US2958112A

US2958112A - Yarn-treating apparatus

Info

Publication number: US2958112A
Application number: US604564A
Authority: US
Inventors: John N Hall
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1956-08-16
Filing date: 1956-08-16
Publication date: 1960-11-01
Anticipated expiration: 1977-11-01
Also published as: ES237143A2

Description

Nov. 1, 1960 J. N. HALL YARN-TREATING APPARATUS Filed Aug. 16, 1956 FIG. v2.

o M W m I? m N. h A

ATTORNEY United States. Patent j'ice YARN -TREATlN G APPARATUS Filed Aug. 16, 1956, Ser. No. 604,564

,6 Claims. (Cl. 281) This invention relates to apparatus for fluid treatment of yarn, especially jet or nozzle apparatus useful in treatingfilaments of yarn to impart increased bulkiness and other desirable properties to the yarn and to fabrics made therefrom.

Yarn may be exposed to flow of fluids for diflerent reasons and in various kinds of apparatus. A primary object of the present invention is provision of a novel kind of jet for fluid treatment of yarn. An object is construction of a jet adapted to convolute individual filaments of yarn passing through it. Another object is design of a jet for economical attainment of the above and other objects, as will be apparent from the following description of the invention and the accompanying diagrams.

Figure 1 is a schematic representation of apparatus of this invention treating yarn. Figure 2 is a front elevation of one form of apparatus of this invention. Figure 3 is an exploded side view of the apparatus of Figure 2. Figure 4 is a cross-sectional side view of the same apparatus taken at 44 through Figure 2. Figure 5 is a bottom view of the apparatus of Figure 2. Figure 6 is a schematic diagram illustrating the spatial arrangement of the axes of the three passageways in the device of this invention.

In general, the objects of this invention are accom plished by providing means for passing yarn at an app'reciable angle into a turbulent fluid stream, introducing the yarn particularly on the downstream side of an obstacle located in the line of flow. The turbulent stream of fluid (usually air) convolutes individual filaments of the yarn. As shown in Figure 1, yarn 1 to be treated usually is fed at a controlled rate, as may be determined by rol1s2 and 3 between which it passes, on its way into the jet. The yarn enters yarn-introducing assembly 6 protruding from housing 30 at the side of the jet, the bottom of the jet being connected through pipe fitting 7 to a source of air under pressure, and passes into a stream of air passing through the jet. The treated yarn issuing from element 40 of the jet is forwarded at a controlled rate by passing between rolls 4 and 5. It is customary for one roll of each group to be rotated by suitable driving means; for instance, rolls 2 and 4 may be driven in such manner, whereupon they positively rotate contacting rolls 3 and 5, respectively. Upon issuing with theair stream from the top of the jet, the individual filaments of the yarn are convoluted or loopy, as suggested by the jagged line representing the yarn from thereon in Figure 1.

Details of a preferred embodiment of jet appear in Figures 2 to 5, inclusive. The exploded view (Figure 3) shows clearly the three major components: yarn-' introducing means 6, housing 30, and fitting 40. Housing 30, which has cylindrical main bore 20 for its entire length from bottom to top, is the element in which the other two major elements of the jet are assembled. The main bore of the housing is triply stepped outward near the top to accommodate fitting 40, which also is bored lengthwise throughout. Neck 48 of the fitting rests in step 21 of the housing. Step 22 is just large enough to accommodate toroidal gasket 47 encircling the neck of the fitting and resting against boss 52, which in turn rests in step 23 of the housing. Screw 38 threads vertically into the top of the housing :to press clamp 39, which is bifurcated to straddle extension 28 of the fitting, tightly against the boss from above to retain the fitting in the housing. The housing also has secondary bore 33, which slants upward at an acute angle to the main bore, beginning at the front of the housing and constricting at intersection with the main bore. This secondary bore accommodates yarn tube 32 in the constricted portion and tube casing 31 in the outer end of the bore. The front of the housing is divided from top to bottom for part of its depth into

