Combination firing device M1Pull firing device M1
LAND MINES
Section V
FUZES AND FIRING MECHANISMS

24.1 FUZE, MINE, COMBINATION, M6 and M7

a. Description.

(1) Fuze, mine, combination M6 and M7 consist of a firing mechanism with a 3-pronged head and base to which is assembled an igniter (M6) or blasting cap (M7).

(2) The fuze consists of a head and a case crimped together, which contain a trigger pin, a relase pin, and a firing pin, each with a spring. A small groove in the firing pin is held in the narrow part of a keyhole slot in the release pin. The release pin is provided with a ring for attaching pull wires. When the release pin is removed to one side the firing pin is allowed to pass through the large opening of the keyhole slot in the release pin. The trigger pin has three 1-inch long prongs of stiff steel wire projecting from its head. A wedge is provided on the bottom of the trigger pin which enters a slot in the release pin, and when sufficient pressure is applied to one or more of the prongs, the release pin is moved aside and the firing pin passes through the large opening of the keyhole slot. Two safety pins are provided with this fuze. The top safety pin, which is inserted through a hole in the firing pin, is located between the three prongs. This pin has a crimp on one side to prevent it from sliding out. The lower safety pin passes through the release pin opposite the release pin ring.

(3) The base is a hollow cylinder which contains the primer. It is threaded above for attachment of the firing mechanism and below for assembly of the fuze to the mine. A tubular projection serves for attachment of the igniter or detonator.

d. Data.

(1) FUZE, mine, combination, M6 is 6.62 inches in length. The threaded portion of the base is ½ inch long. The charge of the igniter consists of approximately 10 grains of black powder. A pull on the release pin of 6 to 10 pounds, moving it 3/32 inch, or a load on the three prongs of 10 to 20 pounds, or on one prong of 10 to 30 pounds moving the trigger pin 3/32 inch, will release the firing pin and operate the fuze.

(2) FUZE, mine, combination, M7 is 7.13 inches in length. The threaded portion of the base is ¼ inch long. The detonator consists of CAP, blasting, U.S. Army special, type A. A pull on the release pin ring of 6 to 10 pounds, moving it 3/32 inch, or a load on the three prongs of 10 to 20 pounds, or on one prong of 10 to 30 pounds, moving the trigger pin 3/32 inch, will release the firing pin and operate the fuze.

Figure 19.1 - FUZE, mine, combination, M6 and M7.

Combination firing device M1Pull firing device M1