Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
- 2178~17
SYSTEM FOR FORNING ~LASTONERIC CORE/STAPLE FIB~R
WRAP YARN ~SING A SPINNING Mp~TNR
R~CR~ROUND OF THE lNV~. lON
This is a continuation-in-part of application Serial
No. 08/470,209, filed June 6, 1995.
The present invention relates to a system for
forming elastomeric core/staple fiber wrap yarn using a
sp;nn;ng machine. The present system all but renders
obsolete all current methods for forming elastomeric
core/wrap yarns.
When used herein, "sp;nn;ng machine" means any type
of textile sp;nn;ng machine such ag air jet gp;nn;ng,
roller-jet 8p; nn;ng, roller gp;nn;ng~ tangential
apron/belt spinning, friction sp;nn;ng, electrostatic
sp;nn;ng, and the like, excluding traditional ring
gp;nn;ng.
It haæ been known in the textile industry to form
core/wrap yarns, consisting of a single elastomeric core
having a multiple staple fiber wrap wound therearound,
e.g., Lycra~ spandex core/cotton wrap yarn, encapsulating
the core with an external sheath of fiber. Such
core/wrap yarns are suitable for use in stretch apparel
such as bathing suits, undergarments, hosiery, or other
snugly fitting clothing items or comfortable regular
fitting clothing. These core/wrap yarns have been formed
by such methods as wrap sp;nn;ng and sliver or roving fed
ring spinning. However, these methods are very labor
intensive and thus expensive, and the quality of the end
product is lower than desired for high speed mass
production.
In recent years, the industry has turned to air jet
spinning to produce synthetic and blend yarns used
extensively in the apparel industry. Currently, Murata
Machinery Ltd., Kyoto, Japan, manufactures an air jet
spinner sold under the trade name MJS, which can form
synthetic and cotton/synthetic blend yarns. Although it
2178~17
has been desired to use a machine like the Murata MJS
machine to form core/wrap yarns like spandex/cotton
yarns, no one has ever successfully adapted a machine
like the MJS machine to allow fully automated, trouble-
free mass-production of such yarns.
A single spinner station or so-called spindle of the
MJS system is shown schematically in Fig. 1 (reproduced
from U.S. 4,517,794, the entire disclosure of which is
incorporated herein by reference). A sliver supply
container 28 is provided behind a drafting assembly 11
for supplying raw material/substrate sliver S to the
spindle. The drafting assembly 11 i8 a three-roller
drafting system including rear rollers 8, apron rollerR
9 and front rollers 10. The rear rollers 8 deliver the
sliver to the apron rollers 9. The apron rollers 9 are
rotating faster than the rear rollers 8 to stretch,
draft, orient and flatten the sliver. The front rollers
10 are rotating even faster than the apron rollers 9 to
draw the sliver at a desired ratio. Additional rollers
can be added between the rear rollers 8 and apron rollers
9 to provide a four- or five-roller drafting assembly.
The sliver is delivered from the front rollers 10 to
an air jet nozzle 12, which, as shown conceptually in
Fig. 2, includes two air jets 12a,12b, which air wrap the
fibers which form the yarn in the same or opposite
directions. As is known in the art, the jet spinners
twist wrapper fibers from the sliver to provide a tightly
wound yarn which is then taken up on a take-up roll 22
provided in take-up assembly 21,22,23. As is also known
in the art, the take-up assembly include~ a yarn clearer
sensor 3, e.g., a Seletex~, Uster, Loepfe, or Peyer
sensor, which optically or capacitively monitors the
quality of yarn exiting the air jet nozzle 12.
The MJS includes an au~tomatic knotter 7, which, in
the event of breakage of yarn Y, will automatically gra~p
2l7~nl7
yarn from the exit of the air jet nozzle 12 via suction
hose 24 and splice or knot that yarn with yarn already
wound on the take-up roll 22. A suction pipe 25 removes
yarn from the take-up roll, and the two yarns are
combined by splicing or knotting mechanism 27. See U.S.
Patent 4,517,794 for an explanation of the remaining
components shown in Fig. 1 herein.
In a typical MJS machine, which includes perhaps 60
separate side-by-side spindles, the knotter can travel up
and down the machine line to service any individual
spindle. In the event of yarn breakage, the
microprocessor for the spindle on which the yarn breakage
occurred sends a signal to the knotter, and the knotter
then travels down the machine line until it contacts a
microswitch located on the back of the spindle in need of
servicing. Once the knotter is in position, the yarns
are joined together via the splicing or knotting device
27.
Murata has several patents on the air jet nozzle and
the splicing or knotting mechanism. See, for example,
U.S. Patents 5,159,806, 4,246,744, 4,263,775, 4,292,796,
4,411,128 and 4,481,761, each of which is fully
incorporated herein by reference.
In the operating manual for the Murata 802MJS it is
alleged that Murata has a system capable of forming
core/wrap yarn having a filament (i.e., non-elastic) yarn
core and a staple fiber wrap. While, that system is not
actually known to the present applicants, it i~ believed
to require manual threading in the event of yarn
breakage, a condition that occurs quite frequently, or is
not reliable for automatic re-threading. A cutter cuts
out bad quality yarn if a defect iæ detected.
Accordingly, the alleged Murata filament feed system is
not suitable for mass production.
217~017
-- 4
SUMMARY OF THE lNvL..~lON
It is an object of the present invention to provide
a core yarn feeding ~ystem to be used with sp;nn;ng
mach;ne~ (e.g., the MJS system), which facilitate6
efficient production of core/wrap yarns, e.g., Lycra~
spandex core/cotton wrap yarns.
It is another object of the present invention to
provide a system for forming elastomeric core/wrap yarn
using a sp;nn;ng machine, comprising:
threading means for feeding elastomeric yarn to
a drafting zone of a sp;nn;ng machine;
feed means for providing a controlled supply of
elastomeric yarn to said threading means; and
elastomeric yarn sensing means provided between
said threading means and said feed means or as part of
said threading means for detecting the presence of the
elastomeric yarn passing from said feed means to said
threading means;
wherein the elastomeric yarn and sliver fed
through the drafting zone are combined in the sp;nn;ng
machine to form an elastomeric core/wrap yarn.
It is yet another object of the present invention to
provide a package feed device for delivering yarn from a
cylindrical creel package to a material handling device,5 comprising:
a vertically oriented mounting plate having a
front surface and opposed rear surface, and upper and
lower portions;
a drive roller extending substantially
perpendicularly from said lower portion of said front
surface of said mounting plate;
means for rotating said drive roller at a
desired speed;
a creel package tube holder subassembly5 extending substantially perpendicularly from said upper
217~017
-- 5
portion of the front surface of said mounting plate, to
carry said creel package; and
means for biasing said creel package tube
holder subassembly toward said drive roller to provide
constant contact between the outer peripheral surface of
the cylindrical creel package and said drive roller.
It is still another object of the present invention
to provide a sensor for sensing the presence and motion
of a moving yarn or thread, comprising:
a housing;
rotatable wheel means provided on said housing
and having opposed metal side surfaces; and
means for generating magnetic eddy currents
through said opposed metal side surfaces to inhibit
rotation of said wheel means at high rotational speeds.
It is yet another object of the present invention to
provide a sensor for sensing the presence and motion of
a moving yarn or thread, comprising:
a housing;
rotatable wheel means provided on said housing
for rotation by a moving yarn or thread; and
means for sensing the rotational speed of said
wheel means.
It is still another object of the present invention
to provide a drafting assembly for conveying yarn,
comprising:
a main body frame;
roller means for conveying a first yarn, said
roller means comprising a pair of opposed apron rollers
and a pair of opposed front rollers;
clearer means for removing fibrous debris from
at least one of said pair of opposed apron rollers;
front roll wrap sensor means for sensing a yarn
wrap condition on at least one of said pair of opposed
front rollers; and
2178017
threA~;ng means for introducing a second yarn
to said front rollers.
