A woven slide fastener stringer

Abstract: A woven stringer for a concealed type of slide fastener having a row of continuous filamentary coupling elements (34) woven integrally into a stringer tape (35). The row of coupling elements (34) are formed into a continuous helical coil structure which is woven into a longitudinal edge (38) of the stringer tape (35) as the latter is woven and which is oriented so that each of the coupling elements (34) has its heel portion (50) disposed to project transversely beyond the longitudinal edge (38) of the stringer tape (35) and its coupling head portion (47) directed toward a web portion of the tape (35) when the stringer is produced. The resulting stringer (33) when in use is folded back on a longitudinal axis so that the coupling head (47) projects beyond the tape edge (38) but is concealed from view when a pair of such stringers (33) are coupled together.

Description: The present invention relates to a woven slide fastener stringer having a row of continous filamentary coupling elements woven integrally into a stringer tape. More particularly, the invention is directed to the provision of a woven slide fastener stringer having such a row of coupling elements which are disposed so as to be concealed or masked from external view when the slide fastener is closed. EP-A-0 275 539 which forms the basis of the preamble of claim 1, discloses a woven slide fastener stringer in which a gap-filling warp thread extends under successive loops of a coiled plastic filament and alternately over and under picks of a foundation weft thread. A concealed type of woven slide fastener is known from US-A-3 961 652. This document discloses a woven slide fastener stringer in which a row of continous filamentary coupling elements is woven in such a way that the head portion of each of the elements is directed toward the web portion of the stringer tape and the heel portion of the element is oriented to project transversely beyond the longitudinal edge of the tape. However, US-A-3 961 652 fails to teach how to introduce the single weft thread and the element-forming filamentary material into the fell of the stringer tape. The present invention seeks to provide a woven slide fastener stringer for a concealed type slide fastener, which stringer has a row of continuous filamentary coupling elements woven to a relatively low profile. According to the invention there is provided a woven slide fastener stringer comprising: (a) a woven stringer tape including a web portion woven of a plurality of foundation warp threads and a single foundation weft thread : (b) a row of continuous filamentary coupling elements disposed on one longitudinal edge portion of said stringer tape and spaced longitudinally from each other, each of said coupling elements including a coupling head portion, a pair of upper and lower leg portions extending from said coupling head in a common direction and spaced from each other vertically in a direction substantially perpendicular to the general plane of said stringer tape, and a heel portion located remotely from said coupling head portion and interconnecting one of said upper and lower leg portions to an adjacent coupling element, and (c) a fixing warp thread system securing said row of coupling elements in position against displacement, said fixing warp thread system consisting of a plurality of clamping warp threads and a plurality of upper and lower binding warp threads, said upper and lower binding warp threads extending substantially in a straight run over said upper and lower leg portions, respectively, of said coupling elements, said clamping warp threads extending over an upper leg portion of one coupling element and under a lower leg portion of an adjacent coupling element and into engagement with said weft thread, and said foundation weft thread passing around the last upper warp binding thread up toward and around the last lower warp binding thread to form a straight span therebetween adjacent said coupling head portion and extending substantially perpendicularly with respect to the general plane of said stringer tape, characterized in that the heel portion of each of said coupling elements is oriented to project transversely beyond said longitudinal edge portion of said stringer tape, while the coupling head is directed toward the web portion of said stringer tape, that said fixing warp thread system consists exclusively of said clamping warp threads and said upper and lower binding warp threads, each of said clamping warp threads extending between two adjacent pairs of said upper and lower binding threads and said straight span of said weft thread defining an axis about which said stringer tape is folded back with said coupling head portion of each coupling element projecting transversely beyond said one longitudinal edge of said stringer tape. The above and other features and advantages of the invention