BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a yarn end retrieving apparatus which releases a
yarn end from a surface of a bobbin (spinning bobbin), cuts the released yarn to a
given length, and sucks the cut yarn into a winding core of the bobbin.
Description of the Related Art
[0002] A yarn end retrieving apparatus of this kind is well known from the Unexamined Japanese
Patent Application Publication (Tokkai-Hei) No.
7-97142. In the yarn end retrieving apparatus, an entire surface of a bobbin is covered with
a suction cylinder. Suction air is applied to the suction cylinder to suck a yarn
end from the bobbin surface. The suction cylinder is supported and guided so as to
elevate and lower freely, by a guide structure provided in the yarn end retrieving
apparatus. An operation cylinder can operate the suction cylinder so that the suction
cylinder moves between a standby position above the bobbin and a lowered position
where the suction cylinder covers the entire surface of the bobbin.
[0003] The suction cylinder is suspended by a cutter device via a flexible cylinder via
a flexible cylinder that can be expanded and contracted in a vertical direction. A
yarn sucked out via the suction cylinder can be cut to a predetermined length by the
cutter device. The cutter device also serves as a shutter that blocks the suction
air. The guide structure is composed of a pair of guide shafts, a slider slidably
guided along the guide shafts, and others. The suction cylinder is fixed to the slider
so as to be able to move together with the slider.
[0004] According to the present invention, an elevating and lowering mechanism using a stepping
motor as a driving source elevates and lowers the suction cylinder. A similar elevating
and lowering mechanism is described in the Unexamined Japanese Patent Application
Publication (Tokkai-Hei) No.
8-324892. According to the Unexamined Japanese Patent Application Publication (Tokkai-Hei)
No.
8-324892, the elevating and lowering mechanism elevates and lowers a yarn end releasing member
and is composed of, for example, a vertical pair of belt rollers, a belt wound around
both belt rollers, and a reversible motor that rotationally drives one of the belt
rollers. The yarn end releasing member is fixed to a straight traveling portion of
the belt so as to be movable together with the belt via a carriage.
BRIEF SUMMARY OF THE INVENTION
[0005] In a yarn end retrieving apparatus of this kind, the standby position of the suction
cylinder is changed depending on the vertical size of the bobbin. A lower end of the
suction cylinder is placed at a predetermined position above an upper end of the bobbin.
In the yarn end retrieving apparatus in the Unexamined Japanese Patent Application
Publication (Tokkai-Hei) No.
7-97142, since the operation cylinder elevates and lowers the suction cylinder, stoppers
are provided in a middle part of a reciprocating stroke of the operation cylinder
to allow the standby position of the suction cylinder to be changed.
[0006] Specifically, the stoppers are installed on the guide shafts of the guide structure.
An elevation upper limit position of a slider can be changed by changing positions
where the stoppers are fixed. Thus, the standby position of the suction cylinder can
be changed in the vertical direction. As described above, in the yarn end retrieving
apparatus in the Unexamined Japanese Patent Application Publication (Tokkai-Hei) No.
7-97142, the fixed positions of the stoppers are manually adjustably changed depending on
the vertical size of the bobbin. Thus, much time and effort is required to change
a lot. Furthermore, the result of the adjustment based on the manual adjustably changing
operation is likely to vary. Since the operation cylinder is used to elevate and lower
the suction cylinder, the suction cylinder needs to be operatively moved at the same
speed both during elevation and during lowering. This is inconvenient.
[0007] Furthermore, in the Unexamined Japanese Patent Application Publication (Tokkai-Hei)
No.
7-97142, the cutter device is fixed to an upper part of one side of the machine body. Thus,
the yarn end sucked into the cutter device is always cut at a constant position regardless
of a change in the standby position of the suction cylinder, that is, a change in
the vertical size of the bobbin. Thus, the length of the yarn resulting from the cutting
by the cutter device may be excessively long or short. For example, the length of
the yarn inserted into the winding core which length is appropriate to a bobbin with
a large vertical size may be excessively large for a bobbin with a small vertical
size. When the length of the yarn inserted into the winding core is excessively long
or short, an automatic winder device for the subsequent step into which the bobbin
is to be fed may fail to properly catch the yarn end. Then, the automatic winder device
may operate improperly.
