Ladder climbing apparatus

1. A ladder climbing apparatus for use with a ladder having a plurality of rungs, the ladder climbing apparatus comprising:

a frame, the frame configured to provide a central channel, the central channel providing clearance for a fall arrest system;

a prime mover mounted to the frame;

a power supply electrically connected to the prime mover;

a pulley system mounted to the frame, the pulley system mechanically connected to the prime mover;

at least two drive belts, each of the drive belts passing around the pulley system, the at least two drive belts connected to the prime mover by the pulley system;

a plurality of gripper elements attached to each of the drive belts;

a ratcheting system connected to at least one of the prime mover, the pulley system, and the at least two drive belts, wherein the ratcheting system is configured to arrest the descent of the ladder climbing apparatus upon detection of a power loss in the power supply, and wherein the ratcheting system is configured to allow controlled descent of the ladder climbing apparatus in the event of power loss in the power supply; and

wherein, the ladder climbing apparatus is configured so that a portion of the plurality of gripper elements are in contact with at least four rungs of the ladder during an ascent or descent, so that weight is distributed over the at least four rungs of the ladder.

2. The ladder climbing apparatus of claim 1 , wherein the power supply is one or more batteries.

3. The ladder climbing apparatus of claim 2 , wherein the one or more batteries are mechanically attached to the ladder climbing apparatus.

4. The ladder climbing apparatus of claim 3 , the ladder climbing apparatus further comprising:

a regenerative braking system connected to at least one of the prime mover, the pulley system, and the at least two drive belts; and

wherein the regenerative braking system is configured to at least partially recharge the one or more batteries during a descent of the ladder climbing apparatus.

5. The ladder climbing apparatus of claim 1 , the ladder climbing apparatus further comprising:

a regenerative braking system connected to at least one of the prime mover, the pulley system, and the at least two drive belts; and

wherein the regenerative braking system is configured to at least partially recharge the power supply during a descent of the ladder climbing apparatus.

6. The ladder climbing apparatus of claim 1 , wherein each of the plurality of gripper elements is comprised of a substantially solid finger.

7. The ladder climbing apparatus of claim 1 , wherein the at least two drive belts are configured to be removable and replaceable, so that drive belts having different gripper element spacing may be installed to accommodate ladders having different rung spacing.

8. The ladder climbing apparatus of claim 1 , further comprising:

means for attaching to a fall arrest system.

9. The ladder climbing apparatus of claim 1 , wherein the frame is configured to have a width equal to or less than the ladder.

10. The ladder climbing apparatus of claim 1 , wherein the frame further comprises:

a step for supporting a user, the step housing at least a portion of at least one of the prime mover, and the pulley system.

11. The ladder climbing apparatus of claim 1 , wherein the frame further comprises:

an upper section and a lower section, and wherein hinges connect the upper section to the lower section; and

wherein the hinges are used for folding the ladder climbing apparatus to reduce a vertical height of the ladder climbing apparatus.

12. A ladder climbing apparatus for use with a ladder having a plurality of rungs, the ladder climbing apparatus comprising:

a frame, the frame configured to provide a central channel, the central channel providing clearance for a fall arrest system;

a prime mover mounted to the frame;

a power supply electrically connected to the prime mover, the power supply comprised of one or more batteries, the one or more batteries mechanically attached to the ladder climbing apparatus;

a pulley system mounted to the frame, the pulley system mechanically connected to the prime mover;

at least two drive belts, each of the drive belts passing around at least a portion of the pulley system, the at least two drive belts connected to the prime mover by the pulley system;

a plurality of gripper elements attached to each of the drive belts, each of the plurality of gripper elements comprised of a substantially solid finger, and each substantially solid finger is attached to one of the drive belts;

a ratcheting system connected to at least one of the prime mover, the pulley system, and the at least two drive belts, wherein the ratcheting system is configured to arrest the descent of the ladder climbing apparatus in the event of power loss in the power supply by a solenoid actuated pawl of the ratcheting system, and wherein the ratcheting system is configured to allow controlled descent of the ladder climbing apparatus in the event of power loss in the power supply;

a regenerative braking system connected to at least one of the prime mover, the pulley system, and the at least two drive belts; and

wherein the regenerative braking system is configured to at least partially recharge the power supply during a descent of the ladder climbing apparatus, and wherein the ladder climbing apparatus is configured so that a portion of the plurality of gripper elements are in contact with at least four rungs of the ladder during an ascent or descent, so that weight is distributed over the at least four rungs of the ladder.

13. The ladder climbing apparatus of claim 12 , wherein the at least two drive belts are configured to be removable and replaceable, so that drive belts having different gripper element spacing may be installed to accommodate ladders having different rung spacing.

14. The ladder climbing apparatus of claim 1 , wherein the frame further comprises:

an upper section and a lower section, and wherein hinges connect the upper section to the lower section; and

wherein the hinges are configured so the ladder climbing apparatus is foldable to reduce a vertical height of the ladder climbing apparatus.