Waterproof slide fastener

A waterproof slide fastener in which an entire surface of a fastener tape is covered with elastomer, through holes are made in a side edge of the fastener tape, and fastener elements each comprising a coupling head, a neck portion, an engaging projection, a leg portion and a tongue piece, are molded by injection molding so as to cover the through holes. Reinforcing portions are provided projectingly from sides of the leg portion so as to cover at least a part of each of the through holes in a longitudinal direction of the through holes made in the fastener tape so that the reinforcing portions surround the through holes, so the reinforcing portions prevent the through holes from being exposed even when the fastener tape is bent, thereby maintaining water-tightness and airtightness.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a waterproof slide fastener having waterproof property in which the entire front and rear surfaces of a woven or knitted fastener tape are covered with elastomer to complete a fastener tape having waterproof property, and then, fastener elements are injection molded on side edges of the fastener tapes by using thermoplastic resin.

2. Description of the Related Art

Conventionally, according to Japanese Utility Model Publication No. 59-42893, there has been known a slide fastener formed into a configuration which prevents its fastener chain101from being broken, the fastener chain101being formed by attaching injection molded type fastener elements103to a fastener tape102, as shown inFIG. 15. In this slide fastener, a core thread140is attached to a side edge of the fastener tape102, and through holes108going through between front and rear surfaces are provided on which the fastener elements103are attached. The part of leg portions114of the fastener element103and a tongue piece extending from the rear end of the leg portion114are attached to the through hole108such that the through hole108is covered therewith. In addition, the side face of the tongue piece provided on the end portion of the leg portion114is provided with a bend restricting piece130in a state in which it keeps contact with the fastener tape102with a larger width than that of the leg portion114in order to prevent the chain from being cracked when the fastener chain101is bent in the longitudinal direction.

Additionally, according to Japanese Patent Laid-Open Publication No. 2005-237577, there has been known another slide fastener having waterproof property as shown inFIG. 16. In this slide fastener, both front and rear surfaces of a woven or knitted fastener tape202are covered with thermoplastic elastomer to complete a fastener tape202having waterproof property. Through holes208going through between front and rear surfaces are provided at each fastener element attachment position on the edge portion of the fastener tape202. Fastener elements203each formed of a coupling head210, a neck portion212, a leg portion214and a tongue piece216are attached to the side edge of the fastener tape202by injection molding using thermoplastic resin. The through holes208are covered with the leg portions214of the fastener elements203, and the leg portions214on the front and rear surfaces are joined by a connecting portion215through the through hole208.

The slide fastener shown inFIG. 15is an ordinary type slide fastener having no water-tightness or airtightness. In order to attach fastener elements103firmly to the side edge of the fastener tape102by injection molding using thermoplastic resin, a core thread140is attached to the side edge of the fastener tape102, through holes108are made in the side edge of the fastener tape102, and fastener elements103are molded at positions in which the through holes108exist. In order to prevent the fastener chain101from being broken, bend restricting pieces130having larger width than that of the leg portion114and projecting to the side are molded on the tongue piece formed at the rear end of the leg portion114of the fastener element103such that the bend restricting pieces130are joined to the fastener tape102. As a result, when the fastener chain101is bent in the longitudinal direction, the bend restricting pieces130keep firm contact with each other, so that a large load is applied to the bend restricting pieces130joined to the fastener tape102. Consequently, the fastener elements103turn unstable, thereby getting loose.

In the waterproof slide fastener shown inFIG. 16, the front and rear surfaces of the fastener tape202are covered with thermoplastic elastomer to complete a fastener tape202having waterproof property, through holes208going through between the front and rear surfaces are provided in the side edge of the fastener tape202, and the through holes208are covered with the leg portions214of the fastener elements203. When a load is applied in the longitudinal direction of the fastener chain, the through holes208are exposed out of the fastener elements203, thereby making it difficult to maintain water-tightness. Particularly, when the size of the fastener element203is reduced, the through hole208cannot be reduced in diameter easily. The present invention is achieved by improving this point.

SUMMARY OF THE INVENTION

The present invention has been accomplished in views of the above problems, and an object of the invention is to provide a waterproof slide fastener having water-tightness and airtightness, in which a fastener tape is finished to have waterproof property by performing simple waterproof treatment on a fastener tape, through holes are made in the side edge of the fastener tape, fastener elements are formed by injection molding at positions in which the through holes are provided by using thermoplastic resin so as to cover the through holes with the leg portions of the fastener elements while intensifying and reinforcing the side face of the leg portion, so that even when a load is applied to the fastener tape, the through holes are not exposed out of the fastener elements, thereby maintaining water-tightness and airtightness for a long term.

