Abstract: A padlock includes a housing, a shackle having a pivoting portion pivotally passing through a first top hole of the housing into an accommodation chamber of the housing and a locking end passing through a second top hole of the housing, a retaining device disposed in the accommodation chamber and having at least two driving wheels for controlling an axial movement of the pivoting portion of the shackle, and at least two pointers located above a dial of the housing and respectively driven by the driving wheels to point to one of figures of the dial. When both of the pointers point to correct figures, the pivoting portion of the shackle is axially moveable relative to the housing under the control of the driving wheels, such that locking end of the shackle is moveable away from the second top hole of the housing to unlock the padlock.

Abstract: A security device for a trailer hitch or similar article which engages with an outwardly extending peripherial flange around the trailer hitch or similar article, and which includes an element which extends into a coupling opening in the trailer hitch or similar article, thus precluding removal of the security device from the trailer hitch or similar article. A padlock is utilized to deter unauthorized removal of the security device from the trailer hitch or similar article, and the security device includes means to protect the shackle of the padlock from unauthorized removal.