US2711626A - Method and apparatus for collecting fibrous material and forming it into a strand - Google Patents

Description

J1me 1955 s. OGLESBY, JR., ETAL METHOD AND APPARATUS FOR COLLECTING FIBROUS MATERIAL AND FQRMING IT INTO A STRAND Filed Oct. 24, 1951 INVENTOR. .S/YBERT OGLESBjc/K- flLfiE/QT 1.. THOMAS IA.

United States Patent METHOD AND APPARATUS FOR COLLECTING FIBROUS MATERIAL AND FORMING IT INTO A STRAND Sabert Oglesby, Jr., and Albert L. Thomas, Jr., Birmingham, Ala., assignors to Southern Research Institute, a corporation of Alabama Application October 24, 1951, Serial No. 252,908

Claims. (Cl. 57-34) Our present invention relates to a method, and apparatus for carrying out the same, by means of which fibers such as those of cotton may be gathered together and made into a strand.

In the prior processes of converting cotton fibers into yarn it has been considered essential to follow the routine of carding to form sliver, attenuating the sliver to form hank roving and then in further attenuating the roving and twisting it to make yarn. Each of these operations in expensive in machinery and labor and the size of the machines requires enormous amounts of floor space. As the fibers progress from step to step they are pulled and stretched, twisted and untwisted, stranded and unstranded. The wear and tear on the individual fibers is appreciable. One serious objection to such working of cotton fibers is that these repeated operations reduce the natural concatentation of the fibers and consequently reduces the strength of yarn ultimately made therefrom. Therefore, viewed in the light of the end to be accomplished and in the light of the concept of this invention we believe that the prior methods of stranding fibers of cotton and the like involves non-essential and wasteful steps and non-essential apparatus.

Our invention is based essentially upon the phenomenon of the behavior of finely separated fibers when brought into an electro-static field set up between two conductors. We have discovered that if an electro-static field be set up between a pair of conductors and individual fibers or small groups thereof passed into the field the fibers align themselves parallel with each other and axially in the field. Thus aligned the number of such fibers in the field at any time depends somewhat on the voltage of the charge, but is more affected by the surface area of the conductors, or, in other words, the effective transverse cross-sectional area of the field. By controlling the cross-sectional area of such field, its voltage, and the approximate rate at which fibers are delivered into such field and withdrawn therefrom, we are able to strand fibers by drawing them axially from the field. Further, concomitantly with controlled axial movement we are enabled to twist such fibers to form a strand. By controlling all of these factors, we can make selectively, sliver, hank roving, or yarn without carding, without intermediate attenuation and with a fraction of the amount of machinery heretofore considered essential. In our process the question of blending cotton from a plurality of bales to obtain uniformity of sample may be taken care of in several ways. First, we can blend in what may be termed an opening or aeration chamber in which cotton from the several bales is fiutfed and mixed by means of air blasts, heaters or the like. Secondly, we may secure mixing by feeding bats of cotton from several bales to a likker end, saw cylinder or the like and remove such mixed fibers by means of a brush, air blast or the like. Suffice it to say that insofar as blending is concerned we do not believe it constitutes a serious problem even when our invention is used to make yarn directly from baled cotton. Obviously, if used to make sliver or hank roving which is to be spun on existing machines, blending can be accomplished both before the cotton reaches our process and after it leaves the same.

With the foregoing general discussion in mind, the prime object of our invention is to form cotton or the like fibers into useful strands by bringing the fibers while in a highly separated condition into an electrostatic field of sufiicient potential to cause the fibers to collect in axially parallel relation to each other, and in drawing such fibers axially from such field in the form of a strand. 1

Another object is to provide a method of the character designated in which the length of the electro-static field is only slightly greater than the average length of the fibers to be stranded, whereby the fibers parallel themselves more readily and span the gap between the electrodes with a relatively low potential impressed on the electrodes.

