Medical mattress with firmness adjustment

Abstract

A mattress for institutional use provides upper and lower surfaces offering different levels of firmness through the use of gradiated firmness in multiple polymer foam layers.

What we claim is: 
     
       1. A reversible, dual-firmness mattress comprising:
 a mattress body having opposed first and second supporting surfaces each sized and adapted to receive and support a supine individual extending along a mattress length when either of the first and second supporting surfaces is upwardly facing and horizontal, the mattress body including at least three polymer foam layers each having a different firmness and extending along substantial portions of the mattress length, a firmness of the polymer foam layers selected to present presenting a lesser firmness to a supported individual lying on the first supporting surface than to the supported individual lying on the second supporting surface; and 
 a cover fitting around the mattress body to retain the mattress body therein; 
 wherein a first polymer foam layer adjacent to the first supporting surface has a lesser indentation force deflection (IFD) than the polymer foam layer adjacent to the second supporting surface and a third polymer foam layer positioned between the first and second polymer foam layers and having an IFD greater than the IFD of the first polymer foam layer and the second polymer foam layer 
 wherein a first polymer foam layer that defines a core layer as positioned between a second and third polymer foam layers has an indentation force deflection (IFD) greater than either of the second and third polymer foam layers and wherein the at least three polymer foam layers are adhered together so that the mattress body is unitary; and 
 wherein the second polymer foam layer has a lesser IFD than the third polymer foam layer. 
 
     
     
       2. The reversible, dual-firmness mattress of  claim 1  further including a fourth polymer foam layer positioned between the first second and third polymer foam layers having a greater IFD than the first at least one of the second and third polymer foam layer layers and a lesser IFD than then the third first polymer foam layer. 
     
     
       3. The reversible, dual-firmness mattress of  claim 1  wherein at least some of the polymer foam layers do not extend over a foot portion of the mattress length, the foot portion adapted to support feet of the supine individual; and
 including at least one foot region polymer foam element extending along the mattress length in the foot portion having firmness no more than a least firmness of the different polymer foam layers outside of the foot portion. 
 
     
     
       4. The reversible, dual-firmness mattress of  claim 3  wherein the foot region polymer foam element has a uniform firmness. 
     
     
       5. The reversible, dual-firmness mattress of  claim 3  wherein the foot region provides a reduced mattress thickness tapering inward to an end of the mattress. 
     
     
       6. The reversible, dual-firmness mattress of  claim 1  providing opposed left and right bolsters of polymer foam having an firmness no less than outermost of the polymer foam layers, the left and right bolsters extending along a left and right edge of the mattress and attached to the polymer foam layers. 
     
     
       7. The reversible, dual-firmness mattress of  claim 1  further including a second cover outside the first cover wherein the second cover includes indicia indicating relative firmness of the first and second opposed surfaces; and wherein the first cover and second cover cover the substantial entirety of the polymer foam layers. 
     
     
       8. The reversible, dual-firmness mattress of  claim 1  wherein the first and second opposed surfaces are substantially planar without a convoluted surface. 
     
     
       9. A reversible, dual-firmness mattress comprising:
 a mattress body having opposed a first supporting surface generally disposed in a first plane and an opposed second supporting surfaces surface generally disposed in a second plane different than the first plane, one of the first or second supporting surfaces overlying the opposed first or second supporting surface when either of the first or second supporting surfaces is upwardly facing and horizontal, each of the first and second supporting surfaces sized and adapted to receive and support a supine individual extending along a mattress length when either of the first and second supporting surfaces is upwardly facing and horizontal, the first supporting surface comprising a first plurality of outer edges generally disposed within the first plane and the second supporting surface comprising a second plurality of outer edges generally disposed within the second plane that are each individually coplanar with at least one of the outer edges in the first plurality of outer edges, the mattress body including at least three polymer foam layers each having a different firmness and extending along substantial portions of the mattress length, a firmness of the polymer foam layers selected to present a lesser firmness to a supported individual lying on the first supporting surface than to the supported individual lying on the second supporting surface; and 
 a cover fitting around the mattress body to retain the mattress body therein; 
 the mattress further including a bottom cover adjustable to be positioned over at least a portion of the bottom of the mattress when the mattress is in either of two orientations with the opposed first or second supporting surface uppermost, the bottom cover including outwardly exposed anti-slip material. 
 
     
     
       10. The reversible, dual-firmness mattress of  claim 9  wherein the bottom cover is permanently attached to a the cover fully surrounding fitting around the mattress body at one edge of the bottom cover and releasably attachable to the cover fully surrounding fitting around the mattress body at an opposed edge of the bottom cover. 
     
     
       11. The reversible, dual-firmness mattress of  claim 10  wherein the first and second surfaces are not convoluted. 
     
     
       12. The reversible, dual-firmness mattress of  claim 9  wherein the bottom cover is releasably attachable to a mattress the cover with hook and loop fasteners. 
     
