Abstract: A pneumatic spinning method includes conducting sliver formed at least partly of spinning fibers through at least one swirl nozzle, and contacting the sliver in the swirl nozzle with at least one heated compressed air jet operating the swirl nozzle, and a device for carrying out the method.

Abstract: There is provided a device for dispensing optical fibers into helical grooves of a ring drawn through optical fiber cabling lines. The dispensing device comprises a holder rotating about the ring and including conduits each containing a grooved fiber-guide receiving at least one optical fiber. The fiber-guides are arranged along generating lines of a cone coaxial with the ring and have first fiber-output ends designed to engage in the ring grooves. To disengage the first ends of the fiber-guides from the ring grooves while feeding the ring through the cabling line, the fiber-guides are slidably mounted in the conduits and the device comprises a nut means enclosing a washer in which second ends of the fiber-guides radially, thereby translationally moving the fiber-guides along generating lines of the cone respectively.

Abstract: Multifilament superconductor strands of less than 1 mm diameter able to carry alternating current are stranded to a pitch of between 7 and 3 diameters, at a temperature above 200.degree. C. and a speed between 30 and 5,000 rpm.

Abstract: A process and apparatus for laying optical fibers in the helical grooves of a core for an optical fiber telecommunication cable in which the rotatable bobbins carrying the optical fibers are held in axially fixed positions while the core with helical grooves and the fibers are fed to and through a rotatable fiber inserting device which has projections extending into the grooves which cause rotation of the device as the core is advanced. Between the bobbins and the fiber inserting device there is a supporting tube through which the core passes and the outer surface of which engages and supports the fibers. The downstream end of the tube terminates in advance of the fiber inserting device so that the fibers may enter the grooves in the core at the fiber inserting device.

Abstract: A drawing wheel is intended for exerting tension on a grooved ring while optical fibers are being laid in helical grooves in the core, in order to stretch the ring in a cabling line. The invention is aimed at defining a radius for the wheel in terms of the dimensional characteristics of the ring so that the fibers are kept longer than the grooves as the ring leaves the cabling line and reverts to an initial tension-free state. The radius of the wheel is such thatR'>(p.sup.2 /(4.pi..sup.2 r))-(r+h)where p and h respectively denotes pitch and depth of the helical grooves, and r denotes radius of a central portion of the core circumscribed by bottoms of the grooves. The wheel radius is preferably on the order of one meter or more.

Abstract: Multi-strand superconducting cables adapted to be used, for example, to wind a magnet is fabricated by directing wire strands inwardly from spools disposed on the perimeter of a rotating disk and wrapping them diagonally around a tapered mandrel with a flattened cross-sectional shape with a core having a wedge-shaped channel. As the cable is pulled axially, flexibly coupled wedge-shaped pieces are continuously passed through the channel in the mandrel and inserted into the cable as an internal support therefor.

Abstract: A method and apparatus for forming a yarn or sewing thread from core and effect yarns. The effect yarn is drawn at no higher than a normal drawing ratio for material from which the effect yarn is made and the effect yarn is softened by sufficient heating, in order to prevent rupturing of the effect yarn during drawing. The core or effect yarn is passed through a wetting device to aid aspiration and entanglement of the core and effect yarns in a fluid jet device. The effect yarn is overfed to the jet device to aid in the formation of a highly entangled looped yarn which is subsequently set by a heated roller while contraction of the yarn is prevented. The core yarn can also be drawn at or below its normal drawing ratio in order to aid in developing thread tenacity and ensure an acceptable elongation at break after dyeing or subsequent wet processing.

Abstract: A method for manufacturing a cotton core yarn which comprises introducing a tension into a core yarn, and bringing a cotton yarn together with the core yarn, said core yarn having a higher tension than that of the cotton yarn and said cotton yarn being supplied at a higher speed than that of the core yarn, whereby the core yarn forms the center fiber and the cotton yarn uniformly covers the surface of the core yarn.

Abstract: A method of and a device for providing a concentric layer of wire material on a cable (C), in which a number of wires (G) are taken simultaneously and in a tangential direction off a common rotating feed reel (27) on which the wires (G) are wound parallel to one another. The wires (G) are guided into the axial direction, are spread in the circumferential direction and are wrapped around the cable (C), which passes through a hollow shaft (11) supporting the feed reel (27). The method can be used both for armouring cables and for providing a screening.

