“Approved for Public Release by SMCAR Form 3002 dated 26 Apr 95 .”

KDI Precision Products, Inc. is the premier design, development, and manufacturing source or highly sophisticated Self-Destruct (SD) Fuzes. KDI in conjunction with the U.S. Army,  developed a fuzing system to substantially decrease the dud rate of grenades deployed by rocket and artillery cargo rounds. To meet this humanitarian need, KDI successfully qualified the M234/235/236 SD fuzes. This unique Self-Destruct Fuze features two autonomous fuze functioning systems. Incorporating an improved primary mode M223 fuze, the M234/235/236 fuzes are provided with a secondary or electronic selfdestruct mode, which operates totally independent from the primary mode which functions following any primary mode failure. If the primary fuze fails-to-function or fails to-arm, the M234/235/236 SD fuze will either function the grenade or sterilize the fuze.

Fuze operation launch environments include acceleration levels up to 23,000 “G’s” and spin rates up to 21,000 RPM. Function is also reliable in the low acceleration and spin  environments of missile systems. When deployed from the projectile or missile carrier, a pack-able slide lock is removed from the grenade which allows a drag-ribbon to be deployed. The ribbon, firmly attached to the firing pin, provides stabilization and maintains orientation while the spinning grenade causes the threaded firing pin to turn relative to the threaded weight. The slide is released and moves to the armed position, aligning the stab detonator with the firing pin and lead charge. This operation arms the primary fuze upon impact. The inertial weight and firing pin are driven into the stab detonator, initiating the detonator and grenade.

The SD backup function is also initiated at cargo ejection. The battery spiral safety, pulled from the fuze assembly by the air stream, releases a spring-loaded lever activating a reserve battery. As the volt-age rises, an electronic delay timer circuit is enabled and the firing capacitor begins to charge. Following deployment, the air stream also removes a short from an Electrical Explosive Device (EED). If the stab detonator is not initiated upon impact, the firing capacitor, following a 3 minute delay, functions the EED. In the event the fuze fails to arm, the delay circuit initiates the EED which detonates the stab detonator and sterilizes the grenade. KDI is currently applying the fundamental components of the self-destruct fuze to the M549 40mm fuze configuration. Electronic Self-Destruct is accomplished in the 40mm round by placing the fundamental SD components (battery, EED, and delay timer circuit) into the existing primary fuze Rotor.