IL25401A - Projectile fuse - Google Patents

Description

, PATENTS & DESIGNS ORDINANCE 15180/66 C O M P L E T E S P E C I F I C A T I O N Projectile fuse We, Industrial Holding Establishment, a Company of the Principality of Liechtenstein of 33 Hauptstrasse, Vaduz, (Principality of Liechtenstein), do hereby declare the nature of this invention and in what manner the same is to be performed, to be particularly described and ascertained in and b the followin statement : The present invention has for object a projectile fuse, of the type operating upon impact and comprising trajectory safety means including a balance-bar actuated by a spring, to control the arming of the fuse, locking means to prevent the operation of the balance-bar before firing, and fire conditioning means, actuated by the gunner and controlling the locking means.

This fuse is characterized in that the actuating spring or springs of the balance-bar are disposed between two members movable the one relative to the other during the fire conditioning operation, these members being shaped to bring about the tightening of this spring during this operation.

The accompanying drawing shows, by way of exemple , two embodiments of the fuse according to the invention.

Pig. 1 is a view thereof in axial section 1-1 of fig. 3.

Fig. 2 is a view in cross section along 2-2 of fig. .

Fig. 3 is a view in cross section along 3-3 of fig. 1 showing the members in the safety position.

Fig. 4 is a view similar to fig. 3, but showing the members in the so-called instantaneous position.

Fig. 5 is a view similar to fig. 3, but showing the members in a so-called delay-action position.

Fig. 6 is a view in partial section along 6-6 of fig. 7, on a larger scale, showing the balance-bar and escapement device.

Fig. 7 is a plan view corresponding to fig. 6.

Fig. 8 is a sectional view similar to fig. 1, but showing the members in the operating position which they occupy after firing and after arming.

Pig. 9 is a view in partial section corresponding to fig. 1, showing certain members in the so-called safety position.

Fig. 10 is a view in cross section corresponding to fig. 9 and along 10-10 of fig. 1 Fig. 11 is a view similar to fig. 9, but showing the same members in the so-called delay-action position.

Fig. 12 is a view similar to fig. 10 and corresponding to fig. 11.

Fig. 13 is a view similar to fig. 9, but showing the position occupied by the same members after arming the fuse.

Fig. 14 is a view similar to fig. 10, but corresponding to fig. 13.

Fig. 15 is a view similar to fig. 10, but relating to an alternative form of construction.

Fig. 16 is a view in axial section of the second embodiment, which differs from the first in that the safety of the trajectory is provided for at will with a long or short period.

Fig. 17 is a view in partial longitudinal section corresponding to fig. 16 and showing certain members in the safety position.

Fig. 18 is a view in cross section corresponding to fig. 17.

Fig. 19 is a view corresponding to fig. 17, but showing the same members in the operative position correspond ing to the long period for the safety of the trajectory.

Fig. 20 is a view similar to fig. 18, but corresponding to fig. 19.

Fig. 21 is a view similar to fig. 19, but showing the members in the position which they occupy- after arming the fuse corresponding to the long period for the safety of the trajectory.

Fig. 22 is a view in cross section similar to fig. 20, but corresponding to fig. 21.

Fig. 23 is a view similar to fig. 19, but showing the members in the operative position corresponding to the short period for the safety of the trajectory.

Fig. 24 is a view similar to fig. 20, but corresponding to fig. 23.

The fuse shown comprises a body 1 on which is rotatably mounted a hood 2 itself provided with a cap 3. A seal joint 4 is provided between the body 1 and the hood 2. The axial immobilisation of the hood relative to the body is effected due to a slit elastic ring 5 disposed in two complementary grooves made the one at 6 in the body 1 and the other opposite at 7 in the hood 2. This elastic ring is normally contracted so as to be entirely in the groove 6. A pointed screw 8 disposed in a corresponding threaded hole of the hood 2 is provided to separate one from the other the two ends of this ring when one firmly screws the screw 8 in its hole. The spacing apart of the ring has for effect to expand the latter and to bring it into the position shown in fig. 1 (on the right) where it is seen- that this ring is partly engaged in the two circular grooves 6 and 7, which prevents any relative axial movement of 1 and 2 while leaving the hood free to When the hood is in the position shown in fig. 1 which corresponds to fig. 3, the members are in a so-called safety position, in which the striker 9 is held stationary by a striker bolt 10. Simultaneously, a solid wall of a primer-holder barrel 11 is opposite the striker. O the other hand, in this safety position, a primer-holder rack 12 ensures the interruption, as will be seen later on, of the pyrotechnic al chain by means of which firing takes place In the safety position, a radial hole 13 made in the body 1 is opposite to a solid part of the hood 2.

