Method of manufacturing portion of slide fastener

A first tape having a first edge is provided. The first tape is provided with a row of coupling elements along the first edge of the first tape. The coupling elements are configured to interdigitate with a further row of coupling elements. A first layer of a fluid resistant material is attached to the first tape. An extending layer of a fluid resistant material is attached to the first layer. The extending layer forms an extension member including a first overhang portion which extends beyond a second edge opposite the first edge. The first layer of the fluid resistant material is attached to the first tape and the extending layer is attached to the first layer.

The present application claims priority to GB Application No. 1310165.4 filed Jun. 7, 2013, which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a slide fastener and method of manufacture of a portion thereof. In particular the slide fastener may be a fluid resistant slide fastener and the manufactured portion of slide fastener may be a portion of a fluid resistant slide fastener.

BACKGROUND

Known slide fasteners (also referred to as zip fasteners) are generally constructed as follows.

Coupling elements (also referred to as teeth) are attached to the edge of a tape to form a stringer. The tape is usually woven or knitted and may be formed from, for example, polyester. The coupling elements are attached to the tape by, for example, crimping or moulding the coupling elements onto a reinforced edge of the tape. Alternatively, the coupling elements may be formed as a continuous coil. In this case the coupling elements are most commonly woven or knitted into the tape or alternatively are stitched to a surface of the tape at the edge of the tape.

Two stringers are brought together, such that the coupling elements of each stringer can attach to one another, for example, by interdigitating, to form chain. A slider is attached to the chain such that it can move along the chain between the two stringers. The slider commonly includes a main body through which the coupling elements of each stringer pass and pull tab attached to the main body which may be grasped by a user in order to effect movement of the slider along the chain.

Movement of the slider along the chain in a first direction causes the coupling elements of the first stringer to attach to the coupling elements of the second stringer. Whereas movement of the slider along the chain in a second direction, opposite to the first direction, causes the coupling elements of the first stringer to detach from the coupling elements of the second stringer.

The chain is cut to a desired length to form a desired length of slide fastener. Stops (often referred to as top stops and bottom stops) are attached to either end of the chain. The stops limit the extent of movement that the slider can undertake along the chain.

Some slide fasteners, may have a single bottom stop which is attached to both the first and second stringers. Other slide fasteners, which may be referred to as a separating slide fasteners, may have two separate bottom stops attached to a corresponding one of the stringers. The two bottom stops may take the form of a retainer box and an insertion pin. The insertion pin can be inserted into the retainer box in order to attach the first and second stringers to one another. Conversely, the insertion pin can be removed from the retainer box in order to detach the first and second stringers from one another.

Some slide fasteners may have two separate top stops attached to a corresponding one of the stringers. Other slide fasteners may have a single top stop attached to both of the stringers.

In certain applications it is desirable for a slide fastener to be fluid resistant, for example liquid and/or gas tight (i.e. for the slide fastener to substantially prevent the passage of liquid and/or gas through the slide fastener when the slide fastener is in a closed configuration). By further way of example, in some applications, it is desirable for a slide fastener to be waterproof, or more specifically, for an article (for example, but not limited to, a garment) of which a waterproof slide fastener forms part to be waterproof when the slide fastener is in a closed configuration.

The applicant has realised there is a requirement for a durable fluid resistant slide fastener.

It is common for slide fasteners to be secured to articles by stitching. Stitching provides a durable attachment between the slide fastener and the article to which the slide fastener is attached. The applicant has realised that a problem exists when trying to attach a fluid resistant slide fastener to an article in this manner whilst maintaining a substantially liquid and/or gas tight seal between the slide fastener and the article. For example, the holes created by stitching which pass through a slide fastener and an article to which the slide fastener is attached, and/or the stitching itself may create a fluid flow path via which fluid can flow, thereby making the slide fastener and article to which the slide fastener is attached undesirably fluid permeable.

Methods other than stitching, for example adhesives or other means of bonding, are known for attaching slide fasteners to an article. However, depending on the application of the slide fastener and/or article, the use of securing means other than stitching may not be suitably durable.

The width of known slide fasteners is defined by size and/or position of the coupling elements and the widths of the tapes. It is desirable for slide fasteners to have greater flexibility as to their width such that slide fasteners can easily be produced with different widths dependent on the width of slide fastener required by an article to which the slide fastener is to be applied.

