Combination lock

A combination lock, comprising:

• a rotatable knob that is rotatable relative to a panel, the rotatable knob having an accommodation chamber, the panel being pivotally connected to the accommodation chamber;
• a bolt, mounted to a side wall of the accommodation chamber;
• and
• a dial assembly;
• including:
• a base having a movement chamber, the base being mounted to the panel and located in the accommodation chamber;
• a dial shaft, passing through the movement chamber and being movable axially relative to the movement chamber, in cooperation with the bolt to realize unlocking and locking;
• a plurality of sets of bushings and dials, the bushings being sleeved on the dial shaft and being selectively stationary or rotatable relative to the dial shaft along with axial movement of the dial shaft, the dials being disposed corresponding to the bushings and selectively rotating together with the bushings or rotating relative to the bushings;
• a position resetting mechanism, configured to reset the dials;
• a positioning member, mounted to the base and disposed opposite to the dials for restricting resetting of the dials;
• a protection frame, mounted to the base, the protection frame being movable axially relative to the base for changing the dials to rotate together with the bushings or to rotate relative to the bushings;
• wherein relative rotation of the rotatable knob and the panel drives the dial shaft and the protection frame to move axially and enables the positioning member to restrict or unlock rotation of the dials so that the rotatable knob can be rotated relative to the panel to a first position, a second position, a third position, or a fourth position;
• in the first position, the dial shaft cannot move and is mutually restricted with the bolt, when a password is correct, the bushings can rotate relative to the dial shaft, the dials can rotate together with the bushings, and the positioning member restricts resetting of the dials;
• in the second position, the bushings are stationary relative to the dial shaft, the dials can rotate relative to the bushings, and the positioning member doesn't restrict resetting of the dials, so as to achieve automatic password resetting;
• in the third position, the bushings can rotate relative to the dial shaft, the dials can rotate together with the bushings, and the positioning member doesn't restrict resetting of the dials, so as to achieve automatic dial position resetting;
• in the fourth position, the bushings being stationary relative to the dial shaft, the dials can rotate relative to the bushings, and the positioning member restricts resetting of the dials, so as to achieve manual password setting.