US2380951A - Method and apparatus for evaluating thread tensioning devices - Google Patents

Description

Aug; 7,1945 F. A. DECKER, JR, ETAL 3 METHOD AND APPARATUS FOR EVALUATING THREAD TENSIONING DEVICES Filed Dec. 30, 1942 Tmw w N a m EEO W. W

A m} mp B Patented Aug. 7, 1945 METHOD AND APPARATUS FOR EVALUAT- ING THREAD TENSIONING DEVICES Ferdinand A. Decker, Jr., and Paul G. Woodward Parkersburg, W. Va" assignors to American Viscose Corporation, Wilmington, DeL, a corporation of Delaware Application December 30, 1942, Serial No, 470,652

8 Claims.

It is a common practice to wind yarns or strands oi filamentary material from one package to another. For example, rayon filaments in the form of a cake resulting from. collecting in a centrifugal spinning bucket are commonly'rewound into cones or other sorts of packages, such as skeins, prior to subsequent treatment or be- !ore shipment. In passing to the package being wound, the filamentary bundle proceeds to suitable traversing guides and tensioning devices in order to form a uniform package. Because of the conditions under which the filamentary material is collected within the spinning bucket in the form of a cake, the windings therein are frequently irregularly disposed and as the filaments areunwound from the cake, there frequently occurs a tendency for the outer windings of the cake either to stick to the filaments being withdrawn or to catch them; This tendency of the filamentary bundle to stick or catch upon the windings of the cake exerts a pull or force resisting the withdrawal of the bundle from the cake which exhibits itself in the 'form of in-' creased tension. This pull or resisting force, frequently reierred to as a pluck, may'at times be sufiicient in magnitude to stretch the yarn along portions of its course of travel where the increased tension is unable to become expended by takin up slack with sumcient rapidity. In' addition, certain tension devices in which the filamentary bundle passes around curves tend to multiply the pluck in the portion of the filamentary bundle extending between the curved surfaces of the tension device and the package being wound. In this manner, plucks which are of themselves quite insufilcient to stretch the yarn are frequently magnified by the tension devices to such an extent that stretching occurs. As is well known in the art, yarns which exhibit localized stretched conditions exhibit what are termed shiners'f' which are particularly objectionable and noticeable in fabrics made from the yarn.

'Heretofore, it has been impossible to compare and to evaluate the numerous tension devices that are available or which may be devised with respect to their tendency to multiply the pull or pluck which occurs in unwinding the rayon or other cake because of the irregular character and occurrence of the plucks which occur throughout such a cake and which can neither be controlled nor reproduced. It is an object of the invention to provide a device which will make it possible to impart to an unwinding yarn or the like a standard reproduceable pluckof any desired magnitude. A further object is to providea method It may be provided for permitting adjustment of desired character.

and apparatus for evaluating tension devices. Further objects and advantages of the invention will be apparent from the drawing and the description thereof hereinafter.

In the drawing, illustrative of the invention.

Figure 1 is a perspective view' showing the standard pluck reproducing device associated with a tension device in a winding procedure, and

Figure 2 is an elevational view of a modified arrangement of the device with a winding apparatus.

As shown in Figure l, a package 2 of filamentary material, such as a bobbin or cone, is placed proceeding from the package through a suitable v guide 5 to control ballooning, thence through the particular tension device 8 it is desired to test or evaluate, then over a tension responsive pulley I and finally to a suitable wind-up device 8, such as a cone or bobbin winder which draws the yarn or the like through the various devices at a controlled rate of speed. 1

The tension measuring device may be of any As shown, it comprises a disk 9 mounted for rotation by suitable clock-work (not shown) and a recording stylus Ill carried with the pulley I by a suitable resilient arm Ii having one end adjustably secured in a standard I! which with the clock-work mechanism may be supported upon a suitable base I3. The resilient arm H which carries the stylus Ill and the pulley "I and is responsive to the tension in the filamentary bundle may be in the form of a flat or ribbon-like spring whose width extends in a direction perpendicular to the drawing. A set screw the standard'and stylus so that it may bear lightly against a recording chart II, which may take the form of a smoked chart adapted to be marked by the mechanical action of the stylus in scraping the coating therefrom. This adjustment of the stylus and standard permit the removal of the stylus from the chart by pivotal action about a vertical axis.

