US2340611A - Yarn production - Google Patents

Description

Feb. 1, 1944. w. E. NEFF 2,340,611

YARN PRODUCTION Filed May 21, 1942 INVENTOR MYJlbmENe/f B l g Patented Feb. 1, 1944 UNITED STATES PATENT OFFICE YARN PaonUcrio I, I William E. Nee, Bridgeport, Conrnfassignor to E. I. du Pont .de Nemours & Company, Wilmington, DeL, a corporation of Delaware Application May 21, 1242, Serial No. 443,907

1 Claims. (01. res-41.5)

This invention relates to a new and improved method and apparatus for guiding a wet yarn passing freely by its own weight from a rotating yarn forwarding roller to a yarn collecting surface positioned under said roller.

Several processes for the. production of yarn include the step of passing the yarn freely by its own weight, that is, free of all tension except that imposed by the weight of the freely falling yarn, from a yarn forwarding roller to a moving collecting surface positioned under said roller. British patent to Topham No. 379,880 and United States patent to Neidich No. 15368,- 687 disclose such processes.

' In such processes, since it is essential that no substantial tension be placed on the yarn moving from the roller to the collecting surface,

difficultyhas been experienced in controlling or regulating the path of the yarn taken between the two above-mentioned elements. The wet yarn, because it possesses a thin film of adherent liquid, clings to the surface of the. forwarding roller and intermittently wraps part way around the roller. Consequently, the descending yarn does not leave the feed wheel at a definite point above the collecting surface to take a non-varyme straight path to the collecting surface. Instead it clingsintermittently to the roller and partially wraps about the same until the angular force is 'sufiicient to strip it from the roller to .apoint back along the periphery of the roller. Thus, the path of the yarn between the roller and collecting surface is intermittently shifted back and forth in a non-uniform oscillatory manner. This non-uniform, oscillatory, lateral displacement of the line of yarn descent prevents the formation of a uniform accumulation of yarn on the moving collecting-means. The accumulation of yarn on the moving collectingmeansin a device of the type above described will have the form of a plurality of overlapping ringlets if the line of yarn descent is maintained substantially constant. The intermittent lateral displacement of the line of yarn descent, however, causes the loops of yarn to travel back and forth on the collecting surface thereby causing snarls and tangles in-the yarn as it is subsequently removed from the accumulated pile of yarn. I p

It has been proposed in the past to overcome this tendency of wet yarn to cling to .a rotating yarn forwarding roller by providing the rollgestion, it has also been proposed to use as the forwarding roller a cylindrical member provided It is an' object of this invention to provide a method and apparatus for controlling the path of a wet yarn freely passing by its own weight from a yarn forwarding roller to a collecting surface.

It is a further object of this invention to provide a new and improved method and apparatus for preventing substantial shifting of the path of yarn descent of a wet yarn passing freely by its own weight from a yarn forwarding roller to a collecting surface.

Other objects ofthe invention will appear hereinafter. q v

The objects of this invention may-be accomplished, in general, by positioning between the yarn forwarding'roller and the yarn collecting surface a yarn contacting member which is adapted tccontact said yarn solely on one side thereof. The yarn as it descends will cling to such a contacting member with sufficient force to be maintained at all times in contact with the latter and thereby maintain the line of yarn descent substantially constant between the'con- 'tacting member and the collecting surface.

Figure 1 is a side elevational view, with parts shown in perspective, illustrating a yarn contacting member in position between a yarn for-' warding roller and a yarn collecting device.

Figure 2 is a perspective view showing a modified form of yarn contacting member. f

er with a. corrugated surface whereby the relative contact of the yarn with the roller is greatly decreased. "as a modification of this sug ed on to roller I! by means of guide pin l9 and Figure 3 is a perspective view. showing a modified manner of controlling the descent of a freely flowing yam passing from a yarn forwarding roller to a moving collecting surface.

Figure 4 is a perspective view of a modified form of contacting member.

ing belt- IS. The yarn is forwarded by means of yarn forwarding roller ll. "I'heyarn H is guid- Referring to Figure l of the drawing reference 2 v the successive wraps of yarn about the forwarding roller are maintained separated from each other by means of displacement roller 2!. The yarn passes freely by its own weight from the forwarding roller H to the collecting belt where it accumulates in small overlapping ringlets. To prevent the yarn II from oscillating in its travel to the collecting belt due to the inter- .mittent wrapping of the yarn on roller H, a

yarn-contacting pin 23 is positioned between the roller I1 and the belt [5. The film of adherent liquid on the yarn to pin 23 and descend in a substantially constant path to the belt.

Referring to Figure 2 of the drawing, the yarn contacting member 23a isshown constructed in the form of a plate instead of a pin. The lower rounded edge of the plate contacts the yarn and causes it to descend to the belt in a substantially straight line of descent. If desired, a small amount of liquid may be continuously passed down the inclined face of the contacting member 2311 whereby the added weight of the liquid flowing on to the yarn will permit the shortening of the distance between the member 23a and the collecting surface below. For this purpose, a conduit 33 leading from a liquid supply container 35 may be provided adjacent member 23a.

Referring to Figure 3 of the drawing, the yarn H is forwarded from the liquid container l3 by means of a yarn forwarding roller I! in the same manner as described with reference to Figure 1. In this case, however, the yarn is traversed back and forth in order to lay the yarn on the belt in rows 25 of overlapping ringlets on the belt l5. The yarn is traversed by reciprocating the yarn contacting plate 23a by means of rotating eccentric 21 and crossbar 29. The amount of traverse which can be imparted to the yarn -depends upon the liquid with which the yarn is wetted and the distance of the yarn contacting plate 23a from the yarn forwarding roller H. The distance of traverse is, of course, limited to that within which the descending yarn will be caused to cling to theyarn contacting plate 23a.

