US2562928A - Grenade - Google Patents

Description

B. LEWIS GRENADE Aug. 7, 1951 Filed OCL. 10, 1945 lmany years has a number of disadvantages.

Patented Aug. 7, 1951 GRENADE Bernard Lewis, Pittsburgh, Pa. Application October 10,y 1945, Serial No. 621,646

2 Claims.

(c1. 1oz-85.6)

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to fuzes which may be used in grenades of the type commonly called hand grenades although they may be projected by other means than by hand, such as from a rifle or other small arm.

An object of the invention is to provide an improved grenade which is safer to handle and less likely to become operative prior to projection.

Another object of the invention is to provide a grenade which is silent before exploding and'does not give off a trail of gases or smoke or sparks upon being actuated, and hence does not allow the location of the thrower to be readily detected.

A further object of the invention is to pro- (Vide an improved grenade fuze, and to avoid any transverse stress on the delay train asa result of crimping during assembly. 2

Another object of the invention is to provide a fuze construction permitting easy Vremoval of the safety pin when desired. Y

Other objects and advantages of the invention will become apparent from the following description as illustrated in the accompanying drawings and in which,

Figure l is a sectional elevation lof `a grenade fuze as seen from the left of Figure l, l.

Figure 4 is a view of the upper 'portion o the fuze as seen from the, right of Figure l, and Figure 5 is a sectional elevation of `a modified form of grenade fuze according to the invention.

In the use of grenades for projection by handy rifle of otherwise, experience has shown that the construction heretofore normally employed for In same instances, severe injury to using personnel has resulted from premature actuation of the -`lower extension I D extending insidel the" cham- CIL ber 4 as shown. The fuze head I2 has a .central bore I4 threaded at I 6 to receive the threaded end portion I8 of lower extension II). The bore I4 is enlarged at 20 to receive an annular gasket or washer 22 made of lead or other suitable soft metaLa collar 24 on lower extension Ill also being receivable in enlarged bore 20 and serving to tightly compress the washer 22 in the -bore to make a tight seal.

The bore I4 4is reduced at 26 to receive a percussion primer 28, the bore being constricted at 30 to form a seat for the primer and also a ash passageway leading from the primer in bore 26 to enlarged bore I4. The upper' lips 32 of bore 26 are crimped to seal in the primer, a suitable sealing compound being also applied over the -joint to make it gas proof and tight.

The lower extension I0 is thus easily removable from the fuze head I2 by merely unsorewing it. The extension I0 has external threads at II for engaging the threads of the opening 6 in the grenade body. The extension Il has a central bore 34 which is enlarged at its upper end 36 and reduced at its lower end 38. A delay charge element 40 of lsuitable non-gaseous composition may be located in the bore 34 and a relay charge located at 42, the reduced bore 38 serving as a flash passageway.

The extension IIJ is reduced in external diameter at 44 and is further reduced at 46, the latter portion being provided with several external annular grooves 48. A hollow cylindrical detonator casel having thin walls and formed of soft metal such as aluminum or other suitable material, has its lower' end 52 closed and is open at its upper end 54. The detonator case 50 has -an inside diameter suiiiciently large to allow it to t snugly over the reduced end 46 of lower extension ID. The detonator case 50 may contain a suitable detonating charge 56 including for example lead azide at 58 and pentaerythrite tetranitrate at 60. The case `5l] may then be crimped into the annular grooves 48, and a suitable sealing composition may be applied to the joint to make a tight seal. If an igniting fuze is desired rather than a detonatingfuze, the case 56 may contain black powder instead of a detonating charge.

The fuze head I2 has a recess 62 which is open at the top and right hand side as seen in Figure 1, and which has two opposite side walls 64 and 66. A pivot pin 68 bridging therecess 62 extends through and' is supported in aligned holes in walls 64 :and 66. A'striker 'I0 is pivotally supported on pin 68 in anysuitablemanner, such as, forex- .the grasp of the operator.

ample, by two lugs 'I2 on the striker bent over and pierced to provide aligned holes through which the pin 68 passes transversely to permit the striker to pivot about pin 68. A spring 14, coiled around the pin 68, has one end 16 bearing against the Wall 'I8 of recess 62 and the other end 80 bearing against the striker so `as to press the striker in a counterclockwise direction about pivot pin 83. The striker has riveted to it a disk-like striker point support 82 having a conical striker point or ring pin 84 protruding from one face thereof as shown. The apex of the conical striker point is preferably made blunt as shown, with .an included angle of about 90 degrees, thus avoiding use of a sharp point and preventing the Vpoint from piercing the primer and a consequent escape of gas from inside the fuze. The exact striker lpoint dimensions Iwill depend considerably upon the strength of spring 'I4 and the, design of the primer, but in any casevpiercing of the primer is to be avoided.

