Multi-Jaw Wrench Head for Confined Aircraft Tube-Nut Torque

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Solution Overview

Problem

Torque wrenches with crow's-foot extensions face difficulties in accurately engaging and measuring torque for tube-nuts in confined spaces within aircraft structures, leading to challenges in assembly operations.

Innovation Solution

A wrench head design featuring a working axis with three or more first-jaw arcuate convex contact surfaces, a pivotable second jaw with arcuate and planar contact surfaces, and a third jaw with arcuate and planar contact surfaces, providing multiple points of contact and preventing closure during ratcheting, allowing for precise engagement and measurement in confined spaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If torque wrenches with crow's-foot extensions are used, then torque measurement capability is provided, but engagement accuracy deteriorates in confined spaces

Engineering Contradiction:

Improvetorque measurement accuracyVSAvoidengagement difficulty in confined spaces

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The wrench head is divided into three separate pivotable jaws (first jaw, second jaw, third jaw) that can independently engage with the tube-nut. This segmentation allows the jaws to be positioned and closed sequentially, enabling accurate engagement even in confined spaces where a traditional crow's-foot extension cannot be properly positioned.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The jaws are designed to be pivotable relative to each other about pivot axes, allowing dynamic adjustment of the jaw configuration. This dynamic capability enables the wrench head to adapt to confined spaces and achieve proper engagement orientation that static crow's-foot extensions cannot provide.

Inventive Principle:

Principle #15Dynamics

2Force

If traditional crow's-foot extensions are used, then torque application is possible, but engagement accuracy deteriorates

Engineering Contradiction:

Improvetorque application capabilityVSAvoidengagement accuracy

Core Design Contradiction:

ForceVSManufacturing precision

Solution Approach 1:

Each jaw is equipped with specific contact surfaces (arcuate convex contact surfaces on the first jaw, arcuate convex contact surface and planar contact surface on the second jaw, arcuate convex contact surface and planar contact surface on the third jaw) designed for optimal engagement with specific portions of the tube-nut. This local specialization of contact surfaces ensures accurate and reliable engagement while maintaining torque application capability.

Inventive Principle:

Principle #3Local quality

3Manufacturing precision

If multiple contact surfaces are provided, then engagement accuracy improves, but device complexity increases

Engineering Contradiction:

Improveengagement accuracyVSAvoidwrench head structure complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Multiple contact surfaces (arcuate convex contact surfaces and planar contact surfaces) are integrated into three compact jaws that pivot relative to each other. This merging of multiple contact functions into a compact multi-jaw structure achieves accurate engagement without proportionally increasing overall device complexity, as the jaws share common pivot mechanisms and housing.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS11235440B2Wrench head

Publication Date: 2022.02.01 THE BOEING CO

AI summary

A wrench head comprises a working axis, a first jaw, a second jaw, and a third jaw. The first jaw comprises first-jaw arcuate convex contact surfaces. The second jaw is coupled with and pivotable relative to the first jaw and comprises a second-jaw arcuate convex contact surface, a second second-jaw arcuate convex contact surface, and a second-jaw planar contact surface. The third jaw is coupled with and pivotable relative to the second jaw and comprises a third-jaw arcuate convex contact surface and a third-jaw planar contact surface.