US3575110A

US3575110A - Nonmetallic antipersonnel mine

Info

Publication number: US3575110A
Application number: US221376A
Authority: US
Inventors: Kenneth Edwin Conroy; Scott Lynn
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-09-05
Filing date: 1962-09-04
Publication date: 1971-04-13
Anticipated expiration: 1988-04-13
Also published as: GB1391589A; CA886120A

Abstract

A two-piece, antipersonnel mine adapted to be driven into the ground comprising, a cylindrical upper body, there being an upper axial bore and a lower axial bore in said upper body, said lower bore being of a smaller diameter than said upper bore; a lower tubular body detachably secured to said upper body, said upper body flaring outwardly towards its upper end and having an annular planer surface on its top face thereof, said lower body having its lower end tapering to a point; a cylindrical charge container axially slidable in said upper bore of said upper body, its upper end normally protruding above the upper face of said upper body; an explosive charge in said charge container; a detonator carrier axially slidable in said lower bore of said upper body and normally abutting said charge container; a detonator in said detonator carrier; a firing mechanism for detonating said detonator and said charge comprising, a firing pin carrier axially slidable in the lower portion of said detonator carrier; a pair of detent balls housed in said firing pin carrier and normally retained therein by the lower wall of said upper body; a firing pin fixed in axial relation in said firing pin carrier and a coil spring axially disposed in the lower portion of said lower body and normally biasing said firing pin carrier, said detonator carrier and said charge container in an upward direction in said mine, whereby when said charge container is depressed, said detonator carrier and said firing pin carrier are moved downwardly to release said balls from said firing pin carrier and into said lower portion of said lower body, whereby said coil spring will move said firing pin carrier upwardly to fire said detonator and said charge.

Description

United States Patent [72] Inventors Kenneth Edwin Conroy 18 Center Blvd.; Scott Lynn, 452 Roxborough Road, Ottawa, Ontario, Canada [211 App] No. 221,376 [22] Filed Sept. 4, 1962 [45] Patented Apr. 13, 1971 [32] Priority Sept. 5, 1961 [33] Canada [31] 831,066

[54] NONMETALLIC ANTI-PERSONNEL MINE 1 Claim, 12 Drawing Figs. 7

[52] US. Cl 102/8, 102/70 [51] int. Cl F42b 23/00 [50] Field of Search 102/7, 8, 1O, 16, 70

[5 6] References Cited UNITED STATES PATENTS 2,830,538 4/1958 Dodge 102/8 2,857,842 10/1958 Malm 102/8 3,923,237 2/1960 Bleikomp 102/8 Primary Examiner-Samuel W. Engle Attorneys-S. J. Rotondi and A. T. Dupont CLAIM: A two-piece, antipersonnel mine adapted to be driven into the ground comprising, a cylindrical upper body, there being an upper axial bore and a lower axial bore in said upper body, said lower bore being of a smaller diameter than said upper bore; a lower tubular body detachably secured to said upper body, said upper body flaring outwardly towards its upper end and having an annular planer surface on its top face thereof, said lower body having its lower end tapering to a point; a cylindrical charge container axially slidable in said upper bore of said upper body, its upper end normally protruding above the upper face of said upper body; an explosive charge in said charge container; a detonator carrier axially slidable in said lower bore of said upper body and normally abutting said charge container; a detonator in said detonator carrier; at firing "mechanism for detonating said detonator and said charge comprising, a firing pin carrier axially slidable in the lower portion of said detonator carrier; a pair of detent balls housed in said firing pin carrier and normally retained therein by the lower wall of said upper body; a firing pin fixed in axial relation in said firing pin carrier and a coil spring axially disposed in the lower portion of said lower body and normally biasing said firing pin carrier, said detonator carrier and said charge container in an upward direction in said mine, whereby when said charge container is depressed, said detonator carrier and said firing pin carrier are moved downwardly to release said balls from said firing pin carrier and into said lower portion of said lower body, whereby said coil spring will move said firing pin carrier upwardly to fire said detonator and said charge.

" Patented 'April 13, 1971 3,515,110

'5 Sheets-Sheet 1 I l I 40 3 2 20 62 I l 32 I II I0 2| 25* l8 I 34 35 24 33 28. 3

6 6 FIG. 2. L I9 FIG. 3.