In this hole are disposed two balls 14, 15, the first completely engaged and the second only partly. The ball 15 is partly engaged in a notch 16 of a rod 17 parallel to the axis of the fuse. This rod is provided to slide in a conduit 18 made in the frame 19 of a safety device which will be described further on. The lower end of this rod 17, which is hollow, is engaged in a socket 20 itself disposed in a housing of the body 1. A compression spring 21 is disposed inside the socket 20 and operates upwardly in fig. 1, on the rod 17. So long as the balls 14 and 15 are in the position shown in fig. 1, the rod 17 is immobilized. In this safety position, the rod 17 immobilizes the striker bolt 10, that is to say prevents it from rotating about its pivoting axis 22 (fig. 2).

The following means are further provided to immobilize the striker bolt 10. A ball 23 is partly engaged in a housing 24 of the lower face of the bolt 10 and partly in a hole 25 parallel to the axis of the fuse and made in the upper part 26 of the frame 19. This frame 19, 26 is in two parts for reasons of mounting. This ball is held in the position shown in fig. 1 by a rod 27 disposed in the hole 26 to slide therein. The lower end of this rod abuts against the primer-holder rack 12 when the members are in the position according to fig. 1.

When it is desired to arm the fuse to bring it either into the instantaneous position shown in fig. 4, or in the delay-action position visible in fig. 2 and 5, one rotates the hood 2 in the desired direction relative to the body 1. One will describe what happens in each of these two cases. , One rotates the hood 2 so as to bring the members into the position according to fig. 4., that is to say up to the moment when the index I figuring on the hood occupies the position which was that of the index S when one was. in the safety position (fig. 3). A driving dog 28 stationary relative to the hood 2 is partly engaged in a slot 29 made in the primer-holder barrel 11. Upon relative rotation of the hood with respect to the body, this dog 28 obliges the barrel to rotate about its own axis causing it to pass from the position visible in fig. 3 to that shown in fig.4.

Thus, the priming 30 has placed · itself in the axis of the fuse. This priming is provided for instantaneous firing upon impact. The other priming 31 of the barrel 11 occupies, in the instantaneous position, the place shown in fig. 4.

In order to pass from the safety position to the delay-action position, one causes the hood to rotate so as to bring the index- R into the position occupied by the index S in the safety position. In the delay-action po-sition, the members are as shown in fig. 2 and 5. The rotation of the hood in the reverse direction to that described previously occasions, through the agency of the dog 28, the rotation of the barrel 11 in such a way that it is the priming 31 which, this time, places itself in the axis of the fuse (fig. 5). This priming differs from the priming 30 by its nature, to ensure slower firing than in the case of the instantaneous.

The bringing into the correct position of the instantaneous or of the delay-action, that is to say the correct angle of rotation of the hood relative to the body, is ensured by the following means: a lug 32 is fixed in the body 1 and is opposite a milling 33 made in the hood 2. In the safety position, this lug is between the two ends of the milling whereas in the instantaneous position it abuts against one of these ends and in the delay-action position, against the other end. Thus, the selection of one of the two operating positions, delay-action and instantaneous, may be effected without the help of the eyes. When the members of the fuse are either in the instantaneous position, or in the delay-action position, the projectile may be fired.

This is what takes place at the moment of firing: the bringing of the hood 2 into one of the positions, instantaneous or delay-action, has for effect to bring opposite the hole 13 a milling 34 of sufficient depth to permit the balls 14, 15 to move so as to reach the position according to fig. 8, where the ball 15 is completely disengaged from the 'notch 16. The rod 17 is therefore no longer immobilized by these balls.

Upon firing, through inertia, the rod 17 passes from the position according to fig. 1 to the position of fig. 8, by compressing its spring 21. As soon as this position is reached, a blade-spring 35 fixed in a manner not shown on a part of the frame of the mechanism slackens and passes from the position according to fig. 1 to that according to fig. 8, where its free end places itself opposite the upper end of the rod 17. From this moment, this spring 35 prevents the rod 17 from obeying the action of the spring 21. This rod is thus immobilized in the lower position.

