US3119337A

US3119337A - Percussion fuze, particularly for unrifled shells, primarily hollowcharge shells

Info

Publication number: US3119337A
Application number: US842975A
Authority: US
Inventors: Przychowski Siegfried Duni Von; Muller Josef; Wimmer Heinrich; Wirth Friedrich; Kaiser Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-08-12
Filing date: 1959-09-28
Publication date: 1964-01-28
Anticipated expiration: 1981-01-28

Description

Jan. 28, 1964 s. D. VON PRZYCHOWSKI ETAL 3, ,337

PERCUSSION F UZE PARTICULARLY FOR UNRIFLED SHELLS. PRIMARILY HOLLOW-CHARGE SHELLS Flled Sept 28, 1959 3 Sheets-Sheet 2 m m m 4 m 4 2 m 72 DJ F 8 3 2 F m a a 2 2 M 4 7 J 2 M// 6'. D. van z yclowskl BY J MUZZEI Jan. 28, 1964 s. D. VON PRZYCHOWSKI ETAL 3,119,337

PERCUSSION F UZE, PARTICULARLY FOR UNRIFLED SHELLS, PRIMARILY HOLLOW-CHARGE SHELLS Filed Sept. 28, 1959 5 Sheets-Sheet s United States Patent PERCUSSHON FUZE, FAETHZULARLY UNREFLED SHELLEE, FRERMRILY HULLGW- (JHARGE SHELlLfi Siegfried Dunin von Przychnwshi, Eulowstrasse 21, Narnberg; .l'osef Muller, Une'tweg 6, Schrarnherg-Sulgen; Heinrich Wirnrner, Mohnwinkel 5, Ruckersdorf; Friedrich Wirth, Etiedlerstrasse 255a, Altenfnrt, near Numberg; and Paul Kaiser, Weihergasse 28, Sehramherg, Germany Filed ept. 23, 1959, Ser. No. 842,975 Claims. (Cl. Jim-78} A percussion fuze has already been proposed particularly for unrifled shells comprising a timing mechanism operated by an inertia member loaded by a feed spring whereby the movement of the inertia member is braked. This fuze has a locking disc engaging in known manner behind the firing pin and carrying a locking finger extending into the path of the inertia member and coming to bear laterally against the inertia member. The inertia member is at the same time constructed as a brake sleeve with rack teeth in which the driving pinion of the braking clockwork mechanism engages. When a shell equipped with such a percussion fuze is fired at a low initial speed, the retarding back pressure on the inertia member is not sufficient to overcome the resistance of the braking clockwork on the inertia member with which it is drive-coupled, so that the release does not take place properly. Consequently in the above-mentioned suggestion, the coupling between the inertia member and the braking clockwork is disengaged in that the driving pinion is shifted out of engagement with the radk teeth of the inertia member. Now braking clockwork mechanisms with disengageable pinion are very sensitive to firing shocks of a certain magnitude and their function cannot always be guaranteed; consequently it is proposed in the present case to dispense with the disengageable braking clockwork mechanism and to make the inertia or retarding member in two parts by forming the rack teeth on a braking sleeve which is not subjected to any retarding backstro e and constructing the retarding member as an inertia sleeve which, for the purpose of braking, is coupled with the sleeve bearing the tooth rack. The new percussion fuze is intended primarily for hollow-charge shells which are to have a relatively low firing speed and are consequently subjected only to low firing pressures.

Therefore, according to the invention, the inertia or retarding member braked during the forward stroke is divided into two members, namely an inert member and a braking member, whereby the braking member performs the function of holding the locking finger on the pin looking slide. The inert member is located in front of the braking member and consists of an inert sleeve, known per se, which telescopically engages in the braking member, a blocking spring being arranged between the two members. The braking member consists of a sleeve provided with a toothed rack which rests on the bottom of the fuze bore and carries the feed spring which presses forward against the end face of the inert sleeve. In the case of backward movement the inert sleeve coupics with the braking sleeve, in that, for example, an annular spring in the front of the braking sleeves snaps into an annular groove in the shank of the inert sleeve. The braking sleeve has on its outer side a longitudinal groove in which a transverse pin mounted in the fuze body engages and secures it against turning.

The locking finger on the pin locking slide is made in one piece with the slide being bent up therefrom.

