Vacuum Cap Seal Installation Using Pressure Differential
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The installation of electromagnetic effect (EME) protective caps on aircraft structures is time-consuming and costly due to the need for manual holding of the caps in position while adhesive sealant cures, especially in challenging orientations like upside down or vertical surfaces, which increases the risk of cap separation or sliding.
Innovation Solution
The EME protective cap assembly incorporates a sidewall with a first opening for the fastener and a second opening with a valve member that allows for reduced air pressure inside the cap, using a vacuum pump to secure the cap against the structure with a pressure differential, ensuring it remains in place during sealant curing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the protective cap is secured with adhesive sealant alone, then the installation process is simple, but the cap cannot maintain position against gravity in challenging orientations
Solution Approach 1:
The patent applies preliminary action by creating a vacuum seal before the adhesive fully cures. The vacuum is established through a valve member that allows air evacuation from the cap interior, creating negative pressure that holds the cap against the structure during the adhesive curing period. This preliminary stabilizing action prevents the cap from sliding or separating under gravity before the adhesive achieves full strength.
Solution Approach 2:
The patent employs pneumatic principles by using a vacuum pump to remove air from the cap interior through the valve member. This creates a pressure differential (negative pressure inside, atmospheric pressure outside) that generates a holding force on the cap, supplementing the adhesive bond and enabling reliable installation in vertical or inverted orientations where gravity would otherwise cause the cap to slide.
2Reliability
If the installer manually holds the protective cap in position during adhesive curing, then the cap remains stable, but the installation process becomes time-consuming and costly
Solution Approach 1:
The patent implements self-service by enabling the cap to hold itself in position through the vacuum mechanism. Once the valve member is closed and the vacuum pump is activated, the cap automatically maintains its position against the structure without requiring continuous manual holding. The vacuum seal provides self-sustaining stabilization during the entire adhesive curing period, freeing the installer from time-consuming manual support tasks.
3Adaptability or versatility
If the protective cap is installed on vertical or inverted surfaces, then the cap can be positioned in difficult-to-reach areas, but gravity causes the cap to slide or separate during adhesive curing
Solution Approach 1:
The patent applies the anti-weight principle by using the vacuum pressure differential to counteract the force of gravity acting on the cap. The negative pressure inside the cap creates an upward holding force that opposes the downward pull of gravity, allowing the cap to remain stable on vertical or inverted surfaces during adhesive curing. This counterbalancing force enables installation in orientations where adhesive alone would be insufficient.
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
This method significantly reduces the installer's time and effort required to secure the protective cap, maintaining its position effectively during adhesive sealant curing, even in difficult orientations, by utilizing air pressure differentials to prevent separation or sliding.
Implementation Method 1
reducing air pressure within the interior space through the valve member
Implementation Method 2
using a vacuum pump to secure the cap against the structure with a pressure differential
Data Source
AI summary
An electromagnetic effect protective cap assembly for enclosing an end portion of a fastener assembly extending through a structure, includes a sidewall configured to define an interior space and having an end portion of the sidewall which defines a first opening aligned with the interior space which allows passage of the end portion of the fastener assembly through the first opening and into the interior space. The protective cap further includes a second opening which is defined by and extends through the sidewall and is spaced apart from the first opening. In addition, the protective cap further includes a valve member positioned in blocking relationship with respect to the second opening with the valve member positioned between the interior space and an exterior of the sidewall.