US3008414A

US3008414A - Self-propelled projectile

Info

Publication number: US3008414A
Application number: US790711A
Authority: US
Inventors: Joseph R Jasse
Original assignee: Hotchkiss Brandt SA
Current assignee: Hotchkiss Brandt SA
Priority date: 1954-01-21
Filing date: 1959-02-02
Publication date: 1961-11-14
Anticipated expiration: 1978-11-14
Also published as: GB853789A; GB768295A; GB834969A; NL106017C; BE567169A; FR1098633A; CH346135A; FR81001E; CH348080A; US2944486A; FR83403E

Description

NOV. 14, J. R. JASSE SELF-PROPELLED PROJECTILE Filed Feb. 2, 1959 2 Sheets-Sheet a lilimllll Nov. 14, 1961 J. R. JASSE SELF-PROPELLED PROJECTILE 2 Sheets-Sheet 2 Filed Feb. 2, 1.959

United States 3,08,414 Patented Nov. 14, 1961 3,008,414 SELF-PRQPELLED PROEECTHJE Joseph R. Jasse, Paris, France, assignor to Hotchkiss- Brandt, Paris, France, a French body corporate 7 Filed Feb. 2, 1959, Ser. No. 79%,711

Claims priority, application France Feb. 3, 1958 Claims. (Cl. 10249) The present invention relates to self-propelled projectiles of the type fired in a firing or launching tube or barrel by means of an auxiliary launching charge. In such projectiles, the self-propelling gas outlet nozzle is provided at the rear with an ejectable obturating and firing device adapted to avoid a premature firing of the selfpropelling charge by the launching charge.

This device, which is ejected after ignition of the self propelling charge, is retained by a shearable ring and it can be provided either with a self-contained firing device for igniting the self-propelling charge or with a passageway filled with a charge forming a time fuze or delay means which permits an automatic ignition of the selfgrcfpelling charge by the launching charge with a suitable e ay.

An object of the invention is to provide an ejectable obturating and firing device having a time fuze for a projectile of the aforementioned type said device being so improved as to permit use of high pressures of about 1000 kg./sq. cm. or more.

According to the invention there is provided a time fuze or delay means which comprises two elements disposed in series, one behind the other. The rear element, constituted by compressed powder, is so arranged that its combustion does not cease before the projectile has travelled completely through the launching tube, this element being capable of withstanding very high launching pressures. The forward element is adapted to burn at the surrounding pressure after the projectile has left the launching tube. This forward element consists of cornpressed powder in a passageway.

Further features and advantages of the invention will be apparent from the ensuing description, with reference to the accompanying drawings to which the invention is inno way restricted.

In the drawings:

FIG; 1 is a longitudinal sectional view of a self-propelled projectile provided at the rear with an ejectable obturating and firing device improved in accordance with the invention;

FIG. 2 is a longitudinal sectional View on an enlarged scale of the obturating and firing device;

FIG. 3 is an elevational view of the rear end of th? forward element of the time fuze means;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is an elevational view of the forward end of the element shown in FIG. 3;

FIGS. 6 and 7 are diametral sectional views taken along lines 6-6 and 77 respectively of FIG. 5, and

- FIG. 8 is a similar sectional view taken along line 8-8 of FIG. 3.

In the illustrated embodiment, the invention is shown to be applied to a rocket adapted to be fired or launched in a smooth-bore launching tube.

According to this embodiment, the rocket comprises a body 1 having a part-conical shape and an attached ogival 2 carrying a conventional percussion fuze F. Directly fixed to the rear of the body 1 is a nozzle T which is formed by an ejectable obturating and firing device P improved in accordance with the invention. To device P is secured a fin arrangement Q capable of receiving an axial tubular tail unit R containing an auxiliary launching charge S.

Fitted in the rear part of the body 1 forward of the nozzle T is a thin longitudinal sheath 3, for example composed of extra mild drawn steel.