INVENTORS KENNETH EDWIN CONROY mzazfswzp Patented April 13, 1971 3,575,110

3 Sheets-Sheet 2 IN V EN TORS KENNETH EDWIN CONROY By SCOTT LYNN MQCZW Patented April 13, 1971 3,575,110

3 Sheets-Sheet 3 9| 96 I as l'l' 9s s5 .ao l 83 I I. as 1 I H" 84 FIG. II

v I35 v I35 use I26 121 9 fi I20 I26 J :2: H4

'08 I09 '03 3 I04 00 I06 I05 FIG INVENTORS KENNETH EDWIN CONROY y SCOTT LYNN NONMETALLIC ANTI-PERSONNEL MINE This invention concerns an antipersonnel mine in general and, in particular, an antipersonnel mine whose parts are, for the most part, nonmetallic.

The mine forming the subject matter of the present invention is the result of an attempt to produce a relatively small, lightweight antipersonnel mine which can normally be quickly and easily emplaced and easily camouflaged and which has a minimum number of metallic parts thus rendering its detection with normal mine detecting equipment normally quite difiicult.

Thus, according to one aspect the present invention concerns an antipersonnel mine which includes a body; a detonator container and a firing mechanism including a firing pin, movably mounted within said body; resilient means associated with said body and said firing mechanism; said detonator container and said firing mechanism being movable as a unit in a first direction with respect to said body, against the action of said resilient means; said firing mechanism being movable with respect to said detonator container in a second direction opposite to said first direction under the reaction of said resilient means to enable said firing pin to contact a detonator in said detonator container; and detent means associated with said firing mechanism for normally preventing said firing mechanism from moving in said second direction, said detent means being releasable on suflicient movement of said detonator container and said firing mechanism in said first direction, to permit said firing mechanism to move in said second direction.

In the accompanying drawings which illustrate one embodiment of the invention:

FIG. 1 is a view in elevation of an armed mine with its detonator and charge in place as it would appear after being emplaced with its safety clip removed;

FIG. 2 is a section along the line of 2-2 of FIG. 1;

FIG. 3 is a perspective view of the detonator container from the mine of FIG. 1;

FIG. 4 is a view in elevation of the upper portion of the mine's body;

FIG. 5 is a bottom view of the upper body portion shown in FIG. 4;

FIG. 6 is a section taken along the line 6-6 of FIG. 4;

FIG. 7 is a perspective view of the mine as normally transported with the charge container removed and a carrying plug inserted in its place;

FIG. 8 is a perspective view of the charge container with its attached safety clip;

FIG. 9 is a perspective view of the safety clip partially shown in FIG. 8;

FIG. 10 is a cross-sectional view in elevation of an alternative form of detonator container;

FIG. 11 is a cross sectional view in elevation of another alternative form of detonator container; and

FIG. 12 is a cross-sectional view in elevation of a practice mine constructed in accordance with the present invention.

Looking firstly at FIGS. 1 to 6 inclusive it will be seen that the mine 1 includes an upper body portion 2, a lower body portion 3, a charge container 4, a detonator container 5 and a mechanism including a firing mechanism generally referred to by the reference numeral 7.

In more detail, the general outer shape of the upper body portion 2 is that of a truncated cone. Its interior is bored out to form a hole 9 for receiving the charge container 4, and a smaller hole 10 for receiving the detonator container 5. A shoulder 11 is thus provided between the two holes and adjacent this shoulder is provided an annular inwardly projecting flange 12 whose use will be described hereinafter. A lower hollow cylindrical portion 14 of the upper body portion 2 is externally threaded at 15 as shown in FIG. 4. The wall of hole 9 is provided with longitudinally extending ribs 17 asshown in FIGS. 2and6.

The lower body portion 3 is substantially cylindrical with its lower end tapering to a point to facilitate its entry into the ground. The upper portion of the interior wall of the lower body portion is threaded at 18 to receive the threaded portion of the upper body portion as illustrated in FIG. 2. A circular, centrally positioned depression or well 19 is provided in the bottom of the interior of the bottom portion. An annular gasket 6, formed from a suitable material such as polyethylene, is provided between the upper and

lower body portions

2 and 3 in order to seal the joint between these members against the entry of water.

Both the upper and lower body portions are moulded from a plastic such as a phenolic plastic.

