U.S. patent application number 10/228410 was filed with the patent office on 2003-01-02 for single end servo motor driven scroll pattern attachment for tufting machine and computerized design system for tufting carpet.
Invention is credited to Bishop, Mike, Morgante, Michael R., Prichard, Richard, Stanfield, Randall E., Vaughen, Eric J..
Application Number | 20030000438 10/228410 |
Document ID | / |
Family ID | 23855680 |
Filed Date | 2003-01-02 |
United States Patent
Application |
20030000438 |
Kind Code |
A1 |
Morgante, Michael R. ; et
al. |
January 2, 2003 |
Single end servo motor driven scroll pattern attachment for tufting
machine and computerized design system for tufting carpet
Abstract
The present invention provides a single end scroll-type yarn
feed attachment for tufting machines characterized by an array of
single end yarn drives operated by servo motor controllers, and
methods of using such an attachment to create and tuft new carpet
patterns.
Inventors: |
Morgante, Michael R.; (East
Aurora, NY) ; Bishop, Mike; (Signal Mountain, TN)
; Stanfield, Randall E.; (Soddy-Daisy, TN) ;
Vaughen, Eric J.; (Chattanooga, TN) ; Prichard,
Richard; (Hixson, TN) |
Correspondence
Address: |
DOUGLAS T. JOHNSON
MILLER & MARTIN
1000 VOLUNTEER BUILDING
832 GEORGIA AVENUE
CHATTANOOGA
TN
37402-2289
US
|
Family ID: |
23855680 |
Appl. No.: |
10/228410 |
Filed: |
August 26, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10228410 |
Aug 26, 2002 |
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09882632 |
Jun 14, 2001 |
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6439141 |
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09882632 |
Jun 14, 2001 |
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09467432 |
Dec 20, 1999 |
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6283053 |
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09467432 |
Dec 20, 1999 |
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08980045 |
Nov 26, 1997 |
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6244203 |
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60031954 |
Nov 27, 1996 |
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Current U.S.
Class: |
112/80.73 |
Current CPC
Class: |
D05D 2205/085 20130101;
D05B 19/08 20130101; Y10T 428/23936 20150401; D05B 19/12 20130101;
D05C 15/32 20130101; D05C 15/18 20130101; D05C 17/02 20130101; D05C
17/026 20130101 |
Class at
Publication: |
112/80.73 |
International
Class: |
D05C 015/18 |
Claims
We claim:
1. A multiple needle tufting machine comprising: (a) a yarn drive
array receiving a plurality of yarns from a yarn supply; (b) a
plurality of laterally spaced needles receiving the plurality of
yarns from the yarn drive array; (c) a main drive for reciprocating
the plurality of laterally spaced needles through a backing fabric
fed longitudinally from front to rear through the tufting machine;
(d) a looper mechanism acting in synchronized cooperation with the
plurality of needles to seize loops of yarn from said plurality of
needles; and (e) a master controller receiving information relative
to the position of the main drive; wherein the yarn drive array
consists essentially of single and yarn drives.
2. The multiple needle tufting machine of claim 1 wherein the
single end yarn drives are comprised of a servo motor in mechanical
communication with a yarn feed roll.
3. The multiple needle tufting machine of claim 1 further
comprising a servo motor controller in communication both with the
master controller and with at least one servo motor in the single
end yarn drives of the yarn drive array.
4. The multiple needle tufting machine of claim 3 wherein the
master controller communicates information relative to the position
of the main drive to the servo motor controller, and information
relative to the yarn amount to be fed for the next stitch by the
yarn roll in mechanical communication with the at least one servo
motor in communication with the servo motor controller.
5. The multiple needle tufting machine of claim 3 wherein the at
least one servo motor provides positional control information to
the servo motor controller.
6. The multiple needle tufting machine of claim 3 wherein there is
two way processing of positional information between the at least
one servo motor and the servo motor controller.
7. The multiple needle tufting machine of claim 1 wherein the yarn
drive array comprises at least about one thousand single end yarn
drives.
8. The multiple needle tufting machine of claim 2 wherein the yarn
feed rolls of each of the single end yarn drives may be rotated at
any one of at least sixteen speeds by mechanical communication with
associated servo motors.