SUMMARY

The present invention is concerned with a slide fastener stringer, a slide fastener and a method of producing at least a portion of a slide fastener which is fluid resistant and which can be attached to an article without creating a fluid flow path through the slide fastener and/or article. The present invention is also concerned with a slide fastener stringer, a slide fastener and a method of producing at least a portion of a slide fastener which enables greater flexibility in the widths of slide fastener which can be achieved. The present invention is also concerned with an alternative slide fastener, alternative slide fastener stringer and alternative method of producing at least a portion of a slide fastener. The slide fastener, slide faster stinger and method of producing at least a portion of a slide fastener according to the present invention seek to obviate or ameliorate problems with known slide fasteners and methods of manufacturing slide fasteners whether discussed above or otherwise.

According to a first aspect of the present invention, there is provided a method of manufacturing a portion of a slide fastener, the method comprising, providing a first tape having a first edge; providing the first tape with a row of coupling elements along the first edge of the first tape, the coupling elements being configured to interdigitate with a further row of coupling elements, attaching a first layer of a fluid resistant material to the first tape, attaching an extending layer of a fluid resistant material to the first layer, the extending layer forming an extension member comprising a first overhang portion which extends beyond a second edge of the first tape opposite the first edge of the first tape; wherein the first layer of fluid resistant material is attached to the first tape and the extending layer is attached to the first layer such that there is no fluid path through the first layer and/or extending layer to the first tape.

The portion of a slide fastener may be a slide fastener stringer.

The first layer may be attached to the first tape such that at least a portion of the first tape is sandwiched within the first layer.

The extending layer may be attached to the first layer such that at least a portion of the first layer is sandwiched within the extending layer.

The portion of the slide fastener may comprise a first sealing portion which is configured to, when the coupling elements are interdigitated with the further row of coupling elements which form part of a further portion of slide fastener, co-operate with a further sealing portion of the further portion of slide fastener to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal.

The first sealing portion may be configured such that the fluid resistant seal is configured to resist the passage of a fluid through the fluid resistant seal either to the interdigitated coupling elements or through the interdigitated coupling elements.

The first layer may comprise a first sealing portion which overhangs the coupling elements along the first edge of the first tape, the first sealing portion being configured to cooperate with a further sealing portion of a further portion of slide fastener to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal to the coupling elements along the first edge of the first tape.

The method may further comprise providing a second tape having a first edge; providing the second tape with a row of coupling elements along the first edge of the second tape, the coupling elements being configured to interdigitate with a further row of coupling elements; attaching a second layer of a liquid resistant material to the second tape; and attaching the extending layer to the second layer, the extending layer forming the extension member, the extension member comprising a second overhang portion which extends beyond a second edge of the second tape opposite the first edge of the second tape; wherein the second layer of fluid resistant material is attached to the second tape and the extending layer is attached to the second layer such that there is no fluid path through the second layer and/or extending layer to the second tape.

The further row of coupling elements with which the row of coupling elements along the first edge of the second tape may be configured to interdigitate is the row of coupling elements along the first edge of the first tape.

The second layer may be attached to the second tape such that at least a portion of the second tape is sandwiched within the second layer.

The extending layer may be attached to the second layer such that at least a portion of the second layer is sandwiched within the extending layer.

The second tape, and second layer may form part of a second stringer. The second stringer may comprise a second sealing portion which is configured to, when the coupling elements of the second tape are interdigitated with the further row of coupling elements which form part of a further portion of slide fastener, co-operate with a further sealing portion of the further portion of slide fastener to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal.

The second sealing portion may be configured such that the fluid resistant seal is configured to resist the passage of a fluid through the fluid resistant seal either to the interdigitated coupling elements or through the interdigitated coupling elements.

The second sealing portion may be configured to, when the coupling elements of the second tape are interdigitated with the row of coupling elements along the first edge of the first tape, co-operate with the first sealing portion to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal.

The second sealing portion may be configured such that the fluid resistant seal is configured to resist the passage of a fluid through the fluid resistant seal either to the interdigitated coupling elements or through the interdigitated coupling elements.

The second layer may comprise a second sealing portion which overhangs the coupling elements of the first edge of the second tape, the second sealing portion being configured to cooperate with a further sealing portion of a further portion of slide fastener to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal to the coupling elements of the first edge of the second tape.

The first sealing portion may be configured to cooperate with the second sealing portion to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal to the coupling elements of the first edge of the first tape and the coupling elements of the first edge of the second tape.

The method may further comprise separating the extension member into first and second portions, wherein the first portion includes the first overhang portion, and the second portion includes the second overhang portion.

The first portion of the extension member may form part of a first slide fastener stringer and the second portion of the extension member forms part of a second slide fastener stringer.

The first slide fastener stringer and the second slide fastener stringer may form part of a slide fastener chain.

According to a second aspect of the invention there is provided a slide fastener including a portion manufactured according to the method of the first aspect of the invention.