The standard pluck device comprises a suitable supporting bracket it which may be fastened to the winding machine, such as to the support I for the unwinding package 2, so that it will be in proximity thereto. The bracket It supports a vertical post i! from which there extends an arm is carrying a freely pivotable yoke I9 supv porting a freely rotatable pulley 20, The vertical post I! is provided at its top with a shoulder yond its point oi contact with the package windlngs, thereby preventing the ballooning action of the yarn from throwing it over the free end of the rod 2!. The cord 24 rides over the pulley II and .the magnitude of the pluck is controlled by varying the weight placed upon the platform N. The two rods carried by the sleeve may be made such sine as to balance each other though this is not essential. The angularity and height oi the arm II with respect to the bracket it may be ad- .iusted by means of the set screw It.

In operation, the angularity oi the arm II is preferably adjusted so that when the rod 22 is in contact with the package 2, the horizontal course oi ms cord it between the pulley it and rod 2; is approximately at right bearing against the windings oi the package. Rod 22 preferably is arranged to extend in a direction substantially pe pendicular to the axis of the package although it may be inclined at any desired angle between this direction and a direction parallel to the axis oi the package. By operating the winding machine with a package to be unwound which is oi a uniiorm character, it will readily be seen that a reproduceable. pluck can be obtained and the repetition of the winding under substantially the same conditions with each of the tension devices that are to be tested will indieats which oi the tension devices is the most suitable ior the purpose. A comparison oi the records ll taken with each tension device reveals at a glance which oi such devices applies the most uniform tension and multiplies the plucks the least.

angles to the rod I3-- Whereas the traveling filamentary bundle is shown in Figure l as proceeding from the tension device 8 up and over the tension responsive pulle'y I oi the recording instrummt and then down to the winding machine I, this arrangement is not mentiai since, as shown in Figure 2, the yarn may proceed from-the tension device 0 over a loose pulley 21, down under, the tension responsive pulley l of the recording instrument and then up to the wind-up device I.

While preferred embodiments of the invention have been disclosed, it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined by the appended claims.

We claim: V

l. A device for evaluating tension devices comprising a supporting bracket, a post in the bracket, a member extending transversely oi and being pivotally mounted on the post, an arm extending irom the post, a pulley pivotally mounted on the arm, and 'a fiexible strand fastened to one end of the member andextendlng over the pulley ior supporting a counterweight.

2. A device ior evaluating tension demos prising a supporting bracket, a pos us mounted in the bracket, a substantially rigid rod extending transversely oi and being pivotally mountsdonthepost, anarmextendingiromtbe post, a pulley pivotally mmmted on the arm, and a fiexiblestrandia'stenedtooneendoitherod andextendingoverthepullegandsupportinga 8. In combination, a woimd package oi filamentary material. a tension device, a tension responsive device, means for drawing at a controlled speed the filamentary material irom the wound package through the tension device and the tension responsive device in succession, a member tangent to the outer windings oi the package, and means for pressing the member with predetermined iorce against the package.

5. In combination, a wound package of diamentary material, a tension device, a tension responsive device, means for drawing at a controlled speed the iiiamentary material from the woimd package through the tension device and the tension responsive device in succession; a substantially rigid member tangent to the outer windings oi the package having extensions oi sufilcient length in opposite directions irom the point oi contact at an angle to the axis of the package to prevent ballooning oi the filamentary material with respect to the package irom throwing the filamentary material around an end of the member, and means for pressing the member with predetermined force against the package.

6. A method of evaluating tension devices comprising the steps of passing a continuous filamentary material at a controlled speed from-a substantially uniformly wound package, against a portion of the outer windings oi which a smooth rigid member is pressed, in succession through the tension device to be evaluated and a tension responsive device.

7. In an apparatus for evaluating tension devices, a support, a wound package oi filamentary material carried by the support, a substantially rigid member tangent to the outer windings oi the package having extensions in opposite directions from the point oi contact arranged at an angle to the axis of the package to prevent the filamentary material from being thrown around an end oi the member by the ballooning oi the filamentary material with respect to the package as it is unwound therefrom, said member being mounted pivoially on an axis substantially parallel to that of the package, and means for swinging the member about its pivot and ior pressing it witha predetermined force against the package.

8, In an apparatus ior'evaluating tension devices, a support, a wound package at filamentary material carried by the support, a substantially rigid rod tangent to the outer windings oi the package and extending in opposite directions iron: the. point of contact at an angle to the axis oi the package to prevent the filamentary material irom beingthrownaroundanendoitherodbyih'e ballooning oi the filamentary material with respect to the package as it is unwoimd therefrom, said rod being mounted pivotally on an-axis substantially parallelto that of the package, and means for winging the rod about its pivot and for pressing it with a predetermined ioroe against the FmDINAND A. DECKER, Ja. PAUL G. WOODWARD.

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