US3768125A

US3768125A - Dyed slide fastener with stitched-on coupling coil

Info

Publication number: US3768125A
Application number: US00227503A
Authority: US
Inventors: A Frohlich
Original assignee: Opti Holding AG
Current assignee: Opti Holding AG
Priority date: 1971-10-13
Filing date: 1972-02-18
Publication date: 1973-10-30
Anticipated expiration: 1990-10-30
Also published as: NL146368B; FR2156282A1; BR7207068D0; CA986689A; FR2156282B1; IT968880B; GB1385999A; NL7207746A; DE2151000A1; IE36752B1; AU4763872A; BE777740A; IE36752L; ES214245U; DK129901C; SE395348B; DD99723A5; FI57051B; ES214245Y; FI57051C

Abstract

A coupling coil is lockstitched to the longitudinal edge of a support tape with a transparent synthetic-resin mono-filamentary thread overlying the individual coil turns. The coil and the tape are dyed and the thread is left transparent. In this manner the color of the coil is visible through the attachment thread and there is no color contrast apparent between this thread and the rest of the stringer. Heat treatment of the dyed and assembled stringer flattens the monofilament over the coil to attach the coil securely to the tape and to make the thread blend in as much as possible. A single needle Type 401 or a double-needle Type 402 double locked stitch may be used.

Description

- United States Patent [19.]

Friihlich '[22] Filed:

. DYED SLIDE FASTENER WITH STITCHED-ON COUPLING COIL [75] Inventor: Alfons Friihlich, Essen, Germany [73] Assignee: Opti-Holding AG, Glarus/Schweiz,

' Germany Feb. 18, 1972 211 App]. No.: 227,503

[30] Foreign Application Priority Data Oct. 13, 1971 Germany P 21 51 000.9

Oct. 13, 1971 Germany P 21 50999.9

[52] US. Cl 24/205.16 C [51] Int. Cl A441) 19/14 [58] Field of Search 24/205.1C, 205.16 C, 24/205.16 R, 205.13 C; 2/265 [56] References Cited UNITED STATES PATENTS 3,022,803 2/1962 Berberich et a1. 24/205.l6 C

Burbank 24/205.1 C

3,484,906 Yoshida 24/205. 1 3 C Primary Examiner-Donald A. Griffin Att0rney-Karl F. Ross [57] ABSTRACT A coupling coil is lockstitched to the longitudinal edge of a support tape with a transparent synthetic-resin mono-filamentary-thread overlying the individual coil turns. The coil and the tape are dyed and the thread is left transparent. In this manner the color of the coil is visible through the attachment thread and there is no color contrast apparent between this thread and the rest of the stringer. Heat treatment of the dyed and assembled stringer flattens the monofilament over the coil to attach the coil securely to the tape and to make the thread blend in as much as possible. A single needle Type 401 or a double-needle Type 402 double locked stitch may be used.

14 Claims, 8 Drawing Figures SHEET 2 OF 2 1 DYED SLIDE FASTENER WITH STITCHED ON COUPLING COIL FIELD OF THE INVENTION The present invention relates to a slide fastener and a method of making such fastener. More specifically this invention concerns a colored slide fastener that is dyed to match the garment in which it is to be installed.

BACKGROUND OF THE INVENTION It is necessary in most garments to coordinate the color of the various accessories with the fabric of the garment. To this end slide fasteners are produced in a wide range of colors, usually achieved by simply dyeing the fully assembled fastener.

Since the fastener is usually made of three different materialstextile support tapes, synthetic-resin coupling elements or coils, and synthetic-resin or naturalfiber thread interconnecting the tapes and coils-it has been found extremely difficult to achieve the same degree of coloration in all of its parts. Dyeing'of the slider is usually found to be unnecessary, and the end-stop members are either metallic staples or are made of the same material as the coils.

The color contrast is particularly marked between the thread forming the stitching attaching each coil to its tape, and the coil tape. This difference is most troublesome when spun or twistedmultifilament thread, be it synthetic or natural, is used. Even when the same polyamide or polyester that is used in the coupling coils is employed for the attachment stitching is this contrast present.

One method of preventing this color difference has been to use only slightly stretched or oriented synthetic-resin thread which, although it lackssomething in stability and strength,.tends to have roughly the same dye-absorbing capacities as the tapes and coils. However, the unavoidable differences between the extent of dye absorption in the stitching on one hand and in the coils and'tapes on the other has generally been accepted as inevitable. I

Another solution has been to make the entire fastener out of transparent material. In this case a synthetic-resin textile is used'for the support'tapes and the coils are woven into. the'edge ofthe tapes no stitching being used. In order to enhance the transparency of such a fastener, as open a weave as possible is used for the tapes. Although such a. solution has its theoretical merits, the fasteners so made are in reality not satisfactory: they are insufficiently transparent, they reflect and shine under certain light, and they are physically weak.

