US2238659A - Fiber drawing mechanism and process - Google Patents

Description

April 15 1941.

W. G. REYNOLDS FIBER DRAWING MECHANISM AND PROCESS Z5 Sheets-Sheet 1 Filed July 25, 1934 2, ff f l INVENTOR. */i JM BY mmm Y ATTORNEY.

Pl'l 15, 1941- w. G. REYNOLDS 2,238,659

FIBER DRAWING MECHAHISM ANDv PROCESS Filed `July 23, 19,34 v 3 Sheets-Sheet 2 7/ u 4 i umm H n V/// (ZZ :i:

- INVENTOR.

www. W

ATTORNEY.

April 15 1941- w. G. REYNOLDS 2,238,659

FIER DRAWING MECHANISM AND PROCESS Filed July `215, ,1934 -3 Sheets-Sheet 5 l d" INVENTOR.

MMM4 ,Q y @el BY @wl-iw.

ATTORNEY.

Patented Apr. 15, 1941 2,238,659 mmm DRAWING M/EcnANrsM AND PaooEss William G. Reynolds, Charlotte, N. C., assigner of one-half to The Terrell Machin e Company,

Qharlotte N. C., a corporation of North Carolina Application July 23, 1934, Serial No. 736,460

' 2s claims. (c1. 57-156) The present invention relates to a process and mechanism for drawing fibrous material arranged in strand form, for the purpose of making yarn therefrom. It has as its object the provision of an improved technique and more efficient devices for drawing ya strand, so as to obtain longer draft in a single continuous operation, and to produce a stronger, smoother, evener roving or yarn with mechanism which is easier to control in operation.

These aims are attainedthrough giving to the strand, preferably before it is drawn, such a shape in cross-section that it will conform to the space in which it is confined by the rolls or equivalent devices which hold it against draft, so

that all the fibers in such cross-section are.

gripped and held with equal resistance to the ydrafting pull exerted on the strand by the sucing the strand into the groove just as itdeparts f from engagement with the preceding pair of drawing rolls; and in furtherance of this control, the strand is wrapped about a substantial arc of the surface of one of these preceding drawing rolls, to hold the fibers, by means of frictional engagement with the surface of such roll, against straying out of their intended position. This early entry of the strand into the groove insures the proper completion of the inward folding of the lateral margins of the strand before being compressed at the nip of the tongue-and-groove rolls. The continuous control thus achieved, while producing a smoother yarn, through keeping the ends of the fibers, particularly the short fibers, from bristling outward out of the parallelized relation achieves through drafting, not only keeps the selvages or edges of the nattened strand from becoming rough and ragged, but goes vfar to prevent stray fibers from getting wholly free from the strand before they can be 'folded inward into the center of the strand by the action of the groove, thus serving to prevent the groove from ,becoming fouled by lint and fly with resultant lapping-up of? the strand in the groove and breakdown of the strand; and this aim of keeping the groove clean is further attained preferably through giving the bottom of the groove a different rate of travel than that bf the opposing surface of the cooperating tongued roll, at the same time fluting this surface of the tongued roll so that the strand will travel at the rate of the tongued roll and slip enough with respect to the bottom of the groove to keep the latter wiped clean. Additionally, the grooved roll is preferably placed above the strand, so that gravity aids in -preventing lapping-up, and in keeping lint, fly and dirt from settling into and packing in the groove, and makes it possible to clear the remaining surfaces of the grooved roll by conventional devices. tainment, are as set forth hereinafter.

An illustrative embodiment of the invention is shown in the accompanying'drawings, in which- Flg. 1 is a view in vertical section of 'a preferred `formof drawing-roll system employing the devices of the invention for making roving, taken on line I-I of Fig..2.

Fig. 2 is a plan view of a portion of a roving frame serving two spindles, the several rolls of Fig. 1 being shown shortened considerably from vtheir actual proportions.

Fig. 3 is a front view, and Fig. 4 -is a sideelevation, of a form of trumpet used to give the strand flat and parallel top and bottom surfaces.

Fig 5 is a detail showing the mounting of one bottom tongued roll and one bottom ordinary roll, illustrating a method of attaining the adjustments needed. i

Fig. 6 is a view in elevation of one section of the tongued rolls,\showing also the gears which drive the superposed grooved rolls, and representing the rearmost line of tongued rolls of Fig. 1.

