Active Chair Joint with Force-Dependent Elastic Gap Control
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Solution Overview
Problem
Existing active-dynamic pendulum chairs lack optimal safety, mobility, restoring force, and manufacturability, leading to potential health issues from prolonged static sitting and limited movement range, while also being costly and having a short service life.
Innovation Solution
A joint arrangement featuring a hollow-cylindrical receiving cylinder with deformable elastic elements between conically tapering outer and inner wall sections, allowing force-dependent actuation and shape change, which reduces the bearing gap and increases deformation with user weight, limiting deflection and enhancing ergonomic support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a rigid connection is used between base and intermediate section, then structural stability is improved, but active dynamic movement capability deteriorates
Solution Approach 1:
The patent applies the dynamics principle by replacing the rigid connection with a dynamic pendulum joint that allows controlled movement. The intermediate section is connected to the base via a pendulum mechanism that enables active dynamic movement while maintaining structural stability through a defined range of motion and restoring force.
2Adaptability or versatility
If a pendulum joint with large bearing gap is used, then movement range is improved, but structural stability and safety deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the bearing gap dimensions to specific ranges (first radial gap: 2-10mm, second radial gap: 1-5mm) and configuring the conical surfaces with specific angles (5-15 degrees). These parameter optimizations ensure adequate movement range while maintaining structural stability and safety.
3Reliability
If complex pendulum joint design is used to improve safety and mobility, then reliability is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The patent applies segmentation by dividing the pendulum joint into modular components: outer joint shell, inner joint shell, receiving cylinder, and elastic elements. This modular segmentation enables independent manufacturing and assembly of each component, simplifying production while ensuring reliable performance through proper component interaction.
Solution Approach 2:
The patent uses elastic elements as intermediary components between the conical surfaces to provide the restoring force. This intermediary approach simplifies the overall design by using a simple elastic element rather than a complex spring mechanism, reducing manufacturing complexity while maintaining reliability.
4Force
If conical surfaces with large angle are used, then restoring force is improved, but movement range deteriorates
Solution Approach 1:
The patent optimizes the conical surface angle parameter to a specific range (5-15 degrees) to achieve the optimal balance between restoring force and movement range. This parameter optimization ensures that the elastic elements generate adequate restoring force while allowing sufficient pendulum movement for active dynamic sitting.
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 safe, varied, and defined movement range with improved ergonomic support, increased durability, and cost-effective production, reducing the risk of health issues associated with static sitting.
Implementation Method 1
The movable mounting of the receiving cylinder (20) is realized by means of deformable elastic elements (50), which are arranged in a bearing gap (60) between an outer wall section (21, 22) of the receiving cylinder (20) and an inner wall section (41, 42) of the joint shell (40), and the receiving cylinder (20) can be actuated in a force-dependent manner
Data Source
Figure 1
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Figure 4~5
AI summary
The invention relates to a joint arrangement (10) comprising a hollow-cylindrical accommodating cylinder (12), which extends in a cylinder-axis direction (Z), designed for accommodating one end of a column (30) of an active chair, wherein the latter is movably mounted in a substantially hollow-cylindrical outer joint shell (40), which is made up in two or more parts from joint-shell segments (45), wherein the movable mounting of the accommodating cylinder (20) is realized by means of deformable elastic elements (50) arranged dimensionally and positionally variably in a bearing gap (60) between a respective outer-wall portion (21, 22) of the accommodating cylinder (20) and an inner-wall portion (41, 42) of the joint shell (40), and the accommodating cylinder (20) can be actuated force-dependently, as result of which the shape and/or position of the elastic elements (50) changes in that the size of the bearing gap (60) changes, preferably decreases, in a radial direction (Rs) when the accommodating cylinder (20) is actuated in a cylinder-axis direction (Z).