US3775956A

US3775956A - Device for separating fibrous material for use with textile machines

Info

Publication number: US3775956A
Application number: US00209705A
Authority: US
Inventors: B Burget; J Rajnoha; L Bures
Original assignee: Elitex Zavody Textilniho
Current assignee: Elitex Zavody Textilniho
Priority date: 1970-12-23
Filing date: 1971-12-20
Publication date: 1973-12-04
Anticipated expiration: 1990-12-04
Also published as: IT943976B; GB1339149A; DE2159230A1; FR2118992A1; CS161233B1; FR2118992B1; CH533697A

Abstract

A device for separating fibrous material, for use with textile machines, particularly open end spinning machines. The device includes a housing, a carding roller rotatable in the housing, and feed means for feeding fibrous silver to be separated to the carding roller. A first guide wall portion is located downstream of the feed means and defines with the peripheral surface of the carding roller a first clearance whose width tapers in downstream direction. The first clearance extends circumferentially of the carding roller and communicates with a second clearance, located further downstream. The second clearance is defined between the peripheral surface of the carding roller and a second guide wall portion. The width of the second clearance is substantially constant. An outlet passage is provided for fibers which have been separated.

Description

O Umted States Patent 11 1 1111 3,775,956 Rajnoha et a]. Dec. 4, 1973 DEVICE FOR SEPARATING FIBROUS 3,381,463 5/1968 Fajt et a1 57/50 x M ATERIALFOR USE WITH TEXTILE 3,439,488 4/1969 Bucic et a1 19/105 X MACHINES 3,571,859 3 1971 Doudlebsky et 8.1.... 57/58.9l x 3,626,681 12 1971 Naruse 57/58.95 x

Inventors: Jaroslav Rajnoha, Tyniste nad Orlici; Ladislav Bures; Bohumir Burget, both of Usti nad Orlici, all

- of Czechoslovakia Filed: Dec. 20, 1971 Appl. No.:209,705

Assignee:

Foreign Application Priority Data Dec. 23, 1970 Czechoslovakia 8731/70 US. Cl. 57/58.91, 57/58.95 Int. Cl. D0lh 1/12 Field of Search 57/50, 58.91, 58.95;

References Cited UNITED STATES PATENTS l/l968 Doudlebsky et a1. 57/58.95

Primary Examiner-John Petrakes Assistant Examiner-Charles Gorenstein Attorney-Michael S. Striker [57 ABSTRACT A device for separating fibrous material, for use with textile machines, particularly open end spinning machines. The device includes a housing, a carding roller rotatable in the housing, and feed means for feeding fibrous silver to be separated to the carding roller. A first guide wall portion is located downstream of the feed means and defines with the peripheral surface of the carding roller a first clearance whose width tapers in downstream direction. The first clearance extends circumferentially of the carding roller and communicates with a second clearance, located further down stream. The second clearance is defined between the peripheral surface of the carding roller and a second guide wall portion. The width of the second clearance is substantially constant. An outlet passage is provided for fibers which have been separated.

5 Claims, 2 Drawing Figures PAIENTED 4'975 INVENTOR ATTORNEY DEVICE FOR SEPARATING FIBROUS MATERIAL FOR USE WITH TEXTILE MACHINES BACKGROUND OF THE INVENTION means. Such feed means comprise typically a pressure block arranged to exert a clamping pressure upon the fibrous material being fed. In this way, the fibrous body is bent over the edge of the pressure block as it passes the point of clamping pressure. Usually, a feed roller forms part of such feed means and cooperate with the clamping means to advance fibrous material towards the carding roller.

The staple fibers separated from the fibrous sliver being processed are ordinarily fed through an appropriate outlet passage to a subsequent stage of the installation, usually to the collecting surface of an adjoining spinning machine. In suchcases, an under-pressure is developed in the spinning chamber, and this underpressure serves to draw the separated fibers out through said outlet passage.

