FUNCTIONING

ARMED CONDITION

FUZES USED WITH

MAX. BODY DIAMETER

OVERALL LENGTH

COLOR

BOMBS USED IN

DESCRIPTION:

This fuze is similar to the No. 895 Mk. I type fuzes, except that the method or arm-ing is altered. The No. 895 Mk. II fuzes are armed by the rotation of the vanes and tie-rod incorporated in the standard British tail assembly. The tie-rod engages the T-bar of the fuze and rotates the centrifugal arming mechanism. This mechanism consists of a spindle, to which the T-bar is attached, with its lower portion enlarged and grooved to form two circular plates loacted one above the other and about ¼ inch apart. The cen-tral column of this spindle is drilled from the bottom to allow insertion of the arming plunger, which is supported by a plunger holder threaded into the top of the fuze. Two semi-circular weights are located between the two plates formed from the enlarged portion of the spindle. A projecting point on the flat edge of each of these weights blocks any upward movement of the arming plunger. Each weight is held inward by a U-shaped stirrup, the stirrups themselves each held tightly against the sides of the plates by an arming spindle. Two screws are located 180° apart, penetrating the circular pla-tes of the spindle. One end of each arming spring is fastened to one of these screws, and the other end of the spring is attached to one of the stirrups. Each screw also ser-ves as a pivot for one of the weights and the corresponding stirrup. A nut threaded to the upper end of each screw completes this assembly. A guide pin is set into the top surface of each weight. Each pin rides in a groove cut in the upper circular plate on the spindle and also is loacted in a slot cut in each end of a diamond-shaped safety bar. This safety bar fits freely around the upper portion of the spindle. A safety pin engages the T-bar, penetrates the cover of the fuze, and passes down along the outside of one of the stirrups. The safety pin thus holds one of the weights securely in position during stoarge and transit.

OPERATION:

In the unarmed positon, the arming plunger is prevented from rising by the projecting points of the two eoghts, and the weights are held in position both by the arming springs and the safety pin.

The safety pin is removed when the fuze is assembled in the bomb; and when the bomb is released from the plane, the arming vanes and tie-rod in the tail engages tne T-bar and rotate the spindle. The centrifugal force imparted by the rotation of the spindle causes the weights to pivot outwards against the action of the stirrups and arming springs. As the weights move outwards, the central hole in the base of the spindle is completely cleared, allowing the arming plunger to move upward when hydro-static action causes the striker to rise. Before arming is fully completed, the weights move out far enough so that a groove in the end of each weight is engaged by the edge of a stirrup when rotation of the vanes cases, preventing the weights from re-turning to their original position.

The purpose of the safety bar is to prevent either of the weights from moving out-ward as the result of a hard jolt or jar on the side of the fuze after the safety pin has been removed. Except for centrifugal action, any force causing one of the weights to move outward will causes the other weight to move inward, and the net effect of the force will be equalized through the safety bar with the result that neither weight will move.

Once the weights have moved out and locked in position, the fuze is fully armed, ex-cept for the offset detonator, and subsequent functioning is identical to that described for the Mk. I types of the No. 895 fuze (see page 303).

REMARKS:

1. The following Mks. of the No. 895 Mk. II type fuze are now in service use for the types of bombs indicated. The designation given to these fuzes includes the nominal depth setting:

(to replaces No. 895 A Mk. I)

No. 895/30 Mk. II

30 ft.

Used in 60 lb. A.S. Mk. I

The greater depth settings are accomplished by substitution of heavier striker springs or by an additional spring placed between the top cap of the fuze and the spring hous-ing.