IMPROVEMENTS IN KNITTING MACHINES
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by Joseph Buchanan Robertson at
the Office of the Commissioners of Patents, with his Petition, ou
the 23rd September 1874.
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 a Provisional Specification filed by me on the 17th April 1874, No.
1327, I describe the nature of certain improvements in knitting
machines for the purpose of rendering such machines applicable for the
production of tapering fabrics, or of fabrics having a varying diameter at
different parts of their length.
My present Invention relates to improvements in machines of tho
kind referred to in the said Provisional 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 pro-
duction of ribbed work as well as plain knitting.

page_text: In order to facilitate the radial adjustment of the needles and their
guides, 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 those 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 down-
wards. 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.
Instead of fitting each of the needle guides with connecting bars and
levers as above described, only one of each 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.
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 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 thick-
ness, 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.

page_text: 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 thic 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 in the manner usually adopted for that
purpose.