CA1069279A - Folded tape slide fastener stringer with external cord - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

One or more external cords are secured to the outside of a folded support tape alongside a bead formed in the folded edge of the tape by interconnecting portions of a continuous coupling element passing through strap portions of the tape defined by slits over the folded edge.

Description

The subject matter of this application is related to that of U.S. Patents Nos. 3,975,802 and 4,100,656 issued on August 2~, 1976 and July 18, 1978, respectively, to George B.
Moertel (assignor to Textron, Inc.).
BACKGROUND OF THE INVENTION
Field of the Invention This invention relates to slide fasteners having stringers formed from a continuous coupling element secured within a folded edge of a support member or tape with head portions of the continuous coupling element extending from - openings in the folded edge.
Description of the Prior Art In commercially available slide fastener stringers utilizing a continuous coupling element such as a spiral coupling element secured to one edge of a carrier or support tape, the continuous coupling element is usually secured to the edge of the tape by sewing or by weaving the coupling element to the tape. The prior art, as exemplified in U.S. Patents No.
1,557,303, No. 1,609,487, No. 1,933,290, No. 1,937,297, No.
20 2,018,099, No. 2,296,880, No. 3,430,304 and No. 3,517,422 and French Patent No. 1,135,269, discloses a number of slide ;~ fasteners having continuous coupling elements secured within a fold of a support member wherein head portions of the coupling element extend from slots across the folded edge of the support member. Additionally, French Patent 452,527 discloses a fastener with a spiral secured by strips of material formed at an angle across a folded edge of a strip. The commercial employment :'` '' . .' l~ - 2 -~69'~9 o slide fasteners with continuous coupling elements secured in a fold of a ~ape has not been significant compared to asteners ; wherein the coupling elements are woven or sewn to textile tapes despite the obvious cost advantage of low cost ~trips such as synthetic polymer or paper strips compared to woven textile tapes. This failure can be attributed to deficiencies in the prior art, such as breakage or tearing of the strap portions of the support member folded over the coupling elements, inferior support or instability for the coupling element, inabil-ity to withstand high slider forces, excessive difficulty in slider operation, etc,~
Various other types o slide fasteners have been disclosed as including bead cords secured to a tape adjacent a coil fastener element, such as in U.S. Patents No.

2,497,821, No. 2,942,33~ and No. 3,002,245; or as including various other cords, braids or strips secured together with continuous coupling elements to tapes, such as in U.S. Patents No. 3,015,868 and Reissue No. 26,086 SUMM~RY OF THE INVENTION

The invention is summarized in a stringer for a slide fastener including a support tape ormed from a longitud-. inally folded strip defining a folded edge and having opposite folded portLon which extend from the folded edge and are secured together,~the support tape having a plura}ity of spaced slits ~ -, ~ :

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; formed in the strip transversely over the folded edge and defining strap portions extending over the folded edge between the slits, a continuous coupling element having a plurali~y of successive sections each including a head portion extending from a respective slit of the plurality of slits and including an interconnecting portion which is joined with an adjoLning section and extends within the folcled edge beneath a respective one of the strap portions r the continuous coupling element having a thickness to form a bead in the folded edge of the tape, and cord means secured to the outside of the support tape and extending longitudinally alongside the bead to form a slider flange bearing member.
An object of the invention is to construct a low cost and reliable slide fastener having a folded carrie~ tape securing a continuous coupling element with reduced tendency for tearing securing strap portions.
Another object of the invention is to provide for ` easier operation of a slider in a slide fastener employing a - ~ .
; continuous coupling secured within a fold of a support member.

It is also an object of the invention to increase the endurance of folded tape slide fasteners.

An advantage of the invention is that cord means on l :~
the outside of a folded support member along a bead formed by the fold over the coupling element greatly improves the ability ~ -to withstand high slider loadings as well as increasing the ease . i ' , ~ ' :

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A further feature of the invention is the lncorporation of both external cord means and internal cord means, the latter abutting the coupling element.
A still further feature of the invention is the employment of a spiral coupling element Eormed from a fllament with an oblong cross section which, ~t leg portions exiting from slits formed at an oblique angle in the folded tape edge, is aligned in the longest dimension with the slit and the other ; 10 leg portion.
; Other objects, advantages and features of the invention will be apparent rom the following description of the preferred embodiment taken in conjunction with the accompanying drawings.
, BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a partial plan view of a slide fastener in accordance with the invention.
Fig. 2 is an enlarged plan view of a portion of one stringer broken away from the slide fastener of Fig. 1.
Fig. 3 is a cross section view of the string,er portion of Fig. 2.
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Fig. 4 is a side view with parts broken away of the stringer portion of Figs. 2 and 3.
Fig. 5 is a view similar to Fig. 2 o a stringer r, .

