GB2528229A

GB2528229A - Slider for a slide fastener

Info

Publication number: GB2528229A
Application number: GB1405638.6A
Authority: GB
Inventors: Yoshikazu Hamada; Massimiliano Di Girolami
Original assignee: YKK Corp
Current assignee: YKK Corp
Priority date: 2014-03-28
Filing date: 2014-03-28
Publication date: 2016-01-20
Anticipated expiration: 2034-03-28
Also published as: DE102015003936A1; GB201405638D0; CN104939445B; DE102015003936B4; GB2528229B; CN104939445A

Abstract

A slider 11a for a slide fastener comprises: an upper portion 30a, connected to a lower portion 32a by a connection post 34; the upper portion 30a, lower portion 32a and connection post 34 co-operate to define a Y-shaped channel 36; the channel 36 is split at a head end of the slider 11a and the shape of the upper portion 30a at the head end of the slider is different to the shape of the lower portion 32a; one of the upper 30a or lower 32a portions preferably includes a pair of concave recesses 50 joined by a straight portion (54, fig 7). A slider 11a for a slide fastener wherein at least one of an upper 30a and lower 32a portion includes a pair of concave recesses 50 is also disclosed.

Description

Slider for a Slide Fastener The present invention relates to a slider for a slide fastener, and a slide fastener including a slider.

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

A coupling portion, usually in the form of coupling elements (also referred to as teeth) is 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 may be 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. The chain is generally planar, and the chain (and the coupling portions which form part of the chain) extends along a longitudinal axis of the 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 sfder along the chain.

Movement of the slider along the chain in a first sliding 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 sliding direction, opposite to the frst sliding 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.

Some applications of slide fastener requre that the slide fastener is bent about an axis which is perpendicular to both the longitudinal axis of the chain and the perpendicular to the plane of the chain. This may happen, for example, when a slide fastener forms part of a suitcase, at the portions of the slide fastener which pass around a corner of the suitcase. In such applications the slide may encounter more friction at the bent portions of the chain compared to portions of the chain which are not bent, and therefore move along bent potions of the chain less easily than compared to portions of the chain which are not bent.

The additional friction between the chain and the slider at bent portions of the slide fastener may result in the slide placing additional stress on the coupling portions relative to their respective tapes. This may cause the coupling portions to become detached from their tapes and therefore result in the slide fastener becoming inoperable. In one example, if the coupling portions are coils which are sewn by thread to their respective tapes, the friction may wear the thread such that the coils detach from the tapes. Furthermore, the additional friction between the chain and the slider at bent portions of the slide fastener may, in extreme cases, result in the slider cutting into the tape of the stringers. Such cutting may result in the slider becoming stuck or detached, or in the slide fastener tearing. All of these may result in the slide fastener becoming inoperable.

The present invention is concerned with providing a slider and a slide fastener of a type which enable the reduction of friction between the slider and the chain when the slide fastener is bent, thereby obviating or mitigating at least one problem with known sliders and slide fasteners, whether discussed above or otherwise. The present invention is also concerned with providing an alternative slider and slide fastener to known sliders and slide fasteners.

According to a first aspect of the present invention, there is provided a slider for a slide fastener, the slider comprising: an upper portion connected to a lower portion by a connection post extending in a first direction from the upper portion to the lower portion; the upper portion, lower portion and connection post co-operating to define a y-shaped channel having a first arm separated from a second arm by the connection post, and a third arm which adjoins the first and second arms; the slider extending in a second direction, generally perpendicular to the first direction, from a head end to a tail end, the first arm and second arm having respective first and second openings at the head end of the slider, and the third arm having a third opening at the tail end of the slider; and wherein the projection, on to a plane substantially perpendicular to the first direction, of the shape of the upper porton at the head end of the slider is different to the projection onto said plane of the shape of the lower portion at the head end of the slider.

A perimeter of said projection of the lower portion at the head end of the slider may define a pair of recesses Each of the pair of recesses may be a generally concave recess.

The perimeter of said projection of the lower portion at the head end of the slider may include a portion which is a generally straight line located between the pair of recesses which extends in the plane of the perimeter of said projection of the lower portion in a direction generally perpendicular to the second direction..

The perimeter of said projection of the lower portion at the head end of the slider may include a portion which is a generally straight line which extends in the plane of the perimeter of said projection of the lower portion in a direction generally perpendicular to the second direction. -A perimeter of said projection of the upper portion at the head end of the slider may define a second pair of recesses Each of the second pair of recesses may be a generally concave recess.

The perimeter of said projection of the upper portion at the head end of the slider may include a portion which is a generally straight line located between the second pair of recesses which extends in the plane of the perimeter of said projection of the upper portion in a direction generally perpendicular to the second direction..

The perimeter of said projection of the upper portion at the head end of the slider may include a portion which is a generally straight line which extends in the plane of the perimeter of said projection of the upper portion in a direction generally perpendicular to the second direction..

