Ceiling Fan Blade Reinforcement and Drop Prevention

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Solution Overview

Problem

Conventional ceiling fans suffer from weak blade strength due to stress concentration at reinforcement points, leading to metal fatigue, and often experience blade drop issues due to improper mounting of the blade drop prevention portion.

Innovation Solution

The ceiling fan design incorporates a blade structure with a longer first reinforcement and multiple shorter second reinforcements to distribute stress, and a blade drop prevention mechanism with a locking portion and fixing holes to ensure secure mounting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a reinforcement is provided in the blade, then the strength is improved in the portion where the reinforcement is provided, but the stress concentrates on the portion where the reinforcement is not provided, causing metal fatigue

Engineering Contradiction:

Improveblade strengthVSAvoidblade reliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The blade is divided into multiple reinforcement portions along its length. Instead of having a single reinforcement, multiple reinforcements are strategically positioned at different locations (near the root, middle, and tip portions) to segment the stress distribution across the blade structure, preventing stress concentration at any single point.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different reinforcement structures are applied to different portions of the blade based on local stress requirements. The root portion, middle portion, and tip portion each have reinforcements tailored to their specific structural needs, with varying dimensions and positions to optimize local strength while maintaining overall blade reliability.

Inventive Principle:

Principle #3Local quality

2Reliability

If the blade drop prevention portion is fastened together with the blade to the support with screws, then the blade is secured, but the tape used to fix the blade drop prevention portion to the blade may peel off, causing improper mounting

Engineering Contradiction:

Improveblade drop prevention reliabilityVSAvoidmounting process simplicity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The blade drop prevention portion is pre-fixed to the blade using tape during the manufacturing process. This preliminary action ensures that the blade drop prevention portion is already in the correct position before the actual assembly, reducing the complexity of the mounting process and ensuring proper alignment when screws are fastened.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Tape is used as an intermediary element to temporarily hold the blade drop prevention portion to the blade during assembly. This intermediary allows for easy positioning and adjustment before final fastening, simplifying the overall mounting process while ensuring reliable connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUSRE48538E1Ceiling fan having reinforcements

Publication Date: 2021.04.27 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A ceiling fan includes blade (11) that is integrally formed of root (12), vane (13), and step (14) for maintaining vane (13) in a state inclined from horizontal. Blade (11) includes bend (16) on upstream side (11c), first reinforcement (17) on upstreamdownstream side (11c)(11b), and a plurality of second reinforcements (18) between bend (16) and first reinforcement (17). First reinforcement length (17a) is longer than second reinforcement length (18a). Further, the ceiling fan includes blade drop prevention portion (37) for locking blade (11) to support (10).