Heat reservoir

Abstract

A fluid reservoir includes a housing shell defining a cavity, and a flexible, resilient water impervious bag-shaped liner mounted in the cavity so as to substantially fill the cavity when the liner is filled with fluid. The liner is formed from a flexible water-imperious sheet by forming the sheet into a cylinder, then forming a water-tight first seam along a bottom edge of the cylinder, then folding outer corners of the first seam over, so as to overlap a center portion of the first seam, and so that bottom edges of the outer corners, once so folded over, register substantially co-linearly within a bottom edge of the center portion of the first seam. An upper portion of the liner is thereby urged to bag open. The upper portion thus forms a substantially frustoconical shape. The upper portion is contiguous with a lower portion of the liner. The lower is portion substantially wedge shaped. The bottom corners overlapping the center portion of the first seam are sealed onto the first seam so as to form a second seal.

1 . a non-pressurized fluid reservoir comprising:
 a housing shell defining a cavity,   a flexible water impervious bag-shaped liner mounted in said cavity so as to substantially fill said cavity when said liner is filled with fluid,   wherein said liner is formed from a flexible water-imperious sheet by forming said sheet into a cylinder, then forming a water-tight first seam along a bottom edge of said cylinder, folding outer corners of said first seam over, so as to overlap with a center portion of said first seam, and so that bottom edges of said outer corners, once so folded over, register substantially co-linearly within a bottom edge of said center portion of said first seam, whereby an upper portion of said liner is urged to bag open thereby forming said upper portion in a substantially frustoconical shape, said upper portion contiguous with a lower portion of said liner, said lower portion substantially wedge shaped,   and wherein said bottom corners overlapping said center portion of said first seam are sealed onto said first seam so as to form a second seal.   
   
   
       2 . The reservoir of  claim 1  wherein said sheet is formed into said cylinder by sealing opposite ends of said sheet to one another along a third seam once said sheet has been curled into a cylindrical shape. 
   
   
       3 . The reservoir of  claim 2  wherein said housing shell is substantially cylindrical and sized so that said upper portion of said liner fits snugly inside said cavity. 
   
   
       4 . The reservoir of  claim 3  wherein said liner is resilient. 
   
   
       5 . The reservoir of  claim 4  wherein said lower portion of said liner folds under said upper portion of said liner when said liner is mounted in said cavity, said liner so mounted to register an upper edge of said liner with an upper rim of said housing shell, wherein said rim extends around an upper opening into said cavity, said lower portion said folding under said upper portion to form a floor surface of said liner and to flatten said floor surface of said liner down against a substantially horizontal supporting surface under said housing shell. 
   
   
       6 . The reservoir of  claim 5  wherein said housing shell is open-bottomed, and said supporting surface is a separate platform surface, separate from said shell. 
   
   
       7 . The reservoir of  claim 5  wherein, when fluid fills said liner in said cavity, said floor surface of said liner spreads out substantially to meet wall of said shell. 
   
   
       8 . The reservoir of  claim 8  wherein said upper edge of said liner is foldable to form a lip, and wherein said rim of said housing shell further comprises a racially spaced apart array of liner-engaging protrusions to engage and lock to said lip. 
   
   
       9 . The reservoir of  claim 1  further comprising an insulating blanket mounted around said housing shell, an insulated lid for closing an upper opening into said cavity, and an insulated base on which is mounted said housing shell. 
   
   
       10 . The reservoir of  claim 1  further comprising a clamp, and wherein said clamp is clamped over said bottom corners and said center portion of said first seam when said bottom corners are abutted together and overlaid over said center portion of said first seam.