US2796649A

US2796649A - Slide fastener manufacture

Info

Publication number: US2796649A
Application number: US387205A
Authority: US
Inventors: John G Soave
Original assignee: Waldes Kohinoor Inc
Current assignee: Waldes Kohinoor Inc
Priority date: 1953-10-20
Filing date: 1953-10-20
Publication date: 1957-06-25
Anticipated expiration: 1974-06-25

Description

June 25, 1957 J. G. SOAVE 2,796,649

SLIDE FASTENER MANUFACTURE Filed Oct. 20, 1953 INVENTOR JOHN G. 30 AVE ATTORNEY Uireci rate Patented June 25, 1957 ice 2,796,649 SLIDE FASTENER MANUFAC John G. Suave, Long Island City, N. Y., assignor to Waldes Kohinoor, Inc., Long Island City, N. Y., a corporation of New York Application October 20, 1953, Serial No. 387,295 7 Claims. (Cl. 24-2il5.16)

This invention relates to improvements in slide fastener manufacture, and more particularly to an improved method of forming the stringers of slide fasteners and to slide fastener stringers produced thereby.

As is well known, a slide fastener or so-called zipper is made in part of two oppositely arranged stringers, each consisting of a tape provided along one longitudinal side edge, usually termed the front edge, with a bead to which the slide fastener elements are clamped and having an opposite or rear edge portion which is adapted to be secured to the corresponding edge of a garment or article opening for. which the slide fastener providesa closure, usually by sewing. ,The clamping of the fastener elements to the front edge head of the tape results in the initially straight tape becoming slightly convex in lengthwise direction, with the convexity being in the direction of its beaded edge, since the clamping of elements to tape bead causes the latter to flatten, and hence to become longer than therear edge portion of the tape. Consequently, fastener elements carried by the tape. bead assume a radial position in which their coupling ends or heads are spaced from eachtother slightly more than the leg portions which clampingly embrace the bead. Obviously, such is detrimental to the accurate meshing of the fastener elements of one stringer with the corresponding elements of the opposite stringer Recognizing this condition, it has therefore become standard practice in the trade to impart to the-tape, by stretching or otherwise elongating its rear edge portion, curvature opposite to that imparted by application'of the fastener elements to the beaded edge thereof as aforesaid. Such procedure results in the tape having an initially concave curvature designed to compensate for the opposite or'convex curvature subsequently imparted by the attachment of the fastener elements, with the result that the completed stringer, before it is sewn to the garment or article, is substantially straight.

However, it was found that this expedient makes no provision for the known fact that the stringer tape is distorted'when it is sewn to the garment or article along its rear edge. Consequent to this sewing operation, the tape contracts lengthwise in its rear edge zone, so that it again becomes shorter in its rear zone than in its front or beaded zone, with the result that, following sewing, the front edge or beaded zone has irregular wavy form which is likely to impair the smooth and easy operation of the fastener slider.

While numerous attempts have been directed to the solution of this problem, such have not been successful. For example, it does not suflice initially to shorten the beaded front edge zone of the stringer tape with respect to its rear edge, as by sewing the bead cord to the front edge under tension, so that the bead will shorten when the tension is relieved, thus giving the tape an initially concave curvature. While such a procedure compensates, after a fashion, for the lengthening of the tape along its beaded edge caused by attaching the fastener elements, it does not counteract the additional convexity causing the irregular waves to be produced along the frontedge of the tape as results fiom the stitching operation. Moreover, it was found to be exceedingly diflicult to control the lengthening of the rear edge by shortening the front edge of the tape to the exact limits required to obtain a tape devoid of irregular waves following sewing thereof to the garment or article.

Accordingly, a major objectof the present invention is to provide a workable and extremely practical method by which a stringer may be lengthened throughout its rear or attaching zone so as to compensate for the shortening of the tape throughout such zone as results from sewing the tape to the garment or article.

Another object of the invention is the provision of a method for forming in a stringer tape a multiplicity of small regular waves or undulations extending transversely inward from the rear edge. thereof, and which give a controlled lengthening of the tape in its rear or attaching zone.

A further object of the invention is the provision of a method for effecting a controlled lengthening of the tape of a fastener stringer along its rear edge ,zone, as compared to its front edge zone, which lengthening is such as not only to compensate for the convexity'imparted to the tape in clamping of the fastener elements to its edge bead, but also to counteract for shortening of the tape along its rear edge zone or portion consequent tothe sewing of the tape to the garment or article.

