Trailer coupling

The trailer coupling has positive connection elements (270,280) on a bearing part (10) and on a bearing head (32). The bearing head is moveable relative to the bearing part in a direction at right angles to a pivot direction, to move the connection elements between locking and release positions. A positioning device is moved into a fixing position or release position, in which it positions the bearing head so that the connection elements are in locking or release position. The positioning device has a power accumulator (132), which generates a return force when it is in release position.