A process for producing a seat element from a portion of an outfit (1) including a relatively compact plastic covering layer, a network formed by a continuous sheet of metal springs (5), the intermingled turns of which, on one side, come substantially flush against the lower face of the covering (1), and an intermediate connecting layer (3) made of a plastic foam which partially encases the turns of the sheet of springs (5). According to the invention, the peripheral edge (7) of the said outfit portion is gripped in an injection mold (11), this mold having a cavity (9) into which the said edge (7) penetrates, a thermoplastic to which an expanding agent has been added is injected into the said cavity at low pressure, and this thermoplastic is allowed to harden there.

A mattress having an anti-roll off feature is disclosed. The mattress has an innerspring unit having an array of coiled compression springs separating opposed parallel surfaces, wherein the surfaces are covered by a webbing made of a nonwoven polypropylene, and wherein the outer periphery of the webbing has horizontally disposed rigid foam planks wrapped and held in place by the webbing. The foam planks are formed from polyethylene foam. Additionally, vertically disposed rigid polyethylene foam planks with cross members are situated within the innerspring unit between the compressions springs at the periphery of the innerspring unit. The foam planks with cross members provide the support needed to achieve the anti-roll off feature. In an alternative embodiment, rigid polyethylene foam cylinders are placed within the rows of compression springs at the periphery of the innerspring unit to provide support at those locations.

A longitudinally extending spring retainer comprising a band of coil springs and a continuous piece of fabric adapted to hold the band of coil springs. The band of coil springs is made of a single length of wire shaped to form a plurality of coil springs arranged in a row, each of the coil springs having an upper and lower end turn. The upper and lower end turns of the coil springs are held in receptacles created in top and bottom portions of a continuous piece of fabric. The fabric is folded upon itself and secured together with connections in order to hold the end turns in place.

A cushion having a series of pods connected in a matrix configuration. The pods are deformable in response to a person seated on the cushion. The pods cooperate to define primary airflow channels through the cushion from side edge to side edge, and from front edge to back edge, thereof. In one feature, a series of cruciform configured recesses are defined in the pods' top surfaces. These recesses cooperate to define secondary airflow channels through the cushion from side edge to side edge, and from front edge to back edge, thereof. In another feature, a series of first pods are located in those cushion areas which underlie and support a person's ischial and coccyx bones, and a series of second pods located in those cushion areas which do not underlie and support a person's ischial and coccyx bones. The first pods have a relatively thin wall covering a foamed interior and are of a relatively greater height to provide relatively soft pods. The second pods have a relatively thick wall covering a foamed interior and are of a relatively lesser height to form relatively firm pods. These difference in load bearing characteristics between the first and second pods aids in minimizing the pressure on a user's ischial and coccyx bones when seated on the cushion.

A spring assembly comprising a plurality of blocks joined together. Each block contains a string of springs. The string of springs comprises a row of springs, an upper fabric retainer and a lower fabric retainer. The row of springs may be a band of springs made from a single length of wire or a plurality of individual springs. The end turns of the springs are located in receptacles created in the fabric retainers.