Patent Publication Number: US-2018042395-A1

Title: Mattress

Description:
The present invention relates to a mattress. 
     Inflatable mattresses and separately foam mattresses, are well known for reducing or alleviating pressure sores for persons who may be confined to a bed for example, for prolonged periods of time. However, as an underlying mattress support frame moves, such as when reconfiguring the mattress to enable an individual to move from a recumbent position to a seated position, the mattress will bend and twist and be subjected to regions of stress and compression, which affect the ability of the mattress to suitably support the individual and thus provide pressure relief. 
     We have now devised an improved mattress. 
     In accordance with the present invention, there is provided a mattress comprising a base having a lower surface and an upper surface, the mattress further comprising a frame which extends around at least a portion of a periphery of the base and which extends above the upper surface of the base to define a mattress cavity, the mattress further comprising an inflatable bladder disposed in the cavity. 
     In an embodiment, the mattress further comprises a cover which is arranged to extend over the cavity for retaining the bladder within the cavity. The cover may comprise a closable opening for receiving the base, frame and bladder therein. The cover further comprises a fastener, such as a zip fastener, disposed along the closable opening for opening and closing the cover. The cover may be formed of a polyurethane material. 
     In an embodiment, inflatable bladder comprises an inflation inlet, which may be provided with a one-way valve, for limiting the flow of a fluid, such as air, into the bladder during inflation thereof. The bladder may further comprise a pressure relief cap, which is removably insertable within the inflation inlet, to cause the valve to open to release air from within the bladder for deflating the bladder. In an embodiment, the inflation inlet is arranged to extend through the frame. 
     In an embodiment, the frame is disposed on the upper surface of the base. The frame is formed of a first foamed material and the base is formed of a second foamed material. Preferably, the first foamed material comprises a greater density than the second foamed material. 
     In an embodiment, the base comprises a rectangular shape and the frame comprises side members which extend along an upper surface of the base along at least a portion of the longitudinal sides thereof. The frame further comprises end members which extend along an upper surface on the base along at least a portion of the lateral sides thereof. In an embodiment, the side members and end members are rigidly coupled to the base, preferably upon the upper surface thereof, via an adhesive or bonding agent for example. 
     In an embodiment, the base comprises a plurality of upper channels formed in the upper surface. The upper channels comprise a first set of channels which extend substantially parallel to each other and a second set of channels which extend substantially parallel to each other. Preferably, the channels of the first set are non-parallel with the channels of the second set. The channels of the second set preferably extend substantially transverse to the channels of the first set, thereby forming an intersecting lattice of channels on the upper surface. 
     In an embodiment, the channels of the first set are separated from each other by a first spacing and the channels of the second set are separated from each other by a second spacing. In an embodiment, the first and second spacing comprise the same spacing. 
     In an embodiment, the channels of the first set extend substantially parallel to a longitudinal axis of the base and the channels of the second set extend substantially parallel to a lateral axis of the base. 
     In an embodiment, the base further comprises a plurality of lower channels formed on the lower surface. The lower channels preferably extend substantially parallel to each other. The lower channels extend across the base, substantially parallel to a lateral axis of the base, and in an embodiment, the lower channels are localised to a first and second region of the lower surface. In an embodiment, the lower channels located within the first region are separated by a first spacing and the lower channels located with the second region are separated by a second spacing, which may be equal to the first spacing. 
     In an embodiment, the frame comprises a plurality of frame channels formed in an upper surface of each side member, which extend across the respective side member. The frame channels formed in each side member are preferably localised to a first and second region of the upper surface of the respective side member. In an embodiment, the frame channels formed in the first and second region of one side member are preferably aligned with the frame channels formed in the first and second region respectively, of the other side member. 
     In an embodiment, the number of lower channels disposed in the first region of the base is the same as the number of frame channels disposed in the first region of each side member. Similarly, the number of lower channels disposed in the second region of the base is the same as the number of frame channels disposed in the second region of each side member. 
     In an embodiment, the lower channels disposed in the first region are aligned substantially directly adjacent the frame channels disposed in the first region of each side member. Similarly, the lower channels disposed in the second region are aligned substantially directly adjacent the frame channels disposed in the second region of each side member. In normal use of the mattress, when positioned on a flat, horizontal support frame, the first and second regions of the frame channels are substantially vertically aligned with the first and second regions of the lower channels, respectively. 
     In an embodiment, the frame channels preferably extend to a depth within the respective side member, which is greater than a depth to which the lower channels extend into the base. 
     Whilst the invention has been described above, it extends to any inventive combination of features set out above or in the following description. Although illustrative embodiments of the invention are described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments. 
     Furthermore, it is contemplated that a particular feature described either individually or as part of an embodiment can be combined with other individually described features, or parts of other embodiments, even if the other features and embodiments make no mention of the particular feature. Thus, the invention extends to such specific combinations not already described. 
    
