SLIDE FASTENERS AND THE LIKE

Abstract: The invention provides a fastener which somewhat resembles a slide fastener but which can be made at least substantially fluid-resistant. It comprises a first component (1), of flexible and resilient material, having an engagement formation having a longitudinal groove (6) and longitudinally spaced mating formations (10), and a second component (2), of similar material, having a rib (16) and longitudinally spaced mating formations (19). The components can be progressively engaged by the introduction of the rib into the groove and the interengagement of the mating formations. The latter prevent significant relative longitudinal movement between the components. Each component can be made by extrusion of a blank followed by the formation of the mating formations by a rotary die (123). The components can be engaged and disengaged by means of a slide (52) like that used in a conventional slide fastener. To prevent the inadvertent disengagement of the components, the component may have longitudinal retaining or locking formations (7,17) and/or interlocking mating formations (10,19). Numerous other examples are illustrated.

Description: This invention relates to slide fasteners and the like. A conventional slide fastener comprises two flexible components, each of elongated form, provided with teeth which can be caused to interengage, and can subsequently be parted, by the movement of a slide pulled along the components. Slide fasteners of that kind are satisfactory for many purposes but suffer from the disadvantage that in use, when the teeth have been interengaged they tend to allow water and other liquids, as well as gases, to pass between them. There are numerous circumstances in which it would be desirable for a slide fastener to be fluid-resistant or at least substantially so, and the present invention stems from work undertaken with a view to providing a fastener which may be suitable for use in place of a conventional slide fastener but which can be made at least substantially fluid-resistant. In addition, however, the present invention also aims to produce other forms of fastener. Another existing type of fastener, which is not a slide fastener, comprises two flexible components, each of elongated form, one of which is formed with a longitudinal groove and the other of which is provided with a longitudinal rib that can be snapped in and out of the groove, it normally being necessary to introduce the rib into the groove progressively, along the length of the fastener, and conversely to remove the rib from the groove progressively, along the length of the fastener. Fasteners of that kind are satisfactory for many purposes, such as providing re-usable seals on plastic bags, but are unsuitable for other purposes as the two components can slide lengthwise relative to each other in use when the rib is engaged in the groove. In US-A-2 869 207 a slide fastener is disclosed which has substantially rigid components, for example metal or hard plastic, one of which has a groove with an internal lip which restricts its mouth, and the other of which has a rib which engages in the groove through the restricted mouth and has a slot to receive the lip to hold the rib in the groove. The rib is so shaped that relative angular movement of the components is required to manoeuvre the rib into and out of the groove. There is no flexing of either component. Another kind of fastener combines elements of both of the first two aforementioned kinds. Examples of that kind of fastener are described and illustrated in US-A-1 929 083 and FR-A-1 067 224 the latter forming the basis for the pre-characterising part of claim 1. Each of two components comprises a securing band with a fastening formation extending along one edge thereof. Each such formation comprises a row of teeth projecting from one face of the band. The teeth on the bands can be engaged and disengaged by relative movement between the bands in a direction normal to the planes of the bands. When the teeth are interengaged and tension is applied to the bands, separation of the formations is resisted or prevented either by the use of tapered teeth which lock more tightly together under the influence of the tension or by the provision of interengaging ribs and grooves which extend lengthwise of the bands, are brought into engagement when the teeth are engaged and are separated when the teeth are disengaged. That last kind of fastener suffers from a number of inherent limitations. The face-to-face relative movement of the fastening formations when applied to a garment, for example, means that the outer formation may have to be pushed quite firmly onto the inner formation during engagement, the pressure being taken by the wearer's body. Moreover, when a sliding clasp is employed (as in US-A-1 929 083) it may be of considerable thickness or depth. When the design is asymmetric the formations may well tilt or partially rotate when they are engaged and tension is applied to the bands, even though they remain engaged, which in the case of a fastener being used on clothing could cause discomfort for the wearer. The present invention aims to provide a form of fastener that enables those and other limitations to be overcome or at least reduced. In accordance with claim 1 the present invention consists in a progressively engageable elongate fastener comprising first and second components