| 摘要 |
<p>The retractable unit (1) has a below ground level sealed casing (2) closed by a cover (5). A carriage (3) slides in the casing by means of a slide system (12,16). The carriage is houses an termination unit (4) and a lever system cooperating with the slide system to displace the carriage (3) and unit (4) between a position inside the casing to a position above ground level. The lever system uses a balanced counterweight (10). The cover (5) forms a support which harmonizes with the ground surface so the unit is not noticeable in the retracted position.</p> |
