Tapered thread configuration with improved durability

摘要

Underground drilling operation often requires connecting a drill tool (e.g., drill bit, backreamer, etc.) to a drill string. It is desirable to connect the drill tools to a drill string in a manner that facilitates quick and easy assembly and disassembly. Low torque coupling, commonly referred to as “torque-less” connection, can provide such functionality. The useful life and strength of such connections can be improved upon. The present disclosure provides a low torque coupling with improved strength and durability.

主权项

1. A method of connecting a drill tool to a drill rod member comprising:
contacting threads located at an end of a drill tool member with threads located at an end of the drill rod member; threading the drill tool member to the drill rod member by relatively rotating the drill rod member and the drill tool member, wherein the step of threading the drill tool member to the drill rod member simultaneously inserts a first boss of the drill tool member within a first aperture of the drill rod member and inserts a second boss of the drill tool member within a second aperture of the drill rod member, the second boss being spaced longitudinally away from the first boss; aligning a structural feature on an external surface of the drill tool member with a structural feature on an external surface of the drill rod member; sliding a collar over a portion of the drill tool member and drill rod member, wherein the collar is configured to engage the structural features on the external surfaces of the drill tool member and drill rod member thereby preventing relative rotation between the drill tool member and the drill rod member; wherein the first boss includes a maximum cross-sectional dimension that is between 0.003-0.006 inches (0.076-0.150 millimeters) less than a maximum cross-sectional dimension of the first aperture on the drill rod member and wherein the second boss includes a maximum cross-sectional dimension that is between 0.003-0.006 inches (0.076-0.150 millimeters) less than a maximum cross-sectional dimension of the second aperture of the drill rod member, and maintaining at least 0.030 inch (0.76 millimeters) offset in pitch diameter between the threads of the drill rod member and the threads of the drill tool member at least in a state wherein the structural feature on the external surface of the drill tool member is aligned with the structural feature on the external surface of the drill rod member.