GB2078799A - A process for automatically according joining together a sheet of material and a net and product so obtained - Google Patents

Abstract

A process for joining together in overlay relationship and by discrete seams, a sheet of material 4 and a net 2 by means of an automatic multineedle sewing machine is disclosed. The material and the net are fed in form of rolled webs to a quilting machine that applies stitches according to prefixed designs. Particularly for manufacturing camouflaged sheets, the material suitably dyed on both faces and partially punched is sewn to the cords of an underlying net with the meshes slightly brought closer by means of longitudinal tension and guide means so as to get crimplings and raisings of areas of material when the sheet is laid over an object having unregular shape. <IMAGE>

Description

SPECIFICATION A process for automatically joining together a sheet of material and a net and product so obtained The invention relates to a process for joining together in overlay relationship and by discrete stitches, a sheet of material and a net.

Whereas the process can be used in several fields of the technique, it is particularly suitable for manufacturing camouflaged covering surfaces or camouflaged sheets adapted to conceal vehicles, persons, works etc. making them undistinguishable from the surrounding vegetation or environment.

So called camouflaged covers, built up by protecting sheets having spotted colours and adapted to hide the object thereunder are well known. An improvement to such covers was achieved by employing a light weight supporting material formed by a wide-mesh net over which a lighter cloth or sheet, often partially punched or indented, is applied, thereby obtaining the advantages of an appreciable weight reduction and a better masking due to the wavy and raised portions of material when the sheet is laid over unregular surfaces. At present these sheets are made by hot sealing a plastic material sheet, e.g. a PVC sheet suitably spot dyed and punched in advance, onto a supporting material formed by a wide-mesh plastic covered net, e.g. coated with PVC.The main inconvenience of this camouflaged sheet is the low resistance of the PVC to atmospheric agents, particularly the exposition to sun rays, which often produces a softening of the material with consequent undesired sticking, tears, etc. that shorten the life and decrease the efficiency of the camouflaged sheet.

It has also been proposed to join the sheet of camouflaged material and the net by means of local sewings at the cords of the meshes, but such a solution, although desirable, involves a very high cost since the necessary sewings must be handmade or by means of special machines that are disadvantageously employed to stitch oniy at limited areas. Besides preventing an automatized mass production because of the unavoidable unevenness of the stitch pattern, the camouflaged sheet so produced generally exhibit a poor quality as well as a low and uneven resistance since the sewings are not uniformly distributed. Moreover the high costs of production tend to have the number of stitches cut down with prejudice to the quality of the product.

It is an object of the present invention to provide a fully automatized process to manufacture the above camouflaged sheets wherein the sheet of camouflaged material is stitched onto an underlaying net at a number of points that can be selected and varied at will according to a predetermined pattern.

It is another object of the invention to provide for the above process wherein a sheet of camouflaged material partially punched is stitched onto an underlaying net extending less than the camouflaged material in order to create a useful tridimensional effect thanks to the crumpling and raising of the latter when the complete camouflaged sheet is laid over an object having unregular shape.

It is still another object of the invention to manufacture a camouflaged sheet by using the above processes, in form of a continuous web having considerable width by feeding simultaneously two or more rolls of camouflaged sheet disposed adjacently.

Finally it is an object of the invention to carry out the process and manufacture the product by means of a particular quilting machine such as the one known as "Farside" that is able to apply local stitches according to predetermined designs.

The invention will now be described with reference to the attached drawings in which: FIGURE 1 is a schematic side view of an apparatus to carry out the process according to the invention; FIGURE 2 is a front view of the camouflaged web material and of the net being fed to the apparatus; FIGURES 3-5 illustrate some preferred stitching patterns carried out according to the invention.

Referring now to Figs. 1 and 2 a quilting machine 1 is fed with a net material 2 unrolling from a roll 3 and with a sheet of camouflaged material 4 unrolling from a roll 5 and overlapping the net before the sewing station, schematically represented by a needle-bearing bar 7.

Preferably the process of the invention is carried out by employing a quilting machine having an electronic sewing control device without any cam, such as the one disclosed in the British Pat. Appln. No. 8006923 filed on February 29, 1980 and produced by Italian Company Meca S.n.c. under the commercial name "FARSIDE". However the process be carried out also by means of other types of sewing or quilting machines adapted to apply local stitches according to a predetermined pattern.

The product 9 so obtained is conveyed to a collecting device and stored as a folded web as can be seen at the left in Fig. 1.

As better seen in Fig. 2 the web of net material 2 is wider than the web of camouflaged material 4. More particularly, since camouflaged material is available in form of rolls having limited width, the process of the invention provides in one embodiment to employ two or more rolls of camouflaged material (e.g. each being 1.5 m wide) that are mounted side by side and unrolled so as to be adjacent along a longitudinal line 10.

Independently of the number of camouflaged material rolls which depends upon the desired width of the final product, the overall width of the camouflaged material is narrower than the underlaying net. Along the feeding path, a net 2 having real transversal and longitudinal dimensions depending on the degree of the applied tension, is gradually restricted in transverse direction. Due to the concurring actions of the longitudinal pull and of guiding members (not shown) the net that may be as wide as 3.4 m at rest condition, is laterally narrowed to the size of the camouflaged material at the sewing stations under the needle-bearing bar 7.

