US2412636A - Grenade fuse - Google Patents

Description

Dec. 17, 1946.

F. SHORT GRENADE FUSE Filed Feb. 18, 1943 Patented Dec. 17, 1946 NHTED STAT GRENADE FUSE v Short, Canton Center, Conn. Application February 18, 1943, Serial No. 476,300

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757),

8 Claims.

holding function to opeting lever 9, which lever, asis usual, is integral with the fuse cap such as that designated by' Hi. The lever's posi- The object of the invention is to provide a dependable fuse that will explode the main grenade charge after a predetermined calculated time or delay period, but upon impact will cause instantaneous explosionof the main'charge if the delay period has not expired or if the delay elements fail to function.

In the drawing: Fig. 1 is a central vertical section of the fuse, applied to a grenade. r

Fig. 2 is a cross section taken on the line 2-2 of Figure 1, showing the preferred form of the safety plug in the upper part of the fuse.

Fig. 3 is a similar view taken further down and on the line 3-3 of Figure 1. v

Figure 4 is a view, of the fuse taken still lower down and on the line 4-4 of Figure 1, showing a preferred arrangement of thequick match element with relationto the detonator. v

Fig. 5 is an enlarged sectional view of the fuse in the neighborhood of the detonator.

Fig. 6 is a vertical sectional view showing the relation between the packed powder delay trains and the means for locking and keeping them locked in separated position under. some conditions.

Fig. 7 is a similar view of thesame parts, in slightly modified form.

In the fuse about to be described, some; parts are old in the art, as for instance the Bouchon head is adhered to, especially in so far as its upper structure is concerned, which involves the throw-off cap,'the operating lever and the striker;

tion normally, relative to the grenade body, is that shown, wherein it .will be grasped to ether with the body in the act of throwing the grenade, and when the whole device is free of the hand, the cap and lever are kicked off by the striker and the released striker then strikes the primer to inaugurate the functions of the powder trains to set off the main bursting charge.- All of the parts and their functions, thus far described, are

old and well known in the art.

Communicating with the chamber 3 is a cylindrical chamber ll of a little less diameter than the conventional chamber, thus presenting a shoulder l2, forming a seat for a'seal I3 protecting the primer M in chamber ll. Below the primer chamber is a bore l5 separated from the chamber I I, by an. apertured web l6, the aperture establishin communication between the chamber and bore for the ignition of a compressed powder delay pellet il formed with a central opening to receive a needle 23 and adapted to burn away therefrom, for a reasonto be explained. The pellet n is' contained in shell l8 which is open at its lower endand firmly secured in the bore I5. supported'in the upper which i of the usual or common construction such time as the grenade is to be thrown, when 1 the pin will be withdrawn, transferring the striker end of the shell is a plug l9, formed with a small concave central depression 20 in line with and immediately below the central aperture in the web IS. The plug is preferably perforated at three points in its perimeter with openings 20' and it is further formed, preferably, with a central comparatively sharp point 2!, to be received in a slight depression 22, in the upper end of the needle 23, whose lower end is pointed and received in a correspondingly shaped recess 24, in the upper enlarged head 24' of a tube 25 the bore of which merges into ducts 26, at the upper end of the bore. The'bore, as well as the ducts, contain a'compressed powder pellet 26'. Near the lower end of the tube a slight reduction in diameter forms a shoulder which engages the edges of a circular opening in a ring 28, firmly secured in the lower portion of a tubular extension 29 of the head 2. The ring may be held inthe extension by crimping as shown, and its underside is a little above the end of the extension, which extension is slightly inturned to form an annular flange 30, forming aseat for the flange 3| of the detonator 32, which is held flrmly in place by reason of the engagement ofits flange with the underside of the ring 28. The ring has a cone shape concavity in its underside into which aciacsc 3 the slightly reduced lower end of the tube ex-. tends, the end of the tube with the wall of the ring forming an annular recess which is packed with quick match material 33, ignited by the roughened portion 34 of the tube upon the moveder such circumstances are are contemplated for the organization.

As shown in Figure 1, the grenade body is threaded on the fuse head in the usual manner,

with the usual washer, ordinarily of steel, having a lateral extension engaging the operating lever and serving to seal the Bouchon.

Referring to Figure 7, there isshown a slight modification of the form of the plug l9 and its associated needle, with the needle pointed at its upper end and a shallow cavity in the bottom of the plug.

In operation the safety pin 8 is withdrawn, and the grenade with the lever pressed against its body is thrown. As soon as the grenade leaves the hand, or other instrumentality by which it may be thrown, the striker 6 will kick the lever and cover off, permitting the striker to strike the primer H, which will ignite the compressed pellet H, which in proper time, will ignite the pellet 26' in the tube 25, and after a predetermined time, figured in seconds, the pellet 26' will ignite the violent charge in the detonator 32. This is the normal and expected action of the fuse. However, should the grenade land before the powder trains have gone through their predetermined and completed routine, the impact of landing will cause an instantaneous explosion of the main charge for the reason that by the time impact occurs the powder pellet H, in which the needle 23 is embedded will have been consumed,

but not necessarily the other powder train 26' in tube 25. As a result, the needle 23 will then be left unsupported except at its ends by the plug l9 and the head 24. The shock of impact will cause the needle 23 to assume an unstable tilted position thus disturbing the alignment between the needle 23 and its supporting elements l9 and 24'. The head 24', tending to be moved upwardly under the influence of the spiral spring 36', will further disturb this alignment resulting in a dislodgement of the needle 23 to permit the pretensioned spring 36' to raise the tube, and in so doing, the roughened end 34 thereof will instantly ignite the detonator charge.

