Variable-Fulcrum Door Hinge for Clearance and Secure Opening

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Solution Overview

Problem

Existing hinges for doors with horizontal rotating axes often interfere with protruding objects during opening, requiring increased vertical space and creating unhygienic recesses, and struggle to securely open heavy doors without adjustments.

Innovation Solution

A hinge device with a variable fulcrum position, featuring balancing means and elastic elements that allow the door to rotate smoothly between vertical and horizontal positions, avoiding interference with objects below and providing a secure stop in extreme opening conditions, suitable for both small and large, heavy doors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional hinge is used to rotate the door from vertical to horizontal position, then the door can be opened, but it interferes with protruding objects below and requires increased vertical space

Engineering Contradiction:
Improvedoor opening operationVSAvoidvertical space required
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The hinge device employs a dynamic fulcrum position that changes during door opening. The fulcrum transitions from an initial position near the door bottom in vertical orientation to a different position as the door opens, allowing the door to clear objects below without requiring excessive vertical space. This is achieved through mobile pivots that relocate the rotation center during operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the rotation path from a simple circular arc to a more complex trajectory by introducing multiple pivots and arm mechanisms. This dimensional change in the rotation path allows the door to open horizontally without interfering with objects below, effectively using spatial reconfiguration to solve the vertical space constraint.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Length of stationary object

If the door is positioned close to objects below, then vertical space is reduced, but the door cannot be opened without interfering with protruding objects

Engineering Contradiction:
Improvevertical spaceVSAvoiddoor opening operation
Core Design Contradiction:
Length of stationary objectVSEase of operation

Solution Approach 1:

The mobile pivots enable the fulcrum position to dynamically adjust during door opening. When the door is in vertical position, the fulcrum is positioned to allow close proximity to objects below. As the door opens, the fulcrum relocates to maintain clearance, enabling both compact vertical space and smooth door operation.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If a simple hinge device is used, then the device complexity is reduced, but it cannot provide secure arrest of heavy doors in extreme opening condition

Engineering Contradiction:
Improvehinge device structureVSAvoiddoor arrest in extreme opening
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The first elastic means (spring) acts as a counterweight mechanism that balances the door weight throughout the opening motion. This allows the hinge to securely hold heavy doors in the extreme horizontal opening position without requiring complex mechanical stops or additional support structures.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The elastic means serve as intermediary elements between the door weight and the hinge structure. The spring and second elastic means mediate the forces during opening and closing, providing secure arrest of heavy doors while maintaining relatively simple device architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If elastic means are added to balance door weight, then the door can be securely opened, but the device complexity increases

Engineering Contradiction:
Improvedoor balancing and securingVSAvoidhinge device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A single first elastic means (spring) is used to balance the door weight, providing reliable door opening and securing functionality. This counterweight approach achieves the desired reliability without excessive complexity by using one primary elastic element rather than multiple complex mechanisms.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

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 device allows for close assembly to objects below, ensures a firm stop in extreme opening, and balances weight forces, preventing interference and ensuring reliable operation without adjustments, suitable for household appliances and large doors.

Implementation Method 1

The first elastic means counterbalances the weight of the door

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the weight of the door

Methodology Applied
Scientific EffectGravitation: Gravitation

Implementation Method 3

The second elastic means assists the movements of the door next to its extreme closing condition

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP1966458B1Door hinge device with fulcrum at variable position
Publication Date: 2010.09.15 C M I CERNIERE MECCANICHE IND
  • EP1966458B1 patent drawingFigure 1~2
  • EP1966458B1 patent drawingFigure 3
  • EP1966458B1 patent drawingFigure 4

AI summary

An hinge device with fulcrum at variable position for a door (2) of a structure (3) is provided with connecting members, first (4) and second (5), mutually connected and respectively fit to be fixed to the door (2) and to the structure (3) for rotating the door between the extreme closing (C) and the extreme opening (A) in which the door (2), in an operating condition of the structure, is respectively almost vertical and approximately horizontally orientated. The second connecting member (5) has a first fixed pivot (6) and a second fixed pivot (7) for the rotating connection respectively with a first balancing mean (8) and a second balancing mean (9) mutually bound. The end opposite to the first fixed pivot (6) of the first balancing mean (8) is connected by means of a first mobile pivot (10) to an end of the first arm mean (11) having the remaining end connected to the first connecting member (4) by means of a second mobile pivot (12). The end opposite to the second fixed pivot (7) of the second balancing means (9) is connected by means of a third mobile pivot (13) to the first connecting member (4).