A padlock includes a housing, a shackle, a limit knob, a movable member and a first locking mechanism. The shackle is movably mounted on the housing and has a root section extended into the housing and a free section having a first end extended from the root section and a second end extended outside...http://www.google.com/patents/US7370497?utm_source=gb-gplus-sharePatent US7370497 - Multifunctional padlock having shackle limit knob
