Coupling device for attaching medical instruments to a holding device

A coupling device for securing medical instruments to a holding device, having a coupler socket configured on one of the components that are to be coupled to one another and a coupler plug configured on the other component and insertable in the coupler socket, where the coupler socket and the coupler plug can be affixed with respect to one another in the position coupled to one another by means of at least one locking element, wherein the coupler socket is configured as a sleeve-shaped collet chuck comprising several spring arms set apart from one another and the coupler plug comprises a coupling pin equipped with at least one stopping cam pointing outward, where the at least one stopping cam of the coupling pin in coupled position catches to form a corresponding back-cut on the collet chuck and the locking element can be screwed onto the collet chuck in such a way that the spring arms of the collet chuck are affixed in the coupled position facing outward in the radial direction and wherein the coupling pin comprises several protrusions set apart from one another that extend in the axial direction and which in the coupled position mesh with corresponding protrusions of the collet chuck.