Blind Nut With Varying Wall Thickness For Tensile Strength

Solution Overview

Problem

Conventional blind nuts do not adequately consider the distribution of tensile force on the internal threaded portion, leading to potential deformation or breakage, and often result in excessive material usage, increasing weight and cost.

Innovation Solution

The design includes tapered and straight portions in the internal threaded portion, with varying wall thickness to distribute tensile force effectively, making the blind nut stronger where necessary and lighter where possible, and incorporating features like knurled channels and projections for secure attachment and conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the wall thickness of the internal threaded portion is increased to prevent deformation under tensile force, then the strength is improved, but the weight and material cost increase

Engineering Contradiction:

Improvestrength of internal threaded portionVSAvoidweight of blind nut

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The patent applies local quality by varying the wall thickness of the internal threaded portion along its axial length. The first end portion (adjacent to the tubular portion) has a greater wall thickness to withstand high tensile forces during installation, while the second end portion has a smaller wall thickness. This non-uniform wall thickness distribution optimizes strength where needed while reducing material usage and weight in less critical areas.

Inventive Principle:

Principle #3Local quality

2Strength

If the wall thickness of the internal threaded portion is increased to prevent deformation under tensile force, then the strength is improved, but the material cost increases

Engineering Contradiction:

Improvestrength of internal threaded portionVSAvoidmaterial usage

Core Design Contradiction:

StrengthVSLoss of substance

Solution Approach 1:

The patent applies local quality by varying the wall thickness of the internal threaded portion along its axial length. The first end portion (adjacent to the tubular portion) has a greater wall thickness to withstand high tensile forces during installation, while the second end portion has a smaller wall thickness. This non-uniform wall thickness distribution optimizes strength where needed while reducing material usage and weight in less critical areas.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If the internal threaded portion is designed with uniform wall thickness, then the manufacturing is simplified, but the tensile force distribution is not optimized leading to potential deformation

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidresistance to deformation

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by varying the wall thickness of the internal threaded portion along its axial length. The first end portion (adjacent to the tubular portion) has a greater wall thickness to withstand high tensile forces during installation, while the second end portion has a smaller wall thickness. This non-uniform wall thickness distribution optimizes strength where needed while reducing material usage and weight in less critical areas.

Inventive Principle:

Principle #3Local quality

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 blind nut achieves sufficient strength to withstand tensile forces without deformation, reducing weight and cost while ensuring reliable attachment without rotation, maintaining contact surface area and preventing breakage.

Implementation Method 1

the screw mandrel is retracted, buckling the tubular portion so as to expand its diameter

Methodology Applied

Scientific EffectBuckling:

Implementation Method 2

incorporating features like knurled channels and projections for secure attachment and conductivity

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS10316883B2Blind nut

Publication Date: 2019.06.11 NEWFREY LLC

AI summary

A blind nut including an internal threaded portion, a hollow tubular portion adjacent to the internal threaded portion, and a flange with hole, formed at the end on the opposite side to the internally threaded portion. The internal threaded portion is inserted into an attaching hole of the attached-to member, a part of the tubular portion is plastically deformed to expand in diameter, and the attached-to member is held between the deformed expanded diameter portion and the flange. The internal threaded portion includes a first straight portion adjacent to the tubular portion, a first tapered portion with an outside diameter gradually decreasing from the first straight portion, a second straight portion with an outside diameter smaller than the first straight portion, a second tapered portion with an outside diameter decreasing from the first straight portion, and a third straight portion with an outside diameter smaller than the second straight portion.