Four-Bar Closure Mechanism for Jam-Resistant Circular Sealing
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Solution Overview
Problem
Existing iris-like shutter mechanisms face issues with jamming, dirt sensitivity, and non-uniform opening cross-sections, making them unsuitable for applications involving viscous or pasty materials, and require complex and costly designs with multiple linear guides.
Innovation Solution
A closure mechanism with segments that form a four-bar linkage, using pivot levers and a cam mechanism to ensure synchronized movement, allowing for a nearly circular opening without gaps, and featuring a compact design resistant to dirt and jamming, with segments moving along a curved path for efficient actuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If segments are moved along linear guides to achieve smooth movement, then movement quality improves, but the mechanism becomes sensitive to dirt and jamming
Solution Approach 1:
Instead of moving segments along linear guides (conventional approach), the patent inverts the approach by using a circumferential guide where segments are displaced radially outward while being guided along the outer circumference. This inversion eliminates the need for complex linear guides and makes the mechanism more resistant to dirt and jamming, as the guide structure is simpler and less susceptible to contamination.
Solution Approach 2:
The patent transitions from linear radial movement to circumferential movement along the outer edge. By guiding segments along the circumference rather than directly radially, the mechanism achieves smooth movement while reducing sensitivity to dirt. The dimensional change from linear to circumferential guidance path resolves the contradiction between movement quality and reliability.
2Ease of operation
If multiple linear guides are used for each segment, then movement control improves, but device complexity and cost increase
Solution Approach 1:
The patent merges the guidance function into a single circumferential guide structure that all segments share, rather than providing separate linear guides for each segment. This consolidation reduces device complexity and cost while maintaining movement control, as the circumferential guide naturally constrains all segments to move in coordination along the outer circumference.
Solution Approach 2:
The circumferential guide serves as a universal guide for all segments simultaneously, replacing multiple individual linear guides. This multi-functional guide structure reduces the overall number of components and simplifies the mechanism while still providing the necessary movement control for each segment during the opening and closing sequence.
3Reliability
If segments press against each other to create a seal, then sealing capability improves, but segments become prone to jamming
Solution Approach 1:
Instead of segments pressing against each other radially to seal (conventional approach), the patent inverts the sealing mechanism by having segments press against a stationary sealing surface at the outer circumference. This inversion eliminates the jamming risk associated with segment-to-segment contact while maintaining sealing capability, as the sealing force is applied against a fixed surface rather than moving segment surfaces.
4Productivity
If rolling guides are used instead of sliding guides, then movement efficiency improves, but sensitivity to dirt increases
Solution Approach 1:
The patent extracts the rolling guide component entirely from the mechanism, replacing it with a simpler circumferential guide structure. By removing the rolling guides that are sensitive to dirt, the mechanism achieves adequate movement efficiency through the circumferential guidance while becoming much less sensitive to contamination from liquids, solids, or dough-like materials.
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 mechanism provides a robust, dirt-resistant, and jam-free operation with rapid actuation, enabling nearly complete closure and uniform cross-sectional adjustment, suitable for various fluid and solid applications.
Implementation Method 1
a second pivot lever is movably mechanically coupled to the first base via a cam mechanism
Implementation Method 2
each segment is a middle part of its own four-bar linkage
Data Source
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AI summary
The invention relates to a closure mechanism for an opening defined by a centre (14) and an outer edge, comprising multiple segments (12) which can all together close the opening. Each segment has a first pivot lever (28) and a second pivot lever (30) and is controlled by the pivoting movements thereof. The segment (12) along with its pivot levers (28, 30) forms a four-bar linkage. All first pivot levers (28) are attached to a first base (20) and all second pivot levers (30) are attached to a second base. The relative movement between the first base (20) and the second base leads to a drive movement for the pivot levers (28, 30), wherein the second pivot lever (30) is mechanically coupled to the first base (20) via a cam gearing.