US2450407A

US2450407A - Mine

Info

Publication number: US2450407A
Application number: US496843A
Authority: US
Inventors: Jr James E Bartgis
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-07-30
Filing date: 1943-07-30
Publication date: 1948-10-05
Anticipated expiration: 1965-10-05

Description

Oct 59 MINE 2 Sheets-Sheet 2 @htm/MMA Patented Oct. 5, 1948 UNITED STATES PAT-.ENT OFFICE 2,450,407 MINE Jamesn. Bartgis, Jr.,`rreaefick, Ma.

:Application July so, 1943,*seria1 Nmaeses (Granted under the act of March v3, 1883, as amended April 30, 1928;.370 0. G1757) 9 Claims.

1 'Theinventi'on Ydescribed herein may be manu- 'factured'and l'used by or for the vGovernment for vgovernmental lpurposes without the ,payment to me 'of `.any royaltythereon. v'Thepresentinvention relates to mines, such as landmines, and'anti-tank mines.

Mines of the present invention may be considered "as .belonging 'to that class of mines Vwhose explosion is initiated 'or brought 'about by impulses Yorfpressure 'applied to'some partl of the mine,l the 'said 'part usually' consisting of an velement 'which may be depressed by the pressure or Weightof'a vehiclepassing thereover.

The term vehicle is used herein in a broad sense as including `anything mounted for travel over road or ground on wheels or'endless belts or tracks, 'and therefore includes all land vehicles, combat `ltanks, caterpillar tractors of all kinds, artillery mounted 'on Wheels or driven endless tracks, trains', and automobiles of all kinds, such as trucks, v'and passenger, reconnaissance, and armored automobiles. d

yThe land mines and anti-tank mines ofthe prior vart'are constructed in such a manner Athat their `'explosive charges explode from one impulse or luponfoneapplicationrof the pressure or weight of the "vehicle passing thereon. That is to say, `a s'ingle actuation of their depressible member or element by the vehicle is more or less immediately followed by the explosion `of the explosive charge-df the mine.

It is among the objects of the present invention to provide a mine whose explosive charge 'may be exploded after Ya selected or predetermined number of passages of vehicles thereon or there-A over, for after `a selected or predetermined number'of impulses'v occasioned by the passages of vehicles or other objects. Thus, mines made in accordance with the present 4invention may be set or adjusted -so -that their explosive charges exl'odeafter 'one vor more passages of 'a'vehicle or of vehiclesth'ereon or thereover, at the election of the `'-user thereof. In the tactical use "of -mines constructedin accordance with'the present-inventiomtheminesin vlarge part, as explained hereinafter, are 'so Vset or adjusted that their explosive charges explode yony some particularly chosen or selected impulse or passage of a vehicle succeedingthe rst impulse Aor passage.

vr'-Anoth'er Yobject of the invention is to provide a`niinewliichinc`ludes a-counter which is actuated Y 'characters applied to the parts indicate-the'same or corresponding parts,

Fig. 1 is a vertical central section 'of anv embodiment of the invention with certain partsin elevation.

Fig. 2 isa partial cross section on theline2-2 of Fig. 1.

Fig. 3 is a cross section on the line "3-3 of Fig. 1.

Fig. l is a somewhat enlarged perspective view ofthe Velectric contact means, spring washenand a part of the ratchet wheel shown in elevationin Fig.

Fig. V5 is a detail, partly in section and partly in elevation, of one of the four adjustable spring means between the depressible head or top ofthe mine and a fixed portion of the mine.

Fig. 6 is a plan view of a road illustrating one manner of using the Amines of the present invention.

Fig. '7 is a vertical section of dele or ravine showing 'another manner of using the mines.

Fig. 8 is an elevation with certain parts insection, showing mechancial means which maybe substituted for the electrical ,means in housing `3 ofFigure 1.

In general, the mine of the present invention may comprise two parts, namely (l) `a case or closed container I within which `an explosive charge -is enclosed, and (2) a device, referred to herein as an exploder for .setting off said -explosive, and indicated generally by the numeral T.2 in Figure 1.

