US2570184A - Cutting tow - Google Patents

Description

Oct. 9, 1951 E. J. ABBOTT 2570'184 CUTTING TOW Filed May 5, 1949 9 g l: Q V 20 I 0- 37 10 A99 3:9 14; A

' I 1,2 0 W "I A I v 2* 14 INVENTOR EDWARD J. ABBOTT, DECEASED,

BY SAMUEL L. ABBOTT, EXECUTOR Patented Oct. 9, 1951 CUTTING TOW Edward J. Abbott, deceased, late of Wilton, N. IL, by Samuel L. Abbott, executor, Wilton, N. IL, assignor, by mesne assignments, to Abbott Worsted Mills, Incorporated, Wilton, N. IL, a corporation of New Hampshire Application May 3, 1949, Serial No. 91,084

2 Claims. (c1. 19-1) This invention relates to converting fibers of a tow of continuous fibers into staple. length fibers, particularly in the preparation of spun yarn in which all of the fibers are converted into staple lengths and the resulting material can be spun' in the manner of natural textile fibers either alone or together with natural fibers.

The invention is an improvement upon United States Patent No. 2,323,300 which discloses tensioning a group of continuous fibers to force the fibers against a cutting edge, causing them to be severed individually, and drafting the group of severed fibers.

The invention aims to improve the cutting action upon the individual fibers, minimizing any longitudinal dragging of the fibers over the cutting means, while providing a sliding cutting action of the cutting edges transversely across the fibers.

The invention further aims to facilitate the handling of a group of fibers in the form of tow, that is, a rope-like or cord-like bundle which usu ally however has little or no twist, and to act upon such tow to sever each of its considerable number of fibers into approximately regular staple lengths. In thus handling a tow, the improved procedure and apparatus of this invention is adapted to spread the fibers of the towlaterally, facilitating the effective contact of the cutting means with each of the numerou fibers, while also, as indicated above, minimizing any longitudinal dragging of the fibers over the cutting means.

Other advantages and objects of the invention will be apparent from its specification and its drawings in which the invention is explained by way of example.

In the drawings, I

Fig. l is a plan view of apparatus for converting fibers of a tow into staple length fibers, according to the present invention, and

Fig. 2 is a side elevation of the apparatus, largely diagrammatic.

In the drawings a spool or other supply of the tow T to be treated is indicated at Hi. It will be understood that this tow may be of any desired continuous filament material such as viscose, acetate rayon or the like and of any desired weight, for instancearound grains per yard in the finer weights that are comparable to the roving usually fed to a spinning machine, or around 200 grains per yard in the heavier weights that are comparable to a sliver of worsted top. The tow is of rope-like or cord-like form but usually has little if any twist and consists of a considerable number of individual filaments usually representing the products of a considerable number of spinnerets.

From the spool or other'supply Ill the tow T is drawn forward into a draft zone defined by a nipping pair of rear draft rolls '2, l3 and a nipping pair of forward draft rolls [4, [5. As indicated in Fig. 1, suitable bevel gearing diagrammatically shown therein is provided to drive the front rolls it, H5 at a substantially greater speed than the rear rolls I2, i3, for instance twice as fast, providing a draft of 2. The distance between the front and rear rolls should be set to exceed somewhat the length into which it is desired to sever the fibers.

A rotary knife-holdin element I1 is located within the draft zone and carries a plurality of radially disposed blades is each terminating in a sharp outer cutting edge, for example, six of such blades as shown in Fig. 2, or some other suitable number, such that the tow T willbe continuously or substantially continuously in contact with at least one of these blades.

As indicated in Fig. 2, the rotary element I1 and its blades is are arranged and disposed with relation to the line of draft of the tow so that the tow is continuously deflected slightly above the straight line between nips of rolls I2, l3 and M, ii, the tow thus bearing against a knife edge.

The rotary element 11 and its knife blades 88 are continuously rotated so that the knife blades in contact with the tow travel at substantially the same speed as the tow, that is, at the surface speed of the rear rolls [2, l3, suitable bevel gear drive connections being provided as diagrammatically shown in Fig. 1, including a shaft 20 onto which the rotary element I1 is connected by a spline connection 2|.

