Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01H—SPINNING OR TWISTING
  • D01H4/00—Open-end spinning machines or arrangements for imparting twist to independently moving fibres separated from slivers; Piecing arrangements therefor; Covering endless core threads with fibres by open-end spinning techniques
  • D01H4/04—Open-end spinning machines or arrangements for imparting twist to independently moving fibres separated from slivers; Piecing arrangements therefor; Covering endless core threads with fibres by open-end spinning techniques imparting twist by contact of fibres with a running surface
  • D01H4/06—Open-end spinning machines or arrangements for imparting twist to independently moving fibres separated from slivers; Piecing arrangements therefor; Covering endless core threads with fibres by open-end spinning techniques imparting twist by contact of fibres with a running surface co-operating with suction means

Definitions

• the invention relates to a spinning process of the loose-end type, in which fibers or bundles of fibers are taken cyclically from a wick of fibers, these fibers are entrained substantially in their longitudinal direction up to near an area of formation of the wire defined by a suction slot on an air permeable surface, moving in front of this slot, the fibers are deposited on the formation area near a conical tip of the wire, this tip is rotated by rolling on the air permeable surface, and the wire thus formed is simultaneously driven in the longitudinal direction.
• the invention also relates to a device for implementing this method, comprising feeding members for advancing a wick of fibers, means for gripping the fibers, arranged to cyclically extract fibers from the wick and to drive them substantially in their longitudinal direction up to the vicinity of an area for forming a tip of the wire, a first air-permeable surface moving in front of a first suction slot which defines the area of formation of the wire on this surface, means for twisting the wire and means for longitudinally driving the formed wire.
• the most common method uses a rotating bowl which collects in the interior of its throat fibers that have been torn from the wick and which arrive in the rain in the bowl. After priming, the wire is pulled through the center of the bowl and it picks up as the circular deposit of fibers formed in said groove.
• the fibers of this deposit are generally very well parallelized, but the method of picking up the fibers by the wire following an elbow, without drawing possible, and the fact that incoming fibers necessarily fall on the pickup point, are reasons which make that the structure of the wire thus obtained and its solidity cannot be as good as that of a conventional wire.
• the development of this process is nevertheless very important, but for the moment it is not applicable to fine threads and it requires, in the section of the thread, a number of fibers systematically higher than for a conventional thread. In addition, it only applies with short fibers.
• the rotational drive of the conical tip of the nascent wire means that the end of the tip turns faster than its base, because of its smaller radius, that is to say that the twist is much stronger in the core of the wire than at its periphery.
• the section of the wire a non-uniform distribution of the longitudinal elasticity and significant differences in tensile stresses when the wire is stretched, which significantly lowers the resistance of the wire.
• the differences in torsion can be attenuated if the permeable surface on which the wire is formed is that of a disc or of a rotating cone, as proposed in EP-A-0 208 274 and EP-A-0214 686.
• the torsional reaction forces in the tip of the emerging wire cause friction on the permeable surface, that is to say a transverse sliding, so that one is not master of the final torsion given to the wire .
• the fibers free in the air can very well marry together and arrive in uncontrolled bundles on the wire in formation.
• the present invention proposes to overcome the drawbacks indicated above, by providing an "open end" process capable of ensuring a uniform twist in the entire section of the wire, that is to say a twist pitch which is substantially the same from the core of the wire to its periphery, in order to best comply with the well-known laws of Koechlin which define the best conditions for manufacturing a wire by obtaining the same pitch in the different cylindrical layers of the wire.
• the invention aims to extend the application of the process to a wide variety of textile yarns, large or fine.
• the method according to the invention is characterized in that the wire formation area is defined by a first suction slot on a first air-permeable surface, in that the fibers are deposited on the '' training area by moving them transversely, parallel to themselves, so that they arrive at once on their entire length on a generatrix of the cone formed by the tip of the wire, in that said tip is driven in longitudinal translation and in rotation by rolling without sliding on the first air-permeable surface so as not to twist the tip, and in that the wire is twisted in a torsion area located downstream of the tip, gradually eliminating its speed of rotation by rolling without sliding, during its longitudinal translation, on a second surface permeable to air moving in front of a second suction slot which defines the torsion area.
• the fibers are gripped at their front end to take them from the wick and move them longitudinally in a direction substantially parallel to the first air-permeable surface, the fibers are kept away from the first air-permeable surface. air during this movement, and the fibers are released when their front end is near the downstream end of the training area, to allow their transverse movement to the tip of the wire.
• the first and the second air-permeable surface consist respectively of a first and a second rotary disc, these discs being consecutive along the wire.
• the transverse speed component of the surface of the first disc relative to the tip of the wire increases from zero to a determined value along the formation area, and the transverse speed component of the surface of the second disc with respect to the wire is decreasing from said determined value to zero along the torsional area.
