US3103305A

US3103305A - Slotted textile core

Info

Publication number: US3103305A
Application number: US148599A
Authority: US
Inventors: Heatherly James Murray
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1961-10-30
Filing date: 1961-10-30
Publication date: 1963-09-10
Anticipated expiration: 1980-09-10

Description

Sept. 10, 1963 J. M. HEATHERLY SLOTTED TEXTILE CORE Filed Oct. 30, 1961 FIG, '1

FIGB

JAM! WWW/227M ATTORNEY a corporation of Delaware Filed Oct. 30, 1961, Ser. No. 148,599 1 Claim. (Cl. 225-6) This invention relates tov an improvement in cores or bobbins on which yarn, threads, filaments, and the like may be wound and unwound. More particularly, it relates to an improved construction of such cores by means of which the yarn may be readily and securely engaged by the core and the loose end Severed by core action to commence the winding operation at very high speeds.

Textile yarns are customarily wound on cores to form yarn packages suitable for shipping or storage. continuous operation the yarn is cut or broken as one package is completed, and the moving yarn is usually then transferred to a waste device or sucker gun while the completed package is removed and replaced by an empty core. The yarn, still maintained in motion by the action of the sucker gun, is then strung up by being brought into contact with the rotating empty core. If the friction between yarn and rotating core is sufliciently high, or if attachment of the yarn to the core is brought about in some other suitable manner, winding is initiated with simultaneous breaking of the yarn between the core and the sucker gun.

Various means have been tested for producing highfniction core surfaces or mechanical aids to yarn pickup, such as a groove in the surface of the core. It is also commonly known that yarn pickup is greatly aided by wetting the surface of the core. However, as yarn pickup speeds have been increased, the efficiency of yarn pickup on conventional cores available hitherto has decreased 7 markedly; and with the advent of higher speeds it has been found that wetting the core surface no longer aids yarn pickup, apparently owing to the liquid droplets being evaporated or thrown ofi by centrifugal force. The

has thus led to increased high incidence of false starts highstring-up time as well as excessive yarn waste at the or windup speeds using previously known cores.

It is an object of the present invention to provide an improved core for winding textile yarns.

Another object is to provide a core having improved means for catching and holding a textile yarn to be wound thereon and for severing the yarn end as winding commences.

A further object is to provide a core of simple construction and low cost, yet having a very high yarn pickup efiiciency, at very high windup speeds.

Additional objects will be apparent from the following specification and claim.

According to the present invention, it has been found that the above objects are achieved by a textile core having a circumferentially disposed groove of uniform depth on the surface of the core near one end of the core, the sides of the groove being curved convexly inwardly toward each other to substantially meet at the bottom of the groove forming a V-shaped cross section; said groove comprising a wide portion and a narrow portion, a given groove width in the narrow portion being closer to the surface of the core than the same groove Width in the wide portion, with an abrupt transition between the wide and narrow portions. It is also preferred that the core is a cylindrical body having the groove on its curved face near the end of the cylinder and substantially parallel to the end. The groove is so disposed with respect to the intended direction of core rotation that the wide portion of the groove is the lead-in portion during rotation of the Ina ihifid Patented Sept. 10, 1963 ice core. The groove cross section is uniquely adapted for permitting the yarn tofind its proper position for sliding through the wide, orlead-in portion; while the abmpt transition between the two portions furnishes a nip, or pinch point, within which the yarn is caught, held, and severed as it rises to a higher level in the narrow portion of the groove.

The term core, as used herein, refers to a supporting means for forming a yarn package comprising an elongated rotatable body having an axis of rotation and a curved outer surface, the transverse cross sections of the periphery of the core taken perpendicular to the axis being circular. The outer surface of the cone therefore usually has the form of a cylinder, cone, frustu-m of a cone, etc, including combinations thereof. Examples include tubes, bobbins, spools, pirns, cones, and other textile yarn carriers. The core is normally hollow to permit its placement-on a chuck or other means for rotating the yarn package as it is being for-med, although the core may be solid with suitable provision made for its rotation.

