US3368340A

US3368340A - Method and apparatus for doffing and straightening fibers during combing and spinning thereof

Info

Publication number: US3368340A
Application number: US580241A
Authority: US
Inventors: Arkadij Barsukov; Ladislav Bures; Ctibor Doudlebsky; Ceska Trebova; Stanislav Kabele; Milan Chrtek
Original assignee: Vyzkumny Ustav Bavlnarsky AS
Current assignee: Vyzkumny Ustav Bavlnarsky AS
Priority date: 1965-10-01
Filing date: 1966-09-19
Publication date: 1968-02-13
Anticipated expiration: 1985-02-13
Also published as: YU31431B; ES331241A1; FR1495729A; CH457216A; DE1510998B2; AT264331B; BE686603A; DE1510998A1; DE1510998C3

Description

Feb. 13, 1968 A BARSUKOV ET AL 3,368,340

METHOD AND APPARATUS FOR DOFFING AND STRAIGHTENING FIBERS DURING COMBING AND SPINNING THEREOF Filed Sept. 19, 1966 3 Sheets-Sheet l N ENTORS l anmlr' Feb. 13, 1968 METHOD AND APP A. BARsuKov ETAL 3,368,340 ARATUS FOR DOFFING AND STRAIGHTENING ING COMBING AND SPINNING THEREOF 3 Sheets-Sheet 2 FIBERS DUR Filed Sept. 19, 1966 INVENTORS mi? m? UQUEM# Fel). 13, 1968 A BARSUKOV ET AL 3,368,340

METHOD AND APPARATUS FOR DOFFING AND STRAIGHTENING FIBERS DURING COMBING AND SPINNING THEREOF Filed Sept. 19, 1966 5 Sheets-Sheet 5 United States Patent O" 3,368,340 METHOD AND APPARATUS FR DUFFING AND STRAIGH'EENlNG FIBERS DURlNG COMBDIG AND SPINNING THEREOF Arkadij Barsulrov, Ladislav Bares, and' Ctibor Doudlebsky, Usti nad Urlici, Milan Chrteh, Ceska Trebova, and Stanislav Kaheie, Usti nad rlci, Czechoslovakia, as signors to Vyzimmny Ustav Bavlnarsky, Usti nad Undici, Czechoslovakia Filed Sept. 19, 1966, Ser. No. 580,241 Claims priority, application Czechoslovakia, Oct. 1, 1965, 5,947/65 20 Claims. (Cl. 7-58.89)

The present invention relates to a method of dofiing and straightening bers while conveying the same from a combing roller into a spinning chamber during a splnning operation, and apparatus for carrying out the method.

Various methods and apparatus are known in the art for dofiing or taking ofi fibers from projecting portions of a combing member and for transporting the fibers 1n substantially straightened condition into a spinning chamber so that the fibers may be spun therein into a yarn. The known methods and apparatus do not, however, work to complete satisfaction, since in the known methods and apparatus the fibers are not reliably straightened during transportation thereof from the combing member into the spinning chamber, nor are the fibers properly separated from each other, which results in inferior yarn spun in the spinning chamber.

It is an object of the present invention to provide for a method in which the drawbacks of known methods of the aforementioned kind are overcome and in which the fibers are not only properly taken off the projections of the combing member but also fed in substantially straightened and separated condition into the spinning chamber.

It is a further object of the present invention to provide for an apparatus for carrying out the method according to the present invention.

It is an additional object of the present invention to provide for such an apparatus which is constructed of relatively few and simple parts so that the apparatus can be manufactured at reasonable cost and will stand up trouble-free over an extended period of time.

With these objects in View, the method according to the present invention of dofiing and straightening fibers during conveying thereof from a combing roller into a spinning chamber wherein the fibers are spun mainly cornprises the steps of engaging the fibers by projections with a combing roller rotating with a given circumferential speed, directing a confined stream of air with a speed greater than the aforementioned circumferential speed of the roller and in substantially tangential direction against the fibers engaged by the projections of the roller, creating thereby in the air stream a pressure difference acting upon the fibers in substantially radial direction away from the combing roller, whereby the fibers are gradually lifted off the projections, straightened, and conveyed by the air stream into the spinning chamber.

