US2800780A

US2800780A - Yarn control means and method

Info

Publication number: US2800780A
Application number: US476657A
Authority: US
Inventors: John L Chivington
Original assignee: Patentex Inc
Current assignee: Patentex Inc
Priority date: 1954-12-21
Filing date: 1954-12-21
Publication date: 1957-07-30
Anticipated expiration: 1974-07-30

Description

y 1957 J. L. CHIVINGTON YARN CONTROL MEANS AND METHOD Filed Dec. 2'1, 1954 HGiZL ATTORNEYS.

a v H w Zfidjidh Patented July 30, 1957 YARN CONTROL MEANS AND METHQD John L. Chivington, Signal Mountain, Tenn, assignor, by mesne assignments, to Patentex, Inn, New York, N. Y., a corporation of New York Application December 21, 1954, Serial No. 476,657

6 Claims. (Cl. 66-126) This invention relates to yarn control means and methods. More specifically, it is concerned with a means for controlling hard twisted yarns which, when unrestrained, have the tendency to snarl incident to being delivered to the yarn manipulating instrumentalifies of textile machines especially knitting machines used in the production of articles such as so called stretch stockings and the like. This snarling characteristic is especially true of hard-twisted synthetic yarns of the thermoplastic polymer types such as nylon, Orlon and the like.

The chief aim of my invention is to provide a simple and inexpensive means and method which can be relied upon to maintain hard twisted yarns of the kind referred to taut, without imposition of undue tension, against snarling enroute, for example, to the needles of stocking knitting machines, notwithstanding dwells occasioned during the periods of reversal in the traverse of the yarn carriers.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein:

Fig. 1 is a fragmentary view, in transverse section of a straight knitting machine of the cotton type with a yarn control means conveniently embodying my invention.

Fig. 2 is a fragmentary view of a portion of the organization shown in Fig. 1 drawn to a larger scale.

Fig. 3 is a detail view in top plan looking as indicated by the angled arrows III-III in Fig. 2.

Figs. 4 and 5 are diagrammatic views showing the theory under which the yarn is controlled in accordance with my invention.

The knitting machine, herein illustrated in part for the purpose of exemplifying my invention, is of the well known cotton type, such as is commonly used in the production of flat fashioned stocking blanks, having a bar 1 with a complement of needles 2, cooperative sinkers 3, a linearly traversing yarn carrier 4, a humidifying box 5, for the stationarily-supported supply package P of the yarn Y to be knitted, a yarn moistening device 6 (which I use dry and only for the purpose of a guide), a yarn directing system including

guide eyes

7, 8, 9, 10 and 11 of which the guide 7 is fixed in the top of the box 5, a weighted take up ring 12, and an intermittentlyactuated snapper 13 for checking the yarn during the intervals of reversal in the traverse of the carrier.

The control means which I have devised to prevent snarling of the yarn enroute to the carrier 4 from the supply package P over which the guide 7 in the top of the humidifying box 5 is centered at a substantial elevation, includes a disk 15 which is fixedly supported in concentric relation to the package atop the core C of the latter somewhat above the top shoulder of the substantially cylindrically wound supply of the yarn on said core. As the yarn Y is drawn endwise from the package P through the guide 7, it is caused to gyrate about the disk 15 while in frictional contact with the edge of the disk. In actual practice, the disk 15 is formed preferably from a dielectric plastic material commercially known as Lucite or Plexiglas on which, through rubbing edge contact of the yarn therewith, a static charge is set up tending to attract and hold the yarn thereto. As a consequence of the angular diversion of the yarn Y about the edge of the disk 15 as it passes from the package P to the guide eye 7 as shown in Figs. 1 and 2 and attraction thereof under the influence of the static charge, it is effectively restrained against snarling even during the dwell periods of the carrier 4 at the ends of the traverse of the latter in opposite directions. It is to be particularly noted that the edge of the disk 15 is rounded, the curvature of the rounding being predetermined to provide a definite area for contact by the yarn, this curvature being varied to provide lesser or greater contact area for yarns having corresponding lesser or greater degrees of twist, or for yarns of the same degree of twist but of different deniers. V v

Although, by preference, I employ a disk of dielectric material, a disk of metal or other conductive material may be used with interposition of insulation between it and the core of the yarn supply package.

The yarn control of my invention is believed to be operable under the following theory:

The yarn and the disk being of diflferent materials and composed of electrons and protons, each of them is characterized by what may be designated as an electron pressure. When the yarn is drawn across the edge of disk, a potential, i. e., a contact potential, is established across the boundary, the flow of electrons across the boundary tending to neutralize such contact potential. Since the yarn and the disk are dielectrics or the latter is of metal or other conductive material with a support of insulation, separation after contact results in the two having equal electrostatic charges of opposite sign. When the yarn of nylon or the like is drawn across the edge of the dielectric disk or an insulated metal disk,

