US2339854A - Tension device for yarn winding machines - Google Patents

Description

1944- J. EJHIG'GINS 2,339,854

TENSION DEVICE FOR YARN WINDING MACHINES Filed March 25, 1942 2 Sheets-Sheet 1 Jan. 25, 1944. J. E. HIGGINS 2,339,854

TENSION DEVICE FOR YARN WINDING MACHINES Fiied March 25, 1942 i 2 Sheets-Sheet 2 8 James/T Hig ins Patented Jan. 25, 1944 UNITED STATES PATENT OFFICE TENSION DEVICE FOR YARN WINDING MACHINES James E. Higgins, Richmond, Va., assignor to E. I. du Pont de Nemours & Compa y, Wilmington, Del.. a corporation of Delaware Application March 25, 1942, Serial No. 436,201

7 claims. (01. 242-45) This invention relates to the winding of yarn, and more particularly it relates to an improved yarn tensioning device for impa ting a uniform tension on a yarn during the winding thereof. The .tensioning device of this invention has particular utility in the tensioning of partially oiled yarn which is being precision wound onto a core of the button guide on the'cone core, this varying oil illm isswept back and'forth with each thread oscillation. does work in continually displacing th oil film and so causes an uncontrollable increase, rather than an accurate decrease of tension to be applied to the yarn during the winding thereof.

while it is being unwound from a package, the

unwinding causing a pull of varying tension on theyarn.

It has long been desired to produce a precision wound package of yarn directly from bucket cakes or yarn which have been subjected to liquid treatment and drying. This desideratum is difficult to attain for the following reason: in order to-precision'wind yarn, ,i. e.,'to wind yam evenly and uniformly along the core, it is essential that the yarn being laid on'the core be maintained imder a low but substantially. uniform tension.

However, in unwinding yarn from bucket cakes,

particularly cakes which have been liquid treated and dried in an unsupported state, the yarn is subjected to pulls of varying tension due to cake deformations arising from'the liquid processing and drying procedures to which the yarn cakes Furthermore, when anoil film forms between the tension elements of the pinch tension device. the flexible tension plate is drawn onto the back plate by the surface tension and adhesive action -of the oil. Under such conditions, an additional uncontrollable increase of tension is applied to the yarn, since actually more pinching action occurs than is desired. The exact increase of tension caused by the oil film is unpredictable (depending, among other things, on the type and viscosity of oil used and the yarn being wound);

hence, it is seemingly impossible to design a tenhave been exposed. Hence, a satisfactory tension-applying device would not only have to operate to compensate for the progressiv change of tension occasioned principally by(1) the progressive change in angular contact of the yarn with the yarn guide of the traversing mechanism, 4

and (2) the progressive increase in linear velocity of the yarn as the package builds 'up, but would also have to operate to render uniform this varying tension inherent in unwinding yarn from a cake.

The pinch tension device disclosed in S.

Patent No. 2,223,912 was designed to overcome the above difllculties, and does so in an eminently satisfactory manner when used in the winding of unoiled yarns. However, it is often desirable to apply an oil finish to the yarn dining the winding operatlon to improve the physical properties of the yarn. When such freshly oiled yarn is wound on a machine employing this pinch tension device, an oil film forms between the yarn contacting or tension elements thereof and as the cone winding operation proceeds these elements of the pinch tension device are forced apart to decrease the tension applied to the yarn to compensate ior'the increase of tension caused by the 1 increase in thread speed and the oil film thus 7 increases in thickness and in area. Since the.

oscillates along the faces of the pinching'device by reasonof the traverse motion sion relief cam to accurately compensate for the increase of tension caused by suchan oil film.

It is, therefore, an object of this invention to provide an improved pinch tension device which will not be susceptible'to the formation of an oil film thereon.

A further object of this invention is to provide a yam tensioning device which will serve to impart the desired minimum and uniform tension to the yarn throughout the winding operation irrespective of the type of package from which the yarn is unwound, and irrespective of whether or not the yarn is oil-finished.

will more clearly apusual winding machine comprising an oiling mechanism and suitable thread guides; it is conveniently positioned between the yarn package being unwound and the yarn package .being wound.

