US2601827A - Fuse - Google Patents

Description

Jul 1, 1952 w. BRANDT FUSE 2 SHEETS-SHEET 1 Filed July 11, 1947 Imventor E. W. BRANDT July 1, 1952 FUSE 2 SHEETS-SHEET 2 Filed July 11, 1947 Zhwentor @Wd (IttornegS Patented July 1, 1952 UNITE FUSE of Liechtenstein Application July 11, 1947, Serial No. 760,424

' In Switzerland December 7, 1946 3 Claims. I

This invention relates to percussion fuzes.

The increase in the number of armoured fighting vehicles and the progress made in connection therewith, compel the defender to employ very powerful weapons specially designed to combat such vehicles.

In this connection, hollow charge projectiles offer great possibilities. These anti-tank projectiles, which have been the subject of numerous improvements, have increased in perforating power, speed and accuracy. It is very important to ensure their correct operation in respect of percussion on impact even at very high incidences, since modern tanks present oblique sur- A faces or sloping shapes, so that the projectiles frequently ricochet off their wall without having functioned, or burst only after having been deflected, which reduces their perforating power.

The present invention aims at providing a hypersensitive percussion fuze, functioning either by being driven in or by inertia, providing safety against dropping, and complying with the requirements of utilization for high incidence firing.

The fuze of the present invention has no arming device requiring any manipulation before firing the projectile. It is therefore of great simplicity of construction and may be very small, light, and so designed that the detonating cap that it carries is sufiicient to ensure its destruction on impact. By reason of this fact, this fuze, which is particularly adapted to be mounted in hollow charge projectiles, has the advantage of in no way reducing the action of the perforating device on the target. 7

The fuze of the present invention is suitable for several types of ammunition, either self-propelled or not, and particularly for those intended to fire on to armoured fighting vehicles. Placed at the head or nose of the projectile, it is equipped to transmit fire by wave effect to a secondary detonator located inside the explosive charge, in rear of the perforating hood of the hollow charge projectiles.

Since the fuze of the present invention is of very low weight, it may be mounted on a very thin jacket without the risk of deforming it by inertia on the firing of the shot, which enables the ammunition to be reduced in weight.

The fuze functions correctly even if the projectile reaches the target, armour for example, at a very high angle of incidence (which may exceed 60), by virtue of the special arrangement of its head, which cuts into the metal and thus prevents sliding off and richochets.

Operation is likewise assured on the ground or other targets affording little resistance, by virtue of the small mass of the members to be driven back and of the low resistance to shearing of the safety members which it includes, particularly in the form of pins. Even if the fuze does not come into contact with the target, it operates by inertia when the projectile undergoes a certain slowing down.

The fuze of the present invention is composed of a fuze body inside which are disposed the firing members (striker and detonator) an elastic member being disposed between these members, one of which is adapted to slide in said body. It is particularly characterized in that its percussion head, integral with the body, extends in front of the fuze-carrier guide, this position being maintained by a retaining member adapted to yield on impact against the target, said body being adapted to slide, after yielding of said retaining memmer, inside a fuze-carrier guide mounted at the front of the projectile, and in that said head of a material harder than normal armour has in front sharp angles adapted to penetrate any targets, even hard ones, in such manner that it adheres and attaches itself to the point of impact, thus ensuring percussion even at high incidences.

The harness of normal armour is that of a selected steel. Thus, for some tank parts, it is Well-known that high-quality alloy steels are used. The strength and hardness data for SAE standard steels, from Machinery Handbook, thirteenth edition, page 1574, gives a hardness for chromium vanadium steel of 661 Rockwell C, and for high speed steel 662 Rockwell C. These are maximum values for steel hardness employed in armour practice.

According to another feature of the invention, the front part of the hard percussion head of the fuze is concave, its annular face forming an angle adapted to cut into the armour on impact. The fuze, sufficiently slowed down on the target, is thus driven back into the fuze-carrier guide, and percussion is ensured.

According to another feature of the invention, the hard head of the fuze also constitutes its striker, which arrangement enables the design thereof to be simplified.

According to still a further feature of the invention, the fuze comprises a locking member preventing its body from being ejected from the fuze-carrier guide in the event of functioning by inertia, while allowing the detonator to slide freely in said body, said member not intervening in the opposite direction in the event of the fuze being driven into the fuze-carrier guide towards the interior of the projectile. This locking member can also fulfil its function in the event of the body of the projectile being abruptly braked against the target without the fuze being touched. The locking member offers greater resistance than the pins which might be sheared by abrupt braking in which case, if there were no locking member, the fuze could be ejected from the fuzecarrier guide.