The present invention will be explained in more
detail below with reference to the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a partial cross-sectional view of a single
spindle of a conventional Murata MJS air jet sp;nn;ng
machine;
Fig. 2 is a conceptual representation of the action
of the air jets in the MJS machine;
Fig. 3 is a side view of a single spindle of an MJS
machine modified in accordance with the present
invention;
Fig. 4 is a partial cross-sectional view of the
package drive assembly of the present invention;
Fig. 5A is a front view of the package drive
assembly with the creel package removed;
Fig. 5B is a front view of a modified package drive
assembly with the creel package removed;
Fig. 6 is a partial cross-sectional view of a yarn
motion and presence sensor of the present invention;
Fig. 7 is a side view of the yarn motion and
presence sensor with the idler wheel removed;
Fig. 8 is a side view of a pattern formed on the
idler wheel;
Fig. 9 is a partial cross-sectional view of another
embodimént of the yarn sensor of the present invention;
Fig. lOA is a partial cross-sectional view of
another embodiment of the yarn sensor of the present
invention;
Fig. lOB is a partial cross-sectional side view of
the sensor shown in Fig. lOA;
Fig. 11 is a side view of the drafting assembly of
the present invention;
2178017
-- 7
Fig. 12A is a cross-sectional view of the thread-up
device of the present invention;
Fig. 12B is a cross-sectional view taken along line
XII-XII of Fig. 12A;
Fig. 13A is an alternative embodiment of the thread-
up device and yarn sensor of the present invention;
Fig. 13B shows the top view of each piston 245,246
of Fig 13A, as it interacts with side plate 262;
Fig. 13C is an enlarged side view of the encircled
area of Fig. 13A;
Fig. 13D is a cross-sectional view taken along line
XIIID - XIIID of Fig. 13A;
Fig. 13E is an alternative embodiment of Fig. 13A,
wherein the idler wheel 265 is positioned outside the
main body 241;
Fig. 13F is an alternative embodiment of Fig. 13A,
wherein the sensor of Fig. 6 i8 employed instead of laser
sensor 266;
Fig. 14A is a top view of a delay cylinder 43 in
accordance with the present invention;
Fig. 14B shows an alternative plunger for the delay
cylinder of Fig. 14A;
Fig. 14C shows an alternative delay cylinder in
accordance with the present invention;
Fig. 14D shows the core/wrap product yarn path
through the sensor 3 and delay cylinder 43;
Fig. 15 is a schematic representation of the outputs
of a conventional MJS spindle unit control box;
Fig. 16 shows the interfacing between the unit
control box of Fig. 15 and the control circuit board 310
of Fig. 17;
Fig. 17 is a schematic view showing a preferred
control circuit 310 used in the present invention;
Fig. 18A is a cut-away partial schematic view of the
circuitry contained in the unit control box;
2178017
-- 8
Fig. 18B shows how the unit control box is modified
to interface with the control circuit board of Fig. 16;
Figs. l9A - 19D are flow diagrams expl~;n;ng the
sequence for controlling the system of the present
invention; and
Fig. 20 is a partially schematic, partially cut-away
illustration of the elastomeric core/staple fiber wrap
yarn according to the present invention.
DET~TT.Tm DESCRIPTION OF THE I~VL..110N
Fig. 3 shows a side view of a single spindle of a
Murata MJS air jet sp;nn;ng machine, modified to include
the features of the present invention. All aspects of
the present invention hereinafter described are equally
applicable to any of the sp;nn;ng machines referred to
earlier herein. Like numerals represent like structure
or elements in Figs. 1 and 3. The improvements which the
present inventors have made to the MJS machine to enable
mass production of elastomeric core/wrap yarn are
collectively referred to hereinafter as a yarn feed
system, although each individual component of the system
has other utilities in addition to that explained herein.
The yarn feed system includes a package drive
assembly 40, yarn motion and presence sensor 41, an
improved drafting assembly 42 and a yarn clearer (e.g.,
Seletex~) delay cylinder 43. An elastomeric yarn 44 is
delivered from the package drive assembly 40, over the
sensor 41 and into the drafting assembly 42. The
elastomeric yarn 44 is combined with the sliver S in the
air jet spinner nozzle 12 to form a core/wrap elastomeric
yarn product. A vacuum exhaust conduit 31 i~ provided
for removing stray or excess sliver from the area around
the spinner nozzle 12. The core/wrap yarn exits the
nozzle 12, passes over the yarn clearer delay cylinder
2178017
g
43, yarn clearer sensor 3, and is wound on take-up roll
22 in a conventional manner.
Each component of the yarn feed system is explained
below herein.
Packaqe Drive AssemblY
Fig. 4 is a side view of the yarn supply creel
package dri~e a~sembly 40 according to the present
invention. The drive assembly has a mounting plate 51
which is positioned above an individual spinner station
as shown in Fig. 3. The mounting plate 51 is oriented
substantially perpendicular to the horizontal plane of
the floor on which the ~pinner station is positioned. A
slide block slot 52 is formed in the center region of the
thickness of mounting plate 51, and a slide block 53 is
positioned in the slot 52. Fig. 5A, which is a front
view of the package drive assembly of Fig. 4 without the
creel package 50 and package tube holder 56, shows that
the slide block slot 52 is substantially rectangular in
shape and extends vertically in the length direction of
the mounting plate 51. The slide block 53 can move up
and down in the slot 52.
A creel package tube holder shaft slot 54 is formed
through the front face 51a of the mounting plate 51 to
communicate with the slide block slot 52. Fig. 5A shows
that the slot 54 i8 substantially concentric with the
slot 52, and that the slot 54 is oblong and extends
vertically along the length of the mounting plate 52. A
package tube holder shaft 55 extends through slot 54 and
is fixed in the front surface 53a of slide block 53. A
freely rotating package tube holder 56 is arranged on
shaft 55, and the axes of both holder 56 and ~haft 55,
collectively the creel package tube holder subassembly,
are oriented substantially perpendicularly to mounting
plate 51.
2l7~nl7
- 10 -
A first tab 57 extends perpendicularly from rear
surface 51b of mounting plate 51 in a region spaced below
and in alignment with the major axis of the oblong slot
54. A second tab 58 extends perpendicularly from rear
surface 53b of slide block 53 and is spaced above and in
alignment with the major axis of the oblong slot 54.
Another slot (not shown) is formed in rear face 51b of
mounting plate 51 so that tab 58 can be fixed to slide
block 53. A coil spring 59 connects the first and second
tabs to bias the package tube holder subassembly 55,56 in
a vertically downward direction. Tab 58 is positioned
above the axis of shaft 55 to relieve some of the
cantilever forces applied to shaft 55 by the weight of
creel package 50.
A package drive roller 60 is positioned on mounting
plate 51 below the package tube holder subassembly. A
shaft 61a of a ~tepper drive motor 61 passes through
mounting plate 51 and extends perpendicularly from the
front face 51a thereof. The package drive roller 60 is
fixed to shaft 61a of motor 61 such that drive roller 60
also extends perpendicularly from the front face 51a of
mounting plate 51. Fig. 5A shows that the axis of the
drive roller 60 and the axis of the package tube holder
shaft 55 are preferably located in the same vertical
plane.
To operate the package feed mechanism of the present
invention, a creel package 50 is mounted on package tube
holder 56 so that the outer peripheral surface of the
creel package contacts drive roller 60. Oblong slot 54
and slot 52 allow vertical movement of shaft 55 and slide
block 53, to accommodate creel packages of various
diameters. Coil spring 59, along with normal
gravitational forces, provides sufficient pressure
between creel package 50 and drive roller 60 to enable
2178~)17
the drive roller to drive the creel pAckAge to meter yarn
from the creel pAckAge at a desired constant speed.
The yarn wound on creel package 50 is drawn at nip
62 formed between drive roller 60 and creel package 50.
The yarn is then fed over yarn sensor 41 and into the
thread-up device of drafting assembly 42. The speed of
motor 61 is controlled by a microprocessor-based printed
circuit board 310 (described below) to correspond to the
speed of the other components of the spindle. The extent
of drafting or stretching of the srAn~eY yarn can be
changed by adjusting an electronic setting at the end of
the machine. This one setting controls all the spindles
on the machine. As yarn is drawn off creel package 50,
the diameter of the creel package decreases and the
package holder subass~mhly moves in the vertically
downward direction. That i8, slide block 53 moves down
slot 52 and shaft 55 moves down oblong slot 54. This
movement is encouraged by the biasing provided by spring
59 and normal gravitational forces, such that sufficient
pressure is always provided between creel package 50 and
drive roller 60. Such pressure is desirable to insure
that drive roller 60 positively drives creel package 50
and uniformly delivers a continuous supply of yarn from
the creel package to the thread-up device at a desired
constant yarn speed.
