GB2598033A - Slide fastener - Google Patents

Abstract

A slide fastener assembly 2 comprising: a first stringer 4 having a first tape 18, a plurality of coupling elements 14 supported by the first tape, and a first sealing member (10, fig.3) extending along the first tape; a second stringer 6 having a second tape 20, a plurality of coupling elements 16 supported by the second tape and a second sealing member (12, fig.3) extending along the second tape; the coupling elements of the first and second stringers being configured to engage one another so as to releasably fasten the stringers together; when the first and second stringers are fastened together the first and second sealing members engage one another to form a seal therebetween; and one or both of the stringers comprise(s) one or more noncoupling zones, each non-coupling zone comprising at least one non-coupling element (42, fig 5) that is configured such that it cannot be fastened to the coupling elements of the other stringer. The fastener has a weak point ensuring it can be released in an emergency situation, and still have a sealing member.

Description

Slide Fastener The present invention relates to a slide fastener assembly and a method of manufacturing the same. In particular, the invention relates to a watertight slide fastener assembly which can be opened from a midpoint without the use of a slider.

Slide fastener assemblies, otherwise known as clasp lockers or zippers, are used to join two pieces of material together, often along an edge of the materials being joined. Slide fastener assemblies have many and varied applications, however some common applications include their use within articles of clothing, tents, footware, bags or the like. Slide fastener assemblies typically comprise a pair of stringers, each stringer comprising a tape and a plurality of coupling elements supported thereon. The coupling elements are receivable within a slider (i.e. a movable fastener body) which is translated along the stringers, from a first terminal end to a second terminal end, in a first direction to bring the opposing sets of coupling elements into contact with one another. The coupling elements are shaped so that the coupling elements bind together once in contact so that the two stringers are fastened. To unfasten the stringers, the slider is translated along the stringers in a second direction opposite the first direction.

Typically the coupling elements define small gaps therebetween which can receive foreign particulate matter such as dust, dirt, fabric fibres or the like. The foreign particulate matter may conglomerate between the coupling elements and prevent the passage of the slider or increase the difficulty of passing the slider along the stringers.

Furthermore, the gaps between the coupling elements may also permit other foreign matter such as liquids to pass from one face of the slide fastener assembly to the other, for example from the front of the slide fastener assembly to the reverse of the slide fastener assembly.

Slide fastener assemblies can be provided with sealing members running along the length of the stringers to prevent foreign matter passing into or through the slide fastener assembly. This is useful in applications such as life jackets, diving suits, dust excluder sheets or the like. The sealing members are brought into contact when the stringers are fastened together to form a seal therebetween. Typically, the sealing members are held in compression whilst the coupling elements are held in tension. The amount of force required to couple and uncouple the coupling elements from one another by sliding the slide fastener is typically large due to the need to place the coupling elements into or out of tension. As such, sealed slide fasteners can be difficult to use in practice and may take longer to couple or uncouple than an ordinary (i.e. unsealed) slide fastener.

In some applications it is necessary to quickly uncouple the stringers from one another faster than the length of time it would take to slide the slider along the length of the stringers. Burstable slide fastener assemblies comprise a pair of stringers in which one stringer comprises at least one coupling element that is configured such that it cannot be joined to the coupling elements of the other stringer. This creates a weak point along the slide fastener assembly which permits the slide fastener assembly to be uncoupled without the use of a slider. The force required to separate the coupling elements in the vicinity of the weak point is typically very low, and therefore burstable slide fasteners are unsuitable in applications where the coupling elements are held under tension.

It is an object of the present invention to obviate or mitigate one or more disadvantages of the prior art, whether identified herein or elsewhere.

According to a first aspect of the invention, there is provided a slide fastener assembly comprising: a first stringer having first tape, a plurality of coupling elements supported by the first tape, and a first sealing member extending along the first tape; a second stringer having a second tape, a plurality of coupling elements supported by the second tape and a second sealing member extending along the second tape; wherein the coupling elements of the first and second stringers are configured to engage one another so as to releasably fasten the first and second stringers together; wherein when the first and second stringers are fastened together the first and second sealing members abut one another to form a seal therebetween; and wherein: (i) the first stringer, or (ii) the second stringer (ii), or (iii) the first and second stringer comprises one or more non-coupling zones, each non-coupling zone comprising at least one non-coupling element that is configured such that it cannot be fastened to the coupling elements of the first or second stringer.

The non-coupling zone defines a weak point along the first stringer in which the first stringer is not coupled to the second stringer and which allows the slide fastener assembly to be unfastened without using a slide fastener. As such, the first non-coupling zone may alternatively be referred to as a burst zone. It has previously been thought that such a non-coupling zone would be incompatible with the use of sealing members, as the presence of sealing members places the coupling elements in tension so that they are pulled apart. However, according to the first aspect of the invention, it has surprisingly been found that it is possible to provide a slide fastener having a non-coupling zone in combination with sealing members.

The combination of a non-coupling zone and sealing members is particularly advantageous in applications where fast uncoupling is required in combination with sealing. One such example is in an inflatable life jacket. In particular, the slide fastener assembly may be used to hold the life jacket in a collapsed state for storage. In the collapsed state, the sealing members prevent the ingress of foreign matter (such as water, dust, debris or the like) into the life jacket which could cause the coupling elements to degrade or become clogged. In an emergency situation, the life jacket must be inflated rapidly, and therefore the slide fastener assembly must be unfastened as quickly as possible. The presence of the non-coupling zone allows the life jacket to be inflated rapidly without the use of a slide fastener, due to the pressure generated in the life jacket as it inflates. Another application for the slide fastener assembly of the first aspect of the invention is within a medical bag, or in any other situation where a watertight or debris-resistant seal is required in combination with rapid uncoupling.

The term "non-coupling zone" encompasses a region defined by the first stringer in which the coupling elements of the first stringer are unable to couple with the coupling elements of the second stringer to fasten the two stringers together. As such, the non-coupling zone defines a region of the first stringer which cannot be joined to the second stringer. The first stringer may be uncoupled from the second stringer by applying a separating force to either the first stringer or the second stringer in the region of the non-coupling zone. The separating force acts to pull the two stringers apart such that the coupling elements uncouple sequentially starting from the non-coupling zone and traversing sequentially up to the respective end (in the case of a terminal non-coupling zone defined below) or ends (in the case of an intermediate non-coupling zone defined below) of the stringers.

The term "plurality of coupling elements" encompasses, as at least one possibility, coupling elements that are formed by a continuous coil of wire that has been bent into loops to define individual coupling elements. The term "plurality of coupling elements" may additionally encompasses coupling elements that are formed as discrete and separate pieces. The particular type of coupling element employed is not essential.

The engagement of the coupling elements encompasses any appropriate means for joining the first set of coupling elements to the second set of coupling elements. This may include, for example, interdigitating or enmeshing.

The term "releasably fasten" encompasses that the coupling elements of the first and second stringers are configured to engage one another to fasten the first and second stringers together and are further configured to disengage to release the first and second stringers from one another. When the first and second stringers are released from one another the first and second sealing members may also disengage one another (so that they no longer abut one another) such that they no longer form a substantially watertight seal therebetween.

