Composite Joint Structure to Prevent Covering Member Creasing

Solution Overview

Problem

Existing joint structures in composite links, such as those described in U.S. Pat. No. 6,324,940, are prone to creasing when the hollow tube is bifurcated, leading to a demand for a joint structure that minimizes crease formation.

Innovation Solution

A joint structure featuring a bent portion with a core shaft connected to first and second members, covered by a fiber-reinforced plastic covering member, where the bent portion is positioned differently from the connecting portions, and a manufacturing method involving covering, connecting, bending, and curing the core shaft with a covering member to prevent creasing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the hollow tube is bent in a U-shape to achieve a flexible joint structure, then the joint can accommodate rotational movement and complex positioning, but the covering member such as resin impregnated fiber forms creases that compromise structural integrity

Engineering Contradiction:

Improvejoint flexibilityVSAvoidcovering member integrity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The joint structure is divided into distinct functional segments: a bendable core shaft that handles the bending and rotational movements, and a separate covering member that remains straight and protects the connecting portions. This segmentation allows the core shaft to absorb all deformation while the covering member maintains its structural integrity without creasing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The core shaft acts as an intermediary element between the covering member and the bent tube assembly. It provides a dedicated component that absorbs bending stresses and rotational movements, preventing these forces from being transmitted to the covering member and causing creases.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If resin impregnated fiber is wound over the end fittings and tube to create a covering member, then the joint structure gains protective coverage and structural reinforcement, but bending the hollow tube causes creases in the covering member

Engineering Contradiction:

Improvejoint strengthVSAvoidcovering member smoothness

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The joint structure is divided into distinct functional segments: a bendable core shaft that handles the bending and rotational movements, and a separate covering member that remains straight and protects the connecting portions. This segmentation allows the core shaft to absorb all deformation while the covering member maintains its structural integrity without creasing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different parts of the joint structure have different functional properties: the core shaft is designed to be bendable and flexible to accommodate movements, while the covering member is designed to remain straight and rigid to maintain structural integrity and protect the connecting portions without creasing.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If the covering member is applied before bending to protect the core shaft, then the core shaft gains protection during assembly, but the covering member will crease when the core shaft is bent

Engineering Contradiction:

Improveassembly protectionVSAvoidcovering member integrity

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The joint structure is divided into distinct functional segments: a bendable core shaft that handles the bending and rotational movements, and a separate covering member that remains straight and protects the connecting portions. This segmentation allows the core shaft to absorb all deformation while the covering member maintains its structural integrity without creasing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bending function is extracted from the covered assembly and assigned exclusively to the core shaft. The covering member is taken out from the bending process entirely, applying only to the straight connecting portions, thereby eliminating the source of crease formation while maintaining protection where needed.

Inventive Principle:

Principle #2Taking out (Extraction)

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 effectively reduces the likelihood of creasing in the covering member, allowing for a lightweight yet strong joint structure suitable for flight control surface drive devices by using a bendable core shaft and high-strength materials for the head and bush, while maintaining structural integrity and preventing moisture infiltration.

Implementation Method 1

heating the covering member to cure

Methodology Applied

Scientific EffectCuring:

Data Source

PatentUS20230061901A1Joint structure and manufacturing method thereof

Publication Date: 2023.03.02 NABTESCO CORP

AI summary

A joint structure includes a bent portion, a first member configured to be connected rotatably to a mating member, a second member configured to be connected rotatably to an actuator for driving the mating member, and a core shaft. The core shaft has a first connecting portion and a second connecting portion. The core shaft is connected to the first member at the first connecting portion and connected to the second member at the second connecting portion. The joint structure further includes a covering member covering the first connecting portion and the second connecting portion. The bent portion is provided at a position different from the first connecting portion.