will become apparent from the following description taken in conjuction with the accompanying drawings. Figures 1 and 2 are schematic perspective views of an apparatus for manufacturing a woven slide fastener stringer, the views showing parts in different postions while the apparatus is in operation; Figure 3 is an enlarged perspective view of a portion of the apparatus shown in Figure 2; Figure 4 is an enlarged perspective view of a portion of an exemplary slide fastener stringer produced by the apparatus of Figure 1; Figure 5 is a diagrammatic transverse cross-sectional view of the stringer of Figure 4; Figure 6 is a diagrammatic transverse cross-sectional view of a pair of the stingers of Figure 5 shown coupled together and Figure 7 is a view similar to Figure 6 but depicting the stringers more realistically. Figures 1 and 2 illustrate an apparatus for manufacturing a woven slide fastener stringer. The apparatus comprises a loom 10 for progressively weaving a stringer tape 11 of warp threads 12, 13, 14, 15 at a fell 16, the loom 10 including conventional heddles or a shedding means not shown for forming a pair of upper and lower warp sheds 17, 18 between the warp threads 12, 13, 14, 15 and for selectively moving the warp threads 12 - 15 up and down, a first filling carrier or weft inserter 19 disposed at one longitudinal edge of the warp threads 12 - 15 and reciprocally movable across the upper shed 17 for inserting a weft thread 20 in double picks in the upper warp shed 17 between the warp threads 12 - 15 and a second filling carrier 21 disposed in parallel spaced relation to the first carrier 19 and reciprocally movable for inserting an element-forming filamentary material of synthetic resin 22 in the lower shed 18 between the warp threads 14, 15 woven along one longitudinal edge 11 a of the stringer tape 11. The apparatus includes a reed 23 movable back and forth for beating the weft thread 20 inserted in the shed 17 against the fell 16, and a knitting needle 24 reciprocably disposed at the opposite edge of the warp threads 12 - 15 for successively knitting loops of the weft thread 20 projecting out the warp shed 17 to form a tape selvage. The reed 23 has a plurality of longitudinal guide slots 23 a through which the warp threads 12, 13 extend to the fell 16. The element-forming filamentary material of synthetic resin 22, which has a plurality of prospective coupling head portions 25 a (Figures 1 and 2) formed in advance thereon at equal intervals, is introduced in the lower warp shed 18 to the fell 16 through a feed tube 54 extending substantially parallel to the warp threads 12 - 15. The apparatus also includes a coiling means operable in synchronism with the loom 10 for coiling the element-forming filamentary material 22 into a row of coupling elements 25 whereby the row of coupling elements 25 is woven integrally into the stringer tape 11 as the latter is woven. The coiling means comprises a rocker arm 26 disposed at the one edge of the warp threads 12 - 15 and rockingly movable about one of its ends. As better shown in Figure 3, the rocker arm 26 has at the opposite or distal end a hook 27 including a head portion 27 a and a nose portion 27 b extending therefrom in a direction parallel to the warp threads 12 - 15. The nose portion 27 b has a transverse cross section which defines a space between a pair of upper and lower legs 28, 29 of each coupling element 25. The rocker arm 26 has a slanted surface 30 contiguous to the head portion 27 a to enable the filamentary material 22 to slide smoothly thereon and over the nose portion 27 b when the filamentary material 22 is brought by the second carrier 21 into hooked engagement with the hook 27 in a manner hereafter to be described. Upon rocking movement of the rocker arm 26, the hook 27 moves, in a plane substantially perpendicular to the general plane of the stringer tape 11, between a first position shown in Figures 2 and 3 in which it is located in alignment with the fell 16 and a second position shown in Figure 1 in which it is located remotely from the fell 16. The coiling means also includes an element-shaping plate 31 removably secured to and movable with the reed 23 toward and away from the fell 16. The element-shaping plate 31 has a straight longitudinal punch edge 31 a extending in parallel alignment with the slots 23 a of the reed 23 and in between the group of warp threads 14 and 15 and adapted to beat the filamentary material 22 against the fell 16, as shown in Figures 2 and 3 and recessed as at 31 b to preclude the danger of interference with the rocker arm 26. The element-shaping plate 31 may be adjusted, by suitable means such as bolts and nuts, in position relative to the reed 23, or may be replaced as and when it becomes worn on repeated frictional contact with the resinous filamentary material 22. The second carrier 21 has a bifurcated end portion 21 a for receiving therein