The seal may be any suitable seal. For example the seal may be substantially watertight and/or may be able to withstand water ingress up to a particular depth or pressure as specified by an appropriate technical standard.

The slide fastener assembly may define a forward side and a reverse side, and the sealing members may be positioned on the forward side and the coupling elements may be positioned on the reverse side. During use, the forward side may be positioned on the outside of an article. That is to say, preferably the sealing members abut each other on the forward side of the fastener assembly so that any moisture or dirt cannot reach the coupling elements.

One of the one or more non-coupling zones may be an intermediate non-coupling zone positioned at an intermediate position along the first stringer. The term "intermediate position" encompasses a position at some point between the terminal ends of the first stringer. That is to say, the non-coupling zone is not positioned at an end of the first stringer, but lies somewhere along the length of the first stringer such that there are "coupling zones" either side of the non-coupling zone. This allows the slide fastener assembly to be uncoupled from the middle, which produces faster uncoupling of the coupling zones and thus the slide fastener assembly than if the non-coupling zone was positioned at the end of the stringer. When the non-coupling zone is positioned at an intermediate point along the stringer this may define a burst zone.

In some embodiments the intermediate non-coupling zone may be a first intermediate non-coupling zone and the second stringer may define a second intermediate non-coupling zone comprising at least one non-coupling element. The second intermediate non-coupling zone may be positioned at an intermediate point along the second stringer. In particular, the first and second intermediate non-coupling zones may be positioned such that when the first and second stringers are fastened together the intermediate non-coupling zones are aligned with one another. The second intermediate non-coupling zone may have an identical construction to the first intermediate non-coupling zone, or may comprise a greater or lesser number of non-coupling elements.

Each intermediate non-coupling zone may comprise at least two consecutively arranged non-coupling elements. The term "consecutively arranged" encompasses non-coupling elements placed adjacent to one another sequentially along the stringer.

Where the non-coupling zone comprises two consecutive non-coupling elements, this ensures that there is at least one coupling element of the second set of coupling elements which is not engaged with any of the first set of coupling elements. This enables the coupling elements to disengage from the non-coupling zone under the action of an external force.

The intermediate non-coupling zone may comprise no more than twelve consecutively arranged non-coupling elements. When the non-coupling zone comprises no more than twelve consecutive non-coupling elements, this ensures that the coupling force joining the first and second stringers is high enough such that the coupling elements do not start to accidentally disengage from one another and that the watertight seal formed by the sealing members is maintained.

The intermediate non-coupling zone may comprise eight consecutively arranged non- coupling elements. When the non-coupling zone comprises eight consecutive non-coupling elements this provides an adequate balance between the prevention of accidental uncoupling and the formation of an adequate seal between the sealing members along the non-coupling zone.

The intermediate non-coupling zone may define a length, and the seal may extend along the entire length of the non-coupling zone so that the intermediate non-coupling zone is covered by the seal when the first and second stringers are fastened together. The length of the non-coupling zone may be the distance in the longitudinal direction of the slide fastener assembly spanned by the coupling elements that define the non-coupling zone. It will be appreciated that in the region of the intermediate non-coupling zone, in the absence of any seal, foreign matter may be more likely to pass from one side of the slide fastener assembly to the other (i.e. from the front to the reverse of the slide fastener assembly). However, because the seal formed by the first and second sealing members extends along the entire length of the intermediate non-coupling zone, foreign matter is prevented from passing across the slide fastener assembly in the region of the intermediate non-coupling zone.

A first terminal non-coupling zone may be positioned at a terminal end of the first stringer; and a second terminal non-coupling zone may be positioned at a terminal end of the second stringer. Put another way, one of the one or more non-coupling zones may be a first terminal non-coupling zone positioned at a terminal end of the first stringer; and another of the one or more non-coupling zones may be a second terminal non-coupling zone positioned at a terminal end of the second stringer. The first and second terminal non-coupling zones may be positioned opposite one another, such that the first and second terminal non-coupling zones are aligned with one another when the first and second stringers are fastened together. That is to say, the first terminal non-coupling zone may be positioned at a first terminal end of the first stringer; and a second terminal non-coupling zone may be positioned at a first terminal end of the second stringer, the first terminal end of the first stringer being aligned with the first terminal end of the second stringer. The term "terminal end" encompasses an end of the stringer in the longitudinal direction of the slide fastener assembly.

Because the first and second terminal non-coupling zones are positioned at the first terminal end of each of the first and second stringers, the first and second terminal non-coupling zones facilitate receipt of the stringers into a slider so that the coupling elements can be fastened together. As such, the first and second terminal non-coupling zones may alternatively be referred to as lead-in zones.

A third terminal non-coupling zone may be positioned at a second terminal end of the first stringer; and a fourth terminal non-coupling zone may be positioned at a second terminal end of the second stringer. Optionally, the second terminal end of the first stringer may be aligned with the second terminal end of the second stringer. Put another way, one of the one or more non-coupling zones may be a third terminal non-coupling zone positioned at a terminal end of the first stringer; and another of the one or more non-coupling zones may be a fourth terminal non-coupling zone positioned at a terminal end of the second stringer.

Known slide fastener assemblies comprise a block and pin type structure at their terminal ends. By contrast, the use of lead-in zones removes the requirement to receive a pin within a block. It has been found that the use of lead-in zones is particularly useful for joining wall or floor panels.

Each coupling element may define a coupling element length in a longitudinal direction of the slide fastener assembly, and one of the first or second terminal non-coupling zones may be shorter than the other of the first or second terminal non-coupling zones by the coupling element length. The coupling element length may be equal for all coupling elements in the slide fastener assembly. Put another way, the coupling element length may be a pitch defining the distance a point on a coupling element to the equivalent point on an adjacent coupling element in the longitudinal direction.

Additionally or alternatively, one of the first or second terminal non-coupling zones may comprise at least one less non-coupling element than the other of the first or second terminal non-coupling zones.

The first and second terminal non-coupling zones may each comprise at least 10 non-coupling elements. It is preferable to use at least 10 non-coupling elements because the distance from a central guidepost of the slider to an exit (i.e. tail) of the slider is normally around 10 elements in length. It is preferable that the length of the first and second terminal non-coupling zones is at least equal to or longer than the distance from the guidepost to the exit of the slider. Alternatively, the first and second terminal non-coupling zones may each comprise at least 15 non-coupling elements, at least 20 non-coupling elements, or at least 25 non-coupling elements.

The first terminal non-coupling zone may comprise 17 non-coupling elements and the second terminal non-coupling zone may comprise 16 non-coupling elements.

The non-coupling elements of the first terminal non-coupling zone may be encased within a covering material and the non-coupling elements of the second terminal non-coupling zone may be also encased within a covering material. The material may be a flexible material. Where the material is a flexible material this enables deformation of the non-coupling zone within the channels of the slider when the non-coupling zones pass through the slider. The flexible material may be more flexible than the material of the coupling elements (which may be a rigid material). The material may be Polyoxymethylene. Additionally or alternatively, the non-coupling elements of any intermediate non-coupling zone or the non-coupling elements of any non-coupling zone may be encased within a covering material.