The space between the body 1 and the sheath 3 is filled with the useful charge, for example an explosive charge 4. Within the sheath 3 is a tubular propelling charge 5 adapted to burn only on its inner face 6 its outer face being coated with a combustion-inhibiting varnish 7.

Disposed forwardly of the charge 5 is a firing or igniting tablet 8 against which a tube 9 rests, this tube 9 being disposed in the central cavity of the charge 5 and being adapted to conduct the flame emanating from the obturating and firing device P to said tablet 8. The tube 9 is fitted in the attached neck 19 of the nozzle T and bears against the device P.

The nozzle T comprises two elements: the nozzle neck 10 which is composed of graphite, and the nozzle body 11 which forms a diverging member and is thrcadedly engaged in the rear tapped end of the body 1. Threadedly engaged on this diverging member 11 is the tubular hub 12 of the fin arrangement Q.

The improved obturating and firing device P of the invention is disposed in said diverging member 11. It comprises, as shown in FIG. 2, a body 14 adapted to rest against the diverging member by a shoulder 15. It is retained in this position by a shearable sealing ring 16 which is inserted in a recess in the diverging member 11 and compressed to a certain extent between the body 14 and a nut 17 threadedly engaged on the rear of said body.

The body 14 comprises, disposed on its longitudinal axis which coincides with the axis XX of the projectile (FIG. 1), a bore communicating with its forward face and comprising a tapped portion 18 and a smooth portion 19 which forms a shoulder 20 perpendicular to the axis XX. At the rear of this shoulder a cavity 21 is limited by a preferably concave part-conical transverse wall 22 or the like. Formed in this wall are two passageways 23 filled with powder 24 and capable of being obturated or opened by a rear rotary obturator 25 maintained against the body 14 by a shoulder formed on the nut 17. This obturator 25 is provided with as many apertures 26 as there are passageways 23 formed in the body 14, namely two in the presently-described embodiment, and these apertures 26 can be brought into alignment with the passageways 23 or can be rotationally shifted away from the passageways 23, as desired, by rotation of the obturator 25. The latter is provided for this purpose with a rear projection or rib 27 which can be driven in rotation through the medium of the tail unit R provided with apertures t (FIG. 1). r

Located in the bore 1819 of the body 14 forward of the cavity 21 is a time fuze or delay means which comprises two removable and independent elements V and W.

The first or rear element V is so adapted that the combustion of its charge ceases only after the projectile has issued from the launching tube. This element comprises a body 28 of plastic material such as, for example, superpolyamide. It has an outer cylindrical shape so that it fits without play in the portion 19 of the bore of the body 14. The rear cavity 21, closed by the element V, is rendered fluid tight by means of a sealing ring 29 clamped against the shoulder 20 in a recess in the body 28. The ring 29 could be advantageously of the selfgrip type.

The first time fuze charge carried by the body 28, comprises a cylindrical axial deflagrable powder column 3t} compressed in an axial passageway 31 extending through the body 28. The powder column 30 is adapted to be ignited by the flames emanating from the powder 24 in the passageway 23 and the cavity 21, ignition of aoosai which powders is insured by the flames emanating from V a the launching charge S contained in the tail R, these flames reaching the powder 24 by way of the apertures 26 in the obturator 25 at a'rate depending on the extent to which the apertures 26 are lined up with thepassageways 23. V

' The ignition of the powder column 30 is rendered more,

, certain, on the one hand, by therpresence of the defiagrable powder either in the cavity 21 or on the wall 22 of this cavity and, on the other hand, by an auxiliary firing relay 32 of deflagrable powder compressed in an axial blind hole 33 formed in the center of the wall 22.

The second, forward element W corresponding to 'the' with three passagewaysz.

(a), Aefirst inclined passageway 39 which communicates with the center ofrthe rear face of the block at a and with the forward face at b (FIG. 4) in the recess 36;

(b) A second inclined passageway 40which is parallel with the passageway 39.and communicates at g with the rear recess 35 and at h with'the center of the forward face of the member 34. r

(c). A third passageway 41 (FIGS; 3, Sand 6) parallel with the axis X-X and communicating respectively at d and e with the recesses-35 and 36. c 1

All the recesses and passages in the body 34 are filled V with compressed black gun powder.

