GB2140864A

GB2140864A - Slide fastener stringer

Info

Publication number: GB2140864A
Application number: GB08413981A
Authority: GB
Inventors: Akira Hasegawa
Original assignee: Yoshida Kogyo KK
Current assignee: YKK Corp
Priority date: 1983-06-01
Filing date: 1984-06-01
Publication date: 1984-12-05
Also published as: BR8402692A; GB8413981D0; HK92288A; KR850007934U; CA1253314A; AU545773B1; EP0127186A3; GB2140864B; DE3474901D1; JPS59189506U; KR850003198Y1; ZA843948B; EP0127186B1; JPS6330245Y2; EP0127186A2; ES279586Y; ES279586U

Abstract

A continuous zigzag-shaped thermoplastic molded coupling element strip (3) includes a succession of spaced coupling elements (5), each having a pair of first and second legs (9, 10) extending from a head (8) in a common direction. A plurality of first and second solid connecting portions (6, 7) is disposed alternately at opposite sides of the strip and extends one between each adjacent pair of the coupling elements. The individual connecting portions are more slender than the coupling element legs. The two adjacent legs interconnected by each connecting portion terminate in a combined broad foot with opposite corners or ends (9b, 9b), (10b, 10b) thereof substantially squared and thus not chamfered. <IMAGE>

Description

1 GB 2 140 864 A 1

SPECIFICATION

Slide fastener stringer The present invention relates to slide fasteners, and more particularly to a slide fastener stringer having a continuous zigzag-shaped thermoplastic molded coupling element strip attached to a stringer tape along a longitudinal edge thereof.

Japanese Utility Model Laid-Open Publication (Jik- 75 kaisho) 58-55513 discloses a slide fastener stringer in which, as illustrated in Figures 10 and 11, a con tinuous zigzag-shaped strip 53 of thermoplastic molded coupling elements 55 is attached to a stringer tape 52 along a longitudinal edge thereof by sewn stitches 54. The successive coupling elements are interconnected by a plurality of thermoplastic molded connecting portions 56 alternately disposed at opposite sides of the strip 53 and extending one between each adjacent pair of the coupling elements 85 55. The two adjacent legs (of adjacent coupling elements 55) interconnected by each connecting portion 56 terminate in a combined footwhich is chamfered at 56b, thus having only a small contact area engageable with the guide flange 64 of one corresponding wing 63a of the slider 63. With this limited contact area of the combined foot, the uncoupled individual coupling elements which are about to enter the Y-shaped guide channel 66 of the slider 63, would tend to easily roll or turn facewise of 95 the fastener as the strip 33 is twisted, causing non-smooth closing operation of the slide fastener.

For the same reason, the individual connecting portions 56 are less resistant to wearing, making the individual coupling elements 55 and thus the slide fastener less durable.

Further, because the individual connecting portion has a uniform thickness equal to the thickness of the adjacent coupling element leg portions and hence has relatively high rigidity, the prior stringer is poor 105 in flexibility, also causing. non-smooth coupling-and uncoupling operation of the slide fastener.

According to the present invention, there is pro vided a slide fastener stringer comprising:

(a) a stringer tape; (b) a continuous zigzag-shaped thermoplastic molded coupling attached to said stringer tape on and along one longitudinal thereof, said strip including (1) a succession of laterally spaced coupling elements, each having a head and a pair of first and second legs extending from said head in a common direction, and (2) a plurality of first and second connecting portions alternately disposed at opposite sides of said strip and extending one between each adjacent pair of said coupling elements, each of said first connecting portions extending between an adjacent pair of said first legs, each of said second connecting portions extending between an adjacent pair of said secondlegs; (c) the two adjacent legs which are interconnected by each said second connecting portion jointly terminating in a combined broad foot with opposite ends thereof substantially squared; and (d) a pair of connector threads extending transversely of said coupling elements along the entire length of said strip and embedded in said first and second legs, respectively, of each said coupling element, each of said connector threads being disposed close to and extending- alongside a respective one of such two series of said first and second connecting portions.