VA primer Yof Aany suitabletype, electrical, per` cuss'ion or friction, .is used Vto re or ignite the explosive charge. The Yprimer may be placed in a well or cavity in the container l or inthe Aexplosive,A or `otherwise closely associated with the explosive charge. Such primers'are well known in the Vart and therefore need no ldetailed illustration lor description here. In this description and in the claims, the vprimer Ais 'considered as forming part of the explosive charge, unless the context indicates otherwise.

The exploder illustrated in Figure 1 is for use with an electrical primer; and Figure 8 illustrates mechanical means which may be substituted for the electrical means of Figure 1 for using the exploder with a percussion primer.

The exploder shown consists of a housing 3 (illustrated as cylindrical) and of the instrumentalities shown within the housing, either in the instance where electrical means, such as shown in Figure 1, are employed, or in the instance where mechanical means, such as shown in Figure 8, are employed for setting ofi the primer. The exploder, although cooper-able or cooperating with the explosive charge and primer, is consideradas a distinct device or distinct component, in this description and in the claims, whether the container I is near the exploder, as in Figure 1,'or far removed from it, as in Figure 8, or whether the explosive charge is placed in an enlargement of housing 3, or container l fastened to, or formed as a part of, housing 3.

A web 4 extends across the interior of the cylindrical housing 3 at right angles to its axis, and nearer the top of said cylindrical housing than to the bottom thereof. A hole is provided through the center of this web and a boss 5 rises around said hole. Said hole and boss are machined to received shaft or plunger 6 with a free sliding nt. Boss 5 is provided with grooves 1, and shaft 6 with recesses 8 for receiving the ball bearings 9.

The top of the shaft 6 is attached to the domeshaped depressible head or member i0 which has a circular contour at its base. Depressible member |D slidingly iits within the cylindrical housing 3 and is depressible by the passage of a vehicle thereon or thereover. It is returnable to elevated position by the action of coil springs il. The downward motion of head I9 is limited by the top of boss 5.

Springs at their upper ends, fit within recesses |2 (see Fig. 5) on the underside of depressible member IE), and at their lower ends t Within cups |3 carried on the upper ends of tension adjustlng screws i4 which engage with mating threads in Web- 4. By turning screws i4 to adjust the tension of spring ll, the minimum weight of vehicle effective to reciprocate shaft 6, may be varied.

At its bottom end, the shaft 3 carries a foot or extension I5, the function of which appears hereinafter. Two lugs i6 extend out radially from the shaft 6 below the web 4 to limit the upward movement of the head Ill under the action of springs A sheet of rubber, or of other ilexible Water shedding or water proof material 2li, closes the top of the cylindrical portion 3, passing over the depressible member l0. The rubber sheet, or sheet of other equivalent material, is secured around the top of cylindrical portion 3 by the clamping action of a ring 2| and screws 22 passing through the ring and engaging threads in holes in the end of the cylindrical portion.

A plate 23 passes diametrically across the interior of the cylindrical portion 3 below the web 4, and is secured to the wall of cylindrical portion 3 by means of bolts 24. Three

pintles

25, 26 and 21 are carried by the plate 23.

A ratchet wheel 36 is mounted for rotation on pintle 26, and is rotated by pawl means hereinafter described. The pintle 26 also carries contact means for closing an electric circuit. This contact means comprises a head 3| offelectrical insulating material having a hole which enables it to be slid into position on said pintle as shown. The said head is xed in position on the said pintle by means of a pin 32 passing through said head and pintle. A spring washer 33 is positioned between the insulating head 3| and the ratchet wheel 30, and urges the latter and spacer 34 (Fig. 2) towards the plate 23.

Two

spring contact arms

35 and 33 of electrically conducting material are secured by means oi screws 31 to head 3|.

Arms

35 and 36 respectfully carry

electrical contacts

38 and 39, which are normally open or separated in the embodiment of the invention illustrated in Fig. l. An electrical conduit or conducting wire 49 is connected with arm 35 and contact 38, and another electric conduit or wire 4| is connectedwith arm 36 and contact 39. The connection of wires 43 and 4| with

arms

35 and 36 and with

contacts

38 and 39 may be accomplished in any suitable manner, for example by means of two screws 42. While contact

arms

35 and 36 have been specifically indicated as being made of electrically conducting material, it is to be understood that they may be made of an electrically non-conducting material if the

contacts

38 and 39 are respectively connected with wires 40 and 4|.

