Taphole opening apparatus for blast furnaces

A taphole opening apparatus for blast furnaces wherein a guide rail (22) is provided, a drill steel centralizer (42) is affixed to one end of said guide rail (22), a carriage (28) is movable along said guide rail (22) and carries a drill hammer (30) thereon, motor means (24) are provided for moving said carriage and drill hammer to and fro along said guide rail, and a drill steel (43) for drilling an initial tap hole in a plugging mass in the blast furnace is connectable to be rotated and impacted by said drill hammer (30) and guided by said centralizer (42) during initial drilling of a taphole and thereafter withdrawn from the partially-drilled taphole, characterized by an extractor carriage (29) forwardly of said drill hammer and movable along said guide rail (22) in unison with said carriage (28), an impact sleeve (50) carried by said extractor carriage (29) so as to receive impacts but not rotation at one end thereof from said drill hammer (30), a socket (51) at the other end of said impact sleeve (50) for a tap bar (53) insertable axially therein to replace said withdrawn drill steel (43) and to receive impacts from said impact sleeve (50), so as to complete and plug said tap hole, said impact sleeve having a first mounting position (FIG. 6) on said extractor carriage (29), wherein said tap bar (53) is free to move axially in and out of said socket (51), and a second mounting position (FIG. 5) thereon wherein coupling means are active to automatically lock said tap bar (53) to said socket (51) in response to axial penetration thereof into said socket.