Method and apparatus for regulating the closing speed of a rolling fire door

摘要

A mechanism for regulating the closing speed of a rolling fire door during an emergency condition. The speed regulating mechanism includes a viscous speed governor which is operatively connected to the support shaft of the fire door for providing a speed regulating damping torque as the door moves to a closed position. Methods for regulating the closing speed of a fire door during an emergency condition are also disclosed.