Parking Lock Release Lever With Rounded Contact Unlocking

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing emergency parking release mechanisms for automatic transmissions are inadequate, particularly during power outages or when the locking system fails, as they may require complex designs and fail to ensure reliable manual unlocking from the park position.

Innovation Solution

An emergency parking unlocking device featuring a gear lever with a disengagement part having a rounded convex face for point contact, allowing the lever to pivot and facilitating manual actuation using a control cable and actuator mechanism, which simplifies design and manufacturing by avoiding complex shapes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional disengagement part with a flat or complex shape is used, then the contact area with the gear lever is larger, but the lever cannot pivot easily around its axis of rotation

Engineering Contradiction:
Improvelever pivoting easeVSAvoiddisengagement part shape complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The disengagement part features a rounded convex face that contacts the gear lever at or near a single point. This curved geometry enables the lever to pivot smoothly around its axis of rotation when the disengagement part is actuated, transforming linear motion into rotational motion without requiring complex lever geometry.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of operation

If a point contact design is implemented, then the lever can pivot easily, but the design and manufacture become more complex

Engineering Contradiction:
Improvelever pivoting capabilityVSAvoiddisengagement part geometry
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

By making the disengagement part itself curved (rounded convex face), the patent achieves point contact and lever pivoting without requiring the gear lever to have complex geometry. The complexity is confined to a single, simple-to-manufacture component rather than requiring complex shaping of multiple parts.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Ease of manufacture

If the rounded portion occupies a small area, then the design is simpler, but the contact reliability during actuation is reduced

Engineering Contradiction:
Improverounded portion design simplicityVSAvoidcontact reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent specifies that the rounded portion should occupy at least 10% of the disengagement part's face area, with preferred ranges of at least 30%, 50%, or 70%. This parameter optimization ensures sufficient contact area for reliable actuation while maintaining the point-contact pivoting action, balancing manufacturing simplicity with operational reliability.

Inventive Principle:
Principle #35Parameter changes

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

Enables reliable and efficient manual unlocking of the gearbox from the park position, ensuring vehicle safety and ease of use even in faulty conditions, with a simplified design that reduces manufacturing complexity.

Implementation Method 1

The rounded shape of the face of the disengagement part opposite the lever allows for substantially point-like contact with the gear lever. This point-like contact allows the lever to pivot around its axis of rotation when the disengagement part is moved.

Methodology Applied
Scientific EffectPoint contact:

Implementation Method 2

The actuating mechanism comprises an actuator on which the user acts and a wired connection arranged to connect the disengagement part to the actuator, such that a movement of the actuator causes a movement of said disengagement part from an initial position of non-contact with the lever to a position of contact with said lever.

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Implementation Method 3

The actuator is preferably rotatable in a first direction, said mechanism being arranged in such a way that a rotation of the actuator in the first direction causes the disengagement part to move from its initial position to its position of contact with the lever, preferably in a linear translation.

Methodology Applied
Scientific EffectMechanical actuation:

Data Source

PatentEP4491912A1Emergency parking lock release device for automatic transmission
Publication Date: 2025.01.15 RENAULT SA
  • EP4491912A1 patent drawingFigure 1~2
  • EP4491912A1 patent drawingFigure 3~4
  • EP4491912A1 patent drawingFigure 5~6

AI summary

Emergency parking release device (1) for an automatic transmission, comprising: - A gear lever (40) movable between a locking position of a gearbox in the parking position and a gearbox unlocking position, - An actuating mechanism (10) capable of being manually actuated by a user to move the gear lever (40) from its locking position to its unlocking position, the actuating mechanism (10) having at one of its distal ends a disengagement piece (14) having on its face (15) opposite the lever a rounded portion convex outwards (16), said rounded portion (16) being arranged to come at least partially into contact with said gear lever (40) when said mechanism (10) is actuated, causing said lever (40) to move from its locking position to the unlocking position.