Projectile Arming Rotor Using Setback and Spin Interlocks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing safety and arming devices for explosive projectiles face challenges in ensuring reliable and safe detonation, particularly in sensing multiple environmental parameters and adapting to various projectile sizes, often relying on complex electronic systems that may not provide sufficient mechanical safety and reliability.
Innovation Solution
The integration of electro-mechanical systems that utilize a rotor with pivotable positions and biasing elements to sense setback acceleration and centrifugal forces, allowing for mechanical obstruction of the firing train until safe conditions are met, combined with a piston actuator for electrical signal-activated arming, ensuring alignment of the detonator with the detonation cord.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electronic elements are used to sense elapsed time and turns counting, then measurement precision is improved, but device complexity increases and mechanical safety obstruction is reduced
Solution Approach 1:
The patent replaces electronic sensing elements with mechanical sensing elements. Specifically, it uses a mechanical inertial unit with a mass and spring assembly to sense acceleration, and a mechanical centrifugal unit with a mass and spring assembly to sense spin rate. This substitution maintains measurement precision while simplifying the system and enhancing mechanical safety obstruction, as the mechanical units physically block the firing train until safe conditions are met.
Solution Approach 2:
The mechanical sensing units are self-contained and self-actuating. The inertial unit uses a mass-spring system that automatically responds to acceleration forces, and the centrifugal unit uses a mass-spring system that automatically responds to centrifugal forces from spin. These units require no external power or control systems, thereby reducing device complexity while maintaining precise sensing capabilities.
2Reliability
If mechanical systems are used to sense two physical environments, then safety and reliability are improved, but adaptability to different projectile sizes decreases
Solution Approach 1:
The patent employs adjustable parameters within the mechanical sensing units to adapt to different projectile sizes. The inertial unit and centrifugal unit contain adjustable masses and spring constants that can be modified to change the threshold acceleration and spin rate values. This allows the same mechanical system design to be adapted to various projectile calibers and flight characteristics while maintaining the reliability benefits of mechanical sensing.
Solution Approach 2:
The mechanical sensing units incorporate dynamic elements such as movable masses and adjustable spring assemblies that can be reconfigured for different operating conditions. This dynamic adjustability enables the system to maintain optimal performance across different projectile sizes without sacrificing the inherent safety and reliability of mechanical sensing.
3Reliability
If a rotor with multiple engagement structures is used, then safety and reliability are improved, but device complexity increases
Solution Approach 1:
The patent combines multiple safety functions into a single integrated rotor assembly. The rotor incorporates both the inertial engagement structure and the centrifugal engagement structure, along with the detonator mounting and arming lever interaction. This merging of functions into one component reduces the number of separate parts and assembly steps, thereby reducing device complexity while maintaining the high reliability achieved through multiple independent safety mechanisms.
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 enhances the safety and reliability of explosive projectiles by using mechanical systems to determine multiple environmental parameters, providing improved performance, adaptability to different projectile sizes, and combining mechanical and electronic safety features for precise detonation timing.
Implementation Method 1
The first biasing element is deformable to allow the mass to displace and disengage from the setback engagement structure upon an axial acceleration of the projectile, which permits rotation of the rotor.
Implementation Method 2
The second biasing element is deformable to disengage the displaceable end from the spin-lock engagement structure upon a centrifugal acceleration of the projectile, which permits rotation of the rotor.
Data Source
AI summary
A safety and arming apparatus for use with a projectile includes a rotor pivotable between a safe position and an armed position. A biasing element holds a mass engaged with the rotor to restrain the rotor from rotation and is deformable to allow the mass to displace and disengage from the rotor in response to a setback force on the projectile. A second biasing element includes a displaceable end for engaging with the rotor to restrain the rotor from rotation and is deformable to disengage the displaceable end from the rotor in response to projectile spin. A piston actuator can rotate the rotor to the armed position if the mass is disengaged and the displaceable end is disengaged. A detonator on the rotor can be aligned with a detonation cord when the rotor is in the armed position and unaligned when the rotor is in the safe position.