According to a second aspect of the invention there is provided a slider for a slide fastener, the slider comprising an upper portion connected to a lower portion by a connection post extending in a first direction from the upper portion to the lower portion; the upper portion, lower portion and connection post co-operating to define a y-shaped channel having a first arm separated from a second arm by the connection post, and a third arm which adjoins the first and second arms; the slider extending in a second direction, generally perpendicular to the first direction, from a head end to a tail end, the first arm and second arm having respective first and second openings at a head end of the slider, and the third arm having a third opening at a tail end of the slider; wherein a perimeter of the projection, on to a plane substantially perpendicular to the first direction, of the shape of the upper portion and/or the lower portion at the head end of the slider, defines a pair of generally concave recesses.

A perimeter of said projection of the lower portion at the head end of the slider may define said pair of recesses and the perimeter of said projection of the lower portion at the head end of the slider may include a portion which is a generally straight line located between the pair of recesses which extends in the plane of the perimeter of said projection of the lower portion in a direction generally perpendicular to the second direction..

A perimeter of said projection of the lower portion at the head end of the slider may define said pair of recesses, and the perimeter of said projection of the upper portion at the head end of the slider may include a portion which is a generally straight line which extends in the plane of the perimeter of said projection of the upper portion in a direction generally perpendicular to the second direction..

A perimeter of said projection of the upper portion at the head end of the slider may define said pair of recesses or, if present, said second pair of recesses and the perimeter of said projection of the upper portion at the head end of the slider may include a portion which is a generally straight line located between the pair of recesses, or, if present, said second pair of recesses, which extends in the plane of the perimeter of said projection of the upper portion in a direction generally perpendicular to the second direction.

A perimeter of said projection of the upper portion at the head end of the slider may define said pair of recesses or, if present, said second pair of recesses, and the perimeter of said projection of the lower portion at the head end of the slider may include a portion which is a generally straight line which extends in the plane of the perimeter of said projection of the lower portion in a direction generally perpendicular to the second direction..

According to a third aspect of the present invention, there is provided a slide fastener including a slider according to either the first or second aspect of the invention.

The slide fastener may include first and second fastener tapes, each fastener tape may include a coupling portion provided along an edge of the fastener tape, the coupling portions of the fastener tapes may be located adjacent one another, the coupling portion of the first fastener tape may be received by the first and third arms of the y-shaped channel of the slider, and the coupling portion of the second fastener tape may be received by the second and third arms of the y-shaped channel of the slider, wherein the slider may be configured such that movement of the slider relative to the fastener tapes in a first sliding direction draws the coupling portions nto securing engagement with one another, and such that movement of the slider relative to the fastener tapes in a second sliding direction, generally opposite to the first sliding direction, separates the coupling portions from each other.

The slide fastener may be configured such that when the slide fastener s bent about an axis which is generally perpendicular to both the first direction and the second direction, each of the pair of recesses may accommodate a respective coupling portion of the fastener tapes, and thereby, whilst the slide fastener is bent, when the slider is moved in the first and/or second sliding direction, the coupling portions may not catch on the ower or upper portion of the slider at the head end of the slider which includes said pair of recesses.

Each of the first and second fastener tapes may include a second coupling portion provided along said edge of the fastener tape, the second coupling portions of the fastener tapes may be located adjacent one another, the second coupling portion of the first fastener tape may be received by the first and third arms of the y-shaped channel of the slider, and the second coupling portion of the second fastener tape may be received by the second and third arms of the y-shaped channel of the slider, wherein the slider may be configured such that movement of the slider relative to the fastener tapes in a first sliding direction draws the second coupling portions into securing engagement with one another, and such that movement of the slider relative to the fastener tapes in a second sliding direction, generally opposite to the first sliding direction, separates the second coupling portions from each other.

Other aspects and preferred features of the present invention will be apparent from the

following description and the accompanying claims.

The invention will now be further described by way of example and with reference to the accompanying drawings, in which: Figure 1 shows a schematic view of a known type of slide fastener including a slider; Figure 2 shows a schematic view of a known type of slider for a slide fastener of the type shown in Figure 1; Figure 3 shows a schematic cross-sectonal view of a portion of the slider shown in Figure 2; Figure 4 shows a schematic view of the slider of the slide fastener shown in figure one with the slider being transparent; Figure 5 shows a schematic side view of a portion of a slide fastener of the type shown in Figure 1 which has been bent; Figures 6, 7, and 8 show schematic views of a slider according to an embodiment of the invention; Figures 9a, Yb and 10 show schematic views of slide fasteners according to different embodiments of the invention which incude sliders of the type shown in Figures 6, 7 and 8; Figure 11 shows a schematic view of a slider in accordance with a further embodiment of the invention; and Figure 12 shows a schematic perspective view of a portion of a further embodiment of slide fastener according to the present invention.

