EP0257235A2

EP0257235A2 - Ventral mine

Info

Publication number: EP0257235A2
Application number: EP87109246A
Authority: EP
Inventors: Ferdinando Topa
Original assignee: VALSELLA MECCANOTECNICA SpA
Current assignee: VALSELLA MECCANOTECNICA SpA
Priority date: 1986-07-01
Filing date: 1987-06-26
Publication date: 1988-03-02
Also published as: EP0257235A3; IT208023Z2; IT8653588V0

Abstract

The mine (1) comprises a main charge (2) and an auxiliary charge (3) for removing the cover, enclosed within separate chambers (20, 19) of a container body (10) sealed from one another.

Description

The present invention relates to a ventral mine, particularly, but not exclusively, an anti-lorry mine of the type comprising a main charge and an auxiliary charge which is positioned above the main charge and separated from this latter by means of an element ("liner") of suitable form. In use, the auxiliary charge is caused to explode before the main charge for the purpose of expelling everything above the said separator element, in particular the cover of the mine, as well as possible camouflaging material conveniently disposed above the mine itself.
In more detail, from the structural point of view such mines essentially comprise a container within which are housed both the main charge, contained in a suitable cup-shape body, and the secondary charge essentially located at the mouth of the cup-shape body and separated from the main charge by means of the said element. Within the container there are also housed all those sensors and electronic and mechanical devices for the activation of the auxiliary charge and the main charge.
In use, the firing of the main charge causes the development of gases which, passing through air spaces which are located between the separator element and the said container flow, in particular, into an inner chamber of the container, positioned between the container itself and the cup-shape body which receives the main charge. Such gases, as well as being of no use for the purpose of expelling the material positioned above the said separator element, also cause a deformation of the container walls delimiting the said chamber and, in certain cases, cause a premature activation of the main charge. The opening of a portion of the container is sometimes facilitated by the adoption of suitable fracture lines along one wall of the container, towards which the auxiliary and main charges face. These fracture lines must, however, not be particularly deep in that this contributes to making the container itself more fragile, whilst on the other hand this latter must be dimensioned both to support mechanical stresses of a certain magnitude (accidental dropping, sowing of the mines by means of helicopters etc.) and considerable heat cycles.
The object of the present invention is that of providing a ventral mine able to overcome the above-listed disadvantages presented by mines of known type.
The said object is achieved with the present invention in that it relates to a ventral mine having a container body with a first chamber housing a main charge and a second chamber housing an auxiliary cover-opening charge, characterised by the fact that it includes means for sealingly separating the said first chamber and the said second chamber.
For a better understanding of the present invention a preferred embodiment is now described purely by way of non-limitative example and with reference to the attached drawings, in which:

Figure 1 is a transverse view of a ventral mine formed according to the present invention; and
Figure 2 is the same section of the mine of Figure 1 illustrated after explosion of an auxiliary, cover-opening charge has taken place.

