[0001] This invention relates to a device for seeking and withdrawing a broken yarn end
on a package being formed in order to unwind a yarn length sufficient to allow a rejoining
operation to take place for automatically reinstating the spinning process in a continuous
ring spinning machine.
[0002] In textile manufacturing operations for various production purposes it is necessary
to seek and release the end of a yarn held fixed in windings which overall form a
yarn package.
[0003] This is necessary in ring spinning machines when the yarn breaks and has to be rejoined
to automatically reinstate the spinning process.
[0004] Automatic carriage apparatus for rejoining broken yarns in ring spinning machines
is already known in the art.
[0005] One of the improvements towards which the present invention tends is in the seeking
and withdrawal of a broken yarn end on a package being formed, from which a length
is unwound sufficient to complete the rejoining cycle with maximum reliability and
speed of implementation, and avoiding any need for unproductive repetition of the
operation.
[0006] In a ring spinning machine for natural or synthetic fibres, during the rejoining
of broken yarns it is necessary to bring an actual yarn into contact with a fascicle
of textile fibres which has no consistency until the twist of the ring binds the individual
fibres together. As the fascicle of textile fibres cannot itself be withdrawn from
the feed zone at the exit of the drafting rollers because it would undergo certain
breakage, it is absolutely necessary to use the yarn already collected on the package
being formed and unwind a part of it to be able to reach the zone for its joining
to the fascicle of textile fibres close to the exit of the feed rollers.
[0007] It is therefore necessary to find the broken yarn end and withdraw it by unwinding
a length of it from the package which is at least sufficient to cover the distance
between the package and the fascicle of textile fibres fed by the feed rollers.
[0008] Devices are already known in the art for disengaging and releasing the broken yarn
lying on the surface of the package under formation.
[0009] Said known devices either do not ensure perfect preparation of the yarn under all
conditions, or require a considerable use of blown air, or comprise blowing nozzles
or sucker elements mounted in a fixed position and therefore unable to be operationally
adapted to the variable position of the formation cone on whose surface the broken
yarn end to be withdrawn is retained. It is apparent that in this latter case the
separation action of the blowing nozzles or sucker elements extends only partly over
the surface of the formation cone, or in the limit not at all, with the result that
the yarn withdrawal device does not operate effectively.
[0010] Other devices of the known art include blower and/or sucker elements aided by blades
of various materials which rub against the package surface, ie against the wound yarn
layers, in an attempt to release the broken yarn end.
[0011] However the contact pressure of these devices often results in damage to the yarn
at several points along the wound surface layers, so creating portions of reduced
strength which exert negative influence during the subsequent transformation passages
towards the finished product. The aforesaid known devices, especially in the case
of yarn which easily felts, have therefore been found unable to sufficiently release
the end of a yarn fixed on the package cone.
[0012] FR-A-2 216 208 discloses a device for seeking and withdrawing a yarn end from a package,
having the features of the preamble of claim 1. In the known device the nozzles are
arranged concentrically to each other with a component direction in the axial direction
of the package, so as to direct the air current onto the external surface of the package
and release the yarn end without the need of simultaneously causing the package to
be rotated. The released end is then sucked into the suction tube.
[0013] The location of the nozzles, which act substantially on a same circle, may however
not be able to withdraw the yarn under any circumstances. To be sure to reach effective
withdrawal it may be necessary to continuously vary the position of the package relative
to the nozzles by moving the package up and down. This, on the other hand, may cause
uncertainty about the real length of yarn withdrawn and may create problems in the
subsequent joining stage, besides complicating the construction of the device.
[0014] The object of the present invention is to provide a device by which the broken yarn
end adhering to the surface of the package formation cone is reliably released and
at the same time a yarn portion of sufficient length is unwound to complete the rejoining
cycle by which the spinning operation can go to completion. A further object of the
invention is to provide a device which when compared to the devices of the known art
is constructionally simple and allows the necessary adjustments to be easily made
as the geometrical parameters of the package being formed vary and as the type of
yarn being wound varies.
[0015] A device according to the present invention has the features claimed in claim 1.
[0016] The device may also comprise a control mechanism arranged both to vertically move
a package support peg upwards or downwards and to intermittently rotate said support
peg to subject the entire surface of the formation cone to the action of the air jets
from the blowing nozzles.
