TECHNICAL FIELD
[0001] The present disclosure relates to a yarn feeding arrangement. In particular the present
disclosure relates to a yarn feeding arrangement suitable for a textile machine operated
at high speed and potentially also with yarns with relative high weight per length
unit.
BACKGROUND
[0002] Yarn pre-winders are used to eliminate yarn tension variations to ensure high textile
quality and productivity of a textile machine, e.g. a shuttleless weaving machine
or a knitting machine.
[0003] A general development trend in weaving is that the speed of the weaving machine is
constantly being increased. At the same time the weavers strive to weave coarser yarns
and also weaker yarns. A similar trend also exists for other textile machines. Coarser
yarns and higher speeds lead to increased tension of the yarn. Using conventional
yarn pre-winders, increased speeds as well as coarser yarns result in a bigger take
off yarn balloon in the yarn pre-winder, which needs to be reduced using a high braking
force but thereby unfortunately leading to an undesirably high output yarn tension.
[0004] For example, when weaving a carpet, coarse Jute is often used as yarn. The balloon
braking element in a conventional yarn pre-winder is typically either a brush ring
or a flexible truncated-cone formed brake element. With the machine speeds of today
a brush ring is often worn out in as little as a day and a flexible truncated-cone
brake element can be worn out in a few months.
[0005] Another example is weaving technical fabric with coarse synthetic yarns; where one
faces the same problem as in a carpet weaving machine.
[0006] Further, when using a shuttleless weaving machine in the form of a rapier weaving
machine, the insertion means in the rapier weaving machine consists of one or two
rigid or flexible rapiers that mechanically transfers the yarn from one end of the
shed of the machine to the other. The most common system is two rapiers which meet
in the middle of the shed where the yarn tip is transferred from the first, giving,
rapier to the second, receiving, rapier. The first rapier is first accelerating from
zero to full speed and then decelerating to zero again at the tip transfer point.
This type of motion is analogous for the second rapier. This leads to a yarn tension
that goes from low to high and then back to low again. In fact, when the rapier decelerates
the mass in the yarn causes it to move faster than the rapier itself causing a surplus
of yarn. This effect increases with the yarn count, i.e. the yarn weight per length
unit, and is a real problem for coarse yarns and fast machines. In order to solve
this problem passive or controlled yarn brakes are being used.
[0007] If the machine speed is to be increased, the mechanical arrangement for the rapier
mechanism must be made as light as possible. On the other hand, higher speeds mean
higher yarn tension which requires a more rigid and stronger rapier system.
[0008] Weaker yarns are cheaper and are thus attractive to use. Weaker yarns have less tensile
strength and if a too high brake force is applied in order to control the balloon,
or to give enough tension for the rapier function, the risk for yarn break is increasing
rapidly.
GB 1355687 describes a yarn feeder where a member directly connected to the weaving machine
moves back and forth to remove yarn in unison with the movement of the rapier from
a yarn package during both a forward and return movement of the rapier. Hereby, the
speed at which the yarn is drawn from the yarn package can be reduced to one half.
The arrangement in
GB 1355687 will form a yarn buffer. In general, a yarn buffer is an arrangement that can hold
a bit of yarn that can be drawn with a small force during at least a part of the weaving
cycle compared to the force required if the yarn would have been drawn directly from
the yarn storage.
[0009] In
US 3825198 a yarn storage is described. The yarn storage is formed by a container and has an endless
belt for advancing the yarn in the container. The yarn storage is used to rid strip
shaped materials from electrostatically charged materials.
[0010] FR 2 558 854, which is regarded as the closest prior art, describes another yarn feeder which
lays the yarn in a zigzag pattern.
[0011] There is a constant desire to improve yarn feeding to textile machines. Hence, there
is a need for an improved yarn feeding device.
SUMMARY
[0012] It is an object of the present invention to provide an improved yarn feeding device
and yarn feeding arrangement.
[0013] This object and/or others are obtained by the yarn feeding device as set out in the
appended claims.
[0014] As has been realized, it would be advantageous to reduce the speed at which yarn
is drawn from a yarn storage, such as a bobbin or a pre-winder to a textile machine.
This would reduce the various forces required to cope with when increasing the speed
of the textile machine, in particular when a coarser yarn having a relatively high
weight per length unit is used such as Jute, some synthetic yarns or carbon fiber.
Another desire is to provide yarn feeding that reduces the yarn tension.
[0015] Also, while the device described in
GB 1355687 allows for a reduced speed at which the yarn is drawn from the yarn feeder, it has
limitations and drawbacks. First the device of
GB 1355687 has a limitation in that the speed reduction can only be 50% and not more. Also,
the fact that the member is directly connected to the weaving machine and moves back
and forth to remove yarn in unison with the movement of the rapier from a yarn package
during both a forward and return movement of the rapier makes it impossible to draw
yarn from the yarn storage when the rapier is not moving such as during beat up. In
other words, in
GB 1355687 it is only possible to draw yarn from a yarn storage when the rapier is moving. As
a result, a significant fraction of the time available during a weaving cycle is not
used to draw yarn from the yarn storage. This is because during a significant fraction
of the weaving cycle the rapier(s) is/are typically not moving. Second, the device
moves in unison with the rapier. This results in that the speed at which the yarn
is drawn from the yarn feeder is directly proportional to the speed of the rapier
and hence varies significantly during a cycle of a rapier machine. The fact that the
device moves in unison with the rapiers as it is mechanically coupled to the rapiers
in the weaving machine limits the functionality as it is not possible to improve the
function by following other movements in the weaving machine in order to even out
the speed even more and/or compensate for other movements in the weaving machine.
