Pressure Vessel Closure Lock to Prevent Opening Above 4 kPa
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Solution Overview
Problem
Existing pressure vessels with removable closure devices do not adequately prevent opening when internal pressure exceeds 4 kPa, as the residual pressure safety device can be manipulated, potentially allowing the vessel to be opened despite hazardous pressures.
Innovation Solution
A closure device with a movably connected outer and central body, featuring locking arms and a signaling area with a transparent cover or spring element, ensures the pressure vessel remains closed at pressures ≥4 kPa, decoupling the cooking signal from the residual pressure safety device and preventing manual unlocking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the residual pressure safety device is directly coupled to the boiling indicator, then the device structure is simplified, but the safety is compromised as the device can be manipulated to release the mechanical lock even at pressures ≥4 kPa
Solution Approach 1:
The closure device is divided into functionally independent components: the outer body with recesses for the locking arms, the central body with locking arms, and the inner body with the boiling indicator. This segmentation decouples the safety locking mechanism from the indicator, so that manipulating the indicator no longer affects the locking arms. The locking arms are held in position by the outer body's recesses and can only be moved by sufficient internal pressure, not by external manipulation of the indicator.
Solution Approach 2:
The outer body acts as an intermediary structure between the locking arms and the boiling indicator. The recesses in the outer body provide a controlled path for the locking arms to move only when sufficient pressure is applied internally, while preventing direct manipulation of the locking arms through the indicator. This intermediary structure ensures that the safety function is protected from unauthorized activation.
2Ease of operation
If the closure device allows quick actuation for ease of operation, then the ease of operation is improved, but the safety is reduced as the vessel can be opened even at hazardous pressures
Solution Approach 1:
The outer body's recesses are designed to preemptively prevent manipulation of the locking arms. The geometry of the recesses and the positioning of the locking arms within them create a mechanical barrier that stops unauthorized activation before it can occur. This preliminary anti-action ensures that even if a user attempts to quickly actuate the closure device by manipulating the indicator, the locking arms cannot be disengaged unless sufficient internal pressure is present.
3Ease of operation
If the locking arms are directly accessible through the outer body, then the ease of operation is improved for quick opening, but the safety is compromised as manipulation can release the lock at hazardous pressures
Solution Approach 1:
The outer body has recesses with specific local geometries that provide different qualities at different locations. The recesses allow the locking arms to protrude for visual indication and controlled movement under pressure, but the walls of the recesses prevent direct manipulation of the locking arms. This local quality differentiation enables the locking arms to be partially accessible for their function while protected from unauthorized activation.
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 3
AI summary
The invention relates to a closure apparatus for a pressure vessel (for a pressure cooker, for example) which provides a greater degree of safety for the user, in particular substantially meeting safety requirements from Annex I of the Directive 2014/68/EU. The closure apparatus has a lock, which prevents opening of the pressure vessel at an interior pressure of > 4 kPa, including in the case of counter pressure exerted on the closure apparatus in the direction of the pressure vessel. The closure apparatus has an outer body for this purpose, which encloses a central body of the closure apparatus and is movably connected thereto. Along a cylinder axis of the outer body, the outer body has a specific distance (x) from the central body and locking arms of the central body are movable by recesses in the outer body at least by the specific distance (x) along the cylinder axis of the outer body.