Abstract: An automatic door closer structure comprises a casing, at least one piston, at least one limiting member, at least one driving member connected with the piston and a shaft. The casing has an outside wall, a chamber, an inside wall and at least one first limiting portion. The piston slidably disposed within the chamber of the casing has an outer wall and a second limiting portion formed on the outer wall. The limiting member has a first end portion and a second end portion both are connected with the first limiting portion of the casing and the second limiting portion of the piston respectively to limit rotation of the piston. The shaft comprises a shaft body pivotally disposed in the casing and an eccentric cam contacts against the driving member.

Abstract: A latch assembly of fire door lock comprises a latch base with a bottom, a latch bolt, a stopper, a resilient member and a linked unit. The latch bolt is retractably pivoted within the latch base and having a blocked surface. The stopper is swayingly pivoted within the latch base and having a blocked protrusion. The resilient member is disposed between the bottom of the latch base and the stopper and contacts against the stopper. The blocked protrusion of the stopper is capable of engaging with the blocked surface of the latch bolt. The linked unit is disposed within the latch base and pivotally connected with the latch bolt.