Rotary locked structure of door lock

A lock comprising:

• a first knob pivotably connected to a first rosette and driving a driving part, the driving part being a tubular part and having at least one restriction portion formed to an inner periphery thereof;
• an inner tube received in the driving part and having a positioning portion located corresponding to the at least one restriction portion so as to restrict rotational movement of the inner tube in the driving part, the inner tube being movable within the driving part axially, at least one restriction unit being formed axially in the inner periphery of the inner tube;
• a shaft having a connection portion formed to one of two ends thereof, the connection portion including a positioning unit located corresponding to the at least one restriction unit so as to restrict rotational movement of the shaft in the inner tube, the inner tube being axially movable relative to the positioning unit of the shaft, a first spring being located between the shaft and the inner tube;
• a second knob located opposite to the first knob, the second knob being pivotably connected to a second rosette and driving a sleeve, the second knob including a spindle and a lock cylinder which is connected to the spindle, the spindle including a lug extending radially therefrom, the second rosette including a mounting plate received therein that has at least one notch, the sleeve including a transmission unit which includes a driving column, a stop being formed to an inner side of the sleeve, the driving column of the sleeve being mounted to an outside of the spindle, one of the driving column and the spindle contacting an inner end of the inner tube, the spindle being connected to the shaft;
• and
• a lock ring mounted to the spindle and connected to the sleeve, the lock ring including a first recess and a second recess located corresponding to the lug of the spindle, and at least one tongue extending radially therefrom and protruding beyond the sleeve and located corresponding to the at least one notch, a second spring being located between the stop and the lock ring,
• wherein the driving part includes a driving ring which is connected to the driving column of the sleeve,
• wherein, when in a locked status, the spindle is rotated to locate the lug in the second recess, such that the lock ring compresses the second spring, and the at least one tongue is engaged with the at least one notch, and
• wherein, when in an unlock status, the spindle is rotated to locate the lug in the first recess, the second spring expands and axially biases the lock ring, such that the lug is engaged with the first recess and the at least one tongue is disengaged from the at least one notch.