| 摘要 |
A fall-arrest apparatus comprises a drum (1) which holds a cable (3) for attachment to a load and has a brake (7-11, 13-15) which automatically stops the drum if it exceeds a certain unwinding speed. The apparatus incorporates a winch mechanism (16-20) by which the drum (1) can be manually turned either to raise or to lower a suspended load. The winch mechanism is associated with a braking means (21) comprising permanently contacting friction braking elements (22, 24, 25) and a one-way torque coupling (22, 28, 31-33). That coupling functions between those friction braking elements and the winch handle shaft (17). When the winch mechanism is set for use said one-way torque coupling prevents unwinding motion of the drum (1) otherwise than against the resistance of said permanently contacting friction braking elements. |
