Retractable Ceiling Fan Blades for Compact Stowage
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Solution Overview
Problem
Combined light fittings and ceiling fans face challenges in providing effective air movement without excessive power consumption and compact storage when not in use, with existing designs often compromising on aerodynamic performance and stowage efficiency.
Innovation Solution
The design incorporates biaxial curvature fan blades that pivot outward for operation and retract inward using centrifugal force and springs, optimizing air movement and compact stowage by overlapping within a defined radius, enhancing aerodynamic performance and space utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If blades are made larger to improve air movement performance, then aerodynamic performance is improved, but the overall size of the fan increases making it less compact when not in use
Solution Approach 1:
The fan blades are designed to be dynamically adjustable between extended and retracted positions. During operation, the blades extend to provide optimal air movement performance. When not in use, the blades retract to minimize the overall fan size, thus resolving the contradiction between performance size and compact storage size.
Solution Approach 2:
The blade assembly is designed to nest within the housing when retracted. The blades can be positioned inside the cylindrical housing structure, allowing the fan to achieve compact storage dimensions while maintaining the capability to extend full-length blades during operation for optimal aerodynamic performance.
2Volume of moving object
If blades are made retractable to improve compact storage, then space efficiency is improved, but the mechanism complexity increases
Solution Approach 1:
The blade retraction mechanism utilizes the fan's own rotational motion and centrifugal force to automatically retract the blades. The system uses the fan's operating characteristics to drive the retraction process without requiring external control systems or complex actuation mechanisms, thereby reducing overall system complexity.
Solution Approach 2:
The patent replaces complex electronic or motorized actuation systems with a purely mechanical retraction mechanism that leverages centrifugal force and spring-loaded systems. This substitution of mechanical principles for more complex systems reduces device complexity while achieving the desired retractable functionality.
3Productivity
If blades move outward under centrifugal force to improve air movement, then aerodynamic performance is improved, but the blades require additional structural support increasing device complexity
Solution Approach 1:
The blade support structure is merged with the housing assembly, integrating the support function into the existing structural framework. The blades are mounted directly to the housing or to a simplified hub structure that utilizes the housing's own structural elements for support, thereby reducing the need for separate complex support mechanisms.
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 provides improved aerodynamic performance and compact stowage, balancing air movement efficiency with power usage and aesthetic considerations, allowing for a more effective and space-efficient combined ceiling fan and light fitting.
Implementation Method 1
U.S. Pat. No. 1,445,402 discloses a light fitting and ceiling fan in which blades move outwards under centrifugal force when the fan is switched on
Implementation Method 2
U.S. Pat. No. 1,445,402 discloses a light fitting and ceiling fan in which blades move outwards under centrifugal force when the fan is switched on, and are retracted by springs when the fan is switched off
Data Source
AI summary
There is provided a combined ceiling fan and light fitting (10) having blades (1-4) that when the ceiling fan is not in use retract and are stowed above an enclosure (12) containing a light emitting device and that when the fan is in use are extended under centrifugal force. The blades are formed in such a way as to both stow compactly above the enclosure and provide reasonable aerodynamic performance. Each blade partially overlies a neighbouring blade when in its stowed position and the blades are so formed as to permit such stacking while limiting the overall height of the assemblage of stowed blades.