Armrest Height Locking Assembly With Audible Position Feedback

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Solution Overview

Problem

Existing height adjustment devices for seating furniture, particularly office chairs, lack adaptability to different chair types and do not provide clear auditory feedback during adjustments, leading to potential uneven armrest positioning.

Innovation Solution

A height adjustment device featuring a pivotable locking pin assembly with a spring-loaded mechanism and audible click feedback, allowing easy adaptation to various chair stems and ensuring secure, even armrest positioning with minimal components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a spring-loaded locking pin assembly with audible click feedback is implemented, then user feedback and positioning precision are improved, but device complexity increases

Engineering Contradiction:
Improvearmrest positioning precisionVSAvoidlocking mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The locking pin assembly is nested within the armrest structure, with the pin itself nested within a groove in the stem. The spring mechanism is contained within the same assembly, creating a compact nested structure that provides audible feedback without requiring separate external components for each function.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The locking and positioning functions are merged into a single locking pin assembly. The audible click feedback is integrated into the locking mechanism itself through the engagement of the pin with notches in the groove, eliminating the need for separate feedback mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a robust locking mechanism with multiple components is used, then reliability of armrest positioning is improved, but manufacturing cost and device complexity increase

Engineering Contradiction:
Improvearmrest locking reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The locking mechanism is segmented into distinct functional elements: the locking pin, the spring, the groove with notches, and the adjustment lever. This segmentation allows each component to be manufactured separately using simple processes and then assembled, improving manufacturability while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spring-loaded locking pin automatically engages with the notches in the groove to secure the armrest at selected heights. The mechanism self-locks without requiring additional fasteners or complex assembly steps, reducing manufacturing complexity while ensuring reliable positioning.

Inventive Principle:
Principle #25Self-service

3Device complexity

If a simple locking mechanism with minimal components is used, then device complexity and manufacturing cost are reduced, but adaptability to different chair types decreases

Engineering Contradiction:
Improvelocking mechanism complexityVSAvoidadaptability to different chair stems
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The locking pin assembly is designed with a universal groove structure that can accommodate various stem diameters and configurations. The notched groove pattern can be adjusted to match different chair types, allowing the same basic mechanism to function across multiple product variants without requiring redesign.

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

4Loss of information

If audible click feedback is added to indicate adjustment position, then user experience and positioning accuracy are improved, but device complexity increases

Engineering Contradiction:
Improveadjustment position feedbackVSAvoidlocking mechanism complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The audible click feedback is generated directly by the locking mechanism itself. As the locking pin engages with each notch in the groove during armrest adjustment, a distinct click sound is produced, providing immediate tactile and auditory confirmation of the selected height position without requiring separate sensors or indicators.

Inventive Principle:
Principle #23Feedback

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 solution provides a robust, cost-effective height adjustment mechanism that is easily adaptable to different chair types, offering clear auditory feedback for precise armrest positioning and automatic return to locked positions, ensuring secure and even adjustments.

Implementation Method 1

a lower part of the armrest 1 preferably encloses the upper part of the stem 5, and thus conceals and protects that part of the locking pin assembly 2 which at any given time projects up and out from the stem 5

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP2874518B1A height adjustment device for an armrest
Publication Date: 2016.04.06 SCANDINAVIAN BUSINESS SEATING
  • EP2874518B1 patent drawingFigure 1
  • EP2874518B1 patent drawingFigure 2
  • EP2874518B1 patent drawingFigure 3~4

AI summary

It is provided a height adjustment device for an armrest (1) for a chair or other seating furniture, preferably an office chair, comprising a stem (5) for the armrest (1), which stem (5) is provided with an internal groove (4) for adjustably and lockably telescopic intake of an inner extended element connected to the armrest (1) for adjusting the height of the armrest (1). The inner extended element includes a locking pin assembly (2) with two mutual in the longitudinal direction displaceable parts (12, 13) for height adjustment, as a number of locking grooves (7) for intervention with a pre-tensioned locking pin (6) are provided in the longitudinal direction of the locking pin assembly (2), which locking grooves (7) in an open position are provided by aligned open portions or notches (15, 16) respectively arranged in the longitudinal direction of the parts (12, 13), and which in a closed position are brought out of alignment and is closed by relative displacement of the two parts (12, 13), and which thus presses the pre-tensioned locking pin (6) out of the locking groove (7) due to relative shaping of the open portions or notches (15, 16), for height adjustment of the armrest (1) to a chosen one of the locking grooves (7) by operating an adjustment lever (11) operatively connected to one of the parts (12, 13) for providing of said displacement between the parts (11, 13).