Abstract: A boucle yarn is produced by entangling a drawn core yarn and an air textured, drawn effect yarn. The air textured, drawn effect yarn provides a plurality of randomly spaced curls or loops around the core yarn to produce the boucle yarn appearance. A number of the random curls or loops are embedded in the core yarn during the entangling process.

Abstract: A method and apparatus is disclsoed for producing a synthetic multifilament yarn having enhanced bulk and hand characteristics, and which is capable of high production rates. Specifically, the invention involves advancing each of at least two continuous multifilament yarn components along respective paths of travel, with a first component being advanced at a higher speed than that of a second component. Also, the second slower yarn component is guided through a liquid bath to moisten the same, while the first faster yarn component is advanced along an essentially linear path of travel and free of contact with the liquid bath, so that the degree of tension in the faster yarn component is minimized upstream of the air jet nozzle, to thereby permit full development of the loops, coils, bows or the like in the filaments thereof in the air jet nozzle.

Abstract: Method of manufacturing core yarns from fiber bands. A part of the fibers of a fiber band is released from the fiber band and is deflected. These deflected fibers do not participate in the spinning process, but are wrapped around the twisted core in a plurality of reinforcing winds. The method of the invention overcomes the problems of manufacturing yarns without requiring expensive and complicated mechanical elements.

Abstract: In an optical fiber cabling line where a ring having helical grooves is drawn at a constant translational speed by a main motor, there is provided a system for slaving a rotational speed of an optical fiber feeding and dispensing device driven by motor means to a number of ring groove pitches per second in order to compensate for groove pitch fluctuations resulting from the ring production process. The system comprises roller and cam means coupled to the ring and to the feeding and dispensing device for detecting a difference between the rotational speed and the number of pitches per second thereby converting the speed difference into a voltage variation. The motor means comprises a differential coupled to a gearbox connected to the main motor, and a corrector motor linked to the detecting means so as to drive rotationally the feeding and dispensing means at a rotational speed proportional to a rotational speed set by the gearbox and continuously corrected by the detected speed difference.

Abstract: A method and apparatus which enables stranding a skein-like element with reduced backtwist characterized by a stranding nipple, a tubular store having an axis, means for rotating the tubular store on its axis in both a first and second rotational direction and means for moving the tubular store longitudinally along its axis as it is being rotated. The change in direction of rotation is selected to occur during displacement from an initial position spaced from the stranding nipple to a final position adjacent the stranding nipple so that during a first portion of a cycle, lays are accumulated on the tubular store then with reversing of the rotating direction, the lays are decreased and finally during a third portion of the cycle the tubular store is shifted from the final position back to the first position for repeating the cycle.

Abstract: A method of obtaining a core-spun yarn, according to which the fibers are subjected to a momentary false twist, and elementary fibers are projected on the spun yarn in the upwardly twisting area by means of a movable surface. According to the invention, all of the fibers (core and sheath) are subjected to the action of a common drawing system. After drawing, part of the fibers are delivered to the guiding surface to form the sheath while the other part of the fibers, which will form the core, is moved away from said surface and returned in contact therewith downstream of the zone in which the first part of the fibers are delivered. It is possible with this method to obtain, from only one supply, a variety of yarns of which the core and sheath can be composed of fibers of the same or of a different nature.

Abstract: Changing relative positions of conductor pairs along a telecommunications cable core by passing the unstranded pairs, as they approach the core unit forming means, through individual guides which are reciprocally moved across a feedpath for the pairs, the guides being disposed in series along the feedpath with each guide aligned for unobstructed passage of its conductor unit along the feedpath. In this construction, means to reciprocate each guide overlaps those of other guides, thereby reducing the total height of the apparatus.

Abstract: A generally cylindrical member, such as a catheter, cannulae, or the like, has a monolithic construction. An inner core of plastic is passed through a conventional reinforcing apparatus, such as a conventional braiding mechanism. The braiding action is interrupted at predetermined intervals while the core continues to be fed so that straight reinforcing strand lengths are disposed on the outer surface of the inner core at predetermined lengths. The member passes through a heated sizing die to adhere the braided strand to the inner core, and a mechanical shear or rotating blade cuts the straight strand lengths off so that they are detached from the core. An over-extrusion of plastic may be provided to encapsulate the reinforcing strands. When the catheter is free of reinforcing strands it is relatively soft and flexible--such as at its tip--and where the reinforcing strands are provided it is relatively stiff. The monolithic construction ensures that components will not detach in a patient's body.