In one embodiment of fuze in accordance with the invention, the locking member consists of a ring partially engaged in a groove provided in, the fuze body and adapted to bear against an internal annular shoulder on the fuze-carrier guide. This device has the advantage of being simple and of offering great resistance.

An annular stop, situated in the lower part of the fuze-carrier guide, prevents it from leaving said fuze-carrier guide towards the interior of the projectile in the event of an unforeseen shock causing it to be prematurely driven in before being fired.

These various arrangements, proportions, dimensions and weights, independently of the technical characteristics obtained, have been elaborated in order to make it possible to design at the same time a very light fuze, which is indispensable for equipping a projectile furnished with a thin shell, at least in its front portion.

Moreover, since the fuze is intended for mounting in a hollow charge projectile, the power and the proportions of the detonator must be sufficient to ensure the total destruction of said fuze in front of the hood or perforating device of said hollow charge projectile, in order to eliminate any obstacle likely to reduce the power of the projectile and the useful effect thereof on the target.

With the object of increasing safety in case of dropping or shock, so that the fuze may be well protected during transport and handling, whilst retaining all its sensitiveness, provision is made for a detachable hood, of a greater diameter than the collar of the shell and extending forwardly beyond the head of said fuze, t cover the fuze completely, said hood bearing by a wide surface upon the front portion of the shell of the projectile and fitting exactly over it.

In the event of the projectile accidentally falling on its nose from a certain height, or receiving an oblique blow, the hood will receive the blow and may be deformed, while the projecting head of the fuze will remain intact.

In order to keep the hood in place, a sheath of plastic or elastic material is interposed between the outer face of the collar of the shell and the inner face of said hood, which has for this purpose a substantially cylindrical portion and fits exactly over the sheath.

The hood is held in position by friction and can'be simply pulled off at the moment of firing.

According to another feature of the invention, the hard head and the fuze body are integral, the striker constituted by one and the same member being of a material different from that of said body.

In this case, the striker, the interposed elastic member (preferably a compression spring), and the detonator are mounted through the rear of the fuze-carrier.

It is obvious that the fuze of the invention may likewise be mounted on a thick-walled artillery projectile, in which case the fuze carrier is preferably screwed on to the ogival head.

Further features and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings which illustrate diagrammatically and by way of example, various embodiments thereof and in which:

Fig. 1 represents, in axial section one embodiment of fuze in accordance with the invention in the position of rest;

Figs. 2 and 3 show the fuze illustrated in Fig. 1 at the moment of its operation on impact, in the case of operation by driving in and in the case of operation by inertia respectively;

Fig. 4 is a partial section showing the fuze of Fig. 1 mounted on a thin shell and provided with a protective cap;

Figs; 5, '7 and 8 illustrate modifications;

Fig. 6 shows a modification of the fuze of Fig. l. mounted on'a thick ogival head.

The various figures refer to an instantaneous percussion head or nose fuze operated by being driven in or by inertia.

The fuze essentially comprises a hollow fuze body I, adapted to slide axially in a fuze-carrier guide 2 integral with the front portion of the shell 3 of the projectile.

One of the firing memberspreferably the striker l-is rigidly mounted in the front of the body I. The other firing member, preferably the cap which is in the shape of a relatively large detonator 5, rests on the rear portion of the body I, which comprises a base 6 preferably open as indicated at I.

A plastic or elastic member, preferably a compression spring 8, is interposed between the striker 4 and detonator 5, this spring being sufficiently strong to maintain the distance between these two firing members during transport and handling.

The striker 4 is integral with a head 9 rigidly mounted at the front of the body and thus constituting the percussion head of the projectile. Said head 9 is, according to the invention, made of very hard material; projecting to the front out of the fuze-carrier guide 2, it is maintained in that position by a member capable of yielding on impact on the target; which member comprises, for example, one or more pins I0 immobilizing the body I in the fuze-carrier guide 2, which pins are shearable on impact under the. effect of shock.

Moreover, the fuze body I is provided with a locking member preventing it from being ejected from the fuze-carrier guide, said locking member consisting, for example, of a ring II engaged in a groove I2 in the body I, but projecting out of said groove, in such a manner as to form a stop against an internal annular shoulder I3 on the fuze-carrier guide 2.

The ring I I does not operate on impact, when the body I is driven into the fuze-carrier guide 2 towards the interior of the projectile, but prevents any forward movement of the fuze in the fuze-carrier guide in the event of the fuze not striking the target, whether it is the fuze-carrier guide or the body of the projectile itself which touches the obstacle.