• the fibers and twist the yarn in two separate phases of this process.
• a fiber deposition zone is created in which each newly arrived fiber is deposited on a conical bundle of fibers, this newly arrived fiber being deposited substantially parallel to the surface of the conical bundle of fibers on which it is deposited.
• the method according to the invention advantageously comprises a phase during which the conical bundle of fibers is rotated, with a constant angular speed along its axis, in such a way that this conical bundle of fibers and the newly arrived fiber which is deposited on it are not subjected to a torsion while they are in said deposit zone.
• said deposition zone is adjacent to a torsion zone in which said bundle of fibers is twisted, this bundle having a substantially constant diameter in said torsion zone.
• the device according to the invention is characterized in that it comprises, between the means for gripping the fibers and the formation area, guide means for determining the orientation of the fibers on this area so that the fibers reach the tip of the yarn at once over their entire length, in this that the shape of the training area is arranged so that the movement of the first air-permeable surface communicates at the tip of the wire a rotation on itself without torsion, superimposed on a longitudinal translation, by rolling without sliding , and in that the means for twisting the wire comprise a second air-permeable surface moving in front of a second suction slot defining a torsion area which is distinct from the training area.
• the means for gripping the fibers comprise protrusions carried by a drum driven in rotation, and an endless belt applied against said protrusions on a part of the periphery of the drum.
• the means for gripping the fibers comprise perforated protruding sectors formed on the periphery of a drum driven in rotation, a stationary wheel arranged to roll against a peripheral surface of said sectors passing in front of it to pinch the wick, and means for sucking air through the sectors towards the inside of the drum to maintain the fibers on the peripheral surface of the sectors on a part of the periphery of the drum.
• English Patent No. 411,862 describes an extraction method of the latter type, in which the fibers are extracted from the food wick by pinching a fluted sector, rolling against a rubberized wheel. In this case, a suction intervening further attempts to prevent the fibers thus extracted from escaping by centrifugal force before they are fully integrated into the wire which, in this process, is pulled through the center of the fluted sector. In fact, this extraction mode remains usable, provided that it is combined with the transverse deposition mode of the fibers on the area where the tip of the thread is reconstituted, and no longer directly on the thread itself.
• said guide means comprise a stationary plate extending between the tip of the wire and the means for gripping the fibers and provided with a toothed edge which extends longitudinally opposite the formation area. and which is inclined transversely in the direction of this area.
• the first and second air-permeable surfaces are constituted respectively by a first and a second rotary disc, these discs being consecutive along the wire.
• the formation area to extend from an initial point to an end point situated near the periphery of the first disc, said initial point being closer to the center of this disc than the end point.
• the longitudinal direction of the formation area at the initial point is substantially perpendicular to the radius going from the center of the disc at this point.
• the torsion area is substantially rectilinear and extends from an initial point located near the periphery of the second disc to an end point which is closer to the center of this disc, and in this . that the direction of the area of torsion is substantially perpendicular to the radius from the center of the disc to the end point.
• the first and the second disc are located substantially in the same plane and the wire is on the same side on the two discs.
• the device comprises a zone for depositing the fibers in which the fibers are deposited on a conical bundle of fibers without undergoing torsion, and an adjacent zone of torsion, in which this bundle is subjected to a torsion.
• Said deposition zone and torsion zone preferably consist of first and second friction surfaces.
• fig. 1 is a perspective diagram illustrating the formation of the wire in a known method of the loose end and friction type
• fig. 2 is a diagram similar to FIG. 1, illustrating the formation of the wire in the method according to the invention
• fig. 3 schematically represents the rolling of a conical tip of the wire on a rotating disc
• fig. 4 is a schematic plan view of a first embodiment of a device implementing the method according to the invention.
• fig. 5 shows a part of the device of FIG. 4, after the upper parts of this device have been removed
• fig. 6 is a sectional view along line VI-VI of FIG. 4,
• fig. 7 is a side view in the direction of arrow VII in FIG. 6,
• fig. 8 is a schematic view of the wire formation area
• fig. 9 is a sectional view along line IX-IX of FIG. 8, and
• fig. 10 is a view similar to FIG. 4, representing a variant of the means for driving the fibers to the area of formation of the wire.
• a wire 1 is formed by means of fibers 2 between two parallel cylinders 3 and 4 porous or perforated, which are rotated in the same direction, as indicated the arrows, so that the wire rotates by friction between them in the direction of arrow A, at the same time as it is driven axially by other means in the direction of arrow B.
• An air suction is carried out in each cylinder 3, 4, while stationary members arranged behind the air-permeable peripheral wall of the cylinder define a slot suction 5 opposite the tip 6 of the wire in formation.