9. The multiple needle tufting machine of claim 1 wherein a
computer is used to communicate pattern information to the master
controller.
10. The multiple needle tufting machine of claim 2 wherein a yarn
guide directs the proper placement of a yarn on the yarn feed roll
of the single end yarn drives.
11. A method of creating and tufting a carpet pattern comprising
the steps of: scanning a color image to create a digital image;
processing the digital image by a computer to calculate
corresponding yarn heights and yarn feed increments for a plurality
of colors of yarns in a carpet pattern to create pattern
information; inputting the pattern information into a master
controller of a multi-needle tufting machine; threading yarn ends
of said plurality of colors of yarns from a yarn supply through a
yarn drive array of single end yarn drives, each comprising a servo
motor and an associated yarn feed roll, to a plurality of laterally
spaced needles; reciprocating the plurality of laterally spaced
needles threaded with said plurality of yarns through a backing
fabric fed longitudinally from front to back through the tufting
machine; sending information relative to the position of the
plurality of needles to the master controller; the main controller
sending information relative to the amount of yarn to be fed for
the next stitch to a servo motor controller; the servo motor
controller directing a servo motor of a single end yarn drive to
rotate the associated yarn feed roll the distance required to feed
the yarn end the appropriate amount for the stitch; and operating a
looper mechanism in synchronized cooperation with the plurality of
needles to seize loops of yarn tufted through the backing
fabric.
12. The method of creating and tufting a carpet pattern of claim 11
wherein the servo motor of the single end yard drive provides
positional control information to the servo motor controller;
13. The method of creating and tufting a carpet pattern of claim 11
wherein there is two way processing of positional information
between the at least one servo motor and the servo motor
controller.
14. The method of creating and tufting a carpet pattern of claim 11
wherein the yarn drive array comprises at least about one thousand
single end yarn drives.
15. The method of creating and tufting a carpet pattern of claim 11
wherein the yarn feed roll may be rotated at any one of at least
sixteen speeds to achieve the desired yarn feed for a stitch.
16. The method of creating and tufting a carpet pattern of claim 11
wherein a yarn guide directs the proper placement of a yarn end on
the yarn feed roll of the single end yarn drives.
17. The multiple needle tufting machine of claim 1 wherein the yarn
drive array consists of at least about 20 rows of single end yarn
drives.
18. The multiple needle tufting machine of claim 1 wherein a
computer network is used to communicate pattern information to the
master controller.
19. The method of creating and tufting a carpet pattern of claim 11
wherein the yarn feed increment for a relatively high yarn height
stitch occurring after a relatively low yarn height stitch is
greater than the yarn feed increment for a relatively high yarn
height stitch occurring after another relatively high yarn height
stitch.
20. The method of cresting and tufting a carpet pattern of claim 11
wherein the yarn feed increment for a relatively low yarn height
stitch occurring after another relatively low yarn height stitch is
greater than the yarn feed increment for a relatively low yarn
height stitch occurring after a relatively high yarn height stitch.
Description
PRIORITY
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/882,632 filed Jun. 18, 2001, which is a
divisional of U.S. patent application Ser. No. 09/467,432 filed
Dec. 20, 1999, which is a continuation-in-part of U.S. Ser. No.
08/980,045 filed Nov. 26, 1997 which claims priority from U.S.
Provisional Application Serial No. 60/031,954 filed Nov. 27, 1996
entitled "Independent Single End Servo Scroll Pattern Attachment
for Tufting Machine And Computerized Design System" which is
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a yarn feed mechanism for a
tufting machine and more particularly to a scroll-type pattern
controlled yarn feed wherein each yarn may be wound on a separate
yarn feed roll, and each yarn feed roll is driven by an
independently controlled servo motor. A computerized design system
is also provided because of the complexities of working with the
large numbers of individually controllable design parameters
available to the new yarn feed mechanism.
[0003] Pattern control yarn feed mechanisms for multiple needle
tufting machines are well known in the art and may be generally
characterized as either roll-type or scroll-type pattern
attachments. Roll type attachments are typified by J. L. Card, U.S.
