Year: 1887

page_text: Date of Application, 17th Mar., 1887
Complete Left, 19th Dec., 1887
Complete Accepted, 20th Jan., 1888
We, ALEXANDER ANDERSON, Manager, and ROBERT ANDREW FERGUSON POLLOCK,
Mechanic, both of the Singer Manufacturing Company's Works, Kilbowie, Dumbar-
tonshire, do hereby declare the nature of this invention to be as follows:-
Our invention relates to sewing machines of the class in which chain stitches are
formed by the use of a looper or horizontal needle, carrying the lower thread, in
conjunction with the usual vertically reciprocating needle and upper thread, and the
invention has for object improvements in the formation and arrangement of the looper
and actuating mechanism for imparting to it a positive motion around the axial line of
the needle, in connection therewith in means for regulating the transverse movement
of the looper to suit the different sizes of needles employed, in means for taking up
the slack of both the looper and needle threads, in the mechanism for actuating the
feed, and in the formation of the feed plate and presser foot to prevent wear or
blunting of the teeth of the plate.
The looper consists of a straight needle formed on or attached to the end of a long
rod or bar which extends horizontally under and lengthwise of the machine bed and is
pin jointed at its opposite end to a lever pivotted on the machine frame and having on it
a stud and roller entering a grooved cam on a cam shaft which also is carried longitudi-
nally under the machine bed the rotation of said shaft imparting through the cam groove
an oscillating movement to the pivotted lever and therethrough a longitudinal recipro-
cating motion to the looper bar. At the end adjacent to the looper needle the needle
bar passes through a swivelling stud or guide attached to a frame or slide which has a
transverse reciprocating movement imparted to it by a cam or eccentric on the cam
shaft. This cam or eccentric acts on an open forked arm of a bell crank whose other
arm is or may be slotted and connected by preference adjustably by a screw pin to an
upright slotted arm on the slide whose movement imparis the transverse motion to the
looper bar; and by adjusting the position of the screw pin relatively with the centre
upon which the bell crank oscillates a greater or less extent of transverse movement
may be given to the looper to suit the size of vertical needle employed.
The cams which impart the longitudinal and transverse movements to the looper

page_text: bar are so formed and positioned that a forward longitudinal movement of the looper
takes place through the loop of the upper thread upon one side of the vertical needle
while the latter is under the fabric this movement continuing while the needle rises
and terminating in a cross movement after which a return longitudinal movement of
the looper takes place upon the opposite side of the path of the needle while the needle
descends through the loop of the lower thread, the path of the eye of the looper being
an oblong figure surrounding the axial line of the vertical needle and the forination of
the stitch being effected in the ordinary way. The lower thread passes to the eye of
the looper through a stationary but adjustable guide eye on the under side of the
machine bed and through an adjustable guide eye on the looper rod, and this latter
guide eye by its reciprocation in proximity to the stationary eye draws the thread out
of its straight course and takes up the slack on the backward movement of the looper
and pays off the thread on its forward movement. The taking up of the slack of the
upper thread is effected by means of a gripper consisting of two blades or springs
through which the thread passes and which are pressed together by the action of a
roller on the needle bar to grasp or hold the thread during the latter part of the
downward movement of the needle. The reciprocating movement of the feed plate is
effected by a cam or eccentric on the cam shaft acting on a crank on a rocking shaft
on which is a quadrant having in it a groove or slot to which is adjustably connected
a link attached to the underside of the feed plate while the vertical movement of the
feed plate is imparted by a cam on the cam shaft working in open forked arms formed
on the link attached to the feed plate the several movements being positive. The teeth
upon the feed plate are formed in rows having parallel grooves or spaces between them,
and the under side of the presser foot is grooved in lines directly over the feed plate
teeth so that when the presser foot is let down the fabric is grasped between the
ridges and grooves of the presser foot and little or no pressure need be exerted between
the toothed portion of the feed plate and the presser foot tending to wear or blunt the
teeth.