The obturating and firing device P terminates at its forward end in the followingmanner; -In the threaded followed by loose powder 44.- Fluid-tightness is insured by a flange 45 rigid with the relay 42 and cold welded to the body 14 and by a disc 46 also cold welded to said relay which is capped by the tube 9.

separation of this column from the adjoining surface of the bore 31 is avoided and, as a, consequence thereof, no firing short-circuit can occur between the powder 21 which fills the chamber 22 and the rear end at a of the powder 39 by-a direct passage of the flames" emanating from, the powder 21 between the column 30 and the sur;

face of the bore 31, as would occur if there were a dif-' V ference in thermal expansion rates in the course of the temperature variation wherefrom would result a, free longitudinal, passagebetween the column 30rand the surface of the bore 31, through which the ignitedgases would be able to pass undersirably and instantaneously.

The element Vof the time fuze means thus provides complete safety in launching, since irrespective of the magnitude of the pressure of the launching'gas, no shortcircuit can occur which would result in flame; travelling rapidly forwardly. a

-At the endof the combustion of the compressed powder. fuse 30, the flames emanating therefrom ignite at a the; charge of compressed black powder in the three passage-V,

ways

39, 40 and-41 and in the recesses 35' and'36of the element W of the time fuz'e means. The ignition propa-' g, h*(FIGS. -31

gates therefore along'the' path a, b to 6), that is, in the following manner: firstly through the inclined passageway 39 from a to b and then through the forward recess'36 along b, c, d (FIG, 5), thereafter through the passageway 41 from dto' e (FIG. 6), then through the recess 35 along e,--f, g (FIG. 3) and finally,

forwardlythrough'the inclined aperture 40 along g, h (FIG. 4). The flame when it arrives at h causes'ignition of the relay 43 and thenthe flames, emanating from the finally ignited charge '44 spread forwardly along the tube 9 and ignite toward the forward end of the projectile the firing tablet'8 which in turn ignites the self-propelling charge 5. The gases'which emanate therefrom eject the" obturating device P owing to shearing of the'retaining ring 16 and thenceforth these gases propel the projectile in issuing fromthe nozzle T.

Although a specific embodiment of the invention has been described, many modificationsand changes may be made therein withoutydeparting from the scope of the invention as defined in the appended claims. a

The device of theinvention operates in the following manner: 7 v

For firing, either obturator 25 closes off theipassageways 23 and the projectile is launched without self-prov pulsion by the launching charge S contained in the axial a tubular tail Rjor'the obturator 25 'has'its apertures26:

in alignment with the passageways 23 and there is selfpropulsion of the projectile, after aninital launching by V the launching charge, due to the fact that theflames from the launching charge ignite the powder 24. The latter a in turn ignites the powder filling the cavity, 211m lining rthe wall 22 as well as the powder of the auxiliary firing relay 32 formed in the center of the wall 22'ofsaid cavity. In this way, there is obtained an absolutely' certain ignition of the rear end of the powder column 30 compressed in the aperture 31 of the rear element V of the time fuze or delay means. l V

This column 30 bears at its forward end against the element W of the time fuse or delay means and, therefore cannot be urged forwardly by the pressure of the launching gas which fills the cavity 21 after combustion of the powder, in the passageway Band in cavity 21, irrespec- Having now described my invention what'I claim as,

new and desire to secure by Letters Patent is: v Y 7 fe provided f with a self-propelling charge and launched by a launching '1 charge, saidfuze being adapted tolinsure ignition'of said,

self-propelling chargefb y ignited gases emanating from I I said launching charge :i a hollow outer body provided with a rear openings forthe admission of said 'gases'and front '-openings for the ignition 'of,said self-propelling charge .1. :In a time fuze fora self propelledproject v nd, in id body, between said rear and front openings, anignition relay in twoparts'disposed in series onebetive of the magnitude of this pressure; the flames can only progress forwardly as the" powder column 30 is 'conthe body 28 is of plastic material and in particular superpolyamide, its coefficient of expansion for temperatures between '40 and +60 C. is of about the same magnitude as that of the powder of the column '30, so that any bind the other,"the rearwardof said parts comprising a 5 7 piece of plastic material; having a rectilinear axial bore and ajcolumn of compressed defiagrable" powder filling completely said bore, the forward of said parts comprising a member having therethrough a long sinuous passageway, I

and black powder in said passageway, said blaclepowder being directly in jco'ntact, at, the rear end of said'passag'eway, with said columnofdeflagrable powder; a

