U.S. patent number 3,670,486 [Application Number 05/096,402] was granted by the patent office on 1972-06-20 for electrostatic spinning head funnel.
This patent grant is currently assigned to North American Rockwell Corporation. Invention is credited to George L. Murray, Jr..
United States Patent |
3,670,486 |
Murray, Jr. |
June 20, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
ELECTROSTATIC SPINNING HEAD FUNNEL
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.
Inventors: |
Murray, Jr.; George L.
(Milford, MA) |
Assignee: |
North American Rockwell
Corporation (Pittsburgh, PA)
|
Family
ID: |
22257185 |
Appl.
No.: |
05/096,402 |
Filed: |
December 9, 1970 |
Current U.S.
Class: |
57/402;
57/332 |
Current CPC
Class: |
D01H
4/28 (20130101) |
Current International
Class: |
D01H
4/28 (20060101); D01H 4/00 (20060101); D01h
001/12 () |
Field of
Search: |
;57/58.89-58.95,106 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Petrakes; John
Claims
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 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.
Description
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 10 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.
Poull 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 electro tatic 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.
* * * * *