US1973581A - Drawing frame - Google Patents

Description

Sept. 11, 1934. M. B. STONE El AL DRAW I NG- FRAME Filed July 26, 1932 2 Sheets-Sheet l .wuar vaz i 5* ATTORNEY Y Sept- 11, 1 3 M. B. STONE ET AL DRAWING FRAME Filed July 26, 1932 2 Sheets-Sheet 2 ATTO R N EYs Patented Sept. 11, 1934 UNITED STATES PATENT OFFlC E DRAWING FRAIVIE Boston, Mass.

Application July 26, 1932, Serial No. 624,744

14 Claims.

This invention relates to the drawing of fibres in the manufacture of yarn, and is concerned more particularly with a novel apparatus for controlling and restraining the fibres in that I part of a fibrous strand undergoing draft, for example, in a drawing, roving, or spinning frame. The apparatus of the invention is particularly adapted for use in the manufacture of yarn from long fibres, such, for example, as those of the bast variety including jute, hemp and flax, and

for purposes of-explanation, embodiments of the invention suitable'for use in spinning and drawing frames for jute will be illustrated and described in detail, though it is to be understood that the utility of the invention is not limited to that particular fibre.

In the manufacture of yarn from jute, the drawing and roving frames of standard construction heretofore employed are provided with gill bars for supporting that portion of the strand undergoing draft between the drawing and retaining rolls, these bars having pins which enter the strand and restrain the fibres. This gill mechanism is objectionable because it is expensive to construct, operate, and maintain, and in addition, there is a, definite limit to its speed of operation which in turn restricts the output of the frames.

In order to avoid the difiiculties and expense involved in the use of gill bars in drawing and roving frames as above described, we have devised novel apparatus for controlling the fibres in that portion of the strand undergoing draft, and our apparatus is superior to gills in that the only moving elements which exercise control on the fibres are of the rotating variety and-they thus perform their functions without the shocks and jars incident to the use of gills and can be operated at much higher speeds.

That form of the new apparatus employed in a drawing frame includes a plurality of control devices which may take the form of sets of rolls disposed between the retaining and drawing rolls of the frame and spaced apart a distance less than the average length of the fibres in the strand. Each set consists preferably of a bottom roll which is fixed and driven, and a movable top roll which rests on the strand only with its own weight, the bottom roll of a set, if desired, being mounted on a shaft which extends the length of the frame. There is an individual floating top roll for each sliver passing through the-machine and this top roll is positively driven at substan-- tially the same rate of speed as the bottom roll. Both top and bottom rolls of a set may have scratched surfaces, both may have plain surfaces, or one roll may have a scratched surface and the other a plain surface. Preferably in a drawing frame, there are four pairs of these rolls placed between the drawing rolls and the retaining rolls but a greater or less number may be used as may be found desirable.

In our o-pending application, Serial No. 545,725, filed June 20, 1931, we have disclosed a frame for spinning sliver, and that frame ineludes means for controlling the fibres in that part of the sliver undergoing draft and the apparatus of our present invention may be advantageously employed for that purpose. In a spinning frame equipped with the new control apparatus, it is ordinarily sufiicient to employ two sets of rolls for each strand, one roll of each set being fixed and driven and the other being carried in a, floating mounting so that the roll exerts a relatively light pressure on the strand and is free to move toward and away from the fixed roll in accordance with variations in the thickness of the strand. In the spinning frame, the rolls used will have surfaces of the types above described.

In our co-pending application, we have disclosed a similar control apparatus in a spinning frame which includes fluted rolls with the top roll havingits ribs cut away so as to provide space for the strand. Further experiments in this connection have indicated that while such fiuted rolls produce the most satisfactory results, rolls with plain or scratched surfaces give results which are entirely satisfactory for certain grades of yarn.

