US3670486A

US3670486A - Electrostatic spinning head funnel

Info

Publication number: US3670486A
Application number: US96402A
Authority: US
Inventors: George L Murray Jr
Original assignee: North American Rockwell Corp
Current assignee: Boeing North American Inc
Priority date: 1970-12-09
Filing date: 1970-12-09
Publication date: 1972-06-20
Anticipated expiration: 1989-06-20

Abstract

An open end electrostatic spinning head apparatus for textile fibers having stationary housing with a throughbore therein; a hollow spindle means rotatably mounted in said housing, the spindle means further comprising a fiber-collecting funnel at the upper end of the spindle means whereby a narrow space bounded by the outer wall of said funnel and said housing throughbore is defined, this funnel having a dielectric shank portion attached to the upper end of the spindle means and electrode means mounted within said housing for electrostatically attracting charged fibers to said collecting funnel. A conductive sleeve means is mounted to and covers the outer surface of the shank portion whereby stray charged fibers entering said space reverse their charge and are repelled from said electrode means upon coming in contact with the conductive sleeve means.

Description

[451 June 20, 1972 ABSTRACT 2 Claims, 2 Drawing figures An open end electrostatic spinning head apparatus for textile fibers having stationary housing with a throughbore therein; a hollow spindle means rotatably mounted in said housing, the spindle means further comprising a fiber-collecting funnel at the upper end of the spindle means whereby a narrow space bounded by the outer wall of said funnel and said housing throughbore is defined, this funnel having a dielectric shank portion attached to the upper end of the spindle means and electrode means mounted within said housing for electrostati- 57/106 cally attracting charged fibers to said collecting funnel. A con- Dolh 1/12 ductive sleeve means is mounted to and covers the outer sur- 575889-5895 face of the shank portion whereby stray charged fibers entermg said space reverse their charge and are repelled from said electrode means upon coming in contact with the conductive sleeve means.

POWER SUPPLY FUNNEL [72] Inventor: George L. Murray, Jr., Milford, Mass.

North American Rockwell Corporation, Pittsburgh, Pa.

Dec. 9, 1970 [21] App]. No.: 96,402

References Cited UNITED STATES PATENTS 1/1971 Chabot................................

United States Patent Murray, Jr.

[54] ELECTROSTATIC SPINNING HEAD [73] Assignee:

[22] Filed:

[58] Field of Primary ExaminerJohn Petrakes I Attorney-John R. Bronaugh, Floyd S. Levison, E. Dennis O- Connor and Richard A. Speer POWER SUPPLY ELECTROSTATIC SPINNING HEAD FUNNEL BACKGROUND OF THE INVENTION Field of the Invention This invention relates to an improved spinning head funnel apparatus for the performance of open end electrostatic spinning of textile fibers into yarn. Normally electrically charged fibers are attracted to an oppositely charged rotating funnel throat of a hollow spindle means. However, some fibers do not follow the normal path into the rotating funnel throat but instead stray into a narrow space defined by a narrowing funnel throughbore opening in a stationary housing in the outer wall of the funnel. These stray charged fibers are attracted to the outer wall of the rotating funnel and have a tendency to seep down the spindle bore hole of the spinning head housing and consequently jam the bearings journalling the hollow spindle. These fibers sometimes adhere to the funnel shank causing a buildup of fibers which may: disrupt the spinning process by windmilling; reduce the rotational speed of the funnel by friction; or cause abrasive damage to the plastic housing or funnel. The fibers sometimes become matted and begin to burn due to frictional heat generated by the fibers being trapped between the rotating funnel wall and the spindle bore wall of the stationary housing. Expensive down time is incurred due to the fact that the spinning process must periodically be interrupted in order to clean out such stray fiber accumulations.

It is the principal object of this invention to provide an improved electrostatic spinning head funnel construction which causes stray charged fibers coming in contact with the funnel shank to quickly reverse charge and be repelled from an electrode mounted adjacent the funnel.

It is a further object of the invention to provide a smooth surfaced funnel shank so that stray fibers are not caught by scratches or abrasion marks on the shank. A smooth surfaced funnel shank further aids centrifugal forces of rotation in throwing off stray fibers.

SUMMARY OF THE INVENTION This invention provides an improved electrostatic spinning head funnel having a smooth metal sleeve mounted to and covering the shank of the rotating dielectric funnel. The smooth metal sleeve enables any charged fibers coming in contact with it to quickly reverse charge and be repelled from an electrode mounted adjacent the funnel, thereby maintaining internal rotating parts of the spinning head free of extraneous fiber debris.

BRIEF DESCRIPTION OF THE DRAWING Other features of the invention will become apparent from the following more detailed description and from the accompanying drawing, in which:

FIG. 1 is a sectional view of the funnel and conductive sleeve of the funnel shank;

FIG. 2 is a side elevational view in partial section showing the conductive sleeve in cooperation with a rotating funnel mounted in an electrostatic spindle system.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the Figures, the fiber receives an electrical charge from rolls 12 connected to a source of potential as the fiber exits from the feed system. The fiber is attracted to a spinning head assembly 14 which includes a normally stationary body 16 and

end caps

18 and 20 mounted respectively on the upper and lower ends of the body 16.

A twisting device including a spindle 22 is journalled in the body 16 by axially spaced aligned

anti-friction bearings

24 and 26 fixed within the central throughbore 28 of the body 16. Body 16 has laterally extending side openings 30 to the enlarged central portion 32 of the spindle 22 which is frictionally driven by an endless belt 34 extending through opening 30 and continuously rotated by a drive portion of the spinning apparatus (not shown).

