PURL STITCH, OR LINKS AND LINKS MACHINE, FOR HAND OR MANUAL POWER
THE purl stitch or links and links machine is a type which may be termed
unique in the class of machinery built to make knitted fabrics. It is
entirely a European development; in fact, to my knowledge there had been
none of these machines built in this country until some time after the
war started, when it was impossible to import them.
The chief individual characteristic of purl stitch machines lies in the
fact that they have two needle plates, but only one set of needles, and
the cams do not act directly on the needles, but act indirectly through
what are called jacks. First we will try to get a thorough knowledge of
the fabric this machine was primarily designed to make, and the stitch
formation required to produce this fabric; then the mechanism and
movements of the different parts of the machine will be more readily
understood as we proceed with the explanation.
Character of Fabric
Fig. 57 shows a photographic reproduction of the fabric with the top
turned over to show both sides, which it will be noted are exactly the
same. Fig. 58 is a line drawing showing the formation of the stitch; the
course that the yarn takes may easily be followed. This is called the
purl stitch and is very popular with milady when making hand knit
sweaters, children’s suits, etc.
If the reader will refer back to Fig. 12, he may be surprised to note
how near this fabric is like the back of the jersey fabric, while the
face of the jersey fabric is so different. I do not think that I should
go very far wrong if I put this in the same class as the jersey fabric,
the same as the half and full cardigan are classed as rib fabrics. It is
made the same as the jersey on one set of needles, but with this
difference: In making the jersey fabric the loop is always drawn through
the previous loop in the same direction. That is, we will suppose we
were making this jersey fabric on an ordinary flat machine, on the front
plate only. In this case the loops would always be drawn toward you
through the previous loops. Now if we should reverse every course the
direction in which we draw these loops, or in other words, if we should
draw them towards you when moving the carriage from right to left, and
away from you when moving the carriage from left to right, and continued
this reversal, we would make a purl stitch fabric.
But, you say, how are we going to do this? The solution is the purl
stitch or links and links machine, with its double ended needle, or a
needle with a hook and latch on both ends to permit the whole needle to
be pushed through the loop every course, thereby casting the previous
loops off one end on one course, and off the opposite end on the next
course. This system of knitting is such that there can be no obstruction
to the free movement of the stitch over any part of the needle,
therefore this fact precludes the use of a butt projecting up from any
part for the cams to operate on, even if there were no other reason,
which there is as the reader will understand after a study of the
subject.
[Illustration: Fig. 57. Plain Purl Stitch Fabric.]
[Illustration: Fig. 58. Construction of the Plain Purl Stitch Fabric.]
This machine is constructed somewhat along the lines of the ordinary
flat machine, which we have been studying. Its points of similarity are
that the table or stand is the same, it has two straight, flat needle
plates, it has a carriage which is moved backward and forward over the
needle plates to operate the needles, and the cams or locks are
practically the same as in the ordinary single lock flat machine. The
main points of difference are that on the purl stitch machine the needle
plates are set so that they are flat, or both are on a horizontal plane,
and the needle slots of both plates are directly in alignment with one
another so a needle may move freely from the front to the back plate, or
vice versa. The ordinary flat machine has the needle plates set at an
angle of about 90 degrees to one another, and 45 degrees to the
horizontal, and they are set lengthwise so the needle slots of one plate
are opposite the space between the needle slots of the opposite plate,
or in a position so the needles of one plate will come up between the
needles of the opposite plate.
Another point of difference is that the purl stitch machine has one set
of needles for both plates, with a hook and latch on both ends of each
needle and no butts to operate them, while the ordinary machine has a
set of needles for each plate with a hook and latch on one end only with
a butt on the other end to operate it. It naturally follows that
inasmuch as the needle plates are set flat, instead of at an angle to
one another, and the needles are operated indirectly through what are
called jacks instead of directly on butts on the needles, the
construction of the purl stitch machine must be somewhat different from
the ordinary flat machine.
