Methods for electro-mechanical safety and arming of a projectile

A method for arming a projectile, comprising:

• displacing a mass away from a setback engagement structure of a rotor pivotally coupled to a housing responsive to an axial acceleration of the projectile above an axial acceleration threshold to enable rotation of the rotor from a safe position to an armed position;
• displacing a displaceable end of a leaf spring away from a spin-lock engagement structure on a side surface of the rotor responsive to a spin rate of the projectile above a spin threshold to further enable rotation of the rotor from the safe position to the armed position;
• rotating the rotor from the safe position to the armed position by activating a piston actuator to align a detonator disposed in the rotor with a detonation cord operably coupled to the housing;
• and
• after the displacing the mass away from the setback engagement structure, displacing a setback retainer disposed in the setback engagement structure over the mass to prevent the mass from engaging with the setback engagement structure.

A method for arming a projectile, comprising:

• displacing a mass away from a setback engagement structure of a rotor pivotally coupled to a housing responsive to an axial acceleration of the projectile above an axial acceleration threshold to enable rotation of the rotor from a safe position to an armed position;
• displacing a displaceable end of a leaf spring away from a spin-lock engagement structure on a side surface of the rotor responsive to a spin rate of the projectile above a spin threshold to further enable rotation of the rotor from the safe position to the armed position;
• rotating the rotor from the safe position to the armed position by activating a piston actuator to align a detonator disposed in the rotor with a detonation cord operably coupled to the housing;
• and
• after the rotating the rotor from the safe position to the armed position, displacing the mass to engage with an indentation in the side surface of the rotor to maintain the rotor in the armed position.