Daubing Device for Bubble-Free Sealant Application
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for applying sealants to fasteners in aircraft and other vehicles to protect against electromagnetic effects, such as lightning strikes, often result in non-uniform seals with air bubbles due to manual application or seal caps, which can compromise EME protection and increase cycle time.
Innovation Solution
A daubing device with a flexible dispenser and pressure-application mechanism that expels viscous material without introducing air, ensuring consistent application and preventing voids in the sealant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional daubing guns use compressed air for sealant ejection, then the sealant can be applied to the fastener, but air bubbles are introduced into the sealant creating voids that compromise EME protection
Solution Approach 1:
The patent uses a pneumatic pump system to deliver sealant from a container through a hose to the daubing gun. This hydraulic/pneumatic delivery system allows the sealant to be transported without direct compression of the sealant itself, avoiding air bubble introduction while maintaining reliable delivery
Solution Approach 2:
The system separates the sealant storage/container from the application point using a hose, allowing the sealant to be pumped through the hose without direct air contact. The daubing gun then applies the sealant without introducing air bubbles, segmenting the storage, transport, and application functions
2Ease of operation
If manual application method is used, then the sealant can be applied to the fastener, but the seals become non-uniform with varying volumes requiring rework
Solution Approach 1:
The daubing gun is designed with a trigger mechanism that allows the operator to control the sealant flow and application process. The tool enables the operator to self-regulate the application process, achieving uniform seals through controlled trigger activation while maintaining ease of manual operation
Solution Approach 2:
The system allows control of sealant application parameters (flow rate, pressure, volume) through the trigger mechanism and pump system. By adjusting these parameters, the operator can achieve consistent, uniform seal application while maintaining manual operation flexibility
3Productivity
If seal caps are pressed over fasteners to apply sealant, then the sealant is applied to the fastener, but squeeze out must be removed or smoothed increasing cycle time
Solution Approach 1:
The patent replaces the mechanical seal cap pressing method with a pneumatic/pump-driven daubing gun system. This substitution allows precise control of sealant delivery, applying the exact needed amount without excessive squeeze-out, thereby eliminating the time-consuming smoothing step while maintaining high application speed
4Ease of manufacture
If seal caps are used to apply sealant, then the sealant can be applied to the fastener, but air may become trapped underneath the shell creating voids
Solution Approach 1:
The system uses a pump-driven hydraulic/pneumatic delivery mechanism that pushes sealant through a hose and out of the daubing gun tip. This method delivers sealant without trapping air underneath a shell, as the sealant is forced out through the hose and applied directly, eliminating the air trapping problem inherent in seal cap design
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 uniform and bubble-free sealant application, enhancing EME protection and reducing cycle time by ensuring air-tight seals without the need for manual smoothing or rework.
Implementation Method 1
deforming a flexible wall of a dispenser located within a housing by expanding a pressure-application device within the housing
Implementation Method 2
deforming a flexible wall of a dispenser located within a housing by expanding a pressure-application device within the housing
Data Source
AI summary
A method of applying a viscous material to a fastener comprises aligning a nozzle relative to the fastener by engaging an aligner with the fastener. Engaging the aligner with the fastener comprises positioning the aligner over the fastener and advancing a biasing tube toward the fastener to establish contact between the aligner and a structure to partially retract the aligner into the biasing tube until a plurality of surfaces of the aligner contacts one or more outer surfaces of the fastener. A flexible wall of a dispenser bellows is deflected by expanding a pressure-application device, which is configured to apply pressure on the flexible wall of the dispenser bellows, wherein the dispenser bellows is in fluid communication with the nozzle. The viscous material is expelled from the dispenser bellows responsive to deforming the flexible wall.