In the spinning, roving, and drawing frames, the rolls of a set have interengaging gear teeth at their ends and the gear teeth on the top roll preferably project slightly beyond the surface of the roll while the teeth on the lower roll terminate fiush with the surface of the roll. When the rolls are placed with their teeth in mesh, the formation of the teeth is such that the cylindrical surfaces of the rolls are slightly separated, thus providing space for the passage of the sliver. While the top roll of each set is in a floating mounting so that it may move toward and away from the fixed driven bottom roll in accordance with variations in the thickness of the sliver passing between the rolls, the gear teeth are in mesh at all times so that both rolls of a set are rotated positively and at approximately the same speed of rotation.

For a better understanding of the invention,

reference may be had to the accompanying drawings, in which Fig. 1 is a view in side elevation and partly in section of a portion of a spinning frame constructed in accordance with our invention.

Fig. 2 is a view in front elevation of the apparatus shown in Fig. 1;

Fig. 3 is an end view in enlarged cross-section through a pair of rolls constituting a part of the apparatus of the invention;

Figs. 4 and 5 are end and side views of one type of roll employed in the new apparatus;

Fig. 6 is a longitudinal sectional view through the rolls shown in Fig. 5;

Figs. 7 and 8 are end and side views, respectively, of another roll employed in the apparatus;

Fig. 9 is a longitudinal sectional view through the roll illustrated in Figs. 7 and 8;

Figs. 10 and 11 are end and side views, respectively, of a roll used in the new apparatus;

Figs. 12 and 13 are end and side views, respectively, of another roll which may be used in the new apparatus;

Fig. 14 is a view in side elevation of a drawing frame in which the new apparatus is incorporated; and

Fig. 15 is a view of the apparatus shown in Fig. 14.

In the drawings, there is conventionally illustrated in Fig. 1, a portion of the spinning frame provided with the new control apparatus, the frame being shown as used in spinning sliver. This frame includes a pair of retaining rolls 20a, 20b forced against each other under heavy pressure so as to grip and retain the sliver 21 which passes between them, one of the rolls being driven to draw the sliver from a supply. The sliver illustrated is a crimped sliver prepared in accordance with the process described in our co-pending application, and it is guided to the rolls by a conductor trough 22. The sliver is subjected to draft by means of drawing rolls 23a and 23b, one of which is positively driven, and these rolls are forced together under heavy pressure and rotate at a greater speed than the retaining rolls 20a, 20b. The distance between the nips of the retaining and drawing rolls is greater than the average length of the fibres.

That portion 24 of the sliver which lies bebetween the nips of the drawing rolls and retaining rolls is subjected to draft and as the fibres therein are nipped by the drawing rolls, they are pulled forward through the sliver. If no means were provided for controlling the fibres undergoing draft, those fibres which are nipped by the drawing rolls and pulled forward thereby at a more rapid rate than the remainder of the sliver would draw along with them fibres not nipped by the drawing rolls and this would cause the drawn product 25 to be irregular and to contain thick and thin spots. To overcome this difficulty, the ordinary spinning frame used for spinning rove is provided with a breastplate against which that portion of the rove undergoing draft contacts, and the friction of the rove against the breastplate and the twist of the rove provide some control of the fibres. When sliver is spun, an ordinary breastplate cannot be used, and the desired control is provided by the apparatus of this invention, the new control device also giving superior results in frames for spinning rove, in which it replaces the breastplate- The apparatus of the form shown comprises two sets of rolls between which the sliver passes successively. The first set includes roll 26a which is fixed in position and driven and this roll may be mounted on a shaft which extends lengthwise of the machine and carries a plurality of roll sections, one for each sliver or strand being treated. The second roll 26b of this set is mounted in arms 27 pivoted on a rod 28, and roll 26b presses the sliver against roll 26a under relatively light weighting. For many purposes, the roll 26b, referred to as the top roll, may press against the strand simply by its own weight although in some instances a light weighting of the top roll is desirable. In any case, the arms 27 supporting the roll swing freely so that the roll may move toward and away from fixed roll 26a in accordance with variations in the thickness of the strand.

