IL38976A - Method and apparatus for the production of an articlecatching strip - Google Patents

Description

; Dan oa τ»χ*,,7 o'jprim ati'i Method and apparatus for the production of an article-catching strip Article-catehiag means are known which are constituted by a strip provided on one side with a multiplicity Of catching means. In a known embodiment, the strip is made of a velvet ©r similar fabric, the pile of which is made of synthetic resin and terminates with incurved hook-shaped ends.

When such a stri engages a similar strip or else another piece of fabric, its hooked pile seizes said othe stri or ~ piece o fabric, whereby the first mentioned stri is held fast o said other strip or piece of fabric. Suc hook-shaped catching means must be woven on special looms and are^ comparatively expensive.

The present invention has for its object a very cheap method of producing article-catching means o the type referred to* It is known in the art to produce extruded brushes b a process in which one extrudes a number having a helieal ridge formed thereupon and subsequently cutting the helical ridge at a plurality Of positions all along to define bristles. Apparatus for such fabrication is shown in the U.S. paten ·· 3,329,998 which provides apparatus for the production from thermoplastics of brushes, eombs and similar articles having bristles or spikes, in combination with a extrusion machi e a die ihsertabl© in said extrusio machine for continuously extruding in a plastic state a ribbed pro-file^ orm having a plurality of tapering ribs extending longitudinall along the extruded form, a movable cutting ade mounted adjacen said die for cutting through and across said ribs in sequential cuts--of. said blade so as to cut said ribs into protrusions a predetermined spaced locations along the extruded form, pulling wheel means spaced om and cooperatin in timed relation with said cutting blade, said pulling wheel means being engageable ed r file form to lon itudinall stretch said spikes while stretching said spaced locations therebetween into uniform spaces of given length, and controlled cooling means located between said die and said pulling wheel means for cooling and setting the extruded form.

As distinct from us patent 3,329,998 the present invention employs extruded members having longitudinal ribs formed with transverse extensions adjacent their to surfaces* According to the invention, article-catching means are constituted as precedingly by a strip provided on on© side with a multiplicity of catching means* Its novelty resides in that it is obtained starting from a shaped stri showing longitudinal ribs on at least one -side while transverse cuts are made across the ribs.

The invention covers also an arrangement for executing said method* said arrangement including means for guiding the strip, means fo cutting across the ribs of the strip and a strip-drawing frame.

The accompanying drawing illustrates by way of example a plant for the execution of the above-described improved method together with the successive stages of the production of the article-catching strip. In said drawing; Fig.1 is a general diagrammatic view of said arrangement! Pig.2 is a perspective view of a portion of the strip as it passes out of an extruding machine? Fig.3 shows a portion of the strip as it passes underneath a cutting system adapted to notch the strip; Fig. shows the modification in shape of the strip when subjected to a hot drawing process; Fig.5 is a perspective view of a portion of the strip in its final condition; Fig. 6 illustrates a cutting system provided with two blades adapted to form notches in the ribs of the strip; Fig.7 is a longitudinal cross-section of the strip, showing the notches obtained by means of the arrangement according to Fig.6.

As illustrated in Fig.1, the improved arrangement includes an extruding machine producing, by means of a die 2, a strip 3 of thermoplastic material, which strip shows (Fig. 2), when it passes out of the extruding machine, a number of longitudinal ribs 4 on one of its sides.

When leaving the extruding machine 1, the strip 3 is comparatively soft and, in order to prevent undesired deformations, it is carried by an endless conveyor belt 5 until it has cooled by a sufficient amount for it to show a sufficient stiffness.

Before the strip 3 reaches the end of the conveyor belt 5» i passes underneath a roller 6 the periphery of which shows areas lying at different distances from its rotary axis. Said roller exerts thus a pressure of variable intensity on the ribs 4, which produces deformations of the webs 7 of the ribs 4, whereby the height and breadth of the latter vary throughout the length of the strip 3 · Such modifications in the transverse size of the ribs are not essential but they act favorably on the catching properties of the strip.

When it has left the conveyor belt 5» the strip passes over a drum 8 in contact with which it is held by two rollers 9 and 10. Said drum is located underneath a cutting system 11 provided with a flat cutting blade 12 adapted to reciprocate so as to cut notches 13 across the ribs 4 on the strip, as shown in Fig.3 · The depth of the notches is such that only the ribs are cut while the solid flat supporting section of the strip is not engaged by the cutting blade 12 .

