US3806998A

US3806998A - Elastically flexible fastener

Info

Publication number: US3806998A
Application number: US00150329A
Authority: US
Inventors: L Laguerre
Original assignee: Minigrip Inc
Current assignee: Minigrip Inc
Priority date: 1971-02-22
Filing date: 1971-06-07
Publication date: 1974-04-30
Anticipated expiration: 1991-04-30
Also published as: BE779045A; LU64822A1; FR2126060B1; FR2126060A1

Abstract

An elastically flexible fastener is provided with separable fastening structure carrying flanges having respective shoulder ribs which normally project to a spacing greater than the spacing between inside surfaces of slider walls and deflectable toward one another to be received between the slider walls and in retaining engagement with slider shoulder structures. Assembly of the slider with the fastener is adapted to be effected by snapping the slider into position by relative transverse assembly movement wherein the slider shoulder structures deflect the fastener shoulder ribs inwardly until the slider shoulder structures have cleared the ribs, whereupon the ribs snap resiliently into engagement with the slider shoulder structures.

Description

United States Patent [191 Laguerre 1 ELASTICALLY FLEXIBLE FASTENER [75] Inventor: Leon Ker Laguerre,

Boulogne-sur-Seine, France [73] Assignee: Minigrip, lnc., Orangeburg, NY.

[22] Filed: June 7, 1971 [21] Appl. No.: 150,329

[30] Foreign Application Priority Data [451 Apr. 30', 1974 3,634,913 l/l972 Ausnit 24/201 C FOREIGN PATENTS OR APPLICATIONS 257,510 10/1967 Austria 24/201 C Primary Eraminen-Bemtard A. Gelak ABSTRACT An elastically flexible fastener is provided with separable fastening structure carrying flanges having respective shoulder ribs which normally project to a spacing greater than the spacing between inside surfaces of slider walls and deflectable toward one another to be received between the slider walls and in retaining engagement with slider shoulder structures. Assembly of the slider with the fastener is adapted to be effected by snapping the slider into position by relative transverse assembly movement wherein the slider shoulder structures deflect the fastener shoulder ribs inwardly until the slider shoulder structures have cleared the ribs, whereupon the ribs snap resiliently into engagement with the slider shoulder structures.

12 Claims, 3 Drawing Figures ELASTICALLY FLEXIBLE FASTENER This invention relates to elastically flexible fasteners and method of assembling sliders therewith and is more particularly concerned with an arrangement in which the slider is adapted to be assembled with the fastener by a relative transverse maneuver as compared to conventional endwise assembly.

In my US. Pat. No. 3,426,396, I have disclosed a slider which is adapted to be assembled with a fastener by relative transverse assembly maneuver, but wherein the slider has flexible side walls to enable clearance of inwardly projecting shoulders along free edges of the slider walls to clear past the body of the fastener into engagement with generally undercut shoulders on the fastener strips and wherein such shoulders are nroamlly conformed to seat on the shoulder structures or noses on the slider walls. Such an arrangement is excellent where the fastener strips are of the multi-interlocking rib and groove type in which the fastener strips assemble together into a substantially solid mass. In such an arrangement after the slider has been assembled with the fastener excellent retention of the slider against displacement from the fastener by forces acting in a transverse separating direction is attained.

However, there are types of elastically flexible fasteners in which there is not the relatively solid body backing, so that after the slider has been mounted on the fastener, there may be a tendency for the slider to separate or come off of the track due to undue flexibility in the area of the shoulder means on the fastener which thus can yield inwardly and slip off of the shoulder or nose structure on the slider walls. It is to the alleviation and solving of this problem that the present invention is particularly directed.

An important object of the present invention is to provide a new and improved elastically flexible fastener expecially equipped for efficient assembly with a slider assembled therewith by a relative transverse maneuver.

Another object of the invention is to provide a separable elastically flexible fastener having new and improved means for retaining cooperation with a slider.

A further object of the invention is to provide a new and improved separable elastically flexible fastener having novel shoulder means thereon for secure interengagement with shoulders on a slider.

Still another object of the invention is to provide a new and improved method of assembling a separable elastically flexible fastener and a slider.

Other objects, features and advantages of the invention will be readily apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawing, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts embodied in the disclosure, and in which:

FIG. 1 is a transverse sectional view through a separable elastically flexible fastener embodying features of the invention;

FIG. 2 is a similar view of the fastener illustrating the method of assembling a slider therewith; and

FIG. 3 is a similar sectional view of the fastener showing the slider fully assembled therewith.

