RIB FABRIC GROUP—HOW STITCH IS MADE FOR DIFFERENT CLOTHS
THERE are numerous conflicting expressions or terms used in the knit
goods industry, and one of the most common of these is the term “flat
goods.” In the older underwear sections, where the circular machine was
used exclusively and the flat machine was practically unknown, the term
flat goods indicated underwear fabric made tubular in the jersey stitch
on circular spring needle machines, as distinguished from tubular rib
fabric made on latch needle machines. At present, in the localities
where mills are using both the circular and flat straight needle bed
machines, it is generally understood that a flat fabric is a fabric of
single thickness made on a flat machine, regardless of the stitch, and
any fabric made on a circular machine is known as a tubular fabric. If
the stitch should be specified it is mentioned separately.
This latter custom appears to me to be the more logical; therefore, when
these terms are used hereafter in this work it should be understood that
flat fabric means cloth of a single thickness made on a flat machine, or
a tubular fabric cut open so it will lie out flat. The “flat goods” of
the old time knitters will be called jersey cloth or fabric.
We will now leave the jersey fabrics for a time, as the making of the
tuck stitch and plated work in the jersey stitch are more or less
complicated and had better be left until we take up fancy stitches and
designs on circular latch needle machines. The tuck stitch is never used
in the jersey fabrics on flat machines.
Rib Fabrics
A rib fabric is one which has a rib or wale on both sides of the cloth.
It has much more stretch or elasticity than cloth of the jersey group;
about twice as much, generally speaking. The elasticity of either one,
however, may be varied to a marked degree by changing the length of loop
drawn.
Rib fabric is peculiarly adapted for such garments or parts of garments
as should be close fitting, such as ladies’ undergarments, cuffs for all
kinds of knitted garments, tops of half hose, etc. Fig. 24 shows very
clearly the course the yarn takes to form this stitch. It would be well
to study this drawing in connection with Figs. 2 and 3 and note
carefully the different course the yarn takes in order to form a wale on
both sides of the fabric. A photographic reproduction of a plain rib
fabric showing both sides is given at _a_, _a_, in Fig. 25.
[Illustration: Fig. 24. Construction of a Plain Rib Fabric.]
A properly constructed plain 1 and 1 rib fabric, such as is shown in
Fig. 24, should be alike on both sides. Very often this is not the case.
A little carelessness on the part of the adjuster in not drawing the
stitch the same length on both sides will make a difference on the flat
machines, while it is impossible to make them the same on an ordinary
circular machine on account of the principles of construction of this
machine.
Fig. 26 is a view of a flat machine making the rib stitch, looking down
from above. It almost fully explains the method of making this stitch to
those who have carefully read and understand the principles of making
the jersey stitch. In this illustration the carriage is moving from
right to left, and both front and back cams are in operation, therefore
both front and back needles are working.
It should be noted that the back plate is set so that the needles of
that plate come up at a point in the middle of the spaces between the
needles of the front plate. The cams, front and back, being made exactly
alike and set exactly opposite one another, must push the needles of
both plates up at the same time and draw them down at the same time.
When we feed the yarn, indicated by the letter _a_ in Fig. 26, down
through the guide, _b_, it is drawn into loops from both sides
alternately, as shown at _c_, by the opposite sets of needles, thereby
making stitches, or ribs, or wales, on both sides of the fabric. This is
the plain 1 and 1 rib stitch.
[Illustration: Fig. 25. Face and Back of Fabric; a, a, Plain Rib; b, c,
Half Cardigan; d, d, Full Cardigan.]
[Illustration: Fig. 26. Flat Knitting Machine Making the Rib Stitch.]
Varieties of Rib
This stitch, by distortion, or by manipulation of the yarns or needles,
or by a combination of two or all three of these things, can produce a
number of fabrics different both in appearance and feel. To enumerate
the principal ones, there are the half cardigan or tuck stitch, also
sometimes called royal rib; the full cardigan, and the rack stitch with
the rack on one side of the fabric and the double rack which shows the
rack on both sides of the fabric. Then there is the zig-zag stitch,
which is quite simple to make but is quite a puzzle to those not
familiar with it. There is also the cotton back, which is a well known
and popular fabric in the sweater trade.
