US2977882A - Projectile fuze - Google Patents

Description

April 4, 1961 Filed 001;. 31, 1956 J. R. JASSE PROJECTILE FUZE 5 Sheets-Sheet 2 April 4, 1961 J. R. JASSE 2,977,882

' PROJECTILE FUZE Filed Oct. 51, 1956 5 Sheets-Sheet a April 4, 1961 J. R. JASSE PROJECTILE FUZE Filed Oct. 31, 1956 5 Sheets-Sheet 4 J. R. JASSE PROJECTILE FUZE April 4, 1961 5 Sheets-Sheet 5 Filed Oct. 31, 1956 Fig-i 2,977,882 PROJECTILE FUZ'E Joseph Raymond Jasse, Paris, France, assignor to Societe Nouvelle des Etablissements Brandt, Paris, France, a French body corporate 7 The present inventionrelates to an improved percussion fuze for a projectile and in particular a finned projectile, this fuze being absolutely safe to use and of the known'type in which the forward part of the fuze body contains a firingjdevice comprising amember longitudinally movable between an inoperative position, in which it is maintained, whenlaunching the projectile, by an automatically retractable locking device, and an armed position to which it is brought by a resiliently deformable device as soon'as the projectile ceases to accelerate on its trajectory, the percussion occurring upon impact.

Ufliwd S at The object of the invention is to provide a percussion fuze comprisingfa body, and, provided in this body at the rear of the firing device, fire connecting or igniting means movable between a first retracted, inoperative position, in which the 'projectileis inexplosive and safe to handle and which the igniting means is locked by said movable member, and asecond, firing position, and a resiliently yieldable device'i which urges the igniting means from the first to the second position thereof as soon as this means is unlocked when said movable mem-' ber moves from its inoperative position to its armed position. fj

Owing. to the locking of the igniting means in itsv inoperative position by the movable member of the firing deviceinfthe unarmed position of the latter, there is absolutely no danger fof prematurely exploding the projectile before the firing device has been fully armed. Thus the fuze affords, complete safety since there is absolutely no possibility of exploding thejpr'ojectile in the course of handling th'eJatter. Furthermore, there is no danger, 'when launchingthe projectile, of the latter exploding in thevicinity ofthe launching device, 'since itis essential for th'e, projectile totravel along a, certain part of its trajectory in order to arm the firing device. I

l- Further features and advantages of the invention will be apparent from the ensuing description with reference to theaccompanying drawings,,to which the invention is in no way limited. a, In the drawing;

Fig. 1 is an axial sectional view of an embodiment of 1 .the invention, the fuze being shown in its unarmed condition;

Fig. 2 is a similar armed condition; 7

Fig. 3 is an end view of the igniting means;

P Fig. 4 is. a sectional view taken along line 4 -4 of ig.3 I a sectional view of the'fuze in its Fig. 5 is a sectional view taken along line 5-5 of-v 1 v Fig, 6 is a -s ectiona l view taken along line 6-6 of F sh I view of another embodiment of the invention provided with an air dash-pot which delays the arming of the firing device, this'fuze being shown in its unarmed condition; I

Fig.10 is a half-axial sectional view of the fuze in its armed condition, and I Fig. 11 is a partial axial sectional view of another embodimentof the invention, the fuze being in its unarmed condition.

In the embodiment of the invention shown in Figs. 1 to 8, the fuze comprises a body of revolution about the longitudinal axis XX which consists of two parts 70 and 71 interconnected by a thread 72. Provided in this body is a forward chamber 4d containing a firing device A a transverse cylindrical chamber 5d which is separated from the chamber 4:1 by the transverse wall 6 and contains a flame guiding means B and a rear recess 7 containing the relay C. p I I The firing device A comprises at the forward end of the chamber 4d and movable therein, a percussion head 9d to which is fixed a short firing pin 15d, this head 9d being urged forwardlyagainst an inner flange 10d of the body of the fuze by a spring 1 2 which bears at its rear end against a forward flange on a'tubular guide 13d. Slidable and rotatable in the guide 13d is a sleeve or carrier 14d provided at its forward end with an inner flange 73 on which is fixed, by a formed-over portion 74, an axial tube 75 carrying a primer 76. This tube 75 extends rearwardly inthe form {of a thinner tubular portion which has such length that, in extending through the aperture 16 in the wall 6,its rear end extends well into the-chamber 5d when the tube 75 is in the position shown in Fig; 1. The head 9d carrying the firing pin 15d has, around the latter, a recess 9a which has such dimensions that, when'the sleeve 14d moves forwardly, the tube 75 is capable of moving sufiicientlyforward for its rear end to withdraw from the chamber 5d in the armed position of the fuze shown in Fig. 2. e

