Patent Publication Number: US-3874039-A

Title: Slide fastener stringer with scoops fabricated of a continuous filament

Description:
United States Patent 1 Takamatsu Apr. 1, 1975 [75] Inventor: Ikuo Takamatsu, Oaza Daikaiji Uozu, Japan [73] Assignee: Yoshida Kogyo K.K., Tokyo, Japan [22] Filed: July 26, 1974 211 App]. No.: 492,061  
 [30] Foreign Application Priority Data Aug. 24, 1973 Japan 48-99845 [52] US. Cl. 24/205.13 C, 24/205.l6 C [51] Int. Cl A44b 19/12 [58] Field of Search 24/205.l2, 205.1 C, 24/205.16 C, 205.13 C  
 [56] References Cited UNITED STATES PATENTS 1,991,320 2/1935 Sipe 24/205.13 C 3,588,967 6/1971 Speck 24/205.13 C  
 FOREIGN PATENTS OR APPLICATIONS 1,404,272 0/1964 France 24/205.l3 C  
 Primary ExaminerPaul R. Gilliam Assistant Examiner-Kenneth J. Dorner Attorney, Agent, or FirmBucknam and Archer [57] ABSTRACT The scoops on each of a pair of fastener stringers are formed of a continuous filament bent in a zigzag configuration. Each scoop is U-shaped, consisting of a pair. of parallel spaced legs and a coupling head interconnecting the legs at the front end of the scoop. Either of the two legs of each scoop is made longer than the other leg and is folded over toward the coupling head to provide a folded portion which is located between the legs in registered relationship. The front ends of the folded portions of each two adjoining scoops on each stringer are interconnected by a front connecting portion which is so positioned relative to the scoops that when the scoops on both stringers are coupled together by a slider moving therealong, the coupling head of every other scoop on each stringer will abut on the corresponding front connecting portion on the other stringer. It is possible in this way to uniformly determine the meshing depth of all the scoops on the pair of stringers.  
 1 Claim, 3 Drawing Figures BACKGROUND OF THE INVENTION This invention relates generally to slide fasteners and more particularly to improvements in a slide fastener stringer construction in which the row of scoops or fastener elements arranged along one of the longitudinal edges of a stringer tape are defined by an elongated continuous filament of a zigzag configuration.  
  There has been known a slide fastener stringer construction including an elongated continuous filament of metal, synthetic resin or like material which is bent in a zigzag configuration to provide a row of ladderlike portions each extending transversely of the stringer tape and functioning as scoops. Each scoop is in the shape of a U, consisting of a pair of parallel spaced legs and a coupling head at one end thereof. The other ends of the legs are bent in the opposite directions to be connected to the corresponding ends of adjacent scoops. The row of scoops thus fabricated of the continuous filament is usually sewed onto the stringer tape, with a core cord inserted linearly through the spacings between the legs of the respective scoops to assure proper meshing with the scoops on the companion stringer tape and to reinforce the anchorage of the legs onto the tape.  
  This prior art stringer construction has a serious deficiency with regard to the core cord inserted through the spacings between the legs of the respective scoops. For it is highly difficult, in the manufacture of the slide fasteners of this type, to sew the scoops onto the stringer tape while maintaining the desired linearity of the core cord which has been threaded through the scoop legs. As a consequence, the core cord tends to meander through the scoop legs thereby causing irregularity in the meshing depth of the scoops on both stringer tapes. The smooth functioning of the reciprocating slider along the scoops is practically impossible if such irregularity exists in the meshing depth of the scoops.  
 SUMMARY OF THE INVENTION It is, therefore, an object of this invention to provide an improved slide fastener stringer construction including scoops fabricated on an elongated continuous filament of a zigzag configuration, such that the meshing depth of all the scoops on a pair of stringer tapes can be regulated to a predetermined constant value thereby permitting the scoops to be smoothly and positively coupled and uncoupled by a slider moving therealong.  
  In order to accomplish this object of the invention, the conventionally known zigzag configuration of a continuous filament adapted to form a row of scoops on one surface of each stringer tape is altered in such a fashion that the coupling head of every other scoop on each stringer tape will abut on parts of the filament on the other stringer tape when the scoops on both stringer tapes are coupled together. The meshing depth ofthe scoops is thus determined by the said parts of the filaments which are solidly anchored to the respective stringer tapes, so that the faulty or irregular intermeshing of the scoops, which has frequently taken place in the prior art stringer construction making use of the core cords, is completely eliminated.  
  The features which are believed to be novel and characteristic of this invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and manner of operation, together with the further objects and advantages thereof, will be best understood from the following description of preferred embodiments when read in connection with the accompanying drawings in which like reference characters denote like&#39;parts throughout the several views.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a fragmentary top plan view of a pair of fastener stringers constructed in accordance with the novel concepts of this invention;  
  FIG. 2 is a cross sectional view taken along the plane of line II-II of FIG. l;&#39;and  
  FIG. 3 is a cross sectional view of a fastener stringer representing a modification of the embodiment shown in FIGS. 1 and 2.  