By way of example, a separable elastically flexible fastener of the type generally represented by the disclosure in US Pat. No. 3,347,298 has been depicted in the drawing and includes (FIG. 1) a rib element part 5 separably receivable in a groove element part 7. These parts are integrally carried respectively on inner faces of and between aligned lower and upper sections of spaced generally

parallel flange portions

8 and 9, which are of generally the same thickness. While the

flange portions

8 and 9 may be fastener strips adapted to be secured in a suitable manner to flexible walls of a reclosable container, these flanges may be the actual integral marginal portions of such walls. In any event, the separably interlocking complementary profiled fastening structure andthe flange portions 8 and are adapted to be integrally extruded from suitable synthetic plastic material providing an elastically, resiliently flexible construction.

For separable interlocking of the rib element 5 with the groove element 7, the rib element is of generally arrow-shape in transverse cross section including a head 10 comprising interlock shoulder hook portions 1 1 and 12 generally convergently related to provide a cam ridge 13 generally aligned with a stem flange 14 by which the head is connected in spaced relation with respect to the supporting flange portion 8. At their surfaces nearest the connecting stem flange 14, the shoulder portions 11 and 12 define reentrant angles therewith providing interlock hooks engageable-with interlock hook flanges l5 and 17 respectively of the groove element 7. Said hook flanges generally converge toward one another and are spread open to receive the head 10 therebetween when said head is pressed into said groove-element 7 until the head is fully received in a groove 18 of said groove element 7 generally complementary to the head and within which the head is interlocked by interengagement of the head shoulder hook portions 1 1 and 12 and the

groove hook flanges

15 and 17. Through this arrangement, as indicated, the head and

groove elements

5 and 7 are adapted to be interlockingly engaged by being pressed together and to be separated when forcably pulled apart, as by means of a generally U-shaped slider 19 (FIGS. 2 and 3).

By preference, the slider 19 is of the kind described din my US. Pat. No. 3,426,396, including a flat back plate 20 adapted to run along free edges 21 on the upper ends of the sections of the

flange portions

8 and 9 as shown in the-drawing. Integrally formed with the back plate 20 and extending in the same direction (downwardly as shown) therefrom are respective coextensive side walls 22 with an intermediate spreader finger 23 extending in the same direction as the side walls at one end of the slider. It will be appreciated, of course, that the side walls 22 are in the form of panels which are laterally divergent from a narrower end of the slider where the

flange portions

8 and 9 are in the nearest approach to one another with the profiled interlocking complementary fastening structure fully interengaged, to a maximum width at the opposite end of the slider where the separating finger 23 is located, and the fastening structure rib and groove elements separated thereby. Thus, a movement of the slider 19 along the elastically flexible fastener in one direction causes the fastener to be closed and movement of the slider along the fastener in the opposite direction causes the fastener to be opened.

In order to retain the slider 19 against transverse displacement from the fastener, that is, against displacement away from the edges 21, the slider walls 22 are each provided with an inwardly projecting shoudler structure 24 flange adapted to engage

respective shoulder ribs

25 and 27 on respectively outer sides of the lower sections of the

flange portions

8 and 9. In a desirable arrangement, the shoulder flanges 24 are inwardly projecting nose flange formations on the terminal or free end portions of the side walls 22 having respective substantially flat shoulder surfaces 28 which extend generally perpendicularly inwardly from the inner surfaces of the side walls 22 and face toward and are parallel with the inner surface of the body plate 20 and against which generally complementary confronting shoulder surfaces 29 on the

shoulder ribs

25 and 27 are engaged in the assembly. Although the shoulder flanges 24 may be provided at either end of the slider 19, a preferred location is at the narrow end where maximum assurance against unintentional pulling of the slider away from the fastener is had because the fastener is fully closed and closely confined by the slider walls 22. This is also desirable where the fastener does not have additional nose flanges located on the separating finger that engage under the

fastener parts

5 and 7 at the wider end of the slider.

Substantial improvement in retention of the slider 19 on the fastener is attained by having the

shoulder ribs

25 and 27 constructed and arranged to be biased firmly into the reentrant angle defined by the respective shoulder surface 28 and the adjacent inner wall surface of the slider. To this end, the

ribs

25 and 27, when not in engagement with the slider, normally project to a spacing which is greater than the spacing between the inside surfaces of the slider walls 22 at least adjacent to the shoulder flanges 24. When the slider is transversely moved over the fastener, the ribs are compressively deflected inwardly toward one another to be finally received in outwardly thrusting relation between the slider walls and in retaining engagement with the slider shoulder structures.

