| 摘要 |
FIELD: mining.SUBSTANCE: skid yoke comprises body with handle and mouth for drill string. It differs from known designs in that said body has intersecting vertical and horizontal channels, the latter being stepped. Note here that yoke has a fork-shape retainer with teeth arranged in the body vertical channels, at outer surface with circular groove. Note also that spring-loaded retainers are arranged in retainer tooth circular grooves at working position. Retainers are composed by balls.EFFECT: higher safety at round-trip jobs.2 cl, 2 dwg |