Third, the device requires a traveler guided along a rail, which imposes additional
friction forces and a moving part, which could be a disadvantage in some applications.
[0016] In a traditional pre-winder, the yarn is drawn from a cylindrical drum. At high speeds
the yarn will form a take-off balloon, which increases the yarn tension significantly.
With a coarse yarn this ballooning effect will be accentuated and the yarn tension
thereby raises even more. It is therefore desired to provide a yarn feeding device
that will not be limited or at least less limited with regard to high speeds for,
in particular, coarse yarns. This would then enable a higher productivity of a textile
machine fed from the yarn feeding device. The here described yarn feeding device does
not store the yarn on a cylindrical drum but instead stores the yarn lying freely
in a meandering pattern. Since the yarn is not drawn from a drum but instead from
yarn lying flat, the yarn take-off balloon from traditional pre-winders will not be
formed. The result is a much lower yarn take-off tension and that the speed of the
textile machine can be increased to ultimately increase the productivity of the textile
machine.
[0017] In accordance with one embodiment a yarn feeding device for feeding yarn to a textile
machine is provided. The yarn feeding device comprises a moveable yarn carrier adapted
to transport yarn in a first, forward direction and a loop former adapted to draw
yarn from a yarn storage. The yarn feeding device further comprises moveable loop
keeping members arranged at both sides of an input section of the moveable yarn carrier,
wherein the loop former is adapted to position yarn on the moving loop keeping members
by moving the yarn from side to side. The movement can comprise a movement being predominantly
perpendicular to the first direction. The moveable loop keeping members are adapted
to hold the yarn positioned thereon and to release the yarn onto the moveable yarn
carrier in a meandering pattern at an input area of the moveable yarn carrier and
the yarn lying on the moveable yarn carrier is adapted to leave the moveable yarn
carrier at an output section of the moveable yarn carrier. Hereby a yarn buffer is
formed that can draw yarn from a yarn storage at a low speed and which can keep a
large yarn buffer that can supply yarn to a textile machine with low or in some instances
practically no yarn tension compared to taking yarn directly from the yarn storage.
[0018] In accordance with one embodiment the moveable loop keeping members are pins. The
pins can be cylindrical or in one embodiment semi-cylindrical. Hereby a yarn can easily
be placed on and leave the moveable loop keeping members.
[0019] In accordance with one embodiment the moveable loop keeping members are located laterally
outside the moving carrier. In an alternative embodiment, the moveable loop keeping
members are located projecting through the moveable yarn carrier.
[0020] In accordance with one embodiment at least one sensor is provided to detect the yarn
on the moveable yarn carrier. For example, the position of the yarn can be determined.
Hereby input to a control mechanism can be provided.
[0021] In accordance with one embodiment a controller adapted to control the drive of the
yarn feeding device in response to one or more pre-determined parameters. The pre-determined
parameters include one or many of sensor signals and input from the weaving machine.
[0022] In accordance with the invention at least one endless belt distanced from the moveable
yarn carrier and moving in parallel with the moveable carrier is provided. Hereby
an improved control of the yarn lying on the moveable carrier can be obtained. Further,
a first yarn movement restriction means can be provided on such a belt moving in parallel
with the moveable carrier.
[0023] In accordance with one embodiment the moveable yarn carrier is an endless belt. Hereby
an efficient carrier can be obtained that is easy to control.
[0024] In accordance with one embodiment an outlet yarn guide is provided at an end section
of the moveable yarn carrier, the yarn guide being located at a flat section of the
moveable yarn carrier. Hereby improved control of yarn about to leave the moveable
yarn carrier is achieved. In accordance with one embodiment a second yarn movement
restriction means are provided and adapted to prevent yarn from leaving the moveable
yarn carrier in an uncontrolled way. The movement restriction means can advantageously
be located at an end section of the moveable carrier.
[0025] In accordance with one embodiment, a spring biased element can be provided to press
yarn against the loop keeping member from the outside of the loop keeping member.
Hereby the yarn can be kept in place while being moved by the loop keeping members.
[0026] In accordance with one embodiment a slip feed device can be located before the yarn
feeding device.
[0027] The invention also extends to methods for controlling a yarn feeding arrangement
in accordance with the above and to a controller and computer program product for
controlling the yarn feeding device in accordance with the above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The present invention will now be described in more detail by way of non-limiting
examples and with reference to the accompanying drawings, in which:
- Fig. 1 is a view illustrating a yarn feeding arrangement,
- Fig. 2 is a view in perspective of a yarn feeding device,
- Fig. 3 is a view of a yarn feeding device comprising a pair of upper belts,
- Figs. 4a and 4b are different views illustrating placing yarn in a meandering pattern
onto a moveable yarn carrier of a yarn feeding device,
- Fig. 5 is a view illustrating a moveable yarn carrier in accordance with one embodiment
with pins projecting through the moveable yarn carrier,
- Fig. 6a and 6b are different views showing the end section of a moveable yarn carrier,
- Fig. 7 shows the general principles of a slip feed device.
- Fig. 8 shows a yarn feeding arrangement with a slip feed device,
- Fig. 9 is a flow chart illustrating different steps performed when forming a yarn
buffer,
- Fig. 10 is a view of a controller, and
- Figs. 11a and 1 1b illustrates further embodiments of a yarn feeding device.
