To provide a light conductor coupling capable of carrying out highly reliable transmission of a signal.

Two optical signal couplings for vehicles coupled with one another and a conductive coupling furnished with such a signal coupling are stated. The signal coupling has first and second coupling members 10, 12 first and second coupling members 10, 12 carried by a respective one of the vehicles and between which the optical signals are transmitted. The first coupling member 10 is furnished with a sending device 38 to generate the optical signals to be transmitted. The second coupling member 12 is furnished with a receiving device 40 to detect the transmitted optical signals.