Fig. '7 is a detail view showing a quickly detachable connecting and adjusting means for the several sections of the tongued rolls.

Fig. 8 is a view of the paired grooved rolls cooperating with the tongued Irolls of Fig. 6 showing also the gear through which they are driven from the tongued rolls.

Fig. 9 is a view in vertical section showing an application of the invention for spinning.

Fig. 10 shows the method of mounting the rolls of Fig. 9 so as to provide for the various `ad justments needed.

The drawings show only so much of a roving frame employing the devices of the invention as is necessary to make plain the arrangement and operation of the improved construction, the parts in Fig. 2 representing the necessary rolls to operate upon four ends and serve four spindles; it is Other objects, and their manner of at-` to be understood that these devices will be duplicated t |roughout the length of the roving frame to prov de for as many spindles as desired; also it should be noted that this showing has been laterally condensed, the tongueand-groove rolls generally having the actual shape shown in Figs. 6 and 8, and that the roll mountings shown in Fig. have been omitted.

'Ihe invention contemplates in its preferred form the use of both ordinary drawing rolls and special tongued and grooved rolls, working successively and simultaneously on the same strand, although certain features of the invention are adapted to be used irrespective of the nature of the drawing rolls and their manner of combination. The tongued and grooved rolls cooperate in opposed relation, with each grooved roll preferably above the strand and its groove occupied by the tongue of its opposing tongued roll, and the groove may be narrower than the width of the strand which enters it, so as to fold the lateral margins of the strand inward, preferably being one-half the width of the strand at that point so that the outer edges will. be caused to meet at the median line of the strand, lthe mouth of the groove being beveled to facilitate entry Without shearing; the pressure at the nip of these opposed rolls incorporates the fold and condenses the strand, so that a very long draft may be given to the strand as it issues from the nip without loss of uniformity.

The various rolls are mounted for free rotation in suitable bottom roll stands such as those indicated at I, 2, 4, 6, in Fig. 10, supported on the bed 3 forming a part of the framework of the roving frame, and 4in top roll guides 9 on a capbar I0, in such manner that each member of a cooperating pair of rolls can be adjusted individually as desired, either to change the spacing of each pair with respect to its adjacent pairs, or to vary the level of each pair to raise or lower its nip with respect to the nip` of the preceding pair of rolls and thus to determine the extent to which the strand is wrapped about one ro11 of either or both of these pairs, or to effect both forms of adjustment. Also, the mounting having these adjustments provides for adjustably tipping the plane in which lie the axes of rotation of each pair of rolls, to aid in adjusting the amount of wrap of the strand about the several rolls.

Thus, in the illustrative roll mountings shown in Figs, 5 and 10 the bottom tongued rolls such as 33, 4I, 49, are each mounted in a small `stand 4 which is slidably mounted on the bed 3 to permit it to be adjusted as a Whole toward and from the front of the frame, being guided by a iin I6 entering an appropriate slot in the bed 3, and being maintained in the desired adjusted position by a clamp screw I8 threaded into bed 3 through a slot in a flange on the side of stand ,4. The shaft 22 of the bottom tongued rolls aforesaid is received in ways 24 formed in the stands 4,

and half-boxes or followers 26 within the ways and receiving the shafts 22 are adjustably positioned by screws 28 to maintain the tongued rollsI at the desired level. Likewise, the ordinary bottom rolls 21, 39, 41, are received in similar. ways in the same stands 4 with similar capacity for ad- ,justment The stands 2 supporting the ilrst or feed rolls, whether ordinary rolls as roll I4 of Figs. 1 and 2 or tongued as roll II, of Figs. 9 and 10, and stands 6, supporting the last ordinary roll comprising the bottom delivery roll, each serve only a single roll, but with the same capacity for Awith the tongued roll the rectangular orifice.

in adjusted position lengthwise thereof by clamp,

screws 30; they are of two different lengths, to accommodate the different elevations of the bottom rolls, and each is provided with ways closed at the bottom by which the journals 32, Fig. 8, of the grooved rolls' and the corresponding ends of the ordinary top rolls are positioned. The capbars I0 are clamped at 34 in the -members 36 which are pivoted at 38 to brackets 40 in connection with the beds 3. The arrangement shown permits the strand to travel substantially horizontally in the intervals where drafting occurs, so that the shafts of the two top rolls involved in each drafting operation are approximately at the same level, simplifying the Weighting of the top rolls if desired, as the usual saddles 42, hooks 44, and weights 46 may be used for this purpose.

