The aim of this study is to develop a firing mechanism activated by inertial forces and study its dynamic behavior. The study presents design principles, utilizes analytical approach and demonstrates it with specific designs. The mechanism uses a well-defined acceleration profile in order to release an inertial mass in a specific acceleration range. The inertial mass hits its target and a certain amount of energy is transferred to the target. The key parameter of the design is the energy being transferred to the target. Two concepts were designed and modeled: 1. Inner spring concept; 2. Outer spring concept. The concepts use single or multiple springs, respectively, perpendicular to the motion of the inertial mass. The springs are attached to stoppers that prevent the inertial mass from moving. The inner spring concept contains one spring located inside the inertial mass while the outer spring concept contains three equally-spaced springs located outside the inertial mass. Both concepts were fully modeled in SW and analyzed under static and dynamic conditions. An analytical model was developed in order to study the dynamic behavior of the mechanism. The model takes into account the masses of the moving parts including inertial mass, stopper mass and spring mass, spring preload, acceleration profile, required impact energy, friction forces, stopper horizontal displacement and inertial mass axial displacement. A MATLAB routine was developed in order to solve the motion equations and perform parametric study and optimization of the independent variables for both concepts. Finally, one of the concepts was manufactured and preliminary experiments show good agreement between the design and the test results. Therefore, the verified analytical model can be utilized as a design tool for inertial activated devices.
