Housing Cover Detection via Monostable Relay Elastic Blade
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional detection systems for unauthorized opening of boxes with power supplies fail to function during power interruptions, as they rely on continuous power to operate, leading to undetected cover removals when the power is restored.
Innovation Solution
A detection device comprising a monostable relay with an elastic blade and a control unit that retains the relay's extended position when the cover is closed, allowing detection of cover removal even during power outages, and a core position sensor to ensure correct operation, enabling alerts upon power restoration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional push button detection device is used, then the device is simple in structure, but the detection function fails during power interruptions
Solution Approach 1:
The elastic blade is pre-positioned to engage with the cover portion, and the monostable relay is pre-configured to maintain the extended position of the core through mechanical retention. This preliminary mechanical arrangement ensures that the detection state is preserved during power interruptions without requiring continuous power supply to maintain the detection configuration.
Solution Approach 2:
The elastic blade acts as an intermediary mechanical element between the cover and the push button. It transfers the mechanical state of the cover (present or removed) to the push button through elastic deformation, enabling the detection device to sense cover presence/absence mechanically rather than requiring continuous electrical power for active sensing.
2Reliability
If the core is retained in extended position during power outage, then cover removal can be detected after power restoration, but the mechanism becomes more complex
Solution Approach 1:
The monostable relay automatically maintains the core in the extended position through its inherent mechanical design when de-energized, without requiring external power or control signals. The elastic blade self-regulates its deformation based on cover presence, automatically indicating the detection state to the push button without requiring active power management or complex control logic.
3Reliability
If the elastic blade is used to retain the core, then power failure detection is enabled, but the blade must be precisely positioned
Solution Approach 1:
The elastic blade is designed with specific local properties: a deformation zone with optimized geometry and material characteristics that enable reliable engagement with the cover portion. The blade's cross-section, thickness, and elastic modulus are locally tailored to ensure consistent deformation behavior and reliable push button actuation, reducing sensitivity to manufacturing tolerances in blade positioning.
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
Ensures accurate detection of cover removal and reinstallation even during power interruptions, preventing false negatives and enabling timely alerts for unauthorized access.
Implementation Method 1
An elastic blade is attached to the end of the core to have a free end spaced from the push button when the core is in the retracted position and facing the push button when the core is in the extended position. Said portion of the cover bears against the blade when the cover is present so that the blade is deformed and actuates the push button
Implementation Method 2
a monostable relay having a core movable between a retracted position towards which the core is elastically returned and an extended position towards which the core is driven by a control unit arranged to detect the state of the push button
Data Source
Figure 1~4
AI summary
A housing comprising a box that is closed by a cover and a detection device comprising a pushbutton facing a portion of the cover and a monostable relay having a core that is movable between a withdrawn position into which the core is elastically returned and a deployed position into which the core is driven by a control unit that is arranged to detect the state of the pushbutton, an elastic strip being attached to the end of the core and said portion bearing against the strip when the cover is present and the core is in the deployed position such that the strip is deformed and actuates the pushbutton, the strip and said portion being arranged such that, when the cover is present, said portion holds the core in the deployed position and does not oppose the entry of the core into the deployed position and does not oppose the actuation of the pushbutton by the strip when the core is driven into its deployed position.