Note: Descriptions are shown in the official language in which they were submitted.
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~his invention relates to apparatus ~-.
for spinning textile fibers comprising a rotary :
drum, which constitutes a first twisting member,
and an also movable second twisting member, which `~
is associated with said drum and defines with the `~
latter a triangular-seceion space3 at least one
of said twisting members having a suction zone `~
ad~oining said space and the fibers being intro-
duced in a flying state into said space and being j
twisted therein about a yarn core, which extends .i
through said space in the longitudinal direction
of the drum to a pair of withdrawing rollers.
Austrian Patent Specification 333,631
discloses apparatus which comprises two closely spaced
apart suction drums, which are perforated and rotate in ~^
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the same sense and have mutallg confronting suction
ziones, which adjoin said triangular-section space be~
tween said drums. In that apparatus, the flying fibers
which are supplied from a disintegrating unit are twi-
sted together in the triangular-section space and are
then withdrawn as a yarn by means of a pair of wi~h-
drawing rollers disposed at one end of the drum and
are held against rotation at the same time. Such spin-
ning apparatus affords the advantage of involving a
relatively low structural expenditure and enabling a
spinning and a withdrawal of yarn at relatively high
speed. This is due to the fact that the twisting speed
and the yarn~withdrawing speed do not depend on ele~
ments of construction which rotate at high speed and
the yarn being formed is merely rolled in contact with
the two suction drums.
In order to produce yarns having a higher ~;
tenacity and thus to enable an operation at still a ~~
higher withdrawing speed and production rate, it has
also been proposed to improve the above-described
spinning apparatus in that a yarn core is withdrawn
through the triangular-section space from that end of
the drums which is opposite with the withdrawing means
~Austrian Published Application A 2586/76).
The yarn core which is used ConsiStS~ as
a rule, of an endless filament or of a previously ex-
isting yarn. Whereas the use of such yarn core increa~
ses the tenacity of the yarn produc~, it results in a -
final yarn having a changed structure, which is some-
times not desired, and/or precludes the production of
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very fine yarn products. Whereas sliver might be used as a yarn core, this
would also result in compar~tively thick yarns because the sliver which
is normally available has a weight of at least Nm 1-2 and for this reason is
large in diameter.
Sliver can be drawn out to a large extent but must be twisted as
it is drawn out because it cannot be transported when it has been drawn out
but has not been twisted.
It is an object of the invention so to improve the above-described
apparatus that even very fine yarn can be spun and withdrawn at high speed.
This object is accomplished in accordance with the invention
through the provision of an apparatus comprising a first twisting member con-
sisting of a rotary drum, a movable second twisting member, which defines a
triangular-section space with said drum, a pair of wi~hdrawing rollers dis-
posed associated with one end of said drum, and a sliver source operable to
deliver a sliver to said space at the other end of said drum, said sliver
source comprising a draw frame, which directly precedes said space and is
operable to draw out said sliver and to hold the drawn-out sliver against
rotation. The twisting members are operable to receive flying fibers in
said space and to twist said drawnout sliver and to twist fibers in said
space around said sliver so as to form a yarn. The withdrawing rollers are
operable to withdraw said yarn from said space.
The sliver is thus drawn out directly before the two twisting
members so that the sliver can be drawn out to 20 to 40 times its original
; length and can then be delivered at a speed up to or above 300 meters per
minute and such operation will not effect the coherence of the drawn-out
sliver because the latter is immediately wrapped in the triangular-section
space between the two twisting members with the fibers flying into said
space. Both twisting members may consist of suction drums. Alternatively, -
one twisting member may consist of a rotary disc. It is not necessary to
provide each twisting member with suction
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means. It will be apparent that the high speed of
operation of the draw frame permits also of a withdra- ;
wal of the yarn product at high speed and that the !~
high draw ratio permits of a manufacture even of very
thin ya~ns.
Because the drawn~out sliver is held
against rotation in the draw frame as well as by the
pair of withdrawing rollers but between the two twist-
ing members is twisted together with the flying fibers
which are supplied, this operation might be considered
as a mere false twisting. Surprisingly it has been i
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found that the sliver fibers retain the twist imparted
to them by the two twisting members behind the draw
frame because the individual fibers which fly into the
triangular-section space and are then wound around the
sliver fibers prevent an untwisting of the latter be-
tween the twisting members and the pair of withdrawing
rollers. The resulting yarn thus has an optimum tena-
city as its core consists of drawn-out fibers which `~
extend substantially in the longitudinal direction
of the yarn and is~provided with a suitable covering
and it is possible to make even fluffy yarns which
in spite of a low twist have an adequate strength.
It is known that fibers which are more
highly parallel and have been drawn out to a larger
extent are required in the manufacture of yarns which
should be spun to a higher fineness number. Besides~
a yarn having a high fineness number should be highly
uniform as regards the number of individual fibers
in successive cross-sections as the absolute number
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of fibers in the cross-section decreases as the
fineness of the yarn is increased Because the
sliver is drawn out, the apparatus according to the
invention permits of a manufacture of yarns having
high fineness numbers up to and above Nm 80 as the
requirements explained hereinbefore are fulfilled.
Whereas the apparatus according to the
invention can be used to spin yarn at a yarn speed
of 300 meters per minute, in accordance with the
speed of the draw frame, modern ring spinning frames
; operate at yarn speeds up to 40 meters per minute
i and modern rotor spinning machines when producing
fine yarns having fineness numbers above about Nm 20
; operate at 80 to 100 meters per minute and can be
used only up to about Nm 40.
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An embodiment of the invention is shown
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strictly diagrammatically and by way of example on
, the accompanying drawing, in which
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Fig. 1 is a transverse sectional view
f 20 showing part of a spinning apparatus viewed on a
plane which is normal to the yarn being fonmed, and
Fig. 2 is a side elevation showing the
apparatus of Fig. 1 without the forward twisting me~- ~;
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Fibers fly freely from a serrated carding
drum 1 into a triangular-section space between two ~-
twis~ing members, which consist of two closely-spaced
~ apart suction drums 2 rotating in the same sense. Two
, 1 .
i suction inserts 3 provided in respective suction drums ~ -
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define suction 7ones, which adjoin the triangular-
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section space and face each other~ A pair of rollers
5 for withdrawing the yarn being formed are provided
at one end of the drums and hold the yarn against
rotation. At that end which is opposite to the rollers ;
5, the drums 2 are directly preceded by a draw frame,
which consists of pairs of rollers 6~ 7~ 8. To pro- -
duce a draft~ the rollers 6~ 7~ 8 are rotated at
speeds which increase f~om each pair to the next. A
sliver 9 is fed through an eyelet 10 to the draw `
frame 6, 7~ 8 and is drawn out by the latter to 20 to
40 times its original length. The drawn-out sliver is
moved through the triangular-section space between
the drums 2 to the pair of withdrawing rollers 5 and t'
by means of the drums 2 is twisted and is wrapped
with the flying fibers delivered by the carding drum ,
1. These fibers prevent the false twisting which would
otherwise result.
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