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EP 0 738 796 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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28.06.2000 Bulletin 2000/26 |
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Date of filing: 15.04.1996 |
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Yarn supply
Fadenliefervorrichtung
Dispositif d'alimentation de fil
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Designated Contracting States: |
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BE DE GB NL |
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Priority: |
21.04.1995 GB 9508197
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Date of publication of application: |
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23.10.1996 Bulletin 1996/43 |
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Proprietor: BRINTONS LIMITED |
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Kidderminister
Worcestershire DY10 1AG (GB) |
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Inventors: |
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- Weston, Paul Anthony Richard
Kidderminster,
Worcestershire DY10 2UA (GB)
- Pilling, John Reginald
Great Witley,
Worcestershire (GB)
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(74) |
Representative: Rackham, Stephen Neil |
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GILL JENNINGS & EVERY,
Broadgate House,
7 Eldon Street London EC2M 7LH London EC2M 7LH (GB) |
(56) |
References cited: :
EP-A- 0 058 478 DE-A- 4 129 028 GB-A- 2 074 618
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AU-A- 558 235 DE-C- 817 875
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] This invention relates to an apparatus for supplying a desired length of yarn.
[0002] Yarn is used in a wide variety of production processes, for example knitting, embroidery,
lace-making, and carpet making. For many of these processes, for example in a gripper
Axminster carpet making process, it is necessary to provide the yarn in a yarn carrier.
[0003] In our earlier European patent EP-B-0,058,478, we disclose the advantage of supplying
predetermined lengths of yarn to a yarn carrier, the length corresponding to that
which will be required for the particular process. It is therefore necessary to accurately
measure lengths of yarn.
[0004] In our earlier patent, we disclose a system in which yarn is supplied from a number
of packages, and is measured into a separate tube. The yarn is fed into the tube by
air jets. As the yarn is fed into the tube, the yarn passes through a pair of measuring
rollers, and from the number of rotations of one roller, the length of yarn measured
into the tube is determined.
[0005] The packages of yarn are typically provided in a creel, and yarn is fed from the
packages, around a series of guide rollers to the measuring rollers. Depending on
the position of the packages on the creel, the yarn is fed around a different number
of guide rollers. The tension in the yarn depends upon the number of guide rollers
around which the yarn is fed, the length of the yarn to the measuring rollers and,
especially where the packages are spools, with the variation in weight of the spools,
the tension being lower for yarn drawn from a partially empty spool compared to what
for yarn drawn from a full spool.
[0006] The yarn tends to stretch as it is drawn to the measuring roller. The amount of stretch
depends on the dampness of the yarn, and the tension of the yarn. As the amount of
stretch varies for each yarn, it is not possible to compensate for this when measuring
a length of yarn, and accordingly it is impossible to accurately measure a desired
length of yarn.
[0007] DE-A-817875 discloses a feeding apparatus for yarn or the like wherein the yarn is
detensioned before being fed to a knitting machine to allow the knitting machine to
produce a knitted product with improved uniformity.
[0008] According to the present invention, an apparatus for dispensing a predetermined length
of yarn comprises a transfer means for drawing yarn from a supply and supplying yarn
to a measuring means, the transfer means including a rotatable transfer member around
which, in use, yarn is wound so that yarn is drawn from the supply upon rotation of
the transfer member,
in which the surface of the transfer member is arranged to move at a speed greater
than the speed at which yarn is supplied to the measuring means, and
wherein said measuring means measures said predetermined length of said yarn while
said yarn is under substantially no tension.
[0009] As the speed of the surface of the rotating member is greater than the speed at which
yarn is supplied to the measuring means, the rate at which yarn is drawn into the
transfer member will exceed the rate at which it is supplied to the measuring means.
Accordingly, the yarn is supplied to the measuring means at a very low tension. This
results in constant stretching of the yarn, thereby improving the accuracy of the
measurement of length. As the transfer member is a rotating member around which the
yarn is wound, any excess yarn supplied to the transfer means causes the yarn to slip
on the rotating transfer member and no further yarn is drawn into the transfer means.
This prevents excessive yarn from becoming tangled in the transfer means.
