[0001] This invention refers to a device and a process for unwinding the yarn from the feeding
spools of spinning machines, in particular in automatic spoolers for controlling the
so-called balloon.
[0002] In order to better evidence both the technical problems faced and solved by this
invention and its advantages with respect to the known technology, brief reference
is made to the fundamental features of the spooling process is given. The basic features
of the spooling unit are illustrated in Figure 1. 1 indicates the unwinding spool
from which the yarn 2 is picked up. The yarn 2 passes through the yarn guiding elements
3, the yarn-presence sensor 4 and the yarn-stretcher 5, which generally consists of
two small facing dishes squeezing the unwinding yarn between each other. The path
further includes a splicer 6, which receives the ends of the yarn to be spliced by
aspirating nozzles, not shown for the sake of simplicity, whenever the yarn is interrupted
by a rupture or by the action of the comb 7 set immediately downstream of the splicer.
The spooled yarn is collected in the reel 8, actuated to a rotating motion by the
roller 9 and held by the reel supporting arm 10.
[0003] The driving action by the roller 9 occurs at a pre-established and substantially
constant speed, as the dimension of the growing reel changes; it attracts the yarn
2, unwinding it at a high rotating speed from the spool 1 held firm on a positioning
pin 11.
[0004] The invention is described here for exemplifying and non-limiting purposes with reference
to its main application to the processing of spools in spoolers and specifically in
a reeling phase, as the device and process according to this invention may find advantageous
applications for a high-speed unwinding of the yarn from a spool even in some textile
technology operations differing from those of a reeling operation.
[0005] A considerable technical problem is encountered while unwinding the spools in the
spooler. It must in fact be taken into account that in the spoolers of the latest
design the unwinding speeds are in the order of 25 m/sec and higher. The underlying
spool 1 is set on a positioning pin 11 and rests on its base.
[0006] The overlying reel 8 recalls the yarn from the spool positioned in the underlying
reeling unit, and the yarn is wound-up in spiraling fashion on its tube 12 to shape
the spool unwinds from the same at a whirling speed in the order of 15,000 rpm. Under
these conditions the unwinding yarn assumes, under the effect of the centrifugal force
on the yarn itself, a curved trajectory and swells out toward the outside, thus forming
the so-called "balloon" 13 around the spool itself and generating considerable centrifugal
stresses which translate to strains which may even exceed the strength of the yarn
and cause its rupturing. They further tend to deviate the spool 1 from its proper
vertical position. These centrifugal forces turn out to directly depend on the maximum
radial size of such a balloon, whose dimensions must therefore be controlled and contained.
It is further observed that the unwinding force of the yarn proceeds in an increasing
manner from the beginning to the end of the spool, depending on the greater length
of the free portion of the yarn generating the balloon 13.
[0007] A certain margin of tolerance between the internal dimensions of the spooling tube
12 and the external dimensions of its positioning pin 11 is necessary to ensure the
loading of the spool on the same by a free-falling action. In the spoolers providing
for a transfer of the spools on a mobile dish, this positioning pin is set in the
upper part of the transport dish. In this case the spool's positioning precision with
respect to the reeling unit is also influenced by the further margin of tolerance
of the positioning precision of the dish in the reeling unit during the unwinding
process. These margins may cause a misalignment of the spool with respect to its specified
position and cause some unsymmetrical strains in the balloon's rotation, thus further
aggravating the difficulties.
[0008] In the known prior art, a number of highly elaborate and complex technical solutions
have been proposed. According to the Italian patent no. 1.263.217, corresponding to
the US-patent 5.377.923, the control of the spool's balloon during the unwinding phase
is entrusted to two cylindrical tubular elements coaxial with the spool, through which
the unwinding yarn is passed; during the unwinding process the first organ remains
fixed immediately above the spool, while the second tubular organ, of a diameter greater
than that of the tube and smaller than that of the spool, follows the evolution of
the unwinding process by lowering itself and thereby evenly following the level of
the flared portion of the spool from which the yarn unwinds, while gradually lowering
itself from the top to the bottom.
[0009] According to the Italian patent application RM9400093, corresponding to the US-patent
5.553.799, the balloon is controlled by a tubular element in the shape of an upside-down
funnel which is gradually lowered, while keeping its conical portion positioned around
the flared portion of the unwinding spool.