By subjecting the fibers, in the region of doliing the same from the combing member, to a confined air stream which has a speed greater than the circumferential speed of the combing roller, a pressure difference is created in the air stream in such a manner that the pressure difference acts upon the fibers substantially in radial direction away from the combing roller so that the fibers are gradually lifted from the projections of the combing member and straightened by the effect of the different velocities and thus transferred in straightened condition into the spinning chamber.

According to a further feature of the present invention 3,368,349 Patented Feb. 13, 1968 it is advantageous that the fibers, dotted and straightened in the area of projection of the combing member into the air stream, are subjected in an area in which the combing member leaves the air stream to another pressure and velocity difference created at this latter region by a swirling of air.

1t is further considered advantageous to maintain the circumferential speed of the combing roller to about 12S-60% of the velocity of the air delivered to the dofiing point. It has also been found advantageous to deliver by the aforementioned air stream a volume of air amounting to 1.5-3.0 liters per second into the spinning chamber.

Preferably the air stream is produced by creating an underpressure of 1D0-25() mm. water column in the spinning chamber and creating by this underpressure a suction effect for producing the air stream.

The method according to the present invention may also include the step of producing in the spinning chamber, into which the fibers are conveyed by the aforementioned air stream, an air swirl so as to subject the fibers before they reach the collecting surface of the spinning chamber to another pressure and speed difference produced by the air swirl. Preferably the method may also include the step of gradually increasing the speed of the air conveying the fibers until the air reaches the collecting surface of the spinning chamber.

The apparatus for carrying out the above method mainly comprises wall means defining a spinning chamber having an axis and being rotatable about the axis, the spinning chamber having an open end and a collecting surface facing the open end, closure means closing the open end of the spinning chamber, a combing roller having fiber engaging projections on the outer peripheral surface thereof and being rotatable about an axis, channel means arranged adjacent the peripheral portion of the combing roller so that the projections on the aforementioned portion project at least partly into the channel means, the channel means having an outer end communicating with the outer atmosphere and an inner end passing through the closure means and communicating with the interior of the spinning chamber, means cooperating with the spinning chamber to create an underpressure in the latter to produce thereby by suction an air stream passing through said channel means, means for feeding slivers to be spun into engagement with the projections on the combing roller at a portion of the latter spaced from the channel means, and means for withdrawing spun fibers from. the collecting surface of the spinning chamber.

According to a further feature of the present invention, the aforementioned channel means preferably gradually taper from the outer to the inner end thereof. The apparatus may also include throttling means cooperating with the channel means for regulating the flow of air passing through the latter.

It is also advantageous that the channel means leads into the spinning chamber at an angle of 20-40 with respect to plane normal to the axis of rotation of the spinning chamber.

The wall means of the spinning chamber define between the open end and the collecting surface thereof an annular surface and the apparatus preferably includes a stationary separator in the spinning chamber having a surface spaced from and facing the annular surface of the wall means. The two aforementioned facing surfaces are preferably arranged in such a manner that they converge in the direction of ithe air flow passing between these surfaces.

The novel features Which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a schematic cross sectional view through the apparatus of the present invention;

FIG. 2 is a partial cross sectional View, drawn to an enlarged scale, and showing a portion of the combing roller and a portion of the channel means adjacent thereto;

FIG. 3 is a partial top view of the appara-tus with the spinning chamber and the separator removed therefrom and illustrating the arrangement of the inner end of the channel means with respect to the axis of rotation of the spinning chamber;

FIGS. 4-7 are partial sectional views likewise drawn to an enlarged scale and schematically illustrating the removing of the fibers from the engaging projections of the combing roller and the straightening of the fibers in the channel means; and

FIG. 8 is a sectional perspective view of the apparatus shown in FIG. l.