After it has registered with the cutting system 11, the strip 3 reaches a drawing frame 14 which includes strip-driving means constituted by the rollers 15 at the input end of the frame and further rollers 16 at the output end. The output end rollers make the strip progress by a speed about 50 higher than the speed imparted by the input rollers 1 . In the actual drawing frame, the strip 3 passes first through heating means 17 which may be, for instance, an electric radiator radiating infra-red rays, and then through cooling means 18 which may be constituted simply by a chamber fed with cool air by a fan 19.

Pig, shows the modified shape assumed by the strip when it has passed through the drawing frame. As illustrated, the surface of the drawn out solid supporting portion of the strip has become longer and thinner as shown at 3' · At the same time, the originally very narrow notches 3 broaden considerably so as to form a comparatively large interval 13' between the successive catching elements.

There is obtained thus a strip 3 the general appearance of which is shown in Fig.5 and wherein each element cut out of a rib 4 and then drawn out acts as a catching element 20.

Obviously, numerous modifications may be brought to the method and means described, chiefly as concerns the shape of the rib 4, which shape defines the final shape given to the catching elements. The latter may, in parti-cular, be in the shape of an arrow or of a harpoon, if it is desired to increase its catching capacity.

Obviously also, if it is desired to obtain a high speed for the production of the notches, the cutting system may be provided with a plurality of cutting blades operating simultaneously.

Figs.6 and 7 relate to a modification of the cutting system which may be used in an arrangement producing article-catching means. The strip 3 passes in this case over a drum 8 of a comparatively large size in registry with a cutting system constituted by an arm 21 carrying two cutting blades. The latter lie in two planes lying to either side of the rotary axis of the drum 8, said blades forming thus notches sloping obliquely in opposite directions with reference to the longitudinal direction of the strip 3· The spacing between the blades 22, 23 and the speed of prog ession of the strip are selected in a manner such that the bottom of a notch executed by one blade may register with that executed by the other blade. It is thus possible to obtain, as illustrated in Fig.7, V-shaped notches providing a sufficient spacing between the successive article-catching elements. This results in a possibility of cutting out the strip drawing step as described with reference to Pigs. 1 and 4.

In the embodiment illustrated, the strip 3 Is provided with ribs on only one side, but, of course, such ribs may be carried on both sides, whereby a succession of article-catching elements is formed on each side of the strip 3* the elements located on one side being similar to or different from those in the opposite side.

Claims (7)

38976/3

1. A method of manufacturing-- a strip including f stener projections to form in combination with a similar strip a closure member, the steps consisting of extruding a strip of synthetic resin having longitudinal ribs formed with transverse extensions adjacent their top surfaces on at least on of its faces, passing said strip beneath a forming member to deform the ribs on an upper f ce and thereby vary the height and width of the ribs throughou the length of said strip, passing the strip partially around a roller disposed: beneath a cutting member, actuating said cutting member to cut substantially evenl spaced transverse notches in said ribs, passing the strip through a heating sone and coolin the thus fonaed strip.

2. * A method according to Claim 1 including the further-step of stretchin said strip longitudinall so as to increase the width of said transvers notches relative to said longitudinal ribs after passin the strip hou h said heating zone,

3. method according to Claim 1* wherein said cutting member includes a pair of spaced blades parallel to > *- · I v 38976/2 each other and to the axis of said roller and actuation of said cutting member forms transverse V-shaped notches in said ribs .

4. An arrangement for the execution of the method •claimed in claim 1, comprising an extruding machine provided with a die, the cross-section of which is adapted to extrude a ribbed strip of synthetic material, means guiding the ribbed' strip beneath a forming member adapted to compress the ribs to a varying extent, the means guiding also the ) ribbed strip around a roller disposed beneath a cutting member, said cutting member being adapted to cut transverse notches in said ribs, means for successively heating and cooling the thus formed strip after the latter has passed the cutting membe .

5. An arrangement as claimed in claim 4, wherein the forming member is constituted by a rotary member, the periphery of which engages the strip and includes parts located at different distances from the stationary rotary axis of said member, thereby to compress the ribs to a varying exten . - '

6. An arrangement as claimed in claims 4 and 5* comprising a drawing frame adapted to give the strip passing out of the cutting member a permanent elongation, said drawing frame being provided at its input and output ends with sets of rollers, said means for first heating; and then 38976/2 cooling the strip being located between the two sets of rollers.

7. An arrangement as claimed in claims 4 and 5> comprising a cutting member, disposed on, the roller, the said cutting member including a pair of spaced blades parallel to each other and to the axis of said roller, and adapted to form transverse V-shaped notches in said ribs. - ?! -