Figure 1 shows a known slide fastener 10. The slide fastener comprises a slider 11 and a pair of stringers 1 2a, 1 2b. Each stringer 1 2a, 1 2b comprises a coupling portion in the form of coupling elements 14a, 14b (also referred to as teeth) which are attached to the edge of a tape iSa, 1Gb. The tape may be woven or knitted and may be formed from, for example, polyester. The coupling elements 14a, 14b may be attached to their respective tape iSa, 16b by, for example, crimping or moulding the coupling elements onto a reinforced edge of the tape iSa, 1Gb. 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.

The two stringers 12a, 12b are brought together (as shown in the bottom portion of Figure 1), such that the coupling elements 14a, 14b of each stringer 12a, 12b can attach to one another, by interdigitating, to form chain 18. The chain 18 is generally planar, and the chain 18 (and the coupling portions which form part of the chain 18) extends along a longitudinal axis [of the chain 18.

The slider 11 is attached to the chain 18 such that it can move along the chain 18 between the two stringers 12a, 12b. Movement of the slider 11 along the chain 18 in a first sliding direction E causes the coupling elements 14a of the first stringer 12a to attach to the coupling elements 14b of the second stringer 12b. Whereas movement of the slider along the chain in a second sliding direction D, opposite to the first sliding direction E, causes the coupling elements 14a of the first stringer 12a to detach from the coupling elements 14b of the second stringer 12b.

The chain 18 is commonly cut to a desired length to form a desired length of slide fastener 10. Stops (often referred to as top stops and bottom stops) are attached to either end of the chain 18. The stops limit the extent of movement that the slider 11 can undertake along the chain 18.

In the slide fastener shown in Figure 1, the stops 20a and 2Db are top stops attached to a top end of the chain 18 on the first tape 16a and second tape 16b respectively. Other slide fasteners may have a single top stop attached to both stringer tapes.

The slide fastener has a single bottom stop 22 which is attached to the tapes 16a, 1Gb of both the first and second stringers 12a, 12b. Other slide fasteners, which may be referred to as a separating slide fasteners, may have two separate bottom stops attached to the tape of 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.

As seen best in figures 2, 3, and 4, the slider 11 includes a main body 24, through which the coupling elements 14a, 14b of each stringer 12a, 12b pass, and a pull tab 26 attached to the main body 24 via a bridge portion 28. The pull tab 26 may be grasped by a user in order to effect movement of the slider 11 along the chain 18 (for example, in the first and second sliding directions E, D previously discussed).

In more detail, the main body 24 of the slider 11 comprises an upper portion 30 connected to a lower portion 32 by a connection post 34 extending in a first direction B from the upper portion 30 to the lower portion 32. The upper portion 30 may be referred to as an upper wing or an upper blade. Likewise, the lower portion may be referred to as a lower wing or lower blade. The connection post 34 may be referred to as the diamond.

The upper portion 30, lower portion 32 and connection post 34 co-operate to define a V-shaped channel 36. The V-shaped channel 36 has a first arm 36a separated from a second arm 36b by the connection post 34. The V-shaped channel 36 also includes a third arm 36c which adjoins the first and second arms 36a, 36b.

The slider 11 extends in a second direction C, generally perpendicular to the first direction B, from a head end 38 of the slider to a tail end 40 of the slider 11. TheY-shaped channel 36 is also defined by lateral flanges 42 and 44 either side of the slider 11 which extend towards each other from the upper portion 30 and lower portion 32 respectively.

The first arm 36a and second arm 36b have respective first and second openings 46a, 46b at the head end 38 of the slider 11. The third arm 36c has a third opening 46c at the tail end 40 of the slider 11.

Some applications of slide fastener requre that the slide fastener is bent about an axis which is perpendicular to both the second direction C (which is generally the same as the longitudinal axis L of the chain 18) and the first direction B (which is generally the same as a perpendicular to the plane of the chain 18). This may happen, for example, when a slide fastener forms part of a suitcase at the portions of the slide fastener which pass around a corner of the suitcase. Figure 5 shows a cross-sectional side view of a slider 11 at a location along a chain 18 at which the slide fastener is bent in a manner discussed above.

As can be seen in figure 5, when the slide fastener is bent as previously discussed, the slider 11 may encounter more friction at a bent portion of the chain 18 of the slide fastener 10 compared to portions of the chain 18 of the slide fastener 10 which are not bent. In particular, it can be seen that when the slide fastener 10 is bent in such a manner that the centre of curvature of the bent slide fastener is located closer to the lower portion 32 of the slider 11 than to the upper portion 30 of the slider 11, the lower portion 32 of the slider 11 at front and tail ends 40, 38 of the slider may be urged by the bend in the slide fastener 10 into contact with the lower portion 32 of the slider 11. The points of contact between the slider 11 and the chain 18 are indicated as 48a and 48b.

The additional friction between the chain 18 and the slider 11 at the bent portion of the slide fastener 10 may result in the slider placing additional stress on the coupling portions (indicated generally as 14c within figure 5). This stress may act so as to attempt to separate the coupling portions 14c from their respective tapes (indicated generally as lGc within figure 5). This may cause the coupling portions 14c to become detached from their tapes 16c and therefore result in the slide fastener 11 becoming inoperable. In one example, if the coupling portions are coils which are sewn by thread to their respective tapes, the friction between the side 11 and the chain 18 may wear the thread such that the coils detach from the tapes.

