Tapered Thread Coupling for Durable Low-Torque Drill Connections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing low torque couplings used in underground drilling operations lack sufficient strength and durability, leading to reduced useful life and increased maintenance costs.
Innovation Solution
A low torque coupling design featuring a tapered threaded connection with asymmetric threads and a collar system that prevents relative rotation between the drill tool and drill string, maintaining an offset between thread peaks and valleys to enhance alignment and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a low torque coupling design is used to facilitate quick assembly and disassembly, then ease of operation is improved, but strength and durability deteriorate
Solution Approach 1:
The patent applies asymmetry by designing threads with unequal lead angles on opposing surfaces. The first thread has a lead angle between 5-15 degrees while the second thread has a lead angle between 75-85 degrees. This asymmetric configuration allows the connection to be easily assembled in one direction while providing high strength and resistance to disassembly in the opposite direction, thus resolving the contradiction between ease of operation and connection strength.
2Ease of operation
If a low torque coupling design is used to facilitate quick assembly and disassembly, then ease of operation is improved, but durability deteriorates
Solution Approach 1:
The asymmetric thread design with significantly different lead angles (5-15 degrees vs 75-85 degrees) creates a connection that is easy to assemble but requires substantially higher torque to disassemble. This asymmetry ensures that during normal operational use, the connection maintains its integrity and durability, while still allowing for controlled disassembly when needed, thus extending the useful life of the coupling.
3Manufacturing precision
If tapered threads with offset peaks and valleys are used to enhance alignment, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent uses asymmetric tapered threads where the first thread and second thread have different lead angles and are offset relative to each other. The peaks and valleys of the threads are intentionally offset to create alignment features. While this increases geometric complexity, the asymmetric design actually simplifies the manufacturing process by providing self-aligning features that guide proper insertion and engagement, reducing the need for complex alignment procedures.
Data Source
Figure 1
Figure 2~4
Figure 5~6
AI summary
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.