EP2715271B1

EP2715271B1 - A lightweight bar armor

Info

Publication number: EP2715271B1
Application number: EP12726770.6A
Authority: EP
Inventors: Tadeusz Niezgoda; Robert PANOWICZ; Kamil SYBILSKI
Original assignee: Wojskowa Akademia Techniczna
Current assignee: Wojskowa Akademia Techniczna
Priority date: 2011-05-27
Filing date: 2012-05-25
Publication date: 2014-09-10
Anticipated expiration: 2032-05-25
Also published as: WO2012163859A1; PL2715271T3; PL395023A1; EP2715271A1; IL229452A; IL229452A0; PL217168B1

Description

TECHNICAL FIELD

The object of the invention is a lightweight bar armor. It relates in general to the technical field of armors and blasting.

BACKGROUND ART

A number of passive protection arrangements can be currently used against cumulative projectile missiles. When protecting vehicles, it is important not to compromise the vehicle mobility and therefore to provide an armor which is both lightweight and effective. This can be achieved by bar armors, which are mounted at a certain distance from the vehicle.
The US patent US3765301 presents a lightweight ribbed composite armor, which comprises a combination of a steel ribbed plate bolted to an aluminum tank shell, wherein the ribbed plate is made up of a series of short vertical or inclined high hardness plates welded to a lower hardness steel plate, wherein the initial ribbed plates break up the incoming projectile and the aluminum tank shell absorbs the fragmented projectile. In order to effectively protect the vehicle from RPG-type projectiles, this requires the use of plates of relatively large dimensions, which results in a relatively high weight of the armor.
The PCT application WO2009064263 discloses a bar armor for protecting a vehicle from RPG-type projectiles, comprising a panel comprised of a plurality of spaced, generally parallel bars positioned in spaced outward relation to the body of the vehicle. The bars may have a circular, square or rectangular cross-section. Use of massive bars results in a relatively high weight of the armor.
The US patent US7191694 presents an edge reinforcement for brittle armor plates, such as windows, for improving the ballistic performance of the outer peripheral margins of such plates to incoming threat projectiles. The shield comprises an opaque armor having a rectangular shape with a perforation field extending outwardly from shield center toward outermost edges of said shield with a solid margin located between said perforation field and said shield edges. The shield protects only the outer edges of the brittle armor plates and is empty inside. The perforation is made in a direction parallel to the direction of the expected incoming missile, therefore it significantly weakens the strength of the armor.
A further bar armor is disclosed in the European patent application EP 2 020 585 A2 , which represents the starting point of the present invention.
The aim of the invention is to provide a lightweight bar armor having high efficiency and relatively low weight.

DISCLOSURE OF THE INVENTION

The object of the invention is a lightweight bar armor comprising a bar panel (20) mounted on a frame (10) and attachable to the protected object by attachments (30). The bar panel (20) comprises a plurality of flat bars (21), which are perforated over their main surface (22), the main surface (22) being inclined at an angle from 30° to 90° with respect to the main plane of the bar panel (20). Furthermore, the flat bars (21) have toothed front edges (25).
Preferably, the main surfaces (22) of the flat bars (21) are perpendicular to the main plane of the bar panel (20).
Preferably, the frame (10) comprises a plurality of flat bars (11) which are perforated over their main surface (12), the main surface (12) being perpendicular to the main plane of the bar panel (20).
Preferably, the attachments (30) have a form of flat bars (31) which are perforated over their main surface (32), the main surface (32) being perpendicular to the main plane of the bar panel (20).
Preferably, the perforations of the flat bars (11, 21, 31) have a form of circular (13, 23, 33) and/or elongated (14, 24, 34) holes.
Preferably, the perforations of the flat bars (11, 21, 31) constitute between 20% and 30%, or between 30% and 40%, or between 40% and 50%, or at least 50% of the total area of the flat bar (11, 21, 31).
Preferably, the flat bars (11, 21) have slots (16, 26) extending from the edge of the bar (11, 21) for coupling the flat bars (11) of the frame (10) with the flat bars (21) of the bar panel (20).
Preferably, the flat bars (11) of the frame (10) are welded or glued with the flat bars (21) of the bar panel (20).
Preferably, the flat bars (11) of the frame (10) have toothed front edges (15).
Preferably, the toothed front edges (15, 25) have a higher hardness than the remaining portions of the flat bars (11, 21).
Preferably, the external surface of the flat bars (11, 21, 31) is hardened.
Use of perforated flat bars in the bar panel, the flat bars being arranged at an angle, preferably perpendicularly, to the main plane of the bar panel, allows to achieve relatively low weight of the armor and provide high resistance against missiles. Moreover, use of toothed edges of the flat bars increases the efficiency of destroying incoming missiles.
The armor is especially useful when mounted on light vehicles, which are normally not protected from cumulative projectile missiles. This increases the safety of both the vehicle and its passengers. When the armor is used on heavy vehicles, then its low weight allows reduction of consumption of fuel and greases, as well as lower wear and tear of the components of the vehicle. Moreover, it does not reduce significantly the mobility of the vehicle due to relatively low weight increase.

BRIEF DESCRIPTION OF DRAWINGS

The present invention is shown by means of exemplary embodiments on a drawing, in which:

Fig. 1 shows a fragment of the bar armor according to the invention;
Fig. 2 shows a single bar constituting the panel,
Fig. 3 shows a single element of the frame.
Fig. 4 shows an attachment element.

