A sensor strip mounted on the elevator car door edge that detects obstructions and reverses or stops the closing door to prevent entrapment.
Full Definition
The door safety edge is a pressure-sensitive or optical sensor strip fitted to the leading edge of the elevator car door. When a passenger, object, or body part intercepts the door during closing, the safety edge triggers the door to immediately stop and reopen, preventing entrapment injuries. Mechanical safety edges use a compressible rubber strip with a contact switch; infrared or light curtain safety edges project a grid of invisible beams across the door opening. EN 81-20 requires that the reopening force shall not exceed 150 N and the door must reopen before the gap reduces below a safe threshold. Modern multi-beam light curtains can detect objects as thin as a finger across the full door height.
