US3373553A - False-twist apparatus - Google Patents

Description

March 19, 1968 H. o. NAUMANN FALSE-TWIST APPARATUS 2 Sheets-Sheet 2 Filed Jan. 26. 1967 MM y N 5 M F m WN 3,373,553 FALSE-TWIST APPARATUS Herbert Gswald Naumann, Laconia, N.H., assignor to American Iyanamid Company, Stamford, Conn., a corporation of Maine Filed .lan. 26, 1967, Ser. No. 612,021 9 Claims. (Cl. 57-77.3)

AESTRAQT 6F TEE DHSQLGSURE A false twisting apparatus comprising, in combination: a first annular tube having an axial passageway therethrough, a second annular tube concentric with and outside said first tube, mounting means for mounting one of said tubes for rotation about its own axis, guide means secured only at one side thereof to one of said tubes so that an operative portion of said guide means is positioned coaxially with both of said tubes and entirely beyond the end of the tube to which it is secured, and means for permitting axial movement of said tubes relative to each other between a first position wherein said guide is entirely external to the tube to which it is not secured and a second position wherein said guide is entirely within the tube to which it is not secured, and for securing said tubes to each other in said second position during rotation thereof.

This invention relates to apparatus adapted for treating continuous filament thermoplastic yarns to impart a false twist therein and thus obtain a textile yarn having a crimped or textured efiect. More particularly, this invention is directed to an improved false-twist spindle characterized by a novel mechanical design providing for ease of yarn thread-up. The invention also includes an improved thread-up method wherein this spindle is used. This improved design enables the spindle to be threaded up with a median section of the yarn with the aid of a conventional aspirator thereby facilitating the continuous production of a fast linearly moving texturized yarn.

In the customary commercial continuous spinning processes, a polymer is extruded through a spinnerette into a coagulating medium to form endless lengths of continuous synthetic filamentary material. The filamentary material is continuously passed through various processing steps to a final thread collecting device. Apparatus for perforrn ing the various processing steps normally includes a plurality of structures about which the thread must be led sequentiall'; such structures including thread advancing rolls, guides, applicators, etc. Each such unit of apparatus is termed a spinning position and conventionally, in a continuous spinning machine there are hundreds of such positions.

It must be appreciated that during processing on such apparatus, the fiber being spun moves at extremely high lineal forward speeds, frequently as high as 1,000 feet per minute and greater. in melt spinning, speeds in excess of 10,000 feet per minute have been reported. It is important to realize that once extrusion has commenced, that is, once the polymer emerges from the face of the spinnerette to form an endless length of filament, these high lineal forward speeds make the handling of the yarn for threadingup the yarn in a position through the various processing steps a most difficult problem.

Because of the yarn speed, manual threading of the position is impossible. The conventional method of handling this moving yarn is by the employment of an air ice aspirator tube, the use of which will be explained in detail later. However, it must be noted that the various process ing structures about which the thread must be led such as rolls, guides and applicators, etc. must be designed so as to permit an aspirator to be used in conjunction therewith.

The forward motion of the leading yarn end cannot be halted or stopped once extrusion has commenced without shutting down the entire position, which is most undesirable. During the thread-up operation if one wishes to temporarily interrupt this operation part way through the process and delay the subsequent thread-up of the position, the yarn must usually be collected as waste until such time as an operator can complete the operation by leading the thread through the remaining processing steps.

The principle upon which false-twist tubes have operated is to cause the running filaments to acquire the rotational motion of the tube by providing for contact with means atfixed to the rotating tube whereby each revolution of the tube imparts one revolution of the filaments. Thus, the filaments may be caused to engage about a pin or a guide mounted Within the tube to apply the twist.