MODES FOR CARRYING OUT THE INVENTION

Fig. 1 shows a fragment of the bar armor according to the invention. The shape of the armor can be adapted to the particular object, in particular a vehicle, to be protected. The armor comprises a bar panel 20 mounted on a frame 10, and attachable to the protected object by means of attachments 30.
The bar panel 20 of the armor comprises a plurality of flat bars 21, as shown in Fig. 2, arranged preferably in parallel to each other, which are perforated over their main surface 22. The distance between the flat bars 21 should be preferably about 80% of the largest diameter of the projectiles from which the vehicle is to be typically protected. The perforation holes 23, 24 have shapes and distribution according to the particular needs of the armor. Preferably, they are evenly distributed. The holes may be circular 23 or elongated 24. The shape and distribution of perforation holes 23, 24 may vary depending on the position of the bar 21 within the panel. Preferably, the area of the perforation holes is between 20% and 30%, or between 30% and 40%, or between 40% and 50%, or at least 50% of the total area of the flat bar 21.
The frame 10 is also formed of flat bars 11 as shown in Fig. 3. The perforation holes 13, 14 in the main surface 12 of the flat bars 11 are arranged in a similar manner as in the flat bars 21. The flat bars 11 are mounted such that their main surface 12 is substantially perpendicular to the main surface of the armor.
The flat bars 11, 21 comprise slots 16, 26 to facilitate assembly of the bar panel 10 on the frame 20. The slots 16, 26 preferably have a length of 50% of the width of the flat bar, such that when the flat bars 11, 21 are assembled, their front edges are arranged in one plane. The inclination of the slots 16 defines the inclination of the flat bars 21 with respect to the main plane of the bar panel 20. The main surfaces 22 of the flat bars 21 are inclined at an angle from 30° to 90° to the main surface of the bar panel 20, i.e. the main surface of the armor. Typically, they are arranged at an angle of 90°, i.e. perpendicularly, as shown in Fig. 1. The inclination depends on the expected angle of missile impact. For larger panels covering large area of the body of the vehicle, the angle of inclination of the flat bars 21 with respect to the plane of the panel 20 may vary depending on the area of the panel.
The flat bars 11 of the frame 10 can be welded or glued with the flat bars 21 of the bar panel 20. The coupling by slots 16, 26 and welding/gluing provides particularly high strength of the armor.
Therefore, the perforation holes 13, 14, 23, 24 significantly reduce the weight of the flat bars 11, 21, but as the edges of the flat bars 11, 21 are directed towards the expected direction of missile impact, the armor is highly resistant.
Moreover, the flat bars 11, 21 may have toothed front edges 15, 25, i.e. the edges directed towards the expected direction of missile impact, which increase the efficiency of destroying cumulative projectile missiles. The teeth are preferably triangular, with the height of the triangle equal about 50% of the base thereof.
The attachments 30 may also have a form of perforated flat bars, as shown in Fig. 3, with perforation holes 33, 34 in the main surface 32 of the flat bars 31 arranged in a similar manner as in the flat bars 21.
The flat bars 11, 21, 31 are preferably made of steel, which provides good strength and can be easily perforated using laser cutting or water-jet cutting. Preferably, the material from which the flat bars 11, 21, 31 are made is treated, for example by nitrogenizing, carbureting or hardening such that its external surface has higher hardness than the interior part, in order to provide both hardness and elasticity of the bars. The hardening treatment may be limited to the teeth 15, 25 only, in order to provide high hardness of the teeth and elasticity of the remaining part of the bar 11, 21.
In one particular embodiment, the flat bars 11, 21, 31 may have a thickness of about 3mm, a width of 3cm-5cm and teeth 15, 25 having a height of about 5 mm. The distance between the flat bars 11 of the frame 10 can be about 50cm and the distance between the flat bars 21 of the bar panel 20 can be about 7 cm to provide effective protection from RPG-type missiles.

Claims

A lightweight bar armor comprising a bar panel (20) mounted on a frame (10) and attachable to the protected object by attachments (30), wherein the bar panel (20) comprises a plurality of flat bars (21), having their main surface (22) inclined at an angle from 30° to 90° with respect to the main plane of the bar panel (20), characterized in that the flat bars (21) of the bar panel (20) are perforated over their main surface (22) and have toothed front edges (25).
The lightweight bar armor according to claim 1, wherein the main surfaces (22) of the flat bars (21) are perpendicular to the main plane of the bar panel (20).
The lightweight bar armor according to any of previous claims, wherein the frame (10) comprises a plurality of flat bars (11) which are perforated over their main surface (12), the main surface (12) being perpendicular to the main plane of the bar panel (20).
The lightweight bar armor according to any of previous claims, wherein the attachments (30) have a form of flat bars (31) which are perforated over their main surface (32), the main surface (32) being perpendicular to the main plane of the bar panel (20).
The lightweight bar armor according to any of previous claims, wherein the perforations of the flat bars (11, 21, 31) have a form of circular (13, 23, 33) and/or elongated (14, 24, 34) holes.
The lightweight bar armor according to any of previous claims, wherein the perforations of the flat bars (11, 21, 31) constitute between 20% and 30%, or between 30% and 40%, or between 40% and 50%, or at least 50% of the total area of the flat bar (11, 21, 31).
The lightweight bar armor according to claim 3 wherein the flat bars (11, 21) have slots (16, 26) extending from the edge of the bar (11, 21) for coupling the flat bars (11) of the frame (10) with the flat bars (21) of the bar panel (20).
The lightweight bar armor according to claim 3, wherein the flat bars (11) of the frame (10) are welded or glued with the flat bars (21) of the bar panel (20).
The lightweight bar armor according to claim 3, wherein the flat bars (11) of the frame (10) have toothed front edges (15).
The lightweight bar armor according to any of claims 1 or 9, wherein the toothed front edges (15, 25) have a higher hardness than the remaining portions of the flat bars (11, 21).
The lightweight bar armor according to any of previous claims, wherein the external surface of the flat bars (11, 21, 31) is hardened.