According to a third aspect of the invention there is provided a slide fastener stringer comprising a first tape having a row of coupling elements along a first edge of the first tape, the coupling elements being configured to interdigitate with a further row of coupling elements, a first layer of a fluid resistant material attached to the first tape, an extending layer of a fluid resistant material attached to the first layer, wherein the extending layer forms an extension member comprising a first overhang portion which extends beyond a second edge of the first tape opposite the first edge of the first tape; and wherein the first layer of fluid resistant material is attached to the first tape and the extending layer is attached to the first layer such that there is no fluid path through the first layer and/or extending layer to the first tape.

The first layer may be attached to the first tape such that at least a portion of the first tape is sandwiched within the first layer.

The extending layer may be attached to the first layer such that at least a portion of the first layer is sandwiched within the extending layer.

The stringer may comprise a first sealing portion which is configured to, when the coupling elements are interdigitated with the further row of coupling elements which form part of a second stringer, co-operate with a further sealing portion of the second stringer to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal.

The first sealing portion may be configured such that the fluid resistant seal is configured to resist the passage of a fluid through the fluid resistant seal either to the interdigitated coupling elements or through the interdigitated coupling elements.

The first layer may comprise a sealing portion which overhangs the coupling elements along the first edge of the first tape, the sealing portion being configured to cooperate with a further sealing portion of a further portion of slide fastener to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal to the coupling elements along the first edge of the first tape.

According to a fourth aspect of the invention there is provided a slide fastener comprising one or two stringers according the third aspect of the invention.

The slide fastener may comprise first and second stringers according to the third aspect of the invention, wherein the first stringer comprises a first sealing portion and the second stringer comprises a second sealing portion, the first and second sealing portions being configured to, when the coupling elements of the first and second stringers are interdigitated, co-operate to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal.

The first and second sealing portions may be configured such that the fluid resistant seal is configured to resist the passage of a fluid through the fluid resistant seal either to the interdigitated coupling elements or through the interdigitated coupling elements.

The slide fastener may comprise first and second stringers according to the third aspect of the invention, wherein the first layer of the first stringer comprises a first sealing portion which overhangs the coupling elements along the first edge of the first tape of the first stringer, wherein a first layer of the second stringer comprises a second sealing portion which overhangs coupling elements along a first edge of a second tape of the second stringer, and wherein the first and second sealing portions are configured to cooperate to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal to the coupling elements along the first edge of the first tape of the first stringer and the second stringer.

The slide fastener may be fluid resistant.

The slide fastener may be at least one of substantially gas tight and substantially liquid tight.

Slide fasteners according to the present invention find particular application in waterproof garments and garments used in outdoor pursuits, for example, walking clothes, diving suits etc. Slide fasteners according to the present invention also find application in waterproof articles, for example, tents and life-rafts. However, it will be appreciated that slide fasteners according to the present invention are not limited to these uses.

Other aspects and preferred features of the present invention will be apparent from the following description and the accompanying claims.

EMBODIMENTS

FIGS. 1aand 1bshow a known slide fastener10of the general type described in EP1150586, the entire contents of which are incorporated herein by reference.

The slide fastener10comprises a chain2formed from two stringers3,4. Each stringer comprises a tape5,6made from a woven fabric such as for example polyester. Continuous coil-shaped elements comprising coupling elements7,8is stitched with threads11,12or woven into the edge13,14of each tape5,6, as is well known in the art. As shown most clearly inFIG. 1a, the continuous coil-shaped elements comprising coupling elements7,8are mounted on an underside15,16of each tape5,6at a side of inner edge thereof, respectively. Portions of the tapes5,6adjacent the coupling elements7,8are not shown inFIG. 1bso as to enhance the clarity of the figure.

A layer of thermoplastic material20,21is extruded onto an upper surface17,18of each tape5,6, the upper surfaces17,18of each tape5,6being opposite the undersides15,16of each tape5,6. The layer of thermoplastic material20,21extends around the outer edge of each tape5,6, which is opposite the inner edge, and along a portion of the underside15,16of each tape5,6. As shown inFIG. 1a, there are gaps on the undersides15,16between the layers of thermoplastic material20,21and the coupling elements7,8so that portions of the undersides15,16of each tape5,6are exposed due to the gaps.

In order to produce a slide fastener from the chain2a slider (not shown) is mounted to the chain2for opening and closing the chain by selectively coupling or uncoupling the coupling elements7,8(and hence the stringers3,4). In addition, it is usual to have end stops (again, not shown) located at either end of the slide fastener to limit the movement of the slider along the slide fastener. Sliders and end stops are well known in the art and will not be discussed in further detail here.

