| 摘要 |
PROBLEM TO BE SOLVED: To keep stable cushion performance over a long period of time by preventing setting of a spring. SOLUTION: Many springs 4 are connected to each other like a plate to form a spring unit 1, sheet-like cushion materials 7, 7 are superimposed at least on the upper surface of the upper and lower surfaces of the spring unit 1, and the whole is covered with a bag-like facing body 8. In this case, the coil part 2 of the spring 4 is loaded with a column-like elastic body 9 having the substantially same height as the spring 4 and the substantially same diameter as the coil part 2.
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