Pat. No. 2,966,866 which disclosed a bank of four pairs of yarn
feed rolls, each of which is selectively driven at a high speed or
a low speed by the pattern control mechanism. All of the yarn feed
rolls extend transversely the entire width of the tufting machine
and are journaled at both ends. There are many limitations on
roll-type pattern devices. Perhaps the most significant limitations
are: (1) as a practical matter, there is not room on a tufting
machine for more than about eight pairs of yarn feed rolls; (2) the
yarn feed rolls can be driven at only one of two, or possibly three
speeds, when the usual construction utilizing clutches is used--a
wider selection of speeds is possible when using direct servo motor
control, but powerful motors and high gear ratios are required and
the shear mass involved makes quick stitch by stitch adjustments
difficult; and (3) the threading and unthreading of the respective
yarn feed rolls is very time consuming as yarns must be fed between
the yarn feed rolls and cannot simply be slipped over the end of
the rolls, although the split roll configuration of Watkins, U.S.
Pat. No. 4,864,946 addresses this last problem.
[0004] The pattern control yarn feed rolls referred to as
scroll-type pattern attachments are disclosed in J. L. Card, U.S.
Pat. No. 2,862,465, are shown projecting transversely to the row of
needles, although subsequent designs have been developed with the
yarn feed rolls parallel to the row of needles as in Hammel, U.S.
Pat. No. 3,847,098. Typical of scroll type attachments is the use
of a tube bank to guide yarns from the yarn feed rolls on which
they are threaded to the appropriate needle. In this fashion yarn
feed rolls need not extend transversely across the entire width of
the tufting machine and it is physically possible to mount many
more yarn feed rolls across the machine. Typically, scroll pattern
attachments have between 36 and 120 sets of rolls, and by use of
electrically operated clutches each set of rolls can select from
two, or possibly three, different speeds for each stitch.
[0005] The use of yarn feed tubes introduces additional complexity
and expense in the manufacture of the tufting machine; however, the
greater problem is posed by the differing distances that yarns must
travel through yarn feed tubes to their respective needles. Yarns
passing through relatively longer tubes to relatively more distant
needles suffer increased drag resistance and are not as responsive
to changes in the yarn feed rates as yarns passing through
relatively shorter tubes. Accordingly, in manufacturing tube banks,
compromises have to be made between minimizing overall yarn drag by
using the shortest tubes possible, and minimizing yarn feed
differentials by utilizing the longest tube required for any single
yarn for every yarn. Tube banks, however well designed, introduce
significant additional cost in the manufacture of scroll-type
pattern attachments.
[0006] One solution to the tube bank problems, which also provides
the ability to tuft full width patterns is the full repeat scroll
invention of Bradsley, U.S. Pat. No. 5,182,997, which utilizes
rocker bars to press yarns against or remove yarns from contact
with yarn feed rolls that are moving at predetermined speeds. Yarns
can be engaged with feed rolls moving at one of two preselected
speeds, and while transitioning between rolls, yarns are briefly
left disengaged, causing those yarns to be slightly underfed for
the next stitch.
[0007] Another significant limitation of scroll-type pattern
attachments is that each pair of yarn feed rolls is mounted on the
same set of drive shafts so that for each stitch, yarns can only be
driven at a speed corresponding to one of those shafts depending
upon which electromagnetic clutch is activated. Accordingly, it has
not proven possible to provide more than two, or possibly three,
stitch heights for any given stitch of a needle bar.
[0008] As the use of servo motors to power yarn feed pattern
devices has evolved, it has become well known that it is desirable
to use many different stitch lengths in a single pattern. Prior to
the use of servo motors, yarn feed pattern devices were powered by
chains or other mechanical linkage with the main drive shaft and
only two or three stitch heights, in predetermined ratios to the
revolutions of the main drive shaft, could be utilized in an entire
pattern. With the advent of servo motors, the drive shafts of yarn
feed pattern devices may be driven at almost any selected speed for
a particular stitch.
[0009] Thus a servo motor driven pattern device might run a high
speed drive shaft to feed yarn at 0.9 inches per stitch if the
needle bar does not shift, 1.0 inches if the needle bar shifts one
gauge unit, and 1.1 inches if the needle bar shifts two gauge
units. Other slight variations in yarn feed amounts are also
desirable, for instance, when a yarn has been sewing low stitches
and it is next to sew a high stitch, the yarn needs to be slightly
overfed so that the high stitch will reach the full height of
subsequent high stitches. Similarly, when a yarn has been sewing
high stitches and it is next to sew a low stitch, the yarn needs to
be slightly underfed so that the low stitch will be as low as the
subsequent low stitches. Therefore, there is a need to provide a
pattern control yarn feed device capable of producing scroll-type
patterns and of feeding the yarns from each yarn feed roll at an
individualized rate.