The slide fastener10is impermeable to fluid, that is, it is gas impermeable and waterproof. In use, the layers of thermoplastic material20,21form a fluid tight/waterproof membrane and abut each other at a plane24, located perpendicularly to the plane of the tapes5,6.

It is usual for the thermoplastic material layers20,21to be applied to each stringer3,4individually. The thermoplastic material layers20,21form sealing lips20a,21a(also referred to as sealing fins), which extend laterally beyond the inner edges25a,26aof the tapes5,6and over the coupling elements7,8. The sealing lips20a,21aextend upwardly at an angle to the plane of the fastener tapes5,6and abut to form a raised area A that is raised above the general plane of the stringers3,4, to form an inverted V or triangular shape when the stringers are joined by the coupling of the coupling elements7,8.

A problem associated with known fluid-proof slide fasteners as shown inFIGS. 1aand 1bis discussed below.

It may be necessary to secure the fastener to a garment or other article requiring fluid-proof characteristics. The usual mechanism by which the zip fastener is secured to the garment for example is by sewing as seen inFIG. 2. Unfortunately, the sewing process causes holes32to be generated in the stringers of the fastener which may allow the ingress of water along a path W1created by sewing threads30.

In addition the sewing thread30and holes32may create a second flow path W2which allows the ingress of water. In the case of flow path W2the water may flow along the sewing thread30and/or through the holes32and then into the tape5. The water can then flow along the tape and exit at point E on the inside of the garment or article of which the slide fastener forms part.

In order to try and avoid the holes formed in the sewing process from serving as a track for the ingress of fluid as seen inFIG. 2, a waterproof backing material34, as shown inFIG. 3may be applied to the underside of the fastener stringer3or directly on the sewing thread30. However, as can be seen inFIG. 3, the application of a waterproof backing material does not block the flow path W2and hence the waterproof backing material34may not prevent the ingress of water.

In addition, the known slide fastener shown inFIGS. 1 to 3, which is produced using known methods, offers very little flexibility in the width of the slide fastener.

Different articles or garments to which a slide fastener is to be attached may require different widths of slide fastener. For example if the slide fastener is to be used to provide a fastening for a relatively wide opening in a garment or article, then a relatively wide slide fastener will be required compared to that which would be required in order to fasten a relatively narrow opening in a garment or article.

The width of known slide fasteners is defined by various factors including the size of the coupling elements, the position at which the coupling elements are secured to the tapes of each stringer, and the width of the tapes of each stringer. Consequently, if it is desired to alter the width of a known slide fastener (e.g. to tailor the slide fastener so that it is suitable for fastening a particular size of opening in a garment or other article), then it would be necessary to change at least one of the characteristics of the slide fastener mentioned above. Changing at least one of these characteristics of the slide fastener (for example, changing the width of the tapes, the size of the coupling elements or changing the positioning of the coupling elements on the tapes) may be a relatively complicated process which requires the use of different components of slide fastener (for example, different sized coupling elements and/or different widths of tape). Consequently, it may be relatively inconvenient to change the width of known slide fasteners. That is, known slide fasteners have relatively little flexibility in their width.

FIG. 4shows a cross-section through a slide fastener110according to an embodiment of the present invention which includes a chain102formed from two slide fastener stringers103,104according to an embodiment of the present invention.

Each of the stringers103and104is substantially the same in this embodiment. However, in other embodiments, this may not be the case.

Within the following description, stringer103is referred to as the first stringer and stringer104is referred to as the second stringer. However, it will be appreciated that, equally, stringer104could be referred to as the first stringer and stringer103could be referred to the second stringer.

Each stringer103,104comprises a tape105,106having a row of coupling elements107,108along a first edge113,114of each tape105,106. The tape105,106is made from a woven fabric such as, for example, polyester. However, it will be appreciated that in other embodiments the tapes105,106may be made from any appropriate material.

The coupling elements107,108of this embodiment are formed by two separate continuous coils which are stitched or woven to the edges113,114of each tape105,106. However, it will be appreciated that in other embodiments, any appropriate coupling elements may be used and they may be attached to the respective edge of the respective tape by any appropriate method. The coupling elements107,108are mounted on an underside115,116of each tape105,106.

The coupling elements107,108along the edge of each tape105,106are configured to interdigitate with a further row of coupling elements. In this case, the coupling elements107of the first stringer103are configured to interdigitate with the coupling elements108of the second stringer104.