The spline connection 2| permits the rotary element II to be reciprocated back and forth along its shaft 20, that is transversely of the tow. Any suitable driving connections may be provided so to reciprocate the rotary element, for instance as shown in Fig. 1, a cam 25 continuously rotating with the driving connections between the rotary element l1 and the rear roll 13 and provided with a cam groove 26 adapted to oscillate a bell crank 21 which is pivoted at 28 and engages a grooved collar 29 on the rotary element 11.

In operation, as the tow proceeds forwardly and contacts the knife blades [8 these blades move at the same forward surface speed as the tow, and longitudinal dragging of the tow over the blades is avoided, each cut ing of a filament occurring at substantially a single point on the filament.

Simultaneously the knife blades reciprocate transversely of the direction of progress of the tow, providing a sliding cutting action.

The draft between the front rolls and rear rolls progressively tightens the individual continuous filaments, progressively increasing the force with which the individual filaments are drawn against a knife edge, thus causing severing of each individual filament as such filament becomes sunlciently tensioned and is pressed sufilciently'firmly against a reciprocating knife blade. Each filament is severed sufficiently frequently to produce staple lengths thereof, and severance of theseveral filaments takes place successively, although not in precisely regular sequence, in such manner as to stagger or distribute the ends of the staple lengths relatively evenly throughout the resulting strand, and leaving no continuous or uncut filaments. The trailing portion-of a filament ahead of the cutting knife blade, when such filament becomes severedris thereupon free to be drawn forward at the faster speed of the front rolls ll, IS. The leading end of the filament from which this staple length has been severed is then carried forward, along with the other vfila ments, but without substantial tension until it is received by the front rolls I, I5. Any leading end of a filament that may tend to drop down from the point of cutting is nevertheless carried forward in contact with the other filaments by the action of the rotary blades is which are continually rising up from in rear of cutting position and moving forwardly with the filaments.

It will be noted that the reciprocation of the rotary knife blades not only gives a transversely sliding cutting stroke of the knife blade for severing each filament, but also serves to shift the filaments of the tow back and forth with a lateral .apparatus the strand will twist drafting the strand. After passing the front rolls the drafted strand of cut fibers may be subjected to any suitable after treatment, for instance, further drafting, the reception of twist, and winding up. Thus the illustrated apparatus may constitute the drafting portion of such machine as a roving frame or spinning frame having suitable twisting and winding mechanism. when the apparatus constitutes the drafting portion of a spin ning frame, the weight 'of the tow T will be selected so that after its draft received in this into yarn of the desired count.

What is claimed is:

1. Apparatus for converting fibers of a tow of continuous filaments into staple-length fibers, comprising means for subjecting the tow to a draft, a rotary element including a plurality of knife blades extending transversely of the line a of draft of the tow, said rotary element and its knife blades being arranged and disposed with relation. to the tow so that the tow bears against .and is deflected by said knife blades, means for causing said knife blades to rotate at a surface speed approximately the same as the forward surface speed of the tow in contact therewith, and means for simultaneously reciprocating said knife blades transversely of the tow, so as to sever the sufficiently strongly tensioned filaments with a sliding and cutting action while minimizing longitudinal drag of the filaments over the blades. 2. Apparatus for converting fibers of a tow of continuous filaments into staple-length fibers, comprising means for subjecting the tow to a draft, a rotary element including a plurality of.

' knife blades extending transversely of the line of draft of the tow, said rotary element and its knife blades being arranged and disposed with relation to the tow so that the tow bears against and is deflected by said knife blades, means for causing said knife blades to rotate 'at a surface speed approximately the same as the forward thus particularly facilitates cutting those filaments which are not initially in a position for immediate contact with a knife blade, as in the case of filaments initially lying buried within the body of the tow. Thus each individual filament of .the initially rope-like or cord-like tow is enabled to draw into effective cutting contact with oneof the blades.

The relatively rapid forward movement of those staple length filaments that are controlled by the faster-moving front rolls I4, I! results in surface speed of the tow in contact therewith, and means for simultaneously reciprocating said knife .blades transversely of the tow, the machine being constructed and arranged to permit shifting of the tow back and forth laterally and spreading of the filaments thereof-at the knife blades under the influence of the knife blades.

the reciprocation of the knife blades being greater than such shifting of the tow. v

SAMUEL L. ABBOTT. Executor 0!- the Will of Edward]. Abbott, De-

ceased.

REFERENCES CITED The following references-are of record inthe file of this patent:

UNITED STATES PATENTS Number Name Date 2,278,032 Youngman Mar. 31, 1942 2,323,300 Abbott July 6, 1943

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