• four parallel planes PO to P3 which separate different processing zones of the wire 1 along the cylinders 3 and 4.
• the wire 1 is driven so as not to rotate.
• PI and P2 is the driving part of the surface of the cylinders which drives the wire in rotation at its maximum speed.
• P2 and P3 there is a transverse sliding of the wire on the cylinders since in P3 the wire no longer turns. P2 is therefore poorly defined.
• the fibers 2 arrive on the tip 6 in the feeding zone located between PO and PI.
• the end of the conical tip 6, having a smaller diameter than its base, can turn faster than the wire if it is pressed on one of the two slots 5.
• the fibers 2 arrive with an inclination fl or f2 , they will be wound on the tip 6 with a different pitch. It will then be impossible to regularize this step later.
• the fibers are generally free and uncontrolled before reaching the tip of the thread, they can mix with each other before being incorporated into the thread. It has been proposed to mechanically extract the fibers from the food wick and transport them by controlling their position to the tip of the wire in formation.
• the present invention aims to provide a method making it possible to avoid to a substantial extent the above-mentioned defects.
• the basic principle of this process is illustrated in fig. 2, in which the parallel planes PO and PI delimit the point 6 of the wire 1, that is to say a zone 7 for forming the wire, while the planes PI and P4 delimit a zone 8 of twist of the wire, which follows zone 7.
• the angular speed of rotation of the wire along zones 7 and 8 is represented by a diagram. In the formation zone 7, this angular speed is constant along the tip 6, while it decreases along the torsion zone 8 to be zero beyond the plane P4.
• the transverse speed (0. r of a point on its surface located at a radius r from the axis of the wire varies with r from zero to the plane PO to a maximum on the plane PI, then it decreases with (0 to the plane P4.
• mechanical means allowing these different tangential speeds to be imposed along the wire.
• the fibers 2 feed the tip 6 of the wire arriving suddenly and parallel to themselves on a generator of the cone, so that they do not wind around the tip.
• the tip 6 As the latter rotates without sliding on an air permeable surface having, in the transverse direction of the tip 6, a transverse component of speed which is equal to U) .r, the tip 6 is not twisted .
• the air permeable surface also has a component of longitudinal speed which is substantially constant along the tip, which advances the tip in direction B without the wire 1 having to pull the tip.
• the wire rolls without sliding on a second air-permeable surface having a transverse component of speed which decreases up to P4, which gradually twists the wire in a perfectly controlled manner, while a longitudinal component of the displacement of the air permeable surface continues to advance the wire.
• a slight stretching can advantageously be provided in the vicinity of PI, before the torsion, by imposing a longitudinal speed a little higher in zone 8 than in zone 7.
• wire 1 is finished and no longer turns on itself. It is naturally ejected from the device without having to be pulled.
• the block diagram of fig. 3 shows how the conical tip 6 of the wire 1 can be arranged in a simple manner on a disc 9 rotating around its center O, so as to roll without sliding and without twisting, while being driven longitudinally at a constant speed. It is recognized that the base of the tip cone 6 coincides with the edge of the disc. If the point occupied position 6 'drawn in broken lines, its vertex S coinciding with the center O, it is obvious that it would roll without being twisted, but also without advancing.
• the angular speed " Y of rotation of the disc 9 determines over the entire length of the point a longitudinal component of constant speed v., Equal to ⁇ T.R.
• Figs. 4 to 9 show an example of a device designed to implement the method illustrated in FIG. 2.
• the device shown may have fiber supply members which are of any known type and in which, for example, a wick of fibers 11 is brought, through a funnel 12, between two belts d feed 13 and 14 which are driven by pulleys 15 and 16 and which define a pinch passage 17 regularly advancing the wick 11 in a second funnel 18.
• another frame supports members for forming the wire 1, comprising two rotary discs 30 and 31 porous or perforated to be breathable, under which are arranged two corresponding suction slots 32 and 33 which occupy a stationary position and which define in known manner, by suction of the air through the discs, corresponding areas on which the suction applies the fibers and the thread.
• the first suction slot 32 defining a wire formation area on the first disc 30, as well as the second suction slot 33 defining a twist area of the wire on the second disc 31.
• the two discs 30 and 31 are located in the same plane and are tangent to each other. They are carried and driven in opposite directions by respective shafts 34, 35 so that the tangential speed of the two discs at their point of contact is substantially the same.
• the torsion area defined by the suction slot 33 is rectilinear and it passes at a distance R ⁇ from the center C of the disc 31, its downstream end D lying precisely in line with the center C, while its upstream end E is located near the edge of the disc, at a distance R. from center C.
• the radius R. forms an angle " ⁇ C l with the direction of the wire.