[0008] An object of the present invention is to provide a yarn end retrieving apparatus
that enables the standby position of the suction cylinder to be automatically changed
depending on the vertical size of the bobbin, thus allowing the setup of the yarn
end retrieving apparatus to be easily and accurately changed in association with a
lot change. An object of the present invention is to provide a yarn end retrieving
apparatus that allows the movement speed of the suction cylinder to be set to be suitable
for elevation and for lowering, thus enabling a reduction in the time required for
a whole yarn end retrieving process. An object of the present invention is to provide
a yarn end retrieving apparatus that allows the length of the yarn resulting from
the cutting by the cutter device to be suitably set depending on a change in the vertical
size of the bobbin.
[0009] A yarn end retrieving apparatus comprises a yarn releasing device sucking and releasing
a yarn end from a surface of a bobbin together with suction air, via a suction cylinder
surrounding a periphery of the bobbin, a cutter device cutting the yarn sucked out
by the yarn releasing device, a cylinder elevating and lowering device including a
driving source elevating and lowering the suction cylinder between a standby position
above the bobbin and a lowered position where the suction cylinder covers the surface
of the bobbin, and a control means for controlling an elevating position and a lowering
position for the cylinder elevating and lowering device. Thus, the cylinder elevating
and lowering device operated by the control means holds the suction cylinder at a
predetermined position.
[0010] The predetermined position where the position of the suction cylinder is held includes
the standby position of the suction cylinder.
[0011] Another yarn end retrieving apparatus according to the present invention comprises
a yarn releasing device sucking and releasing a yarn end from a surface of a bobbin
together with suction air, via a suction cylinder surrounding a periphery of the bobbin,
a cutter device cutting the yarn sucked out by the yarn releasing device, a cutter
elevating and lowering device including a driving source elevating and lowering the
cutter device, and a control means for controlling an elevating position and a lowering
position for the cutter elevating device.
[0012] A sensor sensing shape of the bobbin with the yarn wound therearound is provided
so as to be movable together with the suction cylinder.
[0013] A driving source elevating and lowering the suction cylinder and the driving source
elevating and lowering the cutter device are each composed of a stepping motor.
[0014] In the present invention, the yarn end retrieving apparatus comprises the yarn releasing
device, the cutter device, the cylinder elevating and lowering device including the
driving source elevating and lowering the suction cylinder, and the control means
for controlling the elevating and lowering positions for the cylinder elevating and
lowering device. According to the yarn end retrieving apparatus, the cylinder elevating
and lowering device operated by the control means enables the suction cylinder to
be held at the predetermined position. Thus, an elevating and lowering speed and an
elevating and lowering stroke for the suction cylinder can be freely set to hold the
suction cylinder at the position corresponding to the bobbin to be processed. Thus,
compared to conventional yarn end retrieving apparatuses requiring manual change and
adjustment of the suction cylinder, the present yarn end retrieving apparatus allows
the setup thereof to be quickly and easily changed in association with a lot change.
Furthermore, simply by inputting bobbin data to the control means, the standby position
of the suction cylinder can be automatically determined. Additionally, the suction
cylinder can be held at the predetermined position. When the standby position of the
suction cylinder is to be changed, for example, an expected result of the change is
displayed on a display device. Then, the expected result of the change can be understood
to determine whether or not the change is acceptable.
[0015] When the predetermined position where the position of the suction cylinder is held
includes the standby position of the suction cylinder, the standby position of the
suction cylinder can be automatically changed depending on the vertical size of the
bobbin. Thus, the standby position of the suction cylinder can be accurately changed
in association with a lot change.