[0017] The control source for rotating the peg and thus the bobbin may provide two rotary
movements: firstly a slow rotation for seeking the end of the yarn and extricating
it from the wound layers of the formation cone, and then a sufficiently rapid rotation
to release into the suction duct the yarn length required for rejoining, this rapidity
resulting not only in a reduction in the cycle time but also preventing the yarn fibrillating
substantially under the action of the air stream.
[0018] The pipes of the blowing nozzles may be coupled to respective guide supports fixed
to the outer surface of the suction cap, the couplings allowing the pipes both to
slide vertically and to rotate angularly to be able to perfectly adjust the operating
directions of the air jets blowing against the zone in which the broken yarn end is
to be found, on the basis of the dimensions of the package formation cone and the
type of yarn wound.
[0019] According to a further embodiment, the control mechanism located at the base of the
package support peg may be able to generate an oscillatory reciprocating motion of
limited amplitude straddling the position which the formation cone has assumed, this
being done while the package is being rotated about its axis and in the opposite direction
to the yarn winding.
[0020] The invention is described hereinafter on the basis of the embodiment shown diagrammatically
on the figures of the accompanying drawings which schematically illustrate the characteristics
of the invention. In the accompanying drawings:
Figure 1 is a diagrammatic isometric perspective view showing both the device for
seeking and withdrawing a broken yarn end and the package under formation, at the
moment in which the package formation cone has already been positioned along the helical
arc of the blowing nozzles and the yarn end has already been conveyed through the
suction duct to the sensing and cutting block;
Figure 2 is a cross-sectional view from above, taken on the line A-A of Figure 1,
showing a part of the device of the present invention.
[0021] In the figures identical elements carry the same reference numerals. Again, for reasons
of overall clarity, those parts not necessary for understanding the invention are
omitted from the figures or are shown only generically as they are of known type.
[0022] 1 designates the blowing nozzles which are located to surround the formation cone
5 and which operate by blowing jets of air onto the surface of the formation cone
5. Respective position-adjustable pipes 2 of the blowing nozzles 1 are supported by
a suction cap 3 under which the upper end of the package 7 is located. Said cap has
its lower profile located above the air jets of the nozzles 1 and tapers upperly to
engage a suction duct 6 which extends up to a block 4 containing, in a first zone,
sensing members for the yarn 8 and, in a second zone, cutting elements 12. This block
4 is the source of an air stream for conveying the end of the yarn 8 through a photo-electric
or inductive sensor 9 and into a gap between the cutting blades of the scissor elements
12. On the surface of the package formation cone 5 the broken yarn end is retained.
The suction duct 6 is of a length substantially equal to the length of yarn to be
unwound and sucked from the package 7, and connects the suction cap 3 to the block
4. The yarn 8 sucked from the package 7 is unwound by a length sufficient to allow
the sucked yarn to be sensed by a light barrier 10 arranged in the block 4. The package
7 being formed is held by a peg 11. The scissor elements 12 are so positioned to remove
the excess yarn so that the portion of sucked yarn 8 is of a suitable length for rejoining
as required for reinstatement of the spinning process. Two optical sensors 14, one
emitting and one receiving, are disposed facing each other to form an optical light
curtain which when interrupted by the formation cone 5 halts the upward movement of
the package 7 being formed to position it correctly under the suction cap 3. A control
mechanism block 15 of known type is able to move the support peg 11 for the package
7 vertically upwards and downwards and also able to rotate said peg 11 in the opposite
direction to that in which the yarn is being wound so as to disengage and release
the broken yarn end reliably and rapidly. Said mechanism 15 is also able to generate,
pneumatically or electrically, a reciprocating oscillatory movement of limited amplitude
about the position established by the optical sensors 14 to enable the formation cone
5 to be struck by the air jets of the nozzles 1 more effectively. A locking screw
16 for each pipe 2 allows, when slackened, the exact positioning of the blowing nozzle
1 on a guide support 21 by axially and angularly adjusting each nozzle 1 relative
to the formation cone 5 such that each air jet strikes the formation cone 5 with high
efficiency and in collaboration with the other nozzles. 18 is the direction of rotation
of the support peg 11 and thus of the package 7 by the block 15, this direction being
advantageously the opposite of that in which the yarn 8 is wound onto the package
7 being formed; 20 is the arrow indicating the vertical raising of the package 7 until
its formation cone 5 interrupts the light beam extending between the optical sensors
14. The guide support 21 for the pipes 2 is fixed to the outer surface of the suction
cap 3.
