Powered rope ascender and portable rope pulling device

1. A device for pulling a resilient elongate element, comprising:

a rotational motor having an output;

a rotating drum connected to the output of said rotational motor, the rotating drum having at least one elongate member contacting surface, the at least one elongate member contacting surface being configured to apply a tension to the resilient elongate element; and

a guide mechanism guiding the resilient elongate element onto, around at least a portion of the circumference of, and off of the rotating drum;

wherein the guide is configured to guide the resilient elongate member around the rotating drum more than once;

whereby when said rotational motor turns the rotating drum, the rotating drum thereby continuously pulls the resilient elongate element through the device.

2. The device of claim 1 , wherein the at least one elongate member contacting surface of the rotating drum is characterized by anisotropic friction.

3. The device of claim 1 , wherein the radial splines provide an anisotropic friction effect to the at least one elongate member contacting surface.

4. The device of claim 1 , wherein two elongate member contacting surfaces are provided on the drum.

5. The device of claim 4 , wherein the two elongate member contacting surfaces are arranged substantially in the shape of a V.

6. The device of claim 4 , wherein at least one of the elongate member contacting surfaces includes a plurality of forward spiraling splines.

7. The device of claim 6 , wherein both of the elongate member contacting surfaces include a plurality of forward spiraling splines.

8. The device of claim 7 , wherein the elongate member contacting surfaces and the radial splines are arranged so that increased load on the resilient elongate member results in increased engagement between the drum and the resilient elongate member.

9. The device of claim 1 , wherein the rotating drum includes a plurality of elongate member contacting surfaces.

10. The device of claim 9 , wherein the elongate member contacting surfaces include a plurality of radial splines.

11. The device of claim 10 , wherein the radial splines are arranged in a spiral-forward direction so that increased load on the resilient elongate member results in increased engagement between the drum and the resilient elongate member.

12. A device for pulling a resilient elongate element, comprising:

a rotational motor having an output;

a rotating drum connected to the output of said rotational motor, the rotating drum having at least one elongate member contacting surface, the at least one elongate member contacting surface being configured to apply a tension to the resilient elongate element;

a guide mechanism guiding the resilient elongate element onto, around at least a portion of the circumference of, and off of the rotating drum wherein the guide mechanism includes at least one elongate element guide member provided on a rotating bar, the rotating bar being movable between an open position in which an intermediate portion of the resilient elongate element can be placed around the elongate element guide member and the rotating drum, and a closed position in which the intermediate portion of the resilient elongate element cannot be disengaged from the drum;

whereby when said rotational motor turns the rotating drum, the rotating drum thereby continuously pulls the resilient elongate element through the device.

13. The device of claim 12 , wherein the rotating bar is biased toward its closed position when a tension is present in the resilient elongate element.

14. The device of claim 12 , wherein the guide mechanism comprises an entry tooth that guides the resilient elongate element onto the drum in a direction that is substantially tangent to an inner diameter of the drum.

15. The device of claim 14 , wherein the entry tooth is configured so that a resilient elongate element guided onto the drum by the tooth will engage at least one spline while the spline is substantially orthogonal to the resilient elongate element.

16. The device of claim 14 , wherein the guide mechanism further includes an exit tooth that guides the resilient elongate element off of the drum in a direction that is substantially tangent to an inner diameter of the drum.

17. The device of claim 16 , wherein the exit tooth leads the resilient elongate element to an exit scoop that arcs to a desired exit trajectory for the resilient elongate member.

18. The device of claim 16 , wherein the guide mechanism further comprises a housing cover that substantially constrains the position of the resilient elongate member from an entrance to the guide mechanism to an exit from the guide mechanism.