Abstract: A modified structure of a fixing knuckle commonly used in an aluminum folding ladder is disclosed. The present disclosure is characterized in its locking assembly including a rectangular locking block and a frame consisting of two parallel L-shaped cam plates connecting together at their top ends, and the locking block having a connecting head integrally joined thereto pivotably mounted on the frame. The fixing knuckle is comprised of an outer casing and an inner disk member, rotatably joined together with the inner disk member housed in the outer casing through a splitting opening thereon, and the frame is astride mounted on the inner disk member with a pulling spring attached to the end thereof for allowing the cam plates to reciprocatingly move about a pivot joining the frame and the locking block.

Abstract: The present disclosure is related to a multi-purpose aluminum folding ladder having a detachable stand-on board and a pair of supporting handrails mounted thereto when used as a stepladder, and more particular to a foldable ladder which can be converted into ladders of different forms such as, a stepladder, a stretched climbing ladder, and also into work stations, and tables etc., and can further be assembled into a variety of exercising apparatuses with the assistance of a number of accessory parts on which people can do various kinds of exercise such as rowing, weight-pulling, chest-expanding, arm and leg strengthening; and can also be transformed into a chair for relaxation purpose. The multipurpose folding ladder is characterized by its practicality and readiness in use.