FR2522256A1 - STRIP MATERIAL HAVING THERMALLY-FORMED HOOK HEADS FOR CLOSURES, AND METHOD OF MANUFACTURE - Google Patents

Abstract

STRIP MATERIAL 10 WHICH CAN BE CUT INTO SECTIONS TO FORM AT LEAST ONE PART OF A CLOSURE, MATERIAL COMPRISING A SUPPORT 12 AND A LARGE NUMBER OF FLEXIBLE ELASTIC SECTIONS OF POLYMERIC MONO-FILAMENT LONGITUDINALLY ORIENTED 16, EACH SECTION COMPRISING A CENTRAL PART IN THE SHAPE OF A HANDLE AND TWO NORMAL RODS 20 ON THE SURFACE OF THE SUPPORT, AND AN ENLARGED HEAD 22 AT THE END OF THE RODS; THE SECTIONS OF MONIFILAMENT 16 HAVE A CROSS-SECTION DEFINING SEVERAL LOBES PROPOSING RADIALLY 117, AND THE SAID HEADS 22 INCLUDE HOOK-SHAPED PARTS 26 SPACES OF THE ROD AND MOVING ALONG THE SAME TOWARDS THE SUPPORT FORMED BY HEATING THE END OF THE MONOFILAMENT SECTIONS.

Description

Strip material having shaped hook heads

thermally for closures, and

manufacturing process.

  The invention relates to strip materials which can be cut into sections to form at least parts of closures, and in particular

  such strip materials which include mono-

protruding filaments.

  Strip materials which can be cut

  Weighed in sections to form at least parts of closures are well known, typical examples being those described in US Patents Nos. 3,009,235

  3,138,841; 3,577,607; 3,708,837; 3,770,359;

4,024,003; and 4,290,832.

  Several of these patents describe materials

  strip rials comprising a support which can be woven or comprise a non-fibrous polymer layer,

  and a large number of poly- monofilament sections

  flexible elastic mother oriented longitudinally,

  any of these sections comprising a central handle-shaped part fixed in the support by weaving, fusion or both, two rod-shaped parts which extend from the opposite ends of

  the part in the shape of handle and which advance sensitive-

  normally compared to a main surface

  the support, and enlarged heads at the ends of the rod-shaped parts opposite the support, and

  formed by heating these ends.

  It is well known in the art of iron-

  measures that the heads of such a strip material engage removably in loops making

  protrusion from a support (here called material-

  riau curly) The heads of such a strip material

  are strongly retained by the loops of such a ma-

  curly material when trying to separate the materials

  rials in band and looped by moving their supports in a direction parallel to these supports, since the loops can then engage around

  stems under the heads However the loops re-

  hold heads with much less force

  i 5 bearing when trying to separate the supports

  strip and looped materials in a direction

  substantially normal to the main surface of the

  strip material, since the heads have

  tooth surfaces facing the support which are substantially planar and which extend substantially at right angles radially to the rods which support them, so that the loops cannot

  not cooperate securely with these head surfaces.

  Thus, to obtain closure parts which the loops can retain securely under such conditions (as may be desirable for

  fix a seat cover fabric lined with ma-

  material buckled on a molded seat cushion), manufacturers have molded lengths of material

  strip which have a support, several rods

  protruding normally from a surface

  support, and heads on the ends

  tees of the rods opposite the support, each of these heads comprising two hook-shaped parts spaced from the support rod and advancing along the rod in the direction of the support (for example

  "Velcro Arrowhead No 8 molded tape" from Velcro In-

  industries Limited, New York, New York) Such growth

  chets can be firmly engaged by the loops when the supports are separated from each other

  following a direction substantially normal to the

  main face of the strip material, but the material

  molded tape is not without drawbacks.

  For example, the strength and flexibility of a rod

  molded are weaker than the resistance and the

  plesse of a rod of similar dimensions constituted

  by a longitudinally oriented monofilament; only-

  two hooks can easily be molded

  on each head and these hooks on each head must

  wind be oriented in the same direction relative to the support, which limits the possibility that the loops of certain looped materials to engage the

  hooks; it is difficult to make a material

  molded strip riau with sparsely spaced

  or change the interval between rods to change the holding capacity of the molded strip material; moreover the support layer is fairly rigid for certain applications where the flexibility

is desirable.