The ribs are so designed that their outward thrust, when engaged by the slider walls, is not great enough to impair the movement of the slider along the fastener. The desirable construction of the

shoulder ribs

25 and 27, for this purpose, is as shown in FIG. 1, wherein said ribs are progressively slanted from their fastener strip flange portions to their respective shoulder surfaces 29, so that in each instance said surface is normally at an angle calculated to engage firmly and uniformly with the confronting slider shoulder surface 28 when the angle A is flattened out to become substantially parallel with the engaging surface of the associated slider side wall 22, as best seen in FIG. 3. Advantageously, the progressive thickening of the

ribs

25 and 27 toward the shoulders 29, and the consequent progressive resilient stiffening given to the shoulders increases up to the re-. quired limit the outward thrust pressure under compression in the full assembly, as the mass of material in the shoulders tends to spring back toward normal.

A further advantage of having the shoulder ribs 25 and 27 slanted along the angles A, generally away from the edges 21 is that in applying the slider 19 to the fastener by transverse assembly, the shoulder flanges 24 can without undue resistance press the

ribs

25 and 27 inwardly toward one another, as shown in FIG. 2 until the shoulder surfaces 28 have cleared and receive the rib shoulder surfaces 29. To facilitate this action, the surfaces of the shoulder flanges 24 which face in the opposite downward direction relative to the shoulder surfaces 28 are desirably formed to provide lead-in respective slanting cam surfaces 30 which may be rounded as shown. At the ends where the slider side walls 22 have their greatest resiliency, passage of the shoulder structures 24 past

theshoulder ribs

25 and 27 is further eased by expansible yielding of this part of the slider walls in response to resistance to pressing of the shoulder ribs inwardly beyond the respective normal planes of the inner surfaces of the slider side walls. Additional means to ease the assembly interengagement is afforded by respective relief slots 31 extending into the rib shoulders 29 aligned with the normal adjacent surface of the

respective flange portion

8 or 9. These longitudinal slots 31 are also advantageous during the extrusion molding of the strips to avoid pulling-in deformation of the rib structure due to shrinkage in the setting or curing of the material.

Another feature in avoiding undue resistance to movement of the slider 19 into assembly with the fastener, comprises having the

shoulder rib structures

25 and 27 located on the lower sections of the

flange portions

8 and 9 below the complementary profiled fastening structure parts so as to permit relative inward displacement of the lower sections of the

flange portions

8 and 9 in the rib areas thereof under and toward the fastening structure parts with some clearance. For example, as indicated in FIG. 1, the clearance afforded for this purpose is represented by the angular lines B. In the normal, undefomed condition of the fastener

strip flange portions

8 and 9, the angles which are represented by the lines B and extending from the same point on the outer surfaces of the

flange portions

8 and 9 as the angles A, are greater than the angles A, considered with respect to the flange portion outer surfaces, so that as the rib areas of the flange portions are deflected inwardly toward one another generally about axes at the convergence of the angles A and B there will be minimum pressure against the fastening structure profiles during assembly, and until the shoulder ribs have snapped into theirinterlocking relation with the slider on the fastener, the rib areasof the

flange portions

8 and 9 while remaining inwardly deflected will remain free from pressing against the adjacent profiled fastening structure, thus avoiding excess pressure against the slider walls and enabling easy normal functioning of the slider along the length of the fastener. This relationship is enhanced by having the

shoulder ribs

25 and 27 respectively of less thickness than clearance spacing between the

fastening structure

5, 7 and the inner sides of those lower sections of the

flange portions

8 and 9 carrying the shoulder ribs.

Although the slider 19 may be molded from a semihard plastic, wherein the side walls 22 are stiffly resiliently flexible at least sufficient to enable spreading apart of the terminal portions of the side walls when the shoulder structures 24 are moved transversely in engagement with the

flange portions

8 and 9 past the profiled engaged fastening structure and the

ribs

25 and 27, it may be desirable to form the slider 19 from metal as a die casting or molding, or to mold the same from a hard synthetic plastic material such as one of the thermo-setting materials. Where the profiled fastening structure of the fastener is of the type particularly selected for illustrative purposes herein, there is enough yieldability in the connecting web flange l4 and adjacent portions of the fastening structure to enable sufficient elastic deformation-while moving the slider shoulder flanges 24 past the fastening structure along the

flange portions

8 and 9 for transverse relative assembly movement, even though the shoulder flanges 24 do not yield during the assembly action.