The details of the invention-willbecome more apparent from the following description taken in connection with the acomp'anying illustrationa.

wherein g Fig.1 is a front elevational view showing the This sweeping action of the yarn essential winding elements of one type of a ing machine and the relative positioning of a preferred-form of the yarn tensioning device of the present invention; 3

Figs 2'is an enlarged sketch of the tensioning device or this invention shown in combination in Fig. 1; v

Fig. 3 is an end elevational view of a preferred form of corrugated back plate of the tension device of this invention; and

Fig. 4 is a front view of the corrugated back plate ofFig. 3.v

Referring to Fig. l of the drawings, reference numeral 2! designates the supply package, e. g. a bucket cake, The yarn I is drawn from the supply package, passed through the stationary thread guide 22, through the tension device of the invention, through the button guide 3 of a traversing mechanism, and subsequently is wound on a conical core 2 mounted on a spindle 24 of a winding machine. A conventional stop mechanism, for example, of the fall-wire type, may be placed in the line 'of yarn travel between the tension device and the windup core. The spindle 24 is driven at a constant rate of speed, which of course has the eflect of producing an increasing thread speed. The button guide 3 is held against the package being wound by means of the weight H on the pivoted arm 25 in the conventional manner. The pivot arm at 26 to the winding machine.

The tensioning device is attached to the winding machine by means of arm [1. A corrugated rigid plate 8, preferably of chromium plated steel, comprises the back plate of this tensioning device. A spring steel plate 6, also preferably chromium plated; is fastened to a bracket 9 pivoted 25 is pivoted attached to an arcuate cam I which is pivoted to the winding machine at 21. A rigid link l5, fastened to the cam by means of a screw ll, con nects the cam to the pivoted arm 25 and is pivote thereto by suitable means at point l3. Adjustable counter weight I2 is fastened onto the cam arm in the conventional manner to oifset the mass of the cam and so allow balanced rotation of the cam. Adjustable counter weight I 2| controls the pressure between the button guide 3 and the cone 2 in the usual manner.

The spring steel plate 6 is attached to the pivoted bracket 8 in such a way that the spring plate is pressed against the corrugated plate 8 so that it will contact the rigid plate only at its ridged surfaces. The spring steel plate 6 is positioned relative to the rigid steel plate 8 in such a manner that when the spring steel member ispassed against the corrugated plate 8, the two members are in converging relationship with each other in the direction of the movement of the yarn.

Also attached to the pivoted bracket 9 is a curved steel plate 1, so positioned that it will not interfere with the movement or resilience of the spring plate 6, but placed in such a manner that when, during the threading, cleaning, and inspection of the device, the spring plate 8 is bent away from the back plate, it cannot be bent so far as to exceed the elastic limit of the spring steel pfate and thereby either break the spring steel plate or materially impair its resilience so as to produce improper tensions to the yarn.

As the yarn builds up on the cone 2, the yarn speed increases so it is necessary-that the tension applied to the yam be decreased to compensate for the increased tension caused by the inwindassess;

creased yarh speed and to allow good cone formation, which cone is free of ridges, ribs, bulges, etc.

at the ends of the package. This is accomplished by means of the arcuate cam I 0 which guides the cam follower 28 attached to the pivot bracket 9. It wfll now be readily seen that as the weightedj arm swings in the direction of the arrow,

the 'cam moves upward, that is, in a direction substantially opposite from the direction of movement of the weighted arm 25. By means of the rigid linkage I5, this movement of the cam rotates the pivot arm 9 clockwise about its pivot l6, thereby decreasing the pressure between 'the spring plate 6 and the corrugated back plate 8.

-It is preferred that the yarn be passed as nearly as possible in a straight line from the yarn cake 2| to the cone 2. It is, therefore, desired that the cone spindle 24 be driven in the direction of the arrow to eliminate the abrupt change in direction of the thread as it passes from the traverse-guide. to the cone. While counterclockwise rotation as indicated by the arrow is preferred, it should be understood that the cone spindle can be driven in the conventional clockwise direction of rotation when using the present invention if suitable consideration is given to the angular snubbing caused by the abrupt change in direction of the yarn as it passes from the traverse guide to the cone.

The yarn, as it passes through the tensioning device of the present invention, is maintained in a substantially straight line and, therefore, since all snubbing action on the thread is avoided as it at I 6 to the arm H. The pivoted bracket 0 is passes through the device, the tension imparted to the yarn by the pinch tensioning device is purely additive to the tension already imparted to the yarn.

The spring plate member 6 is preferably constructed of very thin Swedish spring steel of the order of 0.004 inch in thickness. It is also desired that 0.0005 inch chromium plating be applied to each side of the spring plate. This type of construction is preferred since the spring steel plate may be reversed in case one side becomes worn through the frictional action of the yarn. Excessive wear on any one direct line of the tension device is avoided by the oscillating motion of the yarn caused by the traversing motion of the button guide 3.

