Aircraft Canopy Cam Hinge for Zero-Altitude Ejection
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Solution Overview
Problem
Existing aircraft ejection systems require a time delay to ensure the canopy is clear of the seat's path during emergency ejections at zero altitude and zero airspeed, which can be critical in emergency situations and increases system complexity and costs.
Innovation Solution
The design incorporates a canopy with a hinge portion and cam mechanism that restricts release from the pivot pin until a specific release angle is reached, ensuring the canopy's travel path does not intersect with the seat's path, allowing immediate ejection without a time delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a time delay is implemented to ensure canopy clearance during ejection at zero altitude and zero airspeed, then safety is improved, but ejection time is increased and system complexity increases
Solution Approach 1:
The cam mechanism is pre-configured with a specific profile that automatically ensures the canopy reaches a safe clearance angle before release. The cam's geometry is designed in advance to control the hinge portion's rotation, lifting it clear of the seat's travel path before the canopy detaches, thereby eliminating the need for additional time delay systems while maintaining safety.
Solution Approach 2:
The cam acts as an intermediary mechanism between the canopy hinge and the release system. It mediates the motion control by converting the canopy's rotation into a controlled lifting action of the hinge portion, ensuring safe clearance without requiring complex timing mechanisms or additional safety systems.
2Reliability
If a time delay system is added to ensure canopy clearance, then safety is improved, but device complexity increases
Solution Approach 1:
The cam mechanism is designed to automatically perform the safety function through its inherent geometry. As the canopy rotates during jettison, the cam profile self-regulates the hinge portion's motion, lifting it clear of the seat path without requiring external control systems, sensors, or complex timing mechanisms. The system serves itself by using the canopy's own motion to activate the safety clearance.
Solution Approach 2:
The invention extracts the essential safety function from complex timing and control systems, isolating it into a simple mechanical cam mechanism. By removing the need for electronic controls, sensors, and complex sequencing systems, the safety function is achieved through a single, straightforward mechanical component that reduces overall system complexity.
3Reliability
If the cam mechanism extends further in the rotation direction, then canopy release angle is increased improving safety, but manufacturing precision requirements increase
Solution Approach 1:
The cam profile parameters, including its extension length and geometric shape, are optimized to achieve the maximum necessary release angle while maintaining manufacturability. By carefully selecting the cam's dimensional parameters, the design balances safety requirements with practical manufacturing capabilities, ensuring that the cam can be produced with standard tolerances rather than requiring ultra-precise manufacturing.
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 solution enables earlier ejection of the pilot by eliminating the need for a time delay, improving safety and reducing system complexity and costs associated with testing and assembly.
Implementation Method 1
The hinge portion includes a cam. The cam is to restrict the canopy from releasing from the pivot pin until the canopy reaches the release angle.
Implementation Method 2
a canopy jettison rocket motor to, when activated, move the canopy away from the forward fuselage
Implementation Method 3
the canopy (1) rotates about the pivot pin until reaching a release angle
Data Source
AI summary
Aircraft canopy jettison systems, apparatus, and methods are described herein. An example aircraft includes a forward fuselage defining a cockpit, a seat in the cockpit, a pivot pin coupled to the forward fuselage, and a canopy removably coupled to the forward fuselage over the cockpit. The canopy includes a frame having a hinge portion. The hinge portion includes a cam. The cam is dimensioned such that when the canopy is jettisoned while the aircraft is at zero altitude and zero airspeed, a travel path of the hinge portion does not intersect a travel path of the seat when the seat is ejected while the aircraft is at zero altitude and zero airspeed.