| 摘要 |
<p>PURPOSE:To freely adjust the hardness of a bed as required by directly or indirectly engaging both the ends of a resilient contraction body for producing axially contraction force by applying pressurized fluid to a spring for resiliently supporting a mattress. CONSTITUTION:A plurality of springs 16 each has an end fixed to a frame body 14 and the other end resiliently supporting a matterss 18. Both the ends of a resilient contraction body 20 for producing axially contraction force by applying pressurized fluid to at least one spring 16. As a result, the hardness of a bed can be freely adjusted as required.</p> |
