US3829934A

US3829934A - Method and apparatus for homogenizing, teasing out and cleaning mixed fibrous materials

Info

Publication number: US3829934A
Application number: US00242930A
Authority: US
Inventors: H Neu
Original assignee: NEU SA
Current assignee: NEU SA; SA des Ets Neu fr
Priority date: 1971-04-14
Filing date: 1972-04-11
Publication date: 1974-08-20
Anticipated expiration: 1991-08-20
Also published as: BE781822A; DE2217394A1; GB1382093A; FR2175575B2; IT951392B; CH540998A; JPS5438664B1; ES412369A1; FR2133365A5; FR2175575A2; DE2217394B2

Abstract

A method of homogenizing, teasing out and cleaning mixtures of fibre materials is carried out by using a device comprising means for introducing one or a plurality of flows of fibre materials in the downward direction against an air cushion for intimately homogenizing the fibre flocks in suspension before introducing them by combined pneumatic and mechanical means into the operative area of a pair of toothed drums partially surrounded by a cleaning grid opening into vacuumized waste boxes.

Description

lite States Patent [1 1 Men Aug. 20, 1974 METHOD AND APPARATUS FOR [56] References Cited HOMOGENIZING, TEASllNG OUT AND NI S ES PATENTS CLEANING MIXED FIBROUS MATERIALS 2,739,708 3/1956 Denovan et al 209/138 [75] Inventor: Henri Neu, Lille, France Q [73] Assignee: Societe Anonyme des 3:175:252 3/1965 |9/l45.5

Establissements Neu, Lille(Nord), France Primary Examiner-Dorsey Newton [22] Filed: Apr. 11, 1972 Attorney, Agent, or Firm-Fleit, Gripple & Jacobson [21] Appl. No.: 242,930

[57] ABSTRACT [30] Foreign Application Priority Data Apr 14 France 71 14041 A m hmlq om semzm 9 1. 1% qqtands ean ns M 1 972 72'08829 mixtures of fibre materials is carried out by using a device comprising means for introducing one or a plurality of flows of fibre materials in the downward direc- [52] U.S. Cl. 19/202 tion against an air cushion for intimately homogeniz 3 8 ing the fibre flocks in suspension before introducing them by combined pneumatic and mechanical means into the operative area of a pair of toothed drums partially surrounded by a cleaning grid opening into vacuumized waste boxes.

18 Claims, 10 Drawing Figures PATENTED M20 1974 k

sum

3 or 7 METHOD AND APPARATUS FOR HOMOGENIZING, TEASHNG OUT AND CLEANING MIXED FIBROUS MATERIALS The present invention relates to methods and means for homogenizing teasing out and cleaning mixtures of fibrous materials, such as cotton and like fibres in the form of uncompressed or loose flocks or tufts, as delivered by one or a plurality of preparatory fibre-openers, and constitutes an improvement in machines of this character, more particularly on account of a greater efficiency of its cleaning action.

Hitherto known teasing-cleaning machines comprise in general drums provided with pins or saw-tooth linings on their outer surface which is partially enclosed in a grid consisting of bars.

- The textile material to be treated is fed to the operative areas of these drums in the form of a compact web weighing about 1 to 1 V2 kilogram per square meter (14 to 22 psi) by a feed system comprising either a pair of superposed fluted or splined cylinders or a single cylinder co-acting with bucket levers.

As the working or operative area is bound by the relative spacing of the drum from the location where the fibre web is retained by the feed system, the teasing and cleaning action takes place linearly in a relatively narrow gap on a relatively thick web held with force; now this procedure is objectionable in that to prevent an undesired reduction in the fibre length as well as an excessive number of knots and like unequalities the peripheral velocity of the drum must be limited; under these conditions, the efficiency of the device is impaired in such a manner that a satisfactory opening and cleaning action cannot be achieved unless the number of treatment points is increased considerably, this obviously reducing the possibility of adhering to the present trend towards a complete automation in the preparatory operations required in the cotton spinning industry.

