Abstract: A mullion assembly mountable between a floor and a door frame includes an engagement assembly attached to either the floor or the door frame. A mullion defining a mullion cavity is positioned in removable attachment with the engagement assembly, and a cylinder lock assembly is positioned in the mullion cavity. The cylinder lock assembly has a key lock cylinder configured for positioning in either a locked position to engage the engagement assembly and hold the mullion in an upright position in the door frame, or in an unlocked position disengaged from the engagement assembly to permit removal of the mullion from the doorway.

Abstract: The assembly has a multi-tabbed bracket for fixing to a door behind, and parallel with, a latch-actuating rod, and a semi-circular rod guard with latching fingers for slidable engagement with the tabs of the bracket for enclosing and protecting the latch-actuating rod. In addition, the assembly has a shroud-like guard for emplacement over a rod-actuated latch. The shroud-like latch guard has a ramped surface which, when the guard is in place, presents an impingement surface for wheeled devices to facilitate an opening of the door. The shroud-like guard, then, both protects the latch over which it is emplaced and makes the opening of the door more facile.