As shown in Figs. 3 and 4, it is preferred that the corrugated back plate comprises ten horizontally disposed parallel ridges or bars 4| of semicircular cross-section on a rigid plate support. The preferred diameter of these bars 4| is of an inch, and the space 40 between them is preferably of an inch. The raised'portion of the bar .is preferably equivalent to its radius, of an inch.

The plate 8 itself is preferably cold rolled steel which has been milled to shape and the surface of which has subsequently been lapped and polished. This lapping operation produces a a, of an inch flat top on the corrugation of the plate. It is further preferred that a 0.002 inch chromium plated surface be'applied to the 061'- rugated plate.

According to the preferred embodiment of the invention, the spring steel plate 6 is so disposed with relation to back plate 8 that the drop in ten-' sion incident to the winding of a cone is produced by reducing the number of ridges or bars in contact with the spring steel plate, and further by reducing the pressure between the spring plate and the bars by means of the cam mech- 2,339,854 'anism as already described. Thus, at thebeginning of the winding, the spring plate contacts seven bars which produces the maximum tension desired and at the end of the cone formation, the plate contacts two bars producing the desired tension.

It is desirable that 'the yarn contact or run along a few bars prior to the position at which it is subjected to tension by means of the pinching action of the spring plate on the bars. This precaution allows any waves or bulgesin'the yarn .to be smoothed out before the tension is applied to the yarn. The number of such bars is determined by the size of the plate, i. e. the number of bars thereon, the type of yarn being wound, and the initial tension desired.

As has been mentioned, it is preferred that the device include a curved guide plate I to substantially prevent damage of the steel spring plate and so prevent this element from taking set when its elastic limit is exceeded. However, this element is not essential to the operation of the tensiondevice as such.

Although the yarn runs across the face of the spring plate of this device, it is in contact with the corrugated back plate only along its ridges.

It is the presence of these ridges and hollows and consequently the relatively small contact sur-,

face of the spring plate on the,corrugated .back plate which prevents an oil film from forming between the two elements of the device. In the tion are obviously not obtained if the plate'is tilted to such an extent that the bars orcorrugationson the back plate are substantially vertical. It' should be further understood that bars or ridges maybe attached to a-back plate in any c'cnvenient manner. For example, the bars may be screwed, glued, bracketed or' fastened in any convenient manner ontda supporting member, or they may be formed as aii-integral part of the plate bysuitably milling the same.

It has been stated that milled cold rolled steel is the preferred material of construction of the back plate. However, it is to be und that this member may be formed from any substantially hard and serviceable material, metal or alloy, and made in any suitable manner to produce the desired corrugation. For example,

the plate may be made from sintered cast iron,

ceramic, synthetic resin, glass, etc., which has been press shape.

It is also to be understood that the chromium plate preferably applied to the elements of the absence of such an oil film, a uniform decrease in tensionis obtained as is desired.

It is to be understood, of course, that the invention is not restricted to the exact structure and arrangement above described but is susceptible rather to wide variation in all of its features. For example, although it is preferred that the back plate of this tension device be composed of ten bars or ridges, it should be -realized that the device may contain as many or as few bars as may be desired, provided that the number of bars and the actual tension'contact surface be considered in applying tension by means of the spring plate. The actual dimension of the bars and the spaces between them may also vary.

For example, the diameter of the bars may vary from 3 2' of an inch to ofan inch and the spaces between any two adjacent bars may vary from of an inch to of an inch. It is, moreover, possible to vary the extent of the lapped fiat surface of the bars between of an inch and %4 of an inch; or it is even possible to have the top of.the bars substantially round. In fact, the bars may .have any polygonal shape as long as the points at which. the yarn is'pinched theretoform substantially a straight line.

Although it is preferredthat the, spaces .be-

tween any two adjacent bars be uniform over the entire surface of any plate, this uniformity is not absolutely necessary. Forexample, the spacing may increase or decrease progressively up" the plate in the direction of the yarn travel. However, such a modification will necessitate a diiferent tension decrease procedure to compensate for the nonuniform spacing of the corrugation.

It should be further understood that, although it is preferred to have the bars on the back plate substantially parallel and straight, again this is not absolutely necessary. For example, the

bars may be curved in anyway desired or they may be set at any angle or a plate containing parallel bars may be tilted so that the bars are not horizontal. However, the objects of the invenpinchtension device is not essential.