page_text: Improvements in Sewing Machines.
We ALEXANDER ANDERSON, Manager and ROBERT ANDREW FERGUSON POLLOCK,
Mechanic, both of the Singer Manufacturing Company's Works, Kilbowie, Dumbar-
tonshire 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 :-
Our Invention relates to sewing machines of the class in which chain stitches are
formed by the use of a looper or horizontal needle, carrying the lower thread in con-
junction with the usual vertically reciprocating needle and upper thread and the
invention has for object improvements in the formation and arrangement of the looper
and actuating mechanism for imparting to it a positive motion around the axial line of
the needle in connection therewith in means for regulating the transverse movement
of the looper to suit the different sizes of needles employed, in means for taking up the
siack of the looper thread, in the mechanism for actuating the feed, and in the
formation of the feed plate and presser foot to prevent wear or blunting of the teeth
of the plate.
In the accompanying drawings which illustrate our invention figure 1 is a side
elevation of a sewing machine with part of the bed plate removed to show the operating
parts figure 2 is an inverted plan of the same, figure 3 a front elevation and
figures 4 to 12 views of details hereinafter referred to.
As represented in the drawings and particularly at figure 12 the looper consists of
a needle A formed on or attached to the end of a long rod or bar B which extends
horizontally under and lengthwise of the machine bed C and is pin jointed at its
opposite end to a lever D pivotted to brackets E on the machine frame the said
lever D having on it a stud and roller d entering a grooved cam F on a cam shaft G
which also is carried longitudinally under the machine bed C the rotation of said shaft G
imparting through the cam groove F an oscillating movement to the pivotted lever D
and therethrough a longitudinal reciprocating motion to the looper bar B. At the
end adjacent to the looper needle the bar B passes through a swivelling stud or
guide H attached to a frame or slide I which has a transverse reciprocating movement
imparted to it by a cam or eccentric J on the cam shaft G. As shown in detail at
figures 4 and 5 this cam or eccentric J acts on the arm k of a bell crank whose other
arm is or may be slotted and connected by preference adjustably by a screw pin k
to an upright slotted arm on the slide I whose movement imparts the transverse
motion to the looper bar or when adjustment is not desired the eccentric J may be
fitted to act directly on open formed arms i on the slide I as indicated at figure 6. By
adjusting the position of the screw pin 4 relatively with the centre upon which the
bell crank k, k oscillates a greater or less extent of transverse movement may be given
to the looper bar B and looper A to suit the size of vertical needle employed. The
cams F and J which impart the longitudinal and transverse movements to the looper
bar B are so formed and positioned that a forward longitudinal movement of the
looper A takes place through the loop of the upper thread upon one side of the vertical
needle L while the latter is under the fabric this movement continuing while the
needle L rises and terminating in a cross movement after which a return longitudinal
movement of the looper A takes place upon the opposite side of the path of the needle

page_text: while the needle L descends through the loop of the lower thread, the path of the eye
of the looper being an oblong figure surrounding the axial line of the vertical needle
whilst the formation of the stitch is effected in the ordinary way. The lower thread
passes to the eye of the looper A through a stationary but adjustable guide eye m on
the under side of the machine bed and through a guide m' (which may also be adjust-
able on the looper rod and this latter guide eye m by its reciprocation in proximity to
the stationary eye m draws the thread out of its straight course and takes up the slack
on the backward movement of the looper A and pays off the thread on its forward
movement. The reciprocating movement of the feed plate N is effected by a cam or
eccentric O on the cam shaft G acting on a crank P on a rocking shaft p on which is
a quadrant Q having in it a groove or slot q to which is adjustably connected a link R
operating a rock lever or frame S to which is jointed a link or lever arm T connected
to the underside of the feed plate N whilst the vertical movement of the feed plate is
imparted by a cam U on the cam shaft G working in open forked arms formed on
the link Tattached to the feed plate N, as is clearly shown in figures 7 and 8, the
several movements being positive. The teeth n upon the feed plate N are formed, as
shown in figure 9, in rows having parallel grooves or spaces ¹ between them, and the
under side of the presser foot V, as shown at figures 10 and 11, is grooved at v in
lines directly over the feed plate teeth so that when the presser foot is let down the
fabric is grasped between the ridges and grooves of the presser foot and little or no
pressure need be exerted between the toothed portion of the feed plate and the presser
foot. The machine may thus be run without any fabric in it (should one piece not
be followed up, in completion of the sewing, by another piece) without blunting or
damaging the edges of the teeth.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare, that what we
claim is :-
1. In a double chain stitch sewing machine the combination of parts constituting
the under operating mechanism substantially as herein described.
2. In a double chain stitch sewing machine a combined reciprocating looper and
looper bar arranged to operate substantially as herein described.
3. In a double chain stitch sewing machine the combination with the looper bar of
mechanism for reciprocating said bar lengthwise and mechanism for reciprocating it
crosswise substantially as herein described.
4. In a double chain stitch sewing machine the combination with the looper bar of
mechanism for adjustably reciprocating said bar substantially as described with
reference to figures 4 and 5 of the annexed drawings.
5. In a double chain stitch sewing machine the combination with the looper bar of
stationary and adjustable thread guides arranged to take up the slack of the looper
thread substantially as described.
6. In a sewing machine the combination of parts constituting the mechanism for
adjustably operating the feed plate substantially as described.
7. In a sewing machine the combination of the feed plate and presser foot each
formed with grooves and ridges substantially as and for the purpose set forth.
Dated this Seventeenth day of December 1887.
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.