Door security device allowing partial door opening

In combination, a door security device and a doorway, the doorway including a door with a lower edge, a hinged edge, and an opposite edge parallel to said hinged edge, said doorway further including a threshold defining a vertical separation between the door lower edge and a floor adjacent said doorway, the door security device comprising:

• a pivot collar mountable vertically within said floor adjacent said doorway and defining a vertical axis of rotation;
• and
• a one-piece security bar including first and second length portions and a coupling portion rigidly maintaining said first and second length portions in parallel and non-collinear relation, the first length portion being insertable within said collar and rotatable about said axis of rotation whereby said second length portion assumes a vertical upstanding orientation orbiting about said axis of rotation and directly engaging a face of said door which substantially faces a direction in which said door swings, in such manner that said door may partially open to a given point with said coupling portion positioned within said vertical separation but at said given point said second length portion blocks further opening of said door, said first and second length portions extending in opposite directions from said coupling portion, said axis of rotation being spaced from said opposite edge by at least a distance at least as great as a length of said coupling portion.