IMPROVEMENTS IN LOCK STITCH SEWING MACHINES
Year: 1881

page_text: LETTERS PATENT to Carl Pieper, Civil Engineer and Patent Agent, of
109/110, Gueisenaustrasse, Berlin, S.W. Prussia, for
"IMPROVEMENTS IN LOCK STITCH SEWING MACHINES."
from Julius Stern, Merchant, of St. Petersburg, Russia.
an Invention of
A communication
PROVISIONAL SPECIFICATION left by the said Carl Pieper at the Office of
the Commissioners of Patents on the 19th May 1881.
CARL PIEPER, Civil Engineer and Patent Agent, of 109/110, Gneisenaustrasse,
Berlin, S.W Prussia. "IMPROVEMENTS IN LOCK STITCH SEWING MACHINES."
A communication from Julius Stern, Merchant, of St. Petersburg, Russia.
This Invention relates to lock-stitch sewing-machines, and the object of the same
is to provide means for allowing the lower thread to be worked directly off a
common spool, such as form an article of trade, and thereby to avoid the trouble-
some winding-up of the thread on a special spool, as required with ordinary
double-lock-stitch sewing-machines.
The spool which carries the lower thread is contained in a cylindrical_case
terminating at its front end in a cone, by preference flattened at the sides. From
the spool the thread passes outward through a slit or a hole in the wall of the case.
The said case is so enclosed in a cage or carrier that it cannot leave its place; but
between it and the carrier there is a certain amount of play allowing the loop of
the upper thread to pass around the case.
Below the cloth-plate there is a hook, the shank or body of which is pivoted to
a crank fixed on an auxiliary shaft, whereas its lower end is suitably guided by
a radius-rod or otherwise. When the said auxiliary shaft rotates, the hook is
carried around the spool-case in the vertical central plane of the same, and besides
it passes close to the needle. The shank of the hook is suitably bent so that it
may pass along side of the case-carrier without touching it. When the needle
begins to rise the hook seizes the loop of the upper thread draws it lengthwise
over the case, and finally allows it to slip off. The loop is thereupon drawn tight
by a suitable take-up.
The mechanism which the inventor prefers using for this purpose consists of a
lever operated by a cam-groove cut into a boss or cylinder keyed on the aforesaid
auxiliary shaft. Through the top end of this lever the upper thread passes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Pieper in the Great Seal Patent Office on the 12th November
1881.
CARL PIEPER, Civil Engineer and Patent Agent, of 109-110, Gneisenaustrasse,
Berlin, S.W. Prussia. "IMPROVEMENTS IN LOCK-STITCH SEWING-MACHINES."
A communication from Julius Stern, Merchant, of St. Petersburg, Russia.
This Invention relates to lock-stitch sewing machines, and the object of the same
is to provide means for allowing the lower thread to be worked directly off a
common spool, such as form an article of trade, and thereby to avoid the trouble-
some winding up of the thread on a special spool, as required with ordinary
double-lock-stitch sewing-machines.
The improved machine is represented on the annexed two Sheets of Drawings.
Fig. 1, front elevation of the machine.
Fig. 2, front end view.
Fig. 3, section on line 1, 2, looking towards the rear.
Fig. 4, part of front elevation in which some parts have been omitted.
Fig. 5, section on line 3, 4, looking forward.
Fig. 6, view of the feeding-device from below. (Part of this view is repeated in
Fig. 3.)
Fig. 7, developed form of the cam-groove n, Fig. 1.
Fig. 8, section on line 5, 6, 7, 8, Fig. 1, looking towards the rear.
Fig. 9, view of the gear for transmitting motion from the main shaft s to the
shaft h.
Fig. 10, vertical section of the case for the spool of the lower thread with spool
inserted.
Fig. 11, top view of the spool-case and its carrier.
Fig. 12, Transverse section of the spool-case and carrier. (The Figures 10, 11,
and 12, are drawn in full size.)
Figs. 13, 14, and 15, three different positions of the parts serving for drawing the
loop of the upper thread around the case.
The mechanism for imparting motion to the needle is similar as in the well
known shuttle sewing-machines, and has therefore not been shown in the Drawing.
The part of the machine containing the lower thread, and by which the entwining
of the upper thread with the lower one is caused, differs however materially from
the arrangements heretofore employed.
The spool a carrying the lower thread (an ordinary wooden sewing-thread spool)
is contained, as may be seen from Fig. 10, in a cylindrical case b terminating at
its front end in a cone. The said spool turns with a certain friction due to a
spring e on a pin c, the amount of this friction allowing of regulation by means of
the screw d, which keeps the spool in its place. From the spool the thread passes
outward through a longitudinal slit cut into the wall of the case, and for increasing
its tension it may also be drawn through various holes drilled into the case for
this purpose. The case b is so enclosed in a carrier f that it cannot leave its place
(see Figs. 2, 11, and 12); but between it and the carrier there is so much play
that the loop of the upper thread may freely pass around the case.
purpose of allowing the case to be removed from the carrier the front or outer
part of the latter is hinged, while a spring serves to keep it in its place. This
part may however also be screwed on.
For the
The case b being stationary it necessarily follows that the upper thread after
having been carried by the needle below the cloth-plate has to be drawn around
For this purpose serves the hook g, the arrangement and action of which
the case.

