Countersink Hole Tool for Misaligned Stacked Components

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Solution Overview

Problem

Misalignment of preformed holes in stacked components, such as aircraft body panels, due to manufacturing variances and dimensional changes, makes it difficult to properly align countersinks, resulting in inferior connections and reduced lifespan of fasteners.

Innovation Solution

A tool comprising a hole cutter, countersink cutter, and pilot member is used to create full-sized holes and countersinks from near full-size preformed holes, with the pilot member ensuring proper alignment by passing through the overlapping region and centering the countersink cutter between the preformed holes, allowing for accurate positioning and secure fastening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If preformed holes are used in stacked components, then manufacturing efficiency is improved, but alignment precision deteriorates due to manufacturing variances and dimensional changes

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidhole alignment precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The pilot member is designed with a diameter that allows it to pass through the overlapping preformed holes while establishing a common central axis. This preliminary positioning action occurs before the countersink cutter creates the final hole, ensuring that the alignment is established in advance to accommodate manufacturing variances and dimensional changes in the stacked components.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The pilot member acts as an intermediary element between the misaligned preformed holes. It bridges the gap between holes with offset distances by providing a common reference axis, allowing the countersink cutter to create properly aligned holes even when the original preformed holes are not perfectly aligned.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If countersink is provided for flush or recessed fasteners, then connection strength is improved, but alignment difficulty increases when holes are misaligned

Engineering Contradiction:

Improveconnection strengthVSAvoidcountersink alignment ease

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The pilot member performs a preliminary alignment function by establishing a common central axis through the overlapping preformed holes before the countersink cutter operates. This preliminary positioning ensures that the countersink is properly aligned, making the manufacturing process easier even when the original holes are misaligned, while still achieving the strength benefits of flush or recessed fasteners.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The pilot member serves as an intermediary that transfers the alignment function from the misaligned preformed holes to a common axis. This mediation allows the countersink cutter to create accurately aligned countersinks without being directly constrained by the misalignment of the original holes, thus maintaining ease of manufacture while achieving strong connections.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If pilot member diameter is reduced to pass through misaligned holes, then adaptability is improved, but structural strength deteriorates

Engineering Contradiction:

Improvetolerance to misalignmentVSAvoidpilot member strength

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The pilot member diameter is optimized to a specific parameter range that balances adaptability and strength. The diameter is reduced enough to pass through overlapping holes with offset distances up to a maximum allowable offset, providing adaptability to misalignment, while maintaining sufficient structural strength to serve as an effective alignment reference during the countersinking operation.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20220355394A1Tools and methods for forming a hole with countersink in stacked components

Publication Date: 2022.11.10 THE BOEING CO

AI summary

A tool and method are provided for forming a plurality of aligned full-sized holes from a plurality of preformed holes that are near full-size in respective stacked components of a stack-up overlapped in relation to each other. The tool includes a hole cutter having a hole cutter outer diameter, a countersink cutter with a hole widening section, and a pilot member having a pilot diameter smaller than the hole cutter outer diameter and substantially equal to the preformed hole diameter minus the maximum allowable offset distance, so that the hole cutter outer diameter is greater than or equal to the preformed hole diameter plus the maximum allowable offset distance. Other tools and methods for forming countersinks are also provided.