Gearbox Control Cable End With Leaf-Spring Rod Locking

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing solutions for fixing gear selection cable end pieces on internal gearbox control levers are complex and costly, requiring additional locking means due to the lack of efficient use of spring elasticity for adjustment and immobilization.

Innovation Solution

A cable end piece with a two-position leaf spring and a locking button that allows for adjustment and robust fixing, utilizing the spring's elasticity to facilitate the positioning of the control rod, with the button switching between a transport/adjustment position and an operational position to ensure precise alignment and locking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional cable end pieces use a helical spring with additional locking means, then the rod can be immobilized in position, but the device becomes cumbersome and costly

Engineering Contradiction:
Improveimmobilization of rodVSAvoidlocking means
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the locking function from a separate locking mechanism and integrates it into the button itself. The button's head with protrusions directly engages with corresponding recesses in the rod, eliminating the need for additional locking means while maintaining reliable immobilization of the rod in the adjusted position.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges multiple functions into the button component: it acts as both the adjustment actuator (pressing the leaf spring) and the locking mechanism (via its head protrusions engaging the rod). This consolidation simplifies the device structure while ensuring reliable rod immobilization.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If the cable end piece uses additional locking means to secure the rod, then the rod position is fixed, but the assembly process becomes more complex and costly

Engineering Contradiction:
Improvefixing of rod positionVSAvoidassembly process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The leaf spring is pre-configured in the cable end piece to automatically engage with the rod when the button is released. This preliminary setup eliminates the need for complex assembly procedures, as the locking action occurs automatically through the spring's elastic recovery, simplifying both manufacturing and assembly processes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The leaf spring provides self-locking functionality through its elastic properties. When the button is pressed and released, the spring automatically engages or disengages the locking protrusions, eliminating the need for manual intervention or complex assembly steps to secure the rod position.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If the rod position is adjustable during assembly, then precise alignment can be achieved, but additional adjustment mechanisms are required

Engineering Contradiction:
Improvealignment of rodVSAvoidadjustment mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The leaf spring provides dynamic adjustability by allowing the rod to be freely positioned during adjustment, then locking it in place when the button is pressed. This dynamic mechanism enables precise alignment without requiring complex adjustment devices, as the spring's elastic properties allow easy repositioning and secure locking.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The button acts as an intermediary between the adjustment action and the locking function. By pressing the button, the operator mediates the transition from the adjustable state (spring disengaged) to the locked state (spring engaged), enabling precise alignment while maintaining device simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Simplifies the assembly process, reduces costs, and ensures precise alignment and locking of the cable end piece, allowing for efficient transmission of movement between the external and internal control levers, while maintaining robustness and ease of assembly.

Implementation Method 1

a two-position leaf spring (2), and a locking button (3)... overcome the elastic resistance of a spring

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3746682B1Cable end and device for adjusting a control cable on a gearbox
Publication Date: 2022.03.09 RENAULT SA
  • EP3746682B1 patent drawingFigure 1~3
  • EP3746682B1 patent drawingFigure 4~7B
  • EP3746682B1 patent drawingFigure 8A~8C

AI summary

The invention relates to a cable end (1) for external control of a gearbox (1), including an end body (1e) which receives the end of a control rod (5) connected to a gear shift selector, so as to be able to adjust the position thereof on the cable end, and an attachment portion (1a) for attaching the cable end to an internal control lever (12) of the gearbox, characterised in that it comprises a leaf spring (2) which toggles, when pushed by a button (2) inserted onto the cable end, between a first position in which the rod (5) can move longitudinally inside the cable end (1) in order to perform the adjustment, and a second position in which the button (3) holds the rod (5) in the adjustment position inside the cable end.