An elastic device providing means of controlling its stiffness by controlling the tension of the string or group of springs resulting in adjustable transverse stiffness of it, arranged in matrix to enable the control of spatial stiffness of a 2D matrix in unlimited resolution.

A mattress assembly generally includes a tension adjustable and stretchable fabric panel coupled to a rail system. Axial tension of the stretchable fabric panel can be adjusted to change a firmness property associated with the mattress assembly.

A mattress assembly generally includes a tension adjustable and stretchable fabric panel coupled to a rail system. Axial tension of the stretchable fabric panel can be adjusted to change a firmness property associated with the mattress assembly.

A kit (100) for constructing a support surface (10) for a sleeping person. The kit (100) comprises: an air-permeable layer (20) having at least one pair of opposing layer-edge portions stretchable at least in the direction between the layer-edge portions (11, 12, 13, 14) to form the support surface; at least one pair of parallel opposing frame sections (30, 32, 34, 36) fixedly disposable at a distance therebetween for forming at least a portion of a frame (15) supporting the support surface; at least a first of said frame sections (30, 32, 34, 36) comprising a layer-edge engaging portion (31, 33, 35, 37) configured for fixedly engaging a corresponding layer-edge portion (11, 12, 13, 14); and a tensioning mechanism configured for moving the layer-edge engaging portion (31, 33, 35, 37) together with the layer-edge portion (11, 12, 13, 14) relative to the opposing frame section (30, 32, 34, 36) to at least partially tension the air-permeable layer (20) between the frame sections (30, 32, 34, 36).

A kit (100) for constructing a support surface (10) for a sleeping person. The kit (100) comprises: an air-permeable layer (20) having at least one pair of opposing layer-edge portions stretchable at least in the direction between the layer-edge portions (11, 12, 13, 14) to form the support surface; at least one pair of parallel opposing frame sections (30, 32, 34, 36) fixedly disposable at a distance therebetween for forming at least a portion of a frame (15) supporting the support surface; at least a first of said frame sections (30, 32, 34, 36) comprising a layer-edge engaging portion (31, 33, 35, 37) configured for fixedly engaging a corresponding layer-edge portion (11, 12, 13, 14); and a tensioning mechanism configured for moving the layer-edge engaging portion (31, 33, 35, 37) together with the layer-edge portion (11, 12, 13, 14) relative to the opposing frame section (30, 32, 34, 36) to at least partially tension the air-permeable layer (20) between the frame sections (30, 32, 34, 36).