Tufting machine patterning apparatus

A tufting machine includes a pattern attachment mounted between a yarn feeding device and the needles, the yarn feeding device feeding yarn to the needles at a constant rate in an amount sufficient to accommodate the yarn requirements of the needle and looper system. The pattern attachment includes a series of slats rotatable about an axis in timed relationship to the reciprocation of the needles. Each slat includes a yarn receiving groove corresponding to each needle, certain of the grooves being shallower than others. A first yarn guide directs yarn from the feeding device to the pattern attachment while a second yarn guide directs yarn from the pattern attachment toward the needles. The slats are mounted on chains fastened to sprockets mounted on a driven shaft. The yarn is tensioned so that the full amount of yarn fed by the feeding device may be received by the needles, and when yarn enters a shallow groove, the yarn is pulled back from the respective needle resulting in a loop that is shorter than when the full amount of yarn is received by the needle.

BACKGROUND OF THE INVENTION 
This invention relates to tufting machines and more particularly to a 
pattern attachment for a tufting machine for forming high pile and low 
pile tufts in the same row of stitching in accordance with a pattern 
determined by grooves or slots cut into a set of rotating slats. 
In the production of tufted fabrics a plurality of spaced apart yarn 
carrying needles extend transversely across the tufting machine and are 
reciprocated cyclically to penetrate and insert loops of yarn into a 
backing material fed longitudinally through the machine. The loops are 
seized by respective loopers or hooks oscillating below the backing 
material in timed relationship with the needles as the loopers or hooks 
cross the needles just above the needle eye. 
In loop pile machines the loopers point in the direction of feed of the 
backing material and hold the seized loops while the needles are retracted 
from the backing material. The loopers thereafter rock away from the point 
of loop seizure to release the loops. When the needles start their next 
descent the loops have been released from the loopers and carried one 
stitch length away from the needle path. In cut pile machines the hooks 
point in the direction opposite to the direction in which the backing 
material is fed so that the loops are fed onto the closed end of the hooks 
and each hook cooperates with a respective oscillating knife to cut the 
loops thereon in seriatim. 
Although the pile height of cut pile fabric depends solely upon the 
distance that the hooks are disposed beneath the backing material, the 
pile height of loop pile fabric depends on the amount of yarn fed to the 
needles with the maximum being the distance from the loopers to the 
backing material. If the yarn fed to a particular needle is reduced, a low 
pile height loop will result. To control the supply of yarn, various 
methods have been devised in the prior art varying in complexity and 
versatility. Since a needle requires a certain amount of yarn so that it 
may shed a loop which is seized by a looper, when less yarn is fed than 
required by the needle, yarn will be pulled back or "back-robbed" from the 
prior stitch This is the basis for forming fabric with differing pile 
heights. 
Wide use is made of yarn feed roller pattern attachments or assemblies for 
producing variations in pile height in tufted pile fabrics such as 
carpeting. These assemblies include a plurality of yarn feed rollers which 
feed yarn at different speeds to the needles of the tufting machine. Each 
of the feed rollers is selectively driven at one of a plurality of 
different speeds independently of the other feed rollers by means of 
clutches controlled by a pattern control. The amount of yarn supplied to 
the needles of the tufting machine is determined by the rotational speed 
of the feed rollers about which the yarn is wound, so that with a fixed 
needle stroke the amount of yarns supplied to each needle determines the 
pile height of the fabric produced. To create patterned pile effects the 
amount of yarn fed to the individual needle may be varied by driving the 
feed rollers selectively at the different speeds. When less yarn is fed 
than required by the needle, yarn is pulled back or back-robbed from the 
previous stitch which then becomes a lower loop. By feeding yarn at two or 
three speeds in a controlled manner, patterns may be formed by the 
different pile heights. Thus, high and low loops may be produced, or even 
three levels of loop when feed rollers of three different speeds are 
provided. Representative of such feed roller pattern attachments are those 
disclosed in U.S. Pat. Nos. 2,862,465 (Card); 2,875,714 ( Nix); 2,966,866 
(Card); 3,001,388 (MacCaffary); 3,075,482 (Card); 3,103,187 (Hammel); 
3,134,529 (Beasey); 3,272,163 (Erwin et al); 3,375,797 (Gaines); 3,489,326 
(Singleton); 3,605,660 (Short); 3,752,094 (Short); 3,947,098 (Hammel); 
3,926,132 (Lear et al); 3,955,514 (Prichard et al); 4,134,348 (Scott); 
4,608,935 (Bardsley); and 5,182,997 (Bardsley). 