page_text: may be seen from Figs. 1 and 2, but principally from Figs. 13, 14, and 15. The
shank or body of this hook is on one hand pivoted to a crank i fixed on the
shaft h, whereas on the other hand it is jointed to a radius-rod k, as will be
understood from the different Figures without further explanation. The said shank
might however also be guided at its lower end in any other suitable manner.
When the shaft h rotates, the book g is carried around in a curve somewhat
resembling an ellipse. Moreover it has to be stated that the hook, the needle, and
the point of the case b are so arranged with respect to each other that the hook
passes with its point close to the needle, and that besides it executes its motion in
the vertical central plane of the case b. For allowing the latter condition to be
fulfilled, the shank of the hook must be bent in such a manner that it may pass
alongside of the case-carrier f without touching the same. The motion of the needle
and the hook are in such relation to each other that the latter passes the needle
after the same has begun to rise and the upper thread has formed a small loop.
The hook siezes this loop (see Figs. 2 and 13), without however requiring a stoppage
of the needle, as is necessary in shuttle-sewing-machines; it thereupon expands
the same, and draws it along in the direction of its motion. As soon as the hook
has passed the point of the case the loop lays itself upon this point, and is thereupon
drawn lengthwise over the case (see Fig. 14). For facilitating the sliding of the
thread, the conical part of the case b may be flattened at the sides, so that its end
will then form a narrow edge instead of a point. When the loop has attained the
position, Fig. 15, it slips off the hook, and is thereupon drawn tight by the take-up,
shown by Figs. 1 and 8. The same consists of a lever 7 which is put in motion by
the cam-groove n cut into the rotating cylinder m, and through the top end of
which the upper thread is drawn. The said top end of the lever passes outward
through a slit in the frame of the machine. The upper thread runs from its spool
through the thread-guide o, around a projection or point on the disk p to the
tension-device q, thence through the head of the said lever and over the guide r,
and finally through an eye on the needle-bar to the needle. The shape of the
cam-groove n, shown developed on a plane surface in Fig. 7, is such that the lever
will first pay out so much thread as the needle requires when descending; to this
period the part 1, 2, of the groove corresponds. The part 2, 3, then following
causes the lever to stand still, while the needle commences to rise and the hook
enters into the loop. From 3 to 4 the groove causes a further and more extensive
paying out of thread for the expansion of the loop. As soon as the loop has passed
the case b, the lever-head is drawn speedily back by the action of the part 4, 1, of
the groove, for the purpose of taking up the loop and of drawing tight the stitch.
Instead of this take-up however some other device having a similar action may be
combined with the rest of the mechanism described.
To the shaft h motion is or may be imparted from the main-shaft 8 by means of
an eccentric v fixed on 8, and of an eccentric-rod t guided at or near its centre, and
pivoted at its lower end to an intermediate piece or driver u, which oscillates on a
pin z fixed to the cylinder m, and thereby to the shaft h. This arrangement is of
advantage on account of its simplicity, but it may be replaced by any other suitable
and known gear.
The feeding-mechanism, although not presenting any novel features, nevertheless
requires a short description, as the form of the various parts differs frem those
ordinarily employed.
On the shaft the two eccentrics or cam-disks a' and b¹ are placed, as shown by
Figs. 1, 3, 4, 5, and 6. The eccentric al acts against the part c¹ of the variously
bent bar d', which is guided in a groove cut into the bearing w (see especially
Fig. 5), and which by the medium of the lever e¹ and the bar f¹ moves the feed-
bar g (see Figs. 3 and 6); h¹ is a spring which presses the feed-bar against f¹, and
at the same time downward. By shifting the bar f¹ the length of the stitch may
be regulated as usual. The upward motion of the feed-bar is caused by the
eccentric b¹, the bar, and the lever (Figs. 3, 4, and 6), the outer end of the
latter pressing from below against the feed-bar, whose end l' is formed and guided

page_text: in such a manner that the bar inay oscillate on this end and at the same time slide
forward and backward. The presser-foot in connexion with which the feed-bar
works has been omitted in the Drawing.
Having thus described the nature and object of this Invention, as communicated
to me by my correspondent, I hereby claim as new and important features of the
same,
In a sewing-machine, a case b terminating at its forward end in a point or
narrow edge and adapted to contain a spool of thread, and placed in a carrier fin
combination with a hook g, whose shank being guided at its lower end and pivoted
to a crank i moves in such a manner that the hook when passing the needle seizes
the loop of the upper thread and carries it around the case b, whereupon the loop
having slipped off the hook is drawn tight by a suitable take-up, substantially as
hereinbefore described.
In witness whereof, I, the said Carl Pieper, have hereunto set my hand and
seal, this second day of November, in the year of our Lord One thousand
eight hundred and eighty one.
CARL PIEPER. (L.S.)