Another object of the invention is to provide a waterproof slide fastener capable of maintaining water-tightness and airtightness securely by specifying the configuration of the reinforcing portion to be formed on the side face of the leg portion of the fastener element which covers the through hole provided in the fastener tape having waterproof property.

In order to achieve the above object, there is provided a waterproof slide fastener, being characterized in that an entire surface of a fastener tape is covered with elastomer; through holes are made in the fastener tape; fastener elements are integrally molded on front and rear surfaces of the fastener tape using thermoplastic resin such that each of the fastener elements comprises a coupling head having a coupling concave portion provided at a front end of the fastener element, a constricted neck portion, an engaging projection at a neck portion, a leg portion, and a tongue piece projecting from a rear end of the leg portion; a tape edge portion is exposed on a foreside of the engaging projection; and the leg portions are attached to the through holes, the fastener element further comprising reinforcing portions integrally formed therewith and projecting from sides of the leg portion.

Consequently, resin made fastener elements can be attached firmly to the fastener tape having waterproof property through the through holes made in the tape. Further, the through holes are never exposed by the reinforcing portions formed on the side faces of the fastener element even when a load is applied to the fastener tape, thereby not damaging the water-tightness and airtightness. As a result, it is possible to obtain a waterproof slide fastener having an excellent water stopping effect and capable of maintaining the water-tightness and airtightness for a long term.

Preferably, the reinforcing portions projecting from the sides of the leg portion are formed so as to cover at least a part of each of the through holes in a longitudinal direction of the through holes made in the fastener tape.

Consequently, the through holes made in the fastener tape are surrounded by the reinforcing portion and never exposed out of the fastener element, thereby maintaining water-tightness and airtightness securely.

Preferably, the reinforcing portions projecting from the sides of the leg portion are formed thicker than the engaging projection formed at the neck portion and thinner than the leg portion.

For this reason, the slide fastener of the invention can be adopted for fastener elements capable of maintaining water-tightness and airtightness regardless of the size of the fastener element.

Preferably, the reinforcing portions projecting from the sides of the leg portion are formed in a same thickness as the engaging projection and the tongue piece.

As a result, the peripheral portion of each fastener element is protected and reinforced, thereby maintaining water-tightness and airtightness.

Preferably, the reinforcing portions projecting from the sides of the leg portion are formed in a same thickness as the leg portion.

Accordingly, the slide fastener of the invention is suitable for small sized fastener elements, so that water-tightness and airtightness can be attained in a small sized fastener chain.

Preferably, the reinforcing portions projecting from the sides of the leg portion are formed in a larger width than the width of the engaging projection formed at the neck portion.

As a consequence, each fastener element can secure water-tightness and airtightness while it performs its coupling operation securely. Therefore, the effects achieved by the present invention are considerably great.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A waterproof slide fastener of the present invention is configured as shown inFIGS. 1 to 5. More specifically, the waterproof slide fastener comprises a fastener tape2having a covering layer6formed therein. The covering layer6covers the surface of a woven or knitted base fabric5with elastomer such as thermoplastic elastomer or synthetic rubber. Through holes8going through between front and rear surfaces are provided at a constant interval, for example, at positions of the fastener tape2at which fastener elements3are to be attached by injection molding using the thermoplastic resin such that the through holes8are covered therewith.

In the fastener element3, a coupling head10capable of engaging an engaging projection13of a mating fastener element is provided by providing a coupling concave portion11at a front end thereof, and a neck portion12is formed so that the neck portion12is constricted on the inner side of the coupling head10. The neck portion12is provided with the engaging projection13which is fit to the coupling concave portion11, and subsequent to the neck portion12, a leg portion14equal to the engaging projection13in width is molded so as to cover the through hole8provided in the fastener tape2. A connecting portion15for connecting the front and rear surfaces of the leg portions14is provided, and a tongue piece16having the same thickness as the engaging projection13is provided at the rear end of the leg portion14so that the flange of the slider can slide on the tongue piece16.

In the waterproof slide fastener, a reinforcing portion18formed thicker than the engaging projection13and thinner than the leg portion14is provided integrally with the leg portion14facing the through hole8provided in the fastener tape2such that the reinforcing portion18projects from the side of the leg portion14more than the engaging projection13. As a consequence, the through hole8formed in the fastener tape2is prevented from being exposed out of the fastener element3and prevented from being damaged in water-tightness and airtightness when a load is applied to the fastener tape2in the fastener chain1.