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portion of a modified slide fastener in accordance with the invention.
Fig. 6 is a plan view of an unfolded strip for forming the folded tapes in the fasteners.
Fig. 7 is a cross section view of the modified stringer portion of Fig. 5.
Fig. 8 is a cross section view of another modified stringer portion in accordance with the invention.
Fig. 9 is a cross section view of still another modified string portion of a slide fastener in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated in Fig. 1, the invention is embodied , in a slide fastener having planarly disposed support members ; 15 such as tapes indicated generally at 10 and 12 and having continuous coupling elements such as spiral coupling elements indicated generaIly at 14 and 16 along with a slider indicated generally at 18 which is is slidable along ~he coupling elements 14 and 16 for opening an~ cIosing the slide fastener. The tape 10 and the caupling element 14,as viewed in Fig. 1, form a let stringer .. . .
~hile the tape 12 and the coupling element 16 form a right ~ -stringer. The ri.ght stringer is substantially a mirror image .. . .
of the left stringer.

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. I :~ , , The spiral coupling elements 14 and 16 are formed into successive convolutions or sections from a continuous filament, such as a nylon or polyester filament, which has an oblong cross section, such as a D-shaped cross section. As shown in Fig. 2 and 3 each convolution of the coupling elemenk 14 includes a head portion 20, an upper leg portion 22 extending from the upper side of the head portion 20, a lower leg portion 24 extending from the lower side of the head portion 20, and a connecting or heel portion 26 interconnecting the lower leg portion 24 to the upper leg portion of an adjoining convolution.
The tape 10 is formed from a strip 27, Fig. 6, which has a longitudinal row of transverse slits 28 formed in an intermediate sec~ion thereof to define strap portions 30 extending between opposite strip portions or halves of the strip.
As shown in Figs. 2-4, the strip is lon~itudinally ~olded along the row of transverse slits with the coupling elements 14 assembled inside of the fold such that the head portions 20 and the leg portions 22 and 24 protrude from the respective slits 28 with the interconnecting portions 26 extending within the ~old ~ beneath the strap portions 30. The opposite portions !or halves ; of the folded strip are secured together by suitable means, such as adhesive, ultrasonic or thermal bonding to secure the coupling element 14 in the folded edge of the support member 25 10. The strip 27 forming the tape 10 is preferably a low r~ cost material such as a synthetic polymer resin, paper or the ., .
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like.
The slits 28 are formed i.n an oblique angle to the folded edge of the tape 10 so that the leg portions 22 and 24 of each section extend into opposite halves of the respective slit 28 at points spaced longitudinally along the folded edge ~ 5 of the tape 10. The monofilament forming the spiral coupling ; element 14 is twisted such that the longest dimensions of the oblong cross sections of each pair of ley p~rti~ns 22 and 24 are substantially aligned with each other and with the slits 28 where the leg portions 22 and 24 exit from the slits 28.
` 10 The strap portions 30 are substantially wider than the slits 28 and extend generally perpendicular to the interconnecting :
portions 26.
As shown in Fig. 3, the thickness of the monofilament forming the coupling element particularly within the inter- , :
connecting portions 26 is substantially greater than the thickness of the material forming the tape 10 to produce a substantial ~:
bead indicated generally at 32 in the folded edge of the tape 10. Cord means, such as a pair of textile cords 34 and 36~or~ :
the ~ke, ex-tends longitudlnally on the outside of the tape ~-~
: 20 10 alongside and ~n engagement with the bead 32. The textile cords 34 and 36 are illustrated as being secured to the outside ~: ~
~ of the tape 10 by stitches 38. Other means of securing the ! ~
. : textile cords 34 and 36 to the tape may be used such as adhesive, , mechanical, or other bonding means; also an overedge stitch :: ~ , ~:
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2~9 may be used as an alternative to the illustrated straight stitch.
Where a pair of cords 34 and 36 are employed on oppo~ite sides of the folded tape 10 as shown in Fig. 3, the thickness of the combined cords 34 and 36 with the tape therebetween is selected to be generally about equal to the thickness o the bead 32 and the coupling element 14.
The cords 34 and 36 provide a bearing surface for flanges 42 and 44 of the slider 18 and protect the sheet material forming the bead 32 in the tape 10 from wear due to engagement by the slider flanges 42 and 44. Additionally the textile cords 34 and 36 provide a smoother and more compliant' surface for the slider flanges rendering operation of the -slider 18 easier. Also the cords 34 and 36 distribute slider ; stress over a substantial area of the bead 32 to reduce, point stress, such as occurs where the filament engages the taps.
` Thus, the cords 34 and 36 render possible the manufacture and construction of a slide fastener employing folded synthetic polymer tapes with greatly increased wearability and durability as well as the ability to withstand relatively large cross~
wise stress from slider operations.
The cords 34 and 36 in conjunction with the'wide strap portion 30t the oblique angle of the sLits 28 over the , ~ folded edge of the tape 10, and the aligned longitudianl dimensions of the cross sections of the leg portLons with the slit, result in generally the full strength of the strip 27 ~ .
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securing the interconnecting portions 26; the tendency of the strap portions 30 to fail near the ends of the slits 28 or where the leg portions 22 and 24 exit therefrom is reduced by the distribution of forces by the cords 34 and 36.
In the modification shown in Figs. 5 and 7, a cord 50 is disposed within the folded edge of the tape 10 engaging the outside curvatures of the interconnecting portions 26.
Preerabiy the cord 50 is formed from a resilient material such as a textile thus forming suitable seats 52 for the heel portions 26. The cord 50 adds to the stability of the coupling element 14 and allows the strap portions 30 to more securely hold the heel portions 26 to the tape 10 due to the resilience of the - cord 50.
As illustrated in Fig. 8, another modification of the stringer is the use of a single external cord 36 on only one side of the tape wi~h the planar portion of the tape 10 being offset with respect to the bead 32 and the coupling element 14. In Fig. ~, still another modification of the stringer includes the internal cord 50 together with the single .~ ~
external cord 36 and the offset planar portion of the tape 10.
The asymmetrical version o the stringer would be used with a - slider having only flanges on one wing thereof to engage the external cords, the opposite side of the tape presenti~g a .: smooth surface.
: Since many variations, modifications, and changes : in detail may be made to the described embodiment it is :. ' ~.
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intended that all matter in the foregoing description and shown in the acconpanying drawings shall be interpreted as`illustrative and not in a limiting sen~e.

