GB2099963A

GB2099963A - The protection of sheet material from the effect of explosive charges

Info

Publication number: GB2099963A
Application number: GB8213112A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-05-19
Filing date: 1982-05-06
Publication date: 1982-12-15
Also published as: DE3119786A1; IT1151338B; IT8220968A0; FR2506447A1

Abstract

The invention relates to the protection of shaped bodies of sheet material, such as metal floor components (1) of motor vehicles, from the effect of explosive charges. One or more layers of a resin-impregnated, cohesive fibre mat (2) are applied to at least one side of the shaped body (1). The resin- impregnated mat (2) is moulded to the shape of the body (1) before the resin cures, and the cured mat (2) is securely fastened (3, 4, 5, 6) to the shaped body (1). <IMAGE>

Description

SPECIFICATION The protection of sheet material from the effect of explosive charges The invention relates to a protection of a shaped body of sheet material, such as a metal floor component of a motor vehicle, from the effect of an explosive charge.

In order to protect formed bodies of sheet material, especially metal surfaces, for example the sheet metal floor-pans of motor vehicles, against the effect of explosive charges such as hand-grenades or mines which are detonated beneath them, it is known to use metal plates of appropriate thickness, especially of steel armour plate. However, these plates are expensive, and are very heavy so that under some circumstances, they adversely affect the driving capability of the motor vehicle, particularly its mobility and speed.

The object of the invention is to provide a simple and inexpensive device which can be used to protect shaped bodies of sheet material, especially metal floor components of motor vehicles, against the effect of explosive charges, in a manner which is superior to conventional armour plates which cost the same amount.

The invention provides a device for the protection of a shaped body of sheet material, such as a metal floor component of a motor vehicle from the effect of an explosive charge comprising one or more layers of a resin-impregnated, cohesive fibre mat applied to at least one side of the shaped body and securely fastened to that body by fastening devices.

The invention also provides a process for producing a protective device for the protection of a shaped body of sheet material, such as a metal floor component of a motore vehicle, from the effect of an explosive charge, comprising impregnating a cohesive fibre mat on one side with resin, applying the resin-impregnated side of the mat to the shaped body of sheet material so that the mat is moulded against the shaped body, curing the resin after the resin has cured impregnating with resin the side of the mat facing away from the shaped body, and after this resin has cured, so that the mat is now completely impregnated with cured resin, securely fastening the mat to the shaped body.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic view, partly in section of a motor vehicle floor-pan which has been protected against detonating explosive charges, by a device according to the invention, and Figure2 is a diagrammatic partially secioned view of a fibre mat which forms part of the device of Figure 1.

In Figure 1, a portion of the floor-pan 1 of a motor vehicle is represented, as a formed body of sheet material which is to be protected from the effect of explosives acting from below. This floor-pan 1 is usually manufactured from comparatively thin sheet steel. In order to protect this sheet steel against the effect of explosive charges, that is against metal fragments of hand-grenades, mines or the like, which impact with great force, the side of the floor-pan 1 which faces away from a possible explosive charge is lined with a special "blast mat" 2 which is securely fastened to this floor-pan. This fastening is for example, by means of metal strips 3, 4 which are laid over the mat, and bolts 5 with nuts 6.

The blast mat 2 is flexible and easily conforms to any curvature of the shaped body which is to be protected, that is the floor-pan 1.

The blast mat 2 is a cohesive fibre mat in the form of a thick, multi-layer fabric which is impregnated with a curable synthetic resin. The fibres from which the mat 2 is made are wholly or preferably of aramid fibres, especially Kevlarfibres. It has been found that fibres of this type render the blast mat particularly effective.

The construction of a woven mat is shown diagrammatically in Figure 2. The warp threads 11 all of which are preferably aramid yarns, run in several layers perpendicularly to the plane of the drawing.

