automatic threshold closer

automatic threshold closer

[¦ȯd·ə¦mad·ik ′thresh‚hōld ‚klōz·ər] (engineering) automatic door bottom

automatic door bottom

automatic door bottom automatic door bottom A movable plunger, in the form of a horizontal bar at the bottom of a door, which drops automatically when the door is closed; when closed, a horizontal protruding operating rod strikes the door jamb, thereby actuating the plunger, sealing the threshold and reducing noise transmission.