US3115094A

US3115094A - Fuze for projectile

Info

Publication number: US3115094A
Application number: US169426A
Authority: US
Inventors: Simmen Robert
Original assignee: Mefina SA
Current assignee: Mefina SA
Priority date: 1961-02-24
Filing date: 1962-01-29
Publication date: 1963-12-24
Anticipated expiration: 1980-12-24
Also published as: CH368076A; GB987453A; DE1155036B

Description

Dec. 24, 1963 R. SIMMEN FUZE FOR PROJECTILE 4 Sheets-Sheet l Filed Jan. 29, 1962 alunni:

RQBERT S1MMEN ATTORNEY 4 Sheets-Sheet 2 Filed Jan. 29. 1962 FIG.

FIG. 7.

INVENTOR ROBERT 5 IMMN ATTORNEY Dec. 24, 1963 R. SIMMEN FUzE FOR PROJECTILE 4 Sheets-Sheet 5 FIG. 12,.

Filed Jan. 29, 1962 Sir IG. l?)

' INVENTOR ROBERT SIMMEN w DNA m A Dec. 24, 1963 R. SIMMEN 3,115,094

FUZE FOR PROJECTILE Filed Jan. 29, 1962 4 Sheets-Sheet 4 INVENIOR nite States 3,115,094 FUZE FOR PROEECTILE Robert Simmeu, Geneva, Switzerland, assigner to Melina SA., Fribourg, Switzerland, a corporation of Switzerland Filed Jan. 29, 1962, Ser. No. 169,426 Claims priority, application Switzerland Feb. 24, 1961 4 Claims. (Cl. 102-74) The present invention has for its object a fuze for a projectile including a rst primer adapted to be fired upon impact by the forcing back of a striker, said rst primer being secured to an axially shiftable primer carrier, delay-producing pyrotechnic means being inserted between said first primer and a detonator, while a second primer is carried in tandem relationship with the first primer on the primer carrier, the delay-producing pyrotecbnic means being fitted between the two primers and a second striker being positioned in registry with the second primer on the side of the latter facing away from the first striker.

According to the invention, a selecting device allows, at the moment of the impact of the projectile, producing a direct percussion, either of the rst primer through the forcing back of the rst striker against the primer carrier which is held fast against shifting, or else, of the second primer by the second striker associated therewith upon shifting of the primer carrier towards the latter, whereby a delayed ignition or an instantaneous ignition of the projectile charge is obtained as desired.

The accompanying drawings illustrate diagrammatically, by way of example, a preferred embodiment of the fuze according to the invention. In said drawings:

FIG. 1 is an axial sectional view of said fuze in its inoperative condition.

FIG. 2 is a cross-section through line II--II of FIG. 1.

FIG. 3 is an axial sectional View showing the fuze as adjusted for an instantaneous ignition of the detonator.

FIG. 4 is a cross-section through line IV-IV of FIG. 3.

FIG. 5 is a cross-section through line VV of FIG. 3.

FIG. 6 is an axial sectional View showing the different parts of the fuze after the starting of the shot in the case of the fuze having been adjusted for an instantaneous ignition of the detonator.

FIG. 7 is a cross-sectional View through line VII-VII of FIG. 6.

FIG. 8 is a sectional view of the fuze showing the latter at the moment of the impact, when it has been adjusted for an instantaneous ignition.

FIG. 9 is a cross-section through line IX-IX of FIG. 8.

FIG. 10 is an axial sectional View of the fuze upon impact, when it has been adjusted for a delayed ignition of the detonator.

FIG. 11 is a cross-section through line XI-XI of FIG. 10.

FIG. l2 is an axial sectional view showing the fuze upon impact when it has been adjusted for an instantaneous ignition, the impact being obtained while the safety device provided for the detonator is still operative.

FIG. 13 is a cross-section through line XIII-XIII of FIG. 12.

FIG. 14 is an axial sectional view, on a larger scale, of a safety device provided for the fuze detonator.

FIG. l5 is a plan View, partly torn off, of said safety device for the detonator.

