Nested Leaf Spring Assembly for Compact High-Displacement Travel

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Solution Overview

Problem

Existing computing devices face challenges in providing a compact, tunable, and high-displacement spring mechanism that can fit within constrained spaces and offer customizable force profiles.

Innovation Solution

The implementation of a compact tunable leaf spring assembly (CTLSA) utilizing multiple nested leaf springs, where the first and second ends of the leaf springs are contained within the perimeter and not secured to either portion, allowing for interim regions to receive and deliver forces between device portions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If traditional spring configurations are used, then the spring mechanism can provide sufficient displacement and force, but the mechanism occupies excessive space and cannot fit within constrained device spaces

Engineering Contradiction:
Improvespace occupied by spring mechanismVSAvoidspring force and displacement capability
Core Design Contradiction:
Volume of moving objectVSForce

Solution Approach 1:

The patent employs multiple nested leaf springs where smaller leaf springs are positioned inside larger ones, sharing common mounting points. This nesting arrangement allows multiple spring elements to occupy the same spatial envelope, dramatically reducing the overall volume required while maintaining the cumulative force and displacement capabilities of multiple springs.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The nested leaf spring assembly serves multiple functions simultaneously: it provides biasing forces, allows controlled displacement, absorbs shocks, and fits within constrained spaces. The shared mounting points and nested configuration enable the mechanism to perform these functions while occupying minimal volume, making it suitable for portable computing devices.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Volume of moving object

If compact spring mechanisms are used to fit constrained spaces, then the volume is reduced, but the force profile becomes fixed and cannot be customized

Engineering Contradiction:
Improvespace occupied by spring mechanismVSAvoidcustomizability of force profile
Core Design Contradiction:
Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

The spring mechanism is segmented into multiple independent leaf springs that can be individually designed with different dimensions, materials, and mounting configurations. Each leaf spring contributes differently to the overall force profile, allowing engineers to customize the combined force characteristics by selecting appropriate individual spring parameters while maintaining a compact nested arrangement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The nested leaf spring assembly provides a tunable and adjustable force profile through dynamic configuration options. Engineers can modify the force characteristics by changing the number, size, or arrangement of nested springs, allowing the mechanism to adapt to different application requirements while maintaining compact dimensions.

Inventive Principle:
Principle #15Dynamics

3Length of moving object

If high-displacement spring mechanisms are used, then the spring can provide sufficient travel distance, but the mechanism size increases and cannot fit within constrained device spaces

Engineering Contradiction:
Improvedisplacement distance of springVSAvoidspace occupied by spring mechanism
Core Design Contradiction:
Length of moving objectVSVolume of moving object

Solution Approach 1:

The nested configuration allows multiple leaf springs to contribute their displacement in a stacked arrangement, achieving cumulative displacement distance while maintaining a compact overall footprint. The springs nest within each other's spatial envelope, allowing high total displacement without proportionally increasing the mechanism volume.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The nested leaf spring mechanism utilizes the vertical stacking dimension to achieve high displacement. Instead of extending horizontally in a single dimension, the springs are arranged in multiple layers sharing common mounting points, converting displacement accumulation from a one-dimensional extension to a multi-dimensional nested structure that fits within constrained spaces.

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 enables a high displacement spring mechanism that can fit within constrained device spaces, providing customizable force profiles and high stiffness in a small format, thus overcoming the limitations of traditional spring configurations.

Implementation Method 1

multiple nested leaf springs positioned to receive forces between the first portion and the second portion

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4172716B1Compact leaf spring assemblies
Publication Date: 2025.05.28 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP4172716B1 patent drawingFigure 1
  • EP4172716B1 patent drawingFigure 2A
  • EP4172716B1 patent drawingFigure 2B

AI summary

The present description relates to devices that include portions that are moveable relative to one another. One example device includes a leaf spring positioned to receive forces between a first portion and a second portion. The leaf spring can extend from a first end to a second end and can define a perimeter where the first end and the second end are contained within the perimeter and the first end and the second end are not secured to either the first portion or the second portion.