Plastic Barrier Post Elastic Interference Fit Assembly

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for connecting plastic components to metal footplates in barrier systems rely on loose fits and additional securing bolts, lacking a secure, self-supportive interference fit.

Innovation Solution

A method involving a rigid support member with protrusions and an elongate, hollow post made of polypropylene, which is extruded to be undersized and deforms radially to create a strong interference fit and mechanical keying with the steel base plate, eliminating the need for bolts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a loose fit connection is used between the post and support member, then the assembly process is simpler, but the connection strength and stability are insufficient requiring additional bolts

Engineering Contradiction:

Improveassembly processVSAvoidconnection strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The invention changes the dimensional parameters of the post relative to the support member, making the post slightly smaller than the support member opening to create an interference fit. This parameter change enables the post to deform radially outward during assembly, creating elastic gripping that secures the connection without requiring additional bolts

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention utilizes radial deformation of the post during assembly, where the post is compressed radially inward to fit through the support member opening, then expands radially outward to create the interference fit. This radial curvature change enables the elastic gripping effect that provides secure connection

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Strength

If additional securing bolts are used to fasten the post to the support member, then the connection strength is improved, but the device complexity and number of components increase

Engineering Contradiction:

Improveconnection strengthVSAvoidnumber of components

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The invention merges the connection function into the post-support member interface itself by creating an interference fit with radial deformation. The post's own structural deformation provides the securing mechanism, eliminating the need for separate bolts or additional fastening components

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The post serves its own connection function by deforming radially outward during assembly to create elastic gripping of the support member. The post's material properties and geometric design enable it to secure itself to the support member without requiring external fastening devices

Inventive Principle:

Principle #25Self-service

3Stability of the object's composition

If the post is made to fit tightly over the support member, then the connection stability is improved, but the assembly force required increases

Engineering Contradiction:

Improveconnection stabilityVSAvoidassembly force

Core Design Contradiction:

Stability of the object's compositionVSForce

Solution Approach 1:

The invention optimizes the dimensional parameters of the post and support member interface to create a controlled interference fit. By carefully selecting the size difference and material properties, the post can deform radially outward to create stable elastic gripping while requiring only moderate assembly force

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The post is designed with sufficient flexibility to deform radially outward during assembly, allowing it to conform to the support member opening and then expand to create the interference fit. This flexibility enables stable connection with reduced assembly force requirements

Inventive Principle:

Principle #30Flexible shells and thin films

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

This method provides a secure, interference fit connection with high friction and tensile strength, ensuring a stable anchorage for plastic barrier posts without the need for additional fixing devices, utilizing the material properties of polypropylene to grip the steel base plate effectively.

Implementation Method 1

the post being such that it deforms elastically and radially outward as it moves over the support member

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

mechanical keying due to the at least one protrusion

Methodology Applied

Scientific EffectMechanical keying: Mechanical Force

Implementation Method 3

high friction and tensile strength, ensuring a stable anchorage

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentEP2539136B1Barrier post and method of manufacturing thereof

Publication Date: 2020.12.16 THREE SMITH GRP LTD

Figure 1~4
Figure 5
Figure 6A~6D

AI summary

A method is provided for connecting an upwardly extending member (23) to a support member (10, 12), comprising the steps of providing a substantially rigid support member (10, 12), and then extruding plastics material to form a hollow component (23) which will comprise the upwardly extending member, and then forcing the members together such that the hollow component slides over the support member, the hollow member (23) being such that it deforms elastically as it moves relatively over the base member (10, 12), such that the two members are secured together by a combination of interference fit, and the elastic gripping of the support member (10, 12) by the upwardly extending member (23).