IMPROVEMENTS IN BUTTON-HOLE STITCHING APPARATUS FOR SEWING MACHINES
Year: 1879

page_text: LETTERS PATENT to Gerard Wenzeslaus von Nawrocki, of the Firm of
J. Brandt and G. W. von Nawrocki, Patent Agents, of No. 124, Leipziger-
strasse, Berlin, in the German Empire, for the Invention of "IMPROVEMENTS
IN BUTTON-HOLE STITCHING APPARATUS FOR SEWING MACHINES." A commu-
nication by Georg Neidlinger, of Hamburg, in the German Empire.
PROVISIONAL SPECIFICATION left by the said Gerard Wenzeslaus von
Nawrocki at the Office of the Commissioners of Patents on the 1st October
1879.
GERARD WENZESLAUS VON NAWROCKI, of the Firm of J. Brandt and G. W. von
Nawrocki, Patent Agents, of No. 124, Leipzigerstrasso, Berlin, in the German
Empire. "IMPROVEMENTS IN BUTTON-HOLE STITCHING APPARATUS FOR Sewing
MACHINES." [A communication by Georg Neidlinger, of Hamburg, in the German
Empire.]
This Invention relates to apparatus-which when attached to a shuttle sewing
machine such as the Singer's, or others, enables button hole stitching to be produced
thereby without otherwise altering the machine, excepting a slight modification of
the needle plate and presser foot. For this purpose a bracket secured to the side of
the ordinary needle guide carries a needle bar working up and down in an oblique
position in a guide having a curved slot so shaped that a stud on the needle bar in
sliding to and fro therein causes the bar, and with it the needle, to turn partly
round as it moves up and down. This needle is formed with a notch or hook that
at every down stroke catches the shuttle thread and draws it up over the edge of
the button hole in a loop through which the machine needle passes in its descent.
The hook needle having in its ascent been turned partly round as described its
hook is brought into such a position that a striker which is moved forward after
the descent of the machine needle throws the shuttle thread off the hook and allows
it to be drawn tight over the edge of the button bole by the motion of the shuttle.
The motions of the hook needle and striker for the above purposes are produced as
CDC71

page_text: follows:-The hook-needle bar is acted upon by a spring so as to be held in the
raised position. It is connected by a hinged rod to an arm on a spindle carried
by the above mentioned bracket, and this arm has a stud against which bears a
spring detent on the one end of a bell crank lever, the other end of which has a
stud that at every ascent of the machine needle is pulled upward by a lug on the
needle slide. This upward motion causes the detent to descend and in bearing
against the stud on the arm to depress the latter and with it the hook needle which
thus makes its down stroke as before described. When the detent has descended
to a certain point it comes in contact with an adjustable stop which throws it out
of gear with the stud on the arm, whereupon the hook needle is moved rapidly
upwards again by its spring, thus performing its upstroke. The bell crank lever is
also acted upon by a spring so as to cause it to follow the needle slide closely as it
descends, and during this motion a projection on the boss of the lever acts upon an
arm pivotted to the bracket and carrying the striker, which is thereby thrown
forward so as to cast the loop of thread off the hook needle. The arm of the striker
is acted upon by a spring so as to be held in a backward position when not actuated
by the bell crank lever, or the spring may be arranged to throw the striker forward
and the bell crank be made to keep it back until the descent of the machine needle.
The needle plate has a lateral projection in which is a second hole, in addition to
that for the machine needle, the two holes being connected by a slot. In this hole
is a moveable stud or button having a hole through which the hook needle passes
in its descent, and serving as guide for the button hole fabric. For the latter
purpose the stud is acted upon by a spring so as to be kept down flush with the
top surface of the needle plate, except when it is pushed upwards on the passage of
the shuttle by a projection on the shuttle arm. The presser foot has in addition to
the notch for the machine needle a second notch for the said stud guide for the
hook needle, and it also has a hole through which passes a strong thread led from a
reel on the machine, which thread is laid by the foot round the button hole so as
to be enclosed within the button hole stitching and thus to strongthen the edge of
the fabric.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Gerard Wenzeslaus von Nawrocki in the Great Seal Patent Office on
the 17th March 1880.