Abstract: Apparatus and method of manufacturing taped products with double twist machines are disclosed which include paying off one or more continuous filaments, and paying off one or more tapes, the tapes are filaments are pulled through a pre-twisting apparatus which imparts a number of twists twist to the assembled filaments and tapes to a number required to determine the desired tape tension in the final product, the pretwister speed is about twice the speed of the bow of the double-twist machine.

Abstract: A new process is provided for producing highly resilient, textured, continuous multifilament polymeric yarns and combinations of such yarns with other continuous filament yarns and with spun yarns. The unstable or wild loops which form in conventional air jet textured yarns are substantially eliminated in the product yarns of this invention. The product yarns are formed by continuously drawing polymeric yarn under controlled temperature conditions, texturing the yarn in an air jet texturizer and subjecting the textured yarn to saturated steam while restraining the linear shrinkage of the yarn in the presence of the steam, followed by continuous take-up of the yarn on a package.

Abstract: A method and apparatus for producing a fancy yarn, in which a core and effect yarn 5 are fed along a path to a false twist device 6 and a binding yarn 4 is fed via a rotating component 1 adjacent the path, the component rotating about an axis transverse to the path, and having a yarn guiding portion 3 radially spaced from the axis, whereby the binding yarn is caused to perform a reciprocating, oscillating motion with respect to the core and effect yarns.

Abstract: Changing relative positions of conductor pairs along a telecommunications cable core by passing the pairs as they approach a core unit forming means, in an array through a flow of air which causes relative sideways movement of the pairs and continual change in their positions. The array may be arcuate, conveniently circular, and the airflow moves outwardly from within the array. Alternatively, the array is primarily planar with the airflow moving from one side of the array.

Abstract: Changing relative positions of conductor pairs along a telecommunications cable core by passing the pairs, as they approach a core unit forming means, through guides which are held in relative positions in a guide channel. The channel extends in a plurality of directions and has inner and outer channel portions which are preferably arcuate and lie upon arcs of circles. The guides are moved along the channel and from channel portion to channel portion, movement being alternately in each direction. This movement changes the positional relationship of guides in one channel portion to those in the other.

Abstract: A metallic cable comprises a strand of identical helical shaped filaments positioned beside and against each other such that each filament of the strand is in line contact with at least one other filament of the strand. The helixes of the filaments of the strand are sloped in a first direction. A single filament is twisted with the strand in a direction opposite to said first direction. An apparatus and a method for manufacturing the metallic cable are also disclosed.

Abstract: Process for the manufacture of a fancy yarn having stable protuberances along its length, wherein at least one effect yarn is fed onto a core yarn at a greater speed than the latter, the protuberances thus produced and the core yarn being bound together by the combination of feeding of the effect yarn in an oscillating manner relative to the core yarn and increasing the twist of the assembly passing through a simple false twist device, without the need for heat setting means.

Abstract: A thread is provided which comprises a polymeric material onto which has been fixed a symbol or repeating multiple symbols which are detectable and readable under magnification. When incorporated into garments or garment labels, this thread is useful in identifying the true manufacturer of the goods, and the absence of such threads would help in the detection of counterfeit goods.

Abstract: A system for helically wrapping a tape comprises tape twisting means, and, upstream of the twisting means, means for shaping the tape. The shaping means comprises a body over which the tape passes, the body having a first surface of at least partially cylindrical form and an outwardly curved edge surface extending along a side of the first surface. Tape supply means is arranged to feed the tape onto the first surface such that the tape is inclined to a plane at right angles to the axis of the first surface whereby an edge of the tape engages the curved edge surface and is thereby shaped in order to initiate wrapping. The system is particularly suitable for wrapping a paper tape around a nylon core.

Abstract: The deformation of corrugations in a corrugated conductive tape, utilized as a screened layer for screened cables or as an outer conductor for coaxial cables, due to pulling tension of the screened cable is prevented by an apparatus for manufacturing screened cables such that the corrugated conductive tape is transferred at the same rate as a cable core which is covered by the corrugated conductive tape by a forming device.

