Abstract: A foldable cart comprises a handle, a pair of wheels pivotally mounted to the bottom respective ends of the handle, and a loading platform at the bottom of the cart in an opposite direction with respect to the wheels. The loading platform has a pair of conical gears at the rear respective ends adapted to engage with a pair of crown gears located at the bottom ends of the wheel frames to adjust the position of the loading platform with respect to the cart.

Abstract: A zipper lock disposed on a shift plate of a zipper includes a longitudinal box-shaped casing; a lock stand having a hollow, substantially P shape; a lock ward having a shape substantially of a numeral 7 with one arm thereof forming a recess shoulder; at least one spring for pushing the lock stand and the lock ward against an inside wall of the casing; a cylindrical lock shaft having a retracted shoulder on upper and lower ends thereof and a key slot; a lock pin plate with an extended protusion at one end thereof having a length equal to that of a hollow part of the lock stand; and a seat plate corresponding to a zipper sliding plate and having a knot hole, a lock shaft hole and two recess holes adjacent the lock shaft hole and corresponding to the protrusion on the lock pin plate; the improvement being that the lock stand provides a resisting force against the lock ward so that when the lock stand is moved longitudinally and an extended arm thereof leaves the recess shoulder of the lock ward, the lock ward w