Exit devices are designed to be installed onto the secure side of outswinging doors. They restrict access while providing free egress. The exit device developed in the United States was introduced after the loss of lives in a number of building fires, including the infamous Iroquois Theatre Fire of 1903, where more than 600 people died. The exit device solved the problem of people being crushed against the doors because they first did not have prior knowledge of how to open the door or time to unlock and open the door.
Early exit devices used a metal tube (cross bar) between two cases that were attached onto each side of the door. The active case has a latch bolt that would retract when the tube was pushed in a downward and forward direction, permitting the door to swing open. This way, if someone “crashed” into the exit device, the latch would release and the door would swing open.
A number of manufacturers continue to offer the traditional cross bar. Precision Hardware’s Olympian Series crossbar style exit devices chassis is constructed of investment cast steel. Exit devices have evolved to incorporate rail style device using forward mounted pushpad. Any horizontal force on the pad will release the door.
There are three common types of exit devices: rim, mortise lock and vertical rod. Most common is the rim exit device that was probably named “rim” device as their latching mechanism is very similar to the rim locks sold in the East and Midwest during the early 20th century. Both the rim lock and the rim exit device are surface mounted on the secured side of the door. The rim exit device is a self-contained door lock mechanism. The latch bolt is located within the center case or chassis.
Rim exit devices have a surface-mounted latch or bolt that slides over the surface-mounted strike. The more common latch is a Pullman style that swings back at an angle as the bar or pushpad is depressed. The latch is located at the front edge of the center case. A deadlatching mechanism prevents the latch from being forcibly retracted in order to gain unauthorized access. Rim exit devices can be equipped with exterior trim containing a lock cylinder.