Fiber-Optic Alarm Signaling Device with Mandrel Sensor Activation
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Solution Overview
Problem
Existing fiber-optic alarm signaling devices are prone to failure under temperature changes, humidity, and frequent switching cycles, making them unreliable for detecting unauthorized access in telecommunications networks.
Innovation Solution
A current-free, fiber-optic alarm signaling device with a mechanism that maintains optical sensor activation upon door closure, using a mandrel to bend the optical fiber and a spring-loaded contact switch to ensure consistent signal detection, allowing for reliable follow-up control across various infrastructure types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a conventional fiber-optic alarm sensor is used to detect door openings, then the alarm signal is generated rapidly, but the signal is lost when the door is closed and the mechanism resets, preventing follow-up control
Solution Approach 1:
The optical sensor is pre-positioned on the mandrel in an activated bent state before the door opening event occurs. When the door is opened, the contact switch is triggered to generate the alarm signal, and the sensor remains in the activated state on the mandrel even after the door closes and the contact switch resets, enabling follow-up control and delayed alarm signaling.
2Reliability
If the optical sensor is bent strongly to trigger a detectable signal, then the signal detection reliability is improved, but the optical sensor experiences increased stress and potential damage
Solution Approach 1:
The mandrel provides a controlled, localized bending radius for the optical sensor, creating a precise activation point with optimized curvature. This localized quality control ensures the sensor is bent enough to trigger detection while distributing stress evenly, preventing damage and maintaining sensor durability over repeated cycling.
Solution Approach 2:
The mandrel acts as a cushioning element that pre-absorbs and distributes the mechanical stress on the optical sensor before activation. By providing a controlled bending surface, the mandrel prevents sharp, damaging bends while ensuring sufficient curvature for reliable signal detection, protecting the sensor during frequent switching cycles.
3Speed
If the measuring signal transmitter is spring-loaded to return to initial position, then the mechanism resets quickly, but the optical sensor activation state is lost
Solution Approach 1:
The system is divided into two independent functional segments: the contact switch/measuring signal transmitter that resets quickly via spring mechanism, and the optical sensor on the mandrel that maintains its activated bent position. This segmentation allows the contact switch to reset rapidly for repeated triggering while the optical sensor remains activated on the mandrel for follow-up control and delayed alarm signaling.
4Device complexity
If the optical sensor is positioned in a straight line orientation, then the device complexity is reduced, but no detectable signal is generated unless bent into activation state
Solution Approach 1:
The mandrel introduces a controlled curvature to the optical sensor path, transforming it from a straight line to an arc-shaped configuration. This curvature is essential for generating the detectable signal, as the bent optical sensor creates the necessary optical effect for alarm detection. The mandrel provides a consistent, reproducible bend that ensures reliable signal generation with each door opening event.
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 device provides a reliable and consistent signal for detecting unauthorized openings in infrastructure systems, such as street cabinets and telecommunications networks, with enhanced durability and reduced stress on the optical sensor, enabling effective monitoring over long distances.
Implementation Method 1
a mandrel for bending an insertable optical measuring sensor
Implementation Method 2
a spring element for positioning the measuring signal transmitter
Data Source
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AI summary
The invention relates to a powerless, fiber-optic alarm signalling device with track control of the alarm notification, comprising a measurement signal transmitter which is arranged in a housing and can have signal transmission connections, a contact switch and a mandrel for bending an optical measurement sensor that can be introduced, wherein the measurement signal transmitter is adjustable between a first position and at least a second position, and a spring element for positioning the measurement signal transmitter. According to the invention, a guide part having a guide region is formed in the housing, in which guide region the receivable optical measurement sensor can be bent into an activated state, and a receiving space for the optical measurement sensor is formed within the guide region, in which the received activated optical measurement sensor can be accommodated in an activated manner independently of the position of the measurement signal transmitter.