In addition, the additional friction between the chain 18 and the slider 11 at the bent portion of the slide fastener 10 may result in the slider cutting into the tape lSc of the stringers. Such cutting may result in the slider 11 becoming stuck or detached, or in the slide fastener tearing. All of these may result in the slide fastener 10 becoming inoperable.

The present invention relates to a slider for a slide fastener which will mitigate the problem discussed above. In addition. the present invention also provides a slide fastener including such an aforementioned slider.

Figures 6, 7 and 8 show a perspective view from above, a plan view from below, and a perspective view from below respectively of a slider ha in accordance with an embodiment of the present invention.

In common with the previously discussed slider 11 for a slide fastener 10, the slider ha according to the present invention includes the following features.

A main body 24a which may be connected to a pull tab (not shown) via a bridge portion 28a. The main body 24a includes an upper portion 30a connected to a lower portion 32a via a connection post 34a which extends in a first direction B from the upper portion 30a to the lower portion 32a. The upper portion 30a, lower portion 32a and connection post 34a co-operate to define a Y-shaped channel having a first arm 36d separated from a second arm 36e by the connection post 34a, and a third arm 36f which adjoins the first and second arms, 36d, 36e. The slider extends in a second direction C, generally perpendicular to the first direction B, from a head end 38a to a tail end 40a. The first arm 36d and second arm 36e have respective first and second openings 46d, 46e at the head end 38a of the slider 1 la. Furthermore, the third arm 3Sf has a third opening 4Sf located at the tail end 40a of the slider 1 la.

The slider ha according to an embodiment of the present invention differs from the known slider in that the projection, onto a plane substantially perpendicular to the first direction B, of the shape of the upper portion 30a at the head end 38a of the slider 1 la is different to the projection onto said plane of the shape of the lower portion 32a at the head end 38a of slider 11 a. This is explained in more detail below.

As previously discussed, the first direction B is the direction in which the connection post extends from the upper portion 30a of the slider 11 a to the lower portion 32a of the slider ha. A plane which is substantially perpendicular to the first direction B is the plane of figure 7. Figure 7 shows a plan view of the slider ha from below. That is to say, the view shown in Figure 7 is a projection onto a plane substantially perpendicular to the first direction B of the shape of the lower portion. In addition the figure shows, beyond the projection of the lower portion 32a, the projection, onto a plane substantially perpendicular to the first direction B, of the shape of the upper portion 30a.

It can be seen from Figure 7 that the projection, onto a plane substantially perpendicular to the first direction B, of the shape of the upper portion 30a at the head end 38a of the slider 11 a is different to the projection onto said plane of the shape of the lower portion 32a at the head end of the 38a of the slider ha. In particular, in the embodiment shown, the projection, onto a plane substantially perpendicular to the first direction B, of the shape of the lower portion 32a at the head end 38a of the slider 1 ha is smaler than the projection onto said plane of the shape of the upper portion 33a at the head end of the 38a of the slider 11 a.

The applicant has realised that by having different shapes of upper portion and lower portion of the head end of the slider enables the upper and lower portions to beneficially have different operating characteristics when the slider forms part of a slide fastener. This is discussed in greater detail at a later point within the description.

The perimeter (indicated in broken line 48 within figure 7) of said projection of the lower portion 32a at the head end 38a of the slider ha defines a pair of recesses indicated generally as 50a and 50b. Each of the pair of recesses 50a, 50b are configured such that when they form part of a slide fastener which is bent about an axis which is perpendicular to the first and second directions B, C (in the manner previously discussed), the friction between the slider 1 la and chain of the slide fastener at the bent portion of the slide fastener is reduced. This is achieved as follows.

Referring back to figureS it can be seen that for a known slider 11 passing round the bent portion of the slide fastener 10 the lower portion 32 of the slider 11 at the head end 38 of the slider 11 will be urged into contact with the connection portions 14c of the stringers of the chain 18 at the position 48b. The recesses 50a and 50b enable the connection portions 14c of the stringers of the slide fastener 10 to pass through the slider 11 a with a reduced (and in some cases eliminated) contact between the coupling portions of the chain and the slider ha at the head end 38a of the slider when the slider ha is located at a bent portion of slide fastener. This results in reduced friction between the slider 11 a and the chain on which the slider is mounted at a portion of the slide fastener which is bent. Consequently, the occurrence of any of the potential problems described above resulting from friction between the slider and chain is reduced or eliminated by a slider according to the present invention.

Each of the pair of recesses 50a, SOb is a generally concave recess. By concave recess what is meant is that the centre of curvature of the recessed portion of the perimeter 48 is located outside of the perimeter 48 (as opposed to within it). In other embodiments the recesses may have any appropriate shape. For example, they may be convex, polygonal or diagonal (i.e. defined by a substantially straight line).

