US3690584A

US3690584A - Apparatus for maintaining uniform yarn tension during unwinding of a yarn package

Info

Publication number: US3690584A
Application number: US137419A
Authority: US
Inventors: Philip E Wilkerson
Original assignee: Individual
Current assignee: Nycoil Co
Priority date: 1971-04-26
Filing date: 1971-04-26
Publication date: 1972-09-12
Anticipated expiration: 1989-09-12

Abstract

A cone shaped, spherical or otherwise tapered support member seated on the upper end of an upstanding pin engages and supports a textile yarn package or pirn internally at a point above its center of gravity so that the weight of the package causes it to automatically assume a vertical position. A yarn guide eye is positioned directly above and spaced from the support member, whereby the axis of the textile package is self-aligning with the guide eye. Corrugations in the yarn holder surface spiral around the holder at an angle substantially perpendicular to the path of the yarn as it is unwound therefrom.

Description

United States Patent Wilkerson I [54] APPARATUS FOR MAINTAINING UNIFORM YARN TENSION DURING UNWINDING OF A YARN PACKAGE [72] Inventor: Philip E. Wilkerson, Rt. 2, Box 216,

Randleman, NC. 27317 [22] Filed: 4Apri126, 1971 21 App1.No.: 137,419

[52] US. Cl. ..242/128, 66/135, 242/1183,

[51] Int. Cl. ..B65h 49/00 [58] Field of Search ..242/128, l29.5129.8, 242/140, 156, 157 R, 157 C, 171,

[ 51 Sept. 12, 1972 Forca ..66/125 Primary Examiner-Leonard D. Christian Attorney-Hunt, Heard & Rhodes [5 7] ABSTRACT A cone shaped, spherical or otherwise tapered support member seated on the upper end of an upstanding pin engages and supports a textile yarn package or pirn internally at a point above its center of gravity so that the weight of the package causes it to automatically assume a vertical position. A yarn guide eye is positioned directly above and spaced from the support member, whereby the axis of the textile package is self-aligning with the guide eye. Corrugations in the yarn holdersurface spiral around the holder at an angle substantially perpendicular to the path of the yarn as it is unwound therefrom.

13 Claims, 10 Drawing Figures PATENTEDSEP 12 I972 SHEET 1 BF 2 INVENTOR PHILIP E. WILKERSON FIG. 2

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ATTORNEY PATENTEDSEP 12 I912 7 3.690.584

SHEEI 2 OF 2 INVENTOR PHILIP E. WILKERSON FIG. 3 BY M M & M.

ATTORNEY APPARATUS FOR MAINTAINING UNIFORM YARN TENSION DURING UNWINDING OF A YARN PACKAGE BACKGROUND OF THE INVENTION According to one type of yarn delivery method in the textile industry, yarn is supplied to a textile machine or other apparatus as desired by unwinding from the end of a yarn holder such as a bobbin, cone or pirn. From the holder, hereinafter referred to as a pirn, the yarn proceeds through a guide eye positioned in axial alignment above the pirn and then on to the desired destination. Misalignment between the pirn and guide eye causes an uneven drag on the yarn during unwinding and results in unsatisfactory yarn tension variations, and it, has been proven a practical impossibility to economically obtain and maintain axial alignment of support member, pim and guide eye.

Another source of tension variation occurs when sufficient yarn has been unwound from the pirn to expose the surface thereof. Light yarns, particularly yarns too light to balloon outwardly as they are unwound, are attracted to the surface, thereby causing additional drag with a resultant increase in yarn tension. This form of tension, although not existing when the pim is full, usually reaches a maximum during unwinding of the last yarn layer in contact with the pirns surface. At the moment of transfer from the tail end of the spent pim to the starting end of an adjacent full pim to maintain continuous feeding of the yarn, the tension is at its greatest, often interfering with a successful transfer.

Textile knitting represents one field in which tension variation is of particular concern, primarily because it is considered to have a direct affect on quality of the knitted article. As yarn is fed into the knitting machine, tension variation causes excessive strain thereon, leading to cut-outs or breaks. Reduced tension causes kinks and leads also to fabric defects and waste. The problem is particularly acute in knitting operations wherein textured yarns are used to make sheer articles such as stretch stockings.