. As best seen in Figures 2 and 3 the fuze head haswan extension 86 which carries a transverse pivot pin 88 supported at its central portion and, extending laterally to each side are the end portions 90 of the pin 88. The pin, extension 86 and fuze head I2 are Ypreferably cast integral, Vas shown,'for ease of manufacture. Y

A safety lever 92 has'a bifurcated end 94 straddling the extension 86 and includes two downwardly arcuate extensions 96 curved to pivotally engage beneath a portion of the curved surface of extensions 80 of. pivot pin 88. The safety lever 92 has a contour corresponding to the upper surface contour of the fuze head as shown and serves to cover the open top and side of recess 62thereby engaging thepoint 84 ofthe striker and serving to keep the striker retracted until the safety lever is released. rlhe safety lever has a downward extension. 98 which is held close to the@A grenade body by the grasp of the operator. A safety pin 100 having a pull ring .|02 at one end extends through aligned transverse holes at |04 extending through the Walls 64 and 66fofthe fuze head'and also through overhanging portions |08.,

and I08 on each side -of safety lever 92. The safety pin I00 is in the form of a cotter pin, the split ends IIO of which are spread apart by an included angle suilicient to permit the pin to be readily' pulled out whenv desired, but not to be readily accidentally dislodged. It has been found that making the hole I I2 of .a slightly greaterdiameter than the rest of the holes |04, 64,166, permits easier withdrawal of the safety pin 100 when desired since bending the ends I I0 apart does not then result in indenting the surfaces of the ends I I0 which are in immediate contact with the edge of hole II2. Such nicks if present would hinder easy withdrawal of pin |00 when desired.

It is thus to be noted that by means of the construction shown, Withdrawal of the safety pin |00 will not permit the striker to be prematurely released so long as the operator holds safety lever end 98 in place, since the bifurcated end 94 of the safety lever so engages the pivot pin 88 as to pre-l vent disengaging motion of the bifurcated end 94 from the pin 98 in any direction except rotation of the lever 92 in a counterclockwise direction about pin 88,. and such rotation is prevented by Hence the striker 'I0 is positively held retracted luntil the safety lever 92 is actually released by the operator, whereupon the safety lever 92, acting underpressure from the spring pressed striker, isl rotated counterclockwise to a position asindicated by the. dotted lines in Figure l, releasing the striker which thereupon strikes the primer, and actuates the fune. With prior constructions, it was possible, once the safety pin was pulled, for the end of the safety lever corresponding to 94 in the new construction, to accidentally become disengaged from the corresponding lip of the fuze head formerly used, thereby'preventing effective holding of the safety lever and thus releasing the striker prior to the desired time. The present construction has eliminated this danger.

In the use of hand grenades prior to the present invention, gases escaped from the grenade fuze after it wasl projected, the resulting trail of smoke beingvisibleand giving the enemy a good idea of the location of the soldier throwing the grenade. Also,v the prior fuzes with the vented primer gave olf va quite visible flash of ilame and considerable noise as soon as the striker struck the priinenthe thrower being thus readily locatable particularly at night. In the new construction with the sealed-in primer ythis flash and noise are eliminated. In addition, once the grenade had fallen to earth, the tell-tale smoke and noise of escaping gases allowed the enemy to easily locate the grenade even in brush, and to pick it up and quickly toss it back at the original thrower. This Iwas clue tothe factthat these prior types of grenades usually employed a black pcwderdelay train element which gave off a considerable amount of gases, and the old type fuzes could not be made with the primer and delay fuze sealed in because the internal pressure would increase rapidly and cause the black powder delay train to burn through with practically no delay effect at all, thus causing a premature explosionl of the grenade..

But the present construction employs a gasless powder delay fuze which gives off substantially no gas during its burning and whose burning rate is not very much affected by pressure. Hence it is possible to seal in the delay fuze element since no such dangerousrise in'pressure will occurv inside the fuze. The only gases will arise vfrornfthe actuation of the primer 28, and this gas should be provided with an ample expansion space located between the primer 28 and the upper surfaceof the delay charge 40 as seen in Figure 1. The enlarged 'bore portion 36 toge'therwith the unfilled upper portion lof bore I4 just above bore portion 36 should have a .volume of at least about 0.025 cubic inch which space should besufficient to allovvfthe gases from the primer to expand without undue rise in pressure, wherel the primerV 28 incorporates a charge consisting Yof Western Cartridge Company No. 793 primer mixture or other` mixture with similar semi-gasless properties. This will permit the gases to be sealed withinthe'fuze by making a tightseal at all points where gas might escape as already explained.