[0010] Commonly assigned copending application Ser. No. 08/980,045
addressed many of these concerns; however, even that servo scroll
pattern attachment did not allow each end of yarn across the entire
width of a full size tufting machine to be independently
controlled. By providing each end of yarn with an independently
driven yarn feed roll, the use of the tube bank can be eliminated,
and patterns can be created that do not repeat across the entire
width of a broadloom tufting machine.
SUMMARY OF THE INVENTION
[0011] It is therefore an object of this invention to provide in a
multiple needle tufting machine a pattern controlled yarn feed
mechanism incorporating a plurality of individually driven yarn
feed rolls across the tufting machine.
[0012] The yarn feed mechanism made in accordance with this
invention includes a plurality of yarn feed rolls, each being
directly driven by a servo motor. About twenty yarn feed rolls with
attached servo motors, are mounted upon a plurality of arched
mounting arms which are attached to the tufting machine. Each yarn
feed roll is driven at the speed dictated by its corresponding
servo motor and each servo motor can be individually
controlled.
[0013] It is a further object of this invention to provide a
pattern controlled yarn feed mechanism which does not rely upon
electromagnetic clutches, but instead uses only servo motors.
[0014] It is another object of this invention to eliminate the need
for a tube bank in a scroll type pattern attachment, which further
minimizes the differences in yarn feed rates to individual
needles.
[0015] It is another object of this invention to provide a yarn
feed mechanism that operates at high speeds, with great accuracy,
in constant engagement with the yarns.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1A is a side elevation view of the multiple needle
tufting machine incorporating the pattern control yarn feed
mechanism made in accordance with the invention;
[0017] FIG. 1B is a side elevation view of an alternative
embodiment of an arched support for a pattern control yarn feed
mechanism according to the invention, shown in isolation;
[0018] FIG. 1C is a side elevation view of a partially assembled
embodiment of an arched support for a pattern control yarn feed
mechanism according to the invention, showing the motor and wiring
positions.
[0019] FIG. 1D is a rear sectional view of the support of FIG.
1C.
[0020] FIG. 2 is a top elevation view of a segment of an arched
mounting bar with four single end servo driven yarn feed rolls, two
on each side;
[0021] FIG. 3A is a rear elevation view of an arching support
holding two yarn feed rolls, two servo motors that control yarn
feed roll rotation, and yarn guide plate;
[0022] FIG. 3B is an alternative yarn guide plate;
[0023] FIG. 4 is a side elevation view of a yarn drive and the yarn
guide plate of FIG. 3A;
[0024] FIG. 5 is a rear partial sectional view of a servo motor
with feed roll;
[0025] FIG. 6 is a schematic view of the electrical flow diagram
for a multiple needle tufting machine incorporating a yarn feed
mechanism made in accordance with the invention;
[0026] FIG. 7 is a carpet design with a series of concentric
borders made possible by use of the invention.
[0027] FIG. 8 is a schematic view of the electrical flow diagram
for a single arched support carrying twenty servo motors.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Referring to the drawings in more detail, FIG. 1A discloses
a multiple needle tufting machine 10 upon the front of which is
mounted a pattern control yarn feed attachment 11 in accordance
with this invention. It will be understood that it is possible to
mount pattern control yarn feed attachments 11 on both sides of a
tufting machine 10 when desired. The machine 10 includes a housing
12 and a bed frame 13 upon which is mounted a needle plate, not
shown, for supporting a base fabric adapted to be moved through the
machine 10 from front to rear in the direction of the arrow 14 by
front and rear fabric rollers. The bed frame 13 is in turn mounted
on the base 15 of the tufting machine 10.