Then there are many varieties of ribs made either in plain or in
combination with one or more of the above by taking needles out of the
machine at predetermined places, or by the Jacquard system of selecting
needles. There is also the system of making designs by the cut pressers
and pattern wheels, which is used on circular machines only.
Half Cardigan or Tuck Stitch
The half cardigan or tuck stitch is used more than any other of the
ribbed group, though it is generally used in combination with the plain
rib. The body and sleeves of the ordinary rib sweater, and much of the
rib underwear produced, are made in this stitch while the cuffs are
plain rib. The reason for this is that the half cardigan rib will knit
up considerably wider, with the same number of needles, than the plain
rib, therefore it is possible to make a shaped garment without cutting
and sewing up again. Also the plain rib comes out lighter and thinner so
makes a more desirable cuff for sweaters and underwear. It also has more
life or spring to it, which is another desirable feature.
The half cardigan or tuck stitch is the one that is almost invariably
used in making the well known cotton back sweaters. It is believed by
many people who are familiar with this fabric that the back stitch of
cotton does not come through on the face, but in this they are mistaken.
The face stitch does not go through on the back, but the back yarn does
go through on the face.
[Illustration: Fig. 27. Construction of a Half Cardigan Rib Fabric.]
Fig. 27 is a line drawing showing the course the yarn takes in making
this stitch and a careful examination of it will demonstrate to the
reader that this is the case. The dotted line _e_, _e_, indicates the
wale on the face and _f_, _f_, shows the wale on the back. It will be
noted that the back stitches of yarn come through to the face of the
fabric and connect the preceding and succeeding stitches, _c_, _c_, the
same as in the plain rib, but there is this difference, in the plain rib
these face stitches are, or should be, just the same length, while in
the half cardigan, on account of the back stitch of this course holding
over for one course, it necessarily draws a longer stitch in the back
and the yarn for this long stitch must come from the face stitch,
thereby making this face stitch very short.
In the drawing the stitches are not proportioned just as they lie in the
actual fabric, for if they were it would be very difficult to trace
their course. In the fabric the stitches _b_, _b_ are so short that they
are almost completely covered by the large, full, round stitches, _c_,
_c_, _c_. These stitches are full and large from the fact that where
they go through to the back they do not form a loop but simply cross
over the back loop as at _d_, without being drawn through. These are
completely covered by the loops _a_, _a_, in the back wale.
How the Half Cardigan or Tuck Stitch Is Made
The diagram at Fig. 28 shows the method used to make the half cardigan
or tuck stitch on a flat machine. The cams shown are what are known as
the Lamb system and are called the automatic cardigan or drop locks. The
word “locks,” as applied to the flat knitting machine, means a full set
of cams attached to the cam plates ready to affix to the carriage. There
are a number of different systems of constructing these locks, but the
one selected is the most simple of all and for this reason is used for
illustration first. The others will be taken up at the proper place.
[Illustration: Fig. 28. Automatic Locks for Making Half or Full Cardigan
Fabrics.]
In Fig. 28 only a part of the needle plates are shown. They are attached
to a frame at an angle of 90° to each other and 45° to the horizontal as
explained before. The cams are shown in working position with the
carriage (to which they are attached when in use) removed. As indicated
by the thread _h_, they are being moved toward the far end.
It should be noted that the automatic drop V-cams _a_, _a_, are in
different positions. These cams are made so that they swing freely on
the pivots _b_, _b_, and the swing is inside of the limits of the
positions of the two cams in the drawing. It is controlled by pins on
the top side of the swinging ends, the pins coming through a slot of the
proper length in the cam plate to stop them at the right place.
When starting to move these locks from the near end toward the far end,
the cam _a_, on the left, might be in any position within the limits of
the before mentioned slot in the cam plate, but the instant it comes in
contact with the butts of the needles it is automatically forced to the
position shown.