Referring to Figure 4, a modified form of yarn contacting member 23b is illustrated. The yarn contacting member 23b is slightly curved but, for purposes of the present invention, shall be considered as contacting only one side of the yarn.

In operation, it is found that the presence of the yarn contacting member effectively prevents substantial displacement and oscillation of the descending yarn, the yarn descending from the contacting member to the collecting means in a substantially straight line. Although the yarn still has a tendency to cling to the lower portion of the yarn forwarding roller, this tendency is somewhat reduced by the presence of the yarn contacting member. Even this tendency of the yarn to cling to the roller is of no consequence,

however, since the yarn after contacting the yarn contacting member descends to the collecting means in a substantially straight line. The action of the yarn contacting member in eliminating substantial lateral displacement of the line of yarn descent appears to be brought about by the surface tension effect of the liquid contained on the yarn. Close inspection shows that a film of liquid exists at the point where the yarn passes the yarn contacting member so that the yarn does not actually touch that member, but is separated therefrom by a thin film of liquid.

It is preferred to position the yarn contacting member to contact the yarn only on that will cause the same to cling side thereof opposite the side contacted by the yarn forwarding roller.

In accordance with the preferred embodiment of the invention, the yarn contacting member ishighly polished to prevent material degradation of the yarn. Preferably, the yarn contacting member is positioned within the near proximity of the yarn forwarding roller. The yarn contacting member should be composed ofnoncorrosive material such as stainless steel, corrosion-resistant steel, a hard polished ceramic material or the like.

It is preferred that the yarn contacting memher be quite thin at the point where it contacts the yarn. Preferably, the edge of the yarn contacting member at the point where it contacts the yarn is rounded to present-a rounded edge not to exceed about inch in diameter. If the diameter of the rounded edge exceeds this value, it is found that with some liquids the yarn still tends to cling to the yarn forwarding roller. This is probably due to the increased drag caused by the friction of the yarn passing over the contacting member. Such an increased drag appears to overbalance the pull exerted by .the 'weight of yarn below the contacting member by a sufficient amount to prevent the satisfactory removal of the yarn from the forwarding roller.

The present invention has been described with reference to a yarn descending from a yarn contacting roller having a substantially smooth continuous cylindrical surface. The invention can also be used to equal advantage in connection with a yarn descending from a yarn forwarding roller having roughened or even corrugated discontinuous surfaces of the types disclosed in U. S. Patent No. 1.987,942 or U. S. Patent No. 2,181,- 934.

This invention makes possible the removal of undesirable oscillations from the path of a wet, advancing yarn descending freely from a rotating surface such as a feed wheel to which it tends to cling, whereby the yarn is able to descend in a straight vertical line to a collecting means below. The invention thus makes it possible to very accurately control the point at which the yarn is deposited on such. a collecting means.

The invention also makes it possible to impart a controlled oscillation, or reciprocating movement, to a descending yarn, whereby it is possible to traverse that yarn across the width of the collecting means.

The invention, by making it possible to control the descent of a yarn to a collecting means, greatly improves the uniformity of the yarn body formed on the collecting means, whereby it is possible to effect desirable improvements in the washing, drying, and subsequent removal of the yarn from thecollecting means.

Since it is obvious that many changes and modifications can be made in the above-described details without departing from the nature and spirit of the invention, it is to be understood that the invention is not to be limited to the details described herein except as set forth in the appended claims.

I claim:

1. A rotating yarn forwarding roller, a yarn collecting surface positioned below said roller, and a yarn contacting member adapted to contact the yarn passing by its own weight from said roller to said surface, said member adapted to contact only one side of said yarn whereby to cause said yarn to cling to said member with suificient force to be maintained at all times in 2,340,611 contact with said member and maintain the line side contacted by said roller whereby to cause said yarn to cling to said member with sufiicient force to be maintained at all times incontact with said member and maintain the line of yarn descent substantially constant.

3. A rotating yarn forwarding roller, a yarn collecting-surface positioned below said roller,

and a yarn contacting pin adapted to contact a yarn passing by its own weight from said roller to said surface, said pin adapted to contact only that side of the yarn opposite the side contacted by said roller whereby to cause said yarn to cling to said pin with suflicient force to be maintained at all times in contact with said pin and maintain the line of yarn descent substantially constant.

4. A rotating yarn forwarding roller, a yarn collecting surface positioned below said roller, and a yarn contacting pin having a diameter not to exceed A; inch adapted to contact a yarn passing by its own weight from said roller to said surface, said pin adapted to contact only that side of the yarn opposite the side contacted by said roller whereby to cause said yarn to cling to said pin with sufdcient force to be maintained at all times in contact with said pin and maintain the line of yarn descent substantially constant.

5. A rotating yarn forwarding roller, a yarn collecting surface positioned below said roller,

and a yarn contacting plate positioned with the edge of the plate contacting a yarn by its own weight from said roller to said surface, the edge contact only that side of the yarn opposite the side contacted by said roller whereby to cause said yarn to clingv to said member with sumcient force to be maintained at all times in contact with said member and maintain the line of yarn descent substantially constant, and means for traversing said yarn contacting member.

7. The method of guiding a wet yarn passing downwardly by its own weight on to a collecting surface which comprises contacting only one side of said wet yarn in the downwardly moving path thereof with a yarn contacting member, whereby the moving yarn will be made to cling to said member with suflicient force to maintain contact between the yarn and the member and thereby prevent transverse movement of the line of yarn descent.

WILLIAM E. NEFF.

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