The fuze is designed so that it Will function in the event of inclined impact in that the fuze cap has at its front 3,ll9,353? Patented Jan, 28, 1954 end a cylindrical part extending beyond the front face of the fuze body. In the front face of this extension the usual head diaphragm is inserted and the whole extension filled With elastic material. A sheet-metal cone provided with holes is cast in the elastic material so that its rearwardly directed point bears against the head of the striker pin and its forwardly directed base bears against the head diaphragm. A simplification of this fuze cap extension is attained by the fact that the fuze cap extension is closed at its front end and completely filled with elastic material. The striker pin head is of mushroom shape with conical Wall surface and is pressed by the striker pin locking spring into a ring shaped element fitted in the fuze bore and provided with a conical inner surface corresponding to the conical Wall surface of the striker pin head.

An embodiment of the new percussion fuze is illustrated by way of example in the accompanying drawings, in which FIG. 1 is a longitudinal section through the fuze in safety position, taken in the plane 1-1 of FIG. 4;

FIG. 2 is a similar view to FIG. 1, after firing and during the shell acceleration, but taken in the plane ll-H of FIG. 4;

FlG. 3 is also :a similar view to FIGS. 1 and 2., but the fuze is in primed state at the end of the shell acceleration, the section being taken in the plane III-Ill of FIG. 4;

FIG. 4 is a cross-section through the fuze taken on line IV-IV of FIG. 2;

FIG. 5 is a cross section taken in the plane VV of PEG. 3;

v FlG. 6 is a longitudinal section taken through the fuze head with a modification of the construction shown in FIG. 1;

FIG. 7 shows the retarding mechanism in side elevation and FIG. 8 is a longitudinal section taken in the plane VIII-VIII of FIG. 7.

The fuze body ll), which is encompassed by a cap 11, has an axial bore 15 which narrows in steps from the front towards the rear. The axial striker pin 12 extends through the bore 15 and carries on its front end a mushroom-shaped head 16a tapering conically towards the front of the shell, and at its rear end a firing pin 16 which is inserted in its shank l2 and provided with a collar bearing against the rear end face of the shank of the striker pin. The foremost widest portion 15a of the axial fuze bore 15 is shut off from its narrower middle portion by a plate 18 which is fixed by a ring 19 pressed into the fuze body 16. In the middle portion 15 of the bore a retarding sleeve "22 slides on the shank of the striker pin 12 and is guided by means of a head flange in the axial fuze bore 15. A braking sleeve 27 is located behind the retarding or inert sleeve 22 in the same portion of the axial fuze bore 15. A locking spring 28 is located between the front end face of the brake sleeve 27 and the rear face of the head flange of the retarding sleeve 22, which spring presses the head of the sleeve 22 against the closing plate 18 of the middle portion of the fuze bore. The retarding sleeve 22 has a rearwardly extending shank which is of such dimension that it can he slipped in telescope fashion into the braking sleeve 27. A feed spring 23a, is arranged in the braking sleeve 27, through which the striker pin shank 112 extends, and surrounds the striker pin shank 12. This spring 23a bears at its rear end against the bottom of the middle portion of the fuze bore and at its front end against the rear face of the shank of the retarding sleeve 22 engaging in the braking sleeve 2-7. An annular spring 29 extending into the front end of the braking sleeve 27 can snap into an annular groove 33 in the shank of the retarding sleeve 22. A blocking spring 31 is located between the closing plate 18 for the middle portion of the fuze bore and the head 16a of the striker pin.

The braking sleeve 27 has in its outer wall a longitudinal groove 32 in which the inwardly directed end nose 33 of a transverse screw 34, mounted in the fuze body 10, engages and thus secures the braking sleeve against turning. The braking sleeve 27 also has on its outer wall rack teeth 35 in which a pinion 24 engages which is rigidly connected with an escapement wheel (FIG. 7). An anchor 26 engages this escapement wheel 25. It has an arm a with a solid weight 36. This weighted arm 35a is located in the central plane of the weight 36 parallel to the axis of the fuze.

The fuze striker pin is locked in substantially the same fashion as in the construction referred to at the outset. The firing pin 16 projects into an aperture in the rear end of the shank 10a of the fuze. From the roof of this aperture axially parallel blind bores 37 extend in forward direction and retaining pins 20 are pressed into these bores up to a spacer collar 29a formed thereon. A plate 38 is slipped on to these pins 20 as far as the spacer collars 20a will allow and is thus secured against turning and shifting. Between this point and the roof of the aperture, the striker pin locking slide 21 is mounted rotatable about the pivot 39. This slide has a hook-shaped arm 39a which engages the firing pin behind its collar and thus prevents its rearward movement. The other arm 40 of the locking slide 21 is bent upwards at right angles to form a locking finger 23 which in the safety position bears against the periphery of the braking sleeve 27. A torsion coil spring 41 is slipped on to the pivot 39, one arm of this spring being hooked on the pin 42 on the slide 21 whereas the other arm is anchored in the plate 38. The spring 41 is stressed to such an extent that when the striker pin locking slide is released it swings into the priming position in which the hook arm 39a releases the firing pin.

