| 摘要 |
FIELD: mining industry. SUBSTANCE: method of connecting drill-rods includes manufacturing drill-rods with capability of screwing one into another. Each of drill-rods has three landing portions: threaded portion, cone-shaped self-braking portion and cone-shaped non-self-braking portion. Portions are located along drill-rod axis in order from threaded portion to cone-shaped non-self-braking potion through cone-shaped self-braking portion. Portion sizes are selected so that members come into contact in cone-shaped non-self-braking portion after resilient closure in cone-shaped self-braking portion. EFFECT: removal of special operating conditions leading to overloads in separated connection portions. 1 dwg |