DETAILED DESCRIPTION
[0029] In the following a yarn feeding arrangement for a weaving machine will be described.
In the figures, the same reference numerals designate identical or corresponding elements
throughout the several figures. It will be appreciated that these figures are for
illustration only and are not in any way restricting the scope of the invention. Also,
it is possible to combine features from different described embodiments to meet specific
implementation needs, within the scope of the appended claims.
[0030] If the yarn is fed to a weaving machine from a long loose buffer of yarn, the yarn
tension will be very low during insertion in to the weaving machine. The buffer of
yarn can for example be formed by a number of consecutive loops forming a meandering
piece of yarn that can be used during insertion in to the weaving machine.
[0031] In Fig. 1 an exemplary yarn feeding device 16 for providing a yarn buffer is shown.
The yarn feeding device 16 draws yarn 40 from a yarn storage, here represented by
a pre-winder 14. Yarn can also be drawn directly from a bobbin (not shown). The yarn
from the yarn feeding device 16 is supplied to a weaving machine 10, here represented
by a rapier weaving machine. However, the yarn feeding device can be adapted to feed
any type of weaving machine such as an air-jet weaving machine, a water jet weaving
machine or a projectile weaving machine, as well as any other suitable type of textile
machine.
[0032] The yarn can thus be taken either directly from a bobbin, or from a conventional
pre-winder by the yarn feeding device 16. A loop former 18 of the yarn feeding device
16 winds the yarn onto moving loop keeping members 20, e.g. pins provided on the yarn
feeding device. The loop former 18 can be of any suitable design. The loop former
18 will move the yarn from side to side and provide the yarn to the loop keeping members
20. The movement of the loop former 18 can be in a direction essentially perpendicular
or at least predominantly perpendicular to the movement of the loop keeping members
20. The movement of the loop former 18 can however in some embodiments deviate from
a side to side movement only to better position the yarn on to the loop keeping members.
The drive of the yarn feeding device 16 including the drive of the loop former 18
of the yarn feeding device 16 can in accordance with some embodiments be controlled
by a controller 19. The controller 19 can in accordance with some embodiments receive
input signals from different sensors generally represented by a sensor 17 in Fig 1,
and also from the weaving machine 10. This will be described in more detail below.
[0033] In Fig. 2 some parts of the yarn feeding device 16 are shown in more detail. In Fig.
2 the moving loop keeping members 20 are shown mounted on a roller 22. The moving
loop keeping members 20 are moved forward at the same speed as a yarn carrier 24 on
which the yarn leaving the moving loop keeping members is laid out. The carrier 24
can be implemented in different ways. For example, he carrier can be one or several
endless belts, caterpillar tracks or similar. The carrier 24 is also referred to as
yarn carrier or movable yarn carrier herein. In Fig. 2 one endless belt is used as
a yarn carrier 24 and is driven by the roller 22, which means that the yarn carrier
24 in this case is driven in synchronism with the loop keeping members 20. The roller
is in turn driven by a motor 21. The motor 21 can in particular be a controlled motor.
The moving loop keeping members 20 are located and driven in a manner to be accessible
for the yarn to be wound by the loop former 18 onto the moving loop keeping members
20. The loop former can be driven by a separate motor 23. In particular the motor
23 can be a controlled motor. The yarn is subsequently released or disengaged from
the loop keeping members 20 at a later stage for example by the moving loop keeping
members following the roller to get underneath the yarn carrier 24. When the moving
loop keeping members are moved under the carrier the yarn will be pushed off the moving
loop keeping member and lie free on the carrier. The loops are transported forward
in a downstream direction as the carrier 24, in this exemplary embodiment a belt,
is driven forward, thus making space for new loops upstream. Downstream the loops
are consumed by the weaving machine.
[0034] Different yarns will behave in different ways once placed on the carrier 24 as the
yarn is released from the moving loop keeping members. Some yarns will stay on the
carrier in the same or essentially the same position as the yarn is placed on the
carrier. Other yarns have a tendency to twist or move and cause snarls or entanglement
when released from the moving loop keeping members. In order to prevent that the yarn
moves in an undesired manner, the yarn can be held in position on the carrier by a
position keeping means.
[0035] In Fig. 3 an exemplary embodiment where the position keeping means is formed by a
belt or multiple belts. In the embodiment depicted in Fig. 3, where the carrier 24
is a belt (a first, lower, belt), a second, upper, belt 26, moving mainly synchronously
with the first belt 24, can be provided. The second belt 26 can be arranged as two
parallel belts as shown in Fig. 3. The second belt 26 is located above the first belt
slightly distanced from the first belt to make place for the yarn to be placed in-between
the first and second belts. If the distance between the first and second belts is
small enough the yarn has no space to twist or otherwise make undesired movements.
Hence, the distance is preferably smaller than the natural bending radius of a twisting
yarn. However, the distance must be big enough to fit the yarn at the thickest portion
of the yarn, including knots and splices. In accordance with some preferred embodiments,
but not limited to, the distance can be set to be between 1 and 6 mm.
[0036] In accordance with some embodiments the moving loop keeping members 20 are pins.
Such an embodiment is shown in Fig. 3. The pins 20 can be placed outside the belt
or belts 24, 26. The yarn will after release from the pins 20 lie smoothly on the
belt 24. When the yarn is wound on the pins 20 the yarn will be stretched between
the pins. Once released from the pins 20 the yarn 40 is no longer stretched between
the pins 20 and will form loops lying on the belt 24 in a meandering shape.
