| 摘要 |
<p>A fall arrest device movable along a vertical lifeline comprises a toothed wheel (28) rotatable in its own housing which housing is pivoted and spring loaded inside an outer housing, so as to cause the toothed wheel (28) to bear upon a lifeline running within a covered channel at the front of the outer housing. The toothed wheel (28) thus pivots with respect to the outer housing and friction between the wheel (28) and the rope causes the wheel to rotate as the device is moved up or down the rope. When the downward velocity of the outer housing reaches a predetermined rate, a centrifugal clutch mechanism stops the rotation of the toothed wheel so that the friction between the rope and the stationary toothed wheel (28) causes the housing of the toothed wheel (28) to pivot within the outer housing, wedging the rope against the outer housing and causing the rope to jam to prevent further movement of the fall arrest device therealong.</p> |
