Sliding clasp fasteners
United States Patent 1 [111 3,874,036  
 Yoshikawa [45] A r, 1, 1975 SLIDING CLASP FASTENERS [56] References Cited [75] Inventor: Kiichi Yoshikawa,Toy0naka, UNITED STATES PATENTS osakaJapan 3,015,868 1/1962 Ruhrmann 24/205.16 C 3,054,158 9/1962 Yoshida 24/2051 C [73] Ass1gnee: Yoshlda Kogyo Kabushiki Kaisha, 3,149,387 9/1964 Ruhrmann 24/205.16 C Tokyo, Japan 3,255,504 6/1966 Porepp 24/205.l3 C 3,430,304 3/1969 Swainson 24/205.1 C [22] Filed: Aug. 18, 1972 3,494,008 2/1970 Frohlich 24/205.1 C 3,667,089 6/1972 Porepp 24/205.16 c [21] Appl. No.1 281,724 3,708,836 1/1973 Frohlich 24/205.1 C 3,714,683 2/1973 Frohlich 24/205.l6 C  
  Primary Examiner-Bernard A. Gelak Attorney, Agent, or FirmBucknam and Archer [30] Foreign Application Priority Data Aug. 20, 1971 Japan 46-75197 [57] ABSTRACT A sliding clasp fastener is dlsclosed which is provided with means for covering the outer surfaces of the coupling elements and protecting the same against dam- 1 1 C, 24/205.16 C, age during ironing or laundering. The covering means 24/2O5-13 consists of a strip of a warp-knitted fabric having alternate wales and grooves, in which grooves sewing [51] Int. Cl. A44b 19/12, A44b 19/40 threads are accommodated without projecting above [58] Field of Search 24/205.1 c, 205.16 c, the Surface of the element- 24/205.13 C 3 Claims, 8 Drawing Figures PATENTEUAPR 11m SHEET 2 BF 2 FIGS FIG.7&#39;  
 SLIDING CLASP FASTENERS This invention relates to sliding clasp fasteners and has particular reference to fasteners provided with coupling elements made of plastic materials. I  
  lt is the usual practice to provide means for protecting such plastic fastener elements from being deformed or otherwise damaged when the fastener is subjected to ironing or laudering. One known way is to employ fancy stitches in a manner to cover the greater portion of the fastener element. Another conventional practice is to lay a narrow elongate flat strip of braid over exposed surfaces of fastener elements in a row and sew it together with the elements onto a stringer tape. Since such braid strip has a uniform thickness throughout its entire width, it tends to develop irregular surface con-- tour when sewn firmly to the tape; that is, the portions of the strip when in contact with the sewing threads become recessed under the influence of sewing pressure, while the opposite longitudinal marginal edges thereof are conversely turned up or flared. These flared edge portions of the strip become forcibly engaged with the interior walls of a slider and render the movement of the latter heavy and sluggish. lf the fastener is allowed to open and close repeatedly with the slider in such restrained desposition, the braid strip will become stained and damaged in forcible contact with the slider, or sometimes the sewn stitches will even be torn.  
  Whereas, it is the primary object of the present invention to provide a sliding clasp fastener which is free from the above disadvantages.  
  It is a more specific object of the invention to provide improved means for protecting sliding clasp fasteners against physical deformation of their fastening elements when they are subjected to ironing or laundering.  
  These objects and features of the invention will appear clear from the following description taken with reference to the accompanying drawings which illustrate certain preferred embodiments and in which:  
  FIG. 1 is a transverse sectional view ofa sliding clasp fastener embodying the invention with its two rows of fastener elements on opposed stringer tapes coupled together by the agency of a slider;  
  FIGS. 2, 3 and 4 transverse sectional views respectively showing different embodiments of the invention; and  
  FIGS. 5 through 8, inclusive, are plan views respectively illustrating covering strips employed in accordance with the invention.  
  Referring now to the drawings and HG. l in particular, there is shown a sliding clasp fastener which comprises a pair of opposed stringer tapes l1 and rows of fastener element E mounted thereon which are interengageable by the agency of a slider 12. The fastener elements E are formed from a continuous plastic filament into a meandering shape so that they can be mounted astride of an inner longitudinal edge 13 of each stringer tape 11, as shown in FIG. 1. ln accordance with the invention, there is provided an elongate covering or protective means for protectively covering the outer surface of the greater portion of the element E, which means consists of a narrow strip of fabric 15 of a warp-knitted structure essentially consisting of wales 16 of warp stitches and weft threads 17 laid in coursewise to connect the wales 16. A typical example of the construction of this warp-knitted strip 15 is seen in FlG. 5 in which there is further provided tricot stitches l8 linking between adjacent wales 16. There are formed recesses or grooves 19 between adjacent wales l6 wherethe system of the fabric is less dense.  