[0037] In an alternative embodiment, the moving loop keeping members such as pins 20 can
instead of being placed outside the belt as an alternative be placed in the belt or
caterpillar track or a similar carrier. In such an embodiment, a slot 28 (in fig 5)
big enough to allow the pin to project through the belt 24 without contacting the
belt can be provided.
[0038] If the pins are moving in slots, the slot length limits the relation of pin height
over the belt and the distance between each pin. For this reason, it can be advantageous
to place the pins outside the belt. In Fig. 4 a view illustrating how the loop former
18 wounds yarn 40 onto pins 20 located outside the belt 24 is shown. The loop former
18 winds yarn around one pin 20 at one side of the belt 24 and then travels with the
yarn to a pin 20 on the other side of the belt 24. This winding by the loop former
continues as the pins moves forward to continuously generate a meandering buffer of
yarn lying on the carrier.
[0039] In Fig. 5 a view illustrating a belt where the pins 20 are located in the belt is
shown. The belt is provided with slots 28 to allow the yarn to disengage from the
pins. Fig. 5 further also illustrates the limitation with regard to possible pin length
/ pitch.
[0040] Further, as is known some yarns are livelier than other yarns. To keep such lively
yarns under control movement restriction means such as brushes and clamps can be used.
Such movement restriction means can be fixed to the upper belt if one is provided,
or to any other similar arrangement provided to move at the same speed as the carrier
that transports the yarn of the yarn buffer. In Fig 3 such a movement restriction
means 29 is shown. The yarn is pressed between the movement restriction means and
the carrier. An arrangement with movement restriction means can also serve to brake
the front part of the yarn loops at the deceleration of a rapier movement in the weaving
machine, or at the end of weft insertion of an air-jet or waterjet weaving machine.
The properties of the movement restriction means can in accordance with some embodiments
be adapted to a specific weaving application. For example, if a heavy yarn is used,
the stiffness and/or pressure of the movement restriction means can be selected to
be comparatively high, and if a thin yarn is used the stiffness and/or pressure of
the movement restriction means can be selected to be comparatively low. The movement
restriction means can be of various sizes. For a yarn with a high requirement with
regard to controlling the yarn, the movement restriction means can be long, extending
from one side of the carrier to the other, or be continuous following the carrier
in the moving direction. For other yarns, small movement restriction means placed
with distance from each other can be enough to obtain sufficient control of the yarn
on the carrier. As the provision of movement restriction means will increase the yarn
take-off tension from the yarn feeding device, it is typically preferred to provide
as few movement restriction means as possible with as little force against the yarn
as possible while obtaining the desired control of the yarn.
[0041] The yarn feeding device 16 is controlled to be driven in synchronization with the
weaving machine to which it supplies yarn. The yarn buffer formed by the yarn feeding
device is controlled to always have a buffer of yarn that can be inserted into the
weaving machine. In other words, there will always be some amount of yarn placed on
the carrier during operation of the yarn feeding device when feeding a weaving machine.
The length of yarn stored on the carrier can be adapted to the speed, the weft pattern
and the width of the weaving machine. The width of the loops in the meandering yarn
on the carrier, the pitch between each loop and the number of loops possible to store
on the carrier determines the length of yarn possible to store in the yarn feeding
device. The loop former can be set to wind yarn onto the moving loop keeping members
at a speed synchronized with the drive speed of the carrier such that the yarn on
the carrier is moved forward at the speed at which yarn is wound onto the moving loop
keeping members. The speed at which the yarn is wound onto the moving loop keeping
members can be determined in several ways. A stand-alone solution is to have one or
more sensors detecting the yarn, in particular the yarn front, on the belt. The sensor(s)
can for example detect the position of the yarn buffer front edge, the amount of yarn
taken off from the yarn feeding device or similar information. In particular yarn
can be wound onto the moving loop keeping member at the same average speed as the
yarn leaves the yarn feeding device. In an alternative embodiment communication with
the weaving machine can be used. Data is fed from the weaving machine. The data can
comprise one or more of weaving machine width (pick length), speed (rpm), start &
stop of the weaving machine, weft pattern in advance etc. The speed at which the yarn
is wound onto the moving loop keeping members is then determined based on data received
from the weaving machine. In a further alternative embodiment, the yarn wind on speed
control is based on information from both one or more yarn sensors and data received
from the weaving machine.
[0042] The sensor(s) used in the yarn feeding device can be of several types, e.g. optical,
mechanical or capacitive. The sensor(s) can be of point type or an array. Alternatively,
a camera can be used as a sensor.
[0043] In accordance with one embodiment where an upper belt is provided, the upper belt
can be made as two or more separate belts running side by side at the same speed.
The sensor(s) can then be placed in a gap formed between the multiple upper belts.
Alternatively, the belts can be more or less perforated, even a mesh structure is
envisaged. Hereby the sensors can be adapted to register the yarn from both sides.
[0044] The lower belt could potentially be a problem for some sensor types. If for example
an optical sensor is used, it may be difficult for the sensor to see the difference
between a yarn and the belt. In accordance with one embodiment two or more belts are
provided as lower belts and a sensor is located in a gap between the belts. Hereby
the quality of the sensor output signal can be improved.
