Wire Lug Captivation System for Aircraft Terminal Blocks

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Solution Overview

Problem

Existing methods for connecting feeder lugs to terminal blocks in dynamoelectric machines on aircraft are cumbersome, often resulting in the nut or washer being dropped or lost during installation due to the difficulty in handling and securing the feeder line and lug simultaneously.

Innovation Solution

A wire lug captivation system that includes a terminal block with a threaded insert and a captivation device with an upper and lower portion, allowing the feeder lug to be securely held by a bolt, which reduces the risk of dropping or losing the bolt during installation by enabling easy assembly and alignment over the terminal block.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the traditional method of attaching nut and washer separately is used, then the connection can be established, but the installer must handle multiple small components that are easily dropped or lost

Engineering Contradiction:
Improveease of installationVSAvoidrisk of dropping or losing components
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent combines the nut, washer, and bolt into a single integrated fastener assembly. The washer is positioned between the nut and bolt head, creating one unified component that is handled as a single unit during installation, eliminating the risk of dropping or losing separate small components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated fastener assembly serves multiple functions simultaneously: the bolt provides threading engagement, the washer distributes load and prevents damage, and the nut secures the connection. This multi-functional design consolidates what were previously separate components into one universal fastening solution.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If the installer must hold the feeder line and lug while attaching the fastener, then the connection can be made, but the process becomes cumbersome and time-consuming

Engineering Contradiction:
Improveinstallation speedVSAvoidcomplexity of installation process
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The fastener assembly is pre-assembled with the washer positioned between the nut and bolt head before installation. This preliminary preparation eliminates the need for the installer to manually position and coordinate multiple components during the installation process, reducing both time and complexity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3148004B1Wire lug captivation system and method
Publication Date: 2021.03.10 HAMILTON SUNDSTRAND CORP
  • EP3148004B1 patent drawingFigure 1~2
  • EP3148004B1 patent drawingFigure 3~4
  • EP3148004B1 patent drawingFigure 5~6

AI summary

A wire lug captivation system (300) includes a bolt (302) having a head, a shank (402) adjacent the head and a threaded portion (404), the shank (402) having a diameter that is smaller than a diameter of the threaded portion (404). The system also includes a captivation device (304) including an upper portion (502), a lower portion (504) and a connecting member that joins the upper (502) and lower portions (504), the captivation device (304) configured to receive a wire lug (14) between the upper portion (502) and the lower portion (504) and including a threaded hole (404) in the upper portion having diameter that is greater than the diameter of the shank (402).