Referring now to the drawings, and more specifically to FIGS. l and 8 of the same, it will be seen that the apparatus according to the present invention mainly comprises support means which are preferably in the form of block 1 which is formed with a cylindrical cavity in which a combing roller 2 is arranged, driven about a preferably horizontal axis in counter-clockwise direction, as indicated by the arrow shown in FIG, 1, by means not shown in the drawing. The peripheral surface of the combing roller 2 is provided with engaging projections 3, which may have a saw tooth configuration as best shown in FIG. 2, and which may be formed from an appropriately crimped wire wound in a helix having a small lead about the peripheral surface of the roller 2 and connected thereto in any convenient manner. While this specific form of the engaging projections has been found advantageous, it is mentioned that the specific form of the engaging projections shown in the drawing is not essential for carrying out the method according to the present invention, and engaging projections of different constructions may also be used in the apparatus of the present invention.

Channel means 7 are formed in the block 1, which lead into spinning chamber 8 and ldischarge into the space between a stationary separator 9 and the rotating wall 10 of the spinning chamber. The wall 10 has preferably an inner frusto-conical surface leading onto a collecting surface 11. The drive shaft of the spinning chamber 8 is rotatably supported in bearings 13 and 14, which are preferably ball bearings, as shown more clearly in FIG. 8, and the spinning chamber is rotated about a preferable vertical axis by means not shown in the drawing. The lower open end of the spinning chamber is closed by the upper surface of the block 1, which forms therefore a closure means for closing the open end of the spinning chamber 8. Preferably, the upper surface of the block 1 is provided with an annular groove 27 arranged coaxially with the axis of rotation of the spinning chamber and into which the lower edge of the wall 1t) projects to form a labyrinth seal with the groove 27, as best shown in FIG. 8. The spinning chamber 8 is further provided with means `for producing an underpressure therein, which means may be in the form of a plurality of passages or bores 12 extending in substantially radial ydirection through a central upper raised wall portion of the spinning chamber, bu-t instead of the passages 12, other means may be provided in the spinning chamber to produce the desired underpressure therein. The separator 9 iS substantially diskshaped and fastened at its lower small diameter end to the top surface of the block 1 in any convenient manner. The separator 9 is provided at the center thereof with a discharge opening 15 aligned with a corresponding bore through the block 1 through which the finished yarn 16 is withdrawn by a known draw-off and winding mechanism as schematically shown in FIG. l and including a bobbin or spool 26 rotated about its axis by means not shown in the drawing and arranged below the block 1.

The sliver 6 to be spun is positively fed by a feed roller 4 through an inlet 5 in the block 1 into engagement with the engaging projections 3 on the combing roller 2.

The channel means 7 are arranged substantially tangential to the peripheral surface of the combing roller Z and the width of the channel means is advantageously slightly greater than the width of the peripheral surface of the combing roller which is provided with engaging projections. Preferably the channel means tapers from the outer inlet end 17 thereof which communicates with the outer atmosphere toward the outlet end 19 which communicates with the interior of the spinning chamber. The outlet end 19 of the channel means 7 is arranged, as shown in FIGS. 3 and 8 laterally of the axis of rotation of the spinning chamber so as to face the outer frustoconical surface 2t) of the separator 9. Preferably, the channel means 7 is inclined at an acute angle of 20-40 to the upper surface of the yblock 1, that is to a plane extending at right angles to the vertical axis of rotation of the spinning chamber 8. Throttling means may also be provided cooperating with the channel means 7 for regulating the flow of air passing therethrough. The throttling means may comprise damper 1S mounted in front of the inlet end 17 of the channel means movably between a plurality of positions in which the damper covers the inlet end 17 to a greater or smaller extent. The damper 18 may for instance be turnably mounted by means of a screw or the like on the block 1 so that by loosening of the screw the damper plate may be turned from the position shown in FIG. 8 to a position in which it partly overlaps the inlet opening 17, whereafter the screw is tightened to hold the `damper plate 13 in the adjusted position.

As can be seen froml FIG. l the lower surface 20 of the separator 9 and the inner surface of the wall 10 of the spinning chamber converge toward the collecting surface 11, however, their imaginary prolongations do not have to necessarily intersect at a line of the collecting surface 11. As has already been mentioned, the channel means 7 discharge within the space between the surface Ztl of the separator 9 and the inner surface of the wall 10 of the spinning chamber 8.

The apparatus above described forms part of a spinning unit. A plurality of such units are disposed side by side on a frame of a spinning machine not shown, and constitute together with other mechanisms such as drives, counter-shafts, etc., a ringless continuous spinning machine.

