US2559700A - Fiber cutter - Google Patents

Description

y 1951 E. K. BAUER 2,559,700

FIBER CUTTER Filed Spt. 7, 1946 uwahmx.

ERNEST h. BAUER and directed inwardly Patented July 10, 1951 2,559,700 FIBER. CUTTER Ernest K. Bauer, Meadville, Pa., assignor to American Viscose Corporation, Wilmington, Del., a. corporation of Delaware Application September 7, 1946, Serial No. 695,448

1 Claim. 1

The present invention relates to cutting devices for producing staple fiber from continuous filaments and is particularly concerned with the type of cutter shown in Beria Patent 1,723,998.

The type of cutter with which the invention is concerned comprises a rotatable disc having a channel provided with an axial entrance for the continuous filaments and a radial discharge portion. As the bundle of continuous filaments which may vary from 50 to several hundred thousand denier in size, proceeds through the channel, the leading end projects outwardly therefrom and each time this leading end passes the cutting device disposed adjacent the periphery of the disc, a length of staple fiber is severed. Various schemes have already been proposed to adapt this type of cutter to the production of staple fiber of any desired length in a wide range thereof. One of the systems for accomplishing this purpose is to introduce a fiuid such as air under pressure into the entrance along with the filament bundle. The arrangements heretofore utilized for introducing the compressed air are accompanied by certain difficulties. In particular, the air stream has frequently been allowed to rebound from the surrounding walls of the axial entrance and in case of any broken filaments, such filaments have tended to fly back and tangle in the space between the axial entrance and the air nozzle. In severe cases where there are numerous broken filaments, the tangling of such fibers and the building up of the tangled portion thereof causes damage to the product and on occasion has been found to interfere with the uniform operation of the rotating disc of the cutting device.

In accordance with the present invention, a fiuid under pressure is introduced into the axial entrance of the cutter disc in the form of an annular envelope surrounding the filament bundle toward the surface of the bundle in the direction of its advance, so that such fluid envelope assists the feeding of the filament bundle into the deviceby a suction effect in the region of its path immediately preceding its entrance to the envelope.

The more specific objects and advantages of the invention will be apparent from the drawing and the description thereof hereinafter.

In the drawing, which is illustrative of the invention,

Figure 1 is a transverse cross section of one embodiment, and

Figure 2 is a transverse cross section of a modification.

Referring first to Figure 1, the device comprises the rotatable cutter head 2 which may take the form of a disc integral with or secured to a shaft '3 which is mounted in suitable bearings 4 and provided with a pulley 5 or other suitable connection to a driving means (not shown). A cutting element 6, such as a knife blade, engages the periphery of the disc 2 and is held in fixed position by a support 1. Instead of the specific form of knife 6 shown, any suitable cutting means may be employed, such as a pair of circular knives which overlap to form a nip in the path of the projecting filaments. Furthermore, a plurality of cutting elements may be disposed about the periphery of the disc either at equal or unequal distances apart to produce uniform or varied length staple fiber.

The cutter head 2 is provided with a filamentpassage 8 having the axial entrance 9 and the generally radial discharge portion l0. As so far described, the cutting device may have any of the conventional forms disclosed in the prior art but in accordance with my invention, an injector II is disposed substantially concentrically and at least partially projecting into the axial entrance 9. This injector may be supported tion by any suitable bracket such as that indicated by the reference character I2 and has an internal filament-guiding tube l3 and an annular chamber I4 which communicates with a generally frusto-conical annular discharge passage The passage l5 terminates in an annular opening of tube 13 so that any fluid introduced into the chamber I4 by the conduit I1 is discharged as an annular envelope surrounding the filamentary bundle immediately after it leaves tube l3. This fluid stream creates a suction within tube l3 and thereby facilitates the drawing of the bundle therethrough and likewise tends to surround the bundle as it proceeds through the channel 8. Preferably, the annular opening l6 extends to a position within the axial entrance such that it is closely surrounded by the wall of such entrance. By such arrangement, the rebound of the fluid is substantially completely eliminated, since there is a tendency of the air stream discharged from passage 15 to create a suction within the narrow annulus between the injector and the surrounding wall of the axial entrance 9. This arrangement eliminates the necessity to provide a seal between the fixed injector and the axial entrance of the rotatable disc and at the same time prevents the tangling of broken filaments in the narrow unsealed passage. By using a forced draft, a smaller rotating disk may be used and yet proper tension in a fixed posi-.

l6 immediately adjacent the inner end can be retained on the filaments. Also, the disk may be rotated at much slower speed. This condition is useful to obtain a long staple length.

