| 摘要 |
The trolley has a wheeled base from which two parallel posts extend upwardly. Each of the posts has lower, middle and upper tubular sections (1, 2, 3) telescopically arranged and retained in their extended position by first and second retaining pins (541, 41) which are biased to their retention positions. A plug (55) movably received within the upper section (3) is connected to a release bar (50). An inclined camming surface (561) is provided within a cavity (56) of the plug and acts to retract the first retaining pin (541) upon movement of the plug by actuation of the release bar. The resultant telescoping of the upper and middle sections causes an end (550) of the plug to contact the second retaining pin (41) which is thereby retracted to telescope the middle and lower sections.
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