US 3579748 A
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United States Patent Inventor Walter V. Chery Meadville, Pa. 852,331
Aug. 22, 1969 May 25, 1971 Textron Inc.
App]. No. Filed Patented Assignee SLIDE FASTENER DEVICE AND METHOD OF MAKING THE SAME 11 Clailm, 6 Drawing Figs.
0.8. CI v. 24/205.l, 24/205.13, 112/265 Int. Cl A44b, 19/10 A44b 19/32, D05b 3/12 Field of Search 29/20511  References Cited UNITED STATES PATENTS 3,422,503 1/1969 Porepp 24/205.1C
I FOREIGN PATENTS 1,032,554 6/1966 Great Britain 24/205.1C
Primary ExaminerBernard A. Gelak Attorney-Meech & Field 139 39 s 1 IL BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to slide fasteners and, more particularly, to a slide fastener device having a seam-type closure and to the method of making the same.
2. Description of the Prior Art It is conventional practice to form a stringer for a slide fastener from a continuous filament of plastic material and to attach the stringer to a carrier tape. However, the known slide fastener devices of the prior art have resulted in irregular seams for the closure and have not been flexible enough to be utilized for all applications of seam-type closures; f urthermore, the conventional methods of making such devices have required expensive and complicated stitching techniques.
SUMMARY or THE INVENTION f It is, therefore, an object of the present invention to make a slide fastener device which is unencumbered by the disadvantages of the prior art.
The present invention is summarized in that a slide fastener device includes a filamentary stringer having a series of head elements and a series of heel members interconnected by a plurality of spaced legs with a marginal portion of a carrier tape being inserted in the space between the legs, a first stitching thread passing through the tape marginal portion and about an adjacent pair of legs in such a manner that the edge of the tape marginal portion is located intermediate the head elements and the heel members, a layer of the tape covers a series of connected heel members and legs, and a second stitching thread passes through such tape layer and attaches the same to the legs adjacent the head elements.
The present invention has another object in that a slide fastener device has a filamentary stringer attached to a carrier tape by two sets of stitching threads which are independent of each other.
Another object of this invention is to attach a filament stringer to a carrier tape for a slide fastener device by means of two sets of stitching threads which pass through different layers of the carrier tape.
This invention has another object in that the bulkiness of a slide fastener device is substantially reduced.
Another object of the present invention is to increase the flexibility of a slide fastener device having a filamentary-type stringer attached to a carrier tape.
A further object of the present invention is to construct a seam-type closure for a slide fastener in such a manner as to substantially eliminate irregularities in the seam.
Other objects and advantages of the present invention will become apparent from the following description of a preferred embodiment taken in conjunction with the accompanying drawing.
timer DESCRIPTION or THE DRAWING 4 showing a final step in H fasiener embodying the mated stringers according to the present invention. j
DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is embodied in a slide fastener device having a stringer of filamentary material secured to a carrier tape. As is illustrated in FIG. 1, the stringer I0 is made of any type of filamentary material, such as a suitable plastic, and includes a plurality of upper legs 12 and a plurality of lower legs 14 integrally joined at one end at interengaging head element 16. A is apparent from FIGS. 26, the upper leg I2 has a shorter dimension than the lower leg 14 as measured from their common head element 16. Along its top surface, the upper leg element 12 is provided with a triangular cutout the end of which defines a notch 13; similarly, along its bottom surface the lower leg 14 is provided with a rectangular cutout defining a notch 15.
Each pai .of adjacent upper legs 12 are joined by a U- shaped interconnecting member or heel 18; each pair of lower legs 14 are joined by a U-shaped interconnecting member or heel 20. As is shown in FIG. 1 the heel members 18 and 20 are displaced from each other in staggered relationship so as to define a stringer chain of the ladder type.
The two leg members 12 and 14 and their corresponding head element 16 form a generally U-shaped configuration leaving a space 22 between the two legs as seen in FIGS. 3-5. A carrier tape T has a layer or marginal portion 24 disposed in the space 22 and fastened by a stitching thread 26 which encircles the upper and lower legs 12 and 14. The carrier tape has a fold 28 in the form of a reverse curve that covers all of the upper heel members 18 and leads to a second layer 30 which overlies the upper legs 12 and which is attached to the upper and lower legs 12 and 14 by a stitching thread 32; a second tape fold 34 in the form of a reverse curve joins the second layer 30 to a third or upper layer 36.