[0010] It is preferred that the speed of the surface of the transfer member is approximately
10% higher than the speed at which yarn is supplied to the measuring means.
[0011] The measuring means may be in the form of opposed rollers, one of which is rotatably
driven to draw yarn from the yarn supply and through the transfer means.
[0012] Advantageously, the transfer member comprises two capstans, the yarn being wound
around both of these. This is advantageous because the size of the rotating transfer
member can be reduced, or elongated, without reducing the amount of yarn in the transfer
means.
[0013] It is preferred that two yarn brakes are provided, one before the transfer member
and one after. These brakes stop the supply of yarn to the measuring means. Preferably
the rotation of the transfer member is stopped after the application of the yarn brakes
to reduce wear on the transfer member and on the yarn wound around the transfer member.
[0014] The apparatus preferably includes a tensioner between the transfer means and the
measuring means. This applies a predetermined tension to the yarn as this is supplied
to the measuring means. This ensures that the tension of all yarn supplied to the
measuring means is constant and accordingly that all yarns are stretched to the same
extent. This can be compensated for by the measuring means.
[0015] The apparatus of the present invention may advantageously be included in an air cell
filling apparatus such as that disclosed in our earlier patent EP-B-0,058,478.
[0016] Where several yarns are supplied to the measuring means, it is advantageous for the
transfer means to include a plurality of transfer members, each transfer member arranged
to have a single yarn wrapped around it.
[0017] A particular example of the present invention will be described in accordance with
the accompanying diagram.
[0018] Yarn 1 is supplied from one of a number of yarn packages 2 to the transfer means
3. Some of the yarn packages 2 will be full, and some only partially full. The force
required to pull yarn 1 from these packages 2 differs depending on the size and density
of the packages, and the distance over which the yarn must be pulled. The yarn 1 is
fed into the transfer medium 3, and around two capstan rollers 4, 5. The yarn 1 is
fed from the transfer means 3, via a tensioning device such as a pair of opposed nip
rollers 6 over a measuring roller 7 to an air cell filling machine. The capstan rollers
4, 5 are arranged to rotate so that the surface of the rollers 4, 5 move at a speed
approximately 10% quicker than the speed at which yarn 1 is drawn into the filling
machine. The rotation of the capstan rollers 4, 5 assists in drawing yarn from the
yarn package 2 into the transfer means 3.
[0019] When the yarn is tight on the capstans 4, 5, the rotation of the capstans 4, 5 draws
yarn 1 from the package 2 into the transfer means 3. This yarn 1 is supplied to the
measuring roller 7. As the rotation of the capstans 4, 5 is at a greater speed than
that at which the yarn 1 is supplied to the measuring roller 7, the yarn 1 has substantially
no tension as it is supplied. As yarn 1 is drawn into the transfer means 3, and yarn
1 is supplied from the transfer means 3 at a lower rate, excess yarn 1 will be contained
in the transfer means 3 causing this to become loose on the rotating capstans 4, 5
and accordingly the yarn 1 will slip on the surface of the capstans 4, 5 and yarn
1 will not be drawn into the transfer means 3. This prevents an excessive build up
of yarn 1 in the transfer means 3 which could become tangled. As yarn 1 is supplied
from the transfer means 3, the yarn 1 again tightens on the capstans 4, 5 and accordingly
more yarn 1 is drawn into the transfer means 3 from the package 2. In this way, the
tension in the yarn 1 supplied from the transfer means 3 to the measuring roller 7
is always constant.
[0020] It is desirable to have a known low tension on the yarn 1 being fed to the measuring
roller 7, and accordingly a pair of opposed rollers 6 are provided to pinch the yarn
1 with a predetermined force, thereby generating the required tension.
[0021] The yarn 1 is fed over a measuring roller 7 which is rotated by the flow of the yarn
1 over its surface. As the tension in the yarn 1 is known, the amount of stretch of
the yarn 1 is also known, and therefore the rotation of the roller 7 corresponds to
the amount of yarn 1 dispensed.
