| 摘要 |
A descender (10) comprises a rear or base plate (20), a front plate (22) which is fixedly mounted to the base plate, generally parallel to and spaced from the base plate and an arm (30) which is pivotally mounted to the base plate and/or the front plate for movement between the two plates. The arm (30) defines a generally curved channel (38) through which a rope (14) may pass. The channel is defined between a sheave (34) and a wall (37) of the arm and defines an entrance (38a) and an exit (38b) for the rope. The sheave (34) is pivotable about an axis, the sheave being lightly biased towards a first or rest position. Pivoting of the sheave about the axis in a first direction, away from the rest position, causes an increase in the friction applied to the rope passing through the channel, typically by causing the exit of the channel to narrow. A handle (46) is provided, operation of which may cause the sheave (34) to rotate towards its rest or neutral position thereby allowing faster passage of the rope through the descender. The descender (10) includes means for connecting the descender to a harness or the like. |