The invention'willbe more fully understood by reference to the accompanying drawings, in which:

FIGURE 1- is an elevational view of a textile core constructed in accordance with the invention, having a yarn package wound on it;

FIGURE 2 is a cross-sectional view of a portion of the core of FIGURE L'taken through line 11 of FIGURE 1 and enlarged, showing the groove in cross section in the region of the nip; and

FIGURE 3 is a transverse cross-sectional view of the i core of FIGURE 1, taken through the bottom of the groove at line 33, showing the position of a moving incoming threadlineafter positioning in the groove and just prior to being engaged by the narrow portion of the groove.

Turning now to the figures, core 2 is a hollow cylindrical body having a groove 3 cut in its outer surface near one end 4 of the cylinder and parallel to the end. The groove consists of a wide lead-in portion 5 and a narrower trailing portion 6 intersecting relatively abruptly to form nip 7. FIGURE 1 illustrates the normal appearance of the core wound with yam 8 with the initially wound segment of yarn 9 beginning at nip 7, proceeding up narrow portion 6 of the groove for some distance, and

then running over the side of the groove helically around the core to form the lowermost layer of the yarn package.

As illustrated in FIGURE 2, both the lead-in and trailing portions of the groove cross section are cut substantially in a V shape, with the sides of the groove being curved convexly inwardly toward each other. This groove configuration permits the yarn to find its proper maximum position for sliding through the wide, lead-in portion of the groove while acting with maximum efliciency to catch, hold, and sever the yarn as it is pulled into the nip while rising to a higher level in the narrow portion of the groove.

" The 'width of the groove is exaggerated in FIGURE 1 and further enlarged in FIGURE 2. The groove is preferablyplaced approximately half Way between the end 4- of the core and the outside limit ll of yarn traverse in forming the package.

The core may be fabricated from any suitable material. For example, it may be constructed from paper or paperboard sheets spirally wound on a suitable mandrel, using an adhesive to bond the wound paper plies. The core may also be molded or otherwise fabricated from plastic,

' fibers blended with resin, or other suitable material.

his usually preferred that the groove be cut in the surface of the core in a plane perpendicular to the axis of the core; however, this. is not essential and the plane in which the groove is cut may be at an angle to the axis. The groove may run all the way around the surface of the core, although usually the groove is much shorter. Typically, the lead-in section of the groove runs through an arc of about 45 and the trailing section of the groove runs through an arc of about 90, for a total groove length of about =135".

An outstanding advantage of the novel core of the invention is that, during the operation of the windup equipment with which the core is associated, the groove is situated near the end of the core, outside the limit of normal traversing of the yarn. Previously employed grooved cores have generally been constructed with the groove located at the center of the core. With the groove in this position, it is frequently found that many yards of the yarn initially wrapped on the core are defective, and uneven tensions are observed in the-yarn during take-oil from the package.

Use of the novel core is readily understood. The core is placed on a chuck or other rotatable means, being positioned such that the lead-in portion of the rotating groove in the core leads and the trailing portion of the groove follows. The yarn to be wound on the core is usually picked up in a moving condition imparted in. a previous processing step such as spinning or drawing, or if not is suitably set into motion. Preferably, a sucker gun such as the sucker Igun disclosed by Miller in his US. Patent 2,667,964 is employed to maintain the yarn 32 in motion at the desired fixed speed as indicated at moment of engagement in FIGURE 3.

The moving yarn is first placed into position to be en-v gaged by the yarn traverse means. As soon as the traverse means has begun to traverse the moving yarn, the yarn is placed in contact with the rotating slotted core at a wrap angle in the range of approximately 90 to 180, with the direction of the yarn motion opposite to the direction of motion of the surface of the core. Since the yarn is not yet aflixed to the core, the traverse loop is wider than during normal package building, and the yarn quickly slips into the lead-in portion of the groove. Upon slipping into the groove, the yarn slides toward the narrow portion of the groove; and as the yarn is pulled upward into the narrow portion of the groove it is caught in the nip and broken on the narrow side (the sucker gun side), with the end of the incoming yarn held firmly in the nip. As the end of the yarn held by the core is rotated, the length of yarn extending back to the traverse guide is relatively free throughout a portion of the ensuing revolution of the core, until the yarn coming from the traverse guide is again held tangent to the core and winding commences under normal tension. Usually, a short segment of the yarn is laid down in the narrow portion of the groove before the yarn is pulled over the side of the groove to be traversed across the core to form the initial layer of the yarn on the core as shown in FIGURE 1. The incoming yarn end is held in the nip with sufiicient tenacity to accomplish this result.

