Patent ID: 7568741

Claim:
A door lock system comprising: a latch; a ratchet that engages with the latch; a ratchet lever that is interlocked with the ratchet and is configured to disengage the ratchet from the latch; an opening lever that moves from a non-operable position to an operable position in response to a door-opening operation; a first link lever that moves to a first position, in response to an unlocking operation, to allow the ratchet lever to disengage the ratchet from the latch, and moves to a second position, in response to a locking operation, to prevent the ratchet lever from disengaging the ratchet from the latch; a second link lever including a cylindrical bushing and a ratchet driver, wherein the cylindrical bushing is connected to an end of the opening lever; and a spring that is interposed between the first link lever and the second link lever, wherein the spring maintains the second link lever in a first rotational position with respect to the first link lever by a resilient force of the spring when the first link lever moves from the second position to the first position, wherein the ratchet driver is formed integrally with the cylindrical bushing, extends radially outward from the cylindrical bushing, and is rotatable between the first rotational position and a second rotational position with respect to the first link lever, wherein the ratchet driver is configured to allow, when in the first rotational position, the ratchet lever to disengage the ratchet from the latch in response to the door-opening operation performed on the opening lever when the first link lever is in the first position.