each made from a flexible and resilient material, the first component comprising a first engagement formation formed internally with a longitudinally extending groove having a longitudinally extending mouth; a first attachment portion extending laterally away from the first engagement formation; first abutment means; and a plurality of longitudinally spaced first mating formations; and the second component comprising a second engagement formation comprising a longitudinally extending rib shaped for insertion into the groove; a second attachment portion extending laterally away from the second engagement portion; second abutment means; and a plurality of longitudinally spaced second mating formations complementary to the first mating formations, characterised in that the first engagement formation is generally U-shaped in cross-section, having opposed side walls which define the groove between them and are relatively movable resiliently to enable the mouth of the groove to be widened; the first attachment portion extends away from the first engagement formation in a direction opposite to that to which the groove presents its mouth; the first mating formations are joined to at least one of the side walls and are presented in line with or parallel to that side wall; the first abutment means is provided on at least one of the side walls and has a first abutment face extending continuously longitudinally of the groove and facing into the groove away from the mouth; the rib has a narrowing outer extremity; the second abutment means is integral with the rib, is engageable in the groove adjacent to the mouth and has a continuous longitudinally extending second abutment face which is spaced from the outer extremity of the rib and opposes the first abutment face of the first abutment means when the rib is engaged in the groove, the combined cross-sectional shape of the second abutment means and the rib being closely complementary to that of the groove at least in the region adjacent to the mouth and of a width greater than the width of the mouth, the arrangement being such that the components can be engaged with each other by insertion of the rib and second abutment means into the groove, by way of the mouth, by relative lateral movement of the components, that engagement being accompanied by relative movement of the attachment parts towards each other, by resilient relative separating movement of the side walls of the first engagement formation to allow the rib and second abutment means to pass through the mouth and subsequent relative closing movement of the side walls towards one another to embrace closely the rib and second abutment means so as to resist relative movement of the components in directions transverse to the attachment parts, by interengagement of the first and second mating formations so as to preclude any significant relative longitudinal movement between the components, and by the resilient interlocking of the first and second abutment means so that their mutually opposed abutment faces interact to resist forces that may be applied to the fastener tending to separate the components by pulling the rib from the groove. The first and second components preferably have complementary sealing surfaces of elongate form which extend continuously longitudinally of the components and which come into engagement, when the components are engaged, to render the fastener at least substantially fluid-resistant. The first and second abutment means are preferably hook-shaped or undercut in cross-section to provide their abutment faces so that when the components are engaged with each other and forces are applied to the components tending to separate them by pulling the rib from the groove, their mutually opposed abutment faces interact so as to resist separation of the components. The mating formations of each of the first and second components may comprise a row of spaced projections with recesses between them, the arrangement being such that when the components are engaged the projections of each component are received in recesses in the other component, the mating formations of the first component being similarly shaped to the mating formations of the second component and the mating formations being so shaped that they interlock when the components are engaged and thus resist forces that may be applied to the fastener tending to separate the components. In one preferred design the mating formations of the first component are provided inside the groove, and the complementary mating formations of the second component are on the rib. In some designs of fastener, each of the components is of the same shape and form as the other. This makes it possible to manufacture only a single design of component and to form a fastener from two portions of the component. In some designs of fastener the attachment portion of each component is of planar shape and each component is symmetrical about the plane of its attachment portion. Preferably the attachment portions are of planar shape and, when the components are engaged with each other, lie in a common plane, said abutment faces extending on both sides of that common plane. Each of the two components is preferably formed from a plastics material. Each component may be made as a moulding but in a preferred arrangement at least one of the components is made in a process in which, in one step, material from which