The detonator container 5, also moulded from a suitable plastic, fits partially within the hole 10in upper body portion 2 and as shown in FIG. 3 consists basically of a pair of

hollow cylinders

20 and 21 positioned end-to-end with the cylinder 21 being the larger in diameter thus to provide a shoulder 26 between the cylinders. Cylinder 21 is 'a sliding fit within hole 10. A seal, in the form of an O-ring 32 is provided between the shoulder 26 of the detonator container and the flange 12 of the upper body portion. Cylinder 21 is further provided with a pair of elongated

opposed slots

23 and 24 in its lower edge as clearly shown in FIG. 3. A suitable prick-type detonator 22 is positioned within the upper hollow cylinder 20. A circular, centrally situated bore 25 provides communication between the upper and lower cylinders.

In the alternative form of detonator container illustrated by FIG. 10 the upper or smaller hollow cylinder 60 is formed separately from a resilient material such as polyethylene and is provided with an integral annular flange 61 having an outer diameter equal to the outer diameter of a separate lower hollow cylinder 63.

The upper cylinder 60 is also provided below flange 61 with a neck 64 cooperable with an inwardly extending flange 65 integral with cylinder 63 and formed adjacent the upper edge of the inner surface of the cylinder to secure the two

cylinders

60 and 63 together as shown with flange 61 overlying the upper edge of cylinder 63.

A small, circumferentially extending bead 66 is provided adjacent the lower end of the bore in cylinder 60 and the upper end of the bore is closed off by means of a thin flat membrane 68 formed integrally with cylinder 60.

The detonator 69 is pushed into the bore in cylinder 60 past the bead 66 which retains it in position. The disc 68 prevents moisture from entering into the cylinder 60 through its upper end.

Cylinder 63 is also provided with elongated, opposed

slots

71 and 72 which are similar to

slots

23 and 24 in cylinder 21.

One advantage of this form of construction is that no seal such as 32 in FIG. 2 is required, the resilient flange 61 providing the seal.

The alternative form of detonator container illustrated in FIG. 11 is adapted to retain two types of detonators, the one illustrated in FIGS. 2 and 10 which is cylindrical in shape and one which is disc shaped and has a larger diameter than the cylindrically shaped detonator has. The detonator container illustrated in FIG. 11 consists of two members and 81.

Member 81 consists of a lower cylindrical portion 83 provided with a pair of elongated

opposed slots

84 and 85 similar to those provided in the other two detonator containers and an upper cylindrical portion 86 provided with a bore 88 which is counterbored at 89. A circular hole 90 of lesser diameter than bore 88 provides communication between it and the bore in cylinder 83. Hole 90 permits the firing pin to pass into the interior of cylinder 86 to detonate the detonator 91 therein.

If the previously mentioned disc-shaped detonator is to be employed, it is placed in counterbore 89 and rests on the shoulder provided by the counter-bore.

Member 80 fonns a cap which fits over the cylindrical member 86. The cap member 81 is formed from a resilient material such as polyethylene and is provided with a flange 95 which normally rests on the shoulder between the two

cylindrical portions

83 and 86 thus to provide a sealing member which eliminates the necessity of using a seal 32. The cap member 80 is also provided with an integral, thin discshaped top to seal the upper end of the container from moisture.

As the exterior form and dimensions of each of the three detonator containers are the same, any of the three may normally be used interchangeably.

The mechanism, generally referred to by the reference numeral 7 consists of a coil spring 27, a cylindrical firing pin carrier 28, a metal firing pin 29, the pin and its carrier constituting the firing mechanism, and a pair of steel balls 30 and 31. The firing pin 29 has its upper end tapered to a point and its lower end extending beyond the bottom surface of the firing pin carrier 28, as shown. The firing pin 29 is provided with a circumferentially extending groove 35 about which the carrier 28 is moulded to prevent relative movement between it and the firing pin 29. Note that the pin 29 is substantially coaxial with the longitudinal axis of the carrier thus to enable it to pass through bore 25 when the carrier 28 is allowed to move upwardly with respect to the detonator container 5.

The carrier 28 has a sliding fit within the lower cylinder 21 of the detonator container and is further provided with two longitudinally extending opposed grooves 33 and 34 of semicircular cross section formed in its outer curved surface, the diameter of the semicircle being slightly greater than the diameter of the steel balls 30 and 31. As will be apparent from FIG. 2, the upper ends of the grooves 33 and 34 are open and the lower ends are closed. The coil spring 27 fits over the lower. end of the firing pin 29 and is constrained internally at its lower end by the depression 19. It is thus associated with both the body and the firing mechanism.