[0023] The following description of operation given with reference to the said figures relates
firstly to that which is new and therefore takes into consideration only the device
of the present invention which seeks and withdraws the broken yarn end on a package
being formed as required for the subsequent rejoining of the yarn to the roving, it
being understood that additional devices are required for the other operating stages
prior and subsequent to the search for the broken yarn and that these do not form
part of the description.
[0024] It is known to associate a ring spinning machine with a carriage apparatus for automatically
rejoining yarns which break during the operation of the spinning spindles. The carriage
houses various devices required for the various operational stages involved in rejoining,
and therefore also houses the device of the present invention.
[0025] Said carriage is movable along the spinning machine on runways comprising one or
more rails of any shape, cooperating with suitable rolling means such as wheels, rollers
or equivalent means. During the operation of the spinning machine, the yarn rejoining
carriage is driven to and fro to patrol along the spindles. As it patrols, the carriage
apparatus checks by sensor means known in the art whether the yarn is present or not
in each spinning spindle.
[0026] When it detects the lack of one of the yarns the carriage is halted at the spindle
where the yarn has been found to be broken and the mechanism for initiating the rejoining
procedure is started. This procedure involves stopping the spindle and extracting
the package 7 being formed from the spindle line and locating it on the support peg
11 inside the carriage apparatus in a position suitable for seeking and withdrawing
the broken yarn end. The peg 11 together with the block 15 of the control mechanism
are located in a lower waiting position. When the package 7 has been mounted on the
peg 11 the control mechanism 15 is operated to vertically raise the package 7 being
formed in the direction of the arrow 20 until its formation cone 5 intercepts and
obscures the light beam or optical curtain between the facing sensors 14. When the
light beam is intercepted the blowing nozzles 1 are activated and at substantially
the same time the control mechanism 15 effects the rotation of the package 7 in the
direction of the arrow 18 and suction is applied to the cap 3 and duct 6, this latter
being connected to a vacuum pump or similar member, or to any air suction main. The
rotation of the package 7 enables its entire frusto-conical surface 5 to be effectively
exposed to the air jets leaving the nozzles 1, which by virtue of their overall helical
arc arrangement create an air current of ascending vortex type. This latter is channeled
along the entire surface of the suction cap 3 at a velocity which increases both because
of the effect of the suction zone and because of the effect of the upward taper of
the frusto-conical section of the cap 3 which is connected at its top to the suction
duct 6. In addition to the rotation of the package 7 the control mechanism 15 generates
a reciprocating oscillatory motion of limited amplitude about the position assumed
by the package 7 under the suction cap 3 to attain even greater efficiency in disengaging
and releasing the broken yarn end.
[0027] The rotation of the package 7 is advantageously of increasing intensity, ie initially
it comprises a few slow rotations necessary to give the blowing nozzles 1 time to
disentangle the broken yarn end from the formation cone 5 followed a moment after
by a rotation sufficiently rapid to drag along the suction duct the length necessary
for passing the yarn 8 through the light barrier 10 and through the scissor elements
12.
[0028] The presence of the yarn excites the photoelectric barrier 10, which simultaneously
deactivates the blowing nozzles 1, the control mechanism 15 and, simultaneously or
immediately afterwards, the scissor elements 12.
[0029] The aforesaid stages could in fact at least partly overlap in time. Immediately following
the cutting of the yarn 8 by the scissor elements 12 the package 7 begins to descend
by the action of the control mechanism 15. On termination of its descent, the other
operational stages follow in accordance with a programmed cycle under the action of
various known devices, to complete the automatic rejoining of the yarn withdrawn by
the device of the invention to the fascicle of textile fibres leaving the drafting
rollers, in order to reinstate the spinning process on the spindle at which the yarn
had accidentally broken. The described embodiment has been given by way of non-limiting
example only. It is apparent that modifications can be made by experts of the art
to the details of the device within the scope of the appended claims.