Yet another object of the invention is die provision of a method of treating slide fastener stringers during the course of their manufacture in such a way as to produce a stringer which is generally straight following final sew ing thereof to a garment or article, and which is further characterized by the fact that its fastener elements are uniformly spaced from one another throughout their full lengths. V V

Another important object of the invention is the pro vision of stringer tapes for slide fastener or so-called zipper closures chaarcterized in that their rear or attaching edge zones are provided with a multiplicity of small regular wavy undulations which extend transversely in ward from the rear edge of said tapes, and which are of depth and number as to compensate for the relative shortening or contraction of said rear edge zone consequent to the attachment of the fastener elements to the front beaded edge of the tapes and/or to the stringers being sewn to an article or garment; I

Another object of'the invention is the provision of'slide fastener stringers'whose rear edge attaching zones are crimped in such a way as to effect lengthening thereof as compared to their front edge zones by an amount as to compensate for the lengthwise contraction of said rear zones resulting from the sewing of the tapes to the edges of a garment or article opening;

The above and other objects and advantages'of the invention will be clear from the following detailed description, taken with the accompanying drawings, wherein,

Figure 1 is a fragmentary plan view showing a length of the initially straight stringer tape before the fastener elements are afiixed thereto;

Fig. 2 is a similar View of the same stringer tape following attachment of the fastener elements to its beaded edge;

its rear edge zone is effected according to the invention; Fig. 4 is illustrative of another tool by which the tape may be controllably crimped or regularly undulated' along its rear edge zone;

Fig. Sillustrates the stringer tape-shown in Fig. 2 following completion of the crimping operation; and Fig. 6 is a view similar to Fig. 5 but illustrating the Fig. 3 is a section through one form of crimping dieor tool by which crimping or waving of the tape along.

3 a completed stringer following its attachment to the garment or article.

Referring to the drawings, reference numeral 10 designatesa conventionaltape as used in the manufacture of slide .fastenersio'r- 'so-calledzipper'sl. .Such atape is provided at its longitudinal front edge zone orport ion 12a .with a bead 11' .to'which thefastener elements are to be attached andlwith a' rear edgefzone l2 which is adapted to be secured 'to a garment orother article, usuallybysewing.

- Fig. 2 is illustrative of the tape shown in Fig. 1 following attachment of the fastener elements 13 thereto as by clamping their leg portions to the tape bead '11. Asexplained in the foregoing, such clamping causes the tape bead 11 to flatten under the clamping pressure applied thereto by the fastener elements and thereby to lengthen. This lengtheningof-thebeadimparts convex curvature to the complete stringer, the convexity being in the direction of its front or beaded edge. Due to this convex curvature, the'fastener elements 13, instead of being parallel to and uniformly spaced from one another throughout their full lengths, assume an inclined position accord ing to which their coupling heads 14 are'spaced farther from each other than are their leg portions 15 which attach to the tape bead. If such a stringer is now sewn to an article, the convexity thereof is liable to be increased, due to the fact that the sewing operation results in further shortening of the already shorter rear edge zone of the tape.

According to the present invention, not only the aforesaid convexity of the stringer resulting from attachment of the fastener elements as aforesaid, but also the further shortening of the rear edge zone of the stringer tape occurring when the latter is sewn to the garment or article, is overcome in workable and practical manner by a controlled lengthening of the stringer tapealong its rear edge zone, preferably following attachment of the fastener elements thereto, as aforesaid. Such result is simply efiected by imparting a multiplicity of small regular wavy indentations in the rear or attaching zone of the tape and which extend inwardly from its rear edge, as by crimping the tape along said rear e'dge.

Referring to Fig. 3, such crimping of the tape as aforesaid may be eifected in a crimping die consisting of two rack-

like parts

16 and 17 whose

respective teeth

18 and 19 intermesh with one another. Thus, the tape is exposed at regular short-length intervals to the opposing pressures of the intermeshing

teeth

18, 19, such resultingin a multiplicity of small, regular wavy undulations 20 being imparted to the tape and which extend transversely inward a short distance from its rear edge. Upon release of the crimping pressure imparted by the

racklike parts

16, 17, the waves or undulations 20 tend to flatten slightly, and hence the rear edge zone of the stringer tape lengthens by a small amount, as compared to its front or element-carrying edge. It is also'possible to crimp the rear edge zone 12 of the stringer tape 10 by feeding same between two rotating

intermeshing gears

22, 23, as indicated in Fig. 4, such also resulting in the formation of small regular wavy undulations 20 extending transversely inward of the tape from its rear edge, and a corresponding lengthening of the rear. edge zone portion as compared to the front or element-carryingedge thereof. r

As seen in Fig. 5, a stringer whose tape is Provided in its rear edge zone with crimps or small. regular undulations as aforesaid becomes slightly concaveas viewed in plan, due to its rear edge being longer than its front edge. However, by a proper choice of the number and amplitude depth of the crimps imparted to the tape along its rear edge as aforesaid, such lengthening of the rear edge zone of the tape as compared to its front edge may be closely controlled, and hence may be made such as to correspond precisely with the shortening of the tape along its rear edge portion, which takes place when the tape is sewn to the garment or article.

