Fishing tool for freeing boring tool located in borehole - comprises coupling piece with spined hole in which splined striker bar moves forwards and backwards

The coupling piece (1) is for connection to a boring run (2) and connected to it is a catchment casing (3). The bore run incorporates a tube set (4) which rotates a boring tool and a bar set (5) arranged in the tube set transmits striker energy to the boring tool. In the coupling piece is a forwards and backwards moving striker bar (6) which is connected with the catchment casing (3), so that striker energy from the bar set is transmitted by the striker bar to the catchment casing so that the latter is driven firmly on to the boring tool (7) located in the bore hole. The coupling piece incorporates a hole provided with internal splines, and the striker bar is provided with external splines which work in conjunction with the internal splines. The striker bar at its end turned away from the catchment casing is provided with a flange for receiving striker energy from the bar set (5).