U.S. patent application number 09/882632 was filed with the patent office on 2001-10-18 for independent single end servo scroll pattern attachment for tufting machine and computerized design system.
Invention is credited to Bishop, Mike, Morgante, Michael R., Prichard, Richard, Stanfield, Randall E., Vaughen, Eric J..
Application Number | 20010029877 09/882632 |
Document ID | / |
Family ID | 23855680 |
Filed Date | 2001-10-18 |
United States Patent
Application |
20010029877 |
Kind Code |
A1 |
Morgante, Michael R. ; et
al. |
October 18, 2001 |
Independent single end servo scroll pattern attachment for tufting
machine and computerized design system
Abstract
The present invention provides a single end scroll-type yarn
feed attachment for tufting machines characterized by independent
servo-motor control of yarn feed rolls while eliminating tube banks
typical of tufting machine feed attachments and produces new tufted
carpet designs.
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.: |
09/882632 |
Filed: |
June 14, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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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: |
112/80.23 |
Current CPC
Class: |
D05C 15/18 20130101;
D05C 15/32 20130101; D05D 2205/085 20130101; Y10T 428/23936
20150401; D05C 17/02 20130101; D05B 19/12 20130101; D05C 17/026
20130101; D05B 19/08 20130101 |
Class at
Publication: |
112/80.23 |
International
Class: |
A41B 001/00; A41D
001/00 |
Claims
We claim:
1. In a multiple needle tufting machine adapted to feed a backing
fabric longitudinally from front to rear through the machine having
a plurality of spaced needles aligned transversely of the machine
for reciprocable movement through the backing fabric by operation
of a rotary main drive shift, a yarn feed mechanism comprising: (a)
a support having a mounting surface; (b) a plurality of servo motor
driven single end yarn drives removably attached to said mounting
surface; (c) a servo motor controller for processing ratiometric
information, electronically connected to a servo motor of a single
end yarn drive; (d) a master controller which receives rotational
position information for the main drive shaft and sends
corresponding ratiometric pattern information by electrical
connection to the servo motor controller board.
2. The yarn feed mechanism of claim 1 wherein at least about 6
single end yarn drives are attached to said support bar.
3. The yarn feed mechanism of claim 2 wherein said yarn feed
mechanism comprises approximately 20 single end yarn drives
attached to said support bar.
4. The yarn feed mechanism of claim 1 wherein the support is arched
and extends longitudinally away from the tufting machine.
5. The yarn feed mechanism of claim 1 wherein at least about 20
support bars are aligned transversely on the tufting machine and
extend longitudinally away from the tufting machine.
6. The yarn feed mechanism of claim 1 wherein said single end yarn
drives can be rotated at any one of at least sixteen speeds by said
associated servo motor.
7. The yarn feed mechanism of claim 1 wherein the servo motors of
said single end yarn drives operate with less than ten pounds per
inch of torque.
8. The yarn feed mechanism of claim 1 wherein the servo motors
associated with said single end yarn drives are mechanically
connected to yarn feed rolls on said single end yarn drives such
that the rotations of the servo motors correspond to the rotations
of the yarn feed rolls with a 1:1 ratio.
9. The yarn feed mechanism of claim 1 wherein the single end yarn
feed drive comprises a yarn feed roll concentrically placed about
and mechanically connected to the servo motor.
10. The yarn feed mechanism of claim 1 wherein a computer is used
to communicate pattern information to the master controller.
11. The yarn feed mechanism of claim 1 wherein a computer network
is used to communicate pattern information to the master
controller.
12. The yarn feed mechanism of claim 1 wherein said servo motor
associated with said single end yarn drive provides positional
control information to the electronically connected servo motor
controller board.
13. A method of automatically inputting the parameters of tufting
into a tufting machine of the type having an electronically
controlled yarn feed attachment for providing measured increments
of yarn to a plurality of transversely aligned needles adapted to
be reciprocably driven, through a backing fabric passing from front
to back through the tufting machine by a rotary main drive shaft,
thereby placing stitches comprising tufts of yarn through said
backing fabric comprising the steps of: (a) inputting pattern
parameters of width, length, color, a relatively high pile height
and a relatively low pile length, for stitches on a computer
display wherein the width of the pattern is limited only by the
number of transversely aligned needles of the tufting machine; (b)
designing a pattern showing the location of relatively high pile
tufts and relatively low pile tufts on the computer display to
create a graphic representation of tufted carpet in a data file;
(c) processing the data file containing the graphic representation
of tufted carpet to assign yarn feed values to stitches based upon
the pile height selected for that stitch and at least the preceding
stitch.
14. The method of claim 13 wherein the graphic representation
created in the pattern design step (b) comprises the input of a
digital image.
15. The method of claim 13 wherein the assignment of yarn feed
values to stitches is based upon the pile height selected for that
stitch and at least the previous stitch.
16. The method of claim 13 wherein the yarn feed value assigned to
a relatively high pile tuft coming after a relatively high pile
tuft and a relatively low pile tuft is greater than the yarn feed
value assigned to a relatively high pile tuft coming after two
relatively high pile tufts.