 DESCRIPTION OF THE PREFERRED EMBODIMENTS In a pair of slide fastener stringers shown in FIGS. 1 and 2 by way of one adaptation of this invention, each stringer is of the same construction, so that the description of one stringer will apply to both. Reference characters used to denote parts of the one stringer will therefore by simply primed to indicate corresponding parts of the other stringer.  
  The pair of fastener stringers shown in FIGS. 1 and 2 comprise first and second tapes l0 and 10 and first and second elongated continuous filaments l1 and 11 of metal, synthetic resin or like material, the latter being fastened to the opposed inside edges of the former. The first continuous filament 11, for instance, is bent in a zigzag configuration to provide a row of scoops 12 in ladderlike arrangement each extending transversely of the first stringer tape 10. As best shown in FIG. 2, each of the scoops I2 is substantially U- shaped, consisting of a pair of parallel spaced legs 13 and 14, which are disposed in a plane normal to the plane of the first stringer tape 10, and a coupling head 15 interconnecting the pair of legs at their front ends seen to the left in FIG. 2.  
  In the particular embodiment of the invention illustrated in FIGS. 1 and 2, the lower leg 14 of each scoop 12 is made considerably longer than the upper leg 13. The longer lower leg 14 is folded over at 16 toward the coupling head 15 to provide a folded portion 17 which is sandwiched between the upper and lower legs 13 and 14 in registered relationship thereto. The front end of the folded portion 17 is connected via a front connecting portion 18 to the front end of the similar folded portion of an adjoining scoop. On the other hand, the rear end of the upper leg 13 is connected via a rear connecting portion 19 to the rear end of the similar upper leg of an adjoining scoop on the opposite side of the first mentioned adjoining scoop.  
  In accordance with a feature of this invention, the aforesaid front connecting portion 18 between each two adjoining scoops 12 is located in such a position relative to these scoops that when the scoops l2 and 12&#39; on the first and second stringer tapes l0 and 10&#39; intermesh as shown in FIG. 1, the coupling head 15&#39; of every other scoop 12 on the second stringer tape 10&#39; will abut on the corresponding front connecting portion 18 of the filament 11 on the first stringer tape 10. It is of course understood that the coupling head 15 of every other scoop 12 on the first stringer tape 10 will likewise abut on the corresponding front connecting portion 18&#39; of the filament 11&#39; on the second stringer tape 10&#39;.  
  It is possible in this manner to adjust to a desired value the meshing depth D of the two rows of scoops l2 and 12&#39; on the first and second stringer tapes l and respectively. The first and second continuous filaments 11 and 11, each configured as above explained, can be easily anchored to the opposed inside edges of the first and second stringer tapes 10 and 10 as by means of sewing threads 20 and 20 respectively.  
  FIG. 3 illustrates a modification of the embodiment shown in FIGS. 1 and 2, in which the upper leg 13a of each scoop 12a on the first stringer tape 10 is made longer than its lower leg 14a and is folded over at 16a toward the coupling head to provide a folded portion 17a which also is sandwiched between the upper and lower legs 13a and 14a in registered relationship thereto. As in the preceding embodiment, the front end of the folded portion 170 is connected via the front connecting portion 18 to the front end of the similar folded portion, not shown, of an adjoining scoop on the first stringer tape 10. Other details of construction are exactly as previously set forth in connection with FIGS. 1 and 2. It will be apparent that according to this second embodiment, the meshing depth of the scoops 12a and 120&#39; can likewise be regulated by suitably positioning the front connecting portions 18 and 18&#39; relative to the respective scoops 12a and 12a.  
  While the improved slide fastener stringer construction according to this invention has been shown and described hereinbefore in very specific aspects thereof, it  
 is of course understood that the invention itself is not to be restricted by the exact showing of the drawings or the description thereof but is inclusive of various modifications within the usual knowledge of those skilled in the art. It is therefore appropriate that the invention be construed broadly and in a manner consistent with the fair meaning or proper scope of the following claim.  
 What is claimed is:  
  1. In a pair of stringers for a slide fastener, wherein each of said stringers includes a tape and a continuous filament anchored to said tape, said filament being shaped in a zigzag configuration to provide a row of substantially U-shaped scoops which extend transversely of said tape and each of which consists of a pair of parallel spaced legs and a coupling head interconnecting said legs at the front end of the scoop, one of said legs being longer than the other leg and being folded over toward said coupling head to provide a folded portion which is sandwiched between said legs in registered relationship thereto, the improvement comprising a series of front connecting portions each interconnecting the front ends of said folded portions of two adjoining scoops on each tape, said front connecting portions being so positioned relative to the scoops on each tape that when the scoops on both tapes intermesh, the coupling head of every other scoop on each tape will abut on the corresponding front connecting portion on the other tape, whereby the meshing depth of said scoops on both tapes is determined by the position of said front connecting portion relative to said scoops.