Safety Device Actuator Locking Verification via Magnetic Sensor
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Solution Overview
Problem
Existing safety devices with RFID systems can incorrectly report a locked protective door due to the actuator being positioned in a way that releases the guard locking pin, despite the RFID system indicating a closed position, leading to potential unsafe conditions.
Innovation Solution
A safety device with a transponder in the actuator and a reading unit in the safety switch, featuring a locking element with a sensor and an influencing element that changes transponder signals when the locking element is inserted into a receptacle, ensuring accurate monitoring of the guard locking without electrical connections, using a sensor and influencing element forming a non-contact unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the locking element is designed to engage with the actuator receptacle, then the locking function is improved, but the reliability of position monitoring deteriorates because the actuator can be positioned to release the locking element while still indicating closed position via RFID
Solution Approach 1:
A magnetic field sensor is introduced as an intermediary detection mechanism between the locking element and the monitoring system. The sensor detects the magnetic field of a magnet integrated into the locking element, providing independent verification of locking engagement that is not dependent on RFID signal position alone
Solution Approach 2:
The magnetic field sensor provides continuous feedback about the locking element's engagement state. When the locking element engages with the actuator receptacle, the sensor detects the magnet's position and generates a corresponding signal that confirms the locked state, creating a feedback loop that verifies locking reliability
2Measurement precision
If electrical connections are provided to the locking element for sensor supply, then the monitoring function is improved, but the device complexity increases due to additional electrical supply lines
Solution Approach 1:
The patent replaces electrical connection mechanisms with a magnetic field-based detection system. The magnet integrated into the locking element generates a magnetic field that can be detected by the magnetic field sensor without requiring any electrical contacts, wires, or power supply connections to the moving locking element
Solution Approach 2:
The locking element with integrated magnet serves its own detection function without requiring external electrical infrastructure. The magnet's inherent magnetic field provides the detection signal, and the system uses this passive field emission rather than requiring active electrical power delivery to the locking element
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 solution provides high functional safety by accurately monitoring the guard locking, reducing structural complexity and avoiding manipulation, with a compact and robust design that eliminates the need for complex electrical supply lines and ensures reliable detection of the locked state.
Implementation Method 1
A transponder (5) is located in the actuator (3), and a reading unit (4) is located in the safety switch (2)... enabling the reader to receive transponder signals
Implementation Method 2
The actuator (3) has a sensor (11) coupled to the transponder (5)... ensuring that the influencing element (12) is only within the sensor's (11) range of influence when the locking element (6) is inserted into the receptacle (7)
Data Source
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AI summary
The invention relates to a safety device (1) comprising a safety switch (2) and an actuator (3) movably arranged relative to the safety switch. A transponder (5) is arranged in the actuator (3), and a reading unit (4) is arranged in the safety switch (2). The actuator (3) is controlled by the detection of transponder signals from the transponder (5) in the reading unit (4). The safety switch (2) has a locking element (6) with an influencing element (12). The actuator (3) has a sensor (11) coupled to the transponder (5). In the closed position of the actuator (3), the locking element (12) can be inserted into a receptacle (7) of the actuator (3). This results in the actuator (3) being locked. This locking mechanism is controlled by the fact that the influencing element (12) is only within the influence range of the sensor (11) when the locking element (6) is inserted into the receptacle (7).This generates a sensor signal which modifies the transponder signals sent by the transponder (5). The modified transponder signals are detected in the reading unit (4).