Vehicle Door Latch Single-Direction Assembly Mechanism

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Solution Overview

Problem

Existing vehicle door latch devices face inefficiencies in assembly due to the need to connect the outside lever and operating mechanism from perpendicular directions, leading to increased assembly steps, cost, and a larger device size.

Innovation Solution

A vehicle door latch device with an engagement assembly that allows connection from a single direction, utilizing positioning-guide means on casings to guide the engagement assembly, and an outside lever supported by the engagement assembly, eliminating the need for additional steps and reducing the device's height.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the outside lever is supported via a pivot shaft on the casing from a perpendicular direction, then the outside lever can be connected to the casing, but the assembly direction conflicts with the operating mechanism connection direction, requiring multiple assembly steps and reducing assembly efficiency

Engineering Contradiction:
Improveassembly efficiencyVSAvoidassembly steps
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges the outside lever support function into the engagement assembly by providing a pivot shaft on the engagement assembly body rather than on the casing. This allows both the operating mechanism and outside lever to be connected from the same direction (single-sided assembly), eliminating the need for perpendicular direction connections and reducing assembly steps.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the spatial arrangement by moving the pivot shaft from the casing to the engagement assembly body, effectively repositioning the outside lever support in a different dimensional configuration. This allows the outside lever to be connected from the same direction as the operating mechanism, transforming a multi-directional assembly problem into a single-direction assembly solution.

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

2Ease of operation

If the pivot shaft and outside lever are located below the engagement assembly on the casing, then the outside lever can be supported, but the casing height increases, making the whole door latch device larger

Engineering Contradiction:
Improveoutside lever supportVSAvoidcasing height
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The patent combines the pivot shaft and outside lever support function directly into the engagement assembly body, eliminating the need for separate casing structures to support the outside lever. This integration allows the outside lever to be positioned within the engagement assembly footprint rather than extending below the casing, thereby reducing the overall device height.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If the engagement assembly is connected to the operating assembly in a stationary state from different directions, then both components can be connected, but fixing operations are required and assembly efficiency decreases

Engineering Contradiction:
Improveconnection capabilityVSAvoidassembly efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent merges the connection directions by repositioning the pivot shaft on the engagement assembly body, enabling both the operating mechanism and outside lever to be connected from the same direction. This single-sided connection approach eliminates the need for multi-directional fixing operations and allows for more efficient assembly processes.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2940235B1Vehicle door latch device
Publication Date: 2017.09.20 MITSUI KINZOKU ACT
  • EP2940235B1 patent drawingFigure 1
  • EP2940235B1 patent drawingFigure 2
  • EP2940235B1 patent drawingFigure 3

AI summary

A vehicle door latch device comprises an engagement assembly comprising an engagement mechanism which is engagable with a striker of a vehicle body; a first casing which can be connected from one direction to an operating mechanism which can turn to a locking state and an unlocking state; an operating assembly comprising a second casing to which the engagement assembly is attached; an outside lever pivotally supported on the engagement assembly; and positioning-guide means by which the engagement assembly can be connected from the same direction as a direction in which the operating mechanism is connected to the first casing, thereby improving assembling efficiency and getting smaller.