OBJECTS OF THE INVENTION SUMMARY OF THE INVENTION These objects are attained according to the present invention by a slide fastener having a stringer made of a pair of woven or knitted textile support tapes each carrying a coupling coil, and transparent syntheticresin monofilamentary thread overlying the coils and serving to attach them to the tapes. The coils and the tapes are dyed but the visible stitching is transparent so that the color of these tapes and the coils is seen through the stitching.

According to another feature of the present invention the coils are stitched by an upper or needle thread and a looper or locking thread. Only one of these threads overlies the turns of the coils and only this thread need to be a transparent synthetic-resin monofilament. The other thread, that one which overlies the tape, may be a multifilamentary spun or twisted thread.

In accordance with another feature of the invention a highly stretched and oriented monofilament is used as the transparent attachment thread to give two surprising and extremely useful advantages. First such a thread is so very dense that the fastener may be dyed with its stitching, but this stitching will not absorb any dye and will therefore remain transparent. Second'the fastener can be subjected to heat and pressure after assembly to shrink the monofilament somewhat and flatten it where it passes over the turns of the coupling coil, thereby securely fastenin'gthe coil on the tape.

Thus the method according to the present invention lies in the steps of forming at least a slide-fastener stringer half by stitching a coupling element to a support tape with a transparent thread, dyeing the tapes and coupling coil simultaneously, and heating and flattening the transparent thread on the dyed stringer half. Formation of end-stop members and installation of the slider can be carried out before or after the dyeing or heat-treating steps. Since the visible and flattened transparent threads lie directly on the dyed coupling element, color transmission through them is excellent, much better than in the prior-art fully transparent fasteners. In accordance with further features of this invention double locked stitching, corresponding to Types 401, 402, 403, 404, 405, and 406 of the Federal Specifications Board (Federal Standard 751(a)), is used. In this manner at least two parallel bights of thread overlie each turn.

DESCRIPTION OF TI-IVEQDRAWING The above and other objects, features, and advantages will become more readily apparent from the following description, reference being. made to the-acpresent invention;

FIG. 7 is a schematic diagram showing how the stringer of FIGS. 1-4 is made; and

FIG. 8 is a view corresponding to a detail of FIG. 4 showing the flattened threads.

SPECIFIC DESCRIPTION FIGS 1-4 show a pair of coupling coils 1 made of synthetic-resin, here of a Nylon-type polyamide or even a polyester that can be dyed. The coils 1 each have a plurality of turns 5 formed by upper and

lower shanks

6a and 6b, respectively, with coupling heads and bight portions 6d interconnecting neighboring lower shanks 6b to upper shanks 6a. Each coil 1 is stitched to a support tape 2 that defines a plane 1. These tapes 2 are woven or knitted and can be dyed like the coils 1. Either synthetic or natural-fiber textile material may be used for the tapes.

The straight upper and

lower shanks

6a and 6b lie directly over each other and parallel to each other relative to the plane P. The heads 6c are flattened and the bights 6d lie at an angle to the plane P. Similar coils l and tapes 2 are described in patent application Ser. No. 82,323; Ser. No. 82,334(now U. S. Pat. No. 3,714,683); Ser. No. 82,325 (U.S. Pat. No. 3,685,474); and Ser. No. 82,326 filed jointly by myself, M.L. Cappel, and E. Stiibiger on Oct. 20, 1970.

Each coil 1 is secured to the face of its tape 2 at the edge thereof by

longitudinal stitching

3, 4 comprising a transparent non-dye-absorbing monofilament looper thread 3 and a multifilament needle thread 4 which may or may not absorb dye. A Type 401 double locked or chain stitch is used, so that on sewing the needle pierces the stringer from the tape side. FIG. 1 shows that this type of stitch will leave three bights 7 of transparent thread 3 overlying each upper shank 6a, while the point 8 where the upper and

lower threads

3 and 4 cross is buried in a filler cord 10 running longitudinally through the length of each coil 1. The looper thread 3 is never kinked but is only forced to conform at the bights 7 to a diameter of curvature equal to around twice the diameter D of the needle thread 4.

Since these bights 7 lie snugly over the upper shanks 6a, especially as a result of a subsequent heat treatment which flattens the bights 7 as seen in FIG. 8, the color of the element 1 will be clearly visible through the bights. Even if the thread 3 absorbs some dye, its close engagement with the coils 1 will still make it blend in completely. 7

Of course the needle thread 4 can also be transparent. FIG. 3 shows how the single line of stitching of thread 4 is extremely innocuous on the tape side of the fastener.

FIGS. 5 and 6 show a slide-fastener stringer much as described in my commonly assigned and filed patent application Ser. No. 227,485. A pair of coil-type coupling elements 1 have turns 5' secured to tapes 2' by means of a pairof needle threads 4' and a single looper thread 3 of a Type 402 stitching. The tapes 2 are each formed with a longitudinal fold 9 forming a flap 9a to which the elements 1' are stitched.