The individual layers are connected by weft threads 12, 13, running in the plane of the drawing, to form a comparatively open-textured and absorbent fabric, the thickness of which can be between 8 and 24 mm, preferably 12 to 20 mm. In the embodiment represented in Figure 2, the weft threads 12 located at the upper and lower surfaces of the mat 2 are cotton threads, while the remaining weft threads 13 are aramid threads. The ratio of the quantites of cotton fibres to aramid fibres can be, for example, approximately 1: 3, but mats 2 can also be used which consist 100% of aramid fibres. Mixtures of other synthetic fibres, for example of polyamide, with aramid fibres can also be employed in the production of the blast mats. Instead of woven mat 2, it is also possible to use other absorbent textile mats with a substantial content of aramid fibres, for example fleece mats.

In order to install the textile mat 2 on the inner surface of the floor-pan 1, the mat is impregnated with resin, on the side which is to face the floor-pan.

The resin penetrates into the fibre structure of the mat 2, up to approximately half the thickness of the mat. Single-component or multi-component synthetic resins, preferably two-component resins, can be considered for use, in particular a polyurethane resin, a polyethylene resin and a polyvinyl chloride resin.

The fibre mat which is resin-impregnated on one side, is applied to the inner surface of the floor-pan 1, with the impregnated side against this surface, and is moulded against the floor-pan so as to fit its shape as shown in Figure 1. After the resin which impre gnats the lower half of the mat has cured, the side of the mat facing away from the floor-pan 1 impregnated with the same resin, which penetrates into the mat to a distance such that it meets, in the middle of the mat, the resin-impregnation which has already been carried out. After this further resinimpregnation has also cured, the mat 2, which is now completely impregnated with cured resin, is securely fastened to the floor-pan 1 by means of the metal strips 3 and 4, and the bolts 5 with their nuts 6.

The invention is not limited to the armouring of floor-pans of motor vehicles, but can be applied generally to formed bodies of sheet material, especially metal plates of all types which have to be protected against the effect of explosive charges or gunfire.

Depending on the protective effect aimed at, blast mats 2 of different thickness are employed. It is also possible, if appropriate, to apply several mats one above another in a layered arrangement.

Claims

1. A device for the protection of a shaped body of sheet material, such as a metal floor component of a motor vehicle, from the effect of an explosive charge, comprising one or more layers of a resinimpregnated, cohesive fibre mat applied to at least one side of the shaped body and securely fastened to that body by fastening devices.

2. A device according to Claim 1, wherein the fibre mat is composed, wholly or partially, of aramid fibres.

3. A device acccording to Claim 2, wherein the aramid fibres are Kevlarfibres.

4. A device according to Claim 1 or Claim 2, wherein the fibre mat is impregnated with a singlecomponent or multi-component resin.

5. A device according to Claim 4, wherein the resin is selected from the group consisting of polyurethane resins, polyethylene resins and polyvinyl chloride resins.

6. A device according to Claim 2, wherein the fibre mat contains cotton fibre in addition to aramid fibres.

7. A device according to Claim 2, wherein the fibre mat contains polyamide fibres in addition to aramid fibres.

8. A device according to Claim 1 or Claim 2, characterised in that the fibre mat is a fabric comprising several layers of warp threads and weft threads, which layers are connected one to another.

9. A process for producing a protective device for the protection of a shaped body sheet material, such as a metal floor component of a motor vehicle, from the effect of an explosive charge comprising impregnating a cohesive fibre mat on one side with resin, applying the resin-impregnated side of the mat to the shaped body of sheet material so that the mat is moulded against the shaped body, curing the resin and after the resin has cured impregnating with resin the side of the mat facing away from the shaped body, and after this resin has cured, so that the mat is now completely impregnated with cured resin, securely fastening the mat to the shaped body.

10. A device for the protection of a shaped body of sheet material, such as a metal floor component of a motor vehicle, substantially as herein described with reference to the accompanying drawings.

11. A process for producing a device for the protection of shaped body of sheet material, such as a metal floor component of a motor vehicle, substantially as herein described with reference to the accompanying drawings.