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Claims (9)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A stringer for a slide fastener comprising a support tape formed from a longitudinally folded strip defining a folded edge and having opposite folded portions which extend from the folded edge and are secured together, said support tape having a plurality of spaced slits formed in the strip transversely over the folded edge and defining strap portions extending over the folded edge between the slits, a continuous coupling element having a plurality of successive sections each including a head portion extending from a respective slit of the plurality of slits and including an interconnecting portion which is joined with an adjoining section and extends within the folded edge beneath a respective one of the strap portions, said continuous coupling element having a thickness to form a bead in the folded edge of the tape,and cord means secured to the outside of the support tape and extending longitudinally alongside the bed to form a slider flange bearing member.

2. A stringer for a slide fastener as claimed in claim 1 wherein the support tape is formed from a folded strip of synthetic polymer resin.

3. A stringer for a slide fastener as claimed in claim 1 wherein the coupling element is a spiral coupling element formed from a continuous filament and includes a pair of leg portions in each section extending from opposite sides of the head portions into the slits, the looped strap portions have a width substantially greater than the width of the slits,and the slits are formed in the support member at an oblique angle to the folded edge such that opposite halves of each slit receive the respective leg portions of each pair of leg portions at respective longitudinally spaced points on the folded edge of the tape.

4. A stringer for a slide fastener as claimed in claim 3 wherein the continuous filament has an oblong cross section with the longest dimensions thereof in each pair of leg portions aligned with each other and the respective slit where the leg portions exit from the slit.

5. A stringer for a slide fastener as claimed in claim 1 including a cord extending longitudinally within the folded edge of the support tape between the opposite folded portions of the tape and secured in engagement with external surfaces of the interconnecting portions of the continuous coupling element.

6. A stringer for a slide fastener as claimed in claim 5 wherein the coupling element is a spiral coupling element formed from a continuous filament into successive convolutions, and the cord is a resilient cord which is deformed about the interconnecting portions of the spiral coupling element to form seats therefor.

7. A stringer for a slide fastener as claimed in claim 1 wherein the cord means is a pair of cords secured on opposite sides of the tape.

8. A stringer for a slide fastener as claimed in claim 1 wherein the cord means is a single cord secured to one side of the tape with the planar portion of the tape being offset from the coupling element and the folded edge of the tape over the interconnecting portions.

9. A stringer for a slide fastener as claimed in claim 1 wherein the opposite folded portions of the strip are secured together by a threadless bond.