Another object is to strand the fibers by separating the same into small numbers of fibers or individual fibers, entraining the same in an air stream and moving them laterally into the electro-static field, whereby Another object of our invention is to provide ap-j paratus which may be used for carrying out the above method which embodies a chamber in which the fibers to be stranded are entrained in a stream of air, there being an opening in the chamber through which the airborne fibers pass therefrom, together with spaced, statically charged electrodes adjacent the opening between which the air-borne fibers pass, whereby the fibers are separated from the air stream and collect in parallel relation between the electrodes, from whence they.

may be withdrawn as a strand.

Another object is to provide apparatus of the character designated in which one of the electrodes is of annular shape so that the parallel fibers between the electrodes may be drawn axially through the hole in the annular electrode, simplifying the removal and stranding of the fibers.

A further object is to provide such apparatus in which there is associated with the electrodes means to draw the fibers axially out of the electro-static field in timed relation to the collection of the same in the field, together with means to twist the fibers and form a strand thereof as they are withdrawn.

Apparatus illustrating the features of our invention and which is suitable for carrying out the method contemplated by thisinvention is illustrated in the accompanying drawings forming a part of this application in which:

Fig. l is a plan view, certain parts being broken away and in section, showing our invention in operation and with a strand of fibers being formed and withdrawn therefrom;

Fig. 2 is a detailed sectional view taken generally along line IIII of Fig. l; and,

Fig. 3 is an enlarged detail sectional view taken'gen ing of our invention we show our apparatus as embodying" means to place fibers in a stream of air. Such apparatus may embody a pair of feed rolls 10 and 11 between which a bat of cotton fibers indicated at 12 may be fed from any suitable source. The cotton from the rolls 10 and 11 passes to a wire surfaced roller 13 which, if desired, may be similar to the usual likker end of a card, or, which may be in the form of individual wires projecting from the surface of the roll.

As best shown in Fig. l the upper roll 10 may be driven by means of a belt 14 and pulley 16 from a pulley 17. The pulley 17 may be mounted on a shaft 18 in turn supporting the roll or likker end 13. The shaft 18 may be driven through a reduction gear box 19 by means of an electric motor 21.

Adjacent the roller 13 is the rear end of a housing or chamber indicated generally by the numeral 22. The chamber comprises an upper curved wall 23, side walls 24, a rear wall 26 and a bottom wall 27. Mounted adjacent the curved upper wall 23 is a dotfing brush 28 which contacts the surface of roll 13 to remove therefrom fibers carried around by the roll 13. In the manner understood, roll 28 delivers the fibers from the roll 13 either as relatively small bunches containing a few fibers or, in many cases, removes the fibers individually from the roll 13. It will be understood that the rear wall 26 is provided with a slot 29 permitting contact between the brush 2% and the roller 13. Further, and as is also understood in the art, the brush 28 generates sufficient air blast itself to cause the fibers to move to the opposite end of the chamber. At its opposite end the chamber is provided with an opening 31 defined between the bottom wall 27, the upper wall 23 and the side walls.

The brush 28 may be supported in suitable bearings on a shaft 32. The shaft 32 may be driven by an electric motor 33 through a belt 34 and pulleys 36 and 37 in the manner shown.

Placed near the discharge opening 31 of the housing are a pair of electrodes 38 and 39. The electrodes 38 and 39 may be supported on blocks of insulating material 41 and 42, respectively, and may be spaced apart substantially the average length of the fibers to be stranded. Wires 43 and 44 lead from the electrodes 38 and 39 to a source of static potential, indicated diagrammatically at 40.

As best shown in the enlarged view, Fig. 3, the electrode 38 may be in the form of a cylindrical rod of conducting material. The electrode 3? preferably is in the form of a metal washer having a hole 46 therethrough. The hole 46 is aligned with a hole 47 in the block of insulating material 42 which supports the electrode 39. Holes 46 and 47 preferably are axially aligned with the electrode 38.

Outwardly of the electrode 39 with respect to the electrode 33 we provide a cylindrical guide 48 supported on a suitable bracket 49. Adjacent the guide 48 is another bracket 51 which rotatably supports the drilled hub 52 of a twisting roller 53. The roller 53 may carry on its surface a pair of curved spring fingers 54 which are adapted to exert a light spring pressure upon a strand of fibers emerging from the apparatus as will be presently explained. Roller 53 may be driven by a motor 55 through a friction drive roller 55a.

