US2593478A - Drawing frame assembly - Google Patents

Description

April 22, 1952 2,593,478

R. B. NEWTON DRAWING FRAME ASSEMBLY Filed Sept. 28, 1944 2 SHEET SSHEET 1 IN V EN TOR.

JQZZB/Wega A ril 22, 1952 H R. B. NEWTON 2,593,473

DRAWING FRAME ASSEMBLY I Filed Sept 28,. 1944 2 SHEETS-SHEETQ 2 1 43 45 Y Ja \51 49 INVENT R.

Patented Apr. 22, 1952 UNITED STATES PATENT OFFICE;

2,593,478 DRAWING FRAME ASSEMBLY Russell 3., Newton llanville, Va., assignor, b'y mesne assignments,-,to Dan River Mills, 111001! p6rated,'a corporation of Virginia 7 Application September 23, 1944, Serial No. 556,154-

This invention relates to the drafting of. cotton, and particularly to the drafting of cotton in which a clear of a revolving type is used in. connection with upper draf'tin'grolls which cooperate with a clearer in a novel manner;

In the manufacture of cotton yarns, the draw-. ing process follows carding and combing operations and consists in taking the roving or sliver, and by drawing it through a series of three or more rolls, the cotton is made more compact'arid. drawn out and the fibers paralleled. Thisset of drawing rolls forms a part ofwhat is known as a drawing frame assembly and is usually so a; ranged that the first set of rolls moves slowly and each succeeding set moves at a higher speed so the roving is extended by the cotton fibers sliding past one another.

In the drawing of the cotton fibers two main problems have confronted textile machinery de-' signers, the first being the provision of drawing rolls of such shape and surface characteristics that the sliver or roving would be attenuated a considerable amount but without pulling it apart; the second problem being the removal of the loose and short fibers from the roving, it being desirable to permanently remove all the loose and short:

fibers and at the same time keep the drawingrol-l-s clean and further make it possible to easily remove the collected short fibers.

Many attempts have beenmade to design drafting frame assemblies in order to solve'the above metal roll which meshed with'the lower roll, butsuch meshed rolls have been found tobe objectionable due to the fact that metal against metal hasatendency to break the cottonr fibers passing therethrough.

Leather has also been. used'considerably'for the upper pressure rolls but has a-disadvantageqtl'iat' it has to go through a" special. tanning. process inv order to give the proper frictional surface'foreflL' cient operation, and its surface is alsoveryeasily injured and unless properly mounted flattens easily while in use. considerable extent both as a layer of cork" and as acompound; cork having about the samefrio-f 5 tionalproper-ties as specially prepared leatl-i'e'r and Cork has alsobeen used to a" Glaima (01. 19

. 2 also similar defects. In addition to the above objections to leather and cork, one of the biggest defects i'n' the use of such materialin textile drawing rolls has been the cooperation between such leather or cork drawing rolls and the belt of the clearer which issupposed to eollectthe excess material picked up by the drawing rolls because, while the surface ofthe drawing rolls-may be such as to obtain proper attenuatior'r-of the roving o1 sliver; this same surface has-heretofore always presented dimculties in its cooperation with the clearer. I

problem of getting rid of the short fibers and stretching the roving and. the like and keep- 1 ing' the drawing rolls clean, was first attacked by using a flat top stationary clearer which worked fairly satisfactorily if itwere lifted up at very frequent intervals and cleaned, but with thousands of such clearers to take care of in the average cotton mill it obviously is quite a job to lift'upstationary' dealers with necessary regularity. After the stationary clearer had been used fora good many years, attempts were made in Europe and the United States to utilize a'revolving clearer'of the general type disclosed in the British patent to Peip'er No. 4,491 of 1876. However, the drawing frame assembly of the type shown in Peiper was not generally successful'because the revolving clearer surface would not ffelt up uniformlyybut would, vbecause of the] nature'of the surfaces of the drawing rolls, cause the formation of small rolls or rat tails which small" rolls of clearer waste would persistently go over' thedrawi'n' frollers and back down'into the roving orsliver, thus making irregular and irn'' perfect yarn and frequently breaking the end.