Construction of Purl Stitch Machine
Fig. 59 shows a general view of a purl stitch machine built by Dubied &
Co. The letter _a_ indicates the carriage, _b_ the handle used to
operate the carriage, and _c_ is an auxiliary handle which some knitters
like and use, while others take it off, preferring the use of handle _b_
only. The letter _i_ indicates the connection rod for the auxiliary
handle; _d_ is the racking handle for racking the back plate, which
plate is made to rack over usually about 12 needles. The letter _e_ is a
sector of a circle attached to the frame of the machine and acts as a
guide and a stop for the racking handle. This may be studied to better
advantage in Fig. 60, at _e_. It has V-shaped notches cut at the proper
intervals to correspond to the needle spacing with a V-shaped plunger
attached to the handle so that when this plunger springs into one of the
notches it brings the needle slots of the back plate into alignment with
the needle slots of the front plate.
The secondary handle _d_-1 is for releasing this plunger to permit the
handle to be moved. It will be noted that there are holes in this
sector, one back of each notch in the edge, and in two of these holes
there are pins. These pins may be placed in any desired hole and act as
stops for the racking handle and in this way save the operator the
trouble of stopping to count the number of notches every time he racks,
as on this class of work racking over anywhere from two to twelve
needles at one time is common practice.
[Illustration: Fig. 59. Dubied Purl Stitch or Links and Links Machine.
Hand Power.]
To go back to Fig. 59, letter _f_ is a counter for counting the rounds,
_g_ indicates two yarn carrier stops, one on each side of the bar or
gib, while _h_ and _h_ are the yarn take-up frames and springs. Letter
_j_ indicates the two gibs or ways on which the carriage slides, and _k_
is the bar for carrying the yarn carriers.
Now to get an insight into the principle of the method of making this
purl stitch we will first give our attention to Fig. 63, which is a line
drawing of a needle and the two jacks which are required for each needle
in their proper relative positions.
How Needles Are Operated
As will be surmised after looking at the drawing, the jacks are moved
forward and backward by cams operating on the butts _a_ and _a_, which
project above the surface of the needle plate in the same manner as the
cams operate on the needle butts in the ordinary flat machine. The jacks
operate the needles by catching the hook of the needles in the clutches
_b_ and _b_ of the jacks. These needles are simply passed, so to speak,
back and forth across the throat, between the needle plates, from one
jack to the opposite one on each course, and in that way they reverse
the direction of the draw of the loop on each course.
[Illustration: Fig. 60. Looking Down at Top of Purl Stitch Machine.]
We will now give our attention to Fig. 62, which shows the under or cam
side of the carriage. It is understood, of course, that lengthwise of
the carriage, or the direction of movement, would be what is crosswise
or right and left in the illustration. It will be noted that the locks
or stitch cam arrangement are, on the whole, practically the same as in
the ordinary flat machine. This would apply to the cams and locks
including _a_, _h_, _k_ and _g_, also _b_, _i_, _l_ and _j_. The bridges
_c_ and _d_ are for another purpose.
[Illustration: Fig. 61. Top of Carriage. Dubied Purl Stitch Machine.]
It will be noted that while the stitch cams _h_ and _i_, also _g_ and
_j_, are exactly opposite one another, the cams _a_ and _b_ are not. The
bridges _c_ and _d_ have perfectly flat smooth surfaces except at points
_e_ and _f_, and here they have a concave portion about one-eighth of an
inch deep. The space between bridge _c_ and cam _k_, also between bridge
_d_ and cam 1, is filled by the needle gib 1, Fig. 60, and its mate on
the back, which cannot be seen, when the carriage is on the machine. The
reader should carefully study the points just gone over, that is, the
location of the cams _a_ and _b_ in relation to each other, and the
bridges _c_ and _d_ with their concave spots _e_ and _f_, in order to
fully grasp their relation to the jacks and needles in the operation of
the machine.
[Illustration: Fig. 62. Under Side of Carriage With Cam System. Dubied
Purl Stitch Machine.]
