Chair Seat Return Force Mechanism for Reference Position Control
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Solution Overview
Problem
Conventional chairs with integral seats and backrests or synchronized locking mechanisms struggle to effectively return to a reference position when moved forward or backward, leading to reduced functionality and comfort during prolonged sitting.
Innovation Solution
A chair design with a return force generation mechanism that adjusts based on seat movement direction, using separate elastic members for forward and backward movements to ensure the seat can stop at an appropriate position and return to the reference position, while also allowing independent movement in the front-back and left-right directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional reaction force mechanism of a backrest is utilized to return the seat from a backward moved position to a forward normal position, then the seat can return to the forward position, but the chair swings forward or backward from a reference position and the function to return the chair back to the reference position is not realized
Solution Approach 1:
The patent divides the return force generation into two separate mechanisms: one for returning the seat from backward position to forward position (conventional backrest reaction force mechanism), and another for returning the seat to the reference position (new return force generation mechanism). This segmentation allows each mechanism to perform its specific function independently, resolving the contradiction between seat movement functionality and reliable return to reference position.
Solution Approach 2:
The patent introduces a new return force generation mechanism as an intermediary component that works in conjunction with the conventional backrest reaction force mechanism. This intermediary mechanism specifically provides the force needed to return the seat to the reference position, which the conventional mechanism alone cannot achieve, thus ensuring reliable return function while maintaining seat movement capability.
2Adaptability or versatility
If the seat is made movable forward and backward to enhance efficiency and improve posture, then the posture changeable range is increased, but the chair lacks the function to return to the reference position when moved forward
Solution Approach 1:
The patent designs the new return force generation mechanism to handle multiple scenarios: when the seat is moved backward, when the seat is moved forward, and when the seat needs to return to the reference position. This multi-functional design ensures that the chair can reliably return to the reference position regardless of the direction of movement, while maintaining the expanded posture changeable range.
Solution Approach 2:
The return force generation mechanism operates based on feedback from the seat's position relative to the reference position. When the seat deviates from the reference position in either direction, the mechanism generates appropriate return force to bring it back, ensuring reliable reference position return function while allowing freedom of movement for posture adjustment.
3Reliability
If separate elastic members are used for forward and backward movements to ensure appropriate stopping and returning, then the return function is improved, but the device complexity increases
Solution Approach 1:
The patent combines the new return force generation mechanism with the existing backrest reaction force mechanism in a way that they work together as an integrated system. The new mechanism is positioned and configured to complement the conventional mechanism, allowing both to function simultaneously without requiring completely separate systems, thus improving return function while limiting the increase in device complexity.
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 chair provides enhanced posture changeability, comfort, and reduced fatigue during long sitting periods by ensuring the seat can return to a balanced position and adjust to different user preferences, with a cost-effective design that reduces the number of components.
Implementation Method 1
a return force generation mechanism configured to generate a return force in a direction to return the seat moved from the reference position in the front-back direction to the reference position
Implementation Method 2
at the time of either forward or backward movement of the seat, the center of the gravity of the seat is likely to shift downward as the seat moves
Data Source
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AI summary
A chair according to the present invention has a reference position P located midway in a front-back direction in a movable range of a seat 2. The chair includes a return force generation mechanism 4 configured to generate a return force in a direction to return the seat 2 moved from the reference position P at least in the front-back direction to the reference position P. The return force generation mechanism 4 includes an elastic member 40 configured to increase the return force in the direction to return the seat to the reference position P as the amount of movement of the seat from the reference position P increases.