Patent ID: 8061483

Claim:
A fan descender comprising: a tapered spool having a varying diameter and mounted for rotation about a first axis, a line wound helically upon the spool and having a free end extending therefrom and a secured end attached to the spool, a windage braking fan rotatably driven by the spool so that when the spool rotates as the line is drawn off from the spool by said free end, the windage braking fan provides braking which limits rotational speed of the spool which limits a rate at which the line is drawn off, and a retrieval mechanism operative to rewind the line upon the spool when the free end of the line is released, wherein the spool tapers along said first axis from a relatively larger diameter part of said spool to a relatively smaller diameter part of said spool, the secured end of the line is attached to the relatively smaller diameter part and the line is wound on the tapered spool towards the larger diameter part whereby, in use, as the line is drawn off, it unwinds along the spool towards the smaller diameter portion and thus accelerates the spool which accelerates the fan which increases the braking.