Ratchet wheel 30 is provided with a series of holes 45 arranged in the form of a circle somewhatrnearer the center of the wheel than the teeth of the wheel. In the embodiment of the invention illustrated in Figure l, there are twentyfour of such holes and alike number of teeth on the ratchet wheel. A projection or stud 46 having a reduced end which may be tightly and securely placed in any one of the holes 45 is provided for pressing against the contact arm 35 in its path, when -the ratchet wheel 30 is rotated suiiiciently.

In the embodiment of the invention illustrated, ratchet wheel 30 is turned one tooth upon each complete depression of head I6. The downward Y motion or movement of head l0 is utilized to accomplish this turning of wheel 30. To this end, a lever 41 pivoted on pintle 25 and a pawl 48 pivoted on pintle 49, screwed into the lever 41, are provided. A spring 5D fixed in a stud 5|, carried on the lever 41, urges the vpawl 48 against the ratchet wheel. A pin 52 driven through a hole near the free end of pintle 25 holds the lever 41 thereon. As shown, the free end of the pawl 48 is positioned to engage the teeth of the ratchet Wheel 30. The pawl 48 is pivoted to permit it to ride over the teeth of ratchet wheel 3E! when lever 41 returns to initial position after having moved downwardly.

Upon depression of the head |D by a vehicle, the shaft 6 and foot I5, attached'thereto, move downwardly, the foot l5 pressing downwardly against the upwardly extending portion 53 of the lever 41. As illustrated, each downward movement of the foot l5, and therefore each downward movement of the head lll, moves the free end of the lever 41 and pawl 48 downwardly to rotate the ratchet wheel 39 one tooth. With the projection or stud 46 positioned initially as shown in the drawings, ve depressions of the head l0 are required to close the

electrical contacts

36 and 39. By placing the projection or stud 46 in a suitable one of the holes 45, the closing of the

contacts

38 and 36 Vmay be made to occur after any selected or predetermined number of downward movement of head I0, or passages of vehicles thereon or thereover, at the election of the user of the .'mine.

A safety dog 54 is pivoted on pintle 21 secured to plate 23. AY spring 55, secured at one endto the pintle 21 and acting against a stop 56 near the free end of the dog, urges the dog into engagement with the ratchet wheel between the teeth. This dog prevents accidental or backward rotation of ratchet wheel 30, while permitting rotation of it by pawl G3.

The sidewise thrust produced on ratchet wheel 3S by spring washer 33 together with the drag on the ratchet wheel produced by dog are suflicient under usual conditions to prevent overthrow of the ratchet wheel. However, if desired any suitable overthrow preventer known in the art of counters or adding machines may be used. To more eiectively apply the tension of spring washer S3 to' prevent overthrow, the spring washer may be pinned to the insulating head 3i or otherwise secured against rotation on the pintle 26, whereby the ratchet wheel 3d then rotates against the friction between the ratchet wheel and the stationary spring washer.

Means are provided to restore the lever al to initial position after each actuation thereof by the foot l5. This means comprises a rod 513 with a head SI having a slot therein which loosely engages a pin 62 secured to lever d1. At the lower end of the rod 6G is a piston 63 which nts for reciprocating movement in closed cylinder Se carried by bracket 65 secured by any suitable means, such as screws 66, to plate 23. Within the cylinder 6d, between the bottom thereof and the under face of the piston, is placed a coil spring 61 which is compressed by the downward motion of the piston S3, and which urges the piston upwardly again after completion of its downward movement. As will appear from an inspection of the drawings, the downward motion of lever li? imparts downward motionV to the rod Sil and piston S3, whereby coil spring 67 becomes compressed, and the expansion of spring 87 after compression moves the piston 63, rod 5B and lever il upwardly. The upward movement of lever d? is arrested by a stop 68 on plate 23. This stop is positioned to enable pawl 48. at the end of its return movement, to engage the ratchet wheel properly, as shown in Figure 1. In order that the return of said lever may be delayed or retarded, the piston t3 is provided with a bleeder hole 'Hl and a rapid escape hole 'll closed at the top by a spring pressed check valve l2. Cylinder E4 is lled with a liquid of low volatility, such as a hydrocarbon oil of comparatively high boiling point. As shown, both holes pass entirely through the piston, the hole Il being considerably larger in diameter than the hole 7l). The diameter of the hole 'I0 is comparatively small, being adjusted in diameter according to the rate at which is desired that piston S3, rod S9 and lever 41 be returned to the initial position shown in Figure 1.

