Drill rod assembly cutting separation and retention device - has transitional pieces linking separating and retaining appliances, into single unit, cooperating with auxiliary drill linkage

摘要

The separation and a retaining device is intended for application in case of drill rod linkage breaking. This successively introduced as two units via an auxiliary drill rod assembly, the retaining device being sealable against the drill assembly water column by a steel ball. The through-cutting appliance (1) and the retaining appliance (2) are linked by transitional pieces (3,6) to each other and to the auxiliary drill rod assembly (5), and form a unit. Between the auxiliary drill rod assembly and flushing head (6) there is a transitional piece (7) with a closable opening (8) to house a steel ball guided on a cord.