Expandable Sheet Slit Pattern Shifted Arrangements
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Solution Overview
Problem
Existing expandable sheets with uniform slit patterns tend to grip adjacent layers when wound onto a roll, leading to uneven winding and potential tearing during deployment.
Innovation Solution
The use of a slit pattern with shifted arrangements of slits, where different regions have staggered rows of slits with phase-shifted or orientation-shifted pattern features, preventing easy gripping between adjacent layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a uniform slit pattern is used in expandable sheets, then the manufacturing process is simple, but the sheet grips adjacent layers when wound onto a roll causing uneven winding and potential tearing
Solution Approach 1:
The patent applies local quality by varying the slit pattern characteristics in different regions of the sheet. Specifically, adjacent rows of slits have different patterns (e.g., different slit positions, orientations, or densities), creating local variations that prevent uniform gripping between layers while maintaining overall structural integrity and expandability functionality.
2Quantity of substance
If adjacent layers of expandable sheet are wound together, then storage efficiency is improved, but the layers grip each other causing sticking issues and deployment difficulties
Solution Approach 1:
The patent employs asymmetry by designing adjacent rows of slits with different patterns - for example, one row may have slits oriented in one direction while the adjacent row has slits oriented perpendicularly or at a different angle. This asymmetric pattern variation ensures that when layers are stacked, the protruding features of one layer do not align with the recesses of adjacent layers, preventing interlocking and sticking while allowing smooth unwinding.
3Reliability
If the slit pattern is varied to prevent gripping, then winding smoothness is improved, but the pattern complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the sheet into multiple rows of slits, where each row has a distinct but relatively simple pattern. Rather than using a single complex random pattern throughout, the sheet is segmented into repeating units of adjacent rows with different characteristics. This segmented approach achieves the anti-gripping effect through systematic variation while maintaining manufacturability through modular, repeatable pattern units.
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
This solution allows for smooth winding and unwinding of the expandable sheet without sticking issues, enhancing the loftiness and interlocking nature of the sheet while reducing material waste and deployment difficulties.
Implementation Method 1
the slits are configured to expand in response to a minimum tension applied to the substrate in the expansion axis to provide an expanded configuration
Implementation Method 2
portions of the sheet rotate to create an interlocking folded-wall structure that absorbs energy
Data Source
AI summary
An expandable sheet includes a substrate of sheet material defining the major surface and a plurality of slits formed in the substrate in a slit pattern defining a width along the cross axis and a length along the expansion axis. The slit pattern includes at least a first region and a second region, each comprising at least two staggered rows of the slits defining an arrangement of pattern features. At least one of the regions has a different arrangement of pattern features than another region. The slits are configured to expand in response to a minimum tension applied to the substrate in the expansion axis to provide an expanded configuration with folded walls.