     
       13. A reversible, dual-firmness mattress comprising:
 a mattress body having opposed a first supporting surface generally disposed in a first plane and an opposed second supporting surfaces surface generally disposed in a second plane different than the first plane, each of the first and second supporting surfaces sized and adapted to receive and support a supine individual extending along a mattress length when either of the first and second supporting surfaces is upwardly facing and horizontal, one of the first or second supporting surfaces vertically overlying the opposed first or second supporting surface when either of the first or second supporting surfaces is upwardly facing and horizontal, the mattress body including at least three polymer foam layers each having a different firmness and extending along substantial portions of the mattress length, a firmness of the polymer foam layers selected to present a lesser firmness to a supported individual lying on the first supporting surface than to the supported individual lying on the second supporting surface; and 
 a cover fitting around the mattress body to retain the mattress body therein; 
 the mattress further including a top cover adjustable to be positioned over at least a portion of the top of the mattress body when the mattress body is in either of two orientations with the opposed first or second supporting surface uppermost, the top cover providing upwardly extending bolsters positionable at opposed left and right edges of the mattress body. 
 
     
     
       14. The reversible, dual-firmness mattress of  claim 13  wherein the top cover is releasably attachable to a the cover of fitting around the mattress body with hook and loop fasteners. 
     
     
       15. The mattress of  claim 13  wherein the polymer foam is a polyurethane foam. 
     
     
       16. A reversible, dual-firmness mattress comprising:
 a mattress body having at least three layers of polymer foam material of different indentation force deflection (IFD) values and adhered together so that the mattress body is unitary, the layers of polymer foam material extending generally parallel to opposed first and second support surfaces of the mattress and presenting a lesser firmness to a supported individual lying on the first support surface that is generally disposed in a first plane than to the supported individual lying on the second support surface that is generally disposed in a second plane different than the first plane, wherein one of the first or second supporting surfaces overlies the opposed first or second supporting surface when either of the first or second supporting surfaces is upwardly facing and horizontal, the volume weighted IFD values in a half of the mattress closest to the first support surface being lower than volume weighted IFD values in a half of the mattress closest to the second support surface; 
 wherein the first supporting surface comprises a first plurality of outer edges generally disposed within the first plane and the second supporting surface comprises a second plurality of outer edges generally disposed within the second plane that are each individually coplanar with at least one of the outer edges in the first plurality of outer edges; and 
 a fabric cover surrounding the mattress body. 
 
     
     
       17. A reversible, dual-firmness mattress comprising:
 a mattress body having an opposed first supporting surface generally disposed in a first plane and an opposed second supporting surfaces surface generally disposed in a second plane different than the first plane, each of the first and second supporting surface sized and adapted to receive and support a supine individual when the surface is upwardly facing and horizontal, an wherein one of the first or second supporting surfaces overlies the opposed first or second supporting surface when either of the first and second supporting surfaces is upwardly facing and horizontal, wherein the first supporting surface comprises a first plurality of outer edges generally disposed within the first plane and the second supporting surface comprises a second plurality of outer edges generally disposed within the second plane that are each individually coplanar with at least one of the outer edges in the first plurality of outer edges, and a firmness of the first and second supporting surfaces selected to present a greater firmness to a supported individual lying on the first supporting surface than to the supported individual lying on the second supporting surface; 
 an inner cover fitting around the mattress body to retain the mattress body therein; and 
 an outer cover removably positionable over the inner cover to present a slip resistant surface at a bottom of the mattress body and not at a top of the mattress body; and 
 wherein the inner cover and outer cover the a substantial entirety of the polymer foam layers mattress body. 
 
     
     
       18. A reversible, dual-firmness mattress comprising:
 a mattress body having at least three layers of polymer foam material adhered together so that the mattress body is unitary, the at least three layers extending generally parallel to opposed and overlying first and second support surfaces of the mattress when either of the first and second supporting surfaces is upwardly facing and horizontal, the first supporting surface generally disposed within a first plane and comprising a plurality of first supporting surface sides disposed within the first plane, and the second supporting surface generally disposed within a second plane different than the first plane and comprising a plurality of second supporting surface sides disposed within the second plane that are each individually coplanar with a corresponding first supporting surface side, the layers presenting a lesser firmness to a supported individual lying on the first support surface than to the supported individual lying on the second support surface, each of the layers having an indention force deflection (IFD) value such that the total of the IFD values of each given layer or portion thereof located in a first half of the mattress nearest the first support surface times a thickness of the respective given layer or portion thereof located in the first half of the mattress is less than a total of the IFD values of each given layer or portion thereof located in a second half of the mattress nearest the second support surface times a thickness of the respective given layer or portion thereof located in the second half of the mattress;   a cover surrounding the mattress body; and   wherein a first layer positioned between a second and third layer of the at least three layers has an IFD value greater than the other two layers.   
     
     
       19. The reversible, dual-firmness mattress of claim 18 including indicia indicating relative presented firmness of the first and second support surfaces and attached to the reversible, dual firmness mattress. 
     
