US2970544A - Fuse for anti-tank mine - Google Patents

Description

Feb. 7, 1961 K. o. B. MALM FUSE FOR ANTI-TANK MINE Filed Feb. 6, 1958 2 Sheets-Sheet 1 Fig.

5 H M w w 1M rm fl L W 08 L M K Feb. 7, 1961 K. o. B. MALM FUSE FOR ANTI-TANK MINE 2 Sheets-Sheet 2 Filed Feb. 6, 1958 IN V EN T OR.

KARL OLOF BERT/L. A IALM ,47' TORNEYS U ed tes Patent FUSE FOR ANTI-TANK MINE Karl Olof Bertil Malm, Stockholm, Sweden, assignor to Aktiebolaget Bofors, Bofors, Sweden, a Swedish com- The present invention relates to anti-tank mines having an ignition mechanism including an ignition pin which is forced by the weight of a tank or other heavy vehicle to penetrate a priming charge.

Modern tanks are constructed to offer greater resistance to mines than formerly. This means that more eflicient mines are required to produce the desired destructive effect which is usually such that the tank cannot be repaired on the battlefield, and therefore that the weight of explosive contained in the mine should be as great as possible, compared with the total weight of the mine, which from the point of view of handling should not exceed a certain limit.

It should also not be possible to detect the mine with an electric mine detector and the mine therefore should not comprise detectable amounts of metal.

The mine should function under all weather conditions and after having been stored for a long period of time. It should also be easy to handle and arrange and should be easily exploded when hit by'a tank. On the other hand, it should be insensitive to pressure waves from explosions caused by near hits from artillery projectiles, other mines, and the like.

Our invention has for its object to provide an antitank mine which complies with the above requirements.

In the anti-tank mine according to our invention the ignition mechanism comprises a hollow body formed of a resilient material, a shaft mounted in the hollow body and having its inner end provided with a spherical surface, a disc which has a spherical surface abutting the spherical surfacelof the shaft and which will deform on impact, and a spring disc movable by deformation of the first-mentioned disc to cause the ignition pin to penetrate the priming charge.

Our invention will be understood from the following description'with reference to the drawings accompanying the provisional specification, in which:

Figure 1 is an isometric view, partly in section of a mine according to the invention.

Figure 2 is an exploded view of the ignition mechanism, and

Figure 3 is a vertical section through the ignition means when being actuated.

The mine shown in Figure 1 comprises a shell 1 of moulded hexotol or TNT reinforced with glass fibres. The shell is filled with a main charge 2 of moulded explosive and is furthermore provided with a primary charge 3, preferably of pressed explosive. A socket 4 is united with the shell 1 and receives an ignition device 5 which may be screwed into the socket 4.

p The mine may be provided with a handle and with arrangements (not shown) for mounting camouflage.

The ignition device which is shown in detail in Figures 2 and 3, comprises a hollow body 6 which is made of a resilient material and receives an actuating pin in the form of a solid shaft 7 provided at its inner end with a member 8 having a spherical surface 9. The 'o'uterpar't of the body 6 is receivedfin an inwardly taing, radial arms 11, and the inner end of the body is rigidly connected to a hollow threaded plug member 12.

In the plug member 12 is arranged a disc 13 which is provided with a flange 14 that engages a closure member 15 for the hollow body 6 and the plug 12. The upper surface of the disc is convex relative to surface 9 and in contact with or nearly in contact with the spherical surface 9 of the member 8. In the closure member 15 is fitted a conical spring disc 16 in the centre of which is axially mounted a pin'17. The spring disc 16 has two positions of rest, an upper one and a lower one: in the lower position the pin 17 penetrates'a priming charge 18 arranged in the projecting portion of the closure member 15.

All the above mentioned parts of the ignition device, except pin 17, may be made of non-metallic materials, eg, synthetic resins. The advantage is thereby obtained that the mine cannot be detected by any known type of mine detector. The pin 17 may be made of steel as it is so small that in practice it is not detectable.

The parts of the ignition device are preferably glued I together so that the device can be handled as a single unit which has only to be screwed into the mine when the mine is to be laid.

When the treads of a tank pass over the mine and press down one of the arms 11, as indicated in Figure 3 by an arrow the downward force will be transmitted through the shaft 7 and the member 8 to the disc 13, which will be broken. The spring disc 16 will thereby be snapped from the position of rest shown in Figure 2 to the position shown in Figure 3 to cause the pin 17 to enter the priming charge 18, which will ignite the mine.

It will be noted that the ignition device has no safety mechanism which has to be removed after the mine has been laid.

The ignition device is prevented from premature ignition by the body 6 which has to be compressed a little before the shaft 7 can move downwards. Furthermore the disc 13 offers a substantial resistance tobeing broken.

On the other hand the ignition device will function very reliably when subjected to a heavy force. As shown in Figure 3, a force which causes an inclination of the shaft7 will be converted into an axial force by means of the spherical surface 9 of the member 8.

' I claim:

1. A self-contained fuse for insertion into a pressure detonated land mine comprising, in combination, a nonmetallic housing having a pair of longitudinally spaced apart end parts and a central part interposed therebetween, one of said end parts containing a primer charge, the other one of said end parts comprising a resilient sleeve, all of said end and central parts being integrally connected together for insertion as a unit into a land mine, an actuating pin longitudinally mounted within said resilient sleeve, said actuating pin having an end facing said one end part and terminating in a convexly curved surface, a frangible disc interposed within said central part between said pin end and said one end part, said disc being in proximity with said curved pin surface, a'dished springy disc interposed within said central part of said housing between said frangible disc and said one and part, said springy disc being movable into positions of opposite curvature in response to an axial pressure applied thereto, and a firing pin depending from said' dished disc toward the primer charge, said springy disc being sprung into the position of curvature in which said firing pin is remote from the primer charge, moveof said resilient sleeve in response to a substantially longis Patented Feb. 7, 1961 tudinal directed component of an actuating force causes movement of said actuating pin against said frangible disc causing fracturing thereof and snapping of said springy disc into said position of opposite curvature.

2. A fuse according to claim 1 and further comprising a rigid sleeve member receiving said resilient end part and the actuating pin mounted therein, a longitudinally directed pressure component applied to .said rigid sleeve member causing a partial collapse of said resilient end part and then movement of said actuating pin toward the frangible disc.

3. A fuse according to claim 2 wherein the inner wall of said rigid sleeve member is inwardly tapered and said resilient end part is correspondingly tapered.

4. A fuse according to claim 2 wherein said rigid sleeve member comprises radially extending fins at its References Cited in the file of this patent UNITED STATES PATENTS 2,487,818 MacFarland Nov. 15, 1949 2,488,547 Liljegren Nov. 22, 1949 2,514,481 Liljegren July 11, 1950 FOREIGN PATENTS 693,479 Great Britain July 1, 1953

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