The configuration of the reinforcing portion18varies as shown inFIGS. 6 to 14. A reinforcing portion18shown inFIGS. 6 to 8is formed in the same thickness as the engaging projection13formed at the neck portion12and the tongue piece16formed at the rear end of the leg portion14such that the reinforcing portion18projects more than the width of the engaging projection13. A reinforcing portion18shown inFIGS. 9 to 11is formed in the same thickness as the leg portion14such that the reinforcing portion18projects more than the width of the engaging projection13. A lower portion of a reinforcing portion18shown inFIGS. 12 to 14is formed in the same thickness as the engaging projection13and the tongue piece16, and an upper portion thereof is formed into a slope19by tapering together with the leg portion14. The respective reinforcing portions18prevent the through hole8from being exposed even if a load is applied to the fastener tape2in the fastener chain1, thereby not damaging the water-tightness and airtightness.

First Embodiment

In a waterproof slide fastener of a first embodiment as shown inFIGS. 1 to 5, a fastener tape2has waterproof property, comprising a covering layer6formed by covering the entire front and rear surfaces of woven or knitted base fabric5with elastomer, for example, thermoplastic elastomer or synthetic rubber. Through holes8going through between the front and rear surfaces are provided in the side edge of the fastener tape2, that is, at positions at which fastener elements3are to be attached. Then, the fastener elements3are attached by injection molding using thermoplastic resin, such as polyamide, polyacetal, polypropylene, or polybutylene terephthalate so as to cover the through holes8. In the fastener element3, a side of opposing fastener chains1is defined as a front end, and the opposite side thereof is defined as a rear end. Also, a width is the dimension of the fastener element3in the longitudinal direction of the fastener tape2. Also, a thickness is the height of the fastener element3from the surface of the fastener tape2.

In each fastener element3, a coupling head10to engage an engaging projection13of a mating fastener element is provided by providing a coupling concave portion11having concave shape at its front end portion, and a neck portion12constricted inside is formed subsequent to the coupling head10. Then, the flat engaging projection13which substantially coincides with the width of a leg portion14and is wider than the neck portion12is provided, the engaging projection13being capable of engaging with the coupling concave portion11of the mating fastener element. A tape edge portion7of the fastener tape2is formed to be exposed on the front face of the engaging projection13, that is, on the side of the coupling head10as shown inFIGS. 1 to 3. When right and left fastener elements3couple each other, the tape edge portion7exposed from the engaging projection13is pressed to the inner face of the coupling concave portion11, so that as shown inFIG. 4, the tape edge portions7butt against each other in a straight line so as to maintain water-tightness and airtightness at the tape edge portion7securely.

The leg portion14whose width substantially coincides with the width of the engaging projection13is provided subsequent to the neck portion12such that the leg portion14is wider than the neck portion12and the through hole8, and the leg portion14is attached by molding so as to cover the through hole8provided in the fastener tape2. The front and rear surfaces of the leg portion14are connected by a connecting portion15through the through hole8, and a tongue piece16having the same thickness as the engaging projection13is provided at the rear end of the leg portion14, so that flanges on both sides of a slider can make slide on the tongue piece16. The tongue piece16is thin plate shaped and projects from the rear end side of the leg portion14. The tongue piece16is dented in the center of the rear end of the leg portion14, and the width of each of the two tongue pieces16is formed smaller than the width of the reinforcing portion18, which is located back and forth of the leg portion14and projects from the sides of the leg portion14. The reinforcing portion18is formed on the side of the leg portion14, that is, on the side where it opposes adjacent fastener element3.

The reinforcing portion18projecting from the sides of the leg portion14, being thicker than the engaging projection13and thinner than the leg portion14is provided integrally with the leg portion14on the fastener element3attached to the fastener tape2. The reinforcing portion18covers the longitudinal direction of the through hole8provided in the fastener tape2or the longitudinal direction of the fastener chain1, at least part of the through hole8, that is, a range in which the through hole8is formed, for example, so that the through hole8is surrounded by the reinforcing portion18. Consequently, the through hole8formed in the fastener tape2is prevented from being exposed out of the fastener element3attached to the fastener tape2, thereby preventing water-tightness and airtightness from being damaged even when a load is applied to the fastener tape2of the fastener chain1.