After full assembly of the slider 19 with the fastener has been effected, not only does the resilience of the mass of the

shoulder ribs

25 and 27 and the contiguous area of the

flange portions

8 and 9 function to maintain a firm interlocked relation to the shoulder flanges 24 of the slider, but the adjacency of the inner surfaces of the

flange portions

8 and 9 to the adjacent portion of the groove element 7 also serves to impede back-off of the shoulder ribs, because to escape the shoulder flanges 24, the deflection of the

flange portions

8 and 9 must be to the extent of causing compression of the adjacent portion of the hook element 7 as shown in FIG. 2, thus adding the resistance to deformation of that portion of the element 7 to the resistance to deflectional deformation of the

flange portions

8 and 9 and the

ribs

25 and 27. In addition, by reason of the partial separation of the

ribs

25 and 27 by the slots 31, even though compressively closed in the assembled relationship of the parts, the shoulder ribs can remain in their interlocking relation to the slider shoulder flanges 24 while permitting free deflectional yielding of the flange lower sections'of the

portions

8 and 9 below the ribs to a substantial extent as indicated in dash outline, for example, in FIG. 3 without affecting the shoulder ribs. Pulling forces on the

flange portions

8 and 9 are also more effectively resisted because of the separation effected by the slots 31 because the shouldering portions of the ribs by compressing against the shoulder flanges 24 develop increasing resistance to release from the shoulder portions as the pulling force increases.

An additional advantage of ribs and 27, is, that if properly designed, when they are in assembled relationship with the slider, they keep the lower part of the

flanges

8 and 9 away from slider shoulder structure

inner edge tips

32 and 33, which have a tendency to cut the flanges when moved back and forth in normal use. This can be accomplished by having the ribs thicker than the width of the shoulder structures. As shown, the lower slanting surfaces of the slider flanges 24 extend generally outwardly from the respective

inner edges

32 and 33.

It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.

I claim:

1. A flexible fastener of the kind having separably interlocking complementary profiled fastening structure adjacent to free edges of flange portions, and a fastener closing and opening slider of generally U-shape straddling said free edges and having side walls along said flange portions each' provided with an inwardly projecting slider flange the improvement comprising respective shoulder ribs on outer sides of said flange portions spaced from said free edges and engaged by said slider shoulder flanges;

said ribs normally projecting to a spaced relation which is greater than the spacing between inside surfaces of said slider walls adjacent to said shoulder flanges and being compressibly resiliently deflected inwardly toward one another by said walls into conformity with said spacing;

said ribs being located below said fastening structure and having respective outer surface which slant from the associated flange portion outer sides; and

sufficient clearance being provided between the inner sides of said flange portions in the parts thereof aligned with said shoulder ribs to enable deflection of said parts inwardly to angles greater than the slanting angle of said outer surfaces when the ribs are inwardly deflected.-

2. A flexible fastener of the kind having separably interlocking complementary profiled fastening structure adjacent to free edges of flange portions, and a fastener closing and opening slider of generally U-shape straddling said free edges and having side walls along said flange portions each provided with an inwardly projecting slider flange, the improvement comprising respective shoulder ribs on outer sides of said flange portions spaced from said free edges and engaged by said slider shoulder flanges;

said ribs normally projecting to a spaced relation which is greater than the spacing between inside surfaces of said slider walls adjacent to said shoulder flanges and being compressibly resiliently deflected inwardly toward one another by said walls into conformity with said spacing; and

said ribs slanting generally away from said edges and becoming progressively thicker, terminating in shoulders which face generally away from said edges to engage said flanges.

3. A, fastener according to claim 2, in which said shoulders normally extend relatively divergently to the associated flange portions and are moved into alignment with said free flange edges but facing in the opposite direction when in engagement with said shoulder structures.