[0045] The drive of the yarn feeding device 16 including the loop former 18 can be made
by one or more electrical motors. The motors can be individually controlled. If one
motor is used, the different drives for the moving parts such as a belt or belts and
the loop former can be made via mechanical connections. If separate motors are used,
they are advantageously controlled to be driven in synchronization with each other.
[0046] The yarn feeding device 16 can be run in single color, weft mix or in free pattern.
If a low yarn tension is desired at a location upstream the yarn feeding device, it
can be advantageous to run weft mix of two or more channels so the time to fill the
loop buffer is longer, thereby lowering the yarn speed and tension in to the yarn
feeding device.
[0047] As the carrier is moving forward to fill up the buffer of the yarn feeding device
also when the weaving machine connected thereto is not inserting yarn, for example
during beat up, or when another channel is inserted, the belt can continue to feed
the yarn out from the carrier unless this is prevented. One way to prevent this from
happening is to provide an outlet eyelet 34, stationary or movable, before the carrier
ends. By doing this the front yarn will be prevented from leaving the carrier and
hold back the following loops. For example, when a weft insertion is finished, the
yarn buffer is continuously filled up and moved forward by the carrier 24. The moving
carrier will then transport not only the yarn loops in the buffer but also the yarn
that is between the front loops of the buffer and the weaving machine. To prevent
the yarn from leaving the carrier in an uncontrolled way, or even to fall down completely
from the carrier, a second yarn movement restriction means can be used. Such a second
yarn movement restriction means 32 is shown in Figs. 6a and 6b, where the movement
restriction means are exemplified by a brush. Other devices that prevents the yarn
from unintentionally leaving the carrier can be used such as a clip or similar. Also
shown in Fig. 6a and b is an output guide/eyelet 34 via which the yarn leaves the
yarn feeding device 16 to be inserted in to the weaving machine.
[0048] Also brake members, e.g. brushes might be placed at the sides of the lower belt to
prevent the sides of the loops to be pushed off the belt. Another possibility is to
use at least one active member to replace (reshape) some part of the yarn. Such actions
to control the yarn located on the carrier can, but need not, be done controlled by
input signals from one or more sensors provided.
[0049] To lower the yarn tension in to the yarn feeding device, a slip feed device can be
placed before the yarn feeding device. The slip feed device is a driven roller that
rotates with a peripheral speed that is higher than the necessary yarn speed. Such
a device is described in
US 5660213. When the yarn feeding device pulls the yarn during the loop formation, the yarn
will be pulled against the roller and the friction between the yarn and the rotating
roller will contribute to pull the yarn further thus decreasing the yarn tension.
As soon as the roller gives more speed to the yarn than what is consumed by the yarn
feeding device the force from the yarn against the roller will decrease and hence
the pulling force will also decrease until a balance is reached and the roller will
not give any further force to the yarn. Fig. 7 depicts an exemplary slip feed device
38 in two different views.
[0050] Using a slip feed device in the yarn feeding device as described herein can lower
the yarn tension substantially. In Fig. 8 a set-up with a slip feed device 38 before
the yarn feeding device 16 is depicted.
[0051] In Fig. 9 a flow chart illustrating some steps when controlling a yarn feeding device
(16) feeding yarn (40) to a weaving machine (10) is shown. First, in a step 501, yarn
is drawn from a yarn storage using a loop former. The yarn can be drawn from a pre-winder
or directly from a bobbin or via a slip feed device. Next, in a step 503, yarn is
placed in a meandering pattern on a moveable carrier by positioning the yarn on to
moving loop keeping members using the loop former. The loop former positions the yarn
on the moving loop keeping members by moving the yarn from side to side in a direction
perpendicular to a first direction. The moveable carrier and the moving loop keeping
members can be designed as described above. The yarn is then in a step 505 transported
in the first, forward, direction using the moveable carrier. The yarn lying on the
moveable carrier then leaves the moveable carrier at an end section of the moveable
carrier in a step 507 to be inserted into the weaving machine.
[0052] In Fig. 10 a controller 19 for controlling a yarn feeding device 16 is depicted.
The controller 19 can comprise an input/output 81 for receiving input signals for
parameters used for controlling the yarn feeding device as set out above. For example,
the input signals can be various sensor signals from sensors of the yarn feeding device.
For example, sensor signals can be provided from any type of sensor, e.g. optical
sensors, mechanical sensors or capacitive sensors. The sensors can be of point type
or an array of sensors. Alternatively, a camera can be provided to feed input signals
to the controller. Also signals from the weaving machine can be input to the controller
19 and used to control the yarn feeding device. In particular input data from the
weaving machine can comprise one or more of weaving pick length, speed (rpm), start
& stop of the weaving machine, pattern in advance and similar input data. The input/output
81 outputs motor control signal(s) to controlled motors of the yarn feeding device.
The controller 19 further comprises a micro-processor that also can be referred to
as a processing unit 82. The processing unit 82 is connected to and can execute computer
program instructions stored in a memory 83. The memory 83 can also store data that
can be accessed by the processing unit 82. The data in the memory can comprise pre-stored
data relating to the weaving machine 10. The computer program instructions can be
adapted to cause the controller to control the yarn feeding device comprising a motor
in accordance with the teachings herein. The controller can be located at any suitable
location. For example, the controller 19 can be integrated in a motor of the yarn
feeding device. The controller 19 can input output data using any suitable means.
Both wireless and wireline communication devices can be used.
[0053] The above examples are for illustration only. Numerous modifications can be envisaged
and the different embodiments can be combined to meet specific implementation needs.