The slide fastener assembly may comprise a slider, the first or the second or the first and second terminal non-coupling zones may define a length in a longitudinal direction, and the length may be greater than or equal to a longitudinal length of the slider. This enables the operator of the slide fastener assembly to assess whether the stringers couple as intended by considering whether the lower ends of the terminal non-coupling zones emerge from the slider in the same lateral plane.

The first and second stringers may each comprise a coiled or spiral continuous filament extrusion and each coupling element may be defined by a loop of the continuous filament extrusion. By "filament extrusion" it is encompassed a continuous length of a thread-like object.

Each coupling element may define: a base portion configured to support the coupling element on the respective first or second tape; and an engaging portion configured for receipt between a corresponding pair of coupling elements of the opposite stringer to fasten the coupling elements of both stringers together; wherein the non-coupling elements do not comprise engaging portions. When the non-coupling elements do not comprise engaging portions, the coupling elements defining the non-coupling zone are not engageable with the coupling elements of the second stringer.

The engaging portion may comprise a protrusion configured to lockingly engage and disengage a corresponding engaging portion of a coupling element of the opposite stringer. For example, the protrusion may be received behind a corresponding protrusion of the coupling element of the opposite stringer when the first and second stringers are fastened together, and engagement between the protrusions may prevent the coupling elements from uncoupling. In some embodiments the non-coupling elements may not comprise protrusions. In some embodiments the non-coupling elements may be created by cutting a part of a series of coupling elements which comprise protrusions.

The engaging portions of adjacent coupling elements may be spaced apart from one another in a longitudinal direction of the slide fastener assembly to define a gap therebetween, and the non-coupling elements may not pass into the gap when the first and second stringers are fastened together. That is to say, the coupling elements defining the non-coupling zone may not interfere with the coupling elements of the second stringer. In some embodiments the coupling elements defining the non-coupling zone may be spaced apart from the tips (alternatively referred to as the apexes) of the coupling elements of the second stringer.

The non-coupling elements of the one or more non-coupling zones may be enclosed by a covering. This is preferable when the non-coupling elements are formed by cutting coupling elements. The non-coupling elements of the one or more non-coupling zones may be contained within a block of material. Covering the non-coupling elements covers any sharp edges and prevents adjacent fabric from puncturing. This is particularly useful in applications such as life jackets or for other inflatables where any puncturing would prevent the article from inflating. Encasing the non-coupling elements also increases the stiffness of the non-coupling elements defining the non-coupling zone, particularly where more than one non-coupling element is used. Altering the stiffness of the non-coupling elements can be used to adjust the relative strength at which the stringers begin to uncouple.

The covering may not pass into the gap between the engaging portions of adjacent coupling elements when the first and second stringers are fastened together.

The covering may be made from any suitable material, for example a polymeric material. In particular, the material may be Polyurethane or Polyoxymethylene. The covering may be a resin or plastic film on the surface of the elements (and particularly in the area where the elements have been cut), or the covering may be made from a block of material that completely encases a non-coupling element and the gap between two adjacent non-coupling elements. The covering may be made by deforming coupling elements for example by partially melting coupling elements. The covering material may be formed from an adhesive, such as an organic adhesive which hardens by evaporation or by the action of ultraviolet light.

The coupling elements and the non-coupling elements may be attached to the tape by stitches or may be woven or knit into the tape.

The block of material encasing the non-coupling elements may also encase the stitches or the weave of the tape.

The first sealing member may extend along the entire length of the first stringer, and the second sealing member may extend along the entire length of the second stringer.

The first sealing member may comprise a bulbous portion defining a first sealing edge and the second sealing member may comprise a bulbous portion defining a second sealing edge, and the seal may be formed by bringing the first sealing edge into abutment with the second sealing edge. The bulbous portions may be formed such that when the coupling elements for the first and second stringers are coupled each bulbous portion bears against the other. In particular, the bulbous portions may extend beyond the edge of the fastener tape each towards the other.

The slide fastener assembly may further comprise a slider and the slider may be removable from the first and second stringers when the first and second stringers are fastened together. That is to say, the slider need not be present on the stringers when the stringers are coupled to one another. A large amount of force is generally required to bring the sealing members into or out of contact with one another, and therefore if the slider remains on the slide fastener assembly when the stringers are in the process of uncoupling from the non-coupling zone, the presence of the slider can impede the uncoupling process. However, when the slider is removed from the slide fastener assembly, this problem is avoided and the stringers can be rapidly uncoupled.

The slide fastener assembly may further comprise a strap connecting the first and second stringers. The strap acts to hold the stringers together so as to prevent unwanted separation of the first and second stringers that would unfasten the slide fastener assembly.

The strap may be aligned with the first and second terminal non-coupling zones. Aligning the strap with the terminal non-coupling zones ensures that the non-coupling zones do not pull apart from another in a manner that would unfasten the slide fastener assembly.

The sealing members may be made from an opaque material. That is to say, a material with a low optical transmissivity. When the sealing members are made from an opaque material, this prevents ultraviolet light from reaching the coupling elements when the first and second stringers are coupled together, and therefore prevents degradation of the coupling elements and extends the life of the slide fastener assembly.

According to a second aspect of the invention there is provided a method of manufacturing a slide fastener assembly comprising: providing a first stringer having a first tape, a plurality of coupling elements supported by the first tape, and a first sealing member extending along the first tape; providing a second stringer having a second tape, a plurality of coupling elements supported by the second tape and a second sealing member extending along the second tape; and defining one or more non-coupling zones on: (i) the first stringer, or 00 the second stringer, or (iii) the first and second stringers by forming at least one non-coupling element configured such that it cannot be fastened to the coupling elements of the other of the first or second stringers.

The coupling elements of the first and second stringers may be configured to engage one another so as to releasably fasten the first and second stringers together, and when the first and second stringers are fastened together the first and second sealing members may abut one another to form a seal therebetween.

Each coupling element may comprise: a base portion configured to support the coupling element on the respective first or second tape, and an engaging portion configured for receipt between a corresponding pair of coupling elements of the opposite stringer to fasten the coupling elements of both stringers together; wherein the step of forming at least one non-coupling element comprises removing the engaging portion from at least one of the coupling elements of the first stringer.

The step of removing the engaging portion from at least one of the coupling elements may comprise cutting at least one of the coupling elements.

The method may further comprise enclosing the at least one non-coupling element within a covering. When the engaging portion of the at least one coupling element has been removed, sharp edges may remain which could puncture any fabric to which the first and second stringers are attached. Enclosing the at least one non-coupling element in a covering covers any sharp edges, reducing the chance of puncturing the adjacent fabric. This is particularly useful in applications involving inflatable articles such as life jackets, as any puncture would prevent the inflatable article from inflating.

The at least one non-coupling element may be contained in a block of material.

The step of enclosing the non-coupling element may comprise overmoulding the at least one coupling element with a polymeric material.

