Foldable Sofa-Bed Assist Mechanisms for Smooth Bed Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing convertible sofa beds are either overly complex with intricate mechanisms or lack sufficient support and ease of use, particularly in transitioning between sofa and bed configurations.
Innovation Solution
A foldable sofa-bed design featuring a frame with opposed arms, a backrest, seat, and subseat, equipped with an extension-assist mechanism and a folding-assist mechanism that biases the sofa-bed towards the folded or unfolded position as needed, providing assistance during desirable stages of movement and resistance during others, along with a backrest mechanism that includes front and rear swing links for smooth movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complete mattress is folded within the sofa cavity, then the sofa-bed provides a complete sleeping surface, but the mechanism becomes intricate and heavy
Solution Approach 1:
The sleeping surface is segmented into three separate sections (backrest, seat, and subseat) that can unfold independently to form a bed, eliminating the need for a single complex mattress folding mechanism. Each section is simpler in design and can be controlled separately.
Solution Approach 2:
The mattress is extracted from the sofa cavity and replaced with the sofa's own structural sections (backrest, seat, subseat) that unfold to form the sleeping surface. This removes the need for storing and maneuvering a separate mattress within the sofa.
2Device complexity
If the sofa-bed structure is simplified with fewer moving parts, then the device complexity is reduced, but the ease of operation during transition deteriorates
Solution Approach 1:
Extension-assist mechanisms are introduced as intermediary devices that provide mechanical assistance during the unfolding transition. These assists include springs or dampers that smooth out the movement between folded and unfolded positions, making operation easier without adding complex control systems.
Solution Approach 2:
The resistance and assistance forces are varied throughout the transition range. Extension-assist mechanisms provide resistance during certain phases of movement and assistance during others, optimizing the ease of operation across the entire transition from sofa to bed configuration.
3Ease of operation
If extension-assist and folding-assist mechanisms are added, then the ease of operation is improved, but the device complexity increases
Solution Approach 1:
The extension-assist and folding-assist mechanisms are designed to automatically engage and disengage based on the position of the sofa sections. They provide assistance when needed (during transition) and become passive when not needed (in folded or unfolded positions), eliminating the need for manual control or additional complex actuation systems.
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 design enhances the ease and smoothness of converting the sofa-bed between configurations, providing added support in the unfolded position and reducing the effort required for folding and unfolding, while maintaining a compact and user-friendly mechanism.
Implementation Method 1
The folding-assist mechanism is configured such that the sofa-bed is biased toward the folded position as the sofa-bed moves from the unfolded position toward a first intermediate position
Implementation Method 2
The extension-assist mechanism is configured such that the sofa-bed is biased toward the unfolded position as the sofa-bed moves from a second intermediate position toward the folded position
Data Source
AI summary
A sofa-bed includes: a frame with opposed arms; a backrest operatively connected to the frame; a seat; a subseat hinged to the seat and pivotable relative thereto; an extension-assist mechanism attached to the frame and at least one of the seat and the subseat; and a folding-assist mechanism attached to the frame and at least one of the subseat and seat. The frame, backrest, seat and subseat are configured to move between a folded position, in which the backrest is generally upright, the seat is generally horizontal, and the subseat is generally horizontal and positioned beneath the seat in a first inverted orientation, and an unfolded position, in which the backrest, subseat and seat are generally horizontal, and the subseat is positioned between the backrest and the seat in a second non-inverted orientation. The folding-assist mechanism is configured such that the sofa-bed is biased toward the folded position as the sofa-bed moves from the unfolded position toward a first intermediate position. Also, the extension-assist mechanism is configured such that the sofa-bed is biased toward the unfolded position as the sofa-bed moves from a second intermediate position toward the folded position.