  According to the invention, these grooves 19 are utilized to receive sewing threads S from a sewing needle (not shown) which is guided snugly into the grooves 19.  
  In the various embodiments presently shown, the covering strip 15 is provided with two grooves 19 defined by relatively wide marginal wales 16a and a relatively narrow center wale 16b. The marginal wales 16a constituting a longitudinal selvage 20 of the strip 15 are formed by thicker yarns than the remaining yarns in the system or by double pieces of yarns so as to reinforce the selvage 20 which would otherwise be thin and weak due to one less looping of weft thread 17 than at the center web portion of the strip 15.  
  Turning back to FIG. 1, the covering strip 15 is arranged symmetrically on each of two arm portions Ea, upper and lower, of each meandering element E and secured together therewith to the stringer tape 11 by sewn stitches S that are accommodated within the grooves 19 in the strip 15 without imparting sewing pressures to the wales 16a so that these wales do not flare up away from the element E but can be held flat and flush with the plane of the element E. In this manner, the sewing threads S being embedded within the grooves 19 are saved from abrasive wear which would otherwise result from frictional engagement with the slider 12.  
  The embodiment shown in FIG. 2 employs a covering strip 15 of FIG. 7 which is structurally the same as that of FIG. 5 except that an additional weft thread 17 is laid in to connect two of the strip 15 of HG. 5 in a pair at their respective inner selvages 200. This arrangement advantageously facilitates positioning the two similar strips 15 simultaneously on the upper and lower arms Ea of the elements E with the coupling heads Eb thereof projecting outwardly through the loops of connecting weft thread 17.  
  ln the embodiment shown in FIG. 3 there is shown a fastener element E in the form of a coil spring which is mounted on and along the inner longitudinal edge of a stringer tape 11. This tape 1 l is of a warp-knitted structure similar to the structure of the strip 15 shown in FIG. 5 and provided with alternate wales and grooves for the purpose of the invention already described. Designated at 21 is a reinforcing core member inserted through the coils of the elements as in the usual practice for this type of element.  
  FIG. 4 illustrates a sophisticated embodiment which is characterized by the provision of a covering strip 15 which consists of two identical pieces folded back to back so that the strip 15 has one set of wales 16 and grooves 19 in the upper surface for receiving sewing threads S and another set of similar wales and grooves in the lower surface in a symmetrical fashion. The coil element E is provided in its upper arm portion Ea with alternate ridges 22 and grooves 23 to snugly fit with corresponding grooves 19 and wales 16 in the lower surface of the strip 15. This arrangement ensures increased positional stability of the strip 15 relative to the element E when sewn onto the stringer tape 11.  
  FIG. 8 illustrates a wide warp-knitted fabric 24 consisting of a plurality of strips 15 which are interconnected coursewise by a water soluble plastic filament 25, the arrangement being that the fabric 24 may be 3 readily separated into individual covering strips 15 when immersed in water.  
  Having thus described the invention, it will be understood that various changes and modifications may be made in the specific form and construction herein advanced, without departing from the scope of the appended claims. As for example, the tricot stitches 18 in the strip 15 of FIG. may be substituted by warp threads 26 laid in between the wales 16 as shown in FIG. 6.  
 What is claimed is:  
  1. in a sliding clasp fastener having a pair of opposed stringer tapes and rows of coupling elements mounted on the respective longitudinal edges of said tapes, the improvement which comprises a plurality of pairs of warp-knitted fabric strips having alternate wales of warp stitches and weft thread laid in coursewise to connect said wales forming grooves between adjacent wales, said pairs of fabric strips being each positioned to protectively cover a corresponding row of coupling elements along opposite areas thereof oriented to face the sliding clasp, and sewing stitches securing together the fabric strips associated with each stringer tape and the row of coupling elements mounted thereon, said sewing stitches being received and protectively recessed within said grooves out of wiping contact with the sliding clasp.  
  2. The improvement according to claim 1 wherein one of said warp-knitted strips is integrally connected with a corresponding stringer tape.  
  3. The improvement according to claim 1 wherein said coupling elements have ridge parts and at least one of said warp-knitted strips has grooves that received the ridge parts of the coupling elements to stabilize the strip against movement relative to such coupling elements.