Three-Section Folding Bed Frame With Low-Force Linkage

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Solution Overview

Problem

Existing folding frames for beds require significant effort to fold due to complex constructions and high force requirements, making them difficult to use and costly to produce.

Innovation Solution

A folding frame design featuring a support frame with a side-mounted lifting gear, three sub-frames connected by articulated pieces, and a kinematic chain with a simplified folding mechanism using a single spring force and strategically placed control rods, allowing for easy folding and compact closure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If multiple articulated levers and springs are used to enable folding movement, then the bed frame can be folded, but the construction becomes complex and requires great effort to operate

Engineering Contradiction:
Improveeffort required for foldingVSAvoidconstruction complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The bed frame is divided into three sub-frames (first, second, and third sub-frames) that can be independently folded relative to each other. This segmentation allows the folding function to be distributed across multiple simple articulations rather than requiring a single complex mechanism, reducing both construction complexity and operational effort.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lifting gear is extracted from the traditional central position and mounted on the side of the support frame. This extraction simplifies the overall construction by separating the lifting function from the bed frame structure, allowing the folding mechanism to operate with fewer components and less complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If multiple kinematic chains are provided to align the seat support, then the folding function is achieved, but greater forces are required during folding

Engineering Contradiction:
Improveforce required during foldingVSAvoidnumber of kinematic chains
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The control rod is positioned at a specific location (2/3 of the length of the first articulated lever from its joint with the support frame) to optimize the mechanical advantage. This local optimization of the control point position allows the folding mechanism to operate with reduced force requirements while maintaining simplicity in the kinematic chain configuration.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If the lifting gear is mounted on the side of the support frame, then the construction is simplified, but the mechanism must be designed narrowly to save space

Engineering Contradiction:
Improveproduction simplicityVSAvoidspace occupied by lifting mechanism
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

The articulated levers and control rod are arranged in a nested configuration where components are positioned within the spatial envelope of the bed frame structure. The lifting gear components are integrated into the side mounting arrangement, allowing the mechanism to occupy minimal additional space while maintaining manufacturing simplicity.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 reduces the effort required for folding, simplifies production, and results in a stable, cost-effective, and space-efficient folding frame that can be easily folded and closed with minimal force.

Implementation Method 1

The second articulated lever (7) is tensioned to the supporting frame (9) by spring force

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2767189B1Folding frame for a bed
Publication Date: 2016.08.17 SEDAC MECOBEL
  • EP2767189B1 patent drawingFigure 1~2

AI summary

The invention describes a folding frame for a couch, consisting of a supporting frame (9) with a lifting gear mounted on the side, which supports a bed frame consisting of three sub-frames (1, 3, 8) connected via articulated pieces (2) and which can be fitted with a mattress on both sides of the bed frame, in each case by means of articulated levers (4, 7) of the lifting mechanism, four-bar linkages are connected to form a kinematic chain in such a way that the sub-frames (1, 3, 8) can each be moved continuously via a folding movement (F) from a stretched lying position around articulated joints between the partial frame (1, 3, 8) and the articulated piece (2) are to be folded into a lowered, closed position in the support frame by a first articulated lever (4) of the kinematic chain at an articulation point (a) of the articulated piece (2) between the first Sub-frame (1) and the second sub-frame (3) and the support frame (9) is articulated, and a second articulated lever (7) articulated between the support frame (9) and a joint point (e) on the second sub-frame (3) and is connected at its end protruding beyond the second sub-frame (3) to the third sub-frame (8) via a third articulated lever (6), via which the folding movement (F) of the folding frame is carried out by a user, the second articulated lever (7) being stretched towards the support frame (9) by a spring force and a control rod (5) being guided in an articulated manner from the second articulated lever (7) to the first articulated lever (4) and connected to this an articulation point (b) about 2/3 of the length above its articulation point (c) on the support frame (9).