into the first aperture 78 of the holder 74 the third spring 79 has an end 791 mounted to the anchoring hole 73 of the tongue holder seat 7 and an opposite end 792 attached to the third shaft 83 also referring to fig3 and 6 the first boss 43 of the first winglet 41 and the second boss 44 of the second winglet 42 are received in the groove 62 of the movable seat 6 the first mounting hole 45 of the first winglet 41 is rotatably coupled to the fifth mounting hole 391 of the bottom plate 3 and the second mounting hole 46 of the first winglet 41 is rotatably and movably coupled to the first slot 331 of the first slide block 33 the third mounting hole 47 of the second winglet 47 is rotatably coupled to the sixth mounting hole 392 of the bottom plate 3 and the fourth mounting hole 48 of the second winglet 42 is movably and rotatably coupled to the second slot 341 of the second slide block 34 thus when the movable seat 6 is moved rearward the first and second slide blocks 33 34 are driven in a direction into the locking control assembly 5 and as shown in fig9 and 10 the first and second latch bars 35 36 are also driven to release the fire door 9 consequently both latch bars 35 36 and the tongue 52 are actuated or.