The second set of rolls 29a and 29b are similar in construction and mounting to rolls 26a, 26b. Roll 29a is fixed in position and driven and may take the form of a roll section on the shaft extending the length of the frame, while roll 29b is mounted in swinging arms 30 which may be pivotally attached to the rod 20a. Roll 29b presses the strand against roll 29a with a light pressure provided either by its own weight or by relatively light weighting.

Each of the rolls 26b and 29b is positively driven at substantially the same rate of rotation as the rolls with which they cooperate, and to this end all the rolls are provided with inter-engaging gear teeth at their ends. A convenient construction of the rolls is illustrated in Figs. 6 and 9, Fig. 6 illustrating a top roll 26b or 29b, and Fig. 9 a bottom roll 26a or 29a.

The top roll illustrated in Fig. 6 comprises a tubular section 31 in the ends of which are mounted gear sections 32. Each gear section has teeth 33 at its outer end and an extension 34 which enters the tubular section 31. The gear sections are held in place in the tubular section by pins 35 extending diametrically through the latter and the extensions 34. Each gear section is hollow and contains an oil-less bearing 36 in which is received a pin 3'7 carried in the end of one of the arms 27. As illustrated, the gear teeth 33 project outwardly slightly beyond the surface of the tubular section 31 of the roll.

The bottomrolls 26a or 29a may be constructed as illustrated in Fig. 9, in which the roll is shown as comprising a tubular section 38 and gear sections 39 at its ends. Each gear section has an extension 40 which enters the tubular section and the gear sections are hollow so that they can be slipped on a shaft 41 extending from end to end of the frame. The bottom roll assemblies are held in place at. the proper point along the shaft by pins 42, each of which passes through openings in the tubular section, the extension of the gear section, and the shaft. As illustrated, the gear sections are provided at their exposed ends 13 with gear teeth 43 and these teeth terminate flush with the surface of the tubular section.

The tubular sections 31 and 38 of the rolls 26a, 26b, 29a, and 29b may have the plain surfaces illustrated in Figs. 11 and 13, or the scratched 140 surface illustrated in Figs. 5 and 8, or one roll of a set may be scratched and the other plain. The scratching used takes the form of shallow channels 44 cut in the outer surfaces of the tubes and extending lengthwise thereof, these channels 5 being on a regular or irregular spacing, as desired. We have obtained best results up to the present by employing a plain surface bottom roll and a scratched surface top roll.

The rolls oi a set are of the same diameter but 1150 the gear teeth 33 on the top roll extend slightly beyond the surface of the roll, while the gear teeth 43 on the lower roll terminate fiush with the surface of the roll. Accordingly, when the rolls lie with their teeth in engagement, thecylindrical surfaces are slightly separated by reason of the formation of the teeth, and a narrow space is thus provided between the rolls for the passage of the strand. Since the top rolls of the two sets are in floating mountings, they are free to move toward and away from their fixed bottom rolls in accordance with variations in the thickness of the strand, but the gear teeth are of sufficient length so that they remain in engagement throughout the operation of the device. The top roll of each set is positively driven at all times and free to fioat, and there is an individual top roll for each strand being drawn. Preferably, there are a few additional teeth in the gears on the top roll as, for example, the bottom roll of a set may have thirteen teeth and the top roll fifteen. The top roll thus moves at a slightly lower rate of rotation than the bottom roll, although at the same surface speed. a

In the spinning frame, the rolls 26a and 26b rotate at a slightly faster rate than the retaining rolls as, for example, in the ratio of 106 to 100, and the rolls 29a and 29b also rotate slightly faster than the retaining rolls, for example, in the ratio of 109 to 100, rolls 29a and 29b thus rotating slightly faster than rolls 26a and 26b. The drawing rolls 23a and 23b rotate at a much higher rate than the retaining rolls as, for example, in the ratio of 9 to 1.