The improved fuze illustrated includes a tubular body 1 adapted to be secured to a projectile. Said body 1 carries a head 2 adapted to revolve with reference to the body 1. A fluidtight packing 3 prevents the seepage of foreign particles between the body 1 and the head 2. Screws 4 engaging tapped bores 5 in the head 2 carry each a tip 6 engaging a groove 7 in the body 1. Said screws 4 hold thus the head 2 on the body 1, while allowing a rotary movement of the latter with reference to the body 1. The head 2 is provided with a central bore 8 inside which may slide a push member 9, to the central section of which is secured a irst striker 10. Between the upper end of the body 1 and the head 2 is fitted a disc 11 rigid with a socket 12, which serves for the guiding of the striker. Around said socket 12 is fitted a coil spring 13 bearing against the surface of the disc 11 and urging the push member 9 outwardly.

In the central section of the body 1 is arranged a primer carrier 14. Said primer carrier 14 carries two primers, to wit, a rst primer 15 and a second primer 16, these two primers 15 and 16 being arranged in tandem relationship. Pyrotechnic delaying means 17 are inserted between the two

primers

15 and 16.

The primer carrier 14 is carried inside a socket 18. The primer carrier 14 and the socket 18 are rigidly secured to each other by a member which is torn upon impact. In the example illustrated, said member adapted to be torn isconstituted by a washer 19 engaging a groove 2t? in the primer carrier 14. The socket 18 is provided at its front end with an inturned section 21 fitted between said washer 19 adapted to be torn and a forwardly facing shoulder 22 of the primer carrier 14. At its rear end, said socket 18 carries a closing member 23 carrying a second striker 24 extending in a direction facing the first striker 10. Said member 23 is provided with a tubular rear extension 25 facing the fuze detonator 26.

A safety device is adapted to hold the tirs-t primer 15 away from the tip of the striker 110. Said longitudinally shiftable safety device includes a safety ring 27 provided with rearwardly directed elastic blades 28 terminating each with a lbulge 29. The bulges 29 of the blades 28 are adapted to engage a groove 30 in the outer surface of the socket 18. Around said blades 28 is arranged a safety socket 31 engaging the rear surface of the safety r-i-ng 27 provided with an inner shoulder 32. A spring 33 surrounds the lsocket 18 and engages, on one end, a shoulder 34 on the latter and, on lthe other end, the inner shoulder 32 of the safety socket 31. Said spring 33 urges the rear shoulder '34- of the socket 18 against the shoulder 35 of the body 1, whereas the safety ring 2%7 is urged against the disc l11 fitted over the end of the body 1. Said spring 33 is suiciently strong for ensuring the cornpression of `a further spring 36 surrounding the lower section of the socket y18, said `spring 36 being fitted between the shoulder 34 of the socket 18 and a shoulder `37 on the lbody 1.

The safety device described hereinabove, which is of a well-known type, is adapted to hold the first primer 15 away from the striker 10 as long as the projectile has not been subjected to the very high axial acceleration which is imparted thereto at the moment of the tiring of the gun provided with the fuze.

The `operation of said safety device is as follows:

U-nder the faction of the axial acceleration produced by the firing, the safety socket 31 is shifted towards the shoulder 35 of the body `1 and compresses the spring 33. The `safety ring 27 follows the movement of the socket 31, whereby the bulges 29 of the blades 28 move out of the groove 3o :and engage a second similar groove 3S formed in the socket 18. As soon as no Ifurther axial acceleration is present, that is when the projectile has left the gun, the spring 36 urges forwardly the socket '18 which carries along with it the primer carrier 14 together with the safety ring 27 and lthe safety socket 31 which lock each other in position over the socket 18. The parts forming `said safety device occupy then the set position illustrated in FIG. 6.