For example, the moving carrier has been illustrated to be moving yarn horizontally.
It is also possible to move the yarn vertically by providing restrictions means to
keep the yarn in position during transport on the carrier. Further, in the above examples
the loop keeping members 20 are shown as generally cylindrically shaped pins. However,
other loop keeping members are also envisaged such as hooks or other elements suitable
for engaging the yarn and bring it forward. In Figs 11a and 11b an embodiment where
the loop keeping members 20 are formed as semi-cylindrical pins is shown. Using semi-cylindrical
pins, it is possible to increase the radius of the pins without adding to the space
required. Further, a spring biased element 65 can be provided to press the yarn against
the loop keeping member from outside the loop keeping member to keep the yarn better
in place once placed on the yarn keeping member until the yarn is released from the
loop keeping member. The spring biased element 65 can for example be a thin, resilient,
metal plate or a similar element.
[0054] Using the yarn feeding device as described herein will provide numerous advantages.
For example, the yarn tension in to a textile machine can be made very low. Also,
if a pre-winder is used, the ballooning problem that occurs using a conventional pre-winder
is strongly decreased. Generally, the maximum take-off speed from a yarn storage can
be significantly decreased. Multiple yarn feeding devices can be used when running
a weaving machine in weft mix whereby the yarn speed from the yarn storage can be
further reduced.
1. A yarn feeding device (16) for feeding yarn (40) to a textile machine (10), the yarn
feeding device comprising:
- a moveable yarn carrier (24) adapted to transport yarn in a first, forward direction,
- a loop former (18) adapted to draw yarn from a yarn storage (14),
- moveable loop keeping members (20) arranged at opposite lateral sides of an input
section of the moveable yarn carrier,
wherein the loop former is adapted to position yarn on the moving loop keeping members
by moving the yarn from side to side,
wherein the moveable loop keeping members are adapted to hold yarn positioned thereon
and to release yarn onto the moveable yarn carrier in a meandering pattern at an input
area of the moveable yarn carrier;
wherein the moveable yarn carrier comprises an output section, from which output section
yarn lying on the moveable carrier is adapted to leave the moveable yarn carrier;
characterized in that it further comprises at least one endless belt (26) distanced from the moveable carrier
and moving in parallel with the moveable yarn carrier.
2. The yarn feeding device according to claim 1, wherein the loop former is adapted to
position yarn on the moveable loop keeping members using a movement being predominantly
perpendicular to the first direction.
3. The yarn feeding device according to claim 1 or 2, wherein the moveable loop keeping
members are pins (20).
4. The yarn feeding device according to any of claims 1 - 3, further comprising a spring
biased element (65) provided to press yarn against the moveable loop keeping member
from the outside of the moveable loop keeping member.
5. The yarn feeding device according to any of claims 1-4, wherein at least one sensor
(17) is provided to detect yarn on the moveable yarn carrier.
6. The yarn feeding device according to any of claims 1 - 5, further comprising a controller
(19) adapted to control the drive of the yarn feeding device in response to one or
more pre-determined parameters.
7. The yarn feeding device according to claim 6, wherein the pre-determined parameters
comprise sensor signals.
8. The yarn feeding device according to any one of claims 1-7, wherein said at least
one distanced endless belt comprises a first yarn movement restriction means (29).
9. The yarn feeding device according to any of claims 1 - 8, wherein the moveable yarn
carrier is an endless belt.
10. The yarn feeding device according to any of claims 1 - 9, further comprising an outlet
yarn guide (34) at an end section of the moveable yarn carrier, the yarn guide being
located at a flat section of the moveable yarn carrier.
11. The yarn feeding device according to any of claims 1 - 10, further comprising a second
movement restriction means (32) located at an end section of the moveable yarn carrier,
which second yarn movement restriction means (32) is adapted to prevent yarn from
leaving the moveable yarn carrier in an uncontrolled way.
12. A yarn feeding arrangement comprising a yarn feeding device according to any of claims
1 - 11, the arrangement further comprising a slip feed device (38) located before
the yarn feeding device.
13. A method of controlling a yarn feeding device (16) feeding yarn (40) to a textile
machine (10), wherein yarn is inserted into the textile machine, the method comprising:
- drawing (501) yarn from a yarn storage (14), using a loop former (18),
- placing (503) the yarn in a meandering pattern on a movable yarn carrier by positioning
the yarn on to moving loop keeping members provided at both sides of a front section
of the movable yarn carrier, wherein the loop former positions the yarn on the moving
loop keeping members by moving the yarn from side to side,
- (505) transporting yarn in the first, forward, direction using the movable yarn
carrier (24),
- letting (507) the yarn lying on the moveable yarn carrier leave the movable yarn
carrier at an output section of the moveable yarn carrier,
characterized by driving at least one endless belt (26) distanced from the moveable carrier and moving
in parallel with the moveable yarn carrier.
14. A computer program product comprising computer program code adapted to cause a yarn
feeding device in accordance with claim 1 to execute the method of controlling the
yarn feeding device in accordance with claim 13.