The sleeve 14d is urged forwardly and in rotation in the direction of arrow f (Fig. 1) by a spring 18d whose rear end 78 is engaged in an aperture in a fixed washer 79 threadedly engaged at 80in the. guide, 13d, whereas the forward end 81 of .this spring is engaged in an aperture in the sleeve 14d.- The assemblage14d, 75, 76 is in the unarmed position of the fuze, held lockedin the 3 position shown in Fig. 1 by balls 19 each of which is en- ,-;Fig. -7 is a sectional view taken along line 7-7 of gaged partly in a recess 20 in the sleeve 14d and partly in an inclined aperture 21 in the guide 13d. The halls are ordinarily held in position by the arming ring 22 which is slidable onthe guide and is urged forwardly to its ball-retaining position by thetspring 23. The ring 22 has an inner recess 25 adaptedfto engage the rear tabs of the ring 26 which is fixed on the guide 13d and rests against a shoulder formed on the latter.

The guide 13d carries a pin 27 which protrudes from the inner face thereof and is engaged in a zig-zag groove 27d formed on the outer face of the sleeve 14a. The various steps of the groove 27d are disposed along a helix represented in the developed view in Fig. 8 by the inclined line x y Z The arming of the firing device A that is, its passage from the position in Fig. l to the armed position shown in Fig. 2 is efiected in two stages.

Upon launching the projectile, the efiect of inertia causes the ring. 22 to move rearwardly and compress the spring 23 and this ring engages under the tabs of the ring 26. The balls 19 are thus released which releases the sleeve 14d. The head 9d only moves rearwardly until its end encounters the forward end of the guide 13d and this rearward movement is insuflicient to allow the firing pin 15d to-encounter the primer 76.

When the projectile ceases to accelerate, the percussion head 9d assumes its initial position under the effect of the pressure exerted by the spring 12, while the sleeve 14d moves forwardly by the combined actions of inertia andthe' axial thrust exerted by the spring 18d which furthermore, rotates the sleeve in the direction of arrow f. This permits the zig-zag groove 27d to slide along the pin 27 at a speed somewhat slowed down by the action of this pin, the sleeve 14d being prevented from moving in the opposite direction. With a delay corresponding to the number of steps in the groove 27d and the moment of inertia of the sleeve and the characaevaeea teristics of the spring 18d, the sleeve reaches its armed position shown in Fig. 2, in which position, upon striking the head 9d, the firing pin d moves rearwardly with the latter and strikes the primer 76. The flame guiding means B consists of a cylindrical block 28d mounted for rotation aboutaxis YY in the chamber 5d. It abuts the end of the latter by a bearing face 82 of reduced diameter and abuts a central boss 83 'of a plug 6d by another bearing face 84. As the bearing faces 82 and 84 are of reduced diameter, the friction opposing rotation of the block 28d is reduced, which'enables the latter to be rotated by a torsion spring 86 of which one end 87 is fixed to the block whereas the other end 88 is engaged in the body of the fuze.

The block 28d has a diametral aperture 35 in which, in the unarmed position of the fuze, the rear portion of the tube 75 is engaged, so that this block is held stationary in opposition to the action of the spring 86 which tends to rotate it in the direction of arrow f (Figs. 1 and 3). The block 28dmay assume; one or the other of two, angular positions determined by the abutment of av stud 89 (Fig. 3), carried by the block, with either a first abutment 90 rigid with the end of the chamber 5d, correspondingto instantaneous firing, or second abutment 91 by means of which a delayed or timed firing is obtained. The abutment 91 is retractable and formed ZZ. of the aperture 35. Lines intersecting these centers and .the axis-XX of-the block 28d are inclined at angles a and .v relative to the axis ZZ (Fig. 5)- which are equal to those between the side of the stud 89 and the sides of the abutments 90 and-91'(Fig. 3), the latter being in its operative position 91a. Thus the aperture 97 substitutes itself for the aperture 35 on the axis XX (Fig. 1) when the block 28 d is no longer lockedby the tube 75 (at the end of the. arming of the latter) and its stud 89 abuts against the abutment 90, the abutment 91 being in Each of these apertures 106 contains an explosive charge 107 which forms a relay and permits igniting the relay C. In the unarmed position of the fuze, the block 28d is locked by the tube which is engaged in the aperture 35. When an instantaneous firingis required, the journal 92 is brought to theposition shown in Fig. 3, in which the abutment 91 is retracted from the path of movement of the stud 89.

