Patent ID: 8348016

Claim:
A descender for controlling the descent of a person along a rope comprising an entry pin; a fixed guide member comprising an internal lateral face and an oblong end, said face comprising a first jamming surface; an assymetric cam pivotable about a pivot axis from an open position to a closed position, the cam having opposing first and second convex arcuate surfaces, said first arcuate surface terminating in a peak of an elongate horn extending from said pivot axis, said second arcuate surface having a radius less than the radius of the first arcuate surface and defining a second jamming surface, wherein the pivot axis is offset closer to said second jamming surface than to said peak; and an exit pin; the entry pin and said oblong end defining a rope entry; said exit pin and the peak of the horn defining a rope exit; and said internal lateral face, and the peripheral face of said cam, said rope entry and said rope exit defining a rope travel path between said rope entry and said rope exit, wherein said first and second arcuate surfaces define a C-shaped portion of said rope travel path circumscribing the pivot axis of said cam, with said rope in contact with substantially the entirety of said arcuate surfaces with said cam in the closed position; and further comprising: a cam stop positioned to stop the pivoting of said cam in its open position; and a torque arm coupled to said pivot axis of said cam for pivoting said cam from said closed position to said open position.