In the conventional devices, a clearance is defined between the peripheral surface of the carding roller and the inner peripheral wall of the carding chamber, the fibrous sliver being fed though such clearance along such wall. Alternatively, the clearance may be defined between the carding roller surface and specially provided wall means. Hitherto, such wall means was changeable in its position at the point of clamping pressure of the feeding mechanism in circumferential direction of the cardingroller. The feeding body is made in the form of a wall of resilient material which at the feeding point is directed towards the needle surface of the carding roller, and whose position is adjustable by means of an adjustment element, such as an adjustable screw.

In another prior-art device the feeding body is formed by a cylinder adjustable in its position, and which approaches with its peripheral surface the needle surface of the carding roller and forms near the same .a feeding surface.

The disadvantage of these arrangements is that the separated fibers are fed to the collecting surface of the spinning chamber in damaged state, i.e., broken, bent or in the form of fiber agglomerates. In this way the quality of the final yarn is considerably reduced and, conversely, the number of yarn breakages during operation increased.

This disadvantage results from the basic design of such arrangements, and particularly from the design of the fiber separating clearance and the fiber-conveying clearance. Specifically, disadvantageous air-flow conditions prevail in such clearances, resulting from the placement of the feeding means, and other factors. The air flow is forced to bypass such feeding means, which accordingly constitute an aerodynamic irregularity in the air-flow path. The region of the feed means is thus one of considerable turbulence, resulting from abrupt changes in the air-flow speed and direction in this vicinity. It is to be understood that the fibers carried by such air flow will likewise experience changes in speed and direction, with resulting damage.

The most frequent point at which fiber agglomerates form and separated fibers bend is the vicinity of the carding chamber located immediately upstream and downstream of the feeding. Additionally, of course,

such vicinity will serve as a point of accumulation of fibers introduced earlier which have not survived the separation operation intact.

SUMMARY OF THE INVENTION It is accordingly one object of the present invention to overcome such disadvantages of the prior art.

More particularly, it is an object of the invention to provide a novel fiber-separating device which overcomes these disadvantages.

Still more particularly, it is an object of the invention to provide a novel device which accomplishes the separation of fibrous material in a simple and efficient manner, and which will reduce to a minimum both fiber breakage and the accumulation of fibrous agglomerates. Accordingly, with the device of the present inventionthe yarnfinally produced will be of superior quality and strength.

In accordance with these objects, and others which will become apparent hereafter, one feature of the in vention resides, briefly stated, in a device for separating fibers from fibrous material, particularly for use with open end spinning machines, which comprises a housing and a carding roller mounted for rotation in the housing and having a peripheral surface. Feed means is provided for feeding fibrous sliver to be'separated to the carding roller. A first guide wall portion is positioned downstream of the feed means and defines with the peripheral surface of the carding roller a first clearance. The first clearance extends circumferentially of the roller and has a width which tapers in downstream direction. A second guide wall portion is positioned downstream of the first guide wall portion and defines with the peripheral surface of the carding roller a second clearance. The second clearance, too, extends circumferentially of the roller, and has a width which is substantially constant. The second clearance communicates with the first clearance. A fiber outlet passage is located downstream of the second guide wall portion, and communicates with the second clearance. The fiber outlet passage constitutes an outlet for separated fibers.

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 best be understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sectional view of a fiber-separating device according to the invention, sectioned on a plane normal to the axis of rotation of the fiber-separating roller; and

FIG. 2 is an enlarged, schematic illustration of a fiber-separating roller according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The device of the present invention comprises a housing structure 1 schematically illustrated in the drawing, having a carding chamber 2 in which carding roller 3 is mounted for rotation. The mounting of roller 3 has not been illustrated in detail, and of course will be accomplished in whatever manner is most appropriate in a given circumstance.

