Compliant Hole Alignment Tool for Uniform Radial Expansion

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Solution Overview

Problem

Existing hole alignment tools lack full, uniform contact with work pieces, leading to issues such as overexpansion, damage, and getting stuck, especially when aligning multiple work pieces with holes of varying diameters.

Innovation Solution

A doweling body with radially expandable legs and a compliance zone, allowing temporary distortion for uniform radial expansion, is integrated into the alignment tool, enabling full doweling and minimizing work piece deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If expansion elements are used to align holes, then radial expansion capability is improved, but uniform contact with work piece surfaces deteriorates

Engineering Contradiction:

Improveradial expansion capabilityVSAvoiduniform contact with work piece surfaces

Core Design Contradiction:

ForceVSManufacturing precision

Solution Approach 1:

The expansion elements are designed with a compliant outer surface that can flex and conform to the actual geometry of the work piece hole surfaces. This compliance allows the elements to maintain uniform radial contact across varying stack heights and hole diameters, resolving the contradiction between expansion capability and uniform contact.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The outer surface of the expansion elements is designed with varying geometric parameters (such as tapered sections or variable thickness) that allow it to adapt to different work piece configurations. This enables the same expansion element to provide uniform contact across a range of hole diameters and stack heights.

Inventive Principle:

Principle #35Parameter changes

2Length of moving object

If pin length is increased to extend beyond work piece holes, then alignment capability is improved, but risk of overexpansion and damage increases

Engineering Contradiction:

Improvepin lengthVSAvoidrisk of overexpansion and damage

Core Design Contradiction:

Length of moving objectVSReliability

Solution Approach 1:

The expansion elements are designed to be dynamically controllable, allowing the operator to adjust the expansion force and stop the expansion process before the pin extends beyond the work piece holes. This dynamic control prevents overexpansion damage while maintaining the ability to achieve full alignment.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The expansion elements are designed with features that allow preliminary engagement with the work piece surfaces before full expansion occurs. This enables the operator to establish proper contact and alignment before applying full expansion force, preventing damage from uncontrolled overexpansion.

Inventive Principle:

Principle #10Preliminary action

3Force

If expansion elements are used to align holes, then radial displacement capability is improved, but complexity of supporting structure increases

Engineering Contradiction:

Improveradial displacement capabilityVSAvoidcomplexity of supporting structure

Core Design Contradiction:

ForceVSDevice complexity

Solution Approach 1:

The supporting structure for the expansion elements is merged with the pin body itself, eliminating the need for separate complex supporting structures. The pin incorporates the expansion mechanism and supporting features in a unified design, reducing overall complexity while maintaining radial displacement capability.

Inventive Principle:

Principle #5Merging (Combining)

4Manufacturing precision

If expansion elements are used to align holes, then alignment precision is improved, but risk of getting stuck increases

Engineering Contradiction:

Improvealignment precisionVSAvoidrisk of getting stuck

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The compliant outer surface of the expansion elements allows them to flex and release from the work piece surfaces more easily, reducing the risk of getting stuck while maintaining precise alignment during the expansion process.

Inventive Principle:

Principle #30Flexible shells and thin films

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 solution ensures efficient and precise alignment of holes across various diameters without causing deformation, allowing for easy insertion and removal of the tool, reducing the risk of damage and sticking.

Implementation Method 1

each doweling body leg having a transition portion and a compliance zone capable of temporary distortion to allow the doweling body legs to shift outwardly away from a central axis

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS11231057B2Hole alignment tool with compliance zone feature

Publication Date: 2022.01.25 CENTRIX AEROSPACE LLC

AI summary

Hole alignment tools, methods of making such tools, and methods for aligning holes in a plurality of work pieces are disclosed. The hole alignment tools may exert, when fully engaged with similarly sized, stacked holes, a substantially uniform force against the work piece surfaces that define the holes. The hole alignment tool includes a doweling body having a plurality of radially expandable legs, a housing, and a spreader element. The doweling body legs include a decreasing sectional thickness extending from the distal ends thereof towards the proximal end of the doweling body. Depending upon its state, the radial profile of a doweling body's legs may be converging or parallel for tool insertion and removal, or diverging for alignment purposes.