In making the half cardigan stitch the right hand cam is held up to the
top, as shown, at all times by means provided. This position forces the
needles high enough so that the latches are above and clear of the loop
that is on the needle, therefore when the needles are drawn down again
by the cam _f_, they draw new loops and cast the old ones off over the
latch and hook, and they drop down on the new loop, just as explained in
describing how to make the plain rib. This refers only to the needles in
the right plate.
The cam _a_, on the left side, however, having been swung down to its
lowest position by contact with the needle butts, raises the needles
only about one-half of the normal distance. Or to put it differently,
the needles raise high enough to open the latches and catch the yarn
when being drawn down again, but not high enough to permit the loop that
is on the needle to slide down below the latch. Therefore, after the
completion of the course we have the right side with the new loop drawn
through the old one as in plain rib, but the left side still retains the
old or previous loop and also the new one as at _j_. This leaves two
loops on every needle on the left side and one on the right when the
course is completed.
On the return course, from the far end to the near end, when the point
_i_ of the left cam, _a_, comes in contact with the first needle it must
swing up in the same position as the right cam, _a_, therefore all the
needles will draw the new loop through the two preceding ones and clear
themselves, leaving only one loop on each needle as in the plain rib.
On the next course, from the near end to the far end, the left hand
needles again hold the old loop and take on a new one as just explained,
while the right hand needles cast off the old ones and hold only the new
ones.
To condense the operation into a few words let us say that the left hand
needles always must hold the two stitches while moving in one direction,
and clear them off and hold only one on the return course; while the
right hand needles always cast off the old stitch and hold the new ones
only. The right hand needles would make the face side of the fabric.
The writer has made a special effort to explain the formation of this
particular stitch, and the reader should make the same effort to get
this formation clear in his mind, for this stitch is the base of almost
all of the fancy stitches or design work which will be taken up later.
The system used in design work is of course entirely different from the
one just described, being what might be called a selective system, that
is, a method whereby the designer may select the proper needles at the
proper time and place to make the tuck stitches block out the design
wanted.
Fig. 25, at band _c_, shows the tuck or half cardigan stitch; _b_ is the
face and _c_ is the back. If studied carefully the reader will notice
that the face side, _b_, has a full round stitch, while _c_, or the back
of the fabric, has a small narrow stitch.
The Full Cardigan Stitch
The full cardigan stitch is not nearly so generally used as the half
cardigan and plain rib stitches. It is seldom if ever used in making
underwear or any fine fabrics. When it is made it is usually used for
sweater fabrics or other novelty wearing apparel of this character.
[Illustration: Fig. 29. Construction of a Full Cardigan Fabric.]
A line drawing of the full cardigan stitch is shown in Fig. 29. This
stitch, as its name would indicate, is made in the same way as the half
cardigan only the stitches are held alternately on both rows of needles
on alternate courses. Referring again to Fig. 28, in making the full
cardigan stitch the cams would operate exactly the same while moving
toward the far end as shown and explained for the half cardigan. But the
means provided to hold the right hand cam, _a_, at the top position
would have been removed, so that on the return from the far to the near
end this cam would be thrown down to the same position as the left hand
cam, _a_, is shown, while this left hand cam would be forced up into the
position in which the right hand cam is now shown. In other words, the
stitch would be the same with the carriage or cams moving in either
direction, only it would alternate on each course from one row of
needles to the other.
We will refer back to Fig. 25, which shows both sides of a piece of
fabric with the three stitches we have just discussed in one piece. This
shows quite plainly the individual characteristics of each. All have the
same number of needles or wales, the same yarn was used, on the same
machine; yet how different the results!
The most marked difference is in the width. There is proportionately the
same difference in the thickness, but this cannot very well be shown. It
should be observed that the stitch or loops of the plain rib _a_, _a_,
and the full cardigan _d_, _d_, are the same on both sides of the
fabric, while the stitches in the half cardigan, _b_ and _c_, are not.
It will be noted also that the stitch of the plain rib is much smaller
than that of the two cardigans, also that the wales or ribs hug very
close together in the plain rib, while they are separated more or less
in the cardigans.
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