Geological drill of inner and outer pipes uses percussion transfer unit preceding striker and rotary drive in drilling direction in housing containing both pipes aided by adjuster rods and flushing tube.

摘要

The transfer unit (1) precedes the hydraulic hammer (7) and the rotary drive (13) in the drilling direction, the transfer arranged in a housing (4) to include both inner and outer pipes. The transfer unit has an adjuster rod (10) complete with striker shoulder and a connection to the inner pipe at its hole end. Fitted to the striker (7) is a flushing tube (46) set between adjuster rod (10) and drill rod connection (8) to associate with flushing channel in the rod (10). The striker shoulder impacts on annular stop in the housing (4). The shoulder has spring loaded wear elements where it meets the housing stop, peferably in the form of pressure spreader plates.