Changeable couplers

The utility model relates to a changeable car coupler. The front end (4) of a coupler body (5) and the tail end (2) of a joint coupler head (1) both have U-shaped structures with vertical pivot holes; the joint coupler head (1) and a coupler head (13) of a chain coupler device are connected with the coupler body (5) through a pivot (3) which is arranged in the pivot holes; relative to the coupler body (5), the joint coupler head (1) and the coupler head (13) of a chain coupler device rotate, and the pivot is taken as a center. The connecting mode can be chosen according to the differences of the butt joint vehicles, the chain coupler is adopted, chains of the two adjacent vehicles can be mutually hung and connected to the corresponding coupler of counterparts, which is favorable to adopt the progressive mode to select the chain coupler device of railway vehicles.