it is to be made is extruded through a die to form an extrusion and in a subsequent step the extrusion is shaped to afford mating formations. When the first component is made by that process, the extrusion may have portions that are initially spaced apart but in a subsequent step are brought closer together to form the side walls of the first engagement formation and define the groove in the component between the side walls. In the course of making the first component, the mating formations may be formed between the side wall portions before the groove-defining portions are brought to the positions they adopt in the finished component. The mating formations may be formed sequentially by applying at least one rotary die to the extrusion. The fastener is preferably provided with a slide that can be slid to and fro along the components and in so doing is operative to cause the engagement and disengagement of the components, the fastener and slide thus together constituting a slide fastener. A preferred method of making a component for a fastener in accordance with the invention comprises the steps of extruding material from which the component is to be made through a die to form an extrusion, and shaping the extrusion so that it affords mating formations. When it is the first component that is made by that method the extrusion preferably has spaced portions that in a subsequent step are brought closer together to form the side walls of the first engagement formation and define between them the groove in the component. The mating formations may be formed between the spaced portions before said subsequent step. In any of these methods, the mating formations are preferably formed by applying at least one rotary die to the extrusion. The attachment portion of a component may comprise a strip of flexible material by means of which the component may be attached to some other article such as a garment. That strip may be extruded in the first step. The strip and the engagement formation may be made from the same material but if desired one of them may be made of a material having properties different from those of the material from which the other is made. For example the strip may be made of a material which is harder or softer than the material from which the engagement formation is made. Where materials having different properties are employed in this way they may be simultaneously extruded during the first stage so that they become permanently united. The process may therefore be of the kind referred to as a co-extrusion process. Embodiments of the invention are illustrated, by way of example, in the accompanying drawings, in which:- Figure 1 is a perspective view of part of a first component of a fastener of a first design embodying the present invention, Figure 2 is a perspective view of part of a second component of that fastener, Figure 3 is a perspective view, to a smaller scale, of part of a fastener of the first design, incorporating components shown in Figures 1 and 2, Figures 4 to 6 are similar to Figures 1 to 3 respectively, but illustrate a fastener of a second design embodying the present invention, Figures 7 to 9 are also similar to Figures 1 to 3 respectively, but illustrate a fastener of a third design embodying the present invention, Figure 10 is a perspective view of an end piece that can be used with a fastener embodying the present invention and the outline of an end portion of a suitable fastener, Figure 11 is a perspective view of the end piece shown in Figure 10 from a different viewpoint, Figure 12 is a perspective view of a slide that forms part of a slide fastener embodying the present invention and of adjacent portions of first and second components of that slide fastener, said portions being illustrated only schematically, Figure 13 is a perspective view of the slide shown in Figure 12, from a different view point and with parts broken away and omitted for clarity, Figures 14 to 16 are similar to Figures 1 to 3 respectively but illustrate a fastener of a fourth design embodying the present invention, Figure 17 is a perspective view of a component of a fastener that can co-operate with a component of similar shape to form a fastener of a fifth design embodying the present invention, Figure 18 is a section, to a larger scale, along the line 18-18 of Figure 19, Figure 19 is a perspective view of a fastener comprising two components each similar to that shown in Figure 17, Figure 20 resembles part of Figure 17 but illustrates a modification, Figure 21 also resembles part of Figure 17 but illustrates another modification, Figures 22 and 23 are end views of other designs of fasteners, each in accordance with the present invention, and Figure 24 is a schematic view of plant for use in the manufacture of a fastener in accordance with the present invention. The fastener shown in Figure 3 comprises a first component 1 and a second component 2. The first component 1, of which a part is shown in detail in Figure 1, is of elongated form and is of uniform shape along its entire length. The component 1 is made from a thermoplastic material such as polyvinyl chloride, that is both flexible and resilient. The component comprises a strip 3 constituting an attachment portion. At one edge of the strip is an engagement formation comprising a body comprising parallel side walls 4 and 5 which define between them a groove 6. A lip 7 extends from