On the other hand, it is known that with this method the heavy wastes separated from the fibres are discharged through the grid adjacent to the drum by the centrifugal force developed by the drum rotation, while the light impurities are picked up together with the useful fibres by an air stream penetrating through the bars of said grid and carrying along said fibres. The fact that with this basic cleaning principle the light impurities such as dust, short fibres, leaf particles, etc. are not eliminated constitutes a serious inconvenience, especially in the case of leaf particles which, due to the repeated action of the toothed drums, are eventually subdivided minutely and to such a degree that their separation from the useful fibres becomes extremely difficult if not impossible, at the expenses of the cleanliness of the yarn constituting the end product.

With the present invention these inconveniences are avoided in that the mixture of textile materials from one or a plurality of preparatory fibre-openers is firstly retained on an air cushion causing the flocks or tufts of fibre material to be intimately homogenized before they are introduced by combined pneumatic and mechanical means into the operative zone of the pair of toothed drums.

With this method, the teasing action is exerted by the drums on unstressed flocks and tufts, thus facilitating the separation of wastes from useful fibres, inasmuch as the impurities already isolated from the material but not removed by the preparatory openers are no more re-wrapped in a compressed web. Moreover, as the opening and cleaning action is exerted on a reduced volume of material, it is possible to operate the toothed drums according to this invention at peripheral velocities two or three times higher than those of hitherto known machines of this character, thus improving considerably the cleaning efficiency without impairing the fibre characteristics.

in its broadest aspect the present invention comprises a receiving and homogenizing. chest provided at its upper portion with a preferably multiple number of distributors for either discharging into said chest the flocks delivered from a plurality of preparatory openers, or subdividing the material received from a single opener into a secondary stream, as a function of the number of distributors in operation, in order to improve the homogeneity of the fibre mixture.

In a typical form of embodiment of this invention the lower portion of the receiving and homogenizing chest is divided by a longitudinal suction inlet into two compartments constituting guide means opening in front of the supply means provided for introducing the textile material into the operative area of a pair of teasing drums disposed parallel to, and on either side of, said suction inlet.

The aforesaid supply means comprise a pair of cylinders having their outer surface covered with pins and revolving in the same direction as, but at a peripheral speed lower than the peripheral speed of, the drum with which they are operatively associated, so as to tease out the fibres and subsequently separate the impurities from the fibrous material proper.

According to this invention, an air cushion is created in the lower portion of the receiving chest for retaining in suspension the mixture of fibre flocks discharged by the distributors in order to improve its homogeneity and facilitate its uniform distribution'throughout the working area of the pair of teasing drums. Said air cushion is obtained by producing a upward air stream resulting from the air draught obtaining in said suction inlet connected for this purpose to a pneumatic transfer fan with the assistance of a set of ducts consisting of the various sequential elements of this invention.

Alternavitely, the upward air stream necessary for producing said air cushion may be produced not by the single air suction mentioned hereinabove but by providing to this end a suction combined with a blowing effect, or even a blowing effect alone but directed upwards in said chest.

To this end and according to an improved form of embodiment of this invention, the duct to which the various distributors discharging the fibrous material into the receiving chest are connected in succession, instead of terminating at the last distributor of the series is extended towards the inlet dividing the lower portion of said chest into two compartments.

With this arrangement it is possible to reduce the resistance of the pneumatic transport circuit and therefore avoid the agglutination of the fibre flocks and the clogging of the distributors, thus improving the homogeneity of the end product.

Another feature characterising this invention lies in the fact that the cylindrical surface of the teasing drums comprises a great number of perforations, as already known per se. Each drum further comprises internal fan blades capable of producing a radial blowing action or ventilation through said perforations in order to avoid the suction of the air output necessary for discharging the textile material through the bars of the cleaning grid partially surrounding the teasing drums. The air output necessary for this purpose and provided by the drum rotation alone is directed through the unwrapped perforated surface of the drums which register with the outlet port of the pneumatic transport system.

The cleaning grid associated with each drum leads into a waste box connected to an auxiliary suction system in order to modify its vacuum or negative pressure as a function of the waste concents in the treated mixtures.