Other types of pattern attachments may be used such as those having grooved 
or slotted slats as disclosed, for example, in U.S. Pat. Nos. 2,853,032 
(Odenweller); 2,853,033 (Crawford); and 2,853,034 (Crawford). These 
pattern attachments comprise two sets of intermeshing slats mounted on a 
continuously moving roller chain. V-notches on one set are constant in 
height, but those on the other set, or pattern slats, vary in height 
according to the pattern requirements. As the two sets of slats intermesh, 
the length of yarn available for each tuft depends upon the extent to 
which the yarn is deflected by the depth of cut on the pattern slat. 
The simplest of all prior art devices comprises a series of grooved cam 
disks which are eccentrically mounted on a drive shaft. A yarn strand is 
received within each respective groove in its path to a respective needle 
and as the disks rotate the tension of each yarn running in the groove 
changes and, as a result, differences in pile height are created. This 
method is limited to very simple loop pile patterns with very small 
repeats. 
The desirability of providing a relatively simple pattern attachment that 
may produce random high and low, and also intermediate, loop pile fabric 
within a number of stitches substantially greater, i.e., a greater pattern 
repeat, than that produced by the cam disk pattern attachment is apparent. 
Presently, to provide such a pattern array involves utilization of one of 
the more complicated and costly aforesaid yarn feed roller attachments or 
intermeshing slat pattern attachments. 
SUMMARY OF THE INVENTION 
Consequently, it is a primary object of the present invention to provide a 
simple pattern attachment for tufting machines for producing high and low 
loop patterns with a random look. 
It is another object of the present invention to provide a mechanical 
pattern attachment for a tufting machine which permits each needle to form 
high and low loops within a selected number of stitches, there being a 
predetermined number of high and low loops formed. 
It is a further object of the present invention to provide a simple pattern 
attachment for a tufting machine having a single set of slats mounted for 
rotation in timed relationship with the reciprocating cycle of the tufting 
machine, each slat having a groove corresponding to a respective needle 
formed in the periphery to a selected depth for varying the tension on a 
strand of yarn fed at a constant rate to the corresponding needle to 
permit the needle to be supplied either with an amount of yarn adequate to 
meet the yarn requirements of the needle to form a stitch or a lesser 
amount of yarn resulting in back-robbing of yarn from the previous stitch 
to form a stitch, each slat of the set corresponding to a different 
stitch. 
Accordingly, the present invention provides a pattern attachment disposed, 
between a yarn feeding device and the needles of a tufting machine, the 
yarn feeding device feeding yarn at a constant irate toward the needles, 
the pattern attachment having a plurality of slats driven about a closed 
loop, each slat having yarn receiving grooves or slots formed therein to 
at least two different depths, and a pair of yarn guides disposed closely 
to the pattern attachment, one yarn guide being between the feeding device 
and the attachment for guiding yarn into the pattern attachment and the 
other guide being between the attachment and the needles for guiding yarn 
from the pattern attachment, the two guides being located such that the 
yarn continuously is directed into the grooves or slots of the slats. The 
deep grooves permit the full amount of yarn fed by the feeding device to 
be received by the needle, while the shallow grooves apply a greater 
tension to the yarn so that the needle receives less yarn and thus 
requires yarn to be back-robbed from stitches previously formed resulting 
in such previous stitches being shortened loops. 
