A fluid-tight slide fastener comprises a pair of slide fastener halves each including a support tape, a row of continuous coupling elements extending longitudinally along the inner edge of the tape on one side thereof, and an elastomeric sealing member overlying the other side of the tape. The tape has a longitudinal ridge substantially defining the inner edge and supporting the row of coupling elements laterally longitudinally by means of stitching threads. A portion of the threads is disposed adjacent to the ridge to prevent the latter from moving remotely from the coupling elements row for thereby supporting the ridge intimately enough to ensure the abuttment of opposed sealing edges of the tapes when the fastener halves are coupled together.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a slide fastener, and more particularly to 
a fluid-tight slide fastener stringer. 
2. Prior Art 
There are known various fluid-tight slide fasteners. One such fluid-tight 
slide fastener includes a stringer tape which supports edgewisely a row of 
continuous coupling elements on one side and a sealing member on the other 
side. For example a fluid-tight slide fastener of this type is disclosed 
by U.S. Pat. No. 3,501,816 as shown in FIG. 9 of the accompanying 
drawings. This slide fastener produces a seal when a pair of rows of 
coupling elements 102 are coupled underneath the coplanar stringer tapes 
101 urging opposed sealing lips 104 to bear against each other above the 
tapes 101. Each of the sealing lips 104 formed into a wedge-shaped 
projection is raised from a general plane of the coplanar tapes 101 with 
the result that the sealing lips 104 neccessarily bear upon each other 
with a sealing force directed at a level remote from a level at which the 
coupling elements 102 are intermeshed together. In this mutually 
compressed relation, only the tapes 101 support the opposing sealing lips 
104. The supporting tapes 101, however, fail to support the same strongly 
enough to keep the sealing force unidirectional and parallel to the 
general plane of the tapes to obtain most effective seal against leakage. 
Another type of fluid-tight slide fastener is disclosed by Japanese Utility 
Model Publication (Jikkosho) No. 55-31939. This prior fastener as shown in 
FIG. 10 includes a pair of stringer tapes 201, each having a row of 
discrete coupling elements 203 each bracketing a longitudinally folded 
edge 202 of the tape 201 and a sealing member 204 underlying the latter 
for thereby allowing the sealing members 204 to be sandwiched tightly in 
between the elements rows and the folded tape edges. However, each one of 
the discrete coupling elements 203 has a bracketing structure 203a which 
adds to the cost of manufacture of the slide fastener products and also 
impairs the appearance of an article to which the fastener is attached. 
SUMMARY OF THE INVENTION 
According to the principles of the present invention, a fluid-tight slide 
fastener comprises a pair of slide fastener halves or stringers to be 
joined with each other along their respective longitudinal edges. Each 
stringer includes a support tape, a row of continuous coupling elements 
extending longitudinally on one side of the tape, and an elastomeric 
sealing member overlying the other side of the tape. The support tape has 
a ridge extending longitudinally for substantially defining an innermost 
edge of the tape. The sealing member transversely extends over the 
edge-defining ridge and projects beyond a vertical median plane of 
symmetry between the interengaged stringers for thereby forming a 
longitudinal contact edge portion, the latter being supported by the 
ridge. The row of continuous coupling elements is secured to the tape by a 
connecting means such as threads, a portion of which is disposed close to 
the ridge for enabling the latter to fixedly support the coupling elements 
rows, with the result that the threads prevent the ridges from being 
displaced remotely from the coupling elements row. 
It is therefore an object of the invention to provide a slide fastener 
producing an effective fluid-tight seal even when the same has a 
relatively simple structure including a known continuous coupling elements 
stitched thereto by a conventional stitching means. 
Many other advantages, features and additional objects of the present 
invention will become manifest to those versed in the art upon making 
reference to the detailed description and the accompanying drawings in 
which preferred embodiments incorporating the principles of the present 
invention are shown by way of illustrative examples.

DETAILED DESCRIPTION 
The principles of the present invention are particularly useful when 
embodied in a fluid-tight slide fastener such as embodiments shown in the 
accompanying drawings. 