In a preferred embodiment of the invention the creel
package holds elastomeric yarn, e.g., spandex. Due to
the high elasticity of spandex, the motor 61 should have
a high acceleration rate up to the desired feeding speed
to insure that no stretch component breakage of the yarn
occurs during start-up of an individual spindle. It will
be appreciated by those skilled in the art that this
package drive assembly permits feed creels of yarn, such
as highly elastomeric spandex, to be used, as received
from the yarn manufacturer without any re-winding or
2178017
- 12 -
processing before such yarn i8 fed into an air jet
8p; nni ng machine for incorporation into a core/wrap
elastomeric yarn. The package drive assembly of the
present invention also can be used to deliver any type of
yarn or thread to a yarn or thread processing machine,
such as an air jet spinner.
The stepper drive motor 61 is specially designed
with a skewed rotor and avoids the use of a gear train or
expensive frequency invertor. The vibration dampening
ability of the creel package on the drive roll and the
skewed rotor avoid resonance frequencies than can cause
this type of motor to break lock or stall.
Fig. 5B shows a modified version of the package
drive assembly, wherein two auxiliary rollers 60a and 60b
have been added. The auxiliary rollers prevent tension
and extension yarn 1088 back to package 50. The
avoidance of such tension 1088 reduces spandex end
entrapment on the creel package which can cause
unnecessary end breakage, thus reducing machine
efficiency. The auxiliary rollers are driven by the
drive roller 60 via belts. That is, an endless drive
belt is connected directly between drive roller 60 and
second auxiliary roller 60b, while a second belt, twisted
in a figure-eight, is connected between drive roller 60
or second auxiliary roller 60b and first auxiliary roller
60a. Thus, first auxiliary roller 60a rotates in a
direction opposite to that of drive roller 60 and second
auxiliary roller 60b. One or more of the rollers may
have grooves therein for positioning the belts. The path
of the yarn 44 is shown in Fig. 5B. These auxiliary
rollers also may be driven electronically, via a motor,
but belts are typically used to avoid additional expense.
21780l7
- 13 -
Yarn Motion and Presence Sensor
While it has been known to use optical or capacitive
sensors in textile machines, e.g., Peyer, Loepfe, Uster,
or Seletex~ yarn clearers, to detect the presence and
5quality of yarn, elastomeric yarns present unique sensing
problems. The elastomeric yarn used in the present
invention typically is drawn at a ratio that reduces the
yarn denier to as low as 3 denier, which is finer than
human hair. Moreover, ~ince spandex cannot be dyed, it
10is sometimes desirable to use clear spandex yarn to avoid
visual detection in the final product. It is difficult
to detect such fine yarn, and indeed virtually impossible
to detect or see clear yarn with known optical or
capacitive sensors used in the textile industry. The
15yarn motion and pre~ence sen~or of the present invention
not only can provide precise detection of such clear and
fine yarnæ, but is uReful for detecting all types of
moving yarn and thread.
The yarn sensor of the pre~ent invention
20incorporates two novel concepts: (1) the use of
photomicrosen~ors to detect rotational speed of an idler
wheel, and (2) the use of magnetic eddy currents to
provide instantaneous braking of the idler wheel at high
speed with minimal braking at low speed.
25Fig. 6 is a cross-sectional view of the motion and
presence sensor 41 of the present invention. The ~ensor
includes a transparent housing 100 preferably having a
prism ~haped outer sector 101 and a receg~ed bottom 102.
A shaft 103 protrudes from a side surface 104 of the
30housing 100. The side surface 104 has a circular recess
105 therein centered around the ~haft 103. A notch idler
wheel 106 is mounted on the shaft 103 and iB freely
rotatable thereon. One of opposed sides 107 of the idler
wheel extend~ into the recess 105 to prevent lint or
35extraneous material from entering the interface region
217~017
- 14 -
between the wheel 106 and ~haft 103, thereby impairing
the free-sp;nning ability of the idler wheel. The other
one of oppo6ed ~ide~ 108 of the idler wheel extends into
a circular rece~s 109 formed in an idler wheel extension
member 110 fixed to the end of the shaft 103. While the
housing 100 and extension member 110 are fixed, the idler
wheel 106 rotate6 freely on shaft 103.
A bearing 111 is preferably fixed in inner bore 112
of the idler wheel to facilitate rotation of the idler
wheel on shaft 103. Metal disks 113a,113b are secured to
or within opposed sides 107,108 of idler wheel 106. The
metal disks should be made of non-magnetic materials such
as al~ ;nl , magnesium, stainless steel, or brass,
although aluminum is preferred because of its low
density, for reasons explained below, and low material
cost. A ceramic coated, all metal idler wheel can also
serve the same purpose.
While the idler wheel 106 is typically plastic, a
high hardness (e.g., ceramic) ring 114 is formed at the
bottom of the notch in the idler wheel to prevent
destruction by abrasion of the wheel due to contact with
the yarn passing over the wheel. The wheel 106 is
frictionally driven by the yarn 44 (Fig. 3) passing over
it.
A plurality of magnets 115 are arranged on opposite
sides of the idler wheel in housing 100 and extension
member 110. Fig. 7, a side view of housing 100 without
idler wheel 106 and extension member 110, shows that the
magnets are preferably arranged along concentric circles
in housing 100 (and preferably also in extension member
110). It is preferred that the magnets in housing 100
align with the magnets in extension member 110, and that
the N-S orientation of opposed magnets in the housing and
extension member be in the attraction mode, as shown in
Fig. 6. Although any number of magnets can be used in
Z178017
- 15 -
any number of arrangements, the magnets 115 in each of
housing 100 and extension member 110 should be spaced
from each other to prevent cancellation of the magnetic
fields from magnet to magnet. A preferable material for
such magnets is an Nd-Fe-B alloy.
The magnets 115 operate to produce magnetic eddy
currents through the metal disks 113a,113b during
rotation of idler wheel 106. The magnetic eddy currents
are very weak or non-existent during initial start-up
rotation of idler wheel 106, 80 that the idler wheel
inertia at start-up of rotation is very low, and thus the
idler wheel initially spins very freely. When idler
wheel 106 is rotating at normal operating speed, the
magnetic eddy currents are very strong. Aluminum iæ
preferred for the metal disks 113a,113b, because the
density of other non-magnetic materials, e.g., gold,
would create more moving inertial force or ~me~tum of
the idler wheel 106 than possible for the eddy currents
to instantaneously decelerate. The idler wheel should
not contain any ferrous or otherwise magnetic materialc
(such as screws) because such materials may cause undue
additional continuous or pulsed magnetic drag.
A circuit board 120 is mounted in the recessed
bottom of the transparent housing 100 as shown in Fig. 6.
The circuit board includes a photomicro~ensor 121, which
is a combined IR phototransistor and IR LED.
Photomicrosensors of this type are sold by Omron, under
product designation number EE-SMR3-1. The
photomicrosensor emits an IR beam from the IR LED which
i8 reflected from a pattern 116 (Fig. 8) formed on the
side 107 or disk 113a of idler wheel 106 as rotation of
wheel 106 passes the pattern segments through the IR
beam. It is important that the pattern formed on the
side of the idler wheel be perfectly centered around the
2l7snl7
- 16 -
axis of the wheel to ensure accurate detection of wheel
speed.
Instead of sensing a pattern provided on the idler
wheel 106, the photomicrosensor can also detect stainless
steel, aluminum or other non-magnetic material mounting
bolts 116a used to mount the metal disk 113a on the side
107 of the idler wheel 106. The reflected IR beam is
detected by the IR phototransistor to create a voltage
signal. The phototransistor generates voltage
proportional to the amount of detected IR light reflected
from pattern 116. The voltage signal and voltage
frequency are processed by the microprocessor 310 to
derive an average rotational speed of the idler wheel 106
and thus a linear speed of yarn passing thereover.
