Fire door lock

1. A fire door lock comprising:

a base assembly comprising a bottom plate and first and second latch bars, the bottom plate having at least one fixing hole, a first mounting hole and a second mounting hole, the bottom plate also having first and second slide racks and first and second slide blocks which are respectively and slidably received in the first and second slide racks, the first slide block having a first notch and a first slot, the second slide block having a second notch and a second slot, the first latch bar being securely coupled to the first notch of the first slide block while the second latch bar being securely coupled to the second notch of the second slide block;

a locking control assembly comprising a housing, a movable seat, a tongue holder seat, a holder and a tongue, a tongue control plate, a control plate, and a shaft set that is composed of a number of pins and shafts, the housing having at least one housing mounting hole, a control hole, a first elongated hole and first, second, third and fourth through holes, the movable seat having a positioning bar, a first stop, a groove, and at least one through hole, the movable seat having opposite side walls in each of which a second elongated hole and a third elongated hole are formed, the through hole of the movable seat being coupled to a connection end of an operating handle assembly, the tongue holder seat having a second stop, two through holes, an anchoring hole, and a first spring, the holder having two holding sections, a first aperture and two through holes, the tongue having an engaging portion, a first bore, and two second bores, the tongue control plate having two through holes and a second aperture, the control plate having a second spring, a third stop, a fourth elongated hole, and a fifth elongated hole, the pivot set having a control pin and a first shaft, a second shaft, a third shaft, a fourth shaft, and a fifth shaft, the first shaft extending through the first through hole of the housing and the first bore of the tongue and the through hole of the tongue control plate, the third shaft extending through the second through hole of the housing and the through hole of the holder, and the fifth shaft extending through the third through hole of the housing and the first elongated hole of the movable seat and the through hole of the tongue holder seat;

a winglet assembly comprising first and second winglets, the first winglet having first and second mounting holes and a first boss, the first mounting hole of the first winglet being rotatably coupled to the first mounting hole of the bottom plate by a pivot, the second mounting hole of the first winglet being rotatably coupled to the first slot of the first slide block by a pivot, the second winglet having third and fourth mounting holes and a second boss, the third mounting hole of the second winglet being rotatably coupled to the second mounting hole of the bottom plate by a pivot and the fourth mounting hole of the second winglet being rotatably coupled to the second slot of the second slide block; the first and second bosses being received in and coupled to the movable seat.

2. The fire door lock as claimed in claim 1 , wherein the base assembly comprises a lock portion, which comprises a switching block.

3. The fire door lock as claimed in claim 1 , wherein the engaging portion is recessed in the tongue.

4. The fire door lock as claimed in claim 1 , wherein the third stop of the control plate has an inclined edge.