 1 , wherein said polymer film of each of said inner shells is disposed in adjacent and facing relationship with said sleeping compartment, and said low emissivity coating is disposed outwardly of said polymer film. 
     
     
         7 . The sleeping bag as set forth in  claim 6 , wherein said inner shell includes a second polymer film disposed outwardly of said low emissivity coating. 
     
     
         8 . The sleeping bag as set forth in  claim 1 , wherein said low emissivity coating is disposed in adjacent and facing relationship with said sleeping compartment, and said polymer film is disposed outwardly of said low emissivity coating. 
     
     
         9 . The sleeping bag as set forth in  claim 1 , wherein said polymer film is reinforced with man-made or natural fibers to provide added strength to said inner shells. 
     
     
         10 . The sleeping bag as set forth in  claim 1 , further comprising a closure device extending from said entrance end to said lower end to interconnect and secure said first and second halves to one another. 
     
     
         11 . The sleeping bag as set forth in  claim 10 , wherein said closure device is comprised of a zipper assembly. 
     
     
         12 . The sleeping bag as set forth in  claim 1 , further comprising an insulating material inserted and retained between said inner and outer shells of said first and second halves. 
     
     
         13 . The sleeping bag as set forth in  claim 1 , wherein said outer shell is comprised of a lightweight fabric. 
     
     
         14 . The sleeping bag as set forth in  claim 13 , wherein said lightweight fabric is comprised of at least one of nylon or polyester. 
     
     
         15 . The sleeping bag as set forth in  claim 10 , further comprising a draft tube facing said sleeping compartment and disposed in overlaying relationship with said closure device from said entrance end to said lower end to provide insulation along a length of said closure device. 
     
     
         16 . The sleeping bag as set forth in  claim 1 , further comprising a drawstring lock disposed adjacent said entrance end to partially cinch closed said sleeping compartment adjacent said entrance end.