  The present invention provides a strip material which can be cut into sections to form at least part of a closure, a strip material which (1) has rods made from extruded monofilaments protruding from a support and

  having heads comprising hooks which spread apart

  both heads in the direction of the support, which can be firmly engaged by loops emerging from a looped material; (2) is formed using

  known manufacturing techniques which are commonly used

  more flexible than molding, and (3) can easily be made with more than two hooks on each head to facilitate firm engagement

curls with heads.

  The present invention is to manufacture a strip material using longitudinally oriented polymer monofilaments which have a cross section defining several lobes

  protruding radially, and by heating the ex-

  monofilament hoppers to form heads, as a result of which, surprisingly, each of the

  lobes form a crook-shaped part on the head

  chet which is spaced from the rod supporting the head and advances along this rod in the direction of the support.

  Preferably, the monofilaments are in po-

  lypropylene which is extruded in a die

  suitable shape to form the lobes making sail-

  lie radially Two, three, four or more lobes can be provided, but preferably the monofilament will have three lobes A monofilament with three lobes forms three hook-shaped projections spaced around the head to provide more possibilities of engagement with the loops in which the head is pushed, only in the case of two hook-shaped parts, and even ensures a separation

  clear between the hook-shaped parts

  that the loops can securely engage the

  hook-shaped parts, this small separation

  for a monofilament of the same dimensions if a

  more hooks are formed.

  Closures using the new structure

  monofilament and heads described above may

  can generally be manufactured according to the

  Description of US Patent No. 3,770,359, using

  a weaving machine such as a loom

  needle or shuttle loom, or just

  can be made using other similar weaving methods such as the method described in

  US Patents Nos. 3,138,841 and 4,024,003, for obtaining

  provide a flexible woven support; or can be manufactured using the method described in US Patent No. 4,290,832, which allows greater choice in the density and spacing of the portions of head rods provided on the strip material and provides support relatively inexpensive but relatively rigid non-fibrous polymer US Patents Nos. 3,138,841; 3,770,359; 4,024,033; and 4,290,832 which describe these methods are cited here

for reference.

  The invention will be better understood on reading

  of the detailed description which follows and the examination

  men of the accompanying drawings which represent, by way of nonlimiting examples, two embodiments

of the invention.

  Figure 1 is a partial sectional view

  on an enlarged scale of an embodiment of the material

  strip line according to the present invention;

  Figure 2 is a top view of the material

  strip line shown in Figure 1;

  Figure 3 is an approximate sectional view

  vement along line 3-3 of Figure 1 Figure 4 is a partial view on an enlarged scale of a head forming part of the strip material of Figure 1; Figure 5 is a partial sectional view on a smaller scale of the strip material of the

  Figure 1 shown engaged with loops of a ma-

  curly material; Figure 6 is a schematic view of a method for manufacturing the strip material of Figure 1; Figure 7 is a partial sectional view of a second embodiment of the strip material according to the present invention; Figure 8 is a side view of a varian-

  te for the head of a rod of the following strip material

before the present invention; and

  FIG. 9 is a sectional view taken appro-

  along line 9-9 in Figure 8.

  In the figures the identical elements are

  designated by the same references.

  Referring now to the drawing, on the

  FIGS. 1 to 5 show a first embodiment of

  read a strip material according to this

  invention, designated as a whole by the reference-

this 10.

  In general, the strip material 10 (which can be generally produced according to the

  method described in US Patent No. 3,770,359) com-

  carries a flexible woven support 12 comprising an over-

  main face exposed 14, and a very large number

  flexible elastic sections of poly- monofilament

  mother oriented lengthwise 16, having a sec-

  substantially triangular transverse tion defined-

  sant three projecting lobes 17 equidistant (FIG. 3) Each section of monofilament 16 has a central part 18 in the form of a loop fixed in the

  support 12 by being woven into it, two

  ties 20 in the form of rods extending from the

  opposite ends of the handle 18 and deviating sensi-

  normally normally in relation to the main surface

  exposed blade 14 of the support 12, and an enlarged head 22 at the end of each rod 20 which is opposite to the support 12 Each of the heads 22 is formed by heating the end of the monofilament 16 to three

  lobes and has a shape, resulting from such heating

  fage, comprising a surface 24 forming a sensitive cam

  clearly semi-spherical opposite its support rod and three parts 26 in the form of hooks spaced from the rod 20 and advancing along the rod in

support direction 12.

