Electric lock

1. An electric lock comprising:

an outer lock assembly arranged to an outer side of a door plate, the outer lock assembly having an outer handle, an outer panel, an outer transmitting unit, and an outer retaining plate; the outer transmitting unit being slid and arranged to the outer panel from an inner side of the outer panel; the outer handle being connected to the outer transmitting unit from an outer side of the outer panel; the outer retaining plate being fixed to the outer transmitting unit from an inner side of the outer transmitting unit;

a nexus connected to the outer lock assembly, the nexus having a base, a latch spring unit, a latch bolt retaining unit, an actuator, a first transmitting unit, a sleeve, a cover, a second transmitting unit, and a base retaining unit; the latch bolt retaining unit mounted in the base, the latch spring unit provided between the latch bolt retaining unit and the base; the actuator being arranged in the first transmitting unit and the base; the sleeve and the cover being slid upon the first transmitting unit and the base respectively; the first transmitting unit being slid in the base from a side of the base; the second transmitting unit being slid to the base from an opposite side of the base, and the base retaining unit being arranged upon the second transmitting unit and the base;

an inner lock assembly arranged to the nexus from an inner side of the door, the inner locking assembly having an inner handle, an inner panel, an inner transmitting unit and an inner retaining plate; the inner transmitting unit being slid and arranged to the inner panel from an inner side of the inner panel; the inner handle being connected to the inner transmitting unit from an outer side of the inner panel; the inner retaining plate being fixed to the inner transmitting unit from an inner side of the inner transmitting unit; and

a latch bolt linked to the latch bolt retaining unit;

wherein the second transmitting unit includes an outer shell and an inner shell coaxially mounted in the outer shell, the outer shell defining a first cut, the inner shell defining a second cut, which is located from the actuator farther than the first cut, the outer shell capable of engaging with the latch bolt retaining unit, the inner shell adapted to be engaged with the outer handle; the actuator includes a motor, a rotor driven by the motor, a coil spring, a case, an engagement rod, and a protruded block, the case being provided with a guiding tube, the coil spring being provided through the guiding tube and connected between the rotor and the engagement rod, the protruded block being attached to one end of the engagement rod, the engagement rod being engaged in the first cut of the outer shell of the second transmitting unit, the rotor defining a spiral groove around a circumference thereof, the coil spring having a first section, a second section, and a third section, the first section having a dimension greater than the rotor and fitted around a rear portion of the rotor, the second section located between the first section and the third section and fitted in the spiral groove of the rotor, the third section having a dimension less than the guiding tube and greater than the engagement rod and fitted around the engagement rod, one end of the coil spring being attached to the case whereas the other end of the coil spring being attached to the engagement rod;

whereby when the electric lock is inputted with a correct password, the motor can drive the rotor to turn in one direction, so that the coil spring can be driven to extend along the guiding tube to move the engagement rod and the protruded block forward to allow the engagement rod to be further engaged in the second cut of the inner shell of the second transmitting unit, so that the outer shell and the inner shell can be coupled together by the engagement rod to allow rotation of the outer handle to be transmitted to the outer shell, which in turn urges the latch bolt retaining unit to retract the latch bolt to open the associated door; when the electric lock is electrically reset, the motor can drive the rotor to turn in a reverse direction, so that the coil spring can be driven to contract along the guiding tube to move the engagement rod and the protruded block backward, so that the outer shell and inner shell can be uncoupled, so that rotation of the outer handle cannot be transmitted to the outer shell of the second transmitting unit, and thus the associated door cannot be opened.

2. The electric lock as claimed in claim 1 , wherein the motor is fixed to the case by means of a fastening component.

3. The electric lock as claimed in claim 1 , wherein the coil spring is attached to the engagement rod by means of a fastening component.