IN KNITTING MACHINES."
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Thomas Coltman at the Office of
the Commissioners of Patents on the 6th January 1881.
THOMAS COLTMAN, of Leicester, in the County of Leicester.
IN KNITTING MACHINES."
"IMPROVEMENTS
In carrying out my improvements I employ, first, a machine constructed mainly
as described in the Specification of a Patent granted to me for improvements in
knitting machines on the 16th of April 1880, numbered 1555, consisting of a metal
bed supported by suitable standards which carry bearings for a shaft at one end of
the machine provided with pulleys, and a plate or wheel having an axle pin to
receive one end of a connecting link for communicating a rocking motion to two
levers at the opposite end of the machine; these levers each carry a link for
communicating a reciprocating motion to front and back cam plates, which are
carried by boxes which slide in the grooves of bars secured to the front and back
of the machine, the remainder of the machine being of the same construction as
described in my former Patent, except that I employ an improved arrangement of
cams consisting of three drawing cams for lowering the needles, and two cams for
raising them both on the back and front of the machine; such arrangement enables
me to make two courses in traversing from left to right, and two other courses
when traversing from right to left when making the cuff of a sleeve or a one and
one stitch. The three cams above named work up and down in suitable bevelled
slots; each cam carries a stud which takes into a slotted incline bar which
accurately adjusts the cams for the quality of work required. The cams are
adjusted by the attendant moving the incline bar end ways, the bar being securely
held where placed by a notched spring.
When making what is known as the polka stitch, the top part of the needle
raising cams are made separate, and each slides in a groove and is provided with a
stud operated upon by two slotted T shaped bars, one slot in each bar being straight
and the other slot inclined; such arrangement of slotted bars enables me to either
raise one or the other of the top parts of both sets of cams, or raise both or lower
both at pleasure to make different stitches. With the above described parts I
employ two or more traversing thread carrier boxes constructed as described in my
former Patent, but in addition thereto I employ an apparatus for locking the bolts

page_text: when up, and unlocking them when the carrier box reaches the end of each
traverse; this I effect by means of a sliding bar carrying inclines applied to each
carrier box; I also employ a slotted incline plate, which, when moved by the
attendant, will hold down the driving bolt not lowered by the inclines described in
my former Patent. The combination of apparatus working as above described I
employ when making a polka stitch fabric.
The above combination of parts I employ on a machine for making narrow
breadths of fabric, such as sleeves, etc.
Second. When making wide single breadths of fabric, say, for polka jackets or
other garments, I employ a saddle traversed as described in my former Patent to
carry the cam plates.
Third. In a machine for making narrow borders of jackets or other garments I
employ the same construction and combination of parts as in the sleeve machine
first described, but make the divisions much narrower and employ one or more
traversing thread carrier boxes, the cams in each being adjusted to make the
requisite stitch. In this machine I cross the stitches right and left by an excentric
cam reversed by a rod or link operated by one of the traversing levers or by a
sliding bar.
Fourth. My improved machine for making broad ribbed fabrics, ribbed tops, or
a plain fabric, I construct with the front and back needle sleys lying in a groove
at each end, in which grooves the sleys are caused to move up and down by two
studs which are secured in each sley taking into inclines in a bar which slides in a
groove in the sley bed of the machine, both at the front and back, each bar being
moved endways by a screw at one end secured to the sley bed working in a
screw threaded nut secured to the sley bar. By such means the needles sleys can
be lowered to admit of running a rib top on or when making a welt. To cross the
stitches I employ an excentric cam, as described in my former Patent, to move the
whole of the front sleys and sley bed the distance of one needle.
Each of the cams which operate both the front and back needles to raise them
have their lower parts sliding in a bevelled groove, and each lower part being
provided with a stud is operated by the T shaped incline and slotted bars described
in the first modification.
By such means I am enabled to make ribbed or plain fabrics at a much greater
speed than heretofore, besides obtaining greater facilities for making a variety of
stitches.