sides

35 and 36 by intervening slit 37. Threaded aperture 26 in side 36 receives screw 34- through slightly larger unthreaded apertures 25 in side 35 to enable the screw to draw the sides toward one another sufliciently to hold the casing snugly in the secondary bore. Bottom 51 of the housing is threaded externally for connection to a source of pressurized fluid. H The'fitting has secondary bore 41, of essentially the diameter of the constricted portion of the secondary bore in the-housing, extending from the outside corner of neck 48 to an intersection with the main bore in throat 43 at an angle identical with that of the intersection of the respective bores in the housing. Blind extension 42 of the secondary bore past the throat of the fitting is of similar diameter or somewhat smaller, as may be suited to the size and shape of exit end 46 of the yarn tube. The throat is enlarged by counterbore 29 at the bottom of the main bore of the fitting, while mouth 49, which is flared outwardly in venturi fashion, carries hardened insert 50 similarly flared.

' Casing 31 surrounds yarn tube 32 from one end to about the middle of the tube to provide suitable rigidity and to support it when the sides of the housing are drawn together to hold the tube in position. The casing, which is hollow to accommodate the tube, extends beyond one end of the tube into an enlarged nutlike portion 44, whose interior flares outwardly to provide a smooth entrance to the tube and carries insert 45 similarly flared. Exit end 46 of the tube is partly cut away along the axis to half-cylindrical form for a distance approximating the diameter of the throat in the fitting. Nut 44, at the opposite end of the casing, is notched for reference (on the face'parallel to the flat edges of the tube left by the cut) to facilitate orientation of the tube with the opening formed by the cut-out in the downstream direction.

The jet is assembled easily. An operator first slips the fitting into the top of the housing until it seats therein. Looking through the secondary or angled bore, he rotates the fitting slowly about the axis of the main bore until reflection of light from the corner of the neck diminishes abruptly as the secondary bore of the fitting comes into the line of sight. Then he puts the clamp on top of the housing astraddle the fitting and threads the screw through the clamp into the top of the housing sufliciently' tightly to compress the gasket into an airtight seal between fitting and housing. The operator slides the yarn tube "carefully into the secondary bores'to an arbitrary depth known to be suificient to place the end of the tube into the extension of the bore across the throat of the fitting. After rotating the tube to bring the reference notch upward, he inserts the other screw in the side of the housing and tightens it sufliciently to hold the casing firmly in place. Assuming that a source of compressed air has been connected to the threaded end of the housing, the jet is ready for operation. With air flowing through the main bore of and the main bore of the fitting and out of the top, the

-Patented Nov. 1, 1960' the housing jet is self-stringing, i.e., the air flow in the main bore will draw air through the yarn tube to such an extent that an end of yarn introduced at the entrance end and free to travel will enter the tube and issue from the mouth of the fitting. The jet is not merely a forwarding device, however; it is capable of treating yarn so as to modify the configuration. For continuous-filament yarn the treatment may be summarized conveniently as a convolution of the individual filaments into loops along the lengths of filament. While the rate of treatment is so rapid as to hinder effective observation, apparently turbulence existing downstream from the locus of injection of the yarn into the main bore whips the filaments violently and forms loops therein, which remain after the yarn exists from the air stream at the mouth of the jet. The yarn usually is removed fairly abruptly from the issuing blast of air, as by being withdrawn to one side (as shown in Figure 1).

The configuration and accompanying characteristics of yarn treated by the apparatus of this invention depend in part upon the amount and velocity of air (or other driving fluid) and, as well, upon various features of the jet construction and adjustment. For example, the product may have a relatively stable configuration, as described in Breen patent applications Ser. No. 261,635, filed December 14, 1951, now U.S. Patent 2,783,609, and Ser. No. 375,372, filed August 20, 1953, now U.S. Patent 2,852,906, or a relatively unstable configuration, as described in Field patent application Ser. No. 419,355, filed March 29, 1954. The desirable bulkiness and other beneficial attributes of yarns so treated are discussed therein.