[0022] Alternatively, a pair of opposed measuring rollers may be included. In this case,
one of the measuring rollers is a driven roller which draws yarn 1 from a package
2, through the transfer means 3 and the tensioning device 6. The length of yarn is
calculated by the rotation of the other measuring roller.
1. Apparatus for dispensing a predetermined length of yarn comprising:
a transfer means (3) for drawing yarn (1) from a supply (2) and supplying yarn
(1) to a measuring means (7), the transfer means (3) including a rotatable transfer
member (4, 5) around which, in use, yarn (1) is wound so that yarn (1) is drawn from
the supply (2) upon rotation of the transfer member (4, 5),
in which the surface of the transfer member (4, 5) is arranged to move at a speed
greater than the speed at which yarn (1) is supplied to the measuring means, and
wherein said measuring means measures said predetermined length of said yarn (1)
while said yarn (1) is under substantially no tension.
2. Apparatus according to claim 1, in which the speed of the surface of the transfer
member (4, 5) is approximately ten percent higher than the speed at which yarn (1)
is supplied to the measuring means (7).
3. Apparatus according to claim 1 or 2, in which the measuring means (7) comprises a
pair of opposed rollers, one of which is rotatably driven to draw yarn (1) from the
yarn supply (2) and through the transfer means (3).
4. Apparatus according to any one of the preceding claims, in which the transfer means
(3) comprises two capstans (4, 5), in use the yarn (1) being wound around both capstans
(4, 5).
5. Apparatus according to any one of the preceding claims, further comprising two yarn
brakes, one before the transfer means (3) and one after, arranged to stop the supply
of yarn (1) to the measuring means (7).
6. Apparatus according to claim 5, further comprising a means to stop the rotation of
the transfer means (3) after the application of the yarn brakes.
7. Apparatus according to any one of the preceding claims, further including a tensioner
(6) between the transfer means (3) and the measuring means (7), the tensioner (6)
being arranged to apply a predetermined tension to the yarn (1) as this is supplied
to the measuring means (7).
8. Apparatus according to any one of the preceding claims, in which the transfer means
(3) includes a plurality of transfer members (4, 5), each transfer member (4, 5) arranged
to have a single yarn (1) wrapped around it.
9. An air cell filling apparatus including the apparatus according to any one of the
preceding claims.
1. Vorrichtung zum Abgeben einer vorbestimmten Garnlänge, umfassend:
ein Übertragungsmittel (3) zum Abziehen von Garn (1) von einem Vorrat (2) und Liefern
des Garns (1) zu einem Messmittel (7), wobei das Übertragungsmittel (3) ein drehbares
Übertragungsglied (4,5) umfasst, um das das Garn (1) im Gebrauch derart herumgewickelt
wird, so daß Garn (1) vom Vorrat (2) nach Drehen des Übertragungsgliedes (4,5) abgezogen
wird,
wobei die Oberfläche des Übertragungsgliedes (4,5) so angeordnet wird, daß es sich
mit einer größeren Geschwindigkeit bewegt als die Geschwindigkeit, mit der Garn (1)
zum Messmittel zugeführt wird, und wobei das Messmittel die vorbestimmte Garnlänge
misst, während das Garn (1) im wesentlichen nicht unter Spannung steht.
2. Vorrichtung nach Anspruch 1, bei der die Oberflächengeschwindigkeit des Übertragungsgliedes
(4,5) etwa 10% höher ist als die Geschwindigkeit, mit der das Garn (1) zum Messmittel
(7) zugeführt wird.
3. Vorrichtung nach Anspruch 1 oder 2, bei dem das Messmittel (7) ein paar gegenüberliegender
Rollen umfaßt, von denen eine drehbar angetrieben ist, um Garn (1) vom Garnvorrat
(2) ab und durch das Übertragungsmittel (3) zu ziehen.
4. Vorrichtung nach irgendeinem der vorstehenden Ansprüche, bei dem das Übertragungsmittel
(3) zwei Abzüge (4,5) besitzt, wo bei Gebrauch das Garn (1) um beide Abzüge (4,5)
herumgewickelt wird.