A layer120,121of fluid resistant material is attached to each tape105,106. In the present embodiment, the layer of fluid resistant material is a layer of thermoplastic material which is extruded onto an upper surface117,118of each tape105,106, the upper surfaces117,118of each tape105,106being opposite the undersides115,116of each tape105,106. In this case, the thermoplastic material which forms the layers120,121is both substantially impermeable to gas and substantially impermeable to liquid. However, it will be appreciated that in other embodiments, any appropriate fluid resistant material may be used which may be impermeable to either gas or liquid, or may be impermeable to both gas and liquid. The layer of thermoplastic material120,121extends around the outer edge of each tape105,106to the undersides115,116. The layer120,121is also referred to as a first layer.

An extending layer140,142of a fluid resistant material is attached to the layer120,121. In this embodiment, the extending layer140,142of each stringer103,104is formed from a thermoplastic material which is extruded onto each layer120,121. This extrusion process is discussed in more detail further below. It will be appreciated that, in other embodiments, any appropriate method may be used to attach the extending layer140,142to the layer120,121provided that the extending layer140,142is attached to the layer120,121such that there is no fluid path through the layer120,121and/or extending layer140,142to the respective tape105,106. The thermoplastic material which forms the extending layer140,142is a fluid resistant material in that it is impermeable to both liquid and gas. It will be appreciated that in other embodiments any appropriate material may be used to form the extending layer, providing it is fluid resistant. A material is said to be fluid resistant if it is substantially impermeable to liquid and/or gas. In the preferable example, the extending layer140,142and the layer120,121of the thermoplastic material may be made of the same material. The extending layer may be attached to the first layer at the side opposite to the first tape so as to protrude relative to the upper surface of the first layer. Consequently, on the upper surface of the first layer, the thickness of a portion of the first layer to which the extending layer is attached is greater than the thickness of the other portion of the first layer to which the extending layer is not attached. In addition, the extending layer may also be attached to the second layer at the side opposite to the second tape so as to protrude relative to the second surface of the second layer. Consequently, on the upper surface of the second layer, the thickness of a portion of the second layer to which the extending layer is attached is greater than the thickness of the other portion of the second layer to which the extending layer is not attached.

The extending layer140,142forms an extension member144,146comprising an overhang portion148,150which extends beyond a second edge152,154of the tape105,106opposite to the first edge113,114of the tape105,106. In fact, in this embodiment, the overhang portion148,150extends beyond an edge156,158of the first layer which is the edge of the layer120,121which is spaced furthest from the respective coupling elements107,108.

The layer120,121of fluid resistant material is attached to the tape105,106and the extending layer140,142is attached to the layer120,121such that there is no fluid path through the layer120,121and/or extending layer140,142to the respective tape105,106.

In order to secure each stringer103,104(and hence the slide fastener110) to a garment or other article requiring fluid-proof characteristics, the stringers103,104are each sewn to the garment or other article. The points160and162withinFIG. 4indicate where sewing thread (not shown) is passed through the extension member144,146in order to sew the stringers103,104(and hence the slide fastener110) into the garment or other article so that the stringers103,104(and hence slide fastener110) are secured to the garment or other article. At the points160and162withinFIG. 4, each stringer103,104is formed only by the thermoplastic material of the extension member144,146and the extension member144,146is coupled to the first layer. Consequently, the fluid intruding with the sewing threads sewn to the extension member144,146and/or the holes formed by sewing the sewing threads do not intrude into the tapes.

It can be seen that, because the holes (not shown) created by sewing the stringers103,104(and hence slide fastener110) into a garment or other article are created only within the extension member144,146, unlike known slide fasteners (as shown inFIGS. 1 to 3), no fluid flow path which allows the ingress of fluid is created via the respective tape105,106of each stringer103,104. This is because the holes and thread used for sewing the slide fastener do not pass through the tapes105,106of the stringers of the slide fastener. Consequently, when sewn to a garment or other article, the stringers of the present invention (which may form part of a slide fastener according to the present invention) do not provide a fluid flow path along which fluid can flow so as to penetrate the garment or other article via the tape. In order to prevent holes formed in the stringer during the sewing process from serving as a path for the ingress of fluid, a waterproof backing material may be applied to the underside of the stringer or directly on the sewing thread. The waterproof backing material has fluid-proof characteristics. For example, a resin film or a band to which the fluid-proof treatment is applied may be used as the waterproof backing material.

Consequently, the stringers according to the present invention (and hence slide fastener according to the present invention) are fluid-proof and improve the fluid resistance of a garment or other article to which the stringers (and hence slide fastener) are applied.