1. A device for seeking and withdrawing a broken yarn end on a package (7) being formed
and drawing off by suction a yarn length required to allow a rejoining operation to
take place for automatically reinstating the spinning process in a continuous spinning
machine, comprising:
- a series of blowing nozzles (1) located to surround the package cone (5);
- a suction cap (3) having its lower profile located above the air jets produced by
said nozzles (1);
- a suction duct (6) in fluid communication with said suction cap (3) for receiving
a length of yarn (8) unwound and sucked from the package (7) for the subsequent rejoining
operation;
characterised in that:
- the nozzles (1) are arranged along a line geometrically similar to a helical arc;
- a block (4) is connected to the suction cap (3) by the suction duct (6), said block
(4) having a first zone for sensing the yarn (8) by means of a sensing light barrier
or an electric field (9,10) and a second zone controlled by said first zone and provided
with cutting means (12) for cutting the end of the sucked yarn (8) at a position substantially
corresponding to the length of yarn (8) required for rejoining; and
- two facing optical sensors (14) are provided which produce a barrier light beam
for sensing the presence of the package cone (5) in order to position said cone (5)
along the helical arc of the blowing nozzles (1).
2. A device as claimed in claim 1, characterised in that it further comprises a control
mechanism both for vertically moving a package support peg (11) upwards and downwards
relative to said suction cap (3) and for intermittently rotating said support peg
(11) about the axis thereof to subject the entire surface of the cone (5) to the action
of the air jets from the blowing nozzles (1).
3. A device as claimed in claim 1, characterised in that the pipes (2) of the blowing
nozzles (1) are axially slidable and angularly rotatable in respective guide supports
(21) fixed to the outer surface of the suction cap (3) for adjusting the operating
directions of the air jets blowing against the package cone (5) on the basis of the
shape and dimensions of the package cone (5) and the type of yarn (8) wound.
4. A device as claimed in claims 1 and 2, characterised in that said support peg (11)
is further movable with an oscillatory reciprocating motion of limited amplitude straddling
the position which the cone (5) has assumed by the action of the optical sensors (14),
while the package (7) is being rotatable about its axis in the direction (arrow 18)
opposite to the yarn winding direction.
1. Vorrichtung zum Aufsuchen und Herausziehen eines gerissenen Fadenendes einer im Aufbau
befindlichen Fadenwicklung (7) und Ansaugen einer Fadenlänge, die benötigt wird, um
einen Wiederanspinnvorgang zum automatischen Wiederingangsetzen des Spinnvorgangs
einer Endlosspinnmaschine stattfinden zu lassen, mit:
- einer Reihe von Blasdüsen (1), die so angeordnet sind, daß sie den Fadenwicklungskegel
(5) umgeben;
- einer Saugkappe (3), deren untere Kontur oberhalb der durch die Düsen (1) erzeugten
Luftstrahlen angeordnet ist;
- einem Saugkanal (6) in Fluidverbindung mit der Saugkappe (3) zur Aufnahme einer
für den anschließenden Wiederanspinnvorgang von der Fadenwicklung (7) abgewickelten
und angesaugten Länge eines Fadens (8);
dadurch gekennzeichnet daß:
- die Düsen (1) entlang einer Linie angeordnet sind, die geometrisch einer Schraubenlinie
ähnelt;
- ein Block (4) durch den Saugkanal (6) mit der Saugkappe (3) verbunden ist, wobei
der Block (4) eine erste Zone zum Erfühlen des Fadens (8) mittels einer Lichtschranke
oder eines elektrischen Feldes (9, 10) und eine zweite Zone hat, die durch die erste
Zone gesteuert ist und eine Schneideinrichtung (12) zum Abschneiden des Endes des
angesaugten Fadens (8) an einer Stelle aufweist, die im wesentlichen der zum Wiederanspinnen
benötigten Länge des Fadens (8) entspricht; und
- zwei einander zugekehrte optische Sensoren (14) vorhanden sind, die einen Lichtschrankenstrahl
zur Wahrnehmung des Vorhandenseins eines Fadenwicklungskegels (5) erzeugen, um den
Kegel (5) entlang der Schraubenlinie der Blasdüsen (1) in Stellung zu bringen.
