| 摘要 |
A lock for a door includes a bolt or pin 13 that can be extended into the latch plate to lock the door or retracted to unlock the door. A motor driven actuator 65, 68 is movable to rotate the lock pin 13 from the retracted position to the extended position and a spring (not shown in the drawing) is provided to bias the pin back to the retracted position. A latch 36 of the pin driving mechanism is engaged to prevent the pin from moving from the extended position to the retracted position, but when unlatched allows the pin to move from the extended position to the retracted position under the action of the spring. When the pin is in the extended position the mechanism of the lock disengages the actuator 65 from the pin. The lock pin 13 may be rotated about pin shaft 22 between the retracted position and the extended position by the central pivot shaft 47 of an over-centre linkage 44, with the shaft 47 being latched by the latch plate 36 to prevent the pin being retracted. The motor is controlled by a controller which for a door locking operation is programmed to drive the motor in a forward direction to move the pin from the retracted position to the extended position and move the latch to the latched position; drive the motor in a reverse direction from the second position to an intermediate position between the first and second positions to disengage the actuator from the pin but allow the latch to maintain the pin in the extended position; and for a door unlocking operation, to drive the motor in the reverse direction from the intermediate position to the first position to move the latch to the unlatched position to allow the pin to move to the retracted position under action of the spring. |