In addition, slide fasteners comprising at least one stringer according to the present invention have a greater flexibility as to their width compared to known slide fasteners. This because the width WEof the extension member can be readily changed whilst all other components of the slide fastener are kept constant so as to change the width WSof the slide fastener. The ability to use the same components of the slide fastener and only change the width of the extension member of a stringer so as to vary the total width of the slide fastener means that it is relatively simple to produce a slide fastener with any desired width by only changing the width of the extension member. This leads to a reduction in cost and complexity of creating slide fasteners with different widths suitable for different widths of opening within a garment or other article.

In order to produce a slide fastener from the chain102shown inFIG. 4, a slider (not shown) is mounted to the chain102for opening and closing the chain by selectively coupling or uncoupling the coupling elements107,108(and hence the stringers103,104). In addition, end stops (again not shown) located at either end of the slide fastener may be used to limit the movement of the slider along the slide fastener. Sliders and end stops are well known in the art of slide fasteners and hence will not be discussed in any further detail here.

The slide fastener110is impermeable to fluid, that is, it is gas impermeable and liquid impermeable. In use, the layers120,121form a fluid tight membrane. The layer120,121of each stringer103,104comprises a sealing portion164,166which overhangs from the first edge113,114in parallel with and along the first edge113,114of the tape105,106. The sealing portions164,166of each stringer103,104are configured to cooperate with a further sealing portion of a further portion of slide fastener so as to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal to the coupling elements107,108. In this case, the layer120of the stringer103comprises a sealing portion164which overhangs from the first edge113in parallel with and along the first edge113of the tape105of the stringer103. Likewise, the layer121of the stringer104comprises a sealing portion166which overhangs from the first edge114in parallel with and along the first edge114of the tape106of the stringer104. The first and second sealing portions164and166are configured to cooperate to form a fluid resistant seal which is configured to resist the passage of a fluid through the fluid resistant seal to the coupling elements107,108. That is, when the coupling elements107,108are coupled to each other, the sealing portion164comes into contact with the sealing portion166, thereby forming the fluid resistant seal.

At the sealing portions164,166along the first edge113,114, the layers120,121of each stringer103,104form sealing lips120aand121a(also referred to as sealing fins) which come into contact with each other at the time of coupling of the coupling elements. The sealing lips120a,121bare beyond inner edges of the tapes105,106and over the coupling elements107,108. The lips120a,121aabut at an angle to the plane of the fastener tapes105,106and form a raised area A1that is raised above the general plain of the stringers103,104to form an inverted V or triangular shape when the stringers are joined by the coupling of the coupling elements107,108. It will be appreciated that, although within the present embodiment the sealing portion164,166is integral with the respective layer120,121of each stringer103,104, in other embodiments this need not be the case. For example, the sealing portion may be formed from a separate piece to the layer of the stringer. Likewise, any appropriate configuration of sealing portion which is configured to form a fluid resistant seal to resist the passage of fluid through the fluid resistant seal, for example to the coupling elements, or through the coupling elements may be used. For example, the sealing portions described above include sealing lips which form a seal above the coupling elements. In other embodiments the sealing portions may take any appropriate form.

In one example each coupling element may comprise an inner element and an outer element. For example, the inner element may be provided on the lower surface of the first tape and the outer element may be provided on the upper surface of the first tape, which is opposite to the lower surface and on the upper surface of the layer of the sealing material. A layer of sealing material which forms at least part of a sealing portion is located between the inner element and the outer element. In use coupling elements of a first stringer interdigitate with coupling elements of a second stringer such that the inner elements of the coupling elements of the first stringer interdigitate with the inner elements of the coupling elements of the second stringer in order to close the slide fastener chain. Closing the slide fastener chain by the interdigitation of the inner elements result in the sealing portion (e.g. layer of sealing material between the inner and outer elements) of the first stringer and the sealing portion (e.g. layer of sealing material between the inner and outer elements) of the second stringer to abut and be compressed between the outer elements of the first stringer and the outer elements of the second stringer to thereby create a seal.

In some embodiments the coupling elements of each stringer may comprise a first row of coupling elements on a first side of the tape of the stringer and a second row of elements on a second side of the tape of the stringer. At least one of the coupling elements of the first row of coupling elements and at least one of the coupling elements of the second row of coupling elements may be of unitary construction—that is to say that at least one of the coupling elements of the first row of coupling elements and at least one of the coupling elements of the second row of coupling elements may be one piece such that they are formed of a single piece of material. For example, each coupling element of the first row of coupling elements may be unitary with a coupling element of the second row of coupling elements.

The coupling elements of the stringer are all located at a first edge of the tape of the stringer.

