Refrigerator Door Hinge With Torsion Spring for Safe Compact Rotation

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Solution Overview

Problem

Refrigerator cabinet doors face challenges in maximizing transparent area while minimizing non-transparent space for hinges, leading to safety issues due to varying gaps and high production costs associated with complex gear systems, and existing solutions suffer from wear and noise problems.

Innovation Solution

A hinge group with a torsion spring and cam means, where the abutting element is rotatably associated with the first support element, allowing for efficient loading of the torsion spring without wear and noise, and enabling configuration of resistance according to the opening angle, with a pin projecting radially from a cylindrical body for varying thrust.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If the transparent area of the door is increased to improve visibility and display capability, then the non-transparent space for the hinge group must be reduced, but the manoeuvring space required by conventional hinge groups is large

Engineering Contradiction:
Improvetransparent area of doorVSAvoidnon-transparent space for hinge group
Core Design Contradiction:
Area of moving objectVSArea of stationary object

Solution Approach 1:

The hinge axis is positioned at a corner of the second support element rather than at the center, changing the dimensional arrangement of the hinge group. This corner positioning allows the panel to rotate in a compact arc that requires significantly less manoeuvring space, enabling the use of slim frames with large transparent panes while maintaining adequate hinge functionality.

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

Solution Approach 2:

The hinge group incorporates elastic return means with a torsion spring that is decentred with respect to the hinge axis. This dynamic elastic mechanism allows the panel to be held at various positions during rotation and automatically returns the panel to the closed position, reducing the space required for manual manoeuvring while improving the transparency of the door.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If a large gap is provided between the fixed frame and the panel for manoeuvring space, then the hinge can operate, but the gap varies during rotation and creates safety hazards with finger crushing risks

Engineering Contradiction:
Improvehinge operationVSAvoidfinger crushing hazard
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

By positioning the hinge axis at the corner of the second support element and arranging it parallel to the panel, the rotation path is optimized to maintain a consistent, minimal gap between the panel edge and the fixed frame throughout the opening motion. This eliminates the varying gap that creates finger crushing hazards while ensuring smooth hinge operation.

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

Solution Approach 2:

The elastic return means with the torsion spring are pre-configured to provide controlled resistance during panel opening and automatic return. This pre-engineered elastic mechanism cushions the motion, preventing sudden movements that could cause pinching while maintaining the minimal safe gap between panel and frame.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If complex gear systems are used in the hinge group, then the torsion spring can be loaded efficiently, but the production costs and manufacturing complexity increase significantly

Engineering Contradiction:
Improvetorsion spring loading efficiencyVSAvoidgear system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the complex gear transforming means from the hinge group design. Instead of using gears to load the torsion spring, the invention directly couples the panel rotation to the torsion spring through the hinge arrangement, where the torsion spring is decentred with respect to the hinge axis. This extraction of unnecessary mechanical complexity significantly reduces production costs while maintaining reliable torsion spring loading through the inherent geometry of the hinge-spring arrangement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The complex mechanical gear system is replaced with a simpler elastic mechanical system using a torsion spring positioned off-center relative to the hinge axis. This substitution maintains the functional requirement of loading the spring during panel rotation while eliminating the need for gears, reducing manufacturing complexity and production costs.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 solution reduces non-transparent area, prevents finger crushing, and provides silent, durable operation with reduced production complexity and costs, maintaining a consistent gap during panel rotation.

Implementation Method 1

elastic return means interposed between the first and the second support element for return from the open position to the closed position, which comprise a torsion spring

Methodology Applied
Scientific EffectElastic potential energy storage: Elasticity

Data Source

PatentEP2908073B1An improved hinge group for doors of refrigerator cabinets
Publication Date: 2018.07.04 CISAPLAST SRL
  • EP2908073B1 patent drawingFigure 1
  • EP2908073B1 patent drawingFigure 2~3
  • EP2908073B1 patent drawingFigure 4~5

AI summary

A hinge group (50) for closing panels of an access entry of refrigerator cabinets comprising: a first support element (51) fixable to a fixed frame (21) of the access entry; a second support element (54) fixable to the closing panel (30), and hinged to the first support element (51); elastic return means (53) interposed between the first and the second support element (51, 54) for return from the open position to the closed position, which comprise a torsion spring (53) substantially parallel to the hinge axis (X) and decentred with respect thereto; cam means (511, 545) for transforming means of the rotary motion of the second support element (54) with respect to the first support element (51) into rotary motion of the first end (53a) with respect to the second end (53b) of the torsion spring (53), comprising a pin (545) and an abutting element (511) for the pin (545) in which the abutting element (511) is rotatably associated to the first support element (51).