US Patent 11708722 Apparatus and methods for door curtain breakaway detection

An example apparatus includes a sensor to detect a lateral edge of a door curtain within a guide of a door, and a controller to identify when the door curtain transitions from an operational state to a breakaway state based on a signal from the sensor, the operational state corresponding to when the lateral edge of the door curtain is enclosed by the guide as the door curtain moves between open and closed positions, and the breakaway state corresponding to when a portion of the lateral edge of the door curtain below an upper end of the guide breaks away from the guide.