Elastic-Driven Retractable Sofa Seat Frame for Automatic Leg Folding

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Solution Overview

Problem

Manual multifunctional sofas require laborious manual operation to retract the leg mechanism, leading to a poor user experience.

Innovation Solution

An automatically retractable movable seat frame with a linkage mechanism, driven by a driving elastic member, that automatically retracts the leg mechanism through the rotation of a rotating rack, utilizing a stretching device to switch between sitting, relaxing, and lying positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual operation is used to retract the leg mechanism, then the structure remains simple and cost-effective, but the operation becomes laborious and user experience deteriorates

Engineering Contradiction:

Improveease of retracting leg mechanismVSAvoidcomplexity of stretching device

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The elastic member stores energy during the extending process and automatically releases it to drive the leg mechanism during retraction, making the system self-serving without requiring external power sources or complex control systems. The leg mechanism retracts automatically by utilizing the pre-stored elastic energy, eliminating manual operation while keeping the overall structure relatively simple.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The elastic member is pre-loaded with potential energy during the extending phase, preparing the energy source in advance for the retraction phase. This preliminary energy storage enables the automatic retraction function without requiring active intervention during the retraction process itself.

Inventive Principle:

Principle #10Preliminary action

2Ease of operation

If electric driving is used to achieve automatic retraction, then user experience improves, but the cost increases significantly

Engineering Contradiction:

Improveease of retracting leg mechanismVSAvoidmanufacturing cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The system uses the energy stored in the elastic member during the extending phase to power the retraction phase, making the system self-powered without requiring external electric motors, batteries, or control electronics. This eliminates the high manufacturing costs associated with electric driving systems while achieving automatic retraction.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the electric motor-driven mechanical system with an elastic energy storage and release mechanism. Instead of using electrical energy conversion through motors, the system uses pure mechanical energy storage in the elastic member, which is then converted to kinetic energy for automatic retraction, significantly reducing manufacturing complexity and cost.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If the leg mechanism is made fully extendable for lying position, then comfort improves, but the structure becomes more complex and harder to retract

Engineering Contradiction:

Improveability to achieve lying positionVSAvoidcomplexity of leg mechanism

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The leg mechanism is designed to serve multiple functions: it can extend to various degrees to accommodate both relaxing position (legs extended) and lying position (legs and back fully extended). The same elastic-driven mechanism handles both partial and full extension scenarios, eliminating the need for separate mechanisms for different positions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The leg mechanism incorporates dynamic elements that allow it to adapt its configuration based on the required position. The linkage structure and elastic member work together to provide the necessary degrees of freedom for achieving different positions while maintaining structural integrity and enabling automatic retraction regardless of the final position achieved.

Inventive Principle:

Principle #15Dynamics

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 automatic folding of the leg mechanism improves user experience by simplifying the operation and providing comfortable transitions between seating positions.

Implementation Method 1

a driving elastic member, a rotating rack and a linkage rack, the driving elastic member being assembled between the rotating rack and the linkage rack

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20250386936A1Automatically retractable movable seat frame and sofa

Publication Date: 2025.12.25 REMACRO TECHNOLOGY CO LTD

AI summary

The automatically retractable movable seat frame includes at least one stretching device, including a linkage mechanism, including a driving elastic member, a rotating rack, and a linkage rack, the driving elastic member being assembled between the rotating rack and the linkage rack; a leg mechanism, hinged to a front end of the linkage rack, a drag link being hinged between the rotating rack and the leg mechanism; a seat mechanism, hinged to a rear end of the leg mechanism; and a rotating mechanism, connected to the rotating rack, configured to drive the rotating rack to rotate, so that the stretching device is switched between a sitting position and a relaxing position, in which the driving elastic member stretches and retracts with the rotation of the rotating rack, and the rotating rack is driven to rotate, so that the leg mechanism is folded.