Offset Drive Link Assembly for Inaccessible Fastener Torque

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Solution Overview

Problem

Existing torque transmission and multiplication systems for threaded fasteners are often inaccessible or unreachable due to protruding threads, limited clearances, and obstructions, making maintenance and repair challenging, especially in industrial applications.

Innovation Solution

The offset drive link assembly, which includes a drive force input assembly, a drive force output assembly, and a reaction force assembly, allows for the transmission and multiplication of torque to inaccessible fasteners, using modular components and adaptable tools to overcome obstructions and ensure safe and accurate torque application, while minimizing operator error and risk of damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional torque tools are used on fasteners, then tightening function is provided, but accessibility is limited due to protruding threads, limited clearances and obstructions

Engineering Contradiction:
Improveaccessibility to fastenersVSAvoidtool structure simplicity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent introduces an offset link assembly that positions the torque tool in a different spatial dimension relative to the fastener. The link assembly creates an offset configuration where the tool can apply torque to the fastener from a remote location, bypassing obstacles in the direct path. This dimensional repositioning allows access to fasteners that would otherwise be unreachable by conventional direct-action tools.

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

2Ease of operation

If offset link attachments are used to reach inaccessible fasteners, then accessibility is improved, but torque transmission accuracy and multiplication precision deteriorate

Engineering Contradiction:
Improveaccessibility to fastenersVSAvoidtorque multiplication accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The link assembly acts as an intermediary mechanical element between the torque tool and the fastener. It includes drive force input and output assemblies with gear mechanisms that mediate the torque transmission. The intermediary structure incorporates precision gears and drive linkages that maintain accurate torque multiplication ratios despite the offset configuration, ensuring precise torque application to the fastener.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If torque is applied to inaccessible fasteners with obstructions, then fastener tightening is achieved, but side loads and uneven bolt compression increase

Engineering Contradiction:
Improvefastener tightening capabilityVSAvoidside loads and uneven compression
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The link assembly employs asymmetric geometry in its linkages and gear arrangements to compensate for the asymmetric loading conditions created by the offset configuration. The asymmetric design allows the mechanism to self-align and distribute forces more evenly, reducing side loads on the fastener and preventing uneven bolt compression that would occur with symmetric designs in asymmetric positions.

Inventive Principle:
Principle #4Asymmetry

4Weight of moving object

If advanced materials like aircraft-grade aluminum are used in bolting applications, then weight reduction is achieved, but fastener accessibility and torque application difficulty increase

Engineering Contradiction:
Improvefastener assembly weightVSAvoidtorque application ease
Core Design Contradiction:
Weight of moving objectVSEase of operation

Solution Approach 1:

The system is segmented into modular components including the torque tool, link assembly with interchangeable drive linkages, and fastener components. This segmentation allows the use of lightweight materials like aircraft-grade aluminum in the fastener assembly while maintaining ease of torque application through the adaptable link assembly that can be configured for specific accessibility requirements. The modular design enables optimization of each component's weight and performance characteristics.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The offset drive link assembly enables access to previously unreachable fasteners, ensures safe and accurate torque application, and minimizes operator error and damage, while allowing the use of advanced materials and adaptable tools to meet various industrial requirements.

Implementation Method 1

apparatus for transmission and multiplication of torque from a device for tightening or loosening a threaded fastener

Methodology Applied
Scientific EffectTorque transmission: Torque

Implementation Method 2

threaded fasteners including bolts, studs, nuts and washers are known and used in traditional bolting applications

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2988908B1Apparatus for tightening threaded fasteners
Publication Date: 2020.06.10 HYTORC DIV UNEX CORP
  • EP2988908B1 patent drawingFigure 1
  • EP2988908B1 patent drawingFigure 2~3
  • EP2988908B1 patent drawingFigure 4~5

AI summary

An offset drive link assembly for transmission and multiplication of torque from a power tool for tightening or loosening a threaded fastener includes: a drive force input assembly; a drive force output assembly; and a reaction force assembly. Advantageously the offset drive link assembly: allows access to previously unreachable fasteners due to, for example protruding threads, limited clearances and obstructions; makes practical previously unusable devices driven either electrically, hydraulically, manually and/or pneumatically; makes feasible previously unusable advanced materials, such as, for example aircraft-grade aluminum; creates modular components, such as, for example hex-reducing and -increasing drive bushings, male to female drive adaptors, to meet bolting application characteristics; yields accurate and customizable torque multiplication; tames drive force and reaction force application; overcomes corrosion, thread and facial deformation; avoids bolt thread galling; nullifies side load; ensures balanced bolt load for symmetrical joint compression; simplifies link and tool use; minimizes risk of operator error; and maximizes bolting safety.