Abstract: An automatic coupling device for connecting and disconnecting respectively a loading platform (12) from a lifting hook (17) which by means of hoisting cables (16) is operated by a hoisting crane for transferring the loading platform (12). Inside the outercasing (15) of the coupling device a connecting mechanism is provided for engaging and detaining a connecting head (1) provided on a central extension rod (13) of the loading platform (12), which connecting mechanism comprises pivotally mounted legs (2 and 6 respectively), which by one of their end portions are pivotally mounted (at 7) in the outer casing (15) and the free end portions of which thereby may be swung towards each other and away from each other respectively.