It is believed possible by means of the invention to provide a.slide fastener stringer having a zigzagshlaped thermoplastic molded coupling strip which has not only adequate flexibility but also adeaunte flexibility but also good durability, thus enabling smooth and sure coupling operation of the slide fastener, at which time a row of coupling elements is bent arcuately away from the coupling elements of a companion stringer in conformity with Y- shaped guide channel of a slider without rolling of the uncoupled individual coupling elements that are about to enter the slider.

The invention will be described by way of example with reference to the accompanying drawings, wherein:- Figure 1 is a fragmentary plan view of a pair of interengaged slide fastener stringers, each embodying the present invention; Figure2 is a cross-sectional view taken along line 11-11 of Figure 1; Figure 3 is a fragmentary perspective view of a continuous molded coupling element strip; Figure 4 is a cross-sectional view taken along line IV-IV of Figure 3; Figure 5 illustrates the manner in which the opposed coupling element strips are bent in oppo- site edgewise directions as they are being coupled by a slider; I Figures 6, 7, 8 and 9 are cross-sectional views taken along lines VI-Vl, XII-XII, XIII-XIII and IX-IX, respectively, of Figure 5; and Figures 10 and 11 illustrate a prior art problem.

Figures 1 and 2 illustrate a pair of coupled slide fastener stringers 1, 1, each comprising a stringer tape 2 and a continuous zigzag-shaped molded coupling element strip 3 attached to the tape 2 along an inner longitudinal edge thereof by sewn threads 4, the strip 3 being folded on itself along its longitudinal centeriine.

The coupling element strip 3 is continuously produced on a rotating die wheel (not shown) having an endless zig-zag peripheral cavity receptive of heated thermoplastic sythetic resin, such as polyamid, delivered from a fixed extrusion nozzle (not shown) and, before having been bent into a U-shaped cross section (Figures 2, 3 and 4), it has a continuous flat zigzag-shaped structure. The thus folded strip 3 includes a series of laterally spaced coupling elements 5 interconnected by a plurality of first and second solid connecting portions 6,7 alternately disposed at opposite sides of the strip 3 and extending one between each adjacent pair of the coupling elements 5. Each coupling element 5 has a head 8 and a pair of first and second legs 9, 10 extending from the head 8 in a common direction and terminating in their respective feet 9a, 10a (Figure 4). Each first connecting portion 6 extends 2 GB 2 140 864 A 2 between an adjacent pair of the legsfirst 9, 9 and is disposed close to the feet ga, 9a thereof, and each second connecting portion 7 extends between an adjacent pair of the second legs 10, 10 and is disposed close to the feet 1 Oa, 1 Oa thereof.

As best shown in Figures 2 and 4, the first and second connecting portion 6, 7 are thinner or more slender than the first and second legs 9, 10, and are disposed on the respective inner sides of the first and second legs 9, 10to provide a recess or bay6',7' (Figure 3) between each adjacent pair of the coupling elements 5, as viewed in an edgewise direction of the stringer 1.

A pair of first and second connector threads 11, 12 extends transversely of the successive coupling 80 elements 5 along the entire length of the strip 3 and is embedded in the first and second legs 9, 10, respectively, of each coupling element 5. Each of the first and second connector threads 11, 12 is disposed close to and extends alongside a respective one of the two series of the first and second connecting portions 6,7, being disposed close to the side thereof which faces the coupling heads 8. As shown in Figures 2, 3 and 4, the first and second connector threads 11, 12 are disposed on the respective inner sides of the first and second legs 9, 10.

The leg 9, 10 of each coupling element 5 has a generally trapezoidal shape, as viewed in plan (Figure 3), having a width increasing progessively from the coupling head 8 toward the foot 9a, 10a.

Thus the foot 9a, 1 Oa of each leg 9, 10 has a sufficiently large contact area engageable with a resepective one of a pair of f laring guide flanges 14, 14 of a slider 13 when the opposed stringers 1, 1 of a slide fastener are being coupled or uncoupled. Each coupling element 5 can be prevented from turning or rolling facewise of the slide fastener stringer 1 when a thrusting force is exerted on the slide fastener in a facewise direction thereof (Figures 10 and 11), partly because of such large contact area of the foot 9a, 10a and parlly because outer corners or opposite ends 9b, 9b; 1 Ob, 1 Ob of a combined broad foot extending between the two adjacent interconnected legs 9, 9; 10, 10, respectively, are not chamfered, having no slooi-ng or round surfaces. This broad foot makes the corresponding coupling elements 5 less abrasive, guaranteeing improved durability of the coupling element strip 3 and thus of the slide fastener stringer 1.

