| 摘要 |
A helical spring (1) for the spring core of a mattress or other furniture is described and is made of spring wire. The spring has two knotted end coils (2a, 2b) lying in approximately parallel planes. Each end coil contains a single convexity or bulged zone (5a, 5b) in which the spring wire (6a, 6b) runs substantially in a straight line. The region of each end coil lying opposite this convexity follows a circular path (7a, 7b). The two convexities (5a, 5b) of each end coil preferably lie diametrically opposite each other. A spring core manufactured from such helical springs has the same utilization qualities as so-called "Offset spring cores", in which in each end coil two convexities are present. However, it is much easier and cheaper to manufacture on automatic assembly machines than the "Offset spring cores". <IMAGE> |