Attempts to lessen the tension variation caused by misalignment of the pirn and guide eye have, in the past, concentrated upon development of a support means that engages the inner surface of the pim .to rigidly hold the pirn in proper vertical position, axially aligned withthe guide eye. A typicalembodiment, as illustrated by U.S. Pat. No. 2,592,318 to Muecke, includes an upstanding pin rigidly secured to a yarn support plate and extending vertically and centrally into the pirn. Secured near the bottom of the pin is a holding disc, sometimes having athreaded or othergripping type periphery, for engagement with the innersurface of the pirnto rigidly hold itin alignment. The success of this approach depends, however, upon obtaining and maintaining proper alignment of the support means with the guide eye and proper positioning of the pirn thereon, both being conditions that .are diffrcultto obtain and to maintain.

Misalignment between the pirn support and guide eye is caused frequently by vibrations associated with the textile machinery. Although this situation can be remedied, to a degree at least, by careful initial alignment of the parts and the use of secure fastening means, vibration still works against prolonged proper alignment. Most often, however, misalignment of the pirn results from its improper initial positioning on the pim support. As pirns become empty, full pirns are substituted therefore by operators who generally have a bank of machines to tend. By tying the tail end from the yarn on the pirn positioned for delivery to the machine to the starting end of an adjacent pirn, the operator is freed from being at the machine at the moment of yarn depletion on the delivery pirn, and continuous feeding to the machine is maintained. The operator must, however, remove the empty pim and transfer the adjacent pirn to the delivery position, relying upon visual judgement to determine when the pim isin proper vertical position and alignment. As aresult, small deviations exist, hardly noticeable to the eye, but sufficient to cause unsatisfactory tension variations in the yarn as it is pulled from the pirn.

SUMMARY OF THE INVENTION The present invention provides an improved means for lessening tension and automatically minimizing tension variation in strand materials such as textile yarn during over-end feeding operations without the necessity of a time consuming alignment process by the operator. The essence of the invention resides in an apparatus havingmeans associated therewith for supporting a pirn, which is understood to include any tubular strand material holder, at a point above its center of gravity in a manner permitting it to self-gravitate relative to its longitudinal axis, thereby automatically balancing and aligning itself in a true vertical attitude. Vibrations, disruptive to prior art support methods, induce gravitation of a pim supported according to the present invention and, thereby, enhance its obtaining and maintaining proper positioning. Furthermore, the automatic positioning features comprehend by this invention correct the initial misalignments resulting from hasty replacement of empty pirns and avoid the reliance upon sight-judgement in determining proper positioning and alignment.

An additional feature in the practice of this invention is a guide eye which may be adjusted for positioning directly and vertically above the pim support means. Accordingly, a .pirn positioned on the .pirn support means will gravitate and self-align its longitudinal axis in a vertical attitude directly beneath the yarn guide eye. Pigtails and yarn guides familiar to those skilled in the art are suitablefor use as a guide eye; however, a yarn guide eye, supported by a bracket that will enable universal positioning of the guide in one plane is preferable.

The invention is further considered to include corrugations in the surface of the pirn arranged in a spiral path substantiallyperpendicular to the path of the yarn as the yarn is unwound from the pirn. Replacing the pirns smooth surface with corrugations substantially eliminates or at least minimizes theproblem heretofore experienced as unwindingprogresses to the surface of the pirn. Corrugations in the pirns surface reduced the contact area, and accordingly, the drag on the yarn as it is unwound from a partially empty pim is more nearly the same as when the yarn is unwound from a substantially full pirn.

In a preferred embodiment of the invention each of a plurality of yarn supply stations associated with a textile machine, such as a knitting machine, includes a stationary upstanding pin. A support means at the upper end of the pin loosely suspends the yarn holder at a point above its center of gravity and provides the sole point of contact between the pin and the yarn holder during the unwinding operation. In a preferred embodi ment, the pirn is supported at a point above its'center of gravity by the engagement of a tapered surface on the support member with a conventional centering member positioned within the pirn, near its upper end. Supported in this manner, the pim self-gravitates or self-adjusts to a true vertical attitude. A yarn guide eye attached to a lateral, adjustable arm member, associated also with the textile machine, is positioned directly and vertically above the support member, thereby ensuring proper alignment between the guide eye and a pim floatably supported by the support member. Corrugations spiraling around the pirns outer surface in a direction substantially perpendicular to the path of the unwinding yarn reduce frictional drag and tension variations during the latter stages of the unwinding.