In this lower position, another notch 36 of the rod 17 is opposite a balance-bar 37 mounted to pivot about a hollow spindle 38 coaxial with the fuse. Before the firing of the shot, that is to say so long as the rod 17 was in the upper position, this rod blocked the balance-bar and prevented it from oscillating. Now that it is in the lower position, it no longer opposes this oscillation. This balance-bar thus starts to oscillate under the action of a driving spring 39, due to the following means: this -spring 39 is disposed in a case 40 mounted to slide between the frame 19 and the primer-holder rack 12.

In the safety position (fig. 1, 9 and 10), the spring 39 is slackened and the case is engaged in a hollowing 55 of the hood 2, forming, on either side of the spot where this case makes contact, two inclines 56,57. When one passes from the safety position (fig. 10) to the delay-action position (fig. 12), the incline 56 acts on the case 40 and brings about the compression of the spring 39. Similarly, if one passes into the instantaneous position, ,the spring will be compressed, but by the incline 57 At 41 is seen the priming carried by 12 and at 42 (fig. 6 and 7) the escapement cooperating with a toothed wheel 43 integral with a pinion 44 itself meshing with another toothed wheel 45; this latter is integral with another pinion 46 which, itself meshes with the teeth 47 of the primer-holder rack 12. One understands that under the action of the spring 39 (compressed as has been seen) , as soon as the balance-bar can oscillate, the gear train described starts to rotate and the escapement 42 to operate which causes the rack 12 to advance step by step. This movement of the rack 12 in the frame 19 continues until the moment when this rack abuts against a part of the bod of the fuse, as shown in fig. 13. At the end of the travel of the rack, the priming 41 of the latter is in the axis of the fuse and, as from that moment, the different elements of the pyrotechnic al chain 30 or 31, 41 and a relay 53 of a detonator 54 (fig. 8) are in a line and firing may occur. In fact, before arriving at the end of the travel of the rack, the rear end 48 of the latter has passed in front of the lower end of the rod 27, so that this rod is no longer. blocked in the position according to fig. 1. Under the action of a torsion spring not shown, acting on the bolt of the striker 10, this bolt starts to rotate, which forces the ball 23 and the rod 27 downwardly since nothing any longer holds back this rod. As soon as the bolt of the striker has released the striker, the latter is able to bring about firing at the moment when the,.projectile meets an obstacle. The operation of the striker may be carried out in two ways : either by percussion of the central part 49 of the cap 3 which crashes causing the driving back of the striker downwardly in fig.. 1, or simply by inertia, if the projectile hits an obstacle in a skimming way and in this latter case, at the moment of braking or stopping of the projectile, through inertia, the primer-holder barrel 11 is projected forwards and the priming 30 or 31 which is in the axial position strikes the point of the striker. At 50 is seen the spring which normally maintains the striker in the rest position.

It is seen that the fuse shown comprises trajectory safety means including a balance-bar actuated by a spring and regulating the speed of radial movement of a primer-holder rack, this adjustment being effected through the agency of an escapement. These trajectory safety means moreover comprise first locking means. (rod 17) to prevent on the one hand the operation of the balance-bar before firing and on the other hand the movement of the striker bolt. Additional locking means shown by the rod 27 and the ball 25 are provided so as completely to release the striker only after a certain movement of the rack.

The spring 39 for actuating the balance-bar is a flexion spring of general V-shape with unequal legs open in the free position and which are brought to close at least partly when tensioned. Calculation and experience show that such a spring has, as compared with the usual coil spring, the advantage of much less bulkiness , the force being the same. It will be noted, in considering fig. 9 to 14, that the spring 39 is disposed between two members (12 and 2) movable one relative to the other during the work conditioning operation which consists in rotating the hood relative to the body 1 and that the members are shaped, as already seen, to cause tensioning of this spring during this operation. The spring is therefore in the free state so long as the fuse is stocked and can therefore not sustain any fatigue* It is only at the moment of the fire conditioning operation, thus just before the operation of the fuse, that it is armed.

Independently of this advantage, this disposition offers yet another one : the spring 39 not being under tension, if accidentally, for example as a result of the fracture of an element, the safety means break down, the primer-holder rack cannot accidentally take up the alignment position of the pyrotechnic al chain before the fire conditioning, which avoids serious accidents. Due to the inequality of the two legs of the spring 39, one gains an advantage which appears in comparing fig. 9 and 13.