The new fuze is also designed to respond in the case of inclined impact. For this purpose the fuze cap 11 encompassing the fuze body 10 is extended towards the front and forms a short cylinder 43. A diaphragm 44 is beaded in the front end of this cylinder. The hollow space in the cylinder 43 behind the diaphragm 44 is filled with elastic material 45 cast therein, for example a material known under the trade name Mipolam. A cone 4-6 made of sheet metal and provided with holes is also cast in this elastic material 45 so that its apex bears against the mushroom-shaped head 16a of the striker pin. This mushroom-shaped head is surrounded by a ring 47 shaped to conform with the mushroom head and pressed into the axial fuze bore from the front.

As can be seen from FIG. 6 the diaphragm is omitted from the modification of the fuze point therein illustrated. Instead thereof the fuze cap surrounding the fuze body is held by means of its thin cylindrical extension 43 and closed at its front end. The extension has no insertion and is entirely filled with elastic material.

The new fuze operates in the following manner:

On a shell being fired the retarding sleeve 22 flies back thereby compressing its locking spring 28. The braking sleeve 27 remains stationary as in its inoperative position it practically bears at its rear end. The retarding sleeve 22 slides with its shank into the braking sleeve and thereby tensions the feed spring 28a in the braking sleeve. When the annular groove 30 in the shank of the retarding sleeve 22 comes opposite the coil spring 29 in the front end of the braking sleeve 27, this spring snaps into the groove thereby rigidly coupling the two sleeves together.

At the end of the shell acceleration, the feed spring 28a in the braking sleeve commences to operate and pushes the two coupled sleeves forward. This forward movement is braked by the braking clockwork. The rack teeth on the braking sleeve 27 in being pressed forward, rotates the pinion 24 and consequently also the escapement Wheel 25 whose rotation is controlled by the anchor 26.

When the retarding sleeve 22 strikes against the plate 18 it has pulled the braking sleeve 27 so far that the locking finger 23 is removed from the support afforded it by the periphery of the braking sleeve 27. The striker pin locking slide 21 is therefore swung in counter-clockwise direction by its torsion coil spring 41 from FIG. 4 to FIG. 5 so that its hook arm 39a is swung away from behind the collar 16 of the striker pin which is consequently released. The fuze is now primed for firing, FIG. 3.

If the shell strikes straight, the diaphragm is knocked back and, through the intermediary of the elastic material in the fuze cap extension, transmits the shock to the striker pin head 1611 so that the striker pin pierces the fuze detonator pellet 13.

If the shell impacts at an incline, the cap extension 43 is laterally deformed. This deformation is transmitted to the ring 4'7 whose curvature then becomes oval. Consequently the conical head of the striker pin is pushed back so that the pin 16 pierces the pellet 13. In the event of lateral crushing through inclined impact, it may, however, happen that the diaphragm 44 drops out and the elastic material 45 is forced forward instead of backward. To prevent this, the sheet metal cone 46 is cast in the elastic material and its point assists the striking back of the striker pin.

In the event of a jolt in transport or due to the shell being dropped, the delay on impact is very short as compared with the longer acting acceleration in the gun barrel. For example, in the event of the shell being dropped on its bottom, the retarding sleeve 22 will move slightly backwards against its blocking spring 28 but not so far that the retarding sleeve 22 and the braking sleeve 27 become coupled. If, on the other hand, the shell is dropped on its nose, the braking sleeve is not moved forward against the resistance of its blocking spring 28 so far that the two

sleeves

22 and 27 become coupled and the locking finger 23 can be released. The fuze therefore remains locked.

We claim:

1. A percussion fuze particularly for unrified shells and primarily hollow-charge shells, comprising a fuze body having a central bore therein, a striker pin shank slidably mounted in the fuze body, a retarding sleeve slidably mounted on the striker pin shank and in the central bore and having a groove in the outside surface thereof, a braking sleeve slidable in the bore and slidably mounted on the retarding sleeve so that the retarding sleeve may telescope into the braking sleeve upon relative movement of the retarding sleeve on the striker pin shank, said braking sleeve having a partial groove therein, a holding spring mounted in the partial groove in the braking sleeve and adapted to cooperate with the groove in the retarding sleeve when the latter telescoeps a sufficient distance into the braking sleeve, a feed spring around the striker pin shank and in the braking sleeve and bearing against the fuze body at one end and against the retarding sleeve at the other end, a slide member pivotally mounted in the fuze body to hold the striker pin shank in inoperative position, an escapement mechanism in the fuze body connected to the braking sleeve to retard movement thereof, and a locking pin on the slide member abutting against the braking sleeve to keep the slide member in a safety position and when the shell is fired the acceleration force will telescope the retarding sleeve into the braking sleeve, said sleeves being interconnected by engagement of said holding spring with said groove in said retarding sleeve so that at the end of acceleration of the shell the two coupled sleeves will be forced forwardly by the feed spring with a retarding action by the escapement mech anism and thus, when the locking pin abutting against the braking sleeve is freed from the latter the slide memher will be free from the striker pin shank.