When the fuze is armed, which causes withdrawal of the tube 75 from the aperture 35, the block, 2811 is released and rotates through an angle u in the direction. of arrow 1* until the stud 89 abuts the abutment 90. In this position the tube 75'is indirect communication with the detonator by way ofjthe passageway, 95.

When the head9d of the projectilestrikes an, object such as the target the firing pin" 15d -is thrust rearwardly, or the guide 13d and the primer 76 move forwardly under the effect of inertia, and the primer 76 is struck by 'the pin 15d which results in ignition of the detonator 100 which in turn ignites the relay C. I i

If it is required that the fuze be timed to operate with a delayed action, the journal 92 is rotated in the direction of arrow f (Fig. 3). After .tli' block 28d is unlocked, it rotates through an angle v until the stud 98 abuts the abutment 91 which is in its operative position 91:11. In this position, the tube 75' is'in communication with the delaying means 103 by way of the passageways 96 and 101. j

, Preferably, the passage; 101 communicates at 101a (Fig. 6)' with the chamber 5d, was to allow expansion of the gases due to combustion of the primer 76; in this way breakage of the delaying means 103 is avoided.

i In the embodiment shown in Figs.'9 and 10, the body of the fuze consists of two parts 70 and 71 interconnected. by a thread .72. The chamber 4e contains a firing device A and the transverse chamber 52 con- 'tains a flame guiding means 8*. The rear recess 7 contains the relay C. I

. The firing device A comprises movablefin the entrance of the chamber 4e, a percussion head 9e to which'is fixed an axial firing pin 15e. This head and firing pin are urged forwardly against an inner flange'lOe of the body. part 70 of the fuze body by a 'spring12, which bears at its rear end against an outer flange 107 disposed intermediate the ends of a tubular guide 13e. A gasket 106 is provided against the inner face of the flange 10e.

The guide 13e has an axial cylindrical bore 108 in which is slidable a unit comprising a sleeve 14: connected at its forward end, by means of a formed-overportion 109,'to the forward end of a tube 111 which carries at its forward end a primer 76. The tube 111 has atfits rear end an extension 111a of smaller diameter whose length is such that it extends, through an aperture 16 in the retracted position shown in Fig. 3 so as to allow the stud 89 free passage; and the aperture 98 substitutes itself for the aperture 35 when the stud 89 abuts the abutment 91, previously brought, by rotation of the journal 92, into its position 91a in the path of the stud 89.

The passageway 95 is in direct communication with a 1 housing 99 containing a detonator 100 and the passageway96 is connected by. a transverse passageway 101 with another, passageway 102 which contains -a timing or fire delaying means 103 and communicates, by way of an aperture 104 and the housing 99, with the forward end, it

the wall 6, well into the chamber Se in the'unarmed position of the fuze (Fig. 9). i I Threadably engaged on the forward end of the guide 132 at 112, is an annular member 113 whose central aperture 114 forms with the firing pin'15e an annular passage 115 through which a rear chamber 116, formed in the bore 108 between the tube 111 and the member 113, communicates with a forward chamber 117 formed in the part 70 of the-fuze body between the inner face of the latter, the member 113, the firing pin 152 and the head9e.

-When the fuze is unarmed, the annular passage 115 connecting the chamber 116 and 117 is closed bythe pin 152 which carries a flange 118 forming a valve member adapted to bear against a valve seating 119 formed by a boss on the member 113 at the rear end of the passage 114. The fiange or valve 118 is urged against the seating 119 by the pressure exerted'by the spring 12 which urges the head 9e forwardly. The length of the chamber 116 is such that, when the primer-carrying tube 111 and the mobile unit connected thereto move forwardly until'the rear face 120 (Fig. 9) of the member ae ate-see 113' is encountered, the portion lll 'a is withdrawn into the aperture 16 and the "fuze is armed.