[0029] A main drive motor 16, schematically shown in FIG. 6, drives
a rotary main drive shaft 17 mounted in the head 18 of the tufting
machine. Drive shaft 17 in turn causes push rods 19 to move
reciprocally toward and away from the base fabric. This causes
needle bar 20 to move in a similar fashion. Needle bar 20 supports
a plurality of preferably uniformly spaced needles 21 aligned
transversely to the fabric feed direction 14. The needle bar 20 may
be shiftable by means of well known pattern control mechanisms, not
shown, such as Morgante, U.S. Pat. No. 4,829,917, or R. T. Card,
U.S. Pat. No. 4,366,761. It is also possible to utilize two needle
bars in the tufting machine, or to utilize a single needle bar with
two, preferably staggered, rows of needles.
[0030] In operation, yarns 22 are fed through tension bars 23, into
the pattern control yarn feed device 11. Then yarns 22 are guided
in a conventional manner through yarn puller rollers 24, and yarn
guides 25 to needles 21. A looper mechanism, not shown, in the base
15 of the machine 10 acts in synchronized cooperation with the
needles 21 to seize loops of yarn 22 and form cut or loop pile
tufts, or both, on the bottom surface of the base fabric in well
known fashions.
[0031] In order to form a variety of yarn pile heights, a pattern
controlled yarn feed mechanism 11 incorporating a plurality of yarn
feed rolls adapted to be independently driven at different speeds
has been designed for attachment between the tensioning bars 23 and
the yarn puller rollers 24.
[0032] As best disclosed in FIGS. 1A and 1B, a yarn drive array is
assembled on an arching support bar 26 extending across the front
of the tufting machine 10 and providing opposing vertical mounting
surfaces 71, 72 on each of its sides and an upward facing top
surface 73 (shown in FIG. 2). On the opposing side-facing surfaces
71, 72 are mounted a total of 20 single end servo driven yarn feed
rolls 28, ten on each side, shown in isolation in FIGS. 2-5. It
will be understood that the number of rolls on each support bar 26
may be varied for many reasons, especially in proportion to the
gauge of the needles 21 on the needle bar 20. For instance, in the
case of 1/8 gauge needle spacing (8 needles per inch) and support
bars spaced every three inches, it would be desirable to carry 24
independently driven yarn feed rolls on each support bar 26. In
practice, the support bars 26 should carry at least about 6, and
preferably at least about 12, single end servo driven yarn feed
rolls 28.
[0033] As shown in FIG. 1A and in detail in FIG. 2, the arching
support bar 26 accommodates the wiring bundle 53 from the motors
via the wiring path 43, shown in FIG. 3A, built into the arching
support bar 26, which facilitates the wiring of the motors. Wiring
plugs 54a and 54b join the wiring bundle 53 to leads connected to
the motors 31 and allow for easy servicing. Wiring bundle 53 is in
turn connected to servo motor controller board 65 which may be in a
central cabinet or installed on an arching support 26. This latter
wiring configuration minimizes the wire length from the controller
board 65 to the motor 31, thereby reducing tangling, wire damage
due to excessive length, and electrical shorting. Troubleshooting
electrical problems is also improved by this wiring configuration
and shorter overall wire length.
[0034] Each single end yarn drive 35 consists of a yarn feed roll
28 and a servo motor 31, shown in isolation on FIG. 5. The servo
motor 31 directly drives the yarn feed roll 28, which may be
advantageously attached concentrically about the servo motor 31. A
tension roll 32 shown in FIG. 4, controls the feed and wrapping of
the yarn onto the yarn feed roll 28 to insure there is adequate
traction of yarn 22 with roll 28. The yarn 22 is guided onto the
tension roll 32 by the yarn guide plate 27. The position of the
yarn guide plate 27 and the tension roll 32 is fixed with fastening
screw 36. Preferably a yarn 22 is angled so that is wrapped around
nearly 180.degree. of the circumference of the yarn feed roll 28,
and at least about 135.degree. of said circumference. Yarn guide
posts 34 protrude from the rear of yarn guide plates 27 and help
ensure the proper placement of yarn 22 on yarn feed rolls 28.