Furthermore, the present invention is concerned with various ancillary or accessory arrangements directed to improve the operation of the system, as will appear from the following description given by way of example with reference to the accompanying drawings illustrating diagrammatically a typical form of embodiment of the invention. In the drawings:

FIG. I is a diagrammatic plane view showing the connection of a plurality of preparatory openers to the teasing device according to this invention;

FIG. 2 is a diagrammatic view showing the connection between a single preparatory opener and the teasing device and its ancillary means;

FIG. 3 is a plane view showing the supply means of the distributors of FIG. 2, with the dust-removing circult;

FIG. 4 is a detailed sectional view showing the teasing device;

FIG. 5 is a diagrammatic view of the means for driving the various component elements of the teasing device;

FIG. 6 is a detailed view of the teasing cylinder with its supply system;

FIG. 7 is a plane view of the feed cylinders;

FIG. 8 is a diagrammatic plane view showing the connection between the pneumatic transport duct and the distributors, according to a specific form of embodiment;

FIG. 9 is a cross section taken along the line lX-IX of FIG. 8, showing the extension of the pneumatic transport duct and the connection thereof with the inlet disposed in the lower portion of the receiving chest, and

FIG. 10 is a front view of the arrangement shown in FIG. 9, the front wall being removed from the device, to show the interior.

According to this invention, and referring firstly to FIG. 1, the mixture of fibre flocks is delivered in this example from four preparatory openers 1, l, l" and 1" each equipped with a separate motor 2, 2', 2", 2' blowing an air stream loaded with flocks into

ducts

3, 3, 3" and 3" so disposed as to deliver this stream to four

distributors

4, 4', 4" and 4", respectively, arranged in the upper portion of the receiving and homogenizing chest 5; this arrangement is advantageous in that it is capable of mixing four components, especially in the case of fibres having different colours.

A suction circuit connected to the distributors in a manner to be explained more in detail presently comprises a fan and motor unit 6 blowing air through a set of socket filters 7 and is adapted to collect the duct released from the textile material as it separates from the air conveying it. The cleaned and homogenized fibres are discharged towards possible subsequent treatment means by a pneumatic transport system comprising a fan and motor unit 8 connected to 'this end to a duct 9.

The connection of a single preparatory opener with the teasing and cleaning device is illustrated in FIG. 2.

To this end, a loader 10 pours the fibrous material into a preparatory opener 11 adapted through built-in pneumatic means to force the fibre flocks into a duct 12 having its end connected to said

distributors

4, 4, 4 and 4 disposed by pairs in face-to-face relationship, as shown in FIG. 3. Thus, the flow of material travelling in duct 12 is subdivided into four secondary streams adapted to be subsequently re-assembled in a common vessel consisting of the aforesaid chest 5 (FIGS. 2, 3 and 4). With this method the homogeneity of the mixture is improved considerably.

FIG. 4 illustrates in detail all the essential component elements of a typical form of embodiment of this invention. As shown in FIG. 4 the upper portion of chest 5 comprises a set of distributors such as 4 and 4 each comprising in turn a

wheel

13 and 13 provided with flexible sealing blades 14 revolving in a housing made partly perforated sheet metal elements, the upper portion of this housing communicating with duct 12 and its lower portion with chest 5. Thus, the fibre flocks delivered by the aforesaid pneumatic duct common to the set of distributors are extracted therefrom separately by each wheel, and the air having thus conveyed the material is discharged through the perforated sheets such as 15 and 15. The distributors are disposed in face-to-face relationship so that their wheels revolve in opposite directions, as shown by the arrows, and the fibre flocks are thus thrown towards the center of the receiving chest.

These wheels are driven from a

motor

16, 16 and a transmission comprising pulleys l7 and 18, as shown in FIG. 5.

To avoid any spreading of dust, the perforated-sheet walls of the housings of the distributor assembly is connected via ducts l9 and 19 to the dust-removing apparatus already described and illustrated in FIGS. 1 and 2. Shutters 46 and 46' (FIG. 4) are provided for properly balancing the suction in said ducts.

