Adhesive Tank Fill Level Detection via Compressed Air Flow Analysis

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Solution Overview

Problem

Existing glue guns with large adhesive requirements face economic inefficiencies due to the high cost and frequent replacement of small adhesive cartridges, and existing solutions for conveying and dispensing liquid adhesive with compressed air do not provide reliable and intuitive fill level monitoring.

Innovation Solution

A measuring system integrated into a glue gun that uses a sensor to detect the fill level of an adhesive tank by analyzing changes in compressed air flow properties, with an evaluation unit determining the fill level based on signal duration and transmitting information to an output unit for intuitive user feedback, such as LED indicators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a large adhesive tank is used to reduce the frequency of cartridge changes, then productivity is improved, but the device complexity increases due to the need for additional monitoring systems

Engineering Contradiction:
Improveoperational efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical level detection mechanisms with a sensor-based system that uses electrical or optical signals to detect adhesive level. The sensor (e.g., capacitive, optical, or pressure-based) provides continuous monitoring without mechanical moving parts, reducing system complexity while maintaining high productivity benefits of larger tank capacity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback mechanism where the level sensor continuously monitors adhesive level and provides signals to a control unit, which then alerts the user when refilling is needed. This closed-loop feedback system simplifies operation by automatically monitoring tank level without requiring manual inspection, thus improving productivity while keeping the monitoring system simple

Inventive Principle:
Principle #23Feedback

2Loss of information

If a sensor-based fill level monitoring system is added to provide reliable feedback, then information availability is improved, but device complexity increases

Engineering Contradiction:
Improvefill level informationVSAvoidmonitoring system complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent uses non-mechanical sensors (optical, capacitive, or pressure sensors) to detect adhesive level, replacing complex mechanical linkages or float-based systems. These sensors provide reliable fill level information through electrical or optical signals with minimal moving parts, reducing overall system complexity while ensuring continuous information availability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The monitoring system is designed to be self-monitoring, where the sensor automatically detects adhesive level without requiring external intervention or complex processing. The system serves itself by providing direct feedback about its own state (adhesive level) through simple sensor signals to the control unit, minimizing added complexity while maximizing information reliability

Inventive Principle:
Principle #25Self-service

3Device complexity

If the sensor is placed in the compressed air line to utilize existing flow, then device complexity is reduced, but measurement precision may be affected by flow variations

Engineering Contradiction:
Improvesystem integrationVSAvoidfill level detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent uses sensors that detect changes in physical parameters (pressure, optical properties, or electrical characteristics) of the compressed air flow to determine adhesive level. By monitoring parameter variations in the existing compressed air line, the system integrates seamlessly without adding complexity, while the sensor's ability to detect subtle parameter changes ensures maintained measurement precision despite flow variations

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary signal processing mechanism that translates the sensor's detection of compressed air flow properties into accurate fill level measurements. This intermediary layer (signal processing unit) compensates for flow variations by normalizing sensor readings, ensuring measurement precision is maintained while utilizing the existing compressed air line for simple integration

Inventive Principle:
Principle #24Intermediary (Mediator)

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 system provides reliable, space-efficient, and user-friendly fill level monitoring, reducing the need for frequent cartridge changes and enhancing operational efficiency by alerting users when the adhesive level is low.

Implementation Method 1

a sensor (18) by means of which a measurement signal can be generated at least temporarily depending on a flow state of the conveyed medium

Methodology Applied
Scientific EffectFlow detection:

Implementation Method 2

the sensor has an actuating element (20) by which a flow opening (28) of the sensor, arranged between an inlet (26) and an outlet (27) for the conveyed medium, can be closed at least temporarily

Methodology Applied
Scientific EffectPressure force: Pressure Increase

Implementation Method 3

an actuating element (20) by which a flow opening (28) of the sensor, arranged between an inlet (26) and an outlet (27) for the conveyed medium, can be closed at least temporarily

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP3660471B1Measuring system for detecting the fill level of an adhesive tank and an adhesive gun comprising such a measuring system
Publication Date: 2023.03.22 BUHNEN
  • EP3660471B1 patent drawingFigure 1~2
  • EP3660471B1 patent drawingFigure 3~4

AI summary

A measuring system for detecting the fill level of an adhesive tank (11) and a glue gun (10) for dispensing a liquid adhesive are described. The adhesive tank contains a liquid adhesive, at least temporarily. Furthermore, a dispensing nozzle (13) through which the liquid adhesive can be dispensed and a feed unit (15) are provided. When a control element (12) is actuated, the feed unit (15) delivers liquid adhesive from the adhesive tank (11) to the dispensing nozzle (13). The feed unit (15) has at least one compressed air line (17) that is connected to the adhesive tank (11) via a fluid communication system, at least temporarily, such that liquid adhesive is delivered to the dispensing nozzle (13) by means of an overpressure or underpressure generated by an airflow through the compressed air line (17).The described technical solution is characterized in that the compressed air line (17) has a measuring system according to the invention, with at least one sensor (18) by means of which a measuring signal can be generated as a function of the airflow through the compressed air line (17) and transmitted to an evaluation unit (19), which is designed to determine a level value representing the fill level of the adhesive tank (11) on the basis of the measuring signal and to transmit it to an output unit (14).