Although the invention is described in connection with an primarily designed for use in the textile field, it is not limited thereto, but is applicable to any instance where it is necessary to maintain an even tension take off in an over-end unwinding operation.

DESCRIPTION OF THE DRAWING The foregoing and other features and advantages of v the upper end of tubular rod 43, the rounded bottom ing the present invention as practiced in the textile the present invention; and

FIG. 10 is a side elevation similar to FIG. 3, partially in section, except illustrating the self-aligning feature of apparatus embodying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The embodiment of the invention as herein illustrated, is directed to the textile knitting field. Fields other than textile knitting, utilizing over-end delivery of strand material through a guide eye to a subsequent processing station are equally suitable for practice of the invention and are regarded within its scope.

Referring now to FIG. 1, a yarn package or pim 30 is mounted in a vertical attitude at a yarn supply station 40. A yarn guide 20 is attached to stationary arm 29 at a point directly aligned with and above pim 30, and includes a guide eye 21 through which a yarn strand passes on its way to a knitting machine 50. A second yarn guide 20' having a second guide eye therein guides the yarn into proper relationship with the knitting elements. Such a setup is conventional, and the present invention' is directed to the means for maintaining a proper relationship between pim 30 and guide eye 21.

In carrying out and maintaining such relationship, and with reference to FIGS. 2 and 3, yarn supply station 40, including a base or platform 41 having an upright pin 42 attached thereto, is supported by a bracket 46 associated with the knitting apparatus 50.

Pin 42 is adapted to receive a pim 30 .over the upper end thereof, and remains out of contact with the walls of the pirn during the unwinding operation. A tubular extension or rod 43 is mounted onto pin 42 and securely fastened thereto by a suitable fastening means 44 comprising Allen set screws, which engage pin 42 through holes suitably drilled and tapped in the extension member 43. The use of an extension member 43 according to the foregoing description may be eliminated, of course, if the pin 42 is replaced by a tubular member having a suitable length dimension.

A support means at the upper end of rod 43 loosely suspends the pim 30 at a point above the center of gravity of the yarn holder, and provides the'sole contact between the rod 43 and pim 30 during the operation thereof, so that the yarn holder will self-align itself to a true vertical attitude. In this regard, a first element, hereafter referred to as support member 10, which preferably comprises a cone shaped upper portion 12 and a rounded bottom portion 11, is loosely seated in portion 11 forming a ball-and-socket type connection with the opening in the upper end of rod 43. A relatively flexible length of wire or chain 13 depends from the rounded bottom 11 of support member 10 into the tubular member 43 prevents loss or displacement of the support member 10 should it be accidentally bumped or disengaged from its seat atop rod 43, anoccurrence likely experienced during removal of an empty pim 30 from the yarn supply station. A length of bead chain secured by any suitable means to the support members bottom portion 11 is perfectly suitable, however, other materials, such as length of light, bendable wire, is also satisfactory.

A lubricating agent may be added to the ball-andsocket type connection toenhance relative movement of the adjoining parts. Suitable machining and finishing thereof, however, will eliminate this requirement.

A textile strand material holder 30, which can be a bobbin, cone, pim or any other tubular strand material holder, is mounted on support member 10 in a manner to be hereinafter discussed. The strand material comprises a textile yarn 60, a length of which has been wound onto the pim 30 to form a package 61. Yarn 60 is unwound from the pim 30 and delivered to the knitting machine 50 after passing through yarn guide

eyes

21, 21

Pim 30 includes a tubular body 31 with an annular plug 32 inserted in its upper end and a similar plug 33 in its lower end. Located internally within the pim 30, and above the center of gravity of the wound package 61, is a second element, hereafter referred to as a centering means or collar 34 (FIG. 3) which engages and cooperates with support member 10 as hereinbelow described.