According to this invention the lower portion of the receiving chest 5 is divided in the longitudinal direction by the suction inlet 20 into two compartments forming guiding

passages

21 and 22 converging towards

feed cylinders

23 and 24 co-acting with drum 25, and

other cylinders

26, 27 co-acting with drum 28. Also according to this invention, the fibrous material discharged by the distributors before being introduced into the operative area of said drums is retained by an air cushion created in the lower portion of receiving chest 5 by an upward air draught the direction of which is shown by the arrows. This air draught is obtained by connecting said suction inlet from apertures formed at either end thereof to the fan 8 (FIGS. 1 and 2), via intermediate channels formed by said guiding

passages

21 and 22, respectively, on either side of said inlet, the free space provided to this end between the

supply cylinders

23 and 24 on the one hand and 26, 27 on the other hand, a duct bound by the

guide plates

29, 29' and 30, 30' disposed nearly tangentially to the surface of the teasing drums, and the outlet 31 for discharging the treated flocks by pneumatic action. Semi-spherical dampers 32 and 32' are provided for adjusting the cross-sectional passage area of the suction slot located in the upper portion of inlet so as to permit the regulation according to requirements, of the extent of the aircushion.

It is obvious that the air current necessary for producing said air cushion may be created not by the suction effect alone but also by this suction in combination with a blowing effect; alternatively, a blowing action alone may also prove adequate, provided that it is properly directed.

Thus, as already explained in the foregoing, if the upward blowing action alone is used an arrangement of the type illustrated in FIGS. 8, 9 and It) may be provided.

In these FIGS. 8, 9 and It) the reference numeral 61 designates the pneumatic transport duct;

reference numerals

62, 63, 64 and 65 denote the distributors and 66 designates the receiving chest. The fibres supplied from a feed machine of which the operative connection with duct 61 is not shown are discharged into said chest 66 and the air used for conveying them together with the material not separated by the distributors is forced via a connecting duct 67 into outlet 68; this produces on the one hand an upward air stream forming an air cushion in the lower portion of chest 66 for keeping in suspension the fibre flocks discharged by the distributors, and on the other hand an upward projection of flocks not separated from the air and forced through the outlet 68 against the flocks discharged by said distributors, so that these flocks are caused to collide against one another and their homogenization is improved considerably.

A damper 69 disposed downstream of the last distributor of the pneumatic circuit permits of adjusting at will and according to requirements the amount of material forced through the aperture 68.

The air blown into the receiving chest 66 is discharged bya fan (not shown in the drawing) adapted to draw out the treated flocks via ducts consisting of guide means 70 and 71, the free space between

cylinders

72, 73 and the free space between

cylinders

74 and 75, while the fibrous material in suspension is carried along and directed towards the operative areas of

teasing drums

78 and 79, as shown by the arrows.

The above-described pneumatic circuit (FIGS. 1 to 4 and 8 to I0) is also adapted to carry along the flocks in suspension and to introduce them in conjunction with the feed means into the operative areas of the opening drums. As shown in the detailed view of FIG. 6, each supply system comprises a pair of toothed drums such as 23, 24 of which the surfaces move in the same direction, as shown by the arrows, but at a peripheral velocity lower than that of drum 25 in order to tease out the fibrous material retained during this operation mainly by the cylinder 23 disposed upstream of the cleaning grid consisting of triangular-sectioned bars such as 33. The afore-said cylinder is advantageously provided to this end with a set of saw-teeth 34 inclined in a direction opposite to that of the pins 35 pins 35 are mounted on of drum 25 and also to its direction of rotation. To avoid any clogging of this cylinder, separate rings 36 (FIG. 7) disposed in parallel relationship and at relative intervals corresponding substantially to the efficient height of the type of teeth selected as a function of the characteristics of the fibre mixtures to be treated. The other cylinder 24 (FIG. 7) consists of a continuous helical row of teeth having their points 37 inclined in the same direction as those of the drum 25 but in opposition with respect to the direction of rotation of this drum, so as to preserve its clean condition. With this method of positioning the teeth the suction of flocks outside the operative area of drum 25 is avoided since the teeth of the two feed cylinders are inclined in opposition to the direction of the air current created in this area.