[0016] The alternative yarn end retrieving apparatus according to the present invention
comprises the yarn releasing device including the suction cylinder, the cutter device
cutting the yarn sucked out by the yarn releasing device, the cutter elevating and
lowering device elevating and lowering the cutter device, and the control means for
controlling the elevating and lowering position for the cutter elevating and lowering
device. According to the yarn end retrieving apparatus including the cutter elevating
and lowering device elevating and lowering the cutter device, a yarn cutting position
can be optimized according to the vertical size of the bobbin. This enables elimination
of excess or shortage of the yarn sucked into a winding core, allowing a winder to
reliably catch the yarn. Furthermore, simply pre-inputting bobbin data to the control
means allows the control means to automatically determine a vertical position of the
cutter device so that the cutter elevating and lowering device can elevate and lower
the cutter device to appropriate positions. Thus, the setup of the yarn end retrieving
apparatus can be quickly and easily changed in association with a lot change.
[0017] When the sensor moving together with the suction cylinder can sense the shape of
the bobbin with the yarn wound there around, whether the bobbin to be processed is
a full bobbin, a half bobbin, or a smaller bobbin (a bobbin with a small amount of
remaining yarn). This enables the suction cylinder to be elevated and lowered in a
manner compatible with each bobbin. For example, with the half bobbin, the suction
cylinder is quickly lowered from the standby position to a height position where the
yarn is to be sucked and released and then lowered at a speed suitable for the suction
and release. Thus, the waste of time associated with the elevation and lowering of
the suction cylinder can be avoided.
[0018] When the driving source elevating and lowering the suction cylinder and the driving
source elevating and lowering the cutter device are each composed of the stepping
motor, the elevating and lowering speeds for the suction cylinder and the cutter device
can be freely set. Therefore, the suction cylinder and the cutter device can be elevated
and lowered efficiently to allow a displacement operation to be suitably performed.
Furthermore, the suction cylinder and the cutter device can be accurately moved to
the predetermined positions.
[0019] Other features, elements, processes, steps, characteristics and advantages of the
present invention will become more apparent from the following detailed description
of preferred embodiments of the present invention with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020]
Figure 1 is a schematic side view of a yarn end retrieving apparatus.
Figure 2 is a diagram illustrating sequential operations of the yarn end retrieving
apparatus.
Figure 3 is a sectional view taken along line A-A in Figure 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] Figures 1 to 3 show an embodiment of a yarn end retrieving apparatus according to
the present invention. In Figure 1, the yarn end retrieving apparatus has a vertically
long machine body 2 located so as to face a conveying path for a bobbin 1, and a yarn
releasing device 3 extending from an upper front portion of the machine body 2 to
the interior of the machine body 2. The yarn releasing device 3 is composed of, for
example, a fan 4 that generates a suction air flow, a suction pipe 5 connected to
an inlet port of the fan 4, and a pair of nozzles 6 that blows compressed air against
the bobbin 1. The suction pipe 5, located in the upper front portion of the machine
body 2, is bent into an inverse L shape. A yarn sensing sensor 7 is located in an
inner corner of the folded portion of the suction pipe 5. The bobbin 1 includes a
winding core 8 with vertically opposite open ends. A lower end of the winding core
8 is supported on a conveying tray 9 provided along a conveying path.
[0022] A cutter device 10 cutting a middle part of a yarn Y sucked out by the yarn releasing
device 3 is located at a lower end of the suction pipe 5 which projects forward in
the machine body 2. An upper end of a flexible cylinder 12 that can be expanded and
contracted in a vertical direction is fixed to a cylinder wall 11 that is continuous
with a lower end of the cutter device 10. A suction cylinder 13 is connected to a
lower end of the flexible cylinder 12. The cutter device 10 includes a cutter blade
14 and a driving structure (not shown in the drawings) for the cutter blade 14. The
cutter blade 14 also functions as a shutter that blocks a suction air flow acting
on the suction pipe 5. The cutter blade 14 having cut the middle part of the yarn
Y can block the suction air flow.
[0023] The suction cylinder 13 is formed of a cylinder larger than the size of the diameter
of a yarn layer on the bobbin 1. The suction cylinder 13 is elevated and lowered between
a standby position and a lowered position by a cylinder elevating and lowering device
16 provided inside the machine body 2. The cylinder elevating and lowering device
16 is composed of a guide structure and a driving structure that elevates and lowers
the suction cylinder 13 along the guide structure.