     
       20. The reversible, dual-firmness mattress of claim 18 further including a fourth layer positioned between the second and third layers and having a greater IFD value than a closest of second and third layers and a lesser IFD value then the first layer. 
     
     
       21. The reversible, dual-firmness mattress of claim 18 wherein the mattress body is free from rigid elements that would prevent flexure of the mattress body along its length. 
     
     
       22. The reversible, dual-firmness mattress of claim 18 wherein at least one layer is memory foam. 
     
     
       23. The reversible, dual-firmness mattress of claim 18 wherein at least three layers of polymer foam material have different thicknesses. 
     
     
       24. The reversible, dual-firmness mattress of claim 18 wherein the first layer has an IFD value at least twice that of at least one of the second and third layer. 
     
     
       25. The reversible, dual-firmness mattress of claim 24 wherein one of the second and third layers has an IFD value at least one and a half times the IFD value other of the second and third layers. 
     
     
       26. The reversible, dual-firmness mattress of claim 18 wherein the at least three layers of polymer foam material are adhered together by adhesive. 
     
     
       27. A reversible, dual-firmness mattress comprising:
 a mattress body having at least three layers of polymer foam material adhered together so that the mattress body is unitary, the at least three layers extending generally parallel to opposed first and second support surfaces of the mattress, the layers presenting a lesser firmness to a supported individual lying on the first support surface than to the supported individual lying on the second support surface, each of the layers having an indention force deflection (IFD) value such that the total of the IFD values of each given layer or portion thereof located in a first half of the mattress nearest the first support surface times a thickness of the respective given layer or portion thereof located in the first half of the mattress is less than a total of the IFD values of each given layer or portion thereof located in a second half of the mattress nearest the second support surface times a thickness of the respective given layer or portion thereof located in the second half of the mattress;   a cover surrounding the mattress body; and   wherein a first layer positioned between a second and third layer of the at least three layers has an IFD value greater than the other two layers, and   wherein IFD values of each layer decrease progressively without increasing from a center of the mattress halfway between the first and second support surfaces to the first and second support surfaces.   
     
     
       28. A reversible, dual-firmness mattress comprising:
 a mattress body having at least three layers of polymer foam material adhered together so that the mattress body is unitary, the at least three layers extending generally parallel to opposed first and second support surfaces of the mattress, the layers presenting a lesser firmness to a supported individual lying on the first support surface than to the supported individual lying on the second support surface, each of the layers having an indention force deflection (IFD) value such that the total of the IFD values of each given layer or portion thereof located in a first half of the mattress nearest the first support surface times a thickness of the respective given layer or portion thereof located in the first half of the mattress is less than a total of the IFD values of each given layer or portion thereof located in a second half of the mattress nearest the second support surface times a thickness of the respective given layer or portion thereof located in the second half of the mattress;   a cover surrounding the mattress body,   wherein a first layer positioned between a second and third layer of the at least three layers has an IFD value greater than the other two layers, and,   wherein each of the layers has an IFD value such that the total of the IFD values of each given layer or portion thereof located in a first half of the mattress nearest the first support surface times a thickness of the respective given layer or portion thereof located in the first half of the mattress is at least 50% less than the total of the IFD values of each given layer or portion thereof located in a second half of the mattress nearest the second support surface times a thickness of the respective given layer or portion thereof located in the second half of the mattress.   
     
     
       29. A reversible, dual-firmness mattress comprising:
 a mattress body having at least three layers of polymer foam material adhered together so that the mattress body is unitary and adapted to flex along its length, the at least three layers extending generally parallel to opposed first and second support surfaces of the mattress, the layers adapted to present a lesser firmness to a supported individual lying on the first support surface than to the supported individual lying on the second support surface, each of the layers having an indention force deflection (IFD) value such that the total of the IFD values of each given layer or portion thereof located in a first half of the mattress nearest the first support surface times a thickness of the respective given layer or portion thereof located in the first half of the mattress is less than a total of the IFD values of each given layer or portion thereof located in a second half of the mattress nearest the second support surface times a thickness of the respective given layer or portion thereof located in the second half of the mattress; and   a cover surrounding the mattress body;   wherein a first layer positioned between other two layers has an IFD value greater than the other two layer; and   further including indicia indicating relative firmness of the first and second support surfaces attached to the reversible, dual firmness mattress.   
     
     
       30. The reversible, dual-firmness mattress of claim 1, wherein the mattress is adapted to flex to conform to an articulating bed carriage when either of the first and second supporting surfaces are positioned on the articulating bed carriage. 
     
     
       31. The reversible, dual-firmness mattress of claim 16, wherein the mattress is adapted to flex to conform to an articulating bed carriage when either of the first and second support surfaces are positioned on the articulating bed carriage. 
     
     
       32. The reversible, dual-firmness mattress of claim 1, wherein one of the layers comprises a first and second component layer.