1. Fadenzuführungsvorrichtung (16) zum Zuführen von Faden (40) zu einer Textilmaschine
(10), wobei die Fadenzuführungsvorrichtung Folgendes umfasst:
- einen beweglichen Fadenträger (24), der angepasst ist, um Faden in eine erste Vorwärtsrichtung
zu befördern,
- einen Schligenbilder (18), der angepasst ist, um Faden aus einem Fadenspeicher (14)
zu ziehen,
- bewegliche Schlingenhalteelemente (20), die an gegenüberliegenden seitlichen Seiten
eines Eingabebereichs des beweglichen Fadenträgers angeordnet sind,
wobei der Schligenbilder angepasst ist, um Faden durch Bewegen des Fadens von Seite
zu Seite auf den sich bewegenden Schlingenhalteelementen zu positionieren,
wobei die beweglichen Schlingenhalteelemente angepasst sind, um Faden darauf positioniert
zu halten, und um Faden in einem meanderförmigen Muster in dem Eingabebereich des
beweglichen Fadenträgers auf den beweglichen Fadenträger freizugeben;
wobei der bewegliche Fadenträger einen Ausgabebereich umfasst, wobei Faden, der auf
dem beweglichen Träger liegt, angepasst ist, um von dem Ausgabebereich den beweglichen
Fadenträger zu verlassen;
dadurch gekennzeichnet, dass sie weiter mindestens einen Endlosriemen (26) umfasst, der von dem beweglichen Träger
beabstandet ist und sich parallel zu dem beweglichen Fadenträger bewegt.
2. Fadenzuführungsvorrichtung nach Anspruch 1, wobei der Schligenbilder angepasst ist,
um Faden unter Verwendung einer Bewegung, die vorherrschend rechtwinkelig zu der ersten
Richtung ist, auf den beweglichen Schlingenhalteelementen zu positionieren.
3. Fadenzuführungsvorrichtung nach Anspruch 1 oder 2, wobei die beweglichen Schlingenhalteelemente
Stifte (20) sind.
4. Fadenzuführungsvorrichtung nach einem der Ansprüche 1- 3, weiter umfassend ein federbelastetes
Element (65), das bereitgestellt ist, um Faden von der Außenseite des beweglichen
Schlingenhalteelements gegen das bewegliche Schlingenhalteelement zu drücken.
5. Fadenzuführungsvorrichtung nach einem der Ansprüche 1-4, wobei mindestens ein Sensor
(17) bereitgestellt ist, um Faden auf dem beweglichen Fadenträger zu erkennen.
6. Fadenzuführungsvorrichtung nach einem der Ansprüche 1-5, weiter umfassend eine Steuerung
(19), die angepasst ist, um als Antwort auf einen oder mehrere vorbestimmte Parameter
den Antrieb der Fadenzuführungsvorrichtung zu steuern.
7. Fadenzuführungsvorrichtung nach Anspruch 6, wobei die vorbestimmten Parameter Sensorsignale
umfassen.
8. Fadenzuführungsvorrichtung nach einem der Ansprüche 1- 7, wobei der mindestens eine
beabstandete Endlosriemen eine erstes Fadenbewegungseinschränkungsmittel (29) umfasst.
9. Fadenzuführungsvorrichtung nach einem der Ansprüche 1- 8, wobei der bewegliche Fadenträger
ein Endlosriemen ist.
10. Fadenzuführungsvorrichtung nach einem der Ansprüche 1-9, weiter umfassend eine Fadenausgabeführung
(34) in einem Endbereich des beweglichen Fadenträgers, wobei die Fadenausgabeführung
in einem flachen Bereich des beweglichen Fadenträgers gelegen ist.
11. Fadenzuführungsvorrichtung nach einem der Ansprüche 1 - 10, weiter umfassend ein zweites
Fadenbewegungseinschränkungsmittel (32), das in einem Endbereich des beweglichen Fadenträgers
gelegen ist, wobei das zweite Fadenbewegungseinschränkungsmittel (32) angepasst ist,
um zu verhindern, dass Faden den beweglichen Fadenträger auf unkontrollierte Weise
verlässt.
12. Fadenzuführungsanordnung, umfassend eine Fadenzuführungsvorrichtung nach einem der
Ansprüche 1 -11, wobei die Anordnung weiter eine Gleitzuführvorrichtung (38) umfasst,
die vor der Fadenzuführungsvorrichtung gelegen ist.
13. Verfahren zum Steuern einer Fadenzuführungsvorrichtung (16), die Faden (40) zu einer
Textilmaschine (10) zuführt, wobei Faden in die Textilmaschine eingelegt wird, wobei
das Verfahren Folgendes umfasst:
- Ziehen (501) von Faden aus einem Fadenspeicher (14) unter Verwendung eines Schligenbilders
(18),
- Auflegen (503) des Fadens in einem meanderförmigen Muster auf einen beweglichen
Fadenträger durch Positionieren des Fadens auf sich bewegenden Schlingenhalteelementen,
die an beiden Seiten eines Vorderbereichs des beweglichen Fadenträgers bereitgestellt
sind, wobei der Schligenbilder den Faden auf den sich bewegenden Schlingenhalteelementen
durch Bewegen des Fadens von Seite zu Seite positioniert,
- Befördern (505) des Fadens in eine erste Vorwärtsrichtung unter Verwendung des beweglichen
Fadenträgers (24),
- Lassen (507), dass Faden, der auf dem beweglichen Fadenträger liegt, den beweglichen
Fadenträger an einem Ausgabebereich des beweglichen Fadenträgers verlässt,
gekennzeichnet durch Antreiben von mindestens einem Endlosriemen (26), der von dem beweglichen Träger
beabstandet ist und sich parallel zu dem beweglichen Fadenträger bewegt.