Subsequent to the revolving clearer-s and drawing frame assemblies of the Peiper type, attempts were made the textile industry to use a revolving positive drive clearer of the type shown inthe British patent to Ermen No. 3,386 of 1873'. Such positive drive clearers of the Ermen typiusually' utilized'som type of a rake for picking upthe clearer waste ofi of the clearer belt. These positive" drive rake type revolving clearers worked fairly satisfactorily but after a relatively short peri'od ofi operation thesurface of the belt would e we smooth with the result that rat tails" would beformed and be carried back into the roving or sliver. Such positive drive'rake type clearers such as lilrmen were generally discarded by the industry-and up totheintroduction of the present invention the most general practice ili'the Urii t'edst'ats was to use a combination of :a stafcanary-clearer with each drawing rolLthe sur faces of the drawing rolls being usually of leather, cork or metal.

Recent attempts in the drafting of cotton contemplated the use of synthetic drawing rolls with a stationary clearer, but such attempts were not successful because this combination of synthetic roll and stationary clearer resulted in the forming of what are known as eyebrows which were the result of the excessive accumulation of short fibers in the angle between the drawing roll and the surface of the stationary clearer; such accumulation of short fibers building up into the shape of an eyebrow and then dropping down onto the roving or sliver.

I have discovered that the surface of the drafting roll can be made of a synthetic rubber like material of such peculiar properties that the coefficient of friction of such surface is not only ideal for the attenuation of the fibers in the drawing of the roving or sliver but such coefficient of friction so cooperates with the surface of a revolving clearer that the loose and short fibers are picked up from and carried out of the roving without the forming of any frat tails or eyebrows. The drawing rolls are kept clean and the waste is felted uniformly on the revolving clearer cloth. 7

An important feature of this invention is the fact that by using a synthetic drawing roll of definite surface characteristics there is sufiicient friction whereby it may be used with. excellent results with a revolving type clearer because the friction of the rolls pushes the cotton waste against the clearer cloth to the extent that it forms a very firm felted condition;' this same friction surface makes it possible to make use of a medium sized roll placed above the pressure roll to drive the clearer cloth without any additional mechanical device. This combination of synthetic pressure roll and revolving clearer results in the production of much'better cotton yarn with much less supervision labor and maintenance cost than haspreviously been possible.

Other objects of the present invention include the structure of the drawing frame assembly as will be brought outin the specification and claims. a

In-the drawings: I

Figure 1 is a vertical sectional view taken through a drawing frame assembly embodying the principles of the present invention, a clearer being shown in position contacting the top rolls of a textile machine employing drawing or at-' tenuating rolls; and in addition showing as a possible modification a clearer contacting the bottom rolls.

Figure 2 is a perspective view of the clearer shown in Figure 1;

Figure 3 is a vertical section taken on the line 3 3 of Figure 4.

Figure 4 is a section taken on the'line 4-4 of Figure 1.

Figure 5 is a perspective of a clearer embodying a plurality of clearer aprons, and

Figure 6 is a bottom plan view of the clearer shown in Figure 5.

Referring to the drawings, Figure 1 shows conventionally a drawing frame assembly of a. textile machine I having a series of pairsofdrawing or attenuating rolls 2.

In my preferred arrangement the bottom IQ of each pair of rolls 2 is a driven roll and formed of metal and each one of the top rollshas a layer 2a of synthetic rubber. The composition 2a of the surface of these upper pressure rolls may be any one of the four compositions set forth in the patent to Rockoif No. 2,341,656 of February 15, 1944, or may be the butadieneacrylic nitrile 'co-polymer composition set forth in the patent to Rockolf No. 2,304,656 of December 8, 1942. Of the compositions set forth in the Rockofi Patent No. 2,341,656, the preferred one is composition #2 which is known as the perbunan composition Parts by weight 'Perbunan (butadiene polymerization product) Zinc oxide 5 Sulfur 2 Altax (benzothiazyl disulfide) l Whiting 30 Mineral oil 10 Cotton fiber 30 Vulcanizing: 30 minutes at 300 F. steam cure.

Rolls formed of synthetic material such as shown in the Rockofi patents have been made and used for draft aprons and the like in the textile industry, but I believe I am the first to appreciate the peculiar coeificient of friction characteristics of ,this synthetic material for use as pressure rolls in a drafting apron assembly and in combination with a revolving clearer.

The rolls 2 are arranged in vertical pairs, with the upper rolls of the various pairs in horizontal alignment and the lower rolls in horizontal alignment. The pairs of rolls are driven at progressively increasing speeds, the back pair 3 rotating at the slowest speed and the front pair 4 the fastest. Conventional drive mechanism, not shown, rotates the rolls. This provides stretching and slimming of the material 5 between each pair of rolls.

