| 摘要 |
A spring assembly for a mattress includes a plurality of spiral coil springs (16), arranged in substantially parallel rows, a plurality of cross helicals (22) lacing together adjacent springs in the same row, adjacent coil springs with laced-together terminal convolutions (20) being restricted in their movement relative each other to a maximum angle of deflection. The convolutions (20) of adjacent springs have offset portions (24) with overlying alternating projections (30, 32) which permit a hinging action of the adjacent springs relative to each other about the adjacent offset portions of their terminal convolutions, until the maximum deflection angle between the offsets is reached. Further loading of one spring after this angle is reached results in compression of adjacent springs and greater resistance to loading for a given degree of spring compression, i.e. greater firmness. <IMAGE> |
