Patent ID: 6840070
Filing Date: 2005-01-11
Classification: E05B,Y10T

Abstract:
1. A door lock comprising: a cylinder installed in a lock hole of a door and located at an exterior surface of the door, the cylinder having a core rotatably received therein, a flat finger connected with the core, and a plurality of threaded holes defined in the cylinder around the core; a latch movably provided in a latch hole of the door and the flat finger extending through the latch; an inner cover provided at an interior surface of the door opposite to the cylinder, the inner cover having a plurality of sink holes defined therethrough and corresponding to the threaded holes, a plurality of first screws extending through the sink holes and engaged in the threaded holes, and a first central opening defined therethrough; an outer cover provided outside the inner cover and concealing the inner cover, the outer cover having a second central opening defined therethrough and aligned with the first central opening; a knob provided outside the outer cover, the knob having a resilient member against the outer cover provided at an end facing the outer cover, and a hollow shaft extending through the first opening and the second opening and having a front end connected with the finger and a rear end engaged with the knob; and a guard plug provided inside the inner cover and having a first step and a second step, wherein a diameter of the first step is smaller than a diameter of the second step, and the first step and second step are selectively received in the lock hole and the inner cover, a shoulder formed between the first step and the second step and abutting the rim of the inner cover, a plurality of second holes respectively aligned with the sink holes for the first screws extending through the second holes, and a fourth central hole defined through the guard plug for the shaft extending therethrough, whereby, when the knob is turned, the latch can be extended or retracted to lock/unlock the door.