Saddle Vehicle Gear Shift With Neutral Lockout Control

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Solution Overview

Problem

Existing gear shift mechanisms in saddle vehicles, particularly in performance motorbikes, often result in accidental engagement of the neutral gear during gear changes, leading to unbalancing, especially at high speeds.

Innovation Solution

A gear shift mechanism with a block device and control means that prevents accidental engagement of the neutral gear by allowing engagement of the first gear from neutral in one direction and inhibiting it in the opposite direction, featuring a selector drum, stop element, and block element with elastic elements and control levers for remote actuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional gear shift mechanism is used, then gear changes can be made, but accidental engagement of neutral gear occurs during gear changes

Engineering Contradiction:
Improvegear engagement reliabilityVSAvoidgear shifting operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The block device is configured to preemptively prevent accidental neutral gear engagement by blocking the selector drum rotation in the second change direction when the first gear is engaged. The block element positioned against the stop element creates a mechanical constraint that stops the drum rotation before neutral gear can be engaged, thus preventing the harmful effect before it occurs.

Inventive Principle:
Principle #9Preliminary anti-action

2Reliability

If a block device is added to prevent neutral gear engagement, then reliability improves, but device complexity increases

Engineering Contradiction:
Improvegear engagement reliabilityVSAvoidgear shift structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The gear shift mechanism is segmented into functionally independent components: the selector drum for gear selection, the block device with block element and stop element for preventing neutral engagement, and the control means for activating/deactivating the block. This segmentation allows each component to perform its specific function efficiently while maintaining overall system manageability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The block device operates autonomously based on the gear engagement state. When the first gear is engaged, the block element automatically positions itself against the stop element to block neutral gear engagement without requiring continuous external control. The system self-regulates based on the mechanical state of the gear selection.

Inventive Principle:
Principle #25Self-service

3Reliability

If the block device is always active, then neutral gear engagement is prevented, but the rider cannot intentionally engage neutral gear

Engineering Contradiction:
Improveprevention of accidental neutral engagementVSAvoidgear selection flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The block device transitions between two dynamic states: blocked and unblocked. The control means enables the rider to switch between these states based on operational needs. When the control means is in the first position, the block element is positioned against the stop element to prevent neutral engagement. When shifted to the second position, the block element is repositioned to allow neutral gear engagement, providing dynamic adaptability.

Inventive Principle:
Principle #15Dynamics

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 mechanism reliably prevents neutral gear engagement during gear changes, ensuring stable gear transitions and preventing motorbike unbalancing, particularly during high-speed maneuvers.

Implementation Method 1

a block element (142), adapted to switch between a first configuration, wherein the block element (142) is fastened to the stop element (141), and a second configuration, wherein the elastic element pushes the block element (142) against the stop element (141)

Methodology Applied
Scientific EffectElastic element: Elasticity

Data Source

PatentEP3942201B1Gear shift of a saddle vehicle and vehicle comprising this gear shift
Publication Date: 2025.07.30 PIAGGIO & C SPA
  • EP3942201B1 patent drawingFigure 1~1A
  • EP3942201B1 patent drawingFigure 2
  • EP3942201B1 patent drawingFigure 3~4

AI summary

A gear shift (100) is described for a saddle vehicle (M) comprising a shift lever (110), a selecting element (130) actuated through the shift lever (110) and a selector drum (150) connected to the selecting element (130) and adapted to engage gears. The gear shift (100) further comprises a block device (140) functionally connected to the selector drum (150) and configured so as to be switched between: a first configuration, wherein the block device (140) allows engaging a first gear (I) from a neutral gear (N) in a first change direction (Up), a second configuration, wherein the block device (140) inhibits the subsequent engagement of the neutral gear (N) from the first gear (I) in a second change direction (Dwn). Control means (120) of the block device (140) are further provided, actuated by a rider (G) so as to define a third configuration, wherein the block device (140) is disabled in order to allow engaging the neutral gear (N) from the first gear (I) in the second change direction (Dwn).