A disadvantage with existing spindles is their lack of adaptability for use in a continuous spinning operation. Existing spindles are not designed for use in cooperation with an air aspirator because the spindles can only be threaded up by inserting the end of yarn through the rotor tube. As previously explained, the use of an aspirator in a continuous filament process is almost mandatory to achieve thread-up through the various processing steps from extrusion to Wind-up. Since existing spindles cannot be utilized with an aspirator in a convenient manner, it becomes necessary to manually thread-up the spindle. Thus, if crimping or texturizing of the yarn. is desired, it can only be accomplished in a two-step process. The yarn is produced up to the texturizing step in the process, by temporarily winding it onto a bobbin or pirn and then subsequently manually threading the stored yarn through a false-twist spindle for the texturizing or crimping step and rewinding the yarn. Even here, the yarn can only be threaded through the spindle tediously by the use of known thread-up wires and hooks. It is necessary to proceed in this fashion as a free end of the yarn has always been utilized.

This latter procedure is a time consuming operation requiring considerable skill of the operator.

With the spindle design of the present invention, the foregoing difiiculties are overcome. Basically, the improved spindle comprises a rotatably mounted tube hav ing a support extending beyond one end and yarn contact means having one side afiixed to and carried by the support with the other side of the contact means remaining free to permit application of yarn thereto, whereby the rotational motion of the spindle is transferred to the yarn which is wrapped around the contact means to impart twist therein. It is necessary that the contact means be spaced a sufiicient distance from the adjacent end of the tube to permit application of aspirator to the tube for convenient thread-up around the contact means. It can thus be seen that a texturized or crimped continuous filament fiber can be produced as part of the spinning process by employing the instant spindle since its novel design lends itself to use in conjunction with an aspirator. A supplementary cover tube in which the spindle can slide is provided to enclose the rotating yarn contact means during use for improved operating safety.

Accordingly, an object of the present invention is to s. provide a false-twist spindle having an improved threadup means, thus facilitating the continuous production of a fast linearly moving texturized yarn.

Another object of this invention is to integrate a fibermaking operation and subsequent texturizing operation into one continuous system.

A further object of this invention is to provide an improved apparatus for texturizing continuous filament thermoplastic yarn.

Still another object of this invention is to provide a false-twist spindle which, when used in a continuous fiber process, results in increased manufacturing capacity.

A still further object of this invention is to provide a false-twist spindle of reduced hazard to operating personnel and has no projecting parts which could entrap fly during operation. Various other objects and advantages of this invention, together with details of specific embodiments of the invention will appear from the following detailed description when read in conjunction with the accompanying drawings set forth for purposes of illustration in which:

FIG. 1 is a cross-section of one embodiment of the false-twist spindle which incorporates the improved threadup means of this invention;

FIG. 2 is an enlarged schematic elevation of a portion of the apparatus of FIG. 1;

FIG. 3 illustrates a conventional air aspirator;

FIG. 4 illustrates a second embodiment of apparatus incorporating the principles of this invention; and

FIG. 5 illustrates a third embodiment of apparatus incorporating the principles of this invention.

Referring now in detail to the drawings, and more particularly to FIG. 1, there is shown in cross-section, a falsetwist spindle made in accordance with the concepts of this invention:

The spindle assembly 11 is composed of two concentric annuli; an inner annulus 1t} and an outer annulus 14, typically fabricated from metal tubing and of sufficient difference in diameters to allow the inner annulus 1G to be freely movable within the outer annulus 14. They are driven in a rotary motion by belt 13 which directly drives outer annulus 14. Spindle assembly 11 is supported by a pair of ball bearings 8 and 9 which allow free rotation of the spindle. Pin 15 which is fixed to the inner annulus 1t and slips into the transverse oblong grooves 16, 16 of the inverted T-shapcd longitudinal slots 17, 17' in outer annulus 14, transmits the rotary motion of outer annulus 14 to inner annulus it As rotation commences, slippage of the annuli past each other allows pin 15 to slide in a direction opposite to the direction of rotation, to the ex treme edge of the transverse grooves 16, 16' of slots 17, 17 thus locking the annuli in position. When spindle assembly 11 is stationary, pin 15 can be lifted vertically in slots 17, 17 thus telescoping upwards that portion of the inner annulus 1b which is supported upon it. Yarn guide 13, is adhesively bonded to pin 19 which is affixed to its support extending beyond the upper portion of inner annulus 10. Yarn guide is is a conventional guide readily available commercially and is preferably fabricated from a ceramic base material. It need not be shaped as shown in FIG. 1, which is indicated merely for purposes of illustration only. Yarn guide 18 serves as a contact means to transfer the rotational motion of the spindle to the yarn to impart twist therein. Inner annulus 10 has a section cut out and removed along part of its circumference to facilitate threading of yarn guide 18 when it is in a raised position 3.