• the wire formation area defined by the suction slot 32 on the first disc 30 is essentially curved in this example, since it follows the edge of the drum 20 over a large part of its length. It begins at a point H which is substantially aligned with the center F of the disc 30 and the center G of the drum 20, and it ends at a point I close to the edge of the disc 30.
• point H which corresponds to the position of the PO plane of fig. 2
• the direction of the wire defined by the slot 32 is perpendicular to the radius FH, that is to say that the component of transverse speed of the disc relative to the wire is zero.
• this component is maximum at point I and it is practically equal to that of the disc 31 at point E, these two points corresponding to the - Im ⁇
• Fig. 5 also shows that the wire 1 can be guided by a pair of rollers 36, 37 as soon as it leaves the disc 31, to be wound on a reel 38 by known means.
• a horizontal plate 40 mounted in a stationary position between the first disc 30 and the drum 20, has a serrated edge forming a comb 41 which extends above the wire formation area, between the slot suction 32 and the clamping members 21 and 26 bringing the fibers 2 to this area.
• the role of this comb will be explained later, with reference to Figs. 8 and 9.
• the overall operation of the device described above is as follows.
• the wick 11 driven by the belts 13 and 14 has, at the outlet of the funnel 18, ends of fibers which are then pinched between the protrusions 26 of the drum 20 and the belt 21. These fibers are extracted over their entire length. the food wick, so that they constitute a small bundle or bundle of substantially parallel fibers which have various lengths and which are gripped near their front end to be transported longitudinally towards the wire formation area.
• the rear end of a fiber is released, it is sucked towards the air-permeable disc 30 by the slot 32. If it touches the disc, it is brought by the latter onto the teeth of the comb 41 where it hangs.
• the tip 6 of the wire is transported longitudinally at a constant speed by the disc, then the wire 1, which turns, passes over the second disc 31 where its rotation is gradually stopped in the torsion area defined by the slot 33 as described above. At the end of this area, the disc 31 only requests the wire 1 longitudinally, which then goes towards the call and the winding. Evacuation and winding speeds can be the same; a call of the wire is not even essential, the priming being done all alone.
• Figs. 8 and 9 show in more detail the operating principle of the comb 41. It can be seen that the plate 40 is folded above the tip 6 of the wire, so that the teeth of the comb are close to the surface of the disc 30. The tip 6 rolls without sliding on the disc moving in the direction indicated by the arrows M, above the downstream edge of the suction slot 32.
• the fiber 2 (of same as the other fibers of the same package) is released at I that its longitudinal translation ceases and that it can slide laterally on the comb 41, come into contact with the surface of the disc 30 over the entire length, be transported parallel to it- even up to the point 6 of the wire and integrate therein without coiling.
• the outline of the comb 41 is rectilinear, but it can obviously be curved as in the case of FIG. 4, provided that it is substantially parallel to that of the tip 6 of the wire.
• Fig. 10 shows a variant of the fiber extraction members, usable in place of the corresponding members 20 to 26 shown in FIG. 4.
• This device resembles that of British Patent No. 411,862 cited above, but here the entrainment of the fibers is first carried out by pinching between one of the perforated protruding sectors 51 of a rotary drum 50 and a rubberized wheel 52, then by suction through the sector 51, thanks to a suction passage 53 delimited by walls 54 and 55 inside the drum 50.
• the fibers are transported longitudinally and kept away from the first disc 30 thanks to a guide member similar to the comb 41 described above, then they are released in line with the wall 55 at a stage where they are sucked against the first disc 30 by the first suction slot 32.
• the continuation of the operations takes place as described with reference to FIGS. 2 to 5.
• the present invention is not limited to the embodiments mentioned above, but it extends to any modification or variant obvious to a person skilled in the art.
• other means can be provided for bringing the fibers parallel to themselves on the wire formation area, and the geometry of this area on the first disc can be adapted as a function of these means.
• the formation area must have a shape which clearly deviates from an arc of a circle, in particular a rectilinear shape
• the drum 20 can be replaced by a belt equipped with similar protuberances and shouldered by a guide having a desired shape.
• the device described can be used with fibers of different natures and of different lengths.
• the rotary drum 20 or 50 can easily be replaced by a drum with closer protuberances if shorter fibers are to be used.
• the method according to the invention is not limited to the use of rotating discs, since it can also be carried out with other surfaces such as conical or convex, although the construction is more complicated.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Spinning Or Twisting Of Yarns (AREA)

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ID=9369304

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• 1988
  • 1988-08-09 FR FR8810853A patent/FR2635339A1/fr not_active Withdrawn
• 1989
  • 1989-08-08 ES ES8902825A patent/ES2020025A6/es not_active Expired - Lifetime
  • 1989-08-08 EP EP19890908800 patent/EP0380635A1/de not_active Withdrawn
  • 1989-08-08 WO PCT/CH1989/000144 patent/WO1990001575A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

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