Cam Fastening System for Composite Panel Joining

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Solution Overview

Problem

Current methods for joining composite sandwich panels are time-consuming and generate excessive waste, particularly due to the use of potting materials and conventional fasteners that cannot effectively handle the shear loads exerted by composite panels with honeycomb cores.

Innovation Solution

A fastening system comprising a cam assembly and a stud receiving assembly, where the cam assembly engages a stud head and the stud receiving assembly secures the stud end with internal retaining channels, allowing for efficient joining of composite sandwich panels without the need for potting material and minimizing waste, while the stud is designed to transfer shear loads to the panel skins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional joining methods with potting material are used, then the panels can be joined, but the process becomes time-consuming and generates excessive waste

Engineering Contradiction:
Improvejoining capabilityVSAvoidjoining time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent removes the potting material from the joining system and replaces it with a mechanical fastening mechanism consisting of a cam assembly, stud, and retaining assembly. This extraction of the problematic material-based joining method eliminates the associated time consumption and waste generation while maintaining reliable panel joining capability through pure mechanical means

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If conventional joining methods with potting material are used, then the panels can be joined, but excessive material waste is generated

Engineering Contradiction:
Improvejoining capabilityVSAvoidmaterial waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent eliminates potting material entirely from the joining process by implementing a mechanical fastening system. This removal of material-based joining methods prevents the generation of material waste, protective gear waste, and application tool waste that are inherent to conventional potting material application processes

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cam assembly and retaining assembly are designed as reusable mechanical components that can be disassembled and reused for multiple panel joining operations. This contrasts with single-use potting material that generates waste after one application, thereby reducing overall material consumption and waste generation

Inventive Principle:
Principle #34Discarding and recovering

3Reliability

If conventional fasteners are used, then joining can be achieved, but they cannot effectively handle the shear loads exerted by composite panels with honeycomb cores

Engineering Contradiction:
Improvejoining capabilityVSAvoidshear load capacity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The cam assembly utilizes a cam mechanism with curved surfaces that convert rotational motion into linear compression forces. The cam profile is designed to distribute shear loads from the honeycomb core across a broader area of the panel skins, transforming point loads into distributed loads that the composite structure can effectively handle without compromising shear load capacity

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP3312441B1Panel fastening system
Publication Date: 2020.07.22 THE BOEING CO
  • EP3312441B1 patent drawingFigure 1
  • EP3312441B1 patent drawingFigure 2
  • EP3312441B1 patent drawingFigure 3

AI summary

A fastening system (400) for joining a first composite sandwich panel (302) and a second composite sandwich panel (306) comprising a cam assembly (304) and a stud receiving assembly (402). The cam assembly (304) is configured to be positioned within a first hole (310) extending through a thickness of a first composite sandwich panel (302). The cam assembly (400) comprises a housing (312) and a cam connector (314) rotatable within the housing (312). The cam connector (314) is configured to engage a head (420) of a stud (414). The stud receiving assembly (402) is configured to be positioned within a second hole (318) extending through a thickness of a second composite sandwich panel (306). The stud receiving assembly (402) has internal retaining channels (410) configured to secure a first end (412) of the stud (414).