COIL SPRING AND MATTRESS USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a coil spring further reducing the overall coil spring height while ensuring softness and sense of stability of bedding, and a coil spring for mattress further reduced in the thickness by using such a coil spring. SOLUTION: In the irregular-pitch coil spring 1 in which the pitch interval in the vicinity of ends of either one or both of an upper end side 1a and a lower end side 1c is differed from the pitch interval in a central part 1b, the pitch interval in the central part 1b is set larger than the pitch interval in the vicinity of the ends of either one or both of the upper end side 1a and the lower end side 1c, and the central part 1b with the larger pitch interval is subjected to thermal treatment 1d. COPYRIGHT: (C)2010,JPO&INPIT