The peripheral surface 4 of roller 3 is provided with exchangeable combs 5, the spacing between which is chosen'such as to make the pitch B (see FIG. 2) at least equal to or longer than the average length of the staple fibers in the fibrous sliver 8 to be processed. Advantageously, the carding means 5 are exchangeable, so that they can be replaced after wear or damage. In FIG. 2 and by way of example only, the carding components 5 have a dovetail configuration and are mounted in correspondingly configurated undercut recesses.

The chamber 2 communicates with an inlet recess 6, inside which a feeding mechanism 7 is mounted. The feeding mechanism 7, in this embodiment, comprises a feeding roller 9 and a pressing bridge 10 mounted in front of the feeding roller 9 and pressed towards it under the influence of a biasing spring 12. As can be seen, biasing spring 12 bears with one of its ends against a wall of inlet recess 6, and with the other of its ends against the pressing bridge 10.

The feeding mechanism 7 includes a condensing tube 1 l which opens towards the surface of feeding roller 9. The resilient pressure exerted by pressing surface 13 of pressing bridge 10 due to spring 12, produces a clamping pressure exerted on the fibrous sliver fed between the bridge 10 and feeding roller 9.

It will be further seen that, in the exemplary embodiment of FIG. 1, the carding chamber 2 communicates (at the top of FIG. I) with an outlet passage 14. Passage 14 is provided as an exit for separated fibers, and conveys such fibers to the collecting surface 16 of an adjoining spinning chamber 17, or another successive stage of the installation. With the spinning chamber constituting the subsequent stage of the installation, it can be advantageous that it be positioned as near the fiber-separating device as practical.

It should be understood that, during operation of the fiber-separating device, the carding roller 3 and fibrous material being processed will move in direction of the arrow 8,.

Downstream of the feeding mechanim 7 there is provided a first clearance 18a defined between the peripheral surface of the carding roller and a first guide wall portion 20. In the exemplary illustration, guide wall portion 20 is shown as part of the inner peripheral wall of the housing 1, but it will be clear that suitable wall means may be mounted within the housing and constitute the guide walls, depending on considerations of design and expedience,-and that such wall means may be adjustable, if desired. It will be appreciated that carding projections 5 on roller 3 project into clearance 18a in radial direction. Suitable cover means will ordinarily be provided, constituting further boundaries of clearance 18a, and of carding chamber 2 in general.

The cross-section of first clearance 18a corresponds to the cross-section of the fibrous body 8 being fed by the feeding mechanism 7. Behind the nip line, the clearance 18a continuously narrows in direction of advancement of fibers. According to an advantageous feature of this embodiment, the length of clearance 18a, measured in circumferential direction, is at least equal to or longer than four fifths the average length of staple fibers in fibrous body 8.

Downstream of first clearance 1811, there is located a second clearance 18b. As will be seen, second clearance 18b is defined by the peripheral surface of roller 3 and by a second guide wall portion 25. In addition, needless to say, the second clearance will be further defined by whatever members form the end closures of the carding chamber.

Second clearance 18b has a cross-section, measured along a radial section, which is at least equal to the cross-section which the processed fibrous body 8 has 7 upon being subjected to bilateral clamping pressure between feed roller 9 and pressing bridge 10. The passage defined between the periphery of roller 9 and the pressing surface of pressing bridge 10 at which clamping of the sliver takes place constitutes an inlet passage through which fibrous sliver is fed. In the exemplary illustration of FIG. 1, the width A and cross-section of second clearance 18b are substantially constant.

The operation of the illustrated device is as follows:

Fibrous sliver 8 is fed to the device to undergo separation of fibers. Such sliver is introduced through condensing tube 11 to the nip line between feeding roller 9 and pressure surface 13 of pressing bridge 10. By rotary motion of the feeding roller 9, the fibrous body 8 is pushed inside the hollow 2 and is there contacted by the combs 5 of fiber separating roller 3, which latter rotates in direction of arrow 5,. In this embodiment, the fibrous body 8 is bent over the edge of pressing bridge 10, almost perpendicularly to the inlet direction, and then guided towards the feeding surface 20 of the first clearance 18a into the area of actual fiber separation.