As shown in FIG. 5 the two feed systems are controlled and driven from an electric motor 37 connected via couplings 38, 38' to the pair of reduction gearings 39 and 39', preferably of the adjustable type. The grooved pulleys 40 and 40' keyed to the output shafts of these reduction gearings respectively drive through V-belts 41, 41' other pulleys 42, 42' keyed directly to the shafts of the

feed cylinders

24 and 26, respectively,

other pulleys

43, 43 being keyed to separate shafts (not shown in the FIGURES) carrying in addition pinions 44 and 44' meshing with

pinions

45 and 45 respectively, carried by the shafts of

cylinders

23 and 27. With this arrangement the surfaces of each feed assembly travel at the same speed.

According to the present invention the outer periphery of

drums

25 and 28 comprise perforations such as 47 (FIGS. 4 and 6). Similarly, the inner portion of each drum comprise fan blades 48 (FIG. 4). Thus, the air output necessary for ejecting the textile material teased out and cleaned by the machine is provided by the rotation of the drums themselves. The fact of blowing air through the unwrapped surface registering with the discharge passage 21 (FIGS. 4 and 6) permits of releasing all the fibres carried along by the pins of the teasing drums, thus eliminating the repeated return of one fraction of the material into the teasing area and therefore the formation of tuft and the undesired reduction in the fibre length.

For adjusting the air output provided by the drums these comprise at their end a shutter system comprising a fixed member 50 (FIG. 6) formed with openings protected by wire mesh, and a movable member 51 comprising the same openings. The rotation of this movable member 51 permits of closing more or less the apertures formed in said fixed member 50 as a function of the desired air output.

The drums 25 and 28 (FIG. 5) are driven from motors 56 and 56' via transmissions comprising

grooved pulleys

57, 57' and 58, 58' and V-

belts

59 and 59.

The cleaning grid associated with each drum opens into the waste boxes 52, 52' provided with

discharge doors

53 and 53. These waste boxes are equipped with suction means comprising

branch pipes

54 and 54 leading to the above-described dust-removing system, so that a negative pressure or relative vacuum can be obtained therein, with values adjustable by means of dampers such as 55 and 55' (FIG. 4) as a function of the desired degree of cleanliness of the fibre mixture to be treated.

Of course, this invention should not be construed as being strictly limited by the specific forms of embodiment shown and described herein, since they are given by way of example only, for it will readily occur to those conversant with the art that many modifications and variations may be brought thereto without departing from the basic principle of the invention as set forth in the appended claims.

What is claimed as new is:

l. A method of homogenizing, teasing out and clean ing mixtures of textile fibers such as cotton or similar fibers which are delivered in the form of fiber flocks from at least one preparatory opener, the method comprising the steps of: introducing said fiber flocks in the form of at least one flow into a receiving chest; maintaining said fiber flocks in suspension on an air cushion in said receiving chest so as to be homogenized by pneumatic stirring action; carrying said fiber flocks after homogenization and in the unstressed condition by an air current produced on either side of said air cushion into the operative area of a pair of feed cylinders coacting with a pair of drums for teasing out and cleaning said flocks; and ejecting the treated material into a common pneumatic discharge outlet.

