GB2192201A - A device for sewing a reticular material - Google Patents

Abstract

A device for sewing a reticular material with two needle threads and two loop catching threads comprising a sewing needle (1) with two holes or eyes displaced in the longitudinal direction of the needle, and a knot deflector plate (7) having a point (6) projecting upwardly through a cutout (9) of a holding plate (8) disposed above the knot deflector. <IMAGE>

Description

SPECIFICATION A device for sewing a reticular material THE PRESENT INVENTION relates to devices for sewing reticular material.

In order to mend, join, and carry out similar work on nets, seines, trawl bags and the like necessitating sewing operations on reticular material, a perfect seam which is as strong as the remaining portion of the material is required. A previous approach involved using a needle thread and two loop catcher threads and resulted in a strong seam. If, however, the single needle thread snaps or is weakened, the seam no longer satisfies the above mentioned requirement. It would, thus, be desirable to- provide a seam with two needle threads and two loop catcher threads, i.e. a so-called double seam. Such a seam will hold even if one of the threads is weakened or snaps, and it will satisfy the requirements and recommendations made by users and consumers' associations.

An obvious approach would be to use a conventional known machine for sewing with four threads, i.e. two needle threads and two loops catcher threads. This approach was tried, but with a rather poor result. Such a known machine uses two parallel sewing needles. When reticular material is sewn and such needles contact a knot or the mesh material they will, however, slide aside, and either the upper loop catcher does not catch the thread resulting in a scamped stitch, or the needle will break. Attempts were made to increase the needle thickness, but such an increase is limited by the structure of the machine, i.e. the paths of movement of lower and upper loop catcher, respectively. Not much was achieved therefore by re-dimensioning known needle types.Consequently, it looked as if it were impossible to use conventional standard machines for sewing reticular material without accepting the above mentioned disadvantages. If the needle were to be dimensioned to avoid the above disadvantages an expensive change of existing machines seemed to be necessary.

From Norwegian Patents Nos. 147 760 and 1 50 365 machines are known for sewing reticular material with a comparatively strong and stable seam. These machines, however, produce a three-thread seam of the kind mentioned above, with the disadvantages that if the needle thread snaps or is weakened it is no longer possible to rely on the joining or sewing of the reticular material holding.

It is, thus, an object of the present invention to eliminate the above mentioned disadvantages resulting from use of three threads.

It is a further object of the invention to provide a device that may be used in standard machines without requiring changes of said machine to be made and which is, thus, advantageous as regards costs.

Accordingiy, in one aspect, the present invention provides a sewing needle for sewing reticular material using two needle threads and two loop catching threads, which needle has two thread eyes which are disposed in parallel, side-by-side and mutually displaced in the longitudinal direction of the needle.

In another aspect, the invention provides a device for sewing a reticular material, in which a knot deflector is provided forwardly of a sewing needle in a feed direction of the reticular material.

It is, indeed, known to use needles formed with two eyes for knotting and tufting, respectively, see for example GB-PS No. 1 601 802, and EP-A1 0 098 245. Such needles, however, cannot be used in standard sewing machines for sewing with four threads.

By combining both needles into one as in the present invention, a needle is provided which is much more sturdy than each one of the two known needles would be alone and at the same time a standard machine for two needles may be used.

A needle embodying the present invention will, consequently, only bend slightly or not at all, and because of its sturdiness will force aside any knot it contacts. The fact that the needle has a spherical point also contributes to such knot deflection.

In addition to its enhanced strength, the needle will also enable a more simple and less expensive stock of needles to be kept. This is due to the fact that the number of needles in use is reduced to one at the same time as the frequency of breakage is considerably reduced, and consequently the number of spare needles which need to be stocked is correspondingly reduced.

In order to reduce the hazard of so-called scamped stitches, as a result of the needle bending and the loop catcher means failing to catch the needle thread, a knot deflector may be provided in addition to a needle embodying the invention. The knot deflector may also be used for sewing with one needle and three threads or with two parallel needles. The most reliable result is, however, achieved with a sewing needle, embodying the present invention.

By combining a knot deflector with a double-edged needle embodying the invention, the needle is safeguard against ever hitting a knot or a thread in the reticular material, so that the machine may be operated with more speed and supervision of the seams is fairly unnecessary or considerably reduced.

In order that the invention may be readily understood, an embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a double seam of the form sewn with the aid of a sewing device embodying the present invention; Figure 2 shows a seam with one needle thread and two loop catching threads; Figure 3 shows a needle embodying the present invention; and Figure 4 is a diagrammatic view in perspective of the combination of a needle and a knot deflector means.

Figures 1 and 2 show a seam with one needle thread, and with two needle threads, respectively. The seam shown in Figure 1 is of the kind that is formed by a sewing device embodying the present invention. Both kinds of seams are based on the chain overcast stitch principle, i.e. continuous supply of thread.