The following example will illustrate the invention in actual-practice, although it should not be considered as limiting the scope of the invention.

Example A spirally wound lkraft paper textile tube having a double skived outer ply is grooved as shown in the figures. The tube is 5.500 inches in length, its inside diameter or bore diameter is 3.687 inches, and the diameter of the wall is 0.312 inch. v.A single groove approximately 2.5 inches long is cut in the surface of tube parallel to the end of the tube and 0.4 inch 'from the end, using a circular knife. The depth of the out is 0.125 inch. The circular knife has a diameter of 4 inches and the width of the blade at this penetration is inch. A second cut is then made in the surface of the tube, continuing the original 4 groove for an additional 4 inches still parallel to the end of the tube and 0.4 inch from the end. The depth of the cut is again 0.125 inch; however, the width of the second blade is only 6 inch at this penetration.

A series of tubes constructed as described above is evaluated for string-up efficiency. (String-up efficiency is defined as the percentage of successful string-up attempts versus tot-a1 attempts, unsuccessful attempts being those in which the yarn breaks without package build-up being initiated or attempts in which package build-up cannot be initiated at all for some reason.) The tubes are mounted to be surface driven by drive rolls, with a separate barrel cam actuated traverse system. The yarn employed is 70 denier, 14 filament polyethylene terephthalate yarn containing 0.1% TiO and having a tenacity of 4.0 grams per denier. The tubes are driven at a peripheral speed of 2,200 yards per minute, and the yarn is strung up with a sucker gun in the manner previously described, with a wrap angle of about 135". The string-up efiiciency is over 90%.

When a series of grooved tubes prepared as described above, except that the second cut is omitted and the tinished tubes accordingly contain only a single groove with no abrupt change to form a nip, are evaluated in the same manner described above, the string-up efiiciency is lms than 70%.

In compliance with the patent statutes preferred forms of embodiment of the invention have been illustrated and described, but it is to be understood that modifications could be made therein without departing from the spirit of the invention or the scope of the following claim.

I claim:

An improved textile core consisting solely of an elongated cylindrical body member adapted to be rotated in a given direction, said member consisting solely of a first portion intermediate its ends for supporting a yarn package and a second portion spaced from said first portion and adjacent one end of said member for engaging, gripping an incoming moving yarn line for windup on said first portion and severing the loose end from said yarn line to be wound on said core, said first and second portions having a constant transverse cross section taken perpendicularly to the axis of the body member, said second portion of said member provided with a groove of uniform depth extending in a circumferential direction and lying in a plane substantially perpendicular to the axis of said body member, said groove consisting of a first leading grooved portion having sides of the groove convexly curved inwardly toward each other to meet and form the bottom of the groove, and a second trailing grooved portion also having sides of the groove convexly curved inwardly toward each other to meet and form the bottom of the groove, any given groove width in the first leading grooved portion being fiurther from the surface of the core than the same groove width in the second trailing grooved portion, there being an abrupt transition in dimensions between the said leading and said trailing portions to form an abrupt projecting shoulder structure in the groove so that an incoming yarn line is engaged, firmly gripped, in order to commence windup of the incoming yarn line and sever the excess end portion of the incoming yarn line from the portion of the yarn line wound on the core.

References Cited in the file of this patent UNITED STATES PATENTS 594,989 Finn Dec. 7, 1897 2,977,033 Jones Mar. 28, 1961 FOREIGN PATENTS 20,461 Great Britain Dec. 16, 1890