Abstract: Synthetic yarn and yarn-like structures are formed by the method of treating separate strands of thermoplastic material so that at least one has a shrinkage ratio higher than normal at an elevated temperature. The strands are fed forwardly at different rates of overfeed and intermingled in a gas stream with formation of loops on the strands, then heated to cause them to shrink differentially while being held to a predetermined length until shrinkage ceases. Apparatus for performing the method includes yarn drawing means, intermingling means comprising a jet device incorporating intersecting passages for the strands and for a gas under pressure, feeding means and heating and cooling means for the intermingled yarn downstream from the jet device, also means for holding the intermingled yarn to a predetermined length while it is being heated and cooled. Yarn produced by the method incorporates filaments at least some of which present bud-like projections inhibiting relative movement of the filaments.

Abstract: Apparatus for inserting optical fibers into helical grooves in a plastic core advanced through a rotatable, rigid body which has conduits for guiding the fibers from bobbins mounted on a rotatable cage into the grooves, the ends of the conduits engaging the walls of the grooves which cause the body to rotate as the core is advanced, said apparatus having drive means for advancing the core separate from the drive means for the rotatable cage and having detecting and control means for detecting angular and direction of rotation differences between the cage and the rigid body and correcting such differences by control of the rotation of the cage by its drive means.

Abstract: Fiber sheaths are drawn between a pair of drawing cylinders and continuous filaments are introduced upstream of the drawing cylinders to form two strands which are twisted together at a convergence point upstream of a winding mechanism. The tension of the strands is regulated, the strands are wound to form a filament, and the filament thus formed is retwisted on a spinning jenny.

Abstract: Method of and apparatus for making yarn with a core, wherein the free fibers are tightly attached to the core and are wound around it. The core of fibrous material is fed by a pair of feeding rollers, the core being fed through a first jet for the formation of wrapping of fibers. In the first jet, fibers are laterally driven in by an air stream. Simultaneously with the laterally led in fibers in the first jet for the formation of wrapping, there is driven in an additional core thread, which moves with the linear velocity of the core. Such additional core thread is made of fibrous material of staple fibers or is made of filament material. The laterally led in fibers and the additional core thread have a mutual trajectory of movement and are driven in the jet for the formation of wrapping by the suction of the tangentially fed same jet air stream.

Abstract: The invention relates to a process and device for making a spun yarn of fibres comprising an internal core which consists in subjecting the yarn to form the core to a momentary false twist by means of a spindle and projecting elementary fibres onto this yarn. Such elementary fibres are projected by means of a mobile guide surface on which the fibres are delivered tangentially, the core likewise being displaced tangentially with respect to the guide surface in a direction concurrent with the direction of delivery of the fibres.

Abstract: A method is disclosed in which a silver (2) of textile fibers is drawn in a drawing mechanism (3), strengthened in a wrapping unit (4) by wrapping with a fine filament yarn into a roving (5) and the latter is drawn in the drawing mechanism (11, 12) of a spinning machine down to the desired yarn thickness. Rupture of the filament yarns in the drawing mechanism of the spinning machine takes place not in the predrawing zone but only in the main drawing zone. For wrapping of the roving a filament yarn is employed, the tension in which at an elongation of 4% amounts to at least 10 N and the ultimate strength of which amounts at most to 100 cN, and in which the ratio of elastic elongation to total elongation at a loading of 15 CN does not fall below the value of 80%. The wrapping unit (4) is surrounded with a stationary casing one half (45a) of which may be swung out.

Abstract: A method and apparatus for manufacturing a multi-component yarn as well as a multi-component yarn produced thereby, in which staple fibers and at least one endless yarn are combined with each other in a defined manner such that a wrapped yarn will result which purely externally has as far-reachingly as possible the properties of a pure staple fiber yarn; the sliver and the endless yarn or yarns are fed separately to a feed roller pair, are combined thereat travelling at the same velocity and parallel to one another, and are subsequently exposed together to a false twist and finally wrapped by a fine-count binding yarn; the predominantly nonvisible part of the wrapped yarn is constituted by the endless yarns which render the yarn bulky with relatively low material expenditure.