[0035] It will also be noted in FIGS. 1A and 3A that yarns from the
yarn supply are fed through upper 29a and lower 29b apertures on
the support yarn guides 27. Specifically, a yarn 22 for a yarn feed
drive 35 on the support distal from the tufting machine is fed
through upper apertures 29a until it reaches its associated yarn
drive, is fed around approximately 180.degree. of the yarn feed
roll 28 on its associated yarn drive 35, and continues through
upper apertures 29a of the support yarn guides 27 until the
midpoint of the support 26 is reached. At this point, the yarns 22
for the distal yarn feed drives 35 are threaded through lower
apertures 29b in the remaining proximal yarn guides 27. Conversely,
yarns for proximal yarn drives come from the yarn supply through
lower apertures 29b in the distal yarn guides 27 until about the
middle of the yarn drives and the support 26 when those yarns 22
are directed to the upper apertures 29a in the proximal yarn guides
and cross the yarns from the distal yarn drives. In this fashion,
the crossing of yarns occurs substantially at one point 37,
opportunities for yarn friction and breakage minimized, and yarn
threading simplified.
[0036] In a preferred embodiment depicted in FIGS. 1B and 3B, it is
not necessary to cross the yarns, the offset position upper
apertures 29a from lower apertures 29b in the yarn guide plate 27
begin sufficient to permit yarns to continue through the same
aperture position and around their designated yarn feed rolls 28
without significant friction between yarns 22.
[0037] FIGS. 1C and 1D feature the preferred wiring of arched
supports 26 showing motors 31 or yarn feed drives 35 only on one
vertical side 71 of the support 26. The electrical connections 52
from motors 31 end in plugs 54b which mate with plugs 54a set in
cover plates 40. Cover plates 40 are removably secured to arched
support 26 and conceal individual servo motor controllers 69.
[0038] As shown in FIG. 8, the invention is currently wired with
four individual servo motor controllers 69, each controlling five
motors 31. Collectively the four individual servo motor controllers
comprise the servo motor controller board 65. It will be
appreciated that the controllers 69 may be dispersed under separate
cover plates 40 or collectively mounted on a single board 69 under
a single cover plate 40, or even placed in a central controller
cabinet depending upon wiring considerations. The wiring of FIG. 1C
and 8 is presently preferred. It will also be understood that more
powerful controllers 69 might operate more than five motors 31 or
in some instances fewer or even a single motor 31 might be operated
by a controller 69. The most desirable wiring for a given
application will depend upon the speed and price of available
controllers as well as the speed at which the yarn feed attachment
is intended to operate.
[0039] It will also be seen in FIGS. 4 and 5 that the servo motors
31 are set on base plates 30 of greater diameter than the yarn feed
rolls 28 and are mounted onto the arching support bar 26 using four
motor mount bolts 38 through mounting holes 33 in the base
plates.
[0040] Each feed roll 28 has a yarn feeding surface 39 formed of a
sand-paper like or other high friction material upon which the
yarns are fed. Each of these yarn feed rolls 28 may be loaded with
one yarn, which is a light load providing little resistance
compared to the hundred or more yarns that might be carried on a
roll-type yarn feed attachment, the hundreds of individual yarns
typically driven by a single scroll drive shaft, or even the dozen
yarns typically driven in co-pending Ser. No. 08/980,045. Because
of the lighter loads used, this design permits the use of small
servo motors that can mount inside or outside of the yarn feed
rolls 28. For instance, a typical motor for driving a single end of
yarn would be a 24-28 volt motor using 3 amps of power. This motor
would be able to generate 5 lb-in of torque at 3 amps, having a
maximum no load speed of 650 RPM. A representative motor of this
type is the Full Repeat Scroll Motor by Moog, Inc. (C22944), which
meets these general specifications. A motor of this type is
sufficiently powerful to turn the associated yarn feed roll without
the need for any gearing advantage. Thus the preferred ratio of
servo motor revolutions to yarn feed roll revolutions is 1:1.
[0041] Turning now to FIG. 6, a general electrical diagram of the
invention is shown in the context of a computerized tufting
machine. A personal computer 60 is provided as a user interface,
and this computer 60 may also be used to create, modify, display
and install patterns in the tufting machine 10 by communication
with the tufting machine master controller 42.
[0042] Due to the very complex patterns that can be tufted when
individually controlling each end of yarn, many patterns will
comprise large data files that are advantageously loaded to the
master controller by a network connection 41; and preferably a high
bandwidth network connection. For instance, digital representations
of complex scroll patterns for traditional scroll pattern
attachments might be stored in about 2 Kb of digital memory. A
digital representation of a pattern for the single end servo driver
scroll of the present invention might not repeat for 10,000
stitches and could require 20 Gb of disk space before data
compression and about 20 Mb even after compression.
