Use: H.E. projectiles for the 75-mm and 105-mm antiaircraft guns.

Description:

Over-all length: 2 3/32 inches.

Maximum diameter: 3 1/8 inches.

Threaded length: 3/8 inch.

Number of threads: 4, right-hand.

Construction: This fuze is constructed of brass and aluminum. The fuze body, time rings, vent positioning sleeve, and vent locking ring are made of brass, while the vent cap, nose piece, and base plug are aluminum. The striker extension is wood.

The movable time train has setting markings from 1 to 44 seconds, in half-second inter-vals.

The vent positioning sleeve separated the time rings from the central fuze body, and vertical grooves in this sleeve allow the gases from the burning time rings to pass off. A key prevents the sleeve from turning, and the upper time ring is also held stationary by a key which threads into the central fuze body.

The vent locking ring threads on the central fuze body and secures the time rings and the sleeve. It is held off the upper ring by belleville springs. The ring is further secured by a grub screw.

The vent cap threads onto the upper time ring and contains holes for the escape of ga-ses.

Contained in the nose cup is the complete impact firing mechanism, consisting of a woo-den striker extension, striker, centrifugal detent, detent spring, and primer cup.

The fuze body has two longitudinal flash channels through its central part to allow the flash from the impact primer to ignite the black-powder magazine in the base. The time firing-pin safety spring, and timer primer cap are also housed in the central fuze body. A transverse hole in the body between the time firing mechanism and the upper time ring allows the flash of the primer cap to ignite the upper time ring.

The fuze is stored with a protective cap screwed on the fuze body just below the lower time ring.

Operation:

Time: Set-back initiates the timer striker. Because of four longitudinal grooves in the striker, the flash escapes to and through the transverse opening to the upper powder ring. From the lower powder ring a black powder flash channel ignites the black-powder magazine in the base.

Impact: The detent moves from under the striker with centrifugal force. On impact the nose is crushed, driving the striker onto the primer cap. The flash passes through the flash channel in the central fuze body to the black-powder magazine in the base.

Figure 335 – Type 2 Combination Powder Time and Impact Fuze.