[0024] The guide structure is composed of a pair of guide shafts (guide members) 17 arranged
side by side in a front-back direction, brackets 18 that fixedly support an upper
end and a lower end, respectively, of each of the guide shafts 17, and a slider 19
that is slidably guided along both guide shafts 17 so as to be able to elevate and
lower. As shown in Figure 3, the slider 19 is composed of slide blocks 20 slidably
guided along the guide shafts 17, a coupling plate 21 that connects the slide blocks
20 together, and a coupling block 22 fixed to the coupling plate 21 between the slide
blocks 20. The suction cylinder 13 is joined and fixed to the coupling plate 21 via
a joining arm 23 projecting from an outer surface of the suction cylinder 13.
[0025] A driving structure is composed of a stepping motor 25 located above the upper bracket
18 and serving as a driving source. Specifically, the driving structure is composed
of an upper pulley 26 fixed to an output shaft of the stepping motor 25, a pulley
27 rotatably supported by the lower bracket 18, and a driving belt 28 wound around
both pulleys 26, 27. Both pulleys 26, 27 are composed of timing pulleys, and the driving
belt 28 is composed of a timing belt. The driving belt 28 is located so as to sandwich
the coupling plate 21 between an upper part and a lower part of the belt. As shown
in Figure 3, one straight-line transition portion of the belt is fixedly clamped to
the coupling block 22 of the slider 19 via a seat plate 29 by means of a bolt 30.
[0026] The driving belt 28 is located parallel to the guide shafts 17. The straight-line
transition portions of the driving belt 28 enable the slider 19 to be drivingly elevated
and lowered along the guide shafts 17. Thus, the suction cylinder 13 is elevated and
lowered between the standby position (the position shown in Figure 1) above the bobbin
1 and the lowered position (the position shown in Figure 2B) where the suction cylinder
13 covers the surface of a lower part of the bobbin 1.
[0027] The suction cylinder 13 is held at the standby position at a given distance from
the position of an upper end of the bobbin 1 depending on the vertical size of the
bobbin 1. Specifically, size data on the bobbin 1 to be processed is pre-input to
a control circuit (control means) 43. This determines the standby position of the
suction cylinder 13. By counting the number of steps from a reference position taken
by the stepping motor 25, the suction cylinder 13 can be held at an appropriate standby
position.
[0028] A sensor 33 sensing the shape of the bobbin 1 with the yarn wound therearound is
installed on the suction cylinder 13. The sensor 33 senses the external shape of the
yarn layer on the bobbin 1 to enable determination of whether the bobbin 1 is a full
bobbin 1 around which the yarn Y has been fully wound, a half bobbin 1 from which
a part of the yarn layer has been unwound by the winder, or a smaller bobbin 1 with
a small amount of remaining yarn layer.
[0029] Based on pre-input bobbin data, the control circuit 43 automatically determines the
standby position of the suction cylinder 13. Concurrently, the cutter device 10 is
elevated and lowered by the cutter elevating and lowering device 35. Thus, a cutting
position for the yarn Y can be optimized. Here, the standby position of the suction
cylinder 13 is slightly higher than a position corresponding to the vertical size
(height dimension) of the bobbin 1, which is conveyed in an upright condition. When
the standby position is set to be sufficiently higher than the position corresponding
to the height dimension of the bobbin 1, all bobbins 1 can be dealt with. However,
if the bobbin 1 to be processed has a small vertical size, an unwanted elevating and
lowering operation needs to be performed, thus reducing efficiency. In general, the
standby position of the suction cylinder 13 is set to be higher than the upper end
of the bobbin 1 to be processed, by about 10 mm. The cutter elevating and lowering
device 35 is composed of a stepping motor 36 fixed to the machine body 2, a feed screw
shaft 37 rotationally driven by the stepping motor 36, and a female threaded member
38 elevated and lowered by the feeding screw shaft 37. An upper end of the feed screw
shaft 37 is coupled to the stepping motor 36 via a coupling. A lower end of the feed
screw shaft 37 is supported by a bracket 39 fixed to the machine body 2. The female
threaded member 38 is fixed to a coupling frame 40 fixed to the lower end of the cutter
device 10. The stepping motor 36 is started or stopped based on an instruction signal
output by the control circuit 43.