Anysuitable hard plate such as a nickel plate may be applied or,.if desired, the plain polished metal itself may be used for the surface of the elements of the tensioning device of this invention. It

a non-metallic material is used for the back plate,

it may be polished, finished, or coated in any desirable manner. a

Anyconventional means, such as a series of links and levers, may be substituted for the cam mechanism shown in Fig. 1, to produce a decrease in tension on the yarn as the cone builds p vention does not only apply to cone winding, but also to the winding of pirns, spools, cops, skeins, "throw packages," etc. In fact, it may be -used as a tensioni'ng means for'the precision Likewise.

winding of any -type yampackage. the supply package neednot be a bucket cake;

the tension device is applicable to the rewinding of any package to any. other desirable form whether or not oil is applied to the yarn durln the winding operation.

This invention permits the imparting 0f additive tension to yarn during the process of winding yarn onto a cone'from a cake package; 7

The fact that anoil film is not produced from the device of the present invention permits a minimum of maintenance for this improved tensioning device.- In fact, the corrugated type tension device, substantially as described in its preferred embodiment, can operate with only occasional cleaning fora period of upward of three months with no visible change in tension as applied to the yarn. In other words, substantially a constant and reproducible tension relief curve'can be obtained with the device of'the present invention over a prolonged operating period during which time all maintenance is molded or formed to 'the.'d'esired t is obvious that the'tension device of this in- The invention moreover provides f6r a tensioning device which, because of the curved guide plate already described, permits prolonged, ac-

curate, and uniform operation of the spring plate.

The improved tension device allows efiicient yarn winding onto a cone substantially described -in the preferred embodiment of the invention with spindle speeds approximately 20% higher than have been practical with the ordinary pinch tension device. Such increased winding speeds are attained without the breakdowns and yarn said rigid member, said members coacting to pinch the yarn therebetween, said rigid member being provided with a plurality of ridges disposed to contact the yarn transversely of its line of travel, said resilient member having a substantially flat unbroken yam-contacting surface, and means for continuously adjusting the tension imparted to the yarn by the coaction of said members whereby a substantially uniform and continuously smooth tension is imparted to'the yarn throughout the winding operation.

6. In a machine for precision winding of yarn onto a wind-up core directly from packages such as bucket cakes, yarn tension-control means comsaid members, the other of said members having a substantially flat surface.

2. In a yarn tensioning device for winding machines, a pair of yarn-tensioningmembers counbroken yarn-contacting acting to pinch the yarn therebetween, one ofsaid members being provided with a plurality of yarn between said members, the other of said members having a substantially fiat unbroken yam-contacting surface.

4; In a yarn tensioning device for winding ma-' chines, yarn tension-control means comprising a rigid member fixedly mounted in the line of travel of the yarn being wound, and a resilient member mounted in converging relationship with said rigid member, said members coacting to pinch the yarn therebetween, said rigid member being provided with a plurality of coplanar ridges adapted to contact the yarn transversely 'of its line of travel, said resilient member, having a substantially flat unbroken yarn-contacting surface.

5. In a machine for precision winding of yarn onto a wind-up core directly from packages such member mounted in converging relationship with prising a rigid member fixedly mounted between the wind-up core and package in the line of travel of the yarn being wound, a resilient member pivotally mounted at one end and normally urged in converging relationship at the other end with said rigid member, said rigid memberand said resilient member coacting to pinch the yarn therebetween, said rigid member being provided with a plurality of ridges disposed to contact the yarn transversely of'its line of travel, said resilient member having a substantially flat unbroken yarn-contacting surface, and means automatically operated by the wind-up core for moving said resilient member about its pivot and for continuously reducing the tension imposed on the yarn by coaction of said rigid and resilient members as the diameter of the yarn on said wind-up core increases whereby a,substantially uniform and continuously smooth tension is imp rted to the yarn throughout the winding operation. I V

'7. In a machine for precision winding of yarn onto a wind-up core directly from packages such as bucket cakes, yarn tension-control means comprising a rigid member fixedly mounted between the wind-up core and package in the line of travel of the am being wound, a resilient member pivotally mounted at one end andnormally urged into converging relationship at the other end with said rigid member, and ineans associated with said resilient member to prevent the flexing of the resilient member beyond its elastic limit, said rigid member and said resilient member coacting to pinch the yarn therebetween, said rigid member being provided with a plurality of ridges disposed to contact theyarn transversely of its line of travel and means automatically operated by the wind-up core for moving said'resilient member about its pivot and for continuously reducing the tension imposed on the yarn by coaction of said rigid and resilient members as the diameter of the yarn on said wind-up core increases whereby .a substantially uniform and continuously smooth tension is imparted to the yarn throughout the winding operation.

JAMES V E. HIGGINS.

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