Delayed egress exit device

An apparatus for delaying egress through a door pivotally mounted along one edge for movement about an axis, the exit device including a housing adapted to be secured to the door surface, a latch bolt disposed at one end of the housing adjacent an edge of the door and movable relative to the housing between a projected position extending outwardly of the housing for latching the door in a closed position and a retracted position where the latch bolt is inside the housing for allowing the door to be opened, an actuator member mounted on the housing for movement relative to the housing from a first position to a second position, an electrically energizable locking mechanism mounted to the housing operative to prevent the latch bolt form moving to the retracted position when energized, a time delay circuit connected between the locking mechanism and a power source for controlling electrical power supplied to the locking mechanism, and a switch actuated in response to movement of the actuator member toward the second position, the switch connected to the time delay circuit for starting a time interval upon actuation of the switch for temporarily delaying deenergization of the locking mechanism after the actuator member is moved toward the second position, the apparatus for delaying egress comprising:

• a retractor element comprising a first linkage adapted to be operatively connected to the actuator member, a second linkage movable relative to the first linkage and adapted to be operatively connected to the latch bolt, a connector slidably connecting the first and second linkages;
• and a spring positioned between and engaging the first and second linkages for biasing the linkages in opposite directions, and
• a plunger disposed in the locking mechanism for relative reciprocal movement transverse to the direction of movement of the retractor element between a projected locking position and a retracted non-locking position, the retractor element having an opening for receiving the plunger when the plunger is in the projected locking position to prevent movement of the retractor element,
• whereby, when the locking mechanism is energized, movement of the actuator member toward the second position of the actuator member moves the first linkage to the second position of the first linkage loading the spring and starting the time interval, the time delay circuit interrupting electrical power to the locking mechanism upon expiration of the time interval allowing the plunger to move to the non-locking retracted position and the second linkage to move to the second position of the second linkage under force of the spring for moving the latch bolt to the retracted position.

In combination,

• a door frame;
• a door hinged along one edge to the door frame;
• an exit device comprising
• a housing having a longitudinal axis, the housing secured to the door surface,
• a latch bolt disposed at one end of the housing adjacent an edge of the door and movable relative to the housing between a projected position extending outwardly of the housing for latching the door in a closed position and a retracted position where the latch bolt is inside the housing for allowing the door to be opened,
• an actuator member mounted on the housing for movement relative to the housing from a first position to a second position,
• a retractor element disposed in the housing for substantially rectilinear movement relative to the housing from a first position to a second position in a path along the longitudinal axis of the housing, the retractor element operatively connected between the actuator member and the latch bolt, the retractor element moving toward the second position of the retractor element and the latch bolt moving toward the retracted position in response to movement of the actuator member toward the second position of the actuator member, the retractor element including
• a first linkage operatively connected to the actuator member,
• a second linkage movable relative to the first linkage and operatively connected to the latch bolt,
• a connector slidably connecting the first and second linkages, and
• a spring positioned between and engaging the first and second linkages for biasing the linkages in opposite directions,
• an electrically energizable locking mechanism mounted to the housing, the locking mechanism including a reciprocating plunger for movement transverse to the longitudinal axis of the housing between a projected locking position and a retracted non-locking position, the second linkage having an opening for receiving the plunger when the plunger is in the projected locking position, the locking mechanism operative to move the bolt to the projected locking position when energized,
• a time delay circuit connected to the locking mechanism for controlling electrical power supplied to the locking mechanism, and
• a switch actuated in response to movement of the actuator member toward the second position, the switch connected to the time delay circuit for starting a time interval upon actuation of the switch for temporarily delaying deenergization of the locking mechanism for a predetermined time interval after the actuator member is moved toward the second position,
• wherein, when the locking mechanism is energized, movement of the actuator member toward the second position of the actuator member moves the first linkage to the second position of the first linkage for loading the spring and starting the time interval, the time delay circuit interrupting electrical power to the locking mechanism upon expiration of the time interval allowing the plunger to move to the non-locking retracted position and the second linkage to move to the second position of the second linkage under force of the spring for moving the latch bolt to the retracted position.