In Figure 2, the rotatable disc comprises a built-up structure having a main plate 2|! and a bent tube 2| having an axial portion secured,

to one side of the plate 20 by means of suitable clamps 22 and 22a. The axially directed portion of tube 2| serves as the entrance for the filamentary bundle and extends through a central bore in plate 20. There is secured to the hub of the plate 20, such as by screw threads, an injector nozzle 23. This nozzle comprises an inner tube 24 through which the filamentary bundle passes on its way to enter the tube 2|. Tube 24 extends partially into the open end of tube 2| but its outer surface is spaced from the surrounding wall of tube 2|. As shown, the space within the tube 24 and within that portion of the wall of the axial entrance tube 2| beyond the annular fluid discharge opening is free of obstruction. A fluid is introduced under pres- I sure into the annular chamber 25 which communicates with the space between tube 24 and theinside wall of the entrance to tube 2| by means of one or more bores 28 which extends through plate 20 and through connecting bores 26a in a hub 21 secured by bolts 28 to the back of plate 20. The hub 21 is integral with or carried by a hollow shaft 29, the axial passage 30 of which communicates with bores 26a. The hollow shaft 25 is rotatably supported in suitable bearings such as 3| and carries a pulley 32 by which it may be driven. A fluid under pressure may be introduced into the hollow shaft 3|! by a nozzle or fitting 33 extending thereinto. To reduce the windage of the rotating disc, an annular ring 34 may be secured to the outer periphery thereof. This ring 24 shrouds the clamps 22, 22a and other irregularities.

It will be noted that in this form of device, the fluid passing through channel 30, bores 26a and bores 26, enters the annular chamber 25 and then flows around the entrance lip of tube 2| and within the inwardly projecting end of tube 24, thereby forming an annular envelope of the fluid surrounding the filamentary bundle and in direct contact with the inside wall of tube 2|, thus eliminating the rebound of the fluid. Furthermore, since the injector in this embodiment rotates with'the gdisc, there is relatively little opportunity for trouble to arise as a result of broken filaments becoming entangled near the entrance.

Any suitable fluid may be employed. Preferably a gaseous or vaporous fluid under pressure is employed, such as compressed air, steam, either wet, saturated or superheated, and solvent vapor containing air where it is desired to soften the filaments, or the like. A liquid, such as water,

or an aqueous solution of a softening agent for of filaments formed from any particular material,

and particularly such artificial filaments as those obtained from viscose, cuprammonium cellulose, cellulose acetate, other esters and ethers of cellulose, casein and other proteins, vinyl and related resins, nylons and the like.

It is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claim.

I claim:

In combination with a device for cutting filamentary material of indefinite length to discontinuous lengths comprising a rotatable member, a passage for filaments through the member having an axial entrance and a generally radial exit through the periphery of the member, and means positioned adjacent the periphery of the member for cutting filaments projecting therefrom, an injector nozzle carried by the member and projecting at least partially into the axial entrance and having an annular fiuid discharge opening disposed in proximity to the surrounding wall of the axial entrance, said injector having a tube centrally disposed with respect to the annular opening and having its inner end immediately adjacent the annular opening, a hollow shaft secured to the member and projecting axially from that side of the member away from the injector nozzle, passages through the member connecting the nozzle with the hollow bore of the shaft, means for rotating the shaft, and means for introducing a fluid into the bore of the shaft.

I ERNEST K. BAUER.

REFERENCES CITED Thefollowing references are of record in the file of this patent:

UNITED STATES PATENTS

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