GERARD WENZESLAUS VON NAWROCKI, of the Firm of J. Brandt and G. W. von
Nawrocki, Patent Agents, of No. 124, Leipzigerstrasse, Berlin, in the German
Empire. "IMPROVEMENTS IN BUTTON-HOLE STITCHING APPARATUS FOR SEWING
MACHINES." A communication by Georg Neidlinger, of Hamburg, in the German
Empire.
This Invention relates to apparatus which when attached to a shuttle sewing
machine such as the Singer's, or others, enables button hole stitching to be produced
thereby without otherwise altering the machine, excepting a slight modification of
the needle plate and presser foot. For this purpose a bracket secured to the side
of the ordinary needle guide carries a needle bar working up and down in an
oblique position in a guide having a curved slot so shaped that a stud on the needle
bar in sliding to and fro therein causes the bar, and with it the needle, to turn
partly round as it moves up and down. This needle is formed with a notch or
hook that at every downstroke catches the shuttle thread and draws it up over the,
edge of the button hole in a loop through which the machine needle passes in its
descent. The hook needle having in its ascent been turned partly round as
described its hook is brought into such a position that a striker which is moved
forward after the descent of the machine needle throws the shuttle thread off the
hook and allows it to be drawn tight over the edge of the button hole by the
motion of the shuttle. The motions for the hook noedle and striker for the above
purposes are produced as follows:-The hook needle-bar is acted upon by a spring
so as to be held in the raised position. It is connected by a hinged rod to an arın
on a spindle carried by the above mentioned bracket, and this arm has a stud
against which bears a spring detent on the one end of a bell crank lever, the other
end of which has a stud that at every ascent of the machine needle is pulled upward
by a lug on the needle slide. This upward motion causes the detent to descend,
and in bearing against the stud on the arm to depress the latter and with it the
hook needle, which thus makes its downstroke as before described.
When the
detent has descended to a certain point it comes in contact with an adjustable stop'
which throws it out of gear with the stud on the arm, whereupon the hook needle
is moved rapidly upwards again by its spring, thus performing its upstroke. The
bell crank lever is also acted upon by a spring so as to cause it to follow the needle
slide closely as it descends, and during this motion a projection on the boss of the
lever acts upon an arm pivotted to the bracket and carrying the striker, which is
thereby thrown forward so as to cast the loop of thread off the hook needle. The
arm of the striker is acted upon by a spring so as to be held in a backward position
when not actuated by the bell crank lever, or the spring may be arranged to throw
the striker forward and the bell crank be made to keep it back until the descent
of the machine needle. The needle plate has a lateral projection in which is a
second hole, in addition to that for the machine needle, the two holes being con-
nected by a slot. In this hole is a moveable stud or button having a hole through
which the hook needle passes in its descent, and serving as a guide for the button
hole fabric. For the latter purpose the stud is acted upon by a spring so as to be
kept down flush with the top surface of the needle plate, except when it is pushed
upwards on the passage of the shuttle by a projection on the shuttle arm. The
presser foot has in addition to the notch for the machine needle a second notch for
the said stud guide for the hook needle, and it also has a hole through which
passes a strong thread led from a reel on the machine, which thread is laid by the
foot round the button hole so as to be enclosed within the button hole stitching.
and thus to strengthen the edge of the fabric.

page_text: Fig. 1 is a front view, Fig. 2 a part plan, and Fig. 3 au end view of apparatus
according to this Invention applied to a sewing machine such as that known as
the "Singer" machine; Fig. 4 is a plau looking from above, and Fig. 5 a plan
looking from below, and Fig. 6 a side view of the needle plate and its slot for the
feed as altered when the apparatus is used; Figs. 7, 8, 9, and 10, are views of the
pressure foot; Figs. 12 and 13 are back views of the hook mechanism corresponding
to different positions of the needle; Fig. 14 is a plan, and Fig. 15 an end view of
this mechanism. Its frame is a bracket a attached by a clamp a¹ to the front side
of the needle guide and secured by a screw b. To the frame a are fixed the guides
c, c², for the stem d, in the end of which the hook needle f is held by a set screw f'.
