Improvements in Cams for Knitting Machines.
Year: 1898

page_text: Date of Application, 29th Mar., 1898-Accepted, 25th June, 1898
COMPLETE SPECIFICATION.
Improvements in Cams for Knitting Machines.
I, WILLIAM THOMAS BARRATT, of Bennington, in the County of Bennington
and State of Vermont, United States of America, Machinist, 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 has reference to improvements in draw up cams which have
heretofore been made in two parts adjustable with respect to each other, the parts
being hinged together by a knee-joint and so constructed with reference to each
other that when the part provided with a point of the cam is adjusted, it is
necessary also to adjust the casting off part which is not always desirable.
Furthermore, the construction of these cams are such at the casting off point that
ten or twelve stitches are drawn tight at one time. This is objectionable, in that
if the yarn is tender or uneven, when the strain comes on tight stitches it is
liable to break and thereby result in imperfect work.
The object of my invention therefore, is first to provide a cam of the kind
stated, in which the adjustments at either the end where the needles press or the
end where the needles are cast off, are entirely independent of each other, thereby
economizing time in adjusting the cams properly to do the work, and second,
to provide a cam with means for casting off the stitches and drawing them tight,
one at a time, so that when the loops are not all of the same length it will draw
from the loose to the tight ones and even them up and thereby improve the
character of the work and enable the more tender yarn to be more safely used than
heretofore, and to provide adjustable means on the cam for casting off, and my
invention consists in the peculiarities of construction hereinafter described and
more particularly set forth in the claims.
Referring to the drawings:
Fig. 1 is an elevation of a part of a circular knitting machine with my improve-
ments applied thereto :
Fig. 2 is a rear perspective view of the cam, and its supporting bracket,
detached from the machine, and of the casting off means upon the cam:
Fig. 3 is a rear elevation of the supporting bracket alone:
Fig. 4 is a front elevation of the cam, with the casting off means removed, and
Fig. 5 is a perspective view of the casting off and needle returning devices.
Like reference numerals refer to corresponding parts in each figure of the
drawing.
1 designates the upper and lower needle cylinders, 2 the cylinder supporting
rings and 3 the spring bands encircling the needle cylinders, and holding the
needles in position, which parts may be of the ordinary construction.
5 designates the draw up cam and 6 the supporting bracket therefor, said
bracket having a horizontal arm 7 provided with two elongated openings 8
hrough which screw bolts 9 pass into the upper cylinder ring 2 and serve to
ecure said bracket adjustably thereto. The inner surface of the vertical arm 10
of the bracket is formed with two grooves 11 which are located adjacent to the
enter thereof and between each of said grooves and the nearer vertical edge of
aid arm is an elongated opening 12.

page_text: The cam 5 is made in two parts 13 and 14 which are divided from each other
on a straight line. Each cam section is provided with guide pins 15 projecting
into the adjacent groove 11, and extending horizontally through the openings 12
are screw bolts 16 and 17 for securing the cam sections independently in adjusted
positions, while screw-bolts 18 and 19 for adjusting the respective cam-sections
extend through the lower horizontal edge of the bracket arm 10 and into said
openings 12 and engage said screw bolts 16 and 17 respectively. It will be
observed that the construction described permits either part of the cam to be
adjusted independently of the other and to be separately held in the adjusted
positions. This independent adjustment of the respective ends of the cam is
important, as it is not always necessary or desirable to adjust both ends at the
same time.
The cam surface of the part 13 is formed with the successive elevations 20, 21
and 22, and with a depression 23 at the junction of said elevations 21 and 22.
The upper longitudinal edge 24 of the part 14, where said part abuts the vertical
edge of part 13, is beveled, as shown at 25, and rearward thereof said upper edge
is formed with an opening 26 communicating with a groove 27 formed in the
outer face of said part 14. This groove receives the stem 28 of a casting-off
piece, while the laterally enlarged head 29 of said casting off piece sets into said
opening 26 and projects above the plane of said edge 24 and is curved, as shown.
Said stem 28 is provided with a pin 30 which projects into an opening 31 formed
in the inner wall of said groove, said opening being of greater size than the
diameter of said pin. The casting off piece is held adjustably on the cam by
means of a screw bolt 32 as shown in Fig. 1, the head of which engages said
stem 28, while the bolt is secured in opening 33 in said part 14.
34 designates a plate formed with an elongated opening 35 and adjustably held
on the cam-part 14 by a screw-bolt 36 passing through said opening into the open-
ing 37 in said part of the cam, as shown in Fig. 1. The upper end of this plate
is bent at right angles to form the part 38 which extends over the edge 24 of
cam section 14 and at a slight distance therefrom, and from said part 38. extends,
in an upwardly inclined direction, the arm 39 which projects over the head 29 of
the casting off piece. It will be observed that the means for securing the plate 34
to the cam permits said plate and, in consequence, the arm 39 carried by it, to be
adjusted upon the cam and held rigidly in adjusted position. In operation of
the device, the needles 40, shown in Fig. 1, are drawn up the inclined surfaces
of the part 13 of the cam to the depression 23, at which point the barbs are
pressed down so that the points will go under the old loops, thence they travel
up the inclined edge 22 and along the cam until the ends are even
with the edge of the needle cylinder and thence upward and over the
convexed head 29 of the casting off piece, through the race formed conjointly by
said head and the arm 39 and underneath the part 38 and upon the edges 24 to
the cam 41, and are forced down by the latter as is common in this style of
knitting machines.
Thus it will be seen that each needle is raised at the casting off end of the cam
to above the plane of the edge of the cylinder and the loops drawn tight, one at
a time, and that said needles are then returned to position upon the cam by means
of the arm 39 and upper end 38 of the plate 34.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a knitting machine, the combination with a supporting bracket having an
arm formed with two grooves located adjacent to each other, and with an elongated
opening between each of said grooves and the nearer vertical edge of the arm,
of a draw up cam divided upon a straight line into two independently adjustable
parts, guide pins projecting from said parts into the grooves, and two fastening

page_text: bolts projecting into said elongated openings for holding said parts independently
in adjusted position, substantially as and for the purpose set forth.
2. In a knitting machine, the combination with the cam having an opening
in its edge and a groove in its face, of a casting off piece adjustably secured to
said cam, and having a stem received by said groove and a laterally enlarged
curved head received by said opening substantially as and for the purpose set forth.
3. In a knitting machine, the combination with the cam, and the casting off
piece adjustably secured thereto and operating to draw the stitches tight one at
a time, of a plate adjustably secured to said cam and having a bent upper end
extending over the edge thereof, at a slight distance therefrom, and an inclined
arm extending from said bent part of the plate above the casting off piece, sub-
stantially as and for the purpose set forth.
4. The hereindescribed draw up cam comprising two independently adjustable
parts, a casting off piece adjustably secured upon one of said parts and operating
to draw the stitches tight one at a time, and a needle returning plate adjustably
secured to said part of the cam and extending over the end thereof rearward of
the casting off piece and having an arm projecting over said casting off piece,
substantially as and for the purpose set forth.
Dated the 28th day of February 1898
WILLIAM THOMAS BARRATT,
Boult & Wade,
Agents for the Applicant.