Abstract: The present invention pertains to a central buffer coupling for rail-borne vehicles with a two-part coupling shaft formed by a front shaft part (2) carrying the coupling shaft (1) and by a rear shaft part (3) hinged horizontally pivotably to the chassis of the rail-borne vehicle, wherein the two shaft parts (2 and 3) of the two-part coupling shaft are connected to one another by a vertical connecting pin (5). A locking bar (7), which is displaceable in the longitudinal direction to a limited extent in the coupling shaft, is provided as the fixing device, and the said locking bar can be displaced, in the mutually extended position of the two shaft parts (2 and 3), by the force of a spring (13), into a locked position, in which the locking bar (7) associated with one of the shaft parts (2 or 3) engages the vertical groove (6) associated with the other shaft part (3 or 2) to make the coupling shaft rigid.