US2920345A - Method and apparatus for producing variable denier yarn - Google Patents

Description

Jan. 12, 1960 R. F. DYER 2,920,345

METHOD AND APPARATUS FOR PRODUCING VARIABLE DENIER YARN Filed June 3, 1955 3 Sheets-Sheet 1 L *1 I ll 34 E {a Richard .E'Dyer IN V EN TOR.

Jan. 12, 1960 R. F. DYER 2,920,345 METHOD AND APPARATUS FOR PRODUCING VARIABLE DENIER YARN I Filed June 3. 1955 r 3 Sheets-Sheet 2 I I l I I 0 26 4'0 60 so 100 d u H U c -//vc//s0/= YARN T F1931) CENTER FjgZ INCHES OF WIRN I I I I I I 0 2o 4o 60 so 100 F 3 INCHES 0F YARN RichardE'Dyer IN V EN TOR.

Jan. 12, 1960 R. F. DYER 2,920,345

METHOD AND APPARATUS FOR PRODUCING VARIABLE DENIER YARN Filed June 5', 1955 1 3 Sheets-Sheet 3 DEN/ER l I 0 2O '40 60 80 I00 I g Y I I INCHES OF mRN Fig4b I Richer-d1? pger INVEMTORL Patented Jan. 12, 1969 2,920,345 IVIETHOD AND APPARATUS FOR PRODUCING VARIABLE DENIER YARN Claims. (Cl. 18-8) Tenn., assign'or to Eastman Rochester, N.Y., a corporation of The present invention relates to more particularly to a method of ing a variable denier yarn.

There is a continuous demand by fabric designers for a thick and thin acetate yarn having very closely spaced slubs or short heavy denier lengths to impart a novel appearance to fabric woven from the yarn. Heretofore, while it has been possible to produce thick and thin acetate yarn with closely spaced thick slubs, the very low spinning speed required to achieve yarn quality has made such a yarn economically'unfeasible. As a result, most commercially available thick and thin yarns have slubs spaced from 30-50 inches apart. Moreover, the high mechanism speeds required for producing slub acetate yarn, at higher spinning speeds, made the design of the mechanism complicated and subject to excessive breakage.

The invention has as its principal object the provision of a method of making closely spaced slubs in acetate yarn at economically feasible spinning speeds without impairment of yarn quality.

A further object of the invention is the provision of a simple, reliable mechanism capable of operating at high speeds in a manner to produce closely spaced slubs of acetate yarn.

Another object of the invention is the provision of a method of and the apparatus for producing slub yarn having novel patterns of variations in denier.

In essence, the invention consists of randomly and intermittently vibrating a spring restrained guide lever so as to increase and decrease alternately the relative drafting force on the yarn by pulling on and releasing the yarn.

To these and other ends, the invention resides in certain improvements and combinations of parts all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings:

Fig. 1 is a schematic representation of an acetate yarn spinning device, showing the relation thereto of one modification of a slub forming mechanism constructed in accordance with the present invention;

Fig. 2 is a diagrammatic view of the pivoted or movable yarn guide showing the sequence of operations thereto to provide the series of oscillations which provide the desired type of slub yarn;

Fig. 3a is a typical denier variation chart of one type of thick and thin yarn produced by the apparatus and method of the present invention;

Figs. 3b and 30 show variations of the slub effect which can be made by suitable adjustments of the mechanism of the present invention;

Fig. 4a shows a modified movable slub lever guide constructed in accordance with another embodiment of the invention; and

Fig. 4b shows a denier variation chart produced from the lever construction illustrated in Fig. 412.

Similar reference numerals throughout the various views indicate the same parts.

yarn production, and and apparatus for formon the cam 43 to free Fig. 1 of the drawings shows yarn filaments 11 which are extruded from a spinnerette 12 into curing cabinet 13. The cured yarn is passed through a small opening 14 in the bottom of the cabinet 13. This yarn is then passed over a slubbing guide 15 which supplies a light tension to the yarn. The latter then passes through a top fixed guide 16, a loop 35 of a slubbing lever guide, broadly designated by the numeral 17, through a bottom fixed guide 18 and finally over a godet roll 19. From this point, any of several means may be used to wind the yarn up for subsequent processing. It will be noted that the bottom fixed guide 18 is in vertical alignment with the top fixed guide 16 and cooperates therewith to provide a straight path 20, shown in dotted lines, if the slubbing lever guide 17 were removed or inoperative.