With the instant invention, using a conventional aspirator as an aid, a continuously moving high speed yarn can be threaded through the spindle quite conveniently because of the novel design.

An aspirator suitable for use is illustrated in FIG. 3. The aspirator 34 comprises a short length of cylindrical tubing provided with suitable means such as a nozzle 32 for introducing air at high velocity thereto. This air is aspirated at high velocity to the outlet 33 of the aspirator tube 34 thereby producing a suction at the inlet end F91 of the aspirator tube 34. An operator holding the device 34, catches the yarn 35 at the mouth 31 which is flared to minimize the chance of obstructing the entrance of the initial end of the yarn. The catching of the yarn. is made possible by the vacuum that exists at the entrance iil of the aspirator tube 34. The yarn is continually sucked in at the entrance 31, held taut therein; exits the device at 33 and ultimately goes to a storage container. Typically, the aspirator is fabricated from /2" tubing and is small enough in overall dimensions that it is freely movable to accomplish the necessary functions of threading up. It can, of course, be larger in size depending on the denier of yarn produced. The pressurized air is supplied to the nozzle 32 by means of flexible rubber hose so as to allow free movement of the aspirator 34. It is important that the velocity of the air at exit 33 be sufficiently greater than the velocity of the yarn so the yarn is effectively pulled through the tube.

The thread-up is accomplished in the following manner. With the spindle stationary, pin 15 can be slid vertically upward in slots 17, 17' of the outer annulus 14, thus rais ing both the inner annulus 10 and yarn guide 18 to the position 3 in FIG. 1. it is important that yarn guide 18 be raised a sufficient distance above flared lip 22, to posi tion 3 so as to allow an aspirator 34 to be used for wrapping yarn 24 around guide 18. This is accompiished by making slots 17, 17 of suiiicient length so that the re quired distance may be achieved.

A portion of the running yarn is placed under the base 12 of the spindle 11. it is carried up through the inner annulus 10 of spindle 11 by a how of air created by the aspirator 34 which has been placed near the flared lip of spindle 11 thereby catching the end of the running yarn in the aspirator. NVith the aspirator 34- now sucking and pulling on the yarn, a median section of the yarn is wrapped or looped securely and quickly around yarn guide 18. This thread-up operation is facilitated by the fact that inner annulus it is fabricated with a cut out section 23 which makes yarn guide 18 accessible for threading when the inner annulus 10 is raised in slot 17 to position 3. It is important to note that the yarn guide 13 is affixed on but one side to the support atop inner annulus lit, the other end being free so as to permit application of a median section of yarn to it by means of the air aspirator. It is this unique feature which makes the subject spindle so valuable when used in a continuous fiber spinning operation. Contact means other than a yarn guide 18 may be substituted such as a pin or a rod. The only functional limitation being that it securely hold the yarn during rotation and be free on one end.

The subject ffise-twist apparatus 11 can also operate by feeding the yarn 24 from the top 22 of the spindle 11. This is accomplished by reversing the procedure outlined above and placing the aspirator 34 at the bottom 12 of the spindle 11.