In order to generate the turbulence requisite to convolution of the filaments, the jets of the present invention provide a suitable obstacle in the air stream, and introduce the yarn downstream from the obstacle, at an appreciable angle to the axis of the stream, whose inlet is coaxial with the exhaust or outlet passage for both yarn and air. In the illustrated jet this obstacle is integral with the yarn-introducing means; the halfcylindrical end of the yarn tube extends into the air stream in the main bore, and the yarn tube may be inserted deeply enough (as shown in Figure 4) to rest in the extension of the secondary bore in the fitting. The yarn issues from the cylindrical portion of the tube, passing just downstream from the half-cylindrical end, which is cut away in that direction. The upstream portion of the main bore (from the bottom of the jet to the intersection with the secondary conduit for air (or other fluid), while the downstream portion conducts both the air from the upstream portion and the introduced yarn, along with a small amount of air that enters with the yarn through the yarnintroducing means. The depth of insertion of the yarn tube is variable at the election of the operator (as is apparent from Figure 4) but is fixed so long as the adjusting screw is tight. Adjustment of the depth of insertion is simple with the illustrated design of flangelike sides on the housing (as seen quite clearly in Figures 2 and 5).

The turbulence-generating obstacle need not be integral with the yarn-introducing means but may be mounted, either fixedly or adjustably, in the main bore of the fitting. Both the yarn tube and the fitting itself may beintegral with the housing if desired, but the illustrated three-part jet is conveniently assembled and adjusted for optimum performance, as well as readily disassembled for inspection. It is desirable to have the obstacle and the yarn tube made of especially hard material to reduce wear, but as they should be replaceable in the eventuality of wear it is less worth-while to attempt to combine them with any part except one another. When they are integrally formed, the end of bore) is simply a the tube may be closed, instead of open, with merely a notch or slot in the nearby side of the tube for the yarn to issue from. Furthermore, although a single size of yarn tube may be used satisfactorily for a wide range of yarn deniers, as by adjustment of the depth of insertion, other diameters or cross-sectional shapes of yarn tube may be substituted easily when the tube is removable. The fitting is generally not so subject to wear, so it may be made integral with the housing advantageously. Whereas the yarn-introducing means preferably is made of a high-carbon steel of great hardness, the fitting and the housing may be of considerably softer metal, such as ordinary stainless steels or even brass. It is desirable for the mouth of the fitting to be relatively hard, or to carry a hardened insert, because of the wear potential from abrasion by the treated yarn. The yarn tube itself conveniently has a ceramic insert at the inlet end to guide the yarn in without damage.

A substantially straight-flow path provided for the treating fluid in the apparatus of this invention is especially advantageous because less air at lower pressure is required to convolute the filaments of yarn satisfactorily. This contrasts with designs in which the yarn passes more or less straight through and air is introduced at one or more angles thereto. Generation of turbulence by bifurcation of the air stream about a suitable obstacle is more economical of air than impingement upon the wall of the fluid conduit or use of angled multiple streams. (This feature of the illustrated design appears clearly in Figure 5.) When the turbulencegenerating and yarn-introducing means are separate, a like effect may be obtained by placing a pin or other relatively slender obstacle across the main bore upstream from the intersection with the secondary bore. Such a separate obstacle may be of uneven longitudinal or transverse cross-section and may be rotatable or slideably positionable to vary the effect upon the air stream.