Centering collar 34, such as that illustrated in FIG. 3, comprises an annular disc secured to the inner wall of tubular member 31 and having a central opening therein for receiving support member 10. The collar 34 is a conventionalelement of most tubular yarn holders and performs its primary function during winding-on operations, for example spinning, by engaging a driving spindle whereby the yarn holder is positively driven. (See, for example, U. S. Letters Pat. to Schmidt, No. 3,368,767). In the present invention, however, the centering member is used to carry out a different function. It floatably supports or suspends the pirn by engagement with the conical shaped upper portion 12 of support member 10. As a result, support of pim 30 is at a point above the pirns center of gravity, which allows the pim to reposition itself automatically to a true vertical attitude. Other than engagement between the tapered surface 12 of the support member and the centering member 34, the pirn 30 remains out of contact with any part of the apparatus.

Although the preceding paragraph describes the use of a yarn holder having a centering means concentrically therein, the invention relates to floatably supporting the yarn holder above its center of gravity to attain a true vertical attitude. Therefore, different means of accomplishing this result will be obvious to those skilled in the art, including the adaption of a support means to yarn holders not having a centering member.

A guide'means such as yarn guide eye 21 is positioned directly above the yarn supply station 40 in vertical alignment with the longitudinal axis of pim 30 and such positioning is important to the operation of the invention. Normally the guide means consists of a wire pigtail or a guide eye formed of any suitable material such as plastic or ceramic and held by a metal bracket 26 which is in turn adjustably secured to a support such as the lateral arm member 29 associated with the knitting apparatus 50. The guide means of this invention, however, comprises a C-shaped bracket 27 (FIGS. 8 and 9) fabricated from a. strip of relatively rigid metal. The bracket includes a top portion 22 provided with a longitudinal mounting slot 25 therein, a bottom portion 23 including the guide eye 21 and a side portion 24, integrally connecting the top and bottom portions and holding them in spaced apart parallel relation. Although not a critical dimension, the top portion 22 has a length approximately twice the length of the bottom portion 23.

The bracket 27 is adjustably mounted to the lateral arm member 29 by any suitable means. A screw 26 inserted through the mounting slot 25 and threadably eng'aged with the arm member 29 is sufficient (FIG. 9). Only one screw 26 is used, however, to allow pivotal adjustments of the yarn guide 20. Initially the yarn guide 20 is mounted in position above the yarn supply station 40 with the yarn guide eye 21 in approximate alignment with the support member 10. For exact alignment therebetween, the yarn guide 20 may be adjusted longitudinally by means of the mounting slot 25 and pivotally around the screws axis until the yarn guide eye 21 is in the desired position. Any suitable aligning means such as a carpenters plumb bob is used to avoid reliance upon visual alignment. When proper alignment is attained, the screw is tightened to securely lock the yarn guide 20 in position.

An additional feature of the present invention relates to a corrugated surface 60, substantially covering the outer periphery of the pim 30 (FIG. 2). The angle and the direction in which the grooves and ridges, forming the corrugations 60, spiral around the pirns surface relative to its axis are important. If the angle is too steep, that is if the corrugations are substantially parallel to the pirns longitudinal axis, the yarn will not ride across the corrugations as it is pulled over the pirns upper portion, causing tension on the yarn and the abrasion thereto. On the other hand, if the corrugations spiral around the pim in a substantially transverse direction, the yarn will follow the corrugations as it is wound onto the pim, causing similar tension and related problems as the yarn is unwound. For a yarn pirn having an outer diameter of about 5-6 inches, the corrugations will have a proper angle if they complete onehalf to one spirals around the pim for each 12 inches of length. The direction in which the corrugations spiral must be such that they are substantially perpendicular to the yarn path as it is unwound from the pim. Therefore, if the yarn is pulled from around the pirn from right to left, or clockwise, the corrugations must spiral from left to right, or counterclockwise (see FIG. 2). The situation would be reversed, of course, if the yarn is pulled from the pirn from left to right. The corrugations 60 merge into a smooth area 62 at the top of the pirn to provide a smooth edge therearound across which the yarn is pulled. At the bottom, the corrugations extend all the way to the pirns edge 33 and provide openings to channel off excess yarn oil or lubricant that tends to accumulate on the surface of some pirns. Surface contact between the pim 30 and the yarn 60 as the yarn is unwound is thereby reduced, because the corrugations reduce the surface area available for contact therewith. Therefore, the static attraction therebetween is reduced, causing a resulting reduction in yarn tension variation.

