The Combination (Pull or Pressure) firing device M1 is a standard firing device which can be threaded to all of the standard antipersonnel mines, hand grenades, and to the bangalore torpedo.

GENERAL:

The combination firing device M1 is designed for firing explosive charges either by means of a trip wire or by pressure. When the device is employed in the M2 or M3 anti-personnel mine, an igniter or blasting cap is attached to the base and the assembly is designated Fuze. Mine, M2; M2A1; M3; or M3A1 as described below.

DESCRIPTION:

The principal parts of the device are the body, striker spindle, pressure cap, locking screw, release pin, and standard nipple base. The pressure cap is press-fitted onto the top of the striker spindle which extends into the body and is under tension of the firing pin spring. The striker spindle has a circumferential groove to recive the locking screw and release pin, and is drilled to receive the safety pin below the pressure cap. The base, containing the primer, has an extension to which an igniter or blasting cap may be attached.

Modification: Bending beyond 7 degrees has caused the striker spindle to break at the point of the groove. To correct this defect, later productions will have the safety pin 1/8 to 3/16 of an inch below the point of the assembled firing pin instead of through the top portion of the striker spindle. (See posivite safety pin on drawing, page 196).

USE:

The combination firing device can be threaded to the standard anti-personnel mines, hand grenades, and to the bangalore torpedo.

M2 Anti-Personnel Mine: When the M1 device is employed in this mine, an igniter is attached to the base and the assembly is designated Fuze, Mine, Anti-personnel, M2. The M2 fuze as modified with the safety pin below the striker spindle is designated Fuze, Mine, Anti-Personnel, M2A1.

M3 Anti-Personnel Mine: When the M1 device is employed in this mine, a blasting cap is crimped to the base and the assembly is designated Fuze, Mine, Anti-Personnel, M3. The M3 fuze as modified with safety pin below the striker spindle is designated Fuze, Mine, Anti-Personnel, M3A1.

OPERATION:

When the igniter or blasting cap has been attached to the base and inserted in the charge, the locking screw is backed off so that it is no longer engaged in the groove in the striker spindle. The safety pin is then removed. If the safety pin binds, it is quite possible that the release pin is not properly engaged in the groove in this arming spind-le, and the device must be checked carefully. When the safety pin has been removed, the only thing preventing the striker spindle from being forced toward the percussion cap by its spring is the release pin, which is spring loaded inward. The device is now armed and can be fired either by pressure on the pressure cap or pull on the release ring. If over 20 pounds pressure is exerted on the cap it will be sufficient to force the relase pin out against its spring; if a pull of 3 to 6 pounds is exerted on the trip wire, the release pin will be pulled free of the groove in the arming spindle and the striker will be forced against the percussion cap by its spring.

REMARKS:

This firing device is used almost exclusively with the M2 and M3 anti-personnel mi-nes. For installations of this device with those mines, refer to page 196 and 198.