With the apparatus described, the sliver or rove being spun is gripped and retained by the rolls 20a and 20b which are forced together under heavy weighting and the strand is drawn by the action of the drawing rolls which rotate at a much higher speed. The distance between the nips of the drawing and retaining rolls is greater than the average length of the fibres and as a fibre is gripped by drawing rolls, it is pulled rapidly through the strand because of the much higher speed of rotation of the drawing rolls. In its movement, the fibre thus nipped and moving faster than the other fibres would tend to drag along with it fibres which have not yet reached the nip of the drawing rolls, but such fibres not nipped are restrained and held back by the sets of rolls 26 and 29, and positively fed forward by these rolls at the desired rate. The action of the nipped and fast-moving fibres in drawing along with them fibres not nipped is commonly known as the plucking effect, and the sets of rolls 26 and 29 control the plucking effect and at the same time, provide the positive feed of the shorter fibres.

The nips of the sets of rolls 26 and 29 are spaced apart a distance less than the average length of the fibres and the nip of rolls 29a and 29b is closer to the nip of the drawing rolls than the average length of the fibres. With the two rolls of each set positively driven at substantially the samespeed, and the top roll pressing relatively lightly against the strand, the plucking effect of fibres nipped by the drawing rolls is under control, bolting of the shorter fibres is prevented, and theseshorter fibres are positively advanced to the drawing rolls. This results in a greater uniformity in the drawn product 25, without thick and thin places.

The adaptation of the invention to a drawing frame is illustrated in Figs. 14 and 15, and in this frame, the sliver 45 passes through a set of retaining rolls which consists of a pair of fixed driven rolls 46 and a heavy jockey roll 47, the action of these rolls preventing slippage of the fibres. The sliver is drawn by a set of drawing rolls, the lower roll 48a of the set being fixed and driven and the top roll 48b being heavily weighted so as to press the sliver againstthe fixed roll under heavy pressure which prevents slippage. The drawing rolls rotate at a higher speed than the retaining rolls, depending upon the draft to be produced and the distance between the nips of the drawing and retaining rolls is greater than the average length of the fibres.

In' the ordinary drawing frame, gill bars are employed to support that portion 49 of the sliver between the sets of drawing and retaining rolls.

In the new apparatus, the gill bars are dispensed withand a plurality of sets of control rolls are employed, the frame shown in Fig. 14 including four sets of said rolls. The bottom roll 50a of the first set is fixed and driven and may take the form of a roll section mounted on a the lower roll.

The'second set of rolls 55 is similar in construction to the rolls 50a and 50b and the rolls of the third set 56 are similar in construction to the rolls of set 55 except for being of slightly smaller diameter. The rolls of set 57 are of the same construction as rolls 56 but are of slightly less diameter. The spacing between the nips of the successive set of rolls is less than the average length of the fibres and the rolls of the sets rotate at progressively greater rates. Rolls 50a and 50b rotate at approximately the same rate as the retaining rolls 46 and the rolls of set 55 rotate at a slightly greater rate, as, for example, 5% greater. Rolls of set 56 operate at a slightly higher speed, as, for example, 8% greater than the retaining rolls, and rolls of set 5'? operate at a still higher speed as, for example, 12% higher. The drawing rolls operate at a speed depending on the draft which may be, for example, nine times the speed of retaining rolls 46.

With the construction described, that portion of the strand undergoing draft is supported and controlled by the four sets of rolls, which tend to hold back fibres which would otherwise be carried along by entanglement with those nipped by the drawing rolls and feed the fibres to the drawing rolls positively and at the desired rate. The rolls acting on that portion of the strand undergoing draft thus prevent bunching up of the fibres and the drawn product produced is more even and uniform than would otherwise be the case.

