An emergency actuator bar extends across an opening in the housing of a lint cleaner in a cotton gin. Actuator arms which hold the bar also normally hold a trip plate in the run position. However, a workman striking the emergency bar will remove a sear on one of the actuator arms from the trip plate to permit a spring to snap the trip plate into a stop position. When the trip plate moves to the stop position, it disconnects electrical power to a motor driving the machine. The trip plate movement also applies a brake which stops the machine.