Outwardly of the twisting roller 53 we provide a takeup'drum 56. The drum 56 may be driven through a reduction gear box 57 by means of a suitable electric motor 58.

From the foregoing the operation of our improved method of stranding fibers and the construction and operation of the form of apparatus disclosed herein may now be explained and understood.

Cotton or other fibers are fed in bat form 12 or otherwise to the feed rolls 10 and 11 where they are more or less separated into small bunches or individual fibers by the wire roll 13. The fibers are then placed in an air-borne stream by the doffing brush 28, within the '1; between the electrodes.

confines of the chamber 22. With a potential across the electrodes 38 and 39 sufiicient to span the air gap there-' between, the fibers emerging through the discharge opening 31 will be found to collect and be separated from the stream of air bearing them along and to parallel themselves axially between the electrodes. In order to make a strand we may hold the spring fingers 54 open and seed the process by running a length of thread or the like through the bore of the hub 52, the guide 48 and the openings 47 and 46. We then secure the outer end of such a seed strand to the take up roll 56. With all of the motors in operation it will be apparent that with proper speed regulation thereof fibers may be blown in sutficient quantity into the chamber and collected between the electrodes to form a generally uniform strand. That is, the motor 55 which drives the twisting roller 53 is operated in relation to the speed of the take up drum 56 and both roll 53 and drum 56 are operated in timed relation to the collection of the fibers Consequently, we can put more or less twist in the strand simply by speeding up the motor 55. By proper speed regulation and by properly regulating the feed to the rollers 10 and 11 we provide a continuous process for drawing the strand and twisting it, all carried out in timed relation to the collection of the fibers between the electrodes.

In the stranding of the usual cotton fibers the electrodes 38 and 39 should be placed approximately 1% inches apart. A static potential of approximately 20,000 volts, depending upon the usual factors of humidity, and so forth, is ordinarily sufiicient to cause the fibers to collect.

It will be noted that in carrying out our method, if the cotton fed to the rolls 10 and 11 has trash therein the same has ample opportunity to fall onto the lower wall 27 of the housing where it may be removed by any suitable means, not shown.

It will also be noticed that in the stranding of fibers with our improved method and apparatus very little mechanical working of the fibers is necessary and we therefore preserve the natural tendency of the fibers to twist about themselves, thus increasing the strength of yarn ultimately made from such fibers. With our improved method and apparatus it is not necessary, in order to provide yarn, that fibers first be carded, intermediately attenuated and finally placed on a spinning frame. We thus have provided a method and apparatus by means of which fibers may be taken directly from the baled state and converted into yarn. If desired, and in order to adapt our method and apparatus to existing machines, we may so proportion the electrodes 38 and 39 and so adjust and regulate the feed and withdrawal as to form sliver or roving. In the event roving is formed several packages of the same can be fed in the customary manner to a single spindle of a spinning frame, thus to obtain additional blending.

While we have illustrated in somewhat diagrammatic form apparatus for carrying out our invention it will be apparent that the essence of our method consists in taking fibers while in a loose, disintegrated state and collecting them by means of an electro-static field and in then stranding such fibers.

As used in this specification and in the appended claims, the expression electro-static field means either a field which is of substantially constant potential, or one in which the potential does not remain at zero long enough to permit the fibers to lose their charge and fall from between the electrodes.

While we have shown our invention in but one form, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit thereof, and we desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What. we claim is:

1. In the collection of air-borne fibers, the method comprising passing a stream of the air-borne fibers into an electro-static field of a potential suflicient to cause the fibers to assume a substantially parallel relationship relative to each other, and removing the fibers from said field in collected generally parallel relation and in a direction generally normal to the direction of movement of the air-borne stream.

2. In the method of collecting fibers from an air-borne stream of the same and forming the same into a strand, the steps of passing the air-borne stream of fibers into an electro-static field strong enough to cause the fibers to align themselves generally parallel in said field, moving the collected fibers axially out of the field in a direction generally normal to the direction of movement of the air-borne stream, and concomitantly with said movement twisting the fibers into a strand.

