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This is a brass time and percussion fuze with an aluminum graduated ring around the center. The body is fitted within a helical time combustion ring which has four turns. The powder is protected externally by a lead cover. Over this portion fits a brass tube having a vertical window, into which fits a brass piece with four perforations numbered 0 to 3. These perforations are in line with the time rings. In the side of the outer case is a long cavity having a detonator at the base. A brass firing pin fits into the cavity, being held off the detonator by a piece of spring brass. A safety pin is fitted for further protection. The percussion mechanism, fitting centrally into the nose of the fuze, consists of a firing pin at the base and a creep spring. The detonator holder screws into the nose of the fuze. The graduated ring has a reading up to 10. This setting gives the unit figures, the 10's figures being given by the perforations in the brass piece. When the correct setting has been obtained, the time ring is punctured through the correct hole in the brass piece.

On firing, the firing pin in the side of the cover sets back against the spring to fire the detonator. By means of a longitudinal flash-hole, the flash is carried to the perforation made in the time ring. The time ring burns helically to the perforated pellet in the base of the fuze, which sets off the main charge. In the percussion mechanism, no action takes place until impact, when the striker and firing pin set forward against the creep spring and strike the detonator. The flash passes through the center of the striker to the main charge.

Figure 216
Time and Percussion Nose Fuze A.D.E. M99