What is the name of an electromechanical device used to prevent car movement when hoistway doors are open?

The device responsible for preventing car movement when the hoistway doors are open is called an interlock. An interlock ensures that the elevator cannot move unless the doors are securely closed and locked, providing a crucial safety feature that protects passengers from the risk of an elevator moving while the doors are open. This mechanism works by connecting the operation of the elevator car with the status of the doors; if the doors are not in the closed position, the interlock will prevent the elevator from being called or from departing from a floor.

In contrast, an overload switch is designed to detect excessive load in the elevator and stop operation if the weight exceeds a certain limit. A limit switch serves a different function, typically used to stop the elevator at predetermined positions or to ensure that it does not go beyond its intended travel limits. A safety governor is a device that monitors the speed of the elevator car, helping to detect overspeed conditions and initiate safety measures if necessary. Each of these devices plays an important role in elevator safety, but it is the interlock specifically that addresses the function of preventing door-related movement.