Plunger Coil Thickness Measurement Guide Element Deflection
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Solution Overview
Problem
Existing devices for determining the thickness or thickness variation of flat objects, such as vouchers, are prone to malfunctions and imprecise measurements, especially when detecting adhesive tape or counterfeit objects, due to complex and sensitive detection of coverage and gap between magnetic coils and conductive elements.
Innovation Solution
A device with second guide elements rigidly connected to moveable coil cores and stationary coils operating on the plunger coil principle, where changes in inductivity due to thickness variations are detected, allowing for precise and sensitive measurements across the entire width of the object without interference from superposed magnetic fields, using LC resonant circuits and analysis electronics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If flat coils with conductive elements are used for thickness measurement, then measurement sensitivity is improved, but detection reliability deteriorates due to interference and malfunctions
Solution Approach 1:
The patent replaces the electrical detection system (flat coils measuring eddy currents) with a mechanical measurement system (capacitive sensors measuring physical distance). This substitution eliminates the interference problems between magnetic fields and conductive elements, providing reliable thickness measurements without the malfunctions associated with the electrical system.
Solution Approach 2:
The patent introduces a mechanical intermediary (the movable guide element with capacitive sensors) that physically translates thickness variations into measurable distance changes. This intermediary converts the thickness measurement problem into a simple distance measurement problem, avoiding the complex electrical field interactions that caused reliability issues.
2Measurement precision
If coverage detection between coils and conductive elements is implemented, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces the complex electrical coverage detection system with a simple mechanical capacitive sensing system. Instead of measuring electrical field coverage and gap distances, the system directly measures the physical distance between the guide element and the flat object using capacitive sensors, dramatically reducing system complexity.
Solution Approach 2:
The patent extracts the measurement function from the complex electrical coil system and places it on the movable guide element itself. By moving the capacitive sensors to the guide element, the system eliminates the need for complex coverage detection between stationary coils and conductive elements, simplifying the overall system architecture.
3Area of stationary object
If multiple flat coils are used for width coverage, then measurement completeness is improved, but interference from superposed magnetic fields increases
Solution Approach 1:
The patent replaces multiple electrical flat coils with multiple mechanical capacitive sensing points distributed across the width of the guide element. This substitution maintains comprehensive width coverage for detecting adhesive strips while eliminating the magnetic field interference that occurs when multiple coils operate simultaneously.
Solution Approach 2:
The patent segments the width measurement function into multiple independent capacitive sensing points along the guide element. Each sensing point independently measures thickness at its location, and the combined data provides complete width coverage without the magnetic field superposition problems of using multiple overlapping coils.
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 precise, sensitive, and cost-effective thickness measurements for flat objects, including those with adhesive tape or counterfeit variations, with independent deflection of guide elements and no need for additional sensors, enabling accurate identification and verification of object thickness across the entire width.
Implementation Method 1
The stationary coils and the moveable coil cores operate in accordance with the plunger coil principle. A relative movement between a coil and an associated coil core initiated by a change in thickness and a deflection of a second guide element results in a change in the inductivity of the coil.
Implementation Method 2
using LC resonant circuits and analysis electronics
Data Source
AI summary
A device for determining a thickness or thickness variation of a flat object (5), in particular of a voucher, is proposed, having at least one first guide element (1), and having a plurality of second guide elements (2) arranged next to each other in a row and opposite the first guide element (1), wherein the flat object (5) can be transported between the first guide element (1) on the one side and the second guide element (2) on the other side, and having a displaceable arrangement of the second guide elements (2) relative to the first guide element (1) in order to bring about a displacement of one or more of the second guide elements (2) in the event of a thickness variation of the flat object (5) passing between the guide elements (1, 2), and having several coils (10, 11) fixed in location, wherein each second guide element is associated with at least one coil (2), and having at least one coil core (9) rigidly connected to a second guide element (2) and displaceably guided in the coil associated with the second guide element (2), wherein a deflection of a second guide element (2) brings about a deflection of the associated coil core (9), and having an analysis device (16, 17, 18, 19) to determine the influence of the position of the coil cores (9) relative to the coils (10, 11).