[0010] However, these solutions are complex and expensive, also because an automatic spooler
contains dozens of reeling units needing to be individually equipped with such balloon
controlling devices, as well as with instruments and actuators to induce each reeling
unit to follow the evolution of the unwinding of the yarn from the spool, while considerably
complicating the operations of substituting the feeding spools and splicing the yarn
downstream of the combs removing imperfections from the yarn. The operation of such
devices according to the known technology may also be compromised if the spool is
not axially positioned with precision in relation to them.
[0011] This invention therefore refers to a device and a controlling process for the balloon
during the unwinding of the spool. The scope of this invention is to achieve a simplified
control of the balloon, without any of the drawbacks and complications of the similar
devices known at the state of the art.
[0012] In the most general concept of the device, this invention is defined in the first
claim.
[0013] The characteristics and advantages of the balloon controlling device according to
this invention will become more evident from the description of a few typical embodiments
in the Figures numbered from 2 to 4 for exemplifying and non-limiting purposes.
[0014] This invention achieves the control of the balloon by two organs contacted by the
yarn in its unwinding motion. One of them consists in a lever oscillating around a
rotating pin. It is illustrated in the figures according to one of its preferred embodiments
in the shape of an L, but could also perform its function in configurations equivalent
or different from those shown in a simplified manner in Figure 2, for instance in
the shape of a T or Y. Figure 2A illustrates a side view of the reeling unit, which
shows the unwinding spool where the yarn forms the winding 21 on the tube 12, and
where the L-shaped lever 22 is hinged with its upper longitudinal arm on a pin 23
so as to rotate around an axis 24. Figure 2B illustrates another side view, and the
Figure 2C a ground view of the same. The lower cross-arm 25 of the L-shaped lever
constituted by a bar set across the tube is designed to contact the unwinding yarn
and preferably built from a small metallic bar having a smooth and rounded cross-section.
According to another preferred embodiment of the invention, the bar is at its end
designed to face the tube 12 and to contact the yarn shaped in a broken line (25a,
25b, 25c, 25d) coherent with the curvature of the tube surface and designed to force
the yarn of the balloon to approach the tube 12.
[0015] A second controlling organ for the balloon is set-up Just above the top of the tube
12. It consists in an annular or tubular element 27, within which the yarn of the
rotating balloon is forced to pass while sliding over its surfaces and thus reducing
its rotating speed. In its simplest version it may be made of a ring or a metallic
bar ringlet, as already known in the art to define the tip of the balloon. According
to a preferred embodiment of the invention, the element 27 is built in a tubular shape
and with a cross-section configured with radial changes, or by alternating sections
of different curvature or concave and convex elements so as to thereby exert a high
braking action in regard to the balloon's circulating motion. In order to achieve
the best containing and braking effects on the rotation of the balloon during the
spool unwinding operation, this second element 27 is preferably placed at an axial
distance s of 10-60 mm from the tip of the tube 12. The Figures 3A, B illustrate a
few forms of the transversal cross-section of the tubular element 27 according to
the invention.
[0016] This second tubular element for controlling the balloon may be constructed with a
continuous lateral wall, as illustrated in Figure 3A, or be equipped with a longitudinal
slit 28 to insert the yarn, as shown in Figure 3B, depending on the process of starting-up
and resuming the reeling operation adopted to build the spooling machine.
[0017] The first element with an L-shaped lever is equipped with a positioning device in
relation to the lower arm 25 of the L-shaped lever with respect to the tip of the
tube 12, a typical embodiment of which will be described below.
[0018] In order to better evidence the characteristics and advantages of the invention,
we are herewith describing the process of controlling and containing the balloon,
while utilizing the elements of the device described up to this point, with reference
to the Figures 2.
[0019] In the most general meaning of the process, this invention is described in claim
8.
[0020] According to this invention, during the unwinding phase the lower part 25 of the
L-shaped lever of the balloon controlling device is kept as close as possible but
not in contact with the upper part of the tube 12, at a distance d of less than 10
mm and preferably between 1 and 2 mm, at the point of minimum distance between the
tube 12 and the bar 25. In the embodiment according to Figures 2, the bar 25 constituting
the lower arm of the L-shaped lever is shown in a configuration following the broken
line 25a, b, c, d, according to one of its preferred embodiments aimed at enhancing
the contacting effect between the yarn and the bar 25. This precision approach to
the tube must be achieved independently of its more or less exact position and of
the precision of its diameter, in a repetitive manner for all reeling stations and
for each of them at every change of the spool, and even, according to a preferred
embodiment, at each splicing cycle. The possible shortage in the diameter of the tube
and/or of the true positioning of the spool 1 with respect to its exact position may
reach 2-3 mm and more; this change to a greater or lesser value is already highly
significant for the purposes of controlling the balloon.