  As shown in Figure 5, these parts

  26 in the form of hooks can be engaged firmly

  by loops 28 projecting from

  to a surface 29 of a looped material 30 (the material

  looped riau 30 may constitute another part of a closure comprising the looped material 30 and a certain length of the strip material 10; or can be a backing layer on a finishing material such as an interior trim or a coating of

  car seat) Such a commitment will be very

  resistant even if the strip material 10 and the material

  riau curé 30 are spaced from each other in a direction generally normal to their surfaces

  opposite 14 and 29 since the loops enga-

  behind the hook-shaped parts 26 of the heads 22 must be broken so that there is separation. The method for manufacturing the strip material 10 is illustrated diagrammatically in FIG. 6 This method consists in forming the support and the large number of sections of monofilament 16, each section comprising a portion in the form of a loop 18

  fixed in the support 12 and two rods 20 (including each

  can be associated with a different loop) extending from the opposite ends of the loop-shaped part 18 and advancing substantially normally with respect to a main exposed surface of the support 12, this manufacture being able to take place in a 32 weaving machine, like

  described in US Patent No. 3,770,359.

  The monofilaments 16 are then heated to form the enlarged heads 22. This heating can be carried out using a radiation heating device 34 spaced from the monofilaments, or by a hot wire which comes into contact with the monofilaments 16, as it is well known in the art La

  new characteristic of the method according to the pre-

  sente invention consists in using monofilaments 16 which have a cross section defining several lobes 17 projecting radially (see

  figure 3), so that the heating phase

  me the hook-shaped portions 26 of the heads 22 from the lobes 17, said hook-shaped portions 26 being spaced from the rods 20 and advancing

  along the rod 20 in the direction of the support 12.

  When the end of monofilament 16 is softened by a heat source (physically or

  by radiation), the polymer (for example poly-

  propylene) from which the filament is made begins to

  ler of each lobe 17, and a head 22 is formed with three distinct parts 26 in the form of hooks,

as described above.

  FIG. 7 represents a second mode of

  production of an elongated strip material 40

  vant the present invention It can be manufactured according to the method described in US patent number 4,290,832, allows a greater choice of the density and spacing of the head rods which can

  be formed on a support to vary the

  retaining capacity of the strip material 40 It may be less costly to manufacture than the strip material 10, but has a more rigid support than the

  support 12 The strip material 40 comprises a support

  non-fibrous polymer port 42 having an exposed main surface 44, and a large number of flexible elastic sections of longitudinally oriented polymer monofilament 46, each section comprising a central portion 48 in the form of a loop fixed by being embedded and retained by means of a binding or by merger

  in the support 42, two parts of straight rods

  genes 50 extending from opposite ends

  of part 48 in the shape of a handle and generally advancing-

  normally with respect to the main exposed surface 44 of the support 42, and an enlarged head 52 at each of the free ends of the rods 50 Like the heads 22, each of the heads 52 is formed by heating the end of the three-lobed monofilament 46 and has a shape, resulting from this heating, comprising a substantially semi-spherical cam surface 54 opposite its support rod 50 and three parts 56 in the form of spaced hooks

  of the rod 50 and advancing along the rod in di-

support rection 42.

  While we prefer 22 or 52 heads

  carrying three parts 26 or 56 in the form of hooks, heads such as the head 60 shown in FIGS. 7 and 8 comprising two parts 62 in the form of hooks can also be manufactured according to

  the previously described method, starting from mono-

  filaments 64 comprising two opposite lobes 66 (fig.

  re 8) and by heating the ends of the monofila-

ments 64, as described above.