Balls 30 and 31 fit in

slots

23 and 24 respectively as also shown in FIG. 2, and when the firing mechanism is in its cocked or armed position, protrude into grooves 33 and 34 and are trapped between the carrier and the lower end of the upper body portion as a result of the lower ends of the grooves being closed. Note that the interior wall of portion 14 of the upper body portion is slightly relieved in order to accommodate the balls 30 and 31.

The charge container 4 is also of a hollow cylindrical form and is provided with an integral cap 38. Normally, the container 4 is moulded from a plastic such as phenolic plastic. Container 4 further includes a circumferentially extending endless groove 39 formed in its exterior and a circumferentially extending shoulder 40 formed in the interior of the container. An inverted, conical member 41, also moulded from a suitable plastic, to prevent relative movement between it and the firing pin 29. Note that the pin 29 is substantially coaxial with the longitudinal axis of the carrier thus to enable it to pass through bore 25 when the carrier 28 is allowed to move upwardly with respect to the detonator container 5.

The carrier 28 is a sliding fit within the lower cylinder 21 of the detonator container 5 and is further provided with two longitudinally extending opposed grooves 33 and 34 of semicircular cross section formed in its outer curved surface, the diameter of the semicircle being slightly greater than the diameter of the steel balls 30 and 31. As will be apparent from FIG. 2, the upper ends of the grooves 33 and 34 are open and the lower ends are closed. The coil spring 27 fits over the lower end of the firing pin 29 and is constrained internally at its lower end by the depression 19. It is thus associated with both the body and the firing mechanism.

Balls 30 and 31 fit in slots 23 and 2d respectively as also shown in FIG. 2, and when the firing mechanism is in its cocked or armed position, protrude into grooves 33 and 34 and are trapped between the carrier and the lower end of the I upper body portion as a result of the lower ends of the grooves being closed. Note that the interior wall of portion 14 of the upper body portion is slightly relieved in order to accommodate the balls 30 and 31.

The charge container 4 is also of a hollow cylindrical form and is provided with an integral cap 38. Normally, the

container 4 is moulded from a plastic such as phenolic plastic. Container 4 further includes a circumferentially extending endless groove 39 formed in its exterior and a circumferentially extending shoulder 40 formed in the interior of the container. An inverted, conical member 41, also moulded from a suitable plastic, abuts against shoulder 40 as shown. A seal in the fonn of a rubber O-ring 42 is retained in groove 39, to seal out dust and other foreign matter from between the charge container and the upper body portion,

which might otherwise cause the container to jam against the inner walls of the upper body portion. Ribs l7 aid in preventing such jamming should any grit get past the O-ring 42, or fall into the upper body portion 2 during emplacement of the mine.

A cylindrical charge 43 having an inverted conical depression in its upper end which matches the external shape of member 41 is contained within container 4 and is sealed in place by means of a shallow plastic cup 44. The charge is formed in this particular manner in order to take advantage of the Monroe effect.

As previously mentioned the mine illustrated in FIG. 12 has been designed primarily for practice purposes and although in many aspects it is quite similar to the mine previously disclosed it does differ to some slight extent and hence will be briefly described. As will be readily realized on a comparison -of the practice mine illustrated in FIG. 12 with the mine illustrated in FIG. 2 the major differences are those associated with the shape of the charge container and the upper portion of the detonator container as well as with the interior shape of the upper body portion.

Looking now at FIG. 12 it will be seen that the illustrated mine includes a lower body portion threaded into an upper body portion 101, a blunt firing pin 103 extending through a moulded firing pin carrier 104, a coil spring 105 whose lower end seats in a well 106 provided in the lower body portion and whose upper end fits over the lower projecting end of the firing pin 103 and a pair of releasable trapped

balls

108 and 109. In this embodiment the primer or detonator 110 is carried in a container 111 which is separate from the cylindrical member 112 within which, when the balls become untrapped, the firing pin carrier is movable. Cylindrical member 112 is itself movable in a downward direction within the lower cylindrical portion 114 of the upper body portion 101 against the action of spring 105 when the charge container 115 is moved in a downward direction.

