Computer Simulation of Rocket/Missile Safing and Arming Mechanism (Containing Pin Pallet Runaway Escapement, Three-Pass Involute Gear Train and Acceleration Driven Rotor)

A complete simulation of missile and rocket safing and arming SA mechanisms containing an acceleration-driven rotor, a three-pass involute gear train, and a pin pallet runaway escapement was developed. In addition, a modification to this simulation was formulated for the special case of the PATRIOT M143 SA mechanism which has a pair of driving gears in addition to the three-pass gear train. The three motion regimes involved in escapement operation - coupled motion, free motion, and impact - are considered in the computer simulation. The simulation determines both the arming time of the device and the non-impact contact forces of all interacting components. The program permits parametric studies to be made, and is capable of analyzing pallets with arbitrarily located centers of mass. A sample simulation of the PATRIOT M143 SA in an 11.9 g constant acceleration arming test was run. The results were in good agreement with laboratory test data.