IMPROVEMENTS IN KNITTING MACHINES
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by William Prowett at the Office
of the Commissioners of Patents, with his Petition, on the 28th
October 1868.
I, WILLIAM PROWETT, of Wellington Cottage, Gillingham, in the
County of Kent, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN KNITTING MACHINES," to be as follows:-
This Invention has for its object improvements in knitting machines.
In constructing a knitting machine I employ bearded needles similar
or nearly so to ordinary hosiery needles, and I mount them on.
slides which are actuated in such a manner as to give to the needles.
an endway traverse; I generally make the machine double acting by
mounting needles on each end of the slides, the machine in this case
produces simultaneously two fabrics, one at the front, the other at the
back of the machine. The needles are by preference worked in pairs,
so that cach slide carries four needles. The slides are arranged side
by side in suitable guides; their number depends on the width of the
work the machine is required to make, and on the gauge of the
machine. The slides are worked by cams which act upon them in
succession and progressively from side to side of the machine. Each

page_text: pair of needles as its slide is drawn back, passes under a stationary bar
called the presser bar, which by bearing on the beards closes them
down the stems. Beyond the presser bar is another stationary bar
having teeth upon it, and the needles pass between the teeth; this bar
I will call the comb bar. The heads of the needles when they have
passed behind the presser bar enter between the teeth of the comb
bar.
The action in working a course is as follows:-A thread carrier which
traverses from side to side of the series of needles lays a thread on
to the needle stems, and then the. needles, retire underneath the presser
bar, which also, has blades upon it entering between the needles; one
blade to cach pair of needles is sufficient, they serve to keep the thread
forward until it is placed safely under the beards. As the needles
continue to retire they lightly pull upon the thread, and the edges
of the blades being inclined the thread escapes under the presser bar,
and it then comes to bear against the leading edges of the blades upon
the comb bar. As the heads of the needles retire between these blades
the thread is drawn into a zig-zag course, and the length of the loops
of the work is governed by the distance which the heads of the needles
retire into the, guide. comb,. the blades, of which thus act as sinkers.
The work hangs upon the stems of the needles in between the presser
bar and the comb bar, and is there constantly retained; then as the
needles retire as already described when the beards of the needles are
drawn under the presser bar they are closed, the face of the presser
bar being inclined, and as the needles move back the loops of the
work ride over the beards and pass over the heads of the needle or
are knocked over. The cams which give these motions to the needles
are mounted upon a nut. working upon a stationary screw extending
across the machine, and at the end of this screw there is, a loose arm
which is caused to revolve upon the screw, it carries a bar or driver
which thus travels around. the screw, and it takes with it the nut on
which the cams are mounted. Thus the cams as they rotate traverse
from one side of the machine. to. the. other along. the screw, and the
pitch of the screw is such that. cach. cam takes all the needle slides
one by one in succession. The forms of the cams are adapted to give
the required motions; if the machine is single acting all that is required
is to draw back the needles and then return them to their former
position; but if the machine is double acting the second motion is

page_text: made double the length of the first, so as to retire the needles on the
opposite side of the machine through their presser bar and comb bar,
and a third motion brings the slide to the position from which it started.
When the cams have traversed from side to side of the series of needles
their motion is reversed and they return. The arm which carrics
the driver is on an axis, which is clutched alternately by friction clutches
with one or other of two driving pulleys driven by driving bands in
opposite directions, but at the same speed. The axis of the driver arm
by means of a band drives a screw parallel to the fixed screw, and having
a nut upon it, which is thus caused to traverse in unison with the
cams moving along the first screw, and when the cams come to the
end of their course in either direction this nut comes against a stop
or adjustable projection on a bar which is thus caused to slide in its
bearers, and in so doing it reverses the clutches. The same nut also
gives motion to the thread carrier along its guides, and as the thread
carrier is required to be in advance of the cams whichever be the
direction of the motion the cams are allowed to continue to travel
a distance beyond the needle slides at the end of each traverse whilst
the thread carrier is stopped, until the thread carrier has so been passed
from one side of the cams to the other. The thread carrier is stopped by
coming against a stop upon the frame, but the nut which drives it still
travels on the connection between the nut and the thread carrier
being by a yielding or friction holding only. The needles are not fixed
rigidly to the slides, but are jointed to them, and when the fabric is
narrowed the needles which are not required are turned up out of
the way. The presser bars and the comb bars are adjustable in position
to vary the length of the loops. The presser bar is allowed a slight
play in guides, and weights or springs cause it to bear sufficiently on
the beards of the needles. Ribbed work may be produced by turning
up say every fourth ordinary needle out of the way, and substituting
for it a latch needle on another bar receiving independent motions, the
latch needles when they are used stand at right angles to the ordinary
needles.