In the event of yarn breakage, idler wheel 106 is no
longer positively driven by yarn. Immediately after yarn
breakage, the strong magnetic eddy currents induced in
the metal disks 113a,113b by the magnets 115 act as a
brake, causing substantially instantaneous reduction in
rotational speed of idler wheel 106. The faster the
rotational speed just before yarn breakage, the greater
the braking power immediately after yarn breakage. In
contrast, slower wheel speeds result in lower braking
power by not generating as strong magnetic eddy currents.
The microprocessor will detect, via the photomicrosensor
121, the instantaneous decrease in rotational speed of
idler wheel 106 and cause the entire system to shut down,
as explained later herein.
Also mounted on the circuit board is an alarm LED
122 which is illuminated when yarn breakage occurs and
there is an accompanying decrease in ~peed detected by
the photomicrosensor 121. The prism-shaped outer surface
101 of the housing 100 distributes the light emitted by
the alarm LED 122 in several directions for easy visual
detection by a human operator from multiple viewpoints.
2l7snl7
- 17 -
The circuit board also includes a connector 123
located in the recessed bottom 102 of the housing 100,
for electrically connecting the ~ensor to the
microprocessor 310 provided on each spindle. The
connector 123 is protected by the walls of the housing
100 which define the recessed bottom 102 of the housing
100 .
The housing 100 may be made from transparent
injection molded or cast plastic (e.g., polycarbonate,
general purpose polystyrene, acrylic, X-resin (a
clear/highly crystalline polymer with high impact
resistance produced by Phillips Chemicals, Co., Pasadena,
Texas), polyurethane or epoxy), and is thus very
inexpensive. The circuitry is also very inexpensive in
that only a commercially available photomicrosensor, LED
and connector are required to build the sensor.
Moreover, the idler wheel 106 may be a stAn~Ard off-the-
shelf item. Accordingly, a very sensitive motion and
presence sensor can be provided at very low cost.
Fig. 9 shows another embodiment of the sen60r of the
present invention, wherein baffle grooves 117 are
provided in the housing 100 and extension member 110, and
mating baffles 118 are provided on the idler wheel 106.
While the baffles do not inhibit free rotation of the
idler wheel 106, they do assist in preventing lint from
entering the bearing 111 of the idler wheel. By
preventing lint from contacting the bearing 111, the life
and reliability of the sensor is prolonged by assuring
continuous free rotation of the idler wheel 106.
Figs. lOA and lOB show yet another embodiment of the
yarn sensor of the present invention which incorporate~
the baffle design of Fig. 9, but uses a slightly
different sensing mechanism. Like numerals represent
like elements in Figs. 8-lOB.
2l7snl7
- 18 -
The ~ensor in Fig. lOA makes use of teeth or holes
127 formed in baffle 118 (Fig. lOB), and an infrared LED
124 and a phototransistor 125 to detect speed of the
idler wheel via a direct transmit/receive technique. The
teeth or holes 127 interrupt the light transmitted from
infrared LED 124 and detected by phototransistor 125. A
signal is thus generated by the phototransistor
representative of the rotational speed of the idler wheel
106 in the same manner as the sensor of Figs. 8-9. The
LED and phototransistor could also be arranged on
opposite sides of the wheel 106 to interact with a
pattern of holes formed through the sidewall of the wheel
106.
In the sensor shown in Figs. lOA and lOB, a contact
spring 126 provides electrical communication between the
circuit board 120 and power supply rails 128. The power
supply rails are Rlightly different from the connector
123 of Fig. 6, in that the rails 128 (four in total)
enable (if desired) direct two-way communication to
individual RenRors along a central serial data binary bus
(not shown), and also supply power to drive the
individual sensor circuitry. Thi~ bus can simultaneously
service a plurality of sensors at the same time along
only four wires. This can be achieved at a very low cost
by using a set of only four buR rails that run the full
length of the machine line. This system is also suitable
for installation on other textile machinery, including
tufting machines, warping machines, and ring sp;nn;ng
machines. Direct two way communication with an
individual yarn ~enRor can allow variou~ information to
be obtained and digested by a computer. The entire
machine or individual spindle data can include runability
efficiency, total run time, total down time and number of
end breaks. Industrial engineering data is beneficial
for fine tuning textile machinery for greater throughput
2l7~nl7
- 19 -
productivity. Inexpensive two-way communication can
enable the use of devices to stop off-quality product
from being produced by shutting down material feed or
knocking the end down (e.g., on a ring sp;nn;ng frame)
and allowing the waste to run into the vacuum exhaust
conduit 31. This management tool can eliminate off-
quality product, reduce waste, and improve machine
runability and, hence, profitability.
Preferably, the light emitted from the IR LED in the
photomicrosensor 121 is electronically (transistor
switching on/off) pulsed to avoid detection of
spurious/background light by the IR phototransistor. By
pulsing the IR transmission at a specific frequency and
pulsing the IR reception at the same frequency,
extraneous light can be filtered out since it is not
pulsed in sync with the receiver. The phototransistor
can also include an optical filter to remove, and thus
avoid detection of, extraneous IR light, such as
fluorescent lighting and sunlight.
Draftinq Assembly
Fig. 11 shows in cross-section the improved drafting
assembly 42 of the present invention. While a four-
roller drafting system is shown, three or five-roller
systems can also be used. The assembly has a main body
frame 200 including a mounting bracket 201 designed to
hold a roller assembly 220, a thread-up device assembly
240, draft zone clearers 260 and a front roll wrap sensor
280.
i) Roller Assembly
The roller assembly 220 is designed to transport
staple sliver S from the supply container 28 to the air
jet spinner nozzle 12. The roller assembly 220 includes
opposed rear rollers 221, opposed intermediate rollers
2178017
- 20 -
222, opposed apron roller~ 223, and opposed front rollers
224, all of which can come stAn~Ard on a Murata MJS
machine. Each set of opposed rollers forms a nip through
which the sliver S passes. The apron rollers 223 stretch
and orient the sliver and the front rollers 224 are
rotated at a faster speed than the rear rollers 221 and
apron rollers 223 to draw the sliver at a desired ratio
as it passes through the roller assembly 220. Preferably
the upper roller~ closest to the mounting bracket 201 are
rubber and the bottom rollers are metal. A tensor bar
225 (with height adjustment bracket 225a) is provided in
the bottom apron roller 223 to regulate the tension of
the bottom apron and set the height of the apron nipping
action.
ii) Draft Zone Clearers
The advantageous draft zone clearers 260 of the
present invention are arranged on the mounting bracket
201 above and between the upper intermediate roller 222
and upper apron roller 223, and above and between the
upper intermediate roller 222 and upper rear roller 221.
Each clearer 260 resembles a paddle wheel and i~
substantially star shaped, e.g., six vaned, in cross
section. The clearers are each driven by a dedicated
electric motor 261 mounted directly on the mounting
bracket 201. The clearers 260 can be rotated in the same
or opposite direction as the rotation direction of the
upper rollers. The clearers contact the upper rollers to
remove lint, dust, ~tray sliver, or other undesirable
material which is then collected and discarded through
the vacuum exhaust conduit 31 (see Fig. 3). The clearers
can be made from any material that ic ~oft, flexible and
durable, e.g., polyurethane, and preferably have a hollow
or solid, rigid metal shaft for attaching the clearer to
the shaft of the dedicated motor.
2178~17
- 21 -
During operation it is preferred that the clearer
motors are off whenever the roller assembly i6 off.
Also, it i8 preferred that the clearer motors are cycled
on and off to prevent an in-6ync condition between the
apron and any roller. This cycling insures that the
clearer contacts all segments of the upper apron and
upper rollers. The cycling also extends the life of the
motor and clearer.
iii) Front Roll Wrap Sen~or
The front roll wrap sensor 280 is located on the
mounting bracket 201 opposed to and above the upper front
roller 224. The sensor 280 includes a photomicrosensor
to detect the occurrence of roll wrap, that is, yarn
undesirably wrapped around the upper front roller 224.