The recesses being concave recesses may be advantageous in certain applications.

This is explained in more detail at a later point.

Figure 9a shows a slider ha forming part of a slide fastener ba. In this embodiment the slide fastener 1 Qa includes a single slider 11 a.

Figure Sb shows an alternative slide fastener 1 Ob which may be referred to as a double slider type slide fastener. This type of slide fastener includes two sliders (each of which are labelled ha within the figure). The sliders are arranged in head to head relation such that, when the sliders ha are adjacent to one another, the head end of each slider faces that of the other slider. This means that each slider ha operates to couple/uncouple the coupling portions in a direction of movement which is opposite to that of the other slider.

In applications in which a secure fastening is required a double slide fastener of the type shown in Sb may be used in which both of the sliders may be drawn together, thus closing the slide fastener, and subsequently secured. The sliders 11 a within figure Sb are shown in such a configuration. The sliders may be either secured to one another or secured in place so that the slide fastener remains closed. In these cases, the sliders will each include a securing portion which is secured to the securing portion of the other sUder, or a securing portion which can be secured to a fixed point on the slide fastener or elsewhere. In some embodiments the securing portion is preferably located on the upper portion of the slider. Securing portions of the sliders 1 la shown in Figure Sb are indicated schematically by 51.

Even when the sliders ha are positioned along the slide fastener such that they are touching, there is still a portion 52 of the slide fastener lOb between the sliders ha at which the coupling portions of the stringers are not coupled to one another.

This uncoupled portion 52 of the slide fastener lOb is undesirable for several reasons.

First, if the uncoupled portion 52 is particularly large, and if it is not obscured by the sliders 11 a then it may be possible to insert an implement into the uncoupled portion 52 and force the slide fastener open. Secondly, the uncoupled portion 52 allows some lateral movement of the sliders ha relative to the rest of the slide fastener. Lateral movement of the sliders relative to the rest of the slide fastener can also lead to the coupling elements of the slide fastener decoupling, and therefore the slide fastener opening.

As a result of the problems discussed above, the applicant has determined that it is advantageous for at least one of the upper and lower portions of the slider at its head end has a generally flat portion which extends in a direction generally perpendicular to the second direction C and in the plane of the respective portion. In other words, a generally flat portion of either the upper or lower portion of the slider may be defined as follows. The generally flat portion of either the upper or lower portion of the slider may be defined by a portion of the perimeter, of the projection of the respective upper or lower portion on to a plane which is perpendicular to the first direction, which is a generally straight line which extends in the plane ol the perimeter in a direction generally perpendicular to the second direction.

This generally flat portion at the head end of the slider enables two sliders of the same type utilised as part of a double slider type slide fastener to abut one another when the sliders are in their closed positions to substantially prevent any access to the uncoupled portion between the sliders. Whichever of the upper portion or lower portion of the slider which is accessible when the sliders are in their closed position preferably has a head end which is as wide (in a direction perpendicular to both the second direction C (and hence first and second sliding directions) and the first direction B) as possible and desirably at least the width of the coupling elements when coupled together. This ensures that the head end of the upper or lower portion, as appropriate, substantially blocks access to the uncoupled portion 52, thereby preventing an implement from being inserted into the uncoupled portion 52 and used to force the slide fastener open.

In addition, the flat portion means that if the sliders are in their closed positions and are then moved laterally relative to the rest of the slide fastener, then the flat portion helps to ensure that the head ends of the sliders do not move past one another in a direction parallel to the second direction.

In addition, the flat portions of the slider provide a relatively large surface area to support any lock which may form part of the slide fastener, thereby providing a stronger lock.

In light of the above, it can be seen that it may be advantageous to have a slider with different shapes of upper portion and lower portion of the head end of the slider. This is because it enables the upper and lower portions to beneficially have different operating characteristics when the slider forms part of a slide fastener. For example, in the described embodiment, the lower porton may include recesses to reduce friction between the slider and the coupling portions when the slider is moving along a bent portion of slide fastener, and the upper portion may include a flat head portion which is a wide as possible to make the slide fastener more secure in the ways discussed above.

As can been seen most clearly in figures 7 and 8, the perimeter 48 of the projection of the lower portion 32a at the head end 38a of the slider ha defines a generally flat portion 54, between the pair of recesses 50a, Sob, which extends in the plane of the perimeter in a direction generally perpendicular to the second direction C. This may also be expressed as the perimeter 48 of the projection of the lower portion 32a at the head end 38a of the slider ha including a portion 54 which is a generally straight line located between the pair of recesses 50a, SOb which extends in the plane of the perimeter 48 in a direction generally perpendicular to the second direction C. In some embodiments of the slider according to the present invention the lower portion of the slider at the head end may include a generally flat portion of the type previously discussed, however, the projection of the shape of the lower portion at the head end of the slider may not define a pair of recesses as previously discussed.