We will now give our attention to Fig. 60, where it will be noted that
the front gib 1 is abnormally wide. The back gib is the same, and
inasmuch as it cannot be seen we will assume that it is also marked 1
and hereafter call it back gib 1. Just below the center, laterally, of
the front needle plate we see a row of jack butts which are in working
position. In the back plate we see jack butts in every slot but they
alternate with three up in working position, and three down out of
working position. It should be understood clearly that any jacks that
are moved to the outer edge of either plate will not operate as they are
out of range of the cam system, the same as in the ordinary flat
machine.
[Illustration: Fig. 63. Jacks and Needles Used in the Dubied Purl Stitch
Machine.]
Let us now bring together the needles and jacks in Fig. 63, and the
needle plates in Fig. 60. The butts of the jacks _a_ (Fig. 63) are what
we see projecting above the needle plates in Fig. 60. The hump _c_ (Fig.
63) lies under the gib 1 (Fig. 60). The reason for having this gib extra
wide is to cover this hump during most of the knitting operation in
order to keep the needle captive. The depth of the needle slot is just
sufficient to allow this part of the jack to slide under the gib freely
without any up and down play, therefore it follows that when the hook of
a needle is caught in the clutch _b_, as in jack number 1 in Fig. 63,
that needle must move backward and forward with the jack. When the jacks
are moved forward to the point where the butts would be near or against
the gib 1 (Fig. 60) the hump _c_ (Fig. 63) would be inside and clear of
the gib 1, toward the center of the machine, therefore the shank of the
jack being narrower than at the hump, a slight draw on the needle would
free it from the jack as the clutch _d_, which holds the needle, is
beveled off for this purpose. This being the case it follows that when
the jacks are in this position the hooks of the needles may be easily
pushed under and into the clutch _b_ of the jacks. This is how the
machine is filled with needles to begin with, or imperfect ones replaced
with new.
It will now be necessary to study Fig. 62 in connection with Figs. 60
and 63. Referring to Fig. 62, the space between the cam _k_ and bridge
_c_, also cam 1 and bridge _d_, as noted before, is occupied by the two
gibs 1 (Fig. 60) when the carriage is on the machine. The bridges _c_
and _d_ (Fig. 62) come down to the needle plates and the surface we see
is on the same plane as the under side of the gibs 1, Fig. 60. We have
just had the statement that when the butts of the jacks _a_ (Fig. 63)
were moved up to the outside and close to the gibs 1 (Fig. 60), the hump
_c_ of the jacks would be just inside and clear of the gibs 1, therefore
could be raised sufficiently to slip the hook of a needle in or out of
the clutch _b_ of the jack. This is true only at a time when the
carriage is not over and operating the jacks.
When these are moved up to this point by the cams the hump _c_ of the
jacks would come under the bridges _c_ and _d_ (Fig. 62), therefore
could not raise up to release the needles except at the narrow concaves
marked _e_ and _f_ in the bridges. These concaves, it should be noted
again, are not opposite one another. The distance between the top or
narrow part of cam _a_ and cam _b_ is such that when the butts of the
jacks have moved up to this point the clutch _b_ of both of the opposed
jacks cover a hook of the needle. In looking at Fig. 62, the top half of
the carriage would be the part covering the front needle plate and
operating upon the front jacks, and the bottom half would do likewise on
the back plate. When the carriage is at the left end of the machine,
when making the purl stitch the needles should be in the front plate,
and when the carriage is at the right end of the machine the needles
would be in the back plate. This relative position is always the same
when making the purl stitch.
I have assumed that the reader understands that a jack and a needle
together would, when in a normal position as shown by the butts in the
front needle plate in Fig. 60, reach just to the throat between the
needle plates. Having the different parts and their relative positions
in our mind we will now proceed with the modus operandi. We will assume
that the carriage is at the left end of the machine, therefore the
needles would be in the front needle plate and under the control of the
front jacks, as the hooks would be in the clutch _b_ (Fig. 63) of these
jacks, while the hump _c_ being under the gib of the needle plate will
not allow the needles to escape. To obviate some of the difficulties the
reader may have in understanding this explanation we will assume that
the carriage as shown in Fig. 62 is stationary, and the plates with
their jacks and needles are the parts that are moved.
