Lock Bolt Collar for Sealant Squeeze-Out

Solution Overview

Problem

Current lock bolt assembly methods for composite and metal structures with fay surface sealant require a temporary clamp system that increases assembly time and hinders automated assembly, as they necessitate the removal and replacement of temporary fastening systems for sealant squeeze-out before final nut tightening or swaging.

Innovation Solution

A joint fastening system employing a lock bolt with a pull stem and threads or swage rings, where a collar is torqued to produce tension on the lock bolt, generating a clamp force sufficient for fay sealant squeeze-out, eliminating the need for temporary threaded pins and nuts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a temporary threaded pin and nut system is used for sealant squeeze-out, then sealant squeeze-out can be achieved, but assembly time increases and automated assembly is hindered

Engineering Contradiction:

Improvesealant squeeze-out effectivenessVSAvoidassembly time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The invention extracts the temporary fastening function from the permanent lock bolt system by using a separate collar that can be independently applied and removed. The collar is the only temporary component needed, while the lock bolt remains in place throughout the process, eliminating the need to remove and replace temporary pins and nuts.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The collar is designed to be applied preliminarily to the installed lock bolt to achieve sealant squeeze-out before final tightening. This preliminary action allows the sealant to be properly squeezed out while the lock bolt remains in position, avoiding subsequent removal and reinstallation steps.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If a temporary threaded pin and nut system is used for sealant squeeze-out, then sealant squeeze-out can be achieved, but the system complexity increases

Engineering Contradiction:

Improvesealant squeeze-out effectivenessVSAvoidfastening system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the temporary fastening function from the permanent lock bolt system by using a separate collar that can be independently applied and removed. The collar is the only temporary component needed, while the lock bolt remains in place throughout the process, eliminating the need to remove and replace temporary pins and nuts.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The collar serves multiple functions: it provides temporary clamping for sealant squeeze-out, can be applied to various lock bolt configurations, and works with different joint types. This multi-functionality reduces the need for multiple specialized temporary fastening components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Strength

If temporary threaded pins and nuts are removed and replaced with lock bolts, then permanent fastening is achieved, but assembly time is lost due to removal and replacement

Engineering Contradiction:

Improvepermanent fastening strengthVSAvoidtime for removal and replacement

Core Design Contradiction:

StrengthVSLoss of time

Solution Approach 1:

The collar is designed to be applied preliminarily to the installed lock bolt to achieve sealant squeeze-out before final tightening. This preliminary action allows the sealant to be properly squeezed out while the lock bolt remains in position, avoiding subsequent removal and reinstallation steps.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The lock bolt remains continuously in place throughout the entire process from initial installation through sealant squeeze-out to final tightening. The collar is temporarily added and removed without disturbing the lock bolt, maintaining continuous useful action and eliminating idle time for component removal and replacement.

Inventive Principle:

Principle #20Continuity of useful action

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

This solution reduces assembly time and facilitates automated assembly by directly applying tension to the lock bolt through a collar, ensuring effective sealant squeeze-out without the need for temporary fastening systems, thereby streamlining the assembly process.

Implementation Method 1

The collar is torqued to produce tension on the lock bolt to generate a clamp force sufficient for fay sealant squeeze out

Methodology Applied

Scientific EffectTorque: Torque

Implementation Method 2

The collar is torqued to produce tension on the lock bolt to generate a clamp force sufficient for fay sealant squeeze out

Methodology Applied

Scientific EffectTension: Tension

Implementation Method 3

A collar is received over the pull stem to engage the threads or annular rings

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS9644659B2Temporary clamp up system for sealant squeeze out in lock bolt installations

Publication Date: 2017.05.09 THE BOEING CO

AI summary

A joint fastening system employs a lock bolt having a pull stem and locking threads inserted through a bore in a joint having fay sealant between layers. A collar is received over the pull stem to engage the threads, the collar producing tension on the threads to generate clamp force sufficient for fay sealant squeeze out.