Door-in-door common axis hinge assembly with door stops

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Solution Overview

Problem

In door-in-door refrigerator systems with a common axis of rotation, there is a risk of the outer door over-rotating and damaging the appliance or adjacent structures, and limiting both doors to the same rotation can prevent full access to the fresh food storage chamber.

Innovation Solution

A hinge assembly with a cabinet plate and door plate, featuring tabs and stops, limits the rotation of the outer door independently of the inner door, using a pivot axis to allow separate control and prevent over-rotation while maintaining full access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the outer door and inner door are limited to the same rotation degree, then damage to the appliance is prevented, but full width access to the fresh food storage chamber is prevented

Engineering Contradiction:

Improveprevention of appliance damageVSAvoidaccess to fresh food storage chamber

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent divides the rotation control function into two independent segments: one stop limits the outer door rotation while a second stop limits the inner door rotation. This allows each door to have its own maximum rotation angle, enabling the inner door to rotate further than the outer door for full access while the outer door is restrained to prevent damage.

Inventive Principle:

Principle #1Segmentation

2Ease of operation

If the outer door rotates separately from the inner door, then access flexibility is improved, but the outer door may over-rotate and contact the inner door causing damage

Engineering Contradiction:

Improveaccess flexibilityVSAvoidprevention of door contact damage

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The first stop is positioned to limit the outer door rotation angle before the outer door can contact the inner door. This preliminary restriction prevents the harmful contact from occurring in the first place, allowing the outer door to rotate freely within the safe range while maintaining access flexibility.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If the inner door and outer door rotate together as a full door, then access to the fresh food storage chamber is improved, but adjacent structures or appliance may be contacted causing damage

Engineering Contradiction:

Improveaccess to fresh food storage chamberVSAvoidprevention of contact with adjacent structures

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The hinge assembly segments the rotation control into two independent systems with different maximum angles. The outer door is limited by the first stop to a smaller angle that prevents contact with adjacent structures, while the inner door can rotate further by its own hinge to provide full access when needed.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12529506B2Door-in-door common axis hinge assembly with door stops

Publication Date: 2026.01.20 HAIER US APPLIANCE SOLUTIONS INC

AI summary

A refrigerator appliance includes a door-in-door assembly having a single axis of rotation for the inner and outer doors. The inner and outer doors have separate rotation stops to limit the rotation of the doors from a closed position to an open position. The outer door stop is fixed to the inner door and contacts a first tab that rotates with the outer door. The inner door stop is fixed to the cabinet and contacts a second tab that rotates with the inner door. The outer door rotation angle is less than the inner door rotation angle.