The slubbing lever guide 17 is pivoted at 25 for free rocking in a horizontal plane and normal to path 20 as is deemed apparent from an inspection of Fig. 1. The horizontal movement of the lever 17 is restrained by two opposing springs 26 and 27 having adjacent endsconnected to lever 17, and opposite ends 30 and 31 respectively anchored at 32 and 33 to a suitable, stationary support 34, all as shown in Fig. 1. It will be apparent from the above description and viewing of Fig. 1,

that if the lever 17 is displaced horizontal from the' center position, see Fig. 2, and suddenly released, the opposing springs 26 and 27 will cause the lever to vibrate at the natural frequency of the system to provide a series or plurality of oscillations of progressively decreasing size or amplitude, as shown in Fig. 2. The frequency of vibration can be controlled by the stiffness of the springs 26 and 27, Le. stiff springs cause a higher frequency. Also, the frequency of vibration canbe controlled by the weight of the lever itself; aheavy lever vibrates slower because of its greater inertia. The action of the yarn on the lever, of course, is to return the lever to its central position and oppose any removal-therefrom. Since the yarn exertsmore restraint on the lever 17 during its motion away from the center than towards the center, the yarn acts to dampen out or subdue the vibrations of the lever. I

An endless moving chain, or similar member 40, is provided with a plurality of pins 41 spaced therealong, only two of these pins being shown in Fig. l. The chain 40 is moved to the right by any suitable mechanism to bring successively the pins 41 into engagement with an offset or cam portion 43 formed on lever 17.

Such engagement serves to move or rock lever 17 to the right about its pivot 25 to move the lever and yarn laterally or in a direction normal to the path 20 between guides 16'and 18. The contact of each pin 41 and cam 43 is continued until the lever 17 has been moved far enough to the right, Fig. 1, allowing the pin 41 to ride the lever 17. The result is that the springs 26 and 27 cause the lever 17 to continue to oscillate back and forth through its center position on the vertical axis of the guides 16 and 18. As isapparent from Fig. 2, these oscillations are of progressively smaller and smaller amplitude.

The eitect of these oscillations of the slubbing lever guide 17 is to increase the spinning speed or draft and cause lower denier as the lever moves to the right of center, suddenly to decrease the draft and make a heavier denier slub as the lever moves back toward center, to suddenly increase the draft and reduce the denier as the lever moves to the left of center, and then suddenly decrease the draft to make a slub asthe lever. returns toward the center. These oscillations of the leverv 17 and the production of alternately thick and thin spots in the yarn continues to decrease progressively, until the yarn tension dampens out and stops the vibration, or until the next chain pin 41 stops the vibration sequence and'sets up a new series of vibrations. Of course, the dampening efiect of the yarn tension on the lever vibration causes each successive cycle of vibration to be smaller, and a gradual or progressive decrease in the variation in the denier between the slubs and the thin spots takes place.

Referring to Fig. 2, a plan view of lever 17 is shown with extreme right and left positions of the lever with successive oscillations being shown in alphabetical sequence. Fig. 3a shows the corresponding variations in denier, and is lettered to correspond to the lever positions of Fig. 2. It should be kept in mind at this point that the low denier sections of yarn are made during the pull-out movement of the yarn away from the center position, and the heavier denier sections are made during the movement of the lever toward its center position.

It might be thought that the fixed frequency of oscillation of the lever would produce evenly spaced slubs, which would cause undesirable patterns in fabric woven from the yarn. In practice, only four or five successive evenly spaced slubs are made before the denier variations decrease to a negligible amount. Moreover, the pins 41 on the chain 40, which initiates the vibrations, are randomly spaced. Thus, although the four or five slubs in any group are evenly spaced, the group of slubs is random in occurrence in the yarn, and this has been found to be sutficient to avoid any pattern of slubs.

Certain interesting variations in the slub pattern can be made by varying the adjustments of the springs 26 and 27. For example, if spring 27 of Pig. 1 is made tighter than spring 26, the slubber lever guide 17 will not come to rest at the center; but, on the contrary, will actually come to rest on the right of center. This will cause a decrease in its excursions to the left of center and then cause smaller pull-outs to the left and hence smaller slubs. With this setup, the slub pattern is: large slub, small slub, large slub, small slub, etc. as shown in Fig. 3b. By use of a heavy slubbing lever, the vibrations can be prolonged and if chain 40 is moved slowly a long series of slubs, say five to ten, can be made in each group of slubs and the denier pattern as shown in Fig. 3c can be made.

Fig. 4a shows a modified form of slubber lever guide 46. In this embodiment the support 45 for the slubber lever guide 46 is formed with a flat portion 47 against which a bowed leaf spring 43 bears to exert a heavy restraining force on lever 46 only in the center position. The ends of the spring 48 are anchored at 49. This arrangement causes the lever 46 to stop oscillating after only two or three pull outs, and will produce the slub pattern shown in Fig. 4b if the chain speed is not changed. Other novel effects may be produced by combinations and variations in the lever weight, shape, spring tensions and frictional drag placed on the slubber lever. In this embodiment, lever 46 has connected thereto springs 50 and 51 which are similar or identical to springs 26 and 27, Fig. 1.

