Gear Shift Knob Fixing System With Rotating Style Ring

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Solution Overview

Problem

Existing gearshift lever fastening systems are prone to separation under gear change stresses and require complete removal for access, leading to reliability issues and increased costs.

Innovation Solution

A fixing system with studs and a style ring, featuring concave and protruding indentations, allows for secure attachment and easy assembly/disassembly by rotation, distributing tightening forces and minimizing wear, while enabling access to the gear control box.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a collar and groove fixing system is used to attach the gaiter to the knob, then the assembly is simple to manufacture, but the fixing is unreliable under gear change stresses and may separate

Engineering Contradiction:
Improvefixing reliabilityVSAvoidfixing system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fixing system is divided into multiple independent studs (typically three) distributed around the circumference of the knob, each engaging with corresponding notches in the gaiter. This segmentation distributes the mechanical stress across multiple points rather than concentrating it in a single collar-groove interface, significantly improving reliability under gear change stresses while maintaining manufacturing simplicity through modular stud components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The studs are designed with cylindrical geometry and engage with circular notches in the gaiter, creating a radial distribution of fixing points around the knob's circumference. This circular arrangement optimally distributes stress in all directions during gear changes, providing reliable fixation while using simple cylindrical stud shapes that are easy to manufacture.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of operation

If the pommel and bellows are completely removed for access to the gearbox, then full access is achieved, but additional costs are generated and assembly time increases

Engineering Contradiction:
Improveaccess to gearboxVSAvoiddisassembly and reassembly time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The style ring is extracted as a separate, independently removable component from the gaiter-knob assembly. The style ring can be removed without detaching the gaiter from the knob, allowing access to the upper part of the gearbox lever while leaving the lower gaiter portion in place. This selective removal provides necessary access while minimizing disassembly time and avoiding the need to completely remove the pommel and bellows.

Inventive Principle:
Principle #2Taking out (Extraction)

3Strength

If the studs are evenly distributed over the periphery of the style ring, then the tightening force is distributed evenly, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvetightening force distributionVSAvoidstud positioning precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The studs are integrated directly into the mold during gaiter manufacturing, combining the stud formation process with the gaiter molding process. This merging of operations ensures precise circular positioning of the studs relative to each other through the mold's inherent geometric precision, while eliminating separate machining or assembly steps that would otherwise be required to achieve accurate stud distribution.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gaiter is designed as a multi-functional component that simultaneously serves as the protective bellows covering and as the mounting structure for the studs. The studs are formed as integral features of the gaiter itself rather than separate attachments, allowing the gaiter to provide both protective coverage and secure fixation functions while maintaining precise stud positioning through the molding process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2771201B1System for fixing the knob of a gear shift lever to a boot
Publication Date: 2015.11.04 RENAULT SA
  • EP2771201B1 patent drawingFigure 1
  • EP2771201B1 patent drawingFigure 2~3

AI summary

A system for fixing a knob (1) to a boot of a gear shift lever provided with a style ring comprising: at least two studs (3) present on an insert (2) integral with the knob (1) and each having a concave cavity, at least two cutouts (8) allowing the studs (3) to pass therethrough when mounting the knob (1) on the assembly formed by the boot and the style ring, and at least two projecting indentations (10, 11) capable of engaging with the concave cavities of the studs (3) of the insert (2), the cutouts (8) and the projecting indentations (10, 11) being included on the style ring, the style ring being capable of being rotated relative to the gear shift knob (1) in order to fix the gear shift boot to the gear shift knob (1).