In the drawing frame illustrated, the sliver issuing from the drawing rolls passes to a doubling plate 58 where sliver 59 is doubled with sliver 60. The plate is provided with spaced inclined slots 61a, 61b, and sliver 59 passes over the top of the plate through slot 61a and then along the undersurface of the plate and up through slot 61b. Sliver 60 passes beneath the plate and up through slot 61b and over the top of the plate, the two slivers issuing from slot 61b being laid one on top of the other and in this relation carried away from the plate. The frame illustrated is provided with means for crimping the sliver, this means includinga pair of rolls 62a and 62b to which the sliver is fed, the bottom roll 62b being fixed in position and driven and the top roll 62a being forced against the bottom roll by means of the spring 63. The sliver issuing from the rolls enters a conductor trough 64, the top of which is closed by an arm 65 mounted for swinging movement at one end in any convenient way. At its other end, the arm is provided with a weight 66 and as the sliver enters the trough, its escape is prevented by the arm and the sliver begins to bunch up until the amount of sliver collected is sufficient to cause the arm 65 to be raised and permit the escape of the sliver. The packing together of the sliver beneath the arm causes the sliver to be crimped.

In accordance with our invention, the use of gill bars on drawing frames and roving frames is dispensed with and the control of the fibres is accomplished by meansof positively driven rolls arranged in pairs with the topv roll rotating at substantially the same rate as the lower roll and floating so as to move toward and away from the.

fixed bottom roll in accordance with variations in the thickness of the strand. These rolls may also be used in a spinning frame to take the place of the breastplate used when rove is being spun and may be employed in a spinning frame for spinning sliver in place of the fluted rolls disclosed in our co-pending application above-mentioned. Frames in which the new apparatus takes the place of gill bars may be driven at much higher rates of speed than those in which gill bars are employed and the frames have been driven three times faster than similar frames employing gill bars with equally good yarn produced. At the same timethe cost of construction and maintenance of the frames is greatly reduced.

We claim:

1. In apparatus for drawing long fibres for the manufacture of yarn, the combination of retaining rolls for a fibrous strand, drawing rolls for said strand, and means engaging the strand and controlling the fibres in that portion of the strand undergoing shaft comprising at least two pairs of rolls, each pair consisting of a fixed driven roll disposed between the retaining and drawing rolls, an individual floating roll for the strand pressing the latter against the driven roll with sumcient pressure to provide proper control of the plucking effect of the fast-moving fibres nipped by the drawing rolls, said fixed and floating rolls providing a positive means for passing on shorter fibres to the drawing rolls, and means for driving said fixed and floating rolls at approximately the same speed of rotation.

2. In apparatus for drawing long fibres for the manufacture of yarn, the combination of retaining rolls for a fibrous strand, drawing rolls for said strand, and a plurality of devices placing drag upon the strand to control the fibres in that portion of the strand undergoing draft, at least one of said devices comprising a driven roll on a fixed axis disposed between the retaining and drawing rolls, an individual floating roll for the strand pressing the latter against the driven roll with sufficient pressure to provide proper control-of the plucking effect of the fast-moving fibres nipped by the drawing rolls, said driven andfioating rolls lying adjacent to said drawing rolls and 3. In apparatus for drawing long fibres for the manufacture of yarn, the combination of retaining rolls for a fibrous strand, drawing rolls for said strand, and a plurality of devices placing drag upon the strand to control the fibres in that portion of the strand undergoing draft, at least one of said devices comprising a driven roll on a fixed axis disposed between the retaining and drawing rolls, an individual floating roll for the strand pressingthe latter against the driven roll 'with sufficient pressure to prevent fibres not nipped by the drawing rolls from being dragged along by fibres which are nipped while permitting drawing of fibres'which are nipped, said fixed and floating rolls lying adjacent said drawing rolls and positively feeding to the drawing rolls the fibres which are not nipped, and meshing gear teeth attached to said fixed and floating rolls.

4. In apparatus for drawing long fibres for the manufacture of yarn, the combination of retaining rolis for a fibrous strand, drawing rolls for said strand, and a plurality of devices placing drag upon the strand to control the fibres in that portion of the strand undergoing draft, one of said devices comprising a pair of control rolls engaging the strand from opposite sides with a pressure suflicient only to provide proper control of the plucking effect of the fast-moving fibres nipped by the drawing rolls, one roll rotating on a fixed axis and the other roll being individual to said strand and mounted to float toward and away from said fixed roll in accordance with irregularities in said strand, said fixed and floating rolls lying adjacent said drawing rolls and rotating at a higher surface speed than said retaining rolls for positively feeding shorter fibres to the drawing rolls, and means for positively driving said fixed and floating rolls in unison.

