Rock-drilling and bolt-setting apparatus

A bolt-setting and rock-drilling apparatus has a rail which can be swung about and axis and axially displaced therealong to position a drilling carriage and a bolt-setting carriage alternately with respect to a rock wall in which the bolt is to be lodged. The carriages are slidable on opposite sides of the rail and, in the upper end thereof, in alignment with the drill holder, is an opening drill through which the main drill passes. The opening drill, which is of a configuration enabling it to form a conical mouth to the hole bored, by the main drill, is displaceable parallel to the main drill when its holder engages a clutch member carrying the opening drill. The conical mouth facilitates subsequent insertion of the bolt.