Hollow crown drill, for drilling into insulated cellar walls, has an ejection plunge within the drill pot to remove the core plug drilled out of the insulation

摘要

The hollow drill crown (1), for drilling into insulated concrete cellar walls at a building, has a hollow cylindrical drill pot (2) with a cutting edge (3). A rod connector (6) slides axially into an external guide sleeve (5) through a passage opening from the base (4) of the pot. The end of the connector within the pot interior (7) has an ejection plunger (8), with the drill holder (9) at its free end.