| 摘要 |
<p>The system has a shaft (4) rotating in an axis (AA) and bearing a pinion (5), a ratchet wheel (1) and a rotary cam (2). An elongated swiveling lever (3) includes a free end (3a) for actuating a safety device and another end (3b) for holding a swiveling arm (6). The lever swivels around the axis, and the arm swivels around another axis that is parallel with the former axis. The arm comprises a pawl (7) and a rotary roller (8). A cam follower (9) includes a guide rail (19), where the roller cooperates with the cam or with the guide rail of the cam follower. Independent claims are also included for the following: (1) a boom (2) a welding method.</p> |