the side wall 4 to a location part-way across the groove so as to leave an open mouth of the groove that is narrower than the interior of the groove. The lip 7, which constitutes an abutment formation, is of hook-shaped or undercut cross-section; it has an inner face 8 which constitutes an abutment face and is inclined at an acute angle to the adjacent face of the side wall from which the lip projects. An outer part of the lip 7 is chamfered, as shown at 9. The outer face of the side wall 5 is formed with mating formations 10 comprising a row of uniformly spaced projections 11 with recesses 12 between them, the recesses being of a size and shape such that they can receive similarly shaped projections on the second component 2, as described below. Each projection 11 has a stem terminating in a head which is broader than the stem, as shown. Part of the second component, 2, is shown in Figure 2. The component 2 is also of elongated form and is of uniform shape along its entire length. The component 2 is made from the same thermoplastic material as that used for making the component 1 and comprises an attachment portion in the form of a flexible strip 13, similar to the strip 2, at one edge of which is an engagement formation comprising a body 14 with a planar face 15 normal to the strip 13 and facing away from the strip. A rib 16 projects from a part of the face 15 spaced inwards from the edges of the face. An abutment 17 is formed on that edge of the wall remote from the body 14 and projects to one side of the rib. The abutment is so shaped as to be complementary to that of the first component 1; a lower face 18 of the abutment constitutes an abutment face and is inclined at an acute angle to the adjacent surface of the rib 16. Spaced away from the opposite side of the rib 16 there is a row of uniformly spaced mating formations 19 similar in shape to the mating formations 10 and stemming from the face 15 of the body 14. The components 1 and 2 can be engaged in the manner shown in Figure 3. The components can be urged into engagement by the movement of a slide (not shown) but the provision of a slide is not essential. During engagement the rib 16 engages the chamfered surface 9 and deflects the side wall 4 resiliently aside until the abutment 17 is entirely within the groove 6, whereupon the side wall 4 snaps back. At the same time the projections of each of the rows of mating formations 10 and 19 snap into the recesses of the other mating formation. The side wall 5 enters between the rib 16 and the mating formations 19. When the components 1 and 2 are fully engaged, any attempt to disengage them by exerting tension on the strips 3 and 13, so as to pull them away from each other and to pull the rib 16 from the groove 6, is positively resisted by the engagement between the faces 8 and 18. Moreover, the interlock between the mating formations 10 and 19, though less positive, also assists in resisting the disengagement of components. As the abutment face 8 of the lip 7 and the abutment face 18 of the abutment 17 are inclined (the inclinations in fact being equal), the engagement between those faces tends to urge the mouth towards a closed state and thus further to assist in resisting withdrawal of the rib from the groove. The components 1 and 2 can be progressively engaged and disengaged along their lengths as indicated in Figure 3, in which portions of the components to the right of the Figure are shown engaged together and portions of the components to the left are shown disengaged. In an intermediate zone the components are partially engaged. By suitable manipulation of the components the intermediate zone can be caused to progress either towards the left, until the components are fully engaged, or to the right, until the components are fully disengaged. This progressive engagement and disengagement can conveniently be effected with the aid of a slide generally similar to the slide of a conventional slide fastener. The slide may, for example, be of the kind described below and illustrated in Figures 12 and 13. As in a conventional slide fastener those parts of the components to one side of the slide are engaged and those parts to the other side are disengaged. The first component, 1, is made in a series of steps, the first of which is an extrusion process in which a blank is extruded. The blank comprises the strip 3 and portions that are subsequently to form the side walls 4 and 5 and the mating formations 10. Those portions are spaced apart, on opposite sides of the strip 3, and are substantially at right angles thereto. The abutment 7 is also formed in the extrusion process. In a second step of the process the mating formations 10 are sequentially formed from one portion of the blank. This shaping process may be effected by passing the portion of the blank between suitably shaped roller dies. In a third step the portions are brought into parallel relationship, as shown, so as to constitute the side walls 4 and 5 and the mating formations 10. The second component, 2, is made in a generally similar manner. In a first, extrusion step, the strip 13, body 14, rib 16 and abutment 17 are formed together with a second wall, which in a subsequent step is passed between suitably shaped roller dies to provide the mating formations 19. The thermoplastic materials from which the components are made are particularly suitable for the manufacture of the