Folding Ceiling Fan Gear Synchronization for Compact Blade Retraction

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Solution Overview

Problem

Combined ceiling fans and light fittings with retractable blades have faced challenges in synchronization, assembly complexity, high parts count, and dust accumulation due to existing mechanisms, which affect balance and aerodynamic performance.

Innovation Solution

A combined ceiling fan and light fitting with folding blades that use a planet gear system synchronized with a sun gear, secured by resilient means, allowing blades to pivot in synchronization and retract when not in use, with the gears concealed below the blade support for reduced dust accumulation and improved balance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a synchronizing mechanism with links and a rotatable ring is used to coordinate blade movement, then blade synchronization is achieved, but the parts count increases and assembly becomes labour-intensive requiring skill

Engineering Contradiction:
Improveblade synchronizationVSAvoidparts count and assembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the synchronizing function directly into the blade support means by providing a sun gear that rotates with the blades and planet gears on the blade support that mesh with the sun gear. This integration eliminates the need for separate links and a rotatable synchronizing ring, reducing parts count while maintaining synchronization reliability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The planet gears act as intermediaries between the sun gear and the blades, transferring rotational motion to coordinate blade movement. This gear-based intermediary system provides more reliable synchronization than direct link connections while reducing the overall parts count compared to link-and-ring mechanisms

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If links and holes are used to connect blades to a synchronizing ring, then blade coordination is possible, but clearances between parts cause difficulty in achieving accurate synchronization

Engineering Contradiction:
Improveblade synchronization accuracyVSAvoidclearance between parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the link-and-hole mechanical connection system with a gear meshing system. The planet gears mesh with the sun gear through tooth-to-tooth contact, eliminating clearances that plague link-based systems and providing accurate, reliable synchronization without the play and imprecision inherent in hole-and-link connections

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

3Reliability

If the synchronizing mechanism including the synchronizing ring is positioned above the fan motor, then blade coordination is achieved, but achieving a compact design becomes difficult

Engineering Contradiction:
Improveblade synchronizationVSAvoidoverall fan height
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent inverts the conventional arrangement by positioning the sun gear on the blade support means and the planet gears on the blade support below it, rather than placing a synchronizing ring above the motor. This inversion allows the synchronizing mechanism to be integrated within the motor housing space, achieving compact design while maintaining synchronization functionality

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent nests the synchronizing gear mechanism within the existing motor and blade support structure. The sun gear rotates with the blades on the blade support means, while planet gears are mounted on the blade support below, creating a compact nested arrangement that eliminates the need for additional vertical space above the motor

Inventive Principle:
Principle #7Nested doll (Nesting)

4Ease of operation

If blades are made retractable to improve appearance and ease cleaning, then aesthetic and maintenance benefits are achieved, but synchronization difficulties and balance problems occur

Engineering Contradiction:
Improvecleaning ease and appearanceVSAvoidblade synchronization and balance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces the unreliable link-and-ring synchronizing mechanism with a gear-based system where planet gears mesh with a sun gear. This mechanical substitution provides positive engagement through gear teeth, ensuring reliable synchronization of retractable blades and maintaining balance during both extended and retracted positions without the clearance and play problems of link-based systems

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 simplifies assembly, reduces parts count, ensures better synchronization, and conceals gears to prevent dust accumulation, enhancing both the aesthetic and aerodynamic performance of the fan while maintaining a compact design.

Implementation Method 1

resilient means arranged to bias the fan blades into their folded positions

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the fan blades being arranged to be unfolded by centrifugal force when the electric motor is operative

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP1904793B1Combined light fitting and ceiling fan
Publication Date: 2016.11.09 BEACON LIGHTING INT
  • EP1904793B1 patent drawingFigure 1
  • EP1904793B1 patent drawingFigure 2
  • EP1904793B1 patent drawingFigure 3

AI summary

A combined ceiling fan and light fitting (fan/light) (1) having folding fan blades (12) is provided. The fan light (1) has a blade support (13) arranged to be rotated by an electric motor (6), with blades (12) being secured to the blade support (13), a root end of each blade (12) being pivotable between folded and operative positions about a blade pivot axis-(14) fixed in the blade support (13). In one aspect of the invention, an improved mechanism is provided for synchronizing movement of the blades. This uses a sun gear (16) mounted to the blade support and arranged to mesh with planet gears (17) that rotate about the blade pivot axes (14). In addition improvements are provided to blades (12, 33, 60) and blade mounting arrangements that balance compact folding of the blades (12, 33, 60) and good air moving effectiveness.