The photomicrosensor can be the same as that used in the
elastomeric yarn sensor and includes an infrared light
emitting diode which projects infrared light onto the
upper front roller 224. The photomicrosensor also
includes a phototransistor to detect infrared light
reflected from the upper front roller 224. During
initial operation of the drafting assembly 42, the sensor
280 makes an initial detection of the reflectivity of the
upper region of the upper front roller and that detection
i~ represented by voltage generated in the
phototransistor resulting from the IR light reflected
from the upper front roller 224. If roll wrap occur~,
yarn begins to wrap around the circumference of the upper
front roller 224, and the presence of that roll wrap yarn
increases the amount of light reflected back into the
phototransistor of the photomicrosensor. The increased
detected reflectance increases the voltage generated by
the phototransistor, which in turn is monitored by the
microprocessor 310 (explained below). Any significant
2l7snl7
- 22 -
increase in reflectance (e.g., 2 10%) will shut-down the
drafting assembly, as expl A; ne~ below herein.
iv) Thread-Up Assembly
The thread-up assembly 240 is shown in cross-section
and greater detail in Fig. 12A. The device includes a
main body 241 having a yarn delivery bore 242 passing
through the length thereof. The axis of the bore 242
should be arranged at an angle of 30-60, preferably
about 50, relative to the direction of sliver feed
through the drafting assembly. See again Fig. 11. This
arrangement will ensure fewer airjet nozzle chokes and
roll wraps, and increases the chance for the spandex end
to be entrained by the front roll nip point, and then the
first airjet nozzle.
First and second bores 243, 244 extend through a
side surface 241a of the main body to communicate with
the yarn delivery bore 242. Arranged in the first 243
and second 244 bores are pneumatic pistons 245, 246,
respectively. Each of the pistons is biased by a spring
247 away from the yarn delivery bore 242. Each piston
has an inner end 248 arranged adjacent the yarn delivery
bore 242, and an outer plunger end 249 arranged proximate
the side surface 241a of the main body. The inner end
2~8 of each piston mates with an inner surface portion
250 of the bore 242.
A third bore 251 extends through the main body from
the side surface 241a thereof to extend across and
communicate with the yarn delivery bore 242. An air
delivery tube 252 is arranged in the yarn delivery bore
242 and intersects a portion of the third bore 251. The
upper end of the tube 252 is fixed in the upper portion
242a of the yarn delivery bore 242. The lower end of the
tube 252 extends into the lower portion 242b of the yarn
delivery bore 242, and an annular gap 253 is defined
2178(~17
- 23 -
therebetween (Fig. 12B). The annular gap 253 rangeæ from
about .002 inches to about .030 inches in radial
dimension "xn, and preferably ie about 0.005 inches in
order to reduce air flow and maintain high thread-up
aspiration below the tube 252. Instead of using such an
annular gap, air can be supplied by A~; ng an additional
small diameter bore of approximately .032" at an angle of
15 off the yarn delivery bore.
A conduit block 254 is attached to the side surface
241a of the main body 241, and provides air supply
conduits 255,256 and 257 in communication with each of
the first 243, second 244, and third 251 bores,
respectively. Solenoid valves (not shown) are provided
for each of the conduits 255, 256 and 257 to control air
flow therethrough. During operation of the thread-up
device, air is supplied to the outer plunger ends 249 of
each piston to actuate each piston selectively, such that
the inner ends 248 are forced into contact with the
correspo~;ng inner surfaces 250 of the bore 242. The
upper piston 245 acts as a clamp for the yarn passing
through the yarn delivery bore 242. The lower piston 246
acts as a clamp/cutter for the yarn, since continued
rotation of the front rollers 224 after the lower piston
246 is actuated will stretch and break the yarn 44 below
the lower piston 246. The air pressure supplied to each
piston ranges from about 30 to 200 psi, and is preferably
about 100 psi.
The air supply conduit 257 provides air to the third
bore 251 and into the yarn delivery bore 242 via the
annular gap 253 defined between the lower end of the tube
252 and the lower portion 242b of the yarn delivery bore
242. The air thus entering the bore 242 is laminar and
concentrated at the periphery of the bore 242 such that
a suction effect occurs in the bore 242. This suction
effect insures proper feeding of the yarn 44 material
2178017
- 24 -
through eyelet 242c of the bore 242 and out extenRion
pipe 258. The air pressure supplied to bore 251 ranges
from about 20 to 120 psi, and preferably is about 50 p8i.
The spandex yarn finally travels through extension
pipe 258 before merging with the drafted sliver.
Although the extension pipe is shown as a cylindrical
tube in Fig. 12A, the interior thereof preferably
gradually tapers down from about 3/16" to about 1/8",
allowing better front-to-back and side-to-side ~;m;ng of
the fired spandex before redirection by the front roll.
This slight taper results in minimum disruption of air
flow while improving control of directing the spandex
into the front roll.
Fig. 13A shows an alternative embodiment of the
thread-up assembly of the present invention. Wherever
possible like reference numerals have been used to
designate like structure in Figs. 12A and 13A.
The thread-up assembly of Fig. 13A includes a main
body 241 having a square yarn cross-section delivery bore
242 passing through the length thereof. Use of a round
cross-section bore 242 intersecting with a round cross-
section bore 243 causes turbulence of the air passing
through the bore 242. This turbulence can be reduced by
using a square cross-section bore 242 in combination with
the planar-shaped piston ends 248. First and Recond
bores 243, 244 extend through a portion of the main body
to communicate with the yarn delivery bore 242. Arranged
in the first 243 and second 244 bores are pneumatic
pistons 245, 246, respectively. Each of the pistons is
biased by a 6pring 247 away from the yarn delivery bore
242. Each piston has an inner end 248 arranged in the
yarn delivery bore 242 and an outer plunger end 249
arranged within the bores 243, 244. Fig. 13B shows a top
view of each piston 245, 246 as it interacts with side
plate 262, which cooperates with the main body 241 to
217~017
- 25 -
define the square cross-section yarn delivery bore 242.
The inner end 248 arranged in the yarn delivery bore
includes two prongs 260 which ride within correspon~;ng
grooves 261 of the side plate 262. When each piston is
in the fully retracted position, the prongs 260 define
the side walls of the yarn delivery bore 242 at the
location of each piston. That is, the square hole
passing through each piston inner end 248 is roughly the
same dimension as that of the square yarn delivery bore
242. Guide disks 263 are provided in each bore 243, 244,
to guide the inner end 248 of each piston and to provide
stop points for coil springs 247 provided in bores 243,
244.
A third bore 251 extends through a portion of the
main body 241 and communicates with the yarn delivery
bore 242. An air orifice 264 extends from the end of the
third bore 251 at an angle into the yarn delivery bore
242. Air is delivered through the bore 251 and air
orifice 264 to force the yarn 44 through the thread-up
device.
During operation, the upper 245 and lower 246
pistons function in the same way as the thread-up
assembly of Fig. 12A, although in the thread-up assembly
of Fig. 13A each piston, when actuated, closes the yarn
delivery bore 242, thus clamping and clamping/cutting,
respectively, the yarn passing through the yarn delivery
bore 242.
Arranged at the inlet end of the thread-up assembly
shown in Fig. 13A is a ceramic idler wheel 265 on which
the yarn rides as it enters the thread-up assembly. The
wheel can also be arranged outside the body 241, as shown
in Fig. 13E. The ceramic idler wheel 265 prevents
erosive abrasion of the entrance to the yarn delivery
bore 242, especially when feeding spandex through the
thread-up assembly. The ceramic idler wheel is arranged
2178~17
- 26 -
to be freely rotatable, and preferably the bottom of the
V defined by the sidewalls of the wheel is in substantial
alignment with the central axis of the yarn delivery bore
242.
