Tool Coupler Bi-Directional Torque Locking Mechanism

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Solution Overview

Problem

Current methods for coupling tools to a top drive in drilling operations are time-consuming and dangerous, particularly when transferring bi-directional torque, as they rely on limited friction-based solutions that are not effective for high torque applications and often require complex manufacturing processes and additional components.

Innovation Solution

A tool coupler system comprising a first component with a shaft and locking members, a second component with an inner housing and complementary locking members, and an outer housing that rotationally locks the first component to the second, allowing for bi-directional torque transfer through a simple and reliable mechanism that includes a method of inserting the shaft, rotating to engage locking members, and axially moving the outer housing to secure the connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If friction-based locking methods (thread locking mechanisms, hydraulic locking rings, set screws) are used to achieve bi-directional torque holding, then the connection can transfer torque in both directions, but the torque resistance is limited due to friction between component surfaces

Engineering Contradiction:
Improvetorque resistanceVSAvoidconnection reliability
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The locking mechanism is segmented into multiple independent locking members (at least two locking members spaced circumferentially around the shaft) that engage with corresponding features on the tool. This segmentation distributes the torque load across multiple contact points, significantly increasing the overall torque resistance and reliability compared to single-point friction-based methods.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from relying solely on friction (surface phenomenon) to positive mechanical engagement through keys and cross/through-bolting (structural phenomenon). The locking members engage with complementary features in a different dimensional approach, providing positive mechanical interlocking that resists bi-directional torque more effectively than friction alone.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Force

If positive locking methods (keys, clutches, cross/through-bolting) are used to achieve high bi-directional torque capabilities, then the torque resistance is significantly improved, but the manufacturing complexity and cost increase due to requiring both turning and milling operations

Engineering Contradiction:
Improvetorque resistanceVSAvoidmanufacturing simplicity
Core Design Contradiction:
ForceVSEase of manufacture

Solution Approach 1:

The locking mechanism uses segmented locking members that can be manufactured using primarily turning operations rather than complex milling. Each locking member is a discrete component that can be produced independently through conventional turning processes, then assembled into the final coupling structure, thereby maintaining manufacturing simplicity while achieving positive mechanical engagement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of creating complex milled features directly in the shaft or housing to accommodate locking mechanisms, the invention inverts the approach by using simple turned features on the shaft that engage with corresponding features in the locking members and housing. This inversion simplifies the manufacturing of the critical shaft component while still achieving the required positive locking capability.

Inventive Principle:
Principle #13The other way round (Inversion)

3Force

If positive locking methods (keys, clutches, cross/through-bolting) are used to achieve high bi-directional torque capabilities, then the torque resistance is significantly improved, but the device complexity and cost increase due to requiring significant additional components

Engineering Contradiction:
Improvetorque resistanceVSAvoidnumber of components
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The invention merges multiple functions into integrated components. The locking members serve both as torque transfer elements and as alignment features. The outer housing integrates the locking mechanism with the coupling structure, eliminating the need for separate mounting brackets, alignment devices, and adjustment mechanisms that would be required in conventional positive locking systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking members are designed with multi-functionality, serving as both the primary torque transfer mechanism and as features that facilitate alignment and assembly. The same structural features that provide positive mechanical engagement also serve as guides for proper positioning, reducing the need for additional specialized components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Ease of manufacture

If simple male-to-female threaded connections are used, then the manufacturing is simple requiring only turning operations, but the connections cannot provide sufficient bi-directional torque capability

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidtorque resistance
Core Design Contradiction:
Ease of manufactureVSForce

Solution Approach 1:

The shaft is preliminarily prepared with precision-turned features (such as keyways, grooves, or external locking profiles) during the turning operation. These pre-formed features are then used to engage with the locking members, enabling the subsequent assembly to achieve high torque capability without requiring complex milling operations on the shaft itself. The preliminary turning action creates the foundation for the enhanced locking mechanism.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3655618B1Tool coupler for use with a top drive
Publication Date: 2021.08.25 WEATHERFORD TECHNOLOGY HOLDINGS LLC
  • EP3655618B1 patent drawingFigure 1
  • EP3655618B1 patent drawingFigure 2
  • EP3655618B1 patent drawingFigure 3

AI summary

A tool coupler includes a first component having a shaft and a plurality of locking members; a second component having an inner housing for receiving the shaft and a plurality of complementary locking member; and an outer housing configured to rotationally lock the first component to the second component.