Gear Shift Lever Decoupling Device Radial Play

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Solution Overview

Problem

Current gearboxes with Bowden or tie-rod control systems transmit oscillating movements from the gear coupling lever to the gear shift lever inside vehicles, causing troublesome oscillations due to direct connection, which are amplified and result in discomfort.

Innovation Solution

A decoupling device featuring a conical member with a cylindrical pin and a radially playable ball that allows sliding, secured by a fixing means, decouples the gear coupling lever from the Bowden cable or tie-rod, reducing oscillations through the play between the pin and ball.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the gear coupling lever is directly connected to the Bowden cable or tie-rod, then the gear shift control is transmitted directly, but troublesome oscillations are amplified and transmitted to the gear shift lever

Engineering Contradiction:
Improvegear shift control transmissionVSAvoidoscillations of gear shift lever
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary decoupling device between the gear coupling lever and the Bowden cable/tie-rod. This device includes a connection piece with a cylindrical pin and a ball element that provides radial play, serving as a mediator that transmits the gear shift control signal while blocking the transmission of oscillations. The intermediary absorbs harmful vibrations while maintaining functional connectivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention extracts the harmful oscillation transmission path from the gear shift control system by introducing a decoupling mechanism. The ball element with radial play G separates the oscillation component from the control signal, taking out the harmful factor while preserving the useful function of gear shift actuation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Object-affected harmful factors

If a decoupling device with radial play is introduced between the gear coupling lever and Bowden cable, then oscillations are reduced, but the device complexity increases

Engineering Contradiction:
Improveoscillations of gear shift leverVSAvoidcoupling assembly structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The decoupling device segments the gear shift control system into distinct functional components: the gear coupling lever, the connection piece with cylindrical pin, the ball element with radial play, and the Bowden cable/tie-rod. This segmentation allows each component to perform its specific function independently, simplifying the overall system architecture while reducing oscillations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the mechanical parameter of the connection from rigid (direct connection) to compliant (radial play G between pin and ball). By introducing a specific play parameter, the system transforms the transmission characteristics to filter out high-frequency oscillations while maintaining low-frequency control signal transmission.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If a ball and cylindrical pin connection with radial play is used, then oscillations are attenuated, but manufacturing precision requirements increase

Engineering Contradiction:
Improveoscillations attenuationVSAvoidfit between pin and ball
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The decoupling device applies local quality differentiation by providing radial play G only in the radial direction between the cylindrical pin and ball element, while maintaining precise axial positioning. This localized compliance allows oscillation attenuation in radial directions without compromising the axial alignment and connection stability required for proper gear shift actuation.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP1801467B1Decoupling device between a gearbox and gear shift lever of motor vehicles
Publication Date: 2011.10.19 FIAT AUTO SPA
  • EP1801467B1 patent drawingFigure 1
  • EP1801467B1 patent drawingFigure 2

AI summary

There is described a decoupling device between a gearbox and gear shift lever for a motor vehicle, comprising a connecting ball (10) for the end-piece of a Bowden cable or a tie-rod connecting the gear shift lever to a rod (4) for operating the gearbox by means of a connection assembly comprising a pin (8) which is fixedly joined to the rod (4); the ball (10) is engaged with the end-piece of the coupling cable or tie-rod. The ball (10) is mounted on the pin (8) with radial play (G) so as to be free to slide.