[0021] At every change of the spool or at any splicing cycle the L-shaped lever is rotated
to a retracted position, so as not to interfere with these operations. Before restarting
the unwinding process, the L-shaped lever is rotated until it rests on the tube of
the spool, in its upper part and preferably within 10-20 mm from its tip. After contacting
the tube, it is therefore withdrawn by a very small, pre-established distance, which
would preferably, as already described above, be within a range of 1-2 mm. The contact
with the tube, independently of the precision of its diameter or position, allows
establishing a precise reference point for this distance. Shortly before the L-shaped
lever assumes this detached yet very close position to the tip of the tube, the unwinding
of the spool is started or re-started, both to achieve the reeling of the yarn and
to form the upper reel. According to this invention, it is surprising that with this
setup the balloon 13 of the yarn 2 unwinding from the spool 1 swells up to a very
limited extent, because at every turn around the spool the yarn of the balloon is
forced to re-approach its tube due to the constraint represented by the broken-line
bar 25 of the L-shaped, balloon-rupturing lever; the balloon is thereby kept from
swelling up - generally known as "blowing up" - as would on the contrary occur in
the absence of such a constraint, which would not allow it the time to blow up and
attain the configuration of a balloon that it would otherwise spontaneously assume.
The tension of the balloon's yarn as a result of the centrifugal force is thereby
drastically reduced, even during the unwinding of the final portion of the spool with
the greatest free length of yarn which generates the balloon 13.
[0022] Downstream of the bar 25 of the L-shaped balloon-bursting lever the yarn encounters
a second controlling organ of the balloon constituted by the annular or tubular element
31 which exerts both a second radial containment action of the balloon and a braking
action on its rotating speed, which acts along the yarn on the spool and toward the
tip of the tube.
[0023] The Figures 4 show a typical embodiment of the approaching and detaching device of
the L-shaped lever in a direction to the tip of the tube. For simplicity, the figures
show the lower part 25 of the L-shaped lever in a rectilinear configuration. This
device allows the sensing of the true position of the L-shaped balloon-bursting lever
in an operating position during the unwinding process.
[0024] In Figure 4A the device 30 is shown in a position ready for a spool change, with
the L-shaped lever 22 in a retracted position with respect to the tube 12. It consists
of an actuator and in the embodiment shown of an electromagnet 31, governed by the
control cables 32, which retracts the cursor 33 to its interior when excited. A transversal
dish 34 is rigidly coupled to the bar of the cursor 33; it acts as a stop at one end
of a compression spring 35 affixed to the body of the magnet, while the other end,
whenever the magnet is not excited, extends and retracts the cursor 33 to its outermost
position shown in Figure 4A. The dish 34 is also connected with the traction spring
36 which hooks up with the other end to the lever 22, in its part opposite to the
arm 25, so as to rotate around the axis 24 of the rotating pin 23.
[0025] An adjusting plate 37 is mounted around the same axis 24 and on the same pin 23.
This plate is forced to rotate together with the lever 22, both by the presence of
two pegs 40 and 41 constituting the end-stops of the relative rotation between the
lever 22 and the plate 37, and by the pressure spring 43 resting on one side on the
lever 22 and on the other side on a projection 42 of the plate 37.
[0026] In the configuration shown in Figure 4A the actuating magnet 31 is not excited, the
spring 35 is extended and projects the cursor 33 toward the lever 22, causing the
latter to rotate in a counterclockwise direction. This lever 22 compresses the spring
43 and also causes the plate 37 to rotate in a counterclockwise direction toward the
indicated position.
[0027] Figure 4B shows the device 30 in a position to contact the tube of the spool, with
the L-shaped lever 22 advanced to its utmost extent, so as to touch the tube 12 using
the bar 25. In the configuration shown in Figure 4B, the actuating magnet 31 is excited;
it retracts the cursor, compresses the spring 35, and by retrieving the cursor 33
tensions the spring 36 and pulls the lever 22 to the right, so as to rotate it in
a clockwise direction. The lever 22 rests on the peg 40 and also causes the plate
37 to rotate in a clockwise direction to the indicated position. The rotation in a
clockwise direction stops when the arm 25 comes to rest on the tip of the tube 12.
