| 摘要 |
A spring unit comprises a continuous coil spring (5) contained within a sleeve (26) of strong, yet flexible, material. The unit is produced by providing a folding attachment device (2) having oppositely inclined spaced walls (13, 14) which converge from a feed end (3) to an outlet end (4), and simultaneously drawing the flexible material and the coil spring through the folding attachment device from the feed end to the outlet end with the spaced walls acting to fold the material over the coil spring and to apply a substantially uniform compressive force to the coil spring. As the material and the spring are drawn through the outlet end (4), overlapping edges of the flexible material are joined together to complete the spring unit.
|