4. A flexible fastener of the kind having separably interlocking complementary profiled fastening structures adjacent to free edges of flange portions from which the fastening structures project toward one another, and a slider of generally U-shape assembled with the fastener and having side walls each provided with an inwardly projecting shoulder flange on the free marginal portion of the side wall, comprising:

respective ribs on outer sides of said flange portions spaced from said free edges;

said ribs being compressibly deflected inwardly toward one another from a greater spacing than the spacing between the inside surfaces of said slider walls;

said ribs received in limited outwardly thrusting relation between and against said slider walls and in retaining engagement with said shoulder flanges; said ribs having slider-wall engaging surfaces which in normal uncompressed condition of the ribs slant outwardly and generally away from said free edges whereby to facilitate assembling of the slider onto the fastener by a relative transverse assembly movement toward said edges and along said flange portions and with said shoulder flanges camming along said surfaces and thereby compressibly deflecting the ribs inwardly toward one another; and said ribs having shoulders thereon which in the full assembly of the slider with the fastener are retainingly engaged with said shoulder flanges; said rib shoulders comprising surfaces which in the uncompressed condition of the ribs slant outwardly and generally toward said edges at an angle which enables substantially square face-to-face engagement between said rib shoulders and corresponding shoulder surfaces on said shoulder flanges of the slider. 5. A flexible fastener of the kind having separably interlocking complementary profiled faening structure and a fastener closing and opening slider of generally U-shape having a back plate and. spaced side walls each provided with a single inwardly projecting slider flange, and wherein:

said fastener comprises a pair of spaced generally parallel flange portions each having an inner face and an outer face and each carrying on its inner face a respective part of the fastening structure:

each of said flange portions having an upper section extending upwardly from the associated fastener part to a respective free edge and a lower section extending downwardly relative to the associated fastener part, and said sections of each flange portion being aligned and of generally the same thickness;

respective fastener-retaining ribs on the outer faces of said lower flange sections and said ribs being located below the fastening structures;

said ribs having respective surfaces facing generally upwardly;

said slider back plate engaging said free edges and said side walls engaging the outer facesof said flange sections;

an inwardly projecting flange on each of said slider side walls provided with a substantially flat shoulder surface extending generally perpendicularly inwardly from the inner surface of the side wall and terminating at a terminous inner edge which is adjacent to the associated lower flange section;

each of said slider flanges having a lower surface extending generally outwardly from said inner edge;

at least one of said rib surface and said lower slider flange surface at each side of the fastener and slider providing a slanting cam face tofacilitate slipping of the slider flanges past said ribs during lateral assembly of the slider over the fastener; and

said lower flange sections with said ribs being swingably deflectable inwardly under and toward the fastener parts and thereby facilitating inward compressible deflection of the lower flange sections and the ribs for passage of the slider flanges past the ribs I during said lateral assembly and then spring back to effect biased outward thrust of the ribs into retaining engagement with said slider flange shoulder surfaces.

6. A flexible fastener according to claim 5, in which said ribs are thicker than the inwardly extending length of said slider shoulder flanges so that the inner edges of said shoulder flanges will remain spaced from the adjacent outer sides of said lower flange portion sections.

7. A flexible fastener according to claim 5, wherein the inwardly deflected lower flange sections engage with the fastening structure and thpreby assist in maintaining said ribs in retainingengagement with said slider flange shoulder surfaces.

8. A flexible fastener according to claim 5, wherein said ribs are partially separated from said lower flange sections so that said lower flange sections can be freely flexed away from the ribs at the separations without tending to displace the ribs from said slider flange shoulder surfaces.

9. A flexible fastener according to claim 5, wherein said rib surfaces provide said cam faces.

10. A flexible fastener according to claim 5,'wherein said slider' flange lower surfaces provide said cam faces.

11. A flexible fastener according to claim 5, wherein said cam faces are provided by both said rib surfaces and said slider flange lower surfaces.

12. A flexible fastener according to claim 5, wherein said ribs have shoulder surfaces which are complementary to and in the retaining engagement with said slider flange surfaces engage flat against the slider flange shoulder surfaces.

Claims

1. A flexible fastener of the kind having separably interlocking complementary profiled fastening structure adjacent to free edges of flange portions, and a fastener closing and opening slider of generally U-shape straddling said free edges and having side walls along said flange portions each provided with an inwardly projecting slider flange the improvement comprising respective shoulder ribs on outer sides of said flange portions spaced from said free edges and engaged by said slider shoulder flanges; said ribs normally projecting to a spaced relation which is greater than the spacing between inside surfaces of said slider walls adjacent to said shoulder flanges and being compressibly resiliently deflected inwardly toward one another by said walls into conformity with said spacing; said ribs being located below said fastening structure and having respective outer surface which slant from the associated flange portion outer sides; and sufficient clearance being provided between the inner sides of said flange portions in the parts thereof aligned with said shoulder ribs to enable deflection of said parts inwardly to angles greater than the slanting angle of said outer surfaces when the ribs are inwardly deflected.

