Patent ID: 8763757

Claim:
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.