The strand 5 to be drawn, which may be either card or comber sliver which has not previously been drawn, or drawing frame sliver, put through a trumpet or condensing guide 1 which has its'delivery orifice preferably shaped to impart to the sliver a flat top and bottom surface corresponding in shape to the flat prole of the opposed Working surfaces of the two rolls whose nip serves to draw the sliver through the delivery aperture of guide 1. This principle is utilized regardless of the specific types of rolls forming this rst pair of rolls, the feed or holding rolls, as it has obvious advantages .in providing for a uniform grip on all the fibers comprising the entire cross-section of the sliver when it reaches the nip of these rolls, and avoiding to a large extent the fault of leaving fibers at the lateral margins of the sliver free to be drawn forward 4without restraint and hence unevenly by the as for instance in such an arrangement as that of Figs. 9 and 10, where the feed rolls 9, II, are of conforming tongue-and-groove formation, with the sides I3, Fig. 8, of the groove perpendicular to the adjoining flat bottom I5 thereof, the lateral sides or ends 10 of the delivery orice of trumpet 1 are perpendicular to the parallel top and bottom surfaces I9 and the delivery aperture thus is rectangular in shape so that the sliver will have this shape needed Yto conform to the rectangular passage between the grooved roll 9 and 'the tongued roll I I at their nip when the sliver crowds them apart. Because of the inevitable expansion of the sliver when released fromv compression upon leaving the rectangular end of the trumpet, the bottom I5 of the groove may have a width slightly greater than the width of the trumpet orifice, this vincrease being ordinarily on the order of 11g of an inch wider in a horizontal direction than the correspondingy dimension of Thus, by way of illustration with a rectangular trumpet orifice 3/8' inch wide by inch high, the groove of roll 9 may desirablybe 1/2 inch in Width, and 1A inch deep,

'at the speed of travel of the tongued roll, and

II having a, face fitting 'easily but closely Within the width of the groove.

also so as to have a cleaning action on the sliver engaged thereby; for this latter purpose, the teeth are cut deeply to receive the foreign matter always present in the bers, which separates easily therefrom under the present arrangement be approach the nip at an oblique angle to this plane, and hence will encounter the flared or sloping portions I2 of the side walls and the perpendicular portions Il of the side walls of the groove as soon as practicable after the sliver emerges from the trumpet "I, thus controlling any stray lateral fibers and reestablishing or preserving the rectangular cross-sectional shape given to the sliver by the trumpet.

Because of the relationship between the width of the trumpet orifice and that of the groove, there is no folding action of any importance performed by the pair of tongued-and-grooved feed rolls 9, II, the side walls I3 serving merely to hold the strand to the predetermined width. It has been found that folding is unnecessary at this stage, because the sliver is thick and strong and in uncritical condition. The tongue-andgroove rolls-v when used at this point have the advantage of holding every-individual fiber more completely than the usual rolls.

The grooved top rollsl I, 3|, 43, 5I, pressed down when needed by usual weighting means such as indicated in Fig. are each given a rate of travel of its surface I5 yforming the bottom of the groove that is substantiallyy less than that of the rate of travel of the tops of the teeth or flutes I'l formed on the surface of its coacting tongued roll Il, 33, 4I, 49. Since a positive control is desired, the grooved roll is driven from the bottom tongued roll by intermeshing gears 2 I, 23, Figs. 2, 6, 8, on the roll shafts. 'Ihe tongued bottom rolls are driven as usual with bottom rolls from the gears 29.