When the piston 63 moves downwardly in the cylinder, the oil in the cylinder is able to pass freely upwardly through hole 'H and less freely through hole '10. This permits rapid downward motion of the lever 131. However, when the piston 53 moves upwardly under the influence of spring 61, the passage of oil downwardly through the hole 'H is arrested by the check valve l2, while the passage of oil downwardly through the hole is comparatively slow on account of its small diameter. Due to this latter slow passage of oil through the hole 10, the upward motion of the piston S3 is slow or retarded, and as a consequence the return of lever 41 to its initial or starting position, for actuation of ratchet wheel 30, is delayed or retarded.

The above Vdescribed delay or retardation in the return of lever 41 to initial position is introduced for the purpose of securing only one actuation of the lever il downwardly by the single passage of an automobile or other vehicle having wheels near the front and wheels or tracks near the rear. If the above delay were not introduced, the lever il would be in position to be actuated downwardly not only by the passage of the front wheels over the mine but also by the passage of the rear wheels or tracks, because during the interval of time between the passage of the front wheels and rear wheels or tracks of the vehicle, the head i0 would rise quickly, under the innuence of spring H, after having been depressed. The delay introduced should be suicient to allow the rear wheels or tracks to pass over the mine before the lever l? has returned to initial position.

The bottom of the housing or cylindrical portion 3 is closed by a bottom plate 'i3 secured to the end of the housing by means of screws 14. It is advantageous to place a rubber or other water excluding gasket i5 between the end of the housing 3 and the bottom plate 73.

An electric battery le, or box for electric `cells or electric storage battery, is secured in any suitable manner within the housing 3 on the bottom plate 73. The terminals of this source of electrical energy are indicated by the numerals 'l'l and lt. The insulated wire `lili connects terminal Il with contact 38. An insulated electrical conductor 'l is connected with terminal 78 and passes through an insulator Sil inserted in an opening in the bottom plate 73. The insulated conductor il leads from the contact 39 through the insulator 3&3 to the exterior of the housing. The insulator preferably should so t the opening within which it is placed, and so grip the conductors passing through it, that the entrance of Water within the housing will be prevented.

Those portions of the conductors lli and 1S which are on the outside of the housing 3 are well insulated and lead to the terminals of the electric primer or detonating means within the container l of high explosive. The portions of the conductors 4l and 'i9 on the outside of hous ing 3 may be as long as desired, so that the container I may be placed, in use, near or far from the housing 3 or exploder 2.

Operation- Figure l of the drawing shows the position of the various parts of the device ready to receive the irst impulse or passage of a vehicle and with the stud G5 so set on the ratchet wheel .3G to effect explosion of the explosive charge in container l upon the occurrence of the fth impulse or vehicle passage. Upon the depression of head i6, shaft 5 and foot I5 are depressed. Foot l5 presses lever i'l downwardly and this movement of lever di causes pawl d8 to turn ratchet wheel 3Q one tooth. After passage of the vehicle, lever di returns to its normal or initial position very slowly under the action of coil spring 61 pressing upwardly beneath the piston 63. The upward motion of piston 63 is communicated to rod 6G which connects with lever Il? as heretofore described. In the return motion of lever t1, the pawl d8, being pivoted on the lever M, rides backwardly over the ratchet wheel, and when lever 47 again reaches its normal position, the pawl 68 under the iniiuence of spring 5@ engages behind. the tooth to the immediate rear of the one with which it had been in engagement on the preceding downward motion of lever d?.

After the passage of the vehicle over the head l, the latter, under the influence Yof springs l l,

is again raised to undepressed position, and is thereby made ready to actuate lever 41, through shaft 6 and foot I 5, when thek lever 41 reaches its normal starting position. It will be observed, that this single passage of a vehicle only moves the ratchet wheel one tooth so that the

contacts

38 and 39 remain open, owing to the fact that stud or projection 45 still does not press against contact arm 35. Four more actuations of lever 41 are required to cause projection 46 to press against contact arm 35 to close

contacts

38 and 39 with the internal setting of projection 46 illustrated in the drawing. When

contacts

38 and 39 meet, or are closed, an electric current flows through wires 4I and 19 and through the electric primer or detonating means in the container I of high explosive and initiates the explosion of the latter. B-y properly choosing the hole 45 into which the stud t5 is positioned, the explosion may be caused to occur after the passage of any selected number of vehicles or after any selected number of actuations of actuating lever 41.