It may be wondered why it was not possible to speed up the chains or cams of the slubber mechanisms to obtain closer slub spacings. However, when this was done, the yarn strands were broken at the spinnerette. It is believed that such breakage occurs because of frequent, forceful interference with natural longitudinal force waves set up in the yarn strands by the formation of each slub. The pull out action caused by the cams of prior mechanisms Was positive and the only yieldable portion of the system was the yarn which had to give. In the mechanism of the present invention, on the other hand, springs 26 and 27 or 50 and 51 are light, and exert very light force. Lever 17, or 46, is also light and freely pivoted. Thus, the forces in the yarn are relatively strong enough to obtain some yielding in the slubber mechanism. The result is that the instantaneous transient stresses in the yarn are not as great even though they are more frequent, and the chance of breaking the yarn strand is appreciably reduced. It has been found possible to reduce the spots between slubs to about 8" or 9 compared with 30" to 5 in the case of prior mechanisms.

It will be apparent that the substitution of a helical coil spring located at the lever guide pivot point, or other variations of spring arrangements in substitution for springs 26 and 27 or 50 and 51, will not violate the spirit of the invention. Also, it would be possible to make the slubber lever itself out of spring material and mount it in a fixed position at its pivot point and eliminate the strain on springs 26 and 27 or 50 and 51.

The present invention thus provides a novel mechanism and a method for forming a variable denier yarn. ideally, the springs 26 and 27 or St) and 51 are always in a state of tension and are never compressed. Thus, the motion of the slubbing lever is controlled entirely by the tension of the springs and the force of the yarn tension on the lever, and approximately harmonic motion is the result. Due to the geometry of the line of motion of the chain pins and the pivot point of the slubbing lever, the latter travels with a harmonic motion when under the influence of the chain pins as well as after it is released when it comes under the influence of the springs, yarn tension and frictional forces. The harmonic motion of the lever under control of the chain pins is obvious, however, only a portion of a complete harmonic cycle of motion, while the springs cause several complete cycles of another harmonic motion.

While certain embodiments of the invention have been disclosed, it is understood that the inventive idea may be carried out in a number of ways. This application is, therefore, not to be limited to the precise details described, but is intended to cover all variations and modifications which fall within the scope of the appended claims.

What I claim and desire to secure by Letters Patent of the United States is:

1. In an apparatus for producing a variable denier yarn, the combination with yarn forming means, of fixed guide means for guiding said yarn from said forming means along one path, means for imparting a harmonic motion to said yarn to form abrupt variations in the denier of said yarn, said imparting means comprising a pivoted lever engaging said yarn between said fixed guide means, means periodically engaging said lever to move the latter and said yarn in a direction normal to said path, and spring means associated with said lever for imparting a multioscillation harmonic motion of decreasing amplitudes to said lever in said direction to provide a plurality of abrupt variations in the denier of said yarn.

2. In an apparatus for producing a variable denier yarn, the combination with yarn forming means, of fixed guide means for guiding said yarn from said forming means along one path, means for imparting a harmonic motion to said yarn to form abrupt variations in the denier of said yarn, said imparting means comprising a pivoted lever engaging said yarn between said fixed guide means, means periodically connected to and engaging said lever to move the latter and said yarn in a direction normal to said path, and flexible means connected to said lever for imparting a harmonic motion to said lever in said direction to provide a plurality of progressively decreasing cycles of yarn oscillations in said direction to provide a plurality of abrupt yarn variations of progressively decreasing size.

3. In an apparatus for producing a variable denier yarn, the combination with yarn forming means, of fixed guide means for guiding said yarn from said forming means along one path, means for imparting a harmonic motion to said yarn to form abrupt variations in the denier of said yarn, said imparting means comprising a movable lever engaging said yarn, an endless moving member, means on said member periodically engaging said lever to move the latter in a direction normal to said path, and spring means connected to said lever to move the latter in said direction in a series of oscillations to impart a plurality of abrupt variations in the denier of said yarn between each actuation of said lever by said lever engaging means.

4. In an apparatus for reducing a variable denier yarn, the combination with yarn forming means, of fixed guide means for guiding said yarn from said forming means along one path, means for imparting a harmonic motion to said yarn to form abrupt variations in the denier of said yarn, said imparting means comprising a movable lever engaging said yarn, an endless moving member, means on said member periodically engaging said lever to move the latter in a direction normal to said path, and spring means connected to said lever to impart a harmonic motion to said lever to provide a series of decreasing cycles of yarn oscillations to form a plurality of abrupt yarn denier variations of decreasing size between each actuation of said lever by said engaging means.

