CONTENTS 



Page 



INTRODUCTION 1 



BACKGROUND 1 



Requirements 2 



Component Description 2 



DYNAMIC MODEL 2 



MODEL VALIDATION 3 



Poppet Valve Coefficient 3 



Minimized Drill Body Motion 4 



Reductions to Plunger and Piston 5 



Damping Coefficients 8 



RESULTS 9 



CONCLUSIONS 10 



RECOMMENDATIONS 11 



REFERENCES 12 



APPENDLXES 



A - Details of DADS Model A-l 



B - Impact Mechanism Parts Drawings B-l 