' spring 18e but is, before arming'of the fuze, held in the position shown in Fig. by the Iocking balls 19 which "only reached after acertain' period of time, which de pends on the dimensions of the slight clearance between the sleeve 14c and the bore 108. The delayed arming are disposed in apertures 20 in the guide Be and pro trude into an outer recess 121 in the sleeve 14a. The balls19 are held in their locking position by the arming ring 22 which is slidableon the guide 13e and'is urged forwardly to its operative ball-retaining position by a spring 23; The ring 22 is provided with an internal recess 25 adapted to engage reartabs of a ring 26 which is fitted on the guide 13 e and bears against a shoulder formed on the latter; v v I A dash-pot adapted to retard the arming of the fuze that is, the forward 'movementof the movable unit l4 e,

.chamberll'fi to the chamber 122 and thereby the forward displacement 'of the primer-carrying tube 111. The flame guiding means B in the chamber 52 is urged by the pressure of a spring 30 from the position shown in Fig. 9in which it is held by the extension 111a of the tube engaged in the aperture 35, to the position shown in Fig. 10, in which, firstly, a passageway 125 formed in the block is in alignment with thetube 111, or more exactly the axial passageway of the latter and, secondly, a detonator 124 disposed in the passageway 125 is in alignment with an aperture 49 formed in the wall 8, which permits igniting the relay C through the medium .of an explosive relay disposed in the aperture 49.

The connection between the axial passageway in the tube 111 and the detonator 124 has been shown to be by way of this passageway 125, but it will be clear that this connection may be by way of several passageways in'parallel, one of which may include a powder charge forming delay or time means, the selection between these passageways being obtained by anyone of the above-described methods.

This fuze operates in the following manner. When the fuze is unarmed, the various members are in their positions shown in Fig. 9 and the primer-carrying tube 111 is maintained in its rear position by the lockin balls 19; the spring 18 is compressed.

When the projectile is launched, the head 9e and the ring 22 more rearwardly under the elfect of inertia and the balls 19 and tube 111 are released.

When the projectile ceases to accelerate, the tube 111 moves forwardly relative to the latter due to the action of the spring 18e,but is retarded in this movement by the effect of the dash-pot. Although at the moment of launching the projectile the head 9e temporarily moves rearwardly under the elfect of inertia and causes a part of the air contained in the chamber 117 to pass into the chamber 116 through the passage 115 (since the valve 118 is temporarily lifted off the seating 119), as soon as the projectile ceases to accelerate this valve returns to its seating and closes off the chamber 117 from the chamber 116, so that the latter contains air under a certain pressure.

Owing to the forward displacement of the tube 111, the volume of chamber 116 decreases and as the air contained therein cannot escape through the passage 115, since the valve 118 is closed against the seating 119, it passes into the rear chamber 122 between the sleeve 14e and the bore 108 of the guide 13c and thereby clamps or retards the movement of the primer-carrying tube 111.

The armed position of the fuze shown in Fig. 10 is thereby obtained insures that the projectile does not explode in the vicinity of the launching apparatus. The locking action of the balls' 19 rendered the fuze absolutely safe-during the handling thereof before launching.

At the end of the arming of the fuze, the extension 111a of the primer-carrying tube 111 is withdrawn into the aperture 16 in the wall 6 and the block of the igniting means B is released. The pressure exerted by the spring 13 urges this block to the position shown in Fig. 10 so that the passageway 125 comes into alignment with the axial passageway in the'tube 111. In the armed position of the fuze the sleeve 14e abuts therear face of the member 113. r

The fuze may fire the projectileawhen the latter strikes an object such 'as the target, either by the firing pin 15e moving rearwardly or by the primer-carrying tube 111 and the guide 13e moving forwardly under the effect of inertia in opposition to the action of'the spring 12.

Fig. 11 shows a modification of the fuze in its unarmed position, the firing device A of this fuze comprising an air dash-pot. Thelatter is similar to the previously described dash-pot except that one chamber 126 of the dash potis formed. in the part 70 of the fuze body and the other chamber-1 27 isformedbetween the fixed guide 13f and a sleeve 12% which is slidable, in the cylindrical bore 129 in the part 70f. v

The chamber 126 is closed at its forward end by the head 9 which carries the firingpin 15f. .The head and pin are fixed to the part70f by; a pin 1 30. [The primer.-

carrying tube 75f is connected to a sleeve 14 whichv is locked relative to the guide 13f by balls 19 which are in turn held in their locking position by the arming ring 22. The latter is urged to its ball-retaining position by the spring 23.

