Synthetic Leather Steering Device Wrapping With Non-Radial Seams

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Synthetic leather, with lower heat resistance compared to natural leather, faces challenges in reducing distortion at sewing parts due to its inability to utilize heat treatment, leading to potential stress-related issues.

Innovation Solution

A steering device design incorporating synthetic leather parts made of different materials, with varying hardness and stretchability, where sewing parts are oriented away from the center to distribute stress effectively, reducing distortion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If heat treatment is applied to reduce distortion in sewing parts, then distortion is reduced, but this method cannot be used with synthetic leather due to its lower heat resistance

Engineering Contradiction:

Improvedistortion reductionVSAvoidheat resistance

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent changes the orientation parameter of the sewing part from radial (toward center) to non-radial (away from center), which fundamentally alters how stress is distributed in the synthetic leather wrapping, eliminating the need for heat treatment and avoiding the heat resistance limitation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent divides the synthetic leather wrapping into multiple parts with different materials (first synthetic leather part, second synthetic leather part) with different hardness and stretchability properties, allowing each segment to handle stress differently and reducing overall distortion without heat treatment

Inventive Principle:

Principle #1Segmentation

2Ease of manufacture

If sewing parts are oriented toward the center, then assembly is simplified, but stress concentration occurs causing distortion

Engineering Contradiction:

Improveassembly simplicityVSAvoiddistortion

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent introduces asymmetric orientation of sewing parts, positioning them away from the center in a non-radial direction. This asymmetric arrangement creates more uniform stress distribution across the wrapping surface, preventing the stress concentration that would occur with symmetric radial positioning toward the center

Inventive Principle:

Principle #4Asymmetry

3Device complexity

If single material synthetic leather is used, then manufacturing is simpler, but stress distribution is insufficient leading to distortion

Engineering Contradiction:

Improvematerial varietyVSAvoiddistortion

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by using different synthetic leather materials in different regions. The first synthetic leather part has different hardness from the second synthetic leather part, with each material strategically positioned to handle specific stress patterns, creating locally optimized stress distribution that prevents overall distortion

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12409878B2Steering device and method of wrapping synthetic leather

Publication Date: 2025.09.09 TOYODA GOSEI CO LTD

AI summary

The steering device includes a main body including a metal core, and a synthetic leather part wrapped around the main body. The synthetic leather part includes a first synthetic leather part, a second synthetic leather part made of a different material from the first synthetic leather part, and a first sewing part having a linear shape formed by sewing the first synthetic leather part and the second synthetic leather part together. The first sewing part is formed to extend in a direction not toward a center of the steering device in a front view of the steering device.