The yarn, with the aid of the aspirator 34 is then forwarded to the next set of processing rolls, the inner annulus 10 is retracted into the outer annulus 14, and the rotary motion of the spindle 11 is resumed thereby inserting twist into the moving yarn.

Referring to FIG. 4, a second embodiment of the apparatus is shown incorporating the principles of this invention. In contrast to the embodiment of FIG. 1, wherein the outer annulus 14 is fixed and the inner annulus 10 and yarn guide 18 telescope upwards, the instant embodiment is constructed so that the outer tube 52 is adapted for slideable displacement into and out of juxtaposition with fixed yarn guide 56 which is fastened to the rotatably mounted inner tube 55.

Spindle assembly 58 is composed of an inner annulus 55 and outer concentric annulus 52 which may be called a floating sleeve. It is driven in a rotary motion by belt 46 which directly drives inner annulus 55. Spindle assembly 58 is supported by a pair of ball bearings 54 and 47 which allow free rotation of the spindle. Pin 59 which is fixed to the inner annulus 55 serves both as a sliding guide for outer sleeve 52 as it is raised or lowered for threadup in the longitudinal slot 57 located therein and also to transmit the rotary motion of inner annulus 55 to the outer floating sleeve 52. Prior to commencement of rotation, the sleeve 52 and inner tube 55 are slipped past each other, allowing pin 59 to slide in a direction opposite to the direction of rotation, to the extreme edge of the transverse oblong groove 51 of the inverted T-shaped slot 57, thus locking the outer sleeve 52 in position and preventing it from falling during operation of the spindle 58. Yarn guide 56 is fixed to a yarn guide support extending from and attached to inner tube 55. Yarn guide 56 must extend a sufficient distance above the top of inner tube so that it is possible to use an aspirator 34. It is important to note that the yarn guide 55 is afiixed at one side to support So of inner tube 55, the other side being free so as to permit application of a median section of yarn thereto when the floating sleeve 52 is lowered for thread-up.

Referring to FIG. 5, a third embodiment of the apparatus is shown incorporating the principles of this invention. A main differing characteristic over that of the other embodiments lies in that the thread guide 63 is located on the slideably movable outer tube 66 in contrast to being located on the inner tubes as in the other embodiments. Spindle 66 is driven in a rotary motion by belt which directly drives inner tube 61 supported by a pair of ball bearings 69 and 79. Pin 67 which is fixed to the inner annulus 61 serves to transmit the rotary motion to the outer tube 66 thereby rotating yarn guide 63. Yarn guide 63 is fixed'to yarn guide support 68 which is merely an extension of outer tube wall 6%. Thread-up of the spindle 66 is accomplished by raising yarn guide 63 in slot 62 a sufiicient distance out of and above inner tube 61 (as shown in FIG. 5) so that an aspirator may be employed to wrap a median section of the yarn about the yarn guide 63. Again it is important to note that the yarn guide 63 is afiixed on but one side, the other end being free.

Production of a texturized yarn is desirable in some instances in order to produce woven fabrics having an elastic or resilient nature. In other instances the primary reason is to obtain a fabric of increased bulkiness or coverability. In most cases it is desirable to achieve a combination of both the characteristics of elasticity and bulkiness. It will be appreciated that use of this false twist tube enables a texturizing operation to be carried out in a continuous fashion. The texturizing process employing this apparatus generally is one in which the yarn first passes through a heating area before reaching the false twister wherein a false or temporary twist is imparted to the yarn which twist runs, i.e., extends back, from the twister into the heating area and then the twist is removed as the yarn passes through the twister. The heat is thus applied to the filaments when they are in a highly twisted condition and they are then cooled to set this twist so that when the equal and opposite twist occurs after the filaments leave the twist tube, texturizing results.

