| 摘要 |
<p>The latch (13) is housed in a vertical end tube (14) which is welded to a cross tube (3). The vertical end tube fits into a bush (5) which is welded to a vertical scaffolding pole (2). The latch consists of a bar (13), cranked at the top (15) and bottom (11a). The top branch (15) passes through a hole (16) in the vertical end (14) of the cross tube and is retained on the expanded head (17). It pivots about the bottom (10) of the hole. Under its own weight it automatically swings into a locked position when the two tubes are assembled.</p> |