2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß sie zusätzlich eine Steuerung
sowohl zum vertikal nach oben und nach unten Verschieben eines Fadenwicklungsstützdorns
(11) bezüglich der Saugkappe (3) als auch zum zeitweiligen Drehen des Stützdorns (11)
um seine Achse aufweist, um die gesamte Oberfläche des Kegels (5) der Wirkung der
Luftstrahlen aus den Blasdüsen (1) auszusetzen.
3. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die Rohre (2) der Blasdüsen
(1) in entsprechenden Stützführungen (21), die an der Außenfläche der Saugkappe (3)
befestigt sind, axial verschiebbar und winkelmäßig drehbar sind, um die Wirkrichtungen
der gegen den Fadenwicklungskegel (5) blasenden Luftstrahlen hinsichtlich der Gestalt
und Abmessungen des Fadenwicklungskegels (5) und der Art des aufgewickelten Fadens
(8) einzustellen.
4. Vorrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der Stützdorn (11)
zusätzlich in einer oszillierenden Hin- und Herbewegung begrenzter Amplitude bewegbar
ist, die die Stellung überstreicht, die der Kegel (5) durch die Funktion der optischen
Sensoren (14) eingenommen hat, während die Fadenwicklung (7) um ihre Achse in der
Richtung (Pfeil 18) entgegen der Fadenaufwickelrichtung drehbar ist.
1. Dispositif pour chercher et prélever l'extrémité d'un fil rompu sur une bobine (7)
en cours de formation et pour extraire par aspiration une longueur de fil nécessaire
pour permettre d'effectuer une opération de raccordement afin de reprendre automatiquement
l'opération de bobinage dans un bobinoir à bobinage continu, comprenant :
une série de tuyères de soufflage (1) placées de manière à entourer le cône (5)
de la bobine;
une coiffe d'aspiration (3) dont le profil inférieur se trouve au-dessus des jets
d'air produits par les tuyères (1);
un conduit d'aspiration (6) communiquant avec la coiffe d'aspiration (3) pour recevoir
une longueur de fil (8) déroulée et aspirée depuis la bobine (7) en vue d'une opération
de raccordement subséquente;
caractérisé en ce que :
les tuyères (1) sont disposées le long d'une ligne géométriquement similaire à
un arc de spire d'hélice;
une boîte (4) est raccordée à la coiffe d'aspiration (3) par le conduit d'aspiration
(6), ladite boîte (4) comportant une première zone pour détecter le fil (8) au moyen
d'une barrière de lumière de détection ou d'un champ électrique (9, 10) et une seconde
zone commandée par la première zone et pourvue d'un moyen de coupe (12) pour couper
l'extrémité du fil aspiré (8) à une position correspondant sensiblement à la longueur
de fil (8) nécessaire pour un raccordement; et
deux capteurs optiques (14) situés en face l'un de l'autre sont présents, ces capteurs
produisant un faisceau de lumière formant barrière pour détecter la présence du cône
(5) de bobine afin de positionner le cône (5) le long de l'arc hélicoïdal des tuyères
de soufflage (1).
2. Dispositif selon la revendication 1, caractérisé en ce qu'il comprend, en outre, un
mécanisme de commande à la fois pour déplacer verticalement une broche (11) de support
de bobine vers le haut et vers le bas par rapport à la coiffe d'aspiration (3) et
pour faire tourner de façon intermittente la broche de support (11) autour de son
axe pour soumettre la surface totale du cône (5) à l'action des jets d'air des tuyères
de soufflage (1).
3. Dispositif selon la revendication 1, caractérisé en ce que les tuyaux (2) des tuyères
de soufflage (1) peuvent coulisser axialement et tourner angulairement dans des supports
de guidage respectifs (21) fixés à la surface extérieure de la coiffe d'aspiration
(3) pour régler les directions d'intervention des jets d'air soufflés contre le cône
(5) de bobine d'après la forme et les dimensions du cône (5) de bobine et du type
de fil (8) bobiné.
4. Dispositif selon la revendication 1 ou 2, caractérisé en ce que la broche de support
(11) peut, en outre, être déplacée suivant un mouvement de va-et-vient oscillant d'amplitude
limitée autour de la position que le cône (5) a prise sous l'action des capteurs optiques
(14), tandis que la bobine (7) est entraînée en rotation autour de son axe dans la
direction (flèche 18) opposée à la direction d'enroulement du fil.