Figure 6 illustrates one manner in which mines made in accordance with the invention may be employed. In this figure, a road is indicated by the numeral 99. Ten mines 9i to |06 inclusive are planted along one side of the road at any desired or suitable distances apart, for example at distances apart of fty to one hundred yards. Two combat tanks IDI and |92 of a column of ten or more are assumed, for the purposes of illustrating an application of the invention, to be approaching the planted mines. In this application of the invention the container I containing the high explosive is placed near, either below or beside, the exploder 2. The lug or projection 46 of mine 9| is so positioned in relation to the contact arm 35 that the

contacts

38 and 39 will be closed upon ten actuations of the lever 41. Therefore mine 9| explodes after ten passages of a vehicle thereon. In a similar manner mine 92 is set to explode by nine passages of a vehicle thereon, mine 93 by eight passages. mine 94 by seven passages, mine 95 by six passages, mine 96 by ve passages, mine 91 by four passages, mine 98 by three passages, mine 99 by two passages, and mine |09 by one passage.

In the ideal situation the tanks pass in succession over each of the ten mines, and each of the ten mines would explode under a tank. The leading tank IIJI actuates each of the mines 9| to S9 inclusive once, exploding mine IDI] as it passes thereon. In the meanwhile tank |02 has passed over mines 9| to 98 inclusive, actuating each a second time. Mine 99, having already been actuated once by tank IDI, explodes when tank |92 passes thereover. In like manner, mine 98 explodes when it is passed over by the third tank; mine 91 when passed over by the fourth tank, and so on until all ten mines are exploded, and this may be nearly simultaneous.

Under actual warfare conditions it is not expected that this ideal situation will frequently obtain. The operation of the mines under an ideal situation has been given more for the purpose of illustrating the application of the invention than for illustrating what may be expected to take place under battle or warfare conditions.

In warfare, other situations or conditions may be expected to exist. For example the following is more representative of actual warfare application of the mines. Consider, for example, a tank group consisting of twelve combat tanks in a column, and from nity to one hundred yards apart from each other, proceeding along a road mined with ten mines according to the invention as explained above in connection with Figure 6. The column of tanks is assumed to be moving in the direction indicated by the arrow in Figure 6. It is also assumed that the tanks are preceded by motorcycles and followed by maintenance and supply vehicles.

The motorcycles, being comparatively light vehicles, will not be able to actuate any of the mines, owing to the fact that the springs |I under the depressible head IU have been chosen strong enough to resist any actuation of the mines by vehicles as light as motorcycles. Tank No. 1 of the column of tanks will proceed along the mined road, actuating perhaps three of the ten mines. It will be assumed that tank No. 1 gets through the described mine field without becoming a casualty. Tank No. 2, it will be assumed, actuates three of the mines and happens also to actuate mine |90. Mine |09 having been set to explode upon one actuation, tank No. 2 becomes a vehicular casualty when it actuates mine IDS. Tank No. 3, at about one hundred yards behind tank No. 2, will likely actuate mine 99, which, it will be assumed has already been actuated once by a preceding tank. Tank No. 3 therefore becomes a casualtyfrom the explosion of mine 99. By this time the remainder oi' the twelve tanks are in the mine field and are attempting to turn around and go back. The results of this operation will probably be that three or four of the remaining tanks become casualties and the group of tanks and other vehicles disorganized and looking for another avenue of approach. At any event, the assumed mine field will separate and disorganize the group of tanks and other vehicles.

Figure 7 illustrates another application of the mines of the present invention. In this figure the numerals IIE) and Ill indicate steep slopes of a deile or ravine. A road II2, at the base of slope III, runs along the stream 3. One or more exploders 2 of the present invention may be planted in the road II 2 at the foot of slope III, while the containei` I of eachy containing the explosive charge, is planted some distance up the slope. Each exploder 2 is connected with the primer or detonator of each container I by electrical conductors 4| and 1S (see Figure l) and represented by a cable II 4 in Figure 2. Vehicles passing on the roadway actuate the exploders 2 planted in the road I|2; and the exploders 2 may be set, as above explained, to set off the explosive in containers I after a selected number of actuations thereof. The explosion 0f the explosive in container or containers I produces an articial avalanche which descends upon the road producing casualties of personnel and vehicles, and division of the column of vehicles, if some have passed before production of the avalanche.