The method of the second aspect of the invention may comprise any of the features of the first aspect of the invention.

According to a third aspect of the invention, there is provided a life jacket comprising the slide fastener according to the first aspect of the invention.

A detailed description of the invention is set out below with reference to the accompanying drawings, in which: Figure 1 is a schematic front plan view of a slide fastener assembly according to the present invention in a coupled configuration; Figure 2 is a schematic rear plan view of the slide fastener assembly; Figure 3 is a cross-sectional view of the slide fastener assembly through the line A-A of Figure 2 facing towards the direction indicated by the arrows; Figure 4 is a schematic perspective view of a plurality of coupling elements; Figure 5 is a close up schematic rear plan view of an intermediate non-coupling zone; Figure 6 is a schematic cross-sectional view of the intermediate non-coupling zone through the line B-B of Figure 2 facing towards the direction indicated by the arrows; Figure 7 is a schematic perspective view of the intermediate non-coupling zone; Figure 8 is a close up schematic rear plan view of a first terminal end of the slide fastener assembly in an uncoupled configuration; Figure 9 is a schematic plan view of the first terminal end of the slide fastener assembly in a first partially coupled configuration; Figure 10 is a schematic plan view of the first terminal end of the slide fastener assembly in a second partially coupled configuration; Figure 11 is a schematic perspective view of an alternative construction of a coupling element; and Figure 12 is a schematic view of a life jacket comprising the slide fastener assembly of the present invention.

Figure 1 shows a schematic front plan view of a slide fastener assembly 2 according to the present invention. The slide fastener assembly 2 comprises a first stringer 4 and a second stringer 6 which are joinable using a slider 8. The first stringer 4 comprises a 10 15 20 first sealing member 10 and the second stringer 6 comprises a second sealing member 12. Figure 2 shows a schematic plan view of a rear side of the fastener assembly 2. The first stringer 4 comprises a plurality of coupling elements 14 and the second stringer 6 comprises a plurality of coupling elements 16. The first stringer further comprises a first tape 18 and the second stringer 6 comprises a second tape 20.

During use, the tapes 18, 20 are each attached to media, such as a sheet of fabric, and the stringers 4, 6 are used to fasten the media together.

Figure 3 shows a cross-sectional view of the slide fastener assembly 2 taken along the line A-A of Figure 2. The first sealing member 10 is applied as a coating to the first tape 18 such that it substantially covers the first tape 18, and the second sealing member 12 is applied as a coating to the second tape 20 such that it substantially covers the second tape 20. Put another way, the first and second tapes 18, 20 form substrates which support the first and second sealing members 10, 12. The tapes 18, 20 are made from a woven fabric material and the sealing members 10, 12 are made from a flexible polymeric material such as Polyurethane. The sealing members 10, 12 are attached to the tapes 18, 20 by bonding or welding. In one embodiment the manufacturing method for attaching the sealing members to the tapes 18, 20 is a continuous process of extrusion-moulding. The sealing members 10, 12 are preferably made from an opaque material having low transmissivity of visible and/or ultraviolet light so as to prevent the coupling elements 14, 16 from ultraviolet degradation.

The first sealing member 10 comprises a first bulbous (i.e. enlarged) portion 22 forming a first sealing edge and the second sealing member 12 comprises a second bulbous portion 24 defining a second sealing edge. As shown in Figure 1, the bulbous portions 22, 24 extend along the entire length of the stringers 4, 6. As shown in Figure 3, the bulbous portions 22, 24 extend beyond an edge 19 of the first tape 18 and an edge 21 of the second tape 20 towards the opposing bulbous portion 22, 24. When the slide fastener assembly 2 is fastened together, the bulbous portions 22, 24 contact one another approximately at the mid-point between the stringers 4, 6 to form a seal extending down the entire length of the slide fastener assembly 2. The bulbous portions 22, 24 are pressed together when the coupling elements 14, 16 of the first stringer 4 and the second stringer 6 are coupled together as shown in Figure 3. As a result, the fastened slide fastener assembly 2 is curved in a transverse direction (i.e. in a plane perpendicular to the longitudinal direction of the slide fastener assembly 2) with the bulbous portions 22, 24 at the apex of the curve.

The coupling elements 14, 16 are composed of a continuous extrusion of filament 26 formed into loops 28 defining the individual coupling elements 14, 16. The filament 26 is shown in isolation in Figure 4 and is formed into a generally spiralled shape. Each loop of the spiral defines a coupling element 14, 16. Each coupling element 14, 16 comprises a base 30 and an engaging portion 32. The engaging portion 32 defines a tip of the coupling element 14, 16 and comprises protrusions 34. The protrusions 34 extend either side of the engaging portion 32 parallel to the longitudinal direction of the stringers 4, 6. The engaging portions 32 are spaced apart from one another to form a gap 36 therebetween. During use, when the slider 8 is moved along the stringers 4, 6, the engaging portion 32 of a coupling element 14, 16 on one stringer 4, 6 is received within the gap 36 formed between two opposing coupling elements 14, 16 on the other stringer 4, 6 so that the coupling elements 14, 16 interdigitate. The protrusions 34 of the coupling elements 14, 16 on opposite stringer 4, 6 engage one another to prevent the coupling elements 14, 16 from leaving the gaps 36 and thereby fastening the stringers 4, 6 together. As shown in Figure 3, the coupling elements 14, 16 are attached to the tapes 18, 20 by warp yarn 38 (or fight bonding yarn). However, any appropriate means of attachment may be used, for example the coupling elements 14, 16 may be woven or stitched into the fabric of the first and second tapes 18, 20.

With reference to Figure 2, the first and second stringers 4, 6 define a number of non-coupling zones. The non-coupling zones are portions of the first and second stringers 4, 6 in which no mechanical coupling takes place. In particular, the first stringer 4 comprises an intermediate non-coupling zone 40. The intermediate non-coupling zone 40 is positioned at an intermediate point between the terminal ends of the first stringer 4. That is to say, the coupling elements 14 of the first stringer 4 extend either side of the intermediate non-coupling zone in the longitudinal direction of the stringer 4. The intermediate non-coupling zone may be positioned at substantially any suitable point between the terminal ends of the first stringer 4, and does not need to be positioned at the mid-point of the first stringer 4.

The intermediate non-coupling zone 40 defines a length in the longitudinal direction of the slide fastener assembly 2. When the first and second stringers 4, 6 are fastened together, the seal formed by the sealing members 10, 12 extends along the entire length of the intermediate non-coupling zone 40. That is to say, the seal is maintained across the intermediate non-coupling zone 40 even though no mechanical coupling takes place in this portion of the first stringer 4. As will be explained in detail below, the intermediate non-coupling zone 40 is used to unfasten the slide fastener assembly 2 from a mid-point without the use of slider 8. As such, the intermediate non-coupling zone 40 may alternatively be referred to as a burst zone.