The reinforcing portion18is formed in such a thickness that it does not make contact with the reinforcing portion18of adjoining fastener element3although the leg portions14of adjoining fastener elements3make contact with each other when the fastener tape2of the fastener chain1is bent as shown inFIG. 5. As a consequence, the reinforcing portions18never block bending of the fastener chain1. Preferably, the reinforcing portions18are formed to the sides of the leg portion14and correspond to the through hole8. Corresponding to the through hole8means covering a range extending from the side of the leg portion14in the range of the through hole8formed in the fastener tape2on an extended line extending to the side of the fastener element3.

As for condition for providing the reinforcing portion18integrally with the leg portion14, preferably, the following equation is established when the width of the reinforcing portion18provided on both sides of the leg portion14is W and the diameter of the through hole8is D in consideration of the attachment strength of the fastener element3to the fastener tape2.
W/D=1.77 to 2.13

This range is a condition for the through hole8provided on the fastener tape2not to be exposed out of the fastener tape3. Further, because the width of the reinforcing portion18is larger than the width of the engaging projection13, an interval between adjoining fastener elements3is larger at the engaging projection13than at the reinforcing portion18.

Second Embodiment

In a waterproof slide fastener of a second embodiment shown inFIGS. 6 to 8, the configuration of a fastener tape2having waterproof property is the same as that of the first embodiment. Through holes8going through between the front and rear surfaces of the fastener tape2are provided, and then, a fastener element3for covering the through hole8is formed into the same configuration as the above-described embodiment. The fastener element3is formed by injection-molding a coupling head10having a coupling concave portion11, a neck portion12having an engaging projection13, and a leg portion14having a tongue piece16projectingly at the rear end on the through hole8by using the same thermoplastic resin as described previously, so that the front and rear surfaces are connected by a connecting portion15.

In this fastener element3, the reinforcing portion18having the same thickness as the engaging projection13and the tongue piece16provided at the rear end is formed on both sides of the leg portion14in the longitudinal direction of the fastener chain1such that the reinforcing portion18is integrally molded with the leg portion14facing the through hole8. As a consequence, the surrounding of the leg portion14is attached equally and firmly to the fastener tape2, thereby securing water-tightness and airtightness.

Third Embodiment

In a waterproof slide fastener of a third embodiment shown inFIGS. 9 to 11, the configuration of a fastener tape2having waterproof property is the same as that of the first embodiment. Through holes8going through between the front and rear surfaces of the fastener tape2are provided along the side edge of the fastener tape2, and then, a fastener element3for covering the through hole8is formed into the same configuration as the above-described embodiment. The fastener element3is formed by injection-molding a coupling head10having a coupling concave portion11, a neck portion12having an engaging projection13, and a leg portion14having a tongue piece16projectingly at the rear end on the through hole8by using the same thermoplastic resin as described previously, so that the front and rear surfaces are connected by a connecting portion15.

The through hole8provided in the fastener tape2is covered with the leg portion14of the fastener element3, and the reinforcing portions18having the same thickness as the leg portion14are formed on both sides of the leg portion14facing the through hole8such that they project to the side more than the engaging projections13. As a consequence, the through hole8can be blocked from being exposed out of the fastener element3even if the size of the fastener element3is small, and water-tightness and airtightness can be maintained.

Fourth Embodiment

In a waterproof slide fastener of a forth embodiment shown inFIGS. 12 to 14, the configuration of a fastener tape2having waterproof property is the same as that of the first embodiment. Through holes8going through between the front and rear surfaces of the fastener tape2are provided along the side edge of the fastener tape2, and then, a fastener element3for covering the through hole8is formed into the same configuration as the above-described embodiment. The fastener element3is formed by injection-molding a coupling head10having a coupling concave portion11, a neck portion12having an engaging projection13, and a leg portion14having a tongue piece16projectingly at the rear end on the through hole8by using the same thermoplastic resin as described previously, so that the front and rear surfaces of the fastener elements3are connected by a connecting portion15.

The through hole8provided in the fastener tape2is covered with the leg portion14of the fastener element3, and the reinforcing portion18is provided integrally with the leg portion14on both sides of the leg portions14facing the through hole8by forming a lower portion thereof into the same thickness as the engaging projection13and the tongue piece16and forming an upper portion thereof into a slope19by tapering it with the leg portion14. Consequently, the appearance of the fastener element3is formed in an excellent shape and design while water-tightness and airtightness can be maintained.

As for the waterproof slide fastener of the present invention, its large size waterproof slide fastener can be used in products supplied with a large load such as tent or oil fence and the like, and its small size waterproof slide fastener can be used in waterproof clothing, shoes and packaging products.