5. Vorrichtung nach irgendeinem der vorstehenden Ansprüche, ferner umfassend zwei Garnbremsen,
eine vor dem Übertragungsmittel (3) und eine dahinter angeordnete, um den Nachschub
des Garn (1) zum Messmittel (7) anzuhalten.
6. Vorrichtung nach Anspruch 5, ferner umfassend ein Mittel, um die Drehung des Übertragungsmittels
(3) anzuhalten, nach dem die Garnbremsen eingesetzt worden sind.
7. Vorrichtung nach irgendeinem der vorstehenden Ansprüche, ferner einschließend eine
Spannvorrichtung (6) zwischen dem Übertragungsmittel (3) um dem Messmittel (7), wobei
die Spannvorrichtung (6) so angeordnet ist, daß sie eine vorbestimmte Spannung am
Garn (1) anlegt, während dieses zum Messmittel (7) zugeführt wird.
8. Vorrichtung nach irgendeinem der vorstehenden Ansprüche, bei der das Übertragungsmittel
(3) eine Vielzahl von Übertragungsgliedern (4,5) umfaßt, wobei jedes Übertragungsglied
(4,5) so angeordnet ist, daß es ein einziges Garn (1) um sich herumgewickelt besitzt.
9. Luftspeicherfüllvorrichtung, einschließlich der Vorrichtung nach irgendeinem der vorstehenden
Ansprüche.
1. Appareil pour distribuer une longueur prédéterminée de fil, comportant:
un moyen de transfert (3) pour extraire un fil (1) d'une alimentation (2) et délivrer
le fil (1) à un moyen de mesure (7), le moyen de transfert (3) comprenant un organe
rotatif de transfert (4, 5) autour duquel, en cours d'utilisation, le fil (1) est
enroulé de telle sorte que le fil (1) est prélevé de l'alimentation (2) lors d'une
rotation de l'organe de transfert (4, 5),
dans lequel la surface de l'organe de transfert (4, 5) est agencée de manière à
se déplacer à une vitesse supérieure à la vitesse à laquelle le fil (1) est délivré
au moyen de mesure, et
dans lequel le dit moyen de mesure mesure la dite longueur prédéterminée du dit
fil (1) alors que le dit fil (1) est dans un état essentiellement exempt de tension.
2. Appareil selon la revendication 1, dans lequel la vitesse de la surface de l'organe
de transfert (4, 5) est approximativement de 10% supérieure à la vitesse à laquelle
le fil (1) est délivré au moyen de mesure (7).
3. Appareil selon la revendication 1 ou 2, dans lequel le moyen de mesure (7) comporte
une paire de rouleaux opposés, dont l'un est entraîné en rotation pour extraire le
fil (1) de l'alimentation en fil (2) et l'entraîner à travers le moyen de transfert
(3).
4. Appareil selon l'une quelconque des revendications précédentes, dans lequel le moyen
de transfert (3) comporte deux cabestans (4, 5), le fil (1) étant, en cours d'utilisation,
enroulé autour des deux cabestans (4, 5).
5. Appareil selon l'une quelconque des revendications précédentes, comportant en outre
deux freins pour fil, l'un avant le moyen de transfert (3) et l'autre après, agencés
pour arrêter la fourniture de fil (1) au moyen de mesure (7).
6. Appareil selon la revendication 5, comportant en outre un moyen pour arrêter la rotation
du moyen de transfert (3) après l'application des freins pour fil.
7. Appareil selon l'une quelconque des revendications précédentes, comprenant en outre
un tendeur (6) entre le moyen de transfert (3) et le moyen de mesure (7), le tendeur
(6) étant agencé pour appliquer une traction prédéterminée sur le fil (1) pendant
que ce dernier est délivré au moyen de mesure (7).
8. Appareil selon l'une quelconque des revendications précédentes, dans lequel le moyen
de transfert (3) comprend une pluralité d'organes de transfert (4, 5), chaque organe
de transfert (4, 5) étant agencé pour avoir un seul fil (1) enroulé autour de lui.
9. Appareil de remplissage d'une chambre de turbulence comprenant l'appareil selon l'une
quelconque des revendications précédentes.