Plug coupling with strain relief for a connecting cable

A strain relief arrangement (4) for a connecting cable (2), comprising:

• a threaded pin (12), having clamping tongues (13) at a free end of the threaded pin (12), an enlarged diameter (10, 11) on the threaded pin (12) for bearing against a surface of a carrier element (5), and an extension (15) for introducing and fastening the threaded pin in an opening (6) of the carrier element (5), and
• a union nut (3) for screwing onto the threaded pin (12),
• wherein the strain relief arrangement (4) has a passage bore (25) for the passage of the connecting cable (2),
• wherein, by screwing of the union nut (3) onto the threaded pin (12), the clamping tongues (13) are caused to move radially inward and are pressed against an outer circumference of the connecting cable (2) in order to bring about the strain relief of the connecting cable (2),
• wherein the extension (15) is of non-round or polygonal design with a radially larger region (16) and a radially smaller region (17),
• wherein the opening (6) of the carrier element (5) is geometrically complementary (7, 8) to the non-round or polygonal extension (15),
• wherein the radially larger region (16) of the non-round or polygonal extension (15) includes a circumferential groove (20) adjacent to the enlarged diameter (10, 11) and extending over a partial circumference of the polygonal extension (15),
• wherein an axial width of the circumferential groove (20) corresponds to a thickness of the carrier element (5) at the opening (6), and
• wherein a radial depth of the circumferential groove (20) corresponds to a radial dimension of the at least one radially smaller region (17) of the extension (15) in such a manner that the extension (15) is sized to be introduced into the complementary opening (6) of the carrier element (5) and to be fastened to the carrier element (5) by rotation in the complementary opening (6).