US3270937A

US3270937A - Guide elements

Info

Publication number: US3270937A
Application number: US414158A
Authority: US
Inventors: Harrell William Albright
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1964-11-27
Filing date: 1964-11-27
Publication date: 1966-09-06
Anticipated expiration: 1983-09-06

Description

United States Patent Office Patented Sept. 6, l66

3,270,937 GUIDE ELEMENTS William Albright Harrell, Grifton, N.C., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed Nov. 27, 1964, Ser. No. 414,158 2 Claims. (Cl. 226-197) This invention relates generally to textile apparatus and to a method for converging strands of continuous filaments into a tow or rope suitable for crimping and, more particularly, to textile apparatus for stacking individual ribbons of fibers to form a tow.

Synthetic fibers are spun in units of several thousand filaments and several of these units or bundles (ribbons) are then combined to form a tow or rope of several hundred thousand denier which is then crimped. The crimped tow can then be spun into yarn by one of the conventional direct spinning methods by means of the Turbo Stapler or the Pacific Converter or it may be cut into staple fiber which is then carded and spun on either the cotton or woolen spinning systems. In either case it is necessary for the fiber to be crimped; and, if uniform yarns are to be spun, the tow must be uniformly crimped.

The stacking of individual ribbons into a tow is one of the most critical operations in the production of uniformly crimped tows. Thick areas in the tow will result in fiber damage because of the excessive squeeze roll pressure in the crimper and slippage of the crimper rolls. Thin areas in the tow will result in uncrimped or poorly crimped filaments. Poor crimping also results from variations in the tow width. Split tows will cause uneven crimping and also make subsequent operations more difficult.

Accordingly, an object of this invention is to provide means and a method for the uniform stacking of the individual bundles or ribbons of fibers into a tow. Other objects will appear hereinafter.

The objects of this invention are accomplished by providing in an apparatus for continuously receiving a plurality of separate moving ribbons of filaments which comprises means vertically aligning each moving ribbon in a spaced relationship and means converging to form a tow having the moving ribbons uniformly stacked and a width equal to that of a single ribbon, the improvement wherein the converging means comprises a base plate having a plurality of cantilevered guide elements mounted thereon, the guide elements each having a portion having an ovalshaped guide surface with a radius of curvature in the range of from about inch to about 3 inches, the guide elements being positioned on the base plate in such a manner that each guide element guides a single ribbon to a common convergence point, the ribbons contacting the guide elements on the oval-shaped surface.

The embodiments of this invention and their advantages can be more readily understood by referring to the accompanying drawings:

FIGURE 1 is a side elevation view showing an apparatus utilizing one embodiment of this invention and illustrating five ribbons being converged by means of five guide elements,

FIGURE 2 is a side elevation view of the embodiment of the invention shown in FIGURE 1,

FIGURE 3 is a front elevation view of one of the guide elements illustrated in FIGURE 2,

FIGURE 4 is a side elevation view of the guide elements shown in FIGURE 3, and

FIGURE 5 is a sectional view taken generally along line 5-5 of FIGURE 2.

The general arrangement utilizing the preferred embodiment of this invention is best shown in FIGURE 1.

A supporting frame structure 20 extends vertically upward from a supporting base member 22 and 24. Adjustably mounted between the extremities of the supporting frame structure 20 are a plurality of vertically extending supporting beams 26. The supporting beams 26 may be made of suitable angle brackets the ends of which are slidably secured by suitable means such as threaded nuts 28 and bolts 30 in slots in the upper and lower horizontal elements of frame structure 20. These angle brackets 26 may be adjusted in the horizontal direction, and preferably each functions to individually support one of a plurality of first rotatable means or first stage guide units 32.

A plurality of second means which comprise a second stage guiding and arranging assembly 34 are mounted in operative association with the supporting frame structure 20, the first stage guide units 32, and the plurality of moving spaced, relatively narrow filament bundles or ribbons generally designated by the numeral 36. The second stage assembly 34 may either be mounted in an extended portion (not shown) of the frame 20, or it may be aifixed to other suitable structure.

Each of the first stage guide units 32 generally comprises a supporting bracket, a beam member, a roll supporting and canting means, and a rotatable roll as shown in US. Patent No. 3,145,429. The supporting bracket is adapted for vertical positioning movement within the frame 20 by means of its slidable locking engagement in an extended slot provided in the vertically extending angle bracket 26. Angle brackets 26 may be rotatably mounted at each end by suitable conventional means, not shown, for rotary movement about a vertical axis, swinging beam member in a horizontal plane. This arrangement permits alignment of the axis of the rotatable roll perpendicular to ribbon 36. The beam member is mounted in supporting bracket 28 by suitable bolts or screws.

As best shown in FIGURE 2, the second stage guiding and arranging assembly 34 represents the preferred embodiment of this invention and comprises a base plate 2 mounted upon rod 4 (supported by means not shown) and adjusting set screws 6 securing rod 4 in position as .desired. Corresponding in number to the number of ribbons 36, which are forwarded from a drawing operation not shown, guide elements 8 are rotatably mounted on base plate 2 and secured by set screws 10.

FIGURES 3 and 4 show in detail guide elements 8. Each guide element consists of a shaft portion 12, which is mounted in base plate 2, and an oval-shaped portion 14 integral therewith.

FIGURE 5 illustrates the plurality of ribbons 36 after they have been stacked in an aligned vertical relationship.