The apparatus above described will operate as follows:

When the machine is started, the feed roller 4, the combing roller 2 and the spinning chamber 8 with the means 12 for creating an underpressure therein begin to rotate at predetermined speed ratios. The sliver 6, drawn from a not shown supply can or bobbin, is fed by the feed roller 4 into the range of the projections 3 of the combing roller 2, by the action of which the sliver is opened up and the fibers thereof are separated.

As mentioned before, it is an essential feature of the present invention to reliably doff or take off the separate fibers from the engaging projections 3 of the combing roller 2 and to transfer the fibers in substantially straightened condition onto the collecting surface 11 of the spinning chamber 8.

This desired effect is produced with the apparatus of the present invention in the following manner:

Due to the suction effect provided by the means 12 of the spinning chamber and partly also by the ventilatory effect of the rotating combing roller 2 a certain volume of air is sucked from the ambient atmosphere through the inlet end 17 into the channel means 7. The rotational speed of the combing roller 2, that of the spinning chamber 8, and the cross section of the channel means 7 are chosen in such a manner that the air stream passing through the channel means 7 has, in the region where the air stream acts on the engaging projections 3 on the peripheral surface of the combing roller 2, a maximum velocity, which is approximately twice as great as the circumferential Velocity of the combing roller 2.

FIG. 2 schematically illustrates the velocity distribution produced in the air stream passing through the channel 7 in the region in which the air stream acts on the engaging portions 3 of the combing roller 2. As indicated in FIG. 2, the velocity of the air stream at the peripheral surface of the combing roller 2 will be substantially equal to the circumferential speed Vv of the combing roller 2, and the air stream velocity increases in radial outward direction towards the opposite wall 21 of the channel means 7 and at the surface of this wall it will, due to friction, suddenly drop substantially to Zero. This Velocity distribution in the considered area will produce, according to Bernoullis law, in this area of the air stream a pressure distribution in the air stream creating a pressure difference acting approximately in the radial direction away from the combing roller 2. This pressure difference will act on the fibers 22 as shown in FIGURES 4-7 to gradually take the latter off from the engaging projections 3 so that the leading ends of the fiber pass into the area of higher velocity of the air stream whereby the fibers while being taken off from the engaging projections 3 are straightened.

In the event that some of the fibers still cling to the projections 3 of the combing roller 2, they will be taken ofi' in the area of the edge 23 of the block 1, where an air swirl 24 is produced resulting in a condensation of the air stream, as indicated in FIG. 2, so that the air flows through this area at a higher velocity, thus creating favorable conditions for doffing even the last fibers from the engaging projections and for straightening the fibers. The fibers thus straightened enter the rapidly rotating spinning chamber 8 in the space between the outer surface 20 of the separator 9 and the inner surface of the wall 10. By the action of the hydrodynamic forces as well as by the action of the centrifugal and the Coriolis acceleration a movement is imparted to the fibers so that they are gradually deposited, first with their leading ends and subsequently with their remaining portions onto the inner surface of the wall 10 from where they pass under the action of centrifugal forces onto the collecting surface 11. From the latter they are withdrawn in a known manner by the yarn 16 forming on this surface and the yarn is withdrawn through the discharge opening of the separator 9 and finally wound on the bobbin 26.

On reaching the edge 25 of the separator 9 the air stream suddenly changes its direction of flowing and its velocity abruptly drops, due to the widening of the air passage downstream of the edge 25 of the separator, with the result that even those fibers which have not taken their positions on the collecting surface are now separated and by the action of centrifugal forces thrown onto the surface 11. The outer surface of the separator 9 and the inner surface of the wall 10 of the spinning chamber are frusto-conical surfaces which are arranged, as clearly shown in FIG. 1, in such a manner that the space defined between these two surfaces tapers in upward direction toward the collecting surface 11 so that a drop of the air stream velocity is also avoided in this space, which in turn prevents a possible undesirable movement of the fibers.