This configuration attains a position in which it zeroes the distance between the
tube 12 and arm 25, thus creating a true and useful reference point, despite the fact
that the spool - or better said the tip of its tube - is in an imprecise position
which does not fit its precise location.
[0028] Figure 4C shows the device 30 in a position to make contact with the tube of the
spool, with the L-shaped lever 22 held in its most extended position, so as to touch
the tube 12 while using the bar 25. The zeroing position is fixed by blocking the
adjusting plate 37 in a corner, thus preventing it, up to the next unblocking step,
from rotating again around the pin 23. This blockage occurs by using an actuator,
and in the embodiment shown, by using an electromagnet 44 governed by the control
cables 45, which if excited projects a cursor 45 to the outside which engages and
blocks the plate 37 using its extremity 47.
[0029] Figure 4D shows the device 30 in an operating position ready for unwinding the yarn,
while holding the arm 25 of the L-shaped lever retracted at a distance d from the
tube 12. In the configuration shown in Figure 4D the excitation of the actuating magnet
31 is discontinued, the spring 35 extends and projects the cursor 33 toward the lever
22, thereby pushing it so as to rotate in a counterclockwise direction. This lever
22 compresses the spring 43, while rotating counterclockwise by an angle α up to the
point of resting the lever 22 on the peg 41 in the indicated position. After this
rotation the arm 25 finds itself at the distance d and cannot move further, because
the actuator 44 blocks the plate 37 and its peg 41 prevents the L-shaped lever 22
from moving further.
[0030] It can easily be seen that adjusting the distance d corresponds to adjusting the
rotating angle of the lever 22 between the pegs 40 and 41, or by their angular distance
α with respect to the pin 23.
[0031] In summary, the approaching and detaching device of the L-shaped lever to the tip
of the tube consists in an actuator 31 designed to axially move the cursor 33 between
an extracted and retracted position, and to rotate the L-shaped lever in a counterclockwise
and clockwise direction, respectively, around its pin 23, combined with an adjusting
plate 37 which rotates with respect to the same pin 23 together with the L-shaped
lever 22. This adjusting plate 37 is further equipped with the blocking actuator 44,
which acts in a zeroing position, and by the end-stops 40, 41 which allow the L-shaped
lever 22 to rotate with respect to the plate 37 by the angle α, depending on the push
of the actuator 31.
[0032] As an example, the plate 37 can be fitted with a row of perforations for the positioning
of the pegs 40 and 41, at variable angular apertures with respect to the rotating
axis 24 of the pin 23. This embodiment is in a simplified manner described in Figure
4E, which refers to the plate 37 and shows the perforations 50 a-d and 51 a-d in which
the pegs 40 and 41 can be respectively inserted, while gradually restricting the aperture
angle α with respect to the axis 24, by advancing from the index a to the index d.
The distance d is correspondingly reduced by adjusting.
[0033] When the unwinding stops and an operation must be performed at the reeling station,
such as the changing of a spool or the splicing of a yarn cycle, it suffices to unblock
the actuating magnet 44 by shutting off its excitation to cause the compression spring
35 to complete its extension of the cursor 33, until the end-stop configuration of
Figure 4A is attained.
[0034] Based on a further embodiment of this invention, the oscillating lever 22 may be
assigned - during the unwinding operation of the spool - to perform the further function
of a so-called "curling prevention", according to the European patent no. 275.596
by the same Applicant. For this purpose, the release of the lever 22 to touch the
tip 12 of the tube can be obtained according to the configuration in Figure 4C, by
holding the plate 37 blocked by the actuator 44 and activating the excitation of the
magnetic actuator 31, which retracts the cursor 33. This actuation is accompanied
by a connection - for example through the control unit of the machine to the sensor
4, which triggers the excitation of the magnet 31, as soon as it no longer receives
a signal sensing the presence of the yarn 2 moving in its interior. The approaching
of the bar 25 to the tube 12 within short periods of time allows blocking the ascending
end of the yarn between the bar and the tube, thus preventing it from curling up and
allowing it to be easily caught by the service nozzle while avoiding any needless
waste of yarn during the re-splicing phase.
[0035] It can easily be seen that the balloon's controlling device according to the invention
need not follow the course of the unwinding from the spool by displacing it in an
axial direction; once it is set in position, it does not require any axial shifting
during the unwinding process but remains fixed, nor any monitoring of the level from
which the yarn is unwinding. The device according to the invention allows the machine
to accept the processing of spools wound on tubes of various diameter, without the
need to change any parts of the machine, as occurs on the contrary when using the
devices of a known technology. The approaching and positioning actuators of the balloon-bursting
lever are of an on-off type and do not require any sensing instruments, as the device
mechanically zeroes itself to create its own reference in the contact position.