[0030] In the cutter elevating and lowering device 35, when the feed screw shaft 37 is rotationally
driven forward or backward by the stepping motor 36, the female threaded member 38
is displaced upward or downward to elevate or lower the cutter device 10. Thus, the
cutting position for the yarn Y can be optimized depending on a change in the vertical
size of the bobbin 1. The cutting position for the yarn Y is set such that the total
length of the yarn Y sucked into the winding core 8 is slightly smaller than the vertical
size of the bobbin 1. When the cutter device 10 is displaced so as to elevate or lower,
the suction pipe 5 is displaced so as to elevate and lower together with the cutter
device 10.
[0031] Now, an operation of the yarn end retrieving apparatus will be described. When the
full bobbin 1 is conveyed to the vicinity of a yarn setup portion together with the
conveying tray 9, a cut device provided on the left side of the yarn end retrieving
apparatus in a conveying direction is activated to cut the yarn Y fixedly wound around
an upper end or a lower end of the winding core 8. Thereafter, the bobbin 1 is conveyed
to the front of the yarn end retrieving apparatus. Then, the conveying tray 9 is stopped
and held by a stopper (not shown in the drawings). Moreover, a lower part of the bobbin
1 is pressed and held by a presser lever (not shown in the drawings). Then, as shown
in Figure 1, compressed air is blown out from nozzles 6 to blow the yarn Y cut by
the cut device to above the bobbin 1.
[0032] In the above-described condition, the cutter blade 14 is operatively displaced to
a cutting standby position. The cutter blade 14 blocking the suction pipe 5 is thus
displaced to a passage open position. Consequently, the suction pipe 5 and the suction
cylinder 13 communicate with each other via the cutter device 10 and the flexible
cylinder 12 so that a suction air flow can act on the suction cylinder 13.
[0033] In this condition, the stepping motor 25 is started based on an instruction signal
output by the control circuit 43. The suction cylinder 13 is lowered via the slider
19 at a predetermined speed. As the suction cylinder 13 lowers, an upward suction
air flow acts on a peripheral surface of the bobbin 1. Thus, the yarn end being blown
upward by air through the nozzles 6 is sucked into the suction pipe 5 via the suction
cylinder 13, the flexible cylinder 12, and the cutter device 10 as shown in Figure
2B.
[0034] The sensor 7 senses that the yarn Y has been sucked into the suction pipe 5. Then,
as shown in Figure 2C, the stepping motor 25 is reversely driven to return the suction
pipe 13 to the standby position. However, if the yarn Y cannot be sensed by the sensor
7 even though the lower end of the suction cylinder 13 has reached the lower end of
the bobbin 1, the suction cylinder 13 is returned to the standby position and then
lowered again to suck the yarn using a suction air flow. The suction cylinder 13 attempts
to suck the yarn a plurality of times. If the attempts have failed to allow the sensor
7 to output a signal indicating that the yarn Y has been sensed, the stopper for the
conveying tray 9 is released to allow the bobbin 1 to be discharged from the yarn
setup position.
[0035] After the yarn Y is sensed by the sensor 7 and the suction cylinder 13 then returns
to the standby position, a middle part of the yarn Y unwound from the bobbin 1 is
pressed and held against the peripheral surface of an upper part of the winding core
8 by a presser lever 44 (see Figure 2C). In this condition, the cutter device 10 is
actuated to cut the yarn Y and to allow the cutter blade 14 to close the lower end
of the suction pipe 5 to block the suction air flow. Concurrently with the driving
of the cutter device 10, a shutter of a yarn sucking device 45 provided below the
conveying tray 9 is opened. Thus, a downward suction air flow acts on the interior
of the winding core 8 to suck the end of the cut yarn Y into the winding core 8 of
the bobbin 1 as shown in Figure 2D. Finally, the presser lever 44 and the presser
lever 44 pressing and holding the lower part of the bobbin 1 are operatively returned.