With particular reference to Figure 1 a ventral mine, particularly an underbody, shell effect anti-vehicle mine is generally indicated with the reference numeral 1, of the type essentially comprising a main charge 2 and an auxiliary charge 3 disposed above the main charge 2 and having a cover-removing function.
In more detail, the main charge 2 is housed within an essentially cup-shape body 4 over which lies a separator element 5 having an essentially inverted cone structure with an annular base edge 6 which receives a corresponding upper edge 7 of the cup-shape body 4. The conical separator element 5 receives the auxiliary charge 3 within its vertex, and, above this, a suitable sensor device 8 of known type operable to control the firing of the charge 3 itself. The mine 1 further includes a container body 10 essentially comprising an upper half-shell 11 and a lower half-shell 12 which are sealingly joined together enclosing the charges 2 and 3, the associated separator element 5, the sensor device 8 and other control devices of known type generally indicated 13 all within their interior.
The upper half-shell 11 of the container 10 has a wall 15 inwardly from which extends an internally threaded annular projection 16 which is engaged, in use, by a corresponding threaded peripheral portion 17 of the edge 16 of the separator element 5. The edge 6 engages a corresponding facing annular surface of the wall 15 in such a way as to define a chamber 19 essentially delimited by the separator element 5 and the wall 15 of the half-shell 11. The effect of the continuous connection between the separator element 5 and the half-shell 11 is that the chamber 19 is essentially sealingly separated from a corresponding chamber 20 delimited by the facing surfaces of the half- shells 11 and 12 and the cup-shape body 4 containing the main charge 2.
The wall 15 of the half-shell 11 further has, on its outer face, a pair of concentric annular projections, respectively 21 and 22, between which there is an annular groove 23. In particular, the projection 21 extends essentially from the part opposite the threaded projection 16, whilst the projection 22 has a diameter less than the projection 21. Finally, it is observed that, from the inwardly facing side and essentially in correspondence with the annular groove 23, the wall 15 has an annular slot 25 with a triangular cross-section, essentially constituting a pre-fracture line of the wall 15 itself.
In Figure 2 the structure of the mine 1 is illustrated after explosion of the auxiliary charge 3 has taken place. It is noted in particular that the wall 15 of the half-shell 11 has been caused to spring up in correspondence with the pre-fracture slot 25.
From a study of the characteristics of the mine formed according to the present invention the advantages which it allows to be obtained are evident. First of all, the continuous type coupling between the separator element 5 and the half-shell 11 of the container 10 limits the volume exposed to the gas pressure developed by the auxiliary charge 3 essentially to only the chamber 19. This permits a more favourable dimensioning of the pre-fracture slot 25 in the sense that this latter can be made with a reduced transverse section (with consequent greater thickness of the resistant section) than those currently known, largely due to the fact that no dispersion of gas produced by the auxiliary charge 3 exists. Consequently, the overall structure of the container 10 is more robust and therefore stronger both from the point of view stresses of a mechanical natures and stresses of a thermal nature. In particular it is observed that mechanical stresses to which the mine is subjected when it strikes, for example, the ground, are absorbed by the container 10 and discharged directly to the ground without involving the wall 15 in any significant way. This is true both as far as stresses acting laterally are concerned and as far as stresses acting on the projection 21 (which is elevated with respect to the projection 22 belonging to the wall 15) are concerned. In particular, stresses acting on the projection 21 or on the adjacent portion of the container body 10 are discharged by means of the separator element 5 which is fixed to the body 10 by the annular threading, and via the body 10 itself.
The adoption of the projection 21 externally spaced from the pre-fracture slot 25 achieves a "piston effect" in a first stage of expulsion of the wall 15. In this stage, under the guidance of the projection 21, the wall 15 follows a short effective stroke during which the action of the pressure exerted by the gas developed by the auxiliary charge 3 is continuous and therefore a major quantity of kinetic energy is stored. Consequently, an improved yield from the auxiliary charge 3 is obtained as well as the fact that there is a directionality of the expulsion which significantly improves the separating effects of the possible camouflage material which, in use, is located above the mine 1.
Finally, it is clear that the mine 1 described above can have modifications and variations introduced thereto without by this departing from the present invention. For example, the coupling between the edge 6 of the separator element 5 and the projection 16 of the half-shell 11 of the container 10 could also be achieved in any other way as long as it is of continuous type, however, and offers the greatest possible seal. For example, this coupling could be effected by adopting snap-engagement means with the interposition of a resilient sealing ring.
It is likewise evident that the sealing separation between the chamber 19 containing the cover-separating charge 3 and the chamber 20 containing the main charge 4 can be obtained in innumerable other ways without necessarily exploiting the particular manner of connection of the separator element 5 as described above.

Claims

1. A ventral mine having a container body (10) with a first chamber (20) housing a main charge (2) and a second chamber (19) housing an auxiliary cover-removal charge (3), characterised by the fact that it includes sealing separation means (5) between the said first chamber (20) and the said second chamber (19).

2. A mine according to Claim 1, characterised by the fact that the said sealing separation means include a separator element (5) a peripheral edge (6) of which establishes a coupling of essentially sealed continuous type with a corresponding facing portion (16) of the said container body (10).

3. A mine according to Claim 2, characterised by that fact that the said peripheral edge (6) of the said separator element (5) and the said facing portion (16) of the said container body (10) are coupled together by respective threading.

4. A mine according to Claim 3, characterised by the fact that the said portion (16) of the said container body (10) is essentially constituted by an annular projection extending inwardly of the said container body (10).

5. A mine according to any of Claims from 2 to 4, in which the said main charge (2) is housed within an associated cup-shape body (4) and the said auxiliary charge (3) is housed within the said cup-shape body (4) and on the side facing the outlet mouth of this latter, characterised by the fact that the said container body (10) has, opposite the said outlet mouth of the said cup-shape body (4) and on the outwardly facing side, at least a first annular projection (21) the diameter of which is greater than the diameter of the said peripheral edge (6) of the said separator element (5).

6. A mine according to Claim 5, characterised by the fact that the said container element (10) has, on its outwardly facing side and in correspondence with the said outlet mouth of the said cup-shape body (4), a second annular projection (22) co-axial with the said first annular projection (21) and with a diameter less than the maximum diameter of the said peripheral edge (6) of the said separator element (5).

7. A mine according to Claim 5 or Claim 6, characterised by the fact that the said container body (10) has an annular pre-fracture slot (25) on the side facing the said separator element (5), the diameter of which slot is less than the inner diameter of the said first annular projection (21) extending outwardly.

8. A mine according to Claim 7 when dependent on Claim 6, characterised by the fact that the said diameter of the annular slot (25) lies essentially between the respective inner and outer dimaeters of the said first and second projection (21, 22).