Abstract: Apparatus for laying of optical waveguides into sinuous grooves of a support filament in which a laying device surrounding a feed path for the filament has a plurality of elongate guide elements for the waveguides, the elements extending downstream from a carrier and being inclined to the feed path to terminate in free inner ends. The guide elements are rigid and are allowed by the carrier to have lateral swinging movement to enable their free ends to follow the path of a groove in the support filament as it moves along its feed path. A groove locating projection is provided to maintain positional relationship between the carrier and support filament as the filament passes the carrier.

Abstract: The present invention relates to a process for making a core spun yarn, wherein elementary fibres are projected onto a yarn, the yarn being subjected to the action of a false twist spindle. The projection of the fibres is obtained by means of a mobile guiding surface on which the fibres are delivered tangentially and are maintained paralleled and flat. Furthermore, the core is delivered tangentially on the paralleled fibres obliquely and in the direction of displacement of said fibres. The invention also relates to a device for carrying out this process.

Abstract: A process for the manufacture of concentric compressed or compacted stranded conductors at high speed on double-twist bunching machinery while eliminating loose strand, strand crossovers, and spiral propensity of the finished product; and the product thereof.

Abstract: A wrapped yarn spinning unit equipped with a delivery device for a sliver, a hollow spindle that carries a binding thread to be wrapped about the sliver and rotating together with the hollow spindle, a take-off device for the wrapped yarn, a feed tube between the delivery device and the hollow spindle and an air line connected to the feed tube at a distance downstream of the inlet opening of the feed tube and adapted to be connected to a vacuum source; a twist-producing device is further provided within the area of the inlet opening of the hollow spindle.

Abstract: An arrangement for winding yarn (3) from a supply roll (2) by means of a flyer (4) onto a bunch of wires fed through the center hole of the supply roll for automatically transferring to the unwinding of a new supply roll (2') when the yarn on the first supply roll (2) is used up or broken. The new supply roll (2') is disposed downstream of the first supply roll (2) seen in the direction of feed of the bunch of wires and a second flyer (4') is associated with it. Downstream of the new supply roll (2') and the second flyer (4') there is a holding device (13) to loosely hold the free end of the yarn (3') on the new supply roll (2') as long as the yarn (3) on the old supply roll (2) is not used up or broken. At its free end the yarn (3') on the new supply roll (2') is formed into a sliding knot (15) carried by the holding device (13), through which sliding knot the bunch of wires (1) is freely fed.

Abstract: An air nozzle for producing a sheath-core type fancy yarn, comprising a hollow cylindrical nozzle body in which a vortex occurs around an axis thereof due to a suction flow of a subatmospheric pressure source. Within the nozzle body a conical cap and a ring body are arranged in series. A sheath yarn is overfed into the nozzle body in the tangential direction to the inner surface of the body and wraps around the conical cap to form a plurality of loops due to the vortex, then entangles a core yarn running straight through the nozzle body. Since an outer surface of the conical cap and a central opening of the ring body guide the vortex smoothly along a yarn path, a fancy yarn having uniformly and tightly entangled loops can be obtained.

Abstract: Method to produce spun-like yarn and product produced thereby by combining a core yarn and an effect yarn in an air jet. The removal speed of the combined yarn from the air jet is intermediate of the speeds of the draw rolls to produce a composite yarn having crunodal loops in one of the combined yarns.

Abstract: A spindle assembly engages and moves along a length of cable to be wrapped with insulating tape. Reels of insulating tape are mounted on a outer rotatable spindle which revolves around the cable to dispense insulating tape. The rate of movement of the spindle assembly along the length of the cable is controlled by a stepper motor which is programmably synchronized to the rate at which rotatable spindle wraps the cable. The stepper motor drives a roller which engages the cable and moves the spindle assembly along the length of the cable as it is being wrapped. The spindle assembly is mounted at the end of an articulated arm which allows free movement of the spindle assembly and allows the spindle assembly to follow lateral movement of the cable.

Abstract: A method and apparatus for producing novelty yarn with an unusual configuration. An effect yarn is fed to a novelty yarn jet, and a core yarn is fed to a different yarn port in the same jet, the core yarn being maintained substantially taut. The combined core and effect novelty yarn is taken up from the jet and periodically (preferably pseudo-randomly) a pronounced variation in linear density is provided in the combined yarn. This linear density variation is accomplished by introducing a first fluid pulse into the jet at a first position to form a loop in the effect yarn, which loop extends substantially coincident with a portion of the core yarn, and then utilizing a second fluid pulse at a spaced position from the first pulse to impart a spiraling and/or rotating action to the loop of effect yarn to wind the effect yarn around the core yarn.