The circumferential speed of the combing roller 2 amounts to -60% of the maximum air velocity in the channel means 7 and the volume of air delivered from the atmosphere through the channel means 7 into the spinning chamber 8 is preferably in the order of 1.5-3.0 liters per second. The desired air velo-city in the channel means 7 is derived from the suction effect produced by the ventilator 12 which produces in the interior of the spinning chamber 8 an underpressure in the order of 1GO-250 mm. of water column. Due to the above described tapering configuration of the channel means 7 and due to the above described arrangement of the outer surface 20 of the separator 9 and the inner surface on the wall 10 of the spinning chamber and thel additional effect produced by the rotating spinning chamber, the velocity of the air stream gradually increases from the inlet end 17 of the channel means 7 up to the collecting surface 11 of the spinning chamber 8.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of methods and apparatus for dofiing and straightening fi'bers during conveying thereof from a combing roller into a spinning chamber of a ringless spinning machine differing from the types described above.

While the invention has been illustrated and described as embodied in a method and apparatus of dofhng and straightening fibers during conveying thereof .from a combing roller into a spinning chamber of a ringless spinning machine, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A method of doffing and straightening fibers during conveying thereof from a combing roller into a spinning chamber wherein the fibers are spun, comprising the steps of engaging the fibers by projections of the combing roller rotating with a given circumferential speed; directing a confined stream of air with a speed greater than said circumferential speed in substantially tangential direction against the fibers engaged by said projections of said roller and creating thereby in said air stream a pressure difference acting upon the fibers in substantially radial direction away from said combing roller, whereby said fibers are gradually lifted off said projections, straightened and conveyed by said air stream into the spinning chamber.

2. A method as set forth in claim 1, wherein the circumferential speed of the combing roller is 25-60% of the speed of said air stream.

3. A method as set forth in claim 1, wherein the volume of air delivered by said stream is 1.5-3.0 liters per second.

4. A method as set forth in claim 1, and including the step of creating an underpressure of -250 mm. water column in said spinning chamber and creating by said underpressure a suction effect for producing said air stream.

5. A method as set forth in claim 1, and including the step of producing in said spinning chamber, into which said fibers are conveyed by said air stream, an air swirl so as to subject the fibers before they reach a collecting surface of said spinning chamber to another pressure and speed difference produced by said air swirl.

6. A method as set forth in claim 5, and including the step of gradually .increasing the speed of the air conveying the fibers until the air reaches the collecting surface of the spinning chamber.

7. An apparatus for dofiing and straightening fibers during combing and spinning thereof comprising, in combination, wall means defining a spinning chamber having an axis and being rotatable about said axis, said spinning chamber having an open end and a collecting surface facing said open end; closure means closing said open end of said spinning chamber; a combing roller having fiber engaging projections on the outer lperiphery thereof, said combing roller being rotatable about its axis; channel means arranged adjacent a peripheral portion of said combing roller so that the projections on said portion project at least partly into the channel means, said channel means having an outer end communicating with the atmosphere and an inner end passing through said closure means and communicating with the interior of said spinning chamber; means cooperating with said spinning chamber to create an underpressure in the latter to produce thereby suction creating an air stream passing from said outer end of said passage means through the latter; means for feeding siivers to be spun into engagement with said projections of the combing roller at a portion of the latter spaced from said channel means; and means for withdrawing spun fibers from said collecting surface of said spinning chamber.

8. An apparatus as set forth in claim 7, wherein said channel means tapers from said outer towards said inner end thereof.

9. An apparatus as set forth in claim 7, and including throttling means cooperating with said channel means for regulating the flow of air passing therethrough.

1G. An apparatus as set forth in claim 9, wherein said throttling means comprise a damper mounted in the region of said outer end of the channel means.

f1. An apparatus as set forth in claim '7, wherein said channel means lead into said spinning chamber at an angle of 2.0-4()D inclined to a plane extending at right angles to the axis of rotation of the spinning chamber.

12. An apparatus as set forth in claim 11, wherein the axis of rotation of the combing roller extends at an angie of 90 to the axis of rotation of said spinning chamber.

i3. An apparatus as set forth in claim 7, wherein said wall means defines between said open end and said collecting surface of said spinning chamber an annular sun face, and including a stationary separator in said spinning chamber having a surface spaced from and facing said annular surface of said wall means, and wherein said inner end of said channel means is located between said annular surface and said surface of said separator so that the air stream passing through the channel means feeds the fibers into the space between said surfaces.

le. An apparatus as set forth in claim 13, wherein said annular surface of said spinning chamber and said surface of said separator converge towards each other in direction of said air stream.