    
     
       The invention may be performed in various ways, and, by way of example only, embodiments thereof will now be described, reference being made to the accompanying drawings in which: 
         FIG. 1  is an exploded view of a mattress according to an embodiment of the present invention; 
         FIG. 2  is a plan view of a mattress according to an embodiment of the present invention with the cover and bladder removed; 
         FIG. 3  is a sectional view taken along line A-A in  FIG. 2 ; and, 
         FIG. 4  is a magnified view of the region of the end member shown circled in  FIG. 4 ; and, 
         FIG. 5  is a side view of a mattress illustrated in  FIG. 2 ; 
     
    
    
     Referring to  FIG. 1  of the drawings, there is illustrated an exploded view of a mattress  10  according to an embodiment of the present invention, for reducing pressure sores and the like associated with individuals which may be required to remain in a recumbent or seated position for prolonged periods. The mattress  10  comprises a base  20  having a frame  30  formed thereon which defines a cavity  40  for receiving an inflatable bladder  50 . The bladder  50  is held central upon the base  20  by the frame  30 , and the base  20 , frame  30  and bladder  50  are enclosed within a cover  60 , which may be formed of polyurethane, for example. The mattress  10  is arranged to conform with the contour of an underlying frame, such as a bed frame (not shown), to provide a suitable support for an individual. In this respect, the mattress  10  is arranged to flex as the underlying frame (not shown) moves, such as when it is desired to raise an individual from a recumbent position to a more upright position. 
     Referring to  FIG. 2  of the drawings, the base  20  of the mattress  10  is formed of a foamed material and comprises a substantially rectangular shape, when viewed from above, although the skilled reader will recognise that other shapes for the base may be used without departing from the essence of the invention. The base  20  comprises an upper surface  21  and a lower surface  22  which are substantially parallel to each other. The upper surface  21  comprises a plurality of upper channels  23  formed therein which comprise a substantially square cross-sectional profile, as illustrated in  FIG. 3  of the drawings. The upper channels  23  comprise a first set of channels  23   a  which extend along the length of the upper surface  21  of the base  20 , substantially parallel to each other and to a longitudinal axis of the base  20 , and a second set of channels  23   b  which extend across the width of the upper surface  21  of the base  20 , substantially parallel to each other and to a lateral axis of the base  20 . The channels  23   a  of the first set are separated from each other by a first spacing across the width of the base  20  and the channels  23   b  of the second set are separated from each other by a second spacing along the length of the base  20 . In the illustrated embodiment, the first and second spacing&#39;s are substantially equal, such that the channels of the first and second set  23   a ,  23   b  form an intersecting lattice of channels  23  which form islands  24  on the upper surface  21  of the base  20 , having a substantially square shape when viewed from above. However, the first and second spacing&#39;s may differ from each other in which case the islands  24  may take an alternative shape. Also, the spacing between adjacent channels  23   a  of the first set may not be consistent and as such may vary. Similarly, the spacing between adjacent channels  23   b  of the second set may not be consistent, and may vary. 
     The mattress frame  30  extends around a periphery of the base  20  and in an embodiment, the frame  30  comprises side members  31  which extend along longitudinal sides of the base  20  at each lateral end thereof, and end members  32  which extend along lateral sides of the base  20 , at each longitudinal end thereof. The frame  30  is illustrated as extending around the complete periphery of the base  20 , however, in an embodiment, the side members  31  and/or the end members  32  may instead extend along a portion of the respective side of the base  20 . 
     The side and end members  31 ,  32  are formed of a foamed material which comprises a greater density than the foamed material of the base  20 , and are rigidly bonded to the base  20  upon the upper surface  21  thereof. In an alternative embodiment however, it is envisaged that the frame  30  may instead be bonded to the base  20  along an outer periphery thereof. 
     The side and end members  31 ,  32  are bonded to the upper surface  21  of the base  20 , but remain uncoupled from each other at the respective ends where the side and end members  31 ,  32  abut each other. The side and end members  31 ,  32 , together with the base  20 , collectively define the cavity  40  for receiving the inflatable bladder  50 . The frame  30  ensures that the bladder  50  remains suitably positioned upon the base  20  and cannot slide off the base  20 . 
     The inflatable bladder  50  is formed of a flexible plastics material, such as polyurethane, and comprises an outer wall  51  which defines a chamber having a shape which substantially conforms with the shape of the cavity  40  when inflated. Moreover, an upper or support surface  52  of the bladder  50  is arranged to extend substantially in a plane comprising an upper surface of the frame  30 , when inflated. The bladder  50  further comprises an inflation inlet  53  comprising a conduit  54  which is arranged in fluid communication with the chamber and which extends outwardly away from the outer wall from at one longitudinal end thereof. The inflation inlet  53  is disposed proximate a corner region  54  of the bladder  50  and is arranged to extend out through an adjacent end member  32  via a slot or aperture  33  formed in the end member  32 , as illustrated in figured  3  and  4  of the drawings. The inflation inlet  53  further comprises a one-way valve (not shown) for limiting the flow of a fluid, such as air, into the chamber during inflation thereof, and a pressure release cap (not shown) which is removably insertable within the inlet  53  to open the valve for deflation. 