A sealing portion is located between the first and second rows of coupling elements. In use coupling elements of a first stringer interdigitate with coupling elements of a second stringer such that the first row and second row of coupling elements of the first stringer interdigitate with the first row and second row of coupling elements of the second stringer in order to close the slide fastener chain. Closing the slide fastener chain by the interdigitation of coupling elements of the first and second stringers results in the sealing portion of the first stringer and the sealing portion of the second stringer to abut to thereby forming a seal.

In other embodiments the sealing portions may form part of the coupling elements such that it is the coupled coupling elements themselves which form a fluid resistant seal.

The sealing portions in the embodiment described above co-operate such that when the coupling elements of two stringers couple to one another, the sealing portions are drawn into contact to form a fluid resistant seal to resist the passage of fluid through the fluid resistant seal to the coupling elements or through the coupling elements. In other embodiments the sealing members of each stringer may be configured such that they can be brought into contact with one another (in order to form the fluid resistant seal) in a separate operation to the coupling elements of each stringer being coupled to one another.

The overhang portion144,146of each stringer103,104may be said to extend beyond an edge of the layer120,121which is opposite to the edge at which the sealing portions164,166is located.

Within the presently described embodiment the layer of fluid resistant material120,121which is attached to the tape105,106is such that the layer of fluid resistant material extends around the outer edge of each tape105,106. In other embodiments, the layer of fluid resistant material may extend around the outer edge of each tape and along a portion of the underside of each tape. In this way, the layer may be attached to the tape such that at least a portion of the tape is sandwiched within the layer. The layer on the underside is formed with a gap between the layer and the coupling elements which are provided on the underside, and the tape is exposed between the layer and the coupling elements on the underside. The outer edge is an edge opposite to the first edge which is at a side at which the coupling elements are provided.

In the presently described embodiment the extending layer140,142of each stringer103,104is attached to the layer120,121such that a portion168,170of the extending layer140,142extends over an upper surface172,174of the layer120,121. The extending layer140,142extends around the outer edge of each layer120,121. In other embodiments, the extending layer may extend around the outer edge of the first layer and along a portion of the underside of the first layer and/or first tape. That is to say, in other embodiments, the extending layer is attached to the first layer such that at least the portion of the first layer is sandwiched within the extending layer. The outer edge of the first layer is an edge opposite to the first edge which is at a side at which the coupling elements of the tape is provided, and the outer edge of the first layer is positioned close to an outer edge of the tape.

According to another aspect to the invention there is provided a method of manufacturing a portion of a slide fastener as discussed above. The portion of the slide fastener manufactured in accordance with the invention may be a slide fastener stringer. However, it would be appreciated that any portion of a slide fastener which is manufactured in accordance with this aspect of the invention falls within the scope of the present invention.

Referring toFIG. 4, the method of manufacturing a portion of a slide fastener according to a present invention comprises the following. A first tape105is provided, the tape105having a first edge113. The tape105is provided with a row of coupling elements107along the first edge113of the tape105. The coupling elements107are configured to interdigitate with a further row of coupling elements. In the example shown inFIG. 4, the coupling elements107are configured to interdigitate with the row of coupling elements108which form part of a separate stringer104.

A layer120of a fluid resistant material is attached to the first tape105.

An extending layer140of a fluid resistant material is attached to the layer120. The extending layer140forms an extension member144comprising a first overhang portion148which extends beyond a second edge152of the first tape105opposite the first edge113of the first tape105.

The layer120of fluid resistant material is attached to the first tape105and the extending layer140is attached to the layer120such that there is substantially no fluid path through the layer120and/or extending layer140to the first tape105. The extending layer140can be made of only the thermoplastic resin.

The advantages of manufacturing a portion of the slide fastener in this manner have already been discussed above in relation to a slide fastener stringer in accordance with the present invention. As such repetition of these advantages is not made here.

Again referring toFIG. 4, method of manufacturing a portion of a slide fastener may further include the following.

A second tape106is provided, the second tape106having a first edge114. The second tape106is provided with a row of coupling elements108along the first edge114of the second tape106. The coupling elements108are configured to interdigitate with a further row of coupling elements. In this case, the coupling elements are configured to interdigitate with the row of coupling elements107which form part of the stringer103. That is to say the row of coupling elements108along the first edge114of the second tape106is configured to interdigitate with the row of coupling elements107along the first edge113of the first tape105.

A second layer121of a liquid resistant material is attached to the second tape106.

WhereasFIG. 4shows a chain102of a slide fastener110which has been assembled,FIG. 5shows the stringers103and104of the chain102at an intermediate point part way through the manufacture of the chain102.

