摘要 |
The connection between an internally threaded end (12) and the externally threaded end (13) of two members forming an impact operated rock drill spindle, uses threads with straight flanks (20). Between the roots of the external threads and the crests of the internal threads is a gap (a) larger than 1% of the outside dia. (Dy) of the external threads. This gap is at least four times the size of the gap (b) between the roots of the internal threads and the crests of the external threads. The height (h) of the internal threads is less than 5% of the inside dia. (Di) of the internal threads. |