Steering Lock Device With Perpendicular Extension Portions

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional steering lock devices are prone to unexpected movement of the lock member from the locking position to the unlocking position or vice versa due to external shocks or vibrations, caused by the biasing spring's interaction with the helical cam groove or inclined surfaces.

Innovation Solution

The lock member is biased from the locking position to the unlocking position by a displacement spring, and when in either position, it is held by extension portions perpendicular to the sliding direction, preventing unexpected movement by requiring significant force to traverse the displacement portion against the biasing force, eliminating the need for projections or recesses on the sliding contact surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the lock member is held by biasing force from a locking position side to an unlocking position side in the state where the lock member is held at the unlocking position, then unexpected movement due to shock or vibration is prevented, but the device complexity increases due to additional biasing mechanisms

Engineering Contradiction:
Improveprevention of unexpected lock member movementVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of using a spring to bias the lock member toward the locking position (conventional approach), the patent inverts the biasing direction by using the weight of the lock member itself and a cam mechanism to create a biasing force from the locking position side to the unlocking position side. This gravitational biasing replaces the need for additional springs in the unlocking direction, reducing complexity while maintaining reliability.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The lock member's own weight is utilized to generate the biasing force needed for preventing unexpected movement. The cam mechanism converts this gravitational force into the required directional biasing, allowing the system to use its own components (the lock member's mass) rather than requiring separate biasing elements for both directions.

Inventive Principle:
Principle #25Self-service

2Reliability

If the lock member is held at either locking position or unlocking position by extension portions perpendicular to sliding direction, then unexpected movement is prevented without projections or recesses, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveprevention of accidental locking or unlockingVSAvoidprecision of extension portions
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

Instead of using projections or recesses that extend in the sliding direction (one dimension), the patent uses extension portions that protrude perpendicular to the sliding direction (adding a second dimension). This dimensional change allows the lock member to be held at discrete positions without requiring precise machining of sliding surfaces, as the holding mechanism operates in a different spatial dimension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The extension portions create distinct segmented positions (locking and unlocking positions) along the sliding path. By dividing the continuous sliding motion into discrete positional segments held by the perpendicular extension portions, the system achieves reliable position holding without requiring the sliding surfaces themselves to be precisely machined.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the sliding member has a displacement portion with inclined surface, then the lock member can slide between positions, but rapping noises occur when using projections or recesses to hold positions

Engineering Contradiction:
Improvesmooth sliding motionVSAvoidrapping noises
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The holding mechanism is moved from the sliding direction dimension to a perpendicular dimension through the extension portions. This allows the inclined surface to remain smooth and continuous for sliding motion while the perpendicular extension portions provide position holding, eliminating the need for projections or recesses that would cause rapping noises during operation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

This configuration effectively prevents unintended lock member movement due to external forces, reducing the likelihood of accidental unlocking or locking and eliminating rapping noises associated with projections or recesses, ensuring reliable operation and enhanced safety.

Implementation Method 1

the lock member is biased from the locking position to the unlocking position by a displacement spring

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

the lock member slides on the displacement portion of the sliding member

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2578457B1Steering lock device
Publication Date: 2016.05.11 NISSAN MOTOR CO LTD
  • EP2578457B1 patent drawingFigure 1~2
  • EP2578457B1 patent drawingFigure 3
  • EP2578457B1 patent drawingFigure 4~5

AI summary

A steering lock device includes a lock member (7, 8) that is slidable between a locking position P1 and an unlocking position P2 and biased from the locking position P1 to the unlocking position P2 by a biasing member (76), and a sliding member (6) arranged slidably in a direction perpendicular to a sliding direction of the lock member (7, 8). At least any one of the lock member (7, 8) and the sliding member (6) includes a displacement portion (64c) inclined along the sliding direction of the sliding member (6) and toward a steering shaft. The lock member (7, 8) is displaced in conformity to inclination of the displacement portion (64c) in conjunction with slide of the sliding member (6) .