In FIG. 1, a pair of slide fastener halves or stringers 10, 10 are 
substantially mirror images of each other and lying in a general plane. To 
clarify the description of the invention, only one of the stringers is 
described hereinafter. 
The fastener stringer 10 includes a stringer tape or support tape 11 
supporting on one side thereof a row of continuous coupling elements 12 
extending along its innermost longitudinal edge and an elastomeric sealing 
member 15 lying substantially coextensively on the other side thereof. 
The support tape 11 is made of a warp-knitted fabric having alternating 
ridges (or wales) 18 and grooves 19 extending longitudinally in a parallel 
relation to one another on one side of the tape 11. The warp-knitted 
fabric is diagrammatically illustrated in FIG. 5. An innermost one of the 
ridges 18' substantially defines the innermost edge of the tape 11. 
The row of continuous coupling elements 12 formed into a continuous helical 
coil includes a core 13 extending therethrough, and is stitched securely 
to the support tape 11 by means of threads 14 running via the core 13 in 
and out of the tape 11. The threads 14 have a portion 14' disposed 
adjacent to the innermost ridge 18', namely in a groove 19 defined between 
the ridge 18' and another ridge 18 adjacent to the latter, so that the 
threads 14 hold the ridge 18' in place with respect to the row of the 
coupling elements 12, and enable the ridge 18' to support obliquely the 
coupling elements row 12. 
The sealing member 15 is made, of an elastically deformable material such 
as silicone rubber, butyl, neoprene, polyurethane rubber or other 
elastomeric material. 
The sealing member 15 is secured substantially coextensively to the tape 11 
and extends over the ridge 18' for providing a longitudinal contact edge 
portion 16 projecting transversely beyond a vertical median plane of 
symmetry P of the interengaged stringers 10. The contact edge portion 16 
is thus reinforced by the ridge 18' supporting on its innermost side the 
same. The contact edge portions 16 of the stringers 10 are adapted to abut 
on each other to produce a tight seal therebetween when the stringers are 
coupled together as shown in FIG. 2. Each one of the contact edge portions 
16 is transversely reinforced by the ridge 18' of the tape. 
FIG. 5 diagrammatically shows a warp-knitted fabric of which the support 
tapes 11 is made. The warp-knitted fabric comprises a pair of base 
portions or webs 30 and a connector portion 11a extending longitudinally 
therebetween. Each one of the base portions 30 includes a plurality of 
threads 31 knitted as tricot stitches, a plurality of threads 32 knitted 
as chain stitches, and a plurality of weft threads 33 running transversely 
of the threads 31, 32 across the tape. The threads 31, 32 run 
longitudinally to form in combination a plurality of wales 18 each 
including a succession of stitch loops of the threads 31, 32. Each one of 
the weft theads 33 runs over respective five wales 18 in alternately 
reversed directions and looping in either one of the most remote pair in 
five wales 18. The innermost adjacent pair of wales 18' respectively 
includes threads 32' each having a higher degree of strength than the 
other threads 31, 32, 33 so as to solidify the wales 18' defining the 
ridges of the tapes 11. The connector portion 11a includes a connector 
thread 34 extending longitudinally in a zigzag fashion via the innermost 
wales 18' of the base portions 30 for interconnecting the same to each 
other. The connector portion 11a is free from wales, and thus thinner than 
the base portions 30. The base portions 30 in FIG. 5 correspond to a pair 
of the support tapes 11 in FIG. 1, respectively. With this warp-knitted 
fabric structure of a high stitch-density, the wales 18' per se are strong 
enough to suppress an anti-pressing force to due resiliency in the sealing 
material at the contact edge portions 16. 