Abstract: A stranding machine, particularly for making telecommunication cable, having a cage with feed reels, a take-up reel, and a back-rotation device which includes two eccentric discs journalled eccentrically with respect to each other in a rotatable guide ring. The discs have a plurality of corresponding bores in identical patterns, each pair of corresponding bores having an eccentric shaft journalled in the two bores so that eccentric motion of the discs causes the eccentric shafts to rotate. Each eccentric shaft has a bore for feeding a wire strand through it and a clamping member which rotates with the eccentric shaft for imparting torque to the strand, by driving the guide ring independently of the discs, so that back-rotation can be varied.

Abstract: An apparatus for stranding optical fiber cores while slackening the same in which optical fiber cores are pushed into core storing spaces which are to be twisted or twisted core storing spaces. A core delivering system has a passage for passing the optical fiber cores therethrough and a gas which flows from the back position of said passage towards the front position thereof functions to send out the optical fiber cores at the inlet side of said core storing spaces. The tensile forces of the optical fiber cores at the inlet sides of the core delivering system are decreased by a winding drum mechanism.

Abstract: Method and apparatus for the production of fancy yarns from falsely twisted core and fancy threads. Staple fibers are drafted by a cylindrical drafter; the core and fancy threads are false twisted by a hollow spindle. At least one drafting of staple fibers are supplied upon the falsely twisted core and fancy threads by means of a pneumatic transporting channel. The speed of the fibers constituting the fancy threads is greater than the peripheral speed of the rollers delivering the core thread. If desired, two rovings of staple fibers may be used, the two rovings having different titre in a ratio of 1:10 and having different lengths of the fibers in a ratio of above 1:2, both rovings entering from one drafter, the two rovings after being drawn being supplied together to the combined false twisted core thread and fancy thread.

Abstract: A linear material 41 is once wound on a winding drum 3, and then wound on a core bar 1 by a winding disk 2. The winding disk 2 periodically reverses the direction of rotation.

Abstract: In the manufacture of a lightguide fiber cable (21) in which a lightguide fiber core (32) is loosely disposed in a composite sheath 40 it is important to control the ratio of the lengths of the core and sheath. A core which is shorter than the sheath and which follows a shortened path on a reel may be unduly strained when the cable is installed in the field. This problem is overcome by coupling the core to the sheath by a system (25) which includes a constant speed linear capstan (146) and a relatively large variable speed sheave (150) that is positioned between the linear capstan and a takeup reel (154). The coupling of the core to the sheath is accomplished on the sheave after the sheath is elongated between the linear capstan and the sheave. The coupling and the elongation cooperate to compensate for the inherent shortfall in core length which otherwise would occur when the cable is wound on a reel.

Abstract: An improved synthetic twine and method of manufacturing same are disclosed. The synthetic twine comprises at least one longitudinally extending oriented synthetic ribbon which has been fibrillated to provide a net-like structure having fine fibril stems connected by finer fibril branches, and a synthetic binder in thin band form made of a material compatible with the synthetic ribbon. The synthetic binder is spirally wrapped around and fused to the synthetic ribbon. The method of making a twine comprises the steps of providing at least one longitudinally extending ribbon, orienting the synthetic ribbon and fibrillating the synthetic ribbon to provide a net-like structure having fine fibril stems connected by finer fibril branches. Thereafter, a synthetic binder in thin bank form is spirally wrapped and fused around the synthetic ribbon which has been oriented and fibrillated.

Abstract: A method and apparatus for producing novelty yarn with an unusual configuration. An effect yarn is fed to a novelty yarn jet, and a core yarn is fed to a different yarn port in the same jet, the core yarn being maintained substantially taut. The combined core and effect novelty yarn is taken up from the jet and periodically (preferably pseudo-randomly) a pronounced variation in linear density is provided in the combined yarn. This linear density variation is accomplished by introducing a first fluid pulse into the jet at a first position to form a loop in the effect yarn, which loop extends substantially coincident with a portion of the core yarn, and then utilizing a second fluid pulse at a spaced position from the first pulse to impart a spiraling and/or rotating action to the loop of effect yarn to wind the effect yarn around the core yarn.