The first drawing rolls 25, 21, are or may be of the standard type comprising a uted metallic bottom roll 21, like the feed rolls I4, Il, mechanically driven like tongued roll II through the usual gears V29 from the shaft 3l which drives the roving frame, and a covered top roll v 25, which is frictionally driven from the bottom roll, being Dressed thereagainst by weighting means as indicated in Fig. 10, or both rolls'may have metallic working surfaces. The setting of these rolls with respect to the holding or feeding rolls Il, Il', or 8, II, is usually slightly greater than the length of the staple. These drawing rolls 25, 21, operate as usual, and their rate of travel, imparted through gearsA 29, is auch as is needed to produce'the desired drawsubjecting them to further draft. This reassembling is effected in conventional processes by the twisting which marks the `end of each process. Here, vhowever, for this purpose, a pair of tongueand-groove rolls Il, 33, are employed, in which the bottom of the groove is sufficiently narrower than the strand issuing from between the drawing rolls 25, 2l, sov that there will be an inward folding of the latter margins and protruding fibers of the strand, together with a condensing andA compacting action, as described hereinbefore. But in carrying'forward the strand from these first drawing rolls 2l, 2l to the tongueand-groove rolls, 3l,` 33, there is a very strong tendency for the individual fibers to assume their normal curving shape and to curl outward out of parallel with, the axis of the strand. To

counteract this, the Aplane tangent to thesev tongue-and-groove rolls at their nip-is placed considerably below the plane tangent to the preceding drawing rolls at their nip, so that the strand will be wrapped around a .considerable Vlarc of the lower drawing roll 21 and thusbe controlled and held against flaring and the conl depends somewhat on the length and character ing of the strand between the two pairs of compacting and condensingv the fibers before of the fiber being drawn and the size of the strand, but the strand will preferably engage a greater arc of the surface at the bottom of the groove at ingress than at egress. The grooved roll li is set close to the surface of drawing roll 21, without making contact therewith, so that the fibers comprising the lateral margins of the strand are gathered inward toward the axis of the strand through the folding action of the groove while they are still in contact with the surface of preceding roll 21. The early entry of the strand ensures its being completely folded and the straying marginal. fibers included, and its being given a well-defined rectangular shape insuring uniform fiber-grip across its entire section, before being` compressed at the nip. The groove in roll 3| should be narrower than the strand, being on the order of 1A inch wide .by 3, inch deep when used with parts of the climensions referred to hereinbefore, where the feed-rolls are tongued; when ordinary feed rolls are used, as in Figs. 1 and 2, the groove in roll 3l is on the order of 1% inch wide by 5, inch deep. To counteract further the curling tendency of the fibers when released fromthe draft of drawing rolls 25, 21, the strand may be given a slightly greater rate of feed through the nip of the tongue-and-groove rolls 3l, 33, than at the nip of the preceding drawing rolls 25, 21,; this increase is merely a taking-up of the natural expansion of the traveling strand following draft, and of the fullness developed in the middle of the strand by the folding, so as to keep it tight, and is not an actual draft, because it is highly desirable'to prepare the strand by folding and condensing before -each succeeding draft, in order to maintain uniformity.

When it is desired to carry the application of the principles of my invention in a single process beyond the use of a single pair of tongued-andgrooved rolls, the same principle of differential -rate -of travel of their opposed fiber-engaging surfaces is preferably employed with the succeeding tongue-and-groove rolls, with the groovebottom I5 usually driven at a. slower rate than the opposing surfaceofthe tongue. It appears desirable in the combination shown that no lber- ,engaging surface on the grooved roll travel roll, the mouth of the groove, that is, the portion of the sloping side walls |2 which is of full diameter, will be given approximately the same speed of surface travel as that of the tongued roll, so

as to avoid holding back' on and thus deranging or doubling backward the straying marginal bers of the sliver. The slight slip of the top and side surfaces of the sliver resulting from the slower travel of the bottom and sides of the groove with respect to the sliver Iwhose speed is determined by the tongued roll,serves both to smooth the outer fibers into the body of the sliver and also to prevent adherence of fibers to the `bottom and walls of the groove with resultant fouling and lapping-up, because the fibers are always kept moving with respect to these surfaces, which are thus swept clean. The differen- .tial rate of travel of the opposed working surfaces of the tongue-and-groove rolls 9, like the 'depth and width of the groove, and the pitch of the teeth on the tongued roll, may be varied to suit the size of the sliver and the particular kind or character of the ber being drawn: the general rule is that the ner the sliver, the greater the speed differential between the bot-tom of the groove and the opposing surface of the tongued roll For instance, good results have been obtained on 40 to 8O grain sliver in a groove 1/2 inch wide, when a tongued roll having a diameter of 1.125 inches has a rate of travel of its working surface of 3.53 inches for each revolution of this tongued roll, while the opposing working surface of the groove, having a diameter of .875 inch, has a surface speed of 3.22 inches for each revolution ,of the tongued roll, the differential rate of travel being attained thrpugh the ratio of the gears 2|, 23. It is contemplated .d

