Molded Composite Armor

Other advantages and features will be clear from the following description of a number of embodiments of the invention given by way of non-limitative examples and shown in the accompanying drawings in which :

FIG. 1 is a diagrammatic view in section of a mold for casting armor according to the invention:

FIG. 2 is a section along the broken line 11--11 in FIG. 1 showing how the inserts are disposed:

FIG. 3 is a diagrammatic section through an insert according to a variation of the invention, and

FIG. 4 shows how inserts according to FIG. 3 are fitted together.

In the drawings, a mold 10 for casting a plate, inter alia metal armor, bounds a chamber 12 adapted to be filled by metal liquid during casting. The mold and the method of casting are conventional and appropriate to the nature of the cast component, and need not be described.

Inserts are disposed in mold 10 and only six inserts 14, 16, 18, 20, 22, 24, grouped in two parallel rows 26 and 28, are shown in the drawings. Inserts 14-24 are all identical and each have a cylindrical ceramic core 30 embedded in a metal shell 32. Shell 32 has two diametrically opposite projections or tenons 34, 46. The ceramic inserts are manufactured and embedded beforehand by methods well known to the experts, e.g. they are embedded by molding. The inner walls of mold 10 have pairs of facing blind holes 38 receiving the tenons 36 of inserts 14-24. The parts can be interlocked by hand or semi-automatically. It is easy to see that, after mold 10 has been closed, inserts 14-24 are positioned and held in the mold in a network determined by the position of holes 38. Spaces 40 are left between inserts 14-24 and are sufficiently large for the liquid metal to flow through them when mold 10 is filled. In the example illustrated in FIGS. 1 and 2, the height of the cylindrical inserts 14-24 is equal to their diameter and they are disposed regularly in a grid. The axes of each pair of adjacent inserts, e.g. 14, 16 or 14, 20, are perpendicular in order to facilitate the flow of liquid metal between the inserts.

The metal for embedding the inserts can be the same as or different from the metal used for the armor, and the whole is designed so as to prevent shells 32 melting when the armor is cast. Consequently, inserts 14-24 remain in the correct position. After the plate has been taken out of the mold, the projecting parts of tenons 36 can be removed by any appropriate means.

Of course, inserts 14-24 can have a different shape, e.g. prismatic or spherical, or some inserts can have a shape and/or size different from the others, in which case the positioning network will be adapted accordingly. The inserts can be relatively positioned by connections between them, thus simplifying the molds.

The ballistic efficiency is increased by a multi-layer structure, in which case connections are provided between the inserts to form a cross-linked structure which can be inserted into mold 10.

FIG. 4 by way of example, illustrates a three-layer structure comprising an assembly of spherical inserts 42 of the kind shown in FIG. 3. Each insert 42 is embedded in a shell 44 having tenons 46 and diametrically opposite mortices 48 which can be fitted together in a predetermined spatial network in one or more layers. Advantageously, the inserts 42 are disposed in staggered rows and/or are made to partially overlap, by disposing the tenon/mortice pairs 46, 48 at an acute angle as illustrated in the drawings. The resulting cellular structure leaves spaces for liquid metal to flow between inserts 42 and, after the metal has solidified, the inserts are incorporated in the armor in well-defined positions.

Of course, the inserts can be joined by a different method, inter alia by bars which are received in associated orifices in the inserts or by cages which hold the inserts. The inserts are not necessarily embedded, even though embedded inserts are the preferred embodiment of the invention. The metal forming the armor can be steel or a light alloy or any other appropriate metal or alloy.