components in steps of the kind described. The techniques of extrusion are so well understood as to require no further description here, and likewise the passage of extruded material past a rotating die, while the material is still hot and capable of being formed by the die, is known in a technique referred to as post-forming. In the manufacture of the components, the material from which they are made is preferably retained at an appropriate temperature throughout the manufacture and cooled only when all the steps have been completed. Nevertheless, it would be possible to allow the extruded blank to cool and then to reheat it before it passes the rotating die. Turning now to the fastener components illustrated in Figures 4 to 6, Figure 4 shows a first component, 20, which co-operates with a second component, 21, shown in Figure 5. The first component,20, is in part similar to the first component 1 in that it has a strip 22 similar to the strip 3 and a body with side walls 23 each similar to the side wall 4 and provided with an abutment 24 similar to the abutment 7, apart from the absence of any chamfering. Mating formations 25 extend from the tops of the walls 23 and comprise teeth in the shape of blunt triangles, with spaces between the teeth of a shape similar to those of the teeth. The teeth are slightly tapered so as to be thinner at their crests than at their roots. The second component, 21, has a strip 26 similar to the strip 13 and a body 27 at one edge there of. The body comprises a central rib 28, constituting a continuation of the strip 26, with mating formations 29 on each side of it and with an abutment 30 at its free edge, spaced from the mating formations. The mating formations are of the same blunt triangular shape as the mating formations 25. The abutment 30 is of tapered cross-section and has inclined abutment faces 31 each similar to the abutment face 18. The components 20 and 21 can engage each other in the manner shown in Figure 6. When the components are urged together the narrow ridge of the tapered abutment 30 enters between the mating formations 25 and urges them resiliently apart. The side walls 23 are also urged apart and eventually the abutment 30 and part of the rib 28 are wholly contained within the groove between the side walls 23, whereupon the walls snap back into their original positions, and abutment faces of the abutments 24 engage the abutment surfaces 31 of the abutment 30 and resist disengagement of the components. At the same time that the rib is entering the groove the mating formations 25 and 29 interengage each other. The mating formations prevent relative longitudinal movement between the components but do not interlock. Resistance to disengagement of the components is therefore effected solely by the engagement between the abutments 24 and the abutment 30. As with the fastener shown in Figure 3, the fastener shown in Figure 6 can be caused to engage and disengage with the aid of a slide (not shown). The components 20 and 21 are made by multi-step processes, similar to those described above. In the first step blanks are extruded, and in a second step the mating formations are formed from the extruded blanks by passage past a rotating die. In the manufacture of the first component, 20, there is a third step in which the side walls 23 with their locking formations 25 are brought from a co-planar state to a parallel state. It is to be understood that, if desired, mating formations similar in profile to the mating formations 15 and 19 may be used in place of the mating formations 25 and 29. Conversely, mating formations similar in profile to the mating formations 25 and 29 may be used in place of the mating formations 10 and 19. The fastener components shown in Figures 7,8 and 9 are in part similar to the components described above with reference to Figures 1 to 6. A first component, 32, is shown in Figure 7 and a second component, 33, in Figure 8. The first component, 32, has a strip 34 constituting an attachment portion at one edge of which is formed an engagement formation comprising side walls 35 defining between them a groove 36. Each side wall has an inwardly directed abutment 37 of triangular cross-section, the lower or abutment face 38 of which is inclined so as to form an undercut, as shown. Mating formations 39 are provided near the bottom of the groove 36 and comprise part-circular teeth extending transversely of the groove. Each tooth is narrower at the crown than at the root. The second component, 33, comprises a strip 40, similar to the strip 34, with a rib 41 extending along one edge thereof. The rib is provided with lateral enlargements constituting abutments which fit into an inner part of the groove 36 and each of its lower faces or abutment faces 42 is inclined at an acute angle to the adjacent face of the rib so as to abut the adjacent abutment face 38. The rib 41 is formed with mating formations 43 complementary to the mating formations 39, those mating formations extending laterally into the abutments. The components 32 and 33 can be engaged and disengaged in the manner illustrated in Figure 9 with the aid of a slide. When the components are engaged the engagement between the abutment faces 38 and the abutment faces 42 resists any forces trying to pull the components apart, while the mating formations 39 and 43, which interengage each other, prevent relative longitudinal movement between