The previously discussed embodiment of the slider according to the present invention has a lower portion 32a at the head end 38a of the slider which defines a pair of recesses SOa, Sob. In addition, the perimeter of the projection of the shape of the upper portion 40a of the slider 1 la at the head end 38a of the slider 11 a also includes a generally flat portion 55 which extends in a direction generally perpendicular to the second direction C and does not include a pair of recesses. That is to say, the perimeter of the projection of the shape of the upper portion 40a of the slider 1 la at the head end 38a of the slider ha also includes a portion which is a generally straight line which extends in the plane of the perimeter of said projection of the upper portion in a direction generally perpendicular to the second direction.

In another embodiment, as shown in Figure 11, a perimeter of the projection, on a plane to be substantially perpendicular to the first direction, of the shape of the upper portion 30b at the head end 38a of the slider 11 b may define a second pair of recesses SOc, Sod. In such embodiment, both the upper portion 30b and lower portion 32b of the slider 11 bat the head end 38a of the slider 11 b include a pair of recesses. The second pair of recesses 50c, 50d of the upper portion 30b of the slider llb may be generally concave recesses of similar type to those discussed previously in relation to recesses of the lower portion of the slider.

In addition, in some embodiments, the perimeter of the projection of the upper portion of the slider at the head end of the sfder may define a generally flat portion 55a between the second pair of recesses 50c, Süd, the flat portion 55a extending in the plane of the perimeter in a direction generally perpendicular to the second direction.

This may also be expressed as the perimeter of the projection of the upper portion at the head end of the slider may include a portion 55a which is a generally straight line located between the second pair of recesses 50c, 50d which extends in the plane of the perimeter of said projection of the upper portion in a direction generally perpendicular to the second direction C. In some embodiments, the perimeter of the projection of the upper portion of the slider at the head end of the slider may define a generally flat portion 55 which extends in the direction generally perpendicular to the second direction. This may also be expressed as the perimeter of the projection of the upper portion at the head end of the slider may include a portion 55 which is a generally straight line which extends in the plane of the perimeter of said projection of the upper portion in a direction generally perpendicular to the second direction C. For example, this is the case for the slider shown in Figures 8 to 8. In some embodiments, such as those shown in Figures 6 to 8 the perimeter of the projection of the upper portion of the slider at the head end of the slider does not include a pair of recesses (of the type discussed above in relation to the lower portion of the slider).

Referring to the embodiment of slider ha shown in Figures 6 to 8, according to another aspect of the invention there is provided a slider 11 a for a slide fastener. The slider ha comprises an upper portion 30a connected to a lower portion 32a by connection post 34a extending in a first direction B from the upper portion 30a to the lower portion 32a. The upper portion 30a, lower portion 32a, and connection post 34a co-operate to define a Y-shaped channel having a first arm 36d separated from a second arm 36e by the connection post 34a, and a third arm 36f which adjoins the first and second arms 36d, 36e. The slider ha extends in a second direction C, generally perpendicular to the first direction B, from a head end 38a to a tail end 40a. The first arm 36d has a first opening 46d at the head end 38a of the slider ha. The second arm 36e has a second opening 46e at the head end 38a of the slider ha. The third arm 36f has a third opening 4Sf at a tail end 40a of the slider 1 la.

A perimeter 48 of the projection, onto a plane substantially perpendicular to the first direction B, of the shape of the upper portion 30a and/or lower portion 32a at the head end 38a of the slider 11 a defines a pair of generally concave recesses 50a, 5Db.

In the embodiment shown in Figures 6 to 8 only the shape of the lower portion 32a at the head end 38a of the slider ha defines a pair of generally concave recesses 50a, 50b. In the embodiment shown in Figure 11 both the shape of the lower portion 32b and the shape at upper portion 3Db at the head end 38a of the slider llb define a pair of generally concave recesses 50a, Sob, 50c, Sod. In other embodiments not shown, only the shape of the upper portion at the head end of the slider may define a pair of generally concave recesses.

The provision of a pair of generally concave recesses at the head end of the slider in the upper portion and/or the lower portion of the slider has been found by the applicant to be advantageous as follows.

As previously discussed, the provision of recesses enables a reduction in friction between the coupling portions of a slide fastener and the slider when the slider is located at a bent portion of the slide fastener. The concave shape of the recesses has been found to be advantageous in some applications because it enables the provision of the recesses while simultaneously enabling the upper and/or lower portion of the slider which includes the recesses to have a maximised length of generally flat portion which extends in a direction generally perpendicular to the second direction C between the pair of recesses. As previously discussed, providing a generally flat portion which extends in a direction generally perpendicular to the second direction at the head end of the slider, and indeed maximising the length of such a portion will increase the effectiveness of a double slider type slide fastener which includes two such sliders.

Discussion as to why this is the case is set out above. Consequently, in order to avoid repetition, it is not repeated here.

The applicant has appreciated that it is not only advantageous for the head end of a portion of a slider which includes a pair of recesses of the type previously discussed to include a generally flat portion (which extends in a direction generally perpendicular to the second direction), but it may also be advantageous for the same reasons for the head end of the upper or lower portion of the slider which does not include a pair of recesses to include a generally flat portion (which extends in the direction perpendicular to the second direction).