In the preferred form of the invention the slats are mounted to rotate in a 
circular path and the yarn guides effect a tight wrapping about a number 
of slats within a sector of the circular path. The driving of the slats is 
provided by connecting the slats to the links of chains trained about 
corresponding sprockets, the sprockets being driven in timed relationship 
to the tufting machine. The pitch or distance between the periphery of 
adjacent slats may correspond to one stitch so that each stitch is 
controlled by one slat. Thus, a very simple mechanical pattern attachment 
is provided which provides a pattern having a substantially random look 
relative to that formed by eccentrically mounted grooved cam disks since 
it effectively provides disks having diameters that change or vary about 
the periphery.

DESCRIPTION OF THE REFERRED EMBODIMENT 
Referring to the drawings, a tufting machine 10 is illustrated in FIG. 1 
having a cam disk pattern attachment constructed in accordance with the 
prior art, the pattern attachment being mounted on the tufting machine for 
producing the simplest variations in pile height. The pattern attachment 
12 comprises a series of grooved disks 14 eccentrically mounted on a drive 
shaft 16 driven in timed relationship with the tufting machine push rods 
and thus the tufting machine needle bar 20. There is one disk for each 
yarn end, i.e., for each threaded needle 22. The drive shaft 16 is splined 
so that the disks may be selectively mounted thereon in different angular 
phases As the disks rotate eccentrically the tension of the yarns running 
in the respective grooves changes and, as a result, differences in pile 
height are created. As aforesaid, this apparatus is limited to very simple 
high and low loop patterns with very small repeats. 
As illustrated in FIG. 2, a pattern attachment 24 constructed in accordance 
with the present invention is mounted on a conventional tufting machine 10 
having push rods driven from the main shaft 26 by conventional drive means 
such as a connecting rod 28 having an eccentric strap 30 mounted about an 
eccentric disk or cam 32 secured on the main shaft 26. The needle bar 20 
and thus the needles 22 are reciprocated vertically into and out of a 
backing material 34 fed across a bed plate 36 by conventional feed rolls 
38, 40 and take-up rolls 42, 44. Yarn 46 fed to each needle is formed into 
a loop by the needle, the loop being seized and shed by a looper 48 
pointing in the direction of movement of the backing material 34 and 
oscillating in the bed of the tufting machine beneath the bed plate 36 in 
timed relationship to the reciprocation of the needles to produce a pile 
loop during each cycle of the machine. 
In order to provide a pattern effect of at least high and low loops the 
pattern attachment 24 of the present invention is mounted intermediate the 
needles 22 and a yarn feed device such as conventional feed rollers 50, 52 
about which the yarn 46 is trained so as to feed a constant rate or fixed 
amount of yarn toward each needle. Furthermore, the pattern attachment is 
mounted intermediate a pair of yarn guides 54 and 56, the pattern 
attachment being closely proximate the yarn guides for reasons which 
hereinafter will become clear. 
Referring to FIGS. 3 and 4 it may be seen that the pattern attachment 24 
comprises a plurality of elongated substantially rectangular shaped slats 
58, each slat having a tab 60 extending substantially perpendicular to the 
body of the respective slat along one edge, the other edge having 
patterning grooves generally indicated at 65 cut therein. An elongated 
shaft 62 extending substantially transverse to the tufting machine, i.e., 
transverse to the direction of movement of the backing material 34, is 
supported by bearings 64 carried by brackets 66 secured to the head of the 
tufting machine at spaced apart locations. Secured to the shaft 62 at 
spaced locations intermediate each pair of bearings 64 is a respective 
sprocket 68. A chain 70 having a plurality of pairs of links 72 are 
trained about each sprocket 68, each pair of links having a lug or tab 74 
connected thereto on the surface remote from the sprocket. The tab 60 on 
each slat 58 is secured as by screws or the like to a tab 74 of a pair of 
links on each of the sprockets so that each slat is connected to and spans 
a number of chains and sprockets which form an elongated section of the 
pattern attachment, there being a number of sections transversely aligned 
across the width of a full length tufting machine. At least at one end of 
the pattern attachment, the shaft 62 is connected to the output of a 
reducer gear box 76 having an input shaft 78 on which a sprocket 80 is 
mounted. A similar sprocket 82 is mounted on the end of the main shaft 32 
and a chain 84 is trained about the sprockets 80 and 82 to drive the shaft 
62 and thus the slats 58 in timed relationship to the tufting machine 
dependent upon the reduction ratio of the gear box. It is thus clear that 
the slats 58 rotate about a circular path. In a preferred mode, the 
distance between the ends of diametrically opposed slats is approximately 
six inches and there are 20 slats. The slats may be rotated at a speed 
such that control is provided by one slat per stitch resulting in 
substantially 20 stitches being formed for each revolution of the slats, 
so that there are substantially 20 stitches in each pattern before the 
pattern is repeated, or the slats may be rotated faster resulting in less 
stitches being formed for each revolution of the slats so there would be 
less stitches in the pattern repeat. Moreover, by use of variable speed 
means, rotational speed of the slats may be varied selectively. 