the components. The components 32 and 33 are made in multi-step processes similar to those described above. Blanks are first formed by extrusion. Then the mating formations 39 and 43 are formed from the material of the blanks. Finally, in the case of the first component, 32, the side walls 35 are brought from the spaced state to the state illustrated in Figure 7. Any of the components described above with reference to the accompanying drawings may be modified in such a manner that the material from which the strip is formed is different from the material from which the remainder of the component is formed. This can be effected by means of the co-extrusion of the blanks. In each of the three embodiments of components illustrated, the fastener, when engaged, is water-proof or at least substantially water-proof, as it is difficult or impossible for the water to pass from one side of the faster to the other through the groove. In order to enhance the resistance to fluid flow, the arrangement may be such that when the components are engaged there is no free play possible between them; in addition, one of the components may be resiliently deformed so as to bear positively on the other to provide a seal. As with conventional slide fasteners, the two components may be permanently secured together at one end of the fasteners. This may be achieved by anchoring adjacent end portions of the components in an end piece. A suitable end piece 44 is shown in Figures 10 and 11 and comprises a unitary moulding of a plastics material. The end piece is of grooved shape to receive the end portions of the engaged components. A central part 45 of the end piece is of greater width than side parts 46. The walls of the central part are formed with barb-like projections 47 which allow the end of the components to be inserted into the central part but strongly resist their withdrawal. The central part 45 is formed with an opening 48, at the bottom of the groove. When the end piece is being moulded, a tool extends through the opening 48 and defines the end faces of the projections 47. Figure 10 includes an outline of an end portion of a pair of components engaged together. Strips 49 thereof enter the side parts 46 of the end piece, and the thicker part 50 between the strips enters the central part 45. The end piece may be adhesively secured in position. A slide 51 is shown in Figures 12 and 13 and is of substantially conventional form comprising a body 52 and a pull-tag 53 pivoted to the body. The body comprises a pair of parallel plates 54 broader at one end than the other and spaced apart by a pillar 55 nearer the broader ends of the plates. Flanges 56 at the side edges of one plate are directed towards similar flanges on the other plate but there are gaps remaining between the adjacent flanges. A transverse hole through the pull-tag 53 receives trunnions 57 mounted on one of the plates 54. Figure 12 shows, somewhat diagrammatically, parts of two components 58 and 59 each with a strip 60 and thicker portion 61 extending along one edge thereof. The thicker portions may be shaped in any of the ways described above so that they can be engaged and disengaged. The pillar 55 extends between the components, which are therefore disengaged, but the thicker portions are held against the pillar by the adjacent parts of the flanges 56. At the narrower ends of the plates 54 the adjacent parts of the flanges hold the thicker portions in engagement. Longitudinal movement of the slide relative to the components causes progressive engagement or disengagement of the components as in a conventional slide fastener. A fourth design of fastener is illustrated in Figures 14 to 16 and comprises two components 62 and 63. The components are generally similar to those described above and illustrated in Figures 1 to 9 but differ in detail. The component 62 comprises a strip 64 at one edge of which is a body comprising parallel side walls 65 and 66 which define between them a groove 67. Wall 65 is formed with an abutment 68, while wall 66 is formed with mating formations 69. Component 63 comprises a strip 70 with a body 71 at one edge from which projects a wall 72. A portion 74 constituting both rib and abutment projects from an outer part of the wall and leaves a groove 73 between that portion and the body 71. Mating formations 75 are provided on the opposite side of the portion 74 from the groove 73. When the components 62 and 63 are engaged, the portion 74 enters the groove 67, the mating formations 69 and 75 interengage, and the abutment 68 enters the groove 73. Abutment faces on the two abutments abut each other when the components are engaged. As with the fasteners described above, the fastener shown in Figure 16 may be operated with a slide. Figures 17 to 19 illustrate a fifth design of fastener. The fastener comprises two components of identical shape so that each may be considered as constituting a first component and a second component. The component 83 shown in Figure 17 comprises a strip 84 formed at one edge with spaced parallel walls 85 and 86. The wall 85 constitutes a rib, and the inner face of the wall 85 is formed with mating formations 87, while the outer face of wall 85 is formed with an abutment 89. Wall 86 is taller than wall 85 and carries at its free edge an abutment 88 that is offset from the wall towards the wall 85. The walls 85 and 86 define a groove. As shown in Figure 