Expanding Rivet Foot Webs Protect Spreading Arms

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Solution Overview

Problem

Existing expanding rivets fail to protect the delicate free ends of their spreading arms from unintended contact and deformation when inserted into support or carrier parts, which can prevent proper assembly.

Innovation Solution

The expanding rivet incorporates radially projecting foot webs that protrude over the free ends of the spreading arms in the pre-assembly position, providing protection against contact with attachment or carrier parts and preventing unintentional bending or deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the free ends of the spreading arms are left exposed, then the rivet can be easily inserted, but the delicate free ends are vulnerable to unintended contact and deformation with support or carrier parts

Engineering Contradiction:

Improveprotection of spreading armsVSAvoidstructure of rivet body

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The rivet body is segmented into functional zones: the insert section with spreading arms for connection, and the protection section with foot webs for shielding. This segmentation allows the free ends of the spreading arms to be protected without compromising the overall function of the rivet, resolving the contradiction between reliability and structural simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The foot webs act as an intermediary protective element between the delicate free ends of the spreading arms and the external support or carrier parts. These foot webs prevent direct contact and potential deformation of the spreading arms during insertion, while maintaining the simplicity of the rivet structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If the free ends of the spreading arms are designed to be delicate for precise positioning, then assembly precision is improved, but they become more susceptible to damage during insertion

Engineering Contradiction:

Improvepositioning accuracy of spreading armsVSAvoidresistance to deformation of free ends

Core Design Contradiction:

Manufacturing precisionVSStrength

Solution Approach 1:

The foot webs are pre-positioned on the rivet body to provide protective coverage for the free ends of the spreading arms before insertion occurs. This preliminary protective action ensures that the delicate free ends maintain their precise positioning capability without being exposed to damaging contact during the insertion process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The foot webs serve as a beforehand cushioning element that prevents direct impact or contact between the delicate free ends of the spreading arms and the support or carrier parts. This prior cushioning protects the precision-crafted free ends from deformation while maintaining their positioning accuracy.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP2601418B1Expanding rivet

Publication Date: 2017.04.19 A RAYMOND & CO SCS

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AI summary

In an expanding rivet formed with a rivet body (1) and with a rivet pin (2), foot webs (21, 22) are formed on the rivet pin (2), said foot webs (21, 22) projecting laterally in a prefitting position relative to spring arms (7) formed on the rivet body (1). As a result, the free ends of the spring arms (7) are protected against damage when the expanding rivet is inserted into locating recesses.