But if a motor is needed to counter the retracting spring, doesn't that mean any impact must overcome the motor before the spring will engage?
Presumably the motor runs once to extend it and then it locks into position (with some kind of mechanical catch that's calibrated to come loose if you hit anything), rather than being constantly running.
Presumably the motor runs once to extend it and then it locks into position (with some kind of mechanical catch that's calibrated to come loose if you hit anything), rather than being constantly running.