The manner in which the mechanical means illustrated in Figure 8 may be substituted for the electrical means shown in Figure 1 will now clearly appear. Referring particularly to Figure 3, numeral 23 indicates the plate 23 of Figure l, but in this instance extended somewhat below the ratchet wheel. Ratchet wheel 39, holes 45, and stud or projection 46 in Figure 8 correspond to similarly numbered parts in Figure 1. Within the housing 3 (see Fig. l) is xed a guide |20 (see Fig. 8) for firing pin |2I. Near the pointed end of firing pin IZI is fixed a collar |22. A coil spring |23 is placed on the iiring pin between the lcollar fl22and 'the guide l"|20, 1A-shoulder 1| 24fis formed on the firing pin-near th'eend opposite the pointed end. -A-latch l|25,'.having ai hook portion 126,-is. pivoted on a -pintlef l|2`|fxed on plate 23. to the latch |25,` andfat the opposite-endto Va pin |29, xed to plate 23, urges the hook |26Yof the. latch |25 beneath the vshoulderV 124, thereby holding firing pin in elevated position (asshown in Fig. 8) `and sp-ring |-23Yunder compression.

Still referring to Figure V8,v thefnumeral'ls 4indicates a part of -a container-'Which-'holdslian explosive charge I3i. A percussionf-primeril'? ts in a well in the container r'|32V 'ataposition opposite thepoint'of the" firing pin |2I. instance the explosive charge is placed in an enlargement of housing 3 or attached thereto in a suitable manner. In Figure 8, the studY or-projection 46 is set to explode the mine upon Vthe fourth actuation of ratchet wheel .30, assuming,A

or course, that the :ligure represents the starting position of the ratchet wheel. Upon theoccurrence of the fourth actuation' of the ratchetl Wheel,

Itis to be observed fromtheforegoing-detailed description and mode of operation of the mines.

of the present invention, that the ratchet Wheel 3b, lever lll', and pawl 48 constitute a counter which counts the number of passages of vehicles or impulses occasioned by the passage of vehicles or other objects, and that means for exploding the charge contained within the container is under the control of the counter. While a specic form of counter, specific means under control of the counter for exploding the charge and specific means responsive to the passages of vehicles or to impulses have been described, it is to be understood that the invention is not confined to the use of these specic means, because other means accomplishing the same function may be used without departing from the invention, as will be understood by the person skilled in the art. Nor is the use of the means for retarding the return of lever i7 absolutely necessary for the practice of the invention, since the extra actuations of the counter, Which may be occasioned by eliminaticn of the retarding means, may be taken into account in setting the counter to set oi the explosive charge at the desired time.

The mine may be made responsive to the passage of objects other than vehicles by a choice of springs with suitable constants or physical characteristics. For example, the springs Il may be chosen Weak enough to permit the depression of head I9 and actuation of the counter by the weight of a man. Thus, the exploder or component 2, may be set to cause explosion of the mine after a selected number of soldiers or ranks of soldiers have depressed the head l by Walking thereon.

I claim:

1. An exploder comprising means depressible by the pressure engendered by the passage of a vehicle thereover, means for restoring said depressible means to undepressed position after depression thereof, contact means for closing an electric circuit for exploding an explosive, and means actuated step by step by the successive movements of said depressible means for closing said contact means, said last mentioned means being adjustable to close said contact means only A coil spring'` 128, attached at-'one end In this @by a pre-selected depression -of.-saidy depressible yKr-nember.

'7- 2.7i -An v exploder` comprising means depressible 7by `-the passage-of a vehicle, means forrestoring said' depressible means --to fundepressed position 4after depression thereof, contact means for clos- 1- ingy an' 'electric circuit vfor exploding anfexplosive, means'ffor closing Isaid contact means f including I a ratchet; pawl means-movableto and iro along said -ra'tchetfor actuating said ratchetandactuated by the i movementy of saidv depressible means, said paWl-meansduringl its lmovement-*1in"'one I4direction actuating-said ratchet-and returning to `starting position after actuation'o said ratchet; and'y means for retarding the return'of saidv pawl "means to saidY starting position after actuation fof said'trat-chet.