Thus, the shock of impact, irrespective of how the grenade lands, will be sufiicient to cause dislodgement of the needle 23. Should the grenade by chance first land or hit end-first, it would not remain on end but would tumble or turn over due to its momentum which would cause dislodgement of the needle 23 permitting the tube 25 to function in the manner already explained.

I claim:

1. In a fuse, in combination, a body containing an explosive charge, a detonator in said charge, a friction primer for igniting said detonator, a member having a friction 1-portion for igniting said primer, spring means for urging said member relative to said friction primer, dislodgable means for normally locking said member against movement relative to the friction primer, a fuse 4 train for igniting said detonator and having a portion thereof for retaining said dislodgable means in locking position to render said friction device inoperative, said locking mean adapted to be dislodged only after that retaining portion of the fuse train in contact with said dislodgable means has been first consumed and then upon impact of said body to permit the spring urged member to ignite the friction primer, to cause instantaneous explosion of the charge uDOn impact of said body.

2. A grenade fuse comprising a hollow body containing an explosive charge, a closure for said body having an extension extending into said charge, a percussion primer in said closure, a delay powder train in said closure ignitable by the percussion primer, a detonator carried by the extension within the explosive charge, a channeled member in the extension having one end in contact with the detonator and the other spaced from said delay powder train and having a friction device, a friction primer in the extension in proximity to the friction device, dislodgable means supported by said powder train and in engagement with the channeled member to normally prevent movement thereof, means causing movement of the channeled member upon dislodgment of said dislodgable means to ignite the friction charge upon impact of said hollow body, and a second delay powder train in the channeled member communicating with the detonator and ignitable by the first mentioned powder train and capable of igniting the detonator independently of the operation of the friction device.

3. In a combination time and impact fuse, a hollow body containing an explosive charge, a

' delay powder train in said body, means for igniting the train, a second delay powder train ignitable by the first powder train, a detonator within the charge and ignitable by the second powder train, a separate means capable of igniting the detonator independently of the second powder train, and means retained by said first delay powder train and operable upon the same being first consumed and then upon impact of said body to release said separate means to ignite said detonator to cause instantaneous explosion of the charge.

4. In a combination time and impact fuse, a hollow body containing an explosive charge, a percussion primer and a delay powder train in said body and ignitable by the percussion primer, a movable member spaced from said train and containing a second powder train ignitable by the first train, a detonator within the charge and ignitable by the second train, a detonator igniting primer capable of igniting the detonator independently of the second train upon the movement of said movable member, means normally locking said member against movement, said means being dislodgable upon impact, and means causing movement of said member upon dislodgment of said locking means to ignite the detonator primer to cause instantaneous explosion of the charge.

5. In a combination time and impact fuse, a

,hollow body containing an explosive charge, percussion primer and a delay powder train in said body and ignitable by said primer, an extension carried by and within said body and having a detonator in said charge, a movable tubular member in said extension spaced from said train and containing a second powder train ignitable by the first train, said detonator being ignitable by the second train, a detonator igniting primer capable of igniting the detonator independently of the second train, means interposed between the first powder train and said member normally locking said member against movement, said interposed means being dislodgable upon impact of the body, and means causing movement of said member upon dislodgment of said locking means to ignite the detonator primer to cause instantaneous explosion of the charge.

6. In a combination time and impact fuse, a hollow body containing an explosive charge, a closure for said body having a hollow extension extending into said charge and having a detonator at its inner end, a percussion primer in the closure, a shell in the closure and containing a compacted delay powder pellet ignitable by said primer, an apertured plu in said shell, a movable tubular member in said extension and containing a delay powder train capable of igniting tile detonator, a. pretensioned spring normally urging said tubular member toward the shell, a second primer actuated by said tubular member upon the movement of said member to ignite the detonator upon impact of said body independently of the powder train in said member, a pin embedded in the powder pellet and in engagement with said plug and with the tubular member, to ,hold said member normally separated from the shell, said pin being adapted to be dislodged upon destruction of the powder pellet and upon impact of said body, and means causing movement of said tubular member upon dislodgment of said pin to ignite the second, primer and cause instantaneous explosion of explosive charge. 7

7. In a time and impact fuse, in combination, a hollow body having an explosive charge therein, a percussion primer, a compacted powder pellet ignitable by said percussion primer, a. friction primer in said body, a detonator adjacent said 6 friction member, a movable friction member having a friction portion in' said primer and provided with a powder train extending between said pellet and detonator and capable of igniting said detonator, a dislodgable member embedded in and normally at least partially supported by the pellet and adapted to be dislodged upon impact of the body after the destruction of said pellet, said dislodgable member having a portionengaging the friction member normally holding said member against movement, and means for moving said friction member when released by said dislodgable member to ignite the friction primer and thereby the detonator. 8. In a grenade, a body having an explosiv charge, a detonator for said charge, means for instantaneously igniting said detonator, means including an element in alignment with and holding said igniting means in an inoperative position, a percussion primer in said body, a timedelay fuse train adapted to be ignited by psaid primer and in turn ignite said detonator, said time-delay fuse having a portion thereof retaining said element in position to hold said igniting means in the inoperative position, said holding means becoming inoperative to hold said igniting means in the inoperative position only after the said portion of the time-delay fuse retaining said element has been first consumed od has elapsed after ignition of the delay fuse.

and-then upon impact of the grenade body, whereby after a preliminary predetermined peritrain has been initiated by the percussion primer and in which period said retaining portion of said time-delay'fuse willhave been consumed,

said detonator-will'be ignited either by the timedelay fuse train at the termination of its delay period or by said first-mentionedigniting means upon impact of the body: whichever occurs first.

, v FRANKSHOR'I.

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