On the upper (guide c' is a shell having a curved slit in which works a stud d'
projecting from the stem d causing the hook needle as it travels to and fro to turn
about one quarter of a revolution round and back again. The stem d is surrounded
by a helical spring e which butts at one end against the guido c, and at the other
against a collar on d. On the upper end of the stem d is a sleeve g to which one
end of the connecting rod h is linked by a fork joint ¹, the other end of the rod
being linked to the lever i. This lever i works on a stud which is secured to the
frame a by a nut . On the lever i is a tooth at ¹ with which engages the tail ¹
of a detent lever l. This detent lever is mounted on the bell crank lever m which
works on the stud k, and which has its end m¹ resting on the clamp that secures
the machine needle a in its stem, so that at every upstroke of the needle the lever
m is raised. By means of a small blade spring m³ the lever is canted so that its
projection engages with the tooth i', and thus when the lever m rises with the
needle the lever i is depressed and the hook needle is caused to make its down-
stroke. When, however, the lever comes against the point of a set screw n¹
adjustable with a lock nut n² in a dog n it is canted back so that becomes
disengaged from i¹, and the hook needle being then free is caused by the spring c
to make its upstroke. The lever m is pressed down by a spring o so as to follow
the needle x in its downstroke. The bent throw off needle or striker p is held in
a lever p' which is pressed in one direction by a spring q, and in the other by the
cam edge at ¹ of a boss on the lever m, so that is held away from the hook f
during its downstroke, as shewn in Fig. 13, and is advanced to throw the loop of
thread off at its upstroke, as shewn in Fig. 12. The needle plate, Figs. 4, 5, and 6,
has an extension r at one side, and besides the usual needle hole & has a hole t for
the passage of the hook needle f to bring up the loop of shuttle thread, this hole
being bored obliquely through a moveable bush that projects upwards as a knob
entering the button hole and serving as a guide to the fabric. The two holes & and
t communicate by a slit. The bush t is moved up and down in the hole in which
it is fitted in the needle plate, for which purpose it has a sloped end below the
plate acted on by a spring so as to keep the head of the knob down to the level of
the surface of the plate, except when it is pushed up by a projection on the shuttle
driver at the time when the hook needle enters the shuttle race and the fabric
advances. The presser foot, Figs. 7, 8, 9, and 10, has besides the notching &¹ for the
machine needle a father notching t for the hook needle, and a hole through
which is passed from the reel A. the thicker thread or cord employed for edging the
button hole. The under surface of the presser foot is sunk and eased off at one side
so as to give less pressure on the part of the fabric already stitched and avoid
unequal drag of the feed. The action of the button hole apparatus in combination
with the ordinary sewing mechanism is as follows:-
The hook needle passes down in the slit cut in the fabric to form the button
hole through the bush t into the shuttle race, and seizes a loop of the shuttle thread,
which it draws up in its ascent and holds over the edge of the button hole under

page_text: the machine needle x. The needle & descends through this loop which the bent
needle p throws off the hook, and the shuttle passes through a loop of the needle
thread in the usual way.
Having thus described the nature of the said Invention, and in what manner
the same is to be performed as communicated to me by my correspondent, I
claim,―
First. The construction of apparatus applicable to a sewing machine whereby a
reciprocating and partly rotating hook needle and throw off striker are made to
operate in combination with the ordinary sewing mechanism for button hole
stitching, substantially as herein described with reference to the accompanying
Drawings.
Second. The modification of the needle plate as herein described with reference
to Figs. 4, 5, and 6, and of the presser foot as herein described with reference to
Figs. 7, 8, 9, and 10 so as to adapt them to the button hole stitching mechanism.
In witness whereof, I, the said Gerard Wenzeslaus von Nawrocki, have here-
unto set my hand and seal, this Seventeenth day of March, in the year of
our Lord One thousand eight hundred and eighty.
GERARD WENZESLAUS VON NAWROCKI. (L.S.)
GERARD WENZESLAUS VON NAWROCKI. (L.S.)