Fig. 13A also shows that the presence of the yarn
passing through the thread-up assembly can be detected
within the assembly itself. Specifically, as shown in
the exploded view of Fig. 13C, a laser diode module 266
is arranged in a bore 267 which communicates with the
yarn delivery bore 242. The laser diode module includes
a lens 266a, a laser diode 266b, a power rectifier 266c
and a shell 266d. A photodetector 268 i8 arranged in a
bore 269 formed in the back of the thread-up assembly in
communication with the yarn delivery bore 242. The
photodetector 268 is mounted out of the laser diode
generated lightwave beam. The axis 268a of the
photodetector 268 preferably is arranged at an angle of
135 with respect to the axis 266a of the laser diode
266, as shown in Fig. 13D, in order to optimize the
sensitivity of the photodetector 268. A laser anti-
reflection cone 270 is employed on the opposite side of
the yarn delivery bore 242 in alignment with the laser
diode 266 to scatter any extraneous light energy emitted
from the laser diode 266. In order to attenuate the
signal-to-noise ratio for more reliable signal readings
and analysis, light bandpass interference filters may be
used in front of the photodetector 268 to shield
extraneous light from reaching the photodetector, which
extraneous light would otherwise skew or distort the true
signal generated by the yarn passing through the thread-
up ass~mhly. The laser light may also be electronically
pulsed or modulated in synchronization with the
photodetector to filter additional unwanted light.
As the yarn runs through the lightwave beam, light
is reflected and/or refracted toward the photodetector
2l7~nl7
- 27 -
268 creating a proportional voltage based on the amount
of redirected light, which is also directly proportional
to the size of the yarn passing through the lightwave
beam. With calibration, the speed and size of the yarn
passing through the thread-up assembly may be determined.
Calibration also may provide other important information
when using yarns other than spandex, such as quality
consistency (e.g., hairiness, evenness, defect levels,
thick, thin, neps) of yarn material passing through the
lightwave beam.
As i8 the case with the yarn motion and presence
sensor described above, the output from the photodetector
268 is monitored by the microprocessor to determine,
among other things, the presence and/or speed of the yarn
passing through the thread-up assembly. A prism-shaped
LED alarm light 271 is illuminated whenever the
microprocessor fails to detect yarn 44 passing through
the yarn delivery bore 242, much like the alarm LED in
the yarn motion and presence sensor described earlier
herein.
Although any type of laser diode 266 can be employed
in the present invention, a high intensity 1 to 5
milliwatt laser operating at 670 nm wavelength and a
silicon phototransistor detector 268, has been used.
Preferably the laser diode includes a convex plano lens
to focus the lightwave beam into the yarn delivery bore.
Fig. 13F shows an alternative embodiment of the
thread-up device of Fig. 13A, wherein the sensor of Fig.
6 is employed instead of laser sensor 266.
Yarn Clearer DelaY CYlinder
In certain instances that will be explained below,
it is necessary to physically move the core/wrap yarn out
of registration with the yarn clearer sensor 3. The
2178017
- 28 -
present invention employs yarn clearer delay cylinder 43
for this purpose.
Fig. 14A is a top view showing one embodiment of the
yarn clearer delay cylinder 43. The delay cylinder 43 i8
mounted on the front plate of each spindle as shown in
Fig. 3. During normal operation, the final yarn product
passes through head slot 3a of the yarn clearer sensor 3.
The delay cylinder 43 serves to force the yarn out of
head slot 3a, for reasons explained below. A waste
suction duct 31a is provided for removing any defective
yarn and other debris from the area of the sensor 3.
The delay cylinder 43 includes a solenoid 43a having
a plunger 43b attached to an end thereof. A first pin
43c attached to the plunger 43b assures axial alignment
of the plunger during actuation of the solenoid 43a. A
second pin 43d attached to the plunger forces the yarn
product out of head slot 3a. The dotted lines in Fig.
14A show the plunger 43b in the activated position.
Fig. 14B shows an alternative embodiment of the
delay cylinder 43 of Fig. 14A, wherein the plunger 43b is
shaped like a triangle with a front edge 43e rolled
downwardly to provide a ~mooth surface for contacting the
yarn product.
Fig. 14C shows another embodiment of the delay
cylinder 43 of Fig. 14B, wherein slots 43f and 43g, and
set screws 43h and 43i facilitate side-to-side and back-
to-front adjustment of the position of the plunger 43b.
Fig. 14D shows the delay cylinder 43 with the
plunger 43b in the retracted position (solid line~) and
the plunger 43 in the activated position (dotted lines).
When the plunger 43b i~ in the activated po~ition, the
yarn product is forced out of head slot 3a beyond the
sensor 3. It is important, when using capacitance-type
sensors 3, to remove the core/wrap product from head slot
3a as well as the opening to head slot 3a, because the
2l7~nl7
- 29 -
sensing region of such sensors tends to extend somewhat
beyond the head slot 3a.
Interfacing The Yarn Feed
System With a Murata MJS Machine
In developing and teæting the yarn feed system of
the present invention, a Murata MJS Model 801-9786-4 was
used, although other models of Murata's MJS machine may
be adapted to accept the yarn feed system of the present
invention. The description hereinbelow is in the context
of a Murata MJS Model 801-9786-4.
Fig. 15 schematically shows the output configuration
of the MJS unit control box 300 which is a standard
feature on the MJS machine to control various operations
of the machine. Each spindle of the MJS machine has its
own unit control box 300. The unit control box 300
includes integrated circuit chips and jacks 301, to which
connectors 302 of patch cords 303 are connected, for
controlling operation of the spindle in a known manner.
For example, one of the jacks 301c, color coded blue,
feeds signals to the solenoid (324, Fig. 17) of the
spinning/sliver clutch (a standard component on the MJS),
which controls the feed of sliver 3 to the drafting
assembly 200. Room for a spare jack 301g, color coded
black, is provided on the standard MJS unit control box
300.
To seize control of operation of the spindle and
incorporate the functions of the yarn feed system of the
present invention, each spindle is provided with a second
circuit board 310 in accordance with the present
invention.
Fig. 16 schematically shows the interfacing between
the st~n~rd MJS unit control box 300 (with spare jack
301g added) and second circuit board 310. A pin
connector 311 connected to the circuit board 310 has a
first patch cord 312 extending therefrom to access the
- 2l7~nl7
- 30 -
spare jack 301g on the unit control box 300. A second
patch cord 313 extends from the pin connector 311 and
accesses the sp;nn;ng clutch jack 301c of the unit
control box 300. A third patch cord 314 extends from the
pin connector 311 and accesges the gt~n~rd gp;nn;n~
clutch on the MJS. A relay ("Relay 3", Fig. 17) is
provided on the circuit board 310 to allow st~n~d
control of the sp;nn;ng clutch by the unit control box
300 or to allow the second circuit board 310,
particularly the microprocessor chip 320, to seize
control of the sp;nn;ng clutch of the MJS in accordance
with the present invention.
The spare jack 301g includes two pins (7A, 7B; Fig.
18B) for communicating, via patch cord 312, with two pin
connections 322, 323 on the circuit board 310 shown in
Fig. 17. The two pins in jack 301g are connected by
wires to existing wiring in the MJS unit control box 300
as shown in Fig. 18B. The block diagram in Figs. 18A and
18B are from circuit board #881021A included in the unit
control box 300 of the MJS Model 801-9786-4.
In the block diagram of Figs. 18A and 18B, plug
numbers 1-6 correspond to the plugs color coded in Fig.
16 as green, clear, blue, yellow, gray and red,
respectively (i.e., the order of plugs in Fig. 18 being
opposite that Rhown in Fig. 17). Plug number 7 in Fig.
18B corresponds to the black color coded plug in Fig. 16.
Fig. 18A correspond6 to the standard unit control box on
the Murata MJS, and Fig. 18B show~ the Rame unit control
box 300 modified to interface with the yarn feed system
of the present invention.
Plug number 3, controls the sp;nn;ng/sliver clutch
of the MJS. In accordance with the preæent invention,
that plug is removed and replaced with the plug ext~n~;ng
from patch cord 313 shown in Fig. 16. Fig. 18B showæ
that the second wire 3D of the number 3 plug i~ connected
- 2178~17
- 31 -
to the D wire of the number 7 plug. The C wire of plug
number 7 i8 connected to the terminal on the stAn~Ard
Murata circuit board to which the 3D wire of the number
3 plug previously was connected. The 7A and 7B wires
of the number 7 plug are connected to the components
labeled Dg and D3, respectively, on the gtAn~Ard Murata
circuit board. As explained above, the 7A and 7B wires
are connected to pins 322 and 323 shown in Fig. 17. The
block diagram in Fig. 18B shows the extent to which the
circuit board of the existing unit control box 300 on the
Murata MJS is interfaced with circuit board 310 in
accordance with the present invention.