35A land"minecomprising a depressible-m'emvber adapted to be-directly` 'depressed' byrthepressure en-gend'ered'by thepassage of agvehiclethereoverarid returning to an vundepressed` position after vdepression thereof, an explosive ;`v and-,means 'mechanically and directly actuated fromf-thegmotion-of said depressibleA memberjfor detonating saidexplosiveV upon the 'occurrence `of ajpredetermined plurality of depressions of-:said` depressiblemember. l

4.*In* a Aland mine'fcomponent, a reciprocable 'Y member Aadapted 4to 'be-j directly ireciprocatedjV by `the pressure produced by successive passages of vehicles thereover, Wheel means, rst means directly operated by reciprocation of said member to move said wheel means step by step, second means movable in a predetermined path by and in response to movement of said wheel means, and third means lying in said path and operable by said second means, to detonate an explosive charge, said second means being adjustable relatively to said Wheel means whereby to selectively vary the number of reciprocations of said member necessary to operate said third means.

5. In a mine component, a housing, a member in said housing adapted to be reciprocated by successive passages of vehicles thereadjacent, .ratchet means movably mounted within said housing, pawl means in said housing and mounted to be actuated by reciprocation of said member to thereby advance said ratchet means, an abutment movable in a path fixed relatively to said housing by and in response to advance of said ratchet means, detonating means including a part positioned in said path to be operated by said abutment, said detonating means and said abutment being relatively adjustable along said path whereby to selectively vary the number of reciprocations of said member necessary to cause said abutment to engage said part and thereby operate said detonating means.

6. A mine component comprising a housing having means forming a guideway, a plunger reciprocable in said housing and along said guide- Way, said plunger adapted to be reciprocated by successive passages of a vehicle thereadjacent, a ratchet wheel journaled in said housing, pawl means positioned to be actuated by said plunger to thereby rotate said Wheel step by step, an abutment adapted to be fixed to and in circumferentially adjusted position about said Wheel, said means for detonating an explosive charge positioned in the path of said abutment to be operated thereby after a selected number of reciprocations of said plunger as determined by the adjustment of said abutment on said wheel.

'7. A delayed-action land mine component comprising a casing having an opening in its top, a head closing said opening, said head being mounted in said casing for depression in response to pressure externally applied thereto, resilient means urging said head to undepressed position, plunger means connected for movement with said head, counter means in said casing adapted to be directly operated one step at a time by each respective movement of said plunger means, and means under control of said counter for detonating an explosive only upon the occurrence of a pre-selected number of depressions of said head.

8. In a delayed action land mine component, a casing having an opening in its top, a head closing said opening and depressible from a first to a second position in response to the force exerted by a vehicle moving thereover, spring means urging said head to said rst position, plunger means connected for movement with said head, a ratchet wheel journaled in said casing, pawl means operated by said plunger means and operating said wheel step by step in response to respective depressions of said head to said second position, and means settable with respect to said Wheel to detonate an explosive charge by and upon a preselected operation only of said Wheel.

9. In a delayed action mine, a casing having an opening in its top, plunger means reciprocable v. within said opening and depressible by the pressure of a vehicle passing thereover, spring means urging said plunger means to undepressed position, a lever pivoted in said casing and adapted to be pivoted by depression of said plunger means, a wheel journaled in said casing, means carried by said lever to advance said wheel step by step in response to successive actuations of said plunger means, a stud carried by said Wheel and movable in an arcuate path therewith about the pivot axis thereof, and detonatng means adapted to be engaged and operated by said stud, said stud and detonating means being relatively adjustable about the axis of said Wheel to vary the num\ ber of depressions of said plunger means necessary for detonation.

JAMES E. BARTGIS, J R.

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

UNITED STATES PATENTS Number Name Date 2,368,310 Lecky et al. Jan. 10, 1945 2,399,523 Van Atta et al Apr. 30, 1946 FOREIGN PATENTS Number Country Date 541,624 Great Britain Dec. 4, 1941 826,676 France Jan. 8, 1938