Extending ladder and associated manufacturing methods

摘要

Extending ladders and associated manufacturing methods are disclosed. A ladder in accordance with an exemplary embodiment of the present invention comprises a plurality of rung units, each rung unit including a left column, a right column, and a rung extending between the left column and the right column. The ladder may include a first column assembly including a first column and a ring coupled to the first column proximate a distal end thereof, and a second column assembly including a second column and a sleeve coupled to the second column proximate a proximal end thereof. The second column being at least partially disposed within a lumen defined by an internal surface of the first column. The sleeve includes an external guiding surface for contacting the internal surface of the first column and the ring includes an internal guiding surface for contacting an exterior surface of the second column.