Trip Wire

Figure 8-20. Pull-release type demolition firing device
Figure 8-21. Pull-type demolition firing device

to 5 pounds on the trip wire releases the springloaded firing pin that fires the primer.

(2) Box type. Box-type firing devices, consisting of a rectangular steel body and primed coupling base, are actuated by release of pressure.

(a) The pressure-release-type firing device (fig. 822) is a mechanical device used to activate antitank mines equipped with supplementary fuze wells (cap wells). This type is also used for general boobytrap installations with charges having a threaded capwell. This device is activated by a spring-loaded firing pin, which fires the primer, when a restraining load of at least 5 pounds is removed from the release plate.

Figure 8-22. Pressure-release type demolition firing device

Figure 8-22. Pressure-release type demolition firing device

(b) The release-type firing device (fig. 8-23) is used in setting up boobytraps. A restraining weight of at least three pounds is applied on the top face of the latch at the time of installation. After the safety pin has been removed, displacement of the restraining weight releases the latch. This allows a spring lever to actuate the firing pin that strikes the primer.

(3) Inert firing devices. Inert firing devices used for training purposes are to be employed in exactly the same manner and with the same care and precautions as the explosive items they simulate. It is essential that personnel in training fully understand the procedures and instructions given in the manuals pertaining to explosives and firing devices, see TM 9-1375-213-12, TM 9-1375-213-34 and FM 5-250.

(4) Percussion cap primers. When struck by a firing pin, percussion cap primers (fig. 824) produce a small, intense flame to initiate a blasting cap or igniter charge. The primer body is a flanged copper or gilding-metal cup with a hole in the bottom. The body contains an inner inverted cup, an initiating charge and an anvil.

0 0

Post a comment