in certain cases to have 'the groove remain completely at rest, at any one or more of the loca: tions occupied by rolls 9, 3|, 43, or 5|. Under the conditions indicated by the gures given hereinbefore, the grooved roll 3|, /having a diameter of .75 inch at the bottom of the groove, cooperates with a tongued roll 33 of one inch diameter, the two rolls being driven at the same R. P. M., so that while the tongued roll is traveling at a rate of 3.14 inches per revolution,the opposing work-engaging surface of the groove travels at a rate of 2.36 inches per revolution.

Though the amount of draft obtainable in a machine stage depends on the degree of uniformity demanded in the yarn, the character of the fiber and the quality of its preparation, the size of the sliver, and other familiar factors, I have found that a good quality of roving can be made on the arrangement of Figs. 1 and 2 while effecting a draft ranging from 3 to 6 times extension between feed rolls I4, I4, and drawing rolls 25, 21, with tongued roll 33 traveling 1.()4

to 1.06 times as fast as rolls 25, 21, and with a further extension of the sliver ranging from 3 to 6 times effected between rolls 3|, 33, and 31, 39. 75

Drafts of the same order are used in the arrangement of Figs. 9 and 10` wherever extension is effected, so that the four drafts there provided for can give a maximum extension of over`500 times.

In the arrangement of Fig. 1, the second pair of drawingrolls 31, 39, of standard construction, setting, and operation, arewiisposed as before in such manner thatthe strand has a substantially horizontal direction of travel from the nip of the second tongue-and-groove rolls to the nip of this pair of drawing rolls, which as indicated simplifies the problem of weighting. The draft in this stage is as before whatever may be suited to the reduction in weight desired. Here, as well as elsewhere, the smoothest roving or yarn is obtained when the strand leaving the nip of the tongued and grooved rolls wraps around the groove rather than the tongue, as then its margins will not be rendered uneven by being pulled into the clearance space at each side between the tongue and the groove.

As in the arrangement of Fig. 9, additional.4

pairs of tongued and grooved rolls 4|, 43, 49, 5|,

- are employed in alternation with succeeding pairs of standard drawing rolls 45,41, 53, 55, in accordance with the principles of construction and operation already set forth herein,-to. the number and extent desired to bring the strand down to the requisite neness with regard to the character of the original strand and the quality of' the results desired. In the illustrative embodiment of Figs. 1 and 2, four pairs of rolls are shown. This is not restrictive, but when employed with either tongued and grooved or plain feed rolls, proves adequate in many cases, with the nal processes and the twisting-performed on the conventional types of frames.

In general, each groove should desirably be about twice the width of the groove in the grooved roll next following it, for the purpose of folding the strand for each draft; thus, if the groove in roll 43 is 1A; inch in width, that in roll 5| may be 116 inch in width. Each grooved roll shouldV have a bottom diameter of about 75% of the diameter of its corresponding tongued roll.

The devices described are capable of replacing all or any of the various processes or machinestages ordinarily used, from the time the strand is delivered as sliver from the card or comber `down to the degree of fineness desired, and

where thus used for the whole process the strand issuing from the final pair of drawing rolls will be twisted and wound by customary devices, such as the traveler 51 on ring 59, upon a bobbin 6| on spindle B3, in usual manner.

