AU2003268586A1

AU2003268586A1 - Armouring

Info

Publication number: AU2003268586A1
Application number: AU2003268586A
Authority: AU
Inventors: Hans Von Rosbitzky
Original assignee: Blohm and Voss GmbH
Current assignee: Blohm and Voss GmbH
Priority date: 2002-12-13
Filing date: 2003-12-11
Publication date: 2004-07-01
Also published as: DE10258411A1; EP1429105A1

Description

P1ool Section 29 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: Armouring The following statement is a full description of this invention, including the best method of performing it known to me us:

ARMOURING

FIELD OF THE INVENTION The invention relates to multi-layer armour-plating which include at least two sheets or plates of different materials, wherein at least one of the sheets is made of steel.

BACKGROUND OF THE INVENTION Contrivances for armouring, in particular armour-plating, are used for a variety of different civil and military applications. By way of example, there are armour-plating embodiments composed entirely from steel. These provide high impact resistance against projectiles but attract the penalty of high weight.

Equally known is multi-layer armour-plating which incorporates different material combinations, eg plastics with ceramics and aramid fibres.

Known armouring plates thus either have a relatively high weight, which make their use in ship and land vehicle applications problematic, and alternatively meet required specifications only under very specific conditions.

It is an aim of the present invention to provide multi-layer armour plating of the type mentioned above, which is relatively lightweight whilst providing high resistance (or protection) against projectile impact.

SUMMARY OF THE INVENTION In accordance with the invention there is provided armour-plating having at least two sheets or plates of different materials, wherein at least one of the plates or sheets is made of steel, characterised in that an intermediate plate or sheet is made out of wood and is arranged between two steel plates or sheets.

In the present specification, the expressions "sheets" and "plates" are used interchangeably, in so far as it concerns one of the definitional boundaries or differences that exist between these two terms, i.e. the thickness of such planiform objects. In the context of the invention, the thickness of the sheets or plates may vary depending on the use/application of the multi-layer armourplating. Thus in some embodiments one may indeed have individual plates stacked on one another (a plate in itself has a greater rigidity and resistance against out of plane bending as compared to a thin sheet of the same material, due to its thickness) whereas in other applications the multi-layer armouring structure may consist of a plurality of stacked thinner sheets or plates and sheets that make up the overall thickness of the multi-layer armour plating.

The use of two steel sheets (or plates) in between which is arranged the intermediate wooden layer achieves a notable increase in the ballistic efficiency per unit weight of a sandwich armour-plating. An impacting projectile undergoes plastic deformation when hitting/impacting on the first steel layer, the impact and penetration into the steel layer also imparting a change in projectile trajectory.

Within the wooden layer, a further change in the trajectory of the projectile is accomplished, whereby projectile splinters which have been created at impact on the first steel layer will radiate from the impact zone, and a rotary movement with superimposed tumble movement will be imparted on to the projectile splinters and particles. Consequently, on reaching the second steel plate, the kinetic energy of the projectile is transformed into mechanical forming energy over a large(r) impact zone (surface).

Experiments conducted with armour-plating embodiments in accordance with the invention indicate that such armouring has the same armouring efficiency as compared to a comparable armour plate made entirely from steel, but has a weight that is about 30% lower than the steel armour plate. Vice versa, a desired or predetermined armouring efficiency may be achieved with notably reduced overall weight of the plating.

An increased ballistic effectiveness can be achieved in that the intermediate sheet (or layer) is made from at least one hardwood.

It is in particular intended to have at least some portion of the intermediate sheet be composed of beechwood.

The tumbling movement of the impacting and penetrating projectile can be enhanced by arranging the wooden intermediate sheet such that at least some of the ligneous wood fibres extend at least partially parallel to the exterior layers.

A defined positioning of all plate (or sheet) layers in relation to one another may be improved by gluing the steel plates to the wooden intermediate sheet.

An advantageous armour-plating can be provided by employing thin-rolled armouring steel for at least one of the metal plates.

A substantially uniform armouring efficiency may be achieved over the entire armouring zone by ensuring that the layers of the plating are arranged substantially parallel to one another.

To achieve an optimum relationship between armouring efficiency and weight it is advantageous to provide the individual steel plates with a relative distance to one another of about 20 to A further enhancement of the effectiveness may be achieved by using, at least in some areas of the armouring, bonded wood, eg plywood.

To improve traverse deviation of projectile fragments within the wooden sheet, the latter should preferably consists of a plurality of parts that are bonded together. This also achieves an increased internal effectiveness surface of the armouring.

