Gearbox Control Lever Locking for Precise Shift Synchronization

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Solution Overview

Problem

Existing systems for immobilizing control levers in gearboxes lack a reliable method for provisional immobilization at a selected ratio, leading to potential misalignment and synchronization issues between the control lever and the gear change lever.

Innovation Solution

A provisional immobilization part is designed to temporarily fix the control lever at a selected ratio, comprising a positioning and locking frame with a locking boss, a maneuvering handle, and an immobilization arm, all made from a monobloc plastic material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the control lever is manipulated before connecting it to the gearshift lever, then the control lever can be positioned at a selected gear, but the control lever may move to an undesired gear when connecting it to the gearshift lever

Engineering Contradiction:
Improvepositioning precision of control leverVSAvoidsynchronization reliability between control lever and gearshift lever
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by providing a temporary immobilizing part that pre-positions the control lever at the desired gear ratio before connection to the gearshift lever. The control lever is immobilized in advance at the correct position, preventing any unintended movement during the connection process, thus ensuring synchronization reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The temporary immobilizing part acts as an intermediary device between the control lever and the gearshift lever connection process. It provides a stable reference position for the control lever during assembly, mediating the positioning requirement and preventing misalignment when the control cables or rods are connected.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a plastic part is used to immobilize the gear lever, then the immobilization function is achieved, but the structure becomes relatively complex

Engineering Contradiction:
Improveimmobilization reliabilityVSAvoidstructural complexity of immobilizing device
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into a single temporary immobilizing part that combines the positioning feature, the immobilization mechanism, and the lever connection interface. By integrating these functions into one component rather than using separate parts, the structure is simplified while maintaining reliable immobilization of the control lever at the selected gear ratio.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If the control lever is connected by control cables or rods to the gear change lever, then the gear selection is transmitted, but synchronization adjustment becomes difficult

Engineering Contradiction:
Improvegear selection transmission efficiencyVSAvoidadjustment ease of control synchronization
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The temporary immobilizing part enables preliminary positioning of the control lever at the exact desired gear ratio before the control cables or rods are connected. This pre-positioning eliminates the need for difficult synchronization adjustments after connection, as the control lever is already correctly aligned with the gear change lever positions.

Inventive Principle:
Principle #10Preliminary action

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 immobilization part ensures precise positioning of the control lever at the desired gear ratio, preventing synchronization errors and simplifying the assembly process by eliminating the risk of incorrect lever alignment.

Implementation Method 1

the branch with locking boss being able to be elastically separated from the other branch

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3394481B1Temporary locking device for gearbox control lever
Publication Date: 2025.04.09 STELLANTIS AUTO SAS
  • EP3394481B1 patent drawingFigure 1
  • EP3394481B1 patent drawingFigure 2~3
  • EP3394481B1 patent drawingFigure 4~5

AI summary

The invention relates to a motor vehicle gearbox equipped with a component that temporarily immobilises the gearshift lever of this box. According to the invention, the gearbox (1) comprises an immobilising component (4) comprising at least one positioning and locking part (7) for positioning and locking the immobilising component (4) on a lug (8) secured to the casing (3) of the gearbox (1) and an immobilising part (6) for immobilising the gearshift lever (2) of the gearbox in a selected gear, which part (6) comprises an arm (15), of which the free end (17) is configured to immobilise the gearshift lever (2) in the selected gear of the gearbox (1). The invention is suitable for use in the automotive industry.