5. In apparatus for drawing long fibres for the manufacture of yarn, the combination of retaining rolls for a fibrous strand, drawing rolls for said strand, and a plurality of devices imposing drag upon the strand to control the fibres in that portion of the strand undergoing draft, one of said devices comprising a pair of control rolls engaging the strand from opposite sides with a pressure suflicient to prevent shorter fibres not nipped by the drawing rolls from being dragged along by fastermoving fibres which are nipped while permitting drawing of fibres which are nipped, said rolls being disposed so that their nip is nearer to the nip of the drawing rolls than the average length of the fibres in the strand, one of said rolls being fixed and the other, which is individual to said strand, being free to float toward and away from said fixed roll in accordance with the variation in thickness of said strand and means for positively driving said control rolls in unison, said control rolls rotating with a surface speed in excess of that of said retaining rolls and positively feeding said shorter fibres to said drawing rolls.

6. In apparatus for drawing long fibres for the manufacture of yarn, the combination of retaining rolls for a fibrous strand, drawing rolls for said strand, and a plurality of devices engaging that portion of the strand undergoing draft to impose drag upon it and control the fibres therein, at least one of said devices comprising a pair of control rolls engaging the strand from opposite sides with a pressure suflicient to provide proper control of the plucking effect of the fibres which are nipped by the drawing rolls and moving rapidly, said rolls being mounted to be free to approach and recede from each other in accordance only with variations in the thickness of the strand on which said rolls are operating, and means for positively driving said control rolls in unison regardless of said variations, said control rolls rotating with a surface speed, in excess of that of said retaining rolls and positively feeding shorter fibres to the drawing rolls.

'7. In apparatus for drawing long fibres for the manufacture of yarn, the combination of retaining rolls for a fibrous strand, drawing rolls for said strand, and a plurality of devices engaging that portion of the strand undergoing draft to impose drag upon it to control the fibres therein, at least one of said devices comprising a pair of control rolls engaging the strand from opposite sides with a pressure suflicient to provide proper control of the plucking effect of the fastmoving fibres nipped by the drawing rolls, a mounting for one of said rolls permitting it to approach and recede from the other in accordance with variations in the thickness of the strand, said approaching and receding roll being individual to the strand being acted on and means for positively driving said rolls in unison regardless of said variations, said rolls lying adjacent said drawing rolls and positively feeding shorter fibres to the drawing rolls.

8. In apparatus for drawing long fibres for the manufacture of yarn, the combination of retaining rolls for a fibrous strand, drawing rolls for said strand, said retaining and drawing rolls gripping the strand tightly to prevent slippage and having their nips spaced a distance greater than the average length of the fibres, and a plurality of devices for engaging that portion of the strand undergoing draft between the nips of said rolls and controlling the fibres therein, at least one of said devices comprising a driven roll fixed in position and contacting with the strand on one side, a roll individual to said strand and contacting with the strand on the other side and mounted to approaoh and recede freely from said fixed roll in accordance with variations in the thickness of the strand, said fixed and movable rolls gripping the strand sufllciently tightly to provide proper control of the plucking effect of the fast-moving fibres which are nipped by the drawing rolls on the shorter fibres which are not nipped without interfering with the drawing of fibres which are nipped, and means for rotating said fixed and movable rolls in unison and at a surface speed in excess of that of said retaining rolls, said fixed and movable rolls lying adjacent said drawing rolls and positively feeding shorter fibres thereto.

9. In a frame for treating strands of long fibres, the combination of retaining rolls for a strand, drawing rolls for said strand, said retaining and drawing rolls gripping said strand tightly to prevent slippage, and a plurality of devices engaging that portion of the strand undergoing draft and imposing drag upon it to control the fibres therein, at least one of said devices comprising a pair of fixed driven rolls beneath that portion of the strand undergoing draft, a pair of floating rolls individual to said strand and resting on the strand and each pressing the strand against its respective driven roll, said floating rolls being independent of one another and each being individually free to approach and recede from its fixed roll in accordance with variations in said strand, and means for positively driving each fixed roll and its 81 .50- ciated floating roll in unison.