By comparison with the jet shown in Figure 11 of Breen Ser. No. 375,372, the illustrated jet duplicates or betters the results (in terms of desirability of resulting yarn configuration and uniformity of configuration produced over a protracted time of operation) with consumption of less than three quarters as much air, and it permits a reduction of supply pressure for the air stream from a gauge pressure of sixty pounds per square inch (p.s.i.) to 40 p.s.i. for comparable results. Comparison with the other jets shown in the Breen applications is at least as favorable to the present jet. Extremely high overfeeds are attainable with this design at relatively low air supply pressure. For example, the rate of entry of untreated yarn may reach or exceed five times the exit rate of treated or loopy yarn from the jet connected to a 60 p.s.i. source, whereas previous jets so used were limited to less than overfeed. Using 40-denier, 30-filarnent nylon multifilament having three turns per inch, an excellent Breen type of product was obtained at 40% overfeed (controlled by ratio of windup speed to feed speed) and pressure of 50 p.s.i. with consumption of 1.5 cubic feet of air per minute (measured at atmospheric pressure and ordinary room temperature); a high-quality product of the type described in Field Ser. No. 419,355 was obtained from the same yarn, having only one turn per inch, at 250% overfeed and pressure of 40 p.s.i. gauge, consuming 1.4 cubic feet of air per minute. The minimum diameter of the main bore of this particular jet was 0.06 inch, while the diameter of the yarn tube was 0.016 inch. The angle of yarn introduction was forty-five degrees.

The jet elements may be designed with the angle at which the yarn is injected or introduced into the main air stream deviating considerably from the above exemplification. For successful convolution of the filaments it is preferable that yarn be forced to change its path appreciably upon exiting from the yarn tube into the air stream; although the reason for this is not too clear,

perhaps it involves exposure of a suitably extensive surface of the individual filaments to the air flow. A changein path direction of thirty degrees or less is generally unsatisfactory (angle measured between the axis' of the yarn tube and the axis of the upstream portion of the main bore). Furthermore, an injection angle approaching the perpendicular is unsatisfactory because of resulting non-uniformities in the treated yarn, even to the extent of breakage, perhaps because of excessive tensioning by the air or intermittent contact of the yarn with the housing wall opposite the yarn-introducing tube. Because of the economics of air compression, use of this kind of jet having an injection angle much greater than about sixty degrees is unlikely, anyway. Thus, for the purposes of the present invention, the term appreciable, as applied to the angle between the introductory yarn and air paths, may be considered to designate an angle of from about forty-five degrees to about sixty degrees for a jet with a straight-line flow path for fluid through the jet.

. In general, the yarn-treating apparatus of this invention comprises three passageways, as illustrated schematically in Figure 6; namely, (1) a conduit for both yarn and fluid 60, (2) a yarn-introducing means 61, and (3) a fluid entrance-way 62 arranged so that the conduit for both yarn and fluid 60 is intercepted at about the same point by the yam-introducing means 61 and the fluid entrance-way 62, the yarn-introducing means terminating in the conduit 60 and forming an angle (a) of between about 120 and about 180* therewith, and the fluid entrance-way also terminating in the conduit and forming an angle (3) of between 120 and about 180 therewith, the angle (7) between the yarn-introducing means and the fluid entrance-way being between about 30 and about 90. Whatever the relative arrangement of the conduit for both yarn and fluid, the yarn-introducing means, and the fluid entrance-way, it is essential that yarn enter the conduit on the downstream side of an obstruction partially impeding flow of fluid from the fluid entrance-way into the conduit. The obstruction may be integral extension of the yarn-introducing means or may be a completely separate element fixed or removably fixed at about the point of intersection between the fluid entrance-way and the conduit for both yarn and fluid. The obstruction imparts turbulence to the fluid as it leaves the fluid entrance-way. As used herein, the term conduit is used solely to describe that portion of the apparatus carrying both yarn and fluid simultaneously, and entrance-way refers solely to the passageway carrying fluid only.

One or another or" the passageways in the apparatus, namely, conduit for yarn and fluid, yarn-introducing means, or fluid entrance-way, may or may not be of uniform cross section or cylindrical in shape. In certain instances, it may be desirable to have one or another of these passageways in the form of a rightor oblique-conical section inverted or otherwise, and for some applications it may be desirable to have one or more of these passageways in the shape of a venturi or provided with an orifice. Many adaptations of the instant invention designed to achieve a variety of results Will be apparent, all being encompassed within the scope of the invention.