2. Percussion fuze according to claim 1, wherein a fuze cap encases said fuze body, said cap having a cylindrical extension projecting beyond the forward end of the fuze body, said extension being filled with elastic material and having a percussion diaphragm at the forward end thereof.

3. Percussion fuze according to claim 1, wherein a fuze cap encases said fuze body, said cap having a cylindrical extension projecting beyond the forward end of the fuze body, said extension being filled with elastic material and having a percussion diaphragm at the forward end thereof, and wherein a perforated sheet metal cone is provided in the elastic material, the apex of said cone directed to the rear bearing against the forward end of the striker pin shank Whereas its base contacts against the diaphragm.

4. Percussion fuze according to claim 1, further comprising a conical head portion secured to the forward end of the striker pin shank, a ring member having a corresponding conical inner surface secured in said central bore and a spring biasing said head portion and ring member into engagement.

5. Percussion fuze according to claim 1, wherein the braking sleeve has on its outer side a longitudinal groove in which a transverse pin in the fuze body engages and prevents the sleeve from turning but permits sliding movement of the braking sleeve.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

1. A PERCUSSION FUZE PARTICULARLY FOR UNRIFLED SHELLS AND PRIMARILY HOLLOW-CHARGE SHELLS, COMPRISING A FUZE BODY HAVING A CENTRAL BORE THEREIN, A STRIKER PIN SHANK SLIDABLY MOUNTED IN THE FUZE BODY, A RETARDING SLEEVE SLIDABLY MOUNTED ON THE STRIKER PIN SHANK AND IN THE CENTRAL BORE AND HAVING A GROOVE IN THE OUTSIDE SURFACE THEREOF, A BRAKING SLEEVE SLIDABLE IN THE BORE AND SLIDABLY MOUNTED ON THE RETARDING SLEEVE SO THAT THE RETARDING SLEEVE MAY TELESCOPE INTO THE BRAKING SLEEVE UPON RELATIVE MOVEMENT OF THE RETARDING SLEEVE ON THE STRIKER PIN SHANK, SAID BRAKING SLEEVE HAVING A PARTIAL GROOVE THEREIN, A HOLDING SPRING MOUNTED IN THE PARTIAL GROOVE IN THE BRAKING SLEEVE AND ADAPTED TO COOPERATE WITH THE GROOVE IN THE RETARDING SLEEVE WHEN THE LATTER TELESCOPES A SUFFICIENT DISTANCE INTO THE BRAKING SLEEVE, A FEED SPRING AROUND THE STRIKER PIN SHANK AND IN THE BRAKING SLEEVE AND BEARING AGAINST THE FUZE BODY AT ONE END AND AGAINST THE RETARDING SLEEVE AT THE OTHER END, A SLIDE MEMBER PIVOTALLY MOUNTED IN THE FUZE BODY TO HOLD THE STRIKER PIN SHANK IN INOPERATIVE POSITION, AN ESCAPEMENT MECHANISM IN THE FUZE BODY COPNECTED TO THE BRAKING SLEEVE TO RETARD MOVEMENT THEREOF, AND A LOCKING PIN ON THE SLIDE MEMBER ABUTTING AGAINST THE BRAKING SLEEVE TO KEEP THE SLIDE MEMBER IN A SAFETY POSITION AND WHEN THE SHELL IS FIRED THE ACCELERATION FORCE WILL TELESCOPE THE RETARDING SLEEVE INTO THE BRAKING SLEEVE, SAID SLEEVES BEING INTERCONNECTED BY ENGAGEMENT OF SAID HOLDING SPRING WITH SAID GROOVE IN SAID RETARDING SLEEVE SO THAT AT THE END OF ACCELERATION OF THE SHELL THE TWO COUPLED SLEEVES WILL BE FORCED FORWARDLY BY THE FEED SPRING WITH A RETARDING ACTION BY THE ESCAPEMENT MECHANISM AND THUS, WHEN THE LOCKING PIN ABUTTING AGAINST THE BRAKING SLEEVE IS FREED FROM THE LATTER THE SLIDE MEMBER WILL BE FREE FROM THE STRIKER PIN SHANK.