With reference to Figures 5 to 7, the intermediate non-coupling zone 40 comprises the continuous extrusion of filament 26 (as shown in Figure 4), along which three consecutively arranged non-coupling elements 42 are defined. The non-coupling elements 42 are shown in outline in Figure 5. The non-coupling elements 42 differ from the coupling elements 14 of the first or second stringer 4, 6 in that the non-coupling elements 42 do not comprise a portion of the element designed for engaging an opposing coupling element, that is to sat the non-coupling elements 42 do not comprise engaging portions 32. Because the non-coupling elements 42 lack engaging portions 32, the non-coupling elements 42 are unable to enter the gaps 36 between the coupling elements 16 of the second stringer 6. As such, in the region of the intermediate non-coupling zone 40, the first and second stringers 4, 6 cannot be fastened together. This creates a point of weakness at an intermediate position along the slide fastener assembly 2. During use, if it is desired to unfasten the first and second stringer 4, 6, the user can exert a pulling or pushing force at the intermediate non-coupling zone 40 which will cause the coupling elements 14, 16 immediately either side of the intermediate non-coupling zone 40 to begin to uncouple from one another.

The uncoupling occurs sequentially along the slide fastener assembly 2 in longitudinally opposite directions beginning from the intermediate non-coupling zone 40. This is particularly advantageous where it is necessary to uncouple the stringers 4, 6 from one another rapidly without use of the slider 8.

In the embodiment shown, the non-coupling elements 42 are formed by removing the engaging portions 32 from three consecutive coupling elements 14 of the first stringer 4. Specifically, the non-coupling elements 42 are formed by cutting the engaging portions 32 from the base portions 30 of the coupling elements 14. The cut is made at a position spaced apart from the apex of the engaging portions 32 so that the engaging portions 32 of the opposing stringer do not contact the cut ends of the non-coupling elements 42 when the first and second stringers 4, 6 are coupled to one another. Furthermore, the cut is made at a lateral position of the coupling elements 14 that lies inboard of the warp yarn 38 when the slide fastener assembly 2 is fastened (that is to say, at a lateral position that is closer to the point at which the sealing members 10, 12 abut one another than the warp yarn), as shown in Figure 6. In this manner the non-coupling elements 42 will remain attached to the tape 18 and the wrap yarn 38 will not be damaged by the cutting action.

Once the engaging portions 32 have been removed a cut surface is provided on the non-coupling element 42, and the non-coupling element 42 is covered by a covering.

The covering covers at least the cut surface of the non-coupling element 42. In this embodiment, the non-coupling elements 42 and the warp yarn 38 are encased in a covering material 43 to form a single unitary structure (for clarity, the covering material 43 is shown in outline in Figure 7). The covering material 43 does not extend into the gaps 36 of the coupling elements 16 of the second stringer 6, and in particular is spaced apart from the apex of the engaging portion 32 of the coupling elements 16 of the second stringer 6 by a small distance. In other words, as shown in Figures 5 and 6, when the coupling elements 14, 16 of the first and second stringers 4, 6 are fastened together, an outside surface 41 of the covering material 43 is formed between the end of the engaging portion 36 of the coupling elements 16 of the second stringer 6 and the now covered cutting surface of the non-coupling elements 42 of the first stringer 4. It will be appreciated that the outer surface 41 is not in contact with the engaging portion 36 of the coupling elements 16 of the second stringer 6. This ensures that the intermediate non-coupling zone 40 does not interfere with the coupling elements 16 of the second stringer 6 in a manner which might cause the coupling elements 14, 16 of the two stringers 4, 6 to unfasten.

The covering material 43 may comprise a single unit of material or any number of units. In particular, the covering material 43 is formed by overmoulding a polymeric material onto the first tape 10. That is to say, by injection moulding a body of polymeric material onto the first tape so that it encases the non-coupling elements 42. Specifically, in the case of the intermediate non-coupling zone 40, the material is a stiff polymeric material such as Polyoxymethylene (POM), but the material may also be a more flexible material such as Polyurethane (PU). The relative stiffness of the covering material 43 encasing the non-coupling elements 42 of the intermediate non-coupling zone 40 can be adjusted to alter the uncoupling force required to cause the first and second stringers 4, 6 to unfasten. The uncoupling force may be adjusted depending upon the application of the slide fastener. Furthermore, because the non-coupling elements 42 are formed by cutting, once cut the non-coupling elements 42 may comprise sharp edges. The sharp edges could potentially tear or puncture any media to which the stringers 4, 6 are attached. However, by either encasing or overmoulding or encasing and overmoulding the non-coupling elements 42 any sharp edges will be covered over and so the problem of puncturing is avoided.

In this embodiment, because the covering material 43 is formed by overmoulding it adheres to the non-coupling elements 42 and a section of fastener tape 18, 20 adjacent the non-coupling elements 42. The covering material 43 is in the form of a block of polymeric material and during moulding liquid polymeric material will cover all surface contours of the non-coupling elements 42 (including for example any internal parts). Depending on the materials used, this may obtain a stronger adhesion or anchoring effect between the covering material 43 and the non-coupling elements 42. The covering material 43 may comprise an adhesive that hardens by evaporation or which cures in the presence of ultra violet light. The use of an adhesive may increase the adhesion or anchoring effect to the non-coupling elements 42. Alternatively, the covering material 43 may be a film of plastic or other such material adhered to the non-coupling elements 42.

The intermediate non-coupling zone 40 may comprise substantially any suitable number of non-coupling elements 42. At minimum, the intermediate non-coupling zone 40 must comprise one non-coupling element 42, as otherwise no weak point would be created. Preferably, the intermediate non-coupling zone 40 comprises at least two non-coupling elements 42, as this ensures that at least one coupling element 16 of the second stringer 6 is entirely unengaged with a corresponding coupling element 14 of the first stringer 4. Preferably, the number of non-coupling elements 42 does not exceed twelve consecutively arranged non-coupling elements. It has been found that where more than twelve non-coupling elements 42 are used the uncoupling force required to separate the first and second stringers 4, 6 starting from the intermediate non-coupling zone 40 is too low, such that the first and second stringers 4, 6 have a tendency to separate when the slide fastener assembly 2 undergoes even relatively minor manual handling by a user. Even more preferably, the intermediate non-coupling zone 40 comprises eight non-coupling elements 42. It has been found that eight non-coupling elements 42 provides and optimum uncoupling force which is not too strong to cause difficulties unfastening the stringers 4, 6, but which is not too weak that the stringers 4, 6 begin so separate unintentionally.

As an additional consideration, the fastened slide fastener assembly 2 is curved in a transverse direction (i.e. in a plane normal to the longitudinal direction of the slide fastener assembly). The bulbous portions 44, 45 are positioned at the apex of the curve when the first and second stringers are fastened together as shown in Figure 6.

As such, a frontward force acting in a direction causing the first and second stringers 4, 6 to separate from one another is present in the vicinity of the intermediate non-coupling zone 40. This separating force assists the user when it is desired to unfasten the slide fastener assembly 2 from the rear, or in other words the reverse, side.