Referring toFIG. 5, the extending layer140is attached both to the layer120(as previously discussed) and to the second layer121. The extending layer140forms an extension member180which comprises a first overhang portion148which extends beyond a second edge152of the first tape105opposite the first edge113of the first tape105(again as previously discussed). The extension member180further includes a second overhang portion150which extends beyond a second edge154of the second tape106opposite the first edge end114of the second tape106.

Again, the second layer121of fluid resistant material is attached to the second tape106and the extending layer140is attached to the second layer121such that there is no fluid path through the second layer121and/or extending layer140to the second tape106.

In order for the stringers103and104shown withinFIG. 5to form the chain102shown inFIG. 4, the extension member180shown inFIG. 5is separated at the point indicated by dashed line S so as to separate the extension member180into a first portion144and a second portion146. The first portion144includes the first overhang portion148and the second portion146includes the second overhang portion150. The first portion144of the extension member forms part of the first slide fastener stringer103and the second portion146of the extension member forms part of the second slide fastener stringer104. The slide fastener stringers103and104can then be attached by the interdigitation of their respective coupling elements107,108in order to form the chain102of the slide fastener110.

The extension member180includes a groove182. The groove182is located at the position on the extension member180at which the extension member180should be separated into the first and second portions144,146. The groove182acts as a score-line or line of structural weakness of the extension member and not only reduces the effort required to separate the extension member into the first and second portions, but also helps to ensure that the extension member is separated into first and second portions having the desired dimensions.

Although the method illustrated inFIG. 5includes the manufacture of first and second stringers simultaneously, in other embodiments of the present invention, only one stringer may be manufactured at a time. Furthermore, in the method illustrated inFIG. 5first and second stringers of the same chain are manufactured simultaneously. In other embodiments this need not be the case. For example, in some embodiments, two stringers manufactured according to the present invention may form part of different chains.

FIG. 6shows a cross section through a portion of apparatus which may be used in order to carry out the portion of the method described in relation toFIG. 5.

The apparatus shown inFIG. 6includes a roller200and a nozzle208. The roller200includes a central ring204sandwiched between two outer rings202and206. The outer rings each comprise a respective alignment groove210and212. The roller200(and hence the outer rings202,206and central ring204) is generally cylindrical and rotates about an axis indicated schematically by R. The roller rotates about the axis R such that the axis R and cylinder axis of the generally cylindrical roller are substantially co-axial.

The diameter of the central ring204is greater than the diameter of the outer rings202,206. In this case, the diameter is measured relative to the cylinder axis of the generally cylindrical roller.

In use two tapes105,106, their respective coupling elements107,108and attached first and second layers120,121of fluid resistant material are fed between the roller200and nozzle208. In some embodiments the roller200may drive the tapes105,106(with their respective coupling elements and layers of fluid resistant material) between the roller200and nozzle208. The tapes105,106are correctly aligned with respect to the roller200(and hence nozzle208) by the coupling elements107,108being received by respective alignment grooves212,210of the outer rollers206,202.

The nozzle208forms part of an extrusion die. The extending layer180is attached to the first and second layers120,121by being extruded by the nozzle208onto and between the first layer120and second layer121. The material extruded under pressure by the nozzle208of the extrusion die bonds to the first and second layers120,121. Any appropriate material may be extruded by the nozzle208of the extrusion dye, however, in this example, a thermoplastic is extruded by the nozzle208. Examples of suitable thermo plastic material include polyurethane, polypropylene, polyvinyl chloride and rubber. However, we appreciated that any appropriate extruded material may be used.

As discussed, the extending layer180is extruded by the nozzle208. The extending layer180is extruded into a void220defined between the edges of the first and second layers120,121, the surface of the rollers202,204,206and the nozzle208.

Because the central roller204has a diameter which is greater than that of the outer rollers202and206the extending layer180extruded by the nozzle208includes a groove (182inFIG. 5) which is defined by the central roller204.

AlthoughFIG. 6shows an extending layer being extruded onto first and second layers120,121of first and second tapes105,106, it will be appreciated that in other embodiments a similar apparatus may be used to apply an extending layer to only a single layer of fluid resistant material attached to a tape. Such an apparatus may include a roller as shown inFIG. 6, but with one of the outer rings omitted and a suitably modified nozzle. The inclusion of the inner ring, even when only extruding onto a single layer of fluid resistant material attached to a tape, may help to ensure that a uniform edge to the extension member is formed by the extruded extending layer.

It will be appreciated that numerous modifications to the above described method and apparatus may be made without departing from the scope of the invention as defined in the appended claims.

The described and illustrated embodiments are to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the scope of the inventions as defined in the claims are desired to be protected. In relation to the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used to preface a feature there is no intention to limit the claim to only one such feature unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.