A further difference between the present embodiment and that previously described. resides in the fact that in this instance the detonator container 111 fits within the lower cylindrical portion of the charge container 115. Furthermore the exterior shape of the charge container differs in that it is provided with a circumferentially extending exterior shoulder 120. Note also that the detonator container 111 is provided with a circumferentially extending exterior rib 121 which prevents the detonator container from sliding upwardly within the charge container during actuation of the mine and also prevents the detonator container from being forced down into and jammed within the lower cylindrical portion 114 of the upper body portion 101 on actuation of the mine. As with the previous embodiment the charge container is provided about midway of its length with an O-ring 125 to provide a seal between the charge container and the inner wall of the upper body portion 101.

A circumferentially extending interior shoulder 126 is provided in the upper body portion in order to prevent the accidental insertion of the charge container illustrated in FIG. 2, into the practice mine. Thus, there is no possibility of mistakingly inserting other than a practice charge into the practice mine during maneuvers. A smoke bomb 129 and a fuse 127 is contained in the charge container 115, both these components being formed and assembled in order to fit snugly within the charge container 115. An inner cap 130 fits over the fuse and smoke charge once they have been inserted in order to seal them against moisture and an outer cap 131 fits over the upper end of the charge container. The outer cap 131 is provided as a form of smoke deflector in order to avoid an possibility of personnel using the practice mine being injured on its detonation. It will be noted that the upper portion of the charge container is formed quite differently from the upper portion of the charge container illustrated in FIG. 2 in order to accommodate both the inner and

outer caps

130 and 131 respectively and also to provide smoke release orifices 135 through the underside of the outwardly extending flange adjacent the upper end of the charge container.

The mine illustrated in FIG. 12 is shown with a safety clip 136 having a structure similar to that clip illustrated in FIG. 9 attached to it.

As with the mine illustrated in FIG. 2 most of the parts of the practice mine are formed from some form of plastic. The

. smoke deflecting outer cover l3l can be moulded from a glass-polyester mixture to eliminate the danger of cutting edges being formed due to cracking and the detonator container 111 can be moulded from polyethylene to assist in loading and to absorb some of the shock of ignition of the detonator. The remainder of the mine except for the O-ring 125 which can be formed from styrene will normally be moulded from a phenolic resin or a melamine modified phenolic resin. In the latter case the body will have a bright blue color thus rendering it a bit more distinguishable than it would be if the mine were of a black color as it would be if a phenolic resin was employed.

ASSEMBLY To assemble the mine the upper portion 2 is inverted, the

seals

6 and 32 are put in To the detonator container 5, inverted, is fitted into place, the firing pin carrier, also inverted together with the steel balls 30 and 31 positioned in the grooves 33 and 34 are fitted into their position within the detonator container 5 and upper body portion 2, the balls being fitted into their

respective slots

23 and 24 thus assembling the components in their cocked or armed position. Next the coil spring 27 is fitted over the end of the firing pin 27. The lower body portions 3, inverted, is then screwed into place. Lastly, the mine is turned right side up and the detonator 22 placed within hollow cylinder 20 which, K, course, forms part of the detonator container. A plastic dust cap 50 provided with a thong 51 to facilitate its removal, is then fitted in the position normally occupied by the charge container, as shown in FIG. 7. In this form the mine is transported.

If either of the two detonator containers illustrated in FIGS. and 11 are to be employed, the detonator should be placed in its container before the container is placed in position.

The charge container with its sealed-in charge, which may consist of pressed tetryl, is normally transported separately with a safety clip 55, clipped to it as shown in FIG. 8. Clip 55 consists of a U-shaped member 56 formed from a resilient piece of metal, having a pair of

ears

57 and 58 secured to it. The ears are provided to facilitate the clips removal.

The practice mine will also be transported in two pieces but in this instance the one piece will consist of both the detonator container and charge container assembled as shown in FIG. 12 and the other portion will consist of the remainder of the mine. The major difference thus is that in the first instance the charge and detonator are separated during transport whereas in the second instance they are together during transport.

LAYING AND ARMING The laying and arming of the mine is done in one continuous sequence. One of two methods may be used depending upon soil and visibility conditions and the urgency of the task.

The approved procedure of laying and arming is as follows:

aIHold the mine body in one hand, remove the dust cap 50 and insert the charge container with safety clip;

b. Applying pressure to the mine body shoulders only, force the mine into the ground using the hand;

c. Resistance to penetration can be overcome by loosening or removing the soil to the desired depth with a bayonet or similar instrument; and

d. Remove the safety clip 55 with a horizontal motion ensuring that the silicone rubber O-ring on the charge container does not show above the body recess.