The ballistic effectiveness of the intermediate wooden layer itself can be increased by employing compacted/compressed wood.

A typical thickness for the steel plates between which the intermediate wooden sheet is sandwiched is about 5mm, bearing in mind that this value is dependent on the required ballistic protection degree.

Beyond design parameters pertaining to the steel plates themselves, the intermediate sheet may advantageously have a thickness of approximately 20 to In order to achieve an increased acoustic dampening, increased fire resistance as well as improved resistance against radiation, a preferred embodiment of the armouring will employ so-called armouring wood which provides additional increased ballistic protection.

It should be noted that whilst the above described preferential arrangements suggest a three- layer constitution of the armour-plating, additional layers of other materials may be present, the important aspect of the invention residing in the sandwiching of the wooden sheet between facing steel plates.

Further features and advantages of the invention are referred to in the following description of a non-limiting, preferred embodiment of the invention, which is provided with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective illustration of the individual plates/layers of a 3layer sandwich armour-plating before gluing of the plates to one another; and Figure 2 is a cross section of the 3-layer sandwich armour-plating following assembly.

DESCRIPTION OF PREFERRED EMBODIMENT Figure 1 illustrates in perspective view the individual components of the contrivance for armouring in accordance with the invention. An external plate 1 is made out of steel and arranged substantially parallel and with distance to an interior plate 2, which is also made out of steel. An intermediate layer or plate 3 made of wood is positioned between the exterior and interior plates 1, 2. In particular, the intermediate layer is made from hardwood. The use of beechwood has proven particularly useful. Use of compressed or otherwise compacted wood increases the ballistic effectiveness of the intermediate layer 3. The use of compressed and bonded wood sheet layers to form the intermediate sheet 3 has proven particularly advantageous.

Bonding of the exterior and interior plates 1, 2 to the intermediate layer 3 ensures a reliable connection between the layers, whereby use of whole-surface (as compared to spot) bonding provides added efficacy.

Figure 2 illustrates the sandwich structure of the armouring and in particular the direct, surface to surface contact of the exterior and interior plates 1, 2 with the intermediate layer 3. The intimate contact of the layers 1, 2, 3 ensures that the geometric structure of the sandwiched contrivance is maintained upon a projectile impacting on the armouring.

Persons of skill in the art would be aware of specific steel types that can find use in the manufacture of embodiments of armour plating in accordance with the invention, eg thin-rolled armouring steel sheets of a desired thickness, eg mm, in between which is then located and bonded the wooden intermediate plate, eg a 25 mm thick, multi-piece hardwood laminate.

Claims

1. Armour-plating having at least two sheets or plates of different materials, wherein at least one of the plates or sheets is made of steel, characterised in that an intermediate plate or sheet is made out of wood, and in that the intermediate plate or sheet is arranged between two steel sheets or plates.

2. Armour-plating according to claim 1, characterized in that the intermediate sheet is made from at least one hardwood.

3. Armour-plating according to claim 1 or 2, characterized at least some portion of the intermediate sheet is composed of beechwood.

4. Armour-plating according to any one of claims 1 to 3, characterized in that at least some of the ligneous fibres within the wooden intermediate sheet extend at least partially parallel to the steel plates.

Armour-plating according to any one of claims 1 to 4, characterized in that the steel plates and the intermediate sheet are bonded to one another.

6. Armour-plating according to any one of claims 1 to 5, characterized in that at least one of the metal plates consists of thin-rolled armouring steel.

7. Armour-plating according to any one of claims 1 to 6, characterized in that the steel plates are arranged substantially parallel to one another.

8. Armour-plating according to any one of claims 1 to 7, characterized in that the steel plates are arranged with a distance of about 20 to 30mm from one another.

9. Armour-plating according to any one of claims 1 to 8, characterized in that the wooden intermediate sheet consists at least partially of bonded wood, eg plywood.

Armour-plating according to any one of claims 1 to 9, characterized in that the wooden intermediate sheet is composed of a plurality of wooden parts that are bonded together.

11. Armour-plating according to any one of claims 1 to 10, characterized in that the wooden intermediate layer includes or is made of compressed wood.

12. Armour-plating according to any one of claims 1 to 11, characterized in that the steel plates have a thickness of about

13. Armour-plating according to any one of claims 1 to 12, characterized in that the wooden intermediate sheet has a thickness of approximately 20 to

14. Armour-plating according to any one of claims 1 to 13, characterized in that the wooden intermediate sheet consists at least partly of armouring wood. DATED this 11th day of December 2003 BLOHM VOSS GMBH WATERMARK PATENT TRADE MARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN. VIC. 3122.