Anatomical, pressure-evenizing mattress overlay

Abstract

A method and structure for furnishing pressure-evenized, dynamic-reaction anatomical support. The method includes (a) supporting the anatomy with a 100% open cell viscoelastic foam, and (b) thereafter, and within the foam, reacting to both static and dynamic, anatomically-produced foam indentations to expand and contract cell-openness size, whereby deeper/sharper indentations result in greater-size cell-openness. Such reacting includes laterally stretching and flowing regions of the foam adjacent such an indentation The overlay structure features (1) a dynamic-response core expanse formed of a 100% open-cell, compressible and flowable, polyurethane, viscoelastic foam possessing a compressed, relaxed-state volume and (2) an elastomeric, moisture-resistant coating, load-transmissively, interfacially bonded to the entirety of the outside surface of the core expanse to function as a dynamically-responsive unit with the expanse. The coating possesses a relaxed-state prestressed tension condition which is responsible for the expanse's compressed condition.

1 . An anatomical pressure-evenizing mattress overlay comprising
 a dynamic-response core expanse having spaced, upper and lower, surfaces and a perimetral edge extending between said surfaces, formed of a 100% open-cell, compressible and flowable, viscoelastic foam, and having a relaxed-state volume in the overlay which is prestressed, and about 8-10% compressed, thus to create a pre-compression condition in the expanse, and   an elastomeric, moisture-resistant coating, load-transmissively bonded to the entirety of the outside of said expanse to function as a dynamically-responsive unit with the expanse, and possessing a relaxed-state internal prestressed tension condition.   
   
   
       2 . The overlay of  claim 1 , wherein said core expanse exhibits a compressive-deflection vs. compression-force curve which includes an extremely linear region over which a relatively wide change in compressive deflection is accompanied by what turns out to be an anatomically insignificant change in compression pressure. 
   
   
       3 . The overlay of  claim 1 , wherein said core expanse is specifically form of a polyurethane material. 
   
   
       4 . The overlay of  claim 1 , wherein said upper and lower surfaces are, allover, substantially equidistant. 
   
   
       5 . The overlay of  claim 1 , wherein said expanse has a thickness throughout of about 1-inches, and said coating has a thickness, throughout, of about 0.015-inches. 
   
   
       6 . The overlay of  claim 1 , wherein said coating is formed with fifteen, approximately 0.001-inches thick cured, curable initially wet vinyl sublayers initially having, between next-adjacent sublayers, wet, interfacial surfaces of joinder. 
   
   
       7 . The overlay of  claim 1  which further comprises, for said coating-covered core expanse, a removeably fittable/installable, generally form-fitting, allover composite-fabric jacket having an upper-surface portion formed of a selected, lower-friction material, and a lower-surface portion formed of a selected, higher friction material. 
   
   
       8 . The overlay of  claim 7 , wherein said lower-friction material is formed of a woven polyester fabric. 
   
   
       9 . The overlay of  claim 7 , wherein said higher-friction material is formed of a polyurethane-coated, polyester-knit fabric. 
   
   
       10 . The overlay of  claim 9 , wherein said lower-friction material is formed of a polyurethane-coated, polyester-knit fabric. 
   
   
       11 . An anatomical pressure-evenizing mattress overlay comprising
 a core expanse of single-density, 100%, open-cell, compressible and flowable, polyurethane, viscoelastic foam, and   a gas-breathable, moisture-resistant, elastomeric coating extending over the entirety of the surface area of said core expanse, and interfacially, mechanically bonded to said surface area, said coating being everywhere in tension and placing said core expanse everywhere in compression.   
   
   
       12 . A method for furnishing pressure-evenized, dynamic-reaction support for the anatomy comprising
 supporting the anatomy with a 100% open cell viscoelastic foam, and   following said supporting, and within the supporting foam, reacting therein to both static and dynamic, anatomical-unevenness-produced indentations in the foam to expand and contract cell-openness size, whereby deeper and sharper indentations result in greater cell-openness size.   
   
   
       13 . The method of  claim 12 , wherein said reacting includes laterally stretching and laterally flowing regions of the foam adjacent such an indentation.