| 摘要 |
<p>A spring platform (6) for a child, to provide a support to oscillate gently, at a slow rate of about 60 to 100 per minute, is suspended by slow rate springs (5) from a frame (1, 2, 4) which has upright guide members (14) engaged by slide members (11) of the platform and constraining the platform to vertical reciprocation with a horizontal attitude.</p> |