The operation should be readily apparent. As disclosed in US. Patent No. 3,145,429, the roller convergence guides are so arranged that each concave roller can be tilted to guide the various ribbons from lateral adjacent positions as they come from a textile processing step such as a drawing operation to an alignment in a vertical plane as each ribbon approaches its respective guide element. The oval-shaped surface of the guide element provides a relatively large area in contact with the ribbons which change direction only slightly. The greater area of contact (as compared to a circular guide) provides the desired amount of friction on the ribbon to maintain sufficient tension as the ribbons are firmly stacked in a vertical aligned relationship. After contacting the guide elements, the ribbons converge to stack in a vertically aligned relationship.

Table I below illustrates the improvement in tow quality resulting from use of the guide elements of this invention in comparison with a single pound bar. The tow was composed of a 3 denier per filament (.33 Tex.) polyethylene terephthalate fiber. The tow quality index (TQI) is a measure of tow defects per unit of tow produced. Both major and minor defects were counted. Each period represents a three-month operating period during which more than several hundred thousand pounds of fibers were processed.

The face of the oval-shaped extremity must have a radius of curvature in the range of from about /s inch to about 3 inches, preferably about inch or more. Table II, below, illustrates measurements of the guide elements which will be suitable for most purposes.

Table II Measurement, Part: inches Shaft portion- Length 2% Radius /2 Oval-shaped extremity Length 2%; Long radius Short radius Width Depth A If round bars were to be used in place of the guide elements of this invention, diameters twice the radius of curvature of the oval-shaped extremity would have to be used to give the same area of contact. Moreover, the guide elements allow a wide variation in contact area since they can be rotated to any desired position.

The guide elements can be made of any hard, corrosion-resistant material. For example, stainless steel number 304 with a chromium-plated surface and finished to a matte surface of 75 to 95 micro inches R.M.S. has been found to be satisfactory.

Although the description hereinbefore has illustrated only five guide elements, it should be obvious that the number may be more or less, depending, of course, upon the number of ribbons which are to be used to form the tow. Also, the shape of the base plate, as shown in spect to the positioning of the guide elements relative to each other, any arrangement can be used as long as the ribbons are converged to a common point.

The guide elements can be advantageously utilized to form a large denier tow from several ribbons formed of any synthetic fibers, such as polyamides, polyacrylics, polyolefins and polyamides.

The novel guide elements of this invention have been illustrated in conjunction with the roller convergence guides disclosed in US. Patent N 0. 3,145,429. However, the invention should not be so restricted; and it should be obvious that the novel guide elements can be used with any suitable means which can provide a plurality of ribbons in a spaced, aligned vertical plane as the ribbons approach the guide elements.

This invention has provided novel means to accomplish the stacking of a plurality of ribbons in a vertical aligned relationship to form a tow of uniform width and thickness. This has resulted in a reduction in tow defects, as shown in Table I, of about 56 percent and is an important step in producing good quality fibers and fabrics.

Since many different embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not to be limited except to the extent defined in the following claims.

What is claimed is:

1. In an apparatus for continuously receiving a plurality of separate moving ribbons of filaments which comprises means vertically aligning each moving ribbon in a spaced relationship and means converging said ribbons to form a tow having said ribbons uniformly stacked and a width equal to that of a single ribbon, the improvement wherein said converging means comprises a base platev having a plurality of cantilevered guide elements mounted thereon, said guide elements each having a portion having an oval-shaped guide surface with a radius of curvature in the range of from about /s inch to about 3 inches, said guide elements being positioned on said base plate in such a manner that each guide element guides a single ribbon to a common convergence point, said ribbons contacting said guide elements on the oval-shaped surface.

2. The apparatus of claim 1 wherein said radius of curvature is greater than inch.

References Cited by the Examiner UNITED STATES PATENTS 3,145,429 8/1964 Resor 281 M. HENSON WOOD, JR., Primary Examiner.

I. N. ERLICH, Assistant Examiner.

Claims

1. IN AN APPARATUS FOR CONTINUOUSLY RECEIVING A PLURALITY OF SEPARATE MOVING RIBBONS OF FILAMENTS WHICH COMPRISES MEANS VERTICALLY ALIGNING EACH MOVING RIBBON IN A SPACED RELATIONSHIP AND MEANS CONVERGING SAID RIBBONS TO FORM A TOW HAVING SAID RIBBONS UNIFORMLY STACKED AND A WIDTH EQUAL TO THAT OF A SINGLE RIBBON, THE IMPROVEMENT WHEREIN SAID CONVERGING MEANS COMPRISES A BASE PLATE HAVING A PLURALITY OF CANTILEVERED GUIDE ELEMENTS MOUNTED THEREON, SAID GUIDE ELEMENTS EACH HAVING A PORTION HAVING AN OVAL-SHAPED GUIDE SURFACE WITH A RADIUS OF CURVATURE IN THE RANGE OF FROM ABOUT 5/8 INCH TO ABOUT 3 INCHES, SAID GUIDE ELEMENTS BEING POSITIONED ON SAID BASE PLATE IN SUCH A MANNER THAT EACH GUIDE ELEMENT GUIDES A SINGLE RIBBON TO A COMMON CONVERGENCE POINT, SAID RIBBONS CONTACTING SAID GUIDE ELEMENTS ON THE OVAL-SHAPED SURFACE.