Trailer coupling

A coupling head attaches to a towing vehicle and has a grabbing mouth (12) for holding a trailer coupling ring (18) on a tow-bar (20) for a vehicle to be towed. The grabbing mouth is bordered top and bottom grabbing mouth lobes (10). Aligned vertical to the lobes, a coupling bolt (16) can be adjusted by an operating device between an opening/release position and a closing/coupling position.