Improvements in Double Chain-stitch Sewing Machines.
Year: 1896

page_text: Date of Application, 30th Sept., 1896-Accepted, 6th Mar., 1897
COMPLETE SPECIFICATION.
Communicated from abroad by THE SINGER MANUFACTURING COMPANY, of
New York, in the United States of America, Sewing Machine Manu-
facturers.]
Improvements in Double Chain-stitch Sewing Machines.
1, WILLIAM HARVEY INSLEE, Manager of The Singer Manufacturing
Company, Kilbowie, Dumbartonshire, do hereby declare the nature of this
invention and in what manner the same is to be performed as communicated to
me, to be particularly described and ascertained in and by the following
statement:-
My invention relates to double chain-stitch sewing machines, and has for its
main object to provide a machine of this class in which the looper-mechanism will
be compact and simple in construction and at the same time strong and positive in
operation, so as to be well adapted for the high speed now demanded by the
manufacturing trade.
To this end my improved looper-operating mechanism comprises a rocking
looper-carrier which is pivotally mounted in a pivoted yoke, the pivot of the yoke
being at a right angle to the pivots of the looper carrier.
shaft is provided at its forward end with an eccentric and crank, the said eccentric
The looper driving
working in a yoke or opening formed in the looper-carrier and thereby serving to
impart positive lateral movements to the latter, together with its pivoted supporting
yoke, to cause the vibrating looper to advance on one side of the needle or needles,
to carry its thread through the loop or loops of needle thread, and to be retracted
on the other side of the needle or needles to spread the loop of looper thread in
such a manner that the needle or needles will enter the same on their next descent.
The crank adjacent to said eccentric works between flanges formed on the looper
carrier and serves to impart positive rocking or loop taking movements to the said
carrier and its looper.
By thus operating the looper-carrier, both laterally and longitudinally, from an
eccentric and crank located at the forward end of the rotating looper shaft, and
which eccentric and crank are in direct connection or contact with said carrier,
I am enabled to locate the latter centrally with relation to the vertical plane of
the needle or needles, and thus the power will be directly applied to the said looper
carrier and the parts will be evenly balanced; thereby enabling the said carrier
to run with a minimum of friction and vibration. Furthermore this arrange-
nent of parts contributes to compactness and simplicity of construction so as
particularly to adapt my invention to "cylinder" machines, or machines con-
tructed with cylindrical work-supporting armis employed for sewing hollow or
ubular articles.
In the accompanying drawings
Fig. 1 is a front side view of a "left-hand," "cylinder" machine embodying my
vention. Fig. 2 is a front end view thereof with the face-plate removed.
Fig. 3 is a detail view showing a part of the feeding mechanism.
Figs. 4 and 5 are detail views of the throat-plate and feed-bar to show the fixed
nd movable needle guards.

page_text: Fig. 6 represents the thread-guard and loop-spreader in three different views, and
Figs. 7, 8 and 9 are detail views of the looper-carrier, its supporting yoke and
operating devices.
The frame of the machine comprises the standard A, the overhanging bracket
arm A and the work-supporting arm or cylinder A. B is the main or driving
shaft journalled in the lower part of the standard and in the cylinder A², said
shaft carrying at its front end, beyond its front hearing a, the inclined crank b, the
eccentric 6, and the feed lilting eccentric 2, said crank and eccentrics being
preferably formed on or integral with a stud or spindle 63 secured in the hollow
forward end of the driving, looper-operating shaft B.
C is a feed-rock-shaft journalled in the arm or cylinder A2, preferably centrally
beneath the shaft B, and provided at its rear end with an arm c jointed at its lower
end at c² to a slotted lever c the upper end of which is forked to embrace an
eccentric 6 on the said shaft B. D is a feed regulating lever pivoted at d to the
frame of the machine, said lever carrying a fulcrum pin or stud d' adjustable in the
slot of the feed lever c. By varying the position of the feed regulating lever so
as to bring the fulcrum stud nearer to the joint connecting the arm c with the
feed lever c¹ the rocking feed movements of the feed shaft will be lessened and
the feed shortened; and by raising said fulcrum stud the feed will be lengthened,
as will be readily understood. A set nut d2 at the outer end of the lever D and
impinging against a curved bearing portion on the frame, serves to hold the feed
regulating lever in any desired position. The feed shaft C is provided at its
forward end with an arm or block e in which the feed-bar or slide d³ is vertically
movable, said bar or slide having an opening or slot d to receive the feed raising
and lowering eccentric b².
The main shaft B is provided near its rear end with a crank connected by a
pitman 6 to the arm e on the rear end of the needle operating rock-shaft E
journalled in the arm A¹ and having at its forward end the arm e¹ connected by a
pitman to the needle bar E¹ carrying one or more eye-pointed needles e³.
F is the looper-carrier provided with the eyed or thread-carrying looper and
pivoted on centre screws f¹ tapped in the arms of a yoke G arranged transversely
of the machine and loosely pivoted on the extended forward end of the feed rock-
shaft C. The looper-carrier is provided with an opening f forming a yoke
embracing the eccentric 61, and is also formed with flanges between which
the inclined crank works, the latter vibrating the said looper-carrier on its
pivot-screws f, to impart longitudinal movements to the looper, and the eccentric b¹
rocking the said looper-carrier and its supporting yoke G laterally to give the
necessary sidewise movements to the looper. As the transversely arranged, rocking,
supporting yoke G for the looper-carrier is centrally pivoted relative to the vertical
plane of the looper operating shaft and of the needle or needles, so as to rock
equally each side of its pivotal support, and thus be evenly balanced; and as the
loop-taking and lateral movements of the looper-carrier are imparted directly
thereto from a centrally arranged looper-shaft, it will be obvious that said looper-
carrier will be positively operated in all directions with a minimum of friction and
in a smooth and easy manner, thereby adapting the machine for the high rates of
speed for which it is intended.
To completely protect the needle or needles and avoid any danger of damage to
the same by the looper I provide a fixed needle guard preferably consisting
of a block h attached to the under-side of the thread-plate H, this stationary
needle-guard being so placed as to be closely adjacent to that side of the needle
or needles on which the looper makes its backward or return movement, while on
the opposite side of the needle or needles, or on the side thereof on which the
looper makes its forward or loop-taking movement, I provide a movable needle
guard h' which is attached to and thus laterally movable with the feed-bar d³, and
the movements of the latter are so timed that as the looper is moving forward to
take the needle loop or loops, when the needle or needles are rising, the said
movable guard will be brought into close proximity to the said needle or