An annular stop I 3a, located von'the interior portion of the fuze-carrier guide 2, prevents the fuze from leaving said fuze-carrier guide towards .fore does not ricochet or glance off on impact,

though very short, nevertheless substantially extends beyond the fuze-carrier 2 at the front and .at the rear, the whole of the fuze, including the fuze-carrier guide, having a length and a diameter substantially only double those of the detonator 5; this arrangement of a very short, very rigid and light unit has a favourable effect in facilitating correct operation on impact by reason of the fact that neither warping nor jamming can take place.

Moreover, the arrangements and proportions indicated and the power of the detonator are combined in such a manner as to ensure the preliminary and complete destruction of the fuze before the projection of the perforating device takes place.

To this end, the fuze is so designed that the weight thereof, including the detonator, is less than three times that of the detonator alone.

The striker t is disposed at a short distance from the detonator 5, in order to ensure extremely rapid operation of the fuze on impact.

The detonator 5, which constitutes by itself the cap-carrying inertia block, has a height equal to about twice its diameter. Its axial guiding in the body I is thus assured over a sufiicient length to avoid any jamming in the case of an oblique impact.

In order to permit the fixing of the fuze to a thin shell, provision is made for the latter to end at the front in a cylindrical collar which acts as a housing for the fuze-carrier guide 2, a circular groove 22 being provided on said fuzecarrier for the fixation by setting of said collar which, with said fuze-carrier guide, at the front end, bears against a flange 23 on the fuze-carrier guide, thus being immobilised between the two stops 2?. and 23. The pins [0 are covered, after insertion, by the collar 2| and thus cannot leave their mountings.

The mode of operation of the hereinabove described fuze is as follows:

On firing the shot, the pins It) being sufiiciently strong, the body I remains integral with the fuze-carrier guide 2, that is to say with the projectile itself and the parts of the fuze retain their respective positions.

On impact (Fig. 2), the body is abruptly stopped, while the projectile continues its course, and the pins IQ are sheared. The body I is thus practically driven back into the fuze-carrier guide of the projectile, while the detonator 5, through inertia, continues its forward movement and is thrown on to the striker 4, which causes it to fire.

When impact takes place obliquely, as illustrated in Fig. 2, it will be seen that the fuze and projectile tend to pivot around the point of impact and to take up a position, relatively to the armour, approaching the perpendicular and of smaller incidence, which is favourable to perforation.

It may happen that impact does not take place on the fuze and that the projectile merely undergoes a certain slowing down, for example in the event of the shell alone coming into contact with the target, or in the event of said projectile engaging in the meshes of a protective net without its fuze touching it. In such a case, the fuze body I remains integral with the shell 3 of the projectile, the ring H, bearing against the circular shoulder l3, retains the fuze in the fuze-carrier guide. Operation is then ensured through inertia; the fuze and the fuze-carrier guide being slowed down, the detonator is thrown on to the striker 4 (Fig. 3).

During storage and transport or handling, the various members constituting the fuze are in the position illustrated in Fig. l. The spring 8 is sufficiently strong to prevent the detonator 5 from coming into contact with the striker 4 in the case of an accidental fall of the projectile on to its head. If the shock sustained by the head is such that the pins l0 give, the fuze is driven back inside the fuze-carrier guide 2, without there being any danger, since the inertia of the detonator is sufficiently small for the force of the spring to suffice to ensure the desired safety.

This safety can nevertheless be further increased by protecting the fuze against all external shocks during transport and handling, by means of a detachable hood 24 (Fig. 4) of a reater diameter than the collar 2| of the shell 3 and extending forwardly beyond the percussion head 9. This hood 24 bears by a wide surface 25 upon the front portion of the shell 3 of thin metal, and fits exactly over it.

A sheath 26, of plastic material, is interposed between the outer face of the cylindrical collar 2! and the inner face of the hood, which to this end has a cylindrical portion 21. The friction of the plastic sheath of the hood 24 on the collar 2| ensures that said hood is held in place.

Fig. 5 illustrates a modification in which the sensitiveness of the fuze is increased, so that it can operate even against very thin targets.

On firing the shot, an arming system, a ring 32, is peripherally wedged by inertia against the detonator 5 and compresses a spring 33, after which the ring 32 and the detonator 5, rendered integral with one another, serve as an inertia block when the fuze functions. A very weak spring 35 keeps the detonator at a distance during the trajectory of the projectile.