Moreover, the stopper stopping and holding the conveying tray 9 is returned to the
standby position. The conveying tray 9 is fed to the winder.
[0036] When the half bobbin is conveyed to the front of the yarn end retrieving apparatus,
the conveying tray 9 is stopped and held, and the lower part of the bobbin 1 is pressed
and held by the presser lever as described above. Moreover, compressed air is blown
out from the nozzles 6 to blow the yarn Y to above the bobbin 1. At this time, when
the sensor 33 senses that the bobbin to be processed is a half bobbin, the suction
cylinder 13 is lowered quickly to a winding position for the yarn Y. The suction cylinder
13 is then lowered at the predetermined speed as is the case of the full bobbin 1
with a suction air flow acting on the surface of the bobbin 1. Subsequently, the following
operations are performed according to the above-described procedure: suction of the
yarn Y into the suction pipe 5, cutting of the yarn by the cutter device 10, and insertion
of the yarn Y into the winding core 8 by the yarn sucking device 45. With the smaller
bobbin, the series of operations are similarly performed.
[0037] According to the yarn end retrieving apparatus configured as described above, simply
by pre-inputting the bobbin data to the control circuit 43, the standby position of
the suction cylinder 13 can be automatically determined. Furthermore, the suction
cylinder 13 can be accurately held at the standby position by the cylinder elevating
and lowering device 16. The standby position can be accurately changed in association
with a lot change. Thus, compared to the conventional yarn end retrieving apparatuses
requiring manual change and adjustment of the suction cylinder 13, the present yarn
end retrieving apparatus allows the setup thereof to be quickly and easily changed
in association with the lot change.
[0038] Furthermore, since the stepping motor 25 is used as a driving source, an elevating
and lowering speed and an elevating and lowering stroke for the suction cylinder 13
can be freely set. For example, the speed at which the suction cylinder 13 is elevated
and returned to the standby position can be set to be higher than that at which the
suction cylinder 13 is lowered to suck out the yarn Y. The cylinder elevating and
lowering device 16 configured as described above enable s a reduction in the time
required for the yarn setup process. If required, the s uction cylinder 13 can be
stopped and held at a predetermined height to allow the suction air flow to concentrate
on the surface of the bobbin 1.
[0039] Furthermore, in the yarn end retrieving apparatus configured as described above,
the cutting position for the yarn Y can be optimized in association with the vertical
size of the bobbin 1 by allowing the cutter elevating and lowering device 35 to elevate
and lower the cutter device 10 concurrently with the automatic setting of the standby
position of the suction cylinder 13. Thus, with a bobbin 1 with a small vertical size,
the end of the yarn Y sucked into the winding core 8 can be reliably prevented from
being sucked into the yarn sucking device 45. For a bobbin 1 with a large vertical
size, the yarn Y sucked into the winding core 8 is prevented from sticking out from
the winding core 8 during the conveyance of the bobbin as a result of the insufficient
length of the sucked yarn Y.
[0040] In the above-described configuration, the driving structure for the cylinder elevating
and lowering device 16 is composed of the vertical pair of pulleys 26, 27, the driving
belt 28, and others. However, this is not necessary. The driving structure can be
composed of a feed screw shaft, a female threaded member, and others as in the case
of the cutter elevating and lowering device 35. Furthermore, the driving structure
and the cutter elevating and lowering device can be composed of a rack supported and
guided so as to be slidable in the vertical direction, a pinion that drives the rack
in the vertical direction, and a stepping motor that rotationally drives the pinion.
[0041] While the present invention has been described with respect to preferred embodiments
thereof, it will be apparent to those skilled in the art that the disclosed invention
may be modified in numerous ways and may assume many embodiments other than those
specifically set out and described above. Accordingly, it is intended by the appended
claims to cover all modifications of the present invention that fall within the scope
of the invention.