(Fig. 12)

The fuze is used in the nose of the 3.7 cm Pak Stielgranate 41 or hollow charge muzzle stick bomb and excepting the magazine and magazine assembly, is similar to the nose fuze described for the rifle and hand grenade in Pamphlet No. 4.

The aluminium body protruding from the nose of the bomb is ogival in shape with an alu-minium striker protruding from a hole at the top. The weight of the fuze is 2 oz. 4 1/2 drs. The designation has not been stamped on fuzes examined to date.

The ogival aluminium body is screwthreaded externally for insertion in the bomb and is screwthreaded internally at the base to receive the adapter for the magazine. The inte-rior is recessed for the mechanism, the recess being enlarged near the top of permit the expansion of a coiled spring strip.

The aluminium striker is cylindrical with a flange at the base which engages a step in the body and so limits its upward movement. A steel needle protruding from the base of the striker is secured by an aluminium screw inserted in the head. The striker is supported by a spiral spring and a coiled spring strip, both of which are positioned between the base of the striker and an aluminium spring holder.

The spring holder is in the form of a cylinder with a central hole for the needle and a re-cess in the top to receive the base end of the sprial spring surrounding the needle. Near the top the holder is reduced in diameter to form a step for the assembly of the coiled spring strip. The lower part of spring holder is recessed to fit over the top of the maga-zine holder. The wall of the recess is cut away at four places to permit the four arms of the retaining spring to protrude for the support of the arming sleeve. The retaining spring consisting of a steel disc with a hole for the needle in the centre and four arms curved slightly upwards, is held between the spring holder and the top of the magazine holder. The four portions remaining of the wall of the recess in the base of the spring holder are bent inwards to engage an inclined surface near the top of the magazine holder.

The steel arming sleeve, surrounding the coiled spring strip fits around the upper part of the spring holder and is supported by the retaining spring. Inside the sleeve, near the base a circumferential groove is cut to engage the arms of the retaining spring when the sleeve is in the armed position.

The magazine holder consists of a cylindrical aluminium plug recessed and screwthreaded internally at the base for the insertion of the magazine. A shoulder formed around the exterior engages a corresponding shoulder in the adapter and carries a locating pin which enters a hole in the shoulder of the adapter. A projection at the top of the holder is bo-red centrally for the needle and is chamfered near its base for the attachment of the spring holder. The aluminium magazine contains 6.2 grains of P.E.T.N. under a 5.4 grain detonator. The detonator con-tains 93.7 per cent of lead azide and 6.3 per cent of tetrazene.

The aluminium adapter for the attachment of the magazine consists of a screwed ring with a steped hole for the magazine holder. A rubber ring, to cushion the set back of the arming sleeve, is fixed in a groove in the top of the adapter.

Fig. 12

With the arming sleeve supported on the retaining spring, the coiled spring strip prevent the striker spring being compressed and thus holds the needle away from the detonator.

On acceleration the arming sleeve set back on the rubber ring in the adapter and bends back the four arms of the retaining spring. Rebound of the sleeve is prevented by the arms entering the groove inside the sleeve. The coiled spring strip is then free to expand into the enlarged part of the body recess, leaving the striker supported only by the spiral spring.

On impact the striker is forced in and the needle pierces the detonator.