The fuze is provided furthermore with a safety device including a bolt adapted to move radially in the body 1 of the fuze. Said bolt is constituted, in the example illustrated, by a ball 39 a-rranged inside a radial'recess 40 of the body 1 of the fuze. Inrthe safety position, said ball 39 engages a groove l41 provided at the periphery o f a safety rin-g 27. The ball 39 is held in `said safety p osltion by the tip 42 of a screw 43 screwed transversely into the head 2. In its safety or operative position, the boltforming ball 39 locks the safety ring 27 with reference to the body 1, which prevents the setting of the tuze.

As illustrated in FIG. 2, the body 1 is provided with an outer groove 44 extending tr-ansversely to either side of the recess 40 housing the ball 39. Said groove 1s adapted to allow the movement of the tip 42 of the screw 43 during the angular movement of the head 2 with reference to the body l1 as provided for the adjustment of the fuze. The safety position of the tfuze is marked outwardly, in registry with a stationary reference mark 45 on the body 1 of the fuze by a reference mark such as the letter S formed on the head, as shown in its safety position at 46 -in lFIG. 2.

It is apparent that when the head 2 is brought through an angular movement out of said safety position, the ball 39 may move out of its recess 40 and be shifted radially outwardly, so as to release the safety ring 27.

The fuze is provided furthermore with a safety device Iforthe :detonator 26 carried by the body 1. Said device includes an auxiliary primer 47 which is housed in the Afree end 48 of an auxiliary primer carrier 49 movable transversely across the axis of the fuze. In the example illustrated on a larger scale in FIGS. 14 and 15, said auxiliary primer carrier 49 is constituted by an arm pivoting around a pin 50. A spring 51 wound around said pin 50 has a tendency to make the arm 49 pivot, so as to bring the auxiliary primer 47 into registry with the central section of the -fuze, that is across the path following by the re between the first and second primers and `16 and the detonator 26. However, said auxiliary primer carrier 49 is normally held away from the path of the re from

Ysaid primers

15 and 16 by a stop constituted, in the example illustrated, by a pin 52 controlled by a clockwork.

As illustrated in FIGS. 14 and 15, said clockwork mechanism includes a toothed sector 53 pivoting round its axis 54 and subjected to the action of a spring 55 surrounding said axis 54. This toothed sector 53 meshes with a pinion 56 driving an escape wheel 57, of which the rotary movement is braked by a balance 58 rocking round a spindle 59. The pin 52 forming the abovexnentioned stop is carried by said toothed sector 53.

The section 60 of the primer-carrying arm 49 bearing against the pin 52 has an arcuate shape extending substantially along a circle having its center on the axis 54, when the arm 49 is in its llocked posi-tion (see FIGS. 5 and 15). Consequently, during the angular shifting executed by the toothed sector 53 under the control of the clockwork, the pin 52 slides over said section 60 without y'any substantial shifting or the arm 49 being allowed. It is only when the toothed sector 53 has executed a complete rocking movement that the pin 52 releases the arm 49 which 4is then urged by its spring 51 into a position for which the auxiliary primer 47 lies in a central position along the path of the fire produced by the

primers

15 and 16. Said toothed sector 53 is provided with an opening 53a adapted to uncover the path of the fire in the central section of the fuze when said sector 53 has executed its complete rocking movement.

It should also be remarked that the auxiliary primer 47 is iitted inside a recess 61 at the end of the arm 49 and that it is subjected to the action of a spring 62 which has a tendency to urge it out of said recess 61. Thus, when saidarm 49 has brought the auxiliary primer into its central position, said auxiliary primer 47 engages partly an openin-g 63 formed in a plate 64 carrying the clock-work, which opening yforms part of a tire channel leading from the

primers

15 and 16 to the detonator 26.

4 Thus, the auxiliary primer 47 locks the arm 49 in its set position (see FIGS. 6 and 7).

The clockwork movement is normally held in a position corresponding to inoperativeness of the fuze by a control member acting on `a pin 65 carried by the toothed sector 53. In the example illustrated, said control member which serves as an abutment for the pin 65 (FIG. 14) for said inoperative position of the fuze, is constituted by the tubular extension 25 of the member 23. It is apparent therefore that the pin 65 is released by the extension 25 only after the shot has been red, the primer carrier 14 and the socket 18 being thus urged forwardly by the spring 36 (see FIG. 6 as compared with FIGS. 1 and 2). Once released by the forward movement of the extension 25, the pin 65 allows the toothed sector 53 to be Ydriven into movement by its spring 55.

