Abstract: A device capable of extending a foot end of a ladder includes a box tube section with an elongated hole, a long engaging plate with an elongated hole and a plurality of inserting teeth, a short engaging plate with a central fixing hole, two pairs of engaging slots and an engaging nut, and a knob head bolt. The knob head bolt passes through the elongated holes, and the central fixing hole to be tightened to the engaging bolt via a rail of the ladder. The long and short engaging plates are disposed in the box tube section to face to each other. The knob head bolt is loosened or tightened to cause two pairs of the inserting teeth disengaging or inserting into the engaging slots for the box tube section being operated to extend a distance outward the rail stably and safely.

Abstract: A device capable of extending a foot end of a ladder includes a box tube section with an elongated hole, a long engaging plate with an elongated hole and a plurality of inserting teeth, a short engaging plate with a central fixing hole, two pairs of engaging slots and an engaging nut, and a knob head bolt. The knob head bolt passes through the elongated holes, and the central fixing hole to be tightened to the engaging bolt via a rail of the ladder. The long and short engaging plates are disposed in the box tube section to face to each other. The knob head bolt is loosened or tightened to cause two pairs of the inserting teeth disengaging or inserting into the engaging slots for the box tube section being operated to extend a distance outward the rail stably and safely.

Abstract: An articulated joint for a foldable ladder includes an outer casing pair, an inner casing pair pivotally moving with respect to the outer casing pair, a lock device composed of a lock block and a locating pin. The locating pin has a ball end to be slightly squeezed in the locating hole such that the ball end is capable of retained in the locating hole and pivotally joined to the locating hole. The lock block provides triangular prism shaped projections at two opposite long edges of the bottom side of the lock block. Hence, the lock block can move along the guide slot of the outer casing shells steadily and be pivotally joined to fixing pin without loosening apart from each other.