Tie Rod Boot Bellows With Impact-Resistant Nesting Protuberances

Solution Overview

Problem

Existing tie rod boots are prone to punctures from rocks and debris, leading to water and debris ingress, which damages the tie rod and steering mechanism, and require significant longitudinal forces for extension and retraction, while being costly to manufacture.

Innovation Solution

A tie rod boot with a minimally thick accordion-shaped bellows section and strategically located ring-shaped protuberances to resist impacts and minimize holes, combined with an economical two-part clamp mold and central mandrel for injection molding, allowing for efficient manufacturing and reduced operational forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tie rod boot wall is made thicker to resist impacts from rocks and debris, then the resistance to punctures improves, but the forces required to extend and retract the boot increase and manufacturing costs increase

Engineering Contradiction:

Improveresistance to puncturesVSAvoidlongitudinal forces for extension and retraction

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The patent applies local quality by providing protuberances only at specific locations on the bellows walls where impact resistance is most needed, rather than uniformly thickening the entire wall. The protuberances are strategically positioned to face potential impact directions, providing localized reinforcement that resists punctures without requiring increased thickness throughout the entire boot structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs composite construction by combining the base boot material with protuberances made of impact-resistant material. This creates a composite structure where the protuberances provide enhanced puncture resistance at critical locations while the thinner base material maintains flexibility and reduces overall force requirements for extension and retraction.

Inventive Principle:

Principle #40Composite materials

2Reliability

If the tie rod boot wall is made thicker to resist impacts from rocks and debris, then the resistance to punctures improves, but manufacturing costs increase

Engineering Contradiction:

Improveresistance to puncturesVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by providing protuberances only at specific locations on the bellows walls where impact resistance is most needed, rather than uniformly thickening the entire wall. The protuberances are strategically positioned to face potential impact directions, providing localized reinforcement that resists punctures without requiring increased thickness throughout the entire boot structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs composite construction by combining the base boot material with protuberances made of impact-resistant material. This creates a composite structure where the protuberances provide enhanced puncture resistance at critical locations while the thinner base material maintains flexibility and reduces overall force requirements for extension and retraction.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If standard smooth bellows walls are used, then manufacturing is simpler and costs are lower, but the boot is easily punctured by rocks and debris

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidresistance to punctures

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary action by incorporating protuberances into the boot structure during the manufacturing process, specifically during injection molding. These protuberances are pre-formed as integral features of the bellows walls, providing impact resistance before the boot is installed and exposed to rocks and debris. The mold design includes provisions for forming these protective features without requiring post-manufacturing operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent converts the potential harm of complex manufacturing into benefit by using the injection molding process to create both the bellows structure and the protective protuberances in a single operation. The mold design incorporates the protuberance geometry, transforming what could be an additional manufacturing step into an integrated feature of the molding process itself.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS11415179B2Impact resistant tie rod boot

Publication Date: 2022.08.16 BRC RUBBER & PLASTICS INC

AI summary

A tie rod boot includes a minimally thick accordion shaped bellows section. One terminal end of the boot is secured to a steering mechanism and the other is secured to a tie rod. Protuberances are provided and are strategically located on the bellows walls for resisting impacts from rocks and other debris and minimizing holes through the tie rod. When the bellows is retracted and pairs of opposing bellows walls collapse towards each other, the protuberances of adjacent opposing walls nest with each other and contact the opposing wall. The protuberances can be step shaped rings or a ring of discrete protuberances which are step shaped or both. The step shaped protuberances are defined by a riser surface extending along a plane which is substantially perpendicular to the longitudinal axis of the boot and a tread annular surface which is substantially parallel with the longitudinal axis.