Refrigerator Door Closing Unit with Angle-Dependent Moment Control

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Solution Overview

Problem

Existing refrigerators and freezers often lack user comfort in door closure, as they either fail to prevent accidental opening or result in slamming shut, due to inadequate closing mechanisms.

Innovation Solution

A closing unit that applies a closing moment only when the door reaches a certain angle, allowing the door to remain in a desired angular range without opening or closing forces, and includes a lever system with a sliding support and locking element to ensure the door is pulled into a closed position, preventing accidental opening while allowing user-defined positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a closing unit continuously exerts a closing moment on the door, then the door is prevented from remaining open, but the door slams shut causing noise and discomfort

Engineering Contradiction:
Improvedoor closure reliabilityVSAvoidslamming noise
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The closing unit dynamically adjusts its behavior based on door opening angle. When the door opening angle exceeds a certain threshold, the closing unit stops exerting a closing moment, allowing the door to remain stationary without slamming. When the angle falls below the threshold, the closing unit activates to pull the door closed, ensuring reliable closure without continuous force application.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of closing moment application based on door opening angle. By monitoring the angular position and adjusting whether the closing moment is applied or not, the system optimizes between preventing accidental opening and avoiding slamming noise.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a closing unit continuously exerts a closing moment on the door, then the door is pulled into closed position, but the user cannot maintain the door in a desired open position

Engineering Contradiction:
Improvedoor closure functionVSAvoiduser-defined positioning
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The closing unit transitions from a static continuous-force system to a dynamic angle-dependent system. Users can position the door at any angle above the threshold, and the system responds dynamically by activating only when the threshold is crossed, allowing both user-defined positioning and reliable closure.

Inventive Principle:
Principle #15Dynamics

3Reliability

If a lever system with locking element is used to pull the door closed, then the door closure is ensured, but the device complexity increases

Engineering Contradiction:
Improvedoor closed position assuranceVSAvoidclosing mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lever system with locking element operates automatically based on door opening angle. The locking element engages or disengages automatically as the door moves between open and closed positions, eliminating the need for user intervention or complex control systems while ensuring reliable door closure.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The closing unit combines multiple functions (detecting door angle, applying closing moment, locking mechanism) into an integrated assembly that works together through mechanical linkage, reducing the need for separate sensors, actuators, and control electronics.

Inventive Principle:
Principle #5Merging (Combining)

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

Enhances user comfort by maintaining the door in a desired position without accidental opening or slamming, while ensuring the door is securely closed, and achieves a low-noise operation with a modular design that minimizes visibility.

Implementation Method 1

at least one damper can be provided, which is connected to the slide carrier in such a way that the movement of the slide carrier in at least one direction of movement is counteracted by the damper

Methodology Applied
Scientific EffectDamping: Damping

Implementation Method 2

The closing unit can have at least one tension or compression spring that applies the closing moment

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2781864B1Refrigeration and/or freezer device
Publication Date: 2020.06.24 LIEBHERR HAUSGERATE OCHSENHAUSEN GMBH
  • EP2781864B1 patent drawingFigure 3
  • EP2781864B1 patent drawingFigure 4
  • EP2781864B1 patent drawingFigure 5

AI summary

The refrigerator or freezer has a body which includes a refrigerated inner space, and a door which is arranged relative to the body in a pivoting manner, by which the refrigerated inner space is closed in the closing position of the door. A closing unit is formed such that it exercises the closing moment on the door during reaching or falling below a determined door opening angle. A holder (32,36) is arranged on the body. A lever (20) is extended from the holder to the closing unit or to a module.