By reason of the presence of the safety device of the detonator, said fuze is particularly adapted to prevent any mishap in the tiring of guns and chiefly ot mortars, since even if a second projectile is inadvertently introduced -into the gun before the rst has been fired, the charge in said projectiles cannot explode because the auxiliary primer 47 reaches its armed position, illustrated in FIG. 7, only after a certain time.

The fuze includes also a selecting device which allows producing, upon impact, a direct percussion, either of the lirst primer 15 through a driving back of the rst striker 10, or of the second primer 16 by the second striker 24 associated with the latter. The percussion of the iirst primer 15 by the striker 10 produces a delayed ignition of the projectile charge, since the detonator 26 can be ignited only after the pyrotechnic delaying charge 17 has burnt and after the secondary primer 47 has been brought into its central position by the clockwork movement.

The primer carrier 14 is provided with an extension 66 which guides it inside the socket i12. Said extension 66 is formed over at least a part of its length by two teeth 66a, 66h defining between them a channel (FIG. l) for the striker 10. The cross section of the opening 11a in the .disc 1'1 has a shape corresponding to that of the teeth 66a and 66b, so as to prevent any angular shifting of the latter with reference to the disc 11. The striker 10 is provided at its outer end with a portion of a larger diameter 68 inside which are provided grooves 69, whereby the cross-section of the striker in said portion 68 shows two projections 70 (FIG. 11). The free section of the channel 67 between the teeth 66a and 66b as also the cross-section of the striker 10 in that part in which it is provided With projections 70, are selected in a m-anner such that vfor a predetermined relative angular position of the primer carrier 14, including extension 66, with reference to the rst striker 10, the latter, when driven back at the moment of the impact, urges the primer carrier 14 in the direction leading to the second striker 24, so as to produce the instantaneous ignition of the charge. The lthrust exerted on the primer "carrier 14 by the striker 10 is ensured through engagement of the projections 70 against the ends of the teeth 66a, 66h. The percussion tears the washers 19, whereby the primer carrier =14 is allowed to move in the direc-tion of the striker 24, as illustrated in 2FIG. 8.

In contradistinction, if the striker 10 is brought into an angular position for which the projections 70 register with the actual cross-section of the channel 67 (see FIG. 11), the striker 10 moves at the moment of the impact inside said lchannel 67, without driving the primer carrier 14. At the end of its movement, the striker 10 produces the ignition of the tirst primer (see FIG. 10). In this case, the fir-ing of the char-ge is performed with a certain lag, since the ignition of the first primer 15` is propagated towards the second primer 16, as it passes through the pyrotechnic `delaying charge 17.

The selection of the dilerent angular positions of the striker 10, which angular positions allow either instantaneous ignition or delayed ignition of the projectile charge, is obtained by rotating the head 2 of the fuze. As a matter of fact, the push member 9 to which the striker 10 is secured, is angularly rigid with the head 2, as provided by the two pins 71 (see tFIG. 4) secured radially into the head 2 and of which the inner ends extend into longitudinal grooves 72 provided in the push member 9. These grooves 72 -allow complete axial Ireedom of Imovement for the push member 9 with reference to the head 2, while ensuring transmission of angular movements of the head 2 through the push member 9 to the striker 10. The outer wall of the head 2 carries to either side of the reference mark S defining the safety position of the fuze and illustrated at 46, two reference marks R, I in positions illustrated respectively at 73 and 74 in FIG. 2 and lying at 90 with reference to each other. The reference mark R should be brought into registry with the reference mark 45 on the body 1 whenever the fuze is to be ignited with a delay after the impact, whereas the reference mark I should be brought into registry with the reference mark 45 whenever the ignition `of the fuze is to be obtained instantaneously after the impact. In this latter case, a projectile impinging yagainst ground explodes above ground, whereas in the case of an adjustment for delay, the projectile explodes underneath the surface of the ground.

