IMPROVEMENTS IN KNITTING MACHINES
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by Henry Josiah Griswold at the
Office of the Commissioners of Patents, with his Petition, on the
6th March 1872,
I, HENRY JOSIAH GRISWOLD, of No. 273, Oxford Street, in the
County of Middlesex, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN KNITTING MACHINES," to be as follows:
My said improvements relate to circular knitting machines chiefly
designed for family use. In these machines the needles are arranged
within the periphery of a circular cam ring or shell, which is operated
with a rotary or reciprocating motion according as it is required to knit
circular or flat work.
. According to these improvements I construct and arrange cams on the
internal periphery of the cam ring or shell in such a manner as will
permit the reversal of the said cam ring and the knitting of flat work
while the yarn carrier remains rigidly attached to the said cam ring.
I also use a switch cam by means of which the needles or any number
of the same may be automatically thrown out of action to knit a flat
web the full width of the circumference of the needle frame and with,

page_text: all the needles thereof. I adopt a method of readily elevating and
depressing the needle cylinder in order to regulate the length of the
stitch, and I employ a simpler method of retaining the needles in their
places than has heretofore been used. I use an attachment for opening
the needles when by accident or otherwise they are closed, and I also
have another attachment by which I am able to knit the reverse or pearl
stitch on the said machine.
My said improvements are carried into practice as follows:-I dispense
with the frictional ring which has been hitherto used on such machines,
and also the stop pins and the holes in the frame of the machine, and
attach the yarn carrier by screws or otherwise rigidly to the said cam
ring. On the internal surface of the said cam ring or shell I place two
similar cams on either side of the yarn carrier and equidistant therefrom.
These cams are so arranged that in whichever direction the cam ring
may be revolving the cam in advance of the yarn carrier serves to raise
the needles for the purpose of clearing their latches from the loops
previously knit, and the cam which follows the yarn carrier serves to
depress the needles and thus form the new stitches. These cams may be
attached rigidly to the cam ring, or parts of them may be made move-
able for the purpose of varying the length of the stitch. I attach to the
internal periphery of the cam ring an auxiliary cam or switch in such
a position that it may be raised or depressed. When it is in its normal
position it serves to conduct the needles after they have passed the
lifting cam to a position in which they will pass under the depressing
cam. This cam is depressed either by hand or by dogs attached to the
body of the machine, and when it is depressed the needles will be lifted
by it above all the cams to a position wherein they will be out of action.
Instead of fixing the needle frame rigidly to the body of the machine
I fit it accurately to slide up and down in the interior of the said body,
which I extend downward farther than has formerly been the case with
these machines in the form of a hollow cylinder. In the circumference
of this cylinder I form one or more spiral slots. Through these slots
I pass set screws which are tapped into the needle frame. After those
screws have been slackened a partial revolution of the needle frame in one
direction will elevate it in relation to the cam ring and thus lengthen
the stitches, while a partial revolution in the other direction will depress
it and thus shorten the stitch. By tightening the set screws the needle
frame is retained in the required position until a variation in the size

page_text: of the stitch is again required. The clasp ring hitherto employed in
these machines is difficult to construct and easily broken. I therefore
use in its place an elastic band or spring of metal, which is much
cheaper of construction and serves perfectly to keep the needles in their
place, while the cam ring is retained in place by means of brackets on
the body of the machine. I attach one or more small brushes to the
cam in such a position that with the revolution of the cam ring they
will be carried over and impinge upon the tops of the needles in such
a manner that the bristles of the brush serve to open the latches of the
needles if by accident or by any imperfection in the construction of
the needles they are closed: I remove from the aforesaid needle frame
some of the needles which correspond with the rows of stitches to be
pearled. I then place within the said needle frame an auxiliary needle
frame. The latter is preferably constructed in the form of a frustum
of a cone, in which are grooves corresponding with the grooves in the
main needle frame from which the needles have been removed.
these auxiliary grooves I insert extra needles, by preference those which
had been removed from the other frame, in such a position that the
two sets of needles when actuated will cross each other and work
angularly to each other. Over or around the auxiliary needle frame I
construct an auxiliary cam ring with suitable cams on its under surface
for actuating the needles. This auxiliary cam ring is attached to the
main cam ring in such a manner that it revolves simultaneously with it,
but slightly behind it. The stitches formed by the machine are on the
right side, while those formed by the attachment are on the wrong side
of the web.
In