The absolute and relative dimensions of the main and secondary bores (and the internal diameter of the yarn tube) may be varied over fairly wide ranges, although the main bore usually is larger. One advantageous attribute of the jets of this invention is their effectiveness in processing a great variety of yarn counts without necessity of a change in the dimensions; accordingly, the dimensions may vary considerably from those given above, which have been found eflective upon yarn counts (total denier and number of filaments) from 36- 10 and 40-34 through 84-34 to 210-402, among others, without impairing the desirability of configuration of the product. Yarns of higher and lower total deniers and denier per filament may be processed similarly by the apparatus of this invention with comparable satisfactory results. Of course, a particular jet may be selected for its general effectiveness with a particular yarn to be processed and its economy of air consumption, manufacturing expense, or other factors. Jets differing in various ways from the exemplified design may be constructed without departing from the invention.

In accordance with one application of the yarn-treating apparatus of this invention, a random intermittently textured yarn is prepared by varying the rate of feeding yarn to the yarn-treating apparatus. A novel method for varying the yarn feed rate involves feeding the yarn to the yarn-treating apparatus through feed rolls, one roll being a driven feed roll and the other a driving feed roll, the driven feed roll being free to revolve about its axis and the driving feed roll being connected to and rotated by a source of power. The two feed rolls revolve about parallel axes in the same plane, and the driven feed roll is positioned in yielding tangential contact with the driving feed roll. The driven feed roll is of relatively light-weight construction and material and is desirably covered with a resilient material such as rubber or the like. The driving feed roll contains on its exterior periphery one or more pips or bumps of suflicient size to cause the driven feed roll to assume a bouncing motion as it rotates due to frictional contact with the driving feed roll. Contact between the two rolls is, of course, intermittent due to the bouncing motion of the driven feed roll, and, in order to provide for this bouncing action, it is necessary that the driven feed roll be suspended yieldingly in tangential contact with the driving feed roll. In accordance with one embodiment, this yielding suspension, which permits the driven feed roll to move away from the driving feed roll in a substantially radial direction thereto as a result of a blow by a pip on the rotating driving feed roll, is accomplished by attaching the axis of the driven feed roll to lever arms which in turn are attached for pivotal movement at the opposite extremity. (Alternatively, yielding suspension of the driven feed roll may be obtained by positioning the driven feed roll axis for free movement in a pair of tracks (longitudinal slots) extending radially from the axis of the driving roll.) With such an apparatus, the driven feed roll, upon being bounced away from the driving feed roll, will tend to move in a circular path about pivotal axis of the lever arms. Desirably, the driven feed roll will be positioned substantially above the driving feed roll so that after such a bounce gravity alone will return the driven feed roll to contact with the driving feed roll. Obviously, however, the driven feed roll may be positioned elsewhere with respect to the driving feed roll, and return of the driven feed roll to contact with the driving feed roll following a bounce may be accomplished by springs, rubber bands, or other devices for maintaining the driven feed roll in yielding tangential contact with the driving feed roll. Naturally, the weight of the driven feed roll, the rate of rotation of the driving feed roll, the number and size of the pips, etc. will in combination determine the amount of bounce (the distance which the driven feed roll will move apart from the driving feed roll), and the length of the lever arms positioning the driven feed roll and the relative positions of the two rolls must be chosen accordingly.

In feeding yarn to the yarn-treating apparatus of this invention by means of variable and random yarn rate feed rolls described above, bouncing of the driven feed roll due to contact with the pips on the revolving driving feed roll causes changes in tension and unit length of the threadline upstream of the yarn-treating apparatus. Increases in tension (upstream of the yarn-treating apparatus) slow down the rotation of the driven feed roll when it is out of contact with the driving feed roll andlower temporarily the rate of feed of yarn to the apparatus. At the same time slippage occurs between the driven feed roll and the yarn, and the end result of the bouncing motion of the driven feed roll is to supply yarn to the fluid jet apparatus at a random intermittent rate whereby there is produced a random intermittently textured yarn product.