In this embodiment however the stitching is done from the coil side of the fastener, and then the tape if folded over at 9. Either the needle thread 4' or the looper thread 3' or both can be transparent, depending on need. In any case due to the relatively wide transverse lay of the looper thread 3' the fold 9 is maintained for use of the stringer as an invisible-type slidefastener.

FIG. 7 shows schematically an apparatus for carrying out the slide-fastener construction method according to the present invention.

A pair of tapes 2 are fed from supply bobbins 11 to a sewing station 12. A pair of interleaved coils 1 as well as needle and

looper threads

3 and 4 are also fed to this station 12 from respective supplies. A double-needle sewing machine 13 at the station 12 sews the interleaved coils 1 to the edges of the parallel tapes 2 according to principles well known in the art, forming a single-needle double-locked stitch of Type 401 as described above over each coil with the needles piercing the tapes from underneath.

After attachment of the interleaved coils to the tapes with a dye-absorbing needle thread 3 and a non-dye absorbing monofilament 4 the completed stringer 14 is fed to a dyeing station 15 where it is passed through a vat 16 containing textile dye. Subsequently the dyed fastener whose monofilamentary looper threads 4 have absorbed no dye are fed to a station 17 where they are pressed between a pair of driven heated rollers 18 that serve to dye the stringer 14 and to flatten and shrink the threads 4 where they overlap the coil turns 5. In this manner a very tight fastener is obtained.

Finally the dyed and heat-treated stringer 14 is lead in the transport direction T to a station 19 where it is provided with end-stop members, sliders, and where individual slide fateners are cut out of it.

This method produces an excellent coil-type slide fastener which is dyed to blend exactly with whatever color is desired. There is virtually no contrast between the color of the stitching on one hand and that of the coupling element and the tape on the other.

I claim:

1. A slide-fastener stringer having a pair of halves each comprising:

a continuous synthetic-resin dyed coupling element having a multiplicity of turns each provided with a head adapted to engage between two similar heads of a similar element;

an elongated dyed tape having one longitudinal edge carrying said element; and

stitching attaching said element to said tape and formed from a pair of interlocked threads, one of said threads overlying said turns of said element and being composed of a transparent syntheticresin monofilament.

2. The stringer defined in claim 1 wherein said one thread is non-dye-absorbing.

3. The stringer defined in claim 2 wherein said stitching is a single needle double-locked stitch, said one thread being the looper thread.

4. The stringer defined in claim 2 wherein said stitching is a double-needle double-locked stitch, said stitching comprising a pair of needle threads overlying said turns and composed of transparent monofilament.

5. The stringer defined in claim 1 wherein said one of said threads is colorless.

6. The stringer defined in claim 1 wherein said element, tape and threads are dyed in common and have the same coloration.

7. The stringer defined in claim 1 wherein said element is a generally helical coupling coil, said turns of said coil each having a pair of coplanar shanks lying in a plane perpendicular to the axis of the coil, said one of said threads straddling the pairs of shanks.

8. The stringer defined in claim 1 wherein said element is a meander.

9. A method of making a dyed slide-fastener stringer half comprising the steps of:

simultaneously dyeing a synthetic-resin coupling coil and a textile support tape; and

stitching the coupling coil to the longitudinal edge of the support tape with a transparent synthetic-resin mono-filamentary thread to form a stringer half.

10. The method defined in claim 9 wherein said stitching is lockstitching with said transparent thread overlying the turns of said coil.

bights of said transparent thread overlie each turn of said coil.

14. The method defined in claim 13 wherein said bights lie substantially parallel to each other over said turns.

Claims

1. A slide-fastener stringer having a pair of halves each comprising: a continuous synthetic-resin dyed coupling element having a multiplicity of turns each provided with a head adapted to engage between two similar heads of a similar element; an elongated dyed tape having one longitudinal edge carrying said element; and stitching attaching said element to said tape and formed from a pair of interlocked threads, one of said threads overlying said turns of said element and being composed of a transparent synthetic-resin monofilament.

8. The stringer defined in claim 1 wherein said element is a meander.

9. A method of making a dyed slide-fastener stringer half comprising the steps of: simultaneously dyeing a synthetic-resin coupling coil and a textile support tape; and stitching the coupling coil to the longitudinal edge of the support tape with a transparent synthetic-resin mono-filamentary thread to form a stringer half.

11. The method defined in claim 10 wherein said lock-stitching is of the double-locked type.

12. The method defined in claim 11, further comprising the step of subjecting such transparent thread to heat where it passes over said coil turns.

13. The method defined in claim 11 wherein three bights of said transparent thread overlie each turn of said coil.