fig1 shows a foam mattress having highly desirable physical properties . the mattress of fig1 is comprised of a pair of layers of 1 and 2 of elastomer which , in cooperation with the end pieces 7 , define an inner chamber . cylinders 3 , which are also comprised of an elastomer , are disposed within this chamber in abutting relationship . the axes of the cylinders 3 will typically be oriented transversely of the longitudinal or head - to - foot axis of the mattress . the cylinders 3 are formed by rolling rectangular elastomer members so as to place opposite side surfaces in abutting relationship and securing the thus formed cylinders by means of a suitable adhesive or other technique ; the abutting lines where the ends of the elastomer members are joined being indicated at &# 34 ; a &# 34 ;. this technique of forming individual cylinders results in each cylinder being provided , on its axis , with a through hole . stiffener elements , wooden rods 4 for example , are inserted in these through - holes . after the cylinders 3 have been formed and the stiffener elements inserted therein , each cylinder is secured to at least one of the layers 1 and 2 . in the mattress shown in fig1 the cylinders 3 are secured to layer 2 by means of a flattened strip 5 formed by applying a compressive force to the cylinders . the method of attachment of the cylinders to the outer layer will typically consist of adhesive bonding . in addition to being compressed to form a flat which defines adequate surface area to securely bond the cylinder to at least one of the outer layers , the cylinders are compressed laterally to form the flattened regions indicated at 6 and adhesively secured to one another . as noted , the mattress is completed by the application of the end pieces 7 . the fabrication procedure briefly described above produces a mattress which exhibits excellent elastic properties while providing ideal distribution and support of any weight imposed thereon . however , the production technique is quite lengthy with the formation of the cylinders 3 being particularly time - consuming . referring now to fig2 a mattress which has physical properties which are at least comparable to those of the mattress of fig1 and which can be assembled rapidly , is shown . the mattress of fig2 also comprises the top and bottom elastomer layers 8 and 9 and the end pieces 7 which define an inner chamber . however , in the mattress of fig2 the cylinders 3 are replaced by a pair of shaped elastomer layers 10 and 11 . the elastomer layers 10 and 11 are formed , for example by cutting , from blocks of foam material having the desired characteristics are shaped such that one surface of each layer has a sinusoidal contour . on their opposite sides , in direct alignment with the &# 34 ; peaks &# 34 ; of the sinusoidal contour , the layers 10 and 11 are provided with cut - outs ; these cut - outs being formed in flat faces of elastomer layers 10 and 11 and typically extending from one edge of the layer to the opposite edge . during the assembly procedure , the layers 10 and 11 are placed in abutting relationship with the flat faces thereof being in contact and the cut - outs in registration . the layers 10 and 11 are then secured to one another , for example through the use of a suitable adhesive , and the stiffeners 12 are inserted in the through - holes defined by the above - mentioned cut - outs . the stiffeners 12 may , for example , comprise wooden rods which have some flexibility . when fabrication of the inner member comprising the layers 10 and 11 and stiffeners 12 has been completed , this inner member may be easily sandwiched between the outer layers 1 and 2 and , typically , adhesively secured to the outer layers . thus , by cutting layers 10 and 12 by machine and securing these layers together via their abutting flat sides , an intermediate layer having the same response to loading as is exhibited by plural individual abutting cylinders is easily and inexpensively produced . as will be understood by those skilled in the art , the mattresses of both of fig1 and 2 , when completed by the attachment of the end pieces 7 thereto , will be fitted with a case or cover prior to being marketed . as previously noted , the mechanical properties of the mattresses depicted in fig1 and 2 are in principle the same . however , because of its ease of assembly , the mattress of fig2 comprises an improvement over the mattress of fig1 . a mattress in accordance with the present invention is particularly well suited for use on a double bed since any difference in weight imposed on opposite sides may be taken up by the structure of the mattress . by way of example , when the difference in weight is more than 30 kg , the density of the elastomer foam in that part of the mattress which will be consistently exposed to the heavier weight can be increased . in the fig2 embodiment , this may be done by forming the intermediate assembly comprised of the layers 10 and 11 in two pieces and , if this is done , movements which cause deformation in one half of the mattress will not have any effect on the other half . similarly , the stiffening elements 4 or 12 , which have been discussed above as being comprised of wood , may be replaced by other materials and elements having different physical characteristics may be inserted from each end thereby altering the response to the loading of the two halves of the mattress so that such response is dissimilar from one side to the other . while a mattress in accordance with the present invention is preferably formed from a polyurethane synthetic foam , other materials having the same or similar properties may be employed . similarly , while the layers 10 and 11 may be formed by machining blocks of foam , these members may also be produced by other methods such as by extruding or molding . it is also to be noted that , while the above description refers to affixing the various components to one another as required through the use of suitable adhesives , other fastening techniques may be employed . thus , while a preferred embodiment has been shown and described , various modifications and substitutions may be made thereto without departing from the spirit and scope of the present invention and , accordingly , it is to be understood that the present invention has been described by way of illustration and not limitation .
an improved mattress is presented having upper and lower elastomer sheets with an undulating structure of elastomer elements housed between the sheets and containing stiffener elements in the elastomer elements .