In clearance 18a, fibers are separated from fibrous body 8 and are fed in separated state through the second clearance 18b, towards outlet tube 14, and therethrough to collecting surface 16 of spinning chamber 17, to be converted into yarn.

One advantage with the device of the present invention is that the separated fibers are guided from the clamping point in the feeding mechanism as far as the outlet passage entrained by an air fiow which is evenly distributed and correctly oriented, so that the separated fibers may be collected in the form of a continuous ribbon on the collecting surface of the spinning chamber. The possibility of fiber damage during the fiber-separation process is considerably reduced in the device of the invention, in fact reduced to as little as one-tenth that prevailing with prior-art mechanisms, and without producing any additional disadvantages. The quality of the yarn, namely its appearance and strength, is accordingly greatly increased.

It should be understood that the enlarged width of clearance 180, which continuously narrows down, enables successive separation of fibers from sliver 8. The continuously tapering cross-section of the first clearance 18a corresponds to the continuously diminishing cross-section of sliver 8 upon separation of fibers therefrom.

The reduced width of second clearance 18b, which communicates with first clearance 18a, is beneficial for straightening the floating fibers which have been separated at the boundary region of clearances 18a and 18b. In clearance 18b, the fibers which become comtional engagement with the surface of roller 3. The reduced cross-section of clearance 18b, in particular, contributes to the straightening of the floating fibers and to the feeding of the fibers towards outlet 14 in proper orientation. In this way, excessive variations of individual fibers, such as might eventually result in fiber agglomerates, is substantially overcome.

lthas already been stated that the spacing B between groups of carding projections 5 on roller 3 should be at least equal to the average length of staple fibers in the fibrous sliver 8. Thus, as is usually the case the characteristics of the materials being processed determine to a large extent the dimensions of the processing device.

Withsuch proper selection of the pitch B, the fibers are not excessively attached during separation by the tips of carding projections 5, or whatever othercarding means is being employed. This representsa significant improvement over those prior-art constructions wherein the carding needles were distributed about the entire periphery of the carding roller. In fact, it will be appreciated that with such selection of pitch B, individual fibers are subjected to attack by only one group of carding projections, and are not influenced by the following group.

In prior-art constructionsthe fibers were excessively attached by the carding needles, and this resulted in reduction of strength in the final yarn produced, and furthermore resulted in pollution of the collectingsurface of the spinning chamber by fiber dust and fluff, particularly upon commencement of operation. With the present invention, as just explained, an optimum number and disposition of fiber separating elements has been effected, so that no irregular feeding of separated fibers or excessive attacking of them can take place.

It has already been explained that the length of first clearance 18a should be at least substantially equal to four-fifths the average length of staple fibers in the fibroussliver 8. Byway of explaining the criticality of this requirement, it is noted that the bulk of fiber separation occurs in the general vicinity of the boundary between first clearance 18a and second clearance 18b. If the length of clearance 18a were shorter than fourfifths the average length of staple fibers, then the fibers retained at the nip line between parts 9 and 13 would be subjected to stress for a considerably longer time, depending on the feed rate, before their actual separation. Four-fifths of the average staple-fiber length, or longer, determines the region of fiber separation, that is, the vicinity in which clearance 18a communicates with clearance 18b, at which the fiber separating process is occurring at maximum. If the length of clearance 18a were shorter than about four-fifths the staple-fiber length, excessive damage to the fibers by the roller 3 would result.

With the present invention, the fibers are carried through a limited space, in which the velocity of air flow tends to increase, so that the separated floating fibers will be subjected to deformation hardly at all, or only to such extent as permitted within the given space. The deformation in question can result from a variety of factors, such as fiber elasticity, unavoidable friction,

etc. The feeding channel in the inventive device and the channel in the fiber separating area are chosen to be narrow, to reduce the possibility of fiber deformation. In this way, the fibers are carried in a, more or less straightened state to the spinning chamber, and deposited there in such straightened state, so that the resulting yarn will be, of even and high, quality.