As illustrated in FIG. 5, the slats 58 include the patterning grooves 65 
cut therein from the outer edge, i.e., the edge remote from the chains 70 
and sprockets 68. These patterning grooves are cut to various depths 
depending upon the pattern. For example, there are at least deep grooves 
86 and shallow grooves 88, the deep grooves resulting in high height loop 
pile and the shallow grooves resulting in low height loop pile in the 
fabric produced, as will hereinafter be made clear. Additionally, if 
desired, grooves of an intermediate depth 90 may be cut into the slats for 
forming a loop pile of an intermediate height loop. 
As illustrated, the yarn guides 54 and 56 are disposed in relatively close 
proximity to the pattern attachment 24 so as to guide the yarn 46 into and 
out of the grooves of the first and last slat of the slats which are 
disposed about a sector of the array of slats. The tension applied to the 
yarn between the needle and the yarn creel on which the spools of yarn are 
mounted, and the yarn feeding rate of the feed rolls 50, 52, are adjusted 
so that the needles are fed an amount of yarn adequate to meet the needle 
requirements to form a stitch in conjunction with the respective loopers 
to thus produce a high pile height loop. The tension applied between the 
creel and the needles ensures that the yarns may engage the valleys of the 
deep grooves 86 in the slats unless, for example, the slat with the deep 
groove is between a pair of slats with shallow grooves. When a shallower 
groove such as the grooves 88 or the grooves 90 contacts the yarn, the 
yarn requirements of the corresponding needle are not then met so that 
yarn must be pulled back or back-robbed from at least the last stitch 
thereby reducing the height of the loop of the previous stitch to create a 
shorter loop. Accordingly, each needle may produce a high loop and a low 
loop and, if desired, a loop of an intermediate height. 
In effect, the grooves of the plurality of slats form rolls of varying 
diameter. This may be seen in FIG. 4 where the yarn strand 46 serpentines 
closer and further to the axis of the shaft 62. Of course, if one or more 
needles are to produce a loop of constant height for a given number of 
stitches, such that the grooves of all the slats corresponding to that 
needle for that number of stitches are cut to the same depth for the slats 
in the sector corresponding thereto, the yarn strand engaging the grooves 
in that sector would remain at a fixed distance from the axis of the shaft 
62. When using 20 slats, as aforesaid, with a pitch substantially equal to 
a stitch, each needle may produce a random 20 stitch high/low pattern, and 
since each other needle may produce a different 20 stitch pattern, the 
present invention provides a simple pattern attachment for producing 
structured random looking patterns in a very inexpensive manner. 
Numerous alterations of the structure herein disclosed will suggest 
themselves to those skilled in the art. However, it is to be understood 
that the present disclosure relates to the preferred embodiment of the 
invention which is for purposes of illustration only and not to be 
construed as a limitation of the invention. All such modifications which 
do not depart from the spirit of the invention are intended to be included 
within the scope of the appended claims.