FR2815447A1 - Tear or laceration detector for textile covering material such as tarpaulin uses supple electric wire passing through PVC-coated mesh - Google Patents

Abstract

The detector comprises a supple electric wire (2) passed through the mesh of a woven textile material (1) and projecting from the edges of the mesh so that it can be connected to other wires or an alarm system.

Description

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The present invention relates to a device which, added to a tarpaulin (on a fixed or mobile structure, on the ground or on a vehicle) or any other flexible covering assembly (tent canvas, etc.), makes it possible to prevent any attack by laceration or tearing, playing the role of sensor, once connected to an alarm center.

 Attempts have been made to include an electrical conductor in a fabric at the time of weaving; but problems persist to obtain continuity of the electrical circuit in weaving, and in the production of the finished product (tarpaulin, tent, etc.) due to the cutting of the canvas for making. And the problem of repair after deterioration persists, because it is almost impossible to replace a piece of broken wire in a fabric, especially if the latter is coated with a coating.

 The device according to the invention meets the need, while eliminating the drawbacks mentioned above. In fact, it has, according to a first characteristic, a woven grid coated with PVC, cut to the desired size, and, according to a second characteristic, a flexible electric wire passing through the meshes of the grid according to a pre-established scheme aimed at ensuring the best protection. possible. Both ends of the wire protrude from the grid, and are fitted with connectors. The device being relatively limited in its dimensions, due to the mounting difficulties beyond a certain size, the connectors allow an infinite association of devices for the protection of large tarpaulins. The device is integral with the surface which it equips by means of high-frequency welds, or hot welding, if the surface is in canvas coated with PVC, or by means of glue or seams. The free connectors (one at each end of a device or a combination of devices) are connected to an alarm center; once the circuit is energized, if it is broken by a laceration of the sheet, and therefore by a wire cut, the alarm is triggered. In this case, a simple and quick repair can be carried out, without special tools: it is enough to shorten, then to strip the ends of the wire at the location of the cut, and to insert a new piece of wire whose ends have also been stripped, in order to make contact with the wire of the device, by splices.

 The accompanying drawings illustrate the invention: FIG. 1 represents the mode of insertion of the wire on the grid for the device.

Figures 2,3, 4,5 show different possible variants of the device.

FIG. 6 represents an exemplary embodiment of the device.

FIG. 7 represents the possible areas for fixing the device.

FIG. 8 represents an example of use of the device.

 With reference to these drawings, the device comprises a textile grid coated with PVC (1) with 1 to 3 threads per centimeter, through the mesh of which passes a sheathed flexible multi-strand electrical wiring wire (2). The grid can be cut into shapes (square, rectangle) and various dimensions (see Figures 2 to 5); but the difficulties of inserting the wire being proportionally increasing with the size of the grid, we

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2 considère que la surface de celle-ci n'excédera pas 1, 5m2. La mise en place du fil peut se faire selon divers schémas ; en zigzag (figure 2 et 3), en diagonale (figure 4), en quadrillage (figure 5), ou autres... De chaque côté de la grille dépassent les deux extrémités du fil électrique (3), qu'on équipera de connecteurs afin de pouvoir relier aisément le dispositif à un assemblage semblable ou à une centrale d'alarme.

2 considers that the surface thereof will not exceed 1.5m2. The establishment of the wire can be done according to various schemes; zigzag (Figure 2 and 3), diagonally (Figure 4), grid (Figure 5), or other ... On each side of the grid exceed the two ends of the electric wire (3), which will be fitted with connectors in order to be able to easily connect the device to a similar assembly or to an alarm center.

 Figure 6 shows the detail of a possible embodiment of the device. The grid (1) is cut so that it forms a square; the electric wire (2) follows a zigzag pattern, as in figure 2. The wire (2) starts from the bottom of the grid (1), on the left, to go up in zigzag up to the top, then goes down along the right side of the grille (1) to the bottom. The ends of the wire (3) are free and provided with connectors. Whatever the arrangement of the wire (2), the edges of the grid are left unoccupied on a surface sufficient to allow the device to be fixed on the surface to be protected. This fixing zone (4), either by welding, by gluing or by sewing, is represented by hatching in FIG. 7. Fixing zones (4) are also provided on the surface of the grid (1), in more than the edge, and outside the areas occupied by the wire (2), in order to ensure optimal adhesion of the device on the equipped surface.

 FIG. 8 represents an example of use of the device. In the present case, several devices are fitted to the vertical (side) surfaces of a truck tarpaulin. The devices are interconnected by the ends of the wire (3) equipped with connectors, and the free ends are connected to an alarm center fitted to the vehicle. If the tarpaulin is attacked by laceration, the circuit is broken and the alarm is triggered.

 To make the device, it is first necessary to cut the grid (1) to the desired dimensions, using a pendulum chisel for example. The insertion of the electric wire (2) in the grid can be done using a knitting needle, which will have been made a hole serving as an eye, for the passage of the wire (2) (the insertion manual is the only way).

 A variant can be envisaged, but only in the context of industrial production, since it requires investment in specific machines, dedicated to this task, involving significant depreciation to be expected. This involves using a modified embroidery machine to fix the electric wire (2) by stitching on the grid (1), and no longer pass it through the stitches of the grid (1).

This variant implies the possibility of fixing the electric wire (2) directly on the surface to be protected (tarpaulin or other flexible surface), and allows larger surfaces protected by the device.

Claims (7)

 1) Tear or laceration detector device on a tarpaulin, characterized by a flexible electric wire (2) passing through the meshes of a PVC coated textile grid (1). 2) Device according to claim 1 characterized in that the electric wire (2) extends at its two ends outside the grid (1), in order to be able to be connected to other grids identically equipped, or to a central alarm system. 3) Device according to claims 1 and 2, characterized in that the electric wire (2) is terminated, at its ends, by connectors in order to facilitate the electrical connections between identical devices, or between devices and a central alarm. 4) Device according to claims 1,2 and 3, characterized in that a large covering surface can be protected by a set of as many devices as necessary, electrically connected to each other, the first and the last being connected to an alarm center. 5) Device according to claim 1, characterized in that the electric wire (2), in case of cut, can easily be repaired, by replacing the cut end with a piece of new cable, simply laid by splicing, without special tools. 6) Device according to claims 1 to 5, characterized in that it can be adapted to any type of tensile structures (tarpaulins, tents, etc.), either by high-frequency welding, or hot welding, or by gluing, if it is a coated canvas structure, either by sewing. 7) Device according to claims 1 to 6, characterized in that the electric wire (2) can be directly fixed to the grid or to the surface to be protected (tarpaulin, or other flexible support) thanks to an embroidery machine specially modified for attachment by stitch on support.