Consequently, in some embodiments of the present invention the lower portion of the side at the head end of the slider may incorporate a pair of recesses and the upper portion and/or the lower portion of the slider at the head end of the slider may incorporate a generally flat portion which extends in the direction generally perpendicular to the second direction.

In other embodiments, the upper portion of the slider at the head end of the slider may define a pair of recesses, and the upper portion and/or lower portion of the slider at the head end of the slider may have a generally flat portion which extends in the direction generally perpendicular to the second direction.

In further embodiments, both the upper and lower portions of the slider at the head end of the slider may incorporate a pair of recesses, and the upper and/or lower portion of the side at the head end of the slider may incorporate a generally flat portion which extends in a direction generally perpendicular to the second direction.

In all of the potential embodiments discussed above, if the upper portion and/or lower portion of the slider at the head end of the slider includes a pair of recesses and a generally flat portion which extends in the direction perpendicular to the second direction, the generally flat portion may be located between the pair of recesses.

It is also within the scope of the present invention to provide a slide fastener including a slider of the same type as any of those previously discussed.

Figure 10 shows a slide fastener 1 Ob according to an embodiment of the present invention. The slide fastener lOb is a slide fastener with double sliders ha which are arranged in head to head relation. That is to say, the head ends 38a of each slider 11 a face each other when the sliders ha are located adjacent one another. The slide fastener lOb includes first and second fastener tapes 16c, 16d. Each fastener tape 16c, 16d includes a respective coupling portion 14c, 14d provided along an edge of the fastener tape 16c, led. The coupling portions 14c and 14d are located adjacent one another.

The segment of the coupling portions 14c and 14d which are located in between the sliders ha in figure 10 are separate from one another, whereas the segments of the coupling portions 14c and 14d which are not located between the sliders ha within figure 10 are in securing engagement with one another.

The coupling portion 14c of the first fastener tape 16c is received by the first and third arms 36d and 36f of the V-shaped channel of the slider lha. The coupling portion 14d of the second fastener tape 16d is received by the second and third arms 36e, 36f of the V-shaped channel of the slider 11 a.

The slider is configured such that movement of the slider ha relative to the fastener tapes 16c, led in a first sliding direction F will draw the coupling portions 14c, 14d into securing engagement with one another. Furthermore, the slider 1 la is also configured such that movement of the slider 11 a relative to the fastener tape 1 Gc, 1 Gd in a second sliding direction D, generally opposite to the first sliding direction E, will separate the coupling portions 14c, 14d from each other.

It will be noted that as previously discussed, the slide fastener lOb shown in figure 10 is a slide fastener with double sliders 1 la arranged in head to head relation. As can be seen from the figure, the first and second sliding directions F, D for each of the sliders ha are the opposite to those for the other slider. This is because the first and second slider directions are defined by the relative orientation between a sUder (and in particular its Y-shaped channel) and the fastener tape. Consequently, because each of the sliders shown within figure 10 is orientated in the opposite direction relative to the fastening tape compared to the other sde, the first and second sliding directions for each slder are opposite to those of the other slider.

It will be appreciated that although the slide fastener shown in figure 10 is a slide fastener with double sliders, in other embodiments of side fastener according to the present invention the slide fastener may include any appropriate number of sliders (for example, a single slider or more than two sliders).

In embodiments of slide fastener according to the present invention which include a slider of the type previously discussed which includes at least one pair of recesses, the slide fastener lOb may be configured such that when the slide fastener lOb is bent about an axis which is generally perpendicular to both the first direction B and second direction C, each of the pair of recesses 50a, SOb accommodates a respective coupling portion 14c, 14d of the fastener tapes 16c, 16d. In this way, whilst the slide fastener 1 Ob is bent, when the slider 11 a is moved in the first and/or second sliding direction E, D the coupling portions 14c, 14d substantially do not catch on the lower portion of the lower or upper portion 32a, 30a of the slider at the head end 38a of the slider 1 la which includes the said pair of recesses 50a, SOb.

Within the majority of the embodiments described above, the recesses are located at the head end of the slider on the lower portion of the slider. Sliders having recesses of the type described above in the lower portion of the slider are effective at reducing friction between the coupling portions of a slide fastener and the slider (or at reducing or preventing catching between the coupling portions of a slide fastener and the slider) when the slide fastener is bent about an axis such that the centre of curvature of the bend of the slide fastener is located closer to the lower portion of the slider than the upper portion of the slider.

It will be appreciated that in situations where the slide fastener may be bent about an axis (which is generally perpendicular to both the first and second directions) such that the centre of curvature of the bent portion of the side fastener is located closer to the upper portion of the slider compared to the lower portion of the slider, then, according to the invention, it would be desirable for the upper portion of the slider (as opposed to the lower portion) at the head end of the slider to include a pair of recesses to accommodate the coupling portions of the slide fastener such that friction is reduced and/or the coupling portions do not catch on the upper portion of the slider when the slide fastener is bent.