As an example of a successfully Vused gasless A powder, I have employed a delay charge 40 Weighing 25 grains packed in the bore 34 in three tosix increments each compressed under a pressure of about 12,000 pounds per square inch, and a relay charge 42 for giving off an intense fiash of name to actuate the detonating charge and weighing about one grain and compressed in place in one increment under the same or even slightly higher pressure. The delay charge 40 may have a composition by weight yof lapproximatelyv 5% zirconium, 31% nickel, 42% barium chromate, and 22% V*potassium perchlorate.l The relay or detonator igniting charge 42 may have a c0mpo.

sitlon by weight of approximately 15.1% of nickel, 51% potassium perchlorate, 29.1% titanium, yand 4.8% infusorial earth. The actual length of time the delay fuze 40 is to burn will of course depend upon the requirements of the user, and may be varied by changing the length of the delay fuze 40 or by changing its composition. The delay may of course be eliminated by merely omitting the delay charge 40.

In employing the delay charge or the relay charge of the compositions specified in the illustrative example given above, it is to begnoted that the ingredient described as nickel should have the physical and chemical characteristics equivalent to nickel prepared as described, for example in United States Patent No. 1,893,879, for Metallic Catalyst, issued yon January 10, 1933, to Joseph C. W. Frazer and Owen G. Bennett. All of Athe ingredients of the delay and relay charges should of course be in powder form of adequate granulation as is well understood in the art, to faciltate mixing and proper burning.

In Figure is shown a modied form of fuze which may be employed if desired, for example, where only an igniting type of fuze is required. It will be noted that as illustrated, the construction is the same as that already described for Figure 1, except that the lower extension IU of the fuze as shown .in Figure 1 has the reduced portion 4d cut off, thus shortening the available length of bore 35 in lower extension Il of the construction of Figure 5. A shorter length 4l of the same delay charge as 40 of Figure 1, is inserted in bore 3'5 as shown in Figure 5, and a relay charge 43 placed in the same bore beneath charge 4l, the relay charge 53 being similar to charge @2 in Figure 1. Bore 35 is enlarged at its lower end 31 to allow an unperforated sealing disk 39 to be placed as shown, together with an annular washer 4l', the mouth of the opening of bore 3l being then crimped over as at 45. The sealing disk 39 may be made of a pressure sensitive tape about .002 inch thick and consisting of thin metal foil such as aluminum or zinc foil with rubberized adhesive on one face. One type of such tape is known as Metacel Tape. preferably made o metal such as brass. The joint is sealed with a suitable Waterproong sealing compound to make it gas tight and Waterproof such as NRC compound which has a nitrocellulose base. Thus, as already explained for the fuze shown in Figure 1, the fuze shown in Figure 5 is also sealed against escape of any gases or flame from the primer 28, thus eliminating dangers which might result from visible ila-me, smoke or noise of escaping gases. Y

Although the invention has been described in Vscic terms, it is to be understood that numerous possible variations 'and changes might be made in the sizes, shapes, materials and arrangement Without departing from the spirit and scope 6 of the invention as hereinafter claimed,

The washer 4l is I claim:

1. Ina grenade fuze in which the safety lever is secured to the iuze head by a cotter pin extending through aligned holes in the fuse head and the downhanging portions of the lever, the fuze head being between said downhanging portions, and a bifurcated end of the cotter pin protruding from said hole in one of said downhanging portions with the protruding halves of said end spread apart, the improvement comprising forming a diameter of the said hole in the downhanging portion, through which the bifurcated end of the pin protrudes, substantially greater than that of the adjacent hole in the fuze head, whereby Withdrawal of said Cotter pin without nicking is facilitated.

2. In a fuze for a hand grenade, a fuze body having a central bore, a hole of lesser diameter than said bore and having an outwardly-facing shoulder, said hole communicating with said bore and opening through the top of said body, a primer hermetically sealed in said hole and resting on said shoulder, the material of said fuze body around the top of said hole being crimped over said primer to hold the same on said shoulder, a tubular extension having a counterbored end secured in said bore, said extension projecting from the bottom of said bore, a gasless delay charge in said extension, said bore and extension cooperating to form a sealed expansion chamber between said primer and charge, a striker pivoted on said body for movement from a rst retracted position to a second position striking and initiating said primer, spring means urging said striker into second position, and manually operable means secured on said head and releasably holding said striker in rst position, said primer, striker, and spring means being so constructed and arranged that said striker initiates said primer without puncturing the same, whereby all gases therefrom are confined in said expansion chamber.

BERNARD LEWIS.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS

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