The remA;n;ng pin-outs of the control circuit board
310 will be explained hereinbelow.
Operation
By way of example, the exemplary circuit diagram
shown in Fig. 17 and the production of spandex
core/synthetic blend wrap yarn will now be explained in
the context of a Murata MJS Model 801-9786-4 modified to
include the yarn feed system of the present invention
(using the package drive assembly of Figs. 4 and 5A, the
sensor of Fig. 6, and the thread-up assembly of Fig. 12A.
Figs. l9A-D show a detailed flow diagram of the
operational control program stored in the microprocessor
chip 320 on the second circuit board 310. The operation
and control of the MJS as modified in accordance with the
present invention will be explained below in the context
of four sequences: Initial Thread-up; Automatic
Threading; Breakage; and Shut-Down, all with reference to
Figs. l9A-D, respectively. Any operator-assisted steps
or explanatory notes not part of the program are shown in
dotted lines in Figs. l9A-D.
217~017
- 32 -
Initial Thread-up Sequence -- Fig. l9A
During initial threA~;ng of a new spAn~y yarn
pAckAge, or if the yarn breaks above the thread-up device
240, the pAckAge 50 is positioned on the package tube
holder 56 and the outside peripheral surface of the
pAc~Age contacts the pAckAge drive roller 60. The
package tube holder shaft 55 can be moved up and down
through oblong slot 54 formed in front face 51a of
mounting plate 51. The slide block 53 moves up and down
in the slide block channel 52 to maintain the rotating
axis of the package 50 parallel to the rotating axis of
the package drive roller 60. As yarn iB drawn off
package 50, gravitational force and the biasing force of
the coil 6pring 59 cause the package 50 to maintain
constant contact with the drive roller 60.
During initial thread-up, as shown in Fig. l9A, the
spandex yarn sensor 41 is disabled and the solenoid 324
of the sp;nn;ng clutch is disengaged to stop the feed of
sliver to the drafting assembly. A human operator then
meters several inches of spandex yarn from the package 50
and presses the set-up button 61a (shown in Fig. 3) to
initiate the Initial Thread-up Sequence. At this time
the front roll wrap sensor 280 takes an initial reading
from the upper surface of the upper front roll 224 and
that reading is stored in the microprocessor chip 320.
The drive roll motor 61 is then disabled by removing
the current supplied thereto. Since the drive roll motor
is a so-called stepper motor, low levels of current can
be applied thereto to prevent the shaft of the motor from
rotating due to external rotational forces applied to the
shaft. When current is not supplied to the motor, the
shaft can be turned freely, and thus the human operator
can rotate the spandex package accordingly.
Pressing the set-up button also causes the top clamp
245 and the lower clamp/cutter 246 to be released by
2178017
-
- 33 -
operation of their respective solenoid valves provided in
conduits 255 and 256, and alRo causes air to be supplied
to the yarn delivery bore 242 of the thread-up device 240
by operation of the solenoid valve in conduit 257. There
is then a delay of about 4 seconds during which time the
human operator must manually feed the end of the spandex
yarn into eyelet 242c of thread-up device 240.
After the 4 second delay, the top clamp 245 is
activated and simultaneously the air supplied to the yarn
delivery bore 242 i8 terminated. The microprocessor then
again determines whether the set-up button 61a is
pressed. If it is pressed, this means that the human
operator was unable to successfully manually feed the end
of the spandex yarn through the thread-up device 240 and
the set-up sequence begins again as shown in Fig. l9A.
If the set-up button is not pressed, but instead the
human operator was successful in feeding the yarn through
the thread-up device 240 and pressed the red flag (a
st~n~rd switching mechanism in the Murata MJS) to signal
the knotter that the spindle is ready for automatic
threading (discussed below), the microprocessor then
checks whether the microswitch (MS, Fig. 3) on the
spindle has been activated by the knotter. The knotter
sequence (st~n~d on the MJS) is also shown in Fig. l9A.
If the microswitch has not been activated, the computer
program loops or recycles as shown in Fig. l9A until the
microswitch is activated by the knotter. In certain
instances where the operator is manually doffing a full
package of core/wrap yarn, the mechanical microswitch may
be activated manually by the operator.
At this stage, top clamp 245 of thread-up device 240
is holding the spandex yarn end in yarn delivery bore
242, so that the spandex yarn can be introduced into the
drafting assembly during the Automatic Threading
Sequence. The spandex yarn may or may not be visibly
217~017
- 34 -
ext~n~; ng from the exit ~urface of the thread-up device
240. The human operator ~hould index the creel package
in rever~e to remove any ~lack from the ~pandex yarn end.
Automatic Thre~; n~ Sequence -- Fiq. l9B
5Once the knotter i8 ~ituated at the spindle and
activates the micro~witch on the ~pindle, the Automatic
Threading Sequence begin~. The microproceR~or enables
the drive roll motor (via "Enable 61" in Fig. 17) by
providing enough current thereto actively to prevent free
10rotation of the motor ~haft, but insufficient current to
actually rotate the motor ~haft. Then, at the same time,
the upper clamp 245 i~ relea~ed (by operation of the
solenoid valve in conduit 255), ramping current is
supplied to the drive roll motor 61, and air is supplied
15to yarn delivery bore 242 (by operation of the solenoid
valve in conduit 257) via the third bore 251 and air
~upply conduit 257 provided in conduit block 254.
The microprocessor then turn~ on the electronic yarn
clearer bypass, which i~ simply an electronic relay
20switch (Relay 1 in Fig. 17) that prevent~ output from the
yarn clearer sensor 3 (e.g., a Seletex~ sensor) from
being detected by the microprocessor. Allowing the yarn
clearer ~ensor 3 to be active during initial production
of the core/wrap yarn could cauRe a voltage spike in the
25yarn clearer due to the increased ~ize of the yarn in a
relaxed ~tate due to lack of tension. It could take the
yarn clearer up to 15 seconds to recover from the voltage
spike, during which time the spindle would not function.
After about a 2 second delay, the air ~upply to the
30thread delivery bore 242 i8 terminated. At this time,
since the front rollers (and apron rollers) of the
drafting assembly are not disabled by the sp;nn;ng
clutch, the spandex yarn hac been fed through the air jet
2l7snl7
- 35 -
8p; nn; ng nozzle 12. After the air supply to the thread
delivery bore 242 is terminated, there is a 0.2 second
delay to make sure all air i8 out of the thread-up device
240, and then the solenoid 324 of the sp;nn;ng (sliver)
clutch is engaged to feed sliver to nozzle 12. By this
time the knotter has positioned the suction hose 24 at
the exit of the air jet sp;nn;ng nozzle 12, and drafting
assembly 11, in conjunction with suction hose 24 and the
spAn~Y yarn already fed through the air jet sp;nn;ng
nozzle, assist in feeding the drafted sliver synthetic
blend yarn through the air jet sp;nn;ng nozzle 12. The
drafted synthetic blend fibers are wrapped around the
Rpandex yarn core in the air jet sp; nn; ng nozzle 12.
After the sliver clutch is engaged, as Rhown by box
413 in Fig. l9B, there is a 3 second delay, and then the
microprocessor calculates the rotation speed of the idler
wheel 106 in the spandex yarn sensor 41 using signal~
produced by the photomicrosensor, as explained above.
This initial rotational speed of the idler wheel in the
spandex yarn sensor is uQed as a threshold value against
which future rotational speeds will be compared to detect
breakage of the spandex yarn above the thread-up device
240.
The microproceRsor then determines whether the front
roll wrap senRor 280 iR experiencing an alarm condition
(i.e., whether ~pandex and/or synthetic blend yarn are
wrapping around the front roll 224 of the drafting
aRsembly). If 80, then the microprocessor begins the
Breakage Sequence as explained later herein.
