IMPROVEMENTS IN KNITTING MACHINES
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Joseph Buchanan Robertson at
the Office of the Commissioners of Patents, with his Petition, on
the 12th March 1875.
I, JOSEPH BUCHANAN ROBERTSON, of Lurgan, in the County of
Armagh, Ireland, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN KNITTING MACHINES," to be as follows:-
:-
In the Specification of a Patent granted to me on the 17th April 1874,
No. 1327, I described certain improvements in knitting machines for
the purpose of rendering such machines applicable for the production of
tapering fabrics or fabrics having a varying diameter at different parts
of their length.
My present Invention relates to improvements in machines of the kind
referred to in the said Specification, such improvements having for their
object to facilitate the radial adjustment of the needles and their guides,
to provide for reversal of the motion or for the introduction of additional
feeds, and to adapt the machine to the production of ribbed work as well
as plain knitting.
:

page_text: In order to facilitate the radial adjustment of the needles and their
guides according to one of my present improvements I connect each of the
needle guides by a jointed connecting rod or bar to an exterior lever
pivotted on the base of the machine, and I form the edges of thoso levers
sloped or curved, according to the nature of the work to be produced, in
such manner that a ring which can be made to ascend or descend in
contact with these edges shall have the effect of pressing the levers.
outwards or permitting them to move inwards, according as the ring is
moved vertically upwards or downwards. Each of the levers being thus
moved causes the needle guide connected to it to bend outwards or
inwards so as to produce a greater or less diameter of fabric.
The rods or bars connecting the guides to the levers may have rack
teeth or projections on their edges engaging with grooves in a ring, such
grooves having a volute curvature, so that as the ring is turned in the
one direction or the other the connecting bars, and with them the needle
guides, are caused to approach towards or to recede from the axis of the
machine. When this mode of adjusting the needle guides is adopted
the exterior levers may be dispensed with, the connecting bars being
fitted to travel in horizontal guides, and in that case all the flexible
guides below the said horizontal guides may be dispensed with.
Instead of fitting each of the needle guides with connecting bars and
levers, as above described, only one of cach group of these guides may
be so fitted, the said guide having suitable stops, so that as it is shifted
it can cause others of the group to which it belongs to accompany it in
its movement.
According to another method of effecting the radial adjustment of the
needles I employ a ring made with a number of radial grooves, in cach
of which is fitted to slide radially a guide bar. On cach guide bar is
pivotted a jack lever, having at its end a socket holding the needle, which,
as the lever is made to oscillate in a vertical plane slides up and down
in an eye formed at the end of the guide bar. The jack lever has on
each of its edges near its fulcrum a projection extending respectively
upwards and downwards beyond the face of the grooved ring. A cam
segment is placed above the grooved ring and another below the same,
so that as the grooved ring with its guide bars and jack levers is caused
to revolve or as the said cam segments are made to revolve each jack
lever in turn as its projections pass these cam segments has an oscillatory

page_text: movement imparted to it causing the needle at its end to perform its up
and down strokes. The guide bars with their jack levers can be drawn
outwards or pushed inwards so as to bring the needles farther from or
nearer to the axis of the machine, and each guide bar can be held in a
definite position in its groove by means of a catch taking into notches or
teeth of the bar. The cam segments are made to shift outwards or
inwards, so that their cam paths can be brought into proper position for
acting on the projections of the jack levers, according as they are farther
from or nearer to the axis of the machine.
When it is desired to reverse the motion of the machine the cam path
which works the needle jacks requires to be altered. I effect this in one
way by making the ring containing the cam path in two thicknesses,
one within the other, each fitted to slide vertically, and I provide the
studs projecting from the jacks of such length as to pass through both
thicknesses. Each thickness is slotted through with a wide slot, which
on the one side has the form of the one cam path and on the other side
has the form of the other cam path. When the rings are in one position
the studs of the jacks are guided between the side of the slot in the one
thickness and the opposite side of the slot in the other thickness so as to
travel in the one cam path. And when the one thickness is moved
upwards and the other downwards the studs of the jacks are guided by
the opposite sides of the slots in each of the thicknesses so as to travel
in the other cam path.
Another way of altering the cam for the purpose of reversing is to
make that portion which operates to give the needles their stroke jointed,
so that the limbs of this portion can be altered in shape, according to
the direction of revolution.
Instead of making such shifting cam paths in complete rings they
may be made in segments of rings, and some of the segments may be
shifted so as to alter the cam path in parts of its course. In this
manner when it is desired to introduce additional feeds, segments may be
shifted so as to cause the needles to make their strokes at several points
in their revolution, according as the cam path is altered by the shift of
the annular segments.
In adapting machines of the kind referred to for producing ribbed
work I fix the cam and the feed and cause the needles with their guides
to revolve round the axis of the machine, providing cross needles at the
top to effect the ribbing.

page_text: The arrangement which I have above described of guides with jack
levers working in the radial grooves of a ring is most conveniently
adapted for this purpose, the grooved ring being caused to revolve,
and the cam segments being fixed in respect of rotary movement,
though capable of being adjusted to or from the axis of the machino.
Adopting this arrangement I form on the upper face of the upper cam
segment a cam path, and I provide a second radially grooved ring to
revolve above the same at the same speed as the lower ring. In tho
grooves of this upper ring I fit horizontally sliding needle jacks operated
by the uppermost cam path, so that as the two rings with their vertical ]
and horizontal needles are made to revolve the former and the latter
needles by the proper timing of their respective cam paths are made to
produce the ribbed work in the usual manner.
As for different sizes of work it is necessary to introduce or to with-
draw some of the upper cross needles as well as some of the vertical 1
needles I provide the jacks of the former with catches, so that those
which are not in use can be held out of range of the cam path which
works the others that are in use for the time being.
It may also be readily understood that when the machine is set for
work requiring only a portion of the whole number of needles those that 2
are not required may be entirely withdrawn from the machine.