Arcuate Seat and Backrest Assembly for Dynamic Posture Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional seat technologies fail to provide independent and dynamic motion for both the seat and backrest, leading to instability and discomfort during prolonged use, as they do not effectively balance the user's body weight and adjust to various postures.
Innovation Solution
A seat assembly with a mounting system that allows the seat to move independently along an upwardly concaved arcuate path and the backrest to move independently along a forwardly concaved arcuate path, both with centers of curvature proximate to the user's center of mass, using a combination of rollers, sliders, and spring forces to maintain equilibrium and adjust to different postures without manual intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional static seat technology is used, then stability is provided, but comfort and responsiveness to body motion are lost
Solution Approach 1:
The patent applies dynamics by transforming the static seat structure into a dynamic system where the seat and backrest can move independently along arcuate paths. The seat is mounted to move along an upwardly concaved arcuate path while the backrest moves along a forwardly concaved arcuate path, allowing continuous adjustment to user posture without manual intervention. This dynamic capability provides responsiveness to body motion while maintaining stability through controlled movement along predetermined paths.
Solution Approach 2:
The patent segments the seat assembly into independently movable components - the seat pan and the backrest - each capable of moving along its own arcuate path. This segmentation allows each component to respond independently to user posture changes, with the seat providing fore-and-aft motion and the backrest providing recline motion, thereby achieving both stability and responsiveness.
2Device complexity
If the seat and backrest are coupled together for movement, then structural simplicity is maintained, but independent adjustment to various postures is limited
Solution Approach 1:
The patent divides the seating system into two independently movable segments: the seat pan mounted on arcuate rails and the backrest mounted on separate arcuate rails. Each segment has its own movement mechanism with independent degrees of freedom, allowing the seat to move fore-and-aft while the backrest independently adjusts recline angle, providing versatile posture adaptation without excessive structural complexity.
Solution Approach 2:
The patent adds dimensional independence by allowing the seat and backrest to move in different arcuate paths with different centers of curvature. The seat follows an upwardly concaved arc while the backrest follows a forwardly concaved arc, creating independent adjustment capabilities in multiple dimensions rather than coupled single-axis movement.
3Measurement precision
If manual adjustment mechanisms are used, then precise posture control is achieved, but continuous dynamic adjustment is lost
Solution Approach 1:
The patent implements self-service by designing the seat and backrest to automatically adjust to user posture through their own weight and movement. The independent arcuate movement mechanisms allow the components to self-adjust along predetermined paths without requiring manual operation of levers or buttons, providing continuous dynamic adjustment while maintaining precise posture control through the geometry of the arcuate rails.
Solution Approach 2:
The patent transitions from static manual adjustment to continuous dynamic self-adjustment. The seat and backrest are mounted to move continuously along arcuate paths in response to user motion, providing automated posture adaptation that maintains precision through the constrained geometric paths while eliminating the need for manual intervention.
4Device complexity
If the center of curvature is not proximate to the user's center of mass, then mechanical design is simplified, but dynamic balance and equilibrium are compromised
Solution Approach 1:
The patent applies equipotentiality by positioning the centers of curvature of both the seat and backrest arcuate paths proximate to the user's center of mass. This creates a balanced equilibrium position where the user's weight is evenly distributed, providing dynamic balance and stability. The seat's upwardly concaved arc and the backrest's forwardly concaved arc both converge near the user's center of mass, creating multiple equilibrium positions that maintain stability throughout the range of motion.
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 enables continuous support and adjustment to maintain neutral posture, reducing muscle and bone stress while allowing for a range of motions, ensuring comfort and balance during various seating positions.
Implementation Method 1
The downward motion of the backrest is opposed and balanced by spring forces that are sufficient to maintain equilibrium against the gravitational force
Implementation Method 2
using a combination of rollers, sliders, and spring forces to maintain equilibrium and adjust to different postures
Data Source
AI summary
A seat assembly 21 including a seat 22, a backrest 23 and a mounting assembly 24 mounting the seat 22 in a near horizontal orientation for movement along an upwardly concaved arcuate seat path having a center of curvature 37 proximate the center of mass 39 of a person seated on the seat, and mounting assembly 24 further mounting the backrest 23 in a near vertical orientation for movement independently of the seat along a forwardly concaved arcuate path having a center curvature 37 proximate the center of mass 39 of the person. An adjustment assembly 61 is provided for adjusting the radius of curvature of the path of motion of the backrest 23. Also provided are a backrest tilt adjustment assembly 71, an armrest adjustment assembly 90, a seat biasing assembly 110 and a seat motion latching assembly 111. A method of self-adjusting support and alignment of a backrest also is disclosed.