the contact potential causes transfer ofelectrons across the boundary, and a charge is built up on the disk and an equal charge of opposite sign is distributed along the yarn. If the disk is of a material higher in the elec trostatic series than the material of the yarn, the initial transfer ofthe charge will result in a condition such as shown in Fig. 4. However, as soon as the charge is built up on the disk, a phenomenon known as dielectric polarization occurs. In the present instance, the mole cules of the yarn are polarized so. that the potential due to the doublets in the yarn tends to neutralize the contact potential and thereby reduce further transfer of electrons between the yarn and the disk. Accordingly, the charge on the disk continues to accumulate or build up until the polarization potential approaches the same magnitude as the contact potential. If the disk loses some of its charge by reason of conduction through the moist atmosphere or its support, the polarization potential is reduced proportionally, and the contact potential immediately produces a flow of electrons across the boundary and establishes a balance between the polarization potential, the conductive IR drop, and the contact potential. Hence, a condition of equilibrium is maintained wherein the potential of the disk may be considerably below the contact potential due to the conductive losses as diagrammatically shown in Fig. 5. Since opposite charges attract, the charge on the disk will attract the opposite charge on the yarn, and the latter be held against the edge of the disk by a force represented by F :kQE where F is the force (in dynes) normal to the surface, where k is the dielectric'constant of the air, and where E is the electrostatic field due to polarization of the yarn. It therefore follows that, as the yarn is drawn across the edge of the disk a frictional drag f results. This drag is represented by f=uF where u is the coefficient 1. The coefiicient of friction, which is determined by the nature of the materials of the yarn and the disk and the smoothness of the disk surface.

2. The contact potential between the yarn and the disk, which is determined by the nature of the materials.

3. The conductive losses, which are primarily determined by' the humidity of the atmosphere.

While, forthe purposes of exemplification herein, I have shown my invention, in a form suitable for use in connection with a knitting machine to produce blanks for'stockings of thestretch type, it is to be understood that my inventionis not to be considered as limited to such application since, by suitable modifications within the scope of the appended claims, it is equally applicable to circular knitting machines as well as to other kinds of textile machines as will be readily understood.

Having thus described my invention, I claim:

1. Means for controlling hard twisted yarn of nylon or the likeenroute, from a substantially cylindric stationarily-supported supply package, to the yarn manipulating instrumentalities of a knitting machine or other textile machines for the formation of stretch fabrics, said means comprising a guide centered relative to the package at a substantial distance therebeyond; an element of di-electric materialhavingcircular edge of larger diameter than that of the yarn Winding on the package,

, fixedly supported in axial relation to the package somewhat beyond the winding atthe top, about which the yarn is gyrated while in frictional running contact with the circular edge of the element and held thereto under static influence.

2. Yarn control means according to claim 1, wherein the edge of the element is rounded at a curvature to predtermine a definite area for contact by the yarn.

3. Means for controlling. hard twisted yarn of nylon or the like enroute under tension to the yarn manipulating instrumentalities of a knitting machine or other textile machine for the production of stretch fabrics from a substantially-cylindric vertically-positioned stationarily-supported supply package, said means comprising a guide centered over the package at a substantial distance thereabove; and an element of di-electric material having a circular edge of larger diameter than that of the winding on the package, fixedly supported in concentric relation to the package on the end of the core of the latter somewhat above the winding, about which element the 4 yarn is gyrated while in frictional contact with the edge of the element and held thereto under static influence.

4. Yarn control means according to claim 3, wherein the edge of the element is rounded at a curvature to predetermine a definite area for contact by the yarn.

5. A method of producing articles such as stockings of the stretch type from hard twisted synthetic monofilament yarn of nylon or the like in a knitting machine having a complement of needles, a feed for feeding yarn to the needles, and guides for directing the yarn enroute from a substantially cylindrical supply package to the feed, said method comprising the step of causing gyration of the yarn about a fixedly-supported element of di-electric material having a circular edge, stationarily disposed coaxially in an interval between the supply package and one of the guides coaxially aligned therewith, so that the yarn is restrained against snarling through frictional engagement with the edge of said element and held thereto under static influence.

6. A method of producing articles such as fashioned blanks for stockings of the stretch variety from hard twisted monofilament yarn of nylon or the like in a straight knitting machine of the cotton type having a needle bar and cooperative sinkers, a traversing yarn carrier intermittently-actuated snapper means for checking the yarn during the reversal periods of the carrier, and a system of guides for directing yarn enroute from a stationarily supported substantially. cylindrical supply package to the carrier, said method including the step of causing the yarn to gyrate about a fixedly-positioned element of di-electric material having. a circular edge, disposed coaxially in an interval between the supply package and one of the guides axially aligned therewith so that the yarn is restrained against snarling through frictional contact with the edge of said element and held thereto under static influence.

References Cited in the file of this patent UNITED' STATES PATENTS 1,209,179 Lipps Dec. 19, 1916 2,099,178 Snyder Nov. 16, 1937 2,514,582 Johnson July 11, 1950 2,693,096 Quinn Nov. 2, 1954 OTHER REFERENCES Nylon Technical Service, E. I. du Pont de Nemours and Co., Inc., Wilmington 98, Del.; page 2-18.02.

Hosiery and Underwear Review, Dec. 1950, published by Knit Goods Publishing Corp., New York 1, N; Y., page 124.