3. In the method of collecting fibers from an airborne stream of the same and forming them into a strand, the steps of moving the stream of fibers between a pair of electro-statically charged spaced electrodes, maintaining the electrodes under a potential sufficient to cause the fibers to parallel themselves between the electrodes, withdrawing said fibers axially out of the field through one of said electrodes and in timed relation to the collection of the same in the field, and twisting the fibers into a strand as they are withdrawn.

4. The method of forming baled fibers into strands which comprises the steps of entraining the fibers in an air stream, passing the air stream between spaced apart electrodes which are under sufiicient potential to cause the fibers to collect therebetween in generally parallel relation to each other, withdrawing the collected fibers axially of the field in timed relation to the collection thereof, and twisting the fibers into a strand as they are withdrawn.

5. In the formation of yarn direct from baled cotton fibers and the like, the method comprising entraining the fibers in an air stream, passing the entrained fibers between a pair of electrodes spaced apart a distance approximating the average staple length of the fibers, impressing upon said electrodes an electrical potential sufficient to establish an electro-static field between the electrodes whereby the fibers collect therebetween in generally parallel relation to each other, withdrawing the fibers axially of the electro static field and in timed relation to the collection thereof between the electrodes, and concomitantly with the withdrawal thereof twisting the fibers into yarn.

6. In apparatus for forming strands of fibers, a chamber having an opening therein, means to disperse the fibers into an air-borne stream in the chamber, there being an opening in the chamber through which the airborne stream of fibers is discharged, spaced apart electrodes adjacent the opening between which the stream passes, a source of potential, means impressing the potential on said electrodes and causing the fibers in said stream to collect between the electrods in generally parallel relation relative to ach other, means to withdraw the collected fibers, and means receiving the fibers from the electrodes effective to twist the same into a strand.

7. In apparatus for making yarn from fibers, a pair of electrodes spaced apart a distance approximately the length of the fibers, means to impress a potential upon said electrodes of a magnitude to establish an electrostatic field therebetween, means to pass the fibers in a loose, non-agglomerated state between said electrodes, whereby they collect therebetween in generally parallel relation to each other, and means to withdraw the fibers axially of the field and twist the same into yarn.

8. In apparatus for making yarn from fibers, a pair of electrodes spaced apart a distance equal substantially the average length of the fibers, a source of electrical potential connected to said electrodes and establishing an elongated electric field therebetween of a strength to cause the fibers to collect between the electrodes and align themselves in parallel strand-like relation, rotating strand twisting mechanism disposed adjacent an end of the electric field, and means to draw the strand from the field through said twisting mechanism.

9. In apparatus for making yarn from fibers, a pair of electrodes spaced apart a distance equal substantially to the average length of the fibers, a source of electrical potential impressed on the electrodes and establishing therebetween an electric field of a strength to establish an electro-static field between said electrodes, one of the electrodes having an opening therethrough, means to pass fibers between the electrodes in a loose fiutfy state whereby the same collect and align themselves parallel to each other between the electrodes, rotating strand twisting mechanism disposed to receive the parallel fibers through the opening of said electrode, and means to draw the fibers through said opening and said twisting mechanism.

10. Apparatus as defined in claim 9 in which said means to withdraw the fibers includes means to operate the same in timed relation to the collection of the fibers 'between the electrodes.

References Cited in the file of this patent UNITED STATES PATENTS 2,385,873 Melton Oct. 2, 1945 2,442,880 Schwartz June 8, 1948 2,468,827 Kennedy et al. May 3, 1949

Claims (1)

1. IN THE COLLECTION OF AIR-BORNE FIBERS, THE METHOD COMPRISING PASSING A STREAM OF THE AIR-BORNE FIBERS INTO AN ELECTRON-STATIC FIELD OF A POTENTIAL SUFFICIENT TO CAUSE THE FIBERS TO ASSUME A SUBSTANTIALLY PARALLEL RELATIONSHIP RELATIVE TO EACH OTHER, AND REMOVING THE FIBERS FROM SAID FIELD IN COLLECT GENERALLY PARALLEL RELATION AND IN A DIRECTION GENERALLY NORMAL TO THE DIRECTION OF MOVEMENT OF THE AIR-BORNE STREAM.

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