This latter highly desirable result is illustrated in Fig. 6, wherein a fastener stringer having its rear edge zone crimped as aforesaid is shown to be attached by stitching 24 along its crimped rear edge at the corresponding edge 25 of the opening provided in a garment or other article. While the stitching effects shortening or contraction of the rear edge zone of the tape 10, such is'less than the lengthening of said zone imparted by the crimps or undulations 20, with the result that when finally se'wn, at least the front edge zone of the stringer is flat throughout and straightway, and the fastener elements 13 are parallel to and uniformly spaced from one another throughout their full lengths.

Without further analysis, it will be seen that the presently disclosed method of crimping the longitudinal rear or attaching zone of a fastener stringer tape so as to effect a controlled lengthening thereof provides the simple solution of the problem arising from distortion of the tape, as results or can result both from attachment of the fastener elements to its'beaded edge or from sewing of the tape along its rear edge zone to the garment or article. Moreover, it will be seen that the herein described method is' exceedingly simple in its practice, since it may be carried out merely by exposing the rear edge portion or zone of the tape to the action of intermeshing teeth of two rack-like elements or of two rotating gears. The product of the method, namely, a stringer tape characterized by a transversely crimped rear edge portion, may be sewn to the garment or article just as simply as the prior stringer tapes, wi assurance that its edge which carries the fastener elements extends flat and straightway, as distinguished from extending along a curve or being irregularly waved, and that the fastener elements are disposed parallel to and uniformly spaced from one another throughout their full length. a Although the method disclosed in the foregoing has been described in its application to the completed stringer, that is to say, a tape to which the fastener elements have been applied, it may also be used to advantage as a substitute for the process heretofore used for the initial lengthening of the rear zone of the tape to compensate for the lengthening of the front zone resulting from attachment of the fastener elements.

As many changes could be made in carrying out the above methods and constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the ac-' compauying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In the manufacture of slide fastener stringers comprising a tape adapted to carry a row of fastener elements along its front longitudinal edge zone and to be secured to a garment or article along its rear longitudinal edge zone, the step of imparting small regular wavy undulations to the rear edge zone of the tape, said undulations extending inwardly a small distance from the rear edge of said rear edge zone, the number and depth of said undulations being such as to render said rear end zone longer than the front edge of the tape the number and depth of said undulations being such as to render said rear edge zone longer than the front edge of the tape by a controlled amount.

'2. In the manufacture of slide fastener stringers comprising a tape adapted to carry a row of fastener elements along its front longitudinal edgezone and to be secured to a garment or article along its rear longitudinal edge zone, the step of crimping the tape transversely along its rear edge zone, the number and depth of the crimps being such as to render said rear edge zone longer than the front edge zone of the tape by a controlled amount. e

2 3. The method of manufacturingslide fastener string-1 ers, comprising a tape having a bead extending along its front longitudinal edge zone, said bead being adapted to carry a row of fastener elements, said tape being adapted to be secured to a garment or article along its rear edge zone, said method including the steps of clamping the fastener includes the steps of clamping the fastener elements to the tape bead, and thereupon lengthening the rear edge zone of the tape an amount as to compensate for any lengthwise distortion of the tape occurring as the result of the clamping of the elements and/or likely to occur upon securing the tape along its rear edge to the garment or article.

4. The method of manufacturing slide fastener stringers comprising a tape having a bead extending across its front longitudinal edge zone and carrying a row of fastener element along said edge zone and adapted to be secured to a garment or article along its rear edge zone, which includes the steps of clamping the fastener elements to the tape bead, and thereupon transversely crimping the rear edge zone of the tape, the number and depth of the crimps being such as to increase the length of said rear edge zone by a predetermined amount compensating for any lengthwise distortion of the tape occurring as the result of the clamping of the elements and/or likely to occur upon securing the tape along its rear edge zone to the garment or article.

5. In a slide fastener, a stringer tape having a crimped rear edge zone, the crimps extending transversely inward from said rear edge zone and being of number and depth as to efiect a controlled lengthening of the rear edge zone of the tape with respect to the front edge zone thereof.

6. In a slide fastener, a stringer tape whose rear edge portion is provided with a multiplicity of small regular wavy undulations extending transversely inward for a short distance from the rear edge portion of the tape, the number and depth of said undulations being such as to effect a controlled lengthening of said rear edge portion zone of the tape with respect to its front edge portion.

'7. in a slide fastener, a stringer comprising a tape having a bead extending along its front longitudinal edge zone and a plurality of fastener elements clampingly secured to said head, the rear edge zone of the tape being provided with a multiplicity of transverse undulations extending inwardly for a short distance from the rear edge zone of the tape, the number and depth of said undulations being such as to effect a controlled lengthening of the rear edge zone of the tape with respect to its front edge zone.

References Cited in the file of this patent UNITED STATES PATENTS 38,799 Francis June 2, 1863 1,322,650 Sundback Nov. 25, 1919 FOREIGN PATENTS 1,025,919 France 1953