17. The method of claim 13 wherein individually colored yarn ends
are combined to produce a spectrum of colors by: (a) configuring a
tufting machine having two rows of transversely aligned needles
with front and rear single end servo scroll pattern attachments;
(b) loading the front single end yarn drives with alternating yarns
of first and second colors; (c) loading the rear single end yarn
drives with alternating yarns of third and fourth colors; (d)
inputting the color information of each loaded yarn end on the
single end yarn drives into a computer; (e) blending the yarns to
approximate predetermined colors using computer logic to adjust the
yarn feed values.
18. The method of claim 17 wherein the predetermined colors are
selected from a digital image.
19. The method of claim 13 wherein the tufting machine is of the
type having at least one shiftable needle bar and the assignment of
yarn feed values to stitches in step (c) is additionally based upon
the distance said at least one needle bar is shifted for that
stitch.
20. The method of claim 19 wherein the assignment of yarn feed
values to stitches in step (c) is additionally based upon the
distance said at least one needle bar is shifted in the preceding
stitch.
21. The method of claim 19 wherein the assignment of yarn feed
values to stitches in step (c) is additionally based upon the
distance said at least one needle bar is shifted in the following
stitch.
22. A tufted carpet comprising: (a) a generally planar backing
fabric having a top surface, a bottom surface and an outer
perimeter; (b) a first border comprising a first plurality of
bights on the top surface of the backing fabric; (c) a second
border visually distinct from and located interior of said first
border, and comprising a second plurality of bights on the top
surface of the backing fabric; (d) wherein the plurality of bights
comprising at least one of said first and second borders is formed
by feeding stitches of yarn in at least three distinct increments
of length.
23. The tufted carpet of claim 22 further comprising a design
comprised of a third plurality of bights on the top surface of the
backing fabric located interior of said second border.
24. The tufted carpet of claim 22 wherein the second plurality of
bights are cut pile bights.
25. The tufted carpet of claim 22 wherein the first plurality of
bights are loop pile bights.
26. The tufted carpet of claim 22 further comprising a third border
visually distinct from and located interior of said second border
and comprising a third plurality of bights on the top surface of
the backing fabric.
27. A tufting machine comprising: (a) a feed mechanism for
transporting a backing fabric having a back side and a face side
from front to rear through the machine; (b) a plurality of spaced
needles aligned transversely of the machine for reciprocable
movement through the back side of backing fabric; (c) a drive
mechanism in communication with said spaced needles to reciprocably
move the needles through the backing fabric; (d) a yarn feed
mechanism for supplying yarns at selected rates to said spaced
needles, said yarn drive having separate yarn feed rolls for at
least a majority of the yarns supplied to the spaced needles in the
tufting machine and said separate yarn feed rolls being
independently operable to supply yarns of more than three different
lengths for any particular stitch; (e) a controller in
communication with the yarn feed mechanism including a software
control program for controlling the operation of the independently
operable yarn feed rolls in accordance with a predetermined
pattern; and (f) a looper mechanism for seizing yarns off the
spaced needles on the face side of the backing fabric.
28. The tufting machine at claim 27 wherein the separate yarn feed
rolls are independently operable to supply yarns of no less than
eight different lengths.
29. The tufting machine of claim 27 wherein the predetermined
pattern is at least 350 stitches in length.
30. The tufting machine of claim 27 wherein the predetermined
pattern is at least 1000 stitches in length.
31. The tufting machine of claim 27 wherein said independently
operable separate yarn feed rolls are driven by separate servo
motors.
32. The tufting machine of claim 31 wherein a servo motor
controller board is electrically connected to at least one of said
separate servo motors and to the controller.
33. The tufting machine of claim 32 wherein the controller receives
positional information corresponding to the reciprocation of the
needles through the backing fabric and sends corresponding
information concerning the pattern to the servo motor controller
board.
Description
PRIORITY
[0001] This application 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 Ser.
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:
[0004] (1) as a practical matter, there is not room on a tufting
machine for more than about eight pairs of yarn feed rolls;
[0005] (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
[0006] (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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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
[0019] 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;
[0020] 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;
[0021] 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.
[0022] FIG. 1D is a rear sectional view of the support of FIG.
1C.
[0023] 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;
[0024] 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;
[0025] FIG. 3B is an alternative yarn guide plate;
[0026] FIG. 4 is a side elevation view of a yarn drive and the yarn
guide plate of FIG. 3A;
[0027] FIG. 5 is a rear partial sectional view of a servo motor
with feed roll;
[0028] 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;
[0029] FIG. 7 is a carpet design with a series of concentric
borders made possible by use of the invention.
[0030] 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
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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 {fraction (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.
[0036] 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.
[0037] 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.
[0038] 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.
[0039] 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.
[0040] 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.
[0041] 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 FIGS.
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.
[0042] 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.
[0043] 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.
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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.
[0051] 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:
[0052] 1. Previous stitch was a low stitch, next stitch is a low
stitch.
[0053] 2. Previous stitch was a low stitch, next stitch is a high
stitch.
[0054] 3. Previous stitch was a high stitch, next stitch is a high
stitch.
[0055] 4. Previous stitch was a high stitch, next stitch is a low
stitch.
[0056] 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.
[0057] 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
31/4 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.
[0058] 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.
[0059] 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.
[0060] 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.
[0061] 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.
[0062] 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.
[0063] 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.
* * * * *