The travel necessary to tension the spring, thus to bring it into the position according to fig. 11, is notably less than the work travel visible in fig. 13. Moreover, in this figure, the spring is not completely slack since one must be sure that the rack effectively reaches the end of travel under the action of a tension, still sufficient, of the spring.

The embodiment described comprises so-called anti-sabotage means. By sabotage, is to be understood a fuse rendered voluntarily dangerous either during manipulations of the fuse, or during its transport, or again when the shot is fired, without anything being visible from the outside of the fuse. In a fuse of the type de-scribed,' the sabotage will consist in bringing about surreptitiously the arrival of the primer-holder rack Γ2 in the position corresponding to the arming of the fuse, that is to say in the position shown in fig. 13, and for which the elements of the pyrotechnical chain are all in line, of course without rotating the hood 2 relative to the body 1 , thus apparently leaving the members visible from the exterior in the safety position. The anti- sabotage means here provided consist of a pin 58 in the right hand end in fig. 1 of the rack 12. A compression spring 59 disposed in a hole i§> of this rack constantly urges the pin 58 to project outwardly of this rack as is seen in fig. 1. A hole 60 is provided in the part of the body 1 which is opposite the pin 58 when the fuse members are in the safety position. This hole 60 has a diameter just sufficient to allow the pin 58 to pass therethrough.

The hood 2 of the fuse extends lower than the spot where the hole 60 is to be found and it presents opposite this hole (always when the members are in the safety position) a radial hole 61 having a thread 51 in which is screwed a plug 52. If by a sabotage operation, someone succeeds in causing movement of the rack 12 to the right in fig. 1 without rotating the hood 2 relative to the body 1, the result will be that the pin 58 the existence of which is supposed to be ignored by the saboteur, passes through the hole 60 and engages partly in the hole 61. From this moment, the hood 2 is completely immobilized relative to the body 1 and it is no longer possible for the ^gunner to act on this hood so as to bring the members into the fire preparation position. His attention is thus drawn to the fact that something is not in These anti-sabotage means do not hinder the normal operation of the fuse. In fact, when one rotates the hood 2 relative to the body 1 to bring the members either in the so-called instantaneous position, or in the delay-action position, the rack 12 is at the left hand end of its trajectory, that is to say that the pin 58 is out of the holes 60 and 61. The hood may therefore rotate without opposition on the part of the pin 58. When now the spring 39 brings the rack to the right hand end of its, travel, the pin 58 passes through the hole 60 and abuts against a solid part of the hood 2 (fig. 13 and 14) . The spring 59 being much weaker than the spring 39, it gives way and the pin 58 retreats as the rack 12 approaches the end of its travel.

In the case of fig. 15, one has to do with a modified form in which the spring pin 58 is replaced by a pin 62 screwed in the rack 12. One again finds the hole 60 of the body 1, the hole 61 of the hood 2 and the plug 52 outwardly closing this hole 61. A radial hole 63 is provided in the hood 2 opposite the position occupied by the pin 62 when the members are in the delay-action position. Similarly, a radial hole 64 is provided in the hood opposite the position occupied by the pin 62.in the so-called instantaneous position. These holes, which are closed outwardly by plugs 65, 66, serve as a housing at the end of the pin 62, to permit the rack 12 to move to the end of its stroke without opposition from this pin. This disposition offers the additional advantage of im-mobilizing the members in the operative position and thus preventing any accidental relative movement of these members at the moment of im actβ In the embodiment according to fig. 16 to 24, one will not describe the members which are identical or similar to those of the first embodiment. One will restrict oneself to drawing attention to the differences so as not to lengthen the text.

In this fuse, one no longer has a primer-holder barrel permitting of choosing an operation with delay- action or a so-called instantaneous operation upon impact. On the other hand, the primer-holder rack is provided to move at two different speeds, at will, thus permitting of realizing a safety in the trajectory with a long period or with a short period, at will. The rotation of the hood 2 relative to the body 1 thus no longer here functions to rotate a primer-holder barrel, but must permit of bringing the members either in a long period position, or in a short period position for the safety of the trajectory, as will be seen later on. The relative rotation, of the hood 2 and of the body 1 permits, as in the first embodiment, the release of the rod 17 by movement outwardly of the balls 14 and 15 as in the first example. On the other hand, this rod 17 no longer serves, here, to immobilize a striker bolt, because such a bolt no longer exists. The recall spring 35 for the rod 17 in the lower position, when it has reached this position, is here replaced by a blade spring 67 which has the same function. The rod 17 thus merely serves to immobilize the balance-bar 37 so long as the members are in the safety position. When the rod 17 is in the lower position, its notch 36 leaves a free passage for the balance-bar in order to permit it to osc illate .

