Chair Arm Assembly with Multi-Axis Continuous Adjustment
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Solution Overview
Problem
Chairs with fixed arms do not provide sufficient adjustability to accommodate a range of body sizes and sitting preferences, and existing adjustable armrests are often complex, bulky, or require harsh adjustment actions.
Innovation Solution
An arm assembly with a post and a first member that is angularly adjustable relative to the post and an armrest that can translate and angularly adjust relative to the first member, allowing for a non-finite number of smooth, indiscrete adjustments in width and depth directions, with frictional arrangements to control movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If adjustable armrest mechanisms are added to provide adaptability for different body sizes and sitting preferences, then the adaptability is improved, but the device complexity increases
Solution Approach 1:
The armrest system is divided into multiple independent adjustment components: height adjustment via telescopic post, angular adjustment via first member rotating about first axis, and armrest position adjustment via second member rotating about second axis. Each segment handles a specific degree of freedom, simplifying the overall control mechanism while providing comprehensive adjustability.
Solution Approach 2:
The telescopic post features nested cylindrical members where the outer housing receives the inner post member, allowing height adjustment within a compact structure. The armrest assembly similarly nests the second member within the first member, enabling angular adjustment without increasing overall footprint.
2Adaptability or versatility
If multiple adjustment degrees of freedom are provided for width and depth directions, then the adaptability is improved, but the device complexity and bulkiness increase
Solution Approach 1:
The system transitions from fixed armrest positions to continuous dynamic adjustment ranges. The first member can rotate through a first angular range about the first axis, and the second member can rotate through a second angular range about the second axis, providing infinitely variable positioning rather than discrete steps.
Solution Approach 2:
The armrest positioning is achieved through angular rotations about two different axes rather than linear translations in two directions. This angular dimensionality allows width and depth adjustment to occur simultaneously and independently through rotational movements, reducing mechanical complexity.
3Reliability
If frictional arrangements are added to control movement and maintain position, then the stability is improved, but the device complexity increases
Solution Approach 1:
The system uses self-adjusting frictional elements that automatically maintain armrest position without requiring active locking mechanisms. The frictional arrangements between contacting surfaces provide passive position holding, eliminating the need for separate locks or actuators to maintain each adjustment position.
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
Provides adjustable armrests that can accommodate different body sizes and sitting preferences with smooth, continuous adjustments, reducing complexity and bulkiness while maintaining stability.
Implementation Method 1
the arm assembly comprises a non-finite number of angular adjustment positions of the first member relative to the post between the first angular movement limits
Implementation Method 2
the arm assembly comprises a non-finite number of translational adjustment positions of the armrest relative to the first member between the first translational movement limits
Implementation Method 3
the armrest is angularly adjustable relative to the first member about a second substantially upright axis between second angular movement limits, the arm assembly comprising a non-finite number of angular adjustment positions of the armrest relative to the first member between the second angular movement limits
Data Source
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AI summary
An arm assembly 100 for a chair having a post 1, a first member 2, and an armrest 4. The first member 2 is angularly adjustable relative to the post 1 about a first axis 3 between first angular movement limits, with a non-finite number of angular adjustment positions of the first member 2 relative to the post 1. The armrest 4 is operatively connected to the first member 2 to translationally slide generally forward and rearward relative to the first member 2 between first translational movement limits, with a non-finite number of translational adjustment positions of the armrest 4 relative to the first member 2. The armrest 4 is angularly adjustable relative to the first member 2 about a second substantially upright axis 5 between second angular movement limits, with a non-finite number of angular adjustment positions of the armrest 4 relative to the first member 2.