Foldable Articulated Arm Slidably Constrained Flexible Element
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Solution Overview
Problem
Existing foldable articulated arms for parasols, made as single pieces, are prone to twisting and failure due to rigid constraints, especially under wind gusts, leading to breakage of flexible elements.
Innovation Solution
A foldable articulated arm design featuring interconnected rods with flexible elements, where the second flexible element has a portion slidably constrained to both the second and third rods, preventing twisting and breakage by allowing controlled rotation and maintaining structural integrity during opening and closing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the articulated arm is made as a single piece with rigid constraints, then manufacturing complexity is reduced and production is simplified, but the structure becomes prone to twisting and breakage under wind loads
Solution Approach 1:
The second flexible element is divided into multiple segments (first portion, second portion, third portion) connected by hinge joints. This segmentation allows each segment to rotate independently, preventing the twisting that would occur in a rigid single-piece structure while maintaining the overall flexibility needed for the articulated arm's operation.
Solution Approach 2:
The flexible elements incorporate hinge joints that enable dynamic rotation and movement. Instead of rigid fixed connections, the hinges allow the structure to adapt dynamically to external forces like wind gusts, absorbing energy through controlled movement rather than transferring stress that would cause breakage.
2Stability of the object's composition
If flexible elements are hinged with rigid constraints to rods, then structural stability is improved, but the flexible elements are prone to twisting and failure during sheet overturning
Solution Approach 1:
The hinge joints in the flexible elements provide dynamic connection points that allow rotation and movement. This dynamic capability enables the flexible elements to accommodate sheet overturning movements without developing the twisting stresses that would lead to failure, while still maintaining structural stability through the constrained rotational paths.
Solution Approach 2:
The flexible elements change their geometric parameters (orientation, position) through hinge rotation in response to external forces. This parameter change capability allows the structure to adapt to wind loads and sheet movements, preventing the accumulation of stress that would otherwise cause breakage while maintaining overall structural integrity.
3Adaptability or versatility
If the articulated arm uses multiple articulated segments with rivets, then flexibility and adaptability are improved, but manufacturing complexity and production costs increase
Solution Approach 1:
Multiple articulated segments are merged into a single integrated piece through injection molding or similar manufacturing processes. The hinge joints are formed as integral parts of the flexible elements rather than separate components requiring assembly with rivets, thereby maintaining the articulated movement capability while eliminating the complexity of multiple discrete parts and assembly operations.
Solution Approach 2:
The single-piece construction serves multiple functions: it provides the structural framework, incorporates the flexible elements, and includes the hinge joints all in one component. This multi-functionality eliminates the need for separate articulated segments and connection hardware, reducing device complexity while preserving the adaptability needed for parasol operation.
Data Source
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AI summary
This invention relates to a foldable articulated arm comprising at least a first rod (2) and a second rod (3) connected together, each of which is configured for connection to the stem (4) of a parasol (5), at least a third rod (11), connected to the second rod (3), and a fourth rod (15) connected to the third rod (11); a first flexible element (13) which connects the first rod (2) with the third rod (11) and a second flexible element (17) which connects the fourth rod (15) with the second rod (3); the first, second, third and fourth rods (2, 3, 11, 15) and the first and second flexible elements (13, 17) are a single piece; in particular, the second flexible element (17) comprises a first portion (19) slidably constrained to the second rod (3) and a second portion (20) slidably constrained to the third rod (11).