Operation of the invention can now-be summarized in view of the foregoing description. The extension rod 43', extending upwardly from platform 41 (FIG. 10), is illustrated as deviating from true vertical. Ordinarily this deviation would be undesirable because it would cause the pim 30 to deviate from truev vertical, as well as being misaligned with guide eye 21, resulting in objectionable yarn tension variation. The support means of the present invention overcomes this problem by means of the self-adjusting support engagement between support member 10 and collar 34, which causes the pim 30 to automatically assume a true vertical attitude. Guide eye 21 is adjustable in a horizontal plate to permit easy alignment with the axis of the pim. The self-adjusting pim aligned with guide eye 21 insures a uniform tension on the yarn as it is removed over the end of pim 30. Additionally, as the yarn 60 is unwound (FIG. 2), exposing more and more of the pirns surface, corrugations 60 reduce the attraction normally existing between the pirns surface and the yarn and aid in providing uniform tension.

The modified versions of the support member 10, illustrated in FIGS. 4-7, differ from the preferred embodiment in that the ball-and-socket connection has been replaced with a simpler and less expensive connection means. Referring to FIGS. 4 and 6, the support members A and 110B illustrated therein comprise a tapered support surface 120A and 1203 respectively, each having an integrally depending shank portion 111. The embodiment illustrated in FIG. 4 has a conical shaped head portion 120A, while the'one illustrated in FIG. 6 has a spherical shaped head portion 120B. Support members modified in this manner have been used on knitting machines without a noticeable increase in defects resulting from yarn .tension variation when compared to applications of the preferred embodiment. The depending shank portion 111 of modified support member 110A or 1108 is inserted axially into the tubular extension member 43" and a yarn guide eye 21 is axially aligned above the vertex thereof in the manner hereinbefore described. Since the support surface is stationary, it insures alignment at all times.

The embodiments illustrated in FIGS. and 7, support members 110C and 110D respectively, differ from the two discussed in the preceding paragraph by having tapered upper support surfaces 120C and 120D with the unde'meath side being drilled and tapped to threadably engage the upper end of extension member 143, which in this instances is suitably threaded at the upper end thereof. Other than this difference, the mode of operation using the embodiments represented in FIGS. 5 and 7 remains the same.

Although the invention has been described by reference to specific embodiments, it is to be recognizedthat other variations may exist within the scope of the invention, which is defined in the following claims.

What is claimed is:

1. In an over-end delivery system wherein at a yarn supply station a textile yarn is pulled axially from a tubular yarn holder for delivery to a subsequent processing station, apparatus for reducing I tension variation in said strand material when delivered to said processing station, said apparatus comprising:

an upstanding pin having the lower end attached to said base and adapted to receive said tubular yarn holder over the upper end thereof;

support means at the upper end of said pin for loosely suspending said yarn holder at a point above the center of gravity of said yarn holder, said support means further providing the sole point of contact between the pin and the yarn holder during the operation thereof, whereby the yarn holder will self-align itself to a true vertical attitude; and

a yarn guide eye positioned at a point directly above and spaced from said support means, whereby the axis of said yarn holder passes through said yarn guide eye.

2. The apparatus according to claim 1, wherein said support means includes a first element attached to the upper end of said pin and a second element cooperating with the first element and secured within said yarn holder, one of said first and second elements comprising a tapered surface diverging from an apex, the other of said first and second elements engaging said tapered surface to support said yarn holder in self aligning relation to a true vertical attitude. A

3. The apparatus according to claim 2, wherein one of said first and second elements is conical and the other of said first and second elements is disc-shaped 8 v with a central opening for receiving the vertex of said cone therein.