The outline of the camway may be easily traced as it is practically the
same as the ordinary flat machine with which the reader should be
familiar and the action on the needles, through the jacks, is the same
until they reach the first inside corner of the cam _b_. If the reader
will take a straight edge and lay it on the illustration, he will find
that this corner of cam _b_ is just in line with the concave _e_ in the
bridge _c_, and also with the center of the flat portion of the cam _a_.
This being the case, it follows that the center of the flat portion of
the cam _b_ must be in line with the left inside corner of cam _a_ and
the concave _f_ in the bridge _d_.
It should be understood that as the needles are moving across the throat
between the needle plates, the stitch or loop opens the latches, and
guards are provided to keep them open until the needles are ready to
draw the new loop through the previous one.
Now to return to where we left the needles and jacks at the right inside
corner of cam _b_. The jacks of the back plate have reached their
innermost position, and the heads or humps _c_ (Fig. 63) lie under the
bridge _c_ (Fig. 62). At the point where the front jacks opposite are
reaching their innermost position, the heads or humps _c_ of the back
jacks come under the concave _e_, which allows the hook of the needles,
just coming forward from the opposite plate, to raise up the head and
enter the clutch _b_ of the jack. As they move farther to the left, the
heads of these back jacks are under the plane surface of the bridge _c_,
which secures the needles to these jacks. As the jacks start to move
back toward their outermost position, the heads of the jacks of the
front plate are under the concave _f_ of bridge _d_. This allows the
needle hooks of this end to draw out and release themselves from the
jacks of this side, and be drawn through the loop to the back plate, and
by this means to cast the previous loop off from the back plate toward
the front one.
Upon the return from left to right, the needles are exchanged from the
back plate to the front one in the same manner, only of course, the
action is just opposite to that just explained. Therefore, the needles
would pass through the loop from the back to the front plate, and cast
off the previous loop from the front plate toward the back one. This
would make the purl stitch.
While the machine was designed primarily to make this purl stitch, there
can be made on it a larger variety of stitches than on any other
machine, but in general practice the stitches made are limited as a rule
to the purl, jersey and plain rib, 1 and 1, 2 and 2, etc. The term 1 and
1 rib means one needle in each plate alternately. The term 2 and 2 rib
means two needles together alternating in each plate without a needle
working between the two from the opposite plate. It is also possible to
make the half or full cardigan stitch.
The jersey stitch may be made by one of two methods. First, when the
needles are all in one plate move the jacks in the other plate to their
outermost position, where the cams of that side cannot operate on them
and the needles will stay on one side as there are no jacks operating on
the other side to take them across. Second, by moving the handle _b_,
Fig. 61, to the left. By doing this we would draw the cams _a_ and _b_
(Fig. 62) up into the cam plate out of working position, therefore the
jacks would not move to their innermost position so the needles would
not move far enough forward to meet the opposite jacks and could not be
taken over into the opposite plate. This system of being able to operate
any number of selected needles, or all of them, on either the purl or
jersey stitch, either alone or in combination with the rack, is the base
or principle used to make practically all the designed or pattern work
produced on the ordinary purl stitch machine.
Fig. 61 shows the top side of the carriage. The letter _a_ indicates the
handle for operating the carriage; _b_ is the lever for changing the
stitch from purl to jersey, or vice versa, by raising out or putting
into operation the cams _a_ and _b_, Fig. 62. The letter _c_ shows the
lever for changing yarn carriers while _d_1 and _d_2 are the slides for
changing the length of stitch. This change is made the same as has been
explained for the ordinary flat machine; that is, by shifting the stops,
of which there are three for each stitch cam or six on each of the
slides _d_1 and _d_2.
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