Descent assist device for powered ascenders
A descent assist device for powered ascenders is discussed herein. In one embodiment, the descent assist device can include a base plate having a first guide surface, a capstan peg, a second guide surface, and a retention loop extending from the first guide surface to the second guide surface configured to retain a rope on the descent assist device. Where the angle of wrapping of the rope around the first guide surface and the capstan peg is constant during use and the angle of wrapping of the rope around the second guide surface is adjustable by the user of the device to increase or decrease the frictional drag of the rope.
1. A powered rope ascender operational in ascending and descending modes, comprising:
a reversible drive source;
at least one rotating rope pulling jaw, the jaw connected to the reversible drive source so as to be rotated in a first, ascending direction and a second, opposed descending direction, the at least one rotating rope pulling jaw having a plurality of forward sweeping rope gripping features when operated in the ascending direction;
a friction increasing descent assist device configured to provide a rope path having at least three guide surfaces around which the rope wraps angularly including a first, superior guide surface, a second laterally spaced capstan guide surface, and a third inferior guide surface;
wherein the friction increasing descent assist device enhances operation of the powered rope ascender when operating in the descending mode.
2. The powered rope ascender of claim 1 , wherein the friction increasing descent assist device is positioned on the powered rope ascender in an inferior direction from the at least one rope pulling jaw when the powered rope ascender is in use.
3. The powered rope ascender of claim 1 , wherein the first and third guide surfaces form superior and inferior ends of a retention loop.
4. The powered rope ascender of claim 3 , wherein the retention loop comprises a gate allowing a middle portion of rope to be engaged with the friction increasing descent assist device through the gate.
5. The powered rope ascender of claim 3 , wherein the retention loop ensures that a rope stays engaged within the friction increasing descent assist device regardless of whether a free end of the rope is arranged in an optimal rope entry path while descending.
6. The powered rope ascender of claim 3 , wherein the second guide surface is provided on a capstan peg that is laterally spaced from the retention loop.
7. The powered rope ascender of claim 6 , wherein the friction increasing descent assist device is configured to provide a rope path that includes a rope wrap angle around the second guide surface that is greater than 180 degrees.
8. The powered rope ascender of claim 7 , wherein the friction increasing descent assist device is configured to provide a rope path that includes a rope wrap angle around the second guide surface that is greater than 90 degrees.
9. The powered rope ascender of claim 8 , wherein the friction increasing descent assist device is configured to provide a sum of rope wrap angles around the guide surfaces that is greater than 360 degrees.
10. The powered rope ascender of claim 1 , wherein the friction increasing descent assist device enhances the operation of the powered rope ascender by reducing an amount of damage caused to a rope by the forward sweeping rope gripping features when operated in a descending direction.
11. The powered rope ascender of claim 10 , further comprising a rope engaged to the powered rope ascender and the friction increasing descent assist device, the rope having a diameter of 7 mm or less.
12. The powered rope ascender of claim 1 , wherein the friction increasing descent assist device enhances the operation of the powered rope ascender by slowing the rate of descent when a rope is located between the forward sweeping rope gripping features when operated in a descending direction.
13. The powered rope ascender of claim 12 , further comprising a rope engaged to the powered rope ascender and the friction increasing descent assist device, the rope having a diameter of 7 mm or less.