Improvements in Circular Knitting Machines.
Year: 1897

page_text: Date of Application, 23rd Feb., 1897--Accepted, 9th Oct., 1897
COMPLETE SPECIFICATION.
Improvements in Circular Knitting Machines.
I, WILLIAM THOMAS BARRATT, Machinist, of Bennington, in the County of
Bennington, and State of Vermont, United States of America, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
My invention relates to the stitch forming mechanism of knitting machines and is
applied particularly to that class in which there are upper and lower needle cylinders
employed which have uniform rotation. The object of my invention is to relieve the
yarn of undue strain where it is formed into loops by the blades of the stitch wheel
and the needles of the lower cylinder to make stitches of desired length, and in my
mechanism for accomplishing this I employ a cam supported in the path of travel of
the lower cylinder needles, which forces the needles in regular succession a short
distance outwardly from their normal line of travel between the blades of the stitch
forming wheel, with the effect that a less number of needles will be between the
blades of the stitch wheel and the yarn will consequently be in engagement with a
less number of blades and needles than is the case where my device is not used, and
therefore will be subjected to less strain, and to this end my invention consists in
the construction hereinafter described and more particularly pointed out in the
claims.
Referring to the drawing:
Fig. is an elevation, partly in section, of a portion of a knitting machine
embodying my invention:
Fig. 2 is a front view of the cam on enlarged scale, showing the manner in which
it is supported and the means for its adjustinent:
Fig. 3 is a plan view showing the relative position of the needles and the blades
of the stitch forming wheel when my invention is applied:
Fig. 4 is a similar view of the needles and blades when my invention is not
used: and
Fig. 5 is a top view of the cam.
Similar reference numerals indicate corresponding parts in each figure of the
drawing.
The needles are indicated
1 represents the upper cylinder and 2 the lower one.
by 3, and 4 is the ring in which the upper cylinder is supported. 5 indicates the
stitch forming wheel in front of the needles which is properly supported in position
on the frame of the machine, in order that the needles of the lower cylinder, as the
two cylinders revolve, will successively engage the blades of the wheel.
6 represents a bracket secured to the ring 4 by the screw 7. The vertical arm of
the bracket is recessed in its front face as indicated at 8 and in this recess the plate 9
is fitted to have vertical adjustment. The plate 9 is provided with an elongated
opening through which a set screw 11 passes into the bracket 6 to hold the plate 9
in the desired adjusted position. From the front face of the plate 9, below the
opening, a lug 12 projects and to this lug the upper end of an arm 13 is pivoted on
a pin 14. The lower end of the arm 13 carries the arm 15 which may be integral
with the arm or secured to it in any suitable manner. 17 is a set screw working
...11

page_text: through the arm 13 below its pivotal connection to the lug 12, and engaging the
face of the plate 9.
It will be observed by reference to Figs. 1 and 3 that the cam 15 is supported to
engage the upper portions of the lower cylinder needles and force them a short
distance outwardly from their normal line of travel. It will also be observed that by
turning the set screw 17 the extent of this outward movement will be increased or
diminished as desired.
Referring now to Fig. 4 it will be observed that in order to get the proper length
of stitch in the yarn 18, it will be necessary for the blades of the stitch wheel to
project inwardly between the needles a considerable depth and in order to do this
the stitch wheel must be set up close to the needles with the result that from 4 to 6
blades of the wheel will be between the needles to a greater or less depth at the same
time and that consequently the yarn will be drawn over two or three blades and as
many needles before the stitch is formed of the proper length as shown at 19. This
necessarily subjects the yarn to great strain and frequently causes the needles to
spring out of position and make uneven stitches; or the yarn will break or the
blades of the stitch wheel will over reach and get under the barbs of the needles and
cause what is known as a "smash-up," when usually quite a large number of needles
are broken.
By the use of my invention however, these difficulties are avoided, for as the
needles in their travel reach the cam, they will be forced outwardly in between the
blades of the stitch wheel as shown in Fig. 3, with the result that a stitch of sufficient
length will be formed as indicated at 20, after passing over one blade of the stitch
wheel and one needle. The stitch wheel can therefore be set further away from the
needles and consequently as many blades will not be between the needles at one time,
and the strain on the yarn will be correspondingly reduced.
By simply turning the screw 17, the cam 15 can be adjusted to force the needles
outwardly to a greater or less extent and the length of stitch can thereby be varied as
may be desired for different fabrics.
It will be also be observed that the cam 15 forms a support for the needles against
the strain exerted on them by the yarn and they cannot be sprung out of position
by the strain thereby ensuring uniformity in the stitches and consequently greater
elasticity of the fabric.
Having now fully described and ascertained the nature of the said invention, and
in what manner the same is to be performed, I declare that what I claim is:
1. In a knitting machine having revoluble needle cylinders the combination
with the stitch wheel, and the needles of one of the cylinders, of a cam supported
in the path of the travel of said needles to force them successively between the
blades of the stitch wheel, substantially as and for the purpose set forth.
2. In a knitting machine having revoluble needle cylinders, the combination with
the stitch wheel and the needles of one of the cylinders, of a cam supported in the
path of the travel of said needles to force them successively between the blades of
the stitch wheel, and devices to adjust the cam vertically and laterally relative to
said needles, substantially as and for the purpose set forth.
Dated this 23rd February 1897.
CHARLES JUNGE,
Agent for the Applicant.