To register the tongued rolls accurately with the grooves in the corresponding grooved rolls, novel means have been devised for connecting the sections of the tongued rolls together so that they will all be driven in unison from the gears 25 at one end of the machine, while any one roll section may be adjusted axially to vary its enclwise position with respect to its adjacent sections. This is accomplished by providing one end of the shaft 22, which in the form shown in Figs. 2, 6, and 7 has the four tongues and the two driving gears 23 integrally formed thereon, with a reduced *portion 1| which is externally threaded with a right-hand thread to engage a similar thread on the interior of a corresponding bore 13 in .the end of the section of tongued roll which is -adjacent the present one at the left-hand side. The reduced portion 1| is itself bored out and tapped with a left-hand thread to receive a correspondingly threaded screw y15, the head of which strikes the inner end of the bore 13 as the reduced portion 1I is screwed home therein and by the amount of its extent beyond the end of the reduced portion 1I determines the distance to which this re- -duced portion may be screwed into the corresponding bore of its adjacent section. When the screw head strikes the bottom of the bore 13 its frictional engagement with such bottom tends to turn the screw in a direction to back it out of its bore; consequently the whole joint is jammed or locked immediately against further inward movement of the extension ll. `The Joint will stay tight as long as power is applied to rotate the line of combined tongued rolls in one direction, but a very slight rotation in the reverse direction at any joint will freeit easily. As is obvious,"adjustment of the outward extent of the screw when the extension 1I is out of its associated socket serves quickly and simply to adjust axially the position of the tongues of any roll section with respect to their corresponding grooves when the sections are again put together.

With the grooved rolls on top and easily accessible, any simple or standard form of stationary clearer board'such as one clothed with sheepskin may be used to clear these rolls just as is common with usual types of cylindrical top rolls.

While I have illustrated and described certain forms in which the invention may be embodied,

. fibrous material at substantially the same. rate as the surface of the grooved roll adjacent the entrance to the groove and accordingly produces slip of the material within the groove to wipe the groove.

5. Drawing mechanism having in combination pairs of opposed rolls engaging the sliver in succession, the opposed members of at least one pair being positively rotated at predetermined unequal speeds of travel of their opposed sliver-engaging surfaces and having interengaging tongue-andgroove formations, the sliver assuming the speed of one of such opposed sliver-engaging surfaces and thereby wiping the other thereof.

6. Drawing mechanism having in combination, pairs of opposed rolls engaging the sliver in succession, at least one pair ofwhich rolls has conforming tongue-and-groove formations compressing the .sliver betweentheir opposing surfaces, with mechanical connections intermediate a tongued roll and its opposing grooved roll and apart from the tongue and groove causing the sliver-engaging surface of a tongue to travel Yfaster than and effect a wiping action on the .Y opposing surface of the groove.

7. Drawing mechanism having in combination,

I am aware that many modifications may be made therein by any person skilled in the art, without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to the particular forms shown, orito the details Aof construction thereof except as embodied in the appended claims.

.What I claim as my inventionV is:

' 1. Mechanism for drafting fibrous material in the form of sliver or roving including drawing rolls, and traveling surfaces engaging the flbrous material from different sides thereof a'nd cooperating to compress the material between them while the material is free from draft, and positive driving means for causing the said surfaces tor travel at predetermined unequal speeds so that the fibrous material will wipe one of the traveling surfaces through its travel relative thereto.

2. Drawing-roll mechanism for drafting brous material in strand form including a pair of opposed rolls engaging opposite surfaces of the fibrous material as the latter passes between them, and means imparting predetermined unequal rates of travel to the opposed materialengaging surfaces of the two rolls so that one of such surfaces will be' wiped by the relative travel of the brous material with respect thereto.

3. Mechanism for drafting fibrous material in strand form' including a. roll having a groove for the reception of the fibrous material, a roll having a tongue engaging the fibrous material within the groove, and means for positively driving both rolls so that the material-engaging surface of the tongue travels at a definitely different rate than the bottom of the groove and thereby produces relative movement of the fibrous material along the groove to wipe the groove. l

4. Mechanism for drafting fibrous material prising opposed rolls having conforming tongueand-groove formations and plain rolls, with the sliver running to and from the rolls at an angle to engage a substantial arc of the surface of the groove in a grooved roll while momentarily free from draft and before reaching the nip between this roll and any opposing tounged roll.

including a roll having a groove for the reception y 8. Drawing mechanism having in combination pairs of opposed rolls feeding the strand at successively increased rates to extend the strand between successive pairs of rolls, means for limiting the widthwise expansion of the strand in passing between at least one pair of such rolls, v

and mechanical connections apart from the opposed working surfaces ofthe members of such latter pair of rolls driving such surfaces at unequal speeds to produce a slip, counteracting lapping-up.

9. Drawing mechanism having in combinationpairs of opposed holding and drawing rolls cooperating to draw the strand, at least one pair of which rolls has conforming 'tongue-andgroove formations, and means imparting to the strand before its entry between a pair of opposed tongue-and-groove rolls a cross-sectional shape corresponding to the shape of the space through which it passes at the nip of suchrolls so as to cause the fibers of the strand to be uniformly gripped by the rolls throughout its entire width.