10. In a frame for treating strands of long fibres, the combination of retaining rolls for a strand, drawing rolls for said strand, said retaining and drawing rolls gripping said strand tightly to prevent slippage, and means engagin that portion of the strand undergoing draft and imposing drag upon it to control the fibres therein, said means comprising a pair of driven rolls mounted on fixed axes and lying beneath that portion of the strand undergoing draft, a pair of floating rolls individual to the strand and resting on the strand and each pressing the strand against its respective driven roll, said floating rolls being independent of one another and eachbeing individually free to approach and recede from its fixed roll in accordance with variations in said strand, and means for positively driving each fixed roll and its associated floating roll in unison, the pair of rolls nearer the drawing rolls rotating at a surface speed greater than that of the other pair and both pairs of rolls rotating at a surface speed greater than that of said retaining rolls.

11. In a frame for treating long fibres, a pair of retaining rolls, a pair of drawing rolls, a plurality of pairs of rolls placed between the retaining and drawing rolls, the bottom roll of each pair being fixed and driven, and the top roll associated therewith being individual to the strand it acts on and being free to rise and fall in accordance with variations in the thickness of said strand, said pairs of rolls providing control of the plucking effect of the fast-moving fibres nipped by the drawing rolls on the fibres not nipped, and means for driving the rolls of each pair in unison, the rolls of successive pairs in the direction of movement of the-strand rotating at successively higher surface speeds, and all said rolls rotating at higher surface speed than said retaining rolls and positively advancing the fibres to the drawing rolls.

12. In a frame for treating strands made of long fibres, the combination of retaining rolls for a strand, drawing rolls for said strand, said retaining and drawing rolls gripping said strand tightly to prevent slippage, and a plurality of devices acting successively on that part of the strand undergoing draft between the retaining and drawing rolls and restraining the fibres to prevent those which are nipped by the drawing rolls from carrying with them through the drawing rolls fibres which are not nipped by said drawing rolls, said devices including a driven roll on a fixed axis, and a floating roll individual to said strand and pressing said strand against the surface of said driven roll, said floating and fixed roll combination being disposed next adjacent said drawing rolls and the rolls of said combination rotating at a surface speed greater than that of said retaining rolls and less than that of said drawing rolls.

13. In a frame for treating strands made of long fibres, the combination of retaining rolls for a strand, drawing rolls for said strand, said retaining and drawing rolls gripping said strand tightly to prevent slippage, and a plurality of devices acting successively on that part of the strand undergoing draft between the retaining and drawing rolls and restraining the fibres to prevent those which are nipped by the drawing rolls from carrying with them through the drawing rolls fibres which are not nipped by said drawing rolls, said devices including a driven roll on a fixed axis, a floating roll individual to said strand and pressing said strand against the surface of said driven roll with pressure sufiicient to restrain fibres not nipped by the drawing rolls while permitting fibres which are nipped by the drawing rolls to pass betweensaid floating and flxed rolls,

said floating and fixed roll combination being dis-- posed next adjacent to said drawing rolls, and

" means for positively driving said floating and fixed the drag upon the strand to control the fibers in that portion of the strand undergoing draft, at least one 01' said devices comprising a driven roll on -a fixed axis disposed between the retaining and drawing rolls, an individual floating roll for the strand pressing the latter against the driven roll with suflicient pressure to provide proper control of the plucking effect of the fast-moving fibers nipped by the drawing rolls, said driven and floating rolls having smooth strand engaging surfaces and lying adjacent to said drawing rolls for positively feeding shorter fibers to the drawing rolls, and means for driving said floating roll at the same speed as said driven roll.

MALCOLM BOWDITCH STONE. WILLIAM PHILIP WILLIAMSON.

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