When the stringers 10 are coupled together as shown in FIG. 2 by 
interengaging both rows of coupling elements 12, the opposed longitudinal 
edges or ridges 18' of the tapes 11 are forced to move toward each other, 
whereupon the ridges 18' and the contact edge portions 16 supported 
thereon are hindered from moving remotely from the coupling elements rows 
12, in other words upwardly as viewed in FIG. 2. As a result, the 
edge-defining ridges 18' of the tapes supportably push the respective 
contact edge portions 16 in an abuttment relation parallel to the general 
plane of the tapes 11 and hence of the stringers 10 for thereby bearing 
against each other to produce a fluid-tight seal in the median plane P. At 
this time masses of longitudinal edge portions 16 bulge sideways to form 
raised portions 17 ensuring the tight seal between the sealing members 15 
in the median plane P. 
FIG. 3 shows another embodiment similar to the stringers of FIGS. 1 and 2, 
and one difference therefrom is the structure of the support tapes 21. The 
tape 21 is made of a woven fabric comprising a plurality of warp threads 
and a plurality of weft threads (not shown), and has a longitudinal ridge 
28 having a function similar to the ridge 18' of the stringer 10 of FIG. 
1. The ridge 28 is defined by one of the warp threads 28 extending 
longitudinally through the weft threads of the tape 21. The warp threads 
28 have a thickness greater than that of the other warp threads. 
Alternatively, the ridge may be formed into a cord extending similarly 
through the weft threads. The row of coupling elements 12 is secured 
similarly to the tape 21 by means of the threads 14, a portion of which is 
located adjacent to the ridge 28 so that the threads 14 hold the ridge 28 
in place and prevent the same from being displaced remotely from the 
coupling elements row 12 when the stringers 20 are coupled together. Thus 
the tapes 20 also provide the ridges 28 supporting the opposed contact 
edge portions 16 through the threads 14 stably enough to force the latter 
to bear upon each other as shown in FIG. 4. Therefore the stringers 20 
also produce a stable fluid-tight seal when coupled together. 
FIGS. 6 through 8 illustrate a manufacturing process of the fluid-tight 
slide fastener according to the invention. 
In FIG. 6, a pair of coplanar support tapes 11 having the opposed 
longitudinal ridges respectively on one side thereof are laterally 
continuous to each other via the connector portion 11a. The pair of 
continuous coupling elements 12 are stitched to the other sides of the 
tapes respectively by means of the stitching threads 14 along the 
respective innermost edges of the tapes 11. The threads 14 are partially 
disposed adjacent to the respective ridges 18'. 
Then as shown in FIG. 7, the sealing material 15 is attached to all the 
surface of the other side of the coplanar continuous tapes 11. The tapes 
11 with the sealing member attached thereto are cut into a pair of 
fastener halves or stringers 10 by a cutter means C as shown in FIG. 8 
with the result that each one of the separate stringers 10 provides the 
longitudinal contact edge portion 16 projecting beyond the vertical median 
plane P as shown in FIG. 8. At this time, fragments of the connector 
threads 34 remaining in the tapes 11 may be removed as in as the 
embodiment shown in FIG. 1. 
In each one of the embodiments described above, the support tapes have the 
opposed longitudinal ridges disposed adjacent to the corresponding contact 
edge portions of the sealing material. With this arrangement, the slide 
fastener has the ridges of the tapes deliberately supporting the contact 
edge portion strongly enough to suppress a resilient force normally urging 
to recover the original form of the contact edge portion and thus pushing 
back the latter in the opposite direction, with the result that the same 
are kept to bear against each other for producing a fluid-tight seal 
therebetween. 
Advantageously, these embodiments may incorporate conventional continuous 
coupling elements to be stitched to the tape, for thereby eliminating a 
neccessity of relatively complicated structure such as the coupling 
elements 203 having bracket portions 203a of the prior fastener of FIG. 
10. Therefore the slide fastener embodying the invention has a simple 
structure which enables for an economical production of effective 
fluid-tight slide fasteners. 
Although various minor modifications may be suggested by those versed in 
the art, it should be understood that we wish to embody within the scope 
of the patent warranted hereon, all such embodiments as reasonably and 
properly come within the scope of our contribution to the art.