I claim:

1. In a yarn twisting and texturizing apparatus, a spindle comprising in combination a first tube having a yarn guide support extending beyond one end thereof, a yarn guide having one side affixed to and carried by said support and the other side open to permit application of yarn thereto, said yarn guide being spaced from the adjacent end of the tube and a second tube movably engaged with said first tube and adapted to extend longitudinally therefrom around said yarn guide during rotation of the spindle but slideably displaceable to expose said yarn guide when threading up.

2. In a yarn twisting apparatus, in combination, a first spindle tube having a yarn guide support extending beyond one end thereof, a yarn guide having one side afiixed to and carried by said support and the other side open to permit application of yarn thereto, said yarn guide being spaced beyond the end of said first spindle tube, a second tube movably engaged with said first tube and adapted for slideable displacement into and out of juxtaposition with said yarn guide, and means including an aspirator for drawing a length of thread through said tubes and wrapping said thread around said yarn guide.

3. A false-twist spindle for twisting and texturizing moving yarn comprising in combination two rotatably mounted concentric annular tubes, 21 yarn guide affixed on one of its sides to the inner of said annular tubes, the other side being open, means for telescoping said inner tube and said yarn guide relative to the outer of said annular tubes between a first position wherein there is a suflicient distance to permit application of an aspirator to said outer tube for convenient thread-up around the open end of said yarn guide and a second position wherein said yarn guide is disposed within said outer annular tube, and means for locking said annular tubes together to achieve concurrent rotation of the tubes.

4. A false-twist spindle as defined in claim 3 wherein the means for telescoping said inner tube and said yarn guide relative to the outer of said annular tubes comprises two longitudinal slots located degrees apart in said outer tube and a locking pin passing through said inner tube and slideable in said longitudinal slots.

5. A false-twist spindle as defined in claim 4 wherein said longitudinal slots of said outer tube have oblong transverse grooves at the bottom of said slots whereby slippage between the annuli at the inception of rotation of the spindle locks the pin into the said grooves in the bottom of said slot.

6. A false-twist spindle for twisting and texturizing moving yarn comprising in combination two rotatably mounted concentric annular tubes, a yarn guide atfixed on one side to the outer of said annular tubes, the other side being open, means for extending said outer tube and said yarn guide relative to the inner of said annular tubes a sufficient distance to permit application of an aspirator to said inner tube for convenient thread-up around the open end of said yarn guide, and for retracting said outer tube and said yarn guide into said inner annular tube and means for locking said annular tubes together to achieve concurrent rotation thereof.

7. A method for threading-up a twist apparatus in a continuous fiber process which comprises applying an aspirator to an open upper end of a hollow stationary rotatable spindle and thereby drawing a strand of yarn through said spindle and its end into said aspirator, winding an inter-mediate portion of said yarn about a thread guide alfixed to said spindle and having one side free, and then rotating said spindle to impart a twist to the yarn.

8. A false twisting apparatus comprising, in combination:

(a) a first annular tube having an axial passageway therethrough;

(b) a second annular tube concentric with and outside said first tube;

(c) mounting means for mounting one of said tubes for rotation about its own axis;

((1) guide means secured only at one side thereof to one of said tubes so that an operative portion of said guide means is positioned coaxially with both of said tubes and entirely beyond the end of the tube to which it is secured; and

(e) means for permitting axial movement of said tubes relative to each other between a first position wherein said guide is entirely external to the tube to which it is not secured and a second position wherein said guide is entirely within the tube to which it is not secured, and for securing said tubes to each other in said second position during rotation thereof.

9. Apparatus as defined in claim 8 wherein said guide means is secured to said first annular tube and said second annular tube is mounted for rotation in said mounting means.

References Cited UNITED STATES PATENTS 5% Klein 57-773 Comer 57-77.3 XR Meyer 24247.03 XR Genovese 24218 XR Mertens 5777.3 Steele 57--77.45 XR Ashby et al 57-34.5 XR

FRANK J. COHEN, Primary Examiner.

D. WATKINS, Assistant Examiner.

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