Spindle 22 has an axial throughbore 36, the lower end of which defines a yarn discharge opening 38 from which spun yarn (not shown) is drawn by takeup or

drawing rolls

40 and 42.

The upper end of the spindle is counterbored at 44 to receive a gripper 46 into which fibers (not shown) are directed to be twisted and spun into yarn. Gripper 46 may, of course, be one of the types illustrated in U.S. Pat. No. 3,372,537, issued Mar. 12, 1968 to M. Poul] et al. for "Radially Clamping Grips."

The upper end of the spindle 22 has an extension or funnel 48 defining a conical fiber inlet opening. This extension is made of a dielectric material and is positioned for rotation within a centrally disposed through opening 50 in the cap 18. Extension 48 has an aperture 49 terminating in a cylindrical opening 51 in axial alignment with and substantially equal in diameter to the inlet end of the gripper 46. The yarn tail extends through opening 51 from gripper 46 into the aperture 49 and attracts fibers from rolls 12 which are presented to the yarn tail as it rotates to the maximum field where the tail is maintained.

The annular metallic negative electrode, or cathode 52 of the electrostatic system is fixed within the body 16 of the spinning head 14 in axially aligned surrounding relation to the spindle 22 below the cap 18. Electrode 52 is connected by a lead 54 to a terminal of high voltage electrostatic power supply, the other terminal of which is grounded. The upper external surface of electrode 52 is a segment of a sphere for maximum field focusing strength. A configuration of the electrotatic field is represented by dotted lines 56 as it extends from the upper dielectric surface of the cap 18 to the metallic portions of the rolls 12 which provide a ground for the electrostatic field.

In operation fibers entering the electrostatic field are given a charge by passing over the rotating rollers 12. A few of these charged fibers stray from the normal path of flow into the twisting device 22 located within the spinning head 14. Some of these stray fibers are evacuated from this area through a hole 62 by means of a suction tube 60 which extends into the side of cap 18. Suction tube 60 being connected to an air evacuation device (not shown).

Rotating funnel 48 has a shank portion 64 which engages and fits over the upper end of the spindle 22. A smooth metallic sleeve 66 is mounted on and covers shank portion 64. This conductive sleeve controls fiber buildup because the charged fibers coming .in contact with the sleeve quickly reverse charge and are repelled from the area of the oppositely charged electrode 52. The smooth surface of the metallic sleeve will not catch fibers as readily as the scratched or abraded plastic surface. Finally, although a nep or slub of fibers may find itself trapped in this region for some time before being evacuated, it slides easily on the metal sleeve and does not damage the sleeve by abrasion.

It is to be understood that the above detailed description of the present invention is intended to disclose an embodiment thereof to those skilled in the art, but that the invention is not to be construed as limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of being practiced and carried out in various ways without departing from the spirit of the invention. The language used in the specification relating to the operation and function of the elements of the invention is employed for purposes of description and not of limitation, and it is not intended to limit the scope of the following claims beyond the requirements of the prior art.

What is claimed is:

1. An improved spinning head funnel for use with spinning head apparatus used to perform open end' electrostatic spinning of yarn fibers into thread wherein internal rotating parts are maintained free of extraneous fiber buildup comprising:

a. a stationary housing having a throughbore therein;

b. a hollow spindle means rotatably mounted in said housc. drive means within said housing for rotating said spindle nel; and

g. a conductive sleeve means mounted on and covering only Sald sPlndle means R f a dlelecmc fiber the outer surface of said shank portion of said funnel collecting funnel extension constituting the upper end of whereby stray charged fiber entering said space reverse the spmdle means PY a space 5 their charge and are repelled from said electrode means the outer wall of said funnel and said housing upon coming in Contact with said conductive sleeve throughbore is defined; means e. said funnel having a dielectric shank portion mounted over the upper end of said spindle means;

f. electrode means mounted within said housing for electrostatically attracting charged fibers to said collecting fun- 2. The apparatus as defined in claim 1 wherein said conductive sleeve means is smooth surfaced.

l l i Dedication 3,670,486.Geo1"ge L. Mummy, Jra, Milford, Mass. ELECTROSTATIC SPIN- NING HEAD FUNNEL. Patent dated June 20, 197 2. Dedication filed Mar. 23, 1977 by the assignee, Electwospz'n Oarpomtz'on. Hereby dedicates to the Public the entire term of said patent.

[Ofitcz'al Gazette May 10, 1977.]

Claims

1. An improved spinning head funnel for use with spinning head apparatus used to perform open end electrostatic spinning of yarn fibers into thread wherein internal rotating parts are maintained free of extraneous fiber buildup comprising: a. a stationary housing having a throughbore therein; b. a hollow spindle means rotatably mounted in said housing; c. drive means within said housing for rotating said spindle means; d. said spindle means further comprising a dielectric fiber collecting funnel extension constituting the upper end of the spindle means whereby a narrow space bounded by the outer wall of said funnel and said housing throughbore is defined; e. said funnel having a dielectric shank portion mounted over the upper end of said spindle means; f. electrode means mounted within said housing for electrostatically attracting charged fibers to said collecting funnel; and g. a conductive sleeve means mounted on and covering only the outer surface of said shank portion of said funnel whereby stray charged fibers entering said space reverse their charge and are repelled from said electrode means upon coming in contact with said conductive sleeve means.

2. The apparatus as defined in claim 1 wherein said conductive sleeve means is smooth surfaced.