Figure 8 shows the first and second stringers 4, 6 in an uncoupled configuration (i.e. a configuration in which the stringers 4, 6 are not fastened to one another). With reference to Figures 2 and 8, the first stringer 4 comprises a first terminal non-coupling zone 44 positioned at a terminal end of the first stringer 4. In particular, the first terminal non-coupling zone 44 is positioned at a bottom end of the first stringer 4. The second stringer 6 comprises a second terminal non-coupling zone 46 positioned at a terminal end of the second stringer 6. In particular, the second terminal non-coupling zone is positioned at a bottom end of the second stringer 6, such that it is aligned with the first terminal non-coupling zone 44 when the first and second stringers 4, 6 are brought together. As will be explained in detail below, the first terminal and second terminal non-coupling zones 44, 46 are used to guide the slider 8 onto the stringers 4, 6 and may therefore alternatively be referred to as lead-in zones. In this embodiment, the first terminal non-coupling zone 44 and the second terminal non-coupling zone 46 comprise a plurality of non-coupling elements 42, similar (or in some embodiments identical) to the non-coupling elements 42 of the intermediate non-coupling zone 40.

As shown in Figure 8, each coupling element 14, 16 defines a coupling element length (49) in the longitudinal direction of the slide fastener assembly 2, and the coupling element lengths (49) for all of the coupling elements 14, 16 are substantially (or nominally) equal (taking into account any stresses or strains acting on the coupling elements). In order to ensures that the first coupling element 16 of the second stringer 6 (i.e. the coupling element 16 immediately adjacent the second terminal non-coupling zone 46) is able to engage the first coupling element 14 of the first stringer 4 (i.e. the coupling element 14 immediately adjacent the first terminal non-coupling zone 44), the first terminal non-coupling zone 44 is shorter than the second terminal non-coupling zone by a distance equal to the coupling element length. That is to say, the first terminal non-coupling zone defines a first terminal non-coupling zone length 51 in the longitudinal direction, the second terminal non-coupling zone defines a second terminal non-coupling zone length 53 in the longitudinal direction, and the sum of the second terminal non-coupling zone length 53 and the coupling element length 49 is equal to the first terminal non-coupling zone length 51. In some embodiments the first terminal non-coupling zone 44 comprises seventeen non-coupling elements 42, and the second terminal non-coupling zone 46 comprises sixteen non-coupling elements 42. As such, the second terminal non-coupling zone 46 has one less non-coupling element 42 than the second terminal non-coupling zone 44, and is therefore shorter than the first terminal non-coupling zone 44 by the coupling element length 49. Nevertheless, in alternative embodiments the first terminal and second terminal non-coupling zones 44, 46 may each comprise substantially any suitable number of non-coupling elements 42.

In this embodiment an intermediate non-coupling zone 40 is formed on the first stringer 4. However, in other embodiments, the intermediate non-coupling zone 40 may be formed on the second stringer 6. In appropriate cases, more than one intermediate non-coupling zone 40 may be formed on one stringer or on both stringers. When intermediate non-coupling zones 40 are formed on both stringers the zones may be exactly opposite each other (i.e. aligned with one another) or may be positioned at substantially any suitable position Where the first terminal non-coupling zone 44 and the second terminal non-coupling zone 46 comprise seventeen and sixteen non-coupling elements 42 respectively this ensures that the length of the terminal non-coupling zones 44, 46 are approximately the same length as or greater than the length of the slider 8 in the longitudinal direction of the slide fastener assembly 2 and makes the terminal non-coupling zones 44, 46 easy to handle by the user. In particular, it is preferable that the length of the first terminal and second terminal non-coupling zones 44, 46 is greater than the distance between the terminal end of an outlet section 56 of the slider 8 and the lowermost part of a guide post 54 of the slider 8. Preferably both the first terminal and second terminal non-coupling zones 44, 46 each comprises at least ten or at least fifteen consecutively arranged non-coupling elements 42. In some embodiments the first terminal and second terminal non-coupling zones 44, 46 may comprise twenty, twenty-five or more non-coupling elements 42 It will be appreciated that, in some embodiments, the overall shape and size of the coupling elements 14, 16 may be dependent upon the geometry of the slice 8. As such, the coupling element length 49 (i.e. the pitch distance between coupling elements 14, 16) may also be dependent upon the geometry of the slider 8. It follows that in alternative embodiments, the non-coupling zones 40, 44, 46, 64, 66 may comprise greater or fewer numbers of non-coupling elements 42 than otherwise stated herein.

The non-coupling elements 42 of the first terminal non-coupling zone 44 and the second terminal non-coupling zone 46 are covered by a first terminal covering material 45 and a second terminal covering material 47 respectively. The first and second terminal covering materials also encase the warp yarn 38 holding the non-coupling elements 42 to the tapes 18, 20. The first and second terminal covering materials 45, 47 are composed of a polymeric material. Preferably, the first and second terminal covering material 45, 47 are composed of a flexible polymeric material such as Polyurethane (PU), allowing the first and second terminal non-coupling zones 44, 46 to easily flex so that the material is able to deform in accordance with the shape of the passageway of the slide 8 when the first and second terminal non-coupling zones 44, 46 are inserted in the slider 8. Alternatively, the first and second terminal non-coupling zones may be made from Polyoxymethylene (POM). The first and second terminal covering material 45, 47 are therefore preferably composed of a different, more flexible, material to the covering material 43.

Aside from the differences in materials, position and number of non-coupling elements, the intermediate non-coupling zone 40, first terminal non-coupling zone 44, and second terminal non-coupling zone 46 may all be manufactured in substantially the same way.

The first and second terminal covering materials 45, 47 may also be referred to as first and second pins 45, 47 respectively. The first and second pins 45, 47 are formed in the shape of a rod, that is substantially ovoid, circular or any other suitable profile in order to pass easily along the passageway of the slider 8.

In other embodiments not shown, non-coupling elements may not be provided in one or more of the non-coupling zones and particularly the first terminal non-coupling zone 44 and the second terminal non-coupling zone 46. For instance, the whole element may be removed or a gap created on the stringer, alternatively the terminal non-coupling zones 44, 46 may merely comprise first and second terminal covering materials 45, 47 fixed to the respective edges of the tape 18, 20 adjacent to the coupling elements on the first and second stringers. Nevertheless, the relative difference in length between the first terminal non-coupling zone 44 and the second terminal non-coupling zone 46 is preferably still equal to the coupling element length 49.

Figure 9 shows the slide fastener assembly 2 in a first partially coupled configuration. In the first partially coupled configuration the first terminal non-coupling zone 44 and the second terminal non-coupling zone 46 have been received within the slider 8. The slider 8 comprises an inlet section 48 defining a first passageway 50 and a second passageway 52 separated by a divider 54. The slider 8 further comprises an outlet section 56 in which the first and second passageways 50, 52 are merged. The width of the outlet section 56 is narrower than the width of the inlet section 48, and the slider 8 defines a converging section 58 therebetween. During use, the slider 8 is moved longitudinally along the first and second stringers 4, 6 at the same time to bring the two stringers together. Further, slider 8 can separate coupled elements through use of the guide post 54 of the slider 8. The flexible nature of the first and second terminal covering materials 45, 47 ensures that the first terminal and second terminal non-coupling zones 44, 46 are able to bend through the slider 8.