14. Computerprogrammprodukt, umfassend Computerprogrammcode, der angepasst ist, um zu
bewirken, dass eine Fadenzuführungsvorrichtung nach Anspruch 1 das Verfahren des Steuerns
der Fadenzuführungsvorrichtung nach Anspruch 13 ausführt.
1. Dispositif d'alimentation en fil (16) pour l'alimentation en fil (40) d'une machine
textile (10), le dispositif d'alimentation en fil comprenant :
- un porte-fil mobile (24) adapté pour transporter un fil dans une première direction
vers l'avant,
- un dispositif de formation de boucle (18) adapté pour tirer un fil d'un stockage
de fil (14),
- des éléments de maintien de boucle mobiles (20) agencés sur des côtés latéraux opposés
d'une section d'entrée du porte-fil mobile,
dans lequel le dispositif de formation de boucle est adapté pour positionner le fil
sur les éléments de maintien de boucle mobiles par déplacement du fil d'un côté à
l'autre,
dans lequel les éléments de maintien de boucle mobiles sont adaptés pour maintenir
un fil positionné dessus et pour libérer le fil sur le porte-fil mobile selon un motif
de méandres au niveau d'une zone d'entrée du porte-fil mobile ;
dans lequel le porte-fil mobile comprend une section de sortie, à partir de laquelle
section de sortie le fil se trouvant sur le porte-fil mobile est adapté pour quitter
le porte-fil mobile ;
caractérisé en ce qu'il comprend en outre au moins une courroie sans fin (26) à distance du porte-fil mobile
et se déplaçant en parallèle du porte-fil mobile.
2. Dispositif d'alimentation en fil selon la revendication 1, dans lequel le dispositif
de formation de boucle est adapté pour positionner le fil sur les éléments de maintien
de boucle mobiles en utilisant un mouvement qui est perpendiculaire de manière prédominante
à la première direction.
3. Dispositif d'alimentation en fil selon la revendication 1 ou 2, dans lequel les éléments
de maintien de boucle mobiles sont des axes (20).
4. Dispositif d'alimentation en fil selon l'une quelconque des revendications 1 à 3,
comprenant en outre un élément incliné sur ressort (65) prévu pour presser le fil
contre l'élément de maintien de boucle mobile depuis le côté extérieur de l'élément
de maintien de boucle mobile.
5. Dispositif d'alimentation en fil selon l'une quelconque des revendications 1 à 4,
dans lequel au moins un capteur (17) est prévu pour détecter le fil sur le porte-fil
mobile.
6. Dispositif d'alimentation en fil selon l'une quelconque des revendications 1 à 5,
comprenant en outre un dispositif de commande (19) adapté pour commander l'entraînement
du dispositif d'alimentation en fil en réponse à un ou plusieurs paramètres prédéterminés.
7. Dispositif d'alimentation en fil selon la revendication 6, dans lequel les paramètres
prédéterminés comprennent des signaux de capteur.
8. Dispositif d'alimentation en fil selon l'une quelconque des revendications 1 à 7,
dans lequel ladite au moins une courroie sans fin espacée comprend un premier moyen
de restriction de mouvement de fil (29).
9. Dispositif d'alimentation en fil selon l'une quelconque des revendications 1 à 8,
dans lequel le porte-fil mobile est une courroie sans fin.
10. Dispositif d'alimentation en fil selon l'une quelconque des revendications 1 à 9,
comprenant en outre un guide de fil de sortie (34) au niveau d'une section d'extrémité
du porte-fil mobile, le guide de fil étant situé au niveau d'une section plate du
porte-fil mobile.
11. Dispositif d'alimentation en fil selon l'une quelconque des revendications 1 à 10,
comprenant en outre un second moyen de restriction de mouvement (32) situé au niveau
d'une section d'extrémité du porte-fil mobile, lequel second moyen de restriction
de mouvement de fil (32) est adapté pour empêcher le fil de quitter le porte-fil mobile
d'une manière incontrôlée.
12. Agencement d'alimentation en fil comprenant un dispositif d'alimentation en fil selon
l'une quelconque des revendications 1 à 11, l'agencement comprenant en outre un dispositif
d'alimentation glissant (38) situé avant le dispositif d'alimentation en fil.
13. Procédé de commande d'un dispositif d'alimentation en fil (16) alimentant une machine
textile (10) en fil (40), dans lequel le fil est inséré dans la machine textile, le
procédé comprenant les étapes consistant à :
- tirer (501) le fil d'un stockage de fil (14), en utilisant un dispositif de formation
de boucle (18),
- placer (503) le fil dans un motif en méandres sur un porte-fil mobile par positionnement
du fil sur des éléments de maintien de boucle mobiles prévus sur les deux côtés d'une
section avant du porte-fil mobile, dans lequel le dispositif de formation de boucle
positionne le fil sur les éléments de maintien de boucle mobiles par déplacement du
fil d'un côté à l'autre,
- (505) transporter le fil dans la première direction vers l'avant en utilisant le
porte-fil mobile (24),
- laisser (507) le fil se trouvant sur le porte-fil mobile quitter le porte-fil mobile
au niveau d'une section de sortie du porte-fil mobile,
caractérisé par l'entraînement d'au moins une courroie sans fin (26) espacée du support mobile et
le déplacement en parallèle du porte-fil mobile.
14. Produit de programme informatique comprenant un code de programme informatique adapté
pour amener un dispositif d'alimentation en fil selon la revendication 1 à exécuter
le procédé de commande du dispositif d'alimentation en fil selon la revendication
13.