15. An apparatus as set forth in claim 14, wherein said annular surface of said spinning chamber is a substantially frusto-eonical surface and wherein said separator has a frusto-conical wall, the outer surface of which forming said surface facing said annular frusto-conical surface of the spinning chamber.

i6. An apparatus as set forth in claim 15, wherein said collecting surface of the spinning chamber is located in a plane which includes an angle of with the axis of rotation of said spinning chamber.

f7. An apparatus as set forth in claim 16, wherein said closure means is in the form of a block having an upper surface and including sealing means between the lower edge of the wall defining said spinning chamber and said upper surface of said block.

f8. An apparatus as set forth in claim 17, wherein said wall means dening said spinning chamber has a central upg-er raised portion, and said means for forming the underpressure in said spinning chamber including a plurality of substantially' radially extending passages through said upper portion of said wall means.

ll". An apparatus as set forth in claim 17, wherein said separator is fixed to the upper portion of said block substantially coaxial with the axis of rotation of said spinning chamber', said separator and block being formed with an opening extending along said axis of rotation of said spinning chamber for withdrawal of spun yarn from said spinning chamber.

Z0. An apparatus as set forth in claim 19, wherein said inner end of the channel means is located at said upper surface of said block and laterally spaced from said central opening through said separator.

References Cited UNITED STATES PATENTS 3,115,601 1'2/1963 Cizel: et al. 57-58-9l 3,11/,223 1/1964 Meirnberg 57-58-95 XR 3,121,306 2/l964 Cizek et al 57-58-89 3,324,641?. 6/1967 Meimberg et al 57-5S-95 3.328,949 7/1967 Pavek et al. 57--58-89 FOREIGN PATENTS 9/1964 Great Britain. 1,033,074 6/1966 Great Britain.

FRANK l'. COHEN, Prima/'y Examil'zer.

D. WATKINS, Assistant Examiner.

Claims

7. AN APPARATUS FOR DOFFING AND STRAIGHTENING FIBERS DURING COMBING AND SPINNING THEREOF COMPRISING, IN COMBINATION, WALL MEANS DEFINING A SPINNING CHAMBER HAVING AN AXIS AND BEING ROTATABLE ABOUT SAID AXIS, SAID SPINNING CHAMBER HAVING AN OPEN END AND A COLLECTING SURFACE FACING SAID OPEN END; CLOSURE MEANS CLOSING SAID OPEN END OF SAID SPINNING CHAMBER; A COMBING ROLLER HAVING FIBER ENGAGING PROJECTIONS ON THE OUTER PERIPHERY THEREOF, SAID COMBING ROLLER BEING ROTATABLE ABOUT ITS AXIS; CHANNEL MEANS ARRANGED ADJACENT A PERIPHERAL PORTION OF SAID PROJECT AT LEAST PARTLY INTO THE CHANNEL MEANS, SAID CHANNEL MEANS HAVING AN OUTER END COMMUNICATING WITH THE ATMOSPHERE AND AN INNER END PASSING THROUGH SAID CLOSURE MEANS AND COMMUNICATING WITH THE INTERIOR OF SAID SPINNING CHAMBER; MEANS COOPERATING WITH SAID SPINNING CHAMBER TO CREATE AN UNDERPRESSURE IN THE LATTER TO PRODUCE THEREBY SUCTION CREATING AN AIR STREAM PASSING FROM SAID OUTER END OF SAID PASSAGE MEANS THROUGH THE LATTER; MEANS FOR FEEDING SLIVERS TO BE SPUN INTO ENGAGEMENT WITH SAID PROJECTIONS OF THE COMBING ROLLER AT A PORTION OF THE LATTER SPACED FROM SAID CHANNEL MEANS; AND MEANS FOR WITHDRAWING SPUN FIBERS FROM SAID COLLECTING SURFACE OF SAID SPINNING CHAMBER.