Downloaded from https://www.everyspec.com AMCP 706-210 to respond to the initial (weak) signals, it is at ' but provision is made for other arming fine- tbe basic role of the fuze not only to signal the tions such as switch closures all of which are presence of the target and to initiate the ex- finaliy completed at I, and the fuze is fully plosive train, but also to provide safety by armed and ready to function, 1-3 TYPICAL AMMUNITION ITEMS casualties to property and life in the past have been directly traceable to inadequate built-in Ammunition can carry a fuze in its nose, its fuze safety.
base, or anywhere within depending upon its As an approach to providing adequate safety, tactical purpose. To illustrate this versatility, present design philosophy calls for a fuze to several common fuze carriers are briefly des- have at least two independent safing features, cribed below. Greater detail is contained in Part wherever possible, either of which is capable of Three of this handbook. preventing an unintended detonation; at least one of these features must provide delayed 1.3.1 PROJECTILES arming (safe separation). This and other aspects of safety are discussed in detail in Chapter 9. Fig.
1-2 shows a typical round of fixed ammu- Reliability of functioning is also a primary nition for artillery use. The weapon firing pin (at concern of the fuze designer, details of which the bottom of the figure) strikes the cartridge are covered in later chapters (e.g., par. 2-3). primer. This initiates the propelling charge with Fig. 1-1 is a diagram of the steps involved in the help of the igniter., As the propellant burns, a typical arming process. At the left the fuze is gases form that exert pressure upon the base of represented as unarmed so that it may be stored, the projectile and force it out of the gun tube. transported, handled, and safely launched.
The Rifling in the gun tube engraves the rotating arming process starts at a by adding energy to band thus imparting spin to stabilize the pro- the system in a proper manner. At b enough jectile. In flight, centrifugal forces, set up in energy has been added so that the device will the spinning projectile, turn rotor and move continue to completion o; the arming cycle. At interrupter so that a continuous explosive train any time between a and b the device will return is formed. The fuze is now armed. Upon target to the unarmed condition if the energy is re- impact, the firing pin in the fuze is pushed into moved.
After b the fuze is committed to con- the primer which then explodes and ignites tinue the arming process; therefore, b is termed the detonator. It in turn initiates the booster the commitment point. The detonator is aligned that amplifies the detonation sufficiently to reliably detonate the bursting charge. 1-3.2 ROCKETS UNARMED - PART -)AM *ARMED Fig. 1-3(A)' * illustrates Rocket, M28. with a base Fuze, M404A1 that is enlarged in Fig. C i1-3(B). Rockets carry- their own propellant which burns during rocket flight. After the Fu o, F Is rocket exits the launch tube, the ejection pin ME U-'AMED-- ALIGNED ARMED slides away, due to the force of a compressed spring, exposing the detonator.
Upon impact, the inertia weight moves forward and causes Oft the striker to stab the detonator, which causes ALIGNMENT _,___ the booster charge and in turn the high explosive OE-A bursting charge in the rocket head to detonate. TIME -- Supescript nurmber- ,,n pertain tv Ileferences. Nunivri al Refernce's are li,ted at the end of each Chapt,-r hilc lettvred Hejerences are liq ted at the end Figure 1.I. Fuze Arming Process of tlhe text. 1.2