2. A device for homogenizing, teasing out and cleaning mixtures of textile fibers such as cotton or similar fibers which are delivered in the form of fiber flocks from at least one preparatory opener, the device comprising: a receiving chest; at least one textile fiber flock distributor located in the upper portion of said receiving chest; a longitudinal air inlet having an open upper portion facing said at least one distributor, said air inlet dividing the lower portion of said chest into two compartments and extending across the width of said chest, said air inlet being open at one end; first and second pairs of feed cylinders disposed parallel to each other on both sides of said longitudinal air inlet, the sides of said chest and said air inlet forming two guide systems each converging toward one of said pairs of feed cylinders; a pair of teasing drums having saw-teeth adapted to revolve in opposite directions each co-acting with a respective pair of said feed cylinders; a pneumatic discharge outlet downstream of said teasing drums; a discharge fan connected to said discharge outlet; a cleaning grid consisting of bars spaced from the outside surfaces of said drums and extending from the feed cylinders to said discharge outlet; a duct in said discharge outlet comprising two branch sections having their inlets disposed downstream of the area where said pairs offeed cylinders coact with said teasing drums, the suction exerted by said discharge fan connected to said discharge outlet for the pneumatic discharge of material ejected by said teasing drums drawing air into said receiving chest through said longitudinal air inlet, said air being forced in the vertical direction along the walls of said air inlet and producing an upward air stream constituting an air cushion above the open upper portion of said air inlet for maintainint said fiber flocks in suspension and homogenizing them by pneumatic stirring action, said air stream being subsequently divided into two air currents flowing downward through said two guide systems, the free space between each pair of said feed cylinders, and the two branch sections of said duct in said discharge outlet, said two air currents acting to carry said fiber flocks after homogenization and in the unstressed condition into the operative area of said feed cylinders and teasing drums.

3. Device according to claim 2, wherein said at least one distributor comprises a plurality of distributors, said distributors being disposed in face-to-face relationship in the upper portion of said receiving chest so as to form two rows and positioned to introduce said fiber flocks into the central area of said chest.

4. Device according to claim 3, wherein each distributor comprises a rotating wheel having sealing blades of flexible material, and further comprising a casing,

the upper portion of which is connected to a pneumatic transport duct and the lower portion of which opens into said receiving chest, said casing serving to isolate said transport duct from said receiving chest, and to house said rotating wheel.

5. Device according to claim 4, wherein the casings of said distributors are partially perforated and connected to a suction system for removing dust and waste, and for separating the fibrous material from the air which conveyed the same into said casings.

6. Device according to claim 2, and further comprising semi-spherical dampers for adjusting the crosssectional passage area of said open upper portion of said longitudinal air inlet to regulate the extent of said air cushion and said carrying of said fiber flocks after homogenization into the operative area of said feed cylinders and teasing drums.

7. Device according to claim 2, wherein the operative surface of each pair of said feed cylinders disposed upstream of said cleaning grid has pins and travels in the same direction and at a peripheral velocity lower than that of the teasing drum associated therewith for teasing out the flocks and separating the impurities from the useful fibers.

8. Device according to claim 7, wherein the surfaces of said feed cylinders rotate in the same direction and are provided with a set of saw-tooth pins inclined in a direction opposite to the direction of said two air currents.

9. Device according to claim 7, wherein the surface of one feed cylinder of each pair is provided with annular sets of saw-tooth pins disposed in parallel relationship, said saw-tooth pins inclined in a direction opposite to the direction of inclination of the teeth on the teasing drum with which said cylinder is associated, the other feed cylinder of each pair being provided with a continuous helical row of saw-tooth pins having their points inclined in the same direction as said teeth on the teasing drum with which said cylinder is associated.

10. Device according to claim 2, wherein a free gap is provided between each pair of feed cylinders for the passage of one of said two air currents.

11. Device according to claim 2, and further comprising means for separately adjusting the peripheral velocity of each feed cylinder.

12. Device according to claim 2, wherein the teased and cleaned fiber flocks are ejected from the surface of said drums into the inlet of said discharge outlet by air blown by the rotation of said teasing drums, said device further comprising damper means disposed at the two ends of said teasing drums for adjusting the output of said blown air.

13. Device according to claim 12, wherein the peripheral surfaces of said teasing drums are perforated.

14. Device according to claim 13, and further comprising ventilation blades provided on the internal portion of each of said teasing drums.

15. Device according to claim 2, and further comprising a waste box and an auxiliary suction system equipped with dampers for modifying the draught in said box as a function of the waste contents in the treated fiber mixtures; and wherein the cleaning grid of each of said teasing drums opens into said waste box.