FIGS. 12 and 13 show clearly the operation when the fuze is submitted to an impact before the safety device provided for the detonator has yallowed the auxiliary primer 47 to reach its central armed position. In FIG. 12, it has been assumed that the fuze has been adjusted for an instantaneous transmission of the ignition to the detonator after impact. It is apparent that the iginiton produced by the percussion of the second primer 16 by the striker 24 produces an ignition of the auxiliary primer 47 in its eccentric location. The ignition of said aux-iliary primer cannot be transmitted tto the detonator 26, since said auxiliary primer rests on a solid section of the pl-ate 64 and does not allow the transmission of the ame to the detonator 26. The operation of the safety device of the detonator, which is clearly apparent from inspection of FIG. 12, in the case of the adjustment of the fuze for an instantaneous ignition, is :the same in the case of the adjustment of said fuze for a delayed ignition of the charge. As a matter of fact, in this latter case, the striker 10 would produce, as in the case of FIG. 10, the ignition of the first primer 15, which ignition is transmitted by the delaying means 17 to the second primer 16 and thus to the auxili-ary primer 47 in its eccentric location, which makes the ignition of the detonator 26 impossible.

The lfuze described hereinabove with reference to the drawings is adapted for use chiefly on projectiles which are not subjected to a gyratory movement such `as those used in mortars and trench mortars. However, said fuze may also serve on a gyratory projectile. In this case, instead of providing the safety device of the detonator with a clockwork movement for the shifting of the auxiliary primer y47, it is possible to resort to the centrifugal force to which the projectile is subjected so as to produce the shifting of a small mass driving into movement the toothed sector 53.

The tandem arrangement of the two

rst primers

15 and 16 with the interposition of the pyrotechnic delaying means 17 -allows a simple execution and an easy adjustment of .the fuze for an instantaneous or delay-ing ignition. Of course, this special tandem arrangement for the two

primers

15 and 16 between two

strikers

10 and 24 in opposite relationship, may be applied not only to gyratory or non-gyratory projectiles, but also to yfuzes wherein the axial acceleration is much smaller than that to which projectiles fired by a gun are subjected.

I claim:

l. A projectile fuze comprising, in combination, a hollow body, a head rotatably mounted on the upper portion of said body, a push member slidably positioned in said head, spring means operatively associated with said push member :for urging said push member upwardly, a primer carrier member axially movable in said hollow body, said primer carrier member having la channel in its upper portion, means for releasably holding said primer Carrier in a predetermined position during flight of the projectile, main striker member coaxially positioned in said chan nel with respect to said push member and operatively associated with said push member, a main primer and a secondary primer arranged in tandem in the lower portion of said primer carrier member, `said main striker member facing said main primer, a pyrotechnical delay element positioned within said primer carrier member and between and operatively connecting said main primer and said secondary primer, a secondary striker member coaxially positioned with respect to said push member and facing said secondary primer, a fuze detonator mounted in the lower portion of said body, an auxiliary primer carrier positioned between said fuze detonator land said secondary striker member and movable transversely with respect to said fuze detonator, an auxiliary primer positioned in said auxiliary primer carrier, preset selecting means for causing, in one position thereof, upon impact, said main striker member to strike said main primer, whereby there is a delayed ignition of said secondary primer land `of said auxiliary primer, and for causing, in another position thereof, upon impact, movement of said primer carrier member toward said secondary primer, whereby there is instantaneous ignition of said auxiliary primer upon engagement of said secondary primer and said secondary striker member.

2. The projectile fuze of claim 1 including a socket member in said body, said primer carrier member being axially movable in said socket member, and means for connecting said primer carrier member and said socket member, said means being rupturable upon impact.