18, two components, each similar to the component 83, can together constitute a fastener. When the components are engaged, the rib 85 on each component enters the groove in the other component, while abutment faces of the abutments 88 and 89 interengage. If tension is applied to the strips, engagement between the abutments prevents the components separating. If desired the mutually abutting abutment faces may be undercut, like faces 8 and 18 in Figures 1 and 2, further to resist separation. The fastener, like those described above, may be operated with a slide. Figures 20 and 21 illustrate alternative shapes of mating formations, 90 and 91 respectively, either of which may be used in place of the mating formations 87. Each of Figures 22 and 23 shows in end view a different form of fastener embodying the invention, interengaging mating formations being illustrated by a quadrilateral with a cross in it. Each fastener comprises a first component and a second component each of which is generally similar to the components described above. The fastener of Figure 22 has a first component 97 formed with a groove 98 which receives a rib 99 on a second component 100. Mating formations 101 as well as mutually abutting abutments are formed on the components. Finally, the fastener of Figure 23 comprises first and second components 113 and 114 which are of identical shape and form. Each has mating formations 115 lying between a groove and a rib 116 that enters the groove in the other component and carries abutments which engage complementary abutments projecting laterally into the mouth of the groove. Although a wide variety of fasteners in accordance with the invention have been described, it will be apparent that other variations are possible. In particular, features of some of the fasteners described and illustrated can be substituted for the corresponding features of others of the fasteners in order to yield yet further designs of fasteners. In each instance, the fasteners may be used with or without slides, as desired. Further, in each instance, the strip constituting part of a component may be formed from a material different from that from which the remainder of the fastener, or engagement formation, is formed. Figure 24 is a schematic illustration of plant suitable for use in making a fastener in accordance with the present invention. The plant is shown as having a first line 117 for making a first component and a second line 118 for making a second component. The lines are similar, and each comprises a source 119 of granular plastics material that is fed to a variable-speed extruder 120 which extrudes a blank of suitably shaped cross-section, as outlined above. This is cooled in passing through a primary cooler 121 from which it emerges in a self-supporting state. That portion of the blank that is to be further shaped is then heated by rotary heaters 122, using a combination of radiant and contact heating. The blank next passes a forming wheel or rotary die 123, which is cooled so that the mating formations are created in the blank and set in one forming operation. The blank passes next through a final cooler 124 which removes all residual heat. The two blanks from the two lines are caused to engage each other as they pass through a combiner 125 somewhat similar in construction to a slide. The engaged fastener is pulled through the combiner between power-driven endless bands 126. The fastener is cut into lengths by a rotary fly knife 127. Finally the straightness of the fastener is gauged by an optical device 128 incorporating photo-cells. Information from the device is passed to a control system (not shown) which generates signals which vary the rate of operation of the extruders 120 and the rate of rotation of the forming wheels 123 and the rate of movement of the bands 126. Variation in the relative speed of the motor driving one of the forming wheels 123 and the motor driving the bands 126 varies the extent to which the component concerned is stretched and thus varies the spacing between the mating formations of that component. The finished fasteners are stacked at 129. Although it is not illustrated, there may be shaping means operative to shape a component after it has passed the forming wheel 123. When shaping means is employed, the extruded blank is of a cross-section such that the portion of the blank on or in which the mating formations are to be formed is so presented as to be readily accessible to the rotary die. After the mating formations have been formed, the shaping means then operates to bring the parts of the component into the relative positions that they will occupy in the completed component. The shaping means may comprise a stationary guide which progressively causes the reshaping of the component as the component moves past it. Any of the fasteners described above with reference to the accompanying drawings may be made by a process of the kind described. It will be appreciated that in each embodiment, longitudinally extending surfaces of the components engage each other, when the components are engaged, and form a seal which renders the fastener at least substantially fluid-resistant. The arrangement is preferably such that, when the components are engaged, those sealing surfaces do not merely touch each other but are urged into contact with each other as the result of resilient deformation of at least one of the components.