Inapyrotechnictirne fuzeffirst and second elements V disposed in series, said first element comprising a member a a ofplastic material having an axial bore, and a column" of defiagrable powder in saidjbore, said secondelement comprising a metal body having endfafces and'proyided with annular recesses in said end faces and'bores extend-1 in saidcolurnn. a e

3. In a pyrotechnic time fuze, an outer body provided TI ing through said body and communicating said recesses to form a sinuous passageway'and black powder in said" tained therein; said plasticv materialhaving substantially the same thermal coefficient of ,expansion as the powder with rear and forward openings, and in said body, from the rear toward the front first and second elements arranged in series, the first element comprising a member of plastic material having an axial bore and a column of compressed deflagrable powder in said bore, the second element comprising a metal block having forward and rear faces and being provided with an annular recess in each of said forward and rear faces and with three bores, two of said bores being oblique and each communicating the recess of one of said faces with the center of the other face of the block, the third bore communicating the recesses with each other, and compressed black powder in said recesses and bores, said column of deflagrable powder bearing against the rear end of the black powder which fills the bore which communicates the center of the rear face of the metal block with the annular recess arranged in the forward face of said block.

4. In a pyrotechnic time fuze, an outer body having rear and forward openings, and in said body, from the rear toward the front: means defining a cavity, a powder charge in said cavity and forming a relay, and, adjacent said cavity, first and second elements arranged in series, the first element comprising a member of plastic material having an axial bore and a fuze of compressed defiagrable powder in said bore, said plastic material having substantially the same thermal coefficient of expansion as the powder in said column, the second element comprising a metal block having an annular recess in each of the forward and rear faces thereof and three holes in said block, two of said holes being inclined and each putting the recess of one of said faces in communication with the center of the other face of the block, the third hole communicating the two recesses with each other, and compressed black powder in said recesses and holes, said column bearing, rom the rear toward the front against the powder which fills the bore which communicates the center of the rear face of the metal block with the recess arranged in the forward face of said block.

5. In a pyrotechnic time fuze, an outer body provided with rear and forward openings, and in said body, from the rear toward the front: means defining a cavity, in said cavity a powder charge forming a relay; adjacent said cavity, first and second elements arranged in series, the first element comprising a member of plastic material having an axial bore and a column of compressed deflagrable powder in said bore, said plastic material having substantially the same thermal coefficient of expansion as the powder in said column, the second element comprising a metal block having an annular recess in each of the forward and rear faces thereof and three bores in the thickness of said block, two of said bores being inclined and each communicating the recesses of one face with the center of the other face of the block while the third bore communicates the two recesses with each other, and compressed black powder filling said recesses and three bores, said column bearing, from the rear toward the front against the powder which fills the bore which puts the center of the rear face of the metal block in communication with the recess arranged in the forward face of said block; and from the rear toward the front a firing relay in contact with the center of the forward face of the metal block of said forward element, and a column of loose powder in contact with the forward end of said firing relay.

References ijited in the file of this patent UNITED STATES PATENTS 200,223 Rubin et al Feb. 12, 1878 1,513,411 Miller Oct. 28, 1924 1,949,841 Nash Mar. 6, 1934 2,246,429 Brandt June 17, 1941 2,462,135 Skinner Feb. 22, 1949 2,724,237 Hickman Nov. 22, 1955 2,773,448 Jasse Dec. 11, 1956 2,913,983 Lytle Nov. 24, 1959