3. The projectile fuze of claim 2 wherein said selecting means includes spring means for moving said primer carrier member axially toward said main striker member, interlock means for preventing movement of said primer carrier member, radially displaceable latch means for locking said interlock means, said latch means being operatively associated with said rotatably mounted head and being controlled by said head, said head being angularly integral with said main striker member.

4. The projectile fuze of claim 1 wherein said selecting means includes spring means for moving said primer carrier member axially toward said main striker member, interlock means for preventing movement of said primer carrier member, radially displaceable latch means for locking said interlock means, said latch means being operatively associated with said rotatably mounted head `and being controlled by said head, s-aid head being `angularly integral with said main striker member.

References Cited in the tile of this patent UNITED STATES PATENTS 1,648,603 Barker Nov. 8, 1927 2,977,882 Iasse Apr. 4, 1961 2,999,461 Apotheloz et al. Sept. 12, 1961 '3,034,438 Apotheloz et al. May 15, 1962 FOREIGN PATENTS 577,040 `Italy May 21, 1958

Claims

1. A PROJECTILE FUZE COMPRISING, IN COMBINATION, A HOLLOW BODY, A HEAD ROTATABLY MOUNTED ON THE UPPER PORTION OF SAID BODY, A PUSH MEMBER SLIDABLY POSITIONED IN SAID HEAD, SPRING MEANS OPERATIVELY ASSOCIATED WITH SAID PUSH MEMBER FOR URGING SAID PUSH MEMBER UPWARDLY, A PRIMER CARRIER MEMBER AXIALLY MOVABLE IN SAID HOLLOW BODY, SAID PRIMER CARRIER MEMBER HAVING A CHANNEL IN ITS UPPER PORTION, MEANS FOR RELEASABLY HOLDING SAID PRIMER CARRIER IN A PREDETERMINED POSITION DURING FLIGHT OF THE PROJECTILE, MAIN STRIKER MEMBER COAXIALLY POSITIONED IN SAID CHANNEL WITH RESPECT TO SAID PUSH MEMBER AND OPERATIVELY ASSOCIATED WITH SAID PUSH MEMBER, A MAIN PRIMER AND A SECONDARY PRIMER ARRANGED IN TANDEM IN THE LOWER PORTION OF SAID PRIMER CARRIER MEMBER, SAID MAIN STRIKER MEMBER FACING SAID MAIN PRIMER, A PYROTECHNICAL DELAY ELEMENT POSITIONED WITHIN SAID PRIMER CARRIER MEMBER AND BETWEEN AND OPERATIVELY CONNECTING SAID MAIN PRIMER AND SAID SECONDARY PRIMER, A SECONDARY STRIKER MEMBER COAXIALLY POSITIONED WITH RESPECT TO SAID PUSH MEMBER AND FACING SAID SECONDARY PRIMER, A FUZE DETONATOR MOUNTED IN THE LOWER PORTION OF SAID BODY, AN AUXILIARY PRIMER CARRIER POSITIONED BETWEEN SAID FUZE DETONATOR AND SAID SECONDARY STRIKER MEMBER AND MOVABLE TRANSVERSELY WITH RESPECT TO SAID FUZE DETONATOR, AN AUXILIARY PRIMER POSITIONED IN SAID AUXILIARY PRIMER CARRIER, PRESET SELECTING MEANS FOR CAUSING, IN ONE POSITION THEREOF, UPON IMPACT, SAID MAIN STRIKER MEMBER TO STRIKE SAID MAIN PRIMER, WHEREBY THERE IS A DELAYED IGNITION OF SAID SECONDARY PRIMER AND OF SAID AUXILIARY PRIMER, AND FOR CAUSING, IN ANOTHER POSITION THEREOF, UPON IMPACT, MOVEMENT OF SAID PRIMER CARRIER MEMBER TOWARD SAID SECONDARY PRIMER, WHEREBY THERE IS INSTANTANEOUS IGNITION OF SAID AUXILIARY PRIMER UPON ENGAGEMENT OF SAID SECONDARY PRIMER AND SAID SECONDARY STRIKER MEMBER.