What safety feature prevents an elevator from moving if the doors are not secure?

The door interlock system is a crucial safety feature in elevators designed to prevent movement when the doors are not securely closed. This system operates by ensuring that the elevator cannot be dispatched or move unless the doors are properly shut and locked. It uses mechanisms that engage when the doors close, signaling to the elevator control system that it is safe to operate. If the doors are not closed correctly, the interlock keeps the elevator in a stationary position, thereby minimizing the risk of accidents, such as passengers stepping into the elevator shaft or the elevator moving when the doors are still open.

For clarity, other safety features mentioned serve different functions. The emergency stop button allows passengers or operators to halt the elevator's operation in case of an emergency, but it does not address the security of the doors specifically. The emergency brake is designed to stop the elevator in case of malfunction or excessive speed, while the speed governor maintains the elevator's speed within safe limits. However, none of these functions ensure that the elevator will not move when the doors are not properly secured, which is the primary role of the door interlock system.