10. In mechanism for drafting fibrous materials arranged in strand form, in combination, pairs of holding and drawing rolls cooperating to draw the strand, means giving the strand a substantially rectangular shape in section before engaging the holding rolls and delivering the strand to the holding rolls in advance of any elongation by the elements named, and devices engaging the sides of the strand between the said means and the nip of the holding rolls.

11. In mechanism for drawing fibrous materials arranged in strand form, in combination, pairs of holding and drawing rolls cooperating to draw the strand, means imparting a polygonal shape in section to the strand before arriving at the holding rolls and delivering the strand to the holding rolls in advance of any elongation by the elements named, and devices engaging lateral faces thus given to the strand between the said means and the nip of the holding rolls, the holding rolls engaging the sliver on more than two sides at their nip. n

12. In mechanism for drawing fibrous materials arranged in strand form, in combination, pairs of holding and drawing rolls cooperating to draw ,the strand, certain of such pairs comprising opposed rolls having conforming tongue-andgroove formations and others being plain rolls, successive pairs being disposed in vertically offset relation so that the strand is wrapped about a grooved roll before being gripped between this roll and any cooperating tongued roll.

13. vIn mechanism for drawing brous materials arranged in strand form, in combination,

pairs of holding and drawing rolls cooperating to draw the strand, certain of such pairs comprising opposed rolls having conforming tongueand-groove formations 'and others lbeing plain rolls, successive pairs being disposed in vertically offset relation causing the strand to be wrapped about a grooved roll before being grippedV between this roll and any cooperating tongued roll and to be also wrapped about a plain roll after being subjected to draft.

14. In mechanism for drafting fibrous materials arranged in strand form, in combination, pairs of opposed holding and drawing rolls cooperating to draw the strand, certain of such pairs comprising opposed rolls having conforming tongue-and-groove formations, successive pairs being disposed in vertically offset relation so that the strand is wrapped around a substantial arc of a grooved roll after being subjected to draft and while momentarily released from draft.

15. The process of drawing fibrous material arranged in strand form which includes giving fthe strand a substantially uniform thickness throughout its width before drawing, then drawing the strand, and .thereafter restoring the strand to uniform thickness throughout its width, and holding the strand from vertical and transverse expansion throughout substantially the entire portion of its length following the said drawing and preceding the said restoration of uniform thickness.

16. In mechanism for drawing fibrous material arranged in strand form, in combination, pairs of opposed rolls feeding the strand at successively increased rates to extend the strand, one or more of such rolls having a groove to receive the strand. and being located above the strand, a tongued roll cooperating witheach grooved roll, supporting the strand and pressing it upwardly into the groove, and mechanical connections apart from the opposed working sur- `veaces of the members of a pair of tongue-andgroove rolls driving such surfaces at unequal speeds to cause the strand to sweep the bottom of the groove. v

17. In mechanism for drafting fibrous materials arranged in strand form, in combination, pairs of opposed holding and drawing rolls cooperating todraw the strand, certain of such pairs comprising plain rolls and others comprising opposed rolls having conforming tongueand-groove formations in vertically offset relation to the plain rolls, with the tongued roll below the strand and the grooved roll resting in a bend of the strand, the strand entering between the tongue-and-grooved rolls While free from draft.

18. In mechanism for'drawing fibrous material arranged in strand form, in combination, pairs of opposed rolls operating on an untwisted strand, at least one of such rolls having a groove to receive the strand and being located above the strand and positively driven, and a tongued roll having a uted surface engaging the strand within the groove from below, such surface being positively driven at a different rate than the opposing surface of the groove and acting to produce relative motion between the strand and the groove.

19. In mechanism for drawing fibrous material arranged in strand form, in combination, pairs of holding and drawing rolls cooperating to draw the strand, at least one of such rolls being grooved-and a tongued roll pressing the strand into the groove of the grooved roll, with the approaching part of the strand free from draft and entering .the groove at least in advance of its first engagement with a tongued roll.