[0043] Master controller 42 in turn preferably interfaces with
machine logic 63, so that various operational interlocks will be
activated if, for instance, the controller 42 is signaled that the
tufting machine 10 is turned off, or if the "jog" button is
depressed to incrementally move the needle bar, or a housing panel
is open, or the like. Master controller 42 may also interface with
a bed height controller 62 on the tufting machine to automatically
effect changes in the bed height when patterns are changed. Master
controller 42 also receives information from encoder 68 relative to
the position of the main drive shaft 17 and preferably sends
pattern commands to and receives status information from
controllers 46, 47 for backing tension motor 48 and backing feed
motor 49 respectively. Said motors 48, 49 are powered by power
supply 50. Finally, master controller 42, for the purposes of the
present invention, sends ratiometric pattern information to the
servo motor controller boards 65. The master controller 42 will
signal a particular servo motor controller board 65 that it needs
to spin its particular servo motors 31 at given revolutions for the
next revolution of the main drive shaft 17 in order to control the
pattern design. The servo motors 31 in turn provide positional
control information to their servo motor controller board 65 thus
allowing two-way processing of positional information. Power
supplies 67, 66 are associated with each servo motor controller
board 65 and motor 31.
[0044] Master controller 42 also receives information relative to
the position of the main drive shaft 17. Servo motor controller
boards 65 process the ratiometric information and main drive shaft
positional information from master controller 42 to direct servo
motors 31 to rotate yarn feed rolls 28 the distance required to
feed the appropriate yarn amount for each stitch.
[0045] In commercial operation, it is anticipated that a typical
broadloom tufting machine will utilize pattern controlled yarn feed
devices 11 according to the present invention with 53 support bars
26, each bearing 20 yarn feed drives 35 thereby providing 1060
independently controlled yarn feed rolls 28. If any yarn feed roll
28 or associated servo motor 31 should become damaged or
malfunction, the arched support bar 26 can be pivoted downward for
ease of access. A replacement single end yarn drive 35 already
fitted with a yarn feed roll 28 and a servo motor 31 can be quickly
installed. This allows the tufting machine to resume operation
while repairs to the damaged or malfunctioning yarn feed rolls and
motor are completed, thereby minimizing machine down time.
[0046] The present feed attachment 11 provides substantially
improved results by providing scroll type yarn control while
eliminating the need for a tube bank. Historically, tube banks have
been designed in three ways: to minimize tube length, to minimize
differences in yarn drag through the tubes, and to compromise
between these two alternatives. All tube bank designs entail
significant expense and introduce undesirable yarn drag into
tufting operations.
[0047] The present design, unlike the previous art, does not use
tube banks to distribute the yarns 22 to the needle bar 20. Instead
the yarns 22 are directly routed to the needle bars 20 through the
yarn guides 25. This is possible because yarns can be individually
driven by feed rolls in directional alignment with the respective
needles. By eliminating the tube banks, the source of friction
variations is removed, eliminating the need for control schemes to
correct for this problem.
[0048] Another significant advance permitted by the present pattern
control attachment 11 is to permit the exact lengths of selected
yarns to be fed to the needles. Unlike the previous art, each yarn
may be controlled individually to produce the smoothest possible
finish. For instance, in a given stitch in a high/low pattern on a
tufting machine that is not shifting its needle bar the following
situations may exist:
[0049] 1. Previous stitch was a low stitch, next stitch is a low
stitch.
[0050] 2. Previous stitch was a low stitch, next stitch is a high
stitch.
[0051] 3. Previous stitch was a high stitch, next stitch is a high
stitch.
[0052] 4. Previous stitch was a high stitch, next stitch is a low
stitch.
[0053] Obviously, with needle bar shifting which requires extra
yarn depending upon the length of the shift, or with more than two
heights of stitches, many more possibilities may exist. In this
limited example, it is preferable to feed the standard low stitch
length in the first situation, to slightly overfeed for a high
stitch in the second situation, to feed the standard high stitch
length in the third situation, and to slightly underfeed the low
stitch length in the fourth case. On a traditional scroll type
attachment, the electromagnetic clutches can engage either a high
speed shaft for a high stitch or a low speed shaft for a low
stitch. Accordingly, the traditional scroll type attachment cannot
optimally feed yarn amounts for complex patterns which results in a
less even finish to the resulting carpet. The independence obtained
by the single end servo scroll would allow for these minor changes
on a per yarn basis, enabling pattern capabilities that were not
possible before.
