Recliner Chair Linkage for Virtual Pivot Seat-Back Motion

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Solution Overview

Problem

Recliner chair mechanisms often suffer from complexity, high cost, and difficulty in achieving subtle, complex motion while maintaining simplicity and ease of manufacture, with existing solutions failing to provide harmonious and consistent motion with the natural pivot action of a chair occupant.

Innovation Solution

A chair subassembly featuring a seat frame, drive frame, and yoke frame interconnected by pivot links that allow for floating mobility, enabling subtle and complex motion while minimizing the number of components and intercoupling elements, with ancillary slots and followers providing flexibility to avoid jamming and ensure harmonious seat and back movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional recliner chair mechanisms are used, then seat and back adjustment functionality is achieved, but mechanism complexity and component count increase

Engineering Contradiction:
Improveseat and back adjustment functionalityVSAvoidmechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the seat frame, drive frame, and yoke frame into a unified structure where the seat frame is integrally formed with the drive frame, and the yoke frame serves dual functions as both a structural support and a mounting platform for the recline mechanism. This merging reduces the number of separate components while maintaining full adjustment functionality for both seat and back.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The yoke frame is designed to perform multiple functions: it provides structural support for the seat and back, serves as a mounting structure for the recline mechanism, and enables the pivot movement between upright and reclined positions. This multi-functionality reduces the need for additional dedicated components.

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

2Ease of operation

If multiple pivot links and intercoupling elements are used, then subtle and complex motion is achieved, but manufacturing cost and complexity increase

Engineering Contradiction:
Improvesubtle and complex motionVSAvoidmanufacturing cost
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The motion mechanism is segmented into distinct functional zones: the pivot links are separated into those connecting the seat frame to the drive frame and those connecting the drive frame to the yoke frame. This segmentation allows each link to be optimized for its specific motion requirement while simplifying the overall manufacturing process by reducing interdependence between components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using multiple complex intercoupling elements to achieve subtle motion, the patent inverts the approach by using a minimal number of pivot links with strategically positioned pivot points. The subtle and complex motion is achieved through the geometric arrangement and kinematic relationships of these simplified components rather than through component complexity.

Inventive Principle:
Principle #13The other way round (Inversion)

3Stability of the object's composition

If conventional chair actions are used, then structural support is provided, but harmonious motion with natural body pivot is not achieved

Engineering Contradiction:
Improvestructural supportVSAvoidharmonious motion with natural body pivot
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The pivot links are designed with specific geometric properties at different locations: the pivot points are positioned to align with the natural body pivot points (hip joint area), and the link dimensions and orientations are locally optimized to guide the seat and back through motion paths that harmonize with human anatomy. This local quality optimization ensures structural support while achieving natural-feeling motion.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The mechanism transitions from a static structural support system to a dynamic one where the pivot links enable continuous adjustment of the seat and back angles. The dynamic configuration allows the structure to adapt to the occupant's position and movement, providing harmonious motion that follows the natural pivot action of the body throughout the range of motion.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2615945B1Link chair action
Publication Date: 2015.04.22 BIRKBECK HILARY ROLF
  • EP2615945B1 patent drawingFigure 1A~1C1
  • EP2615945B1 patent drawingFigure 1D~1E1
  • EP2615945B1 patent drawingFigure 2A~2AC

AI summary

A (recliner) chair action of relatively movable seat frame (11), (back) drive frame (12) and yoke frame (13), with intervening links (16, 17, 18, 19), independently grouped respectively between seat frame and drive frame and between drive frame and yoke frame; for seat translation and elevation upon back recline operable under a potential energy function in an inter-relationship between back recline and seat movement, for a common or harmonious experience between different occupancy weights.