US2923237A - Mine fuse - Google Patents

Description

Feb. 2, 1960 R. H. BLEIKAMP, JR 2,923,237 I MINE FUSE Filed Nov. 5, 1957 Fig: 1.

IN VEN TOR. RoY H. BLEIKAMBJR. B

, V MINE FUSE 7 Roy H. Bleikamp, Jr., St. Louis, Mo., assignor to Olin Mathieson Chemical Corporation, East Alton, 111., a corporation of Virginia Application November 5, 1957, Serial-No. 695,478 a 2 Claims. (Cl. 102-8) This invention relates to an improvement in a percussion type fuse and particularly in fuses for land mines.

Heretofore, certain types of explosive mines have included a fuse mechanism with a solid mechanical linkage including a dished resilient washer or spring, disk of the Belleville type to efiect explosion of the mine when it is run over by a vehicle, for example, as the mines lie either exposed or buried in the ground for concealment. Such constructions have had the disadvantage of requiring considerable height for the linkage and requiring placement of the mines at some particular orientation rather than placement at random orientation. Mines of this construction have had the further disadvantage of requiring that the ambulating target tread directly over the mine before explosion and destruction of the target would occur consistently. This:limited the possibility of distributing such mines by strewing them upon the ground since they would then take a random orientation and most of them. would be quite ineffective.

It is an object of thisinvcntion to provide a percussion type fuse relatively shallow and relatively free from directionality for land mines which will enable operation of the mines even when they are emplaced out of orientation with the direction of the line of application of the actuating pressure, either angularly or by separation. Another object is to provide a pressure sensitive fuse device for mines of relatively simple, small and economical construction. Still other objects and advantages will become obvious from a description of specific embodiments shown in the accompanying drawing in which: 1

Figure 1 is an elevational view in cross section of an embodiment shown prior to loading and 'of a type adapted for sub-surface emplacement;

Figure 2 is an elevational view in cross section of another embodiment shown loaded at the moment of firing and of a type adapted for surface emplacement; and Figure 3 shows mines according to the embodiment of Figure 1 provided with a valve and prior to arming.

In accordance with this invention there is provided a fuse having a snap action element such as a dished resilient disk or washer arranged so as to be actuated by a fluid pressure element sensitive to exertion of an adjustable level of pressure over a relatively wide area applied at any one of various directions. A pneumatic or hydraulic motivating link instead of a solid linkage is contemplated.

The fluid pressure element includes a pliable protruding cap or dome and a captive pneumatic fluid enveloped between the snap element and the cap for acting on the snap action element. The element is specifically a washer of the Belleville spring type and may consist of spring metal but optionally consists of a suitable nonmetallic plastic. Cellulose acetate, nylon, ethyl cellulose, polyvinyl acetate, polyvinyl chloride are suitable. 'Ihis snap action element when of plastic is preferably of laminated fabric non-stretchable construction reinforced vt S ates, Pa n by means of a suitable strand, fiber, or glass fabric "ma-- terial. The stiffness and uniformity of such a fabric con-- struction tends to provide homogenous snap action. The- Belleville spring element carries a firing pin normally in: a position in whichthe pointed end of the firing pin is spaced from a primer charge for setting off the main blasting charge of themine. The dome or bag memberassociated in sealing relationship with said washer member may consist of any suitable material but also pref erably consists of some suitable plastic so as to avoid easy detection leading to disarming.

The fluid pressure actuating element may take vari-- ous forms such as that of a captive fluid containing. dome extending outwardly as an appendage fromone side of the mine or it may take the form of a surrounding fluid enveloping bag. In any event, this shape makes possible actuation of the mine by pressures applied in other directions than that of the firing pin axis and along lines more displaced from the axis of movement of said firing pin. For adjustment of the arming and pressure levels of operation suitable for different weights of objccts to be destroyed, a suitable 'valve may be provided, The valve may be advantageously located in the dome or cap, for example. It may be one or two way.

The dome or bag shaped closure member is in effect a fluid impervious membrane and consists of any suitable deflectablenrnaterial of a composition, thickness, and/ or shape characterized by less stretch and deflection than that available in the spring element, sothat relative to the element the closure is unstretchable and deflectable to a lesser degree. Depending upon the mechanical design, size, operating pressure level, type of fluid employed (liquid or gas), and the predetermined sensitivity, the relative deflectability of closure and spring element is adjusteduntil satisfactory operation is attained at the predetermined pressure level.

The closure membrane consists of one of the suitable plastics such as plasticized polyvinyl acetate, silicone 'or nitrile rubber, polyethylene of suitable type and grade, and the like. In addition to these plastics, however, other plastics are contemplated for either the element or closure in attainment of the desired degree of deflect ability. I v

With reference to the embodiment of Figure 1, the device includes a fuse body or. casing 1 of polystyrene, the snap spring diaphragm 2.carrying the firing pin 3, and the motivating dome 4 of suitable plastic which together with the casing and diaphragm forms a fluid chamber in whichthere is enveloped the fluid 5 making a link between dome 4 and spring 2. l

