Steering Lock Gear Nesting for Compact Low-Force Operation

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Solution Overview

Problem

Conventional steering lock devices face challenges in compactness due to their three-dimensional or planar structures, which affect their spatial efficiency and operational forces.

Innovation Solution

A steering lock device with a two-stage gear and internal teeth main gear configuration, where the worm and rod are accommodated in the circumferential region of the main gear, allowing for a compact planar structure and enhanced operational efficiency by increasing the number of teeth and reduction ratio, thereby reducing the operating force required.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the motor shaft is inclined with respect to the frame surface and the gear rotation surface is orthogonal to the frame surface, then the steering lock device achieves proper mechanical engagement, but the device has a three-dimensional structure that increases space occupation

Engineering Contradiction:
Improvemechanical engagementVSAvoidspace occupation
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent reorients the motor shaft and gear rotation surface to be parallel with the frame surface instead of inclined/orthogonal, transforming the spatial arrangement from three-dimensional to planar. This dimensional change allows components to be arranged in a two-dimensional plane, reducing overall space occupation while maintaining proper mechanical engagement through alternative positioning of the worm and gear within the planar configuration

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

2Ease of operation

If the worm and rod are positioned outside the circumferential region of the main gear, then the components have sufficient space for operation, but the device occupies more space and loses compactness

Engineering Contradiction:
Improvecomponent operation spaceVSAvoiddevice compactness
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent positions the worm and rod within the circumferential region of the main gear, nesting these components inside the gear's operational space. The worm is arranged to engage with the gear teeth from within the circumferential boundary, and the rod is positioned to operate along with the cam member without exceeding the gear's outer diameter. This nesting arrangement allows all components to function properly while maintaining a compact, space-efficient device configuration

Inventive Principle:
Principle #7Nested doll (Nesting)

3Force

If the number of teeth on the gear is increased to reduce operating force, then the reduction ratio increases and operating force decreases, but the gear diameter increases occupying more space

Engineering Contradiction:
Improveoperating forceVSAvoidgear diameter
Core Design Contradiction:
ForceVSVolume of moving object

Solution Approach 1:

By nesting the worm within the circumferential region of the main gear and arranging the rod to operate within the same boundary, the patent enables the gear to have a larger number of teeth for higher reduction ratio without proportionally increasing the overall device diameter. The compact nested arrangement allows the gear to utilize its circumferential space more efficiently, accommodating more teeth within the same radial envelope, thus reducing operating force without significantly increasing space occupation

Inventive Principle:
Principle #7Nested doll (Nesting)

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 device achieves a compact size while maintaining efficient operation by overlapping the worm and rod with the main gear, preventing reduction in operating force and improving initial pulling force for unlocking.

Implementation Method 1

a worm (30) attached to the motor shaft (21)

Methodology Applied
Scientific EffectWorm drive: Worm Drive

Implementation Method 2

a two-stage gear (40) configured to rotate along the planar portion and includes a first gear (41) engaged with the worm

Methodology Applied
Scientific EffectGear meshing: Gear

Implementation Method 3

a cam member (60) which is provided integrally with the main gear (50) and rotates around the same axis as the main gear

Methodology Applied
Scientific EffectCam mechanism: Cam

Data Source

PatentEP4219248B1Steering lock device
Publication Date: 2024.11.20 ALPHA
  • EP4219248B1 patent drawingFigure 1
  • EP4219248B1 patent drawingFigure 2
  • EP4219248B1 patent drawingFigure 3~4

AI summary

A steering lock device includes a motor that is configured to rotate a motor shaft, a worm attached to the motor shaft of the motor, a main gear that is configured to rotate along with rotation of the worm, a cam member integrally provided with the main gear, and a rod which includes an insertion and extraction portion that is configured to be inserted into and extracted from an opening provided on a steering shaft side in accordance with an operation of the cam member along with rotation of the main gear. At least a part of at least one member of the worm and the insertion and extraction portion is configured to be accommodated in a circumferential region of the main gear when the main gear is viewed in a plan view along a rotation axis direction of the main gear.