The fuze is of the destroying type with a direct action and a self-destroying action which depends upon the loss of rotational velocity for operation. The fuze is used in 2-cm shell.

The steel head of the fuze is plated with brass and has a large internal recess which houses the striker head. The recess is closed against air pressure at the nose by a metal closing disc.

The striker head is of light alloy and is fitted with a steel needle. A flange formed near the base of the striker head supports one end of a strong steel spiral spring and is groo-ved to carry eight steel balls. The balls are retained in position by a steel ring which in-creases in its internal diameter towards the front and is supported by the body of the fuze. The striker is supported by a split collar assembled round the needle and retained by a coil of strip brass. The split collar is supported by the body.

The steel bods is plated with brass and is screw-threaded externally for the assembly of the head and for insertion in the shell. A central hole is formed for the needle and a brass magazine of the type described for the A.Z. 1501 or one of the delay type, shown in Fig. 33, is screwed in at the base.

Fig. 33

GERMAN FUZE Z.Z. 1505 MAGAZINE WITH DELAY FITMENT

In the delay type of magazine the intermediary filling and the detonator do not extend so far up the body of the magazine and the space thus provided in the upper portion is oc-cupied by the delay fitment. The fitment consists of a light alloy plug, flanged at the head and of a suitable diameter to fit into the magazine. A small detonator of the igni-ferous type is fitted in the head of the plug, below the striker needle, and a flash chan-nel behind the detonator communicates, by way of a groove round the body and another flash channel near the base, with the main detonator in the base portion of the maga-zine.

During flight the steel balls in the striker head are moved outwards by centrifugal force against the inclined portion of the steel ring and in this position support the striker against the pressure of its spiral spring. The coil of the brass strip surrounding the split collar is also loosened and the split collar thrown clear of the striker. On impact the stri-ker is forced in so that the inclined surface of the steel ring directs the balls back into their housing. With impact on a light plate the striker is then driven through the steel ring by its spiral and the needle pierces the detonator. Impact with a plate offering more re-sistance would probably result in the striker being driven directly into the detonator by the impact and consequently a more rapid action.

When impact does not occur before the rotational verlocity has fallen sufficiently, the pressure of the striker spring overcomes the decreasing centrifugal force and causes the striker to move in. This movement directs the balls back into their housing thus permit-ting the spiral spring to drive the striker through the steel ring and the needle to pierce the detonator.

With the delay type of magazine the flash from the pierced detonator passes to the main detonator by way of the flash channels and the groove round the delay plug and in con-sequence causes a slight delay.

Fig. 32

GERMAN SELF DESTROYING FUZE Z.Z. 1505