Casing 1 71135 two passageways in a IT-arrangement, but only one of thesepassageways 9 which housesa detonator slide 10 is shown. The slide carries a stabtype detonator 11 and any'suitable timing arrangement 12. One such arrangement consists of a suitable barrier and a vial containing a chemical which is released by impacting with the point 13 on slide stop plug 14 carried in the casing so that in the event that the fuse is not set ofl as intended after a suitable interim of time, the composition in vial 12 is released and finds its way through bore 15 of slide 10 to de-activate the fuse det' onator 11. Passageway 9 also contains a compression slide spring 16 which puts the primer or detonator 11 into alignment with the firing pin 3 as shown as soon as the arming latch, carried in the other casing passageway athwart passageway 9,-is pulled out of the arming latch striker opening 17 through slide 10 for central alignment with the cross passageway and its latch. Casing 1 also contains a major recess for holding the main explosive charge 20 ignitable through the thin casing partition 22 opposite firing pin 3, and also a minor recess 21 which is a relief well alignable with the detonaspring diaphragm 2 through outer'casing vent 2318M;

to permit proper fluid-operation Ofthefuse system ofthe dome 4, fluid link'5 and spring} allsuitably sealed: I

Casing 1 is provided with a guardfs eh as ring 2f4-so as to prevent any likelihood ofjalmz-chanical"connection between snap spring-land; ome 4 should the latter be, collapsed abnormally. I 7 j i I In the embodiment of Figure 2; the fuse casing 1 is substantially identicalwith that of the previous ernbodi ment, but the'fluid linkmotivating rr'i erribrane takes the shape era substantially" fuse surroundingfluid envelop.- ing bag 40 having an external configuration such as to givebag 40 the appearanee'of so'me naturally occurring object-such as a stone'or pieceof timber; This embodiment has a vent 33 functioningsimilarly to the vent 23 of Figure '1. It will'be appreciated that the embodiment of Figure2 is suitable for surfacelemplaeement While the embodimentofFigure 1 is more suitable for the type of mine which is'huried. F s

- In operation these embodiments are quite similar except for differences in 'pre s sure leyels at which the fuse ignites the explosive charge; and, therefore, operation will be describeclin connection withiFigure l".

a In the position shown an arming plunger in'the cross passageway not shown pulls a slide latch' out of, the

opening 17 which allowsthe slide "acting"under the,

bias of spring 16to move to the armediposition shown;

in Figure l with the detonator 11 underthe firing pin 3 and over the explosive base charge 20; Movement of the slide 10 also causes point13;'of ;plug liflto pierce the timing arrangement 12. Thus :fully' arined the fuse is responsive to any pressure on the pressure-dome 4 which creates a pressure in fluidfS acting o'nthesnap spring 2 to flex it and drive thepin 3 int of the detonator 11 thereby initiating the mine. i I

This dome is designed to safely carry a, minimum load and any loadin excess of-this'will pressurizegthe fluid at a predetermined pressure 'level beforethe spring element 2 goes into operation; quickly to drivefiring pin 3 into firing engagement andthus explode the mine, It will be appreciated that, an incompressible, liguidiwill valve provides advantages for certain purposes. As shown in Figure 3, a valve 50 may be located in the motivating dome 4. The valve may be of the one-way type so that the domes of the devices may be collapsed making for compact storage. Upon release the domes snap out into position and the trapped atmosphere provides the fluid link. With thetwo-way valve other variations are possible such as evacuation to provide a further safety factor since under this condition spring 2 is withdrawn,*dome 4 is collapsed to virtual inoperability and the fluid link 5 i s very weak. Another modification is to pressurize the device at above atmospheric pressures,

It will'be understood that the foregoing embodiments now believed preferred are intended to be illustrative and not to limit the invention except as set forth in the claims, and that other changes and modifications may occur to those skilled in the art within the sp irit and scope ofthe invention asset forth; in theappended claims.

' What is claimed is 1, A mine comprising a casing containing an explosive charge, a stab initiated primer mounted on said casing, an impcrforate'Belleville spring mounted within said casing and having-a firing pin'secured thereto within the periphery of saidspring said pin normally 'heldin spaced relationship with-respect to said primer, said periphery beingsecured in sealing relationship with respect to'sa'id casing, and a substantially dimensionally stable, flexible protuberant closure sealingly secured to said casing,- said=casing, spring and'closure'forming there between an envelope, said envelope being substantially completely filled with'a singlebody-of captive fluid, said fluid forming-a positive fluid pressure link between said' closure and-spring, said closure being deflectable under pressure applied emmanyrmm' an y 'direction, thereby reducing the volume of the envelope and increasing the pressure of said fluidtherein upon said spring to deflect said spring and snap it beyond'its equilibrium position for driving" said firing pin'into said primer.

provide a more sensitive"arrangement-operable over a 2. The mine of claim-1 wherein the closure is a domeshaped member of substantially dimensionally stable, flexible plastic material'from the group including plasticized polyvinyl acetate, a silicone rubber, nitrilerub her, and polyethylene. V

References Cited in. the file of this patent STATES PATENTS 2,488,547 Liljegren Nov-. 22, 1949 2,555,318 Christensen June 5, 1951 2,656,792.. Dumas; Oct. 27, 1953 2,790,387 Billon Apr. 30, 1957 FOREIGN PATENTS 821,529 France Aug. 30, 1937 1,113,367

France Dec. 5, 1955

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