Exoskeleton Arm Support with Spring Cam Torque

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Solution Overview

Problem

Existing exoskeletons fail to effectively reduce fatigue and prevent injuries in workers engaged in repetitive tasks that require holding tools at static postures or above eye level, as they often obstruct blood flow and cause discomfort due to poor heat dissipation and restricted range of motion.

Innovation Solution

The exoskeleton vest design transfers the weight of the wearer's arms and tools through a structure that includes adjustable arm supports and a hip belt, providing assistive torque and adjustable cuffs to distribute force comfortably, allowing for prolonged use without strain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If exoskeleton devices apply forces to support the wearer's arms, then the wearer's stamina and strength are augmented, but the wearer experiences discomfort due to forces applied to the arms

Engineering Contradiction:

Improveaugmenting stamina and strengthVSAvoiddiscomfort from applied forces

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The arm support assembly applies force locally at the optimal position on the arm (between elbow and shoulder) rather than distributing force across the entire arm. This localized force application provides support where needed while minimizing discomfort and avoiding obstruction of motion in other areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The arm support assembly is designed to move dynamically with the wearer's arm movements rather than being a fixed structure. The assembly pivots about a horizontal axis and moves in transverse planes, allowing it to adapt to the wearer's range of motion and avoid obstructing natural arm movement while providing continuous support.

Inventive Principle:

Principle #15Dynamics

2Object-affected harmful factors

If exoskeleton devices use heavily padded force-applying surfaces, then the forces are distributed more comfortably, but heat dissipation is obstructed

Engineering Contradiction:

Improvecomfort from force distributionVSAvoidheat dissipation

Core Design Contradiction:

Object-affected harmful factorsVSTemperature

Solution Approach 1:

Instead of using extensive padding across the arm, the invention applies force locally at a specific region (upper arm between elbow and shoulder) through a cuff. This localized approach provides sufficient force distribution for comfort while leaving the rest of the arm exposed for heat dissipation.

Inventive Principle:

Principle #3Local quality

3Object-affected harmful factors

If exoskeleton devices increase the surface area of force application, then the forces are distributed more comfortably, but the range of motion is obstructed

Engineering Contradiction:

Improvecomfort from force distributionVSAvoidrange of motion

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The arm support assembly is designed as a dynamic structure that pivots about a horizontal axis and moves in transverse planes, matching the wearer's arm movements. This dynamic design provides sufficient force application area for comfort while maintaining full range of motion by moving with the arm rather than restraining it.

Inventive Principle:

Principle #15Dynamics

4Duration of action of moving object

If exoskeleton devices provide continuous support forces, then the wearer's fatigue is reduced, but blood flow to the extremities is impeded

Engineering Contradiction:

Improvereduced fatigue durationVSAvoidblood flow obstruction

Core Design Contradiction:

Duration of action of moving objectVSObject-affected harmful factors

Solution Approach 1:

The cuff applies support force locally at the upper arm region rather than constricting the entire arm. This localized force application provides continuous support to counteract fatigue while avoiding compression that would impede blood flow to the hand and forearm.

Inventive Principle:

Principle #3Local quality

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 exoskeleton vest enhances the wearer's stamina and strength, reduces fatigue, and prevents injuries by distributing the weight of tools and arms, ensuring comfortable use and adequate blood flow during prolonged tasks.

Implementation Method 1

The arm support assembly includes a spring configured to generate an assistive torque that counteracts gravity

Methodology Applied

Scientific EffectSpring: Spring

Implementation Method 2

The arm support assembly is configured such that contact between the spring, cam follower and cam profile determines an amount of the assistive force provided by the arm support assembly

Methodology Applied

Scientific EffectCam: Cam

Data Source

PatentUS10569413B2Exoskeleton and method of providing an assistive torque to an arm of a wearer

Publication Date: 2020.02.25 EKSO BIONICS INC

AI summary

An exoskeleton includes a first link that pivots in a transverse plane about a first vertical axis and a second link that pivots in a transverse plane about a second vertical axis. The second link is coupled to the first link. An arm support assembly is coupled to the second link and pivots about a horizontal axis. The arm support assembly includes a spring that generates an assistive torque that counteracts gravity. The arm support assembly provides the assistive torque to an arm of a wearer to support the arm of the wearer. The arm support assembly further includes a cam profile and a cam follower. Contact between the spring, cam follower and cam profile determines an amount of the assistive force provided by the arm support assembly. A cuff is coupled to the arm support assembly and the arm of the wearer.