Where soil and visibility conditions (daylight operations) minimize the possibility of stones or debris falling into the mine body recess on the removal of the dust cap 50, and a more rapid method of laying and arming is desirable, the following procedure can be followed:

a. Drive the mine body, with dust cap 50 in place, into the ground using the heel of the hand or boot;

b. Resistance to penetration can be overcome by loosening or removing the soil to the desired depth with a bayonet or similar instrument;

.. c. Makesure stones or debris are clear of the dust'cap 50 r and mine shoulders;

d. Remove the dust cap by placing one hand on the shoulders of the mine to maintain position and pulling on the nylon thong 51 with the other;

e. Insert the charge container until the safety clip 55 rests on the shoulders of the mine;

f. Remove the safety clip with a horizontal motion ensuring that the silicone O-ring on the charge container does not show above the body recess.

ACTUATION The mine is actuated when the charge container is pressed downwardly thus moving the detonator container 5, the firing pin carrier 28 and the steel balls 30 and 31 downwardly as a unit against the action of the spring 27. When the balls 30 and 31 pass the lower edge of the upper body portion they are untrapped and fall out of the grooves 33 and 34 thus permitting the carrier 28 to be forced upwardly within cylinder 21 under the reaction of spring 27 to cause the firing pin 29 to pass through bore 25 into the interior of the cylinder 20 where it pricks the detonator which detonates the charge. It should be noted that the actuation of the mine is not dependent on gravitational forces as the balls 30 and 31 are forced out of their trapped positions and are not merely released to fall out.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

We claim:

1. A two-piece, antipersonnel mine adapted to be driven into the ground comprising, a cylindrical upper body, there being an upper axial bore and a lower axial bore in said upper body, said lower bore being of a smaller diameter than said upper bore; a lower tubular body detachably secured to said upper body, said upper body flaring outwardly towards its upper end and having an annular planer surface on its top face thereof, said lower body having its lower end tapering to a point; a cylindrical charge container axially slidable in said upper bore of said upper body, its upper end normally protruding above the upper face of said upper body; an explosive charge in said charge container; at detonator carrier axially slidable in said lower bore of said upper body and normally abutting said charge container; a detonator in said detonator carrier; a firing mechanism for detonating said detonator and said charge comprising, a firing pin carrier axially slidable in the lower portion of said detonator carrier; a pair of detent balls housed in said firing pin carrier and normally retained therein by the lower wall of said upper body; a firing pin fixed in axial relation in said firing pin carrier and a coil spring axially disposed in the lower portion of said lower body and normally biasing said firing pin carrier, said detonator carrier and said charge container in an upward direction in said mine, whereby when said charge container is depressed, said detonator carrier and said firing pin carrier are moved downwardly to release said balls from said firing pin carrier and into said lower portion of said lower body, whereby said coil spring will move said firing pin carrier upwardly to fire said detonator and said charge.

Claims

1. A two-piece, antipersonnel mine adapted to be driven into the ground comprising, a cylindrical upper body, there being an upper axial bore and a lower axial bore in said upper body, said lower bore being of a smaller diameter than said upper bore; a lower tubular body detachably secured to said upper body, said upper body flaring outwardly towards its upper end and having an annular planer surface on its top face thereof, said lower body having its lower end tapering to a point; a cylindrical charge container axially slidable in said upper bore of said upper body, its upper end normally protruding above the upper face of said upper body; an explosive charge in said charge container; a detonator carrier axially slidable in said lower bore of said upper body and normally abutting said charge container; a detonator in said detonator carrier; a firing mechanism for detonating said detonator and said charge comprising, a firing pin carrier axially slidable in the lower portion of said detonator carrier; a pair of detent balls housed in said firing pin carrier and normally retained therein by the lower wall of said upper body; a firing pin fixed in axial relation in said firing pin carrier and a coil spring axially disposed in the lower portion of said lower body and normally biasing said firing pin carrier, said detonator carrier and said charge container in an upward direction in said mine, whereby when said charge container is depressed, said detonator carrier and said firing pin carrier are moved downwardly to release said balls from said firing pin carrier and into said lower portion of said lower body, whereby said coil spring will move said firing pin carrier upwardly to fire said detonator and said charge.