Universal chuck for a machine for piercing a tap hole of a shaft furnace

A universal chuck for a machine for piercing a tap hole of a shaft furnace, the piercing machine comprising a working member equipped with a spindle defining a longitudinal axis "0", said working member being mounted on a sliding carriage of the piercing machine and being capable of generating at least a rotational moment about the axis "0" and a percussive/tensile force along the axis "0", said universal chuck comprising:

• an oblong body equipped at one end with means for making the oblong body axially integral with the spindle and at the opposite end, equipped with a front cavity arranged about the axis "0" for the insertion therein of one end of a drill bit or a piercing rod;
• first gripping means for gripping the end of a piercing rod in said cavity, said first gripping means enabling said percussive/tensile force to be transmitted to a piercing rod;
• immobilizing means for immobilizing the end of a drill bit in said cavity, said immobilizing means enabling a rotational moment to be transmitted from the chuck to a drill bit;
• said first gripping means and said immobilizing means being arranged in said oblong body about said front cavity;
• a rigid support structure rigidly attached to said sliding carriage and extending along said oblong body;
• and
• said support structure having at least one bearing which supports and guides said oblong body radially, permitting at the same time a rotational movement about the axis "0" and a relative sliding movement of said oblong body.