     To enable the mattress  10  to contort and conform with the underlying contour of a support frame (not shown), the base  20  further comprises a plurality of lower channels  25  formed in the lower surface  22  of the base  20 , as illustrated in  FIG. 5  of the drawings. The lower channels  25  extend in a substantially parallel orientation, and substantially parallel to a lateral axis of the base  20 , across the base  20 . The lower channels  25  are localised to two separated regions  26   a ,  26   b  of the base  20 , namely a first and second region  26   a ,  26   b , which are separately centred at approximately one third of the length of the base  20 , from each longitudinal end thereof. The lower channels  25  within the first region  26   a  are separated from each other by a first spacing and the lower channels  25  within the second region  26   b  are separated from each other by a second spacing, which is the same as the first spacing. However, the first and second spacing of the channels  25  in the first and second regions  26   a ,  26   b  may be different spacing&#39;s. 
     The mattress  10  further comprises a plurality of frame channels  34  formed within an upper surface  35  of each side member  31 , which extend across a width of each side member  31 . The frame channels  34  formed in each side member  31  extend substantially parallel to each other and to a lateral axis of the base  20 . The frame channels  34  are localised to a first and second region  36   a ,  36   b  of the upper surface  35  of the respective side member  31 , which are separately centred at approximately one third of the length of the base  20 , from each longitudinal end thereof. The frame channels  34  disposed within the first and second region  36   a ,  36   b  of one side member  31  are aligned with the frame channels  34  disposed within the first and second region  36   a ,  36   b  respectively, of the other side member  31 . 
     The spacing of the frame channels  34  within the first and second regions  36   a ,  36   b  forms ridges  37  in the side members  31  between each channel  34 . In the illustrated embodiment, the ridges  37  comprise a curved upper region having a radius of curvature of approximately 5 mm, whereas a lower region of each channel  34  comprises a curved base having a radius of curvature of approximately 5 mm. The channels  34  and thus the outer sides of each ridge  37  are inclined at approximately 80° to the horizontal, such that the angular separation between adjacent sides of the channel  34  is substantially 20°. The frame channels  34  and ridges  37  formed therebetween thus form a substantially harmonically varying profile, and the pitch, namely the separation of adjacent channels  34  comprises approximately 40 mm. 
     Similarly, the spacing of the lower channels  21  within the first and second regions  26   a ,  26   b  of the base  20  forms ridges  27  within the base  20 , between each channel  25 . In the illustrated embodiment, the ridges  27  comprise a flattened outer region (with respect to the base) which extends in the plane of the lower surface of the base  20 , whereas an inner region (with respect to the base) of each channel  25  comprises a curved profile having a radius of curvature of approximately 10 mm. The channels  25  and thus the outer sides of each ridge  27  are inclined at approximately 80° to the horizontal, such that the angular separation between the sides of adjacent channels  25  is substantially 20°, similar to the frame channels  34 . The lower channels  25  thus comprise a similar profile to the frame channels  34 , having a pitch of approximately 40 mm. However, owing to the outer region of each ridge  27  in the lower surface  22  of the base  20  being truncated in the plane of the lower surface  22 , the frame channels  34  extend to a depth into the side members  31  which is greater than the depth to which the lower channels  25  extend into the base  20 . 
     The frame channels  34  associated with the first and second region  36   a ,  36   b  of each side member  31  are aligned substantially directly opposite the lower channels  25  associated with the first and second regions  26   a ,  26   b  of the base  20 , and as such, the number of frame channels  34  equals the number of lower channels  25 . 
     The frame channels  34 , upper channels  23  and lower channels  25  permit the frame  30  and base  20  to bend and flex for example, and thus readily conform with an underlying support frame (not shown), without unduly stressing the base  20  and frame  30  material. This stress-relief maintains a suitable pressure relief across all regions of the base  20  while providing the necessary support to an individual. 
     In use, the bladder  50  is inflated via the inflation inlet  53  using a pump (not shown) for example, and then located within the cavity  40  formed between the frame  30  and the base  20 . The conduit  54  is subsequently passed through the adjacent slot or aperture  33  formed within the end member  32  of the frame  30 , and the base  20 , frame  30  and bladder  50  are then positioned within the cover  60 . This is achieved by opening the cover  60  using a fastener  61  which extends along a closable opening  62  of the cover  60 . The fastener  61  is arrange selectively open and close the cover  60  and may comprise a zip, for example, which is arranged to extend around a periphery of the cover  60  adjacent a side of the base  20  when positioned therein. The cover  60 , in combination with the frame  30 , maintain a suitable positioning of the bladder  50  upon the base  20  as the mattress  10  moves with movement of the individual supported thereon, and with any movement of the underlying support frame (not shown), to maintain a suitable support and pressure relief for the individual.