The fuze of the present invention may also be mounted in an artillery projectile provided with a thick ogival head 28 (Fig. 6), the fuzecarrier guide 2 being then screwed on to said ogival head.

Figs. 1, 2, 3, 5 and 6 illustrate a fuze the head 9 of which is fixed on the body I by setting at 22. Fig. 7 illustrates a modification in which a head 30 of greater diameter is screwed on to the body 3|, beyond which it extends laterally.

Finally, a fuze may also be designed the head and the body of which are constituted by the same part 35 (Fig. 8). The striker 4, the spring 8, and the detonator 5 are then installed through the rear of the body, while a ring 36 set at the rear of said body holds then in place. The striker 4, preferably made of a material different from that of the body 35, is held in its housing by any appropriate means, for example by set- What I claim is:

1. A percussion nose fuze for a projectile, said fuze operating by driving in and inertia, and adapted to operate upon impact even at a high angle of incidence in relation to the normal to the target, comprising a fuze-carrier guide, a fuze body, two firing members disposed inside said body, said firing members comprisinga striker and a detonating means, anelastic member interposed between said firing members'to keep them away from one another up to the instant of impact, said detonating means being held against sliding forward relative to said striker by the force of said'elastic memberduring-flight of and until impact of said projectile and upon impact being slid relatively forwardly by inertia against the force of said elastic member, a percussion head secured fixedly to said striker and extending in front of said fuze-carrier guide, retaining means between said body and said guide for maintaining said body in its normal position until after firing, said body being adapted to slide within saidfuze-carrier guide uponrelease of said retaining means, said percussion head having at least-its front peripheral edge portion made of a harder material than normal armour, said peripheral edge portion having a sharpangled cross-section for cutting into a hard target and thereby effective to cause said head to engage the target and adhere firmly at the point of impact, thus ensuring percussion even at a high angle of incidence.

2. A percussion nose fuze for a projectile, said fuze operating by driving in and inertia and adapted to operate upon impact even at a high angle of incidence in relation to the normal to the target, comprising a fuze-carrier guide, a striker and a detonating means located'one in front of the other and each slidable in said fuzecarrier guide, a hollow member slidable within the fuze-carrier guide and Supporting said detonating means, the striker being located within said hollow member, a percussion head fixedly connected to said striker and extending in front of the fuze-carrier guide for contact with the target and effective upon impact for causing said striker to be driven rearwardly relative to the fuze-carrier guide, said detonating means being slidable forwardly by inertia within and relative to said fuze-carrier guide upon impact, and safety elements including safety means effective for preventing axial movement of the striker upon accidental dropping beforefiring and a coil spring engaged with said hollow member and interposed between and effective to press the striker and detonating means away from one another up to thetime of impact and to prevent movement of the hollow member during flight, said percussion head having at least its front peripheral edge portion made of a harder material than normal armour, said peripheral edge portion having a sharp-angled cross-section for cutting into a hard target and thereby effective to cause said head to engage the target .and adhere firmly at the point of impact, thus ensuring percussion even at a high angle of incidence.

3. A percussion nose fuze assembly for a projectile, said fuse operating by driving in and inertia, and adaptedto operate even at a high angle of incidence in relation to the normal to the target, comprising; a fuze-lcarrier guide; a hollow fuze body slidable relatively rearwardly in the fuze-car'rier guide when stopped and driven in by impact upon the target; a retaining member effective to connect the body and the fuze-carrier guide for maintaining the body in a normal forward position and adapted to shear upon the impact of the body on thetarget, said body being adapted to slide rearward inside said fuze-carrier guide. after shearing of said retaining member; two firing members disposed'inside said body and comprising a rearwardly directed striker fixed to the body and a detonator guided by and slidable relatively forwardly in the body by inertia upon impact and into detonating engagement with thestriker; a compression coil spring interposed between said firing members to keep them away from one another up to the instant of impact of thefuze upon the target; and a percussion head rigidly mounted at the front of and forming part of said body and in the said normalrforward position of the body extending in front out of said fuze-carrierguide for impact upon the target, said percussion head havinga peripheral cutting edge at the front end with parts of thefront end being inclined inwardly and rearwardly from the periphery, and of a harder material than normal armour for cutting into a hard target and thereby eifective to cause said head to engage said target and adhere firmly at the point of impact, for ensuring percussion even at a high angle of incidence and also upon oblique impact efiective for exertion of a force tending to cause the fuze and projectileto pivot around the point of impact toward a position of smaller incidence relative to the target.

EDGAR WILLIAM BRANDT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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