Abstract: The present disclosure is related to an improved foldable ladder, and more particularly to a foldable one equipped with a pair of wheels so that the ladder can be converted into a push cart of various types for transportation of goods with ease. The foldable ladder is made up of a number of sections joined together one by one by way of adjustable knuckles which can be put in a number of different positions so that the ladder can be transformed into a plurality of forms of cart when a pair of wheels are removably attached to the bottom of the ladder.

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.