20. In mechanism for drawing fibrous material arranged in strand form, in '-combination, pairs of opposed rolls extending the strand, including a roll having a groove to receive the strand, and a roll having a tongue engaging the strand within the groove, positively driven at a different rate of travel of its surface engaging the strand than that of the opposing surface of the groove, and having teeth compelling the strand to travel at a speed other than that of the said opposing surface of the groove.

21. The method of cotton spinning consisting in first imparting hat and parallel top and bottom surfaces to a sliver, extending the sliver in a plurality of drafts by passing it between opposed rolls, condensing the strand thusformed between successive drafts, restraining the strand from ,vertical and transverse expansion throughout its travel between the drafting and condensing operations, and finally twisting the attenuated strand directly into finished yarn, with the steps named being performed in one continuous operation on a single machine.,

22. The method of cotton spinning consisting in the successive steps of drawing a strand of fibrous material, relieving it from all appreciable draft throughout a substantial length, holding it from transverse and vertical expansion throughout this length, condensing and folding it at the end of this length, and thereafter subjecting it to a further draft, in one continuous process.

23. In mechanism for drafting brous materials arranged in substantially untwisted strand form, in combination, a pair of holding rolls rceiving the strand, a pair of drawing rolls arranged to draw the strand held by said holding rolls, a second pair of holding rolls comprising a groovd roll anda tongued roll mating therewith positivelyI driven at predetermined dinerential speeds so that the surface speed of the tongue materially exceeds that of the bottom of the grooved roll, with/the said second pair of holding rolls operating to fold a flattened strand received from the immediately preceding pair of drawing rolls and with the second pair of holding rolls arranged closely to and' vertically offset from the preceding drawing roll pair so as to partially wrap the strand about both the grooved roll and one of said preceding drawing roll pair, and a second pair of 'drawing rolls drawing the strand from said second pair of holding rolls and arranged substantially opposite and closely adjacent thereto.

241 In mechanism `forrdrawing fibrous materials arranged in strand form, in combination, pairs of holding and drawing rolls cooperating to draw the strand, certain -of such pairs comprising opposed rolls having conforming tongueand-groove formations and others being plain rolls, and withv successive pairs disposed in verticallyv oflset relation so that the strand is wrapped about the groove in a grooved roll before being gripped between this roll and any cooperating tongued roll, and means to keep the bottom of the groove and the opposing surface of the tongued roll travelling at predetermined unequal speeds.

25. Mechanism for drafting fibrous material in strand form having in combination means for drawing the strand, pairs of driven opposed rolls propelling the strand, means acting on the strand intermediate its extent from the nip of one of `such pairs to the nip of the next succeeding pair thereof to fold the strand longitudinally inward upon itself so that the fibers which lie at `the lateral margins of the strand as the latter passes the first of such pairs of Arolls are continuously shifted to occupy a position intermediate the width of the strand as the latter passes the succeeding pair of rolls, the latter pair of rolls propelling the strand at a faster rate than the first of such pairs to take upv the slack in certain portions of the cross-section of the strand incident to folding but without effecting any materlal draft of the entire width of the strand.

26. Mechanism for drafting fibrous material in strand form having in combination pairs of opposed rolls propelling the strand, stationary grooved means engaging the strand, and means engaging the strand at points within the groove to cause the sides of the groove to shift the lateral margins of the strand into positions within the width of the strand.

27. Mechanism for drafting fibrous material in strand form including pairs of opposed rolls propelling and elongating the strand, stationary means located between pairs of such rolls' engaging the lateral sides of the strand and diverting them inward toward the median line of the strand, and means pressing the strand in a vertical direction cooperating with the stationary means to cause the fibers comprising such lateral sides to be shifted inwardly past the fibers forming intermediate portions of the strand and to assume a position nearer the median line than such latter fibers and to maintain such position as they pass between a following pair* of propelling rolls.

28. Mechanism for drafting fibrous material in strand form including pairs of opposed rolls propelling and elongating the'strand,` stationary means engaging the lateral sides of the strand and diverting them inward toward the median line of the strand, and roll means propelling the strand and pressing the strand inv a-vertical direction cooperating with the stationary means to cause the fibers comprising such lateral sides to be shifted inwardly past the fibers forming intermediate portions of the strand and to assume and maintain after such pressing a position nearer the median` line than such latter iibers.

WILLIAM G. REYNOLDS.

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