Aircraft Door Lifting Assembly With Integrated Lift Track and Idler

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Solution Overview

Problem

Existing aircraft door assemblies lack efficient mechanisms for guiding and supporting door movements, particularly during emergency evacuations, and often require multiple separate components for lift, weight compensation, and actuation, which can complicate assembly and maintenance.

Innovation Solution

A support assembly for aircraft doors that integrates a forearm, links, and a lifting assembly, including a latch idler and lift track, to facilitate seamless door opening and closing movements, with optional emergency puller assist, reducing the need for separate components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple separate components are used for lift, weight compensation, and actuation, then each component can be optimized for its specific function, but the assembly complexity and maintenance difficulty increase

Engineering Contradiction:
Improvefunctional reliabilityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the lift mechanism, weight compensation system, and actuation components into a single integrated support assembly. The forearm assembly integrates the lift track, roller, and link mechanisms that previously required separate components, reducing assembly complexity while maintaining functional reliability through unified design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The support assembly performs multiple functions simultaneously: it provides lift during door opening, compensates for weight changes, and enables actuation control. The forearm assembly with its integrated linkages serves as a universal mechanism that handles all three functions that previously required dedicated separate systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of repair

If multiple separate components are used for lift, weight compensation, and actuation, then each component can be independently replaced, but the maintenance time and procedures increase

Engineering Contradiction:
Improvecomponent replaceabilityVSAvoidmaintenance time
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

By merging previously separate components into an integrated support assembly, the patent reduces maintenance time. Instead of requiring separate replacement procedures for lift components, weight compensation elements, and actuation parts, technicians now maintain a single unified assembly, directly reducing the time loss associated with multiple separate maintenance operations.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If a simple door support structure is used, then the assembly is easier to manufacture, but it cannot efficiently guide and support door movements during emergency evacuations

Engineering Contradiction:
Improveassembly simplicityVSAvoiddoor movement support
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The support assembly is segmented into functional modules: the forearm with lift track for vertical movement guidance, the roller for smooth operation, the link for motion transmission, and the counterweight mechanism. This segmentation allows each component to be manufactured relatively simply while collectively providing reliable door movement support during emergency evacuations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs dynamic elements including the movable roller that follows the lift track, the articulated link that changes position during door opening, and the counterweight that dynamically compensates for door weight changes. These dynamic features enable the simple structure to reliably guide and support complex door movements during emergency evacuations.

Inventive Principle:
Principle #15Dynamics

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 integrated support assembly enhances door movement efficiency, simplifies assembly, and reduces the number of required parts, improving reliability and ease of maintenance.

Implementation Method 1

The first roller may be configured to roll along the lift track between and to the lower track end and the upper track end

Methodology Applied
Scientific EffectRolling motion: Roller

Implementation Method 2

The latch idler may include an idler body having a center axis. The idler body may include a first arm portion and a second arm portion

Methodology Applied
Scientific EffectPivoting motion: Hinge

Data Source

PatentEP4403460B1Lifting assembly for an aircraft door
Publication Date: 2026.03.04 ROHR INC
  • EP4403460B1 patent drawingFigure 1
  • EP4403460B1 patent drawingFigure 2~3
  • EP4403460B1 patent drawingFigure 4A~4B

AI summary

A door assembly (26) for an aircraft (20) includes a door (28), a door handle (34), a door hinge (32), a support assembly (50), and a lifting assembly (58). The door handle (34) is rotatable between an unlatched position and a latched position. The support assembly (50) rotatably mounts the door hinge (32) to the door (28). The lifting assembly (58) includes a latch cam (120), a lift track (123), and a latch idler (122). The latch cam (120) is mounted to the door handle (34), rotatable with the door handle (34) about the door handle rotational axis (124), and forms an eccentric roller path (126) extending about the door handle rotational axis (124). The latch idler (122) includes a first roller (146) and a second roller (148). The first roller (146) is disposed on a lift track (123) of the support assembly (50) and configured to roll along the lift track (123). The second roller (148) is disposed within the eccentric roller path (126). The latch idler (122) is configured to lift the door (28) as the door handle (34) rotates from the latched position to the unlatched position.