  The present invention has been described in detail.

  referring to several embodiments It appears

  tra those who are familiar with this technique that many modifications and additions can be made to the embodiments described and that

  the web material can be used in other ways

  Let us say that those described, without going beyond the

  the invention For example, four or more lobes

  can be designed to form heads with four or more hook-shaped parts, the shape of the lobes can be changed to modify the shape of the hook-shaped parts for different reasons Adhesive layers can be provided on

  the side of the coverings opposite the rods to facilitate

  ter the fixing of the strip material on a struc-

  Similarly, by selecting the correct density

  and the spacing between the rods and / or in selection-

  In the shape of the hook-shaped parts, the heads will be able to engage with each other with a desired degree of engagement so

  than two other sections of strip material can-

  feels to be used together to form a farm

  ture. Of course, the invention is in no way limited to the embodiments of the example described and shown, it is capable of numerous variants accessible to those skilled in the art, depending on the applications envisaged and without departing from it.

of the scope of the invention.

Claims (6)

  1 elongated strip material (10, 40) which can be cut into sections to form at least part of a closure, said strip material (10, 40) comprising a support (12, 42) having a   main exposed surface (14, 44) and a large number-   bre of flexible elastic sections of monofilament   longitudinally oriented polymer (16, 46, 64), cha-   that section (16, 46, 64) comprising a central part   handle-shaped bale (18, 48) fixed in said support   port (12, 42), two rod-shaped parts (20,) extending from the opposite ends of said central handle-shaped part (18, 48) and generally advancing normally with respect to said surface main exposed (14, 44), and an enlarged head (22, 52, 60) at the ends of said rod portions (20, 50) opposite to said support (12, 42), characterized in that said sections of monofilament (16, 46, 64) have a cross section defining a plurality of radially projecting lobes (17, 66), and that said heads   (22, 52, 60) have cross-shaped parts   chets (26, 56, 62) spaced from said rod-shaped part (20, 50) and advancing along said rod-shaped part (20, 50) towards said support   (12, 42), formed by heating the ends of said   your monofilament sections (16, 46, 64) so   that each of the lobes (17, 66) forms one of said parts   hook-shaped ties (26, 56, 62).   2 Strip material (10, 40) as shown   vendication 1, characterized in that in addition said monofilament (16) comprises three lobes (17) and that said heads (22, 52) comprise three parts in shape of hooks (26, 56, 52).   3 Strip material (10) as claimed   cation 1 or claim 2, characterized in that in addition said support (12) is a structure   woven, and that the an-shaped central parts   its (18) of said sections of monofilament (16) are woven into said support (12).   4 Strip material (40) as claimed   cation 1 or claim 2, characterized in that, in addition, said support (42) comprises a uniform non-fibrous polymeric binding layer, and that the central, loop-shaped parts (48) of said monofilament sections (46) are drowned and fixed in said tie layer.   A method of making an elongate strip material (10, 40) according to claim 1, comprising forming a support (12, 42) having an exposed main surface (14, 44) and a large   number of flexible elastic sections of monofila-   longitudinally oriented polymer (16, 46, 64), each section (16, 46, 64) comprising a central portion in the form of a loop (18, 48) fixed in said support (12, 42), two portions in the form of rods (20, 50) extending from opposite ends of the loop-shaped portion (18, 48) and advancing substantially normally relative to the surface   main exposed (14, 44); and to heat the mono-   filaments (16, 46, 64) to form an enlarged head (22, 52, 60) at the end of each shaped part   rod (20, 50) opposite the support (12, 42), charac-   characterized in that the forming operation consists in using monofilaments (16, 46, 64) having a cross section defining several radially projecting lobes (17, 66) having a shape such that said heating operation forms heads (22 , 52) comprising hook-shaped parts (26, 56, 62) spaced from said part in   rod-shaped (20, 50) and advancing along the-   said rod-shaped part (20, 50) towards of said support (12, 42).   6 Method according to claim 5, charac-   terrified in that said training operation con-   is to weave said support (12), and to weave the central portions in the form of loops (18) of said   sections (16) in said support (12).   7 Method according to claim 5, charac-   terrified in that said training operation con-   is to use a polymer support (42), to heat   the support (42) to soften it, and to drown the   central ties in the form of handles (48) of the sections of   monofilament (46) in the softened support (42).