In the safety position, the striker 9 is opposite a hole 68 provided in the rack 12 to allow the striker 9 to fall when the shot is fired without risk of damage to it. As soon as the projectile has issued out of the muzzle and that acceleration ceases, the striker resumes the upper position in fig. 16, under the action of the spring 50. The priming 41 carried by the rack 12 will preferably be a priming ensuring the instantaneous explosion upon impact. One could if necessary provide that this priming produce the explosion after a certain delay.

The spring 39 of the first embodiment is here replaced by a different sprin -69 which also is V-shaped with unequal legs but which differs in that the short leg includes' two outer parts 70 more open than the middle part 71 comprised between the two parts 70. On the other hand, for the tensioning of the spring 69, there is provided in the hood 2 a hollowing 72 of a shape different to the hollowing 55 (fig. 10). In fact, instead of having two symmetrical sides, the hollowing 72 has on one side an incline 73 similar to 56 and on the other side a shorter incline 74 prolonged by a cylindrical part 75 of greater diameter than the inner diameter of- the hood 2 where the incline 73 ends. The diameter of this part 75 is such that when one rotates the hood relative to the body 1 in order to cause the members to pass from the position according to fig. 18 to the position according to fig. 20, alone the two parts 70 of the spring 69 are deformed, the middle part 71 not being subjected to the action of the incline 74 of the part 75· On the other hand, if one rotates the hood relative to the body in the reverse direction, in order to bringthe members into the position according to fig. 24, the spring is still more deformed because not only the parts 70, but also the middle part 71 submit to the action of the final part of the incline 7 Thus, in the first case (fig. 19), the spring is less strongly wound up than in the case of fig. 23. The force developed by this spring in order to act on the rack is lower in the case of fig. 18 than in the case of fig. 19, which has for result that in the first case the rack will reach the end of its travel only after a longer time than in the second case. Thus is ensured the safety of the trajectory with a long period or with a short period.

Taking into account what has preceded, the operation of the fuse will be easily understood : figures 17 and 18 correspond to the position of the members in the safety position, fig. 19 and 20 correspond to the arming of the spring 39 in the case of the safety of the trajectory with a long period, fig. 23 and 24 correspond to the arming of the spring 39 for the safety of the trajectory with a short period and fig. 21 and 22 show the position of the spring 39 and, of the rack, at the end of the travel of the latter, when the priming 41 is in line with 53. Fig. 21 and 22 correspond in fact to the arrival at the end of travel of the rack in the case of a long period operation. The final shape of the spring would be slightly different (greater residual tension) if one had to do with the final position of the rack during the short period operation. The spring according to fig. 16 to 24 could, in a modified form, be replaced by the two V-shaped springs having different characteristics.

Although the springs 39 and 69 described have considerable advantages over and above the springs usually employed in fuses, the invention is not limited to the case of such V-shaped springs, the main idea of the invention being the tensioning of the driving spring during the fire conditioning operation.

Claims (3)

WHAT IS CLAIMED IS:

1. Projectile fuse operating on impact comprising trajectory safety means consisting of a rack actuated by a spring and of locking means in the form of a balance arm locking the rack prior to firing and a covering sleeve which is manipulatable and turnable by hand which latter controls the locking by the balance arm so as to bring about the firing condition, characterized thereby, that the spring (39) positioned intermediate the said sleeve (2) and the rack (12) is tensioned into pre-firing condition by the turning of the sleeve*

2. * Projectile fuse as claimed in Claim 1, characterized thereby that the said sleeve (2) or the said rack (12) are provided at that location where they co-operate with the said spring(39) with at least one surface (56.57) which is designed to cause the tensioning of the spring by

3. Projectile fuse as claimed in Claim 1 or 2, characterized thereby that the spring is formed as a flexion spring which in untensioned condition is substantially of V-shap© with unequal legs, which legs on tensioning are closed upon one another. Cohen Ze<¾¾k and Spisbach P.O. Box 33H6 Tel Aviv Attorneys for Applicants