The clearer which is indicated at 6 has a housing? of sheet material which covers the top, the metal being downturned to form flanges 8 and 9 at the front and rear. The housing is braced by frame members If! and II extending from front to back which have downwardly projecting hinge lugs l2 and [3 at the rear to pivotally connect the clearer to the textile machine frame. Bearing blocks l4 and I5 are positioned against the underside of the housing with the cut-away portions receiving bosses l8 and i9 which project from the housing. Strips 2E! and 2|, extending the full length of the bearing blocks, have screws 22 and 23 passing through them; the screws threading into the bosses l8 and I9 and securing the blocks within the housing.

The bearing blocks are grooved as at 24, 25, 26

' and 21, 28, 29 to slidably receive the reduced ends of clearer rollers 30, 3| and 32. The grooves are so spaced that the clearer rollers, when in position, will occupy positions directly overlying certain rolls of the drawing mechanism 2. One of the clearer rollers will be over the front pair of rolls 2, another will be over the back pair, and one or more clearer rollers will be positioned above one or more of the remaining pairs. All of the clearer rollers, with the exception of roller 32 which is over the back drawing rolls, are of relatively light Weight, while the roller 32 is weighted and quite heavy. An apron 33 of wool or other endless fabric material passes around the clearer rollers and is in contact with the drawing rolls.

When the clearer is swung downwardly into operative position as is shown in Figure 1, the apron will be brought into contact with all of the drawing rolls. The clearer rollers are freely movable in a vertical direction due to their free mounting in the grooves of the bearing blocks, and these rollers will keep the, apron in firm contact with the drawing rolls. The heavy, weighted roll-er 32 will press the apron against the top back drawing roll with suflicient force to cause the drawing roll to impart motion to the apron. The other clearer rollers being lighter will have no driving pressure upon the apron. As the drawing rolls are rotated at progressively increasing speeds from the rear rolls to the front and the apron k is moved at a speed comparable to that of the rear rolls, there will be a differential in surface speeds between the apron and the rest of the drawing rolls which will result in a sliding or wiping motion of the drawing rolls against the bottom flight of the apron. Any lint or fiber picked up by the drawing rolls will be caught by the nappy surface of the apron and the sliding motion between the apron and roll will cause it to befelted into the material. The surface 2:; of the pressure rolls, being made of synthetic rubber of the composition above noted, has just the right amount of surface frictional contact to carry the roving 5 through the drawing rolls without grabbing and pulling it apart and yet has just sufficient frictional properties so as to pick up the loose and short fibers and push this cotton waste against the clearer cloth to the extent that it forms a very firm felted condition. This same peculiar frictional surface of the pressure rolls makes it possible to utilize a medium sized roll placed above the pressure rolls whereby to drive the clearer cloth without any extra mechanical devices.

The apron is in continuous motion and carries away the picked up waste presenting fresh portions of its surface of the rolls. Due to the movement of the apron and the fact that the waste is felted into the surface of the apron material,

large quantities of waste can be picked up before the apron becomes so filled with fibers that it will no longer function to clear the drawing rolls. This materially reduces the frequency with which the machine must be shut down in order to break the felt and strip the waste from the clearer cloth.

All of the clearer rollers float freely and may shift their angular positions to agree with that of the particular drawing roll which they overlie and thus ensure contact between the drawing rolls and apron regardless of any misalignment of the drawing rolls. This also provides constant pressure of the weighted roller 32 throughout its length upon the apron to secure uniform frictional engagement between the apron and the top rear driving roll and continuous movement 6f the apron while the machine is running.

Figures 5 and 6 illustrate a modified form of clearer employing a plurality of aprons instead of the single apron described above.

In this form of the invention the housing 34 is of substantially the same shape as that of the first form, and is secured to end castings 35 and 36 which take the place of the bearing blocks and stiffening or bracing frame members of the first form. The end castings are provided with vertical slots 31, 38 and 39, 40 to receive the reduced ends of rollers 4| and 42 formed of the same synthetic material as the top pressure rolls 2, and slots 43 and 44 to adjustably position a longitudinal brace 45 extending the length of the clearer housing between the end castings. Cover plates 46 and 41 of sufficient size to extend across the two front slots on each end casting prevent axialmovement of the rollers 4| and 42. Extensions 48 and 49 of the end castings provide hinge arms for pivotal connection between the-clearer and the textile'machine.