5. In an apparatus for producing a variable denier yarn, the combination with yarn forming means, of fixed guide means for guiding said yarn from said forming means along one path, means for imparting a harmonic motion to said yarn to form abrupt variations in the denier of said yarn, said imparting means comprising a yarn engaging lever, means to pivot said lever adjacent one end thereof, a yarn guide positioned on the other end of said lever, an endless moving member, pins spaced along said member and periodically engaging said lever to rock said lever about said pivot to shift said yarn in a direction normal to said path, and spring means connected to said lever to impart a harmonic movement to said lever in a direction normal to said one path to irnpart cycles of decreasing yarn oscillations to provide a plurality of abrupt yarn denier variations of progressively decreasing sizes.

6. In an apparatus for producing a variable denier yarn, the combination with a pair of spaced fixed yarn guides to direct the yarn along one path, of means positioned between said guides for producing abrupt variations in the denier of said yarn, said means comprising a movable yarn guide, an endless moving member, a pin on said movable member engaging said movable guide to move the latter and said yarn in a direction normal to said path, said pin finally moving out of engagement with said movable guide to free the latter, and spring means connected to said movable guide to impart to the latter a series of oscillations of progressively decreasing amplitude in said direction to form a plurality to form a plurality of abrupt yarn denier variations of gradually decreasing sizes along the yarn.

7. In an apparatus for producing a variable denier yarn, the combination with a pair of spaced fixed yarn guides to direct the yarn along one path, of means positioned between said guides for producing abrupt variations in the denier of said yarn, said means comprising a pivoted yarn guide, an endless moving member, a plurality of pins spaced along said member, the pins being movable progressively into engagement with said pivoted guide to move the latter and the yarn in a direction normal to said path, at the end of each of said last movements the pivoted guide moving out of contact with the pin to free the pivoted guide, and a pair of springs connected in opposed relation to said pivoted guide to impart to the freed pivoted guide a series of oscillations of progressively decreasing magnitude in a direction normal to said path to provide a series of abrupt yarn denier variations of progressively decreasing sizes along the length of said yarn.

8. In an apparatus for producing a variable denier yarn, the combination with a pair of spaced fixed yarn guides to direct the yarn along one path, of means positioned between said guides for producing abrupt variations in the denier of said yarn, said means comprising a pivoted lever, a yarn guide on the free end of said lever engaging said yarn between the fixed guides, an endless moving member, a plurality of pins spaced along said member, each of said pins being movable into engagement with said lever to pivot the latter to move the guide thereon and the yarn in a direction normal to said path, the pin finally moving out of engagement with said lever to free the latter, and a pair of springs connected to opposite sides of said lever to impart to the freed lever a series of oscillations of progressively decreasing magnitude in a direction normal to said path to provide a series of abrupt yarn denier variations of progressively decreasing size along the length of the yarn between successive engagements of the pins with said lever.

9. An improved yarn oscillating apparatus for varying the denier of freshly spun yarn of uniform denier by oscillating the yarn transversely of a normal path along which the yarn runs between a pair of spaced, fixed guides and while the yarn is so running, said apparatus comprising a guide means supported for oscillation across said normal path between two extreme positions of oscillation, resilient means normally biasing said guide to a position between said extreme positions in the vicinity of said path, said resilient means being adapted upon impulse to impart to said guide means an harmonic motion comprising a series of oscillations of decreasing amplitudes across said path, and means for supplying impulses to said resilient means at predetermined intervals of time.

10. An improved yarn oscillating apparatus for varying the denier of yarn by oscillating the yarn while the yarn is running along a normal path between a pair of spaced, fixed guides, said apparatus comprising a guide means adapted to oscillate across said path between extreme positions on opposite sides thereof, said guide means providing a yarn guiding surface which contacts yarn on said path between said fixed guides, intermittent means adapted to repeatedly engage and successively disengage said guide means, said intermittent means being adapted upon engagement thereof with the guide means to move the guide means away from said normal path toward one of the extreme positions, and resilient means normally biasing said guide means to said position between said extreme positions and in the vicinity of said path, said resilient means being adapted to impart to said guide means upon disengagement therefrom of the intermittent means and prior to subsequent engagement thereof a damped harmonic motion comprising a series of oscillations of decreasing amplitudes, said oscillations crossing said path.

References Cited in the file of this patent UNITED STATES PATENTS 771,720 Damon et al. Oct. 4, 1904 2,038,722 Dreyfus et al. Apr. 28, 1936 2,064,279 Taylor et al. Dec. 15, 1936 2,152,222 Taylor et al Mar. 28, 1939 2,293,981 Jackson Aug. 25, 1952 FOREIGN PATENTS 175,829 Germany Aug. 25, 1953 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION January 12, 1960 Patent No. 2,920,345

Richard F. Dyer It is hereby certified that error appears in the -printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 4, for "reducing" read producing line 48, strike out "to form a plurality".

Signed and sealed this 12th day of July 1960.

(SEAL) Attest: KARL H. AXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents

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