' It should ,additonally be noted that, in the construction according to the invention, the stream of air passing around the carding roller will be of excellent uniformity and controlled strength. In particular, there will be noregions of turbulence in the vicinity of the feed mechanism, because the feed mechanism has been significantly withdrawn out of the air-flow path. Specifi- .ance quality resulting from this expedient will be very considerable.

It hardly need be explained that the basic concept of the invention may be realized in a large number of specific embodiments, and is susceptible of considerable variation. The feed mechanism 7, for example, is clearly only exemplary and may be replaced by any suitable equivalent. Depending on the equivalent chosen, as well as other factors, it may or may not be absolutely, necessary for the feed mechanism to be withdrawn out of the spinning chamber 2 in the manner illustrated. Likewise, the exact construction of the carding means on roller 3 may be of a variety of types. The structure of the housing for the arrangement may have a great variety of configurations. As already mentioned,

theguide walls

20 and 23 may be in the form of discrete, wall means mounted 'adjustably, and of course the positioning of the various components, and their various relative dimensions, may be made adjustable to a greater or lesser extent--or be different from that herein described--depending on the specific applications involved. Likewise, the particular fibrous sliver being treated may, have such characteristics as to require further elements or components, whose addition does not change the basic concepts outlined herein.

It will be understood that each of the elements described above, or two or more together, may also find a useful appliation in other types of constructions differing from the types described above.

. While the invention has been illustrated and described as embodied in a fiber-separating device for use with textile machines, particularly open-end spinning machines, 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 fuly 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 protected by Letters Patent is set forth in the appended claims:

1. A device for separating fibers from fibrous sliver, in which the fibrous sliver to be separated has staple fibers of an average fiber length, particularly for use with open-end spinning machines, comprising a housing; a carding roller mounted for rotation in said housing, and having a peripheral surface; carding means provided on said peripheral surface of said carding roller, said carding means comprising groups of carding projections, the circumferential spacing between said groups being at least equal to said average fiber length; feed means for feeding fibrous sliver to be separated to said carding roller; a first guide wall portion positioned downstream of said feed means and defining with said peripheral surface a first clearance extending circumferentially of said roller and having a width which tapers in downstream direction and having a length equal to at least about four-fifths said average fiber length; a second guide wall portion positioned downstream of said first guide wall portion and defining with said peripheral surface a second clearance also extending circumferentially of said roller and having a width which is substantially constant and communicating with said first clearance; and a fiber outlet passage downstream of said second guide wall portion communicating with said second clearance and constituting an outlet for separated fibers.

2. A device as defined in claim 1, wherein said feed means includes an inlet passage through which fibrous sliver is fed, and wherein said inlet passage has during operation of said device a narrowest operational crosssectional area, and wherein the cross-sectional area of said second clearance radially of the axis of rotation of said carding roller is at least substantially equal to said narrowest cross-sectional area of said inlet.

3. A device as defined in claim 1, wherein said first wall portion merges continuously into said second wall portion.

4. A device as defined in claim 1, wherein said housing encloses a carding chamber in which said roller is mounted, and wherein said chamber is defined by an inner peripheral wall, said first and second wall portions being portions of said peripheral wall.

5. A device as defined in claim 1; and further including a third wall portion upstream of said feed means and defining with said peripheral surface a third clearance extending circumferentially of said roller and having a radial clearance, and wherein the smallest radial distance between said peripheral surface and said feed means is at least substantially equal to said radial clearance.

Claims

2. A device as defined in claim 1, wherein said feed means includes an inlet passage through which fibrous sliver is fed, and wherein said inlet passage has duRing operation of said device a narrowest operational cross-sectional area, and wherein the cross-sectional area of said second clearance radially of the axis of rotation of said carding roller is at least substantially equal to said narrowest cross-sectional area of said inlet.