2. A flexible fastener of the kind having separably interlocking complementary profiled fastening structure adjacent to free edges of flange portions, and a fastener closing and opening slider of generally U-shape straddling said free edges and having side walls along said flange portions each provided with an inwardly projecting slider flange, the improvement comprising respective shoulder ribs on outer sides of said flange portions spaced from said free edges and engaged by said slider shoulder flanges; said ribs normally projecting to a spaced relation which is greater than the spacing between inside surfaces of said slider walls adjacent to said shoulder flanges and being compressibly resiliently deflected inwardly toward one another by said walls into conformity with said spacing; and said ribS slanting generally away from said edges and becoming progressively thicker, terminating in shoulders which face generally away from said edges to engage said flanges.

3. A fastener according to claim 2, in which said shoulders normally extend relatively divergently to the associated flange portions and are moved into alignment with said free flange edges but facing in the opposite direction when in engagement with said shoulder structures.

4. A flexible fastener of the kind having separably interlocking complementary profiled fastening structures adjacent to free edges of flange portions from which the fastening structures project toward one another, and a slider of generally U-shape assembled with the fastener and having side walls each provided with an inwardly projecting shoulder flange on the free marginal portion of the side wall, comprising: respective ribs on outer sides of said flange portions spaced from said free edges; said ribs being compressibly deflected inwardly toward one another from a greater spacing than the spacing between the inside surfaces of said slider walls; said ribs received in limited outwardly thrusting relation between and against said slider walls and in retaining engagement with said shoulder flanges; said ribs having slider-wall engaging surfaces which in normal uncompressed condition of the ribs slant outwardly and generally away from said free edges whereby to facilitate assembling of the slider onto the fastener by a relative transverse assembly movement toward said edges and along said flange portions and with said shoulder flanges camming along said surfaces and thereby compressibly deflecting the ribs inwardly toward one another; and said ribs having shoulders thereon which in the full assembly of the slider with the fastener are retainingly engaged with said shoulder flanges; said rib shoulders comprising surfaces which in the uncompressed condition of the ribs slant outwardly and generally toward said edges at an angle which enables substantially square face-to-face engagement between said rib shoulders and corresponding shoulder surfaces on said shoulder flanges of the slider.

5. A flexible fastener of the kind having separably interlocking complementary profiled faening structure and a fastener closing and opening slider of generally U-shape having a back plate and spaced side walls each provided with a single inwardly projecting slider flange, and wherein: said fastener comprises a pair of spaced generally parallel flange portions each having an inner face and an outer face and each carrying on its inner face a respective part of the fastening structure: each of said flange portions having an upper section extending upwardly from the associated fastener part to a respective free edge and a lower section extending downwardly relative to the associated fastener part, and said sections of each flange portion being aligned and of generally the same thickness; respective fastener-retaining ribs on the outer faces of said lower flange sections and said ribs being located below the fastening structures; said ribs having respective surfaces facing generally upwardly; said slider back plate engaging said free edges and said side walls engaging the outer faces of said flange sections; an inwardly projecting flange on each of said slider side walls provided with a substantially flat shoulder surface extending generally perpendicularly inwardly from the inner surface of the side wall and terminating at a terminous inner edge which is adjacent to the associated lower flange section; each of said slider flanges having a lower surface extending generally outwardly from said inner edge; at least one of said rib surface and said lower slider flange surface at each side of the fastener and slider providing a slanting cam face to facilitate slipping of the slider flanges past said ribs during lateral assembly of the slider over the fastener; and said lower flanGe sections with said ribs being swingably deflectable inwardly under and toward the fastener parts and thereby facilitating inward compressible deflection of the lower flange sections and the ribs for passage of the slider flanges past the ribs during said lateral assembly and then spring back biased outward thrust of the ribs into retaining engagement with said slider flange shoulder surfaces.

7. A flexible fastener according to claim 5, wherein the inwardly deflected lower flange sections engage with the fastening structure and thpreby assist in maintaining said ribs in retaining engagement with said slider flange shoulder surfaces.

10. A flexible fastener according to claim 5, wherein said slider flange lower surfaces provide said cam faces.