Closing mechanism for double fire doors has an interlock which blocks the opening of the side door until the main door has reached a preset opening angle

摘要

A closing mechanism for double fire doors ensures that the secondary door (1) is closed before the main door (2) closes. The closing sequence ensures that the doors are correctly sealed in the closed position. Both doors are fitted with separate closing drives (3a, 3b) with a locking mechanism (11) which holds the secondary door in the closed position until the main door has been opened by a preset angle. The drive linkage of the main drive is coupled to a linear drive which operates the blocking mechanism which inhibits the release of the locking mechanism for the secondary door. The door closing drives are able to close the doors in the reverse sequence as a result of the angular offset in the opening sequences of the two doors. No separate closing aid is required.