[0054] In a typical configuration, the single end yarn drives would
be spaced at about four to seven inch intervals along the support
bar. This spacing is necessary to ensure proper yarn travel and
minimal yarn resistance and stretching while still allowing for
enough space between the yarn feed rolls 28 to allow minor
adjustments. The distance between support brackets is typically 3
1/4 inches but may vary in either direction. This variability is
necessary because of variations in the needle gauge that may be
used. For instance, a larger needle gauge will require the needles
be spread at further intervals allowing more space between the
support arms. However, for the smaller needle gauge, the support
arms will need to be closer together due to the increased proximity
of the needles.
[0055] There are several advantages to having independently
controlled single end yarn drives, particularly with regards to the
patterns that can be created. By having each end of yarn
independently controlled by its own dedicated yarn drive, this
pattern device can produce designs that are not possible using
previous broad loom tufting machines. For instance, a
non-continuous repeating pattern may be made across the width of
the tufting machine, utilizing three or more yarn heights for each
yarn. This pattern could consist of any design such as a word
message or non-repeating geometric design across the entire carpet
in various colors. Another design type that this type of pattern
device may create is a rug with central design surrounded by a
border. For example, a rug with a word phrase surrounded in the
center by one color, then surrounded by a border of another color
could easily be produced with this device without special
consideration. A rug 52 with a series of centric borders, 55, 56,
57, 58, 59, 61, as shown in FIG. 7 may also be tufted. Each yarn in
rug 52 is tufted through a backing fabric so that a series of back
stitches are on the bottom of finished rug while the tufted bights
form cut or loop pile stitches on the top or face of the finished
rug. The yarns in each border may be tufted at three or more
lengths to precisely control the yarns for color transitions or
sculptured effects.
[0056] Although the illustrated borders are shown in two colors,
the border patterns could also be created in a high/low textured or
sculpted manner from a single color of yarn. Typically the borders,
55, 56, 57, 58, 59, 61, will surround a central area 64. The
central area 64 may or may not be textured or contain a design
52.
[0057] A second type of design possible with this pattern
attachment is one that involves the creation of color picture
designs that are facimiles of digital images. By loading a front
pattern device with A and B yarns fed to a front needle bar and
loading a rear pattern device with C and D yarns fed to a rear
needle bar, full color pictures may be created from the yarns.
Typically, the A, B, C, and D yarns will consist of shades of red,
yellow, and green or red, yellow, and blue, combined with another
color for aid in light and dark shading. Many other combinations of
colored yarns may be used to achieve varied results.
[0058] In the preferred embodiment, a color image is digitally
input into a computer using a scanner, as typified by Hewlett
Packard ScanJet 5100c or other digital device. The digital image is
processed by the computer, which calculates the correct yarn color
mixes and corresponding yarn heights to produce the desired
spectral effect. The yarn height information is translated into
rotational instructions for each yarn drive. Using this
information, an approximation of the digital image can be recreated
within the yarns of a carpet.
[0059] The prior art for the creation of carpet of individually
tufted yarns is typified by U.S. Pat. No. 4,549,496 where a
pneumatic system is used to direct each strand of yarn in the
pattern control device. This process has significant limitations
involving size of rugs it can produce and the production speed due
to the complexity of directing the various colored yarns using
pneumatic technology, and the limited number of needles sewing each
stitch. With the single end servo scroll pattern attachment
described, broad loom carpets with complex color pictures are
created with greater efficiency and speed.
[0060] While preferred embodiments of the invention have been
described above, it is to be understood that any and all equivalent
realizations of the present invention are included within the scope
and spirit thereof. Thus, the embodiments depicted are presented by
way of example only and are not intended as limitations upon the
present invention. While particular embodiments of the invention
have been described and shown, it will be understood by those
skilled in the art that the present invention is not limited
thereto since many modifications can be made. Therefore, it is
contemplated that any and all such embodiments are included in the
present invention as may fall within the scope or equivalent scope
of the appended claims.
* * * * *