Such an operation causes the net cords or longitudinal threads 8 to be somewhat raised but maintaining their relative positions. More particularly, when using two rolls of camouflaged material as shown in Fig. 2, the narrowing almost completely occurs at the lateral portions so that the central area or strip of the net surrounding junction line 10 between the two rolls of camouflaged material keeps its size unchanged and substantially equal to that of the net laid over a flat surface without any tension applied.

Camouflaged material 4 can be a sheet of PVC or of any other material, plastics, cloth or plastic covered cloth, being no longer required that it can be hot sealed to the underlaying net. For the same reason the net too can be of any suitable material such as nylon or other plastic yarns, natural fibers, etc.

The camouflaged material is furthermore partially punched, that is cut along various non closed lines, e.g. along arcs of circumferences as illustrated with dashed lines in Figs. 3-5.

Moreover the camouflaged material may be either uniformly coloured with a different hue on each surface, or spot dyed with two or more different hues on both surfaces. In case two uniform colouring are used, one for each face, the masking effect is obtained by the raising of portions of material thanks to the partial punching when the sheet is laid over an object to be hidden, particularly when the latter has unregular contours. This so-called tridimensional effect is due to the weight of the sheet that spreads the net widening to meshes relatively to the superimposed camouflaged sheet.

Referring now to Figs. 3-5 there are shown some preferred but non limiting sewing patterns.

In Fig. 3 reference P indicates stitches that are transversely aligned and applied by a row of needles of the needle-bearing bar. After sewing a row of stitches P, applied simultaneously during a stop of the fed materials according to the quilting technique, the materials are caused to advance for a predetermined length, preferably multiple of the longitudinal size of the mesh and stopped again.

There stitches Q still transversely aligned but staggered with respect to the P stitches, are applied. The next row of stitches will be again of the P type so as to form "sewing areas" having rhomboidal shape with the longer axis transverse to the direction of advancing. At the right side of Fig. 3 there are shown some examples of the stitches that can be applied to the local sewing.

There are shown stitches having a rectangular configuration with different pitches and a zig-zag stitch. The height H of said stitches, i.e. the transverse extension of the stitch, is preferably greater than the thickness of the mesh cords in order to account for possible misalignment of the longitudinal net cords 8 and ensure anyhow that the camouflaged material is sewed to the net.

Thread F connect;ng a stitch with the next one can be cut or otherwise eliminated, or left in place since the applied stitches are not to be loosed even if said thread portion F is pulled.

In Fig. 5 it is shown another pattern of stitches substantially similar to the one of Fig. 3 but having the major axis aligned with the longitudinal direction.

The stitch pattern shown in Fig. 4 is such as to define rectangular or square areas and allows for a simpler programming of the machine since the rows of stitches P and Q are not staggered to each other and are obtained through the same procedure.

Although the invention has been described with reference to a particular machine and for well defined type of the camouflaged and net materials, the same is not to be restricted to the illustrated embodiments or to the manufacturing of a product suitable to be used as a camouflage, but is to cover all the modifications and applications that will be apparent to the skilled of the art.

Claims (9)

1. A process for joining together in overlay relationship by means of local seams, a sheet of material and a length of net employing an automatic sewing machine for sheet materials fed as continuous webs from rolls, characterized in that it comprises the following steps: a) feeding at least one continuous web of said sheet material and a web of said net in overlay relationship, the total width of said sheet material being narrower than the width of the net when spread; b) partially narrowing the width of the net through the combined effect of a longitudinal tension and guide means that brings nearer at least a portion of the meshes until the total width of the sheet material and the width of the net are equal;; c) stopping the advancing of the materials and applying said discrete seams at predetermined locations transversely aligned and corresponding to the positions of the longitudinal cords of the net, each of said seams transversally extending at least for a length twice the thickness the longitudinal cords; d) repeating step c) over subsequent portions of the sheet material and the net.

2. A process as claimed in claim 1 characterized in that the seams of step c) are applied at points that are transversely aligned but longitudinally staggered.

3. A process as claimed in claim 1 or 2 characterized in that the webs of sheet materials are two, placed side by side, and that the transversal dimension of the spread mesh is not reduced adjacent the strip underlaying the contact line of said two webs.

4. A web product formed by joining together a sheet of material and a net by the process of claim 3.

5. A product as claimed in claim 4, particularly for manufacturing camouflaged sheets, characterized in that said sheet material is uniformly coloured with different hues on the two surfaces and partially punched without detaching of material, so that it crumples and raises when laid over an unregular surface making visible surface areas of both sides.

6. A product as claimed in claim 5 characterized in that said sheet material is a sheet of plastic material, such as PVC and that the net is plastic or plastic covered material.

7. A camouflaged sheet sewn to an underlaying net according to the process of the preceding claims.

8. A process for joining together a sheet of material and a length of net substantially as described herein with reference to the accompanying drawings.

9. Camouflage material substantially as described herein with reference to the accompanying drawings.