16. Device according to claim 2, and further comprising auxiliary means for blowing air through said longitudinal air inlet and upward into said receiving chest to combine with the suction action in forming said air cushion as well as pneumatically conveying said fiber flocks in suspension to said discharge outlet.

17. Device according to claim 2, wherein said at least one distributor comprises distributors connected in sequential order to a pneumatic transport circuit means; and further comprising a duct disposed downstream of the last distributor in said transport circuit means and connected to said longitudinal air inlet to aid in creatair inlet.

Claims

1. A method of homogenizing, teasing out and cleaning mixtures of textile fibers such as cotton or similar fibers which are delivered in the form of fiber flocks from at least one preparatory opener, the method comprising the steps of: introducing said fiber flocks in the form of at least one flow into a receiving chest; maintaining said fiber flocks in suspension on an air cushion in said receiving chest so as to be homogenized by pneumatic stirring action; carrying said fiber flocks after homogenization and in the unstressed condition by an air current produced on either side of said air cushion into the operative area of a pair of feed cylinders coacting with a pair of drums for teasing out and cleaning said flocks; and ejecting the treated material into a common pneumatic discharge outlet.

2. A device for homogenizing, teasing out and cleaning mixtures of textile fibers such as cotton or similar fibers which are delivered in the form of fiber flocks from at least one preparatory opener, the device comprising: a receiving chest; at least one textile fiber flock distributor located in the upper portion of said receiving chest; a longitudinal air inlet having an open upper portion facing said at least one distributor, said air inlet dividing the lower portion of said chest into two compartments and extending across the width of said chest, said air inlet being open at one end; first and second pairs of feed cylinders disposed parallel to each other on both sides of said longitudinal air inlet, the sides of said chest and said air inlet forming two guide systems each converging toward one of said pairs of feed cylinders; a pair of teasing drums having saw-teeth adapted to revolve in opposite directions each co-acting with a respective pair of said feed cylinders; a pneumatic discharge outlet downstream of said teasing drums; a discharge fan connected to said discharge outlet; a cleaning grid consisting of bars spaced from the outside surfaces of said drums and extending from the feed cylinders to said discharge outlet; a duct in said discharge outlet comprising two branch sections having their inlets disposed downstream of the area where said pairs of feed cylinders coact with said teasing drums, the suction exerted by said discharge fan connected to said discharge outlet for the pneumatic discharge of material ejected by said teasing drums drawing air into said receiving chest through said longitudinal air inlet, Said air being forced in the vertical direction along the walls of said air inlet and producing an upward air stream constituting an air cushion above the open upper portion of said air inlet for maintainint said fiber flocks in suspension and homogenizing them by pneumatic stirring action, said air stream being subsequently divided into two air currents flowing downward through said two guide systems, the free space between each pair of said feed cylinders, and the two branch sections of said duct in said discharge outlet, said two air currents acting to carry said fiber flocks after homogenization and in the unstressed condition into the operative area of said feed cylinders and teasing drums.

4. Device according to claim 3, wherein each distributor comprises a rotating wheel having sealing blades of flexible material, and further comprising a casing, the upper portion of which is connected to a pneumatic transport duct and the lower portion of which opens into said receiving chest, said casing serving to isolate said transport duct from said receiving chest, and to house said rotating wheel.

6. Device according to claim 2, and further comprising semi-spherical dampers for adjusting the cross-sectional passage area of said open upper portion of said longitudinal air inlet to regulate the extent of said air cushion and said carrying of said fiber flocks after homogenization into the operative area of said feed cylinders and teasing drums.

17. Device according to claim 2, wherein said at least one distributor comprises distributors connected in sequential order to a pneumatic transport circuit means; and further comprising a duct disposed downstream of the last distributor in said transport circuit means and connected to said longitudinal air inlet to aid in creating said air cushion while introducing into said chest the fiber flocks not separated by said distributors whereby the fiber flocks introduced into said chest by said distributors in the downward direction and through said air inlet in the upward direction collide in said chest.

18. Device according to claim 17, and further comprising an adjustable damper disposed downstream of said last distributor in said transport circuit means for modifying the amount of fiber material forced into said air inlet.