the element-forming filamentary material 22 having the equidistantly spaced prospective coupling head portions 25 a (better shown in Figures 4 and 5). The second carrier 21 is actuated in timed relation to the rocker arm 26 so that while the hook 27 is at its second position shown in Figure 1, the bifurcated end portion 21 a of the carrier 21 engages the element-forming filamentary material 22 and carries the same over the slanted surface 30 and the hook's head portion 27 a into engagement with the nose portion 27 b . The apparatus thus constructed operates with a cycle of operation which for purpose of illustration begins under the conditions shown in Figure 1 in which the element-forming filamentary material 22 is displaced by the second carrier 21 beyond the warp threads 14, 15 into hooked engagement with the hook 27; the weft thread 20 inserted or laid in by the first carrier 19 through the upper warp shed 17 is ready for hooked engagement with the knitting needle 24; and the reed 23 is retracted in a position away from the fell 16 of the stringer tape 11 being woven. Then, the rocker arm 26 is actuated to move angularly toward the fell 16 whereupon the hook 27 moves from the second position of Figure 1 to the first position of Figures 2 and 3. At the same time, the reed 23 is actuated to move forward to beat the weft thread 20 just inserted against the fell 16 and the element-shaping plate 31 likewise moves forward in between the warp threads 14, 15 to beat the filamentary material 22 against the fell 16 along the longitudinal edge 11 a of the tape 11. During that time, the element-forming filamentary material 22 is coiled around the hook's nose portion 27 b substantially in parallel relation to the fell 16 to thereby form a coupling element 25. Thereafter, while the rocker arm 26 and hence the hook 27 is at rest at the first position shown in Figures 2 and 3, the reed 23 is retracted together with the element-shaping plate 31 away from the fell 16, then the heddle not shown is actuated to move the warp threads 12 - 15 up and down across the warp sheds 17, 18, and the first carrier 19 is again actuated to insert the weft thread 20 in the upper warp shed 17. After the reed 23 has beaten the weft thread 20 just inserted against the fell 16, the rocker arm 26 moves angularly away from the fell 16 to bring the hook 27 into the second position shown in Figure 1. Simultaneously therewith, the reed 23 and the plate 31 are moved back again to their retracted position. Finally, the heddle is actuated to change the respective positions of the warp threads 12 - 15 into those shown in Figure 1, to thereby complete a cycle of operation of the apparatus. Figures 4 - 7 show an example of woven slide fastener stringer 33 produced by the apparatus of the present invention. The slide fastener stringer 33 comprises a row of coiled coupling elements 34 formed of synthetic resin fixed to a slide fastener stringer tape 35 woven of foundation warp threads 36 and a single foundation weft thread 37, the row of coupling elements 34 extending along a longitudinal edge portion 38 of the stringer tape 35. The foundation warp threads 36 and the foundation weft thread 37 jointly constitute a web portion 39 of the stringer tape 35. The row of coupling elements 34 is secured to one longitudinal edge portion 38 of the stringer tape 35 by means of a fixing warp thread system including a plurality of clamping warp threads 40 a , 41 a , 42 a , 40 b , 41 b , 42 b and a plurality of upper and lower binding warp threads 43 a , 44 a , 45 a , 43 b , 44 b , 45 b . Each of the coupling elements 34 comprises a coupling head 47 and a pair of upper and lower legs 48, 49 extending from the coupling head 47 in a common direction and spaced from each other vertically in a direction substantially perpendicular to the general plane of the stringer tape 35. The upper and lower legs 48, 49 are merged into and interconnected by a heel portion 50 located remotely from the coupling head 47. According to an important aspect of the invention, the heel portion 50 is oriented to project transversely beyond the longitudinal edge portion 38 of the tape 35, while the coupling head 47 is directed toward the web portion 39 of the tape 35. The upper and lower binding warp threads 43 a - 45 a and 43 b - 45 b extend substantially in a straight run over the upper and lower legs 48 and 49, respectively of the coupling elements 34 so as to provide enhanced positional stability of the elements 34 in the longitudinal direction of the stringer 33. The binding warp threads 43 a - 45 a and 43 b - 45 b intersect the weft thread 37 in between adjacent coupling elements 34 as shown in Figure 4. The clamping warp threads 40 a , 41 a , 42 a , 40 b , 41 b , 42 b are adapted to bring both legs 48, 49 of the elements 34 closely together. The foundation weft thread 37 passes around the last upper warp binding thread 45 a up