Door lock equipped with indicator

A cylindrical-shaped door lock equipped with an indicator, the door lock comprising:

• a body assembly;
• a latch assembly coupled to a front side of the body assembly;
• an inner plate assembly coupled to an inner portion of the body assembly with an inner mounting plate interposed therebetween;
• a lock indicator assembly coupled to an outer portion of the body assembly with an outer mounting plate interposed therebetween;
• an inner lever coupled to the body assembly from an outside of the inner plate assembly;
• and
• an outer lever coupled to the body assembly from an outside of the lock indicator assembly,
• wherein, when a lock button assembly coupled to an inner spindle of the body assembly is moved forwards, a first small spindle support of a small spindle assembly coupled to an outer spindle is rotatably moved forwards along a second small spindle support so as to rotate a small spindle cam,
• wherein, when the small spindle cam is rotated, an indicator cam of the lock indicator assembly is rotated clockwise such that “IN USE” displayed on an upper display part of the indicator cam and “IN USE” displayed on a lower display part of an outer spring cage are exposed to an outside through display windows respectively provided at an upper portion and a lower portion of an outer plate,
• wherein, when the lock button assembly is moved rearwards by the inner lever or a cylinder of the body assembly, the first small spindle support and the second small spindle support of the small spindle assembly return to initial positions thereof by a spring, and
• wherein, when the small spindle cam is freed by return of the first small spindle support, the indicator cam of the lock indicator assembly is rotated counterclockwise by a torsion spring such that “VACANT” displayed on an upper display part of the outer spring cage and “VACANT” displayed on a lower display part of the indicator cam are exposed to the outside through the display windows respectively provided at the upper portion and the lower portion of the outer plate.