As is well known in the art, separable fasteners of the present type are utilized by mounting a pair of such fasteners in interlocking relationship that is accomplished by means of a slider. Such a slider S is shown in FIG. 6 wherein rightand left-hand units are joined to form a closure. For the sake of convenience only the right-hand unit has been described above but it is to be understood that the left-hand unit has the same structure and the structural elements are identified in FIG. 6 with added to similar reference numerals found in FIGS. 1-5. The slider S has a bottom wing 37 and a pair of top flanges 38 and 138 joined to the bottom wing 37 by a pair of side flanges 39 and 139, respectively. The upper flanges 38 and 138 are disposed under the upper layers 36 and 136, respectively, of the carrier tape. A pull P is utilized for manual movement of the slider S causing the mating and unmating of the interengaging head elements 16 and I16 to close and open the device, respectively.
The steps in making the slide fastener device according to the present invention are illustrated in FIGS. l-5. The marginal portion 24 of the tape T is inserted in the stringer chain I0 between the upper and lower legs 12 and 14 to the position where it substantially occupies the entire spaces 22 between such legs. The continuous stitching thread 26 is passed through the tape marginal portion 24 adjacent each head element 26 and about each set of legs 12 and 14 whereby theentire length of the stringer chain 10 is secured to such legs.
As is illustrated in FIG. 2, the stitching thread 26 for each set of legs 12 and 14 has a top section across the top surface of leg 12 and a bottom section disposed in and across the notch 15 in the bottom surface of leg 14. Relative movement between the stringer chain 10 and the tape T is now accomplished by any suitable means such as pulling the free end of the tape T to the right as viewed in FIG. 3 to a position where the top section of the stitching thread abuts the notch 13 which defines the limit of such movement. The tape marginal portion 24 is now displaced in the spaces 22 from its position (FIG. 2) to a position (FIG. 3) where its edge is intermediate the head elements 16 and the heel members 20.
The tape marginal portion 24 constitutes a bottom layer, the unattached end of which is now everted into the fold 28 leading to the intermediate layer 30. The tape fold 28 constitutes a reverse curve that covers or encases the upper heel members 18, while the intermediate layer 30 overlies or covers the top surfaces of the upper legs 12.
The second continuous stitching thread 32 is passed through the tape layer 30 adjacent each head element and about each set of legs 12 and 14 whereby the entire length of the stringer chain is secured to such legs at a second location remote from the location of the first stitching thread 26 as is apparent from FIG. 4. The stitching thread 32 has a bottom section disposed in and across the notch in the bottom surface of leg 14. FIGS. 4 and 5 clearly illustrate that the second stitching thread 32 does not pass through any of the tape disposed between the legs 12 and 14 but merely passes through that portion of the space 22 which has been vacated by movement of the tape marginal portion 24 therefrom.
The intermediate layer 30 of the tape T is everted as shown in FIG. 5 into the fold 34 leading to the third layer 36 of the tape. The tape fold 34 constitutes a reverse curve that is opposite to the first fold 28 and that terminates short of the interengaging edge of the head elements 16. The stringer l0 and attached carrier tape T is assembled in the slider S as the righthand part of the closure with a similarly constructed left-hand part adapted to mesh therewith by means of the interengaging head elements 16 and 116.
In the above arrangement, the rigidity of the fastener device is substantially reduced by reducing the bulkiness normally associated with such a device; i.e., the tape marginal portion 24 only occupies approximately half of each space 22. Elimination of tape material from that part of space 22 which is adjacent the head element 16 results in a greater flexibility of the fastener device since the legs 12 and 14 are not impeded from movement toward each other. ln addition, a certain amount of bulk is eliminated by the use of the short leg 12; for example, as shown in FIG. 6, the tape fold 28 is substantially aligned with the edge of the heel members 20.