Figure 10 shows the slide fastener assembly 2 in a second partially coupled configuration. In the second partially coupled configuration the first terminal non-coupling zone 44 and the second terminal non-coupling zone 46 have passed almost entirely through the slider 8, such that the slider 8 has begun to interdigitate the coupling elements 14, 16 on the first and second stringers 4, 6 to fasten the first and second stringers 4, 6 together. For simplicity, in Figure 9 the portion of the slide fastener assembly 2 in which the interdigitation occurs is not shown in detail, and is denoted by dashed lines. The pins 44, 46 are sufficiently long that they protrude from the outlet section 58 of the slider 8 so that the user may make a visual inspection to ensure that the terminal ends of the pins 44, 46 are aligned with one another so that that the coupling elements 14, 16 of the first and second stringers 4, 6 will successfully interdigitate with one another.

With reference to Figure 2, the first stringer 4 comprises a third terminal non-coupling zone 64 positioned at the opposite terminal end of the first stringer 4 to the first terminal non-coupling zone 44. Furthermore, the second stringer 6 comprises a fourth terminal non-coupling zone 66 positioned at the opposite terminal end of the second stringer 6 to the second terminal non-coupling zone 46. The third terminal non-coupling zone 64 comprises two non-coupling elements 42 and the fourth terminal non-coupling zone comprises three non-coupling elements 42, although any suitable number of coupling elements may be used. The third terminal and fourth terminal non-coupling zones 64, 66 may be manufacture in the same manner and using the same materials as any of the other non-coupling zones discussed above. During use, the slider 8 can be pulled along the entire length of the slide fastener assembly 2 to join the stringers 4, 6 together along their entire length and can then be removed from the slide fastener assembly 2 by passing over the third and fourth non-coupling zones 64, 66. This is because all of the terminal non-coupling zones 44, 46, 64, 66 are smaller than the channels of the slider 8 and can therefore pass through the slider 8 in their entirety. As such, the slider 8 does not need to be retained on the slide fastener assembly 2 when the stringers 4, 6 are fastened to one another, as shown in Figure 1. Uncoupling can be achieved faster by pulling the slide fastener assembly 2 apart at the intermediate non-coupling zone 40 (i.e. burst zone). If the slider 8 is retained on the slide fastener assembly 2 this will hinder uncoupling, and therefore it is beneficial to remove the slider 8 In alternative embodiments, the slide fastener assembly 2 may comprise any suitable number of non-coupling zones. For example, the second stringer 6 may comprise a non-coupling zone aligned with the intermediate non-coupling zone 40 of the first stringer 4 at the same position on the second stringer 6 as the intermediate non-coupling zone 40 is on the first stringer 4 in the tape longitudinal direction. Alternatively the first and/or second stringer 4, 6 may comprise multiple non-coupling zones spaced along intermediate points of the slide fastener assembly 2. The number, size and configuration of the non-coupling zones may be chosen depending upon the application of the slide fastener assembly 2 (i.e. the article into which the slide fastener assembly 2 is integrated).

With reference to Figure 1, the slide fastener assembly 2 comprises a strap 68 connecting the first and second stringers 4, 6. In particular, the strap 68 is attached at either end to the sealing members 10, 12 to permanently join them together. The strap 68 is positioned at a bottom end of the stringers 4, 6 on the reverse side of the stringers 4, 6 to the first terminal and second terminal non-coupling zones 44, 46. That is to say, the strap 68 is aligned with the first terminal and second terminal non-coupling zones 44, 46. The strap 68 ensures that the slide fastener assembly 2 does not begin to unfasten from the first terminal and second terminal non-coupling zones 44, 46 by preventing the bottom ends of the stringers 4, 6 from being pulled apart. The strap 68 may alternatively be formed on the side of and connected to the tapes 18, 20. The strap 68 may be made from the same material as the sealing members 10, 12 or may be made from any suitable material such as fabric or the like. In the embodiment shown, the strap 68 is fixed at either end to the stringers 4, 6, however in alternative embodiments the strap 68 may be detachable from at least one of the stringers 4, 6.

Although not shown in Figure 1, in alternative embodiments the slide fastener assembly 2 may comprise a second strap positioned at the top end of the stringers 4, 6 so as to prevent the slide fastener assembly unfastening from the third terminal and fourth terminal non-coupling zones 64, 66. It is not necessary to provide a strap aligned with the intermediate non-coupling zone 40 (i.e. the burst zone) as the relative coupling strength between the stringers 4, 6 in this region is greater due to the presence of coupling elements 14, 16 on either side of the intermediate non-coupling zone 40, and additionally because the inclusion of a strap in this region would hinder the stringers 4, 6 from unfastening correctly.

Figure 11 shows an alternative construction of coupling element 68. The coupling elements 68 of Figure 11 are made from individually moulded teeth which are joined by two lengths of fibre 70. The coupling elements 68 are generally u-shaped (for example comprising two generally parallel and coextensive branches bridged by a transversely extending central portion). The coupling elements 68 are then attached to the tape by moulding. The coupling elements define engaging portions 72 at their distal ends. The individual teeth type coupling elements 68 are suitable for use within the slide fastener assembly 2. During manufacture, the engaging portions 72 are removed from the coupling elements 68, for example by cutting, to form non-coupling elements (not shown). The non-coupling elements may then be covered by a covering of material, in the same manner as discussed above in relation to the non-coupling elements 42 formed by continuous filament extrusions 26. Generally speaking, it will be appreciated that any type of coupling element may be used provided that the engaging portions can be removed to form non-coupling elements along a portion of the associated stringer.

Although the non-coupling elements 42 described above are encased in a polymeric material, it will be appreciated that in alternative embodiments the non-coupling elements may be encased in substantially any suitable structure. For example, the non-coupling elements 42 may be cut and encased in a metal clamp.

In some embodiments the non-coupling zones (i.e. any intermediate non-coupling zone 40 and any or all of the first to fourth terminal non-coupling zones 44, 46, 64, 66) may be formed by entirely removing the continuous filament extrusion 26 (or, in the case of the coupling elements 68 in Figure 11, by not providing the coupling elements 68). In such situations, an insert may be attached to the stringer to form the non-coupling zones. The insert may be formed by overmoulding a polymeric material such as that described above, or by any other suitable means. In such embodiments, the insert may be considered to define a non-coupling element and the insert may define a length in the longitudinal direction that is equal to or greater than the coupling element length 49.