Claims: A progressively engageable elongate fastener comprising a first component (1;20;32;62;83;97;113) and a second component (2;21;33;63;83;100;114) each made from a flexible and resilient material, the first component comprising a first engagement formation formed internally with a longitudinally extending groove (6;36;67;98) having a longitudinally extending mouth; a first attachment portion (3;22;34;49;60;64;84), extending laterally away from the first engagement formation; first abutment means (7;24;37;68;88); and a plurality of longitudinally spaced first mating formations (10;25;39;69;87;90;91;101;115); and the second component (2;21;33;63;83;100;114) comprising a second engagement formation comprising a longitudinally extending rib (16;28;41;74;85;86;99;116) shaped for insertion into the groove; a second attachment portion (13;26;40;49;60;70;84) extending laterally away from the second engagement formation; second abutment means (17;30;42;74;89); and a plurality of longitudinally spaced second mating formations (19;29;43;75;87;90;91;101;115) complementary to the first mating formations, characterised in that the first engagement formation is generally U-shaped in cross-section, having opposed side walls (4,5;23;35;66,67;85,86) which define the groove between them and are relatively movable resiliently to enable the mouth of the groove to be widened; the first attachment portion extends away from the first engagement formation in a direction opposite to that to which the groove presents its mouth; the first mating formations are joined to at least one of the side walls and are presented in line with or parallel to that side wall; the first abutment means is provided on at least one of the side walls and has a first abutment face (8;38) extending continuously longitudinally of the groove and facing into the groove away from the mouth; the rib has a narrowing outer extremity; the second abutment means is integral with the rib, is engageable in the groove adjacent to the mouth, and has a continuous longitudinally extending second abutment face (18;31;42) which is spaced from the outer extremity of the rib and opposes the first abutment face of the first abutment means when the rib is engaged in the groove, the combined cross-sectional shape of the second abutment means and the rib being closely complementary to that of the groove at least in the region adjacent to the mouth and of a width greater than the width of the mouth, the arrangement being such that the components can be engaged with each other by insertion of the rib and second abutment means into the groove, by way of the mouth, by relative lateral movement of the components, the engagement being accompanied by relative movement of the attachment parts towards each other, by resilient relative separating movement of the side walls of the first engagement formation to allow the rib and second abutment means to pass through the mouth and subsequent relative closing movement of the side walls towards one another to embrace closely the rib and second abutment means so as to resist relative movement of the components in directions transverse to the attachment parts, by interengagement of the first and second mating formations so as to preclude any significant relative longitudinal movement between the components, and by the resilient interlocking of the first and second abutment means so that their mutually opposed first and second abutment faces interact to resist forces that may be applied to the fastener tending to separate the components by pulling the rib from the groove. A fastener according to claim 1 characterised in that the first and second components have complementary sealing surfaces of elongate form which extend continuously longitudinally of the components and which come into engagement, when the components are engaged, to render the fastener at least substantially fluid-resistant. A fastener according to claim 1 or claim 2 characterised in that the first and second abutment means are hook-shaped or undercut in cross-section to provide their abutment faces so that when the components are engaged with each other and forces are applied to the components tending to separate them by pulling the rib from the groove, their mutually opposed abutment faces interact so as to resist separation of the components. A fastener according to any one of the preceding claims characterised in that the mating formations of each of the first and second components comprise a row of spaced projections with recesses between them, the arrangement being such that when the components are engaged the projections of each component are received in recesses in the other component, the mating formations (10;90) of the first component being similarly shaped to the mating formations (19;90) of the second component and the mating formations being so shaped that they interlock when the components are engaged and thus resist forces that may be applied to the fastener tending to separate the components. A fastener according to any one of the preceding claims characterised in that the mating formations (39;87;90;91;101) of the first component (32;83;97) are provided inside the groove, and the complementary mating formations (43;87;90;91;101) of the second component (33;83;100) are on the rib. A fastener according to any one of the preceding claims characterised in that each of the components (83;113,114) is of the same shape and form as the other. A fastener according to any one of claims 1 to 5 characterised in that the attachment portion of each component (22,26;34,40) is of planar shape and each component (20,21;32,33) is symmetrical about the plane of its attachment portion. A fastener according to any one of the preceding claims characterised in that the attachment portions are of planar shape and, when the components are engaged with each other, lie in a common plane, said abutment faces extending on both sides of that common plane. A fastener according to any one of the preceding claims characterised that it is in combination with a slide (51) that can be slid to and fro along the components and in so doing is operative to cause the engagement and disengagement of the components by relative lateral linear movement of the components, the fastener and slide thus together constituting a slide fastener. A method of making a component for a fastener in accordance with any one of the preceding claims, characterised in that it comprises the steps of extruding material from which the component is to be made through a die to form an extrusion, and shaping the extrusion so that it affords mating formations. A method according to claim 10 characterised in that it is the first component that is made by the method, and in which the extrusion has spaced portions that in a subsequent step are brought closer together to form the side walls of the first engagement formation and define between them the groove in the component. A method according to claim 11 characterised in that the mating formations are formed between said spaced portions before said subsequent step. A method according to any one of claims 10 to 12 characterised in that the mating formations are formed by applying at least one rotary die (123) to the extrusion.

Inventors: CLARK, DAVID FRANCIS
Applicants: ANDERSON, ALISON ELIZABETH, CLARK, DAVID FRANCIS
Application year: 1988
Main classification: A44B19
IPC codes: A44B19, B65D33, B29D5, F16B5