The sleeve 128 is fixed at its forward end 131 to the tube 751 and a very slight clearance is provided at 132 between the sleeve 128 and the bore 129. Grooves 133, similar to the grooves 123 of the least-described embodiment, serve to retard the flow of air through this clearance from the chamber 126 to the chamber 127.

When the arming ring 22 moves rearwardly and re leases the balls 19, the movable unit 75 14 128 moves forwardly and the speed of this movement depends on the rate of flow of the air from the chamber 126 to the chamber 127 through the clearance 132.

To prevent the sliding of the tube 75f from hindering that of the sleeve 128, the forward flange 134 of the tube 75f is mounted with sutficient clearance in its housing in the sleeve 14 p In the armed position of the fuze, the point of the firing pin 15f rests against a thin metal sheet 135 placed in front of the primer 76. This sheet assumes the position shown in dot dash line at 135a in Fig. 11.

The projectile may be fired either by the firing pin 15 moving rearwardly after shearing of the pin and perforation of the sheet or by inertia bya forward displacement of the primer-carrying tube 75f with the sleeve 128 after perforation of the sheet 135.

Although specific embodiments of the invention have been described, many modifications and changes may be 'made therein without departing from the scope of the ac'mss'a for being ignited by flame passingthrough said chamber, said means including a rearwardly extending tube adapted for guiding flame from said priming charge toward said chamber; said tube, with said means supporting said priming charge in unarmed position, extending rearwardly into said chamber and, with the priming charge in armed position, being withdrawn from said chamber; flame guiding means displaceable in said chamber but being normally fixed in the latter by said tube, displacement means in the chamber to displace theigniting meanswith said tube withdrawn, said priming charge being independent of and spaced from said flame guiding means said flame guiding means being provided with instantaneous and delay passages for coupling said tube and guiding the flame from the priming charge to said relay charge in accordance with the displacement of said flame. guiding means, and selection means for selectively controlling .the displacement of said flame guiding means by said displacement means for selecting instantaneous,and'delayed firing.

2. A fuze as claimed in claim '1 wherein said chamber and flame guiding means are of cylindrical form, the flame guiding means being rotatable in said chamber, and have a diametral bore for engaging said tube- 3. A fuze as claimed in claim 1 comprising an inflammable plug in the delay passage.

4. A fuze as claimed in claim 1, wherein said flame guiding means is rotatable in said chamber and includes an extension, said selection means comprising an adjustable interception device adapted to intercept said extension to terminate rotation of saidflame guiding means.

5. A fuze as claimed in claim 1 wherein said displacement means is a spring engaging said flame guiding means.

'6. A fuze "as claimed in claiml comprising locking meansholding said, support means against displacement until-said projectile is fired. 1 3, Q, 31;

7.; A fuze as claimed in claim 6 comprising retardation 5 means to retard movement of said support means.

.8. A fuze as claimed in claim 7 wherein-the retardation means is a pin and zig-zag groove arrangemen't, coupling said; body and'support means. i i

9. A fuze as claimed in claim 7 wherein the retardation 10 means is a dashpot coupling said body and support means References Cited in the file of this patent UNITED STATES PATENTS 1,079,383 Wieser No\?. 25, 1913 1,169,747 Moren. .Jan. 25, 1916 1,600,303 Adelman Sept. 21, 1926 1,648,603 Barker Nov. 8, 1927 1,687,341 Lukens Oct. 9, 1928 1,916,244 Woodberry July 4, 1933 1,944,780 Brandt Jan. 23, 1934 "2,030,085 Woodberry .j Feb. 1 1, 1936 2,129,692 Hottinger Sept. 13, 1938 2,360,043 Del Prato Oct. 10, 1944 25 "2,435,415 Thompson. Feb. 3, 1948 2,651,993 Ber zof Sept. 15, 1953 2,664,822 Hale Jan..5, 1954 2,709,962 I Funk Iuue 7, 1955 2,712,284 Thomas July 5, 1955 30 2 2,872,868 Donahue Feb. 10, 1959 FOREIGN PATENTS

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