Drilling crown for drilling tube - has teeth welded at equal intervals around its leading edge perimeter and is then welded to tube

摘要

The drilling crown has a number of teeth welded on to its leading edge distributed around the perimeter. A circular basic unit (1) is welded on to the end of a drilling tube, and around the perimeter of the unit (1) there are a series of evenly spaced insets (3) into which teeth (4) can be welded or removed for exchange. The individual teeth may be of trapezoidal shape, and are designed to fit firmly into the insets. USE/ADVANTAGE - The crown can be easily removed from the drilling tube. The system may be used for drilling large dia. bores.