Earth drill drive rod extension connection - has threaded tube connection inside hexagonal sleeve and sliding connection for positive drive

摘要

The earth drilling tool (6) with holes through it near the cutting point, for drilling fluid, is designed for connection to a drive rod (1) which in turn is designed for connection to an extension rod (2). This similarly has its other end similarly designed for connection to further extensions. The hollow rear part (5") of the tool is internally threaded with a right hand thread (9) for attachment to the next rod section (7). This rod is enclosed inside a hexagonal sleeve (3) which slides over the hexagonal exterior of the rear part of the tool (5") ensuring positive drive. The connection between this extension and the next is similarly an internal screwed connection and an external hexagonal connection, but the screw thread is left handed.