toward and around the last lower warp binding thread 45 b to form a straight run or span 51 therebetween adjacent the coupling head 47 of the element 34 which extends substantially perpendicularly with respect to the general plane of the stringer tape 35. The straight span 51 of the weft thread 37 defines an axis about which the stringer tape 35 is folded back so that the coupling head portion 47 of each coupling element 34 now projects transversely beyond the longitudinal edge portion 38 of the tape 35, while the heel portion 50 of the element 34 is concealed from view by the web portion 39 of the tape 35 which has been turned over to overlie the heel portion 50 as shown in Figures 6 and 7. A portion of the weft thread 37 inserted in double picks, which is interlaced with the foundation warp threads 36 in the region of the straight span 51, forms an abutment 52 transversely projecting toward the coupling head 47 of the element 34. The abutment 52 on one of a pair of stringers 33 is brought into abutting engagement with that on the other of the paired stringers 33 when the two stringers 33 are coupled together in a well known manner by a slider not shown. The abutments 52 thus effectively conceal the row of coupling elements 34 from view and can remain joined together against lateral pull or vertical thrust by the fixing warp thread system described herein which holds the coupling elements 34 firmly in place with the upper and lower legs 48, 49 of the respective elements 34 substantially superimposed one upon another to lie substantially perpendicular to the general plane of the stringer 33 and flattened to assume a relatively low profile as shown in Figures 5 - 7.

Claims: A woven slide fastener stringer (33) comprising: (a) a woven stringer tape (35) including a web portion woven (39) of a plurality of foundation warp threads (36) and a single foundation weft thread (37): (b) a row of continuous filamentary coupling elements (34) disposed on one longitudinal edge portion (38) of said stringer tape (35) and spaced longitudinally from each other, each of said coupling elements (34) including a coupling head portion (47), a pair of upper and lower leg portions (48, 49) extending from said coupling head (47) in a common direction and spaced from each other vertically in a direction substantially perpendicular to the general plane of said stringer tape (35), and a heel (50) portion located remotely from said coupling head portion (47) and interconnecting one of said upper and lower leg portions (48, 49) to an adjacent coupling element (34), and (c) a fixing warp thread system securing said row of coupling elements (34) in position against displacement, said fixing warp thread system consisting of a plurality of clamping warp threads (40a-42a, 40b-42b) and a plurality of upper and lower binding warp threads (43a-45a, 43b-45b), said upper and lower binding warp threads (43a-45a, 43b-45b) extending substantially in a straight run over said upper and lower leg portions (48, 49), respectively, of said coupling elements (34), said clamping warp threads (40a-42a, 40b-42b) extending over an upper leg portion (48) of one coupling element (34) and under a lower leg portion (49) of an adjacent coupling element (34) and into engagement with said weft thread (37), and said foundation weft thread (37) passing around the last upper warp binding thread (45a) up toward and around the last lower warp binding thread (45b) to form a straight span (51) therebetween adjacent said coupling head portion (47) and extending substantially perpendicularly with respect to the general plane of said stringer tape (35), characterized in that the heel portion (50) of each of said coupling elements (34) is oriented to project transversely beyond said longitudinal edge portion (38) of said stringer tape (35), while the coupling head (47) is directed toward the web portion (39) of said stringer tape (35), that said fixing warp thread system consists exclusively of said clamping warp threads (40a-42a, 40b-42b) and said upper and lower binding warp threads (43a-45a, 43b-45b), each of said clamping warp threads (40a-42a, 40b-42b) extending between two adjacent pairs of said upper and lower binding threads (43a-45a, 43b-45b) and said straight span (51) of said weft thread (37) defining an axis about which said stringer tape (35) is folded back with said coupling head portion (47) of each coupling element (34) projecting transversely beyond said one longitudinal edge (38) of said stringer tape (35). A woven slide fastener stringer (33) according to claim 1 characterized in that said straight span (51) forms an abutment (52) on one of a pair of stringers (33) in abutting engagement with a corresponding abutment (52) on the ohter stringer (33).

Inventors: SHIMANO MUCHIJI, SHIMANO, MUCHIJI
Applicants: YKK CORP, YKK CORPORATION
Application year: 1990
Main classification: A44B19
IPC codes: A44B19