Further, partly because the connecting portions 6, 115 7 are more slender than the legs 9, 10 and partly because the connector threads 11, 12 are disposed close to and extend alongside the respective series of connecting portions 6, 7, the coupling element strip 3 has not only adequate flexibility but also good 120 durability; the solid slender connecting portions 6,7 and the connecting threads 11, 12 close thereto coact to produce such advantageous characteristics. This construction enables the coupling element strip 3 to be bent arcuately away from the corresponding strip 125 3 of a companion stringer 1 in conformity with the curvature of the respective guide flange 14 of the shder 13 when the opposed stringers 1, 1 of the slide fastener are being coupled or uncoupled, as shown in Figures 5. At that time the connector threads 11, 130 12, which are disposed close to the respective sides of the connecting portions 6,7 which sides are facing the heads 8, serve to preventthe slender connecting portions 6,7 from being excessively bent and thus being broken or otherwise damaged.

Another advantage of the fastener stringer 1 is that since the first and second slender connecting portion 6,7 are disposed on the respective inner sides of the first and second legs 9, 10 to provide the bay 6', 7' (Figure 3) - between each adjacent pair of the coupling elements 5, the stringer 1 and thus the coupling element stringer 1. At that time, the first (upper) connecting portions 6 are bent so as to expand the upper bays 6 and, on the contrary, the second (lower) connecting portion 7 are bent so as to shrink the lower bays 7'. At the same time, the inter coupling-element portions of the first (upper) con nector thread 11 are expanded and, on the contrary, the inter-coupling-element portions of the second (lower) connector thread 12 are compressed. Accordingly, the connector threads 11, 12 facilitate expansion of the connecting portions 6,7, thus preventing the latter from being broken. The connecting portions 6,7 in turn protect the connector threads 11, 12 from sudden undue stress, thus preventing the connector threads 11, 12 either from being broken or from being removed from the coupling element legs 9, 10. With this arrangement, smooth and sure coupling-and-uncoupling of the coupling elements 5 is guaranteed fora longtime.

Claims

1. A slide fastener stringer comprising:

(a) a stringer tape, (b) a continuous zigzag-shaped thermoplastic molded coupling element strip attached to said stringer tape on and along one longitudinal thereof, said strip including (1) a succession of laterally spaced coupling elements, each having a head and a pair of first and second legs extending from said head in a common direction, and (2) a plurality of first and second connecting portions alternately disposed at opposite sides of said strip and extending one between each adjacent pair of said coupling elements, each of said first connecting portions extending between an adjacent pair of said first legs, each of said second connecting portions extending between an adjacent pair of said secondlegs; (c) the two adjacent legs which are interconnected by each said connecting portion jointly terminating in a combined broad foot with opposite ends thereof substantially squared; and (d) a pair of connector threads extending transversely of said coupling elements along the entire length of said strip and embedded in said first and second legs, respectively, of each said coupling element, each of said connector threads being disposed close to and extending along a respective one of such two series of said first and second connecting portions.

2. A slide fastener stringer according to claim 1, said connecting portions being more slender than t A 4P 4 t, 3 GB 2 140 864 A 3 said legs.

3. A slide fastener stringer according to claim 1 or 2, said first and second connector threads being disposed close to the respective sides of said connecting portions which are facing to said heads.

4. A slide fastener stringer according to claim 1, 2 or 3, said first and second connecting portions being disposed on the respective inner sides of said first and second legs to thereby provide an outwardly opening bay between each adjacent pair of said coupling elements as viewed in an edgewise direction of said stringer tape.

5. A slide fastener stringer according to any preceding claim, said first and second connector threads being disposed on the respective inner sides of said first and second legs.

6. A slide fastener stringer substantially as described with reference to and as illustrated in Figures 1 to 9 of the accompanying drawings.

Printed in the U K for HMSO, D8818935,10184,7102. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.