Door interlocks on household elevator serve a critical safety function by ensuring that the elevator doors operate in coordination with the elevator car's position. These interlocks are designed to prevent the doors from opening or closing unless it's safe to do so. Here's how they work and why they are important:

Preventing Opening in Unsafe Conditions: The interlock system prevents the elevator doors from opening when the elevator car is not at the same level as the floor landing. This ensures that passengers cannot accidentally step into an empty shaft or an area where the elevator car is not present, which could lead to serious injury.

Coordinating Door Movement: When the elevator car arrives at a specific floor, the door interlock system ensures that the doors are aligned with the floor landing. This alignment allows passengers to safely enter and exit the elevator without having to step over a gap between the car and the landing.

Safety During Movement: While the elevator car is in motion between floors, the door interlocks ensure that the doors remain securely closed. This prevents any unintended opening of the doors while the elevator is in motion, reducing the risk of accidents.

Emergency Situations: In the event of a malfunction or emergency, the door interlocks play a role in preventing the doors from opening at an inappropriate time. For instance, if the elevator car is not level with a floor due to a mechanical issue, the interlock system will prevent the doors from opening until the car is safely positioned.

Preventing Door Entrapment: The interlocks work in conjunction with safety sensors to prevent the doors from closing on an object or person in the doorway. If an obstruction is detected, the interlocks will prevent the doors from closing and may initiate a door reopening sequence.

Door interlocks are a crucial safety feature in household elevators because they ensure that the elevator doors are only operable when it is safe to enter or exit the elevator car. By preventing access to unsafe areas and coordinating door movement with the elevator's position, interlocks help to prevent accidents and enhance the overall safety of elevator usage.