If the roll wrap sensor is not experiencing an alarm
condition, the microprocessor then determines whether the
spandex yarn sensor 41 is experiencing an alarm
condition. That is, the microprocessor determines
whether there iR breakage above the thread-up device 240.
If no alarm condition is sensed in the spandex yarn
2l7snl7
- 36 -
sensor, the microprocessor then proceeds to activate the
yarn clearer delay cylinder 43 (by operation of solenoid
43 ~hown in Fig. 17). A~ explained above, the delay
cylinder 43 is a solenoid activated mechanical plunger
which extends outwardly from the front of the spindle to
push the core/wrap yarn in and out of yarn clearer sensor
3. Delay cylinder 43 prevents the initially produced
core/wrap yarn from entering the yarn clearer sensor
head, because the quality of this yarn is not yet
acceptable. An erroneous quality re~;ng would result if
the initial core/wrap yarn was detected by the yarn
clearer ~ensor 3.
After activating the yarn clearer delay cylinder 43,
there is then about a 7 second delay during which the
knotting cycle is completed and all kink~ are pulled out
of the core/wrap yarn product being produced by the
machine. That is, as in the conventional MJS machine,
the suction hose 24 of the knotter 7, in con~unction with
the suction pipe 25 of the splicer 27, tie the core/wrap
yarn exiting the nozzle to the core/wrap yarn already
wound on the take-up roll 22. The clearer delay cylinder
43 is then retracted so that the core/wrap yarn is
allowed to pass through the head of the yarn clearer
sensor 3, and then, after a 3.5 ~econd delay, the yarn
clearer electronic bypass is released (by operation of
Relay 1). At this time the modified MJS is now producing
high quality core/wrap yarn and the microprocessor now
simply waits until an alarm condition i8 detected by one
(or more) of the spandex yarn ~ensor, front roll wrap
sensor or by monitoring the microswitch (MS).
Breakaqe Sequence -- Fiq. l9C
If spandex and/or synthetic blend yarn begins to
wrap around the front roll 224 of the drafting assembly,
the front roll sensor 280 sends an alarm signal to the
2l78nl7
- 37 -
microprocessor. The microprocessor then begins the
Breakage Sequence shown in Fig. l9C. Likewise, if the
yarn clear sensor 3 detects excessively slubbed, thick,
or thin core/wrap yarn, it releases the spi nn; ng lever
(stAn~Ard on MJS), which in turn causes the microswitch
(MS) to be released. The microprocessor would also begin
the Breakage Sequence at this point.
Fig. l9C shows that the Breakage Sequence begins by
disabling all alarms, turning off the electronic yarn
clearer sensor (e.g., a Seletex~ sensor) bypass, and
activating the clearer delay cylinder 43. Then the lower
clamp/cutter 246 is activated to cut the supply of
spAn~eY yarn to the drafting assembly, and at the same
time the sliver clutch is disengaged to stop the flow of
sliver to the drafting assembly. Continued rotation of
the front rollers 224 breaks the spandex yarn below the
lower clamp/cutter 246 and conveys any remnant sliver out
of the drafting assembly. After a 160 millisecond delay,
the upper clamp 245 is activated and a delay value (X)
(Fig. 17) is retrieved from memory to determine the
deceleration ramp or rate of deceleration of the drive
roller motor 61. The delay value (X) is programmed by
the operator based on how much draw (extension) is
desired to be maintained in the spandex yarn between the
spandex package 50 and the thread-up device 240. The
amount of draw produced by the rollers in the drafting
assembly of the MJS is communicated to the microprocessor
via the "Draw" pin-out shown in Fig. 17. The delay value
(X) iB communicated to the drive roller motor, which
begins deceleration. The upper clamp 245 i8 then
deactivated and the driving current supplied to the drive
roll motor is terminated (via "Enable 61", Fig. 17).
Again, a n~ ;n~l current is supplied to the drive roll
motor to prevent free rotation of the spandex package 50.
21780~7
- 38 -
After the upper clamp 245 is deactivated and the
drive roll motor is stopped, there is a 0.2 second delay
to allow the creel package to index to release tension in
the sp~n~Y 44 between the activated lower clamp/cutter
246 and the package 50, and then the upper clamp 245 i8
again activated to hold the spandex in place. After
another 0.2 second delay, the lower clamp/cutter 246 is
deactivated, the yarn clearer delay cylinder 43 i8 turned
off, and the drive roll motor 61 is disabled, all
occurring simultaneously, as shown in Fig. l9C. The
program then proceeds to the "check set-up" command as
shown by box 414 in Fig. l9A. The machine is now again
ready to start the Automatic Threading Sequence.
Shutdown Sequence -- Fig. l9D
If the microprocessor does not detect any alarm in
the front roll sensor 280, it then determines whether the
micro~witch is off due to an abnormal condition detected
by the yarn clearer sensor 3 (discussed above). If the
microswitch is off, then the microprocessor accesses the
Breakage Sequence as explained above. If the microswitch
is on, the microprocessor then determineæ whether there
is an alarm condition in the spandex yarn sensor 41. If
no alarm condition exist~, the microprocessor simply
continues looping or cycling in the monitoring loop as
shown in Fig. l9B. If there is an alarm condition in the
spandex yarn senæor 41, this mean~ that the spandex yarn
has broken above the thread-up device 240. The
microprocessor will then proceed to the Shutdown Sequence
of Fig. l9D and shut off the electronic yarn clearer
sensor bypass, activate the yarn clearer delay cylinder
(to push the core/wrap yarn out of the yarn clearer
sensor head to avoid an erroneous quality reading), and
immediately stop the drive roll motor 61. After about a
2 second delay, the yarn clearer delay cylinder is
- 2178017
- 39 -
released, the drive roll motor is disabled (i.e., all
current to the motor is terminated via the "shut-off 61"
pin-out shown in Fig. 17), and all alarms are disabled.
After the human operator clears any debris from the
drafting assembly, the system is now ready to proceed to
the Initial Thread-up Sequence explained earlier herein.
The Core/WraP Yarn
Prior to the present invention, there was no
commercially viable system for producing elastomeric
core/wrap yarn using air jet sp;nn;ng techniques. The
system of the present invention produces a superior
quality elastomeric core/wrap yarn using air jet sp;nn;ng
techniques.
Fig. 20 is a partially schematic, partially cut-away
illustration of the core/wrap yarn 500 of the present
invention. The elastomeric core yarn 501 typically is a
coalesced multifilament spandex yarn such as that
available from DuPont under the trademark Lycra~,
although it may be a single filament or multifilament
highly elastic yarn, as desired. The elastomeric core
yarn can be white or clear, depending upon the desired
end use of the core/wrap yarn. The wrap 502 comprises
staple fibers of synthetic or synthetic-cotton blend
materials.
This core/wrap yarn is distinguishable from
elastomeric core/wrap yarns formed by former methods such
as ring sp;nn;ng~ in that the core/wrap yarn of the
present invention includes wrapper fibers twisted around
the exterior of the bundle of wrapper fibers which encase
the core, whereas ring spun core/wrap yarns do not
include such twisted outer wrapper fibers. Additionally,
there is no residual twist in the present core/wrap yarn,
as is present in ring spun core/wrap yarns.
- 2178~17
- 40 -
The system of the present invention all but renders
obsolete the prior mach;neR for making elastomeric
core/wrap yarns, in that the present system allows a 60
spindle MJS machine to perform the work of 600-900 roving
fed ring sp;nn;ng machines. Additionally, the core/wrap
yarn of the present invention is extraordinarily free of
defects, such as splicing knots due to breaks, over
lengths of at least 15,000 yards. In fact, entire doff
packages of about 32,000 yards of defect-free core/wrap
yarn have been produced on a regular basis.
While the present invention has been described above
in detail, it will be appreciated by those skilled in the
art that variou6 change6 and modification6 could be made
thereto without departing from the scope and æpirit
thereof as defined in the attached claims. For example,
the invention has been explained in the context of a
Murata MJS machine, but could be adapted for use on other
6p; nn; ng machines.
