Protective Sleeve Fastener Assembly for Shear and Bending Loads

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Solution Overview

Problem

Previous splitter bar style fasteners are susceptible to degradation due to shear and bending stresses, and their clamping legs are prone to damage during insertion and removal, leading to alignment issues and reduced durability.

Innovation Solution

A fastener assembly with a protective sleeve that circumferentially surrounds the clamping legs and splitter bar, providing slots for the extensions of the splitter bar and reinforcement sections to enhance structural integrity, decouple bending and shear stresses from the clamping legs, and prevent damage during tooling operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If clamping legs are designed as independent elements in previous splitter bar fasteners, then the fastener allows for simple construction and rapid clamping/unclamping action, but the clamping legs become susceptible to shear and bending stresses and cannot cooperatively interact to withstand loads

Engineering Contradiction:
Improveconstruction simplicityVSAvoidability to carry shear and bending loads
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The patent merges the previously independent clamping legs into a unified structure where the legs are formed as a single piece with integrated reinforcement features. This allows the legs to cooperatively interact and share shear and bending loads, transforming them from independent elements into a coordinated load-bearing system that maintains construction simplicity while significantly improving strength.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If clamping legs are positioned adjacent to workpiece apertures during clamping, then the fastener enables workpiece securing through accessible openings, but the legs experience unwanted loading and become prone to damage from workpiece shifts

Engineering Contradiction:
Improveaccessibility for clampingVSAvoidresistance to damage during operation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent incorporates reinforcement features and structural design elements into the clamping legs before they are subjected to operational loads. These pre-built reinforcement features act as cushioning elements that absorb and distribute unwanted loading from workpiece shifts, protecting the legs from damage while maintaining their positioning adjacent to workpiece apertures for ease of operation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Adaptability or versatility

If clamping legs are allowed to slide back and forth independently during fastener use, then the legs can accommodate movement, but they cannot cooperatively interact to withstand shear and bending stresses

Engineering Contradiction:
Improvemovement accommodationVSAvoidcooperative load resistance
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent combines the movement accommodation capability with cooperative load resistance by forming the clamping legs as an integrated structure. The unified design allows the legs to move together as a coordinated system rather than independently, enabling them to accommodate workpiece movement while maintaining structural integrity and sharing shear and bending loads effectively.

Inventive Principle:
Principle #5Merging (Combining)

4Strength

If the protective sleeve is added to surround clamping legs and splitter bar, then the fastener's structural integrity and ability to carry shear and bending loads is significantly increased, but the device complexity increases

Engineering Contradiction:
Improveability to carry shear and bending loadsVSAvoidstructural complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent merges the protective sleeve with the clamping legs and splitter bar into an integrated assembly. The sleeve is designed to work in unison with these components, creating a unified load-bearing system where the reinforcement features are built into the overall structure rather than being separate add-on elements. This integration increases strength while minimizing the increase in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3848595B1Fastener assembly and method for operation of said assembly
Publication Date: 2023.07.26 CENTRIX INC(US)
  • EP3848595B1 patent drawingFigure 1
  • EP3848595B1 patent drawingFigure 2
  • EP3848595B1 patent drawingFigure 3~4

AI summary

A fastener assembly is provided. The fastener assembly comprises a clamping unit including two clamping legs each having a shank and a clamping foot extending therefrom and a splitter bar including two extensions and a shaft extending between the two clamping legs and radially expanding and retracting the clamping feet responsive to axially translation of the clamping unit. The fastener assembly further comprises a protective sleeve partially circumferentially surrounding at least a portion of the clamping leg shanks and the splitter bar, where the protective sleeve comprises two slots having the two extensions extending there through.