Fastening Clip With Retention Arms for Bolt Alignment Stability

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Solution Overview

Problem

Current fastening clips used in the automobile industry for attaching heat shields to threaded bolts are unreliable during high-speed automated assembly, often resulting in misalignment and incomplete connections due to weak retention and instability.

Innovation Solution

A fastening clip with resilient retention arms and a frustoconical aperture design that provides a strong, secure, and demountable connection, featuring engagement members with extruded lips and reinforcing ribs for improved contact with the bolt, along with apertures for temporary attachment to installation tools, ensuring accurate positioning and easy disassembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional clips with claws or teeth are used to attach heat shields to bolts, then the clips can be easily installed, but the connection becomes unstable and insecure due to single-point contact with thread ridges

Engineering Contradiction:
Improveease of installationVSAvoidconnection stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The retention member is divided into multiple engagement points along its length, with each segment contacting a different thread ridge. This distributes the locking force across multiple points rather than relying on a single contact point, significantly improving connection stability while maintaining ease of installation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retention member features locally optimized engagement surfaces with specific geometries designed to match thread ridge profiles. These localized quality enhancements at contact points maximize friction and mechanical interlocking, providing secure retention without complicating the overall installation process

Inventive Principle:
Principle #3Local quality

2Productivity

If automated assembly systems operate at high speed, then productivity increases, but alignment accuracy decreases causing misalignment and incomplete connections

Engineering Contradiction:
Improveassembly speedVSAvoidalignment accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The clip incorporates preliminary alignment features such as guide pins or tapered leading edges that automatically center and position the clip on the bolt before the retention members engage the thread ridges. This preliminary positioning action ensures accurate alignment even at high assembly speeds where manual adjustment is not feasible

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The fastening system is designed to be self-aligning through inherent geometric features that guide the clip onto the bolt during insertion. The structure automatically corrects minor misalignments through elastic deformation of resilient components, eliminating the need for high-precision external positioning equipment

Inventive Principle:
Principle #25Self-service

3Strength

If resilient retention arms with multiple engagement points are used, then connection strength increases, but the device complexity increases

Engineering Contradiction:
Improveconnection strengthVSAvoidfastener structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

Multiple retention members are integrated into a single monolithic component formed from one piece of material. This merging of multiple functional elements into one unified structure provides the strength of multiple engagement points while avoiding the complexity of assembling separate parts, as the entire retention assembly is formed in a single manufacturing operation

Inventive Principle:
Principle #5Merging (Combining)

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 ensures reliable central alignment and secure mounting during high-speed automated assembly, maintaining pressure against vibrations while allowing for easy disassembly without damaging the fastener or attachment bolt, enhancing the stability and usability of the fastening clip.

Implementation Method 1

the resilient deformability of the retention arms... Apertures have been provided to the retention arms to allow for a temporary attachment to the installation tool (i.e. when moved into position by the tool) via a friction fit between the resilient retention arms and the installation tool

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the frustoconical aperture of the base plate allows for easy and accurate positioning of the fastener on the stud or bolt, especially when mounted automatically in a high-speed action

Methodology Applied
Scientific EffectMechanical guidance through conical geometry: Geometry

Implementation Method 3

each one of said end portions of said resilient retention arms may comprise an engagement member at a distal end adapted to matingly engage with a corresponding thread section of the threaded elongate fastener

Methodology Applied
Scientific EffectThread engagement: Screw

Data Source

PatentEP3889447B1A fastener
Publication Date: 2025.01.15 ILLINOIS TOOL WORKS INC
  • EP3889447B1 patent drawingFigure 1~2
  • EP3889447B1 patent drawingFigure 3(a)~3(c)
  • EP3889447B1 patent drawingFigure 4(a)~4(d)

AI summary

The present invention provides for a fastening clip (100) for attachment to a threaded elongate fastener (300), comprising a base plate (102), having a proximal face and a distal face, comprising a central through hole (104) defining a centre axis (108) and forming a frustoconical sleeve extending away from said proximal face along said centre axis (108) and which is configured to guidingly receive the threaded elongate fastener (300); at least two diametrically opposing resilient retention arms (106a, 106b), each one extending from a peripheral edge of said base plate (102) radially outward and invertingly folding back towards said centre axis (108), so as to provide two cooperating end portions (110a, 110b) operable to resiliently move substantially parallel to said centre axis (108) between a first position, where said end portions (110a, 110b) are operably disengaged from the threaded elongate fastener (300), and a second position, where the end portions (110a, 110b) are retainingly and biasingly engaged with the threaded elongate fastener (300) when inserted through said central through hole (104), and wherein each one of said two cooperating end portions (110a, 110b) further comprises at least one recessed portion (122a, 122b) adapted to receivingly and attachingly engage with a corresponding installation tool (200).