Wedge-Shaped Input Device for Hinge Stress Distribution

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Solution Overview

Problem

Existing hinged devices suffer from damage to displays and hinge assemblies due to concentrated stress forces when the device portions are closed, leading to potential cracking and hinge failure.

Innovation Solution

Employing a wedge-shaped input device with a rotational hinge assembly that distributes stress forces evenly across the device surfaces, reducing the risk of damage by ensuring the device portions contact along a continuous surface area when closed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the device portions are closed conventionally, then the device achieves a compact form factor, but concentrated stress forces cause damage to displays and hinge assemblies

Engineering Contradiction:
Improvecompact form factorVSAvoidconcentrated stress forces
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The input device is designed with a wedge-shaped profile where the thickness varies along its length, creating different local contact characteristics. The tapered configuration ensures that stress is distributed across multiple contact points rather than concentrated at a single location, protecting the display and hinge assembly from damage while maintaining compact form factor when closed.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the device portions are closed with conventional input devices, then portability is improved, but display cracking and hinge failure occur due to stress concentration

Engineering Contradiction:
ImproveportabilityVSAvoiddisplay and hinge assembly integrity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The input device employs an asymmetric wedge-shaped profile rather than a symmetric or uniform thickness design. This asymmetric configuration ensures that when the device portions are closed, the contact surface area is optimized to distribute forces evenly, preventing stress concentration that would lead to display cracking or hinge failure while maintaining ease of portability.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3834050B1Hinged device and associated input device
Publication Date: 2026.03.25 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3834050B1 patent drawingFigure 1A
  • EP3834050B1 patent drawingFigure 1B~1C
  • EP3834050B1 patent drawingFigure 2A~2B

AI summary

The description relates to hinged devices, such as hinged computing devices and associated input devices. One example can include first and second device portions and a hinge assembly rotatably securing the first portion and the second portion through a range of orientations. This example can also include a wedge-shaped input device extending between a first end having a first thickness and a second end having a second greater thickness. In a closed orientation the first and second portions simultaneously contact the first end and the second end.