Secured fastening of the stringer chain l0 to the carrier tape T is accomplished by the two sets of stitching threads 26 and 32 which are spaced from and independent of each other; both ofthe threads secure the tape T to the legs 12 and 14, the thread 26 only passes through a single layer of the tape while the thread 32 only passes through a different layer of the tape. With such an arrangement the flexibility of the device is further enhanced without sacrificing any fastening features because any twisting force applied to the thread 32 would be substantially absorbed by the single layer 30 without much resistance from the remote thread 26 and tape layer 24.
A slide fastener device constructed in accordance with the present invention has the particular advantage of resisting wear caused by slider movement. As shown in H6. 6, the tape fold 28 is not engaged by the slider side flanges 39 because of the use of the shorter leg 12 whereby the tape fold 28 will not wear at this point. Furthermore, the notch 13 permits the tape layer 30 to be slightly sloped toward the stitching thread 32 after being fastened thereby; this precludes full engagement of the slider flange 38 with the tape layer 30 and/or with the top section of the thread 32 whereby wear of the tape layer 30 and wear of the thread 22 are practically eliminated.
in the manufacture of slide fastener devices to the present invention, the stitching thread 26 is applied to the stringer 10 and the tape 2 as by a machine. After the first stitching operation is complete, the stitch 26 is displaced from the original area adjacent the head elements 16 so that it rests adjacent the heel members 18. The second stitching thread 32 is now applied to the stringer and the carrier tape in the same general area as the first thread was initially applied. Such an operation permits the sewing machine to see a bigger area in which to apply the stitching threads; this reduces the accuracy which the stitching operation requires and the probability of a fastener device being made with improper stitching is virtually eliminated.
inasmuch as the present invention is subject to many variaall matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.
1. A method of making a slide fastener device from a filamentary stringer having a series of head elements and two series of heel members, each head element having a pair of spaced legs with one leg of adjacent head elements being interconnected by a heel member, comprising the steps of inserting a marginal portion of a tape in the space between each pair of legs,
stitching said tape marginal portion to said legs with each stitching thread passing through said tape marginal portion and around said legs adjacent the corresponding head element thereof,
displacing said tape marginal portion and each stitching thread from the head elements and toward the heel members,
folding said tape about one series of heel members to cover those legs interconnected to the said one series of heel members,
fastening the folded portion of said tape to said legs with thread passing through said tape folded portion and about said legs adjacent the head elements.
2. The method of claim 1 wherein the fastening thread about said legs is in a location vacated by said tape marginal portion after its displacing step.
3. The method of claim 1 wherein said tape is additionally folded in superimposed relation to the first mentioned folded portion.
4. The method of claim 1 wherein said stitching thread only passes through said tape marginal portion and said fastening thread only passes through said tape folded portion.
5. The method of claim 1 wherein notch means on said legs limits the displacement of said marginal portion toward the heel members.
6. The method of claim 5 wherein notch means on one of said legs locates the fastening thread adjacent the corresponding head elements.
7. In a slide fastener device, the combination comprising a stringer having a plurality of head elements and a plurality of heel members integrally connected by a plurality of legs,
said plurality of legs including an upper leg and a lower leg extending from each head element in a generally U- shaped configuration to define a space between said upper and lower legs,
said plurality of heel members including an upper and lower heel member with each upper heel member interconnecting a pair of adjacent upper legs and with each lower heel member interconnecting a pair of adjacent lower legs,
a carrier tape having first, second and third layers with a first fold connecting the first and second layers and with a second fold connecting the second and third layers,
said first layer being disposed between each of said upper and lower legs remote from their corresponding head elements,
first stitching thread means securing said first layer to said plurality of legs remote from said plurality of head elements whereby said first layer partially occupies the space between each of said upper and lower legs,
said first fold covering said upper heel members and said second layer overlying said upper legs, and
second stitching thread means securing said second layer to said plurality of legs adjacent said plurality of head elements.
8. The invention as recited in claim 7 wherein each of said upper legs has shorter dimensions than its corresponding lower leg.
9. The invention in claim 7 wherein said upper heel members are disposed closer to said head elements than said lower tions, modifications and changes in detail, it is intended that heel members.
layer comprises a marginal portion of said tape having an edge terminating in the space between said u termediate said head elements and heel pper and lower legs inmembers.