IMPROVEMENTS IN CIRCULAR KNITTING MACHINES
Year: 1864

page_text: LETTERS PATENT to Thomas Coltman, of Leicester, Machinist, for the
Invention of "IMPROVEMENTS IN CIRCULAR KNITTING MACHINES."
Sealed the 30th September 1864, and dated the 1st April 1864.
PROVISIONAL SPECIFICATION left by the said Thomas Coltman at the
Office of the Commissioners of Patents, with his Petition, on the
1st April 1864.
I, THOMAS COLTMAN, of Leicester, Machinist, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN CIRCULAR KNITTING MACHINES,"
to be as follows:-
My Invention of "Improvements in Circular Knitting Machines" relates to
certain mechanical arrangements to be adapted to circular knitting machines
for the purpose of stopping the machine when any of the threads break.
To this end the several threads of which the fabric is to be made are passed
from their stationary, bobbins through eyes in fixed standards, and from thence
through eyes at the end of the longer arms of rocking levers, from the outer
or shorter ends of which are suspended, by means of hooks, rings, or other
equivalent contrivances, horizontal weighted levers, which are suspended
immediately above notches or teeth cut in a horizontal wheel fixed on to the
rotating cylinder of the machine, and therefore rotates therewith. The tension
of the threads as they pass to the work is sufficient to keep the long end of
the rocking-levers in their proper position while the threads are whole and
unbroken; but immediately one of these threads breaks the lever flies up and

page_text: allows the book or ring at the opposite end to slip off and drop the horizontal
weighted lever, which will thereby come into contact with the teeth of the hori-
zontal wheel and stop the same, and with it the rotating cylinder. The machine
is driven by friction gear, the amount of friction just sufficient to drive the
machine being regulated by tightening the friction band. This friction gear
may be adapted to and form part of the machine itself, or, if preferred, it may
be applied to the driving shaft. It is necessary to drive the machine by
friction gear, because it will not be convenient to adopt any self-acting
mechanism to throw off the driving bands, or throw the toothed driving
wheels out of gear. When the machine is stopped in the manner already
explained (by the breakage of a thread) the driving shaft continues to rotate
and drive the bevil-toothed gear, but the friction band will allow this to be
done without actuating the working parts of the machine. The driving band
may then be thrown off at leisure, or if not thrown off it will do no damage,
and the machine will at once start again when the weighted lever is lifted out
of the notches of the horizontal wheel.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Coltman in the Great Seal Patent Office on the
1st October 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
COLTMAN, of Leicester, Machinist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of April, in the year of our Lord One
thousand eight hundred and sixty-four, in the twenty-seventh year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas Coltman, Her special license that I, the said Thomas
Coltman, my executors, administrators, and assigns, or such others as I,
the said Thomas Coltman, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN CIRCULAR KNITTING MACHINES," upon the condition (amongst
others) that I, the said Thomas Coltman, by an instrument in writing under
my hand and seal, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be performed,

page_text: and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Thomas Coltman, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement, reference being had to the Drawing hereunto annexed, and
to the letters and figures marked thereon (that is to say):
My Invention of "Improvements in Circular Knitting Machines" relates to
certain mechanical arrangements to be adapted to circular knitting machines
for the purpose of stopping the machine when any of the threads break.
The mechanical arrangement whereby this is effected is shewn in the
accompanying Drawing, in which Fig. 1 is an elevation representing so much
of a circular knitting machine as is necessary to render the application of my
Invention intelligible; Fig. 2 is a vertical section of part of the driving gear.
The several threads a, of which the fabric is to be made, are passed from
their stationary bobbins, not shewn in the Drawing, through eyes or holes
made in the fixed standards a', and from thence through eyes b at the end of
the longer arms of rocking levers 6', from the outer or shorter ends of which
are suspended, by means of hooks rings c, or other equivalent contrivances
provided with pendent cords or wires d, the horizontal weighted levers or
bars e, which are suspended immediately above notches or teeth cut in a hori-
zontal wheelf fixed on to the rotating cylinder of the machine, and therefore
rotate therewith. The tension of the threads a as they pass to the work is
sufficient to support the long end of the rocking levers 6 in their proper
position while the threads a are whole and unbroken, but immediately one of
these threads a breaks, the lever 6¹ flies up, and allows the book or ring c at
the opposite end to slip off and drop the horizontal weighted lever e, which
will thereby come in contact with the teeth of the horizontal wheel f, and will
stop the rotation of the same, and with it the motion of the rotating cylinder.
The machine is driven by gear consisting of a metallic band g, which is
tightened round the neck of the rotating cylinder by means of a tightening
screw g', as shewn at Fig. 1; the amount of friction just sufficient to drive
the machine is regulated by tightening the friction band by means of the
screw g¹. This friction gear may be adapted to and form part of the machine
itself, or, if preferred, it may be applied to the driving shaft. It is necessary
to drive the machine by friction gear, or some other analogous contrivance,
which will admit of the motions of the machine being suddenly arrested
automatically, because it will not be convenient to adopt any self-acting

page_text: mechanism to throw off the driving bands, or throw toothed driving wheels
out of gear. When the machine is stopped, as already explained, by the
breakage of a thread, allowing the lever e to drop into the teeth of the
wheelf, the driving shaft will continue to rotate and drive the bevil toothed
wheel h, but the friction band g will allow this to be done without actuating
the working parts of the machine, as it will slip round the neck without
carrying the cylinder round with it. The driving band may then be thrown
off at leisure, or if not thrown off it will do no damage, and the-machine will
at once start again when the weighted lever e is lifted out of the notches
of the horizontal wheel, so as to allow it to rotate and carry round the
cylinder.
Having now described my Invention of "Improvements in Circular Knitting
Machines," and having explained the manner of carrying the same into effect,
I claim as the Invention secured to me by Letters Patent as aforesaid, the
mode herein set forth, or any mere modification thereof, for stopping the action
of circular knitting machines when any of the threads break.
In witness whereof, I, the said Thomas Coltman, have hereunto set my
hand and seal, the Twenty-eighth day of September, in the year of
our Lord One thousand eight hundred and sixty-four.
TITOR