Figure 12 shows a life jacket 60 comprising the slide fastener assembly 2. The life jacket 60 in Figure 11 is shown in an uninflated (i.e. collapsed) configuration. In the uninflated configuration the life jacket 60 is rolled into a tube and is held in together using the first and second stringers 4, 6. The first and second stringers 4, 6 are oriented with the sealing members 10, 12 facing outwardly so as to protect the coupling elements 14, 16 from foreign matter such as liquids or dirt that may clog or degrade the functioning of the slide fastener assembly 2. Furthermore, because the sealing members 10, 12 are opaque, the sealing members 10, 12 prevent ultraviolet light from reaching the coupling elements 14, 16 to prevent ultraviolet degradation of the coupling elements. The intermediate non-coupling zone 40 is positioned underneath a protective cover flap 62. However, in alternative embodiments the cover flap 62 may be absent and the intermediate non-coupling zone 40 will be covered from the outside by the sealing members 10, 12. During use, the user inflates the life jacket 60 using a cylinder of compressed air, which causes the life jacket 60 to expand rapidly. This results in a force acting on the slide fastener assembly 2 at the intermediate non-coupling zone 40 which causes the coupling elements 14, 16 of the stringers 4, 6 to disengage starting from the intermediate non-coupling zone and travelling along the entire length of the slide fastener assembly 2. As such, the life jacket 60 can be inflated rapidly, under the force of compressed air only, and without the need for a slider 8. This is faster than if the user needed to manually slide the slider 8 along the entire length of the slide fastener assembly 2 and is well suited for emergencies. It will be appreciated that the cover flap 62 will also open when the slide fastener opens in this manner.

Claims (15)

1. CLAIMS: 1. A slide fastener assembly (2) comprising: a first stringer (4) having a first tape (18), a plurality of coupling elements (14) supported by the first tape (18), and a first sealing member (10) extending along the first tape (18); a second stringer (6) having a second tape (20), a plurality of coupling elements (16) supported by the second tape (20) and a second sealing member (12) extending along the second tape (20); wherein the coupling elements (14, 16) of the first and second stringers (4, 6) are configured to engage one another so as to releasably fasten the first and second stringers (4, 6) together; wherein when the first and second stringers (4, 6) are fastened together the first and second sealing members (10, 12) abut one another to form a seal therebetween; and wherein: (i) the first stringer (4), or (ii) the second stringer (6), or (iii) the first and second stringers (4, 6) comprise(s) one or more non-coupling zones (40, 44, 46, 64, 66), each non-coupling zone (40, 44, 46, 64, 66) comprising at least one non-coupling element (42) that is configured such that it cannot be fastened to the coupling elements (14, 16) of the other of the first or second stringers (4, 6).
2. 2. A slide fastener assembly (2) according to claim 1, wherein one of the one or more non-coupling zones (40, 44, 46, 64, 66) is an intermediate non-coupling zone (40) positioned at an intermediate position along the first stringer (4).
3. 3. A slide fastener assembly (2) according to claim 2, wherein the intermediate non-coupling zone (40) comprises at least two and no more than twelve consecutively arranged non-coupling elements (42), and preferably eight consecutively arranged non-coupling elements (42).
4. 4. A slide fastener assembly (2) according to any preceding claim, wherein the intermediate non-coupling zone (40) defines a length, and wherein the seal extends along the entire length of the intermediate non-coupling zone (40) when the first and second stringers (4, 6) are fastened together.
5. 5. A slide fastener assembly (2) according to any preceding claim, wherein: a first terminal non-coupling zone (44) is positioned at a terminal end of the first stringer (4); and a second terminal non-coupling zone (46) is positioned at a terminal end of the second stringer (6).
6. 6. A slide fastener assembly (2) according to claim 5, wherein each coupling element (14, 16) defines a coupling element length (49) in a longitudinal direction of the slide fastener assembly, and wherein one of the first or second terminal non-coupling zones (44, 46) is shorter than other of the first or second terminal non-coupling zone (44) by the coupling element length (49).
7. 7. A slide fastener assembly (2) according to any of claims 5 or 6, wherein the first and second terminal non-coupling zones (44, 46) each comprises at least 10 non-coupling elements, and preferably wherein the first terminal non-coupling zone (44) comprises 17 non-coupling elements and the second terminal non-coupling zone (46) comprises 16 non-coupling elements.
8. 8. A slide fastener assembly (2) according to any of claims 5 to 7, wherein: another of the one or more non-coupling zones (40, 44, 46, 64, 66) is a third terminal non-coupling zone (64) positioned at an opposite terminal end of the first stringer (4) to the first terminal non-coupling zone (44); and another of the one or more non-coupling zones (40, 44, 46, 64, 66) is a fourth terminal non-coupling zone (66) positioned at an opposite end of the second stringer (6) to the second terminal non-coupling zone (46).
9. 9. A slide fastener assembly (2) according to any preceding claim, wherein the first and second stringers (4, 6) each comprises a coiled or spiral continuous filament extrusion (26), and wherein each coupling element (14, 16) is defined by a loop (28) of the continuous filament extrusion (26).
10. 10. A slide fastener assembly (2) according to any preceding claim, wherein each coupling element (14, 16) defines: a base portion (30) configured to support the coupling element (14, 16) on the respective first or second tape (18, 20); and an engaging portion (32) configured for receipt between a corresponding pair of coupling elements (14, 16) of the opposite stringer to fasten the coupling elements (14, 16) of both stringers together (4, 6); wherein the non-coupling elements do not comprise engaging portions (32).
11. 11. A slide fastener assembly (2) according to claim 10, wherein the engaging portions (32) of adjacent coupling elements (14, 16) are spaced apart from one another in a longitudinal direction of the slide fastener assembly to define a gap (36) therebetween, and wherein the non-coupling elements (42) do not pass into the gap when the first and second stringers (4, 6) are fastened together.
12. 12. A slide fastener assembly (2) according to any preceding claim, wherein the non-coupling elements (42) of the one or more non-coupling zones (40, 44, 46, 66, 64) are enclosed by a covering, preferably wherein the non-coupling elements (42) of the one or more non-coupling zones (40, 44, 46, 66, 64) are contained within a block of material (43, 45, 47).
13. 13. A method of manufacturing a slide fastener assembly (2) comprising: providing a first stringer (4) having a first tape (18), a plurality of coupling elements (14) supported by the first tape (14), and a first sealing member (10) extending along the first tape (18); providing a second stringer (8) having a second tape (20), a plurality of coupling elements (16) supported by the second tape (20) and a second sealing member (12) extending along the second tape (20); and defining one or more non-coupling zones (40, 44, 46, 64, 66) on: (i) the first stringer (4), or (ii) the second stringer (6), or (iii) the first and second stringers (4, 6) by forming at least one non-coupling element (42) configured such that it cannot be fastened to the coupling elements (14, 16) of the other of the first or second stringers (4, 6).
14. 14. The method of claim 13, wherein each coupling element (14, 16) comprises: a base portion (30) configured to support the coupling element (14, 16) on the respective first or second tape (18, 20), and an engaging portion (32) configured for receipt between a corresponding pair of coupling elements (14, 16) of the opposite stringer (4, 6) to fasten the coupling elements (14, 16) of both stringers (4,6) together; wherein the step of forming at least one non-coupling element (42) comprises removing the engaging portion (32) from at least one of the coupling elements (14, 16) of the first or second stringer (4, 6), preferably by cutting at least one of the coupling elements.
15. 15. The method of any of claims 13 or 14, further comprising enclosing the at least one non-coupling element within a covering, and preferably by overmoulding the at least one coupling element with a polymeric material.