| 摘要 |
Bent wire spring units for use in combination with a rectangular base frame embodying longitudinally-spaced, parallel, transverse support bars and a grid frame embodying a rectangular border wire and longitudinally and transversely-extending grid wires connected at their ends to the border wire and to each other at their crossings, each bent wire spring unit comprising upper and lower attaching elements connected to each other by integral lengths of wire resistant to bending and torsion. The bent wire spring units are transversely symmetrical from side to side and asymmetrical from front to back and are positioned transversely and longitudinally of the base frame and grid frame with their front sides on adjacent support bars facing and with their lower and upper ends attached, respectively, to the support bars of the base frame and the transverse wires of the grid frame. If there are an odd number of support bars, the spring units are alternately positioned in oppositely-facing directions. At the corners, the spring units are positioned with their front sides facing inwardly.
|