The seam shown in Figure 2 has the following operational sequence: Loops of needle A are passed through the material (cloth) and new loops are formed underneath said material. Bobbin thread B is passed through the latter underneath the material and on to the margin of the material to form loops. Upper thread C is passed through said loops of bobbin thread and onto the upper face of the material and to the needle which catches the upper thread and connects it with needle thread A in the next stitch.

The seam type shown in Figure is made from four threads, with the needle threads designated A and A1, bobbin thread designated B, and the upper thread designated C.

The procedure is the same as to operational sequence as- in case of the above-mentioned seam type, except for the fact that this stitch type comprises two parallel needle threads.

Figure 3 shows a needle for sewing the Figure 1 seam with four threads. Needle 1 is provided with a spherical point 2 and two elongated thread eyes or holes 4 and 5. In the preferred embodiment holes 4 and 5 are mutually displaced to permit the needle thread in a standard machine to be caught by upper loop catcher and lower loop catcher, respectively, in sequence. If the holes are provided in any other- in any other manner than as mentioned above a different design of upper and lower loop catcher of the standard machine will be required.

In the embodiment illustrated the needle is shaped with a thin flat portion t, in the area around the point and the holes, whereas an upper portion t2 of the needle is thicker. The distance between the point 2 of the needle and the transition 3 between the thin and the thick portions of the needle is determined by the path of movement of the upper or lower loop catcher, The needle may,-e.g. have a rectangular cross-section in its thicker portion, with a width of 10 mm, and a thickness of 25 mm in the thinner area. A width b =8 mm and a thickness t1 = 3 mm are, however, preferred. The preferred dimensions are based on use of the needle in a standard machine. If a standard machine is modified other sizes of the needle may be used as mentioned above.

A knot deflector may be provided in front of the needle in the feed direction of the reticular material to be sewn, as shown in Figure 4. The knot deflector consists of a plate 7 which is bent upwardly and has a point 6 across which the mesh of the reticular material is placed. A holding plate 8 provided on top of the material is spring-biassed and is in contact with the support, comprising a cutout 9 through which the point 6 of knot deflector projects. Holding point 8 may be lifted by a lever 11 against the spring force (not shown) when reticular material is provided on the knot deflector. Furthermore, a guide rail 12 is provided for guiding and contacting the reticular material to be sewn.

During sewing a mesh distributing means, e.g. of the kind disclosed n NO-PS No. 139 831, will pull the material on, one mesh at a time with the meshes sliding on over point 6 due to means (not shown in detail) for intermittently feeding the reticular material, so that needle 1 will always hit inside the mesh.

When the reticular material is pulled forwards the mesh will, thus, slide off pin 6, the holding plate 8 being lifted up against spring force. This holding plate 8, however, will always cause reticular material to be in place with a mesh over the knot deflector plate.

Claims (7)

1. A sewing needle for sewing reticular material using two needle threads and two loop catching threads, which needle has two thread eyes which are disposed in parallel, side-byside and mutually displaced in the longitudinal direction of the needle.

2. A sewing needle according to claim 1, in which the thread eyes are oval and extend in the longitudinal direction of the needle.

3. A sewing needle according to claim 1 or 2, in which a lower portion of the needle is thinner than an upper portion thereof in order to make room for the upper loop catcher means when used in a sewing machine intended for sewing with two needles.

4. A sewing needle according to claim 3, in which the needle has a rectangular cross-section with a width of 3 to 10 mm and a thickness of 2 to 5 mm in its thinner portion.

5. A sewing needle according to claim 4, in which the said width is 8 mm and the said thickness is 3 mm.

6. A sewing needle according to any preceding claim, in which the needle has a spherical point.

7. A device for sewing a reticular material comprising a sewing needle according to any preceding claim, in which a knot deflector is provided forwardly of a sewing needle in a feed direction of the reticular material,

7. A device for sewing a reticular material, in which a knot deflector is provided forwardly of a sewing needle in a feed direction of the reticular material.

8. A device according to claim 6, in which the knot deflector comprises a bent plate having an upward projecting point.

9. A device according to claim 7 or 8, in which a spring-biassed holding plate with a cutout for the point of the knot deflector plate is provided above the knot deflector.

10 A device according to claim 9 in which a lifting lever is provided for raising the holding plate against the spring force.

11. A sewing needle substantially as hereinbefore described with reference to Figure 3 of the accompanying drawings.

12. A sewing device substantially as hereinbefore described with reference to Figure 4 of the accompanying drawings.

13. Any novel feature or combination of features described herein.

CLAIMS Amendments to the claims have been filed, and have the following effect: Claims 7 above has been deleted or textually amended.

New or textually amended claims have been filed as follows: