Reclinable Seating Apparatus with Virtual Pivot to Minimize Seat Lift
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Solution Overview
Problem
Conventional reclining chairs with spring-based mechanisms fail to provide optimal recline resistance for occupants of varying sizes, leading to discomfort due to improper alignment and pressure points on the legs.
Innovation Solution
A weight-sensitive reclinable seating apparatus featuring a backrest pivot mechanism with a virtual pivot projected above the seat surface, utilizing motion-facilitating components and ramps to minimize seat lift and backrest drop during recline, thereby maintaining an ergonomic relationship between the seat and backrest.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a spring-based reclining mechanism is used, then the backrest can be biased in the upright position and provide resistance to reclining motion, but the recline resistance force cannot be customized to different occupant weights and sizes
Solution Approach 1:
The occupant's own weight is utilized to provide the recline-resistance force through the weight-sensitive mechanism. As the occupant reclines, their weight automatically generates the counterbalancing force needed, eliminating the need for externally adjusted springs or complex mechanical systems. The system serves itself by using the occupant's body weight as the primary resistance source.
Solution Approach 2:
The recline resistance force is dynamically adjusted based on the occupant's weight through the weight-sensitive mechanism. The system automatically adapts the resistance parameter to match different occupant sizes and weights, providing optimal recline control for each user without manual intervention or complex adjustment mechanisms.
2Ease of operation
If the pivot point is moved forward to reduce front seat lift, then the occupant's feet can stay on the floor, but the body angle between torso and legs remains unchanged and eye level drops undesirably
Solution Approach 1:
The invention introduces a vertical dimension to the pivot point by projecting it above the seat surface rather than placing it at or below the seat level. This elevated pivot position allows the backrest to rotate in an arc that maintains proper body angles and eye level while still controlling front seat lift to keep feet on the floor.
Solution Approach 2:
The weight-sensitive mechanism acts as an intermediary between the occupant's weight and the backrest positioning. It dynamically adjusts the backrest angle based on occupant weight, ensuring that the pivot point remains at the optimal elevated position throughout the recline range, thereby maintaining ergonomic body angles and eye level.
3Adaptability or versatility
If the pivot point is placed below the seat proximate to hip joints, then the weight-sensitive mechanism can function, but the pivot point is displaced from its ideal position during reclining actions
Solution Approach 1:
The pivot point is elevated to a third dimension above the seat surface, creating a virtual pivot that remains stationary in space while the backrest rotates around it. This elevated position ensures the pivot point stays at the ideal location throughout the entire recline range, maintaining proper ergonomic relationships between the seat and backrest.
Solution Approach 2:
The invention creates a virtual pivot point that replicates the ideal pivot location needed for ergonomic reclining. This virtual pivot, projected above the seat surface, mimics the function of a physical pivot at the optimal position, allowing the weight-sensitive mechanism to function correctly while maintaining proper body mechanics throughout the recline 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 provides a comfortable and ergonomic reclining experience by customizing the recline resistance force to the occupant's weight, minimizing seat lift and backrest drop, and maintaining an optimal body angle during recline.
Implementation Method 1
Weight-sensitive reclinable chairs feature recline mechanisms that cause the seat to rise against the weight of the occupant as the backrest is reclined. In this manner, the occupant's own weight provides at least a portion of the recline-resistance force
Implementation Method 2
Conventional reclining chairs utilize one or more springs to bias the backrest in the upright position and provide resistance to the reclining motion. Springs, by their very nature, exhibit a linear increase in the output force as the spring is deformed
Data Source
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AI summary
A weight-sensitive, reclinable seating apparatus that features a backrest pivot mechanism positioned entirely within the seat assembly (200) of the seating apparatus. The backrest pivot mechanism comprises a plurality of ramp assemblages positioned within the seat assembly (200), with the ramp assemblages each comprising one or more motion-facilitating components (272a, 272b, 222a, 222b, 252a, 252b) that engage one or more ramps (215a, 215b, 255a, 255b, 217a, 217b). The motion-facilitating components (272a, 272, 222a, 222b, 252a, 252b) cooperate with the ramps (215a, 215b, 255a, 255b, 217a, 217b) to provide a virtual pivot (400) for the backrest (317) that is projected above the seat surface. The backrest pivot mechanism minimizes the vertical drop of the backrest during the recline motion, which in turn minimizes the seat lift during the recline motion. By minimizing the magnitude of the backrest drop and the seat lift during a recline operation, the seating apparatus reduces the displacement of the functional pivot from the ideal pivot point as the chair reclines.