Ballistic armor having a flexible load distribution system

• US 5,738,925 A
• Filed: 04/10/1996
• Issued: 04/14/1998
• Est. Priority Date: 04/10/1996
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Chaput, Armand Joseph
• Primary Examiner(s): Ahmad, Nasser
• Application Number:
  US08/629,808
• Time in Patent Office: 734 Days
• Field of Search: 428/101, 428/911, 428/156, 428/161, 428/173, 428/174, 428/178, 89/36.01, 89/36.02, 2/2.5
• US Class Current: 428/101
• CPC Class Codes: B32B 2571/02 defensive, e.g. armour plates, anti-ballistic clothing camouflage nets B32B2459/00
• CPC Class Codes: B32B 3/10 characterised by a discontinuous layer, i.e. formed of separate pieces of material
• CPC Class Codes: B32B 3/18 characterised by an internal layer formed of separate pieces of material which are juxtaposed side-by-side B32B5/02 takes precedence
• CPC Class Codes: B32B 38/0012 Mechanical treatment, e.g. roughening, deforming, stretching
• CPC Class Codes: B32B 5/06 characterised by a fibrous or filamentary layer mechanically connected, e.g. by needling to another layer, e.g. of fibres, of paper
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: F41H 5/0428 Ceramic layers in combination with additional layers made of fibres, fabrics or plastics
• CPC Class Codes: F41H 5/0492 Layered armour containing hard elements, e.g. plates, spheres, rods, separated from each other, the elements being connected to a further flexible layer or being embedded in a plastics or an elastomer matrix
• CPC Class Codes: Y10S 428/911 Penetration resistant layer
• CPC Class Codes: Y10T 428/24025 Superposed movable attached layers or components
• CPC Class Codes: Y10T 428/24479 including variation in thickness
• CPC Class Codes: Y10T 428/24521 with component conforming to contour of nonplanar surface
• CPC Class Codes: Y10T 428/2462 with partial filling of valleys on outer surface
• CPC Class Codes: Y10T 428/24628 Nonplanar uniform thickness material
• CPC Class Codes: Y10T 428/24661 Forming, or cooperating to form cells

Abstract

A flexible protective armor is provided with a very hard microstructure and a flexible macrostructure for flexurally deforming along smooth curves when impacted by a ballistic projectile, and then rebounding after the impact. The flexible protective armor includes an outward layer of hard geometric shapes, preferably spheres, which are firmly mounted to an outward side of a flexible membrane. The flexible membrane is preferably a ballistic fabric which is formed of a sixty degree weave of ballistic fibers. The spheres have mounting portions and side engagement portions. The mounting portions of the spheres are firmly bonded to the flexible membrane by a rigid adhesive, with the spheres tightly packed to mechanically interlock the side engagement portions of adjacent ones of the spheres for rotating relative to on another, free of the rigid adhesive. The kinetic energy of a fast moving projectile is absorbed upon impact with the flexible protective armor by curving of the layer of spheres and the flexible membrane, tensioning the ballistic fibers of the flexible membrane within the elastic range of the ballistic fibers so that the flexible protective armor will rebound after impact. A fiber reinforced pliable material is disposed within the interstitial spaces between the spheres and the flexible membrane to absorb the energy of the spheres when the flexible protective armor is rebounding after impact. A flexible, impact resistant polyurethane coating extends across on outward side of the layer of spheres.

Claims

1. A flexible protective armor for protecting against impacts of fast moving projectiles, the flexible protective armor comprising:

a first flexible membrane having a 60 degree weave of ballistic fibers;

a first layer of hard spheres having mounting portions and mechanical engagement portions, the first flexible membrane and the first layer of spheres comprising a first armor layer;

adhesive fixedly bonding the first layer of the spheres to the flexible membrane, outward of the flexible membrane, with the mounting portions of the spheres being bonded to the ballistic fibers such that the spheres are tightly packed with the mechanical engagement portions of adjacent ones of the spheres in contact for rotating relative to one another, free of the adhesive;

a second armor layer having a second flexible membrane and a second layer of hard spheres, the second layer of spheres being rigidly bonded to one side of the second flexible membrane and adjacent ones of the spheres disposed in contact for rotating relative to one another;

a slipping attachment means for mounting the second armor layer to the first armor layer, with the second layer of spheres disposed outward of the first armor layer and the second flexible membrane; and

wherein kinetic energy of the fast moving projectiles is absorbed by flexural bending of the layers of spheres and the flexible membranes, with a portion of the spheres rotating relative to adjacent spheres, stretching the ballistic fibers.

2. The flexible protective armor according to claim 1, wherein the slipping attachment means comprises a hook and loop fastener.

3. A flexible protective armor for protecting against impacts of fast moving projectiles, the flexible protective armor comprising:

a flexible membrane having a weave of ballistic fibers;

a plurality of hard spheres having engagement portions, the engagement portions of the spheres being in contact with the spheres; and

each of the spheres being independently bonded to the membrane by a discrete adhesive portion which is spaced apart from adjacent adhesive portions such that the spheres are tightly packed and mechanically interlocked with the engagement portions of adjacent ones of the spheres allowing limited rotational movement relative to one another.

4. The flexible protective armor according to claim 3, further comprising:

a pliant material disposed in interstitial spaces between the spheres; and

an impact resistant layer disposed on one side of the spheres, opposite the flexible membrane.

5. The flexible protective armor according to claim 3 wherein the engagement portion of each of the spheres comprises a portion of an exterior surface of each of the spheres.

6. The flexible protective armor according to claim 3 wherein the engagement portion of each of the spheres comprises a concave socket on each of the spheres and a protuberance between adjacent ones of the spheres for engaging each of the sockets.

7. The flexible protective armor according to claim 3 wherein the engagement portion of each of the spheres comprises a spherical protuberance on one side of each of the spheres and a concave socket on an opposite side of each of the spheres for receiving the protuberance of an adjacent one of the spheres.

8. A flexible protective armor for protecting against impacts of fast moving projectiles, the flexible protective armor comprising:

a layer of cushioning material on a first side;

a first layer of hard spheres located on one side of the layer of cushioning material;

a flexible first membrane having a weave of ballistic fibers bonded to the first layer of spheres opposite of the layer of cushioning material;

a layer of ballistic fibers located on an opposite side of the first membrane from the first layer of spheres;

a flexible second membrane having a weave of ballistic fibers located on an opposite side of the layer of ballistic fibers from the first membrane; and

a second layer of hard spheres bonded to an opposite side of the second membrane from the layer of parallel ballistic fibers.

9. The flexible protective armor according to claim 8 wherein the spheres within each of the layers of spheres contact one another at a point on an exterior surface of the spheres.

10. The flexible protective armor according to claim 8, further comprising:

a flexible third membrane having a weave of ballistic fibers located on an opposite side of the second layer of spheres from the second membrane; and

a third layer of spheres bonded to an opposite side of the third membrane from the second layer of spheres.

11. The flexible protective armor according to claim 8, further comprising an attachment layer connecting the third membrane to the second layer of spheres, the attachment layer having means for allowing portions of the second layer of spheres to detach from the third layer of spheres in the event of an impact of sufficient magnitude.

12. The flexible protective armor according to claim 11 wherein the attachment layer comprises hook and loop fasteners.

13. The flexible protective armor according to claim 8 wherein the spheres of each of the layers are independently bonded to their respective membranes.