It will further be appreciated that in situations where a slide fastener may have to be subjected to bending in both of the directions discussed above (i.e. such that the centre of curvature of the bent portion of the side fastener may either be located closer to the upper portion of the slider compared to the lower portion of the slider or be located closer to the lower portion of the slider compared to the upper portion of the slider), then, according to the invention, it may be desirable for both the upper portion of the slider and the lower portion of the slider at the head end of the slider to include a pair of recesses. In such embodiments there will be a first pair of recesses in one of the upper and lower portions a! the slider, and a second pair a! recesses in the other of the upper and lower portions of the slider. The first and second pairs of recess will accommodate the coupling portions of the slide fastener when the slide fastener is bent in either of the directions discussed above such that friction is reduced and/or the coupling portions do not catch on the upper or lower portions of the slider when the slide fastener is bent in the manner discussed above.

All embodiments of slider described above are such that they are symmetrical along a line of symmetry which runs parallel to the direction C and which passes through the centre (in a direction F perpendicular to both the first and second directions B, C) of the connection post 34a. In other words, all embodiments of slider described above are such that they are symmetrical along a me of symmetry which is the longitudinal axis of the slide fastener of which the slider forms part. In other embodiments of the invention the slide fastener need not be symmetrical in the manner described above.

In the embodiments above the slide fastener is such that each stringer comprises a single coupling portion such that the coupling portion of one stringer can couple with the coupling portion of the other stringer. In other embodiments the slide fastener may be such that each stringer comprises a plurality (for example, 2) coupling portions.

Each of the coupling portions of one stringer can couple with a respective corresponding coupling portion of the other stringer. An example of such a slide fastener is shown in Figure 12.

In order to aid clarity within Figure 12 the lateral flanges which extend from the upper and lower portion 30a, 32a of each slider ha and which in part define the Y-shaped channel have been omitted. In addition, again to aid clarity, the upper and lower portions 30a, 32a of the sliders ha have been made transparent. The connection portion 34a of each of the sliders ha shown in Figure 12 is schematic -that is to say, its shape and location within the sliders 11 a may differ from that shown.

From above, the slide fastener bc shown in Figure 12 will appear substantially identical to the slide fastener lOb shown in Figure 10. However, as can be seen in Figure 12, which shows a side view of slide fastener bc, each of the first and second fastener tapes 1Cc, 16d includes a second coupling portion 14e, 14f provided along said edge of the fastener tape. Features of the slide fastener lOc which are equivalent to those of the slide fastener lOb shown in Figure 10 have been given the same numbering. The second coupling portions 14e, 14f of the fastener tapes 16c, lCd are located adjacent one another. The second coupling portion 14e of the first fastener tape 1 6c is received by the first and third arms 36d, 36f of the y-shaped channel of the slider ha, and the second coupling portion 14f of the second fastener tape 16d is received by the second and third arms 36e, 36f of the y-shaped channel of the slider ha.

It will be appreciated that although the slide fastener shown in figure 12 is a slide fastener with double sliders, in other embodiments of side fastener according to the present invention the slide fastener may include any appropriate number of sliders (for example, a single slider or more than two sliders).

The slider ha is configured such that movement of the slider ha relative to the fastener tapes 16c, 16d in a first sliding direction E draws the second coupling portions 14e, 14f into securing engagement with one another, and such that movement of the slider ha relative to the fastener tapes 1Cc, lCd in a second sliding direction D, generally opposite to the first sliding direction E, separates the second coupling portions 14e, 14f from each other. As such, in this embodiment of slide fastener according to the present invention the slider ha has a single y-shaped channel which simultaneously guides both the first and second coupling portions 14c, 14d, 14e, 14f through the slider 11 a to simultaneously effect coupling/securing or decoupling/separating of both the first and second coupling portionsl4c, 14d, 14e, 14f.

In other embodiments of slide fastener which include stringers with a plurality of coupling portions, the slider may include the same number of Y-shaped channels (and connection posts) as the number of coupling portions. In these embodiments the slider will not only include an upper portion and a lower portion, but also a number of intermediate portions (substantially parallel to the upper and lower portions) which is equal to one less than the number of coupling portions. In such cases at least one of, or all of, the intermediate portions may either: have a shape such that the projection, on to a plane substantially perpendicular to the first direction, of the shape of the intermediate portion at the head end of the slider is different to the projection onto said plane of the shape of the upper and/or lower portion at the head end of the slider; and/or have a shape such that a perimeter of the projection, on to a plane substantially perpendicular to the first direction, of the shape of the intermediate portion at the head end of the slider defines a pair of recesses. The recesses may be concave.

Within both the description and claims, where reference is made to a projection, on to a plane substantially perpendicular to the first direction, of an article or a shape of the article (for example, that of the upper portion or lower portion of a slider), this may also be expressed as a cross-section substantially perpendicular to the first direction of said article or shape of article.