A mechanical linkage device on the car door that engages the landing door drive mechanism to open and close the landing door simultaneously with the car door.
Full Definition
The car door coupler — also called a door vane, clutch, or truck — is mounted on the car door panel and engages a roller or pin on the landing door when the car is within the landing zone. As the car door motor drives the car door open, the coupler pulls the landing door open with it; on closing, the coupler releases the landing door, which is then held shut by its own lock. Proper coupler adjustment is critical: insufficient engagement causes failed door opening and entrapment; excessive engagement can cause door lock damage. The coupler gap, vane height, and roller contact position are adjusted during installation and verified at periodic maintenance. Wear of the coupler vane is a common maintenance finding requiring replacement.