1. Device for containing and controlling the balloon while unwinding the feeding spools
in spinning machines and in particular in automatic spoolers, said device consisting
of two elements interacting with each other, characterized in that the first element
consists of an oscillating lever hinged on a pin (23) formed by an upper longitudinal
arm (22) and a lower cross-arm (25) designed to contact the unwinding yarn, where
said lever is equipped with devices (30) to move its cross-arm (25) in a radial direction
with respect to the tip of the tube (12), and by a second element set above the tip
of the tube (12) and consisting in an annular or tubular element (27) within which
the yarn of the rotating balloon passes while sliding over its walls and decreasing
its rotating speed.
2. Device for containing and controlling the balloon according to claim 1, characterized
in that the first element consists of an oscillating L-shaped lever.
3. Device for containing and controlling the balloon according to claims 1 or 2, characterized
in that the cross-bar (25) is configured according to a broken line (25a, b, c, and
d).
4. Device for containing and controlling the balloon according to claim 1, characterized
in that the second element (27) for controlling and containing the balloon is placed
at an axial distance (s) of 10-60 mm from the tip of the tube (12).
5. Device for containing and controlling the balloon according to claim 1, characterized
in that the second element (27) for controlling and containing the balloon is constructed
in a tubular form and with a cross-section configured with radial changes, so as to
exert a high braking action with respect to the balloon's circulating motion.
6. Device for containing and controlling the balloon according to claim 4, characterized
in that the second element (27) is built by alternating sections of different curvature,
or by alternating concave and convex elements.
7. Device for containing and controlling the balloon according to claim 1, characterized
in that the devices (30) for moving its transversal arm (25) are susceptible to cause
said arm to alternatively assume a retracted non-interfering position in which said
arm comes to rest on the upper part of the tube (12) of the spool, and a retracted
position at a very short and pre-established distance from the tube (12).
8. Device for containing and controlling the balloon according to claim 7, characterized
in that the devices (30) for moving its cross-arm (25) consist in an actuator (31)
to move a cursor (33) in an axial direction between an extended and a ratracted position,
so as to cause the lever (22) to rotate in a respectively counterclockwise and clockwise
direction around a pin (23), and in an adjusting plate (37) rotating with respect
to the same pin (23) together with the lever (22), where said adjusting plate (37)
is equipped with blocking devices (44) in a zeroing position and with end-stops (40,
41) allowing the lever (22) to rotate with respect to the plate (37) by an angle α
depending on the push of the actuator (31).
9. Device for containing and controlling the balloon according to claim 8, characterized
in that the actuator (31) retracting the cursor (33) is accompanied by a connection
to the sensor (4) of the yarn, thereby allowing the oscillating lever (22) to also
perform a curling-prevention function during the spool unwinding operation.
10. Device for containing and controlling the balloon while unwinding the feeding spools
in spinning machines, and in particular in automatic spoolers while using the device
according to one or several of the foregoing claims, characterized in that the lower
part (25) of the lever (22) of the balloon controlling device is during the unwinding
phase kept close to the upper part of the tube (12), as close as possible but not
in contact with the same, at a distance d below 10 mm and preferably between 1 and
2 mm, at the point of the minimum distance between the tube (12) and the bar (25).
11. Process for containing and controlling the balloon according to claim 10, characterized
in that at every change of the spool or at every splicing cycle the lever (22) is
rotated to a retracted position so as not to interfere with these operations, that
prior to restarting the unwinding operation the lever (22) is rotated to the point
of resting with the arm (25) on the upper part of the tube (12) of the spool (1) and
preferably at a distance of 10-20 mm from its summit, that after contacting the tube
(12) it is retracted to the distance pre-established for the unwinding operation,
and that shortly before the lever (22) assumes this position of being detached and
very close to the tip of the tube the spool's unwinding operation is started or restarted
to reel up its yarn (2) and to form the upper reel (8).
12. Process for containing and controlling the balloon according to claim 10, characterized
in that during the unwinding operation of the spool the sensor (4), when it no longer
senses the signal of a presence of the yarn (2), causes the excitation of the actuator
(31), thus inducing the bar (25) to approach the tube (12) and block the ascending
end of the yarn between the bar and the tube.