This application is a continuation-in-part of application Serial No. 424,860, filed April 22, 1954, by John N. Hall, now abandoned.

What is claimed:

1. Yarn-treating apparatus comprising fluid-conducting means having a substantially straight bore for flow of fluid therethrough, yarn-introducing means terminating therein in thedownstrcam direction at an appreciable acute angle therewith, and turbulence-generating means joined to the upstream edge of the yarn-introducing means and extending across the bore of the fluid-conducting means so as to bifurcate flow of fluid therethrough.

2. Yarn-treating apparatus comprising a fitting bored longitudinally and bored transversely therewith at an appreciable angle, tubular yam-conducting means extending into the longitudinal bore from within the transverse bore, and a housing holding the fitting and the tubular means in fixed relationship adjustable for depth ofv insertion of the tubular means up to the entire diameter of the longitudinal bore.

3. Yarn-treating apparatus comprising a fitting bored longitudinally and bored transversely to intersect therewith at an angle of from about fortyfive degrees to about sixty degrees, tubular yarn-conducting means slitted at one end and slideably mounted to terminate in the transverse bore, and a housing holding the fitting and the tubular means in fixed relationship.

4. Yarn-treating apparatus comprising a fitting bored longitudinally and bored transversely therewith at an angle of about forty-five degrees, tubular yarn-conducting means inserted in the transverse bore and completely across the longitudinal bore and opening toward the portion of the longitudinal bore which forms an obtuse angle therewith, and a housing holding the tubular means in slideable relationship with the fitting.

5. Yarn-treating apparatus comprising a housing bored longitudinally to form a main bore extending therein throughout the length of the housing, bored transversely therewith to form a secondary bore therein at an angle of about forty-five degrees to said main bore and extending from the outside of the housing to an intersection with the main bore, and slitted longitudinally from the outside of the housing to a depth less than the distance to the main bore, the slit being parallel to and intersecting the secondary bore to form flanges in the housing flanking a portion of the secondary bore, one of the flanges having a threaded passage and the other flange being bored coaxially with the threaded passage in the other flange for insertion of a screw adapted to draw the flanges together; a fitting bored longitudinally to form a main bore extending therein throughout the length of the fitting, bored transversely therewith to form a secondary bore therein at an angle with the main bore of the fitting identical with the angle between the main bore and secondary bore of the housing and extending from the outside of the fitting to an intersection with the main bore thereof and straight across the main bore into a blind extension of the secondary bore, the fitting being adapted to seat airtight against the housing with the main bores of the housing and fitting communicating coaxially and with. the

secondary bores of the housing and the fitting column-- nicating coaxially; and a cylindrical yarn tube extending from the outside of the housing through the secondary bores of the housing and the fitting and terminating in a half-cylindrical portion resting in the extension of the secondary bore in the fitting with the openside of the half-cylindrical portion of the tube communicating with the portion of the main bore of the fittingwith which the yarn tube makes an angle of about one hundred thirty-five degrees, the yarn tube being slideably mounted in the secondary bores and held therein by a drawing together of the flanges of the housing.

6. Yarn-treating apparatus of claim 2 in which the tubular yarn-conducting means and bores in the fitting define essentially three passageways: (l) a fluid entranceway, (2) a yarn-introducing means, and (3) a conduit for yarn and fluid, said passageways being arranged so that the axes thereof intersect at the same point, the axes of the fluid entranceway and yarn-introducing means each forming an angle of between about and about with the axis of the conduit for yarn and fluid and forming an angle of between about 30 and about 90 with each other.

References Cited in the file of this patent UNITED STATES PATENTS 2,224,923 Pool Dec. 17, 1940 2,435,891 Lodge Feb. 10, 1948 2,681,729 Griset June 22, 1954 2,783,609 Breen Mar. 6, 1957 2,807,862 Griset Oct. 1, 1957 2,852,906 Breen Sept. 23, 1958 FOREIGN PATENTS 1,100,529 France Apr. 6,1955