Foldable Tent Frame With Rotating Ridge Purlin Nesting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing foldable tent frames face issues with purlins protruding from the frame when folded, requiring additional space and potential collisions during unfolding, and posts needing securement to prevent accidental collapse under wind forces.
Innovation Solution
The frame design incorporates rotationally mounted purlins with limiting members to prevent protrusion and accidental turning, and securing pins to stabilize posts and rafters, allowing compact folding and secure unfolding without external components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If ridge purlins are disconnected into two parts when the frame is folded, then the purlins can be accommodated within the folded frame envelope, but the purlins interfere with eave purlins and require additional securing mechanisms
Solution Approach 1:
The ridge purlin is divided into two parts that nest within each other when the frame is folded. The first part is attached to the ridge portion and the second part is attached to the rafter, with the second part receiving the first part in a nested arrangement. This allows both purlin segments to be accommodated within the folded frame envelope without protruding outward, resolving the volume constraint while maintaining structural integrity.
Solution Approach 2:
The ridge purlin is segmented into two separate parts (first part and second part) that can be independently positioned and connected. This segmentation allows the purlin to be folded in a specific manner where the parts can be received one within the other, eliminating interference with eave purlins and reducing the need for additional securing mechanisms during folding.
2Volume of moving object
If the ridge purlin is made telescopic to avoid obstruction during unfolding, then the purlin fits within the folded envelope, but the telescopic mechanism increases device complexity
Solution Approach 1:
Instead of using a telescopic mechanism, the invention employs a nested arrangement where the first part of the ridge purlin is received within the second part when folded. This nested configuration achieves compact folding without requiring complex telescopic mechanisms, as the parts simply nest within each other's spatial envelope during the folding process.
Solution Approach 2:
The ridge purlin is designed with dynamic positioning capability through rotational mounting. The second part can rotate around an axis perpendicular to the pin joint axis, allowing it to dynamically adjust its position during folding and unfolding operations. This rotational freedom enables the purlin to clear obstacles and fit within the folded envelope without requiring telescopic adjustment mechanisms.
3Reliability
If posts are secured with securing pins after unfolding, then accidental collapse is prevented, but additional securing components and operations are required
Solution Approach 1:
The securing function is merged into the existing pin joint structure. The pin joint that connects the rafter to the post also serves as the securing mechanism, eliminating the need for separate securing pins. The pin joint's mechanical stop and geometric configuration inherently prevent accidental collapse when properly engaged, combining the connection and securing functions into a single integrated element.
Solution Approach 2:
The pin joint structure is designed to be self-securing through its geometric configuration and mechanical stops. When the frame is unfolded and the rafter rests against the mechanical stop formed in the pin joint, the structure automatically secures itself without requiring additional securing operations or components. The design leverages the natural geometry and loading conditions to maintain stability.
4Ease of operation
If purlins are folded parallel to the rafter in the same direction as eave purlins, then the folding direction is simplified, but the folded purlin collides with the ground during unfolding
Solution Approach 1:
The second part of the ridge purlin is mounted to rotate around an axis perpendicular to the pin joint axis, providing dynamic positioning capability. During the unfolding process, this rotational freedom allows the second part to clear the ground and other obstacles that would be collided with in a fixed parallel arrangement. The dynamic adjustment eliminates ground collision while maintaining the simplified folding direction benefit.
Solution Approach 2:
The ridge purlin's second part is oriented in a different dimensional direction compared to the eave purlins. Instead of being strictly parallel to the rafter in the same plane, the second part extends in a different orientation that allows it to clear the ground during unfolding. This dimensional differentiation resolves the ground collision issue while preserving ease of folding operation.
Data Source
AI summary
A foldable tent frame (1), which comprises portal frames (3) including rafters (4) connected to the ridge part (2, 24) of the portal frame (3) by pin joints (9) and posts (5) connected to the rafters (4) by pin joints (10), where the portal frames (3) are connected in a row by purlins (6), where the purlins (6) including ridge purlins (7) and eave purlins (8) are connected to the portal frames (3) by pin joints (11), and the purlins (6) comprise a pin joint (12) also on their length, where at least the ridge purlin (6, 7) is mounted rotationally around the axis perpendicular to the axis of the pin joint (11) of the purlin (6, 7) and the portal frame (3).