4. The apparatus according to claim 2, wherein one of said first and second elements is spherical and the other of said first and second elements is disc-shaped with a central opening for receiving said spherical element therein and having a diameter less than said spherical element.

5. The apparatus according to claim 1, wherein said yarn guide eye is attached to a bracket, and wherein said bracket includes means thereon for universally adjusting said guide eye in a horizontal plane.

6. The apparatus according to claim 1, wherein the surface of said yarn holder includes a plurality of parallel grooves therein, said grooves arranged in a spiral pattern diagonally around the longitudinal axis of the yarn holder at an angle substantially perpendicular to the path of the yarn during unwinding.

7. The apparatus according to claim 6, wherein said parallel grooves merge into a smooth portion at the upper end of said yarn holder to avoid interference with the unwinding operation.

8. The apparatus according to claim 7, wherein said parallel grooves terminate coextensive with the lower edge of said yarn holder to channel off excessive yarn oil and lubricant.

-9. A yarn holder for use in an over-end delivery system wherein a textile yarn is pulled axially from a non-rotating package for delivery to a subsequent processing station, said yarn holder comprising atubular member, the surface of said tubular member including a plurality of parallel grooves therein throughout the major portion of the length of said tubular member, said grooves arranged in a spiral pattern diagonally around the longitudinal axis of the tubular member at an angle substantially perpendicular to the path of the yarn during unwinding, therebyreducing the drag on the yarn during the latter stages of the operation as the yarn holder is unwound.

10. The yarn holder according to claim 9, wherein the surface of said tubular member includes at the upper end thereof a smooth portion, free of grooves, to avoid interference with the unwinding operation.

11. The yarn carrier according to claim 10, wherein said parallel grooves terminate coextensive with the lower edge of said tubular member to channel off excessive yarn oil and lubricant remaining on the surface of the yarn holder.

12. A yarn guide for use in an over-end delivery system wherein a textile yarn is pulled axially from a non-rotating yarn holder, through said yarn guide, for delivery to a subsequent processing station, said yarn guide comprising a bracket, a guide eye attached to said bracket, and adjusting means on said bracket for pivotally and slidably attaching said bracket to a support member, whereby said guide eye is universally adjustable in a horizontal plane above said yarn holder.

13. The yarn guide according to claim 12, wherein said adjustable means comprises a longitudinal mounting slot in said bracket, a single screw passing through said mounting slot and into the support member, whereby said bracket is pivotally and slidably attached to the support member.

Claims

1. In an over-end delivery system wherein at a yarn supply station a textile yarn is pulled axially from a tubular yarn holder for delivery to a subsequent processing station, apparatus for reducing tension variation in said strand material when delivered to said processing station, said apparatus comprising: a base; an upstanding pin having the lower end attached to said base and adapted to receive said tubular yarn holder over the upper end thereof; support means at the upper end of said pin for loosely suspending said yarn holder at a point above the center of gravity of said yarn holder, said support means further providing the sole point of contact between the pin and the yarn holder during the operation thereof, whereby the yarn holder will self-align itself to a true vertical attitude; and a yarn guide eye positioned at a point directly above and spaced from said support means, whereby the axis of said yarn holder passes through said yarn guide eye.

2. THe apparatus according to claim 1, wherein said support means includes a first element attached to the upper end of said pin and a second element cooperating with the first element and secured within said yarn holder, one of said first and second elements comprising a tapered surface diverging from an apex, the other of said first and second elements engaging said tapered surface to support said yarn holder in self aligning relation to a true vertical attitude.

3. The apparatus according to claim 2, wherein one of said first and second elements is conical and the other of said first and second elements is disc-shaped with a central opening for receiving the vertex of said cone therein.

9. A yarn holder for use in an over-end delivery system wherein a textile yarn is pulled axially from a non-rotating package for delivery to a subsequent processing station, said yarn holder comprising a tubular member, the surface of said tubular member including a plurality of parallel grooves therein throughout the major portion of the length of said tubular member, said grooves arranged in a spiral pattern diagonally around the longitudinal axis of the tubular member at an angle substantially perpendicular to the path of the yarn during unwinding, thereby reducing the drag on the yarn during the latter stages of the operation as the yarn holder is unwound.