Near therear edge of the clearer a strip 50 is fastened to the underside of the housing. A plurality of U-shaped' stirrups 5| are fixed to the strip 50 arranged in spaced groups of two intermediate the ends of the strip, with a single stirrup near each end of the strip. Relatively short weighted rollers 52 are loosely mounted for rota tion in the stirrups and are free to move vertically within the stirrups. Aprons 53 of substantially thesame width as the weighted rollers 52 are placed about the clearer rollers. Therefore, the clearer contains a plurality of aprons, with each apron having an independently mounted weighted roller to press its apron against the drawing roll. Both forms of clearer disclosed herein are similar, as each ha all ofits apron-supporting rollers free to move in vertical planes, and each has a weighted; roller to provide frictional driving contact between the apron and the top rear drawing roll, and lighter weight rollers at the front of the clearer to keep the apron in contact with the other faster moving drawing rolls to secure a sliding or wiping action of the rolls against the apron.

As a modification, the drawing frame assembly of Figure 1 may have a secondary clearer generally designated as at 60 in Figure 1, mounted beneath the lower driving rolls 2. In such a modification a second clearer belt 33a would be used for contacting the lower set of rollers 2 the same way that the clearer belt contacts the upper set of rollers 2. In case such a bottom clearer member would be used the surfaces of the lower set of rolls 2 would be formed of the same synthetic material as the surfaces 2a of the upper set of rolls 2. Such bottom clearer would not need to be covered as the top clearer 6 but need only be lowered out of position to remove the felted waste.

It will thus be seen that I have provided a drafting frame assembly which brings together a new combination of elements which in actual commercial use has resulted in the production of a much better cotton yarn with far less supervision and less maintenance cost than has been possible with standard devices used in the past.

Cork and rubber pressure rollers have, in combination with stationary clearers, worked with a fair degree of success, but these same rollers have not been satisfactory with revolving clearers while, on the other hand, synthetic rollers such as shown in Rockoff when attempted to be used as replacement for cork and rubber rollers with stationary clearer combinations have not proven satisfactory. However, by combining synthetic surface pressure rolls with a particular type of revolving clearer I have produced a new combination in which the peculiar coefficient of friction of the pressure rolls cooperates with the clearer cloth so that rolls have just sufficient frictional properties to pick up the loose and short fibers and carry them on the roving and push or attach this cotton waste against the clearer cloth, at the same time this frictional surface is such it will not grab the short fibers and pull them around the pressure rolls as has been the case with rubber and cork pressure rolls when used with revolving clearers, nor does it pile up the short fibers in front of the pressure rolls as is the case when synthetic surfaced rolls are used with a stationary clearer.

What I claim is:

1. In a drawing frame assembly of the type having a revolving clearer cloth, and a pressure roll for driving said cloth by friction, said r011 having a driving surface formed of clear synthetic rubber like compound with a coefiicient of friction with respect'to the clearer cloth substantially equivalent to that of a vulcanized composition comprising by weight 100 parts perbunan, 5 parts zinc oxide, 2 parts sulfur, 1 part benzothiazl disulfide, 30 parts whiting, 10 parts mineral oil and 30 parts cotton fiber, such that all short fibers picked up by the roll will be felted onto the cloth and the pressure rolls kept clean. 2. In a drawing frame assembly of the type having a revolving clearer cloth, and a pressure roll for driving said cloth by friction, said roll having a driving surface comprising butadieneacrylic nitrile co-polymer with a coeflicient of friction such that all short fibers picked up by 8 the roll willbe. felted'onto the cloth and the pressure rolls kept'clean.

- 7 RUSSELL B. NEWTON.

REFERENCES CITED The following references are of record in the file of this patent? UNITED STATES PATENTS Number Name Date 2,111,966 Davis Mar. 22, 1938 2,258,033 Presley Oct. '7, 1941 2,304,656 Rockoff Dec. 8, 1942 2,341,656 Rockoff Feb. 15, 1944 FOREIGN PATENTS Number Country Date .153 Y Great Britain 7 of 1858 3,386 Great Britain of 1873 4,491 Great Britain of 1876 Austria Jan. 10, 1931

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