page_text: needles to guard them so that they cannot be struck by the looper, the needle
or needles being thus at this time protected on both sides by the two guards which
are now just far enough apart to permit the needles to move vertically freely
between them.
To hold the needle thread or threads, running from the looper to the work, out
of the way of the descending needles, so that the latter will not enter their own
loops. I provide a needle thread guard which is laterally movable with the feed
and which is formed on a plate i, arranged just above the path of movement of the
looper, and which is carried by a shank herein shown as being attached to the
arm or block at the forward end of the feed rock-shaft C; the shoulder or portion ;*
of said plate i assuming such a position, as the feed moves forward, as to hold the
needle thread or threads, running from the looper to the work, out of the path of
the descending needle or needles. The portion of the plate i serves as a spreader
for the looper-thread, the said portion of said plate being formed with a slight
prong or hook which, on the backward movement of the looper and the forward
movement of the feed, catches the looper-thread running up to the work and holds
it out laterally so that the needle or needles on their next descent will not fail to
enter the looper loop.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a double chain-stitch sewing machine, the combination with a needle and
its operating mechanism, of a looper operating shaft extending. longitudinally of
the machine, a pivoted yoke arranged transversely of said shaft, a looper-carrier
pivoted on its opposite sides in said yoke, a thread-carrying looper arranged to
vibrate longitudinally in a plane transverse to said yoke, and devices operated by
said shaft and in contact with said looper-carrier to vibrate the latter, to move the
said looper back and forth longitudinally, and through said looper-carrier to
rock said yoke to move the looper laterally.
2. In a double chain-stitch sewing machine, the combination with a needle and
its operating mechanism, of a pivoted yoke extending transversely of the machine,
a looper-carrier pivoted in said yoke, the axis of said looper-carrier being at a right
angle to the axis of said yoke, a thread-carrying looper supported by said carrier
and extending longitudinally in a plane transverse to said yoke, and a rotating
looper-shaft provided with a crank and eccentric in contact with said looper-carrier
and acting through the latter to move the looper longitudinally and to rock said
carrier and said yoke, to move the looper laterally.
3. In a double chain-stitch sewing machine, the combination with a needle and
its operating mechanism, of a thread carrying looper, means for moving said
looper both longitudinally and laterally, a fixed needle guard at one side of the
path of movement of said needle, a movable needle guard at the opposite side of
the path of movement of said needle, and a feeding device by which said movable
needle guard is carried and which causes it to approach the needle when the said
looper is moving forward, thereby avoiding danger of collision between the looper
and needle.
4. In a double chain-stitch sewing machine, the combination with a needle-bar
and its operating mechanism, of the rotating looper-operating shaft B provided
with the inclined crank b and the eccentric 6', the pivoted yoke G, the looper
carrier F provided with the thread-carrying looper f, said carrier being pivotally
mounted in said yoke and having the flanges f between which said crank works to
vibrate said looper longitudinally, and having also the opening in which said
eccentric works, to rock said looper carrier and looper laterally.
5. In a double chain-stitch sewing machine, the combination with a needle-bar
and its operating mechanism, of the rotating looper operating shaft B provided
with the incliued crank 6 and the eccentric b', the pivoted yoke G, the looper
carrier F provided with the thread-carrying looper f, said carrier being pivotally

page_text: mounted in said yoke and having the flanges f³ between which said crank works to
vibrate said looper longitudinally and having also the opening 2 in which said
eccentric works, to rock said looper carrier and looper laterally, and the work-
supporting arm or cylinder through which said shaft B extends and at the forward
end of which said looper-carrier is mounted.
6. In a double chain-stitch sewing machine, the combination with the needle,
the thread-carrying looper, and the feeding device and their operating mechanism,
of the combined needle-thread guard and looper-loop spreader laterally movable
with said feeding device, said guard and spreader consisting of the plate i having
the portion which acts as a needle-thread guard, and the portion which serves
as a loop spreader, and the said plate having a suitable shank, as i¹, by which it is
attached to a laterally movable part of the feeding device.
Dated this 29th day of September 1896.
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62 St. Vincent Street, Glasgow, Agent for the Applicant.