A device is designed for optionally connecting a crank (3) and a motor shaft with a drill rod (2) of a tool for drilling holes through thick outdoor ice, on lakes and the like, by rotating the drill rod, for converting the tool between a tool for hand driven and a tool for motor driven drilling. The device has for this sake locking members for locking the crank and the motor shaft, respectively, to the drill rod, which are releasably arranged for removing the crank and the motor shaft, respectively, from the drill rod.
